全文获取类型
收费全文 | 725篇 |
免费 | 44篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 20篇 |
妇产科学 | 22篇 |
基础医学 | 56篇 |
口腔科学 | 19篇 |
临床医学 | 120篇 |
内科学 | 143篇 |
皮肤病学 | 19篇 |
神经病学 | 47篇 |
特种医学 | 129篇 |
外科学 | 62篇 |
综合类 | 13篇 |
预防医学 | 70篇 |
眼科学 | 3篇 |
药学 | 16篇 |
肿瘤学 | 43篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 16篇 |
2017年 | 8篇 |
2016年 | 12篇 |
2015年 | 14篇 |
2014年 | 16篇 |
2013年 | 54篇 |
2012年 | 24篇 |
2011年 | 26篇 |
2010年 | 22篇 |
2009年 | 36篇 |
2008年 | 31篇 |
2007年 | 58篇 |
2006年 | 32篇 |
2005年 | 30篇 |
2004年 | 25篇 |
2003年 | 21篇 |
2002年 | 15篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 48篇 |
1997年 | 50篇 |
1996年 | 25篇 |
1995年 | 23篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 9篇 |
1989年 | 10篇 |
1988年 | 14篇 |
1987年 | 13篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 6篇 |
排序方式: 共有783条查询结果,搜索用时 15 毫秒
91.
Dionisio KL Howie SR Dominici F Fornace KM Spengler JD Donkor S Chimah O Oluwalana C Ideh RC Ebruke B Adegbola RA Ezzati M 《Journal of exposure science & environmental epidemiology》2012,22(2):173-181
Smoke from biomass fuels is a risk factor for pneumonia, the leading cause of child death worldwide. Although particulate matter (PM) is the metric of choice for studying the health effects of biomass smoke, measuring children's PM exposure is difficult. Carbon monoxide (CO), which is easier to measure, can be used as a proxy for PM exposure. We measured the exposure of children ≤ 5 years of age in The Gambia to CO using small, passive, color stain diffusion tubes. We conducted multiple CO measurements on a subset of children to measure day-to-day exposure variability. Usual CO exposure was modeled using a mixed effects model, which also included individual and household level exposure predictors. Mean measured CO exposure for 1181 children (n=2263 measurements) was 1.04 ± 1.46?p.p.m., indicating that the Gambian children in this study on average have a relatively low CO exposure. However, 25% of children had exposures of 1.3?p.p.m. or higher. CO exposure was higher during the rainy months (1.33 ± 1.62?p.p.m.). Burning insect coils, using charcoal, and measurement done in the rainy season were associated with higher exposure. A parsimonious model with fuel, season, and other PM sources as covariates explained 39% of between-child variation in exposure and helped remove within-child variability. 相似文献
92.
Background
Pneumocystis jiroveci pneumonia (PCP) is an important opportunistic infection among immunosuppressed patients, especially in those infected with human immunodeficiency virus (HIV). The clinical presentation of PCP in immunosuppressed patients have been well-reported in the literature. However, the clinical importance of PCP manifesting in the setting of an immunorestitution disease (IRD), defined as an acute symptomatic or paradoxical deterioration of a (presumably) preexisting infection, which is temporally related to the recovery of the immune system and is due to immunopathological damage associated with the reversal of immunosuppressive processes, has received relatively little attention until recently. 相似文献93.
The effect of fibrin polymers on thrombin-catalyzed factor XIIIa formation was studied in afibrinogenemic plasma. Fibrin polymers derived from des A fibrinogen and des A,B fibrinogen increased sixfold the rate of thrombin-catalyzed factor XIIIa formation in the presence of EDTA. Calcium chloride accelerated factor XIIIa formation 14-fold in the presence of des A,B fibrinogen without increasing the rate of thrombin formation. Fibrinopeptides A and B had no effect on factor XIIIa formation in afibrinogenemic plasma. Des A,B fibrinogen reduced by 20- to 40-fold the thrombin concentration required to activate factor XIII. Glycyl-L-prolyl-L-arginyl-L-proline (gly-pro-arg-pro), a fibrin polymerization inhibitor, inhibited des A and des A,B fibrinogen from enhancing thrombin-catalyzed factor XIIIa formation. Gly-pro-arg- pro did not modify factor XIIIa formation in afibrinogenemic plasma and did not inhibit thrombin cleavage of the chromogenic substrate S-2238. These results demonstrate that fibrin polymers accelerate thrombin- catalyzed plasma factor XIIIa formation. 相似文献
94.
Delaney CP Weese JL Hyman NH Bauer J Techner L Gabriel K Du W Schmidt WK Wallin BA;Alvimopan Postoperative Ileus Study Group 《Diseases of the colon and rectum》2005,48(6):1114-1129
PURPOSE Postoperative ileus presents significant clinical challenges that potentially prolong hospital stay, contribute to readmission, and increase morbidity. There is no approved treatment for postoperative ileus. Alvimopan is a novel, peripherally acting, mu opioid receptor antagonist currently in development for the management of postoperative ileus.METHODS Patients undergoing partial colectomy or simple or radical hysterectomy were randomized to receive alvimopan 6 mg (n = 152), alvimopan 12 mg (n = 146), or placebo (n = 153) orally 2 hours before surgery and twice daily thereafter until discharge or for up to seven days. The primary efficacy end point, time to return of gastrointestinal function, was a composite measure of passage of flatus or stool and tolerating solid food. Secondary end points included time to the hospital discharge order written. Adverse events were monitored throughout the study.RESULTS Mean time to gastrointestinal recovery was significantly reduced in patients treated with alvimopan 6 mg vs. placebo (hazard ratio = 1.45; P = 0.003), with a smaller reduction seen with alvimopan 12 mg (hazard ratio = 1.28; P = 0.059). Mean time to the hospital discharge order written was significantly accelerated in patients treated with alvimopan 6 mg (hazard ratio = 1.50; P < 0.001). The most common treatment-emergent adverse events across all treatment groups were nausea, vomiting, and hypotension; the incidence of nausea and vomiting was reduced by 53 percent in the alvimopan 12-mg group.CONCLUSIONS In patients undergoing major abdominal surgery, alvimopan accelerated gastrointestinal recovery and time to the hospital discharge order written compared with placebo and was well tolerated.Presented at the meeting of The American Society of Colon and Rectal Surgeons, Dallas, Texas, May 8 to 13, 2004. 相似文献
95.
AP-1和肿瘤的关系研究进展 总被引:4,自引:0,他引:4
转录因子AP-1(activatorprotein1),主要由Jun、Fos、ATF及JDP亚家族组成,亚家族单体以同源或异源二聚体的形式结合DNA靶序列,参与靶基因调节.对基因修饰小鼠和细胞的研究表明,AP-1参与细胞的正常生长和癌性转化过程,其在细胞中的作用取决于细胞类型、AP-1的组成和各组分的相对比例,也与刺激的种类密切相关.AP-1的活性受多种核因子调节,同时单体间也存在相互促进或拮抗作用.AP-1对各种刺激如应激、辐射或生长信号等作出生理或病理应答,参与细胞的增殖、分化和转化等过程,在肿瘤的形成、转移和侵袭中发挥重要作用,已经有学者研究通过抑制AP-1活性来发展抗肿瘤药物. 相似文献
96.
Comparison of clinical and self-reported diagnoses for participants on a community-based arthritis self-management programme 总被引:2,自引:0,他引:2
OBJECTIVE: With the advent of community-based arthritis education
programmes, it is important to determine the accuracy of participants'
self-reported diagnoses. The purpose of this study was to determine the
level of agreement between general practitioner (GP)-recorded and self-
reported diagnoses of participants attending an Arthritis Self- Management
Programme (ASMP). METHODS: Participants enrolling on the ASMP were asked to
(a) identify their type of arthritis via a self- administered postal
questionnaire and (b) obtain a written confirmation of their diagnosis from
their GP. The sample (n = 613) comprised mainly women (83%) with a mean age
of 58.8 yr (S.D. 12.6) and a mean disease duration of 15.4 yr (S.D. 12.5).
RESULTS: Participants' self-reported diagnoses were confirmed by GPs in 534
cases [87.1%, 95% confidence interval (CI): 84.4 89.8%]. Confirmed
diagnoses were reported by 86.9% (95% CI: 83.1-90.7%) of those with
osteoarthritis (OA) and 96.1% (95% CI: 93.6 98.6%) of those with rheumatoid
arthritis (RA). The concordance rate for all other types of arthritis
combined was lower at 60.5% (95% CI: 49.5-71.5%). There were no significant
differences with respect to age, gender, education, physical functioning,
duration of disease and number of GP visits between those who correctly
identified their type of arthritis and those who did not. CONCLUSIONS: This
study suggests that the majority of RA and OA participants attending an
arthritis education programme can correctly identify their specific type of
arthritis.
相似文献
97.
98.
Colette H. Duggan Kathie J. Albright Anthony Lequerica 《Disability and rehabilitation》2013,35(12-13):978-990
Purpose. This article describes the use of the World Health Organization's (WHO) International Classification of Functioning, Disability and Health (ICF) as a conceptual framework for processing and analyzing the narratives of 50 community-dwelling women with a spinal cord injury. The women were participants in a federally-funded study of stress and coping over the life course.Method. The paper describes the development of a coding scheme and data reduction techniques used to process qualitative data.Results. The initial results of three phases of data analysis are then presented: (i) the construction of matrices to display data so as to permit pattern finding; (ii) the mapping of specific ICF codes to text to produce a more finely grained analysis of environment-related stressors, and (iii) a thematic analysis of text depicting the dynamics of person-environment interaction.Conclusions. Of potential value to the further elaboration of the ICF is a fleshing out of the personal factors component of the ICF and the provision of a context-driven, process view of person-environment interaction. It is hoped that this article will stimulate continued discussion of person-level factors. The concept of coupling suggests also a need to focus research attention on the bi-directional and ever evolving linkages connecting person to environment. 相似文献
99.
100.
The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry 总被引:8,自引:1,他引:8
Nistico L; Buzzetti R; Pritchard LE; Van der Auwera B; Giovannini C; Bosi E; Larrad MT; Rios MS; Chow CC; Cockram CS; Jacobs K; Mijovic C; Bain SC; Barnett AH; Vandewalle CL; Schuit F; Gorus FK; Tosi R; Pozzilli P; Todd JA 《Human molecular genetics》1996,5(7):1075-1080
Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus
is determined by a combination of environmental and genetic factors, which
include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin
gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2
cannot explain the clustering of type 1 diabetes in families, and a role
for other genes is inferred. In the present report we describe linkage and
association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte
associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong
candidate gene for T cell- mediated autoimmune disease because it encodes a
T cell receptor that mediates T cell apoptosis and is a vital negative
regulator of T cell activation. In addition, we provide supporting evidence
that CTLA-4 is associated with susceptibility to Graves' disease, another
organ- specific autoimmune disease.
相似文献