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   4093篇
  免费   298篇
  国内免费   21篇
耳鼻咽喉   42篇
儿科学   89篇
妇产科学   85篇
基础医学   531篇
口腔科学   112篇
临床医学   324篇
内科学   873篇
皮肤病学   82篇
神经病学   639篇
特种医学   96篇
外科学   743篇
综合类   16篇
预防医学   198篇
眼科学   40篇
药学   189篇
中国医学   2篇
肿瘤学   351篇
  2024年   7篇
  2023年   36篇
  2022年   74篇
  2021年   150篇
  2020年   70篇
  2019年   117篇
  2018年   153篇
  2017年   120篇
  2016年   100篇
  2015年   126篇
  2014年   174篇
  2013年   179篇
  2012年   332篇
  2011年   342篇
  2010年   202篇
  2009年   141篇
  2008年   220篇
  2007年   219篇
  2006年   199篇
  2005年   208篇
  2004年   201篇
  2003年   167篇
  2002年   141篇
  2001年   39篇
  2000年   48篇
  1999年   64篇
  1998年   36篇
  1997年   25篇
  1996年   24篇
  1995年   28篇
  1994年   21篇
  1993年   13篇
  1992年   37篇
  1991年   31篇
  1990年   27篇
  1989年   33篇
  1988年   28篇
  1987年   29篇
  1986年   24篇
  1985年   12篇
  1984年   26篇
  1983年   21篇
  1982年   10篇
  1980年   8篇
  1979年   16篇
  1978年   15篇
  1977年   10篇
  1975年   10篇
  1974年   13篇
  1969年   9篇
排序方式: 共有4412条查询结果,搜索用时 546 毫秒
111.
Loss of heterozygosity affecting chromosome 7q is common in acute myeloid leukemia and myelodysplastic syndromes, pointing toward the essential role of this region in disease phenotype and clonal evolution. The higher resolution offered by recently developed genomic platforms may be used to establish more precise clinical correlations and identify specific target genes. We analyzed a series of patients with myeloid disorders using recent genomic technologies (1458 by single-nucleotide polymorphism arrays [SNP-A], 226 by next-generation sequencing, and 183 by expression microarrays). Using SNP-A, we identified chromosome 7q loss of heterozygosity segments in 161 of 1458 patients (11%); 26% of chronic myelomonocytic leukemia patients harbored 7q uniparental disomy, of which 41% had a homozygous EZH2 mutation. In addition, we describe an SNP-A-isolated deletion 7 hypocellular myelodysplastic syndrome subset, with a high rate of progression. Using direct and parallel sequencing, we found no recurrent mutations in typically large deletion 7q and monosomy 7 patients. In contrast, we detected a markedly decreased expression of genes included in our SNP-A defined minimally deleted regions. Although a 2-hit model is present in most patients with 7q uniparental disomy and a myeloproliferative phenotype, haplodeficient expression of defined regions of 7q may underlie pathogenesis in patients with deletions and predominant dysplastic features.  相似文献   
112.
BackgroundTobacco smoking is the leading cause of preventable deaths worldwide, but many smokers are simply unable to quit. Psychosocial and pharmaceutical treatments have shown modest results on smoking cessation rates, but there is an urgent need to develop treatments with greater efficacy. Brain stimulation methods are gaining increasing interest as possible addiction therapeutics.ObjectivesThe purpose of this paper is to review the studies that have evaluated brain stimulation techniques on tobacco addiction, and discuss future directions for research in this novel area of addiction interventions.MethodsElectronic and manual literature searches identified fifteen studies that administered repetitive transcranial magnetic stimulation (rTMS), cranial electrostimulation (CES), transcranial direct current stimulation (tDCS) or deep brain stimulation (DBS).ResultsrTMS was found to be the most well studied method with respect to tobacco addiction. Results indicate that rTMS and tDCS targeted to the dorsolateral prefrontal cortex (DLPFC) were the most efficacious in reducing tobacco cravings, an effect that may be mediated through the brain reward system involved in tobacco addiction. While rTMS was shown to reduce consumption of cigarettes, as yet no brain stimulation technique has been shown to significantly increase abstinence rates. It is possible that the therapeutic effects of rTMS and tDCS may be improved by optimization of stimulation parameters and increasing the duration of treatment.ConclusionAlthough further studies are needed to confirm the ability of brain stimulation methods to treat tobacco addiction, this review indicates that rTMS and tDCS both represent potentially novel treatment modalities.  相似文献   
113.
114.
115.
Morales  David  Wu  Andres  Wu  Lihteh 《International ophthalmology》2021,41(6):2187-2196
International Ophthalmology - Report the foveal avascular zone (FAZ) area imaged by OCT angiography (OCTA) using a full spectrum probabilistic algorithm in eyes of healthy individuals from Costa...  相似文献   
116.

Background

Remission of type 2 diabetes (T2D) is a desired outcome after bariatric surgery (BS). Even if this goal is not achieved, individuals who do not strictly fulfill remission criteria experience an overall improvement. The aim of this study was to evaluate the metabolic control status in patients considered as diabetes “non-remitters.”

Methods

A retrospective study of 125 patients (59.2 % women) with preoperative diagnosis of T2D who underwent BS in a single center (2006–2011) was conducted. We collected anthropometric and metabolic parameters before surgery and at 1-year follow-up. T2D remission was defined according to the 2009 consensus statement: glycosylated hemoglobin (HbA1c) <6 %, fasting glucose (FG) <100 mg/dLs, and absence of pharmacologic treatment. We evaluated metabolic status of non-remitters, according to the American Diabetes Association's (ADA) target recommendations: HbA1c <7 %, LDL-c <100 mg/dL, triglycerides <150 mg/dL, and HDL-c >40 (male) or >50 mg/dL (female). Statistics: analysis of variance.

Results

Baseline characteristics (mean ± SD): age 53.5?±?9.7 years, BMI 43.5?±?5.6 kg/m2, time since diagnosis of T2D 7.7?±?7.9 years, FG 162.0?±?56.3 mg/dL, HbA1c 7.7?±?1.6 %. ADA's target recommendations were present in 12 patients (9.6 %) preoperatively, and in 45 (36.0 %) at 1-year follow-up (p <0.001). Sixty-two (49.6 %) patients did not achieve diabetes remission; 26 (41.9 %) had now diet treatment, 30 (48.4 %) oral medications, and 6 (9.7 %) required insulin. Of the non-remitters, 57 (91.9 %) had HbA1c <7 % and 18 (40.0 %) achieved ADA's target recommendations. There were no differences between remitters and non-remitters in the number of individuals reaching ADA's combined metabolic control.

Conclusions

Although almost 50 % of the patients may not be classified as diabetes remitters, their significant improvement in metabolic control should be regarded as a success, according to most scientific societies' target recommendations.  相似文献   
117.
118.
119.
120.

Purpose

We investigated the incidence, natural history, and functional consequences of a newly developed flexion contracture after total knee arthroplasty (TKA).

Methods

Forty patients with full knee extension preoperatively who developed a postoperative flexion contracture were match-paired 1:2 with 80 patients who had full extension. The incidence of a newly developed flexion contracture, ROM, and Knee Society scores (KSS) at six weeks, four months, and one year were analysed.

Results

The incidence of a new flexion contracture at six weeks was 14 %, but diminished to 5 % and 0.3 % at four months and one year, respectively. One year after surgery, there was no difference in the KSS (p = 0.5).

Conclusions

This study showed that the majority of patients who developed a new flexion contracture after TKA have full knee extension one year postoperatively. Moreover, knee extension and KSS at one year are equivalent to those patients who did not developed a flexion contracture.  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