全文获取类型
收费全文 | 384篇 |
免费 | 24篇 |
专业分类
408篇 |
出版年
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 18篇 |
2014年 | 19篇 |
2013年 | 25篇 |
2012年 | 19篇 |
2011年 | 16篇 |
2010年 | 26篇 |
2009年 | 26篇 |
2008年 | 15篇 |
2007年 | 15篇 |
2006年 | 13篇 |
2005年 | 15篇 |
2004年 | 13篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 10篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 8篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 18篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有408条查询结果,搜索用时 0 毫秒
401.
402.
403.
404.
405.
Antibodies raised against porcine pancreatic phospholipase A2 (PLA2) react in immunoblottings with both the antigen as well as with one protein band of about 14 kDa from hamster spermatozoa extracts. Immunoblottings of proteins extracted from spermatozoon head and tail fractions also show similar results. Anti-PLA2 purified IgGs were employed for light and electron microscopic immunocytochemistry in order to detect PLA2 in hamster cauda epididymal spermatozoa. When whole mount spread spermatozoa were used under light (employing the PAP complex) or electron microscopy (using anti-rabbit gold conjugated), the acrosomal area of the gametes shows a noticeable labelling; a characteristic which is not observed in samples treated with the pre-immune serum. Immunocytochemistry undertaken in ultrathin sections from spermatozoon samples embedded in Lowicryl, demonstrates that the antigen appears preferentially distributed in the acrosome. Besides, sperm tails showed a scattered distribution of gold granules in the mitochondria of the midpiece. Results suggest that the antibody used recognizes a PLA2 which is preferentially located in the acrosome and mitochondria. On the other hand, the presence of a surface PLA2 in the plasma membrane covering the acrosome is suggested. This surface PLA2 would be probably related to the acrosome reaction phenomenon that occurs in the spermatozoon before penetrating the oocyte. 相似文献
406.
407.
Transgenic mice bearing two fragments of the rabbit uteroglobin 5'-flanking region fused to the new reporter gene (pac) encoding puromycin N-acetyltransferase (PAC) showed a different pattern of expression. Transgenic lines (C0.4) harboring a 404-bp fragment (-396/+8) had a uterus-specific expression slightly inducible by estrogen, lacking detectable expression in other tissues where the uteroglobin-encoding gene is naturally expressed in rabbit. Transgenic lines (C3.2) bearing a longer fragment of 3.2-kb (-3254/+8) showed hormonally regulated expression in the uterus and the male genital tract, and detectable expression in the lung. In addition, the nonstimulated uterine expression of the transgene was higher in C0.4 lines than in C3.2 lines. It could be concluded that all sequences required for uterus-specific expression should be present within the 404-bp fragment, and that other upstream (-396) sequences are responsible for expression in the lung and male genital tract, as well as for a possible down modulation of expression in the uterus. 相似文献
408.
Sixty male Wistar rats were used for this experiment and assigned at random to the control group or to the stimulation method. Control rats show cerebral asymmetry with right bias at the frontal and occipital lobes. In the case of stimulated rats the differences from the occipital zone increase while those from the frontal lobe disappear. 相似文献