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   123405篇
  免费   11528篇
  国内免费   8043篇
耳鼻咽喉   1050篇
儿科学   1579篇
妇产科学   1597篇
基础医学   14074篇
口腔科学   2341篇
临床医学   16368篇
内科学   18275篇
皮肤病学   1383篇
神经病学   6799篇
特种医学   4226篇
外国民族医学   63篇
外科学   11841篇
综合类   20541篇
现状与发展   47篇
一般理论   28篇
预防医学   8826篇
眼科学   3494篇
药学   13050篇
  124篇
中国医学   7224篇
肿瘤学   10046篇
  2024年   474篇
  2023年   2130篇
  2022年   5187篇
  2021年   6401篇
  2020年   4921篇
  2019年   4194篇
  2018年   4418篇
  2017年   4120篇
  2016年   3731篇
  2015年   5655篇
  2014年   6761篇
  2013年   6228篇
  2012年   9346篇
  2011年   10239篇
  2010年   6543篇
  2009年   5191篇
  2008年   6593篇
  2007年   6717篇
  2006年   6402篇
  2005年   6347篇
  2004年   4111篇
  2003年   3776篇
  2002年   3220篇
  2001年   2289篇
  2000年   2471篇
  1999年   2716篇
  1998年   1908篇
  1997年   1761篇
  1996年   1347篇
  1995年   1177篇
  1994年   1007篇
  1993年   686篇
  1992年   812篇
  1991年   708篇
  1990年   629篇
  1989年   530篇
  1988年   444篇
  1987年   397篇
  1986年   308篇
  1985年   241篇
  1984年   150篇
  1983年   136篇
  1982年   110篇
  1981年   91篇
  1980年   67篇
  1979年   53篇
  1978年   32篇
  1977年   31篇
  1974年   18篇
  1973年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
对16例垂体腺瘤采用单侧鼻前庭切口经蝶切除,效果满意,既可减少手术创伤,又缩短了手术距离,且避免了美容缺陷,是一种设计巧妙,较为实用的手术方法,尤其适用于生长激素腺瘤。  相似文献   
43.
44.
45.
Nuclear factor-kappaB (NF-kappaB) plays a key role in inflammation, which is involved in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). In the present study, we assessed the potential role of NF-kappaB in regulation of cerebral vasospasm. Nuclear factor-kappaB DNA-binding activity was measured in cultured vascular smooth muscle cells (VSMCs) treated with hemolysate and pyrrolidine dithiocarbamate (PDTC, 80 micromol/L), an inhibitor of NF-kappaB. Forty-two rabbits were divided into three groups: control, SAH, and PDTC groups (n=14 for each group). The caliber of the basilar artery was evaluated. Nuclear factor-kappaB DNA-binding activity and the gene expression levels of cytokines and adhesion molecules in the basilar artery were measured. Immunohistochemical study was performed to assess the expression and localization of tumor necrosis factor (TNF)-alpha, intercellular adhesion molecule (ICAM)-1, and myeloperoxidase (MPO). It was observed that NF-kappaB DNA-binding activity was significantly increased by treatment with hemolysate in cultured VSCMs, but this increase was suppressed by pretreatment with PDTC. Severe vasospasm was observed in the SAH group, which was attenuated in the PDTC group. Subarachnoid hemorrhage could induce increases of NF-kappaB DNA-binding activity and the gene expression levels of TNF-alpha, interleukin (IL)-1 beta, ICAM-1, and vascular cell adhesion molecule (VCAM)-1, which were reduced in the PDTC group. Immunohistochemical study demonstrated that the expression levels of TNF-alpha, ICAM-1, and MPO were all increased in the SAH group, but these increases were attenuated in the PDTC group. Our results suggest that NF-kappaB is activated in the arterial wall after SAH, which potentially leads to vasospasm development through induction of inflammatory response.  相似文献   
46.
目的 :探讨地塞米松减轻曲马多术后镇痛时恶心呕吐的临床效果。方法 :选择术后自愿硬膜外镇痛(PCEA)的病例 6 0例 ,随机分为试验组 (地塞米松 曲马多 0 .15 %布比卡因 )和对照组 (格拉司琼 曲马多 0 .15 %布比卡因 )。结果 :两组病人术后疼痛评分 (VAS法 ) ,镇静评分及恶心呕吐的发生率无明显差异 (P >0 .0 5 )。结论 :地塞米松可以减轻曲马多术后镇痛时恶心呕吐的发生 ,效果良好 ,不增加副作用 ,价格便宜  相似文献   
47.
48.
理顺功能关系、理清业务流程是构建社区卫生服务信息系统的前提和基础,功能建模是理顺功能关系的一个重要手段。在研究现有的各种功能分析方法的基础上,本文以IDEF0模型方法为基础,提出了社区卫生服务信息系统功能建模方法。通过建立功能、数据和约束之间的内在联系,为系统的功能设计和数据分析提供了基础。  相似文献   
49.
PURPOSE: Type I IFNs (IFN-alpha/beta) have shown significant antitumor activity in preclinical models but limited efficacy and significant toxicity in clinical trials. We hypothesized that the antitumor activity of type I IFNs could be enhanced by chronic, low-dose systemic delivery and sought to test this in murine neuroblastoma models. EXPERIMENTAL DESIGN: Continuous liver-generated expression of human IFN-beta (hINF-beta) was achieved through a gene therapy-mediated approach using adeno-associated virus vectors encoding hIFN-beta (AAV hINF-beta). Orthotopic localized retroperitoneal and disseminated models of neuroblastoma were established using three different xenografts. Immunohistochemical analysis and ELISA were used to evaluate the antiangiogenic effect of therapy. RESULTS: The development of both localized orthotopic (retroperitoneal) and disseminated neuroblastoma was prevented in all mice expressing hINF-beta. Continued growth of established retroperitoneal tumors, treated with AAV hINF-beta as monotherapy, was significantly restricted, and survival for mice with established, disseminated disease was significantly prolonged following administration of AAV hINF-beta. Analysis of treated tumors revealed a significant antiangiogenic effect. Mean intratumoral vessel density was diminished and expression of the angiogenic factors vascular endothelial growth factor and basic fibroblast growth factor were both decreased. Finally, combination therapy in which AAV hIFN-beta was used together with low-dose cyclophosphamide resulted in regression of both established retroperitoneal and disseminated disease. CONCLUSIONS: AAV-mediated delivery of hIFN-beta when used as monotherapy was able to restrict neuroblastoma growth due in part to inhibition of angiogenesis. When used in combination with conventional chemotherapy, AAV hIFN-beta was able to effect complete tumor regression.  相似文献   
50.
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