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   2816篇
  免费   409篇
  国内免费   14篇
耳鼻咽喉   10篇
儿科学   69篇
妇产科学   289篇
基础医学   248篇
口腔科学   40篇
临床医学   936篇
内科学   571篇
皮肤病学   58篇
神经病学   81篇
特种医学   253篇
外科学   148篇
综合类   75篇
一般理论   9篇
预防医学   169篇
眼科学   111篇
药学   96篇
肿瘤学   76篇
  2023年   43篇
  2021年   17篇
  2020年   41篇
  2019年   28篇
  2018年   63篇
  2017年   107篇
  2016年   84篇
  2015年   112篇
  2014年   121篇
  2013年   122篇
  2012年   77篇
  2011年   103篇
  2010年   132篇
  2009年   119篇
  2008年   75篇
  2007年   106篇
  2006年   82篇
  2005年   80篇
  2004年   58篇
  2003年   65篇
  2002年   59篇
  2001年   69篇
  2000年   49篇
  1999年   69篇
  1998年   102篇
  1997年   118篇
  1996年   111篇
  1995年   100篇
  1994年   72篇
  1993年   54篇
  1992年   53篇
  1991年   37篇
  1990年   25篇
  1989年   55篇
  1988年   54篇
  1987年   53篇
  1986年   49篇
  1985年   56篇
  1984年   29篇
  1983年   26篇
  1982年   25篇
  1981年   25篇
  1980年   27篇
  1979年   34篇
  1978年   32篇
  1977年   37篇
  1976年   22篇
  1975年   25篇
  1973年   18篇
  1970年   27篇
排序方式: 共有3239条查询结果,搜索用时 15 毫秒
71.
I Kass  J E Dyksterhuis  H Rubin  K D Patil 《Chest》1975,67(4):433-440
Despite the magnitude of the public health problem presented by respiratory diseases, there have been few studies concerned with vocational rehabilitation (VR) potential of patients with chronic obstructive pulmonary disease (COPD). Certain physiologic variables which show a high degree of relationship to VR success are identified. The three independent variables which most highly correlate with the VR potential of patients with COPD are the percentages predicted for the first-second forced expiratory volume (FEV(1.0)), forced expiratory flow between 25 and 75 percent of the forced vital capacity (FEF(25-75 percent)), and maximum voluntary ventilation (MVV). The mean "cutting" percentages for inclusion in VR programs were 50, 27, and 40, respectively. The emotional variables studied do not differentiate potential VR success or failure as clearly as the physiologic factors. The criteria set forth not only can be used by rehabilitation workers but could serve as a basis for future demonstration studies.  相似文献   
72.
This report describes the effect of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on platelet production and platelet function in humans. Subjects with advanced solid tumors received PEG-rHuMGDF daily for up to 10 days. There was no increase in circulating platelet count at doses of 0.03 or 0.1 microgram/kg/d by day 12 of study. At doses of 0.3 and 1.0 microgram/kg/d there was a threefold median increase (maximum 10-fold) in platelet count by day 16. The platelets produced in vivo in response to PEG-rHuMGDF showed unchanged aggregation and adenosine triphosphate (ATP)-release responses in in vitro assays. Tests included aggregation and release of ATP in response to adenosine diphosphate (ADP) (10, 5, 2.5, and 1.25 mumol/L), collagen (2 micrograms/mL), thrombin-receptor agonist peptide (TRAP, 10 mumol/L) and ristocetin (1.5 mg/mL). Administration of aspirin to an individual with platelet count of 1,771 x 10(3)/L resulted in the typical aspirin-induced ablation of the normal aggregation and ATP-release response to stimulation with arachidonic acid (0.5 mg/mL), collagen, and ADP (2.5 and 1.25 mumol/L). There was no change in the expression of the platelet-surface activation marker CD62P (P-selectin) nor induction of the fibrinogen binding site on glycoprotein IIb/IIIa as reported by the monoclonal antibody, D3GP3. An elevation of reticulated platelets was evident after 3 days of treatment with PEG-rHuMGDF and preceded the increase in circulating platelet count by 5 to 8 days; this reflected the production of new platelets in response to PEG-rHuMGDF. At later time points, the mean platelet volume (MPV) decreased in a manner inversely proportional to the platelet count. Levels of plasma glycocalicin, a measure of platelet turnover, rose 3 days after the initial increase in the peripheral platelet count. The level of plasma glycocalicin was proportional to the total platelet mass, suggesting that platelets generated in response to PEG-rHuMGDF were not more actively destroyed. Thus, the administration of PEG-rHuMGDF, to humans, increased the circulating platelet count and resulted in fully functional platelets, which showed no detectable increase in reactivity nor alteration in activation status.  相似文献   
73.
We have infused recombinant factor VIIa into patients with hereditary factor VII deficiency with marked reductions in plasma concentrations of factor IX activation peptide (FIXP), factor X activation peptide (FXP), and prothrombin activation fragment F1+2. These investigations show substantial elevations in these markers of coagulation activation and thereby demonstrate that the factor VII-tissue factor pathway is largely responsible for the activation of factor IX as well as factor X in the basal state (ie, the absence of thrombosis or provocative stimuli). We have administered a monoclonal antibody purified factor IX concentrate to individuals with hemophilia B. These studies show an increase in the plasma levels of FIXP that were initially greatly decreased, but no change in FXP or F1+2. We have also infused highly purified factor VIII concentrate into patients with hemophilia A. The data demonstrate no significant changes in the plasma concentrations of FXP and F1+2. The above observations indicate that factor IXa generated by the factor VII-tissue factor pathway is unable to activate factor X under basal conditions. Based upon the above findings, we outline a model of blood coagulation system function under basal conditions, and suggest a process by which the generation of factor Xa and thrombin might be accelerated during normal hemostasis and in the setting of thrombotic disorders.  相似文献   
74.
The prevalence of type 2 diabetes is rapidly rising, especially among minority and low-income youth. There is an unmet need to engage youth in identifying solutions to reverse this trajectory. Social marketing campaigns and entertainment education are effective forms of health communication for engaging populations in health-promoting behaviors. Critical to curbing the epidemic is moving the diabetes conversation away from individual behavior alone and toward a socioecologic perspective using a public health literacy framework. The authors developed an academic-community partnership to develop, implement, and evaluate a type 2 diabetes prevention campaign targeting minority and low-income youth. The Bigger Picture campaign uses hard-hitting, youth-generated spoken-word messages around key environmental and social drivers of the type 2 diabetes epidemic. Campaign goals included promoting health capacity and civic engagement. This article focuses on the development and implementation of the campaign, including (a) rationale and theoretical underpinnings, (b) steps in campaign creation, (c) testing the campaign messaging, and (d) campaign dissemination and evaluation planning. A youth-created health communication campaign using a public health literacy framework with targeted, relevant, and compelling messaging appears to be a promising vehicle for reaching at-risk youth to increase knowledge of and attitudes about preventing type 2 diabetes, change social norms, and motivate participation in health-promoting initiatives.  相似文献   
75.
Background Involving service users and carers in decisions about their health care is a key feature of health‐care practice. Professional health and social care students need to develop skills and attributes to best enable this to happen. Aims The aims were to explore service user and carer perceptions of behaviours, attributes and context required to enable shared decision making; to compare these perceptions to those of students and academic staff with a view to utilizing the findings to inform the development of student assessment tools. Methods A mixed methods approach was used including action learning groups (ALG) and an iterative process alongside a modified Delphi survey. Participants The ALGs were from an existing service user and carer network. The survey was sent to sixty students, sixty academics and 30 service users from 16 different professional disciplines, spanning four Universities in England. Results The collaborative enquiry process and survey identified general agreement that being open and honest, listening, showing respect, giving time and being up to date were important. The qualitative findings identified that individual interpretation was a key factor. An unexpected result was an insight into possible insecurities of students. Conclusions The findings indicate that distilling rich qualitative information into a format for student assessment tools could be problematic as the individual context could be lost, it is therefore proposed that the information could be better used as a learning rather than assessment tool. Several of those involved identified how they valued the process and found it beneficial.  相似文献   
76.

Background

Social connection is a fundamental human need. Its absence can lead to loneliness and social isolation, adversely impacting health and well-being. Given their regular contact and trusted relationships with older people, practitioners delivering community-based primary care are well-positioned to address this issue. However, their contribution to addressing loneliness and social isolation is unclear.

Aim

This integrative review explores the contribution of the primary care workforce to interventions aimed at reducing loneliness and social isolation in community-dwelling older people.

Method

Using an integrative review method, Scopus, Web of Science, CINAHL and PubMed were searched for original research published between 2000 and 2022. Fourteen papers reporting 13 primary studies were appraised for methodological quality and included in the review. Data were extracted into a summary table and analysed using thematic analysis.

Results

Included studies came from over six countries. Internationally, primary care services have diverse structures, funding and workforces influencing their response to loneliness and social isolation. All but one intervention was multi-component, with ten studies including a group-based activity and three providing primarily individual-level activities. Only six studies reported reductions in loneliness following the intervention. Three themes were identified: characteristics of interventions; implementation context, barriers and facilitators; and differing contributions of primary care practitioners in addressing loneliness and social isolation of older people.

Conclusion

There is increasing demand and scope for primary care practitioners to assist lonely and socially isolated older people. It is important to understand how to equip and incentivise these practitioners to routinely identify, assess and respond to lonely and socially isolated older people despite varying implementation contexts. There is a need for further research that explores how the primary care team can be better utilised to deliver effective interventions that reduce the health impacts of loneliness and social isolation.  相似文献   
77.
78.
79.
80.
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