OCLC Online Computer Library Center, Incorporated d/b/a OCLC is an American nonprofit cooperative organization "dedicated to the public purposes of furthering access to the world's information and reducing information costs". It was founded in 1967 as the Ohio College Library Center. OCLC and its member libraries cooperatively produce and maintain WorldCat, the largest online public access catalog in the world. OCLC is funded by the fees that libraries have to pay for its services. OCLC maintains the Dewey Decimal Classification system. OCLC began in 1967, as the Ohio College Library Center, through a collaboration of university presidents, vice presidents, library directors who wanted to create a cooperative computerized network for libraries in the state of Ohio; the group first met on July 5, 1967 on the campus of the Ohio State University to sign the articles of incorporation for the nonprofit organization, hired Frederick G. Kilgour, a former Yale University medical school librarian, to design the shared cataloging system.
Kilgour wished to merge the latest information storage and retrieval system of the time, the computer, with the oldest, the library. The plan was to merge the catalogs of Ohio libraries electronically through a computer network and database to streamline operations, control costs, increase efficiency in library management, bringing libraries together to cooperatively keep track of the world's information in order to best serve researchers and scholars; the first library to do online cataloging through OCLC was the Alden Library at Ohio University on August 26, 1971. This was the first online cataloging by any library worldwide. Membership in OCLC is based on use of services and contribution of data. Between 1967 and 1977, OCLC membership was limited to institutions in Ohio, but in 1978, a new governance structure was established that allowed institutions from other states to join. In 2002, the governance structure was again modified to accommodate participation from outside the United States.
As OCLC expanded services in the United States outside Ohio, it relied on establishing strategic partnerships with "networks", organizations that provided training and marketing services. By 2008, there were 15 independent United States regional service providers. OCLC networks played a key role in OCLC governance, with networks electing delegates to serve on the OCLC Members Council. During 2008, OCLC commissioned two studies to look at distribution channels. In early 2009, OCLC negotiated new contracts with the former networks and opened a centralized support center. OCLC provides bibliographic and full-text information to anyone. OCLC and its member libraries cooperatively produce and maintain WorldCat—the OCLC Online Union Catalog, the largest online public access catalog in the world. WorldCat has holding records from private libraries worldwide; the Open WorldCat program, launched in late 2003, exposed a subset of WorldCat records to Web users via popular Internet search and bookselling sites.
In October 2005, the OCLC technical staff began a wiki project, WikiD, allowing readers to add commentary and structured-field information associated with any WorldCat record. WikiD was phased out; the Online Computer Library Center acquired the trademark and copyrights associated with the Dewey Decimal Classification System when it bought Forest Press in 1988. A browser for books with their Dewey Decimal Classifications was available until July 2013; until August 2009, when it was sold to Backstage Library Works, OCLC owned a preservation microfilm and digitization operation called the OCLC Preservation Service Center, with its principal office in Bethlehem, Pennsylvania. The reference management service QuestionPoint provides libraries with tools to communicate with users; this around-the-clock reference service is provided by a cooperative of participating global libraries. Starting in 1971, OCLC produced catalog cards for members alongside its shared online catalog. OCLC commercially sells software, such as CONTENTdm for managing digital collections.
It offers the bibliographic discovery system WorldCat Discovery, which allows for library patrons to use a single search interface to access an institution's catalog, database subscriptions and more. OCLC has been conducting research for the library community for more than 30 years. In accordance with its mission, OCLC makes its research outcomes known through various publications; these publications, including journal articles, reports and presentations, are available through the organization's website. OCLC Publications – Research articles from various journals including Code4Lib Journal, OCLC Research, Reference & User Services Quarterly, College & Research Libraries News, Art Libraries Journal, National Education Association Newsletter; the most recent publications are displayed first, all archived resources, starting in 1970, are available. Membership Reports – A number of significant reports on topics ranging from virtual reference in libraries to perceptions about library funding. Newsletters – Current and archived newsletters for the library and archive community.
Presentations – Presentations from both guest speakers and OCLC research from conferences and other events. The presentations are organized into five categories: Conference presentations, Dewey presentations, Distinguished Seminar Series, Guest presentations, Research staff
In medicine, some blood tests are conducted on venous blood obtained by fingerstick. The site, free of surface arterial flow, where the blood is to be collected is sterilized with a topical germicide, the skin pierced with a sterile lancet. After a droplet has formed, venous blood is captured in a capillary tube. Blood cells drawn from fingersticks have a tendency to undergo hemolysis if the finger is "milked" to obtain more blood. Tests conducted on the capillary blood collected are: Glucose levels – Diabetics have a portable blood meter to check on their blood sugar. Mononucleosis – Fingerstick testing can be used to test for mononucleosis. Hemoglobin levels – Fingerstick testing of hemoglobin is a quick screening procedure to ensure a blood or plasma donor has an acceptably high blood count for donating blood or blood components. Genetic testing – Heelprick testing of a newborn's DNA allows for early diagnosis and mitigation of common hereditary disorders. CBC Prothrombin timeFingersticks are routine for hardy adults, but are performed on children and the elderly only if a small amount of blood suffices for needed tests.
Neonates are given heelpricks instead, as this is less to cause permanent damage. Heelpricks, section "Blood collection on babies"
Insulin is a peptide hormone produced by beta cells of the pancreatic islets. It regulates the metabolism of carbohydrates and protein by promoting the absorption of carbohydrates glucose from the blood into liver and skeletal muscle cells. In these tissues the absorbed glucose is converted into either glycogen via glycogenesis or fats via lipogenesis, or, in the case of the liver, into both. Glucose production and secretion by the liver is inhibited by high concentrations of insulin in the blood. Circulating insulin affects the synthesis of proteins in a wide variety of tissues, it is therefore an anabolic hormone, promoting the conversion of small molecules in the blood into large molecules inside the cells. Low insulin levels in the blood have the opposite effect by promoting widespread catabolism of reserve body fat. Beta cells are sensitive to glucose concentrations known as blood sugar levels; when the glucose level is high, the beta cells secrete insulin into the blood. Their neighboring alpha cells, by taking their cues from the beta cells, secrete glucagon into the blood in the opposite manner: increased secretion when blood glucose is low, decreased secretion when glucose concentrations are high.
Glucagon, through stimulating the liver to release glucose by glycogenolysis and gluconeogenesis, has the opposite effect of insulin. The secretion of insulin and glucagon into the blood in response to the blood glucose concentration is the primary mechanism of glucose homeostasis. If beta cells are destroyed by an autoimmune reaction, insulin can no longer be synthesized or be secreted into the blood; this results in type 1 diabetes mellitus, characterized by abnormally high blood glucose concentrations, generalized body wasting. In type 2 diabetes mellitus the destruction of beta cells is less pronounced than in type 1 diabetes, is not due to an autoimmune process. Instead there is an accumulation of amyloid in the pancreatic islets, which disrupts their anatomy and physiology; the pathogenesis of type 2 diabetes is not well understood but patients exhibit a reduced population of islet beta-cells, reduced secretory function of islet beta-cells that survive, peripheral tissue insulin resistance.
Type 2 diabetes is characterized by high rates of glucagon secretion into the blood which are unaffected by, unresponsive to the concentration of glucose in the blood. Insulin is still secreted into the blood in response to the blood glucose; as a result, the insulin levels when the blood sugar level is normal, are much higher than they are in healthy persons. The human insulin protein is composed of 51 amino acids, has a molecular mass of 5808 Da, it is a dimer of a B-chain, which are linked together by disulfide bonds. Insulin's structure varies between species of animals. Insulin from animal sources differs somewhat in effectiveness from human insulin because of these variations. Porcine insulin is close to the human version, was used to treat type 1 diabetics before human insulin could be produced in large quantities by recombinant DNA technologies; the crystal structure of insulin in the solid state was determined by Dorothy Hodgkin. It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system.
Insulin may have originated more than a billion years ago. The molecular origins of insulin go at least as far back. Apart from animals, insulin-like proteins are known to exist in the Fungi and Protista kingdoms. Insulin is produced by beta cells of the pancreatic islets in most vertebrates and by the Brockmann body in some teleost fish. Cone snails Conus geographus and Conus tulipa, venomous sea snails that hunt small fish, use modified forms of insulin in their venom cocktails; the insulin toxin, closer in structure to fishes' than to snails' native insulin, slows down the prey fishes by lowering their blood glucose levels. The preproinsulin precursor of insulin is encoded by the INS gene. A variety of mutant alleles with changes in the coding region have been identified. A read-through gene, INS-IGF2, overlaps with this gene at the 5' region and with the IGF2 gene at the 3' region. In the pancreatic β cells, glucose is the primary physiological stimulus for the regulation of insulin synthesis.
Insulin is regulated through the transcription factors PDX1, NeuroD1, MafA. PDX1 is in the nuclear periphery upon low blood glucose levels interacting with corepressors HDAC1 and 2, downregulating the insulin secretion. An increase in blood glucose levels causes phosphorylation of PDX1 and it translocates centrally and binds the A3 element within the insulin promoter. Upon translocation it interacts with coactivators HAT p300 and acetyltransferase set 7/9. PDX1 affects the histone modifications through deacetylation as well as methylation, it is said to suppress glucagon. NeuroD1 known as β2, regulates insulin exocytosis in pancreatic β cells by directly inducing the expression of genes involved in exocytosis, it is localized in the cytosol, but in response to high glucose it becomes glycosylated by OGT and/or phosphorylated by ERK, which causes translocation to the nucleus. In the nucleus β2 heterodimerizes with E47, binds to the E1 element of the insulin promoter and recruits co-activator p300 which acetylates β2.
It is able to interact with other transcription factors as well in activation of the insulin gene. MafA is degraded by proteasomes upon low blood glucose levels
Salicylic acid is a lipophilic monohydroxybenzoic acid, a type of phenolic acid, a beta hydroxy acid. It has the formula C7H6O3; this colorless crystalline organic acid is used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin. In addition to serving as an important active metabolite of aspirin, which acts in part as a prodrug to salicylic acid, it is best known for its use as a key ingredient in topical anti-acne products; the salts and esters of salicylic acid are known as salicylates. It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. Salicylic acid as a medication is used most to help remove the outer layer of the skin; as such, it is used to treat warts, acne, ringworm and ichthyosis. Similar to other hydroxy acids, salicylic acid is a key ingredient in many skincare products for the treatment of seborrhoeic dermatitis, psoriasis, corns, keratosis pilaris, acanthosis nigricans and warts.
Salicylic acid is used in the production of other pharmaceuticals, including 4-aminosalicylic acid and landetimide. Salicylic acid was one of the original starting materials for making acetylsalicylic acid in 1897. Bismuth subsalicylate, a salt of bismuth and salicylic acid, is the active ingredient in stomach relief aids such as Pepto-Bismol, is the main ingredient of Kaopectate and "displays anti-inflammatory action and acts as an antacid and mild antibiotic". Other derivatives include methyl salicylate used as a liniment to soothe joint and muscle pain and choline salicylate used topically to relieve the pain of mouth ulcers. Salicylic acid is used as a bactericidal and an antiseptic. Sodium salicylate is a useful phosphor in the vacuum ultraviolet spectral range, with nearly flat quantum efficiency for wavelengths between 10 and 100 nm, it fluoresces in the blue at 420 nm. It is prepared on a clean surface by spraying a saturated solution of the salt in methanol followed by evaporation. Aspirin can be prepared by the esterification of the phenolic hydroxyl group of salicylic acid with the acetyl group from acetic anhydride or acetyl chloride.
Salicylic acid directly and irreversibly inhibits the activity of both types of cyclo-oxygenases to decrease the formation of precursors of prostaglandins and thromboxanes from arachidonic acid. Salicylate may competitively inhibit prostaglandin formation. Salicylate's antirheumatic actions are a result of its anti-inflammatory mechanisms. Salicylic acid works by causing the cells of the epidermis to slough off more preventing pores from clogging up, allowing room for new cell growth. Salicylic acid inhibits the oxidation of uridine-5-diphosphoglucose competitively with nicotinamide adenosine dinucleotide and noncompetitively with UDPG, it competitively inhibits the transferring of glucuronyl group of uridine-5-phosphoglucuronic acid to the phenolic acceptor. The wound-healing retardation action of salicylates is due to its inhibitory action on mucopolysaccharide synthesis; as a topical agent and as a beta-hydroxy acid, salicylic acid is capable of penetrating and breaking down fats and lipids, causing moderate chemical burns of the skin at high concentrations.
It may damage the lining of pores if the solvent is acetone or an oil. Over-the-counter limits are set at 2% for topical preparations expected to be left on the face and 3% for those expected to be washed off, such as acne cleansers or shampoo. For wart removal, such a solution should be applied once or twice a day – more frequent use may lead to an increase in side-effects without an increase in efficacy; some people are hypersensitive to related compounds. If high concentrations of salicylic ointment are applied to a large percentage of body surface, high levels of salicylic acid can enter the blood, requiring hemodialysis to avoid further complications. Salicylic acid has the formula C6H4COOH, it is known as 2-hydroxybenzoic acid. It is poorly soluble in water. Salicylic acid is biosynthesized from the amino acid phenylalanine. In Arabidopsis thaliana it can be synthesized via a phenylalanine-independent pathway. Sodium salicylate is commercially prepared by treating sodium phenolate with carbon dioxide at high pressure and high temperature – a method known as the Kolbe-Schmitt reaction.
Acidification of the product with sulfuric acid gives salicylic acid: It can be prepared by the hydrolysis of aspirin or methyl salicylate with a strong acid or base. Hippocrates, Pliny the Elder and others knew that willow bark could ease pain and reduce fevers, it was used in China to treat these conditions. This remedy is mentioned in texts from ancient Egypt and Assyria; the Cherokee and other Native Americans used an infusion of the bark for fever and other medicinal purposes. In 2014, archaeologists identified traces of salicylic acid on 7th century pottery fragments found in east central Colorado; the Reverend Edward Stone, a vicar from Chipping Norton, Engla
An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. Electrically, such a solution is neutral. If an electric potential is applied to such a solution, the cations of the solution are drawn to the electrode that has an abundance of electrons, while the anions are drawn to the electrode that has a deficit of electrons; the movement of anions and cations in opposite directions within the solution amounts to a current. This includes most soluble salts and bases; some gases, such as hydrogen chloride, under conditions of high temperature or low pressure can function as electrolytes. Electrolyte solutions can result from the dissolution of some biological and synthetic polymers, termed "polyelectrolytes", which contain charged functional groups. A substance that dissociates into ions in solution acquires the capacity to conduct electricity.
Sodium, chloride, calcium and phosphate are examples of electrolytes. In medicine, electrolyte replacement is needed when a person has prolonged vomiting or diarrhea, as a response to strenuous athletic activity. Commercial electrolyte solutions are available for sick children and athletes. Electrolyte monitoring is important in the treatment of bulimia; the word electrolyte derives from the Greek lytós, meaning "able to be untied or loosened". Svante Arrhenius put forth, in his 1884 dissertation, his explanation of the fact that solid crystalline salts disassociate into paired charged particles when dissolved, for which he won the 1903 Nobel Prize in Chemistry. Arrhenius's explanation was that in forming a solution, the salt dissociates into charged particles, to which Michael Faraday had given the name "ions" many years earlier. Faraday's belief had been. Arrhenius proposed that in the absence of an electric current, solutions of salts contained ions, he thus proposed. Electrolyte solutions are formed when a salt is placed into a solvent such as water and the individual components dissociate due to the thermodynamic interactions between solvent and solute molecules, in a process called "solvation".
For example, when table salt, NaCl, is placed in water, the salt dissolves into its component ions, according to the dissociation reaction NaCl → Na+ + Cl−It is possible for substances to react with water, producing ions. For example, carbon dioxide gas dissolves in water to produce a solution that contains hydronium and hydrogen carbonate ions. Molten salts can be electrolytes as, for example, when sodium chloride is molten, the liquid conducts electricity. In particular, ionic liquids, which are molten salts with melting points below 100 °C, are a type of conductive non-aqueous electrolytes and thus have found more and more applications in fuel cells and batteries. An electrolyte in a solution may be described as "concentrated" if it has a high concentration of ions, or "diluted" if it has a low concentration. If a high proportion of the solute dissociates to form free ions, the electrolyte is strong; the properties of electrolytes may be exploited using electrolysis to extract constituent elements and compounds contained within the solution.
Alkaline earth metals form hydroxides that are strong electrolytes with limited solubility in water, due to the strong attraction between their constituent ions. This limits their application to situations. In physiology, the primary ions of electrolytes are sodium, calcium, chloride, hydrogen phosphate, hydrogen carbonate; the electric charge symbols of plus and minus indicate that the substance is ionic in nature and has an imbalanced distribution of electrons, the result of chemical dissociation. Sodium is the main electrolyte found in extracellular fluid and potassium is the main intracellular electrolyte. All known higher lifeforms require a subtle and complex electrolyte balance between the intracellular and extracellular environments. In particular, the maintenance of precise osmotic gradients of electrolytes is important; such gradients affect and regulate the hydration of the body as well as blood pH, are critical for nerve and muscle function. Various mechanisms exist in living species that keep the concentrations of different electrolytes under tight control.
Both muscle tissue and neurons are considered electric tissues of the body. Muscles and neurons are activated by electrolyte activity between the extracellular fluid or interstitial fluid, intracellular fluid. Electrolytes may enter or leave the cell membrane through specialized protein structures embedded in the plasma membrane called "ion channels". For example, muscle contraction is dependent upon the presence of calcium and potassium. Without sufficient levels of these key electrolytes, muscle weakness or severe muscle contractions may occur. Electrolyte balance is maintained by oral, or in emergencies, intravenous intake of electrolyte-containing substances, is regulated by hormones, in general with the kidneys flushing out excess levels. In humans, electrolyte homeostasis is regulated by hormones such as antidiuretic hormones and parathyroid hormones. Serious electrol
Cola is a sweetened, carbonated soft drink flavored with vanilla, citrus oils and other flavorings. Most contain caffeine, sourced from the kola nut, leading to the drink's name, though other sources are now used. Cola became popular worldwide after pharmacist John Pemberton invented Coca-Cola in 1886, his non-alcoholic recipe was inspired by the coca wine of pharmacist Angelo Mariani, created in 1863. Most modern colas contain caramel color, are sweetened with sugar and/or high-fructose corn syrup, they now come in numerous different brands. Among them, the most popular are Pepsi; these two companies have been competing since the 1890s, but their rivalry has intensified since the 1980s. The primary modern flavoring ingredients in a cola drink are citrus oils, vanilla, an acidic flavorant. Manufacturers of cola drinks add trace flavorings to create distinctively different tastes for each brand. Trace flavorings may include a wide variety of ingredients, such as spices like nutmeg or coriander, but the base flavorings that most people identify with a cola taste remain citrus and cinnamon.
Acidity is provided by phosphoric acid, sometimes accompanied by citric or other isolated acids. Coca-Cola's recipe is maintained as a corporate trade secret. A variety of different sweeteners may be added to cola partly dependent on local agricultural policy. High-fructose corn syrup is predominantly used in the United States and Canada due to the lower cost of government-subsidized corn. In Europe, however, HFCS is subject to production quotas designed to encourage the production of sugar. In addition, stevia or an artificial sweetener may be used. In the 1940s, Coca-Cola produced White Coke at the request of Marshal of the Soviet Union Georgy Zhukov. Clear colas were again produced during the Clear Craze of the early 1990s. Brands included Crystal Pepsi, Tab Clear, 7 Up Ice Cola. Crystal Pepsi has been reintroduced in the 2010s. In Denmark, a popular clear cola was made by the Cooperative FDB in 1976, it was known for being the "Hippie Cola" because of the focus of the harmful effects the color additive could have on children and the boycott of multinational brands.
It was inspired by a campaign on harmful additives in Denmark by the Environmental-Organisation NOAH, an independent Danish division of Friends of the Earth. This was followed up with a variety of sodas without artificial coloring. Today many organic colas are available in Denmark, for nostalgic reasons, clear cola has still maintained its popularity to a certain degree. In June 2018, Coca-Cola introduced Coca-Cola Clear in Japan. A 2007 study found that consumption of colas, both those with natural sweetening and those with artificial sweetening, was associated with increased risk of chronic kidney disease; the phosphoric acid used in colas was thought to be a possible cause. Studies indicate "soda and sweetened drinks are the main source of calories in American diet", so most nutritionists advise that Coca-Cola and other soft drinks can be harmful if consumed excessively to young children whose soft drink consumption competes with, rather than complements, a balanced diet. Studies have shown that regular soft drink users have a lower intake of calcium, vitamin C, vitamin A.
The drink has aroused criticism for its use of caffeine, which can cause physical dependence. A link has been shown between osteoporosis in older women; this was thought to be due to the presence of phosphoric acid, the risk was found to be the same for caffeinated and noncaffeinated colas, as well as the same for diet and sugared colas. Many soft drinks are sweetened or with high-fructose corn syrup, rather than sugar; some nutritionists caution against consumption of corn syrup because it may aggravate obesity and type-2 diabetes more than cane sugar. Amrat Cola, popular in Pakistan Big Cola, popular in Indonesia Bovonto, popular in South India Campa Cola, India's most popular brand prior to the introduction of Coca-Cola and Pepsi to the Indian market in 1991 Clemon by Akij Group, popular in Bangladesh Cola Turka is a local brand in Turkey Est Cola, a local brand in Thailand Future Cola, a local brand in China Laoshan Cola, a local brand in China Mecca Cola, sold in the Middle East, North Africa, as well as parts of Europe Pakola, popular in Pakistan Parsi Cola, popular in Iran Red Bull Cola, popular in Thailand Thums Up, popular in India Topsia Cola, popular in Iran Zamzam Cola, popular in Iran and parts of the Arab world Afri-Cola, a German brand, was relaunched in April 2006 with the original formulation with the higher caffeine content.
Barr Cola made by A. G. Barr in the United Kingdom Breizh Cola is a local brand from Brittany. Brisa Cola is a local brand from Madeira and produced by Empresa de Cervejas da Madeira. Cadet-Cola, an Irish brand Cockta is a local brand from former Yugoslavia, which does not contain any caffeine or phosphoric acid. Corsica Cola is a regional cola distributed by the Corsican brewery Pietra. Cuba Cola is a brand from Sweden. Evoca Cola is a cola made with mineral water made by Evoca Drinks. Fentimans Curiosity Cola, is an upmarket botanically brewed cola produced by Fentimans, from the UK. Fritz-Kola, a cola soft drink from Hamburg, uses the highest possible concentration of caffeine for beverages allowed by German law. Jolly Cola, which had a 40% share of the cola drink market in Denmark from the mid-1960s to the late 1980s. Karma Cola, fair trade c