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   10190篇
  免费   807篇
  国内免费   196篇
耳鼻咽喉   102篇
儿科学   228篇
妇产科学   400篇
基础医学   1299篇
口腔科学   212篇
临床医学   1155篇
内科学   2078篇
皮肤病学   214篇
神经病学   651篇
特种医学   346篇
外科学   1453篇
综合类   379篇
现状与发展   1篇
一般理论   2篇
预防医学   478篇
眼科学   197篇
药学   995篇
  4篇
中国医学   196篇
肿瘤学   803篇
  2023年   95篇
  2022年   147篇
  2021年   288篇
  2020年   189篇
  2019年   289篇
  2018年   321篇
  2017年   225篇
  2016年   207篇
  2015年   322篇
  2014年   404篇
  2013年   529篇
  2012年   683篇
  2011年   789篇
  2010年   507篇
  2009年   396篇
  2008年   558篇
  2007年   555篇
  2006年   515篇
  2005年   504篇
  2004年   442篇
  2003年   364篇
  2002年   329篇
  2001年   269篇
  2000年   221篇
  1999年   193篇
  1998年   98篇
  1997年   102篇
  1996年   72篇
  1995年   100篇
  1994年   83篇
  1993年   75篇
  1992年   137篇
  1991年   102篇
  1990年   109篇
  1989年   87篇
  1988年   75篇
  1987年   80篇
  1986年   45篇
  1985年   50篇
  1984年   53篇
  1983年   38篇
  1982年   36篇
  1981年   30篇
  1980年   24篇
  1979年   31篇
  1977年   25篇
  1976年   30篇
  1975年   26篇
  1973年   23篇
  1972年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
T lymphocytes play a fundamental role in the initiation and regulation of chronic inflammatory responses in patients with asthma. CD69 is an early marker of T‐cell activation. The levels of intercellular adhesion molecule‐1 (ICAM‐1, CD54) and L ‐selectin have been reported to increase in patients with allergic diseases and asthma. The present study was therefore undertaken to investigate the expression of CD69, CD54, and L ‐selectin by T lymphocytes of children with asthma, before and after immunotherapy. Eighteen children newly diagnosed with asthma, 11 good and nine poor responders to immunotherapy, and 16 normal subjects, were enrolled in this study. The percentages of CD69+, CD54+, and CD62L+ cells in T lymphocytes were measured by using flow cytometry. The levels of CD69, CD54, and CD62L in serum and culture supernatants were determined by using enzyme‐linked immunosorbent assay (ELISA). The expression of CD69 and CD54 on CD3+ T lymphocytes was significantly higher in children with asthma than in control patients. All the patient groups expressed (spontaneously and following stimulation with phorbol myristate acetate and ionomycin together with mite‐extract proteins) greater amounts of CD69 and CD54 than did control subjects. With long‐term immunotherapy, the percentages of CD69+ and CD54+ T lymphocytes were significantly lower in patients with a good response to immunotherapy. Our results also showed significantly lower serum L ‐selectin levels following immunotherapy. In conclusion, successful immunotherapy resulted in decreased expression and production of CD69 and CD54. These results may explain, in part, the clinical efficacy of immunotherapy.  相似文献   
7.
8.
9.
BACKGROUND: A venous lake is a venous ectasia that appears mostly on the lower lip and other sun-exposed areas of an older person. Treatment of lip venous lake includes surgical excision, laser therapy, infrared coagulation, and cryotherapy. Although the use of sclerotherapy on varicose veins, leg telangiectasia, hemorrhoids, and hemangiomas is well established, the use of sclerotherapy for lip venous lake has not been reported. OBJECTIVE: We present two cases of lip venous lake treated with intralesional injection of 1% polidocanol. METHOD: Two cases are reported, and literature is reviewed. RESULT: The lesions virtually disappeared, leaving an inconspicuous scar, with two sessions of sclerotherapy. Side effects were not observed. CONCLUSION: Sclerotherapy with polidocanol is effective in the treatment of lip venous lake and offers an alternative to conventional methods.  相似文献   
10.
Effects of stimulation of brainstem sites on hemodynamics and plasma catecholamine levels were assessed in cats under chloralose-urethane anesthesia. Pressor areas of the dorsal medulla (DM) and ventrolateral medulla (VLM) and the depressor area of the paramedian reticular nucleus (PRN) were stimulated electrically using a monopolar electrode, or chemically using sodium glutamate microinjection. Plasma levels of norepinephrine (NE) and epinephrine (EPI) were measured in caval blood above the adrenal veins. Electrical stimulation of the DM and VLM produced increases in blood pressure and in plasma NE and EPI levels that were enhanced after acute vagotomies. The NE and EPI responses were attenuated after acute, bilateral adrenalectomies, confirming augmented adrenomedullary secretion, whereas the pressor responses were intact. Injection of sodium glutamate into the same pressor regions of the DM or VLM also produced pressor responses and elevated plasma catecholamine levels, indicating that the responses resulted from activation of neuronal perikarya. Stimulation of the PRN attenuated pressor and catecholamine responses during stimulation of the DM and VLM. The results indicate that pressor responses during stimulation of the DM and VLM are due at least partly to activation of perikarya in these regions, are associated with but not dependent on adrenomedullary activation, and are enhanced after vagotomy; and that neurons of the PRN exert inhibitory modulation of the pressor and adrenomedullary responses during stimulation of VLM and DM.  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