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   27271篇
  免费   2372篇
  国内免费   44篇
耳鼻咽喉   238篇
儿科学   810篇
妇产科学   703篇
基础医学   3481篇
口腔科学   520篇
临床医学   3607篇
内科学   4688篇
皮肤病学   328篇
神经病学   2667篇
特种医学   673篇
外科学   3217篇
综合类   677篇
一般理论   45篇
预防医学   3170篇
眼科学   712篇
药学   2104篇
中国医学   26篇
肿瘤学   2021篇
  2023年   165篇
  2022年   204篇
  2021年   473篇
  2020年   356篇
  2019年   521篇
  2018年   624篇
  2017年   473篇
  2016年   529篇
  2015年   577篇
  2014年   764篇
  2013年   1129篇
  2012年   1642篇
  2011年   1592篇
  2010年   884篇
  2009年   786篇
  2008年   1376篇
  2007年   1486篇
  2006年   1349篇
  2005年   1364篇
  2004年   1309篇
  2003年   1220篇
  2002年   1148篇
  2001年   677篇
  2000年   609篇
  1999年   567篇
  1998年   333篇
  1997年   248篇
  1996年   268篇
  1995年   244篇
  1994年   224篇
  1993年   224篇
  1992年   407篇
  1991年   398篇
  1990年   428篇
  1989年   381篇
  1988年   377篇
  1987年   358篇
  1986年   350篇
  1985年   306篇
  1984年   249篇
  1983年   199篇
  1982年   145篇
  1981年   126篇
  1979年   238篇
  1978年   164篇
  1977年   138篇
  1976年   122篇
  1975年   143篇
  1974年   167篇
  1973年   136篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Patient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty-four reviews were quantitative or mixed-methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost-effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost-effectiveness of navigation in screening programs.  相似文献   
2.
This article describes a case of anaphylaxis secondary to chlorhexidine during urethral catheterisation. Despite little evidence for the use of antiseptic lubricants in preventing catheter-associated urinary tract infections, the distribution and use of such products continues to be widespread. Chlorhexidine-free lubricating gel is widely available and should be used for urological procedures wherever possible.  相似文献   
3.
4.
5.
Inbred mouse strains are the most widely used mammalian model organism in biomedical research owing to ease of genetic manipulation and short lifespan; however, each inbred strain possesses a unique repertoire of deleterious homozygous alleles that can make a specific strain more susceptible to a particular disease. In the current study, we report dystrophic cardiac calcinosis (DCC) in C.B‐17 SCID male mice at 10 weeks of age with no significant change in cardiac function. Acquisition of DCC was characterized by myocardial injury, fibrosis, calcification, and necrosis of the tissue. At 10 weeks of age, 38% of the C.B‐17 SCID mice from two different commercial colonies exhibited significant calcinosis on the ventricular epicardium, predominantly on the right ventricle. The frequency of calcinosis was more than 50% for mice obtained from Taconic's Cambridge City colony and 25% for mice obtained from Taconic's German Town colony. Interestingly, the DCC phenotype did not affect cardiac function at 10 weeks of age. No differences in echocardiography or electrocardiography were observed between the calcinotic and non‐calcinotic mice from either colony. Our findings suggest that C.B‐17 SCID mice exhibit DCC as early as 10 weeks of age with no significant impact on cardiac function. This strain of mice should be cautiously considered for the study of cardiac physiology.  相似文献   
6.
7.
8.
9.
Ischemic brain injury causes neuronal death and inflammation. Inflammation activates protein-tyrosine phosphatase 1B (PTP1B). Here, we tested the significance of PTP1B activation in glutamatergic projection neurons on functional recovery in two models of stroke: by photothrombosis, focal ischemic lesions were induced in the sensorimotor cortex (SM stroke) or in the peri-prefrontal cortex (peri-PFC stroke). Elevated PTP1B expression was detected at 4 days and up to 6 weeks after stroke. While ablation of PTP1B in neurons of neuronal knockout (NKO) mice had no effect on the volume or resorption of ischemic lesions, markedly different effects on functional recovery were observed. SM stroke caused severe sensory and motor deficits (adhesive removal test) in wild type and NKO mice at 4 days, but NKO mice showed drastically improved sensory and motor functional recovery at 8 days. In addition, peri-PFC stroke caused anxiety-like behaviors (elevated plus maze and open field tests), and depression-like behaviors (forced swimming and tail suspension tests) in wild type mice 9 and 28 days after stroke, respectively, with minimal effect on sensory and motor function. Peri-PFC stroke-induced affective disorders were associated with fewer active (FosB+) neurons in the PFC and nucleus accumbens but more FosB+ neurons in the basolateral amygdala, compared to sham-operated mice. In contrast, mice with neuronal ablation of PTP1B were protected from anxiety-like and depression-like behaviors and showed no change in FosB+ neurons after peri-PFC stroke. Taken together, our study identifies neuronal PTP1B as a key component that hinders sensory and motor functional recovery and also contributes to the development of anxiety-like and depression-like behaviors after stroke. Thus, PTP1B may represent a novel therapeutic target to improve stroke recovery. All procedures for animal use were approved by the Animal Care and Use Committee of the University of Ottawa Animal Care and Veterinary Service (protocol 1806) on July 27, 2018.Key Words: adhesive removal test, anxiety, depression, elevated plus maze, forced swimming test, Iba1, interleukin-1β, microglia, open field test, tail suspension test, tumor necrosis factor-α

Chinese Library Classification No. R453; R741; R364.5  相似文献   
10.
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