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   68篇
  免费   5篇
  73篇
  2021年   1篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2016年   1篇
  2015年   2篇
  2014年   1篇
  2013年   1篇
  2012年   4篇
  2011年   1篇
  2010年   2篇
  2009年   5篇
  2008年   4篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2004年   3篇
  2003年   3篇
  2002年   3篇
  2001年   3篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1995年   2篇
  1993年   1篇
  1992年   1篇
  1991年   4篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1984年   3篇
  1983年   1篇
  1981年   5篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有73条查询结果,搜索用时 15 毫秒
21.
22.
23.
Bortezomib is a chemotherapeutic agent used to treat several cancers; however, it exhibits severe side effects in testicular tissue. We investigated the use of agomelatine to prevent testicular tissue damage caused by bortezomib. We used 36 male Sprague-Dawley rats divided randomly into six equal groups: group 1, no treatment control; group 2, agomelatine treatment only; group 3, bortezomib treatment only for 48 h; group 4, bortezomib + agomelatine treatment for 48 h; group 5, bortezomib treatment only for 72 h; and group 6, bortezomib + agomelatine treatment for 72 h. After treatments, the rats were sacrificed and testicular tissue was harvested. Lipid oxidation (LPO) and superoxide dismutase (SOD) levels in the tissues were determined using biochemical methods. Tissue samples also were examined using histopathological and immunohistochemical techniques. The LPO level was increased, while the SOD level was decreased in the bortezomib treated groups. We found that agomelatine treatment normalized LPO and SOD activities in the bortezomib treated groups. In the spermatogonia and Sertoli cells, the staining density of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and caspase 3 were decreased in the bortezomib + agomelatine groups at both 48 and 72 h compared to bortezomib only treated groups. We observed maturation arrest, basal membrane thickening, increase in inflammatory cells and connective tissue, and edema between germ cells in the bortezomib only treated groups. By contrast, normal basal membrane, less edema and more normal maturation were observed in the bortezomib + agomelatine groups at 48 and 72 h. We found that agomelatine reduced the damaging effects of bortezomib. The use of agomelatine to prevent bortezomib induced testicular tissue damage in human patients should be investigated further.  相似文献   
24.
25.
The first Australian record of the lily thrips, Liothrips vaneeckei Priesner, is reported from a bulb farm in Warragul South, Victoria. It is an occasional pest of Lilium bulbs, both in the field and in storage, particularly in the USA and several European countries, and is also infrequently found in considerable numbers on the corms of orchids.  相似文献   
26.
27.
Most estrous cycles in cows consist of 2 or 3 waves of follicular activity. Waves of ovarian follicular development comprise the growth of dominant follicles some of which become ovulatory and the others are anovulatory. Ovarian follicular activity in cows during estrous cycle was studied with a special reference to follicular waves and the circulating concentrations of estradiol and progesterone. Transrectal ultrasound examination was carried out during 14 interovulatory intervals in 7 cows. Ovarian follicular activity was recorded together with assessment of serum estradiol and progesterone concentrations. Three-wave versus two-wave interovulatory intervals was observed in 71.4% of cows. The 3-wave interovulatory intervals differed from 2-wave intervals in: 1) earlier emergence of the dominant follicles, 2) longer in length, and 3) shorter interval from emergence to ovulation. There was a progressive increase in follicular size and estradiol production during growth phase of each wave. A drop in estradiol concentration was observed during the static phase of dominant anovulatory follicles. The size of the ovulatory follicle was always greater and produced higher estradiol compared with the anovulatory follicle. In conclusion, there was a predominance of 3-wave follicular activity that was associated with an increase in length of interovulatory intervals. A dominant anovulatory follicle during its static phase may initiate the emergence of a subsequent wave. Follicular size and estradiol concentration may have an important role in controlling follicular development and in determining whether an estrous cycle will have 2 or 3-waves.  相似文献   
28.
We have determined the nucleotide sequence of a 1,200-base pair (bp) genomic fragment that includes the kappa-chain constant-region gene (C kappa) from two species of native Australian rodents, Rattus leucopus cooktownensis and Rattus colletti. Comparison of these sequences with each other and with other rodent C kappa genes shows three surprising features. First, the coding regions are diverging at a rate severalfold higher than that of the nearby noncoding regions. Second, replacement changes within the coding region are accumulating at a rate at least as great as that of silent changes. Third, most of the amino acid replacements are localized in one region of the C kappa domain--namely, the carboxy-terminal "bends" in the alpha-carbon backbone. These three features have previously been described from comparisons of the two allelic forms of C kappa genes in R. norvegicus. These data imply the existence of considerable evolutionary constraints on the noncoding regions (based on as yet undetermined functions) or powerful positive selection to diversify a portion of the constant-region domain (whose physiological significance is not known). These surprising features of C kappa evolution appear to be characteristic only of closely related C kappa genes, since comparison of rodent with human sequences shows the expected greater conservation of coding regions, as well as a predominance of silent nucleotide substitutions within the coding regions.   相似文献   
29.
Two immobilisation methods for enterokinase were developed, which yielded high remaining activities for the cleavage of the fusion protein MUC1-IgG Fc. Different carrier materials were compared regarding remaining enzyme activity and storage stability. Immobilisation procedures involving support material activation using glutardialdehyde were found to result in low remaining activities. Applying less aggressive activation procedures, remaining activities of approximately 60% were received when immobilising enterokinase on either Estapor paramagnetic microspheres or hexamethylamino Sepabeads. In case of hexamethylamino Sepabeads we were able to increase the half-life time 4.3-fold at 23 degrees C and 3.8-fold at 4 degrees C compared to the free enzyme at the same temperatures. By immobilising the biocatalyst the downstream process is simplified allowing the easy removal of the enzyme from the reaction mixture. The immobilised enterokinase cleaves the fusion protein MUC1-IgG Fc in at least two repeated batches, proving the efficiency of the immobilisation method and the reusability of the biocatalyst.  相似文献   
30.
Abstract  Two new species of Nysius Dallas, N. orarius sp. n. and N. tasmaniensis sp. n. are described from New South Wales and Tasmania (Australia), respectively. A new monotypic genus, Reticulatonysius , with type-species R. queenslandensis sp. n. is described from Queensland, and its systematic relationship with other orsilline genera is discussed.  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