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   2462篇
  免费   138篇
  国内免费   22篇
耳鼻咽喉   14篇
儿科学   82篇
妇产科学   23篇
基础医学   237篇
口腔科学   82篇
临床医学   215篇
内科学   566篇
皮肤病学   56篇
神经病学   196篇
特种医学   80篇
外科学   322篇
综合类   52篇
一般理论   2篇
预防医学   168篇
眼科学   122篇
药学   227篇
中国医学   30篇
肿瘤学   148篇
  2023年   30篇
  2022年   24篇
  2021年   89篇
  2020年   88篇
  2019年   112篇
  2018年   133篇
  2017年   89篇
  2016年   94篇
  2015年   101篇
  2014年   154篇
  2013年   161篇
  2012年   256篇
  2011年   251篇
  2010年   112篇
  2009年   95篇
  2008年   151篇
  2007年   159篇
  2006年   95篇
  2005年   91篇
  2004年   55篇
  2003年   48篇
  2002年   31篇
  2001年   14篇
  2000年   9篇
  1999年   12篇
  1998年   10篇
  1997年   7篇
  1996年   13篇
  1995年   5篇
  1994年   3篇
  1993年   6篇
  1992年   10篇
  1991年   13篇
  1990年   9篇
  1989年   8篇
  1987年   10篇
  1986年   10篇
  1985年   6篇
  1984年   4篇
  1983年   7篇
  1982年   2篇
  1981年   4篇
  1980年   4篇
  1979年   8篇
  1978年   4篇
  1977年   2篇
  1974年   6篇
  1972年   3篇
  1971年   4篇
  1956年   2篇
排序方式: 共有2622条查询结果,搜索用时 31 毫秒
91.
92.
93.
94.
Angiotensin II (Ang II) might induce pro‐inflammatory effects directly in the vascular wall independently of its haemodynamic effects. The aim of our study was to investigate the putative direct pro‐inflammatory and vasomotor effects of Ang II and compare to those of lipopolysaccharides (LPS) in mouse isolated mesenteric resistance‐sized arteries (MRA) supported by experiments in cultured human primary endothelial and vascular smooth muscle cells. Results showed that 24‐hr organ culture of mouse MRA with 10 nM Ang II had, unlike 100 ng/mL LPS, no effects on IL‐6 or MCP‐1 secretion, VCAM1 mRNA expression or endothelial function, while Ang II significantly decreased maximal vasomotor responses to phenylephrine. In support, 24‐hr organ culture of mouse MRA significantly suppressed Agtr1a mRNA and augmented Tlr4 mRNA along with attenuated vasomotor responses to Ang II. Moreover, contrary to LPS and TNF‐α, Ang II and [Sar1]‐Ang II had no concentration‐ or time‐dependent effects on IL‐6 and MCP‐1 secretion in human umbilical vein endothelial cells (HUVEC) and human aortic smooth muscle cells (HASMC). AGTR1 or AGTR2 mRNA expression was undetectable in HUVEC, whereas HASMC expressed only AGTR1 mRNA. In summary, contrary to previous studies and the observed effects of LPS, we could not demonstrate direct vascular pro‐inflammatory effects of Ang II ex vivo or in vitro. As indicated by our results, down‐regulation or desensitization of AT1R during culture may explain our findings.  相似文献   
95.
Mansoor A  Akbari M  Auer I  Lai R 《Human pathology》2007,38(5):797-802
We describe 3 unusual B-cell non-Hodgkin's lymphomas in which the entire tumors histologically mimicked marginal zone B-cell lymphoma. All patients were male (mean age, 65 years). Excisional biopsy from lymph node (2 of 3) and parotid gland (1 of 3) showed proliferation of monocytoid B-cells with plasmacytoid features (2 of 3) and conspicuous absence of large lymphoma cells (3 of 3). By immunohistochemistry, cyclin D1 was positive (3 of 3), CD23 was negative (3 of 3), and aberrant expression of CD5/CD43 was present in 1 case. Ki67 labeling was greater than 50% in 1 case and 10% to 25% in the other 2 cases. Evidence of the t(11;14) was detectable in all by molecular techniques. One patient died within 15 months, and the other 2 patients had widely disseminated diseases at the last follow-up (8 months). Based on these features, we believed that the best classification for these lesions is the marginal zone B-cell lymphoma-like mantle cell lymphoma.  相似文献   
96.
目的:评估社区药房药师抗生素耐药认知与不凭处方调配抗生素行为,分析二者之间的关系。方法:于2016年对西安市社区药房药师开展问卷调查,使用视觉模拟量尺,测量受访药师对抗生素耐药的认知,自报不凭处方调配抗生素行为,应答率为77.3%(99/128)。对数据进行描述,检验不同行为组间认识的差异性。结果:多数受访药师对抗生素耐药具有基本认知,74.8%(74/99)的被调查者报告了不凭处方调配抗生素的行为;未发现抗生素耐药认知与不凭处方调配抗生素行为之间的显著性关系。结论:社区药房药师不规范的抗生素调配行为比较普遍。仅通过强化认知水平来降低不凭处方的调配行为难以取得良好效果。管理药师群体和公众抗生素用药习惯,治理社区药房不规范药品销售行为,可能是更好的策略。  相似文献   
97.
Oxidative stress has a causative role in ischemic reperfusion-induced cell death. Evidence has shown that metformin is capable to reduce ischemic reperfusion injuries. The current study investigated the effect of metformin on ischemia/reperfusion-induced apoptosis in PC12 cells by evaluation of Bcl-2 family proteins expression. Cells were exposed to a time-dependent in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) injury and then treated with metformin. The intracellular reactive oxygen species (ROS) levels were measured. Western blotting was used to examine the expression of anti- and pro-apoptotic proteins. Moreover, the number of apoptotic cell death was evaluated by TUNEL assay. Our results showed that metformin attenuated ROS generation, downregulated pro-apoptotic BAX expression, and upregulated expression of the Bcl-2 protein in the PC12 cells. Moreover, metformin reduced cell death under OGD/R condition which was confirmed by lower apoptotic cell death in the TUNEL assay. These findings suggest that neuroprotective effect of metformin on OGD/R-induced cell death is possibly mediated by inhibition of ROS-induced apoptosis pathway.  相似文献   
98.
Are  Chandrakanth  Tyler  D.  Howe  J.  Olivares  A.  Nissan  A.  Zippel  D.  Gupta  A.  Savant  D.  D’Ugo  D.  Rubio  I.  Bargallo-Rocha  J. E.  Martinez-Said  H.  Takeuchi  H.  Taketomi  A.  Oliveira  A. F.  Ribeiro  H. S. Castro  Cheema  M. A.  Majid  H. J.  Chen  G.  Roviello  F.  Gronchi  A.  Leon  A.  Lee  W. Y.  Park  D. J.  Park  J.  Auer  R.  Gawad  W. A.  Zaghloul  A. 《Annals of surgical oncology》2022,29(5):2773-2783
Annals of Surgical Oncology - The purpose of this article is to summarize the opinions of the surgical oncology leaders from the Global Forum of Cancer Surgeons (GFCS) about the global impact of...  相似文献   
99.
Cell therapy with autologous donor‐specific regulatory T cells (Tregs) is a promising strategy to minimize immunosuppression in transplant recipients. Chimeric antigen receptor (CAR) technology has recently been used successfully to generate donor‐specific Tregs and overcome the limitations of enrichment protocols based on repetitive stimulations with alloantigens. However, the ability of CAR‐Treg therapy to control alloreactivity in immunocompetent recipients is unknown. We first analyzed the effect of donor‐specific CAR Tregs on alloreactivity in naive, immunocompetent mice receiving skin allografts. Tregs expressing an irrelevant or anti‐HLA‐A2‐specific CAR were administered to Bl/6 mice at the time of transplanting an HLA‐A2+ Bl/6 skin graft. Donor‐specific CAR‐Tregs, but not irrelevant‐CAR Tregs, significantly delayed skin rejection and diminished donor‐specific antibodies (DSAs) and frequencies of DSA‐secreting B cells. Donor‐specific CAR‐Treg–treated mice also had a weaker recall DSA response, but normal responses to an irrelevant antigen, demonstrating antigen‐specific suppression. When donor‐specific CAR Tregs were tested in HLA‐A2‐sensitized mice, they were unable to delay allograft rejection or diminish DSAs. The finding that donor‐specific CAR‐Tregs restrain de novo but not memory alloreactivity has important implications for their use as an adoptive cell therapy in transplantation.  相似文献   
100.
Journal of Robotic Surgery - Inadequacies exist in the ergonomics of upper body positioning of robotic surgeons; these deficits in biomechanical efficacy predispose surgeons to musculoskeletal...  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