(n.) The act or process of making ether; specifically, the process by which a large quantity of alcohol is transformed into ether by the agency of a small amount of sulphuric, or ethyl sulphuric, acid.
Example Sentences:
(1) Thus, as it proceeds, this etherification leads to products having higher reactivity towards the epoxide.
(2) The feature distinguishing the effect produced by the ration with saccharose, as compared with that containing starch, was an accelerated etherification of cholesterol in the blood.
(3) This suggests that de-etherification could occur, leading to estradiol.
(4) The etherification of the alcohol functions of oestradiol allows an adequate protection of the hormone against hepatic catabolism.
(5) The study described the technique for gas chromatographic identification of sebacic acid in the work zone air in the form of diethyl ether produced due to sebacic acid etherification by absolute ethyl alcohol in the presence of 0.3 ml of concentrated sulphuric acid during heating up to 70 degrees C for 15 min.
(6) Evaluation of these derivatives against murine P-388 lymphocytic leukemia indicated that, while the hydroxyphenyl styryl ketones and related esters were devoid of significant anticancer activities, etherification of the nuclear hydroxyl group gave compounds with a discernible increase in mean survival time.
(7) The results of quantitative acetic acid determination in the cadaveric organs by LGC method after etherification are influenced upon by its "background" values.
(8) Considerable differences in the reactivities toward acylation and etherification of the two axial hydroxyl groups in 4 permitted the preparation, in good yields, of the 4-acetate (9) and of the 4-methyl ether (12).
(9) Etherification of the phenolic group of 7 by N-(2-chloroethyl)pyrrolidine and subsequent methanesulfonate salt formation provided [3,4-dihydro-2-(4-methoxyphenyl)-1-maphthalenyl]]4-]2-(1-pyrrolidinyl)ethoxy]phenyl]methanone, methane sulfonic acid salt (3).
(10) Arteether (6) has been prepared from dihydroquinghaosu (3) by etherification with ethanol in the presence of Lewis acid and separated from its chromatographically slower moving alpha-dihydroqinghaosu ethyl ether (7).
(11) The vindoline radical thus formed eliminates a second electron and a proton to produce a highly reactive iminium derivative which undergoes intramolecular etherification and dimerization.
(12) On the basis of the estimate of the raw material use for regeneration of butyl acetate from the butanol-butyl acetate solutions by etherification of butanol with acetic anhydride, the technical and economic advantages of the processing of such solutions by the described method were shown.
(13) Substitution of the glycosidic moiety of 1 or 2 by ester and ethers, as well as the esterification and etherification of alpha-peltatin (4) including its glucosidic ethylidene and thenylidene cyclic acetals (25 and 26), has afforded compounds of much less activity than that of 1.
(14) Blockage of the C-9 carbinolamide via etherification markedly reduces antileukemic and cytotoxic activity and slightly reduces antitubulin activity but has relatively little effect on antimitotic activity against sea urchin eggs.
(15) 1-O-Hexadecyl-2-C,O-dimethyl-rac-glycero-3-phosphocholine (2-methyl-2-methoxy PAF) was prepared in a synthetic scheme beginning with the etherification of 2-methylpropen-1-ol.
(16) Modifications in the structure of isoalloxazine ring, etherification of OH-groups in the lateral D-ribityl chain, and the introduction of volume substitutors (N-piperidyl, D-ribitylamine, hydroxyethylamine) prevented the interaction of the analogue with riboflavin kinase.
(17) 5'-O-alkyl cytidines and uridines, resistant to catabolic enzymes, were as effective as the natural inducers cytidine and uridine; but etherification of one of the cis 2' or 3'hydroxyls fully abolished activity, pointing to a requirement of an intact ribose cis-glycol system for activity.
(18) The synthesis of 3-chloro-4-cyclopropylmethoxyphenylacetic acid (I) from 3-chloro-4-hydroxyacetophenone (III) by the etherification with cyclopropylmethyl bromide and by the Willgerodt reaction is described.
(19) Further reactions, such as hydrolysis, etherification and chromic oxidation, afforded many differently substituted [16,15-c]-pyrazoles of the estradiol and estrone series.
(20) Data on Liquid Gas Chromatographic method for detection of the acetic acid after etherification in the cadaveric organs are presented.
Petroleum
Definition:
(n.) Rock oil, mineral oil, or natural oil, a dark brown or greenish inflammable liquid, which, at certain points, exists in the upper strata of the earth, from whence it is pumped, or forced by pressure of the gas attending it. It consists of a complex mixture of various hydrocarbons, largely of the methane series, but may vary much in appearance, composition, and properties. It is refined by distillation, and the products include kerosene, benzine, gasoline, paraffin, etc.
Example Sentences:
(1) This paper reviews the epidemiologic studies of petroleum workers published in the English language, focusing on research pertaining to the petroleum industry, rather than the broader petrochemical industry.
(2) Case mothers were more likely to report occupational exposure to metals (odds ratio [OR] = 8.0, P = 0.01), petroleum products (OR = 3.7, P = 0.03), and paints or pigments (OR = 3.7, P = 0.05).
(3) Therefore, the presence on a refinery site of a carcinogen other than petroleum has not been ruled out, and further study is urged.
(4) Onerous new regulations could threaten the shale energy revolution, America’s role as a global energy superpower, and the dramatic reductions in CO2 emissions made possible by an abundant and affordable domestic supply of clean-burning natural gas,” Jack Gerrard, president of the American Petroleum Institute, said in a statement.
(5) In forest, removal of olfactory substances from the human skin, by vigorous washing and application of petroleum jelly, or by wearing impermeable clothing, greatly reduced the numbers of flies attracted.
(6) Likewise, greater occupational exposure to chemicals (paint, petroleum products, and unspecified chemicals) during pregnancy was found for mothers of patients (RR = 2.4, 95% CI = 1.2-4.6).
(7) Experimental controlled ecosystems have provided essential information about the fate of petroleum at sea.
(8) A proprietary insecticidal mulesing powder containing diazinon and an experimental liquid dressing based on eucalyptus oil, naphthalene, cresylic acid and chlorfenvinphos in a carrier of liquid hydrocarbons and petroleum oil were compared for their ability to promote wound healing and reduce the incidence of fly strike in freshly mulesed lambs.
(9) Extraction with petroleum ether-chloroform-phenol yielded a protein fraction free of detectable lipopolysaccharide, in which group 3 OMPs (28,500 apparent molecular weight [28.5K], 27.0K, and 25.5K) represented 81% of the total.
(10) Interestingly, however, various fractions--especially those extracted by organic solvents such as petroleum ether, hexane, and chloroform, as well as some purified compounds from these plants--could strongly inhibit the mutagenicity of aflatoxin B1 (AFB1), an indirect mutagen, when tested in the presence of S-9 mix but not that of 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2), which does not require metabolic activation for its mutagenicity.
(11) BP would need to bring equipment from Texas to contain South Australia oil spill Read more BP plans to drill the first of four exploratory wells off the South Australian coast next year and submitted an environmental plan (pdf) for approval to the National Offshore Petroleum Safety and Environmental Management Authority last week.
(12) The nature of organic substance appearing in the petroleum stratum is discussed.
(13) In this chapter the authors examine the toxicologic and epidemiologic literature for a broad range of petroleum-derived products in order to assess the carcinogenic potential of these compounds.
(14) Unlike aspiration pneumonitis, which follows petroleum distillate ingestion, chemical pneumonitis from pine oil cleaner may occur from gastrointestinal absorption of pine oil and deposition in lung tissue.
(15) Mutagenicity, polynuclear aromatic compound content, and skin carcinogenicity were compared for a series of complex oil mixtures derived from the refining and processing of petroleum.
(16) Serum samples were extracted with petroleum ether following precipitation of proteins with ethanol.
(17) BP credit rating downgraded after Tony Hayward's grilling by Congress 19 June One of BP's partners, Anadarko Petroleum, refuses to accept any responsibility for the Deepwater Horizon explosion despite owning a quarter of the well.
(18) In the past, the Saudis have encouraged Opec (Organisation of the Petroleum Exporting Countries) to reduce its output targets during periods of low oil prices.
(19) We report the case of a child who sustained partial thickness burns from a garlic-petroleum jelly plaster, which had been applied at the direction of a naturopathic physician.
(20) The extraction of carotenes with petroleum ether under the same conditions does not change the electrophoretic mobility of the chlorophyll-protein complexes.