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991.
992.
Abstract —Virus-host cell interactions may be investigated by study of the enhancement of infectivity of ultraviolet (UV)-irradiated virus obtained by UV-irradiating the host cell [ultraviolet reactivation (UVR)]. This phenomenon was studied with Herpes simplex virus and normal (embryonic lung) and malignant (HeLa) human cells. Although the lung cells displayed no UVR, both the HeLa cells and a Sendai-virus carrier culture of HeLa cells demonstrated UVR capabilities. This UVR persisted at equal or increased levels for at least 24 h. Since the lung cells and HeLa cells have similar host-cell-reactivation (HCR) abilities, the differences in UVR suggests that UVR and HCR may operate by different mechanisms. 相似文献
993.
Signs of the dipole moment derivatives, ?px/?S4 and ?px/?S5 where px is the dipole moment vector along an axis perpendicular to the CO bond in the plane of the molecule and Sj are the symmetry coordinates for the B1 vibrations of Br2CO have been re-evaluated from the reported ?p/?Qi values (p being the dipole moment of the molecule and Qi the normal coordinates) and the L matrix elements. The new set of dipole moment derivatives fits well with similar parameters for Cl2CO and F2CO. 相似文献
994.
A carbon-rod atomizer (CRA) fitted with a 'mini-Massmann' carbon rod was evaluated for routine analysis of petroleum and petroleum products for trace metal content by atomic-absorption spectroscopy. Aspects investigated included sensitivity, detection limit, effect of solvent type, and interferences. The results of analysis of oil samples with this technique were compared with those obtained by other techniques. Metals studied were silver, copper, iron, nickel, and lead. Sensitivity and detection limit values obtained with the CRA were similar to those obtained with the carbon-filament atomizer. Strong 'solvent effects' were observed as well as interference by cations. On the basis of this study, design changes for the CRA are suggested, with the object of minimizing 'solvent effects' and interferences, increasing the atomization efficiency, and increasing the residence time of the atomic vapour in the optical path of the instrumental system. 相似文献
995.
J. L. Cotter 《Journal of mass spectrometry : JMS》1973,7(1):11-16
The pyrolysis of some perfluoroalkylene-linked aromatic and heteroaromatic polymer precursors and a poly(1,3-phenylenehexafluorotrimethylene) has been studied using a combined pyrolysis-gas chromatographic-mass spectrometric method. Whereas the electron-impact induced fragmentations of the polymer precursors are almost exclusively controlled by cleavage β to the aromatic or heteroaromatic ring, thermolysis of these compounds yields products whose formation is consistent with the occurrence of primary cleavage processes that are not confined β to the ring. 相似文献
996.
Benzo[b] thiophene derivatives. XVIII. The sulfur isosteres of harmaline,harmine and related isomers
T. R. Bosin R. P. Maickel A. Dinner A. Snell E. Campaigne 《Journal of heterocyclic chemistry》1972,9(6):1265-1266
The sulfur analogs of harmaline, 7-methoxy-3,4-dihydro-1-methyl[1]benzothieno[2,3-c]-pyridine (Ib), harmine, 7-methoxy-1-methyl[1]benzothieno[2,3- c ]pyridine (IIb), and corresponding 6-methoxy isomers (Ic and IIc) have been synthesized for pharmacological evaluation as monoamine oxidase inhibitors. 相似文献
997.
The results of allowing tetrahydro-as-triazine-3(2H)-thiones to react with various α,β-diiunctional compounds, such as, α-bromoethyl p-toluenesulfonate, chloroacetaldehyde, α-bromophenylacet-uldehyde, phenaeyl bromide, chloroacetonitrile, α-bromophenylaeelonitrile, and α-cyanobenzyl p-toluenesulfonate are discussed. These condensations give either a 5H-thiazolo[3,2-b]-as-triazine or a 2H-thiazolo[2,3-c]-as-triazine. 相似文献
998.
Conclusion The reaction of 2-[N,N-bis(trimethylsilyl)]amino-4,5-benzo-1,3,2-dioxaphospholane with acetyl and benzoyl chlorides leads to the formation of silicon-containing diazadiphospheti-dines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 939–940, April, 1986. 相似文献
999.
Zh. V. Bren' V. A. Bren' L. M. Sitkina V. I. Minkin 《Chemistry of Heterocyclic Compounds》1979,15(1):56-59
A number of phenylmercury derivatives of 3-hydroxymethylene- and 3-aminomethylene-substituted 1-methyloxindoles, 1-indanones, and 1,3-indanediones were synthesized. It is shown that the preferred tautomeric structures of the potentially metallotropic and prototropic hydroxymethylene keto (hydroxy vinyl aldehyde) derivatives of the indicated compounds and 3-hydroxybenzo[b]-2-formylthiophene coincide precisely. An aminomethylene structure with an N-H bond is realized for the phenylmercury derivatives of the corresponding azomethines in all cases.Communication 28 from the series Benzenoid-Quinoid Tautomerism of Azomethines and Their Structural Analogs. See [1] for communication 27.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 65–68, January, 1979. 相似文献
1000.
Quantitative measurement of both bulk and localized oxygen concentrations is of importance in the study of oxidation kinetics.
We describe the combined application of two nuclear techniques, fast neutron activation analysis and (d, p) nuclear microprobe,
to the determination of oxygen concentrations and surface profiles for steam-oxidized Zircaloy-4 cladding specimens. Results
of measurements using these techniques are presented.
Work partially supported by Electric Power Research Institute Contract T.S.A. No. 20. 相似文献