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   23670篇
  免费   1843篇
  国内免费   77篇
耳鼻咽喉   394篇
儿科学   820篇
妇产科学   392篇
基础医学   2428篇
口腔科学   525篇
临床医学   2157篇
内科学   5211篇
皮肤病学   547篇
神经病学   1285篇
特种医学   1103篇
外国民族医学   1篇
外科学   4549篇
综合类   326篇
一般理论   15篇
预防医学   1156篇
眼科学   822篇
药学   2040篇
中国医学   38篇
肿瘤学   1781篇
  2023年   224篇
  2022年   401篇
  2021年   990篇
  2020年   476篇
  2019年   814篇
  2018年   943篇
  2017年   610篇
  2016年   649篇
  2015年   675篇
  2014年   1017篇
  2013年   1185篇
  2012年   1750篇
  2011年   1724篇
  2010年   871篇
  2009年   816篇
  2008年   1285篇
  2007年   1209篇
  2006年   1124篇
  2005年   983篇
  2004年   883篇
  2003年   749篇
  2002年   653篇
  2001年   587篇
  2000年   550篇
  1999年   488篇
  1998年   160篇
  1997年   135篇
  1996年   138篇
  1995年   142篇
  1994年   113篇
  1993年   97篇
  1992年   268篇
  1991年   284篇
  1990年   248篇
  1989年   212篇
  1988年   208篇
  1987年   219篇
  1986年   192篇
  1985年   177篇
  1984年   111篇
  1983年   126篇
  1982年   85篇
  1981年   70篇
  1979年   129篇
  1978年   77篇
  1977年   69篇
  1975年   58篇
  1974年   65篇
  1973年   88篇
  1970年   58篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.

Objective

Intramedullary nailing (IMN) of obese patients with femoral fractures can be difficult due to soft tissue considerations and overall body habitus. Complications including malrotation can occur and have significant impact on postoperative function. The purpose of this study was to evaluate femoral rotation after intramedullary nailing of obese and non-obese patients to see if there was a difference in rotation, complications and any risk factors for malrotation.

Materials and methods

Between 2000 and 2009, 417 consecutive patients with femur fractures treated with IM nail at Level I trauma and tertiary referral center. Of these, 335 with postoperative computed tomography (CT) scanogram of the bilateral lower extremities were included in this study. Baseline demographic, perioperative and postoperative femoral version calculations were included in the dataset. Statistical analysis included chi-squared test for categorical data, t-test for continuous data, and univariate and multivariate regression analysis. Significance was set at p < 0.05.

Results

Of the 417 patients with femur fractures between 2000 and 2009, 335 met criteria for this study. There were 111 patients with a BMI <25, 129 with BMI 25–29.9, and 95 patients with a BMI >30. When BMI was categorised into 3 groups (<25, 25–29.9, or 30+), none of these groups were predictive of version in univariate or multivariate regressions. Among only obese patients (BMI 30+), BMI of 35+ was not a significant predictor of version when compared to BMI 30–34.9. There were no significant differences in femoral version based on entry point (antegrade vs. retrograde) in any BMI category. There were also no significant difference between groups of patients with a DFV of >15? (p = 0.212).

Conclusions

Based on this study, BMI did not have an effect on postoperative difference in femoral version. In fact, in our multivariate regression analysis, BMI of over 30 was actually predictive of significantly lower difference in femoral version. While other studies have documented the intraoperative difficulties encountered with obese patients with femur fractures, the outcome of femoral rotation is not affected by an increasing BMI.  相似文献   
992.
993.
994.
995.
With increasing scrutiny of prostate cancer (PCa) diagnosis and treatment, much attention has been given to the morbidity caused by radical prostatectomy (RP) and/or radiotherapy (RT). One of the most common side-effects of either treatment is erectile dysfunction (ED).1 Approximately, 40% of patients will experience ED after RT for PCa. The post-RT ED causes significant patient dissatisfaction with cancer treatment as well as decrease in patient and partner psychosocial function,z To address this issue in patients undergoing RT, Pisansky et al.3 conducted a prospective, randomized, double-blinded, placebo-controlled trial to assess the efficacy of a phosphodiesterase enzyme-5 inhibitor (PDE5i), tadalafil, as a preventive measure for patients undergoing RT for PCa and found no difference in erectile function between the control and treatment groups.  相似文献   
996.
997.

Background

The efficacy and safety profile of retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We sought to perform a weighted meta-analysis of the success and complication rates of retrograde CTO PCI.

Methods

We conducted a meta-analysis of 26 studies published between 2006 and April 2013 reporting in-hospital outcomes of retrograde CTO PCI. Data on procedural success, frequency of death, emergent coronary artery bypass graft surgery (CABG), stroke, myocardial infarction (MI), perforation, tamponade, stent thrombosis, major vascular or bleeding events, contrast nephropathy, and radiation skin injury were collected.

Results

A total of 26 studies with 3482 patients and 3493 target CTO lesions were included. Primary retrograde CTO PCI was attempted in 52.4%. Pooled estimates of outcomes were as follows: procedural success 83.3% [95% confidence interval (CI): 79.0% to 87.7%]; death 0.7% (95% CI: 0.5% to 1.2%); urgent CABG 0.7% (95% CI: 0.4% to 1.2%); tamponade 1.4% (95% CI: 1.0% to 2.2%); collateral perforation 6.9% (95% CI: 4.6% to 10.4%); coronary perforation 4.3% (95% CI: 1.2% to 15.4%); donor vessel dissection 2% (95% CI: 0.9% to 4.5%); stroke 0.5% (95% CI: 0.2% to 1.0%); MI 3.1% (95% CI: 0.2% to 5.0%); Q wave MI 0.6% (95% CI: 0.4% to 1.1%); vascular access complications 2% (95% CI: 0.9% to 4.5%); contrast nephropathy 1.8% (95% CI: 0.8% to 3.7%); and wire fracture and equipment entrapment 1.2% (95% CI: 0.6% to 2.5%).

Conclusions

Retrograde CTO PCI is associated with high procedural success rate and acceptable risk for procedural complications.  相似文献   
998.
999.

Background

Hepatocellular carcinoma (HCC) is a leading cancer-related cause of death worldwide. There are widespread global differences in HCC risk. Although the impact of geographic prevalence of specific causes of chronic liver disease on HCC is recognized, the contribution of the underlying genetic architecture to the risk of HCC remains undefined. Our aim was to characterize evolutionary trends in genetic susceptibility to HCC.

Methods

We examined the genetic risk associated with HCC risk alleles identified from genome-wide association studies and correlated these with geographic location and temporal and spatial patterns of human migration.

Results

A moderate increase in differentiation was noted for rs2596542 (F st = 0.106) and rs17401966 (F st = 0.116), single nucleotide polymorphisms (SNPs) associated with an increased risk of HCC in patients with chronic HCV and HBV, respectively. Both of these SNPs show a recent increase in allelic frequency with the most recent human migrations into East Asia, Oceania and the Americas. In contrast another SNP associated with an increased risk of HCC, rs9275572, showed a lack of differentiation (F st = 0.09) with stable allelic expression across populations. The genetic risk score for HCC, based on the allelic frequency and risk odds ratio of five SNPs associated with increased risk of HCC, was greatest in populations from Africa and decreased with subsequent migration into Europe and Asia. However, a major increase was noted with the most recent migrations into Oceania and the Americas.

Conclusions

There are differences in directional differentiation of HCC risk alleles across human populations that can contribute to population-based differences in HCC prevalence.  相似文献   
1000.
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