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R. J. Smith P. J. Woods R. Chapman J. L. Durell J. N. Mo B. R. Fulton R. A. Cunningham 《Zeitschrift für Physik A Hadrons and Nuclei》1986,324(3):283-287
The ground-state masses of35Si and34Si have been measured using the reactions64Ni(36S,35,34Si)65,66Zn at a36S beam energy of 198 MeV.34,35Si14+ ions were analysed and identified in a QMG/2 magnetic spectrometer and gas-filled focal-plane detector. The experimental mass excess of35Si was determined to be ?14.58± 0.12 0.07 MeV while that of34Si was measured as ?19.961±0.034 MeV. A comparison is made with the results of mass model predictions. 相似文献
56.
In earlier work we nave described and partially characterized two histone kinases from regenerating rat liver and other tissues which catalyze the transfer of the γ-phosphoryl group from ATP to histones. The histone phosphates thus formed were observed to be acid-labile and base-stable. In the present study we report on the specificity of one of these enzymes, namely, the kinase which is optimally active at pH 9. This enzyme appears to be relatively specific for the two histidine residues of histone H4. These histidines occur at positions 18 and 75, and both are phosphorylated. However, when regenerating rat liver was the source of enzyme, the product was 1-phosphohistidine, whereas the enzyme from Walker-256 carcinosarcoma catalyzed the formation of 3-phosphohistidine. 相似文献
57.
We have partially purified active delta and epsilon subunits of the E. coli membrane-bound Mg2+-ATPase (ECF1). Treating purified ECF1 with 50% pyridine precipitates the major subunits (alpha, beta, and gamma) of the enzyme, but the two minor subunits (delta and epsilon), which are present in relatively small amounts, remain in solution. The delta and epsilon subunits were then resolved from one another by anion exchange chromatography. The partially purified epsilon strongly inhibits the hydrolytic activity of ECF1. The epsilon fraction inhibits both the highly purified five-subunit ATPase and the enzyme deficient in the delta subunit. The latter result indicates that the delta subunit is not required for inhibition by epsilon. By contrast, two-subunit enzyme, consisting chiefly of the alpha and beta subunits, was insensitive to the ATPase inhibitor, suggesting that the gamma subunit may be required for inhibition by epsilon. The partially purified delta subunit restored the capacity of ATPase deficient in delta to recombine with ATPase-depleted membranes and to reconstitute ATP-dependent transhydrogenase. Previously we reported (Biochem, Biophys. Res. Commun. 62:764 [1975]) that a fraction containing both the delta and epsilon subunits of ECF1 restored the capacity of ATPase missing delta to recombine with depleted membranes and to function as a coupling factor in oxidative phosphorylation and for the energized transhydrogenase. These reconstitution experiments using isolated subunits provide rather substantial evidence that the delta subunit is essential for attaching the ATPase to the membrane and that the epsilon subunit has a regulatory function as an inhibitor of the ATPase activity of ECF1. 相似文献
58.
G. K. Bratspies J. F. Smith J. O. Hill P. J. Derrick 《Journal of Thermal Analysis and Calorimetry》1979,16(2):369-379
A new tin dithiocarbamate containing sulphur bridges, di--sulphidobis [bis(N,N-diethyldithiocarbamato)tin(IV)], has been isolated from the thermal decomposition of tetrakis(N,N-diethyldithiocarbamato)tin(IV). A dimeric structure is proposed on the basis of results from mass spectrometry, infrared spectroscopy, thermal analysis and vapour pressure osmometry.
The authors gratefully acknowledge the assistance given by Dr. A. G. Wedd with the vacuum sublimation technique. One of us, G. K. B., is grateful for a research scholarship provided by La Trobe University. 相似文献
Zusammenfassung Ein neues, Schwefelbrücken enthaltendes Zinn-Dithiocarbamat, Di--sulfidobis[bis(N,N-diäthyldithiocarbamato)Zinn(IV)], wurde bei der Zersetzung von Tetrakis(N,N-diäthyl-dithiocarbamato)Zinn(IV) isoliert. Aufgrund der Ergebnisse der Massenspektrometrie, der Infrarotspektroskopie, der Thermoanalyse und der Dampfdruck-Osmometrie wird eine Dimerstruktur vorgeschlagen.
Résumé Un nouveau dithiocarbamate d'étain contenant des ponts de soufre, le di--sulfidobis[bis(N,N-diéthyl-dithiocarbamato)é tain(IV)], a été isolé lors de la décomposition thermique du tétrakis(N,N-diethyl-dithiocarbamato) étain(IV). Une structure dimère est proposéeà partir des résultats obtenus par spectrométrie de masse, spectroscopie infrarouge, analyse thermique et osmométrie sous pression de vapeur.
—-- [/N,N- (/IV)], [/N,N- (/IV)], , (N,N- ) (IV). - , , .
The authors gratefully acknowledge the assistance given by Dr. A. G. Wedd with the vacuum sublimation technique. One of us, G. K. B., is grateful for a research scholarship provided by La Trobe University. 相似文献
59.
Abstract —Various low-potential viologen dyes enhance light-induced absorption changes in the near-infrared region (ΔA870) in chromatophore preparations from Rhodospirillum rubrum in the presence of dichlorophenol indophenol and a high concentration of ascorbate (DCPIP + asc). An increase in ΔA870 was also observed in large reaction-center preparations from R. rubrum with viologens in the presence of ascorbate. Our results indicate that E'0 , of the primary electron acceptor X may be as low as -0.37 V, as suggested recently by P. A. Loach (1973, personal communication). 相似文献
60.
Douglas F. Foster Barry S. Nicholls Anthony K. Smith 《Journal of organometallic chemistry》1982,236(3):395-402
Reactions of Rh6(CO)16 with bis(diphenylphosphino)methane (dppm) gave Rh6(CO)14(dppm), Rh6(CO)12(dppm)2, or Rh6(CO)10(dppm)3, depending upon the reaction conditions. Rh4(CO)10(dppm) may be obtained from the reaction of Rh4(CO)12 with dppm, but this derivative rapidly decomposes in solution to give Rh4(CO)8(dppm)2, Rh6(CO)14(dppm), and Rh6(CO)12(dppm)2. Ir4(CO)10(dppm) and Ir4(CO)8(dppm)2 have also been prepared, and their structures are discussed on the basis of infrared and 31P NMR spectroscopic data. 相似文献