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Dextran
Dextran is a complex branched glucan (polysaccharide derived from the condensation of glucose), originally derived from wine. IUPAC defines dextrans as "Branched poly-α-d-glucosides of microbial origin having glycosidic bonds predominantly C-1 → C-6". Dextran chains are of varying lengths (from 3 to 2000 kilodaltons). The polymer main chain consists of α-1,6 glycosidic linkages between glucose monomers, with branches from α-1,3 linkages. This characteristic branching distinguishes a dextran from a dextrin, which is a straight chain glucose polymer tethered by α-1,4 or α-1,6 linkages. Occurrence Dextran was discovered by Louis Pasteur as a microbial product in wine, but mass production was only possible after the development by Allene Jeanes of a process using bacteria. Dental plaque is rich in dextrans. Dextran is a complicating contaminant in the refining of sugar because it elevates the viscosity of sucrose solutions and fouls plumbing. Dextran is now produced fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allene Jeanes
Allene Rosalind Jeanes (July 19, 1906 – December 11, 1995) was an American chemical researcher, whose studies focused mainly on carbohydrates and the development of Dextran, a substance that replaced blood plasma in the Korean War. A member of the American Chemical Society, Jeanes published over 60 works, compiled 24 presentations, and received ten patents. Early life and education Jeanes was born July 19, 1906, in Waco, Texas to Viola (Herring) and Largus Elonzo Jeanes, a switchman and later a yardmaster for the Cotton Belt Route of the St. Louis Southwestern Railway. In 1928, she received a bachelor's degree from Baylor University; in 1929, Jeanes obtained a master's degree from the University of California, Berkeley. She was Jewish. From 1930 to 1935, Jeanes was employed as the head science teacher at Athens College in Athens, Alabama. From 1936 to 1937, she held a position as chemistry instructor at the University of Illinois. She received her PhD in organic chemistry f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dextran 70
Dextran 70 is a type of fluid given by intravenous, injection into a vein to expand blood volume. Specifically it is used for Shock (circulatory), shock such as that caused by bleeding or burns when blood transfusions are not quickly available. However, it does not carry oxygen. Common side effects include vomiting, fever, and joint pains. Other side effects include allergic reactions and poor blood clotting. It is not recommended in people with kidney failure, significant heart failure, or a clotting disorder. It is not recommended during pregnancy. It works by pulling fluid from the extravascular space into the blood vessels. Dextran 70 was approved for medical use in 1947. It is on the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines. It comes in either sodium chloride solution or glucose solution. References External links * {{portal bar, Medicine World Health Organization essential medicines Wikipedia medicine artic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leuconostoc Mesenteroides
''Leuconostoc mesenteroides'' is a species of lactic acid bacteria associated with Fermentation (biochemistry), fermentation, under conditions of salinity and low temperatures (such as Lactic acid fermentation, lactic acid production in fermented sausages). In some cases of vegetable and food storage, it was associated with pathogenicity (soft rot, slime and unpleasant odor). ''L. mesenteroides'' is approximately 0.5-0.7 µm in diameter and has a length of 0.7-1.2 µm, producing small grayish colonies that are typically less than 1.0 mm in diameter. It is facultatively Anaerobic respiration, anaerobic, Gram-positive bacteria, Gram-positive, Non-motile bacteria, non-motile, non-sporogenous, and Coccoid bacteria, spherical. It often forms lenticular coccoid cells in pairs and chains, however, it can occasionally form Bacillus (shape), short rods with rounded ends in long chains, as its shape can differ depending on what media the species is grown on. ''L. mesenteroides'' grows best a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Mutans
''Streptococcus mutans'' is a facultatively anaerobic, gram-positive coccus (round bacterium) commonly found in the human oral cavity and is a significant contributor to tooth decay. It is part of the " streptococci" (plural, non-italic lowercase), an informal general name for all species in the genus ''Streptococcus''. The microbe was first described by James Kilian Clarke in 1924. This bacterium, along with the closely related species ''Streptococcus sobrinus'', can cohabit the mouth: Both contribute to oral disease, and the expense of differentiating them in laboratory testing is often not clinically necessary. Therefore, for clinical purposes they are often considered together as a group, called the mutans streptococci (plural, non-italic due to its being an informal group name). This grouping of similar bacteria with similar tropism can also be seen in the viridans streptococci, another group of ''Streptococcus'' species. Ecology ''S. mutans'' is naturally present in the hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sucrose
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined from either sugarcane or sugar beet. Sugar mills – typically located in tropical regions near where sugarcane is grown – crush the cane and produce raw sugar which is shipped to other factories for refining into pure sucrose. Sugar beet factories are located in temperate climates where the beet is grown, and process the beets directly into refined sugar. The sugar-refining process involves washing the raw sugar crystals before dissolving them into a sugar syrup which is filtered and then passed over carbon to remove any residual colour. The sugar syrup is then concentrated by boiling under a vacuum and crystallized as the final purification process to produce crystals of pure sucrose that are clear, odorless, and sweet. Suga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucan
A glucan is a polysaccharide derived from D-glucose, linked by glycosidic bonds. Glucans are noted in two forms: alpha glucans and beta glucans. Many beta-glucans are medically important. They represent a drug target for antifungal medications of the echinocandin class. Types The following are glucans (The α- and β- and numbers clarify the type of O-glycosidic bond and the specific carbons involved): Alpha * dextran, α-1,6-glucan with α-1,3-branches * floridean starch, α-1,4- and α-1,6-glucan * glycogen, α-1,4- and α-1,6-glucan * pullulan, α-1,4- and α-1,6-glucan * starch, a mixture of amylose and amylopectin, both α-1,4- and α-1,6-glucans Beta * cellulose, β-1,4-glucan * chrysolaminarin, β-1,3-glucan * curdlan, β-1,3-glucan * laminarin, β-1,3- and β-1,6-glucan * lentinan, a strictly purified β-1,6:β-1,3-glucan from ''Lentinus edodes'' * lichenin, β-1,3- and β-1,4-glucan * oat beta-glucan, β-1,3- and β-1,4-glucan * pleuran, β-1,3- and β-1,6-gluca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with water (hydrolysis) using amylase enzymes as catalyst, which produces constituent sugars (monosaccharides, or oligosaccharides). They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch, glycogen and galactogen and structural polysaccharides such as cellulose and chitin. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure, these macromolecules can have distinct properties from their monosaccharide building blocks. They may be amorphous or even insoluble in water. When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called a homopolysaccharide or homoglycan, but when more t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dental Plaque
Dental plaque is a biofilm of microorganisms (mostly bacteria, but also fungi) that grows on surfaces within the mouth. It is a sticky colorless deposit at first, but when it forms tartar, it is often brown or pale yellow. It is commonly found between the teeth, on the front of teeth, behind teeth, on chewing surfaces, along the gumline (supragingival), or below the gumline cervical margins (subgingival). Dental plaque is also known as microbial plaque, oral biofilm, dental biofilm, dental plaque biofilm or bacterial plaque biofilm. Bacterial plaque is one of the major causes for dental decay and gum disease. Progression and build-up of dental plaque can give rise to tooth decay – the localised destruction of the tissues of the tooth by acid produced from the bacterial degradation of fermentable sugar – and periodontal problems such as gingivitis and periodontitis; hence it is important to disrupt the mass of bacteria and remove it. Plaque control and removal can be achieved w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactic Acid Bacteria
Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical (cocci) bacteria that share common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and milk products, produce lactic acid as the major metabolic end product of carbohydrate fermentation, giving them the common name lactic acid bacteria (LAB). Production of lactic acid has linked LAB with food fermentations, as acidification inhibits the growth of spoilage agents. Proteinaceous bacteriocins are produced by several LAB strains and provide an additional hurdle for spoilage and pathogenic microorganisms. Furthermore, lactic acid and other metabolic products contribute to the organoleptic and textural profile of a food item. The industrial importance of the LAB is further evidenced by their generally recognized as safe (GRAS) status, due to their ubiquitous appearance in food and thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Gluco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across. They are so small that accurately predicting their behavior using classical physics, as if they were tennis balls for example, is not possible due to quantum effects. More than 99.94% of an atom's mass is in the nucleus. The protons have a positive electric charge, the electrons have a negative electric charge, and the neutrons have no electric charge. If the number of protons and electrons are equal, then the atom is electrically neutral. If an atom has more or fewer electrons than protons, then it has an overall negative or positive charge, respectively – such atoms are called ions. The electrons of an atom are a ... [... |
