全文获取类型
收费全文 | 423篇 |
免费 | 14篇 |
专业分类
437篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 16篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 10篇 |
2015年 | 15篇 |
2014年 | 15篇 |
2013年 | 29篇 |
2012年 | 14篇 |
2011年 | 14篇 |
2010年 | 5篇 |
2009年 | 18篇 |
2008年 | 25篇 |
2007年 | 28篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 14篇 |
2003年 | 8篇 |
2002年 | 8篇 |
2001年 | 9篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 11篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1974年 | 10篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 2篇 |
排序方式: 共有437条查询结果,搜索用时 0 毫秒
431.
432.
433.
If cultured in media supplemented with adenosine triphosphate (ATP), EDTA, trypsin, thrombin, or incubated at 0-15 degrees C, human skin fibroblasts (HSF) and human gingival fibroblasts (HGF) change from long attached elliptical to round floating cell cultures. Also, if treated with ATP, EDTA, trypsin, thrombin, or incubated at 0-15 degrees C, the attached HFS or HGF monolayers detach from plastic substratum and form floating round cells that progressively aggregate together and die. The described experiments examined the role of cellular and extracellular ATP on HSF and HGF attachment. These two types of fibroblasts differed in their cellular ATP levels and their response to metabolic inhibitors. ATP causes destruction of microtubules as monitored by colcemid uptake and cellular detachment. Fibronectin protects both HSF and HGF from the effects of extracellular ATP. 相似文献
434.
Raziel S. Hakim 《Journal of morphology》1976,149(4):547-565
The labial gland of the adult sphingid moth, Manduca sexta, is composed of five distinct regions, each made of a single cellular type. Four of these regions are derivatives of the single specialized cellular population that makes up the caterpillar labial duct. Both the larval labial duct and its derivatives are large, polyploid cells with pleiomorphic nuclei. There is a definite cellular continuity between the larval and adult forms of these cells throughout metamorphosis; no mitoses or cell deaths are seen to occur in the gland during transformation. Cytological studies indicate that in the process of cell transformation the ducts first “dedifferentiate,” elongate, then redifferentiate. Intermediates in this process have well defined structures which should make this system useful in studying covert events in the transformation process. 相似文献
435.
436.
437.
The bronchial flow is approximately 1% of the total pulmonary flow. Anastomosis between the bronchial and pulmonary vessels occurs primarily at the microcirculatory level. It is assumed that bronchopulmonary anastomoses are present in a homogeneous manner throughout lung parenchyma. To investigate this issue, an in situ blood-perfused left lower lung lobe (500 ml/min) was prepared in a live dog. The bronchial flow rate in the entire lobe was monitored using the rate of volume gain in the reservoir while the pulmonary and bronchial flow in the subpleural region was monitored using laser-Doppler flowmetry. The results were expressed as ratio of bronchial to pulmonary flow rate for the entire lobe and for the subpleural region. We found that, for the entire lobe, bronchial flow was 1.0% of pulmonary flow, while for the subpleural region this ratio was much higher, with an average of 12%. In two different experimental conditions that were imposed to affect the global bronchial flow, these ratios changed in the same direction as the global bronchial flow. After transfusion of blood into the animal, bronchial flow increased to 1.7%, while the subpleural bronchial flow increased to 18% of the subpleural pulmonary flow. During elevation of venous pressure, bronchial flow decreased to 0.6%, while the subpleural bronchial flow decreased to 10% of the subpleural pulmonary flow. The differences in the ratios between the global and subpleural region may be explained by having low pulmonary blood flow in the periphery compared with the interior regions of the lung.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献