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   27168篇
  免费   3916篇
  国内免费   162篇
耳鼻咽喉   535篇
儿科学   833篇
妇产科学   695篇
基础医学   2950篇
口腔科学   587篇
临床医学   4575篇
内科学   5629篇
皮肤病学   828篇
神经病学   2269篇
特种医学   876篇
外国民族医学   1篇
外科学   3537篇
综合类   569篇
现状与发展   2篇
一般理论   20篇
预防医学   3309篇
眼科学   552篇
药学   1209篇
  1篇
中国医学   102篇
肿瘤学   2167篇
  2023年   462篇
  2022年   207篇
  2021年   464篇
  2020年   604篇
  2019年   367篇
  2018年   804篇
  2017年   766篇
  2016年   828篇
  2015年   934篇
  2014年   1023篇
  2013年   1509篇
  2012年   1092篇
  2011年   1065篇
  2010年   898篇
  2009年   1019篇
  2008年   1021篇
  2007年   961篇
  2006年   986篇
  2005年   936篇
  2004年   802篇
  2003年   767篇
  2002年   754篇
  2001年   811篇
  2000年   827篇
  1999年   717篇
  1998年   495篇
  1997年   474篇
  1996年   474篇
  1995年   426篇
  1994年   335篇
  1993年   280篇
  1992年   579篇
  1991年   575篇
  1990年   509篇
  1989年   532篇
  1988年   480篇
  1987年   483篇
  1986年   451篇
  1985年   437篇
  1984年   401篇
  1983年   283篇
  1982年   192篇
  1981年   205篇
  1980年   212篇
  1979年   276篇
  1978年   228篇
  1977年   184篇
  1976年   191篇
  1974年   220篇
  1973年   205篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
目的:通过Meta分析评价火针对脑卒中痉挛性偏瘫患者肢体功能康复的影响。方法:计算机检索Cochrane Library、Medline、Web of Science、EMbase、Ovid、Pubmed、中国生物医学文献数据库、中国知网、维普数据库、万方数据库中火针对脑卒中痉挛性偏瘫患者肢体功能进行干预的随机对照试验(RCT)。试验组为火针疗法或在对照组的基础上进行火针治疗,对照组为常规的康复锻炼、常规针刺(体针、电针等)、常规治疗等。采用Revman5.3软件对2组Fugl-Meyer运动功能量表(FMA)评分、临床痉挛指数(CSI)、有效率进行Meta分析。结果:共纳入16篇文献,包括1 061例研究对象。Meta分析结果显示:与对照组比较,试验组CSI [Z=4.55,P0.05,MD=-0.82,95%CI=(-1.17,-0.47)]、FMA评分[Z=7.43,P0.05,MD=9.00,95%CI=(6.63,11.38)]、有效率[Z=6.35,P0.05,OR=3.37,95%CI=(2.32,4.91)]均较优。结论:火针能改善脑卒中痉挛性偏瘫患者的肢体功能,促进患者的康复。  相似文献   
992.
Three separate approaches were applied to examine the general relationship between R, the rate of induction of specific enzymes (mitochondrial alpha-glycero-phosphate dehydrogenase and cytosolic malic enzyme) and q, the fractional nuclear occupancy by triiodothyronine in male Sprague-Dawley rats. Daily 200-microgram injections of triiodothyronine per 10u g body wt for 7 days resulted in saturation of the hepatic nuclear sites and the achievement of an apparent new steady state of enzyme levels. The increase achieved over base-line hypothyroid levels was then compared with the increment over hypothyroid base line characteristic of intact euthyroid animals with 47% of nuclear sites occupied. The maximal theoretical reate of steady-state enzyme induction could be protected on the basis of the observed maximal increase in enzyme activity observed 1 day after the injection of graded doses of hormone and lambda, the known fractional rate of enzyme dissipation. The 24-h dose-response studies were used to generate R as a continuous function of q, both in hypothyroid as well as in euthyroid animals. This approach involved the numerical solution of an ordinary differential equation describing the rate of change of enzyme as a function of R, which was assumed to be uniquely related to q. Results of these analyses indicated that the ratio of the maximal rate of induction of enzyme at full occupancy to the rate of induction under euthyroid conditions assumes a value between 9.0 and 19.5, depending on the precise analytic and experimental approach applied. This value is far in excess of the theoretical ratio 2.13 which on would anticipate if R were linearly related to q and 47% of the nuclear sites occupied under physiological conditions. Thus, the signal for enzyme induction appears to undergo progressjive amplification with increasing nuclear occupancy. Moreover, the curve describing the relationship between R and q appears highly nonlinear throughout (concave upwards). Although the molecular mechanism responsible for amplification is unknown, recognition of this phenomenon may be helpful in understanding tissue effects of thyroid hormone excess. Moreover, the analytic technique for determining R as a function of q may be of general applicability in studying hormonal response systems under nonsteady-state conditions.  相似文献   
993.
Promoting and retaining junior faculty are major challenges for many medical schools. High clinical workloads often limit time for scholarly projects and academic development, especially in anesthesiology. To address this, we created the East/West Visiting Scholars in Pediatric Anesthesia Program (ViSiPAP). The program's goal is to help “jumpstart” academic careers by providing opportunities for national exposure and recognition through invited lectures and collaborative opportunities. East/West ViSiPAP benefits the participating scholars, the home and hosting anesthesia departments, and pediatric anesthesia fellowship training programs. By fostering a sense of well‐being and inclusion in the pediatric anesthesia community, East/West ViSiPAP has the potential to increase job satisfaction, help faculty attain promotion, and reduce attrition. Faculty and trainees are exposed to new expertise and role models. Moreover, ViSiPAP provides opportunities for women and underrepresented in medicine faculty. This program can help develop today's junior faculty into tomorrow's leaders in pediatric anesthesia. We advocate for expanding the concept of ViSiPAP to other institutions in academic medicine.  相似文献   
994.
995.
996.
997.
The enthesis is a mineralized fibrocartilage transition that attaches tendon to bone and is vital for musculoskeletal function. Despite recent studies demonstrating the necessity of muscle loading for enthesis formation, the mechanisms that regulate enthesis formation and mechanoresponsiveness remain unclear. Therefore, the current study investigated the role of the gap junction protein connexin 43 in these processes by deleting Gja1 (the Cx43 gene) in the tendon and enthesis. Compared with their wild-type (WT) counterparts, mice lacking Cx43 showed disrupted entheseal cell alignment, reduced mineralized fibrocartilage, and impaired biomechanical properties of the supraspinatus tendon entheses during postnatal development. Cx43-deficient mice also exhibited reduced ability to complete a treadmill running protocol but no apparent deficits in daily activity, metabolic indexes, shoulder muscle size, grip strength, and major trabecular bone properties of the adjacent humeral head. To examine enthesis mechanoresponsiveness, young adult mice were subjected to modest treadmill exercise. Gja1 deficiency in the tendon and enthesis reduced entheseal anabolic responses to treadmill exercise: WT mice had increased expression of Sox9, Ihh, and Gli1 and increased Brdu incorporation, whereas Cx43-deficient mice showed no changes or decreased levels with exercise. Collectively, the results demonstrated an essential role for Cx43 in postnatal tendon enthesis formation, function, and response to loading; results further provided evidence implicating a link between Cx43 function and the hedgehog signaling pathway. © 2020 American Society for Bone and Mineral Research.  相似文献   
998.
We report a rare case of a 44-year-old male who underwent a diagnostic coronary angiogram following a non-ST elevation myocardial infarction complicated by an aortic valve leaflet tear requiring surgical intervention. Routine transthoracic echocardiogram demonstrated a mobile echogenic structure prolapsing into the left ventricular outflow tract. An intraoperative transesophageal echocardiogram confirmed that the structure originated from the ventricular side of left coronary cusp, causing malcoaptation between left and right coronary cusps, and subsequent moderate to severe aortic regurgitation.  相似文献   
999.
We report a case of invasive candidiasis causing a mycotic pseudoaneurysm involving the ascending aorta and pulmonary artery. The patient presented two years after heart-kidney transplant with acute limb ischemia resulting from embolization of fungal vegetations. Operative findings included a pseudoaneurysm resulting from near-complete dehiscence of the aortic suture line, and large vegetations within the ascending aorta extended to the aortic arch and pulmonary artery, with localized dehiscence of the pulmonic suture line. The ascending aorta was replaced, and the pulmonary artery was repaired with bovine pericardium. The patient did well, and blood cultures were negative at 6 months follow-up.  相似文献   
1000.
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