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   926204篇
  免费   67565篇
  国内免费   1336篇
耳鼻咽喉   12947篇
儿科学   24303篇
妇产科学   23228篇
基础医学   132107篇
口腔科学   28276篇
临床医学   80090篇
内科学   181921篇
皮肤病学   19216篇
神经病学   71746篇
特种医学   36766篇
外国民族医学   79篇
外科学   151735篇
综合类   18006篇
现状与发展   1篇
一般理论   234篇
预防医学   61291篇
眼科学   21256篇
药学   72353篇
  3篇
中国医学   2119篇
肿瘤学   57428篇
  2018年   8963篇
  2017年   7029篇
  2016年   7762篇
  2015年   8862篇
  2014年   11985篇
  2013年   17502篇
  2012年   24086篇
  2011年   25035篇
  2010年   14803篇
  2009年   14265篇
  2008年   24604篇
  2007年   25695篇
  2006年   26485篇
  2005年   25430篇
  2004年   24547篇
  2003年   23544篇
  2002年   23094篇
  2001年   54663篇
  2000年   56446篇
  1999年   46758篇
  1998年   10271篇
  1997年   8983篇
  1996年   9130篇
  1995年   8879篇
  1994年   8250篇
  1993年   7568篇
  1992年   35460篇
  1991年   33909篇
  1990年   32724篇
  1989年   31859篇
  1988年   28973篇
  1987年   28242篇
  1986年   26275篇
  1985年   25138篇
  1984年   17816篇
  1983年   15118篇
  1982年   7766篇
  1981年   6736篇
  1979年   15759篇
  1978年   10582篇
  1977年   9025篇
  1976年   7860篇
  1975年   8616篇
  1974年   10456篇
  1973年   9850篇
  1972年   9354篇
  1971年   8847篇
  1970年   8414篇
  1969年   7916篇
  1968年   7197篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
91.
92.
93.
94.
95.
96.

Background

Major depressive disorder (MDD) is a multifactorial disease which often coexists with cognitive deficits. Depression-induced cognitive deficits are known to be associated with aberrant reward processing, neurochemical and structural alterations. Recent studies have shown that chronic electrical stimulation of brain reward areas induces a robust antidepressant effect. However, the effects of repeated electrical self-stimulation of lateral hypothalamus - medial forebrain bundle (LH-MFB) on depression-induced cognitive deficits and associated neurochemical and structural alterations in the prefrontal cortex (PFC) are unknown.

Objectives

We investigated the effect of chronic rewarding self-stimulation of LH-MFB in neonatal clomipramine (CLI) model of depression. During adulthood, neonatal CLI and saline administered rats were implanted with bilateral electrodes stereotaxically in the LH-MFB and trained to receive intracranial self-stimulation (ICSS) for 14 days. The rats were tested for depressive-like behaviors, learning and memory followed by estimation of PFC volumes, levels of monoamines and its metabolites in the PFC.

Results

We found that chronic ICSS of LH-MFB reverses CLI-induced behavioral despair and anhedonia. Interestingly, self-stimulation normalizes the impaired novel object and location recognition memory in CLI rats. The amelioration of learning impairments in CLI rats was associated with the reversal of volume loss and restoration of monoamine metabolism in the PFC.

Conclusion

We demonstrated that repeated intracranial self-stimulation of LH-MFB ameliorates CLI-induced learning deficits, reverses altered monoamine metabolism and the atrophy of PFC. Our results support the hypothesis that chronic brain stimulation rewarding experience might be evolved as a potential treatment strategy for reversal of learning deficits in depression and associated disorders.  相似文献   
97.
98.

Aims

To assess current national practice in the management of severe open tibial fractures against national standards, using data collected by the Trauma and Audit Research Network.

Materials and methods

Demographic, injury-specific, and outcome data were obtained for all grade IIIB/C fractures admitted to Major Trauma Centres in England from October 2014 to January 2016.

Results

Data was available for 646 patients with recorded grade IIIB/C fractures. The male to female ratio was 2.3:1, mean age 47 years. 77% received antibiotics within 3?h of admission, 82% were debrided within 24?h. Soft tissue coverage was achieved within 72?h of admission in 71%. The amputation rate was 8.7%. 4.3% of patients required further theatre visits for infection during the index admission. The timing of antibiotics and surgery could not be correlated with returns to theatre for early infection. There were significant differences in the management and outcomes of patients aged 65 and over, with an increase in mortality and amputation rates.

Conclusions

Good outcomes are reported from the management of IIIB/C fractures in Major Trauma Centres in England. Overall compliance with national standards is particularly poor in the elderly. Compliance did not appear to affect rates of returning to theatre or early infection. Appropriately applied patient reported outcome measures are needed to enhance the evidence-base for management of these injuries.  相似文献   
99.
Background: Poor anger regulation is considered a risk factor of aggression in individuals with mild or borderline intellectual disabilities. Psychomotor therapy (PMT) targets anger regulation through body- and movement-oriented interventions. This study aims to inform practitioners on efficacy and research-base of PMT in this population.

Method: This systematic review evaluated nine studies which met inclusion criteria in terms of participants, intervention procedures, outcomes and certainty of evidence.

Results: Seven studies revealed a substantial reduction of aggressive behaviour or anger. Certainty of evidence was rated inconclusive in most cases due to absence of experimental control.

Conclusions: We can conclude that body-oriented PMT, involving progressive relaxation and meditation procedure “Soles of the Feet”, is a promising approach. However, the paucity of studies and methodological limitations preclude classifying it as an evidence-based practice. This suggests stronger methodological research and research aimed at PMT’s mechanisms of action (e.g., improved interoceptive awareness) is warranted.  相似文献   

100.
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