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291.
V. L. Yeager D. J. Anderson J. J. Taylor 《Cellular and molecular life sciences : CMLS》1985,41(2):262-265
Summary The amount and arrangement of smooth muscle in the intrahepatic vessels suggests that the guinea pig would be a good animal model for studying mechanisms controlling intrahepatic portal vein blood flow, while the raccoon would be good for studying hepatic vein mechanisms of control. 相似文献
292.
293.
Résumé Le broyage mécanique deSerratia marcescens pigmentés produit un liquide rouge clair. Après centrifugation à 105 000×g, le pigment se sédimente sous forme d'un agglomérat rouge et la phase liquide reste incolore. La courbe du matériel de l'agglomérat remis en suspension montre à l'ultracentrifuge un seul sommet coïncidant avec le pigment.S. marcescens non pigmentés ne produisent pas d'agglomérat après broyage et centrifugation et donnent une courbe différente à l'ultracentrifuge. 相似文献
294.
A protein with several possible membrane-spanning domains encoded by the Drosophila segment polarity gene patched 总被引:10,自引:0,他引:10
The patterning of cells in insect segments requires the exchange of information between cells, which in Drosophila depends on the activity of members of the segment-polarity class of genes. Here we report the molecular characterization of one such gene, patched. We find that patched encodes a large protein with several possible membrane-spanning domains and is expressed in a complex pattern during embryogenesis. 相似文献
295.
The metabolism of benzoic acid was studied in Plasmodium berghei infected mice both in vitro and in vivo. Results of in vitro studies showed a considerable decrease in the ability of the infected liver to detoxify benzoic acid by hippuric acid formation. The in vivo study showed that hippuric acid formation decreases with increasing parasitemia and the emergence of benzoyl-glucuronide. This new pathway stops operating with further increase in parasitemia. 相似文献
296.
297.
Population structure of the human pseudoautosomal boundary 总被引:13,自引:0,他引:13
The mammalian sex chromosomes are composed of two genetically distinct segments: the pseudoautosomal region, where recombination occurs between the X and Y chromosomes, and the sex chromosome-specific parts. Between these two segments the human sex chromosomes differ by the insertion of an Alu element on the Y chromosome. We have surveyed the sequence variation in the boundary region using the polymerase chain reaction. Fifty seven Y and sixty X chromosomes from ten different human populations were analysed. The X chromosomes were found to be polymorphic at five positions in a 300-base-pair region. By contrast, all Y chromosomes were identical except for one distal polymorphism shared with the X chromosome. 相似文献
298.
Maze JR Stanwix PL Hodges JS Hong S Taylor JM Cappellaro P Jiang L Dutt MV Togan E Zibrov AS Yacoby A Walsworth RL Lukin MD 《Nature》2008,455(7213):644-647
Detection of weak magnetic fields with nanoscale spatial resolution is an outstanding problem in the biological and physical sciences. For example, at a distance of 10 nm, the spin of a single electron produces a magnetic field of about 1 muT, and the corresponding field from a single proton is a few nanoteslas. A sensor able to detect such magnetic fields with nanometre spatial resolution would enable powerful applications, ranging from the detection of magnetic resonance signals from individual electron or nuclear spins in complex biological molecules to readout of classical or quantum bits of information encoded in an electron or nuclear spin memory. Here we experimentally demonstrate an approach to such nanoscale magnetic sensing, using coherent manipulation of an individual electronic spin qubit associated with a nitrogen-vacancy impurity in diamond at room temperature. Using an ultra-pure diamond sample, we achieve detection of 3 nT magnetic fields at kilohertz frequencies after 100 s of averaging. In addition, we demonstrate a sensitivity of 0.5 muT Hz(-1/2) for a diamond nanocrystal with a diameter of 30 nm. 相似文献
299.
Taylor M. J. Moynihan E. P. Wood-Harper A. T. 《Systemic Practice and Action Research》1998,11(4):419-434
Business systems maintenance represents a large proportion of the work of IT staff in most organizations. Many methodologies relevant to IT concentrate on systems development and give little attention to systems maintenance. In this paper we discuss the relevance and benefits of the Soft Systems Methodology (SSM) to systems maintenance. Payroll administration is then used to provide an outline illustration of the use of SSM for systems maintenance projects. Aspects of the use of SSM for systems maintenance projects are also discussed. 相似文献
300.
Summary At low doses, theophylline blocks the neuronal depressant effects of 5-AMP, but not cyclic AMP. Higher doses (100 mg/kg) block cyclic AMP responses and reduce the effects of noradrenaline and GABA. It is concluded that cyclic AMP does not depress neurones via the adenosine receptor.We are grateful to the Wellcome Trust and Royal Society for travel grants. 相似文献