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   2700篇
  免费   194篇
  国内免费   27篇
耳鼻咽喉   23篇
儿科学   79篇
妇产科学   77篇
基础医学   348篇
口腔科学   48篇
临床医学   240篇
内科学   692篇
皮肤病学   45篇
神经病学   380篇
特种医学   55篇
外科学   206篇
综合类   12篇
预防医学   266篇
眼科学   15篇
药学   185篇
中国医学   5篇
肿瘤学   245篇
  2024年   7篇
  2023年   50篇
  2022年   96篇
  2021年   144篇
  2020年   71篇
  2019年   90篇
  2018年   109篇
  2017年   87篇
  2016年   100篇
  2015年   121篇
  2014年   135篇
  2013年   145篇
  2012年   249篇
  2011年   239篇
  2010年   102篇
  2009年   112篇
  2008年   187篇
  2007年   178篇
  2006年   152篇
  2005年   143篇
  2004年   102篇
  2003年   113篇
  2002年   80篇
  2001年   13篇
  2000年   6篇
  1999年   15篇
  1998年   13篇
  1997年   10篇
  1996年   12篇
  1995年   9篇
  1994年   2篇
  1993年   3篇
  1992年   4篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1987年   2篇
  1985年   2篇
  1983年   1篇
  1982年   2篇
  1980年   1篇
  1973年   4篇
  1972年   1篇
  1970年   1篇
  1967年   1篇
  1964年   1篇
  1963年   1篇
  1960年   1篇
排序方式: 共有2921条查询结果,搜索用时 15 毫秒
21.

Background  

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is currently the gold standard bariatric procedure for the treatment of morbid obesity. Laparoscopic sleeve gastrectomy (LSG) is a relatively innovative procedure which has been increasingly applied lately as a sole bariatric procedure. A randomized trial was conducted in a Greek population to evaluate perioperative safety and 3-years results.  相似文献   
22.
The aim of this study was to examine the monetary cost of dietary change among pregnant women before and after receiving low glycaemic index (GI) dietary advice. The pregnant women in this study were a subgroup of participants in the Pregnancy and Glycaemic Index Outcomes (PREGGIO) study. Twenty women from the low GI dietary advice group, who had completed their pregnancies, were randomly chosen. All these women had completed three day food records at 12–16 weeks and again around 36 weeks of gestation. Consumer food prices were applied to recorded dietary intake data. The mean ± SD GI of the diet reduced from 55.1 ± 4.3 to 51.6 ± 3.9 (p = 0.003). The daily cost of the diet (AUD) was 9.1 ± 2.7 at enrolment and 9.5 ± 2.1 prior to delivery was not significantly different (p = 0.52). There were also no significant differences in the daily energy intake (p = 0.2) or the daily cost per MJ (p = 0.16). Women were able to follow low GI dietary advice during pregnancy with no significant increase in the daily costs.  相似文献   
23.
24.
Developments in nanotechnology and in the formulation of liposomal systems provide the opportunity for cosmetic dermatology to design novel delivery systems. Determination of their physico-chemical parameters has importance when developing a nano-delivery system. The present study highlights some technological aspects/characteristics of liposomes formulated from egg or soy lecithins for topical use. Alterations in the pH, viscosity, surface tension, and microscopic/macroscopic appearance of these vesicular systems were investigated. The chemical composition of the two types of lecithin was checked by mass spectrometry. Caffeine, as a model molecule, was encapsulated into multilamellar vesicles prepared from the two types of lecithin: then zeta potential, membrane fluidity, and encapsulation efficiency were compared. According to our observations, samples prepared from the two lecithins altered the pH in opposite directions: egg lecithin increased it while soy lecithin decreased it with increased lipid concentration. Our EPR spectroscopic results showed that the binding of caffeine did not change the membrane fluidity in the temperature range of possible topical use (measured between 2 and 50 °C). Combining our results on encapsulation efficiency for caffeine (about 30% for both lecithins) with those on membrane fluidity data, we concluded that the interaction of caffeine with the liposomal membrane does not change the rotational motion of the lipid molecules close to the head group region. In conclusion, topical use of egg lecithin for liposomal formulations can be preferred if there are no differences in the physico-chemical properties due to the encapsulated drugs, because the physiological effects of egg lecithin vesicles on skin are significantly better than that of soy lecithin liposomes.  相似文献   
25.
26.

BACKGROUND

Diet quality is associated with brain aging outcomes. However, few studies have explored in humans the brain structures potentially affected by long-term diet quality. We examined whether cumulative average of the Alternative Healthy Eating Index 2010 (AHEI-2010) score during adult life (an 11-year exposure period) is associated with hippocampal volume.

METHODS

Analyses were based on data from 459 participants of the Whitehall II imaging sub-study (mean age [standard deviation] (SD)?=?59.6 [5.3] years in 2002-2004, 19.2% women). Multimodal magnetic resonance imaging examination was performed at the end of follow-up (2015-2016). Structural images were acquired using a high-resolution 3-dimensional T1-weighted sequence and processed with Functional Magnetic Resonance Imaging of the Brain Software Library (FSL) tools. An automated model-based segmentation and registration tool was applied to extract hippocampal volumes.

RESULTS

Higher AHEI-2010 cumulative average score (reflecting long-term healthy diet quality) was associated with a larger total hippocampal volume. For each 1 SD (SD?=?8.7 points) increment in AHEI-2010 score, an increase of 92.5 mm3 (standard error?=?42.0 mm3) in total hippocampal volume was observed. This association was independent of sociodemographic factors, smoking habits, physical activity, cardiometabolic health factors, cognitive impairment, and depressive symptoms, and was more pronounced in the left hippocampus than in the right hippocampus. Of the AHEI-2010 components, no or light alcohol consumption was independently associated with larger hippocampal volume.

CONCLUSIONS

Higher long-term AHEI-2010 scores were associated with larger hippocampal volume. Accounting for the importance of hippocampal structures in several neuropsychiatric diseases, our findings reaffirm the need to consider adherence to healthy dietary recommendation in multi-interventional programs to promote healthy brain aging.  相似文献   
27.
Clinical Rheumatology - Kawasaki disease (KD) is the most frequent cause of acquired heart disease in children in high-income countries because of coronary artery involvement. Risk factors for...  相似文献   
28.
Tick-borne encephalitis virus (TBEV) is an emerging human pathogen that causes potentially fatal disease with no specific treatment. Mouse monoclonal antibodies are protective against TBEV, but little is known about the human antibody response to infection. Here, we report on the human neutralizing antibody response to TBEV in a cohort of infected and vaccinated individuals. Expanded clones of memory B cells expressed closely related anti-envelope domain III (EDIII) antibodies in both groups of volunteers. However, the most potent neutralizing antibodies, with IC50s below 1 ng/ml, were found only in individuals who recovered from natural infection. These antibodies also neutralized other tick-borne flaviviruses, including Langat, louping ill, Omsk hemorrhagic fever, Kyasanur forest disease, and Powassan viruses. Structural analysis revealed a conserved epitope near the lateral ridge of EDIII adjoining the EDI–EDIII hinge region. Prophylactic or early therapeutic antibody administration was effective at low doses in mice that were lethally infected with TBEV.  相似文献   
29.
30.
Annals of Biomedical Engineering - Age-related pelvic floor muscle (PFM) dysfunction is a critical defect in the progression to pelvic floor disorders (PFDs). Despite dramatic prevalence of PFDs in...  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