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   21581篇
  免费   1352篇
  国内免费   82篇
耳鼻咽喉   286篇
儿科学   642篇
妇产科学   476篇
基础医学   3173篇
口腔科学   1312篇
临床医学   2307篇
内科学   4145篇
皮肤病学   447篇
神经病学   1901篇
特种医学   422篇
外科学   1982篇
综合类   160篇
一般理论   10篇
预防医学   2602篇
眼科学   354篇
药学   1453篇
中国医学   136篇
肿瘤学   1207篇
  2024年   18篇
  2023年   204篇
  2022年   306篇
  2021年   848篇
  2020年   503篇
  2019年   754篇
  2018年   819篇
  2017年   575篇
  2016年   597篇
  2015年   735篇
  2014年   968篇
  2013年   1161篇
  2012年   1831篇
  2011年   2008篇
  2010年   984篇
  2009年   846篇
  2008年   1442篇
  2007年   1346篇
  2006年   1248篇
  2005年   1130篇
  2004年   967篇
  2003年   892篇
  2002年   859篇
  2001年   213篇
  2000年   163篇
  1999年   136篇
  1998年   164篇
  1997年   107篇
  1996年   88篇
  1995年   76篇
  1994年   82篇
  1993年   59篇
  1992年   76篇
  1991年   68篇
  1990年   61篇
  1989年   42篇
  1988年   46篇
  1987年   57篇
  1986年   45篇
  1985年   46篇
  1984年   43篇
  1983年   50篇
  1982年   43篇
  1981年   32篇
  1980年   35篇
  1979年   33篇
  1978年   21篇
  1975年   17篇
  1973年   15篇
  1970年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Alterations in autophagy are increasingly being recognized in the pathogenesis of proteinopathies like Alzheimer's disease (AD). This study was conducted to evaluate whether melatonin treatment could provide beneficial effects in an Alzheimer model related to tauopathy by improving the autophagic flux and, thereby, prevent cognitive decline. The injection of AAV‐hTauP301L viral vectors and treatment/injection with okadaic acid were used to achieve mouse and human ex vivo, and in vivo tau‐related models. Melatonin (10 μmol/L) impeded oxidative stress, tau hyperphosphorylation, and cell death by restoring autophagy flux in the ex vivo models. In the in vivo studies, intracerebroventricular injection of AAV‐hTauP301L increased oxidative stress, neuroinflammation, and tau hyperphosphorylation in the hippocampus 7 days after the injection, without inducing cognitive impairment; however, when animals were maintained for 28 days, cognitive decline was apparent. Interestingly, late melatonin treatment (10 mg/kg), starting once the alterations mentioned above were established (from day 7 to day 28), reduced oxidative stress, neuroinflammation, tau hyperphosphorylation, and caspase‐3 activation; these observations correlated with restoration of the autophagy flux and memory improvement. This study highlights the importance of autophagic dysregulation in tauopathy and how administration of pharmacological doses of melatonin, once tauopathy is initiated, can restore the autophagy flux, reduce proteinopathy, and prevent cognitive decline. We therefore propose exogenous melatonin supplementation or the development of melatonin derivatives to improve autophagy flux for the treatment of proteinopathies like AD.  相似文献   
7.
8.
器官移植术是20世纪出现的针对器官功能衰竭的最有效治疗方法,每年拯救全球超过12万例患者。但供器官短缺的现状,与器官移植技术和辅助药物的发展不匹配,制约了器官移植事业的发展。我国自2015年起已成为全球器官捐献和移植大国之一,2017年公民逝世后器官捐献数量超过5 000例,占全球捐献总量的15%以上。黄洁夫教授总结的器官捐献与移植"中国模式"得到了世界卫生组织、国际移植界的高度重视和充分肯定。本文通过整理全球及各国的器官捐献与移植数据,剖析全球现状与发展趋势,进一步探索我国公民器官捐献的影响因素并提出针对性的应对策略,以期实现我国器官捐献和移植的"自给自足"。  相似文献   
9.
Changes in resting energy expenditure (REE) of cancer patients vary depending on type of tumor, treatment time point and kind of treatment. Little is known about REE of acute leukemia adult patients after treatment, especially with results related to body weight or fat free mass (FFM). This study aimed to assess changes in REE of acute leukemia adult patients before and after the first remission induction. Evaluation of REE was performed by indirect calorimetry and predicted REE was calculated by Harris-Benedict equation. Weight and height were measured and compared to a control group of healthy individuals. FFM was assessed by bioelectrical impedance for adjusting REE values. We evaluated 18 patients and 26 healthy individuals. At diagnosis, patients presented REE, REE/weight, and REE/FFM higher than the controls. Reductions of REE, REE/weight, and REE/FFM were also observed in patients after the first cycle of chemotherapy. The predicted REE for the patients group showed significant lower value compared with measured REE. Before the first cycle of chemotherapy REE was increased but undergoes a reduction after treatment, reaching values similar to the controls. For predictive Harris-Benedict equation, stress factors should be added to avoid underestimation of REE before and after chemotherapy.  相似文献   
10.
The spatial distribution of enteroparasitosis in an indigenous village from Paraná was evaluated to identify areas of risk for these infections. A cross-sectional study (from November 2010 to June 2011) was performed using Three Faecal Test® and Kato &; Katz method and a questionnaire on housing and hygiene conditions was administered. Local geostatistical analyses were performed to determine the spatial distribution of intestinal parasitic infections. The overall prevalence of enteroparasites was 67.2?% (457/680), and the most prevalent taxa were Ascaris lumbricoides (48.8?%) and Trichuris trichiura (44.7?%). The prevalence of heavy infection by soil-transmitted helminths was 3.6?% and the families lived in houses with an average of 5.1 residents and < 2 bedrooms per household. The average number of species per individual present spatial heterogeneity with the highest values (≥0.8) in areas with high clustering of residences. The visualization of the spatial distribution of intestinal parasites in this indigenous village is an important contribution to determining health risk areas and planning decisions and services.  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