The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Gastric analysis for determination of free acid or total acid.
The balance between acids and bases in the BODY FLUIDS. The pH (HYDROGEN-ION CONCENTRATION) of the arterial BLOOD provides an index for the total body acid-base balance.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity.
The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.
A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.
A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
A flammable, poisonous gas with a characteristic odor of rotten eggs. It is used in the manufacture of chemicals, in metallurgy, and as an analytical reagent. (From Merck Index, 11th ed)
Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.
A pathologic condition of acid accumulation or depletion of base in the body. The two main types are RESPIRATORY ACIDOSIS and metabolic acidosis, due to metabolic acid build up.
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.
A strong corrosive acid that is commonly used as a laboratory reagent. It is formed by dissolving hydrogen chloride in water. GASTRIC ACID is the hydrochloric acid component of GASTRIC JUICE.
Respiratory retention of carbon dioxide. It may be chronic or acute.
The rate dynamics in chemical or physical systems.
The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.
The liquid secretion of the stomach mucosa consisting of hydrochloric acid (GASTRIC ACID); PEPSINOGENS; INTRINSIC FACTOR; GASTRIN; MUCUS; and the bicarbonate ion (BICARBONATES). (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p651)
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
One of the CARBONIC ANHYDRASE INHIBITORS that is sometimes effective against absence seizures. It is sometimes useful also as an adjunct in the treatment of tonic-clonic, myoclonic, and atonic seizures, particularly in women whose seizures occur or are exacerbated at specific times in the menstrual cycle. However, its usefulness is transient often because of rapid development of tolerance. Its antiepileptic effect may be due to its inhibitory effect on brain carbonic anhydrase, which leads to an increased transneuronal chloride gradient, increased chloride current, and increased inhibition. (From Smith and Reynard, Textbook of Pharmacology, 1991, p337)
A group of genetic disorders of the KIDNEY TUBULES characterized by the accumulation of metabolically produced acids with elevated plasma chloride, hyperchloremic metabolic ACIDOSIS. Defective renal acidification of URINE (proximal tubules) or low renal acid excretion (distal tubules) can lead to complications such as HYPOKALEMIA, hypercalcinuria with NEPHROLITHIASIS and NEPHROCALCINOSIS, and RICKETS.
A state due to excess loss of carbon dioxide from the body. (Dorland, 27th ed)
The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.
The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
An acidifying agent that has expectorant and diuretic effects. Also used in etching and batteries and as a flux in electroplating.
The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
The amount of a substance secreted by cells or by a specific organ or organism over a given period of time; usually applies to those substances which are formed by glandular tissues and are released by them into biological fluids, e.g., secretory rate of corticosteroids by the adrenal cortex, secretory rate of gastric acid by the gastric mucosa.
Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A genus of chiefly Eurasian and African land snails including the principal edible snails as well as several pests of cultivated plants.
A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.
A white, crystalline powder that is commonly used as a pH buffering agent, an electrolyte replenisher, systemic alkalizer and in topical cleansing solutions.
A ubiquitous sodium salt that is commonly used to season food.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
Elements of limited time intervals, contributing to particular results or situations.
Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
Inorganic salts of phosphoric acid.
The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.
Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. (Grant & Hackh's Chemical Dictionary, 5th ed)
A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.
Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.
Electrodes which can be used to measure the concentration of particular ions in cells, tissues, or solutions.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
A plasma membrane exchange glycoprotein transporter that functions in intracellular pH regulation, cell volume regulation, and cellular response to many different hormones and mitogens.
A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
The ability of a substrate to allow the passage of ELECTRONS.
A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.
Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.
A photoprotein isolated from the bioluminescent jellyfish Aequorea. It emits visible light by an intramolecular reaction when a trace amount of calcium ion is added. The light-emitting moiety in the bioluminescence reaction is believed to be 2-amino-3-benzyl-5-(p-hydroxyphenyl)pyrazine (AF-350).
Lining of the STOMACH, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. The surface cells produce MUCUS that protects the stomach from attack by digestive acid and enzymes. When the epithelium invaginates into the LAMINA PROPRIA at various region of the stomach (CARDIA; GASTRIC FUNDUS; and PYLORUS), different tubular gastric glands are formed. These glands consist of cells that secrete mucus, enzymes, HYDROCHLORIC ACID, or hormones.
Organic compounds that contain two nitro groups attached to a phenol.
A synthetic pentapeptide that has effects like gastrin when given parenterally. It stimulates the secretion of gastric acid, pepsin, and intrinsic factor, and has been used as a diagnostic aid.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
Chemical agents that increase the permeability of biological or artificial lipid membranes to specific ions. Most ionophores are relatively small organic molecules that act as mobile carriers within membranes or coalesce to form ion permeable channels across membranes. Many are antibiotics, and many act as uncoupling agents by short-circuiting the proton gradient across mitochondrial membranes.
Hydrochloric acid present in GASTRIC JUICE.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Inorganic salts of sulfuric acid.
The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)
A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)
A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)
The lymph fluid found in the membranous labyrinth of the ear. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Cationic ionophore antibiotic obtained from Streptomyces lasaliensis that, among other effects, dissociates the calcium fluxes in muscle fibers. It is used as a coccidiostat, especially in poultry.
A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.
Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
A group of peptide antibiotics from BACILLUS brevis. Gramicidin C or S is a cyclic, ten-amino acid polypeptide and gramicidins A, B, D are linear. Gramicidin is one of the two principal components of TYROTHRICIN.
Hydrogen cyanide (HCN); A toxic liquid or colorless gas. It is found in the smoke of various tobacco products and released by combustion of nitrogen-containing organic materials.
The decrease in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.
A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
An element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.
The physical or physiological processes by which substances, tissue, cells, etc. take up or take in other substances or energy.
Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane.
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
A salt used to replenish calcium levels, as an acid-producing diuretic, and as an antidote for magnesium poisoning.
Stable potassium atoms that have the same atomic number as the element potassium, but differ in atomic weight. K-41 is a stable potassium isotope.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
The dissociation of molecules in the air into positive and negative ions under the influence of an electric field.
Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
Liquid components of living organisms.
Positively-charged atomic nuclei that have been stripped of their electrons. These particles have one or more units of electric charge and a mass exceeding that of the Helium-4 nucleus (alpha particle).
A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.
A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.
The accumulation of an electric charge on a object
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.
A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.
A fluorescent calcium chelating agent which is used to study intracellular calcium in tissues.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
The fluid inside CELLS.
Substances that dissociate into two or more ions, to some extent, in water. Solutions of electrolytes thus conduct an electric current and can be decomposed by it (ELECTROLYSIS). (Grant & Hackh's Chemical Dictionary, 5th ed)
Degree of saltiness, which is largely the OSMOLAR CONCENTRATION of SODIUM CHLORIDE plus any other SALTS present. It is an ecological factor of considerable importance, influencing the types of organisms that live in an ENVIRONMENT.
The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.
Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Substances produced from the reaction between acids and bases; compounds consisting of a metal (positive) and nonmetal (negative) radical. (Grant & Hackh's Chemical Dictionary, 5th ed)
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

The chemical ecology of Biomphalaria glabrata: the effects of ammonia on the growth rate of juvenile snails. (1/46035)

When juvenile specimens of Biomphalaria glabrata were subjected to concentrations of ammonia ranging from 1-100 mug/ml in various media the following effects were observed: the addition of ammonia to borate buffered media caused mortality. Both borate and tris-buffered media caused a decrease in the growth rate of snails when compared with controls in SSW. The growth rates of the snails could be enhanced by increasing the concentration of ammonia to critical thresholds, but further increases beyond these thresholds resulted in growth inhibition. The toxicity of ammonia in ambient water was augmented by an an increase in pH. The possible causation and ecological significance of these effects are discussed. There are indications that the snails are physiologically well-adapted to utilize ammonia when required and also to control its excretion and uptake from the medium.  (+info)

Does gill boundary layer carbonic anhydrase contribute to carbon dioxide excretion: a comparison between dogfish (Squalus acanthias) and rainbow trout (Oncorhynchus mykiss). (2/46035)

In vivo experiments were conducted on spiny dogfish (Squalus acanthias) and rainbow trout (Oncorhynchus mykiss) in sea water to determine the potential role of externally oriented or gill boundary layer carbonic anhydrase in carbon dioxide excretion. This was accomplished by assessing pH changes in expired water using a stopped-flow apparatus. In dogfish, expired water was in acid-base disequilibrium as indicated by a pronounced acidification (delta pH=-0.11+/-0.01; N=22; mean +/- s.e.m.) during the period of stopped flow; inspired water, however, was in acid-base equilibrium (delta pH=-0.002+/-0.01; N=22). The acid-base disequilibrium in expired water was abolished (delta pH=-0.005+/-0.01; N=6) by the addition of bovine carbonic anhydrase (5 mg l-1) to the external medium. Addition of the carbonic anhydrase inhibitor acetazolamide (1 mmol l-1) to the water significantly reduced the magnitude of the pH disequilibrium (from -0.133+/-0.03 to -0.063+/-0.02; N=4). However, after correcting for the increased buffering capacity of the water caused by acetazolamide, the acid-base disequilibrium during stopped flow was unaffected by this treatment (control delta [H+]=99.8+/-22.8 micromol l-1; acetazolamide delta [H+]=81.3+/-21.5 micromol l-1). In rainbow trout, expired water displayed an acid-base disequilibrium (delta pH=0.09+/-0.01; N=6) that also was abolished by the application of external carbonic anhydrase (delta pH=0.02+/-0.01). The origin of the expired water acid-base disequilibrium was investigated further in dogfish. Intravascular injection of acetazolamide (40 mg kg-1) to inhibit internal carbonic anhydrase activity non-specifically and thus CO2 excretion significantly diminished the extent of the expired water disequilibrium pH after 30 min (from -0.123+/-0.01 to -0.065+/-0.01; N=6). Selective inhibition of extracellular carbonic anhydrase activity using a low intravascular dose (1.3 mg kg-1) of the inhibitor benzolamide caused a significant reduction in the acid-base disequilibrium after 5 min (from -0.11+/-0.01 to -0.07+/-0. 01; N=14). These results demonstrate that the expired water acid-base disequilibrium originates, at least in part, from excretory CO2 and that extracellular carbonic anhydrase in dogfish may have a significant role in carbon dioxide excretion. However, externally oriented carbonic anhydrase (if present in dogfish) plays no role in catalysing the hydration of the excretory CO2 in water flowing over the gills and thus is unlikely to facilitate CO2 excretion.  (+info)

Inward rectification in KATP channels: a pH switch in the pore. (3/46035)

Inward-rectifier potassium channels (Kir channels) stabilize the resting membrane potential and set a threshold for excitation in many types of cell. This function arises from voltage-dependent rectification of these channels due to blockage by intracellular polyamines. In all Kir channels studied to date, the voltage-dependence of rectification is either strong or weak. Here we show that in cardiac as well as in cloned KATP channels (Kir6.2 + sulfonylurea receptor) polyamine-mediated rectification is not fixed but changes with intracellular pH in the physiological range: inward-rectification is prominent at basic pH, while at acidic pH rectification is very weak. The pH-dependence of polyamine block is specific for KATP as shown in experiments with other Kir channels. Systematic mutagenesis revealed a titratable C-terminal histidine residue (H216) in Kir6.2 to be the structural determinant, and electrostatic interaction between this residue and polyamines was shown to be the molecular mechanism underlying pH-dependent rectification. This pH-dependent block of KATP channels may represent a novel and direct link between excitation and intracellular pH.  (+info)

The disulfide-bonded loop of chromogranin B mediates membrane binding and directs sorting from the trans-Golgi network to secretory granules. (4/46035)

The disulfide-bonded loop of chromogranin B (CgB), a regulated secretory protein with widespread distribution in neuroendocrine cells, is known to be essential for the sorting of CgB from the trans-Golgi network (TGN) to immature secretory granules. Here we show that this loop, when fused to the constitutively secreted protein alpha1-antitrypsin (AT), is sufficient to direct the fusion protein to secretory granules. Importantly, the sorting efficiency of the AT reporter protein bearing two loops (E2/3-AT-E2/3) is much higher compared with that of AT with a single disulfide-bonded loop. In contrast to endogenous CgB, E2/3-AT-E2/3 does not undergo Ca2+/pH-dependent aggregation in the TGN. Furthermore, the disulfide-bonded loop of CgB mediates membrane binding in the TGN and does so with 5-fold higher efficiency if two loops are present on the reporter protein. The latter finding supports the concept that under physiological conditions, aggregates of CgB are the sorted units of cargo which have multiple loops on their surface leading to high membrane binding and sorting efficiency of CgB in the TGN.  (+info)

Calorimetric studies on the stability of the ribosome-inactivating protein abrin II: effects of pH and ligand binding. (5/46035)

The effects of pH and ligand binding on the stability of abrin II, a heterodimeric ribosome-inactivating protein, and its subunits have been studied using high-sensitivity differential scanning calorimetry. At pH7.2, the calorimetric scan consists of two transitions, which correspond to the B-subunit [transition temperature (Tm) 319.2K] and the A-subunit (Tm 324.6K) of abrin II, as also confirmed by studies on the isolated A-subunit. The calorimetric enthalpy of the isolated A-subunit of abrin II is similar to that of the higher-temperature transition. However, its Tm is 2.4K lower than that of the higher-temperature peak of intact abrin II. This indicates that there is some interaction between the two subunits. Abrin II displays increased stability as the pH is decreased to 4.5. Lactose increases the Tm values as well as the enthalpies of both transitions. This effect is more pronounced at pH7.2 than at pH4.5. This suggests that ligand binding stabilizes the native conformation of abrin II. Analysis of the B-subunit transition temperature as a function of lactose concentration suggests that two lactose molecules bind to one molecule of abrin II at pH7.2. The presence of two binding sites for lactose on the abrin II molecule is also indicated by isothermal titration calorimetry. Plotting DeltaHm (the molar transition enthalpy at Tm) against Tm yielded values for DeltaCp (change in excess heat capacity) of 27+/-2 kJ.mol-1.K-1 for the B-subunit and 20+/-1 kJ.mol-1.K-1 for the A-subunit. These values have been used to calculate the thermal stability of abrin II and to surmise the mechanism of its transmembrane translocation.  (+info)

A new alkali-resistant hemoglobin alpha2J Oxford gammaF2 in a Sicilian baby girl with homozygous beta0 thalassemia. (6/46035)

A 10-mo-old baby girl with homozygous beta0 thalassemia and alphaJOxford, presenting the clinical picture of homozygous beta thalassemia is described. Hemoglobin electrophoresis showed three bands: the first two with the mobilities of hemoglobin Hb A2 (1%) and Hb F (69%), respectively, the third migrating a little faster than Hb A (30%). About 30% of her alpha chains were J Oxford which, bound to her gamma chains, produced a new alkali-resistant hemoglobin, alpha2 J Oxford gamma F2, which has not been described previously. Hemoglobin synthesis in vitro showed the absence of beta chain synthesis and an alpha/non-alpha ratio of 2. The patient's father was heterozygous for both the Hb J Oxford and beta0 thalassemia genes, the mother a carrier of beta0 thalassemia; four other relatives were carriers of Hb J Oxford, and one was a carrier of beta thalassemia.  (+info)

Phe161 and Arg166 variants of p-hydroxybenzoate hydroxylase. Implications for NADPH recognition and structural stability. (7/46035)

Phe161 and Arg166 of p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens belong to a newly discovered sequence motif in flavoprotein hydroxylases with a putative dual function in FAD and NADPH binding [1]. To study their role in more detail, Phe161 and Arg166 were selectively changed by site-directed mutagenesis. F161A and F161G are catalytically competent enzymes having a rather poor affinity for NADPH. The catalytic properties of R166K are similar to those of the native enzyme. R166S and R166E show impaired NADPH binding and R166E has lost the ability to bind FAD. The crystal structure of substrate complexed F161A at 2.2 A is indistinguishable from the native enzyme, except for small changes at the site of mutation. The crystal structure of substrate complexed R166S at 2.0 A revealed that Arg166 is important for providing an intimate contact between the FAD binding domain and a long excursion of the substrate binding domain. It is proposed that this interaction is essential for structural stability and for the recognition of the pyrophosphate moiety of NADPH.  (+info)

Insulin-like growth factors I and II are unable to form and maintain their native disulfides under in vivo redox conditions. (8/46035)

Insulin-like growth factor (IGF) I does not quantitatively form its three native disulfide bonds in the presence of 10 mM reduced and 1 mM oxidized glutathione in vitro [Hober, S. et al. (1992) Biochemistry 31, 1749-1756]. In this paper, we show (i) that both IGF-I and IGF-II are unable to form and maintain their native disulfide bonds at redox conditions that are similar to the situation in the secretory vesicles in vivo and (ii) that the presence of protein disulfide isomerase does not overcome this problem. The results indicate that the previously described thermodynamic disulfide exchange folding problem of IGF-I in vitro is also present in vivo. Speculatively, we suggest that the thermodynamic disulfide exchange properties of IGF-I and II are biologically significant for inactivation of the unbound growth factors by disulfide exchange reactions to generate variants destined for rapid clearance.  (+info)

TY - JOUR. T1 - Electrostatic energy calculation on the pH-induced conformational change of influenza virus hemagglutinin. AU - Ho, Sup Choi. AU - Huh, June. AU - Won, Ho Jo. PY - 2006. Y1 - 2006. N2 - The pH-induced conformational change of influenza virus hemagglutinin (HA) has been investigated by calculating the change of electrostatic energy of the fragment of HA2 upon pH change. The average charge and electrostatic free energy are calculated as a function of pH for the fusion peptide (residues 1-20 of HA2) and the polypeptide of residues 54-77 of HA2 by using the finite difference Poisson-Boltzmann method. It is found that as pH decreases from 8 to 5, the electrostatic free energy of the fusogenic state is lowered by ∼2 kcal/mol and the fusogenic state is less ionized compared to that of the native state for both polypeptides. For the fusion peptide at the fusogenic state, most of ionizable residues are neutral at acidic pH except Glu-11. For the polypeptide of residues 54-77 at the ...
Authors: MURAT CENGİZ, GÜLÇE HEPBOSTANCI Abstract: In this study, combination antimicrobial therapy, due to its higher potential against resistant bacteria, was evaluated for the inhibition of multidrug-resistant E. coli strains. The influence of pH as an environmental variable on the activity of antimicrobial combinations was evaluated by calculating the factional concentration indexes at pH values 5.0, 6.0, 7.3, and 8.0. The highest synergistic activity rates of ceftriaxone + colistin, danofloxacin + colistin, danofloxacin + ceftiofur, and ceftiofur + gentamicin combinations were 50%, 33%, 100%, and 50%, respectively measured at ≥7.3 pH. The lowest synergistic activity rates for all combinations were observed at the acidic pH values of 5.0 and 6.0. The results of this study clearly demonstrated that acidic pH of the medium impaired the activity of the antimicrobial combinations. Although ceftriaxone and ceftiofur exert optimal activity at acidic pH values, the synergistic activity of the ...
Increasing the extracellular pH over the range pH 7.4-8.9 stimulated protein synthesis by about 60% in the rat heart preparation anterogradely perfused in vitro. Protein degradation was inhibited by this pH increase. The magnitudes of the effects at pH 8.9 on protein synthesis and degradation were similar to those of high concentrations of insulin. Cardiac outputs were increased, as were cardiac phosphocreatine contents, indicating that the alterations in extracellular pH did not adversely affect the physiological viability of the preparation. ATP contents were unaltered. The creatine kinase equilibrium was used to assess the magnitude of the change in intracellular pH induced by these treatments. The increase in intracellular pH was about 0.2 for a 1-unit increase in extracellular pH. Thus small changes in intracellular pH have dramatic effects on cardiac protein turnover. ...
In the new study, Young and his colleagues found that toxin entry occurred at near neutral pH conditions when it was bound to the TEM8 receptor, but at strongly acidic conditions when bound to CMG2. The researchers in Young s lab at Salk revealed the two different pH levels when they created cells that had only TEM8 receptors or CMG2 receptors, but not both. They then used a drug that neutralizes the pH inside cells to test how it affected toxin entry in both cell types ...
Understanding and predicting the effect of various environments that differ in terms of pH and the presence of cosolutes and macromolecules on protein properties is a formidable challenge. Yet this knowledge is crucial in understanding the effect of cellular environments on a protein. By combining thermodynamic theories of solution condition effects with statistical mechanics and computer simulations we develop a molecular perspective of protein folding and amyloid formation that was previously unobtainable. The resulting Molecular Transfer Model offers, in some instances, quantitatively accurate predictions of cosolute and pH effects on various protein properties. We show that protein denatured state properties can change significantly with osmolyte concentration, and that residual structure can persist at high denaturant concentrations. We study the single molecule mechanical unfolding of proteins at various pH values and varying osmolyte and denaturant concentrations. We find that the the ...
In this work, the near-neutral photo-Fenton process, as a means of wastewater disinfection, was enhanced by the addition of Organic Acids (OAs), namely citric, ascorbic, tartaric and caffeic acid. The addition of OAs exhibited significant bacterial inactivation enhancement, compared to the classic photo-Fenton systems (Fe2+/H2O2/solar and Fe3+/H2O2/solar). The improved disinfection performance was not attributed to pH variations by the addition of OAs, but to the increase of the initial dissolved iron in the system, facilitating the Fe3+/Fe2+ turnover in the catalytic photo-Fenton reaction and consequently, the hydroxyl radicals production. For citric and tartaric acid, increased photo-activity of the complexes was associated with their high capability to complex Fe3+ and to promote ligand-to-metal charge transfer (LMCT), which is of key importance to feed Fe2+ to the Fenton process. On the other hand, for ascorbic and caffeic acid, the acceleration of the homogeneous Fenton reaction was ...
When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, the equilibrium is shifted to the left, in accordance with Le Châteliers principle. Because of this, the hydrogen ion concentration increases by less than the amount expected for the quantity of strong acid added. Similarly, if strong alkali is added to the mixture the hydrogen ion concentration decreases by less than the amount expected for the quantity of alkali added. The effect is illustrated by the simulated titration of a weak acid with pKa = 4.7. The relative concentration of undissociated acid is shown in blue and of its conjugate base in red. The pH changes relatively slowly in the buffer region, pH = pKa ± 1, centered at pH = 4.7 where [HA] = [A−]. The hydrogen ion concentration decreases by less than the amount expected because most of the added hydroxide ion is consumed in the reaction ...
Many E. coli genes show pH-dependent expression during logarithmic growth in acid (pH 5-6) or in base (pH 8-9). The effect of rapid pH change, however, has rarely been tested. Rapid acid treatment could distinguish between genes responding to external pH, and genes responding to cytoplasmic acidification, which occurs transiently following rapid external acidification. It could reveal previously unknown acid-stress genes whose effects are transient, as well as show which acid-stress genes have a delayed response. Microarray hybridization was employed to observe the global gene expression of E. coli K-12 W3110 following rapid acidification of the external medium, from pH 7.6 to pH 5.5. Fluorimetric observation of pH-dependent tetR-YFP showed that rapid external acidification led to a half-unit drop in cytoplasmic pH (from pH 7.6 to pH 6.4) which began to recover within 20 s. Following acid treatment, 630 genes were up-regulated and 586 genes were down-regulated. Up-regulated genes included amino-acid
TY - JOUR. T1 - A new technique for measurement of pharyngeal pH. T2 - Normal values and discriminating pH threshold. AU - Ayazi, S.. AU - Lipham, J. C.. AU - Hagen, J. A.. AU - Tang, A. L.. AU - Zehetner, J.. AU - Leers, J. M.. AU - Oezcelik, A.. AU - Abate, E.. AU - Banki, F.. AU - DeMeester, S. R.. AU - DeMeester, T. R.. PY - 2009/7/1. Y1 - 2009/7/1. N2 - Introduction Identifying gastroesophageal reflux disease as the cause of respiratory and laryngeal complaints is difficult and depends largely on the measurements of increased acid exposure in the upper esophagus or ideally the pharynx. The current method of measuring pharyngeal pH environment is inaccurate and problematic due to artifacts. A newly designed pharyngeal pH probe to avoid these artifacts has been introduced. The aim of this study was to use this probe to measure the pharyngeal pH environment in normal subjects and establish pH thresholds to identify abnormality. Methods Asymptomatic volunteers were studied to define the normal ...
We show that pH homeostasis varies among individual bacterial cells, both among planktonic cells adhered to a slide and among cells within a biofilm grown on a slide. This variability implies that the pH response and recovery measurements obtained for cell suspensions miss important aspects of pH homeostasis of individual cells. The variation we saw could be associated with substrate adherence and with variability among suspended cells. Properties of adherent cells are highly important for medical, environmental, and industrial applications.. To measure pH homeostasis, we used ratiometric GFP combined with fluorescence microscopy, both for E. coli (Fig. 4) and for B. subtilis (Fig. 8). Ratiometric pHluorin (18) combines the advantages of GFP fluorimetry (14, 15, 36) and fluorescence microscopy. Fluorimetry reports only the average response of cell populations, with no capacity to monitor individual cells. For single cells, cytoplasmic pH has been measured previously by ratio imaging with a ...
Filamentous fungi have the ability to efficiently decompose plant biomass, and thus are widely used in the biofuel and bioprocess industries. In process, ambient pH has been reported to strongly affect the performance of the applied functional filamentous fungi. In this study, Trichoderma guizhouense NJAU4742 was investigated under the fermentation of rice straw at different initial pH values for a detailed study. The results showed that NJAU4742 strain could tolerate ambient pH values ranging from 3.0 to 9.0, but had significantly higher growth speed and extracellular enzyme activities under acidic conditions. At low ambient pH (| 4), NJAU4742 strain achieved rapid degradation of rice straw by elevating the ambient pH to an optimal range through environmental alkalinization. Further proteomic analysis identified a total of 1139 intracellular and extracellular proteins during the solid-state fermentation processes, including the quantified 190 carbohydrate-active enzymes (CAZymes) responsible for rice
1. An accurate quantitative method of measuring the penetration of dye into the living cell is described. 2. Cresyl blue is unable to penetrate rapidly unless the pH outside the cell is decidedly greater than that inside. The rate of penetration increases with increasing pH. 3. Around pH 9 penetration of the dye is rapid while the reverse is true of exosmosis. At low pH values (5.9) exosmosis is rapid and penetration is very slow. ...
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H3O+ + OH-. The position of any equilibrium is given by an equilibrium constant, K, which for the dissociation of water according to the acid-base reaction just described is:. K = a(H3O+)a(OH-)/a2(H2O). In this equation, the chemical activities a can be approximated by the appropriate molar concentrations, indicated here by the use of square brackets in the form K = [H3O+][OH-]/[H2O]2 Since the concentration of water is approximately constant, it is normally included with the equilibrium constant of water (in other words, the chemical activity of water is taken as that of pure water, which is unity). In that case the equilibrium constant above is known as the ion product of water or the autoionization constant of water and indicated by the subscript w, so that by definition:. Kw = [H3O+][OH-]. The ionization constants of acids and bases other than water are dealt with in a similar way. The ionization of acetic acid in water is described by the equilibrium. CH3COOH(aq) + H2O ...
Comparative Evaluation of Magnesium Bisulfite Pretreatment under Different pH Values for Enzymatic Hydrolysis of Corn Stover. Jiwei Ren,a Lei Liu,b Qianqian Xu,b Xin Li,b Qiang Yong,c and Jia Ouyang b,c,*. During pretreatment, the pretreatment pH often plays an important role in removing hemicelluloses and lignin for improving the conversion of biomass to sugars. In this study, corn stover was subjected to magnesium bisulfite pretreatment (MBSP) under various pH conditions. The obtained data showed that the hemicelluloses and lignin were solubilized by MBSP, which led to changes in the structural and chemical properties of the pretreated material. The pretreatment pH could alter the existing forms of SO2, and magnesium bisulfite was the most effective reagent for removing lignin. A relatively neutral MBSP (pH 5.13) not only considerably improved the enzymatic hydrolysis yield (80.18%), but also produced a large amount of high-value xylo-oligosaccharides in the spent liquor. Furthermore, only the ...
The hydrogen ion concentration is extremely important to the structural and functional integrity of living systems. Even slight changes in may cause profound changes in the large molecules and
Toxic chemicals and both prescription and over-the-counter drugs lower body`s pH levels, which is the reason why they come with a wide range of side effects and little or no effectiveness. Enzymes are deactivated when the pH drops below 6.4, which in turn compromises both digestion and assimilation of vitamins, minerals, and food supplements. Acid reduces the energy production on cellular level, the ability to detoxify heavy metals, the capacity to repair cells, and makes the body more prone to illness and fatigue.. It has been scientifically shown that disease cannot thrive in an alkaline environment, and that bacteria, yeast, mold, candida, fungus, and cancer cells thrive in an acidic and low pH environment. The most common causes of an acidic pH include emotional stress, toxic overload, an acid forming diet, and depletion of oxygen and nutrients. In turn, the body tries to compensate for acid by using alkaline mineral reserves, which then leads to development of a wide array of ...
Ethanol oxidation in 0.1 M NaOH on single-crystal electrodes has been studied using electrochemical and FTIR techniques. The results show that the activity order is the opposite of that found in acidic solutions. The Pt(111) electrode displays the highest currents and also the highest onset potential of all the electrodes. The onset potential for the oxidation of ethanol is linked to the adsorption of OH on the electrode surface. However, small (or even negligible) amounts of COads and carbonate are detected by FTIR, which implies that cleavage of the ...
The pH levels in dental biofilms are highly variable and frequently shift from above pH 7.0 in the resting pH state to as low as pH 3.0 during the ingestion of dietary carbohydrates by the host. Thus, pH exerts a significant ecological pressure on S. mutans, and its ability to tolerate and grow in low pH environments is crucial to its survival and eventual dominance in dental plaque, leading to caries (27). Considerable evidence has shown that S. mutans has evolved a number of sophisticated mechanisms to survive these pH changes including induction of an ATR in which exposure of S. mutans cells to a mild or moderately acidic pH (5.0-6.0) results in enhanced survival of a significant proportion of the cell population in a lower pH of 3.0-3.5 (28). This ATR involves a number of de novo proteins that appear to be important for adaptation to an acidic environment (29). Although many of the molecular mechanisms of the ATR in S. mutans remain unclear, this signal pH that results in synthesis of ...
The pH effect on the bleached hair was presented by Dr. Ernesta Malinauskyte during the Hair S19 Conference, organized by DWI in September of 2019. We have received many requests to share our findings by attendees of the conference, as well as those who attended our seminar held at TRI at the end of 2019. Unfortunate
Background Cytoplasmic pH homeostasis in Escherichia coli includes numerous mechanisms involving pH-dependent catabolism and ion fluxes. An important contributor is transmembrane K+ flux, but the actual basis of K+ compensation for pH stress remains unclear. Osmoprotection could mediate the pH protection afforded by K+ and other osmolytes. Methods and Principal Findings The cytoplasmic pH of E. coli K-12 strains was measured by GFPmut3 fluorimetry. The wild-type strain Frag1 was exposed to rapid external acidification by HCl addition. Recovery of cytoplasmic pH was enhanced equally by supplementation with NaCl, KCl, proline, or sucrose. A triple mutant strain TK2420 defective for the Kdp, Trk and Kup K+ uptake systems requires exogenous K+ for steady-state pH homeostasis and for recovery from sudden acid shift. The K+requirement however was partly compensated by supplementation with NaCl, choline chloride, proline, or sucrose. Thus, the K+ requirement was mediated in part by osmolarity, possibly by
1. Na+/H+ antiport activity was measured in peripheral blood polymorphonuclear and mononuclear cells of 12 healthy subjects by using an intracellular pH clamp technique to determine the external Na(+)-dependent H+ efflux rate in cells loaded with a pH-sensitive fluorescent dye, bis(carboxyethyl)carboxyfluorescein. The change in external Na+ concentrations for all pH measurements was similar in both cell types. 2. A significant difference between the two types of cells was found, the polymorphonuclear leucocytes having a higher Na+/H+ antiport activity than the lymphocytes. Cellular intrinsic buffering capacity measured in the absence of HCO3- was also higher in the polymorphonuclear cells than in the lymphocytes. 3. These differences may be associated with a difference in the role of the Na+/H+ exchanger in these two types of cells, although in vivo the presence of HCO3-/Cl- exchangers may also contribute to intracellular pH homoeostasis.
Around here, we talk a lot about feedback loops. A feedback loop is simply some way to objectively quantify some measurement to gain insight to our current location.. An example we commonly use to bring light to this idea of a feedback loop is how we find our way around a shopping mall weve never been in before.. Of course, we would go find the kiosk/map of the mall. And the first thing we look for is the You Are Here big red arrow, right?. Why? Because knowing where we are gives us perspective to determine if whatever action we undertake helps us to move in the right direction or not.. Saliva pH is a helpful feedback loop to see how well our systems are doing managing an optimal oral pH environment. If the saliva pH is too high, were asking for trouble. And if the pH is too low, this provokes more tooth decay because the bugs implicated with tooth decay thrive in a low pH environment.. Heres an article that dives into this fascinating subject, titled Tracking your saliva pH - part 2 ...
1. Pyridine reacts with alkaline haematin to form a dipyridine dihydroxy dimeric haematin in which there is no competition between pyridine and OH− for coordination positions on the iron of haematin. 2. Imidazole competes directly with OH− to form the monomeric imidazole parahaematin in alkaline media. 3. The monomeric imidazole parahaematin aggregates readily to form a species that is precipitated on standing. 4. A structure is proposed for the haematin-pyridine compound in alkaline media.. ...
1 ml of urine is diluted to 4 ml with a phosphate buffer at pH 6. 1ml of blood is de-proteinized by mean of sonication (15 minutes), vortex mixing (30 sec) and added with a phosphate buffer at pH 6. 5 min. Centrifugation is following (5 min. 300 r/min) and the precipitate eliminated. The B.E.C. column is conditioned with 2 ml of Methanol, 2 ml of water and 3 ml of a phosphate buffer solution at pH 6. Conditioning flow rate is 1.5 ml/min. The sample is then loaded onto the column at a flow rate of 1 ml/min. Before elution, the column is rinsed with 1 ml of buffer solution and dried under vacuum for 5 min. Column pH is lowered to the value of 3 by Acetic Acid teatment at a flow rate of 1.0 ml/min. Stationary phase is dried again under vacuum for 5 min and wet with 1.0 ml of hexane. Elution is performed at a flow rate of 0.5 ml/min with the following conditions: ...
TY - JOUR AU - Tripković, Amalija AU - Popović, Ksenija AU - Lović, Jelena PY - 2007 UR - http://cer.ihtm.bg.ac.rs/handle/123456789/290 AB - The electrochemical oxidation of methanol in NaOH solution was examined on a thin film Pt2Ru3/C electrode. The XRD pattern revealed that the Pt2Ru3 alloy consisted of a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru. It was shown that in alkaline solution, the difference in activity between Pt/C and Pt2Ru3/C is significantly smaller than in acid solution. It is proposed that the reaction follows a quasi bifunctional mechanism. The kinetic parameters indicated that the chemical reaction between adsorbed COad and OHad species could be the rate limiting step. AB - Elektrohemijska oksidacija metanola ispitivana je na nanokatalizatoru Pt2Ru3 dispergovanom na aktivnom uglju kao nosaču u alkalnoj sredini. Katalizator je karakterisan difrakcijom X-zraka (XRD) i dobijeni rezultati su pokazali da se legura Pt2Ru3 sastoji od ...
All growers should do their own media pH and EC testing every week, at least on key crops. They can then send in periodic samples to a reputable testing lab for complete media (and tissue) analysis to back up their own findings, when they have problems showing up, or when they change something big such as the media or fertilizer program. Samples should be taken from commercial mixes out of the bag or your own hopper before sowing or planting the crop. To determine the true effect of the lime in the media, I suggest you also take samples after watering the flats or trays for one and two weeks with just your water, no feed. You should be able to see how the lime will affect the media pH within the first two weeks. Afterwards, I tell growers to monitor key crops, the ones more likely to show problems with media pH or EC. Here are my recommendations:. If you test one or more crops from each list weekly, you can avoid problems on those crops before they show up. All other crops will fall somewhere in ...
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For improving the therapeutic efficiency of tumors and decreasing undesirable side effects, ternary complexes were developed by coating pH-sensitive PEG-b-PLL-g-succinylsulfathiazole (hereafter abbreviated as PPSD) with DNA/PEI polyplexes via electrostatic interaction. PPSD can efficiently shield the surface charge of DNA/PEI. The gene transfection efficiency of ternary complexes was lower than that of DNA/PEI at pH 7.4; however, it recovered to the same level as that of DNA/PEI at pH 6.0, attributed to the pH-triggered release of DNA/PEI from ternary complexes. Cell uptake results also exhibited the same trend as transfection at different pH values. The suitable ability for pH-triggered shielding/deshielding estimated that PPSD demonstrates potential as a shielding system for use in in vivo gene delivery.
Accurate predictions of pKa values of titratable groups require taking into account all relevant processes associated with the ionization/deionization. Frequently, however, the ionization does not involve significant structural changes and the dominating effects are purely electrostatic in origin allowing accurate predictions to be made based on the electrostatic energy difference between ionized and neutral forms alone using a static structure. On another hand, if the change of the charge state is accompanied by a structural reorganization of the target protein, then the relevant conformational changes have to be taken into account in the pKa calculations. Here we report a hybrid approach that first predicts the titratable groups, which ionization is expected to cause conformational changes, termed
Several inwardly-rectifying (Kir) potassium channels (Kin l 1, Kir41 and Kir4 2) are characterised by their sensitivity to inhibition by intracellular H+ within the physiological range The mechanism by which these channels are regulated by intracellular pH has been the subject of intense scrutiny for over a decade, yet the molecular identity of the titratable pH-sensor remains elusive In this study we have taken advantage of the acidic intracellular environment of S cerevisiae and used a K+-auxotrophic strain to screen for mutants of Kin 1 1 with impaired pH-sensitivity In addition to the previously identified K80M mutation, this unbiased screening approach identified a novel mutation (S172T) in the second transmembrane domain (TM2) that also produces a marked reduction in pH-sensitivity through destabilization of the closed-state However, despite this extensive mutagenic approach, no mutations could be identified which removed channel pH-sensitivity or which were likely to act as a separate H+-sensor
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CheY, the 129 amino acid chemotactic protein from Escherichia coli, is a good model for studies of folding of parallel alpha/beta proteins. We report here the thermodynamic characterization of the wild-type CheY at different pH values and in different buffers and denaturation conditions. The denaturation of CheY by urea monitored by circular dichroism and fluorescence fits the two-state unfolding model. The stability of the protein is ionic strength dependent, probably due to the presence of three Asp residues in very close proximity in its active site. The presence of a Mg2+ ion, which seems to interact with Asp 13 in the active site, stabilizes the native structure by up to 6.9 kJ mol-1. The CheY maximum stability (31.7 +/- 2.1 kJ mol-1), without magnesium, is reached at pH 5.1. Analysis of scanning calorimetry data has shown that temperature-induced unfolding of CheY is not a two-state process and proceeds through a highly populated intermediate state, corresponding to protein dimers, as was ...
pH dependent ion exchange matrices are provided, with methods for making such matrices, and methods for using such matrices to isolate a target nucleic acid, such as plasmid DNA, chromosomal DNA, or RNA from contaminants, including proteins, lipids, cellular debris, or other nucleic acids. Each pH dependent ion exchange matrix of this invention comprises at least two different ion exchange functional groups, one of which is capable of acting as an anion exchanger at a first pH, and the other of which is capable of acting as a cation exchanger at a second, higher pH. The matrix has an overall neutral charge in a pH range between the first and second pH. The pH dependent ion exchange matrices of the present invention are designed to bind to the target nucleic acid at a pH wherein the overall charge of the matrix is positive, and to release the target nucleic acid as the pH of the surrounding solution is increased. The target nucleic acid can be released from the pH dependent matrix in little or no salt
Urine PH Measurement Device PHS-2F for Sale, US $ 120 / Piece, Guangdong, China, OEM, PHS-2F.Source from Guangzhou Allfine Medlab Co., Ltd. on Alibaba.com.
According to Florida State Universtiy, pH affects enzyme activity by altering or inhibiting an enzyme from catalyzing a reaction. Changes in pH affect polar and non-polar forces, alter the shape of...
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I know cancer develops in an acid environment and can not survive in an alkaline medium; I usually have with me an alkalizing called Alkalife; I soaked a cotton ball directly with Alkalife, which is extremely alkaline and to my surprise after passing the cotton by the swelling it went away as if would be just a patch of foam; in this area remains today a small sink but the problem disappeared until today; I burned an area of adjacent good tissues because of the extreme alkalinity, but I no longer worried about the matter, as I have reviewed many times the area and has no symptoms of reproduction; I think I should have diluted a little the preparation. ...
HPLC Application #16098: Non-Polar Acids at pH 2.5 using Onyx C18 3.0mm ID. Column used: Onyx™ Monolithic C18, LC Column 100 x 3 mm, Ea Part#: CH0-8158
The enzymatic controlled metabolic processes in cells occur at their optimized pH ranges, therefore cellular pH homeostasis is fundamental for life.
TY - JOUR. T1 - Biliverdin-copper complex at physiological pH. AU - Dimitrijević, Milena S.. AU - Bogdanović Pristov, Jelena. AU - Žižić, Milan. AU - Stanković, Dalibor M.. AU - Bajuk-Bogdanović, Danica. AU - Stanić, Marina. AU - Spasić, Snežana. AU - Hagen, Wilfred. AU - Spasojević, Ivan. N1 - Accepted Author Manuscript. PY - 2019. Y1 - 2019. N2 - Biliverdin (BV), a product of heme catabolism, is known to interact with transition metals, but the details of such interactions under physiological conditions are scarce. Herein, we examined coordinate/redox interactions of BV with Cu 2+ in phosphate buffer at pH 7.4, using spectrophotometry, HESI-MS, Raman spectroscopy, 1 H NMR, EPR, fluorimetry, and electrochemical methods. BV formed a stable coordination complex with copper in 1:1 stoichiometry. The structure of BV was more planar and energetically stable in the complex. The complex showed strong paramagnetic effects that were attributed to an unpaired delocalized e - . The delocalized ...
Interpretations of pH values are soundest when associated with dilute aqueous solutions of simple solutes; they become unsound when associated with nonaqueous solvents, colloids, or solutions of high ionic strength. For most applications the pH value may be regarded as a practical and comparative measure of acidity, and no attempt need be made to interpret it rigorously in terms of single-ion activity. In many calculations the hydrogen ion concentration is more accessible than the activity. For example, the electroneutrality condition is written in terms of concentrations rather than activities. Ka CA- + [HI] Solution of strong acid A strong acid, by definition, is one for which (3-11) is complete to the right, so that [HA] is essentially zero. From (3-14) [H] = + CHA [OH-] (3-18) The total concentration of hydrogen ion is that from the strong acid plus that from the water (equal to [OH-]). Unless the solution is extremely dilute (CHA< M), the second term may be neglected. Consider, for ...
The surface enhanced Raman scattering (SERS) spectrum of a reporter molecule attached to gold or silver nanostructures, which is pH-sensitive, can deliver information on the local pH in the environment of the nanostructure. Here, we demonstrate the use of a mobile SERS nanosensor made from gold nanaoaggregates and 4-mercaptobenzoic acid (pMBA) attached as a reporter for monitoring changes in local pH of the cellular compartments of living NIH/3T3 cells. We show that SERS nanosensors enable the dynamics of local pH in individual live cells to be followed at subendosomal resolution in a timeline of cellular processes. This information is of basic interest for a better understanding of a broad range of physiological and metabolic processes as well as for a number of biotechnological applications ...
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Supplementary MaterialsSupplementary data 1 mmc1. acids that become pH sensors. Since the membrane fusion event happens in the pH range of 5C6, the most likely residues to function as pH detectors are histidines, aspartates and/or glutamates, which possess pKa in the appropriate pH range (Zhou et al., 2014). Based on a number of studies, multiple pH detectors are involved. First, from biochemical, x-ray, EM and virological studies, HA is known to undergo multiple reversible conformational changes when exposed to low pH (Xu and Wilson, 2011, Fontana et al., 2012, Leikina et al., 2002). Second, despite a high degree of structural homology within HA subtypes, examination of HA sequences does not reveal totally conserved titratable residues (Zhou et al., 2014, Mair et al., 2014). Third, membrane fusion happens at different pH ideals for different HA subtypes (Scholtissek, 1985, Puri et al., 1990, Korte et Rabbit Polyclonal to VAV3 (phospho-Tyr173) al., 2007). Fourth, mutagenesis studies possess ...
This free online seminar addresses various ways in which temperature impacts pH measurements and discusses temperature compensation during calibration of instruments with buffers and measurement of pH in samples.
Effect of Intraluminal pH on the Absorption of Pteroylmonoglutamic Acid: The administration of pteroylmonoglutamic acid and either sodium bicarbonate or phenyto
A base is also called alkaline, is the opposite of an acid. Some examples of a base substance are baking soda and ammonia. The body needs balance to function optimally, but the number 7 is not necessarily the magic number for all parts of the body. Inside, the bodys biochemical environment prefers to be on the slightly more on the alkaline side. The optimal measurement here actually is 7.39.. The blood however, functions properly only as long as the pH measurement falls within the range of 7.36 (a bit more acidic) to 7.45 (a bit more alkaline). This range of 7.36 and 7.45 is vital to persons well being. The body will go through great lengths to maintain the appropriate, slightly alkaline, nature of its internal environment. Measurements outside this range significantly compromise the bloods ability to function properly and can even result in death.. Alkalosis results when the bloods pH measurement falls between 7.42 and 7.8. Acidosis results when the bloods pH measurement ranges from 7 to ...
1)   solvent phase  ,  2)  aqueous phase  ,  3)  precipitates ,  4)  both ( and (
Four WIN compounds with anti-picornavirus activities were tested for their ability to stabilize human rhinovirus serotype 2 (HRV-2) against low pH-induced conformational changes in vitro, as determined by specific immunoprecipitation. These results were compared to the minimal inhibitory concentration (MIC) as measured in a plaque reduction assay. A direct relationship was observed between the concentration of the compound that prevented the low pH-induced conformational changes and the MIC, indicating that stabilization is an important element in the mode of action of these drugs against HRV-2.
The hydrogen ion concentration in the lesions of experimental pneumococcus infection has been estimated directly by pH determinations on exudates from living animals. For indirect evidence of an increase in hydrogen ion concentration within the lesions, the difference in sugar content between exudate and blood from animals with pneumococcus infection has been measured.. With sanguinous exudate from the consolidated lungs of dogs with experimental pneumococcus pneumonia, the findings were not always consistent, but usually there was either direct or indirect evidence of increased hydrogen ion concentration. The physicochemical changes in exudate from animals treated with artificial pneumothorax showed no important differences from those in other specimens. In concurrence with Lords (1, 2) observation of increased acidity in pneumonia exudate obtained at autopsy, sugar concentrations, which are low in the blood, were markedly reduced in exudates from animals which had died of the ...
Methanol electro-oxidation reaction over carbon-supported platinum nanoparticles, including methanol adsorption, apparent reaction order and activation energy, in acidic and alkaline media was investigated comparatively. The results show that the rate constant for methanol adsorption in 1 M NaOH is significantly higher than that in 0.5 M H2SO4 at the relatively low potential and the COad removal in alkaline media is easier, due to the availability of oxygen-containing species, than in acidic media at the same potential. The apparent activation energy for the MOR in alkaline media is 25.3-14.6 kJ mol(-1), significantly lower than that in acidic media (34.9-28.5 kJ mol(-1)). The better MOR activity of Pt/C in alkaline media is attributed to the faster methanol adsorption and the availability of oxygen-containing species. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved ...
|p|Oxidation of isatins (isatin, 5-methylisatin, 5-bromoisatin and 5-nitroisatin) to their anthranilic acids was performed efficiently with sodium N-chlorobenzenesulfonamide or chloramine-B (CAB) in alkaline medium at 35±0.1°C. The reactions follow identical kinetics for all the isatins, being first-order dependence each in [CAB]o and [Isatin]o and inverse fractional-order on [NaOH]. Addition of halide ions and benzenesulfonamide, reduction product of CAB, do not significantly affect the rate. Variation of ionic strength of the medium had no effect on the rate, while the dielectric effect is negative. The solvent isotope effect was studied using D2O. Activation parameters for the overall reaction have been computed. The rates satisfactorily correlate with the Hammett σ relationship and the reaction constant ρ is −0.31 signifies that electron releasing groups accelerate the reaction while the electron withdrawing groups retard the rate. Values of ΔH≠ and ΔS≠ are linearly
Acid-Treated Nickel-Rich Platinum-Nickel Alloys for Oxygen Reduction and Methanol Oxidation Reactions in Alkaline MediaAcid-Treated Nickel-Rich Platinum-Nickel Alloys for Oxygen Reduction and Methanol Oxidation Reactions in Alkaline Media ...
Near-neutral electrolytes based on zinc chloride and ammonium chloride are examined for rechargeable zinc-air battery application. The effects of pH value, salt concentration, and polyethylene glycol and thiourea additives are investigated and a chloride electrolyte is developed. The reversible zinc deposition and zinc stripping processes are studied by cyclic voltammetry with rotating-disc electrode technique. The zinc anode and air cathode behaviors in near-neutral chloride electrolyte are characterized by quasi steady-state polarization and impedance spectroscopy. Prototyped zinc-air battery with near-neutral chloride electrolytes can sustain more than 1000 hours and hundreds of discharge-charge cycles with minimized zinc dendrite formation and no carbonate formation problem, under discharge-charge capacity ranging from 20 to 120 mAh. The near-neutral chloride electrolyte provides a safer and more robust alternative to traditional alkaline electrolyte for rechargeable zinc-air batteries. © ...
Water pH level is a measure of how acidic the water is. Water is considered acidic if it has a pH level below seven, and it is considered alkaline if it has a pH level above seven. If the water has a pH level of exactly seven, it is considered neutral. A safe pH level range for drinking water is considered to be between six and 8.5.. You may notice some issues with your water if it falls outside the acceptable pH range. For example, water with a high pH level may feel slippery, have a taste similar to baking soda, and leave deposits on your sinks and fixtures. Alkaline water can be caused by mineral deposits such as limestone in groundwater, or contamination of drinking water from wastewater that contains cleaning agents. Water with a low pH level may have a metallic taste, and cause corrosion on your sink and fixtures. Acidic water can be found in areas that are affected by acid rain, and is sometimes found in glacier water due to dissolved carbon dioxide. The EPA also warns that drinking ...
We have used Thomas-type recessed-tip pH-sensitive microelectrodes to measure the intracellular pH (pHi) in Xenopus eggs during both fertilization and ionophore activation. The average pHi in unfertilized eggs is 7.33 +/- 0.11 (SD; n = 21) with a resting membrane potential of -10.1 +/- 3.5 (SD; n = 38) mV. Within 2 min after the onset of the fertilization potential, there is a slight, transient pHi decrease of 0.03 +/- (SD, n = 8), followed by a distinct, permanent pHi increase of 0.31 +/- 0.11 (SD; n = 7) beginning approximately 10 min after the start of the fertilization potential and becoming complete approximately 1 h later. The pHi remains near this level of 7.67 +/- 0.13 (SD, n = 10) through at least 10 cleavage cycles, but it is possible to discern pHi oscillations with a mean amplitude of 0.03 +/- 0.02 (SD, n = 38). Eggs perfused for at least 2 h in Na+-free solution with 1 mM amiloride exhibited all of these pHi changes, so these changes do not require extracellular Na+. Similar ...
Strong ions are cations and anions that exist as charged particles dissociated from their partner ions at physiologic pH. The SID (Strong Ion Difference) is the difference between the positively- and negatively-charged strong ions in plasma. This method of evaluating acid-base disorders was developed to help determine the mechanism of the disorder rather than simply categorizing them into metabolic vs. respiratory acidosis/alkalosis as with the Henderson-Hasselbalch equation. Strong cations predominate in the plasma at physiologic pH leading to a net positive plasma charge of approximately +40: SID = [strong cations] - [strong anions] = [Na+ + K+ + Ca2+ + Mg2+] - [Cl- + lactate- + SO42-] Disturbances that increase the SID increase the blood pH while disorders that decrease the SID lower the plasma pH. According to the law of electroneutrality the sum of positive charges is equal to the sum of negative charges. Therefore the SID must be equal to the sum of weak anions in the body (such as ...
Spawning market squid lay embryo capsules on the seafloor of the continental shelf of the California Current System (CCS), where ocean acidification, deoxygenation and intensified upwelling lower the pH and [O2]. Squid statolith geochemistry has been shown to reflect the squids environment (e.g., seawater temperature and elemental concentration). We used real-world environmental levels of pH and [O2] observed on squid-embryo beds to test in the laboratory whether or not squid statolith geochemistry reflects environmental pH and [O2]. We asked whether pH and [O2] levels might affect the incorporation of element ratios (B:Ca, Mg:Ca, Sr:Ca, Ba:Ca, Pb:Ca, U:Ca) into squid embryonic statoliths as (1) individual elements and/or (2) multivariate elemental signatures, and consider future applications as proxies for pH and [O2] exposure. Embryo exposure to high and low pH and [O2] alone and together during development over four weeks only moderately affected elemental concentrations of the statoliths, and
A preparation of ATPase from the membranes of Micrococcus lysodeikticus, solubilized and more than 95% pure, showed two main bands in analytical polyacrylamide gel electrophoresis. They did not correspond to isoenzymes because one band could be converted into the other by exposure to a mildly alkaline pH value. The conversion was paralleled by changes in molecular weight, circular dichroism and catalytic properties. Denaturation by pH at 25 degrees C was followed by means of circular dichroism, ultracentrifugation and polyacrylamide gel electrophoresis. A large conformational transition took place in the acid range with midpoints at about pH = 3.6 (I = 10(-4) M), 4.3 (I = 0.03 M) and 5.3 (I = 0.1 M). The transition was irreversible. Strong aggregation of the protein occurred in this range of pH. The final product was largely random coil, but even at pH 1.5 dissociation into individual subunits was not complete. However, partial dissociation took place at pH 5 (I = 0.028 M). At this pH value the enzyme
Growth of C. thermarum strain TA2.A1 on nonfermentable carbon sources is pH dependent.When strain TA2.A1 was grown in non-pH-controlled batch culture at an initial pH of 7.5 on a nonfermentable carbon source, such as sucrose, glutamate, or succinate, the final pH was always ,9.0 regardless of the carbon source (data not shown). These data demonstrated that the medium used to grow strain TA2.A1, even though strongly buffered (i.e., 100 mM NaHCO3), lacked the necessary buffering capacity to hold the external pH near neutral pH. Uninoculated medium was tested in parallel, and the pH remained unchanged over the same time period of incubation. On the basis of these observations, all growth experiments were performed in pH-controlled batch culture.. The pH limits for growth of strain TA2.A1 were examined using alkaline basal medium supplemented with either succinate, malate, or sucrose under pH-controlled conditions. Strain TA2.A1 grew at a doubling time (td) of 1.5 h in basal medium with no added ...
TY - JOUR. T1 - Methods for accelerating nitrate reduction using zerovalent iron at near-neutral pH. T2 - Effects of H2-reducing pretreatment and copper deposition. AU - Liou, Y. H.. AU - Lo, S. L.. AU - Lin, C. J.. AU - Hu, C. Y.. AU - Kuan, W. H.. AU - Weng, S. C.. PY - 2005/12/15. Y1 - 2005/12/15. N2 - Both surface treatments, H2-reducing pretreatment at 400 °C and the deposition of copper as a catalyst, were attempted to enhance the removal of nitrate (40 (mg N) L-1) using zerovalent iron in a HEPES buffered solution at a pH of between 6.5 and 7.5. After the iron surface was pretreated with hydrogen gas, the removal of the passive oxide layers that covered the iron was indicated by the decline in the oxygen fraction (energy dispersive X-ray analysis) and the overlap of the cyclic polarization curves. The reaction rate was doubled, and the lag of the early period disappeared. Then, the deposition of copper onto freshly pretreated iron promoted nitrate degradation more effectively than that ...
SUMMARY: Upon repeated subculture in media of gradually increasing pH value a strain of Bacillus cereus developed the ability to grow under strongly akaline conditions. Organisms with the highest alkali resistance could grow at pH 10·3, and stocks of intermediate resistance were also obtained. When growing on alkaline agar, resistant bacteria underwent marked morphological changes. In liquid media, the bacteria retained the ability to synthesize lecithinase. Resistance was not lost upon several transfers on a neutral medium. Resistant bacteria when growing in alkaline media caused a rapid decrease in pH value. A similar pH decrease was caused by sensitive bacteria in media of the highest degree of alkalinity in which they could grow. The decline of pH value accompanied, but did not precede, growth; acid production by the resistant bacteria does not appear to be a primary mechanism of resistance.
In the Bochevarov et al. implementation the user defines the titrateable group for which the apparent pKa is computed. However, in my approach all possible protonation states so the assignment of the apparent pKa value to a particular ionizable group is not immediately obvious. Inspection of Eq $\ref{eqn:pkapp}$ shows that the largest microscopic pKa values will dominate the sum over $N$, while the smallest of these maximum pKa values will dominate the sum over $M$. Thus, the apparent pKa is assigned to the functional group corresponding to the microscopic ...
In the Bochevarov et al. implementation the user defines the titrateable group for which the apparent pKa is computed. However, in my approach all possible protonation states so the assignment of the apparent pKa value to a particular ionizable group is not immediately obvious. Inspection of Eq $\ref{eqn:pkapp}$ shows that the largest microscopic pKa values will dominate the sum over $N$, while the smallest of these maximum pKa values will dominate the sum over $M$. Thus, the apparent pKa is assigned to the functional group corresponding to the microscopic ...
Semantic Scholar extracted view of Blood and erythrocyte hydrogen ion concentrations in acid-base imbalance from respiratory disorders. by A. Rizzo et al.
This is 100th anniversary of the glass pH electrode yet we still do not know much about what affects their life. Not much has been published about application problems and practices. There have been a few academic studies on the effect of process conditions on the glass electrode but these are over 20 years old. The best book on the theory of pH measurement The Determination of pH is over 35 years old. The glass electrode is more important than ever because of its extraordinary rangeability and sensitivity to hydrogen ion concentration. What other measurement can cover 14 orders of magnitude of concentration and detect changes as small as 0.00000000000001 (0 to 14 pH scale).. While the fundamentals of the glass pH electrode have not changed in a hundred years, there have been significant improvements in the glass formulation and construction so that it can handle high pH and high temperature fluids and repeated sterilizations. For example a new high temperature electrode increases the life ...
The kinetics of the auto-oxidation of 2-aminophenol (OAP) to 2-amino-phenoxazin-3-one (APX) was followed in air-saturated aqueous solutions and the influence of temperature and pH on the auto-oxidation rate was studied. The kinetic analysis was based on a spectrophotometric method following the increase of the absorbance of APX. The process follows first order kinetics according to the rate law-d[OAP]/dt=k′[OAP]. The experimental data, within the pH range 4-9.85, were analyzed using both differential and incremental methods. The temperature variation of the overall rate constant was studied at pH=9.85 within the range 25-50°C and the corresponding activation energy was evaluated ...
A robust pH sensor from Endress+Hauser can now solve the problem of reference contamination commonly experienced during pH measurement in ultra harsh conditions such as mining slurries and paper & pulp applications.. pH measurement within ultra harsh applications that include high solid content poses several challenges. Because of the harmful ions that defuse into the pH electrode reference system and the high solid content, the potential to disable the electrode by blocking the diaphragm under these extreme conditions is high. The surface area of the pH electrode diaphragm therefore needs to be enlarged to avoid blockage. However this increases the risk of reference contamination as the diaphragm is porous and more harmful ions can now enter the reference system of the pH electrode.. Traditionally, these enlarged diaphragms have been made from wood due to its resistance to contamination, but the wooden diaphragm is relatively thick and slows down the electrodes response time. In most critical ...
TY - GEN. T1 - Respiration gating and Bloch fitting improve pH measurements with acidoCEST MRI in an ovarian orthotopic tumor model. AU - Jones, Kyle M.. AU - Randtke, Edward A.. AU - Howison, Christine M.. AU - Pagel, Mark Marty. PY - 2016. Y1 - 2016. N2 - We have developed a MRI method that can measure extracellular pH in tumor tissues, known as acidoCEST MRI. This method relies on the detection of Chemical Exchange Saturation Transfer (CEST) of iopamidol, an FDA-approved CT contrast agent that has two CEST signals. A log10 ratio of the two CEST signals is linearly correlated with pH, but independent of agent concentration, endogenous T1 relaxation time, and B1 inhomogeneity. Therefore, detecting both CEST effects of iopamidol during in vivo studies can be used to accurately measure the extracellular pH in tumor tissues. Past in vivo studies using acidoCEST MRI have suffered from respiration artifacts in orthotopic and lung tumor models that have corrupted pH measurements. In addition, the ...
AWV #17B: In this experiment, you will Use a Gas Pressure Sensor to measure the production of oxygen gas as hydrogen peroxide is destroyed by the enzyme catalase or peroxidase at various enzyme concentrations. Measure and compare the initial rates of reaction for this enzyme when different concentrations of enzyme react with H2O2. Measure the production of oxygen gas as hydrogen peroxide is destroyed by the enzyme catalase or peroxidase at various temperatures. Measure and compare the initial rates of reaction for the enzyme at each temperature. Measure the production of oxygen gas as hydrogen peroxide is destroyed by the enzyme catalase or peroxidase at various pH values. Measure and compare the initial rates of reaction for the enzyme at each pH value.
API Freshwater/Saltwater High Range pH Test Kit, Test kit of 250 tests Use to measure pH changes in marine aquariums, aquariums with African cichlids, and very alkaline tap water. Reads the pH of water within the high range of 7.4 to 8.8.250 tests per kit.Freshwater/Saltwater High Range pH Test Inst
Introduction. How does pH affect the activity of the Amylase? In this investigation I am going to consider how different pH levels will affect the rate in which amylase will break down the starch molecules. I will be measuring the time it takes for a yellow brown liquid to be shown, which would show that there is no starch present in the solution because it would have been broken down by amylase in solutions under ph levels. Hypothesis I would expect that when the pH is increasing towards the optimum level the rate of reaction would be at the highest point but when it has reached its optimum level the rate of the activity of the enzyme would decrease. The change in pH would affect the ionisation of the side groups in the enzymes amino acid residues this would then affect the overall shape of the enzyme molecule and would then affect the efficiency of formation of enzyme-substrate complexes. Variables The independent variable is pH as I am adjusting the pH in each experiment, the pHs that are ...
Green colour in green vegetables is due to the presence of a pigment known as chlorophyll, which is affected by pH. In an acid medium the colour of a green vegetable changes to olive green and in alkaline medium it changes to bright green. This is the reason why some cooks add cooking soda or any other alkaline medium while cooking greens. When a green vegetable is cooked covered, the plants natural acid is leached into the cooking liquid and is trapped there creating an acidic cooking medium. This, combined with the heat present, destroys the pigment. Green vegetables should also be cooked uncovered so that the natural acids present, are expelled into the air. ...
We used the pH-sensitive fluorescent dye BCECF to study intracellular pH (pHi) regulation in primary cultures of rat astrocytes and C6 glioma cells. Both cell types contain three pH-regulating transporters: (1) alkalinizing Na+/H+ exchange; (2) alkalinizing Na+ + HCO3 −/Cl−exchange; and (3) acidifying Cl−/HCO3− exchange. Na+/H+ exchange was most evident in the absence of CO2; recovery from acidification was Na+ dependent and amiloride sensitive. Exposure to CO2 caused a cell alkalinization that was inhibited by DIDS, dependent on external Na+, and inhibited 75% in the absence of Cl− (thus mediated by Na+ + HCO3−/Cl− exchange). When pHi was increased above the normal steady-state pHi, a DIDS-inhibitable and Na+ -independent acidifying recovery was evident, indicating the presence of Cl− /HCO3−exchange. Astrocytes, but not C6 cells, contain a fourth pH-regulating transporter, Na+ −HCO3− cotransport; in the presence of CO2, depolarization caused an alkalinization of 0.12 +− 0.01 (n
The effect of pH on the formation of biogenic amines has mainly been studied in broths in which pH has been fixed before incubation. However, in the fermentation of dry sausage, pH quite rapidly decreases from the initial value to a certain level. In this study glucono-delta-lactone (GDL) was used to decrease pH in meat, Six minced meat samples were each divided into three portions (A-C): 0% (A), 0.5% (B), or 1.0% (C) of GDL was added and the samples were incubated at 20-22°C for 7 d. The amounts of biogenic amines (histamine, tyramine, putrescine, cadaverine, phenylethylamine, tryptamine, spermine, and spermidine) as well as pH, water activity, and the bacterial counts of lactic acid bacteria, fecal streptococci, coliforms, and total plate count were measured. Addition of GDL resulted in a significant decrease in pH and in the levels of histamine and putrescine as well as in the levels of fecal streptococci, coliforms, and total plate counts. Of 87 fecal streptococci, seven Enterococcus ...
Carbon-14 (radiocarbon, 14C) is a long-lived radionuclide (5730 yr) of interest regarding the safety for the management of intermediate level wastes (ILW). The present study gives an overview of the release of 14C from irradiated Zircaloy cladding in alkaline media. 14C is found either in the alloy part of Zircaloy cladding due to the neutron activation of 14N impurities by 14N(n,p)14C reaction, or in the oxide layer (ZrO2) formed at the metal surface by the neutron activation of 17O from UO2 or (U-Pu)O2 fuel and water from the primary circuit in the reactor by 17O(n,α)14C reaction. Various irradiated and unirradiated Zircaloys have been studied. The total 14C inventory has been determined both experimentally and by calculations. The results seem to be in good agreement. Leaching experiments were conducted in alkaline media for several time durations. 14C was mainly released as carboxylic acids. Further, corrosion measurements were performed by using both hydrogen measurements and ...
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Table 1: |i|N|/i|-Terminal Region of GbIspH1, |i|Ginkgo biloba|/i| IspH Type 1, May Be Involved in the pH-Dependent Regulation of Enzyme Activity
TY - JOUR. T1 - Administration and 1H MRS, detection of histidine in human brain. T2 - Application to in vivo pH measurement. AU - Vermathen, Peter. AU - Capizzano, Aristides A.. AU - Maudsley, Andrew A.. PY - 2000/5/17. Y1 - 2000/5/17. N2 - Measurement of histidine in vivo offers the potential for tissue pH measurement using routinely performed 1H MR spectroscopy. In the brain, however, histidine concentrations are generally too low for reliable measurement. By using oral loading of histidine, this study demonstrates that brain concentrations can be significantly increased, enabling detection of histidine by localized 1H MR measurements and making in vivo pH measurement possible. In studies carried out on healthy human subjects at 1.5 T, a consistent spectral quality downfield from water was achieved using a PRESS sequence at short echo times. Measurements at different TE values helped to characterize the downfield spectral region. Histidine loading of 400 mg/kg of body weight increased brain ...
E+h Ph Meter, Wholesale Various High Quality E+h Ph Meter Products from Global E+h Ph Meter Suppliers and E+h Ph Meter Factory,Importer,Exporter at Alibaba.com.
What Is The pH Meter Principle? Working principle of pH sensor electrode and pH meter used in quality control and manufacturing area. A pH meter is used to determine the acidity or alkalinity of the solution. pH is the concentration of hydrogen ions in the solution. A solution containing more H+ ions
ABSTRACT: Spironucleus vortens were cultivated in either an artificial medium at different temperatures, or in medium at various pH conditions or supplemented with different bile concentrations at 25°C. Temperature, pH and bile requirements for the optimal growth of the parasite were determined. Parasites multiplied quickly at 28 and 31°C and reached maximum numbers on Day 4 of cultivation, whereafter they did not survive. At 25°C, parasites survived longer than those at 28 and 31°C with no difference in multiplication rate during the exponential phase. The longest survival period was seen at 22°C, although the growth rate of the parasite was not as high as those at 25°C. At a higher temperature of 37°C, no parasites were observed alive after the second day of cultivation. Optimal pH range for the parasite¹s growth was 6.5 to 7.5, with the highest cell number at pH 7.5. Parasites survived longest (15 d) at pH 6.0, although the maximum number of cells was lower than those at the optimal ...
The link between cancer metabolism and immunosuppression, inflammation and immune escape has generated major interest in investigating the effects of low pH on tumor immunity. Indeed, microenvironmental acidity may differentially impact on diverse components of tumor immune surveillance, eventually contributing to immune escape and cancer progression. Although the molecular pathways underlying acidity-related immune dysfunctions are just emerging, initial evidence indicates that antitumor effectors such as T and NK cells tend to lose their function and undergo a state of mostly reversible anergy followed by apoptosis, when exposed to low pH environment. At opposite, immunosuppressive components such as myeloid cells and regulatory T cells are engaged by tumor acidity to sustain tumor growth while blocking antitumor immune responses. Local acidity could also profoundly influence bioactivity and distribution of antibodies, thus potentially interfering with the clinical efficacy of therapeutic antibodies
Ph Meter, Wholesale Various High Quality Ph Meter Products from Global Ph Meter Suppliers and Ph Meter Factory,Importer,Exporter at Alibaba.com.
Two nanofiltration membranes, a Dow NF 270 polyamide thin film and a TriSep TS 80 polyamide thin film, were investigated for their retention of ionic species when filtering mine influenced water streams at a range of acidic pH values. The functional iso-electric point of the membranes, characterized by changes in retention over a small pH range, were examined by filtering solutions of sodium sulphate. Both membranes showed changes in retention at pH 3, suggesting a zero net charge on the membranes at this pH. Copper mine drainage and synthetic solutions of mine influenced water were filtered using the same membranes. These solutions were characterized by pH values within 2 and 5, thus crossing the iso-electric point of both membranes. Retention of cations was maximized when the feed solution pH was less than the iso-electric point of the membrane. In these conditions, the membrane has a net positive charge, reducing the transmission rate of cations. From the recoveries of a range of cations, the ...
Alkaline protease from Bacillus amyloliquefaciens SP1 has been characterized in detail for its ecofriendly application of release of silver particles from gelatin layers of used X-ray films. It exhibited optimum activity at broad temperature range and maximum at 60⁰C under alkaline pH environment (8-12). Thermal inactivation of the crude enzyme followed first order kinetics. The half-life of the enzyme at 50, 60 and 65⁰C was 70, 15 and 12.6 min, respectively and the denaturation energy was 114.87 kJ/mol. Enzyme retained 53.83 and 108.33% of its initial activity after heating for 15 min at pH 8.0 and temperature 60⁰C, in presence and absence of 10 mM MnSO4, respectively. Enzymatic decomposition of gelatin layers was enhanced by increase of enzyme concentration from 38 to 3630 µg/ml/min, at 60⁰C and pH 8.0. This study reported the shortest time of 1.30 min at 3630 µg/ml/min and 4 : 30 min at 74 µg/ml/min of enzyme concentration for hydrolysis of gelatin layers. Keeping in mind that, ...
Dr. William Kelly, author, Cancer Cure.. Over the past decade, there has been a growing interest in alkaline diets and living an alkaline lifestyle. Part of this interest may involve drinking alkaline, ionized water from a water ionizer as a way to improve wellness, enhance performance, and prolong vitality. Alkaline, ionized water is water that has been selectively altered in a water ionizer to raise pH from neutral to pH 9 or more and also to display negative change (-ORP). Water above a pH 7 is alkaline and water below pH 7 is acidic. pH can be easily measured by using pH reagent or a meter, and ORP is measured using an ORP meter.. Life on earth depends on appropriate pH levels in and around living organisms and cells. Human life requires a tightly controlled pH level in the serum of about 7.4 (a slightly alkaline range of 7.35 to 7.45) to survive. The ability of the body to maintain this level of pH can be compromised by poor diet, lack of or excessive exercise, pollutants, dehydration, and ...
What other measures or recommendations should be taken in order to minimize the risk of corrosion?. As we have seen, the extraordinary alloy combination design and manufacturing process of CLIMETALs coils assure a very low risk of corrosion. However, you should also think of your HVAC unit as a whole. Once we understand the nature of aluminum and how galvanic corrosion works there are some simple rules you should take into account to make your coils last for years:. 1. Avoid extreme pH environments.. 2. Avoid contact between aluminum and other metals by using some plastic, rubber or polymer washers. Be aware that there are some materials that have a high metal content like pressure treated wood (plywood) and concrete.. 3. Avoid grounding electrical circuits to aluminum coils. Make sure your AC systems are completely ground isolated and that there is no electrical derivation going through the coil.. 4. Cleaning: Pollutants with extreme pH levels can attack the aluminum oxide layer. Therefore, ...
1. It is well known that neutral salts depress the osmotic pressure, swelling, and viscosity of protein-acid salts. Measurements of the P.D. between gelatin chloride solutions contained in a collodion bag and an outside aqueous solution show that the salt depresses the P.D. in the same proportion as it depresses the osmotic pressure of the gelatin chloride solution.. 2. Measurements of the hydrogen ion concentration inside the gelatin chloride solution and in the outside aqueous solution show that the difference in pH of the two solutions allows us to calculate the P.D. quantitatively on the basis of the Nernst formula. See PDF for Equation. if we assume that the P.D. is due to a difference in the hydrogen ion concentration on the two sides of the membrane.. 3. This difference in pH inside minus pH outside solution seems to be the consequence of the Donnan membrane equilibrium, which only supposes that one of the ions in solution cannot diffuse through the membrane. It is immaterial for this ...
Experimental Methods.Microsomal binding incubations. Microsomal binding in human liver microsomes was performed in triplicate using a 96-well equilibrium dialysis as adapted from a previous described method (Banker et al., 2003). Each dialysis membrane strip was conditioned sequentially for 15 min in deionized water, 30% ethanol, and then 0.1 M potassium phosphate buffer, pH 7.4. A conditioned membrane strip was then loaded into a 96-well dialysis apparatus. Experimental compound was diluted in dimethyl sulfoxide to a concentration of 100 μM. Human liver microsomes were thawed and diluted with 0.1 M potassium phosphate buffer (pH 7.4) to a final protein concentration of 0.76 mg/ml. Experimental compound was then further diluted 100-fold to yield 1 μM final concentration with the diluted microsomal solution. The compound and microsomes were thoroughly mixed, and 150 μl of the resulting solution was added to one side of the dialysis well as a donor side and 20 μl of this solution was retained ...
1. Interactions of proteins with neutral polysaccharides and such polyacids as polygalacturonic acid, chondroitin sulphate, RNA and DNA in a two-phase system composed of phenol and aqueous buffers in the
The hydrolysis rate of dodecamethylcyclohexasiloxane (D6) has been estimated using two different methods (Dow Corning Corporation, 2009). In the first method, acid and alkali catalysed rate constants were extrapolated from reliable measured data for the related siloxanes hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5). The rate constants at pH 4, 7 and 9 were then calculated using the equation: k(pred)/h-1= K(H+)[H+] + k(-OH)[-OH] Hydrolysis half-lives of 42 h at pH 4, 401 d (approximately 9600 h) at pH 7 and 125 h at pH 9 and 25°C were determined. In the second method, screening experiments were carried out at elevated temperature and basic pH (40°C and pH 10, and 60°C and pH 9). A hydrolysis half-life of 4600-7500 h at pH 9 was determined; half-lives at pH 4 and 7 could not be determined using the data from this method. The two results obtained by method 2 were in reasonable agreement with each other but differ significantly from the ...
FracBlack® Near-neutral buoyancy proppant (NBP) is designed for stimulation of unconventional wells to provide significantly greater fracture conductivity via unparalleled proppant placement in the far field fracture area and improved reservoir contact. FracBlack® is an advanced thermoset nanocomposite bead, featuring near-neutral buoyancy, high strength and thermal stability for application in most reservoirs with or without conventional proppants. This breakthrough NBP provides technical resolution to the primary limitations which impair conventional proppant placement and performance. The high strength and near-neutral specific gravity of FracBlack® NBPis designed to optimize proppant transport, placement, and conductivity longevity allowing you to Prop What You Frac.. Utilization: FracBlack® NBPis used to provide effective propped fracture conductivity throughout the fracture network due to the materials low specific gravity and near-neutral buoyancy in water-based fluids. The ...
FracBlack® Near-neutral buoyancy proppant (NBP) is designed for stimulation of unconventional wells to provide significantly greater fracture conductivity via unparalleled proppant placement in the far field fracture area and improved reservoir contact. FracBlack® is an advanced thermoset nanocomposite bead, featuring near-neutral buoyancy, high strength and thermal stability for application in most reservoirs with or without conventional proppants. This breakthrough NBP provides technical resolution to the primary limitations which impair conventional proppant placement and performance. The high strength and near-neutral specific gravity of FracBlack® NBPis designed to optimize proppant transport, placement, and conductivity longevity allowing you to Prop What You Frac.. Utilization: FracBlack® NBPis used to provide effective propped fracture conductivity throughout the fracture network due to the materials low specific gravity and near-neutral buoyancy in water-based fluids. The ...
The question of bioaccessibility of nutrients within a food matrix has become of increasing interest in the fields of nutrition and food science as bioaccessibility is the precursor to bioavailability. By analyzing the propagation of the wetting front of acidic water in raw carrot core and Edam cheese as model systems, we show that the diffusion of the acidic water is dependent on the pH of the gastric fluid and the food matrix. In addition, we demonstrate that the diffusion of NaCl during cheese brining is also dependent upon the concentration of the NaCl. This demonstrates that Fickian diffusion, along with a concentration dependent diffusion coefficient, is a valid model for describing concentration profiles in multiple food systems.Utilizing the diffusion rates found at various pH levels (1.50, 2.00, 3.50, 4.30, 5.25 and 7.00), we developed a model to describe the measured non-linear rate of soluble solid loss during digestion at various constant pH levels. Additionally, we have developed a ...
1. It is shown that a neutral salt depresses the potential difference which exists at the point of equilibrium between a gelatin chloride solution contained in a collodion bag and an outside aqueous solution (without gelatin). The depressing effect of a neutral salt on the P.D. is similar to the depression of the osmotic pressure of the gelatin chloride solution by the same salt.. 2. It is shown that this depression of the P.D. by the salt can be calculated with a fair degree of accuracy on the basis of Nernsts logarithmic formula on the assumption that the P.D. which exists at the point of equilibrium is due to the difference of the hydrogen ion concentration on the opposite sides of the membrane.. 3. Since this difference of hydrogen ion concentration on both sides of the membrane is due to Donnans membrane equilibrium this latter equilibrium must be the cause of the P.D.. 4. A definite P.D. exists also between a solid block of gelatin chloride and the surrounding aqueous solution at the ...
The influence of hydrogen ion concentration. Physiologia Plantarum, 6, 848-858. Olsen, C. (1954) Hvilke betingelser må være ... 2] Olsen, C. (1923) Studies on the hydrogen ion concentration of the soil and its significance to the vegetation, especially to ... Olsen, C. & Linderstrøm-Lang, K. (1927) On the accuracy of the various methods of measuring concentration of Hydrogen ions in ... Olsen, C. (1921) The concentration of hydrogen ions in the soil. Science 54 (1405), 539-541. [1] Olsen, C. (1921) The ecology ...
This causes decreased circulating hydrogen ion concentration, and increased pH (alkalosis).[9][10] ... Circulating hydrogen ions and bicarbonate are shifted through the carbonic acid (H2CO3) intermediate to make more CO2 via the ... The Davenport diagram allows clinicians or investigators to outline blood bicarbonate concentrations (and blood pH) after a ...
Quirk, A.J. & Fawcett, E. H. (1923). Hydrogen-ion concentration vs. titratable acidity in culture mediums. Quirk, A.J. & Smith ... Agnes J. Quirk (1923). Hydrogen-ion concentration vs. titratable acidity in culture mediums. Retrieved 30 March 2012. "Norwich ...
Brandis K. "2.6 Regulation of Intracellular Hydrogen Ion Concentration". Acid-Base Physiology. Anaesthesia Education Website. ... Since the microelectrode has fluid with a high H+ concentration inside, relative to the outside of the electrode, there is a ... Intracellular pH is typically lower than extracellular pH due to lower concentrations of HCO3−. A rise of extracellular (e.g., ... Based on the ratio between the concentrations of protonated, compared to deprotonated, forms of phosphate compounds in a given ...
With increasing concentration of HF the concentration of the hydrogen difluoride ion also increases.[24] The reaction ... The acidity of hydrofluoric acid solutions varies with concentration owing to hydrogen-bond interactions of the fluoride ion. ... anions to form clusters.[20] At high concentrations, HF molecules undergo homoassociation to form polyatomic ions (such as ... have shown by infrared spectroscopy that the predominant solute species in dilute solution is the hydrogen-bonded ion pair H. 3 ...
This results in decreased gastric acid secretion and gastric volume, and reduced hydrogen ion concentration. ... Ranitidine enters breast milk, with peak concentrations seen at 5.5 hours after the dose in breast milk. Caution should be ...
McClendon J. F. New hydrogen electrodes and rapid methods of determining hydrogen ion concentrations. Amer. J. Physiol., 1915, ... The hydrogen ion concentrations of the contents of the small intestine. J. of Biological Chemistry, Feb 19, 1918. XXXIV, No 1. ... McClendon J. F. A direct reading potenciometer for measuring hydrogen ion concentration. Amer. J. Physiol., 1915, 38, 2, 186. ... stomachs and duodenums of adults and infants plotted with the acid of imported methods of measuring hydrogen ion concentration ...
Menten, M.L.; Crile, G.W. (1915). "Studies on the hydrogen-ion concentration in blood under various abnormal conditions". Am. J ... This relationship between reaction rate and enzyme-substrate concentration is known as the Michaelis-Menten equation. After ... but also that the rate of reaction rate increases to saturation as the substrate concentration increases. The constant K m {\ ... in terms of the substrate concentration a {\displaystyle a} and constants V {\displaystyle V} and K m {\displaystyle K_{\mathrm ...
Thomas, A. W., & Kelly, M. W. (1923). The influence of hydrogen-ion concentration in the fixation of vegetable tannins by hide ... Thomas, A. W. (1920). Tabulation of hydrogen and hydroxyl ion concentrations of some acids and bases. Journal of the American ... Influence of hydrogen-ion concentration upon enzymatic activity of three typical amylases. Journal of the American Chemical ... Contrasting effects of chlorides and sulfates on the hydrogen-ion concentration of acid solutions. Journal of the American ...
The sudden change of the indicator during a typical titration means, as is known, that the concentration of hydrogen ions in ... "hydrogen ion exponent" and the notation p H {\displaystyle p_{\mathrm {H} }} ). By the hydrogen ion exponent ( p H {\ ... die colorimetrische Methode genannt." (There are still two procedures by which the hydrogen or hydroxyl ion concentration of a ... On the measurement and the importance of hydrogen ion concentration during enzymatic processes]. Biochemische Zeitschrift (in ...
Poel, L. W. (April 1949). "Germination and Development of Heather and the Hydrogen Ion Concentration of the Medium". Nature. ... However, it is well known that hydrogen ions form the basis of pH balance in any solution, which can explain why this form of ... "Hydrogen in air: 2,400 K, Hydrogen in Oxygen: 3,080 K" Tilden, William Augustus (1926). Chemical Discovery and Invention in the ... An oxyhydrogen torch (also known as hydrogen torch) is an oxy-gas torch that burns hydrogen (the fuel) with oxygen (the ...
For instance, carbon dioxide increases the hydrogen ion concentration of rain water (pH = 5.6) by a factor of 25 compared to ... they are Arrhenius acids because they increase the hydrogen ion concentration of water. ... oxide is the anhydride of the aqueous ferrous ion: [ Fe ( H 2 O ) 6 ] 2 + ⟶ FeO + 2 H + + 5 H 2 O {\displaystyle {\ce {[Fe(H2O) ...
More precisely, it is a measure of hydrogen ion concentration in an aqueous solution and ranges in values from 0 to 14 (acidic ... Hydrogen ions have a single charge and one-thousandth of a gram of hydrogen ions per 100 grams dry soil gives a measure of one ... Arnon, Daniel I.; Johnson, Clarence M. (1942). "Influence of hydrogen ion concentration on the growth of higher plants under ... since the two concentrations are equal, they are said to neutralise each other. A pH of 9.5 has 10−9.5 moles hydrogen ions per ...
The average concentration of hydrogen ions was 0.0001 milligrams per liter. The total concentration of nitrogen in the waters ... The concentration of hydrogen ions in the waters of Fishing Creek near Bloomsburg between 2002 and 2012 ranged from 0.00001 to ... The date of the lowest concentration of hydrogen ions at that location was on March 1 and July 16, 2003. The date of the ... highest concentration of hydrogen ions at the location on the creek was December 17, 2003. ...
The hydrogen ion concentrations of the contents of the small intestine. Journal of Biological Chemistry, Feb 19, 1918. XXXIV, ...
Chemoreceptors in the body sense a change in partial pressures and pH (hydrogen ion concentration) in the blood. Chemoreceptors ... leading to lowered plasma calcium ions and increased nerve and muscle excitability. This explains the other common symptoms of ...
... hydrogen ion concentration) of the solution. Crosslinking of guar with borate occurs at high pH (approximately 9-10) of the ... The crosslinking of guar with metal ions results in a gel that does not block the formation and helps efficiently in formation ... Guar and its derivatives make gel complexes with ions of Aluminium, Zirconium, Titanium, Chromium and Boron.[19] The borate- ... PHGG as sold commercially is completely soluble, acid and heat stable, unaffected by ions, and will not gel at high ...
Alkaline substances have, instead of hydrogen ions, a concentration of hydroxide ions (OH-). ... H+] indicates the concentration of H+ ions (also written [H3O+],[1] the equal concentration of hydronium ions), measured in ... The p stands for the German potenz, meaning power or concentration, and the H for the hydrogen ion (H+). ... The pH indicator is a chemical detector for hydronium ions (H3O+) or hydrogen ions (H+).[1] Normally, the indicator causes the ...
"The Absorption of Water by Plant Tissue in Relation to External Hydrogen-Ion Concentration" (PDF). The Journal of Experimental ...
1924 The Electrical Charge on a Clay Colloid as Influenced by Hydrogen-Ion Concentration and by Different Salts. With W. C. ... 1917 The Effect of Hydrogen and Hydroxyl Ion Concentration on the Growth of Barley Seedlings. Soil Sci., 3(6) :547-560. 1918 ... Hydrogen-Ion Effects and the Accumulation of Salt by Barley Roots as Influenced by Metabolism. With T. C. Broyer. Am. J. Bot., ... Relation of the Concentration and Reaction of the Nutrient Medium to the Growth and Absorption of the Plant. J. Agr. Res., 18(2 ...
In aqueous solution the concentration of the hydroxide ion is related to the concentration of the hydrogen ion by ... If the electrode is calibrated in terms of known hydrogen ion concentrations it would be better to write p[H] rather than pH, ... The concentration quotient K. c. {\displaystyle K^{c}}. has the dimension 1/concentration, but the thermodynamic equilibrium ... Replace each concentration term [. X. ]. {\displaystyle [X]}. by the dimensionless quotient [. X. ]. [. X. 0. ]. {\displaystyle ...
pH is the negative logarithm (or cologarithm) of molar concentration of hydrogen ions in the ECF. It indicates the acidity in ... bicarbonate ions are excreted into the urine, and hydrogen ions into the plasma. These combine with the bicarbonate ions in the ... pH is the negative logarithm of molar concentration of hydrogen ions in the ECF, as before. ... 3 ions are simultaneously secreted into the blood plasma, thus raising the bicarbonate ion concentration in the plasma, ...
When the pH (or equivalent e.m.f., E).is measured, the free concentration of hydrogen ions, [H], is obtained from the measured ... Constant-boiling hydrochloric acid may also be used as a primary standard for hydrogen ion concentration. The most widely used ... A solution of known hydrogen ion concentration may be prepared by standardization of a strong acid against borax. ... With aqueous solutions the concentrations of proton (hydronium ion) and hydroxide ion are constrained by the self-dissociation ...
Redman, Thirza (1929). "The hydrogen ion concentration and the calcium and phosphorus content of the faeces of rachitic ...
... is the result of a process reducing hydrogen ion concentration of arterial blood plasma (alkalemia). In contrast to ... mechanisms for this would include increased dissociation of the carbonic acid buffering intermediate into hydrogen ions, and ... Metabolic alkalosis is usually accompanied by low blood potassium concentration, causing, e.g., muscular weakness, muscle pain ... It may also cause low blood calcium concentration. As the blood pH increases, blood transport proteins, such as albumin, become ...
In water the concentration of hydroxide is related to the concentration of hydrogen ions by the self-ionization constant, Kw. K ... The concentration, or activity, of the hydrogen ion is monitored by means of a glass electrode. The data set used for the ... Hence by following the hydrogen ion concentration during a titration of a mixture of M and HL with base, and knowing the acid ... Under conditions of equal copper concentrations and when then concentration of methylamine is twice the concentration of ...
... s are adapted to live in an environment where the hydrogen ion concentration is at equilibrium. They are sensitive ... to the concentration, and when the pH become too basic or acidic, the cell's proteins can denature. Depending on the microbe ...
Hydrogen ions are pumped against a high concentration gradient by proton pumps, specifically a unique vacuolar-ATPase. This ... The osteoclast releases hydrogen ions through the action of carbonic anhydrase (H2O + CO2 → HCO3− + H+) through the ruffled ... This appearance is due to a high concentration of vesicles and vacuoles. These vacuoles include lysosomes filled with acid ... With the isolation of the ruffled border, ion transport across it was studied directly in biochemical detail. Energy-dependent ...
However beyond this pH range, the effective hydrogen-ion activity changes much more rapidly than the concentration. This is ... concentration of 1012 mol/L, as measured by its ability to protonate weak bases. Although the Hammett acidity function is the ... which would imply an impossibly high H3O+ concentration of 10+12 mol/L in ideal solution). Instead it means that the acid ... 15.1 Hydrogen fluoride: −15.1 Triflic acid (1940): −14.1 Perchloric acid: −13 Chlorosulfuric acid: -13.8; −12.78 Sulfuric acid ...
... s are hydrogen-bond acceptors. Ketones are not usually hydrogen-bond donors and cannot hydrogen-bond to themselves. ... Ketonium ions (i.e., protonated ketones) are strong acids, with pKa values estimated to be somewhere between -5 and -7.[6][7] ... the formation of equilibrium concentrations of protonated ketones is nevertheless an important step in the mechanisms of many ... In aldehydes, the carbonyl is bonded to one carbon and one hydrogen and are located at the ends of carbon chains. Ketones are ...
In this variant, the number of f electrons in the most common (trivalent) ions of the f-block elements consistently matches ... Yttrium can be found in edible plants in concentrations between 20 ppm and 100 ppm (fresh weight), with cabbage having the ... Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus ... Pyykkö, Pekka (2011). "A suggested periodic table up to Z ≤ 172, based on Dirac-Fock calculations on atoms and ions". Physical ...
... the hydrogen ion is very small (radius around 150 fm compared to the 50-220 pm size of most other atoms and ions) and so is ... At low concentrations (below 3 M), the solution is dark blue and has ten times the conductivity of aqueous sodium chloride; at ... 4 ions.[66] The chemistry of alkali metal germanides, involving the germanide ion Ge4− and other cluster (Zintl) ions such as ... they generate hydroxide ions and hydrogen gas. This reaction is vigorous and highly exothermic and the hydrogen resulted may ...
1998). "Microstructure and nanohardness of hafnium diboride after ion irradiations". Journal of Nuclear Materials. 256 (2-3): ... These coating materials exhibit uniform distribution of fine particles and porous microstructures, which increased hydrogen ... or the defect concentration can be increased. SiC can react with the surface oxide layer in order to provide diboride surfaces ...
Upon binding, it triggers the GABAA receptor to open its chloride channel to allow chloride ions into the neuron, making the ... The four steroid rings form a rigid framework for positioning these hydrogen groups in three-dimensional space.[32] Analogues 5 ... The mice also had increased corticosterone concentration which is a symptom in major depression in humans. The y2 subunit is ... The earliest compounds were ions, such as bromide. Barbiturates[edit]. In 1903, the first psychoactive derivative of barbituric ...
soluble in hydrogen chloride, ethanol, chloroform, carbon tetrachloride slightly soluble in benzene ... ions. Wells, A. F. (1984) Structural Inorganic Chemistry, Oxford Press, Oxford, United Kingdom. ISBN 0198553706. ... Lethal dose or concentration (LD, LC): LD50 (median dose). anhydrous: 380 mg/kg, rat (oral) hexahydrate: 3311 mg/kg, rat (oral ...
The concentration of radon gases is miniaturized by realtime detectors. In June, 2001 typical radon concentrations in water ... The Sun and about 80% of the visible stars produce their energy by the conversion of hydrogen to helium via ... A cartridge polisher (CP) eliminates heavy ions which also reduce water transparency and include radioactive species. The CP ... Typical radon concentration in the dome air is measured to be 40 Bq m−3. Radon levels in the mine tunnel air, near the tank ...
... halide ions such as chloride ions, have a large effect on the corrosivity of alcohol fuels. Halide ions increase corrosion in ... At concentrations greater than 2,000 ppm (0.2%) it is generally quite noticeable, however lower concentrations may remain ... Ethanol, natural gas, hydrogen, and other existing fuels offer similar fire-safety challenges, and standard safety and ... Methanol occurs naturally in the human body and in some fruits, but is poisonous in high concentration. Ingestion of 10 ml can ...
Their electrical conductivities are very sensitive to impurity concentrations, and this allows for the use of doping to achieve ... ions and molecules are arranged and bonded to each other. This involves the study and use of quantum chemistry or quantum ... storing hydrogen for fuel cell powered cars, filtration systems, longer-lasting and faster-charging batteries, sensors to ... ion implantation, crystal growth, thin-film deposition, sintering, glassblowing, etc.), and analytic methods (characterization ...
Blood concentrations of minerals[edit]. Minerals are present in a healthy human being's blood at certain mass and molar ... Sigel, Astrid; Sigel, Helmut; Sigel, Roland K. O. (27 January 2014). Interrelations between Essential Metal Ions and Human ... including hydrogen, carbon, nitrogen and oxygen) are suggested to be used by mammals, as inferred by biochemical and uptake ... Depending on the concentrations, some are in upper part of the picture, while others are in the lower part. The figure includes ...
... to the oxidation of hydrogen sulfide or elemental sulfur by species of Sulfolobus, using either oxygen or metal ions as ... structures that are resistant to osmotic shock and allow the archaea to survive in water at low salt concentrations, but these ... In the Halobacteria, light-activated ion pumps like bacteriorhodopsin and halorhodopsin generate ion gradients by pumping ions ... This process releases hydrogen as a waste product, but high levels of hydrogen reduce energy production. When methanogens ...
The methanol economy is an alternative to the hydrogen economy, compared to today's hydrogen production from natural gas. ... Atmospheric alcohols and aldehydes concentrations measured in Osaka, Japan and in São Paulo, Brazil ... Research in lithium-ion batteries. *Silicon-air battery. *Thermal energy storage. *Ultracapacitor ... Syngas can be used to produce methanol, DME and hydrogen, or converted via the Fischer-Tropsch process to produce a diesel ...
It also reduces the permeability of the plasma membrane to protons (positive hydrogen ions) and sodium ions.[6] ... higher concentrations of LDL and lower concentrations of functional HDL are strongly associated with cardiovascular disease ... Increased concentrations of HDL correlate with lower rates of atheroma progressions and even regression. A 2007 study pooling ... Conditions with elevated concentrations of oxidized LDL particles, especially "small dense LDL" (sdLDL) particles, are ...
... separated ions,[18] but was later proven that the vapors formed consisted of ion-pairs.[19] Some ionic liquids (such as 1-butyl ... Carbon monoxide is less soluble in ionic liquids than in many popular organic solvents, and hydrogen is only slightly soluble ( ... as sub-lethal concentrations change organisms' life histories in meaningful ways. Balancing VOC reductions against waterway ... ionic liquids are largely made of ions and short-lived ion pairs. These substances are variously called liquid electrolytes, ...
Argon-hydrogen gas compositions with hydrogen concentration below the low flammable limit can be used, eliminating the safety ... Flux residues also tend to outgas in vacuum and space applications, and traces of water, ions and organic compounds may ... Atomic hydrogen is much more reactive than molecular hydrogen. In contact with surface oxides it forms hydroxides, water, or ... The addition of hydrogen to the plasma[which?] augments the removal efficiency by chemical mechanisms.[citation needed] ...
Lunar Polar Hydrogen Mapper (LunaH-Map), a lunar orbiter designed at the Arizona State University,[35] will map hydrogen within ... Lunar Flashlight is a lunar orbiter that will seek exposed water ice, and map its concentration at the 1-2 km (0.62-1.24 mi) ... distance communications while in heliocentric orbit and show low-thrust trajectory control techniques by employing a hybrid ion ... the inside of the anthropomorphic phantoms at precise locations of sensitive tissues and high stem cell concentrations.[24][25] ...
The concentration of ionized hydrogen (as protonated water) in a cooling water system is expressed as pH.[16] Low pH values ... Water can accelerate corrosion of machinery being cooled as both an electrical conductor and solvent for metal ions and oxygen ... Concentrations of polyphosphates or phosphonates with zinc and chromates or similar compounds have been maintained in cooling ... Temperature increases initially favor a population shift from species requiring the high-oxygen concentration of cold water to ...
First, silicon is treated with hydrogen chloride at about 300 °C to produce trichlorosilane, HSiCl3, along with hydrogen gas, ... Unlike methane, silane is fairly toxic: the lethal concentration in air for rats (LC50) is 0.96% (9,600 ppm) over a 4-hour ... ion in the Mg2Si antifluorite structure can serve as a Brønsted-Lowry base capable of accepting four protons. It can be written ... They called the compound siliciuretted hydrogen.[8] For classroom demonstrations, silane can be produced by heating sand with ...
... hydrogen chloride, hydrogen sulfide, nitrogen dioxide, ozone, and ammonia are among the most important irritant gases. Hydrogen ... In low concentrations, phosgene's odor resembles freshly cut hay or grass. Because of this, the gas may not be noticed and ... Type 2 pneumocytes are more resistant to damage, which is important as these cells produce surfactant, transport ions and ... Smoke, chlorine, phosgene, sulfur dioxide, hydrogen chloride, hydrogen sulfide, nitrogen dioxide, ozone, and ammonia are common ...
By regulation, OC products with a maximum OC concentration of 10% and weight range of oleoresin of capsicum and inert ... and use OC sprays with a maximum concentration of 5%. *CS is considered a weapon and is not permitted. *Police carry OC sprays ... and a maximum concentration of capsaicin and capsaicinoid substances not exceeding 2,5%; ... Hydrogen peroxide. *Icilin. *Isothiocyanate. *Ligustilide (celery, Angelica acutiloba). *Linalool (Sichuan pepper, thyme) ...
The hydrogen fluoride, HF, molecule is polar by virtue of polar covalent bonds - in the covalent bond electrons are displaced ... Concentration. and related quantities. *Molar concentration. *Mass concentration. *Number concentration. *Volume concentration ... One common form of polar interaction is the hydrogen bond, which is also known as the H-bond. For example, water forms H-bonds ... In a molecule of hydrogen fluoride (HF), the more electronegative atom (fluorine) is shown in yellow. Because the electrons ...
... even at the subnanomolar concentrations achieved by the high concentrations of SOD within cells, superoxide inactivates the ... The superoxide anion radical (O2−) spontaneously dismutes to O2 and hydrogen peroxide (H2O2) quite rapidly (~105 M−1s−1 at pH 7 ... The ligands of the manganese ions are 3 histidine side-chains, an aspartate side-chain and a water molecule or hydroxy ligand, ... Thus, the half-life of superoxide, although very short at high concentrations (e.g., 0.05 seconds at 0.1mM) is actually quite ...
That is, substances with a higher Ka are more likely to donate hydrogen ions in chemical reactions than those with lower Ka ... Thus, solutions that have a low pH have a high hydronium ion concentration and can be said to be more acidic. The other ... Main article: Ion. An ion is a charged species, an atom or a molecule, that has lost or gained one or more electrons. When an ... According to Brønsted-Lowry acid-base theory, acids are substances that donate a positive hydrogen ion to another substance in ...
... s are part of a major mechanism by which cells regulate the concentration of particular proteins and degrade ... as peptides bind by hydrogen bonding and by close contacts with a region called the "B pocket" on the MHC surface. Many MHC ... cells expressing these proteasomes show enhanced resistance to toxicity induced by metallic ions such as cadmium.[23][25] ...
in order to determine various relationships between transmittance and concentration, and absorbance and concentration.[3]:21- ... hydrogen lamp with ultraviolent continuum and a better monochromator.[8] It was produced from 1941 to 1976 where the price for ... The concentration of a protein can be estimated by measuring the OD at 280 nm due to the presence of tryptophan, tyrosine and ... Bial's test for concentration of pentoses. Experimental application[edit]. As described in the applications section, ...
It is roughly the negative of the logarithm to base 10 of the concentration, measured in units of moles per liter, of hydrogen ... ion. An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.. ionic bond. A type of ... An organic compound consisting entirely of hydrogen and carbon atoms. Hydrocarbons from which one hydrogen atom has been ... This is brought about by positively charged sodium ions rapidly passing into the axon.. desmosome. Also called the macula ...
As a result, it is possible for one element to be substituted for another.[51] Chemical substitution will occur between ions of ... The sheets are weakly bound by van der Waals forces or hydrogen bonds, which causes a crystallographic weakness, in turn ... Ores are minerals that have a high concentration of a certain element, typically a metal. Examples are cinnabar (HgS), an ore ... In all minerals, one aluminium ion is always in six-fold coordination with oxygen. Silicon, as a general rule, is in four-fold ...
... reach underlying vascular smooth muscle cells at a concentration sufficient to activate ion channels, and initiate smooth ... In addition, in some cases hydrogen peroxide has been suggested to function as an EDHF in some vascular beds;[3] although the ... It has been suggested that EDHF is potassium ions (K+), as the activation of endothelial K-Ca+ channels causes an efflux of K+ ... However, the involvement of K+ ions in EDHF-mediated relaxation does not necessarily involve the activation Na+-K+-ATPase ...
Useful ions are most commonly found in the trivalent state. Er+. ions have been the most used. Er3+. ions absorb solar ... They assumed no carriers were collected at the IB and that the device was under full concentration. They found the maximum ... from silane gas and hydrogen gas. Depending on the deposition parameters, this can yield amorphous silicon (a-Si or a-Si:H), ... ions that have absorbed this radiation can interact with each other through an upconversion process. The excited ion emits ...
Hydrogen sensor. *Hydrogen sulfide sensor. *Infrared point sensor. *Ion selective electrode. *ISFET ... For very large flows, tracer methods may be used to deduce the flow rate from the change in concentration of a dye or ... A solution with a known tracer concentration is injected at a constant known velocity into the channel flow. Downstream the ... After complete mixing, the concentration is measured. The dilution rate equals the flow rate. ...
The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more ... The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more ... The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more ... The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more ...
The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more ... The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more ... The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more ... The concentration of hydrogen ions in a solution determines the acidity of a solution. If concentration of hydrogen ion is more ...
How to use hydrogen-ion concentration in a sentence. ... the concentration of hydrogen ions in a solution expressed ... Learn More about hydrogen-ion concentration. Share hydrogen-ion concentration Post the Definition of hydrogen-ion concentration ... Dictionary Entries near hydrogen-ion concentration. hydrogenide hydrogen iodide hydrogen ion hydrogen-ion concentration ... Comments on hydrogen-ion concentration What made you want to look up hydrogen-ion concentration? Please tell us where you read ...
Actually, it is determined by the concentration of hydrogen ions, the percentage of hydrogen ions contained in the solution.. ... that a hydrogen-ion concentration of a solution with a pH of 4 is 10-4mol/l, meaning it contains 0.0001 mol of hydrogen ions in ... a solution with a pH of 5 contains 10-5mol/l of hydrogen ions, a solution with a pH of 6 contains 10-6mol/l of hydrogen ions, ... and hydroxide ions, (OH-), as illustrated in the figure.. Actually, this balance of hydrogen ions and hydroxide ions determines ...
HYDROGEN ION CONCENTRATION IN EXUDATES OF PNEUMOCOCCUS INFECTION. William H. Kelley, E. N. Scadron, B. M. Shinners ... While these hydrogen ion concentrations are similar to those attained in the pneumonic exudate from dogs, they are of lesser ... The hydrogen ion concentrations in exudate from dermal pneumococcus infection in rabbits varied between pH 6.87 and 6.66 but ... The hydrogen ion concentration in the lesions of experimental pneumococcus infection has been estimated directly by pH ...
2.Given the molar concentration of hydroxide ion [OH -] = 4.6 X 10 -13, calculate the concentration of hydrogen. ... 1.Given the molar concentration of hydrogen ion [H+] = 6.2 x 10 -7, calculate the concentration of hydroxide ion. ... 1.Given the molar concentration of hydrogen ion [H+] = 6.2 x 10 -7, calculate the concentration of hydroxide ion. ... 2.Given the molar concentration of hydroxide ion [OH -] = 4.6 X 10 -13, calculate the concentration of hydrogen ion. ...
Hydrogen ion concentration is not the sole determinant of muscle metaboreceptor responses in humans.. ... Hydrogen ion concentration is not the sole determinant of muscle metaboreceptor responses in humans.. ...
Research Topics about Experts and Doctors on hydrogen ion concentration in Sydney, New South Wales, Australia ... Experts and Doctors on hydrogen ion concentration in Sydney, New South Wales, Australia. Summary. Locale: Sydney, New South ... You are here: Locale , Australia , New South Wales , Experts and Doctors on hydrogen ion concentration in Sydney, New South ... Posterino G, Fryer M. Effects of high myoplasmic L-lactate concentration on E-C coupling in mammalian skeletal muscle. J Appl ...
Baseline concentrations of total calcium (Ca), ionized calcium (Ca2+), albumin, total protein, and hydrogen ion concentration [ ... Massive Blood Replacement: Correlation of Ionized Calcium, Citrate, and Hydrogen Ion Concentration. ...
... in order to address this hydrogen ion concentration jump and at the same time ensure zero hydrogen ion flux at the PEL-rigid- ... Our theory considers for the first time the explicit variation of the hydrogen ion concentration inside and outside the PEL and ... Such uniformity causes unphysical hydrogen ion concentration jump across the PEL-electrolyte interface. In fact we demonstrate ... effect of consideration of appropriate hydrogen ion concentration distribution G. Chen and S. Das, RSC Adv., 2015, 5, 4493 DOI ...
... the hydrogen ion concentration in the resulting mixture is a. always equal than the concentration of the hydroxide ions b. ... Show that the hydroxide-ion concentration in an aqueous solution is 1x10-4 M when the hydronium-ion concentration is 1x10-10 M ... Find the hydrogen ion concentration of a saturated solution of calcium hydroxide whose pH is 13.3. (If you enter your answer in ... pure water has a hydrogen ion concentration of 1 x 10-7 m and a ph of 7. a student measures a basic solution and finds that it ...
... hydrogen ion) concentration of an aqueous solution that has a pH of 2? 0.01 M Which carbon ... Bio Exams 1-3 Exam #1 1) What is the H+ (hydrogen ion) concentration of an aqueous solution that has a pH of 2? • 0.01 M 2) ...
The effect of hydrogen ion concentration on the precipitating and protective actions of mixtures of two proteins on colloidal ... The effect of hydrogen ion concentration on the precipitating and protective actions of mixtures of two proteins on colloidal ... The effect of hydrogen ion concentration on the precipitating and protective actions of mixtures of two proteins on colloidal ... The effect of hydrogen ion concentration on the precipitating and protective actions of mixtures of two proteins on colloidal ...
REGULATION OF THE HYDROGEN ION CONCENTRATION AND ITS RELATION TO METABOLISM AND RESPIRATION IN THE STARFISH. Laurence Irving ... The optimum pH found for carbon dioxide production is a true one for the effect of hydrogen ion concentration on the tissue. It ... REGULATION OF THE HYDROGEN ION CONCENTRATION AND ITS RELATION TO METABOLISM AND RESPIRATION IN THE STARFISH ... Because the normal excised cæca maintain a definite hydrogen ion concentration and change their internal environment toward ...
Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the United States and Europe from 1978 ... Lajtha, K., & Jones, J. (2013). Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the ...
The hydrogen ion concentration is extremely important to the structural and functional integrity of living systems. Even slight ... Hydrogen ion concentration is expressed in terms of PH units, representing a measure of the acidity or the alkalinity of a ... The hydrogen ion concentration is extremely important to the structural and functional integrity of living systems. Even slight ... A Brief Note on Hydrogen Ion Concentration and the Role of Buffers Akhila Mol ...
3. At a hydrogen ion concentration of about 5.1 or higher, the pneumococcus does not survive longer than a few hours. ... THE RELATION OF THE PNEUMOCOCCUS TO HYDROGEN ION CONCENTRATION, ACID DEATH-POINT, AND DISSOLUTION OF THE ORGANISM Frederick T. ... 4. In hydrogen ion concentrations of about 6.8 to 7.4 the pneumococcus may live for at least many days. ... Frederick T. Lord, Robert N. Nye; THE RELATION OF THE PNEUMOCOCCUS TO HYDROGEN ION CONCENTRATION, ACID DEATH-POINT, AND ...
THE USE OF THE FINAL HYDROGEN ION CONCENTRATION IN DIFFERENTIATION OF STREPTOCOCCUS HÆMOLYTICUS OF HUMAN AND BOVINE TYPES ... 2. Of 124 strains of Streptococcus hæmolyticus from known human origin, 116 reached a final hydrogen ion concentration of from ... Oswald T. Avery, Glenn E. Cullen; THE USE OF THE FINAL HYDROGEN ION CONCENTRATION IN DIFFERENTIATION OF STREPTOCOCCUS ... 40 reached a final hydrogen ion concentration of pH 4.3 to 4.5. Of the remaining 5 which reached a pH of 5.0 to 5.2, two were ...
Blood and erythrocyte hydrogen ion concentrations in acid-base imbalance from respiratory disorders. by A. Rizzo et al. ... Blood and erythrocyte hydrogen ion concentrations in acid-base imbalance from respiratory disorders.. *. A. Rizzo, Giuseppe ... article{Rizzo1981BloodAE, title={Blood and erythrocyte hydrogen ion concentrations in acid-base imbalance from respiratory ...
Part of the product was aliquoted into two CLX bags, 60 ml into each, on day 0. L-carnitine (LC) to a final concentration of 5 ... A concentrated aqueous extract was prepared from the fruit of T. chebula . A mouth rinse of 10% concentration was prepared by ... First, D-optimal design was used to evaluate the effects of variables, including concentrations of substrate (chebulic ...
It is obvious that $\ce{HCl}$ and organic acid cannot have such concentration of hydrogen ions. Both ammonia and natrium ... Is the concentration of negative ions always equal to that of positive ions? ... The equilibrium concentrations for an unknown $x$ reacted amount (in concentration units) would be ... How do we know the concentration of hydroxide ions in this derivation? ...
Ferric Hydroxide as an Adsorbent, Hydrogen Ion Concentration of Cheese and more. ...
1. What are Hydrogen Ions - Definition, Properties 2.. Hydrogen Ion Concentration is the composition of hydrogen ions in a ... In this way, pH is determined by hydrogen-ion concentration.. Key Concepts Concentration of hydrogen ions in an aqueous ... It is defined by the negative of the logarithm of hydrogen ion concentration: The higher the hydrogen ion concentration the ... the concentration of hydrogen ions in the solution decreases. As the pH decreases, the concentration of hydrogen ions in the ...
pH (Hydrogen ion concentration). Proctor and Hughes Chemical Hazards of the Workplace. 4th Edition. Van Nostrand Reinhold, New ...
pH (Hydrogen ion concentration). Chemical Hazards of the Workplace. JB Lippincott Company. 1978.. ...
Indwelling blood hydrogen ion concentration (pH) analyzer.. (a) Identification. An indwelling blood hydrogen ion concentration ... 868.1170 Indwelling blood hydrogen ion concentration (pH) analyzer.. §868.1200 Indwelling blood oxygen partial pressure (PO2) ... the hydrogen ion concentration (pH) in blood to aid in determining the patients acid-base balance. ... a) Identification. An argon gas analyzer is a device intended to measure the concentration of argon in a gas mixture to aid in ...
For hydrogen ion concentration the specified performance characteristics are that the method of analysis used must be capable ... a) is free from any micro-organisms and parasites and from any substances which, in numbers or concentrations, constitute a ... three times the relative within batch standard deviation of a natural sample containing a low concentration of the parameter, ... that a parameter is not likely to be present in a given supply in concentrations which could lead to the risk of a breach of ...
hydrogen ion synonyms, hydrogen ion pronunciation, hydrogen ion translation, English dictionary definition of hydrogen ion. n. ... The positively charged ion of hydrogen, H+, formed by removal of the electron from atomic hydrogen and found in the form of ... Related to hydrogen ion: hydrogen ion concentration. hydrogen ion. n.. The positively charged ion of hydrogen, H+, formed by ... Hydrogen ion - definition of hydrogen ion by The Free Dictionary https://www.thefreedictionary.com/hydrogen+ion ...
  • If concentration of hydrogen ion is more than the solution is more acetic, if it is low, solution is less acidic. (bartleby.com)
  • When the hydrogen ions outnumber the hydroxide ions, the solution is acidic. (horiba.com)
  • The acidic, basic and neutral character of a solution can be found out by the Hydrogen Ion Concentration. (livingnlimbo.com)
  • An acidic environment is enriched in hydrogen ions, whereas a basic environment is relatively depleted of hydrogen ions. (encyclopedia.com)
  • These microorganisms can actively pump hydrogen ions out of the cell into the environment, creating more acidic conditions. (encyclopedia.com)
  • A solution with a high concentration of hydrogen ions is acidic. (wikihow.com)
  • The pH scale, which measures the concentration of hydrogen, runs from 1, the most acidic and highest concentration of ions, to 14, the most alkaline, with almost no ions. (nytimes.com)
  • An acid-forming food contributes hydrogen ions to the body, making it more acidic. (angelfire.com)
  • The hydrogen ion concentration of an alkaline solution, which experiences a lowering of p H, moves in the direction of acidity, but does not become acidic until neutrality is first reached and then passed. (wattsupwiththat.com)
  • Since this is where hydrogen and hydroxyl ions are equal in number, a pH of 7 represents neutrality, that is, a midpoint between acidity and alkalinity. (preservearticles.com)
  • Solutions with pH values of less than 7 have more hydrogen ions in the solution than hydroxyl ions, and those with pH values greater than 7 have more hydroxyl ions in solution than hydrogen ions. (preservearticles.com)
  • Basicity refers to the ratio of hydrogen and hydroxyl (OH - ) ions in solution, and is directly related to pH. (epa.gov)
  • Effect of soil pH (Hydrogen and hydroxyl ions concentration) on the lifecycle of the Tunga penetrans. (ac.ke)
  • Keivoro P, Oyieke F, Ochanda H, Ngunjiri J. "Effect of soil pH (Hydrogen and hydroxyl ions concentration) on the lifecycle of the Tunga penetrans. (ac.ke)
  • The pH of growth media is kept relatively constant by the inclusion of compounds that can absorb excess hydrogen or hydroxyl ions. (encyclopedia.com)
  • Some of the water molecules in pure water will naturally dissociate into hydrogen (hydronium) ions (cation) and hydroxyl ions (anion) in equal amounts. (wattsupwiththat.com)
  • The use of the hydrogen ion concentration alone is a convenience that implies that the hydroxyl ion is also present in inverse proportion to the hydrogen ion. (wattsupwiththat.com)
  • The important point, which is usually overlooked in discussions of the chemistry of seawater, when talking about the hydrogen ion concentration, is that it is the ratio of hydrogen ions to hydroxyl ions that determines the chemical behavior. (wattsupwiththat.com)
  • Aug 04, 2017 · The concentration of hydrogen ions in a solution is the amount of hydrogen ions (in the units of mol) present in a liter of solution. (livingnlimbo.com)
  • A solution with a low amount of hydrogen ions is basic, or also known as alkaline. (wikihow.com)
  • Hydrogen ion concentration is expressed in terms of PH units, representing a measure of the acidity or the alkalinity of a solution. (preservearticles.com)
  • Soil pH (potential Hydrogen ions) is an indicator for relative soil alkalinity or acidity. (proflowers.com)
  • Acidity and alkalinity are measured in pH (potential of hydrogen). (angelfire.com)
  • Keeping our acidity and alkalinity balanced means regulating the hydrogen ion concentration in our body fluids. (angelfire.com)
  • Show that the hydroxide-ion concentration in an aqueous solution is 1x10-4 M when the hydronium-ion concentration is 1x10-10 M. (jiskha.com)
  • Bio Exams 1-3 Exam #1 1) What is the H+ (hydrogen ion) concentration of an aqueous solution that has a pH of 2? (coursehero.com)
  • The positively charged ion of hydrogen, H + , formed by removal of the electron from atomic hydrogen and found in the form of hydronium ion in all aqueous solutions of acids. (thefreedictionary.com)
  • The results showed that SSA combined with green manuring decreased bulk density, pH, salinity, and exchangeable sodium percentage of the topsoil (0-20 cm soil layer) and increased aggregate stability, cation exchange capacity, and N and P concentration of the topsoil. (hindawi.com)
  • It will be noted that the hydrogen ions released by the ionization of hydrochloric acid are used to form carbonic acid, which ionizes only to a slight degree. (preservearticles.com)
  • Blood and erythrocyte hydrogen ion concentrations in acid-base imbalance from respiratory disorders. (semanticscholar.org)
  • It is obvious that $\ce{HCl}$ and organic acid cannot have such concentration of hydrogen ions. (stackexchange.com)
  • Mar 13, 2018 · Use the original concentration of the acid as the hydrogen ion concentration for a strong acid in solution: all of the acid ionizes. (livingnlimbo.com)
  • Jun 13, 2019 · Usually, you aren't given the hydrogen ion concentration in a problem but have to find it from a chemical reaction or acid concentration. (livingnlimbo.com)
  • Whether this is easy or not depends on whether you're dealing with a strong acid or a weak acid.Most problems asking for pH are for strong acids because they completely dissociate into their ions in water. (livingnlimbo.com)
  • An acid is a substance that increases the concentration of hydrogen ions (H +) in a solution, usually by dissociating one of its hydrogen atoms. (livingnlimbo.com)
  • One is the acid equilibrium of water and the other is the hydrogen bond between water molecules. (livingnlimbo.com)
  • formation of ions by dissociation of an acid. (livingnlimbo.com)
  • Because these ions are capable of combining with and neutralizing excess hydrogen ions (H+) upon addition of acid to a body of water, they can help maintain a relatively constant hydrogen ion concentration, and therefore a consistent pH. (thefreedictionary.com)
  • That molecule, a salt of cyanoform, has the same structure as the acid except it has lost the positive hydrogen ion , resulting in a negative molecule that is paired with a positive sodium ion. (thefreedictionary.com)
  • Lactic acid bacteria haveantagonistic properties which make them particularly useful as biopreservatives.When LABs compete for nutrients, their metabolites often include activeantimicrobials such as lactic and acetic acid, hydrogen peroxide, and peptidebacteriocins. (slideshare.net)
  • Acid rain mobilizes and leaches metals (e.g., aluminum) into groundwater and streams, resulting in higher dissolved metal concentrations combined with low pH. (epa.gov)
  • Drug release from HME tablets was dependent upon the concentration of TEC, the presence of citric acid, PVP K30, and Carbopol 971P in the matrix, and pH of the dissolution media. (biomedsearch.com)
  • Recipes containing a larger quantity of a very acid fruit juice may need a higher concentration of gelatin to produce a texture desired for serving. (chestofbooks.com)
  • A pH of 0 corresponds to 10 million more hydrogen ions per unit volume, and is the pH of battery acid. (encyclopedia.com)
  • Acid releases hydrogen ions. (brainscape.com)
  • Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water . (wikipedia.org)
  • Digestion of the mineral with sulfuric acid at elevated temperatures releases a mixture of gases, including hydrogen fluoride, which may be recovered. (wikipedia.org)
  • Hydrogen ions are considered acid cations. (proflowers.com)
  • This study aimed at evaluating the concentration of erythrocyte purine nucleotides (ATP, ADP, AMP, IMP) in trained and sedentary subjects before and after maximal physical exercise together with measuring the activity of purine metabolism enzymes as well as the concentration of purine (hypoxanthine, xanthine, uric acid) and pyrimidine (uridine) degradation products in blood. (springer.com)
  • The concentrations of hypoxanthine, xanthine, uric acid and uridine were determined in the whole blood before exercise, after exercise, and 30 min after exercise testing. (springer.com)
  • Maximal physical exercise in the group of trained subjects results not only in a lower post-exercise increase in the concentration of hypoxanthine, xanthine and uric acid but also in that of uridine. (springer.com)
  • An acid is a molecule or ion (an ion is an atom that carries a positive or negative electric charge) that can contribute a hydrogen ion to a solution. (angelfire.com)
  • Since acetic acid is a weak acid there will be a lot of the acetate ion tied up as undissociated acetic acid. (yarchive.net)
  • My opinion not backed by any research is that the 5% concentration of acetic acid in vinegar probably isn't the optimum concentration. (yarchive.net)
  • I ran through some equations below to show why increasing the acetic acid concentration doesn't increase the hydrogen ion concentration at the same rate as occurs with hydrochloric acid. (yarchive.net)
  • At 5% acetic acid I doubt if the hydrogen ion concentration is high enough to dissolve iron. (yarchive.net)
  • If a quantity of an acid, such as hydrochloric acid (HCl) is added, there will be an increase in the concentration of hydrogen ions. (wattsupwiththat.com)
  • It is disingenuous to cite an equivalent change of 30% in the untransformed active hydrogen ion concentration ( http://www.huffingtonpost.ca/alex-mifflin/oceans-co2-seafood_b_7286392.html ) without noting the percentage change required to reach even neutrality, let alone an actual significant acid condition. (wattsupwiththat.com)
  • McClendon J. F. Acidity curves in the stomachs and duodenums of adults and infants plotted with the acid of imported methods of measuring hydrogen ion concentration. (wikipedia.org)
  • During the dawn of Big Bang, when the temperature of the young universe had cooled down, the first molecular bond of HeH+ was created through the association of the H+ ( hydrogen ion or proton) and helium atoms due to radiation, scientists proposed. (thefreedictionary.com)
  • Heating increases the kinetic (translational, rotational, and vibrational) energy of the atoms composing elements and the molecules or ions composing compounds. (explorelearning.com)
  • As the kinetic (translational) energy of the atoms, molecules, or ions increases, the temperature of the matter increases. (explorelearning.com)
  • Heating a sample of a crystalline solid increases the kinetic (vibrational) energy of the atoms, molecules, or ions. (explorelearning.com)
  • Oxygen & hydrogen atoms. (brainscape.com)
  • An alkalizing food removes hydrogen ions from the body, making it more alkaline. (angelfire.com)
  • The kidneys help maintain the blood Ph mainly by excreting hydrogen ions and reabsorbing bicarbonate ions as needed. (wikibooks.org)
  • Regulation of plasma hydrogen ion concentration (pH). (wikibooks.org)
  • For each hydrogen or hydroxide ion concentration listed. (bartleby.com)
  • what are the hydronium-ion and the hydroxide ion concentration of a solution at 25 C that is 0.0050 M strontium hydroxide, Sr(OH)2? (jiskha.com)
  • It is defined by the negative of the logarithm of hydrogen ion concentration: The higher the hydrogen ion concentration the lower the pH value. (livingnlimbo.com)
  • The concentration of a certain sodium hydroxide solution was determined by using the solution to titrate a sample of potassium hydrogen phthalate (abbreviated KHP). (jiskha.com)
  • If 0.10 mo of sodium hydroxide is added to 1 L of 0.0001 M Ca(OH)2, what is the final concentration of the calcium ion? (jiskha.com)
  • Because increased sodium in the tubules increases hydrogen ion loss at the same time as potassium, diuretics may also induce a hypokalaemic metabolic alkalosis. (thefreedictionary.com)
  • Carbon dioxide tension (PaCO 2 ) and concentrations of sodium, potassium, chloride, [H + ], bicarbonate and haemoglobin were measured and strong ion difference calculated. (biomedcentral.com)
  • Calcium chloride was included to prevent dissociation of the heavy and light chains of r-VIII SQ. Sodium chloride was chosen as the primary bulking agent since the concentration of sodium chloride necessary for dissolution of r-VIII SQ in the buffer will inhibit the crystallization of many potential cake formers. (nih.gov)
  • Aldosterone promotes the kidneys to reabsorb the sodium (Na+) ions. (wikibooks.org)
  • In the monomer state, sodium transport is blocked, the orange pore does not permit ion. (eurekalert.org)
  • KR2 was shown to selectively transport a particular kind of particles -- sodium ions -- outside the cell. (eurekalert.org)
  • These conditions are a prerequisite for the protein to do what researchers expect it to do -- that is, pump sodium ions, while also forming pentamers in the cell membrane. (eurekalert.org)
  • We examined ROS production in suspensions of isolated rat heart and liver mitochondria, using fluorescent probes that are sensitive to hydrogen peroxide. (mendeley.com)
  • The aim of this study was to determine the effect of different hydrogen peroxide concentrations (HP) on mercury and other metal ions release from admixed and spherical dental amalgam . (bvsalud.org)
  • Danish biochemist S.P.L. Sorensen was the first to use the pH system we know today, which defines inverse numbers of hydrogen-ion concentration shown in common logarithm as pH. (horiba.com)
  • In summary, the pH of a solution is the negative logarithm of its hydrogen ion concentration. (preservearticles.com)
  • Expression of the negative logarithm of hydrogen ion (H + ) concentration. (medscape.com)
  • Mathematically, pH is calculated as the negative logarithm of the hydrogen ion concentration. (encyclopedia.com)
  • I am not sure how to find the concentration of hydroxide in $\ce{NH3}$ and $\ce{NaOH}$ properly. (stackexchange.com)
  • Roots of high-yielding grain and forage crops remove basic cations from the soil and release hydrogen into soil solution to maintain an ionic charge balance within the tissue. (osu.edu)
  • However, a very tiny percentage of those molecules have broken up into hydrogen ions (H+) and hydroxide ions, (OH-), as illustrated in the figure. (horiba.com)
  • In this system, both molecules are hydrogen sources, yielding a theoretical weight efficiency of 8.4% assuming one equivalent of water and one equivalent of formaldehyde. (livingnlimbo.com)
  • Chloride (Cl −) and hydrogen (H +) ions are secreted separately in the stomach fundus region at the top of the stomach by parietal cells of the gastric mucosa into a secretory network called canaliculi before it enters the stomach lumen. (livingnlimbo.com)
  • The chloride ion forms a stable complex with trivalent iron. (yarchive.net)
  • The chloride and/or the acetate ions form stable complexes with iron ions which aids in the dissolution of rust. (yarchive.net)
  • If you're taking a science or chemistry class, you may need to know how to calculate pH based off concentration instead. (wikihow.com)
  • The purpose of this in vitro study was to measure the concentration of hydrogen ions ( pH ) of calcium hydroxide [(Ca(OH)2] pastes combined with different vehicles over 7 periods of time . (bvsalud.org)
  • hence, the hydrogen electrode potential measures [H + ] or pH. (thefreedictionary.com)
  • Tenders are invited for Supply of Low hydrogen electrode size 4 mm x 350 mm , uts 52 to 55 kgf/sq. (thefreedictionary.com)
  • The rubber tube is connected at K with a tube, L, leading from a hydrogen generator, and a slow stream of H2 passes down the rubber tube and out at G, thus converting the platinum wire from H to F into a hydrogen electrode. (wikipedia.org)
  • [2] X Research source For pH, you have to use molar concentration for the formula to work out. (wikihow.com)
  • Molar concentration, which is also called molarity, denotes the number of moles of dissolved compound per liter of solution. (wikihow.com)
  • Other aspects of its function include regulating the concentrations of various electrolytes in the body fluids and maintaining normal pH of the blood. (wikibooks.org)
  • Soil pH measures hydrogen ion concentration in soil water. (proflowers.com)
  • This may be have been the result of greater haemodilution in the on- compared to the off-pump group, compensating for change in SID by reducing the concentration of weak acids. (biomedcentral.com)
  • Compounds that contribute hydrogen ions to a solution are called acids. (encyclopedia.com)
  • Students will understand the properties that describe solutions in terms of concentration, solutes, solvents, and the behavior of acids and bases. (uen.org)
  • Differentiate between acids and bases in terms of hydrogen ion concentration. (uen.org)
  • An alkalizing substance is one that contains a molecule or ion that combines with hydrogen ions to remove them from a solution_it neutralizes acids and acts as a buffer. (angelfire.com)
  • calculate the concentration of the complementary ion and the pH and pOH of the solution. (bartleby.com)
  • The concentration of hydrogen ions in a solution determines the acidity of a solution. (bartleby.com)
  • Actually, it is determined by the concentration of hydrogen ions, the percentage of hydrogen ions contained in the solution. (horiba.com)
  • The concentration of hydrogen ions in any solution we are likely to encounter will range from 1 mol to 0.000001 mol per liter of solution. (horiba.com)
  • This means, for example, that a hydrogen-ion concentration of a solution with a pH of 4 is 10-4mol/l, meaning it contains 0.0001 mol of hydrogen ions in a solution of 1 liter. (horiba.com)
  • In the same way, a solution with a pH of 5 contains 10-5mol/l of hydrogen ions, a solution with a pH of 6 contains 10-6mol/l of hydrogen ions, while the solution with a pH of 7 contains 10-7mol/l of hydrogen ions. (horiba.com)
  • What is the pH of a solution having a hydrogen ion concentration of 1x10^-5 M? (jiskha.com)
  • a student measures a basic solution and finds that it has a hydrogen ion (H+) concentration of 1 x 10-3. (jiskha.com)
  • A solution with pH off 7 would contain _____ times the number of hydrogen ions as a solution with a pH of 8. (livingnlimbo.com)
  • A solution with a hydrogen ion concentration of 1.0 x 10-1 per liter would have a pH of: C. 1. (livingnlimbo.com)
  • Hydrogen Ion Concentration is the composition of hydrogen ions in a solution. (livingnlimbo.com)
  • A base provides either hydroxide ions (OH - ) or other negatively-charged ions that react with hydrogen ions in solution, thereby reducing the concentration of H + and raising the pH. (livingnlimbo.com)
  • SOLUTION: What is the concentration of hydrogen ions in moles per liter of the solution? (studypool.com)
  • As the concentration of H + ions in solution increases, acidity increases and pH gets lower, below 7 (see Figure 1). (epa.gov)
  • Courtesy of USGS Biology, Contaminant Biology Program Because pH is a logarithmic function, one unit change in pH (e.g., 7 to 6) indicates a 10x change in H + concentration in that solution. (epa.gov)
  • The term pH refers to the concentration of hydrogen ions (H+) in a solution. (encyclopedia.com)
  • In science, pH is a measure of ions within a solution. (wikihow.com)
  • The pH is a measure of the concentration of hydrogen ions in a solution. (wikihow.com)
  • Concentration is the number of particles of a compound in a solution relative to the volume of the same solution. (wikihow.com)
  • pH is a measure of the hydrogen (H + ) ion concentration in solution. (osu.edu)
  • High concentrations of hydrogen in soil solution (low soil pH) may cause the release of soluble aluminum from soil minerals. (osu.edu)
  • Soil pH measurement reveals the amount of active acidity (free hydrogen ions) in the soil solution and whether or not lime should be applied. (osu.edu)
  • The acetate ion forms soluble complexes with iron in solution which aids in the dissolution. (yarchive.net)
  • It's based on the hydrogen ion concentration in a solution. (swpp.co.uk)
  • Either ion could be used to characterize the chemical activity of the solution. (wattsupwiththat.com)
  • pH is the logarithmic value of the inverse of the hydrogen ion concentration. (livingnlimbo.com)
  • Acidosis during cardiopulmonary bypass (CPB) has been related to the strong ion difference (SID) and the composition of intravascular fluids that are administered. (biomedcentral.com)
  • This study aimed to explore the role of CPB in the development of acidosis by comparing changes in hydrogen ion concentration ([H + ]) and electrolytes in patients undergoing on- and off-pump coronary artery bypass graft (CABG) surgery. (biomedcentral.com)
  • Kw is called the ion product of water or dissociation constant of water. (horiba.com)
  • This causes decreased circulating hydrogen ion concentration, and increased pH (alkalosis). (wikipedia.org)
  • The optimum pH found for carbon dioxide production is a true one for the effect of hydrogen ion concentration on the tissue. (rupress.org)
  • During times of intense activity, the cells produce higher amounts of carbon dioxide so the concentration of carbon dioxide inside the cell is higher than normal. (enotes.com)
  • Diffusion of carbon dioxide from the cell to the blood stream will occur at a higher rate than when the concentration of carbon dioxide is at more normal levels. (enotes.com)
  • Those sewer users who discharge wastewater with concentrations in excess of domestic strength wastewater as identified in the current user charge system. (ecode360.com)
  • McClendon J. F. New hydrogen electrodes and rapid methods of determining hydrogen ion concentrations. (wikipedia.org)
  • 6. Cloudy suspensions of washed pneumococci in hydrogen ion concentrations varying from 8.0 to 4.0 show, after incubation, dissolution of organisms in lower hydrogen ion concentrations than about 5.0. (rupress.org)
  • Other than that the hydrogen ion does not participate in the dissolution of the rust. (yarchive.net)
  • Calculate the hydrogen ion concentration, in moles per liter, for solutions with each of the following pOH values. (bartleby.com)
  • Baseline concentrations of total calcium (Ca), ionized calcium (Ca2+), albumin, total protein, and hydrogen ion concentration [H+] were measured prior to transfusion, at intervals during transfusion of 2500 ml of blood, and at the end of transfusion. (ovid.com)
  • The concentration of the tetrodotoxin receptor in crustacean membranes is about 10 pmol/mg of membrane protein, 7 times less than the acetylcholinesterase, 30 times less than the Na+, K+-ATPase, and 30 times less than the nicotine binding component in the lobster membrane. (nih.gov)
  • Rather than allow the passage of these ions in both directions, the protein performs active transport, serving as a "pump. (eurekalert.org)
  • Actually, this balance of hydrogen ions and hydroxide ions determines the pH of the water. (horiba.com)
  • The hydrogen ion concentration in water determines the pH level. (gov.mb.ca)
  • Driven by light, such proteins can facilitate the translocation of charged particles such as ions across the cell membrane. (eurekalert.org)
  • There, he worked on plant uptake of ions, especially iron, nitrogen fixation and calcicolous plants. (wikipedia.org)
  • Olsen, C. (1928) On the significance of hydrogen-ion concentration for the cycle of nitrogen transformation in the soil. (wikipedia.org)
  • Ammonium-based fertilizers release hydrogen when oxidized to form nitrate, contibuting to soil acidity. (osu.edu)
  • An argon gas analyzer is a device intended to measure the concentration of argon in a gas mixture to aid in determining the patient's ventilatory status. (ecfr.gov)
  • The hydrogen ion concentration in the lesions of experimental pneumococcus infection has been estimated directly by pH determinations on exudates from living animals. (rupress.org)
  • For indirect evidence of an increase in hydrogen ion concentration within the lesions, the difference in sugar content between exudate and blood from animals with pneumococcus infection has been measured. (rupress.org)
  • With sanguinous exudate from the consolidated lungs of dogs with experimental pneumococcus pneumonia, the findings were not always consistent, but usually there was either direct or indirect evidence of increased hydrogen ion concentration. (rupress.org)
  • The hydrogen ion concentrations in exudate from dermal pneumococcus infection in rabbits varied between pH 6.87 and 6.66 but were not always proportional to the difference in sugar concentrations between the exudate and blood. (rupress.org)
  • While these hydrogen ion concentrations are similar to those attained in the pneumonic exudate from dogs, they are of lesser magnitude than those which Takahashi (3) has described in the pus of secondary empyema due to the pneumococcus. (rupress.org)
  • 3. At a hydrogen ion concentration of about 5.1 or higher, the pneumococcus does not survive longer than a few hours. (rupress.org)
  • 4. In hydrogen ion concentrations of about 6.8 to 7.4 the pneumococcus may live for at least many days. (rupress.org)
  • The kidneys regulate osmolarity because they have direct control over how many ions and how much water a person excretes. (wikibooks.org)
  • This is still just diffusion because during diffusion a substance is moving from areas of high concentration to areas of low concentration, so by measuring the rate at which a substance is becoming concentrated in the area of low concentration, you are measuring the rate of diffusion. (enotes.com)
  • When the quantity of lemon juice added was just sufficient to bring the hydrogen-ion concentration of the mixture to about pH 4.7, the isoelectric point of gelatin, the jelly formed was cloudy and more turbid than when the pH of the mixture was lower than 4.7. (chestofbooks.com)
  • An indwelling blood oxyhemoglobin concentration analyzer is a photoelectric device used to measure, in vivo, the oxygen-carrying capacity of hemoglobin in blood to aid in determining the patient's physiological status. (ecfr.gov)
  • Those sanitary sewer users who discharge normal domestic strength wastewater with concentrations of biochemical oxygen demand (BOD), suspended solids (SS) and phosphorus (P) no greater than the concentrations identified in the current user charge system. (ecode360.com)
  • The pH of seawater has decreased by 0.1 since the beginning of the industrial era, corresponding to a 26 per cent increase in hydrogen ion concentration. (thefreedictionary.com)
  • Users whose wastewater exceeds the concentrations for any one of these parameters shall be in Category B. (ecode360.com)
  • Wastewater with concentrations of BOD no greater than 250 mg/l, total suspended solids (TSS) no greater than 200 mg/l, and phosphorus (P) no greater than eight milligrams per liter (mg/l). (ecode360.com)
  • Wastewater which has a pollutant concentration greater than that defined for domestic strength waste and not otherwise classified as an incompatible waste. (ecode360.com)