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   3152篇
  免费   193篇
  国内免费   19篇
耳鼻咽喉   21篇
儿科学   71篇
妇产科学   80篇
基础医学   586篇
口腔科学   109篇
临床医学   281篇
内科学   693篇
皮肤病学   47篇
神经病学   330篇
特种医学   81篇
外科学   177篇
综合类   28篇
一般理论   1篇
预防医学   232篇
眼科学   58篇
药学   296篇
中国医学   20篇
肿瘤学   253篇
  2024年   4篇
  2023年   25篇
  2022年   89篇
  2021年   183篇
  2020年   94篇
  2019年   114篇
  2018年   112篇
  2017年   78篇
  2016年   119篇
  2015年   110篇
  2014年   169篇
  2013年   192篇
  2012年   284篇
  2011年   312篇
  2010年   164篇
  2009年   101篇
  2008年   221篇
  2007年   191篇
  2006年   196篇
  2005年   161篇
  2004年   138篇
  2003年   115篇
  2002年   96篇
  2001年   12篇
  2000年   3篇
  1999年   4篇
  1998年   9篇
  1997年   7篇
  1996年   4篇
  1995年   7篇
  1994年   9篇
  1993年   4篇
  1991年   1篇
  1990年   2篇
  1989年   4篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1983年   3篇
  1982年   2篇
  1981年   2篇
  1980年   2篇
  1979年   3篇
  1977年   1篇
  1975年   1篇
  1973年   1篇
  1971年   1篇
  1970年   2篇
排序方式: 共有3364条查询结果,搜索用时 15 毫秒
111.
112.
113.
114.

Objective

To identify possible predictors of post-cessation weight gain in smoking abstainers.

Patients and methods

A sample of 607 successful abstainers seen at the Centre for Tobacco-Dependent in Prague, Czech Republic, between 2005 and 2010, was included in this analysis. This sample was followed up for 1 year and included 47.9% women (N = 291) with the mean age of 48 years (18–85).

Findings

Post-cessation weight gain occurred in 88.6% of the 607 abstainers. The mean weight gain after one year post-quit was 5.1 kg (95% confidence interval 4.7–5.5 kg). Baseline characteristics associated with increased weight gain included a higher baseline smoking rate (p < 0.001), more severe cigarette dependence (p = 0.003), less physical activity (p = 0.008), and a report of increased appetite on the baseline assessment of withdrawal symptoms (p < 0.001).

Conclusions

Smokers who are more dependent and have minimal physical activity are at increased risk for post-cessation weight gain. For these smokers, incorporating interventions targeting the weight issue into tobacco dependence treatment is recommended. Further research should be done to identify reasons for this important quitting complication.  相似文献   
115.
Aims: The IATPAD (Improvement in Access to Treatment for People with Alcohol and Drug Related Problems) study explored barriers and facilitators to accessing alcohol and drug treatment services in eight European countries.

Methods: Results from individual interviews and focus group discussions with 246 service users who had experienced alcohol and drug treatment in Bulgaria, Greece, Italy, Poland, Slovakia, Slovenia, Spain and Scotland are described. Thematic analysis was used to interpret the data.

Results: The study identified a number of consistent facilitating factors and barriers across all eight European countries, despite different health care systems. The results suggest that five main factors were implicated in the help-seeking behaviour of the service users interviewed. These were: information, service organisation, staff attitudes, significant others and personal disposition. All these factors could be viewed as both facilitators and barriers.

Conclusions: To enhance access to alcohol and drug treatment, local, non-stigmatising and available services are required alongside support from significant others which should increase motivation and skills of potential service users.  相似文献   

116.
Reducing greenhouse gas emissions and dependence on fossil fuels is the cornerstone of all European climate and energy strategies. Consequently, renewable energy sources are becoming more competitive with fossil fuels. The largest source of bioenergy in the European Union is biomass-fired power plants. Therefore, the European coal phase-out strategy led to an increased use of wood biomass as a sustainable fuel, generating large amounts of wood biomass ash (WBA). In the research studies reported so far, WBA has been mainly used in cementitious composites. However, given the similarities between the chemical composition of WBA and hydraulic lime (HL), this research focused on its potential classification as a building lime. Overall, three different sources of fly WBA were considered for the preparation of binders as mixtures of WBA and coal fly ash (CFA) in different ratios. The contribution of each binder mixture on the paste and mortar properties was analyzed based on the chemical composition, setting time, volume stability, and contribution to the mortar strength (compressive and flexural). In general, it can be concluded that the studied binders can meet the criteria of EN 459-1. However, special attention should be paid to the volume deformations and the setting time.  相似文献   
117.
118.
Detailed longitudinal studies of patients with X-linked lymphoproliferative disease (XLP) may increase our understanding of the immunologic defects that contribute to the development of lymphoma and hypogammaglobulinemia in XLP. We describe progressive changes observed in immunoglobulin concentrations, lymphocyte subsets, and Epstein-Barr virus (EBV) loads occurring in a 2-year period in a newly infected, but otherwise healthy, carrier (patient 9). We compare these findings with those observed in the patient's brother, who had hypogammaglobulinemia and XLP (patient 4). Immunoglobulin G (IgG), IgM, and IgA concentrations increased in patient 9 during acute EBV infection, but thereafter they decreased steadily to concentrations consistent with hypogammaglobulinemia, reaching a plateau 5 months after infection. In both patients, CD19+ B-lymphocyte rates remained lower than 3%, with a contraction of the B-cell memory compartment (CD27+ CD19+/CD19+) to 20% (normal range, 32%-56%). T-lymphocyte subpopulations showed a reduction in CD4+ T-cell counts and a permanent CD8+ T-cell expansion. Interestingly, CXCR3 memory TH1 cells were expanded and CCR4+ TH2 lymphocytes were reduced, suggesting that abnormal skewing of memory T-cell subsets might contribute to reduced antibody synthesis. Despite an expanded number of CD3+CD8+ lymphocytes, increased EBV loads occurred in both patients without overt clinical symptoms of mononucleosis, lymphoproliferative disease, or lymphoma.  相似文献   
119.
120.
FreeSurfer software package automatically estimates the cerebral cortical thickness. Its use is widely accepted, albeit this tool was validated against histologic measurements in only two post-mortem isolated brain MR scans. Indeed, a comparison between histologic measurements and FreeSurfer estimation from in vivo data was never performed. At the “Claudio Munari” Center for Epilepsy and Parkinson Surgery we have included FreeSurfer in our presurgical workflow since 2008, mainly because the automatic reconstruction of the brain surface is useful for carefully planning the surgical resection. We therefore compared cortical thickness values obtained by the automatic software pipeline with manual histologic measurements performed on 27 histologic specimens resected from the corresponding brain regions of the same epileptic subjects. This method-comparison study, including Passing–Bablok regression and Bland-Altman plot analysis, showed a good agreement between FreeSurfer estimation and histologic measurements of cortical thickness. The mean cortical thickness values (±Standard Deviation) obtained with FreeSurfer and histologic measurements were 3.65 mm?±?0.44 and 3.72 mm?±?0.36, respectively (P value?=?0.32). Our findings strengthen previous reports on cortical thickness changes as biomarkers of different neurological conditions.  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