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   34415篇
  免费   2174篇
  国内免费   799篇
耳鼻咽喉   225篇
儿科学   840篇
妇产科学   345篇
基础医学   2338篇
口腔科学   184篇
临床医学   6097篇
内科学   7305篇
皮肤病学   109篇
神经病学   1959篇
特种医学   2007篇
外国民族医学   4篇
外科学   4918篇
综合类   4452篇
现状与发展   1篇
一般理论   1篇
预防医学   1524篇
眼科学   1432篇
药学   2123篇
  16篇
中国医学   586篇
肿瘤学   922篇
  2024年   50篇
  2023年   559篇
  2022年   772篇
  2021年   1272篇
  2020年   1223篇
  2019年   1148篇
  2018年   1091篇
  2017年   1155篇
  2016年   1127篇
  2015年   1197篇
  2014年   2276篇
  2013年   2233篇
  2012年   2092篇
  2011年   2226篇
  2010年   1810篇
  2009年   1707篇
  2008年   1704篇
  2007年   1636篇
  2006年   1478篇
  2005年   1305篇
  2004年   1153篇
  2003年   927篇
  2002年   797篇
  2001年   687篇
  2000年   568篇
  1999年   525篇
  1998年   514篇
  1997年   494篇
  1996年   345篇
  1995年   330篇
  1994年   341篇
  1993年   286篇
  1992年   257篇
  1991年   214篇
  1990年   153篇
  1989年   156篇
  1988年   183篇
  1987年   130篇
  1986年   129篇
  1985年   172篇
  1984年   132篇
  1983年   100篇
  1982年   113篇
  1981年   120篇
  1980年   96篇
  1979年   85篇
  1978年   68篇
  1977年   59篇
  1976年   61篇
  1975年   34篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
3.
PurposeIn 2018, The Journal of Vascular and Interventional Radiology (JVIR) updated its guidelines regarding periprocedural antibiotics. However, some institutions are slower to adopt these new guidelines. Additionally, antibiotic-resistant bacteria and sepsis are serious concerns due in part to incorrect usage of antibiotics. The purpose of this study is to assess institutional adherence to 2018 JVIR guidelines for the purpose of improving antibiotic stewardship.Materials and methodsA total of 800 cases over a 10-month time period were retrospectively identified and charted following the release of guidelines. Inclusion criteria for the study were adults aged 21 years or older undergoing mediport placement, tunneled central line (TCL) placement, nephrostomy tube exchange, percutaneous biliary drain, or cholecystostomy tube exchange. Exclusion criteria included immunocompromised and pregnant individuals as 2018 guidelines may not fit these patient populations. Guideline adherence for each procedure was recorded as a percentage; the timing of the antibiotic usage was also recorded and compared to the guidelines (within 60 minutes before incision).ResultsIn total, 49 mediport placements, 118 tunneled central line placements – 44 hemodialysis (HD) catheters and 74 nonhemodialysis (non-HD) catheters, 100 nephrostomy exchanges, and 82 biliary tube exchanges were included. Antibiotics were used in 83.6% (41/49) of mediport patients, 11.3% (5/44) of non-HD TCL patients, 20.5% (15/74) of HD TCL patients, 55% (55/100) nephrostomy tube changes, and 65.4% (55/84) of biliary or cholecystostomy tube exchanges. Out of those given prophylaxis, guideline-recommended antibiotics were used in 100% (41/41) of mediport, 100% (20/20) of TCL (both HD and non-HD catheters), 9% (5/55) of nephrostomy tube exchanges, and 1.8% (1/55) of biliary tube exchanges. Guideline-recommended timing was followed in 75.3% across all cases (ranging from 72.2% in mediports to 79.3% in biliary exchanges).ConclusionThis study of antibiotic practices at a single university-based academic institution revealed that antibiotic usage is not fully up to date with 2018 guidelines. For mediports, non-HD TCL placements, and nephrostomy tube exchanges, institutional changes should be made to reduce periprocedural antibiotic use, as antibiotics are no longer recommended for these procedures. For HD TCL and biliary exchanges, proper adherence to recommended prophylactic antibiotics should be followed. In addition, education about the correct antibiotic timing should be emphasized to increase compliance with guidelines.  相似文献   
4.
5.
6.
7.
8.
BackgroundOur meta-analysis from 2013 showed that inserting a catheter intrathecally after an observed accidental dural puncture can reduce the need for epidural blood patch in labouring women requesting epidural analgesia. We updated our conventional meta-analysis and added a trial-sequential analysis (TSA).MethodsA systematic literature search was conducted to identify studies that compared inserting the catheter intrathecally with an epidural catheter re-site or with no intervention. The extracted data were pooled and the risk ratio (RR) and 95% confidence interval (95%CI) for the incidence of post-dural puncture headache (PDPH) was calculated, using the random effects model. A contour-enhanced funnel plot was constructed. A TSA was performed and the cumulative Z score, monitoring and futility boundaries were constructed.ResultsOur search identified 13 studies, reporting on 1653 patients, with a low risk of bias. The RR for the incidence of PDPH was 0.82 (95%CI 0.71 to 0.95) and the RR for the need for epidural blood patch was 0.62 (95%CI 0.49 to 0.79); heterogeneity of both analyses was high. The TSA showed that the monitoring or futility boundaries were not crossed, indicating insufficient data to exclude a type I error of statistical analysis. Contour-enhanced funnel plots were symmetric, suggesting no publication bias.ConclusionsConventional meta-analyses showed for the first time that intrathecal catheterisation can reduce the incidence of PDPH. However, TSA did not corroborate this finding. Despite increasing use in clinical practice there is no firm evidence on which to base a definite conclusion.  相似文献   
9.
Purpose: To describe how central venous access devices (CVADs) are utilized for ambulatory oncology patients and to evaluate the rate of complications. Method: Single institution retrospective study of oncology patients with CVADs who received systemic treatment at the Walker Family Cancer Centre (WFCC) between 1 January and 31 December 2018. Results: A total of 480 CVADS were placed in 305 patients, of which 408 (85%) were peripherally inserted central catheters (PICCs) and 72 (15%) were implanted vascular access devices (PORTs). The incidence of early and late complications was 9% and 24%, respectively. For the entire cohort, the rate of venous thromboembolism (VTE) was 16%, of which 9% were CVAD-related thrombosis (CRTs) and 7% were distant VTE. The CRT rates were similar for PICCs and PORTs (9% vs. 7%). A total of 6% of CVADs were complicated by infection (i.e., localized infections and bacteremia), with a total infection rate of 0.43 and 0.26 per 1000 indwelling days for PICCs and PORTs, respectively. The incidence of central line associated bloodstream infections (CLABSI) was greater for PICCs than PORTs, at a rate of 0.22 compared with 0.08 per 1000 indwelling days, respectively. The premature catheter removal rate was 26% for PICCs and 18% for PORTs. PORTs required more additional hospital visits. Conclusions: PICCs were utilized more frequently than PORTs and had a higher rate of premature removal. The rates of VTE and CRT were similar for both CVAD types. PORTs had a lower rate of infection per 1000 indwelling days. However, the management of PORT related complications required more visits to the hospital and oncology clinic.  相似文献   
10.
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