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   18847篇
  免费   1313篇
  国内免费   186篇
耳鼻咽喉   391篇
儿科学   407篇
妇产科学   354篇
基础医学   2915篇
口腔科学   289篇
临床医学   1699篇
内科学   3588篇
皮肤病学   540篇
神经病学   1444篇
特种医学   1039篇
外科学   2619篇
综合类   161篇
现状与发展   1篇
一般理论   6篇
预防医学   1160篇
眼科学   626篇
药学   1400篇
中国医学   173篇
肿瘤学   1534篇
  2023年   117篇
  2022年   300篇
  2021年   640篇
  2020年   337篇
  2019年   530篇
  2018年   625篇
  2017年   434篇
  2016年   612篇
  2015年   853篇
  2014年   1022篇
  2013年   1180篇
  2012年   1694篇
  2011年   1542篇
  2010年   957篇
  2009年   774篇
  2008年   1101篇
  2007年   1078篇
  2006年   1039篇
  2005年   908篇
  2004年   766篇
  2003年   694篇
  2002年   667篇
  2001年   290篇
  2000年   227篇
  1999年   184篇
  1998年   126篇
  1997年   105篇
  1996年   91篇
  1995年   81篇
  1994年   69篇
  1993年   63篇
  1992年   113篇
  1991年   116篇
  1990年   92篇
  1989年   81篇
  1988年   82篇
  1987年   105篇
  1986年   81篇
  1985年   67篇
  1984年   56篇
  1983年   52篇
  1982年   42篇
  1981年   37篇
  1980年   29篇
  1979年   26篇
  1978年   48篇
  1977年   15篇
  1976年   21篇
  1975年   16篇
  1974年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Alopecia areata (AA) is an autoimmune disease that results in spot baldness in humans. Adequate animal models for AA are currently lacking. The objective of this study was to elucidate the mechanism of autoimmune-like alopecia (ALA) in C57BL/6.CD80CD86-deficient (B6.CD80CD86−/−) mice. Incidence and severity of alopecia were analysed in 58 B6.CD80CD86−/− mice using histological examination, flow cytometry, multiplex enzyme-linked immunosorbent assay, quantitative RT-PCR and CD25 inhibition test. Both male and female B6.CD80CD86−/− mice showed almost 100% incidence of hair loss at 40 weeks of age. Moreover, CD4+FoxP3+Treg (Treg) cell population in B6.CD80CD86−/− mice was significantly lower than in B6 mice, which presumably underlined autoimmune reaction. Histologically, B6.CD80CD86−/− mice showed CD4+ and CD8+ T-cell infiltration around terminal follicle region and exhibited hair follicle destruction in the anagen or catagen stage. Negative correlation between the number of CD4+FoxP3+ Tregs and ALA was confirmed by the CD25 depletion test in B6 mice, as follicle destruction was similar to that observed in B6.CD80CD86−/− animals. CD80CD86 deficiency disrupted CD4+FoxP3+ Treg homoeostasis and prompted the development of ALA. We demonstrated that B6.CD80CD86−/− mice might have several advantages as an ALA model, because they exhibited high incidence of disease phenotype and epipathogenesis similar to that observed in human AA.  相似文献   
992.

Background  

Hemifacial spasm is commonly caused by arterial compression of the facial nerve. Although vascular compression usually occurs at the facial nerve exit zone, in some cases, the facial nerve is compressed more distally. We analyzed the clinical outcome of microneurovascular decompression in patients with hemifacial spasm caused by either distal or proximal compression.  相似文献   
993.
994.
We analyze the pattern of inter-regional functional association between cortical activities during auditory oddball tasks, and the influence of task difficulty on it. Event-related electroencephalograms were recorded from 17 subjects during auditory oddball tasks with two task difficulty levels. The task difficulty was controlled by changing the difference between the frequencies of standard and target tones. The changes in behavioral response and P300 component due to the difficulty were consistent with previous findings, whereby successful control of difficulty was verified. Significant gamma- and theta-band phase synchronization (PS) was observed primarily between frontal and posterior electrodes along the midline, which is interpreted as functional connectivity among cortical regions devoted to the task execution. Apparent differences in PS were identified between two difficulties in both gamma- and theta-bands. On the whole, the number of electrode pairs showing significant PS was much smaller for higher task difficulty. The overall result is in agreement with our recent study which reported similar difference in PS due to the difficulty of ‘visual’ oddball task.  相似文献   
995.
996.
997.

Purpose  

To determine the accuracy of multi-detector CT (MDCT) compared with the surgical findings, such as peritoneal seeding and metastatic lymph nodes, in ovarian cancer patients.  相似文献   
998.
999.
We report a case of an acute spontaneous epidural hematoma (EDH) due to skull base metastasis in a 46-year-old male patient with hepatocellular carcinoma (HCC). The patient presented with the acute onset of severe headache followed by unconsciousness, and computed tomography showed a large EDH in the right temporal and parietal lobes with midline shift. Emergency evacuation of the EDH was performed, and the hemorrhage was determined to be secondary to skull base metastasis of HCC.  相似文献   
1000.
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