首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   408篇
  免费   40篇
  2023年   3篇
  2021年   6篇
  2019年   3篇
  2018年   3篇
  2017年   2篇
  2016年   17篇
  2015年   23篇
  2014年   16篇
  2013年   19篇
  2012年   30篇
  2011年   35篇
  2010年   18篇
  2009年   14篇
  2008年   15篇
  2007年   28篇
  2006年   21篇
  2005年   14篇
  2004年   14篇
  2003年   19篇
  2002年   12篇
  2001年   6篇
  2000年   8篇
  1999年   5篇
  1998年   10篇
  1997年   4篇
  1996年   5篇
  1994年   2篇
  1993年   8篇
  1992年   8篇
  1991年   5篇
  1990年   4篇
  1989年   3篇
  1988年   4篇
  1986年   2篇
  1985年   9篇
  1984年   4篇
  1983年   2篇
  1982年   4篇
  1979年   6篇
  1977年   3篇
  1976年   2篇
  1975年   4篇
  1974年   5篇
  1973年   3篇
  1972年   3篇
  1971年   2篇
  1970年   5篇
  1966年   2篇
  1965年   1篇
  1963年   1篇
排序方式: 共有448条查询结果,搜索用时 406 毫秒
441.
442.
443.
444.
A new isoflavone was isolated from soya beans and shown to be 7,4′-dihydroxy, 6-methoxyisoflavone, for which the name glycitein is proposed.  相似文献   
445.
Within the target area (VL) used for the stereotactic treatment of parkinsonian tremor and spasmodic torticollis, electrical stimulation as well as recording of somatosensory evoked potential (SEP) was performed. The effects of stimulation in the target area are facilitation of muscle tone showing some degree of somatotopic distribution. The recorded SEPs indicate a projection of an afferent system (probably of muscle afferents) to the target area. We assume that the target area is a relay station involved in the control of muscle tone. The interruption of muscle afferents in combination with the correct somatotopic localization of the lesion is important for the therapeutic efficacy in parkinsonian tremor and spasmodic torticollis.  相似文献   
446.
Two trypsin-like enzymes were isolated from the digestive tract of the African migratory locust Locusta migratoria migratorioides. Primary purification was carried out on a DEAE-cellulose column, from which the two trypsins emerged in the anionic fraction. Further purification was achieved by affinity chromatography on a p-aminobenzamidine (PABA)-Sepharose column, which also separated the two trypsins (TLEAff.1. and TLEAff.2.), or by HPLC on an anion exchange column. The purity and homogeneity of the trypsins were demonstrated by electrophoresis of cellulose acetate strips and in polyacrylamide gels, with and without SDS. The molecular weights of TLEAff.1 and TLEAff.2, as determined by SDS-PAGE, were 17,000 and 24,000 respectively. The amino acid compositions of the locust trypsins were similar to those of trypsins from the digestive systems of other insects, which are characterized by the lack or low content of half cystines. The isoelectric points were 3.2 for TLEAff.1 and 3.5 fold for TLEAff.2. Since most of the locust trypsin comprised TLEAff.2, the latter served as the main object of this study. TLEAff.2 was unstable at low pH, differing in this respect from mammalian trypsins. The optimum activity was at pH 8.5-9.0. The Km and kcat, values were similar to those for bovine trypsin. Activation by substrate, a phenomenon in bovine trypsin, was also observed for TLEAff.2. The locust trypsin was full inhibited by the proteinaceous trypsin inhibitors Bowman-Birk (BBI) and Kunitz from soybeans, CI from chickpeas, chicken ovomucoid (COM), and turkey ovomucoid (TOM). It was inactivated by phenylmethylsulfonyl fluoride (PMSF) and tosyl-L-lysine chloromethyl ketone (TLCK), indicating the involvement of serine and histidine in the active site.  相似文献   
447.
We investigated the utility of the fluorescent dye Deep Red Anthraquinone 5 (DRAQ5) for digital staining of optically sectioned skin in comparison to acridine orange (AO). Eight fresh-frozen thawed Mohs discard tissue specimens were stained with AO and DRAQ5, and imaged using an ex vivo confocal microscope at three wavelengths (488 nm and 638 nm for fluorescence, 785 nm for reflectance). Images were overlaid (AO + Reflectance, DRAQ5 + Reflectance), digitally stained, and evaluated by three investigators for perceived image quality (PIQ) and histopathological feature identification. In addition to nuclear staining, AO seemed to stain dermal fibers in a subset of cases in digitally stained images, while DRAQ5 staining was more specific to nuclei. Blinded evaluation showed substantial agreement, favoring DRAQ5 for PIQ (82%, Cl 75%-90%, Gwet's AC 0.74) and for visualization of histopathological features in (81%, Cl 73%-89%, Gwet's AC 0.67), supporting its use in digital staining of multimodal confocal micrographs of skin.  相似文献   
448.
The activities of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and transketolase were studied in the cytoplasmic fractions of transplanted mouse hepatomas differing in their growth rates, and in the liver, spleen and cortical layer of kidneys of tumour carriers and normal mice. It was shown that transplantation of hepatomas changes the activity of the pentose phosphate pathway enzymes in tumour carrier tissues unaffected by neoplasm. Deviations from normalcy were mainly similar to those observed in the hepatomas. The changes in the enzymatic activities were especially well-pronounced in the mice having rapidly growing hepatomas. This may be due to a generalized effect of the tumour on the organism, which is concurrent with malignancy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号