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   4593篇
  免费   174篇
  国内免费   172篇
耳鼻咽喉   57篇
儿科学   78篇
妇产科学   28篇
基础医学   187篇
口腔科学   33篇
临床医学   215篇
内科学   744篇
皮肤病学   8篇
神经病学   84篇
特种医学   102篇
外国民族医学   1篇
外科学   2233篇
综合类   576篇
现状与发展   1篇
预防医学   93篇
眼科学   92篇
药学   132篇
  5篇
中国医学   22篇
肿瘤学   248篇
  2023年   79篇
  2022年   120篇
  2021年   156篇
  2020年   156篇
  2019年   184篇
  2018年   161篇
  2017年   110篇
  2016年   130篇
  2015年   120篇
  2014年   295篇
  2013年   285篇
  2012年   207篇
  2011年   216篇
  2010年   180篇
  2009年   220篇
  2008年   272篇
  2007年   283篇
  2006年   170篇
  2005年   187篇
  2004年   170篇
  2003年   147篇
  2002年   133篇
  2001年   100篇
  2000年   87篇
  1999年   92篇
  1998年   75篇
  1997年   48篇
  1996年   48篇
  1995年   64篇
  1994年   49篇
  1993年   32篇
  1992年   31篇
  1991年   27篇
  1990年   31篇
  1989年   28篇
  1988年   31篇
  1987年   30篇
  1986年   33篇
  1985年   31篇
  1984年   33篇
  1983年   13篇
  1982年   18篇
  1981年   12篇
  1980年   12篇
  1979年   12篇
  1978年   7篇
  1977年   4篇
  1976年   5篇
  1975年   2篇
  1971年   1篇
排序方式: 共有4939条查询结果,搜索用时 390 毫秒
71.
72.
73.
74.
75.
76.

Background

According to recent American Society for Metabolic and Bariatric Surgery estimates, sleeve gastrectomy (SG) is now the most commonly performed procedure in the United States (~53.8% of all bariatric procedures), followed by Roux-en-Y gastric bypass (RYGB; 23.1% of all procedures).

Objectives

The objective of this study was to evaluate outcomes and safety of these 2 procedures in the first 30 days postoperatively using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program data registry.

Setting

University health network, United States.

Methods

We reviewed all SG and RYGB cases entered between January 1 and December 31, 2015 in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program data registry. Demographic characteristics and 30-day outcomes were analyzed based on separate Mann-Whitney rank sums tests, χ2, or Fisher's exact tests as appropriate, with P<.05 denoting statistical significance and no adjustment for multiple testing.

Results

A total of 141,646 patients were analyzed; 98,292 underwent SG and 43,354 underwent RYGB. Average age was 44.5 and 45.4 years for SG and RYGB, respectively. Preoperative body mass index was 45.1 and 46.1 for SG and RYGB, respectively. The 30-day mortality was .1% for SG and .2% for RYGB (P<.05). The incidence of unplanned intensive care unit admission after RYGB was twice as high compared with SG (1.3% versus .6%, respectively, P<.05). The incidence of at least 1 intervention or reoperation after RYGB was significantly higher compared with SG (2.8% and 2.5% for GB versus 1.2% and 1% for SG, P<.05). After RYGB, .4% of patients had a drain left in place at 30 days postoperatively versus .3% for SG (P<.05). The incidence of readmission was 2.8% for RYGB and 1.2% for SG (P<.05).

Conclusions

The incidence of postoperative complications in the first 30 days after surgery is low for both RYGB and SG. However, SG seems to have a better safety profile in the first 30 days postoperatively compared with RYGB. These findings should be considered in the preoperative evaluation and counseling of bariatric patients. Long-term follow-up is needed to compare safety and efficacy of SG versus RYGB.  相似文献   
77.

Background

Numerous studies have established the effectiveness of Roux-en-Y gastric bypass (RYGB) for weight loss and co-morbidity amelioration. However, its safety and efficacy in elderly patients remains controversial.

Objectives

To evaluate outcomes in patients aged ≥60 years who underwent RYGB compared with nonsurgical controls with the hypothesis that RYGB provides weight loss benefits without differences in survival.

Setting

University-affiliated tertiary center.

Methods

All patients who underwent RYGB from 1985 to 2015 were identified and divided into elderly (age ≥60) and nonelderly (age <60) groups. A nonsurgical elderly control population was identified using a clinical data repository of outpatient visits to propensity match elderly patients 4:1 on demographic characteristics, co-morbidities, and relevant preoperative substance/medication use. Unpaired appropriate univariate analyses compared each stratified group. Kaplan-Meier survival curves were fitted based on social security death data.

Results

A total of 2306 patients underwent RYGB. The 107 elderly patients had lower median body mass index (47.0 versus 49.9; P?=?.007) and higher rates of co-morbidities. Rates of complications did not differ between elderly and nonelderly patients. Elderly surgical patients were propensity matched 4:1 (10,044 controls) yielding 428 well-matched nonsurgical controls. The elderly group demonstrated significant percent reduction in excess body mass index compared with the control group (81.8% versus 10.3%; P < .001). Kaplan-Meier survival analysis with log-rank test demonstrated no difference in midterm survival (P?=?.63).

Conclusions

A significant weight reduction benefit was identified after RYGB in elderly patients without a difference in midterm survival compared with propensity-matched controls, suggesting RYGB is a safe and efficacious weight loss strategy in the elderly.  相似文献   
78.
79.

Background

Spexin is a novel peptide predominantly produced in human white adipose tissue and has recently been implicated as a potential signal in the regulation of body weight, energy homeostasis, and satiety. The effect of bariatric surgery on spexin is unknown.

Objectives

To study the effect of Roux-en-Y gastric bypass (RYGB) surgery on endogenous spexin concentration and various risk factors of type 2 diabetes and cardiovascular disease in youth with severe obesity.

Setting

University hospital, United States

Methods

Spexin, body mass index (BMI), insulin, glucose, total and high molecular weight adiponectin, leptin, and high sensitivity C- reactive protein were measured longitudinally (baseline, 6 mo, and 12 mo) after RYGB surgery in girls with severe obesity (n?=?12; age?=?16.7 ± 1.5 years; BMI?=?51.6 ± 2.9 kg/m2).

Results

Serum spexin concentration increased (P?=?.01) at 6 months after surgery and stabilized afterward. Spexin level correlated negatively with homeostatic model assessment insulin resistance, HOMA-IR (Spearman correlation r?=??.796, P < .001) and positively with high molecular weight adiponectin (Spearman correlation r?=?.691, P?=?.011). The change in spexin concentration, from baseline to 6 months after surgery, was inversely correlated with the corresponding change in BMI (Spearman correlation r?=??.573, P?=?.051). Furthermore, the 6-month changes in spexin and HOMA-IR were inversely correlated (slope [standard error, SE]?=??.0084 (.0019), P?=?.001)], even after adjusting for the change in BMI.

Conclusions

The enhancement of circulating spexin concentration in response to RYGB and correlations with beneficial postoperative changes in various adipokines in youth are novel findings that require further validation.  相似文献   
80.

Background

Studies reporting revisionary options for weight loss failure after Roux-en-Y gastric bypass (RYGB) have been underpowered and lacking long-term data. We have previously shown that short-term (12 mo) and midterm (24 mo) weight loss is achievable with laparoscopic adjustable gastric banding (LAGB) for failed RYGB. The present study represents the largest published series with longest postoperative follow-up of patients receiving salvage LAGB after RYGB failure.

Objective

To investigate long-term results of salvage gastric banding.

Setting

University Hospital, New York, United States.

Methods

Data were prospectively collected with retrospective review. Baseline characteristics were evaluated and weights at multiple time intervals (before RYGB, before LAGB, each year of follow-up). Additional data included approach (open or laparoscopic), operative time, hospital length of stay, and postoperative complications.

Results

A total of 168 patients underwent statistical analysis with 86 patients meeting inclusion for RYGB failure. The mean body mass index before RYGB was 48.9 kg/m2. Before LAGB, patients had an average body mass index of 43.7 kg/m2, with 10.4% total weight loss and 21.4% excess weight loss after RYGB. At 5-year follow-up, patients (n?=?20) had a mean body mass index of 33.6 kg/m2 with 22.5% total weight loss and 65.9% excess weight loss. The long-term reoperation rate for complications related to LAGB was 24%, and 8% of patients ultimately had their gastric bands removed.

Conclusion

The results of our study have shown that LAGB had good long-term data as a revisionary procedure for weight loss failure after RYGB.  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