首页 | 官方网站   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   10911篇
  免费   674篇
  国内免费   84篇
医药卫生   11669篇
  2024年   6篇
  2023年   76篇
  2022年   61篇
  2021年   367篇
  2020年   191篇
  2019年   361篇
  2018年   464篇
  2017年   290篇
  2016年   282篇
  2015年   360篇
  2014年   500篇
  2013年   602篇
  2012年   953篇
  2011年   969篇
  2010年   537篇
  2009年   436篇
  2008年   704篇
  2007年   739篇
  2006年   616篇
  2005年   668篇
  2004年   617篇
  2003年   540篇
  2002年   539篇
  2001年   103篇
  2000年   73篇
  1999年   88篇
  1998年   96篇
  1997年   54篇
  1996年   53篇
  1995年   45篇
  1994年   33篇
  1993年   36篇
  1992年   33篇
  1991年   29篇
  1990年   15篇
  1989年   20篇
  1988年   16篇
  1987年   13篇
  1986年   23篇
  1985年   11篇
  1984年   5篇
  1983年   8篇
  1982年   3篇
  1981年   5篇
  1979年   4篇
  1975年   4篇
  1974年   5篇
  1973年   3篇
  1971年   3篇
  1970年   3篇
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
91.
Aim: Fabry disease is considered primarily as a progressive small vessel disease, with ischaemic degenerative lesions involving the kidneys, brain and heart. Macrovascular involvement in male patients includes an accelerated wall hypertrophy of the radial artery and a thickening of the intima–media of the common carotid artery. The aim of this study is to evaluate the prevalence and severity of carotid artery atherosclerosis in hemizygous and heterozygous patients with Fabry disease, compared with a matched control population.
Methods: The common carotid artery intima–media thickness (IMT) of 53 patients with Fabry disease (24 men, 29 women) was measured by high-definition ultrasonography, and the presence or absence of atherosclerotic plaques reported. Results were compared with those of 120 age-matched healthy individuals (83 men, 37 women).
Results: The common carotid artery IMT was increased to the same extent in male and female patients with Fabry disease (706±211 µm and 749±395 µm, respectively) compared with that of the control population (614±113 µm). In the Fabry population, IMT did not correlate with either systolic blood pressure or with renal function (plasma creatinine). In the control population, only systolic blood pressure was positively and significantly correlated with IMT. Atherosclerotic plaques in the common carotid artery were not observed in any patient with Fabry disease, whereas 34% of the control population had carotid artery plaques, as evidenced by focal non-homogeneous intima–media thickening greater than 1.2 mm.
Conclusion: This study presents evidence of a major increase in common carotid artery IMT, both in hemizygous and heterozygous patients with Fabry disease, in the absence of focal atherosclerotic plaques. These results suggest that the conduit arteries may be protected from atherosclerosis in Fabry disease.  相似文献   
92.
Background: To date, only few data are available on how family burden in schizophrenia changes over time. In addition, no study has explored how such factors as coping styles and social support influence burden over time. This paper presents the 1-year follow-up data from the BIOMED I study on family burden and coping strategies in schizophrenia. Methods: A sample of 159 relatives of patients with schizophrenia living in five European countries was followed up prospectively for 1 year with regard to burden and coping strategies, using validated questionnaires. Results: In the sample as a whole, the burden was stable. A reduction of family burden over time was found among relatives who adopted less emotion-focused coping strategies and received more practical support from their social network. In addition, family burden decreased in relation to the improvement of patient's social functioning. Conclusions: When relatives of patients with schizophrenia are able to improve their coping strategies, it is possible for burden to be reduced even after several years. This points to the necessity to provide families of chronic psychotic patients with psychoeducational interventions emphasising the adoption of an effective coping style. Accepted: 22 November 1999  相似文献   
93.
It has been reported that benzylamine reduces blood glucose in rabbits, stimulates hexose uptake, and inhibits lipolysis in mouse, rabbit, and human adipocytes. In the presence of vanadate, benzylamine is also able to improve glucose disposal in normoglycaemic and diabetic rats. Such insulin-mimicking properties are the consequence of hydrogen peroxide production during benzylamine oxidation by semicarbazide-sensitive amine oxidase (SSAO). The aim of the study was to determine whether other SSAO-substrates could share such potential antidiabetic properties. Thus, mafenide, a synthetic antimicrobial sulfonamide structurally related to benzylamine, and which has been recently reported to interact with SSAO, was tested in the above mentioned models, in parallel with methylamine, a proposed endogenous SSAO-substrate. All tested amines stimulated glucose uptake and inhibited lipolysis in rat and mouse fat cells. Methylamine and benzylamine, but not mafenide, reduced the hyperglycaemic response during a glucose tolerance test in rabbits while the three amines tested were devoid of insulin-releasing activity under both in vivo and in vitro conditions. In human adipocytes, mafenide did not stimulate glucose transport since it was not a high-affinity substrate for SSAO and generated less hydrogen peroxide than benzylamine or methylamine. Therefore, mafenide could not be considered as an antidiabetic drug despite being oxidized and exhibiting insulin-mimicking effects in rat and mouse adipocytes. By contrast, the endogenous substrate methylamine improved glucose utilization in all in vitro and in vivo models, leading to consider novel SSAO substrates as drugs with potential anti-hyperglycaemic properties.  相似文献   
94.
95.
Serum beta2-microglobulin, the light chain of the HLA class I molecular complex, remains one of the best survival prognostic factors in multiple myeloma, but other HLA class I molecules might be of interest in monoclonal gammopathies. In this study, we evaluate total soluble HLA class I (HLA-Is) and soluble HLA-G (HLA-Gs) in 103 patients with newly diagnosed multiple myeloma, 30 patients with monoclonal gammopathy of undetermined significance (MGUS), and 30 healthy subjects, studying their prognostic value in multiple myeloma. In multiple myeloma patients, HLA-Is and HLA-Gs median values were 0.8 microg/mL and 28 ng/mL, respectively. Median HLA-Is concentration was higher in stage II and III multiple myeloma patients than in stage I multiple myeloma, MGUS, and control patients. Median HLA-Gs was significantly lower in healthy controls than in MGUS and multiple myeloma patients. A high level of HLA-Is (> or =2.1 microg/mL) was predictive of short survival (P = 0.017). For each given level of beta2-microglobulin, the relative risk of death was higher for patients with HLA-Is > or = 2.1 microg/mL than in patients with a lower level (P = 0.047). HLA-Gs, a marker of monoclonal gammopathy, was of no prognostic value, but the addition of HLA-Is to beta2-microglobulin produced an efficient prognostic score (P < 0.0001). HLA-Is is a new marker of multiple myeloma tumor load and provides additional survival prognostic information to beta2-microglobulin.  相似文献   
96.
We describe herein the structural optimization of new piperamide analogues, designed from two natural prototypes, piperine 1 and piperdardine 2, obtained from Piper tuberculatum Jacq. (Piperaceae). Molecular modeling studies using semiempirical AM1 method were made in order to establish rational modifications to optimize them by molecular simplification. The targeted compounds (10) and (11) were respectively obtained using benzaldehyde (12) and para-anisaldehyde (13) as starting materials. 1H NMR spectra showed that the target compounds were diastereoselectively obtained as the (E)-isomer, the same geometry of the natural prototypes. These new synthetic amides presented significant hypotensive effects in cardiovascular essays using in vivo methodologies. Compound 11 (N-[5-(4′-methoxyphenyl)-2(E)-pentenoyl]thiomorpholine) showed a potency 10,000 times greater than its prototype 5, evidencing an optimization of the molecular architecture for this class of hypotensive drug candidates.  相似文献   
97.
In the approach to lipid-related risk factors for cardiovascular diseases, serum high density lipoprotein-cholesterol (HDL-C) levels bear a particular significance as this lipoprotein is considered to be an antiatherogenic factor mainly, but not only, because of its influence and impact on reverse cholesterol transport. Hence the need and requirement to consider serum HDL-C levels for both primary and secondary prevention of cardiovascular disease. A particularly important aspect is the association of the 'low HDL syndrome' with the metabolic syndrome. These factors force us to consider serum HDL-C level as a therapeutic target by itself, or even in association with low density lipoprotein-cholesterol (LDL-C) levels when the latter are increased. This review stresses the aspects connecting serum HDL-C levels and cardiovascular risk, and looks at the populations that should be considered amenable to therapeutic management because of low serum HDL-C levels. We review therapeutic strategies, both pharmacological and nonpharmacological. The aim of this review is to present therapeutic management recommendations for correcting the proportion of cardiovascular risk that is attributable to changes in HDL-C. Serum HDL-C levels of >40 mg/dL must be a therapeutic target in primary and secondary prevention. This goal is particularly important in patients with low serum HDL-C levels and ischemic heart disease (IHD) or its equivalents, even if the therapeutic target for serum LDL-C levels (<100 mg/dL) has been achieved. The first choice for this clinical condition is fibric acid derivates. The same therapeutic option should be considered in patients without IHD with low serum HDL-C levels and high cardiovascular risk (>20%), hypertriglyceridemia, type 2 diabetes mellitus, or metabolic syndrome.  相似文献   
98.
99.
ObjectivesTo use an “evidence-mapping” approach to assess the usefulness of Cochrane reviews in identifying research gaps in the maternal health.Study Design and SettingThe article describes the general mapping, prioritizing, reconciling, and updating approach: (1) identifying gaps in the maternal health research using published systematic reviews and formulating research questions, (2) prioritizing questions using Delphi method, (3) reconciling identified research priorities with the existing literature (i.e., searching of ongoing trials in trials registries), (4) updating the process. A comprehensive search of Cochrane systematic reviews published or updated from January 2006 to March 2011 was performed. We evaluated the “Implications for Research” section to identify gaps in the research.ResultsOur search strategy identified 695 references; 178 systematic reviews identifying at least one research gap were used. We formulated 319 research questions, which were classified into 11 different categories based on the direct and indirect causes of maternal mortality: postpartum hemorrhage, abortion, hypertensive disorders, infection/sepsis, caesarean section, diabetes, pregnancy prevention, preterm labor, other direct causes, indirect causes, and health policies and systems. Most research questions concerned the effectiveness of clinical interventions, including drugs (42.6%), nonpharmacologic interventions (16.3%), and health system (14.7%).ConclusionIt is possible to identify gaps in the maternal health research by using this approach.  相似文献   
100.
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-23

京公网安备 11010802026262号