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51.
Trifluoroacetonitrile was condensed with diethyl malonate to give a novel ethyl 2,6-bis(trifluoromethyl)-4-hydroxypyrimidine-5-carboxylate ( 2 ) in 88% yield. Derivations of 2 are also described. 相似文献
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53.
Araujo K Colina M Mazurek R Delgado J Ledo H Gutierrez E Herrera L 《Analytical and bioanalytical chemistry》1996,355(3-4):319-320
The mercury concentrations in wastewater and sewage sludge of a stabilization pond system have been evaluated. The system is built by three parallel facultative ponds followed by two systems of three maturation ponds in series. The samples of wastewater and sludge were digested using nitric acid and placed into a Parr-type bomb for 4 h at 110 degrees C. Mercury was measured by Cold Vapour Atomic Absorption Spectrometry (CV-AAS) at 253.7 nm with sodium tetrahydroborate as reductant. The methodologies were checked with an USEPA quality control sample, a standard reference material from NIST and with another method of mineralization (cold mineralization) showing good results. Concentrations of mercury in wastewater between 1.47 +/- 0.75 microgl(-1) have been found at the entrance of the system and 0.74 +/- 0.0 microgl(-1) at the exit, while in sludge the results were between 0.29 +/- 0.12 microgkg(-1) in the facultative pond and 0.04 +/- 0.02 microgkg(-1) in the second maturation pond (exit). 相似文献
54.
Wex B Kaafarani BR Oliver AG Krause Bauer JA Neckers DC 《The Journal of organic chemistry》2003,68(21):8258-8260
The photochemical [2pi +2pi] cycloaddition of dimethyl acetylenedicarboxylate to benzo[1,2-b:4,5-b']dithiophene has been used to synthesize substituted cyclobuta[b]thieno[2,3-f][1]benzothiophene. The first [2pi + 2pi] photocycloaddition reaction of a series of butadiynes to benzodithiophene is reported to yield regioselective and acetylene-substituted cyclobutene derivatives containing an aromatic thiophene moiety. 相似文献
55.
Katrin de Graaf Hanna Czajkowska Sabine Rottmann Len C Packman Richard Lilischkis Bernhard Lüscher Walter Becker 《BMC biochemistry》2006,7(1):7
Background
The U2 small nuclear ribonucleoprotein particle (snRNP) component SF3b1/SAP155 is the only spliceosomal protein known to be phosphorylated concomitant with splicing catalysis. DYRK1A is a nuclear protein kinase that has been localized to the splicing factor compartment. Here we describe the identification of DYRK1A as a protein kinase that phosphorylates SF3b1in vitro and in cultivated cells. 相似文献56.
[reaction: see text] Irradiation of isoquinolinium hydroxytris(pentafluorophenyl)borate, 1, and phenanthridium hydroxytris(pentafluorophenyl)borate, 2, in either CH2Cl2 or CH3CN resulted in C6F5 transfer to the isoquinolinium and phenanthridium cations, generating 2-methyl-1-(2,3,4,5,6-pentafluorophenyl)-1,2-dihydroisoquinoline, 3, and 2-methyl-1-(2,3,4,5,6-pentafluorophenyl)-1,2-dihydrophenanthridine, 4, respectively. In addition, photogeneration of H2O x B(C6F5)3 resulted from 1. Photogeneration of C6F5-C6F4H from HO-B(C6F5)3(-) and of C6H5-C6F4H from C6H5-B(C6F5)3(-) was discovered. 相似文献
57.
Len Roza Kees J. M. van der Wulp Sandra J. MacFarlane Paul H. M.Lohman Robert A. Baan 《Photochemistry and photobiology》1988,48(5):627-633
Abstract— A hybrid cell line (hybridoma) has been isolated after fusion between mouse-plasmacytoma cells and spleen cells from mice immunized with a thymine dimer-containing tetranucleotide coupled to a carrier protein. Monoclonal antibodies produced by this hybridoma were characterized by testing the effect of various inhibitors in a competitive enzyme-linked immunosorbent assay (ELISA). The antibodies have a high specificity for thymine dimers in single-stranded DNA or poly(dT), but do not bind UV-irradiated d(TpC)5 . Less binding is observed with short thymine dimer-containing sequences. In vitro treatment of UV-irradiated DNA with photoreactivating enzyme in the presence of light, or with Micrococcus luteus UV-endonuclease results in disappearance of antigenicity. Antibody-binding to DNA isolated from UV-irradiated human fibroblasts (at 254 nm) is linear with dose. Removal of thymine dimers in these cells during a post-irradiation incubation, as detected with the antibodies, is fast initially but the rate rapidly decreases (about 50% residual dimers at 20 h after 10 J/m2 ). The induction of thymine dimers in human skin irradiated with low doses of UV-B, too, was demonstrated immunochemically, by ELISA as well as by quantitative immunofluorescence microscopy. 相似文献
58.
D. C. Neckers 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(3-4):431-448
This paper reviews the author's work in polymeric metal catalysts and reagents. The discussion focuses on polymeric bipyridines and on polymer-protected A1C13. 相似文献
59.
60.
Katrin de Graaf Hanna Czajkowska Sabine Rottmann Len C Packman Richard Lilischkis Bernhard Lüscher Walter Becker 《BMC biochemistry》2006,7(1):1-13