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   3373414篇
  免费   244761篇
  国内免费   8772篇
耳鼻咽喉   46853篇
儿科学   112155篇
妇产科学   94924篇
基础医学   478063篇
口腔科学   94420篇
临床医学   303621篇
内科学   659501篇
皮肤病学   79131篇
神经病学   273675篇
特种医学   130853篇
外国民族医学   1047篇
外科学   510010篇
综合类   69419篇
现状与发展   6篇
一般理论   1192篇
预防医学   257762篇
眼科学   76828篇
药学   249319篇
  9篇
中国医学   6798篇
肿瘤学   181361篇
  2018年   36119篇
  2017年   27607篇
  2016年   31943篇
  2015年   36104篇
  2014年   49736篇
  2013年   75087篇
  2012年   100034篇
  2011年   106188篇
  2010年   63956篇
  2009年   61155篇
  2008年   99906篇
  2007年   106599篇
  2006年   108578篇
  2005年   104477篇
  2004年   100657篇
  2003年   97434篇
  2002年   94566篇
  2001年   158022篇
  2000年   161942篇
  1999年   136934篇
  1998年   39744篇
  1997年   35255篇
  1996年   35508篇
  1995年   34174篇
  1994年   31628篇
  1993年   29670篇
  1992年   108012篇
  1991年   104686篇
  1990年   101930篇
  1989年   98771篇
  1988年   90974篇
  1987年   89322篇
  1986年   84272篇
  1985年   80536篇
  1984年   59834篇
  1983年   51377篇
  1982年   30603篇
  1981年   27183篇
  1979年   54262篇
  1978年   38297篇
  1977年   32826篇
  1976年   30583篇
  1975年   33006篇
  1974年   38865篇
  1973年   37098篇
  1972年   35175篇
  1971年   32576篇
  1970年   30394篇
  1969年   29177篇
  1968年   27048篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
133.
134.
135.
136.
Interstitial cystitis/bladder pain syndrome (IC/BPS) and vulvodynia are chronic pain syndromes that appear to be intertwined from the perspectives of embryology, pathology and epidemiology. These associations may account for similar responses to various therapies.  相似文献   
137.
Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses.  相似文献   
138.
139.
140.
Preimplantation genetic diagnosis (PGD) was originally developed to diagnose embryo-related genetic abnormalities for couples who present a high risk of a specific inherited disorder. Because this technology involves embryo selection, the medical, bioethical, and legal implications of the technique have been debated, particularly when it is used to select features that are not related to serious diseases. Although several initiatives have attempted to achieve regulatory harmonization, the diversity of healthcare services available and the presence of cultural differences have hampered attempts to achieve this goal. Thus, in different countries, the provision of PGD and regulatory frameworks reflect the perceptions of scientific groups, legislators, and society regarding this technology. In Brazil, several texts have been analyzed by the National Congress to regulate the use of assisted reproduction technologies. Legislative debates, however, are not conclusive, and limited information has been published on how PGD is specifically regulated. The country requires the development of new regulatory standards to ensure adequate access to this technology and to guarantee its safe practice. This study examined official documents published on PGD regulation in Brazil and demonstrated how little direct oversight of PGD currently exists. It provides relevant information to encourage reflection on a particular regulation model in a Brazilian context, and should serve as part of the basis to enable further reform of the clinical practice of PGD in the country.  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