全文获取类型
收费全文 | 524篇 |
免费 | 25篇 |
国内免费 | 26篇 |
专业分类
儿科学 | 45篇 |
妇产科学 | 8篇 |
基础医学 | 34篇 |
口腔科学 | 24篇 |
临床医学 | 55篇 |
内科学 | 132篇 |
皮肤病学 | 4篇 |
神经病学 | 6篇 |
特种医学 | 116篇 |
外科学 | 27篇 |
综合类 | 4篇 |
预防医学 | 18篇 |
眼科学 | 5篇 |
药学 | 72篇 |
肿瘤学 | 25篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 9篇 |
2011年 | 4篇 |
2010年 | 8篇 |
2009年 | 16篇 |
2008年 | 11篇 |
2007年 | 25篇 |
2006年 | 6篇 |
2005年 | 11篇 |
2004年 | 4篇 |
2003年 | 12篇 |
2002年 | 6篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 8篇 |
1998年 | 39篇 |
1997年 | 44篇 |
1996年 | 51篇 |
1995年 | 39篇 |
1994年 | 30篇 |
1993年 | 30篇 |
1992年 | 9篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 20篇 |
1988年 | 20篇 |
1987年 | 13篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 9篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1954年 | 1篇 |
排序方式: 共有575条查询结果,搜索用时 15 毫秒
41.
Background and purpose:
We investigated the effects of a synthetic flavonol, 3′,4′-dihydroxyflavonol (DiOHF) on the expression of monocyte chemoattractant protein-1 (MCP-1) in rat vascular smooth muscle cells.Experimental approach:
MCP-1 expression was assessed by quantitative real-time PCR and protein phosphorylation by immunoprecipitation and Western blots.Key results:
DiOHF (1–30 µmol·L−1) concentration-dependently reduced MCP-1 expression in both quiescent cells and cells stimulated with platelet-derived growth factor (PDGF) or interleukin 1-β. The effect of DiOHF was associated with a suppression of focal adhesion kinase (FAK)-mediated signalling. In vitro kinase assays demonstrated that DiOHF is a potent inhibitor of FAK kinase activity (EC50= 2.4 µmol·L−1). Expression of FAK-related non-kinase reduced basal MCP-1 expression, but not that induced by PDGF or interleukin 1-β. DiOHF also inhibited autophosphorylation of PDGF receptors. The PDGF receptor inhibitor AG-1296 potently suppressed basal and PDGF-induced MCP-1 expression. Inhibition of extracellular signal-regulated kinase activation by DiOHF, either directly or indirectly, may also be involved in its effects on MCP-1 expression. DiOHF had no inhibitory effect on either p38 or nuclear factor-κB activation. Moreover, DiOHF inhibited smooth muscle cell spreading (a FAK-mediated response) and proliferation.Conclusions and implications:
This is the first report on a flavonoid compound (DiOHF) that is a potent FAK inhibitor. DiOHF also inhibits PDGF receptor autophosphorylation. These effects underlie the inhibitory action of DiOHF on MCP-1 expression in smooth muscle cells. Our results suggest that DiOHF might be a useful tool for dissection of the (patho)physiological roles of FAK signalling.British Journal of Pharmacology (2009) 157, 597–606; doi:10.1111/j.1476-5381.2009.00199.x; published online 9 April 2009 相似文献42.
We measured red blood cell iron incorporation (RBC-inc) in 13 human milk-fed premature infants (birthweight 1037 +/- 289 g, gestational age 27 +/- 2 wk, weight at start of study 1571 +/- 426 g) who were receiving full tube-feedings of human milk fortified with a commercial human milk fortifier (FortHM). The relative RBC-inc of supplemental iron (2 mg/kg/d of ferrous sulfate) was assessed using 57Fe sulfate mixed directly into a 24-h volume of FortHM, and 54Fe sulfate given as a bolus between two FortHM feedings the next day. RBC-inc was similar between the two methods of supplemental iron administration (4.7 +/- 2.5% vs 4.6 +/- 1.5%, respectively). Although these values are lower than RBC-inc expected from iron native to human milk, the relatively large amount of iron in the supplements contributed most of the iron incorporated into RBC by the infants. There was a significant positive correlation between the reticulocyte count and RBC-inc. As the high nutrient (especially calcium) content of the FortHM did not interfere with iron utilization, adding iron directly to FortHM, or incorporating it into commercial fortifiers, may be a practical method to provide iron to premature infants. 相似文献
43.
Measuring disability, the agreement between self evaluation and observation of performance 总被引:1,自引:0,他引:1
Gert Jan Wijlhuizen 《Disability and rehabilitation》1999,21(2):61-67
Purpose: In 1981, eight countries and the World Health Organization (WHO) reached consensus about applying a similar disability questionnaire in their health surveys that was related to the ICIDH. In 1992 a revised version, the WHOdisability questionnaire, was recommended. In this paper the concurrent validity of 10 items of the questionnaire is evaluated by measuring the agreement with observed performance of corresponding tasks. Method: The disability questionnairewas sent to 750 subjects. From the respondents (468) 93 were selected, based on their reported disability, and 10 performance tasks were observed. The agreement was measured for individual items and for all items together in distinguishing between persons with no, or at least one disability. Results: A low to moderate agreement was found between self reported and observed disability. In general, observation resulted in lower disability ratings. Among 24% of those who reported at least one disability, no disability was observed. Persons among whom at least one disability was observed, only 2% (n= 1) reported no disability in the questionnaire. Conclusions: Although the concurrent validity is low to moderate between the results of the WHO-disability questionnaire and observation, the questionnaire is highly sensitive for detecting persons with at least one disability. The specificity of the questionnaire must be increased by additional questions. 相似文献
44.
OBJECTIVE: The purpose of this study was to assess the clinical and economic impact of the introduction of inhaled corticosteroid therapy for asthma in a cohort of children 12 years and younger who were North Carolina Medicaid enrollees.
METHODS: The North Carolina Medicaid claims database was used to retrieve clinical and economic variables for the purpose of this study. The case group, which was comprised of 84 children who started corticosteroid inhaler therapy between March 1994 and March 1995, was followed up for 1 year before and 1 year after the start of the therapy. The control group was comprised of 72 children with similar severity of asthma who remained on any other therapy other than corticosteroids for a continuous 2-year period. Paired t-tests were used to compare differences, and multiple regression analysis was used to adjust for potential confounders.
RESULTS: There was a 58% reduction in hospital visits, and a 19% reduction in physician visits in the case group after initiation of inhaled corticosteroids. In the control group, an increase of 34% in the number of outpatient visits occurred in the second year. All the decreases and increases were statistically significant. Children with regular patterns of inhaled corticosteroid refills were found to be significantly lower costing for Medicaid. However, after adjusting for potential confounders, no significant change in health care costs per asthmatic child occurred as a result of the introduction of inhaled corticosteroid therapy.
CONCLUSION: Overall, the study found that introduction of inhaled corticosteroids in a cohort of asthmatic children enrolled in Medicaid was beneficial to Medicaid because it brought about dramatic decreases in health care utilization without additionally increasing costs. 相似文献
METHODS: The North Carolina Medicaid claims database was used to retrieve clinical and economic variables for the purpose of this study. The case group, which was comprised of 84 children who started corticosteroid inhaler therapy between March 1994 and March 1995, was followed up for 1 year before and 1 year after the start of the therapy. The control group was comprised of 72 children with similar severity of asthma who remained on any other therapy other than corticosteroids for a continuous 2-year period. Paired t-tests were used to compare differences, and multiple regression analysis was used to adjust for potential confounders.
RESULTS: There was a 58% reduction in hospital visits, and a 19% reduction in physician visits in the case group after initiation of inhaled corticosteroids. In the control group, an increase of 34% in the number of outpatient visits occurred in the second year. All the decreases and increases were statistically significant. Children with regular patterns of inhaled corticosteroid refills were found to be significantly lower costing for Medicaid. However, after adjusting for potential confounders, no significant change in health care costs per asthmatic child occurred as a result of the introduction of inhaled corticosteroid therapy.
CONCLUSION: Overall, the study found that introduction of inhaled corticosteroids in a cohort of asthmatic children enrolled in Medicaid was beneficial to Medicaid because it brought about dramatic decreases in health care utilization without additionally increasing costs. 相似文献
45.
46.
47.
48.
JH Raphael JL Southall TV Gnanadurai GJ Treharne GD Kitas 《BMC musculoskeletal disorders》2002,3(1):17-8
Background
Continuous intrathecal drug delivery has been shown in open studies to improve pain and quality of life in those with intractable back pain who have had spinal surgery. There is limited data on long term effects and and even less for patients with mechanical back pain without prior spinal surgery. 相似文献49.
Efficacy study of the small-bowel examination 总被引:8,自引:0,他引:8
50.