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   31316篇
  免费   2580篇
  国内免费   176篇
耳鼻咽喉   320篇
儿科学   1082篇
妇产科学   706篇
基础医学   3639篇
口腔科学   642篇
临床医学   2950篇
内科学   6650篇
皮肤病学   554篇
神经病学   2427篇
特种医学   1018篇
外科学   4714篇
综合类   806篇
一般理论   14篇
预防医学   2101篇
眼科学   1309篇
药学   2346篇
  1篇
中国医学   131篇
肿瘤学   2662篇
  2023年   218篇
  2022年   346篇
  2021年   741篇
  2020年   475篇
  2019年   702篇
  2018年   810篇
  2017年   570篇
  2016年   663篇
  2015年   755篇
  2014年   1031篇
  2013年   1228篇
  2012年   1999篇
  2011年   2054篇
  2010年   1187篇
  2009年   1038篇
  2008年   1802篇
  2007年   1759篇
  2006年   1635篇
  2005年   1561篇
  2004年   1560篇
  2003年   1387篇
  2002年   1229篇
  2001年   1129篇
  2000年   1024篇
  1999年   878篇
  1998年   309篇
  1997年   242篇
  1996年   216篇
  1995年   214篇
  1994年   191篇
  1993年   168篇
  1992年   515篇
  1991年   481篇
  1990年   439篇
  1989年   403篇
  1988年   366篇
  1987年   340篇
  1986年   333篇
  1985年   328篇
  1984年   224篇
  1983年   210篇
  1982年   142篇
  1981年   105篇
  1980年   111篇
  1979年   161篇
  1978年   93篇
  1977年   103篇
  1976年   70篇
  1974年   85篇
  1973年   71篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
891.
Angiogenesis is a very complex physiological process, which involves multiple pathways that are dependent on the homeostatic balance between the growth factors (stimulators and inhibitors). This tightly controlled process is stimulated by angiogenic factors, which are present within the tumor and surrounding tumor-associated stromal cells. The dependence of tumor propagation, invasion and metastasis on angiogenesis makes the inhibitors of new blood vessel formation attractive drugs for treating the malignancies. Angiogenesis can be disrupted by several distinct mechanisms: by inhibiting endothelial cells, by interrupting the signaling pathways or by inhibiting other activators of angiogenesis. This strategy has shown therapeutic benefit in several types of solid tumors, leading to Food and Drug Administration (FDA) approval of anti-angiogenic agents in the treatment of kidney, non-small cell lung, colon and brain cancers. Although no angiogenesis inhibitors have been approved for patients with metastatic prostate cancer, therapies that target new blood vessel formation are still an emerging and Dromising area of prostate cancer research.  相似文献   
892.
893.
Multimorbidity, defined as the presence of two or more chronic conditions, leads to a substantial public health burden. This study evaluated its association with adherence with cardiovascular medications in a Chinese population.  相似文献   
894.
An earlier age of diagnosis (r = −0.28, p < 0.0001) and longer duration of type 2 diabetes (r = 0.26, p < 0.0001) were each found to correlate with higher HbA1c level, on analysis of a diabetes centre database in people under regular shared care. When combined, these biological variables strongly associate with the current HbA1c level.  相似文献   
895.
896.
Journal of Natural Medicines - Jatropha multifida is a medicinal plant that belongs to the Euphorbiaceae family. Our investigation revealed that the chloroform extract of J. multifida stems showed...  相似文献   
897.
898.

Background

Renal denervation is a new interventional approach to treat hypertension with variable results.

Objectives

The purpose of this study was to correlate response to endovascular radiofrequency ablation of renal arteries with nerve and ganglia distributions. We examined how renal neural network anatomy affected treatment efficacy.

Methods

A multielectrode radiofrequency catheter (15 W/60 s) treated 8 renal arteries (group 1). Arteries and kidneys were harvested 7 days post-treatment. Renal norepinephrine (NEPI) levels were correlated with ablation zone geometries and neural injury. Nerve and ganglion distributions and sizes were quantified at discrete distances from the aorta and were compared with 16 control arteries (group 2).

Results

Nerve and ganglia distributions varied with distance from the aorta (p < 0.001). A total of 75% of nerves fell within a circumferential area of 9.3, 6.3, and 3.4 mm of the lumen and 0.3, 3.0, and 6.0 mm from the aorta. Efficacy (NEPI 37 ng/g) was observed in only 1 of 8 treated arteries where ablation involved all 4 quadrants, reached a depth of 9.1 mm, and affected 50% of nerves. In 7 treated arteries, NEPI levels remained at baseline values (620 to 991 ng/g), ≤20% of the nerves were affected, and the ablation areas were smaller (16.2 ± 10.9 mm2) and present in only 1 to 2 quadrants at maximal depths of 3.8 ± 2.7 mm.

Conclusions

Renal denervation procedures that do not account for asymmetries in renal periarterial nerve and ganglia distribution may miss targets and fall below the critical threshold for effect. This phenomenon is most acute in the ostium but holds throughout the renal artery, which requires further definition.  相似文献   
899.
900.
Clinical Oral Investigations - To identify salivary metabolite biomarkers to differentiate patients with oral squamous cell carcinoma and oral epithelial dysplasia (OSCC/OED) from those with...  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