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   148篇
  免费   7篇
  2023年   1篇
  2022年   3篇
  2018年   3篇
  2017年   3篇
  2016年   2篇
  2015年   3篇
  2014年   4篇
  2013年   5篇
  2012年   18篇
  2011年   18篇
  2010年   8篇
  2009年   4篇
  2008年   6篇
  2007年   8篇
  2006年   6篇
  2005年   4篇
  2004年   7篇
  2003年   5篇
  2002年   3篇
  2000年   2篇
  1999年   4篇
  1998年   2篇
  1997年   3篇
  1996年   1篇
  1995年   2篇
  1994年   4篇
  1992年   2篇
  1991年   2篇
  1989年   6篇
  1988年   2篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1982年   1篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   3篇
排序方式: 共有155条查询结果,搜索用时 31 毫秒
1.
Proteins present in the seminal plasma of mammals are known to influence functions associated with ejaculated spermatozoa such as motility, capacitation, acrosome reaction and fertilising ability. The proteins isolated and characterised so far influence only one of the above functions of spermatozoa. Seminalplasmin, a protein isolated from the seminal plasma of bull is exceptional in that it influences many of the above spermatozoal functions. It is also a potent antimicrobial protein and capable of lysing microbial and mammalian cells. The physiological function of seminalplasmin as nature's own antifertility agent is discussed.  相似文献   
2.
Ten cultures of Pseudomonas spp. were established from soil samples collected in and around a lake in Antarctica. Based on their morphology, biochemical and physiological characteristics, and moles percent G + C of their DNA, they were identified as P. fluorescens, P. putida, and P. syringae. This is the first report on the identification of Pseudomonas spp. from continental Antarctica.  相似文献   
3.
Five cultures isolated from soil samples collected in Schirmacher oasis, Antarctica, have been identified as members of the familyMicrococcaceae, with 3 belonging to the genusMicrococcus and two toPlanococcus. The 3Micrococcus isolates (37R, 45R and 49R) were red-pigmented and h a d ∼ 75 mol% G + C in their DNA; they were identified asMicrococcus roseus. The twoPlanococcus isolates (30Y and Lz3OR) were yellow and orange in colour, and had 43.5 and 40.9 mol % G + C in their DNA respectively; they were identified asPlanococcus sp.  相似文献   
4.
S Shivaji 《FEBS letters》1986,196(2):255-258
The binding of seminalplasmin, a protein secreted by the accessory sex glands of bull, to the plasma and outer acrosomal membrane of bovine spermatozoa was studied using three different fluorescent probes. 8-Anilino-1-naphthalenesulfonate fluorescence, pyrene excimer fluorescence and diphenylhexatriene fluorescence polarisation studies indicate that seminalplasmin binds to the spermatozoal membranes, and leads to an increase in the fluidity of both the plasma and the acrosomal membranes. Calcium was found to have no influence on the interaction of seminalplasmin with the spermatozoal membranes. These results suggest that protein(s) present in the seminal plasma could interact with spermatozoal membranes and increase their fluidity.  相似文献   
5.
6.
Changes in the cell surface of vaginal epithelial cells were studied by scanning microscopy and fluorescence spectroscopy. Microvilli which are prominent features of the vaginal epithelial cells in proestrus and diestrus are replaced by sheet-like structures in the estrus phase. Surface morphology of vaginal epithelial cells of estradiol primed rat resembles the vaginal cells from estrus phase rats whereas vaginal cells from control rats resembles the diestrus phase. Measurement of the fluidity of the membranes indicated that the vaginal epithelial cell membrane of estrus rats is more fluid compared to proestrus and diestrus. Similarly, estradiol primed immature rat vaginal epithelial cell membrane was observed to be more fluid than the corresponding control.  相似文献   
7.
Extracellular protease from the antarctic yeast Candida humicola.   总被引:5,自引:1,他引:4       下载免费PDF全文
The psychrotrophic, dimorphic yeast Candida humicola, isolated from Antarctic soil, secretes an acidic protease into the medium. The secretion of this protease by C. humicola was found to be dependent on the composition of the medium. In YPD or yeast nitrogen base medium containing either amino acids or ammonium sulfate as the nitrogen source, the activity of the protease in the medium was low (basal level). However, when yeast nitrogen base medium was depleted of amino acids or ammonium sulfate and supplemented with proteins, the activity of the enzyme increased. The secretion of the enzyme was greater during exponential growth at low temperatures than during growth at higher temperatures. The purified protease had a molecular mass of 36,000 Da and was inhibited by pepstatin, iodoacetamide, and sodium dodecyl sulfate. Despite the prevalent cold temperatures in Antarctica, this extracellular protease of the psychrotrophic yeast C. humicola was active at temperatures ranging from 0 to 45 degrees C, with an optimum activity at 37 degrees C.  相似文献   
8.
M K Ray  G S Kumar    S Shivaji 《Journal of bacteriology》1994,176(14):4243-4249
Phosphorylation of lipopolysaccharide (LPS) from a psychrotrophic bacterium, Pseudomonas syringae, from Antarctica was studied by using sucrose gradient-separated membrane fractions. The bacterium was found to possess an LPS kinase which could phosphorylate more LPS postsynthetically at higher temperatures. The phosphorylation was low at a lower temperature and was also found to occur in vivo. After phosphorylation of LPS in vitro, it was found that the major part of the radioactivity (> 85%) was associated with the core oligosaccharide region of the LPS. The phosphate groups of this region are probably involved in the binding of metal ions, which could be removed by EDTA. The cells grown at the lower temperature probably contained fewer divalent cations because of the smaller amount of phosphate and thereby were more sensitive to EDTA. The cells were also more sensitive to cationic antibiotics at the lower temperature. A possible role of this differential phosphorylation of LPS in modulating the function of the outer membrane as a permeability barrier in the psychrotroph is discussed.  相似文献   
9.
Extracellular protease from the antarctic yeast Candida humicola.   总被引:3,自引:0,他引:3  
The psychrotrophic, dimorphic yeast Candida humicola, isolated from Antarctic soil, secretes an acidic protease into the medium. The secretion of this protease by C. humicola was found to be dependent on the composition of the medium. In YPD or yeast nitrogen base medium containing either amino acids or ammonium sulfate as the nitrogen source, the activity of the protease in the medium was low (basal level). However, when yeast nitrogen base medium was depleted of amino acids or ammonium sulfate and supplemented with proteins, the activity of the enzyme increased. The secretion of the enzyme was greater during exponential growth at low temperatures than during growth at higher temperatures. The purified protease had a molecular mass of 36,000 Da and was inhibited by pepstatin, iodoacetamide, and sodium dodecyl sulfate. Despite the prevalent cold temperatures in Antarctica, this extracellular protease of the psychrotrophic yeast C. humicola was active at temperatures ranging from 0 to 45 degrees C, with an optimum activity at 37 degrees C.  相似文献   
10.
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