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   1211篇
  免费   70篇
  国内免费   6篇
耳鼻咽喉   15篇
儿科学   22篇
妇产科学   22篇
基础医学   135篇
口腔科学   41篇
临床医学   161篇
内科学   229篇
皮肤病学   27篇
神经病学   181篇
特种医学   37篇
外科学   164篇
综合类   19篇
预防医学   64篇
眼科学   49篇
药学   79篇
中国医学   3篇
肿瘤学   39篇
  2024年   1篇
  2023年   13篇
  2022年   25篇
  2021年   36篇
  2020年   43篇
  2019年   50篇
  2018年   49篇
  2017年   41篇
  2016年   46篇
  2015年   40篇
  2014年   60篇
  2013年   80篇
  2012年   104篇
  2011年   94篇
  2010年   58篇
  2009年   59篇
  2008年   75篇
  2007年   78篇
  2006年   59篇
  2005年   45篇
  2004年   31篇
  2003年   32篇
  2002年   26篇
  2001年   9篇
  2000年   10篇
  1999年   9篇
  1998年   10篇
  1997年   7篇
  1996年   3篇
  1995年   4篇
  1994年   1篇
  1992年   4篇
  1991年   6篇
  1990年   11篇
  1989年   7篇
  1988年   8篇
  1987年   12篇
  1986年   9篇
  1985年   7篇
  1984年   6篇
  1983年   7篇
  1982年   2篇
  1981年   3篇
  1980年   2篇
  1979年   5篇
排序方式: 共有1287条查询结果,搜索用时 9 毫秒
1.
Herpes zoster probably occurs more often than generally thought. Since it produces a radicular distribution of pain, it should be included in the differential diagnosis of radiculopathy. A case is presented in which evaluating the radicular low back pain before the characteristic rash appears was misleading. Careful history-taking concerning the exact nature of the pain and sensory changes is needed to differentiate between zoster and radiculopathy, if no rash is evident.  相似文献   
2.
3.

Background  

The aim of the current study is to investigate the relationship between physical anhedonia and psychopathological parameters, pharmacological parameters or motor side-effects in a sample of inpatients with schizophrenia in an acute episode of their illness.  相似文献   
4.
Current perspectives on childhood depression: an overview   总被引:2,自引:0,他引:2  
The rapidly increasing research interest in childhood depression indicates that it has become a recognized disorder. The authors review the literature on depression in children, focusing on epidemiology, various diagnostic criteria, classification schemes, assessment instruments, and intervention studies that have been applied to childhood depression. Given that there are many etiological factors, it will be important to study the disorder from various conceptual frameworks, including biochemical, genetic learned helplessness, life stresses, cognitive distortion, behavioral reinforcement, and sociological models.  相似文献   
5.
The pathophysiology of diabetic wound healing and the identification of new agents to improve clinical outcomes continue to be areas of intense research. There currently exist more than 10 different murine models of diabetes. The degree to which wound healing is impaired in these different mouse models has never been directly compared. We determined whether differences in wound impairment exist between diabetic models in order to elucidate which model would be the best to evaluate new treatment strategies. Three well-accepted mouse models of diabetes were used in this study: db/db, Akita, and streptozocin (STZ)-induced C57BL/6J. Using an excisional model of wound healing, we demonstrated that db/db mice exhibit severe impairments in wound healing compared with STZ and Akita mice. Excisional wounds in db/db mice show a statistically significant delay in wound closure, decreased granulation tissue formation, decreased wound bed vascularity, and markedly diminished proliferation compared with STZ, Akita, and control mice. There was no difference in the rate of epithelialization of the full-thickness wounds between the diabetic or control mice. Our results suggest that splinted db/db mice may be the most appropriate model for studying diabetic wound-healing interventions as they demonstrate the most significant impairment in wound healing. This study utilized a novel model of wound healing developed in our laboratory that stents wounds open using silicone splints to minimize the effects of wound contraction. As such, it was not possible to directly compare the results of this study with other studies that did not use this wound model.  相似文献   
6.
OBJECTIVE: The purpose of this investigation was to test a modified telescopic anastomosis in large muscular arteries. MATERIAL AND METHODS: The right carotid arteries in 30 sheep (average weight 57+/-5.7 kg) were transected and anastomosed end to end using two guided sutures and compared with a control group (10 sheeps) using two external sutures (Lauritzen method). RESULTS: The mean time to complete the anastomosis (4.5 min) and hemostasis (4.3 min) in the experimental group was less than the control group (17.3 min for anastomosis and 6.4 min for hemostasis) (P<0.05). In addition, the total amount of blood loss during the modified anastomosis was significantly lower than Lauritzen method (3.8 versus 8 ml). In both experimental and control groups the scanning electron microscopy (SEM) at 90th day post-operation revealed a continuous smooth layer of endothelial cells covering the anastomotic junction. CONCLUSIONS: Anastomosis with two guided sutures is easy and faster to perform and could be applicable to an acutely transected vessel.  相似文献   
7.
BACKGROUND: Human cytomegalovirus (CMV) infection is an important risk factor in the post-transplant (Tx) recovery phase for both hematopoietic stem cell Tx (HSCT) and solid organ Tx (SOT) recipients. CMV infection may be prevented or controlled by simultaneously inducing both CMV-specific neutralizing antibody (nAb) and cellular immunity. Soluble (s) UL55 (surface glycoprotein), UL83 (tegument protein) and UL123/e4 (nuclear protein) are immunodominant in eliciting both CMV nAb and cellular immunity. An attenuated poxvirus, modified vaccinia Ankara (MVA) was selected to develop this vaccine strategy in Tx recipients, because of its clinical safety record, large foreign gene capacity, and capability to activate strong humoral and cellular immune responses against recombinant antigens. OBJECTIVES: A subunit vaccine that targets multiple CMV antigens will be used to gain maximal coverage and protective function against CMV infection. rMVA simultaneously expressing sUL55, UL83 and UL123/e4 will be generated, and humoral and cellular immunity it elicits will be characterized, after murine immunization and in vitro to amplify clinical recall responses. STUDY DESIGN: rMVA will be constructed in two steps using UL123/e4-pLW22 followed by sUL55-UL83-pLW51 transfer plasmids. Western blots will be used to characterize expression levels of each antigen. Primary immunity will be evaluated in mouse models, while recall responses to the virally expressed CMV antigens will be assessed in human peripheral blood. RESULTS: We generated CMV-MVA via homologous recombination, and demonstrated high expression levels of sUL55, UL83 and UL123/e4 by Western blot. CMV-MVA immunization potently induced both humoral and cellular immunity to sUL55, UL83 and UL123 after murine immunization, and cellular immunity to UL83 and UL123 by in vitro amplification of T cell recall responses in human PBMC. CONCLUSIONS: rMVA promotes high level expression of three immunodominant CMV antigens, which is reflected in results of immunization studies in which high titers of UL55-specific antibodies and CD4+ T-help are detected, as well as high levels of UL83-specific and moderate levels of UL123-specific CD8+ CTL.  相似文献   
8.
ObjectivesThe aim of this study was to calculate the burden of stroke in Kurdistan Province, Iran between 2011 and 2017.MethodsIncidence data extracted from the hospital information system of Kurdistan Province and death data extracted from the system of registration and classification of causes of death were used in a cross-sectional study. The World Health Organization method was used to calculate disability-adjusted life years (DALYs).ResultsThe burden of stroke increased from 2453.44 DALYs in 2011 to 5269.68 in 2017, the years of life lost increased from 2381.57 in 2011 to 5109.68 in 2017, and the years of healthy life lost due to disability increased from 71.87 in 2011 to 159.99 in 2017. The DALYs of ischaemic stroke exceeded those of haemorrhagic stroke. The burden of disease, new cases, and deaths doubled during the study period. The age-standardised incidence rate of ischaemic stroke and haemorrhagic stroke in 2017 was 21.72 and 20.72 per 100 000 population, respectively.ConclusionsThe burden of stroke is increasing in Kurdistan Province. Since health services in Iran are based on treatment, steps are needed to revise the current treatment services for stroke and to improve the quality of services. Policy-makers and managers of the health system need to plan to reduce the known risk factors for stroke in the community. In addition to preventive interventions, efficient and up-to-date interventions are recommended for the rapid diagnosis and treatment of stroke patients in hospitals. Along with therapeutic interventions, preventive interventions can help reduce the stroke burden.  相似文献   
9.
(1) Background: Whey protein lowers postprandial blood glucose in health and type 2 diabetes, by stimulating insulin and incretin hormone secretion and slowing gastric emptying. The branched-chain amino acids, leucine, isoleucine and valine, abundant in whey, may mediate the glucoregulatory effects of whey. We investigated the comparative effects of intragastric administration of leucine, isoleucine and valine on the plasma glucose, C-peptide and glucagon responses to and gastric emptying of a mixed-nutrient drink in healthy men. (2) Methods: 15 healthy men (27 ± 3 y) received, on four separate occasions, in double-blind, randomised fashion, either 10 g of leucine, 10 g of isoleucine, 10 g of valine or control, intragastrically, 30 min before a mixed-nutrient drink. Plasma glucose, C-peptide and glucagon concentrations were measured before, and for 2 h following, the drink. Gastric emptying of the drink was quantified using 13C-acetate breath-testing. (3) Results: Amino acids alone did not affect plasma glucose or C-peptide, while isoleucine and valine, but not leucine, stimulated glucagon (p < 0.05), compared with control. After the drink, isoleucine and leucine reduced peak plasma glucose compared with both control and valine (all p < 0.05). Neither amino acid affected early (t = 0–30 min) postprandial C-peptide or glucagon. While there was no effect on overall gastric emptying, plasma glucose at t = 30 min correlated with early gastric emptying (p < 0.05). (4) Conclusion: In healthy individuals, leucine and isoleucine lower postprandial blood glucose, at least in part by slowing gastric emptying, while valine does not appear to have an effect, possibly due to glucagon stimulation.  相似文献   
10.
The purpose of this study is to determine the individual contribution, or importance number, of the symptoms to an analysis of depression, utilizing a neural network model. In addition, the presence of hopelessness and somatic complaints was examined, to determine their relevance to depression. Using Wave 1 data from Duke University's contribution in the Epidemiological Catchment Area (ECA) study, we created a mathematical model, a neural network, to map the relationship of nine symptoms of major depression, hopelessness and somatic complaints to the presence or absence of the formal diagnosis of depression, and performed a contribution analysis. The contribution analysis using the neural network revealed that the symptoms with the greatest impact on the occurrence of depression, or with the largest importance number for depression, were sadness, loss of interest, tiredness and sleeping trouble, in that order. The most frequently reported symptoms, though, were sadness, sleeping trouble, suicidal ideation, tiredness and poor concentration, in that order. Hopelessness and somatic symptoms were the lowest in their contribution to the diagnosis of depression. The study thus provides the hierarchy of the symptoms of depression and supports the DSM classification of major depression.  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