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71.
A number of antitumor-active octahedral organotin complexes of the type R2SnX2L2, where R=ethyl or phenyl, X = chloride or bromide, and L2 = o- phenanthroline or 2-(2-pyridyl)benzimidazole, have been shown to exhibit in vitro antiherpes activity towards both herpes simplex virus types 1 and 2 (HSV-1 and HSV-2). In addition, a series of mono-, di-, and tri-organotin halides (alkyl and phenyl) demonstrated weak antiherpes activity in the same viral assay system. Selectivity indexes for the tin compounds were calculated and compared with those available in the literature for a number of well-characterized and commercially important antivirals, e.g. adenine-9-β-D-arabinofuranoside (ara-A), cytosine-β-D-arabinofuranoside (ara-C), 5-iodo-2′-deoxyuridine (IDU) and 9-(2-hydroxyethoxymethyl)guanine (acyclovir, ACY). Although the organotin complexes are less effective in vitro than either ACY or IDU, as determined by their selectivity indexes, they are comparable in activity with both ara-A and ara-C in this particular assay. With few exceptions, most notably (C2H5)2SnBr2(o-phen), the organotin compounds examined in this study are more active against HSV-1 (F strain) than HSV-2 (MS strain). The results presented here represent the first study of the potential antiviral properties of organotin compounds. 相似文献
72.
73.
F. J. Hartmann P. Baumann H. Daniel T. von Egidy S. Grunewald R. Lipowsky E. Moser W. Schott P. Ackerbauer W. H. Breunlich M. Fuchs M. Jeitler P. Kammel J. Marton N. Nägele J. Werner J. Zmeskal H. Bossy K. M. Crowe R. H. Sherman K. Lou C. Petitjean V. E. Markushin 《Hyperfine Interactions》1993,82(1-4):259-269
The experiments on pt fusion performed at Paul Scherrer Institut, Villigen, Switzerland, are described. Liquid triple mixtures of protium, deuterium and tritium with low concentrations on deuterium and tritium were used. Gamma rays, X-rays, neutrons and, for the first time, conversion muons, were measured. Preliminary results are: Rate for spin flip from the triplet to the singlet state of t(1s), 10=(1.0±0.2) × 103s–1; rate for muon-catalyzed pt fusion from the (I=1) nuclear-spin state,
pt
f
(I=1)=0.07±0.01s–1; and the molecular formation rate,
pt
m
=(7.5±1.3)s–1 (all normalized to liquid hydrogen density). 相似文献
74.
Lisa K. Seidel Thomas W. Crowe 《International Journal of Infrared and Millimeter Waves》1989,10(7):779-787
The GaAs Schottky diode is predominantly used as the critical mixer element in heterodyne receivers in the frequency range from 300 GHz to several THz[1]. At operating frequencies above one THz the skin effect adds significant parasitic resistance to the diode which degrades the receiver sensitivity. A novel diode structure called the Schottky barrier membrane diode is proposed to decrease the skin effect resistance by reducing the current path between the Schottky and ohmic contacts. This is accomplished by fabricating the diode on a very thin membrane of GaAs (about 1 m thickness). A theoretical analysis has shown that this will reduce the substrate resistance by 60% at 3 THz. This reduction in resistance corresponds to a better frequency response which will improve the device's performance as a mixer element.This work has been supported by a grant from Texas Instruments and the National Science Foundation under contract ECS-8412477 相似文献
75.
Baoguo Sun Gregory Miller Wan Yee Lee Kelvin Ho Michael A. Crowe Leslie Partridge 《Journal of chromatography. A》2013,1271(1):163-169
Analytical methods were developed for a directed enzyme evolution research programme, which pursued high performance enzymes to produce high quality l-ribose using large scale biocatalytic reaction. A high throughput HPLC method with evaporative light-scattering detection was developed to test ribose and ribitol in the enzymatic reaction, a β-cyclobond 2000 analytical column separated ribose and ribitol in 2.3 min, a C18 guard column was used as an on-line filter to clean up the enzyme sample matrix and a short gradient was applied to wash the column, the enzymatic reaction solution can be directly injected after quenching. Total run time of each sample was approx. 4 min which provided capability of screening 4 × 96-well plates/day/instrument. Meanwhile, a capillary electrophoresis method was developed for the separation of ribose enantiomers, while 7-aminonaphthalene-1,3-disulfonic acid was used as derivatisation reagent and 25 mM tetraborate with 5 mM β-cyclodextrin was used as electrolyte. 0.35%of d-ribose in l-ribose can be detected which can be translated into 99.3% ee of l-ribose. Derivatisation reagent and sample matrix did not interfere with the measurement. 相似文献
76.
77.
C. Amsler A. V. Anisovich C. A. Baker B. M. Barnett C. J. Batty P. Blüm K. Braune V. Credé K. M. Crowe M. Doser W. Dünnweber D. Engelhardt M. A. Faessler R. P. Haddock F. H. Heinsius N. P. Hessey H. Kalinowsky D. Jamnik P. Kammel J. Kisiel E. Klempt H. Koch M. Kunze U. Kurilla R. Landua H. Matthäy C. A. Meyer F. Meyer-Wildhagen R. Ouared K. Peters B. Pick M. Ratajczak C. Regenfus J. Reinnarth A. V. Sarantsev U. Strohbusch M. Suffert J. S. Suh U. Thoma S. Wallis-Plachner D. Walther U. Wiedner 《The European Physical Journal C - Particles and Fields》2004,33(1):23-30
78.
Petitjean C. Ackerbauer P. Balin D. V. Breunlich W. H. Case T. Crowe K. M. Daniel H. von Egidy T. Gartner B. Hartmann F. J. Kammel P. Kminek G. Lauss B. Maev E. M. Markushin V. E. Marton J. Mühlbauer M. Petrov G. E. Prymas W. Schott W. Semenchuk G. G. Smirenin Yu. V. Vorobyov A. A. Voropaev N. I. Zmeskal J. 《Hyperfine Interactions》1996,101(1):1-11
A new experiment was started at PSI aiming for high-precision and complete studies of dµd fusion in D2, HD and D2/H2 gas mixtures. A high-pressure ionization chamber surrounded by a set of neutron counters is used to observe dd-fusion at temperatures between 25 and 350 K. Here we report preliminary results from the first test run with pure D2 filling. 相似文献
79.
D. T. McLaughlin B. P. Donnelly A. Crowe 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1994,29(4):259-263
Electron-photon polarisation correlations measured in the scattering plane defined by the incident and scattered electron momenta are reported for 40 eV electron impact excitation of the 31 D state of helium and for electron scattering angles in the range 40°≦?≦120°. When combined with the results of our earlier polarisation analysis on radiation emitted perpendicular to the scattering plane, detailed information on the shape and dynamics of the exicted state is obtained. In the small angular range of overlap (40–60°) there is excellent agreement with a pervious experimental study. The behaviour of the linear polarisation of the radiation emitted in the scattering plane is well reproduced by a multichannel eikonal theory for ?≦80°. Otherwise theories totally fail to described the excitation process. 相似文献
80.