Silicic Acid
Chromatography, Thin Layer
Diatoms
Chromatography
Silicon Dioxide
Chromatography, Gas
Silicon
Cerebrosides
Glycolipids
Porifera
Glycosphingolipids
Gangliosides
Fatty Acids
Glycosides
Chemistry
Chemical Phenomena
Lipids
Chromatography, High Pressure Liquid
Phospholipids
Polycationic peptides from diatom biosilica that direct silica nanosphere formation. (1/110)
Diatom cell walls are regarded as a paradigm for controlled production of nanostructured silica, but the mechanisms allowing biosilicification to proceed at ambient temperature at high rates have remained enigmatic. A set of polycationic peptides (called silaffins) isolated from diatom cell walls were shown to generate networks of silica nanospheres within seconds when added to a solution of silicic acid. Silaffins contain covalently modified lysine-lysine elements. The first lysine bears a polyamine consisting of 6 to 11 repeats of the N-methyl-propylamine unit. The second lysine was identified as epsilon-N,N-dimethyl-lysine. These modifications drastically influence the silica-precipitating activity of silaffins. (+info)Review article: alginate-raft formulations in the treatment of heartburn and acid reflux. (2/110)
Alginate-based raft-forming formulations have been marketed word-wide for over 30 years under various brand names, including Gaviscon. They are used for the symptomatic treatment of heartburn and oesophagitis, and appear to act by a unique mechanism which differs from that of traditional antacids. In the presence of gastric acid, alginates precipitate, forming a gel. Alginate-based raft-forming formulations usually contain sodium or potassium bicarbonate; in the presence of gastric acid, the bicarbonate is converted to carbon dioxide which becomes entrapped within the gel precipitate, converting it into a foam which floats on the surface of the gastric contents, much like a raft on water. Both in vitro and in vivo studies have demonstrated that alginate-based rafts can entrap carbon dioxide, as well as antacid components contained in some formulations, thus providing a relatively pH-neutral barrier. Several studies have demonstrated that the alginate raft can preferentially move into the oesophagus in place, or ahead, of acidic gastric contents during episodes of gastro-oesophageal reflux; some studies further suggest that the raft can act as a physical barrier to reduce reflux episodes. Although some alginate-based formulations also contain antacid components which can provide significant acid neutralization capacity, the efficacy of these formulations to reduce heartburn symptoms does not appear to be totally dependent on the neutralization of bulk gastric contents. The strength of the alginate raft is dependant on several factors, including the amount of carbon dioxide generated and entrapped in the raft, the molecular properties of the alginate, and the presence of aluminium or calcium in the antacid components of the formulation. Raft formation occurs rapidly, often within a few seconds of dosing; hence alginate-containing antacids are comparable to traditional antacids for speed of onset of relief. Since the raft can be retained in the stomach for several hours, alginate-based raft-forming formulations can additionally provide longer-lasting relief than that of traditional antacids. Indeed, clinical studies have shown Gaviscon is superior to placebo, and equal to or significantly better than traditional antacids for relieving heartburn symptoms. Alginate-based, raft-forming formulations have been used to treat reflux symptoms in infants and children, and in the management of heartburn and reflux during pregnancy. While Gaviscon is effective when used alone, it is compatible with, and does not interfere with the activity of antisecretory agents such as cimetidine. Even with the introduction of new antisecretory and promotility agents, alginate-rafting formulations will continue to have a role in the treatment of heartburn and reflux symptoms. Their unique non-systemic mechanism of action provides rapid and long-duration relief of heartburn and acid reflux symptoms. (+info)Accumulation of a polyisoprene-linked amino sugar in polymyxin-resistant Salmonella typhimurium and Escherichia coli: structural characterization and transfer to lipid A in the periplasm. (3/110)
Polymyxin-resistant mutants of Escherichia coli and Salmonella typhimurium accumulate a novel minor lipid that can donate 4-amino-4-deoxy-l-arabinose units (l-Ara4N) to lipid A. We now report the purification of this lipid from a pss(-) pmrA(C) mutant of E. coli and assign its structure as undecaprenyl phosphate-alpha-l-Ara4N. Approximately 0.2 mg of homogeneous material was isolated from an 8-liter culture by solvent extraction, followed by chromatography on DEAE-cellulose, C18 reverse phase resin, and silicic acid. Matrix-assisted laser desorption ionization/time of flight mass spectrometry in the negative mode yielded a single species [M - H](-) at m/z 977.5, consistent with undecaprenyl phosphate-alpha-l-Ara4N (M(r) = 978.41). (31)P NMR spectroscopy showed a single phosphorus atom at -0.44 ppm characteristic of a phosphodiester linkage. Selective inverse decoupling difference spectroscopy demonstrated that the undecaprenyl phosphate group is attached to the anomeric carbon of the l-Ara4N unit. One- and two-dimensional (1)H NMR studies confirmed the presence of a polyisoprene chain and a sugar moiety with chemical shifts and coupling constants expected for an equatorially substituted arabinopyranoside. Heteronuclear multiple-quantum coherence spectroscopy analysis demonstrated that a nitrogen atom is attached to C-4 of the sugar residue. The purified donor supports in vitro conversion of lipid IV(A) to lipid II(A), which is substituted with a single l-Ara4N moiety. The identification of undecaprenyl phosphate-alpha-l-Ara4N implies that l-Ara4N transfer to lipid A occurs in the periplasm of polymyxin-resistant strains, and establishes a new enzymatic pathway by which Gram-negative bacteria acquire antibiotic resistance. (+info)A novel fluorescent silica tracer for biological silicification studies. (4/110)
BACKGROUND: Biological silica production has drawn intense attention and several molecules involved in biosilicification have been identified. Cellular mechanisms, however, remain unknown mainly due to the lack of probes required for obtaining information on live specimens. RESULTS: The fluorescence spectra of the compound 2-(4-pyridyl)-5-((4-(2-dimethylaminoethylaminocarbamoyl)methoxy)phenyl)oxazole (PDMPO) are affected by the presence of >3.2 mM silicic acid. Increase in intensity and shift in the fluorescence coincide with the polymerization of Si. The unique PDMPO-silica fluorescence is explored here to visualize Si deposition in living diatoms. The fluorophore is selectively incorporated and co-deposited with Si into the newly synthesized frustules (the outer silica shells) showing an intense green fluorescence. CONCLUSIONS: We suggest that a fluorescence shift is due to an interaction between PDMPO and polymeric silicic acid. PDMPO is an excellent probe for imaging newly deposited silica in living cells and has also a potential for a wide range of applications in various Si-related disciplines, including biology of living organisms as diatoms, sponges, and higher plants, clinical research (e.g. lung fibrosis and cancer, bone development, artificial bone implantation), and chemistry and physics of materials research. (+info)Aluminum-dependent regulation of intracellular silicon in the aquatic invertebrate Lymnaea stagnalis. (5/110)
Silicon is essential for some plants, diatoms, and sponges but, in higher animals, its endogenous regulation has not been demonstrated. Silicate ions may be natural ligands for aluminum and here we show that, in the freshwater snail (Lymnaea stagnalis), intracellular silicon seems specifically up-regulated in response to sublethal aluminum exposure. X-ray microanalysis showed that exposure of snails to low levels of aluminum led to its accumulation in lysosomal granules, accompanied by marked up-regulation of silicon. Increased lysosomal levels of silicon were a specific response to aluminum because cadmium and zinc had no such effect. Furthermore, intra-lysosomal sulfur from metallothionein and other sulfur-containing ligands was increased after exposure to cadmium and zinc but not aluminum. To ensure that these findings indicated a specific in vivo response, and not ex vivo formation of hydroxy-aluminosilicates (HAS) from added aluminum (555 microg/liter) and water-borne silicon (43 microg/liter), two further studies were undertaken. In a ligand competition assay the lability of aluminum (527 microg/liter) was completely unaffected by the presence of silicon (46 microg/liter), suggesting the absence of HAS. In addition, exogenous silicon (6.5 mg/liter), added to the water column to promote formation of HAS, caused a decrease in lysosomal aluminum accumulation, showing that uptake of HAS would not explain the loading of aluminum into lysosomal granules. These findings, and arguments on the stability, lability, and kinetics of aluminum-silicate interactions, suggest that a silicon-specific mechanism exists for the in vivo detoxification of aluminum, which provides regulatory evidence of silicon in a multicellular organism. (+info)A phase separation model for the nanopatterning of diatom biosilica. (6/110)
Diatoms are encased in an intricately patterned wall that consists of amorphous silica. Species-specific fabrication of this ornate biomineral enables taxonomists to identify thousands of diatom species. The molecular mechanisms that control this nanofabrication and generate the diversity of patterns is not well understood. A simple model is described, in which repeated phase separation events during wall biogenesis are assumed to produce self-similar silica patterns in smaller and smaller scales. On the basis of this single assumption, the apparently complex patterns found in the valves of the diatom genus Coscinodiscus can be predicted. Microscopic analysis of valves in statu nascendi from three different Coscinodiscus species supports the conclusions derived from the model. (+info)Simple procedure for the removal of nonspecific inhibitors of rubella virus hemagglutination. (7/110)
The adsorption of serum lipoproteins onto an insoluble matrix of colloidal silicic acid results in the removal of nonspecific inhibitors of rubella virus hemagglutinin. The procedure can be performed in 15 min at room temperature. Comparative studies using both the dextran sulfate-CaCl2 and heparin-MnCl2 methods for removal of inhibitors demonstrated that the colloidal silicic acid procedure yielded identical hemagglutination inhibition titers. In addition, it is technically feasible to read titers below 1:8. (+info)Pantoprazole maintenance therapy prevents relapse of erosive oesophagitis. (8/110)
OBJECTIVES: To compare the safety and efficacy of pantoprazole with ranitidine for the maintenance of endoscopically documented healed (grade 0 or 1) erosive oesophagitis. METHODS: Patients (371) were randomly assigned to receive pantoprazole 10, 20 or 40 mg or ranitidine 150 mg. Endoscopies were performed after 1, 3, 6 and 12 months or when symptoms suggesting relapse (grade = 2) developed. Gastric biopsies were obtained at baseline and on at least one postbaseline visit. Symptom-free days and Gelusil use were assessed. RESULTS: Pantoprazole was significantly (P < 0.001) more effective in maintaining erosive oesophagitis healing. After 12 months, 33%, 40%, 68% and 82% of patients remained healed for the ranitidine and pantoprazole 10, 20 and 40 mg groups, respectively. Daytime and night-time heartburn were eliminated in > 90% of days for the pantoprazole 40 mg group. Gelusil use was significantly lower with pantoprazole 20 and 40 mg than with ranitidine (P < 0.02) during the first 9 months. CONCLUSIONS: Twelve months of maintenance therapy with pantoprazole (10-40 mg once daily) was superior to ranitidine (150 mg twice daily) in maintaining erosive oesophagitis healing. Pantoprazole 40 mg provided the most consistent efficacy and was well tolerated. (+info)I'm sorry for any confusion, but "Silicic Acid" is not a recognized medical term. Silicic acid, also known as orthosilicic acid, is a compound that contains silicon and oxygen in a ratio of 1:2 (Si(OH)4). It's commonly found in water, soil, and various plants.
In the context of health and medicine, silica or silicic acid supplements are sometimes used for their potential benefits to bone health, collagen production, and hair and nail growth. However, more research is needed to fully understand these effects and their optimal usage.
If you have any questions related to a specific medical condition or treatment, I would recommend consulting with a healthcare professional.
Thin-layer chromatography (TLC) is a type of chromatography used to separate, identify, and quantify the components of a mixture. In TLC, the sample is applied as a small spot onto a thin layer of adsorbent material, such as silica gel or alumina, which is coated on a flat, rigid support like a glass plate. The plate is then placed in a developing chamber containing a mobile phase, typically a mixture of solvents.
As the mobile phase moves up the plate by capillary action, it interacts with the stationary phase and the components of the sample. Different components of the mixture travel at different rates due to their varying interactions with the stationary and mobile phases, resulting in distinct spots on the plate. The distance each component travels can be measured and compared to known standards to identify and quantify the components of the mixture.
TLC is a simple, rapid, and cost-effective technique that is widely used in various fields, including forensics, pharmaceuticals, and research laboratories. It allows for the separation and analysis of complex mixtures with high resolution and sensitivity, making it an essential tool in many analytical applications.
Diatoms are a major group of microscopic algae (single-celled organisms) that are widely distributed in both marine and freshwater environments. They are an important part of the aquatic food chain, serving as primary producers that convert sunlight and nutrients into organic matter through photosynthesis.
Diatoms have unique cell walls made of biogenic silica, which gives them a glass-like appearance. These cell walls often have intricate patterns and structures, making diatoms an important group in the study of nanotechnology and materials science. Additionally, diatomaceous earth, a sedimentary rock formed from fossilized diatom shells, has various industrial uses such as filtration, abrasives, and insecticides.
Diatoms are also significant in the Earth's carbon cycle, contributing to the sequestration of atmospheric carbon dioxide through their photosynthetic activities. They play a crucial role in the ocean's biological pump, which helps regulate the global climate by transporting carbon from the surface ocean to the deep sea.
Chromatography is a technique used in analytical chemistry for the separation, identification, and quantification of the components of a mixture. It is based on the differential distribution of the components of a mixture between a stationary phase and a mobile phase. The stationary phase can be a solid or liquid, while the mobile phase is a gas, liquid, or supercritical fluid that moves through the stationary phase carrying the sample components.
The interaction between the sample components and the stationary and mobile phases determines how quickly each component will move through the system. Components that interact more strongly with the stationary phase will move more slowly than those that interact more strongly with the mobile phase. This difference in migration rates allows for the separation of the components, which can then be detected and quantified.
There are many different types of chromatography, including paper chromatography, thin-layer chromatography (TLC), gas chromatography (GC), liquid chromatography (LC), and high-performance liquid chromatography (HPLC). Each type has its own strengths and weaknesses, and is best suited for specific applications.
In summary, chromatography is a powerful analytical technique used to separate, identify, and quantify the components of a mixture based on their differential distribution between a stationary phase and a mobile phase.
Silicon dioxide is not a medical term, but a chemical compound with the formula SiO2. It's commonly known as quartz or sand and is not something that would typically have a medical definition. However, in some cases, silicon dioxide can be used in pharmaceutical preparations as an excipient (an inactive substance that serves as a vehicle or medium for a drug) or as a food additive, often as an anti-caking agent.
In these contexts, it's important to note that silicon dioxide is considered generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA). However, exposure to very high levels of respirable silica dust, such as in certain industrial settings, can increase the risk of lung disease, including silicosis.
Chromatography, gas (GC) is a type of chromatographic technique used to separate, identify, and analyze volatile compounds or vapors. In this method, the sample mixture is vaporized and carried through a column packed with a stationary phase by an inert gas (carrier gas). The components of the mixture get separated based on their partitioning between the mobile and stationary phases due to differences in their adsorption/desorption rates or solubility.
The separated components elute at different times, depending on their interaction with the stationary phase, which can be detected and quantified by various detection systems like flame ionization detector (FID), thermal conductivity detector (TCD), electron capture detector (ECD), or mass spectrometer (MS). Gas chromatography is widely used in fields such as chemistry, biochemistry, environmental science, forensics, and food analysis.
I'm sorry for any confusion, but "Silicon" does not have a specific medical definition. Silicon is a chemical element with the symbol Si and atomic number 14. It is a metalloid, which means it has properties of both metals and nonmetals. In the human body, silicon is not considered an essential nutrient, although it is found in trace amounts in various tissues. Some research suggests that silicon might play a role in collagen synthesis and bone health, but more studies are needed to confirm these findings and establish recommended intake levels.
Cerebrosides are a type of sphingolipid, which are lipids that contain sphingosine. They are major components of the outer layer of cell membranes and are particularly abundant in the nervous system. Cerebrosides are composed of a ceramide molecule (a fatty acid attached to sphingosine) and a sugar molecule, usually either glucose or galactose.
Glycosphingolipids that contain a ceramide with a single sugar residue are called cerebrosides. Those that contain more complex oligosaccharide chains are called gangliosides. Cerebrosides play important roles in cell recognition, signal transduction, and cell adhesion.
Abnormalities in the metabolism of cerebrosides can lead to various genetic disorders, such as Gaucher's disease, Krabbe disease, and Fabry disease. These conditions are characterized by the accumulation of cerebrosides or their breakdown products in various tissues, leading to progressive damage and dysfunction.
Glycolipids are a type of lipid (fat) molecule that contain one or more sugar molecules attached to them. They are important components of cell membranes, where they play a role in cell recognition and signaling. Glycolipids are also found on the surface of some viruses and bacteria, where they can be recognized by the immune system as foreign invaders.
There are several different types of glycolipids, including cerebrosides, gangliosides, and globosides. These molecules differ in the number and type of sugar molecules they contain, as well as the structure of their lipid tails. Glycolipids are synthesized in the endoplasmic reticulum and Golgi apparatus of cells, and they are transported to the cell membrane through vesicles.
Abnormalities in glycolipid metabolism or structure have been implicated in a number of diseases, including certain types of cancer, neurological disorders, and autoimmune diseases. For example, mutations in genes involved in the synthesis of glycolipids can lead to conditions such as Tay-Sachs disease and Gaucher's disease, which are characterized by the accumulation of abnormal glycolipids in cells.
Porifera, also known as sponges, is a phylum of multicellular aquatic organisms characterized by having pores in their bodies. These pores allow water to circulate through the body, bringing in food and oxygen while expelling waste products. Sponges do not have true tissues or organs; instead, they are composed of specialized cells that perform specific functions. They are generally sessile (non-mobile) and live attached to rocks, coral reefs, or other underwater structures. Some species can be quite large, while others are microscopic in size. Sponges have a long fossil record dating back over 500 million years and play important roles in marine ecosystems as filter feeders and habitat providers for many other marine organisms.
Glycosphingolipids are a type of complex lipid molecule found in animal cell membranes, particularly in the outer leaflet of the plasma membrane. They consist of a hydrophobic ceramide backbone, which is composed of sphingosine and fatty acids, linked to one or more hydrophilic sugar residues, such as glucose or galactose.
Glycosphingolipids can be further classified into two main groups: neutral glycosphingolipids (which include cerebrosides and gangliosides) and acidic glycosphingolipids (which are primarily gangliosides). Glycosphingolipids play important roles in various cellular processes, including cell recognition, signal transduction, and cell adhesion.
Abnormalities in the metabolism or structure of glycosphingolipids have been implicated in several diseases, such as lysosomal storage disorders (e.g., Gaucher's disease, Fabry's disease) and certain types of cancer (e.g., ganglioside-expressing neuroblastoma).
Gangliosides are a type of complex lipid molecule known as sialic acid-containing glycosphingolipids. They are predominantly found in the outer leaflet of the cell membrane, particularly in the nervous system. Gangliosides play crucial roles in various biological processes, including cell recognition, signal transduction, and cell adhesion. They are especially abundant in the ganglia (nerve cell clusters) of the peripheral and central nervous systems, hence their name.
Gangliosides consist of a hydrophobic ceramide portion and a hydrophilic oligosaccharide chain that contains one or more sialic acid residues. The composition and structure of these oligosaccharide chains can vary significantly among different gangliosides, leading to the classification of various subtypes, such as GM1, GD1a, GD1b, GT1b, and GQ1b.
Abnormalities in ganglioside metabolism or expression have been implicated in several neurological disorders, including Parkinson's disease, Alzheimer's disease, and various lysosomal storage diseases like Tay-Sachs and Gaucher's diseases. Additionally, certain bacterial toxins, such as botulinum neurotoxin and tetanus toxin, target gangliosides to gain entry into neuronal cells, causing their toxic effects.
Fatty acids are carboxylic acids with a long aliphatic chain, which are important components of lipids and are widely distributed in living organisms. They can be classified based on the length of their carbon chain, saturation level (presence or absence of double bonds), and other structural features.
The two main types of fatty acids are:
1. Saturated fatty acids: These have no double bonds in their carbon chain and are typically solid at room temperature. Examples include palmitic acid (C16:0) and stearic acid (C18:0).
2. Unsaturated fatty acids: These contain one or more double bonds in their carbon chain and can be further classified into monounsaturated (one double bond) and polyunsaturated (two or more double bonds) fatty acids. Examples of unsaturated fatty acids include oleic acid (C18:1, monounsaturated), linoleic acid (C18:2, polyunsaturated), and alpha-linolenic acid (C18:3, polyunsaturated).
Fatty acids play crucial roles in various biological processes, such as energy storage, membrane structure, and cell signaling. Some essential fatty acids cannot be synthesized by the human body and must be obtained through dietary sources.
Glycosides are organic compounds that consist of a glycone (a sugar component) linked to a non-sugar component, known as an aglycone, via a glycosidic bond. They can be found in various plants, microorganisms, and some animals. Depending on the nature of the aglycone, glycosides can be classified into different types, such as anthraquinone glycosides, cardiac glycosides, and saponin glycosides.
These compounds have diverse biological activities and pharmacological effects. For instance:
* Cardiac glycosides, like digoxin and digitoxin, are used in the treatment of heart failure and certain cardiac arrhythmias due to their positive inotropic (contractility-enhancing) and negative chronotropic (heart rate-slowing) effects on the heart.
* Saponin glycosides have potent detergent properties and can cause hemolysis (rupture of red blood cells). They are used in various industries, including cosmetics and food processing, and have potential applications in drug delivery systems.
* Some glycosides, like amygdalin found in apricot kernels and bitter almonds, can release cyanide upon hydrolysis, making them potentially toxic.
It is important to note that while some glycosides have therapeutic uses, others can be harmful or even lethal if ingested or otherwise introduced into the body in large quantities.
In the context of medical research, "methods" refers to the specific procedures or techniques used in conducting a study or experiment. This includes details on how data was collected, what measurements were taken, and what statistical analyses were performed. The methods section of a medical paper allows other researchers to replicate the study if they choose to do so. It is considered one of the key components of a well-written research article, as it provides transparency and helps establish the validity of the findings.
In the context of medicine, "chemistry" often refers to the field of study concerned with the properties, composition, and structure of elements and compounds, as well as their reactions with one another. It is a fundamental science that underlies much of modern medicine, including pharmacology (the study of drugs), toxicology (the study of poisons), and biochemistry (the study of the chemical processes that occur within living organisms).
In addition to its role as a basic science, chemistry is also used in medical testing and diagnosis. For example, clinical chemistry involves the analysis of bodily fluids such as blood and urine to detect and measure various substances, such as glucose, cholesterol, and electrolytes, that can provide important information about a person's health status.
Overall, chemistry plays a critical role in understanding the mechanisms of diseases, developing new treatments, and improving diagnostic tests and techniques.
Chemical phenomena refer to the changes and interactions that occur at the molecular or atomic level when chemicals are involved. These phenomena can include chemical reactions, in which one or more substances (reactants) are converted into different substances (products), as well as physical properties that change as a result of chemical interactions, such as color, state of matter, and solubility. Chemical phenomena can be studied through various scientific disciplines, including chemistry, biochemistry, and physics.
Lipids are a broad group of organic compounds that are insoluble in water but soluble in nonpolar organic solvents. They include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, and phospholipids. Lipids serve many important functions in the body, including energy storage, acting as structural components of cell membranes, and serving as signaling molecules. High levels of certain lipids, particularly cholesterol and triglycerides, in the blood are associated with an increased risk of cardiovascular disease.
High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.
In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.
HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.
Phospholipids are a major class of lipids that consist of a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. The head is composed of a phosphate group, which is often bound to an organic molecule such as choline, ethanolamine, serine or inositol. The tails are made up of two fatty acid chains.
Phospholipids are a key component of cell membranes and play a crucial role in maintaining the structural integrity and function of the cell. They form a lipid bilayer, with the hydrophilic heads facing outwards and the hydrophobic tails facing inwards, creating a barrier that separates the interior of the cell from the outside environment.
Phospholipids are also involved in various cellular processes such as signal transduction, intracellular trafficking, and protein function regulation. Additionally, they serve as emulsifiers in the digestive system, helping to break down fats in the diet.
Mass spectrometry (MS) is an analytical technique used to identify and quantify the chemical components of a mixture or compound. It works by ionizing the sample, generating charged molecules or fragments, and then measuring their mass-to-charge ratio in a vacuum. The resulting mass spectrum provides information about the molecular weight and structure of the analytes, allowing for identification and characterization.
In simpler terms, mass spectrometry is a method used to determine what chemicals are present in a sample and in what quantities, by converting the chemicals into ions, measuring their masses, and generating a spectrum that shows the relative abundances of each ion type.
Silicic acid
Chaetoceros pseudocurvisetus
Orthosilicic acid
Silicon isotope biogeochemistry
Liesegang rings
Hydrated silica
Silica cycle
Pedosphere
Sodium silicate
Pyrosilicic acid
Choanoflagellate
Silane
Biogenic silica
Iron
Kaolinite
Iron in biology
Barium
Porous silicon
John Diederich Haseman
VRLA battery
Nutrition
Particulate inorganic carbon
Pfahl (Bavarian Forest)
Great Calcite Belt
Protist shell
Flammenmergel
Silica fiber
Wellheim Formation
Silicate
Princeton Chert
Silicic acid - Wikipedia
Colloidal silicic acid for oral and topical treatment of aged skin, fragile hair and brittle nails in females
Silicic acids | American Journal of Science
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Ingredientes
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Resources - Fertilizer
Silica11
- Silicic acids can be seen as hydrated forms of silica, namely 2 H2xSiOx+2 = SiO2·(H2O)x. (wikipedia.org)
- In such dilute solutions, silica is assumed to exist as orthosilicic acid. (wikipedia.org)
- Theoretical computations indicate that the dissolution of silica in water proceeds through the formation of a SiO2·2H2O complex and then orthosilicic acid. (wikipedia.org)
- overset {silicic\ acid}{H2SiO3}}}}} Based on the vapor pressure curves for silica gel, Reinout Willem Van Bemellen argued that no silica hydrates existed, only silica gel. (wikipedia.org)
- Some acids can adsorb and intercalate organic molecules, and therefore are interesting alternatives to silica. (wikipedia.org)
- Concurrent measures of silica dissolution rates allowed net silicic acid uptake to be estimated. (columbia.edu)
- More efficient recycling of particulate nitrogen in surface waters compared to biogenic silica led to the selective depletion of silicic acid over nitrate, creating a positive feedback between [Fe] and the silicate pump, where low [Fe] accelerates the onset of Si limitation and diminishes the export of organic matter relative to silica. (columbia.edu)
- Contains silicic acid - the purest most soluble basic form of silica on the market! (planetnatural.com)
- Based on a formula of silicic acid ethyl ester, its substance reacts with atmospheric humidity to form silicic acid gel, or natural silica. (csmonitor.com)
- Diatoms use silicic acid to create their silica cell wall, which is made during cell division. (confex.com)
- Recent studies have revealed that some smaller marine organisms (e.g. the picocyanobacterium Synechococcus) also take up silicic acid (dissolved silica, dSi) and accumulate silica, despite not exhibiting silicon dependent cellular structures. (lu.se)
Silicates4
- Orthosilicic acid has calculated dissociation potentials pKa1 = 9.84, pKa2 = 13.2 at 25 °C. Silicic acids and silicates in solution react with molybdate anions, yielding yellow silicomolybdate complexes. (wikipedia.org)
- Crystalline silicic acids can be prepared by removing the sodium cations from solutions of sodium silicates with an ion-exchange resin, or by treating sodium silicates with concentrated sulfuric acid. (wikipedia.org)
- Many readers may have already heard of the potential benefits of supplementing soil or hydro cannabis plants with silicon in the form of silicates or silicic acid. (hightimes.com)
- Soil growers can also use silicates or silicic acid, but organic options also exist. (hightimes.com)
Mono silicic1
- This mono silicic acid bio stimulant is designed to increase plant vigour along with the number of node sites, Vitalize helps to protect and strengthen you plant throughout its entire grow cycle. (camgrow.com)
Colloidal2
- In an open study, women with biologically aged skin and fragile or thin hair, or brittle nails were treated orally with 10 ml colloidal silicic acid (Silicol) once daily for 90 days and applied colloidal silicic acid to the face for 10 min twice daily. (nih.gov)
- A 30% solution of Si02, purified colloidal solution of silicic acid in water that has been formulated for the rapid sedimentation of yeast. (countrymalt.com)
Nitrate3
- Factors influencing concentrations of nitrate, silicic acid, dissolved Fe, and dissolved Mn in the near-field Columbia River plume were examined during late spring and summer from 2004 to 2006 as part of the River Influences on Shelf Ecosystems program. (stccmop.org)
- Rates of silicic acid, nitrate, ammonium and urea uptake were measured along with simultaneous estimates of net and gross carbon uptake derived from net oxygen production and 180 gross production rates. (columbia.edu)
- Comparison of integrated rates of gross silicic acid uptake, gross carbon uptake, and total nitrogen (nitrate+ammonium+urea) uptake revealed that gross uptake ratios within the bloom closely matched Redfield proportions. (columbia.edu)
Silicate4
- Like the silicate anions, which are their better known conjugate bases, silicic acids are proposed to be oligomeric or polymeric. (wikipedia.org)
- On the other hand, Gustav Tschermak von Seysenegg believed that he had observed different silicic acids as decomposition products of natural silicate gels. (wikipedia.org)
- Hydroponic growers may want to invest in silicon's most water-soluble forms for their nutrients solutions: silicic acid (sometimes in the form of orthosilicic acid) or potassium silicate. (hightimes.com)
- Silicic acid is more available, but far more expensive than potassium silicate. (hightimes.com)
Crystalline6
- The first crystalline silicic acid was prepared from the phyllosilicate natrosilite (Na2Si2O5) in 1924. (wikipedia.org)
- More than 15 crystalline acids are known and comprise at least six modifications of H2Si2O5. (wikipedia.org)
- one of the tannic acids, extracted from CATECHU as a white, crystalline substance. (absp.org.uk)
- as in dodecanoic acid, a crystalline fatty acid occurring as glycerides in natural fats and oils (especially coconut oil and palm-kernel oil). (absp.org.uk)
- as in erucic acid, a crystalline fatty acid. (absp.org.uk)
- as in gallic acid, a crystalline substance present in gallnuts, tea, and various plants. (absp.org.uk)
Silicon dioxide1
- Indeed, in concentrated solutions, silicic acids generally polymerize and condense, and ultimately degrade to silicon dioxide and water. (wikipedia.org)
Ascorbic2
- antiscorbutic, as in ascorbic acid, vitamin C. (absp.org.uk)
- as in cevitamic acid, another name for ascorbic acid. (absp.org.uk)
Soluble2
- They are typically colorless weak acids that are sparingly soluble in water. (wikipedia.org)
- In addition to hydrogen fluoride at room temperature, it is difficult to react with other substances, insoluble in water, nitric acid, hydrochloric acid, and soluble in hydrofluoric acid and alkali. (mis-asia.com)
Uptake2
Esters3
- Evonik strengthens its position in functional silanes with the acquisition of US company Silbond, a leading supplier of silicic acid esters. (process-worldwide.com)
- Evonik buys US silicic acid esters specialist Silbond. (process-worldwide.com)
- We are now able to supply our customers with TEOS from a local production capacity and monitor future growth in the silicic acid esters market", explained Dr. Johannes Ohmer, Head of Evonik's Inorganic Materials Business Unit in the Resource Efficiency Segment. (process-worldwide.com)
Amino8
- as in domoic acid, a poisonous amino acid found in marine algae. (absp.org.uk)
- It contains all essential vitamins, amino acids, minerals and trace elements. (windycityparrot.com)
- In addition, NEKTON-Breed-Star has a high content of vitamin E and essential amino acids in a special ratio and is ideal for preparation of and during breeding. (windycityparrot.com)
- The bird's amino acid requirements increase during breeding. (windycityparrot.com)
- NEKTON-Breed-Star contains 18 amino acids and a particularly high proportion of arginine, lysine, methionine, threonine, and tryptophan, which are very important for the bird during breeding. (windycityparrot.com)
- These amino acids are limited, which means they must be supplied with the feed. (windycityparrot.com)
- The addition of these amino acids primarily increases reproductive performance and also counteracts stress factors. (windycityparrot.com)
- Contains 18 amino acids. (windycityparrot.com)
Citric1
- as in citric acid, an acid derived from citrus fruits. (absp.org.uk)
Orthosilicic3
- Orthosilicic acid is a representative example. (wikipedia.org)
- In a typical preparation, monomeric orthosilicic acid was found to react completely in 75 seconds, dimeric pyrosilicic acid in 10 minutes, and higher oligomers in considerably longer time. (wikipedia.org)
- Orthosilicic Acid (Si(OH)4), % by weight (min. (exagro.in)
Diatoms1
- Silicat Ex helps against silicic acid which promotes diatoms. (jbl.de)
Folic acid2
- folic acid. (absp.org.uk)
- as in folic acid, an acid in the vitamin B complex. (absp.org.uk)
Benzoic Acid1
- as in benzoic acid, an acid found in benzoin and other gums. (absp.org.uk)
Arachidonic acid2
- Gamma-linolenic acid reduces production of metabolites of arachidonic acid oxidation, which activate inflammatory reaction. (rxmed.com)
- as in arachidonic acid, an unsaturated fatty acid occurring in animal cells. (absp.org.uk)
Hydrofluoric acid1
- as in hydrofluoric acid, a strong acid used for etching glass. (absp.org.uk)
Urea1
- applied to an acid got from malonic acid and urea, a source of important sedatives. (absp.org.uk)
Chlorine3
- as in chloric acid, an acid derived from chlorine. (absp.org.uk)
- applied to an acid composed of hydrogen and chlorine, hydrogen chloride, still sometimes called MURIATIC acid. (absp.org.uk)
- Other contaminants are added, like the chemicals used for sanitation - chlorine, chloramine, and fluor silicic acid. (filtersfast.com)
Concentration1
- Therefore, this study experimentally examined the apparent deposition rate constant, k (m/s), by considering the supersaturated concentration of silicic acid and deep-underground temperatures (288-323 K). As a result, the apparent deposition rate constants, obtained experimentally, were not affected by an initial supersaturated concentration and were only slightly affected by temperature. (elsevierpure.com)
Boric2
- Boric acid Greenwood, N. N. (wikipedia.org)
- as in boric acid, an acid obtained from borax. (absp.org.uk)
Fatty2
- In the oil of Borage, gamma-linolenic and cislinoleic fatty acids, necessary for the synthesis of prostaglandin with anti-inflammatory action, were detected. (rxmed.com)
- applied to a type of fatty acid, found in butter and having a goatlike smell. (absp.org.uk)
Organic1
- Si-OH + HO-Si#}}} Like organic silanols, silicic acids are weak acids. (wikipedia.org)
Chemistry1
- In chemistry, a silicic acid (/sɪˈlɪsɪk/) is any chemical compound containing the element silicon attached to oxide (=O) and hydroxyl (−OH) groups, with the general formula [H2xSiOx+2]n or, equivalently, [SiOx(OH)4−2x]n. (wikipedia.org)
Insoluble1
- as in hexanoic acid, an insoluble oily carboxylic acid. (absp.org.uk)
Water1
- The degree of polymerization of silicic acids in water solution can be determined by its effect on the freezing point of the solution (cryoscopy). (wikipedia.org)
Products1
- Supplements - formulated without ingredients prohibited in OTC products plus no amygdalin, ephedra, kratom, ethylenediaminetetraacetic acid (EDTA) anti-oxidants, pharmaceuticals like benfotiamine, phentermine and sulbutiamine, and more. (target.com)
Roots1
- scientists think that roots absorb and transport silicon in the form of silicic acid. (hightimes.com)
Form5
- Well defined silicic acids have not been obtained in a form that has been characterized by X-ray crystallography. (wikipedia.org)
- overset {pyrosilicic\ acid}{(HO)3Si-O-Si(OH)3}}}}} Alternatively, metasilicic acid is liable to form cyclic polymers [−SiO(OH)2−]n, which can be opened by hydration to chain polymers HO[−SiO(OH)2−]nH. (wikipedia.org)
- Similarly, disilicic acid is liable to form complex polymers with a tetravalent unit, [=Si2O3(OH)2=]n. (wikipedia.org)
- as in acetic acid, a diluted form of which is vinegar. (absp.org.uk)
- containing iron in its trivalent form, as in ferric acid, a hypothetical acid. (absp.org.uk)
Hypothetical1
- The silicon-oxygen double bond of metasilicic acid, implied by the formula H2SiO3, is hypothetical or highly unstable. (wikipedia.org)
Content1
- Production of Concentrated Phosphoric Acid Using Phosphate Rock with a High Iron and Aluminium Content. (fertilizer.org)
Primarily1
- No simple silicic acid has ever been identified, since these species are primarily of theoretical interest. (wikipedia.org)
Natural1
- The use of silicic acid helps builds the plants natural defence to environmental stresses. (camgrow.com)
Solutions2
- Silicic acids are rarely observed in isolation, but are thought to exist in aqueous solutions, including seawater, and play a role in biomineralization. (wikipedia.org)
- Silicic acid was added to sample solutions to quench excess diazomethane. (cdc.gov)
High1
- In contrast, high alkaline groundwater, caused by the use of cementitious materials, induces supersaturated conditions with regard to silicic acid. (elsevierpure.com)
Addition1
- The deliberate addition of silicic acid controls cell division, henceforth the production of stress-induced metabolites, such is lipids. (confex.com)
Formula1
- A little goes a long way with Power Si the original patented formula of monosilicic acid for plants. (growlightheaven.com)
Results1
- These results suggest that silicic acid deposition contributes to retardation effects via the decrease of the hydraulic conductivity in backfilled tunnels. (elsevierpure.com)
Source2
- Elevated silicic acid in the river is the dominant source, with concentrations of 60-80 μM in the near-field plume. (stccmop.org)
- Borage is an excellent source of Omega-6 acids. (rxmed.com)
Free1
- Diazomethane in solution was employed to convert 2,4-D as the free acid to the methyl ester in each of the three methods for ease of gas chromatography. (cdc.gov)