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   297876篇
  免费   22650篇
  国内免费   8080篇
耳鼻咽喉   2673篇
儿科学   10524篇
妇产科学   5014篇
基础医学   45915篇
口腔科学   7492篇
临床医学   19441篇
内科学   56742篇
皮肤病学   6334篇
神经病学   22726篇
特种医学   8717篇
外国民族医学   57篇
外科学   37091篇
综合类   25921篇
现状与发展   30篇
预防医学   14181篇
眼科学   4343篇
药学   29851篇
  23篇
中国医学   7427篇
肿瘤学   24104篇
  2023年   6005篇
  2022年   9770篇
  2021年   13154篇
  2020年   10603篇
  2019年   17656篇
  2018年   14945篇
  2017年   10956篇
  2016年   8256篇
  2015年   10279篇
  2014年   14146篇
  2013年   14336篇
  2012年   12871篇
  2011年   18235篇
  2010年   13326篇
  2009年   13119篇
  2008年   12575篇
  2007年   10953篇
  2006年   9805篇
  2005年   9021篇
  2004年   8059篇
  2003年   6599篇
  2002年   5905篇
  2001年   5627篇
  2000年   6021篇
  1999年   6048篇
  1998年   5443篇
  1997年   4254篇
  1996年   3258篇
  1995年   2525篇
  1994年   2364篇
  1993年   1837篇
  1992年   1686篇
  1991年   1465篇
  1990年   1338篇
  1989年   1033篇
  1988年   992篇
  1987年   718篇
  1985年   3340篇
  1984年   4590篇
  1983年   3278篇
  1982年   3294篇
  1981年   3005篇
  1980年   2639篇
  1979年   2403篇
  1978年   1959篇
  1977年   1681篇
  1976年   1798篇
  1975年   1508篇
  1974年   1322篇
  1973年   1232篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Thoracic endovascular aortic repair (TEVAR) for aneurysmal chronic dissection is often complicated by retrograde filling of the false lumen and dissected distal landing zone. A “cheese wire”-style fenestration of the dissection intimal flap can create a landing zone facilitating TEVAR. This technique successfully aided TEVAR in 3 patients with an average age of 57.3 years. Complications included type III endoleak requiring relining and renal artery occlusion requiring stent placement. Average duration of clinical follow-up was 19 ± 4 months. Imaging follow-up was 8 ± 10 months. All patients have survived for more than 1 year without aneurysm enlargement.  相似文献   
92.
93.
94.
PurposeTo retrospectively evaluate the safety and effectiveness of the Covera stent graft (SG) for the treatment of dysfunctional or thrombosed arteriovenous grafts (AVGs).Materials and MethodsWithin 29 months (February 2016–August 2018), 79 patients underwent Covera SG placement in the authors’ department for the treatment of dysfunctional AVGs. Data were available for 64 patients who underwent 64 procedures, using 64 devices. Minimum follow-up was 6 months, unless reintervention occurred. Mean follow-up was 277 days (6–923 days). Treatment characteristics were 51 cases with venous-graft anastomosis (VGA) stenosis (79.7%), 13 cases of puncture zone stenosis (20.3%), 14 cases of in SG stenosis (21.9%), 8 cases of pseudoaneurysm treatment (12.5%) (1 treatment area might have had more than 1 characteristic). Thirty-six patients presented with thrombosis (56.2%), and 31 of 64 case were de novo treatment areas (48.4%). Primary outcome measurements were technical success and post-intervention primary patency (PIPP) at 6 months, whereas secondary outcome measurements included factors influencing primary outcome.ResultsTechnical success was 100%. Median PIPP was 336 days, and 73.6% of treatment areas were patent at 6 months. There were no significant differences in terms of PIPP when de novo treatment areas were compared with restenotic areas (519 vs. 320 days, respectively; P = .1); patients who presented with versus those who presented without thrombosis (320 vs. 583 days, respectively; P = .07); puncture zone stenosis or elsewhere (329 vs. 686 days, respectively; P = .52); and VGA stenosis or elsewhere (336 vs. 335 days, respectively; P = .9).ConclusionsUse of the Covera SG for AVG treatment was safe and effective in every type of treatment area presented in this retrospective analysis.  相似文献   
95.
BackgroundBurnout in teachers has been linked to decreased effectiveness as educators, and suboptimal interactions with students. The purpose of this pilot study was to assess the outcomes of a brief Stress Management and Resiliency Training (SMART) program for public school staff.Materials and methodsThis single-arm, prospective trial involved an investigation of the effects of a brief SMART program on participant stress, anxiety, resilience, gratitude, happiness, life satisfaction, and quality of life (QOL).ResultsSignificant improvements were noted in participant anxiety (P < 0.001), stress (P = 0.003), gratitude (P = 0.001), happiness (P < 0.001), life satisfaction (P < 0.001), and QOL (P < 0.001). Most participants reported that the skills learned positively affected interactions with students (77.2%) and coworkers (72.2%).ConclusionsThe SMART program showed promising effectiveness for improving anxiety, stress, gratitude, happiness, life satisfaction and QOL. Given the prevalence and impact of teacher burnout, larger, controlled trials and broader dissemination of the intervention are warranted.  相似文献   
96.
《Cancer cell》2021,39(11):1497-1518.e11
  1. Download : Download high-res image (282KB)
  2. Download : Download full-size image
  相似文献   
97.
Caring is typically constructed as a feminised practice, resulting in women shouldering the burden of care-related work. Health-seeking behaviours are also constructed as feminine and men have poorer health outcomes globally. Employing men as carers may not only improve the health of the men they assist but also be transformative with regards to gendered constructions of caring. Using semi-structured interviews and observational home visits, this study explored the techniques that community care workers employ when working with male clients. The empirical analysis draws on the perspectives of eight care workers and three of their male clients from the Cape Town area. Interviews reveal how care workers and clients perform and negotiate masculinities as they navigate hegemonic masculine norms that require men to act tough, suppress emotions and deny weakness and sickness. Both parties bump up against ideals of what it means to be a man as they strive to provide care and receive support. Community care workers avoid rupturing client performances of hegemonic masculinities which inhibit confession and support. To do this, they use techniques of indirectly broaching sensitive subjects, acting in a friendly way and being clear about the intention of their work.  相似文献   
98.
99.
《Vaccine》2020,38(33):5337-5342
Freezing of alum-based vaccines drastically alters their colloidal composition and leads to irreversible cluster formation. The loss of stability is well described, but the impact of frost damage on the functionality of the induced and secreted antibody repertoire has not been studied in detail. We therefore applied our single-cell measurement platform to extract the frequencies of Immunoglobulin G-secreting cells in combination with individual secretion rates and affinities. We showed that, frost-damaged or not, the tested vaccine was able to generate similar frequencies of total and antigen-affine IgG-secreting cells. Additionally, the frost-damaged vaccine stimulated a similar T-cell cytokine secretion pattern when compared to the regularly stored vaccine. However, frost-damaged vaccines induced no efficient affinity maturation and a complete collapse of the affinity distribution was observed. This study unveiled the impact of frost-damage to alum-based vaccines on the induced secreted antibody repertoire, and illustrated the power of functional single-antibody analysis.  相似文献   
100.
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