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   117305篇
  免费   6132篇
  国内免费   139篇
耳鼻咽喉   1773篇
儿科学   5228篇
妇产科学   3959篇
基础医学   16251篇
口腔科学   2906篇
临床医学   8487篇
内科学   22285篇
皮肤病学   3364篇
神经病学   9061篇
特种医学   5109篇
外国民族医学   32篇
外科学   19184篇
综合类   1611篇
一般理论   29篇
预防医学   5871篇
眼科学   3402篇
药学   8206篇
中国医学   323篇
肿瘤学   6495篇
  2018年   915篇
  2017年   797篇
  2016年   1120篇
  2015年   1235篇
  2014年   1642篇
  2013年   2414篇
  2012年   3181篇
  2011年   3237篇
  2010年   2022篇
  2009年   1970篇
  2008年   3307篇
  2007年   3544篇
  2006年   3674篇
  2005年   3788篇
  2004年   3725篇
  2003年   3618篇
  2002年   3564篇
  2001年   7068篇
  2000年   7007篇
  1999年   5900篇
  1998年   1641篇
  1997年   1568篇
  1996年   1350篇
  1995年   1208篇
  1994年   1098篇
  1993年   1129篇
  1992年   3785篇
  1991年   3602篇
  1990年   3580篇
  1989年   3371篇
  1988年   3007篇
  1987年   2918篇
  1986年   2819篇
  1985年   2630篇
  1984年   1952篇
  1983年   1605篇
  1982年   934篇
  1981年   922篇
  1980年   773篇
  1979年   1837篇
  1978年   1360篇
  1977年   1124篇
  1976年   946篇
  1975年   1190篇
  1974年   1221篇
  1973年   1208篇
  1972年   1065篇
  1971年   980篇
  1970年   892篇
  1969年   803篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
BACKGROUND The adenoma detection rate(ADR) is inversely associated with the incidence of interval colorectal cancer and serves as a benchmark quality criterion during screening colonoscopy. However, adenoma miss rates reach up to 26% and studies have shown that a second inspection of the right colon in retroflected view(RFV) can increase ADR.AIM To assess whether inspection of the whole colon in RFV compared to standard forward view(SFV) can increase ADR.METHODS Patients presenting for screening or surveillance colonoscopy were invited to participate in this randomized controlled trial and randomized into two arms. In RFV arm colonoscopy was initially performed with SFV, followed by a second inspection of the whole colon in RFV. In the SFV arm first withdrawal was performed with SFV, followed by a second inspection of the whole colon again with SFV. Number, size and morphology of polyps found during first and second inspection in each colonic segment were recorded and all polyps were removed and sent for histopathology in separate containers.RESULTS Two hundred and five patients were randomly assigned to the RFV(n = 101) and SFV(n = 104) arm. In the RFV arm, both polyp detection rate(PDR) and ADR were increased under second inspection in RFV(PDR 1~(st) SFV: 39.8%, PDR 2~(nd)RFV: 46.6%; ADR 1~(st) SFV: 35.2%, ADR 2~(nd) RFV: 42%). Likewise, in the SFV arm,PDR and ADR were increased under second inspection(PDR 1~(st) SFV: 37.5%, PDR 2~(nd) SFV: 46.6%; ADR 1~(st) SFV: 34.1%, ADR 2~(nd)SFV: 44.3%) with no significant differences in ADR and PDR between the SFV and RFV arm. Mean number of adenomas per patient(APP) was increased in the RFV and SFV(APP RFV arm: 1~(st) SFV: 1.71; 2~(nd) RFV: 2.38; APP SFV arm: 1~(st) SFV: 1.83, 2~(nd)SFV:2.2). The majority of adenomas additionally found during second inspection in RFV or in SFV were located in the transverse and left-sided colon and were 5 mm in size.CONCLUSION Second inspection of the whole colon leads to increased adenoma detection with no differences between SFV and RFV. Hence, increased detection is most likely a feature of the second inspection itself but not of the inspection mode.  相似文献   
3.
4.
5.
6.
7.
8.
9.
Hillermann  T.  Homburg  K.  Rainer  M.  Budde  U. 《Der Anaesthesist》2022,71(4):299-302
Die Anaesthesiologie - Eine junge Patientin erleidet während der Anlage einer axillären Plexusblockade einen generalisierten Krampfanfall. Die Mechanismen, im Wesentlichen die vermutlich...  相似文献   
10.

Objective

Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.

Methods

Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.

Results

We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.

Conclusions

Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients.  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