全文获取类型
收费全文 | 41389篇 |
免费 | 3324篇 |
国内免费 | 84篇 |
专业分类
耳鼻咽喉 | 315篇 |
儿科学 | 1782篇 |
妇产科学 | 1345篇 |
基础医学 | 5479篇 |
口腔科学 | 446篇 |
临床医学 | 5082篇 |
内科学 | 7572篇 |
皮肤病学 | 711篇 |
神经病学 | 4856篇 |
特种医学 | 777篇 |
外科学 | 4008篇 |
综合类 | 403篇 |
现状与发展 | 1篇 |
一般理论 | 78篇 |
预防医学 | 5595篇 |
眼科学 | 616篇 |
药学 | 2957篇 |
中国医学 | 38篇 |
肿瘤学 | 2736篇 |
出版年
2024年 | 83篇 |
2023年 | 630篇 |
2022年 | 1007篇 |
2021年 | 1984篇 |
2020年 | 1195篇 |
2019年 | 1715篇 |
2018年 | 1924篇 |
2017年 | 1304篇 |
2016年 | 1469篇 |
2015年 | 1555篇 |
2014年 | 2033篇 |
2013年 | 2571篇 |
2012年 | 3716篇 |
2011年 | 3600篇 |
2010年 | 1830篇 |
2009年 | 1566篇 |
2008年 | 2402篇 |
2007年 | 2494篇 |
2006年 | 2118篇 |
2005年 | 1948篇 |
2004年 | 1705篇 |
2003年 | 1422篇 |
2002年 | 1288篇 |
2001年 | 270篇 |
2000年 | 221篇 |
1999年 | 283篇 |
1998年 | 270篇 |
1997年 | 167篇 |
1996年 | 140篇 |
1995年 | 153篇 |
1994年 | 121篇 |
1993年 | 118篇 |
1992年 | 123篇 |
1991年 | 120篇 |
1990年 | 117篇 |
1989年 | 89篇 |
1988年 | 82篇 |
1987年 | 73篇 |
1986年 | 77篇 |
1985年 | 74篇 |
1984年 | 77篇 |
1983年 | 51篇 |
1982年 | 46篇 |
1981年 | 52篇 |
1980年 | 43篇 |
1979年 | 53篇 |
1978年 | 36篇 |
1977年 | 39篇 |
1976年 | 34篇 |
1974年 | 34篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Prerequisites for translating intervention research findings into practice are maintenance of results, generalization of effects and consistency of implementation. This report presents 12 months follow-up information on a randomized 2x2 factorial trial evaluating the incremental effects of adding (1) telephone follow-up or (2) a community resources utilization component to a basic touchscreen computer-assisted dietary goal-setting intervention for 320 type 2 diabetes patients. All conditions evidenced significant improvement from baseline to the 12 months follow-up across behavioral, biological and psychosocial measures. There were few consistent differences between conditions, but results were robust across interventionists and clinics. The telephone follow-up component appeared to enhance long-term results on some measures. When considered along with earlier results from a randomized trial that included a control condition without goal setting, it is concluded that this basic goal-setting intervention can be consistently implemented by a variety of interventionists and produce lasting improvements. 相似文献
72.
Preferences for self-care or professional advice for minor illness: a discrete choice experiment 下载免费PDF全文
Terry Porteous Mandy Ryan Christine M Bond Phil Hannaford 《The British journal of general practice》2006,56(533):911-917
AIM: To determine the relative importance of factors that influence decision making in the management of minor illness, and how people trade between these factors. DESIGN OF STUDY: Discrete choice experiment.Setting:Scottish electoral roll. METHOD: Six hundred and fifty-two responders of a previous national survey were invited to complete a discrete choice experiment questionnaire. This was used to measure relative preferences for managing symptoms of minor illness often associated with analgesic use. Three attributes were identified as important to participants: type of management, availability, and cost of managing symptoms. Trade-offs between these attributes were examined. RESULTS: A 57% response rate was achieved (51% valid response rate). People preferred to manage symptoms by self-care and were willing to pay almost pounds 23 to do so. Community pharmacy was the preferred source of advice. Responders preferred less waiting time and paying less money when managing symptoms, and were willing to trade between factors. A less preferred type of management became more attractive when waiting times and cost were reduced. CONCLUSION: Findings suggest that self-care is the preferred method of managing symptoms of minor illness. When developing services to support self-care, policy makers should invest in services that reduce waiting times and incur least cost to users. 相似文献
73.
Risk and protective factors for suicidal behavior in abused African American women 总被引:12,自引:0,他引:12
Kaslow NJ Thompson MP Okun A Price A Young S Bender M Wyckoff S Twomey H Goldin J Parker R 《Journal of consulting and clinical psychology》2002,70(2):311-319
This study examined risk and protective factors that differentiate low-income, abused African American women (N = 200) who attempted suicide from those who had never made a suicide attempt. Results from multivariate analyses revealed that numerous and/or severe negative life events, a history of child maltreatment, high levels of psychological distress and depression, hopelessness about the future, and alcohol and drug problems were factors associated with attempter status. Protective factors associated with nonattempter status included hopefulness, self-efficacy, coping skills, social support, and effectiveness in obtaining material resources. Culturally competent intervention approaches for abused women should target increasing their protective factors and reducing their risk factors to decrease the likelihood that these women engage in suicidal behavior. 相似文献
74.
Carl F Weems Alan H Zakem Natalie M Costa Melinda F Cannon Sarah E Watts 《Journal of clinical child and adolescent psychology》2005,34(4):712-723
This study examined the physiological response (skin conductance and heart rate [HR]) of youth exposed to a mildly phobic stimulus (video of a large dog) and its relation to child- and parent-reported anxiety symptoms and cognitive bias in a community-recruited sample of youth (n = 49). The results of this study indicated that HR and skin-conductance response were associated with youth report but not parent report of their child's symptoms of anxiety disorders and that HR response was more strongly associated with anxiety symptoms than skin-conductance response. Physiological response was uniquely associated with youth-reported symptoms of anxiety rather than youth-reported depression. Finally, HR response interacted with cognitive bias in predicting childhood anxiety disorder symptoms in a manner consistent with theories of the etiology of anxiety disorders. 相似文献
75.
Involvement of protein kinase C in HIV-1 gp120-induced apoptosis in primary endothelium 总被引:2,自引:0,他引:2
We previously showed that HIV-1 gp120-induced apoptosis in primary human umbilical vein endothelial cell cultures (HUVEC), through CCR5 and CXCR4. Here, we have found that agonists of protein kinase C (PKC), basic fibroblast growth factor (bFGF), and short exposure to low concentrations of phorbol esters were found to block gp120-induced apoptosis in HUVEC cultures. PKC antagonists, sphingosine, H7, and extended exposure of cultures to high concentrations of phorbol esters were also found to block gp120-induced apoptosis in HUVEC cultures. A significant increase in the total amount of cellular PKC enzymatic activity was observed on exposure of HUVEC to gp120. No increase in total PKC activity was observed on exposure of HUVECs to the natural ligands SDF-1alpha, or regulated-on-activation normal T-expressed and secreted (RANTES) cells, and gp120-induced PKC induction was found to be totally blocked by CXCR4 antibodies and partially blocked by the caspase 3 inhibitor, DEVD-CHO. Alternatively, CXCR4 antibodies and DEVD-CHO totally blocked apoptosis. Finally, gp120-induced effects were found to be insensitive to pertussis toxin. Accumulated evidence suggests PKC involvement at multiple points in the gp120-induced apoptotic pathway; also suggests involvement of the CXCR4 receptor internalization pathway, and potentially suggests different downstream effects of gp120-receptor interactions and natural ligand-receptor interactions. 相似文献
76.
Michael Rossdale Terry Kemple Sarah Payne Michael Calnan Rosemary Greenwood 《The British journal of general practice》2007,57(535):152-154
Out-of-hours organisations are responsible for the care of patients 70% of the time, and their GPs act as gatekeepers to secondary care services. This observational study identifies the variations in GPs' out-of-hours referral rates to secondary care and factors that could explain these variations. One hundred and forty-nine GPs who worked in one UK general practice out-of-hours cooperative which served 19 practices with 167 000 registered patients. Data on patients who accessed the out-of-hours service over 3 years (2001-2004) were examined. Factors thought to be predictors of variation in referral rates were investigated using logistic regression analysis. There was a fivefold difference in referral rates between the lowest and highest referring quartiles of GPs (OR [odds ratio] = 4.56, CI [confidence interval] = 3.86 to 5.38). The sex (female) of the clinician, the time of the consultation (11 pm to 7 am), and the place of the consultation (home visit) accounted for some, but not all, of the increased referral rates. A doctor working out-of-hours disproportionately influences the fate of the patient, the number of hospital admissions, and extra costs to the health service. There is a need for follow-up studies to investigate the factors associated with referral behaviour, and how the variation relates to patient factors and the resources available. These findings could be used when planning the staffing of out-of-hours services to optimise appropriate care and minimise patients' exposure to unnecessary intrusive and expensive hospital care. 相似文献
77.
78.
Mode of delivery and risk of developing allergic disease 总被引:3,自引:0,他引:3
McKeever TM Lewis SA Smith C Hubbard R 《The Journal of allergy and clinical immunology》2002,109(5):800-802
The aim of this study was to quantify the relationship between mode of delivery and subsequent incidence of allergic disease. The analysis is based on data derived from a birth cohort of 24,690 children who contributed data to the West Midlands General Practice Research Database. We found no convincing evidence to suggest that babies born by caesarean, forceps, or breech delivery had an increased risk of developing allergic disease. 相似文献
79.
Quantification of Human Immunodeficiency Virus Type 1 RNA Levels in Plasma by Using Small-Volume-Format Branched-DNA Assays 总被引:2,自引:0,他引:2 下载免费PDF全文
Torange Yeghiazarian Yuqi Zhao Stanley E. Read William Kabat Xiaoyi Li Sarah J. Hamren Patrick J. Sheridan Judith C. Wilber David N. Chernoff Ram Yogev 《Journal of clinical microbiology》1998,36(7):2096-2098
We have developed small-volume (50 or 250 μl)-format branched-DNA assays for human immunodeficiency virus type 1 (HIV-1) RNA for use with specimens in which the volume is limited and/or a high viral load is anticipated. These formats exhibited good correlation with the standard 1-ml format; high specificity, reproducibility, and linearity; and no significant difference in the quantification of HIV-1 subtypes. 相似文献
80.
De AK Roach SE De M Minielly RC Laudanski K Miller-Graziano CL Bankey PE 《Journal of immunoassay & immunochemistry》2005,26(1):35-42
Polymorphonuclear leukocytes (PMNs; commonly known as neutrophils) play essential roles in innate immunity and inflammation. Although there are standardized methods for the isolation of human neutrophils, they are time consuming and demand considerable technical expertise, making them unfeasible for many clinical applications. Here, we describe a simple and time-efficient technique for the isolation of human neutrophils, which adapts a readily available commercial cell preparation tube (CPT) currently in use for isolation of peripheral blood mononuclear cells (PBMC) and plasma and is now adapted to also yield neutrophils. The total time required for neutrophil isolation was less than 1 hr. Neutrophils isolated by this method were highly purified (> or =97%) as assessed by surface expression of the neutrophil specific marker, CD66b. Neutrophils isolated by this method were functional as demonstrated by their ability to secrete interleukin-1 receptor antagonist (IL-1RA). Neutrophils isolated using this new technique secreted significant amounts of soluble IL-1RA (929.3+/-197 pg/10(6)cells/mL) in response to lipopolysaccharide (LPS). Use of this adapted CPT method allows simultaneous isolation of functional human neutrophils as well as PBMC and plasma. Adoption of this new method will allow the conduct of different neutrophil assays at any clinical site without requiring trained laboratory personnel or a large staff time commitment. 相似文献