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921.
Vimal K. Jain 《Transition Metal Chemistry》1996,21(6):494-497
Summary Binuclear PdII and PtII complexes of the type [M2Cl2(-Opy)2(PR3)2] [M = Pd or Pt; Opy = 2-OC5H4N (2-hydroxypyridinate ion); PR3 = PEt3, Pn-Bu3, PMe2Ph or PMePh2] were synthesized and characterized by elemental analysis, 1H- and 31P-n.m.r. spectroscopies. The Pd complexes exist in the sym trans form, whereas the corresponding Pt complexes were generated as different isomers. 相似文献
922.
923.
The incorporation of (±)-nor-laudanosoline, (±)-N-nor-protosinomenine, (±)-N-nor-orientaline, (±)-N-nor-reticuline, and N-[2-(3-hydroxy-4-methoxyphenyl) ethyl]-2-(4'-hydroxyphenyl) ethylamine into laurifinine has been studied and the specific utilisation of the (±)-N-norprotosinomenine demonstrated. Double labelling experiments with (±)-[1-3H, 4'-methoxy-14C]-, and (±)-[1-3H, 7-methoxy-14C]-N-norprotosinomenines showed that 4' and 7, OMe groups and the H atom at the asymmetric centre of the precursor are retained in the bioconversion into laurifinine. Parallel experiments with (+)- and (-)-N-norprotosinomenine demonstrated specific utilisation of (+)-isomer into laurifinine. 相似文献
924.
Vanillin forms insoluble complexes with thorium and cerium(IV) at pH 4.0–6.2 and 2.5–7.0 respectively. Thorium and cerium can be determined gravimetrically and separated from each other as well as from uranium(VI) and typical trivalent rare earths. The precipitates obtained are ignited to the corresponding oxide and weighed; as little as 4.4 mg of ThO2 and 4.9 mg of CeO2 can be determined. 相似文献
925.
Effects of Photofrin II on energy metabolism and metabolic viability were studied in a mammalian transformed cell line (BHK-21) in dark and after photo-irradiation with visible light. Cells were allowed to accumulate Photofrin by incubating for 4 h in buffer containing Photofrin (5-60 micrograms/ml). The results show that Photofrin significantly affects the cellular energy metabolism even in the absence of light; activity of cytochrome c oxidase is decreased and glucose utilization and lactate production (glycolysis) are increased. Irradiation with light resulted in a significant decrease in the activity of cytochrome c oxidase, glycolysis, ATP content, energy charge, ratios of adenine nucleotides like ATP/ADP, ATP/AMP and cell viability (dye exclusion test). Presence of inhibitors of energy metabolism, potassium cyanide (respiration) and 2-deoxyglucose (glycolysis), further enhanced the cytotoxic effects induced by hematoporphyrin derivative and light. 相似文献
926.
A. Sameena Begum V. K. Jain C. L. Khetrapal N. C. Shivaprakash 《Journal of chemical crystallography》1987,17(4):545-555
The structure of oxalohydroxamic acid has been investigated by X-ray and spectroscopic analyses. It has been shown that oxalohydroxamic acid exists in the oxamic form in the solid as well as in solution. The variable-temperature nuclear magnetic resonance (NMR) studies reveal an exchange of OH and NH protons, the exchange being faster at higher temperatures. The kinetic and the thermodynamic parameters such as the rate constant (K), the free energy of activation (G
DG), and the energy of activation (E
a) for the exchange process have been obtained. The compound crystallizes in the monoclinic space groupP21/c witha=5.208,b=3.864,c=11.482 Å,=111.45°, andZ=2. The structure was solved withMultan 80. The refinement by block diagonal least squares and Fourier methods providedR=0.035. There is strong hydrogen bonding between the molecules which form dimer. 相似文献
927.
Single step methods for general second order singular initial value problems with spherical symmetry
R. K. Jain 《BIT Numerical Mathematics》1988,28(4):817-824
A one parameter family of self-starting explicit Runge-Kutta-Nyström methods has been obtained for the solution of the general second order singular initial value problem with spherical symmetry of the formu+2r
–1
u=f(r, u, u),u(0)=A, u(0)=0. The methods are exact foru(r)=r
–1, l,r, r
2,r
3 andr
4. 相似文献
928.
929.
930.