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   53231篇
  免费   2890篇
  国内免费   59篇
耳鼻咽喉   411篇
儿科学   1941篇
妇产科学   1606篇
基础医学   7389篇
口腔科学   2862篇
临床医学   6851篇
内科学   7849篇
皮肤病学   632篇
神经病学   5683篇
特种医学   2296篇
外科学   6473篇
综合类   143篇
一般理论   24篇
预防医学   5125篇
眼科学   627篇
药学   2636篇
中国医学   78篇
肿瘤学   3554篇
  2023年   934篇
  2022年   878篇
  2021年   1231篇
  2020年   1392篇
  2019年   1127篇
  2018年   1465篇
  2017年   1749篇
  2016年   1629篇
  2015年   1304篇
  2014年   2272篇
  2013年   2914篇
  2012年   2488篇
  2011年   2419篇
  2010年   2034篇
  2009年   2078篇
  2008年   2286篇
  2007年   2261篇
  2006年   2094篇
  2005年   1906篇
  2004年   1641篇
  2003年   1597篇
  2002年   1516篇
  2001年   1482篇
  2000年   1394篇
  1999年   1330篇
  1998年   597篇
  1997年   584篇
  1996年   616篇
  1995年   429篇
  1994年   405篇
  1993年   361篇
  1992年   1080篇
  1991年   1025篇
  1990年   963篇
  1989年   919篇
  1988年   916篇
  1987年   550篇
  1986年   255篇
  1985年   382篇
  1984年   395篇
  1983年   261篇
  1982年   290篇
  1981年   265篇
  1980年   278篇
  1979年   247篇
  1978年   272篇
  1977年   222篇
  1976年   226篇
  1975年   187篇
  1974年   212篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
1.
2.
BackgroundThe clinical importance of postoperative hyperamylasemia (POHA) grade is unknown. Our objectives were to evaluate the association of POHA grade with clinically relevant postoperative pancreatic fistula (CR-POPF) and compare its prognostic utility against postoperative day 1 drain fluid amylase (DFA-1).MethodsPatients who underwent pancreatectomy from January 2019 through March 2020 were identified in the ACS NSQIP pancreatectomy-targeted dataset. POHA grade was assigned using post-operative serum amylase and clinical sequelae. The primary outcome was CR-POPF within 30 days. The association of POHA grade with CR-POPF was assessed using multivariable logistic regression, and c-statistics were used to compare POHA grade versus DFA-1.ResultsPOHA occurred in 520 patients at 98 hospitals, including 261 (50.2%) with grade A, 234 (45.0%) with grade B, and 25 (4.8%) with grade C POHA. CR-POPFs were increased among patients with grade B (66.2%, OR 9.28 [5.84–14.73]) and C (68.0%, OR 10.50 [3.77–29.26]) versus grade A POHA (19.2%). POHA-inclusive models better predicted CR-POPF than those with DFA-1 alone (p < 0.002) and models with both predictors outperformed POHA alone (p = 0.039).ConclusionPOHA grade represents a measure of post-pancreatectomy outcomes that predicts CR-POPF and outperforms DFA-1 but must be aligned with new international definitions.  相似文献   
3.
《Clinical neurophysiology》2022,52(2):157-169
ObjectiveTo assess the inter-rater reliability of MScanFit MUNE using a “Round Robin” research design.MethodsTwelve raters from different centres examined six healthy study participants over two days. Median, ulnar and common peroneal nerves were stimulated, and compound muscle action potential (CMAP)-scans were recorded from abductor pollicis brevis (APB), abductor digiti minimi (ADM) and anterior tibial (TA) muscles respectively. From this we calculated the Motor Unit Number Estimation (MUNE) and “A50”, a motor unit size parameter. As statistical analysis we used the measures Limits of Agreement (LOA) and Coefficient of Variation (COV). Study participants scored their perception of pain from the examinations on a rating scale from 0 (no pain) to 10 (unbearable pain).ResultsBefore this study, 41.6% of the raters had performed MScanFit less than five times. The mean MUNE-values were: 99.6 (APB), 131.4 (ADM) and 126.2 (TA), with LOA: 19.5 (APB), 29.8 (ADM) and 20.7 (TA), and COV: 13.4 (APB), 6.3 (ADM) and 5.6 (TA). MUNE-values correlated to CMAP max amplitudes (R2-values were: 0.463 (APB) (p<0.001), 0.421 (ADM) (p<0.001) and 0.645 (TA) (p<0.001)). The average perception of pain was 4.DiscussionMScanFit indicates a high level of inter-rater reliability, even with only limited rater experience and is overall reasonably well tolerated by patients. These results may indicate MScanFit as a reliable MUNE method with potential as a biomarker in drug trials.  相似文献   
4.
5.
6.
7.
BackgroundSafe pharmaceutical care requires competent nurses with specific knowledge, skills and attitudes. It is unclear whether nursing students are adequately prepared to perform pharmaceutical care in practice. Mapping their pharmaceutical care competences can lead to a better understanding of the extent to which curricula fit expectations of the labour market.ObjectivesTo assess pharmaceutical care competences of final-year nursing students of different educational levels.DesignA cross-sectional survey design.SettingsIn 14 European countries, nursing schools who offer curricula for level 4 to 7 students were approached.ParticipantsThrough convenience sampling 1741 final-year student nurses of level 4 to 7 were included. Sampling strategies were country-specific.MethodsA web-platform was developed with an assessment of the level in which students mastered pharmaceutical care competences. Knowledge questions, case studies (basic/advanced level), self-reported practical skills and attitudes were evaluated.ResultsMean scores for knowledge questions differed significantly (p < 0.001) between level 5 (56/100), level 6 (68/100) and level 7 students (72/100). For basic cases level 5 students reached lower scores (64/100) compared with level 6 (71/100) and level 7 (72/100) students (p = 0.002 and p = 0.005). For more advanced cases no difference between levels was observed (overall mean 61/100). Most students (63–90 %) considered themselves skilled to perform pharmaceutical care and had positive attitudes towards their participation in pharmaceutical care (65–97 %).ConclusionsRelatively low knowledge scores were calculated for final-year student nurses. In some domains, lower levels of students might be insufficiently prepared to take up responsibilities in pharmaceutical care. Our assessment can be used as a tool for educators to evaluate how prepared nursing students are for pharmaceutical care. Its further implementation for students of different educational levels will allow benchmarking between the levels, both within and between countries.  相似文献   
8.
When the COVID-19 pandemic hit, blood transfusion services worldwide started collection of convalescent plasma as early as possible, as exemplified by the response in Norway. There were challenges related to donor selection, donor safety, testing for relevant antibodies and indications for and dosing of the convalescent plasma. As more knowledge became available, the product quality was more standardised. Multiple case reports, observational studies and some randomized studies were published during the pandemic, as well as laboratory studies reporting different approaches to antibody testing. The results were conflicting and the importance of convalescent plasma was disputed.Even though there has been strong international collaboration with involvement of many key organisations, we may better prepare for the next pandemic. An even stronger, more formalised collaboration between these organisations could provide more clear evidence of the importance of convalescent plasma, based on the principles of passive immunisation.  相似文献   
9.
10.
Glaucoma is a leading cause of irreversible blindness. The use of topical eye drops to reduce intraocular pressure remains the mainstay treatment. These eye drops frequently contain preservatives designed to ensure sterility of the compound. A growing number of clinical and experimental studies report the detrimental effects of not only these preservatives but also the active pharmaceutical compounds on the ocular surface, with resultant tear film instability and dry eye disease. Herein, we critically appraise the published literature exploring the effects of preservatives and pharmaceutical compounds on the ocular surface.  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