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   1599667篇
  免费   133446篇
  国内免费   2577篇
耳鼻咽喉   21646篇
儿科学   52928篇
妇产科学   46225篇
基础医学   227764篇
口腔科学   47196篇
临床医学   140899篇
内科学   314758篇
皮肤病学   34090篇
神经病学   130102篇
特种医学   64721篇
外国民族医学   474篇
外科学   243790篇
综合类   39712篇
现状与发展   3篇
一般理论   544篇
预防医学   122856篇
眼科学   36470篇
药学   121249篇
  3篇
中国医学   2974篇
肿瘤学   87286篇
  2018年   14763篇
  2016年   12898篇
  2015年   15025篇
  2014年   20645篇
  2013年   31350篇
  2012年   42545篇
  2011年   44749篇
  2010年   26335篇
  2009年   25303篇
  2008年   42995篇
  2007年   45238篇
  2006年   46047篇
  2005年   44671篇
  2004年   44089篇
  2003年   42178篇
  2002年   41291篇
  2001年   75682篇
  2000年   78326篇
  1999年   66387篇
  1998年   17731篇
  1997年   16334篇
  1996年   16314篇
  1995年   16019篇
  1994年   15070篇
  1993年   14217篇
  1992年   55428篇
  1991年   53775篇
  1990年   52561篇
  1989年   50832篇
  1988年   47221篇
  1987年   46560篇
  1986年   44284篇
  1985年   42843篇
  1984年   32033篇
  1983年   27565篇
  1982年   16144篇
  1981年   14436篇
  1980年   13564篇
  1979年   30460篇
  1978年   21064篇
  1977年   17765篇
  1976年   16694篇
  1975年   17574篇
  1974年   21486篇
  1973年   20672篇
  1972年   18853篇
  1971年   17770篇
  1970年   16289篇
  1969年   15268篇
  1968年   13949篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Early management of congenital dislocation of the hip has been necessary and has resulted in a high percentage of normal-appearing and functioning hips. The risk of complications and problems has been lessened. Further, the techniques employed are simpler and less demanding or difficult for patients, family, or physicians.  相似文献   
992.
The cell-free medium of isolated human glomeruli exhibited a procoagulant activity and stimulated thromboxane (TXB2) synthesis in human platelets in a dose-dependent manner. The amount of TXB2 measured was 16-fold higher than what could have been predicted (TXB2 synthesized by the platelets under control conditions plus TXB2 present in the glomerular supernatant). The lipid extract of the glomerular supernatant and its purified fraction including the fatty acids was still able to stimulate--although at a lesser degree--TXB2 synthesis in platelets. Stimulation was abolished after treatment of this fraction by charcoal or albumin. Gas chromatography/mass spectrometry analysis demonstrated the presence in the purified glomerular fraction of several long-chain saturated or monoenoic fatty acids at a total concentration of 80 microM with the following order of abundance: stearic, palmitic, myristic and oleic acids. Addition to human platelets of these same exogenous synthetic acids resulted in a dose-dependent stimulation of TX synthesis. It was maximum with three or four fatty acids tested in combination, but still present with myristic acid used separately. Arachidonic acid was absent in the glomerular supernatant. Thus the stimulation observed could not be related to a greater availability of substrate. Fatty acids did not act on platelets through a non-specific detergent effect since addition of high doses of detergents inhibited TXB2 formation in platelets. The combination of fatty acids from glomerular origin identified in the present study represents a novel factor involved in the control of intracapillary hemostasis, but different from the procoagulant activity common to many tissues.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
993.
A general overview of the literature concerning the development of diabetic neuropathic arthropathy is discussed. A case report is presented dealing with spontaneous fractures of the lesser metatarsal in a patient with an amputated hallux and peripheral neuropathy secondary to diabetes mellitus.  相似文献   
994.
995.
996.
Pericardial effusion complicating breast cancer.   总被引:2,自引:0,他引:2       下载免费PDF全文
Thirty-five patients with metastatic breast cancer and pericardial effusions are described. They were treated with specific endocrine or chemotherapy. Twenty-two (63%) had presented in cardiac tamponade and were rapidly relieved by pericardiocentesis. Eighteen (82%) of these required no further local treatment, 2 obtained relief from a second aspiration and 2 needed additional treatment (intrapericardial bleomycin instillation and surgical pleuropericardial window). The median survival was 13.2 months. No patient relapsed again in the pericardium, suggesting that their prognosis was that of the underlying disease. Cardiac tamponade should be considered in any breathless patient with malignancy. In breast cancer, periocardiocentesis is lifesaving and systemic treatment can usefully prolong life.  相似文献   
997.
Mouse polyclonal antisera were raised to the Mr 130,000 and Mr 115,000 cell surface glycoproteins, desmocollins, of desmosomes from bovine nasal epithelium. Immunoblotting confirmed that the antisera were specific for the desmocollins. An immunofluorescence study showed that the antisera distinguished between the basal and suprabasal layers of bovine and human epidermis. The antibodies reacted with cultured keratinocytes only after calcium-induced stratification. In epidermis, therefore, there appears to be a difference between the desmocollins of basal and suprabasal cells that may be important in relation to epidermal differentiation. Previous work has shown that polyclonal antisera raised in other animals (guinea pigs and rabbits) against desmocollins, as well as against other desmosomal components, react with all desmosome-containing epithelia. In contrast, an immunofluorescence survey of bovine, rat, and human tissues showed that the present mouse antisera stained only suprabasal skin cells and the arachnoid layer of the meninges, demonstrating that these have common determinants that distinguished their desmocollins from those of all other tissues. The antibodies also stained 11 of 12 meningiomas and, therefore, may be useful as a marker not only for the diagnosis of these tumors but also for investigation of their histogenesis.  相似文献   
998.
Platelet activation: role of an ADP receptor   总被引:3,自引:0,他引:3  
  相似文献   
999.
The cytologic findings in peritoneal washings of two women, one of whom had an ovarian ependymoma and the other a primary omental ependymoma, are reported. The ependymomas were characterized by the presence of numerous, isolated, spindle and stellate cells as well as groups of cells forming true rosettes. The tumor cells displayed slightly pleomorphic, round-to-oval eccentric nuclei and abundant fibrillary cytoplasm with tapering cytoplasmic processes. In addition, one of the patients had numerous papillae and cell clusters with associated psammoma bodies indistinguishable from those found in low-grade serous carcinoma. The demonstration of glial fibrillary acidic protein (GFAP) in both cases by immunocytochemical procedures indicates the usefulness of this method in cytologic preparations to confirm the diagnosis of these uncommon neoplasms.  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