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   278101篇
  免费   23644篇
  国内免费   6502篇
耳鼻咽喉   3554篇
儿科学   5976篇
妇产科学   4271篇
基础医学   22687篇
口腔科学   8131篇
临床医学   25982篇
内科学   27998篇
皮肤病学   2940篇
神经病学   13094篇
特种医学   7491篇
外国民族医学   16篇
外科学   35484篇
综合类   45500篇
现状与发展   12篇
一般理论   29篇
预防医学   32126篇
眼科学   2794篇
药学   26099篇
  433篇
中国医学   32737篇
肿瘤学   10893篇
  2024年   707篇
  2023年   5331篇
  2022年   8050篇
  2021年   13713篇
  2020年   12775篇
  2019年   14288篇
  2018年   12778篇
  2017年   11170篇
  2016年   10176篇
  2015年   9557篇
  2014年   18864篇
  2013年   19038篇
  2012年   16425篇
  2011年   18199篇
  2010年   15123篇
  2009年   12746篇
  2008年   11863篇
  2007年   12039篇
  2006年   10559篇
  2005年   8963篇
  2004年   7398篇
  2003年   6478篇
  2002年   5035篇
  2001年   4306篇
  2000年   3655篇
  1999年   3049篇
  1998年   2494篇
  1997年   2255篇
  1996年   1873篇
  1995年   1852篇
  1994年   1681篇
  1993年   1427篇
  1992年   1329篇
  1991年   1222篇
  1990年   1050篇
  1989年   1030篇
  1988年   952篇
  1987年   859篇
  1986年   783篇
  1985年   2209篇
  1984年   2500篇
  1983年   1600篇
  1982年   2086篇
  1981年   1536篇
  1980年   1350篇
  1979年   1223篇
  1978年   1009篇
  1977年   790篇
  1976年   875篇
  1975年   586篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
82.
《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   
83.
84.
目的 探讨模拟诊疗在留学生心血管内科实习带教中的应用效果。方法 将35名留学生随机编号,分成试验组和对照组。试验组18名学生分成3组(每组6名)进行模拟诊疗教学,对照组17名学生进行常规实习。通过填写评价单和相关的临床能力测试对两组教学效果进行评价。选用SPSS 19.0软件进行t检验。结果 参与模拟诊疗教学的留学生均希望在各科实习中多采用此方法。在临床能力测试方面,试验组学生在病史采集[(22.16±2.17)vs.(20.33±2.03)]、体格检查[(23.05±1.79)vs.(19.78±2.05)]及回答问题[(23.50±1.47)vs.(19.56±1.92)]方面均优于对照组,差异有统计学意义(P<0.05)。但是在病历书写方面,两组差异无统计学意义(P>0.05)。结论 利用高仿真的模拟诊疗教学手段,弥补了留学生在实习期间不能充分接触患者的缺陷,有助于提高其临床操作技能、增强医患沟通能力等医学职业素养。  相似文献   
85.
《Clinical neurophysiology》2020,131(1):259-264
ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS.  相似文献   
86.
87.
88.
89.
90.
Caring for patients with end-stage kidney disease (ESKD) in the United States is challenging, due in part to the complex epidemiology of the disease's progression as well as the ways in which care is delivered. As CKD progresses toward ESKD, the number of comorbidities increases and care involves multiple healthcare providers from multiple subspecialties. This occurs in the context of a fragmented US healthcare delivery system that is traditionally siloed by provider specialty, organization, as well as systems of payment and administration. This article describes the role of care fragmentation in the delivery of optimal ESKD care and identifies research gaps in the evidence across the continuum of care. We then consider the impact of care fragmentation on ESKD care from the patient and health system perspectives and explore opportunities for system-level interventions aimed at improving care for patients with ESKD.  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