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   18763篇
  免费   1180篇
  国内免费   200篇
耳鼻咽喉   239篇
儿科学   637篇
妇产科学   453篇
基础医学   2508篇
口腔科学   217篇
临床医学   1509篇
内科学   3507篇
皮肤病学   332篇
神经病学   1361篇
特种医学   595篇
外国民族医学   1篇
外科学   2385篇
综合类   465篇
一般理论   24篇
预防医学   2955篇
眼科学   487篇
药学   1096篇
  2篇
中国医学   136篇
肿瘤学   1234篇
  2024年   28篇
  2023年   184篇
  2022年   353篇
  2021年   612篇
  2020年   280篇
  2019年   516篇
  2018年   623篇
  2017年   437篇
  2016年   461篇
  2015年   540篇
  2014年   718篇
  2013年   1019篇
  2012年   1461篇
  2011年   1514篇
  2010年   902篇
  2009年   710篇
  2008年   1094篇
  2007年   1179篇
  2006年   1106篇
  2005年   930篇
  2004年   882篇
  2003年   824篇
  2002年   709篇
  2001年   353篇
  2000年   300篇
  1999年   252篇
  1998年   102篇
  1997年   100篇
  1996年   74篇
  1995年   69篇
  1994年   68篇
  1993年   45篇
  1992年   151篇
  1991年   140篇
  1990年   160篇
  1989年   172篇
  1988年   143篇
  1987年   140篇
  1986年   113篇
  1985年   104篇
  1984年   73篇
  1983年   58篇
  1982年   24篇
  1981年   31篇
  1980年   27篇
  1979年   45篇
  1975年   29篇
  1974年   21篇
  1973年   23篇
  1972年   21篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
This study deals with a series of operations to isolate the micro-cellulose from the palm tree spathe sheath by using a modified chemical method to take into account the low cost and the completion speed and its characterization using X-ray diffraction technique (XRD), infrared spectroscopy (FTIR) and scanning electron microscope coupled with element analyzer (SEM/EDX). The results showed that the extraction method succeeded in obtaining very pure microscopic fibers with a width of 2–10 μm with a crystallinity index equal to 79.21%, containing the two cellulose features Iβ and II, that, the conversion ratio of the first to the second was estimated at 32, 87%.  相似文献   
6.
7.

Objectives

The current study investigated the effects of two exercise interventions on cognitive function amongst breast cancer survivors.

Design

Pilot randomised-controlled trial.

Methods

Seventeen female cancer survivors (mean: 62.9 ± 7.8 years) were randomised into three groups: high-intensity interval training (HIIT, n = 6); moderate-intensity continuous training (MOD, n = 5); or wait-list control (CON, n = 6). The HIIT and MOD groups exercised on a cycle ergometer 3 days/week for 12-weeks. Primary outcomes were cognitive function assessments utilising CogState. Secondary outcomes were resting middle cerebral artery blood flow velocity, cerebrovascular reactivity and aerobic fitness (VO2peak). Data were analysed with General Linear Mixed Models and Cohen’s d effect sizes were calculated.

Results

All 17 participants who were randomised were available for follow-up analysis and adherence was similar for HIIT and MOD (78.7 ± 13.2% vs 79.4 ± 12.0%; p = 0.93). Although there were no significant differences in the cognitive and cerebrovascular outcomes, HIIT produced moderate to large positive effects in comparison to MOD and CON for outcomes including episodic memory, working memory, executive function, cerebral blood flow and cerebrovascular reactivity. HIIT significantly increased VO2peak by 19.3% (d = 1.28) and MOD had a non-significant 5.6% (d = 0.72) increase, compared to CON which had a 2.6% decrease.

Conclusions

This study provides preliminary evidence that HIIT may be an effective exercise intervention to improve cognitive performance, cerebrovascular function and aerobic fitness in breast cancer survivors. Considering the sample size is small, these results should be confirmed through larger clinical trials.  相似文献   
8.
While once considered as incurable systemic disease, treatment options for liver metastases have increased over the last 30 years and safety has improved dramatically, such that for a selected group of patients the hope of cure can now be offered with radical treatment, and low morbidity interventions can be offered which prolong survival, even in patients with more widely disseminated disease. Advances have been made in selection and surgical technique for liver resection and several adjuncts to resection now exist in the form of portal vein embolization, thermal ablation and targeted drug or radiotherapy delivery options. A natural consequence of these developments has been the delivery of services within fewer specialist units, with the result that later complications of therapy may present to local hospitals, rather than directly to the specialist centres. This article will describe the current common liver-directed therapies and outline the presentation and management of their complications.  相似文献   
9.
目的探讨脉冲微波治疗前列腺炎的效果。方法收治前列腺炎病人532例。用南京亿高ECO—100型电脑微波前列腺炎治疗仪,经肛门途径发射脉冲微波,前列腺部位温度控制在41℃~42℃,每次持续45~60min,共七次。以显效、有效为判断疗效标准。结果17~25岁组显效47.93%,有效52.07%,26~45岁组显效52.06%,有效47.94%,两组有效率100%。结论脉冲微波经肛门途径治疗前列腺炎效果明显,有推广价值。  相似文献   
10.
Background:  Previous studies into leisure have employed methodologies that may understate the significance of experiential components. This exploratory study investigated the leisure experiences of retired Australians over 65 years of age.
Methods:  Five semistructured interviews were used to explore the leisure experience of older people from metropolitan Adelaide. Data were coded and analysed thematically.
Results:  Relaxation and engrossment emerged as commonly expressed experiences, yet were found to emerge as a result of engagement in occupations predefined as leisure. Experiences of freedom from both necessary duties and a sense of obligation were discussed as potential determinants of leisure consciousness.
Practice implications:  This study highlights a need for therapists to actively access clients' subjective leisure experiences to enable engagement in personally meaningful leisure occupations.  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