We developed a new approach for chemical ligation of oligonucleotides using the electrophilic phosphorothioester (EPT) group. A nucleophilic phosphorothioate group on oligonucleotides was converted into the EPT group by treatment with Sanger's reagent (1-fluoro-2,4-dinitrobenzene). EPT oligonucleotides can be isolated, stored frozen, and used for the ligation reaction. The reaction of the EPT o...

THE POOR QUALITY of reagent chemicals in the United States by 1916 led to the statement by Hillebrand (1) that “the situation is particularly deplorable just now.” In 1919, to overcome the handicap of poor reagent chemicals, representatives of iiidustry, together with representatives of reagent users, undertook jointly under the sponsorship of the American Chemical Society, the task of establis...

background fenton (fe2+ and h2o2) and modified fenton (fe3+ and h2o2) are two popular methods used in advanced oxidation processes (aop) and degradation of persistent organic pollutants (pops), such as dye compounds. in these processes, fe2+ and fe3+ as catalysts and h2o2 as the oxidizing agent are added to the reactor. objectives the aim of the current study is to assess the abovementioned met...

CENTA is a newly synthesized, beta-lactamase-labile, chromogenic cephalosporin reagent which changes color from light yellow (K maximum ca. 340 nm) to chrome yellow (A maximum ca. 405 nm) concomitant with hydrolysis of the betalactam ring. This compound offers promise as a diagnostic reagent comparable to other chromogens (PADAC and nitrocefin) for the early detection of betalactamase-producing...

tripropylammonium fluorochromate(vi) (tpafc), is an efficient and new reagent, which isprepared easily and oxidizes thiols to the corresponding disulfides, quickly. the reactions areperformed cleanly and are controlled to stop at the disulfide stage, without over-oxidation andside products. coupling of thiols to their corresponding disulfides, are studied in solution atroom temperature and in s...

To contribute to the development of a reference reagent for monitoring heparin therapy, a lyophilized partial thromboplastin time (PTT) reagent was prepared from synthetic dioleoylphosphatidylcholine, dioleoylphosphatidylserine, and dioleoylphosphatidylethanolamine, with colloidal silica as activator. The reagent, coded 91/558, was contained in sealed glass ampoules; it deteriorated in a heat d...

Rubinstein J (1995) Cohtmn Flotation: Processes, Designs and Practices. New York: Gordon and Breach. Schubert Hand Bischofberger C (1979) On the optimization of hydrodynamics in flotation processes. In: Laskowski J (ed.) Proceedings of the 13th International Mineral Process Congress, pp. 1261-1287. Warsaw: Elsevier. Wills BA (1992) Introduction to Mineral Processing Technology, 5th edn, pp. 558...

Inspired by the discovery of dimeric motor proteins capable of undergoing transportation in living cells, significant efforts have been expended recently to the fabrication of track-walking nanomotors possessing two foot-like components that each can bind or detach from an array of anchorage groups on the track in response to local events of reagent consumption. The central problem in fabricati...

R ECENTLY a new reagent was proposed for the determination of cholesterol (1, 2). This reagent was purported to be saturated ferrous sulfate in glacial acetic acid. Since it has been reported that ferrous sulfate is qualitatively insoluble in anhydrous acetic acid (3, 4) and that ferrous iron is “subject to pronounced air oxidation in glacial acetic acid” (5), it was felt that several factors s...

Transition-metal-substituted  (TMS)  polyoxometalates  of  the  general  formula  [SiW9M3O39], (where M = first row transition metal), has been synthesized and supported on anatase by sol–gel method under oil-bath condition. The tetrabutylammonium (TBA) salts of the Keggin-type polyoxotungstates  [SiW9M3O39],  (M = VII, CrII, MnII,  FeII CoII  and NiII),  proved  to  be  green, reusable,  and  ...