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   4221702篇
  免费   361412篇
  国内免费   15062篇
耳鼻咽喉   60856篇
儿科学   132599篇
妇产科学   112020篇
基础医学   645343篇
口腔科学   118561篇
临床医学   384655篇
内科学   760719篇
皮肤病学   103220篇
神经病学   361567篇
特种医学   170332篇
外国民族医学   912篇
外科学   648268篇
综合类   125882篇
现状与发展   23篇
一般理论   2613篇
预防医学   356663篇
眼科学   100048篇
药学   300610篇
  20篇
中国医学   10976篇
肿瘤学   202289篇
  2021年   49815篇
  2020年   35513篇
  2019年   58631篇
  2018年   73276篇
  2017年   55620篇
  2016年   61936篇
  2015年   75191篇
  2014年   110011篇
  2013年   175456篇
  2012年   118249篇
  2011年   121398篇
  2010年   123102篇
  2009年   126171篇
  2008年   108539篇
  2007年   115159篇
  2006年   124658篇
  2005年   119839篇
  2004年   120710篇
  2003年   111021篇
  2002年   101398篇
  2001年   153620篇
  2000年   149366篇
  1999年   137139篇
  1998年   65479篇
  1997年   61926篇
  1996年   59741篇
  1995年   60932篇
  1994年   55132篇
  1993年   51147篇
  1992年   103149篇
  1991年   98859篇
  1990年   93884篇
  1989年   91485篇
  1988年   85041篇
  1987年   83588篇
  1986年   79275篇
  1985年   77735篇
  1984年   65635篇
  1983年   58445篇
  1982年   47695篇
  1981年   44439篇
  1980年   41719篇
  1979年   57478篇
  1978年   46703篇
  1977年   41172篇
  1976年   38284篇
  1975年   37537篇
  1974年   42189篇
  1973年   40355篇
  1972年   37923篇
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
91.
Major depressive disorder and other neuropsychiatric disorders are often managed with long-term use of antidepressant medication. Fluoxetine, an SSRI antidepressant, is widely used as a first-line treatment for neuropsychiatric disorders. However, fluoxetine has also been shown to increase the risk of metabolic diseases such as non-alcoholic fatty liver disease. Fluoxetine has been shown to increase hepatic lipid accumulation in vivo and in vitro. In addition, fluoxetine has been shown to alter the production of prostaglandins which have also been implicated in the development of non-alcoholic fatty liver disease. The goal of this study was to assess the effect of fluoxetine exposure on the prostaglandin biosynthetic pathway and lipid accumulation in a hepatic cell line (H4-II-E-C3 cells). Fluoxetine treatment increased mRNA expression of prostaglandin biosynthetic enzymes (Ptgs1, Ptgs2, and Ptgds), PPAR gamma (Pparg), and PPAR gamma downstream targets involved in fatty acid uptake (Cd36, Fatp2, and Fatp5) as well as production of 15-deoxy-Δ12,14PGJ2 a PPAR gamma ligand. The effects of fluoxetine to induce lipid accumulation were attenuated with a PTGS1 specific inhibitor (SC-560), whereas inhibition of PTGS2 had no effect. Moreover, SC-560 attenuated 15-deoxy-Δ12,14PGJ2 production and expression of PPAR gamma downstream target genes. Taken together these results suggest that fluoxetine-induced lipid abnormalities appear to be mediated via PTGS1 and its downstream product 15d-PGJ2 and suggest a novel therapeutic target to prevent some of the adverse effects of fluoxetine treatment.  相似文献   
92.
93.
94.
95.
Biomedical Engineering - We present here an experimental study demonstrating the action of noninvasive high-intensity focused ultrasound (HIFU) on vein walls in the treatment of varicose disease....  相似文献   
96.
Bulletin of Experimental Biology and Medicine - Using the biomicroscopy method, we studied the reaction of arterial and venous vessels of the broad ligament of the uterus in outbred female rats to...  相似文献   
97.
98.

Interstitial lung disease (ILD) represents a significant cause of morbidity and mortality in systemic sclerosis (SSc). The purpose of this study was to examine recirculating lymphocytes from SSc patients for potential biomarkers of interstitial lung disease (ILD). Peripheral blood mononuclear cells (PBMCs) were isolated from patients with SSc and healthy controls enrolled in the Vanderbilt University Myositis and Scleroderma Treatment Initiative Center cohort between 9/2017–6/2019. Clinical phenotyping was performed by chart abstraction. Immunophenotyping was performed using both mass cytometry and fluorescence cytometry combined with t-distributed stochastic neighbor embedding analysis and traditional biaxial gating. This study included 34 patients with SSc-ILD, 14 patients without SSc-ILD, and 25 healthy controls. CD21lo/neg cells are significantly increased in SSc-ILD but not in SSc without ILD (15.4 ± 13.3% vs. 5.8 ± 0.9%, p = 0.002) or healthy controls (5.0 ± 0.5%, p < 0.0001). While CD21lo/neg B cells can be identified from a single biaxial gate, tSNE analysis reveals that the biaxial gate is comprised of multiple distinct subsets, all of which are increased in SSc-ILD. CD21lo/neg cells in both healthy controls and SSc-ILD are predominantly tBET positive and do not have intracellular CD21. Immunohistochemistry staining demonstrated that CD21lo/neg B cells diffusely infiltrate the lung parenchyma of an SSc-ILD patient. Additional work is needed to validate this biomarker in larger cohorts and longitudinal studies and to understand the role of these cells in SSc-ILD.

  相似文献   
99.
Lersch  F.  Zingg  T. J. G.  Knapp  J.  Stüber  F.  Hight  D.  Kaiser  H. A. 《Der Anaesthesist》2023,72(9):662-676
Die Anaesthesiologie - Die Elektroenzephalogramm(EEG)-gesteuerte Anästhesie ist aus modernen Operationssälen nicht mehr wegzudenken und hat sich als Standard-Monitoring etabliert. Viele...  相似文献   
100.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia.  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