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   58419篇
  免费   4662篇
  国内免费   502篇
耳鼻咽喉   902篇
儿科学   1135篇
妇产科学   1038篇
基础医学   9362篇
口腔科学   936篇
临床医学   5433篇
内科学   11707篇
皮肤病学   1973篇
神经病学   4984篇
特种医学   3288篇
外科学   7092篇
综合类   541篇
现状与发展   2篇
一般理论   17篇
预防医学   3569篇
眼科学   1500篇
药学   5103篇
中国医学   555篇
肿瘤学   4446篇
  2023年   274篇
  2022年   732篇
  2021年   1624篇
  2020年   877篇
  2019年   1339篇
  2018年   1545篇
  2017年   1226篇
  2016年   1769篇
  2015年   2288篇
  2014年   2735篇
  2013年   3117篇
  2012年   4570篇
  2011年   4415篇
  2010年   2657篇
  2009年   2246篇
  2008年   3182篇
  2007年   3098篇
  2006年   2744篇
  2005年   2667篇
  2004年   2214篇
  2003年   1956篇
  2002年   1801篇
  2001年   1181篇
  2000年   1164篇
  1999年   970篇
  1998年   427篇
  1997年   379篇
  1996年   339篇
  1995年   302篇
  1994年   271篇
  1993年   273篇
  1992年   635篇
  1991年   675篇
  1990年   572篇
  1989年   632篇
  1988年   610篇
  1987年   604篇
  1986年   519篇
  1985年   523篇
  1984年   405篇
  1983年   333篇
  1982年   243篇
  1981年   231篇
  1980年   214篇
  1979年   320篇
  1978年   267篇
  1977年   193篇
  1974年   203篇
  1973年   223篇
  1972年   176篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.  相似文献   
2.
3.
Moderate sedatives have been increasingly used to improve patient comfort during flexible bronchoscopy (FB). However, routine use of moderate sedation during FB is controversial because its efficacy and safety are not well established.This study aims to evaluate the efficacy and safety of moderate sedation during FB.A search was made of Medline, EMBASE, and the Cochrane Library to May 2014.Randomized controlled trials (RCTs) and quasi-RCTs were included.The main analysis was designed to examine the efficacy of moderate sedation during FB in sedation than no-sedation.The willingness to repeat FB was significantly more in sedation than no-sedation (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.11–4.73; P = 0.02; I2 = 22.5). The duration of FB was shorter in sedation group than no-sedation group (standardized mean difference [SMD] −0.21; 95% CI −0.38 to −0.03; P = 0.02; I2 = 78.3%). Event of hypoxia was not significantly different between sedation and no-sedation groups (OR 0.86; 95% CI 0.42–1.73; P = 0.67; I2 = 0%). The SpO2 during procedure was not different between sedation and no-sedation groups (SMD −0.14; 95% CI −0.37 to 0.08; P = 0.21; I2 = 49.9%). However, in subgroup analysis without supplemental oxygen, the SpO2 was significantly lower in sedation than no-sedation group (SMD −0.45; 95% CI −0.78 to −0.11; P = 0.01; I2 = 0.0%).According to this meta-analysis, moderate sedation in FB would be useful in patients who will require repeated bronchoscopies as well as safe in respiratory depression. To our knowledge, although the various sedative drugs are already used in the real field, this analysis was the first attempt to quantify objective results. We anticipate more definite and studies designed to elucidate standardized outcomes for moderate sedation in FB.  相似文献   
4.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
5.
6.
7.
8.
Erythema induratum of Bazin (EIB) is a form of tuberculid resulting from hypersensitivity to tuberculosis antigen. EIB occurs most commonly in middle‐aged women and is not typically seen in children. Here, we present a rare case of EIB, presenting as a chronic nodular panniculitis, in a 10‐year‐old Korean boy.  相似文献   
9.
10.
No national epidemiological investigations have been conducted recently regarding facial lacerations. The study was performed using the data of 3,634,229 people during the 5-year period from 2014 to 2018 archived by the National Health Information Database (NHID) of the Health Insurance Review and Assessment Service. Preschool and children under 10 years old accounted for about one-third of patients. Facial lacerations were concentrated in the “T-shaped” area, which comprised forehead, nose, lips, and the perioral area. The male to female ratio for all study subjects was 2.16:1. Age and gender are significantly related with each other (P < .001). Mean hospital stays decreased, and numbers of outpatient department visits per patient were highest for hospitals and lowest for health agencies. Over the study period, hospital costs per patient in tertiary and general hospitals increased gradually. Preschool and school-aged children are vulnerable to trauma. Male patients outnumbered female patients by a factor of more than 2. The “T-shaped’” area around forehead is vulnerable to injury. Total cost of medical care benefits per patient in tertiary hospitals was about 7 times on average than in health agencies. Regarding functional, behavioral, and aesthetic outcomes, more attention should be paid to epidemiologic data and hospital costs for facial lacerations.  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