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   322550篇
  免费   23758篇
  国内免费   5295篇
耳鼻咽喉   4992篇
儿科学   10073篇
妇产科学   5473篇
基础医学   28736篇
口腔科学   10223篇
临床医学   29799篇
内科学   43456篇
皮肤病学   5406篇
神经病学   18783篇
特种医学   10717篇
外国民族医学   11篇
外科学   44606篇
综合类   37634篇
现状与发展   10篇
一般理论   25篇
预防医学   32781篇
眼科学   4185篇
药学   25211篇
  348篇
中国医学   27039篇
肿瘤学   12095篇
  2023年   7105篇
  2022年   11146篇
  2021年   15491篇
  2020年   14181篇
  2019年   20303篇
  2018年   17217篇
  2017年   12602篇
  2016年   9327篇
  2015年   9399篇
  2014年   17661篇
  2013年   16893篇
  2012年   14371篇
  2011年   18821篇
  2010年   13076篇
  2009年   11893篇
  2008年   11409篇
  2007年   10929篇
  2006年   9248篇
  2005年   8493篇
  2004年   7366篇
  2003年   6332篇
  2002年   5609篇
  2001年   5291篇
  2000年   5903篇
  1999年   5734篇
  1998年   5064篇
  1997年   3921篇
  1996年   2863篇
  1995年   2355篇
  1994年   2249篇
  1993年   1784篇
  1992年   1772篇
  1991年   1529篇
  1990年   1452篇
  1989年   1235篇
  1988年   1231篇
  1987年   974篇
  1985年   3862篇
  1984年   5141篇
  1983年   3733篇
  1982年   4070篇
  1981年   3475篇
  1980年   3055篇
  1979年   2811篇
  1978年   2316篇
  1977年   1949篇
  1976年   2176篇
  1975年   1735篇
  1974年   1509篇
  1973年   1437篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
81.
82.
83.
84.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
85.
86.
目的探讨中西医结合护理改善老年高血压患者心理状态及生活质量的效果。方法在医院2018年1月—2018年6月就诊的老年高血压患者中选出60例,按照随机数字法的原则,分成研究组(n=30)和参考组(n=30)。参考组采用单一西医护理,研究组在此之外联合中医护理,比较两组患者的临床疗效。结果入院时研究组与参考组SAS、SDS、SF-6评分差异不显著(P>0.05),护理后1月、3月与参考组相比,研究组SAS、SDS评分显著降低(P<0.05),SF-6评分显著升高(P<0.05);研究组患者对中西结合护理满意度为96.67%,参考组患者对西医护理满意度为73.33%,研究组满意度较参考组高,差异显著(P<0.05)。结论中西医结合护理能够有效改善老年高血压患者的心理状态,提高生活质量。  相似文献   
87.
David Marr's three-level method for completely understanding a cognitive system and the importance he attaches to the computational level are so familiar as to scarcely need repeating. Fewer seem to recognize that Marr defends his famous method by criticizing the “reductionistic approach.” This sets up a more interesting relationship between Marr and reductionism than is usually acknowledged. I argue that Marr was correct in his criticism of the reductionists of his time—they were only describing (cellular activity), not explaining (cognitive functions). But a careful metascientific account of reductionistic neuroscience over the past two decades reveals that Marr's criticisms no longer have force. Contemporary neuroscience now explains cognition directly, although in a fashion—causal-mechanistically—quite different than Marr recommended. So while Marr was correct to reject the reductionism of his day and offer an alternative method for genuinely explaining cognition, contemporary cognitive scientists now owe us a new defense of Marr's famous method and the advantages of its explanations over the type now pursued successfully in current reductionist neuroscience. There are familiar reasons for thinking that this debt will not be paid easily.  相似文献   
88.
89.
《Vaccine》2020,38(45):7118-7128
IntroductionToward the Global Vaccine Action Plan 2020 goal, almost 90% of countries have established a National Immunization Technical Advisory Group (NITAG). However, little is known about NITAG's contributions to governance.MethodsIn 2017–2018, a two-step, qualitative retrospective study was conducted. Jordan (JO), Argentina (AR), and South Africa (SA) were selected owing to government-financed NITAGs from middle-income countries (MICs), geographic diversity, and a vaccine introduction with NITAG support. Country case studies were developed, collecting data through desk review and face-to-face key informant interviews (KIIs) from Ministry of Health (MoH) and NITAG. Case studies were analyzed together, to assess governance applying the European Observatory on Health Systems and Policies framework focusing on transparency, accountability, participation, integrity, and policy capacity (TAPIC).ResultsDocument review and 53 KII (22 AR, 20 SA, 11 JO) showed NITAGs played a pivotal role as advisors promoting a culture of evidence-informed policies. NITAGs strengthened governance, although practices varied among countries. Meetings were conducted behind-closed-doors, participation restricted to members, only in one country agendas, and recommendations were public (AR). To increase participation, policy capacity, and transparency, countries considered adding experts in communications, advocacy, and economics. AR and SA contemplated including community members. NITAGs functioned autonomously from the government, with no established internal or external monitoring or supervision. NITAG meeting minutes allowed the review of integrity, adherence to terms of reference, standard operating procedures, and conflict of interest (CoI). For the most part, NITAGs abided by their mandates. Significant issues were related to the level of MoH support and oversight of CoI declaration and documentation.ConclusionsSystematically implementing governance approaches could improve processes, better tailor policies, and implementation. The long-term survival and resilience of NITAGs in these countries showed they play a significant role in strengthening governance. Lessons learned could be useful to those promoting country-driven evidence-informed decision-making.  相似文献   
90.
  1. Download : Download high-res image (232KB)
  2. Download : Download full-size image
  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