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   1022440篇
  免费   80510篇
  国内免费   2157篇
耳鼻咽喉   15320篇
儿科学   29589篇
妇产科学   28438篇
基础医学   147421篇
口腔科学   30499篇
临床医学   89672篇
内科学   195135篇
皮肤病学   21411篇
神经病学   87090篇
特种医学   42251篇
外国民族医学   171篇
外科学   161394篇
综合类   25397篇
现状与发展   2篇
一般理论   311篇
预防医学   75722篇
眼科学   23746篇
药学   75556篇
中国医学   1837篇
肿瘤学   54145篇
  2018年   11181篇
  2017年   9017篇
  2016年   10623篇
  2015年   11537篇
  2014年   15570篇
  2013年   23829篇
  2012年   32242篇
  2011年   34273篇
  2010年   19942篇
  2009年   17573篇
  2008年   32620篇
  2007年   35133篇
  2006年   34544篇
  2005年   34025篇
  2004年   32890篇
  2003年   32001篇
  2002年   30703篇
  2001年   40520篇
  2000年   42240篇
  1999年   34325篇
  1998年   10860篇
  1997年   9885篇
  1996年   9520篇
  1995年   8858篇
  1994年   8560篇
  1992年   27359篇
  1991年   26698篇
  1990年   26171篇
  1989年   25235篇
  1988年   23714篇
  1987年   23409篇
  1986年   22182篇
  1985年   21716篇
  1984年   17047篇
  1983年   14530篇
  1982年   9411篇
  1981年   8703篇
  1979年   17138篇
  1978年   12516篇
  1977年   10612篇
  1976年   9692篇
  1975年   10528篇
  1974年   12987篇
  1973年   12423篇
  1972年   11764篇
  1971年   10920篇
  1970年   10430篇
  1969年   10116篇
  1968年   9114篇
  1967年   8420篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
91.

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   
92.
93.
94.
95.
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade.  相似文献   
96.
97.
98.
Unpredictable hypertrophic scarring (HS) occurs after approximately 35% of all surgical procedures and causes significant physical and psychological complaints. Parallel to the need to understanding the mechanisms underlying HS formation, a prognostic tool is needed. The objective was to determine whether (systemic) immunological differences exist between patients who develop HS and those who develop normotrophic scars (NS) and to assess whether those differences can be used to identify patients prone to developing HS. A prospective cohort study with NS and HS groups in which (a) cytokine release by peripheral blood mononuclear cells (PBMC) and (b) the irritation threshold (IT) after an irritant (sodium lauryl sulphate) patch test was evaluated. Univariate regression analysis of PBMC cytokine secretion showed that low MCP‐1, IL‐8, IL‐18 and IL‐23 levels have a strong correlation with HS (P < .010‐0.004; AUC = 0.790‐0.883). Notably, combinations of two or three cytokines (TNF‐a, MCP‐1 and IL‐23; AUC: 0.942, Nagelkerke R2: 0.727) showed an improved AUC indicating a better correlation with HS than single cytokine analysis. These combination models produce good prognostic results over a broad probability range (sensitivity: 93.8%, specificity 86.7%, accuracy 90,25% between probability 0.3 and 0.7). Furthermore, the HS group had a lower IT than the NS group and an accuracy of 68%. In conclusion, very fundamental immunological differences exist between individuals who develop HS and those who do not, whereas the cytokine assay forms the basis of a predictive prognostic test for HS formation, the less invasive, easily performed irritant skin patch test is more accessible for daily practice.  相似文献   
99.
100.
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