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   683篇
  免费   22篇
  705篇
  2022年   4篇
  2021年   11篇
  2020年   6篇
  2019年   12篇
  2018年   19篇
  2017年   18篇
  2016年   25篇
  2015年   10篇
  2014年   13篇
  2013年   27篇
  2012年   21篇
  2011年   21篇
  2010年   26篇
  2009年   18篇
  2008年   17篇
  2007年   29篇
  2006年   36篇
  2005年   27篇
  2004年   22篇
  2003年   28篇
  2002年   23篇
  2001年   24篇
  2000年   24篇
  1999年   18篇
  1998年   4篇
  1992年   10篇
  1991年   14篇
  1990年   9篇
  1989年   8篇
  1988年   9篇
  1987年   11篇
  1986年   10篇
  1985年   5篇
  1983年   8篇
  1981年   4篇
  1979年   12篇
  1978年   6篇
  1977年   7篇
  1976年   8篇
  1975年   7篇
  1974年   8篇
  1973年   9篇
  1972年   9篇
  1971年   16篇
  1970年   9篇
  1969年   7篇
  1968年   7篇
  1967年   4篇
  1966年   3篇
  1965年   6篇
排序方式: 共有705条查询结果,搜索用时 0 毫秒
11.
12.
Both leptin and ghrelin used separately at the concentrations corresponding to trimesters II–III of pregnancy increase the number of CD56bright NK cells in mononuclear cell suspension; their combination also enhances the L-selectin expression on the surface of these cells in the culture. These hormones do not affect the production of TGF-β1, IL-17А, or IFN-γ by NK cells, and they inhibit the production of IL-10. Leptin decreses the IL-4 production by NKp46+ cells, but the presence of ghrelin abrogates this effect.  相似文献   
13.
The species composition of fleas in the Moiynkum Desert (Chu-Talas interfluve) and indices of their domination on different hosts was established on the basis of long-term observations (1973–2000). The most significant and prolonged changes in the population density of mass flea species (Xenopsylla gerbilli minax and Coptopsylla lamellifer, parasites of the great gerbil) occur in association with changes of the population density of rodents. Changes in the population density of rodents are usually observed year after similar changes in the population density of hosts. The leading role in the transmission of the plague vector belongs to the flea X. gerbilli minax.  相似文献   
14.
Journal of Ichthyology - The species status is justified for the Okhotsk lumpsucker Eumicrotremus ochotonensis based on the morphological characters. The differences from the closely related...  相似文献   
15.
Journal of Ichthyology - Samples of Greenland halibut Reinhardtius hippoglossoides (Jordan and Snyder, 1901) from the Atlantic, Arctic, and Pacific Oceans were compared using eight microsatellite...  相似文献   
16.
The fauna of fleas in the East Kisil-Kum includes 24 species. Different physicogeographic regions of sands are characterized by different spectra and number of species of fleas. The greatest share in collections is composed by Xenopsylla gerbilli caspica--the parasite of Rhombomys opimus. In autumn the other parasite of this rodent, Coptopsylla lamellifer, is a mass species. All the most significant and long changes in the number of these species are associated with changes in the density of their hosts' population. The most significant in epizootic respect is the flea X. gerbilli caspica from which about 50% of plague agent cultures were isolated.  相似文献   
17.
Dynamic behavior of stem cells population of the "critical" tissue (normal population) and tumor cell population under periodic treatment with a phase-specific cytotoxic agent was considered. The results were used for optimization of anticancer chemotherapy. The schedules of treatment were found which provide a maximum rate of tumor-cell elimination for any given rate of the normal population size decrease. If the mean generation times of normal and tumor populations differ (which was stated for many tumors), usage of the optimal period markedly increases the selectivity of therapy, while application of other periods can result in selective elimination of the normal population. Problems concerned with practical realization of the proposed regimes are discussed.  相似文献   
18.
Cardiac energy metabolism with emphasis on mitochondria was addressed in atrial tissue from patients with overload-induced atrial dilation. Structural remodeling of dilated (D) atria manifested as intracellular accumulation of fibrillar aggregates, lipofuscin, signs of myolysis and autophagy. Despite impaired complex I dependent respiration and increased diffusion restriction for ADP, no changes regarding adenylate and creatine kinase occurred. We observed 7-fold overexpression of HK2 gene in D atria with concomitant 2-fold greater activation of mitochondrial oxygen consumption by glucose, which might represent an adaption to increased energy requirements and impaired mitochondrial function by effectively joining glycolysis and oxidative phosphorylation.  相似文献   
19.
20.
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