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   5209篇
  免费   392篇
  国内免费   60篇
耳鼻咽喉   41篇
儿科学   144篇
妇产科学   210篇
基础医学   657篇
口腔科学   93篇
临床医学   445篇
内科学   1348篇
皮肤病学   115篇
神经病学   636篇
特种医学   203篇
外科学   459篇
综合类   7篇
一般理论   3篇
预防医学   305篇
眼科学   61篇
药学   341篇
  1篇
中国医学   9篇
肿瘤学   583篇
  2025年   1篇
  2024年   49篇
  2023年   158篇
  2022年   288篇
  2021年   452篇
  2020年   264篇
  2019年   273篇
  2018年   322篇
  2017年   205篇
  2016年   243篇
  2015年   269篇
  2014年   272篇
  2013年   318篇
  2012年   423篇
  2011年   347篇
  2010年   191篇
  2009年   142篇
  2008年   241篇
  2007年   246篇
  2006年   210篇
  2005年   176篇
  2004年   150篇
  2003年   138篇
  2002年   102篇
  2001年   25篇
  2000年   11篇
  1999年   21篇
  1998年   24篇
  1997年   14篇
  1996年   11篇
  1995年   11篇
  1994年   12篇
  1993年   9篇
  1992年   2篇
  1991年   6篇
  1990年   3篇
  1989年   4篇
  1988年   6篇
  1987年   4篇
  1986年   3篇
  1985年   1篇
  1984年   3篇
  1983年   2篇
  1982年   3篇
  1981年   3篇
  1979年   3篇
排序方式: 共有5661条查询结果,搜索用时 15 毫秒
1.
Introduction: Budesonide belongs to low-bioavailability steroids class. A novel oral formulation of budesonide, which uses the Multi-Matrix System (MMX) for delivering drugs to the colon, is now available as a possible treatment of ulcerative colitis patients intolerant or not-responding to first-line therapy with 5-ASA.

Areas covered: in this review we present information about the development and the use of budesonide MMX and we provide data about its mechanism of action as well as, pharmacodynamics and pharmacokynetics. Moreover, we present the available literature data about the efficacy and, mainly, the safety of budesonide-MMX.

Expert opinion: budesonide-MMX is a new therapeutic option in mild-to-moderate UC patients. Its good safety profile in clinical trials undoubtedly represents a strength for a possible wide use in clinical practice, mainly if it will be confirmed by post-marketing data. Other indications, such as treatment of colonic Crohn’s disease, could theoretically be considered, if sustained by reliable scientific data.  相似文献   

2.
Parasitology Research - Diagnosis of Schistosoma haematobium relies primarily on microscopical analysis of urine. The method is time consuming and requires some expertise. Genus-specific real-time...  相似文献   
3.
The terminology used in pharmacovigilance can cause confusion, because there are similar terms that describe different phenomena (e.g. adverse reactions, adverse drug reactions, and side effects). Incorrect use of terminology can have negative effects on the reporting of adverse drug reactions and on the interpretation of these reports. To explain the most common terms used in pharmacovigilance, this article first describes the pharmacovigilance workflow process in the European Union and, as an example, in Italy. Then, the article reviews common pharmacovigilance terms.  相似文献   
4.
Pharmacovigilance started about 170 years ago, although it was not yet named as such at that time. It is structured activity in the professional health field, with important social and commercial implications aimed at monitoring the risk/benefit ratio of drugs, improving patient’s safety and the quality of life. In this commentary we report the milestones of pharmacovigilance up to the present day, in order to understand all the steps that have characterized the historical evolution; from the first reports, which were essentially letters or warnings sent by clinicians to publishers of important and famous scientific journals, up to today’s modern and ultra-structured electronic registries. The historical phases also help us to understand why pharmacovigilance helped us to achieve such important results for man’s health and for pharmacology itself, and to identify the challenges that await Pharmacovigilance in future years.  相似文献   
5.
The objective of this study was to compare the dental arch dimensions in the mixed dentition in two modern samples living in the same geographic area and separated by almost 35 years. A group of 83 subjects (39 boys and 44 girls) born between 1953 and 1959 (mean age: eight years and three months +/-15 months for the boys and seven years and 11 months +/-12 months for the girls) were compared with a group of 84 subjects (38 boys and 46 girls) born between 1990 and 1998 (mean age: eight years and eight months +/-12 months for the boys and eight years and four months +/-11 months for the girls). Measurements were taken on dental casts for posterior and anterior arch segments, intermolar and intercanine width, and mesiodistal size of incisors. The available anterior space in both arches and the posterior and anterior transverse dimensions were calculated. Groups were compared using a nonparametric test (Mann-Whitney U-test) for independent samples (P < .05). Results show that both boys and girls of 1990s showed significantly smaller maxillary intermolar width when compared with 1950s. Posterior transverse interarch discrepancy was significantly minor in girls of 1990s. The present population has a greater probability of developing a malocclusion as a consequence of the secular trend toward the reduction of the width of the upper arch.  相似文献   
6.

Background  

We describe the risk indicators for oral mucositis (OM) in paediatric oncology patients hospitalised in the Institut Gustave Roussy (Villejuif-Paris) and treated with alkylant chemotherapy with autologous peripheral blood progenitor cells.  相似文献   
7.
A patient was treated with a maxillary gold-palladium alloy fixed partial denture (FPD). Shortly after placement, the patient contracted severe contact mucositis. Patch-testing revealed a positive reaction to palladium chloride (PdCl 2 , 1% petrolatum) but not to any other component of the prosthesis. After removal of the FPD and placement of a provisional acrylic resin restoration, all signs and symptoms disappeared. A definitive metal-ceramic (titanium-porcelain) prosthesis was placed, and no signs of lesions appeared. This clinical report demonstrates that titanium may be a satisfactory alternative for patients who require prostheses and are sensitive to other metals.  相似文献   
8.

Background

Chronic Achilles tendinopathy is responsible for a severe reduction in physical performance and persistent pain. There is currently a number of therapeutic options and the local administration of growth factors is an emerging treatment strategy. In particular, platelet-rich plasma (PRP) is a widely used way to provide a local regenerative stimulus for tendon healing. The aim of this study was to document the mid-term results obtained after treating recalcitrant Achilles tendinopathy with injections of high concentrate, leucocyte-rich PRP.

Materials and methods

Twenty-seven patients (mean age: 44.6 years; 22 men and 5 women) affected by chronic mid-portion Achilles tendinopathy (7 bilateral, for a total of 34 tendons), refractory to previous treatments, were enrolled. Patients were treated with three ultrasound-guided intra-tendinous injections of PRP at 2-week intervals. Patients were prospectively evaluated at baseline, and then at 2, 6, and up to a mean of 54.1 months of follow-up (minimum 30 months), using the following tools: Blanzina, VISA-A, EQ-VAS for general health, and Tegner scores.

Results

The VISA-A score showed a significant improvement: the baseline score of 49.9±18.1 increased to 62.9±19.8 at 2 months (p=0.002), with a further improvement at 6 months (84.3±17.1, p<0.0005), and stable results at 4.5 years (90.0±13.9). The EQ-VAS score also showed a similar positive trend. An evaluation of the activity level confirmed these findings, showing a significant improvement in the Tegner score over time (p=0.017 for the final evaluation). The longer duration of symptoms before treatment was associated with a slower return to sport (p=0.041).

Discussion

PRP injections produced good overall results for the treatment of chronic recalcitrant Achilles tendinopathy with a stable outcome up to a medium-term follow-up. Longer symptom duration was related with a more difficult return to sporting activity.  相似文献   
9.
10.
Endothelial dysfunction begins in early CKD and contributes to cardiovascular mortality. HDL is considered antiatherogenic, but may have adverse vascular effects in cardiovascular disease, diabetes, and inflammatory conditions. The effect of renal failure on HDL properties is unknown. We studied the endothelial effects of HDL isolated from 82 children with CKD stages 2–5 (HDLCKD), who were free of underlying inflammatory diseases, diabetes, or active infections. Compared with HDL from healthy children, HDLCKD strongly inhibited nitric oxide production, promoted superoxide production, and increased vascular cell adhesion molecule-1 expression in human aortic endothelial cells, and reduced cholesterol efflux from macrophages. The effects on endothelial cells correlated with CKD grade, with the most profound changes induced by HDL from patients on dialysis, and partial recovery observed with HDL isolated after kidney transplantation. Furthermore, the in vitro effects on endothelial cells associated with increased aortic pulse wave velocity, carotid intima-media thickness, and circulating markers of endothelial dysfunction in patients. Symmetric dimethylarginine levels were increased in serum and fractions of HDL from children with CKD. In a longitudinal follow-up of eight children undergoing kidney transplantation, HDL-induced production of endothelial nitric oxide, superoxide, and vascular cell adhesion molecule-1 in vitro improved significantly at 3 months after transplantation, but did not reach normal levels. These results suggest that in children with CKD without concomitant disease affecting HDL function, HDL dysfunction begins in early CKD, progressing as renal function declines, and is partially reversed after kidney transplantation.Patients with CKD no longer die from renal failure but from cardiovascular disease. There is an independent, graded association between a reduced eGFR and the risk of death and cardiovascular events.1 Typically, patients with CKD develop calcification in the tunica media of their arteries,2 but a concomitant process of endothelial damage leading to atherosclerosis is also3 present beginning in predialysis CKD.4,5LDL is crucially involved in the pathogenesis of atherosclerotic cardiovascular disease in the general population,6 whereas HDL is thought to be antiatherogenic by promoting reverse cholesterol transport and exerting direct protective endothelial effects.7 HDL from healthy participants increases the bioavailability of nitric oxide (NO) by activating endothelial NO synthase inducing vasodilation and decreasing arterial BP. Moreover, HDL diminishes the production of reactive oxygen species such as superoxide (SO) radicals, which have been demonstrated to reduce NO bioavailability leading to endothelial dysfunction and promoting atherogenesis. However, recent evidence suggests that HDL may lose its vasoprotective properties in patients with manifest cardiovascular disease (e.g., coronary artery disease), diabetes, or inflammatory disease states (e.g., antiphospholipid syndrome).810 Similarly, in adults on dialysis, HDL has reduced cholesterol efflux capacity and proinflammatory effects on mononuclear cells.1113 Observational studies have shown a strong association between high HDL levels and reduced risk of cardiovascular disease in the general population14 but not in dialysis patients.15Cardiac and vascular damage has also been documented in children on dialysis,2,16,17 and cardiovascular disease accounts for the majority of deaths in pediatric dialysis patients.17 In contrast with adult patients with CKD, in whom cardiovascular risk factors such as diabetes dyslipidemia, hypertension, and smoking are highly prevalent,18 CKD in children is mainly caused by inherited disorders such as malformations of the kidney or urinary tract.18 Accordingly, examining HDL function in children who are free of “traditional” cardiovascular risk factors and underlying inflammatory diseases and who are nonsmokers gives us an unique opportunity to study the effects of renal failure on the vascular functions of HDL.We studied the endothelial properties of HDL in a cohort of children at different stages of CKD on dialysis and after transplantation and compared them with healthy children. Furthermore, to determine the clinical relevance of in vitro effects of HDL, we examined its relationship with clinical measures of the vascular phenotype as well as circulating markers of endothelial dysfunction. Finally, to show a causal link between renal function and HDL properties, we examined children on dialysis and 3 months after kidney transplantation. This study allowed us to examine when HDL dysfunction develops during the natural history of renal decline, its effects on vascular function, and the potential for recovery after kidney transplantation.  相似文献   
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