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   34305篇
  免费   2114篇
  国内免费   819篇
耳鼻咽喉   490篇
儿科学   1519篇
妇产科学   522篇
基础医学   2411篇
口腔科学   258篇
临床医学   4180篇
内科学   4487篇
皮肤病学   178篇
神经病学   1864篇
特种医学   1610篇
外国民族医学   3篇
外科学   7460篇
综合类   4626篇
现状与发展   2篇
预防医学   2469篇
眼科学   210篇
药学   2873篇
  20篇
中国医学   832篇
肿瘤学   1224篇
  2024年   28篇
  2023年   503篇
  2022年   824篇
  2021年   1276篇
  2020年   1243篇
  2019年   1174篇
  2018年   1168篇
  2017年   1072篇
  2016年   1190篇
  2015年   1228篇
  2014年   2495篇
  2013年   2316篇
  2012年   1991篇
  2011年   2138篇
  2010年   1706篇
  2009年   1726篇
  2008年   1735篇
  2007年   1694篇
  2006年   1568篇
  2005年   1342篇
  2004年   1146篇
  2003年   914篇
  2002年   838篇
  2001年   739篇
  2000年   536篇
  1999年   520篇
  1998年   420篇
  1997年   345篇
  1996年   321篇
  1995年   294篇
  1994年   253篇
  1993年   253篇
  1992年   243篇
  1991年   203篇
  1990年   187篇
  1989年   167篇
  1988年   150篇
  1987年   140篇
  1986年   148篇
  1985年   177篇
  1984年   133篇
  1983年   93篇
  1982年   139篇
  1981年   99篇
  1980年   75篇
  1979年   57篇
  1978年   69篇
  1977年   49篇
  1976年   30篇
  1973年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
PurposeTo report the 5-year results from the Pivotal Multicenter Trial of Ultrasound-Guided Percutaneous Arteriovenous Fistula (pAVF) Creation for Hemodialysis Access.Materials and MethodsThe retrospective review of 107 intent-to-treat (ITT) patients from the pivotal trial provided a long-term follow-up population (LTP) of 85 patients with a median follow-up duration of 50 months (range, 12–60 months). Data evaluated in the LTP group were fistula maturation and usage, secondary procedures, and complications. The Kaplan-Meier analysis of primary patency, assisted primary patency, cumulative patency, and functional patency (time from 2-needle cannulation to abandonment) were performed for the ITT population.ResultsIn the LTP, 99% (84 of 85) of fistulae were mature, with 99% (78 of 79) of patients requiring hemodialysis using their pAVF. Sustained fistula use (2-needle cannulation at the prescribed rate, 2 of 3 sessions) was achieved in 92% (78 of 85) of patients, with 7 patients not using their pAVF because they were not on dialysis (n = 4), were on peritoneal dialysis (n = 2), and refused to use fistula (n = 1). Fistula maintenance was required in 31.8% (27 of 85) of patients and included fistula dysfunction (21.2%), thrombosis (5.9%), cannulation injury (12.9%), and arm swelling (4.7%). The number of procedures performed per patient per year to maintain function and patency was 0.32 (91 of 288) for years 2–5. The cumulative patency rates were 89.5%, 88.4%, 88.4%, 85.6%, and 82.0% for years 1, 2, 3, 4, and 5, respectively. The functional patency was 91.8% at the end of the study. There were no major complications related to pAVF during the long-term follow-up.ConclusionsPercutaneous fistulae have provided clinically effective and durable access for hemodialysis with low complications. The continued use and evaluation of pAVF are warranted.  相似文献   
64.
65.
66.
BACKGROUNDCurrently, rectovaginal fistula (RVF) continues to be a surgical challenge worldwide, with a relatively low healing rate. Unclosed intermittent suture and poor suture materials may be the main reasons for this.AIMTo evaluate the efficacy and safety of stapled transperineal repair in treating RVF.METHODSThis was a retrospective cohort study conducted in the Coloproctology Department of The Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China). Adult patients presenting with RVF who were surgically managed by perineal repair between May 2015 and May 2020 were included. Among the 82 total patients, 37 underwent repair with direct suturing and 45 underwent repair with stapling. Patient demographic data, Wexner faecal incontinence score, and operative data were analyzed. Recurrence rate and associated risk factors were assessed.RESULTSThe direct suture and stapled repair groups showed similar clinical characteristics for aetiology, surgical history, fistula features, and perioperative Wexner score. The stapled repair group did not show superior results over the suture repair group in regard to operative time, blood loss, and hospital stay. However, the stapled repair group showed better postoperative Wexner score (1.04 ± 1.89 vs 2.73 ± 3.75, P = 0.021), less intercourse pain (1/45 vs 17/37, P = 0.045), and lower recurrence rate (6/45 vs 17/37, P = 0.001). There was no protective effect from previous repair history, smaller diameter of fistula (< 0.5 cm), better control of defecation (Wexner < 10), or stapled repair. Direct suture repair and preoperative high Wexner score (> 10) were risk factors for fistula recurrence. Furthermore, stapled repair gave better efficacy in treating complex RVFs (i.e., multiple transperineal repair history, mid-level fistula position, and poor control of defecation).CONCLUSIONStapled transperineal repair is advantageous for management of RVF, providing a high primary healing rate and low recurrence rate.  相似文献   
67.
BackgroundIt is new clinical interest higher serum amylase level with pancreatitis after pancreaticoduodenectomy (PD) correlates with postoperative pancreatic fistula (POPF). Nevertheless, its evidence and study were scarce. We aimed to investigate correlation of serum amylase level immediate after PD and POPF occurrence.MethodsOf 163 patients who underwent PD at between January 2009 and December 2019, retrospective analysis was conducted to identify risk factors including serum amylase level immediate after PD for POPF occurrence.ResultsOverall incidence of POPF (25/163) was 15.3%. The patients occurred a POPF had significantly higher level of serum amylase on POD0 compared to in whom without a POPF (414 vs 253, p < 0.001). In univariate analysis, ASA classification, post pancreatectomy acute pancreatitis (POAP, serum amylase on POD0 >285IU/L) and Fistula Risk Grade were correlated with POPF occurrence. In multivariable analysis, Fistula risk grade and POAP were significantly associated with developing POPF.ConclusionIn patients with higher serum amylase (>285IU/L) on POD0 with higher fistula risk grade, comprehensive management to achieve mitigation of POPF is important.  相似文献   
68.
A 70‐year‐old man with a history of coronary artery bypass grafting 15 years back and arteriovenous (AV) fistula creation in the left arm 1 month back presented with acute coronary syndrome (ACS). He had not received dialysis before his referral. We felt the most likely etiology for these complaints was increased cardiac oxygen demand from an increased cardiac output related to the newly formed left AV fistula. Coronary angiography was done to detect any significant stenosis in the native or grafted vessels. This revealed that the left subclavian artery was totally occluded in the ostioproximal segment and the coronary arteries did not have occlusions to explain the ACS setting. CT angiography confirmed the angiographic findings of the totally occluded left subclavian artery followed by a well‐developed and patent left internal mammary artery to left anterior descending artery. This led to the consideration of a steal syndrome from the coronary artery by the subclavian artery distal to the occlusion. A successful percutaneous endovascular intervention on the left subclavian artery occlusion was performed. Subsequently, the patient became asymptomatic and experienced a dramatic increase in left ventricular ejection fraction.  相似文献   
69.
70.
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