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991.
A. A. KYAGOVA L. G. KORKINA T. V. SNIGIREVA E. P. LYSENKO S. K. TOMASHAEVA A. YA. POTAPENKO 《Photochemistry and photobiology》1991,53(5):633-637
Psoralen-sensitized photodamage (PUVA) of rat peritoneal exudate cells was investigated. Quartz-activated luminol-dependent chemiluminescence (ChL) was registered and the amount of trypan-positive cells was determined. Irradiation of peritoneal exudate cells in the presence of psoralen resulted in a dose-dependent monotonous inhibition of ChL. The reciprocity law of irradiation intensity and duration of irradiation was not valid for the observed inhibition of ChL: the inhibition increased with higher intensity. When psoralen previously photooxidized in ethanol (POP) was added to peritoneal exudate cell suspension, a double-phase response depending on psoralen irradiation dose was obtained: ChL activation was observed at low doses of UVA, ChL inhibition at high doses. Chemiluminescence inhibition correlated well with the increase in the number of trypan-positive cells. It may be supposed that the observed effects of PUVA or POP treatment are caused by cell cytoplasmic membrane damage. 相似文献
992.
Ibrahim A. Salem 《国际化学动力学杂志》1995,27(5):499-505
The kinetics of the H2O2 decomposition in presence of Fe(III)- and Cr(III)-complexes of mono-, di-, and triethanolamine supported on Dowex-50W resin have been investigated. The decomposition process proceeded with first-order kinetics for the substrate concentration. The rate of reaction increased with increasing number of the coordinated ligands in the metal complex as well as with increasing ligand basicity. The decomposition reaction involved the formation of an intermediate active species, which converts into a peroxo-metal complex of brown, green, or gray color. A mechanism describing the decomposition process is proposed. © 1995 John Wiley & Sons, Inc. 相似文献
993.
Given a fixed line L (in Rn) and a uniform distribution of points (c) on the unit sphere, L(tc), the point of intersection of L and the hyperplane P · c = 0, leads to a mapping Xn : Rn → R, which is shown to have a Cauchy distribution. 相似文献
994.
Ibrahim Haddad Shaun Hurley C. S. Marvel 《Journal of polymer science. Part A, Polymer chemistry》1973,11(11):2793-2811
Poly(phenylene sulfides) were synthesized from m-benzenedithiol and aromatic dibromides in a basic medium of potassium carbonate in dimethylformamide or dimethylacetamide. The products obtained were slightly off-white with relatively low melting ranges and had inherent viscosities in the 0.2–0.4 dl/g range in hexamethylphosphoric triamide. Similar poly(phenylene sulfides) containing pendant cyano groups along the polymer chains were obtained by the use of 5 mole-% of either 2,4-dichlorobenzonitrile or 3,5-dichlorobenzonitrile. The products were similar to the pure polyphenylene sulfides, except that they showed lower melting ranges and gave insoluble products when heated alone or in the presence of zinc chloride. 相似文献
995.
Summary In the1H-n.m.r. spectra of (acetylacetonato)chloro-(2-cyanoetheiie)platinum(II), the three protons of the ligand appear to be equivalent.13C-n.m.r., i.r. and further1H-n.m.r. studies indicate that the metal-ligand bonding is of orthodox -olefin type (as formulated in the name of the compound above). The two 2-hydrogens are made equivalent by fluxion, but there is an accidental degeneracy with 1-hydrogen atom. 相似文献
996.
997.
F. Ibrahim P. Kilcher B. Roussière J. Sauvage J. Genevey A. Gizon A. Knipper G. Marguier D. Barnéoud R. Béraud G. Cata-Danil J. Blachot I. Deloncle R. Duffait A. Emsallem D. Hojman A. J. Kreiner F. Le Blanc J. Libert J. Oms 《Zeitschrift für Physik A Hadrons and Nuclei》1994,350(1):9-10
Low-spin states in doubly-odd184Au have been populated in the +/EC decay of184Hg produced by bombarding184Sm targets with an 185 MeV40Ar beam. Radioactive Hg nuclei were transported by a He jet system. A new level scheme has been established from --t and X--t coincidence measurements. Spin and parity values I=5+, I =2+ and I=3– were assigned to the ground state and the two isomeric states of184Au, respectively. The structure of these states is discussed using B(E1) values. 相似文献
998.
The kinetic stopped flow method has been used to study the reaction rates of Ni(II) and Pd(II) with methioninehydroxamate (MX). Two reaction rates were observed in the MX? Ni(II) system whereas three rates were observed in the MX? Pd(II) system. Most of the rate steps were dependent on pH as well as on TMX (total concentration of methioninehydroxamate). The observed pseudo-first-order rate constants at constant pH are expressed empirically as k = mi + m′i TMX. The parameters mi and m′i are pH-dependent. It has been concluded that hydroxy metal species contributed to the explanation of the rate of the metal complexation with MX. Similar systems have been correlated with the systems of current work. © 1995 John Wiley & Sons, Inc. 相似文献
999.
Amin Ibrahim Philip B. Oldham Terrance E. Conners Tor P. Schultz 《Microchemical Journal》1997,56(3):393-402
FT-Raman spectroscopy is used for the rapid measurement of wood pulp lignin. A total of 23 western softwood pulp samples with known kappa numbers (10–38) are used. Each sample is divided into three portions and scanned separately. The integrated area of the lignin band at approximately 1600 cm−1is ratioed against the integrated area of the cellulose bands in the 1200–1010 cm−1region and correlated to known kappa numbers. The measured ratios behave linearly with the kappa number (r= 0.99) and can be reproducibly determined with an error of approximately 2% or less. The data are presented and discussed in view of the potential for at-line analysis of lignin associated with chemical delignification of wood pulp. 相似文献
1000.
Anwar Usman Ibrahim Abdul Razak Suchada Chantrapromma Hoong‐Kun Fun A. Sreekanth S. Sivakumar M. R. Prathapachandra Kurup 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):m461-m463
One half of the molecule of the title complex, [Mn(C14H13N4S)2], is related to the other half by a twofold axis passing through the Mn atom. This high‐spin Mn atom is six‐coordinated, in an octahedral geometry, by the azomethine N, the pyridyl N and the thiolate S atom of two planar 1‐(pyridin‐2‐yl)ethanone N(4)‐phenylthiosemicarbazone ligands. In the crystal, the molecules are interconnected by N—H?S and C—H?N interactions, forming a three‐dimensional network. 相似文献