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   3460篇
  免费   248篇
  国内免费   7篇
耳鼻咽喉   39篇
儿科学   87篇
妇产科学   79篇
基础医学   550篇
口腔科学   55篇
临床医学   324篇
内科学   719篇
皮肤病学   85篇
神经病学   364篇
特种医学   63篇
外科学   390篇
综合类   19篇
预防医学   389篇
眼科学   71篇
药学   257篇
中国医学   15篇
肿瘤学   209篇
  2023年   63篇
  2022年   100篇
  2021年   231篇
  2020年   140篇
  2019年   151篇
  2018年   178篇
  2017年   107篇
  2016年   107篇
  2015年   97篇
  2014年   146篇
  2013年   171篇
  2012年   252篇
  2011年   253篇
  2010年   146篇
  2009年   123篇
  2008年   164篇
  2007年   165篇
  2006年   151篇
  2005年   137篇
  2004年   139篇
  2003年   99篇
  2002年   85篇
  2001年   25篇
  2000年   31篇
  1999年   35篇
  1998年   16篇
  1997年   19篇
  1996年   16篇
  1995年   22篇
  1994年   8篇
  1993年   15篇
  1992年   23篇
  1991年   20篇
  1990年   30篇
  1989年   28篇
  1988年   24篇
  1987年   29篇
  1986年   17篇
  1985年   24篇
  1984年   8篇
  1983年   12篇
  1982年   8篇
  1979年   11篇
  1978年   8篇
  1977年   7篇
  1975年   11篇
  1974年   8篇
  1973年   13篇
  1972年   6篇
  1971年   8篇
排序方式: 共有3715条查询结果,搜索用时 250 毫秒
1.
Introduction: Major Depressive Disorder (MDD) and General Anxiety Disorder (GAD) significantly contribute to the global burden of disease. Vilazodone, a combined serotonin reuptake inhibitor and 5-HT1A partial agonist, is an approved therapy for the treatment of MDD and which has been further investigated for GAD.

Areas covered: This article covers the pharmacokinetics and pharmacodynamics of vilazodone and provides an evaluation of the clinical usefulness of vilazodone for the treatment of MDD and anxiety disorders. A literature search was performed using PubMed/MEDLINE, Web of Science and the Cochrane Library.

Expert opinion: Studies have shown that vilazodone is significantly superior to placebo. However, vilazodone cannot as yet be recommended as a first-line treatment option for MDD as it is unclear whether the drug’s dual mechanism of action provides greater efficacy than prevailing treatment options. Moreover, more phase IV studies are needed to establish its efficacy and long-term safety in larger and more diverse populations. Although vilazodone may have an additional advantage for the treatment of anxiety symptoms in MDD, here also additional studies are required to confirm its efficacy over and above SSRI alternatives and other antidepressant treatments. Therefore, presently, vilazodone should be considered as a second- or third-line treatment option for MDD and GAD.  相似文献   

2.

Objective

To discover the experiences of end-of-life patients attended by the emergency services, through the discourse of the family caregivers who accompanied the family member in this care transit.

Method

A qualitative approach study, based on the paradigm of hermeneutical phenomenology. In total, 81 family caregivers participated. The techniques used were the in-depth interview and the discussion group, with a total of 5 discussion groups and 41 interviews. The period of data collection was carried out between January 2013 and June 2014.

Results

In the network of discourses obtained with respect to “Urgent Care”, all the codes were grouped in relation to a single argumentative line: deficiencies in urgent care. Among them, we found different dimensions that are established depending on the different times of care, or the different determinant aspects of these deficiencies: disorganization of the care received, lack of experience of the professionals in emergencies, application of general protocols in the emergency services, inadequate care in the treatment received, delays in emergency care.

Conclusions

In general, we highlight the dissatisfaction of the family members with respect to the care received from the emergency services. The needs of these types of situation are not covered from these services and are of low quality. Therefore, it is necessary to reorient the care protocols for these patients.  相似文献   
3.
In this piece I describe the process of mourning my mother since her death in 2001, via my short animated documentary ‘Oneironauts – the Dream Travellers’ (2011) and my more recent experiences as the mother of a young baby. I consider my experience in the context of Freud's ‘Mourning and Melancholia’.  相似文献   
4.
5.
1. Two polydeoxyribonucleotides, produced by the controlled hydrolysis of DNA of mammalian lung (defibrotide and its lower molecular weight fraction, P.O. 085 DV), were studied for their ability to modify the release of nitrite and the coronary flow in perfusates collected from isolated, normally perfused hearts of guinea-pigs and from hearts subjected to regional ischaemia and reperfusion. 2. In guinea-pig normally perfused hearts, both defibrotide (DFT) and its fraction, P.O. 085 DV, increase the amount of nitrite appearing in perfusates in a concentration-dependent fashion. At the highest concentration studied (10(-6) M), P.O. 085 DV was more effective than DFT. A concomitant increase in the coronary flow was observed. 3. The increase in nitrite in perfusates and the increase in coronary flow induced by both DFT and P.O. 085 DV were significantly reduced by NG-monomethyl-L-arginine (L-NMMA, 10(-4) M), an inhibitor of nitric oxide synthase (NOS). 4. The endothelium-dependent vasodilator, acetylcholine (ACh), enhances the formation of nitrite and the coronary flow. Both the increase in coronary flow and in the formation of nitrite were significantly reduced by L-NMMA (10(-4) M). 5. In guinea-pig hearts subjected to ischaemia and reperfusion, the effect of both compounds in increasing the amount of nitrite in perfusates was more evident and more pronounced with P.O. 085 DV. 6. Reperfusion-induced arrhythmias were significantly reduced by both compounds to the extent of complete protection afforded by compound P.O. 085 DV. 7. The cardioprotective and antiarrhythmic effects of DFT and P.O. 085 DV are discussed.  相似文献   
6.
7.
The issue of the preparation of effective teachers becomes more critical for teachers of early childhood programs. It has been hypothesized that better program quality depends on better-educated teachers. The purpose of this investigation was to explore the importance of a high level of education for all early childhood education teachers. This issue has intrigued early childhood researchers and has prompted a large amount of research studies over the past decades. In order to assess the status of this line of inquiry and to provide guidance for future research, a critical analysis of 40 studies on the preparation of early childhood education teachers and the quality of their educational programs that were published within a 15-year (1989-2004) period is presented here. The analysis consisted of literal and allegorical critical analysis and interpretative critical analyses, which generated results in three main areas that focused on the professional development of the teachers, including teachers' professional development, the importance of a Bachelor's Degree and educational standards for early childhood education teachers.  相似文献   
8.
This study investigated the extent of impairment in functional parameters of liver mitochondria from rats treated for 60 days with hexachlorobenzene (HCB). A constant amount of mitochondrial uncoupling was found throughout the treatment period. At the same time a nearly constant amount of pentachlorophenol was detected in these mitochondria. In contrast, the level of mitochondrial porphyrins increased progressively. There was good correlation between the concentration of mitochondrial pentachlorophenol and the degree of uncoupling of oxidative phosphorylation.  相似文献   
9.
BACKGROUND: Emerging evidence suggests that type 2 diabetes may be related to diminished cognition, but little data are available directly regarding the role of insulin levels. OBJECTIVE: The objective of this prospective cohort study was to examine the relation of insulin secretion to cognitive function among men without diabetes. SETTING: The study setting was the Physicians' Health Study-U.S. male physicians. PARTICIPANTS: Three hundred sixty-seven men who provided blood samples in 1982, when they had no lifetime history of diabetes and ranged in age from 47-65 years (mean age: 57 years). MEASUREMENTS: The authors assayed plasma C-peptide, reflecting insulin secretion, in the stored blood samples. Beginning in 2001, an average 18 years after blood collection, the authors administered telephone interviews, including tests of general cognition (Telephone Interview of Cognitive Status [TICS]), verbal memory, and category fluency. The authors used regression models to estimate mean differences in cognitive performance across levels of C-peptide controlling for a wide variety of potential confounding factors. RESULTS: On the TICS, men in the top tertile of C-peptide performed significantly worse than those in the bottom (multivariable-adjusted mean difference: -1.01 points, 95% confidence interval: -1.78 to -0.24); this apparent impact of C-peptide on cognition was equivalent to the cognitive differences the authors observed between men 6 years apart in age. Performance on the global score (combining results from all the individual tests) and verbal memory score (combining results from four tests of verbal memory) appeared lower among men in the highest C-peptide tertile, but results were not statistically significant. CONCLUSION: Higher midlife insulin secretion may be related to decreased later-life cognitive function, even among men without diabetes.  相似文献   
10.
Cianchi  F.  Cortesini  C.  Perna  F.  Fabbroni  V.  Uliva  C.  Fabrizi  F.  Giannini  L.  Vannacci  A.  Masini  E. 《Inflammation research》2006,55(1):S81-S82
Inflammation Research - .  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