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In medicine, the urea-to-creatinine ratio (UCR [1]), known in the United States as BUN-to-creatinine ratio, is the ratio of the blood levels of urea (mmol/L) and creatinine (Cr) (μmol/L). BUN only reflects the nitrogen content of urea (MW 28) and urea measurement reflects the whole of the molecule (MW 60), urea is just over twice BUN (60/28 ...
Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols , normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.
This glossary of chemistry terms is a list of terms and definitions relevant to chemistry, including chemical laws, diagrams and formulae, laboratory tools, glassware, and equipment. Chemistry is a physical science concerned with the composition, structure, and properties of matter , as well as the changes it undergoes during chemical reactions ...
Alchemical symbols were used to denote chemical elements and compounds, as well as alchemical apparatus and processes, until the 18th century. Although notation was ...
The Green Book is a direct successor of the Manual of Symbols and Terminology for Physicochemical Quantities and Units, originally prepared for publication on behalf of IUPAC's Physical Chemistry Division by M. L. McGlashen in 1969. A full history of the Green Book's various editions is provided in the historical introduction to the third edition.
Mineral symbols (text abbreviations) are used to abbreviate mineral groups, subgroups, and species, just as lettered symbols are used for the chemical elements. The first set of commonly used mineral symbols was published in 1983 and covered the common rock-forming minerals using 192 two- or three-lettered symbols. [ 1 ]
The list given in ISO 31-8:1992 was quoted from the 1998 IUPAC "Green Book" Quantities, Units and Symbols in Physical Chemistry and adds in some cases in parentheses the Latin name for information, where the standard symbol has no relation to the English name of the element. Since the 1992 edition of the standard was published, some elements ...
Chemistry. In chemical terms, creatinine is a lactam and an imidazolidinone, a spontaneously formed cyclic derivative of creatine. [26]