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

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 ...

1. The very fast pre-steady-state formation of NADH catalysed by pig M4 lactate dehydrogenase was equivalent to the enzyme-site concentration at pH values greater than 8.0 and to one-half the site concentration at pH6.8. 2. The rate of dissociation of NADH from the enzyme at pH8.0 (450s−1) in the absence of other substrates is faster than the steady-state oxidation of lactate (80s−1). The latter process is therefore controlled by a step before NADH dissociation but subsequent to the hydride transfer. 3. The oxidation of enzyme-NADH by excess of pyruvate was studied as a first-order process at pH9.0. There was no effect of NADD on this reaction and it was concluded that the ternary complex undergoes a rate-limiting change before the hydride-transfer step. 4. Some conclusions about the reactions catalysed by the M4 isoenzyme were drawn from a comparison of these results with those obtained with the H4 isoenzyme and liver alcohol dehydrogenase.. ...

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 ...