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1.
G. Renner 《Life sciences》1983,33(14):1427-1431
Studies on the biotransformation of N-acetyl-S-(pentachlorophenyl) cysteine, a mutual polar metabolite of the lipophilic fungicides pentachloronitrobenzene and hexachlorobenzene, showed metabolic conversions in rats. The rate of its metabolism, leading in return to more lipophilic and toxic products (1) was investigated by determination of pentachlorothioanisole, its major metabolite in blood and liver of rats. The metabolic rate was found to be very small. 相似文献
2.
Wm. Renner 《BMJ (Clinical research ed.)》1911,1(2611):110-111
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Alan B Oelkers Erick J Schutte David R Tyler 《Photochemical & photobiological sciences》2008,7(2):228-234
The photochemistry of the [(CpR)Mo(CO)(3)](2) molecules, where CpR = eta(5)-C(5)H(4)(CH(2))(2)C(O)NCH(3)(CH(2))(n)CH(3) (n = 3, 8, 13, and 18), was examined using femtosecond pump-probe transient absorption spectroscopy. The goal of this study was to investigate the importance of radical size and mass on the dynamics and efficiency of geminate radical-radical recombination. The femtosecond results demonstrated the lack of any size/mass dependence of the recombination efficiency. This finding contrasts with results from a prior study that did find a size/mass dependence using a steady-state photochemical technique. To explain these conflicting results, it is proposed that the femtosecond pump-probe results are a measurement of the efficiency of primary geminate recombination whereas the steady-state method results are a measurement of the sum of primary and secondary geminate recombination efficiencies. The size/mass dependence is evident in the latter because secondary geminate recombination is a slower diffusive recombination process and therefore depends on the steric properties of the radicals. Although the existence of primary and secondary recombination channels is often taken for granted, experimental differentiation of primary and secondary caging has proven to be difficult because it is not possible for a single experimental technique to span the entire timescale for recombination of a radical cage pair and adequately resolve these recombination pathways. 相似文献
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Effect of citric acid-cycle intermediates on oxaloacetate utilization and succinate oxidation 总被引:2,自引:1,他引:1
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D. B. Tyler 《The Biochemical journal》1960,76(2):293-297
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The ultrastructure and distribution of receptor cells near the mouth and (where present) the pharynx of Hofstenia miamia, Proporus bermudensis, Conaperta thela, and Convoluta convoluta (Acoela) were investigated by transmission electron microscopy and confocal laser scanning microscopy of specimens stained with a fluorescence marker for actin. Five types of monociliary receptors were identified: (1) non‐collared receptors with a single long and narrow ciliary rootlet; (2) non‐collared receptors with a wide main ciliary rootlet and a smaller posterior rootlet; (3) non‐collared receptors with a single wide and hollow ciliary rootlet with a granulated core; (4) Collar (?) receptors with obliquely radial filament bundles in the cell apex and with a single hollow ciliary rootlet composed of numerous strand‐like elements; and (5) Collar receptors lacking a striated rootlet but with a granular body (swallow's nest rootlet). While H. miamia bears the first two receptor types, P. bermudensis has receptors of type 1, 3 and 5, and Cona. thela and Conv. convoluta have receptors of type 3, 4 and 5. The density of receptors is generally highest at the anterior body tip, regardless of where the mouth is located. Most receptor types occur scattered over the whole body but type 2 receptors of H. miamia are restricted to the pharynx and mouth region. The lack of a common receptor type specific for the mouth and pharynx of the investigated species points to an independent origin of the pharynges in Hofsteniidae and in Proporidae and of the mouth tube in Convolutidae. Moreover, the homology of the so‐called collar receptors in Acoela with typical collar receptors in other invertebrates is questioned. 相似文献
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Photoautotrophic cell suspension cultures of Chenopodium rubrumrequire high concentrations of nitrate and ammonium. Duringthe growth phase total NH4+ and the greater portion of NH3were consumed. During the stationary phase nitrate uptake continuedbut at a substantially smaller rate than during the growth phase.During growth the bulk of the absorbed N was incorporated intoprotein, the amount of which was then maintained constant untilsenescence. NH3 was accumulated upon transition betweenthe growth and the stationary phase. NH3, like the freeamino acids, was deposited in the vacuole but, unlike thesecompounds, could not be remobilized upon transfer of the cellsinto N-free medium. Readdition of NH4+ to the medium, however,resulted in a mobilization of the vacuolar NH3-pool.Reutilization of both vacuolar N-storage pools must have beenaccomplished by recycling from the vacuole to the cytoplasmbecause N-metabolizing enzymes could not be detected in isolatedvacuoles. Transfer of the cells of the stationary phase intomedium containing NH3 and NH4+ resulted in an inductionof nitrate uptake by the cells, but only after a lag phase of45 days. It is conceivable that NH4+ induces NH3-translocatingsystems in the plasmalemma and in the tonoplast. (Received December 19, 1988; Accepted March 2, 1989) 相似文献
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The Scientific Board of the California Medical Association presents the following inventory of items of progress in anesthesiology. Each item, in the judgement of a panel of knowledge physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, research workers, or scholars to stay abreast of these items of progress in anesthesiology that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another.The items of progress listed below were selected by the Advisory Panel to the Section on Anesthesiology of the California Medical Association and the summaries were prepared under its direction. 相似文献