全文获取类型
收费全文 | 465篇 |
免费 | 49篇 |
国内免费 | 2篇 |
专业分类
516篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 20篇 |
2014年 | 29篇 |
2013年 | 40篇 |
2012年 | 46篇 |
2011年 | 32篇 |
2010年 | 19篇 |
2009年 | 24篇 |
2008年 | 27篇 |
2007年 | 31篇 |
2006年 | 26篇 |
2005年 | 29篇 |
2004年 | 37篇 |
2003年 | 26篇 |
2002年 | 22篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 5篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有516条查询结果,搜索用时 0 毫秒
511.
Cecile Gache Yolande Berthois Pierre-Marie Martin Simone Saez 《In vitro cellular & developmental biology. Animal》1998,34(4):347-351
Summary In the mammary gland, mesenchymal-epithelial interactions are of paramount importance during normal and tumoral developments.
We have studied the paracrine growth regulation of a variety of breast epithelial cells in coculture with normal or pathological
breast fibroblasts. Two models of coculture were used in which the two cell types were seeded and grown, either together in
microchamber slides or separated by a microporous membrane. Under these two conditions, all fibroblasts were shown to stimulate
the proliferation of the hormono-responsive breast carcinoma MCF-7 cell line, suggesting that cell contacts were not indispensable
for the paracrine stimulation of MCF-7 cell growth by fibroblasts. Moreover, in the Transwell coculture system, the proliferation
of a variety of other breast carcinoma cells (MDA-MB231, T47D, and BT-20) was also stimulated by fibroblasts. However, the
amplitude of the proliferative response seemed to be dependent on the carcinoma cell line considered. Moreover, the proliferative
response of normal mammary epithelial cells to the presence of fibroblasts was shown to be significantly higher than the tumor
cell response. The nature of the tissue of fibroblast origin, normal or pathological, did not influence the growth response
of the epithelial cells. In this study, we thus demonstrate that fibroblasts are able to stimulate the proliferation of normal
and carcinoma cells through paracrine exchange mechanisms. We also conclude that the target epithelial cell phenotype will
essentially determine the extent of the proliferative response. 相似文献
512.
513.
514.
Submaximal and/or maximal exercise was carried out by 357 women without a history of cardiovascular disease, using a bicycle ergometer and/or treadmill while monitored by a bipolar ECG lead CM5. In 40- to 60-year-old women the incidence of an ischemic ECG pattern during or after exercise ranged from 20 to 50%. Because clinical coronary disease can be expected in less than 10% of normal women followed for 16 years, most of these ECG changes were not considered to be due to occult coronary disease. At the present time exercise ECG changes in women cannot be used with any reliability as an aid in the diagnosis of chest pain or in screening normal female populations for coronary heart disease. 相似文献
515.
516.
1. Mitochondria outer membranes prepared from mouse livers were purified on a discontinuous sucrose gradient. Control in electron microscopy and marker enzymes assays confirmed purity and homogeneity of this fraction. 2. Purified mitochondria outer membranes exhibited significant UDP-galactose: glycoprotein galactosyltransferase activities when incubated with endogenous or exogenous glycoprotein acceptors in presence of detergent (Nonidet P40). 3. Some properties of two distinct mitochondrial galactosyltransferases, acting respectively on ovomucoid and ovine asialo-mucin were investigated. 4. Transfer of galactose on ovomucoid was maximal for a pH of 7.6 at 33 degrees C whereas asialo-mucin galactosyltransferase exhibited an optimum pH of 5.6 for an optimal temperature of 46 degrees C. 5. These two distinct membrane-bound enzymes were both inhibited by diacylglycerophospholipids whereas lysophospholipids modulated both enzymes in a different way: at 5 mM lysophosphatidylcholine, asialo-mucin galactosyltransferase was slightly stimulated while ovomucoid galactosyltransferase was markedly activated. 6. The most important activating effect on ovomucoid galactosyltransferase was obtained with a phospholipid containing a long aliphatic side chain linked by an ester bond in sn-1 of glycerol, an hydroxyl group or hydrogen atoms in sn-2 and a phosphorylcholine head group in sn-3. 相似文献