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Amorphous Calcium Carbonate
Amorphous calcium carbonate (ACC) is the amorphous and least stable polymorph of calcium carbonate. ACC is extremely unstable under normal conditions and is found naturally in taxa as wide-ranging as sea urchins, corals, mollusks, and foraminifera. It is usually found as a monohydrate, holding the chemical formula CaCO3·H2O; however, it can also exist in a dehydrated state, CaCO3. ACC has been known to science for over 100 years when a non-diffraction pattern of calcium carbonate was discovered by Sturcke Herman, exhibiting its poorly-ordered nature. ACC is an example of crystallization by particle attachment (CPA), where crystals form via the addition of particles ranging from multi-ion complexes to fully formed nanocrystals. Research of such systems have diverse application; however, the current lack of unambiguous answers to fundamental questions (i.e. solubility product, interfacial forces, structure, etc.) causes them to be topics of study in fields ranging from chemistry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residues ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biogeochemical Cycle
A biogeochemical cycle (or more generally a cycle of matter) is the pathway by which a chemical substance cycles (is turned over or moves through) the biotic and the abiotic compartments of Earth. The biotic compartment is the biosphere and the abiotic compartments are the atmosphere, hydrosphere and lithosphere. There are biogeochemical cycles for chemical elements, such as for calcium, carbon, hydrogen, mercury, nitrogen, oxygen, phosphorus, selenium, iron and sulfur, as well as molecular cycles, such as for water and silica. There are also macroscopic cycles, such as the rock cycle, and human-induced cycles for synthetic compounds such as polychlorinated biphenyls (PCBs). In some cycles there are reservoirs where a substance can remain or be sequestered for a long period of time. Overview Energy flows directionally through ecosystems, entering as sunlight (or inorganic molecules for chemoautotrophs) and leaving as heat during the many transfers between trophic levels. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Delivery
Drug delivery refers to approaches, formulations, manufacturing techniques, storage systems, and technologies involved in transporting a pharmaceutical compound to its target site to achieve a desired therapeutic effect. Principles related to drug preparation, route of administration, site-specific targeting, metabolism, and toxicity are used to optimize efficacy and safety, and to improve patient convenience and compliance. Drug delivery is aimed at altering a drug's pharmacokinetics and specificity by formulating it with different excipients, drug carriers, and medical devices. There is additional emphasis on increasing the bioavailability and duration of action of a drug to improve therapeutic outcomes. Some research has also been focused on improving safety for the person administering the medication. For example, several types of microneedle patches have been developed for administering vaccines and other medications to reduce the risk of needlestick injury. Drug deliv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Bone And Mineral Research
The American Society for Bone and Mineral Research (ASBMR) is a professional, scientific and medical society established in 1977 to promote excellence in bone and mineral research and to facilitate the translation of that research into clinical practice. The ASBMR has a membership of nearly 4,000 physicians, basic research scientists, and clinical investigators from around the world. Mission The mission of the ASBMR is to promote excellence in bone and mineral research, foster integration of clinical and basic science, and facilitate the translation of that science to health care and clinical practice. The Society's broad goals include supporting the educational development of future generations of basic and clinical scientists, and disseminating new knowledge in bone and mineral metabolism. Founding In the 1970s, a growing number of US-based scientists began to focus their research on the understanding of basic bone biology and the disease osteoporosis. This led to the rise of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. However, when a medication is administered via routes other than intravenous, its bioavailability is generally lower than that of intravenous due to intestinal endothelium absorption and first-pass metabolism. Thereby, mathematically, bioavailability equals the ratio of comparing the area under the plasma drug concentration curve versus time (AUC) for the extravascular formulation to the AUC for the intravascular formulation. AUC is used because AUC is proportional to the dose that has entered the systemic circulation. Bioavailability of a drug is an average value; to take population variability into account, deviation range is shown as ±. To ensure that the drug taker who has poor absorption is dosed appropriately, the bottom value o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin ''calx'' "lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and pharma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ynet
Ynet (stylized as ynet) is one of the major Israeli news and general-content websites, and is the online outlet for the '' Yedioth Ahronot'' newspaper. However, most of Ynet's content is original work, published exclusively on the website and written by an independent staff. History Ynet was launched in June 2000 in Hebrew only; and in 2004 launched its online English edition Ynetnews. In addition, Ynet hosts the online version of Yedioth Aharanot's media group magazines: Laisha (which also operates Ynet's fashion section), Pnai Plus, Blazer, GO magazine, and Mentha. For two years, Ynet had also an Arabic version, which ceased to operate in May 2005. Ynet's main competition comes from Walla! Mako and Nana. Since 2008, Ynet is Israel's most popular internet portal, as measured by Google Trends. In celebration of Israel's independence day in 2005, Ynet conducted a poll to determine whom Ynet readers consider to be the greatest Israelis of all time. The top 200 results were publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dietary Supplement
A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in order to increase the quantity of their consumption. The class of nutrient compounds includes vitamins, minerals, fiber, fatty acids, and amino acids. Dietary supplements can also contain substances that have not been confirmed as being essential to life, but are marketed as having a beneficial biological effect, such as plant pigments or polyphenols. Animals can also be a source of supplement ingredients, such as collagen from chickens or fish for example. These are also sold individually and in combination, and may be combined with nutrient ingredients. The European Commission has also established harmonized rules to help insure that food supplements are safe and appropriately labeled. Creating an industry estimated to have a 2020 value of $ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Structural Biology
The ''Journal of Structural Biology'' is a peer-reviewed scientific journal concerning the structural analysis of biological materials at all levels of organization and the functional consequences of such observations. The editors-in-chief are A.C. Steven ( Silver Spring, MD, United States) and Wolfgang Baumeister ( Max-Planck-Institute of Biochemistry). According to the ''Journal Citation Reports'', the journal has a 2014 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 3.231, ranking it 109th out of 289 journals in the category "Biochemistry & Molecular Biology", 23rd out of 73 journals in the category "Biophysics", and 98th out of 184 journals in the category "Cell Biology". References External links * {{Official website, http://www.journals.elsevier.c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Crystal Growth
The ''Journal of Crystal Growth'' is a semi-monthly peer-reviewed scientific journal covering experimental and theoretical studies of crystal growth and its applications. It is published by Elsevier and the editor-in-chief is J. Derby (University of Minnesota). History The ''Journal of Crystal Growth'' was founded following the 1966 International Conference on Crystal Growth (ICCG) held in Boston, Massachusetts, United States. Ichiro Sunagawa, who participated in ICCG, wrote in the ''Journal of the Japanese Association of Crystal Growth'' that before then, "The crystal growth community was totally fragmented and had remained as a peripheral field at the mercy of other organizations." Michael Schieber (Hebrew University) later recounted feeling the need for an individual journal on the subject after the conference proceedings were published as a supplement to the ''Journal of Physics and Chemistry of Solids'' that had to be additionally ordered by journal subscribers. Feeling as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
