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   2601678篇
  免费   185154篇
  国内免费   7647篇
耳鼻咽喉   34378篇
儿科学   85385篇
妇产科学   71816篇
基础医学   365507篇
口腔科学   69999篇
临床医学   235375篇
内科学   519010篇
皮肤病学   62669篇
神经病学   214590篇
特种医学   100430篇
外国民族医学   736篇
外科学   388536篇
综合类   50458篇
现状与发展   5篇
一般理论   969篇
预防医学   196516篇
眼科学   57097篇
药学   188999篇
  8篇
中国医学   5377篇
肿瘤学   146619篇
  2021年   20221篇
  2019年   20830篇
  2018年   29554篇
  2017年   22796篇
  2016年   26493篇
  2015年   29765篇
  2014年   40816篇
  2013年   60889篇
  2012年   80974篇
  2011年   85284篇
  2010年   51448篇
  2009年   49501篇
  2008年   79710篇
  2007年   84529篇
  2006年   86214篇
  2005年   82406篇
  2004年   79494篇
  2003年   76733篇
  2002年   74033篇
  2001年   128772篇
  2000年   131696篇
  1999年   110853篇
  1998年   31452篇
  1997年   28081篇
  1996年   28333篇
  1995年   27503篇
  1994年   25178篇
  1993年   23507篇
  1992年   85438篇
  1991年   81760篇
  1990年   79001篇
  1989年   76262篇
  1988年   69665篇
  1987年   68133篇
  1986年   63695篇
  1985年   60661篇
  1984年   45052篇
  1983年   38043篇
  1982年   22506篇
  1981年   20029篇
  1979年   39054篇
  1978年   27504篇
  1977年   23313篇
  1976年   21535篇
  1975年   22855篇
  1974年   26841篇
  1973年   25415篇
  1972年   23807篇
  1971年   22017篇
  1970年   20231篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
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   
73.
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   
74.
75.
76.
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.  相似文献   
77.
78.
79.
The value of adding simeprevir (SMV) vs placebo (PBO) to peginterferon and ribavirin (PR) for treatment of chronic hepatitis C virus infection was examined using patient‐reported outcomes (PROs); further, concordance of PROs with virology endpoints and adverse events (AEs) was explored. Patients (= 768 SMV/PR,= 393 PBO/PR) rated fatigue (FSS), depressive symptoms (CES‐D) and functional impairment (WPAI: Hepatitis C Productivity, Daily Activity and Absenteeism) at baseline and throughout treatment in three randomised, double‐blind trials comparing the addition of SMV or PBO during initial 12 weeks of PR. PR was administered for 48 weeks (PBO group) and 24/48 weeks (SMV group) using a response‐guided therapy (RGT) approach. Mean PRO scores (except Absenteeism) worsened from baseline to Week 4 to the same extent in both groups but reverted after Week 24 for SMV/PR and only after Week 48 for PBO/PR. Accordingly, there was a significantly lower area under the curve (baseline–Week 60, AUC60) and fewer weeks with clinically important worsening of scores in the SMV/PR group at any time point. Incidences of patients with fatigue and anaemia AEs were similar in both groups, but FSS scores showed that clinically important increases in fatigue lasted a mean of 6.9 weeks longer with PBO/PR (P < 0.001). PRO score subgroup analysis indicated better outcomes for patients who met the criteria for RGT or achieved sustained virological response 12 weeks post‐treatment (SVR12); differences in mean PRO scores associated with fibrosis level were only observed with PBO/PR. Greater efficacy of SMV/PR enabled reduced treatment duration and reduced time with PR‐related AEs without adding to AE severity.  相似文献   
80.
Platelet transfusions are a life-saving medical intervention used for the treatment of thrombocytopenia or hemorrhage. Extensive research has gone into trying to understand how to store platelets prior to the transfusion event. Much has been learned about storage bag materials, synthetic solutions, and how temperature impacts platelet viability and function. While room temperature storage of platelets preserves 24-hour in vivo platelet recovery and survival there is a greater risk for bacterial growth. Therefore, cold storage of platelets has become attractive due to the reduction in potential bacterial proliferation and the maintenance of platelet function beyond 5 days of storage. Cold stored platelets, however, have their own set of challenges. Cold stored platelets become activated through several mechanisms. The morphological and molecular changes that occur due to cold exposure enhance their ability to participate in the hemostatic process at the cost of rapid clearance from circulation. This review focuses on the underlying mechanisms leading to cold platelet activation and the receptor modifications involved in platelet clearance.  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