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   31072篇
  免费   1244篇
  国内免费   135篇
耳鼻咽喉   350篇
儿科学   733篇
妇产科学   712篇
基础医学   4434篇
口腔科学   2059篇
临床医学   2540篇
内科学   6662篇
皮肤病学   894篇
神经病学   2576篇
特种医学   524篇
外科学   2624篇
综合类   111篇
一般理论   18篇
预防医学   3532篇
眼科学   489篇
药学   2340篇
  7篇
中国医学   207篇
肿瘤学   1639篇
  2024年   184篇
  2023年   380篇
  2022年   796篇
  2021年   1463篇
  2020年   847篇
  2019年   1198篇
  2018年   1435篇
  2017年   926篇
  2016年   934篇
  2015年   1140篇
  2014年   1477篇
  2013年   1800篇
  2012年   2755篇
  2011年   2920篇
  2010年   1479篇
  2009年   1202篇
  2008年   2004篇
  2007年   1902篇
  2006年   1676篇
  2005年   1456篇
  2004年   1253篇
  2003年   1074篇
  2002年   906篇
  2001年   157篇
  2000年   126篇
  1999年   117篇
  1998年   111篇
  1997年   114篇
  1996年   69篇
  1995年   58篇
  1994年   58篇
  1993年   43篇
  1992年   60篇
  1991年   43篇
  1990年   33篇
  1989年   29篇
  1988年   24篇
  1987年   22篇
  1986年   20篇
  1985年   15篇
  1984年   18篇
  1983年   13篇
  1982年   17篇
  1981年   12篇
  1980年   9篇
  1979年   8篇
  1977年   7篇
  1976年   6篇
  1972年   6篇
  1969年   8篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
11.
12.
13.
Introduction: Allergic diseases constitute one of the most common causes of chronic illness in developed countries. The main mechanism determining allergy is an imbalance between Th1 and Th2 response towards Th2.

Areas covered: This review describes the mechanisms underlying the natural tolerance to food components and the development of an allergic response in sensitized individuals. Furthermore, therapeutic approaches proposed to manage these abnormal immunologic responses food are also presented and discussed.

Expert opinion: In the past, management of food allergies has consisted of the education of patients to avoid the ingestion of the culprit food and to initiate the therapy (e.g. self-injectable epinephrine) in case of accidental ingestion. In recent years, sublingual/oral immunotherapies based on the continuous administration of small amounts of the allergen have been developed. However, the long periods of time needed to obtain significant desensitization and the generation of adverse effects, limit their use. In order to solve these drawbacks, strategies to induce tolerance are being studied, such as the use of either adjuvant immunotherapy in order to facilitate the reversion of the Th2 response towards Th1 or the use of monoclonal antibodies to block the main immunogenic elements.  相似文献   

14.
15.
Objective: Parkinson's disease (PD) is characterized by deterioration of the nigrostriatal system and associated with chronic neuroinflammation. Glial activation has been associated with regulating the survival of dopaminergic neurons and is thought to contribute to PD through the release of proinflammatory and neurotoxic factors, such as reactive nitric oxide (NO) that triggers or exacerbates neurodegeneration in PD. Polyunsaturated fatty acids (PUFAs) exert protective effects, including antiinflammatory, antiapoptotic, and antioxidant activity, and may be promising for delaying or preventing PD by attenuating neuroinflammation and preserving dopaminergic neurons. The present study investigated the effects of fish oil supplementation that was rich in PUFAs on dopaminergic neuron loss, the density of inducible nitric oxide synthase (iNOS)-immunoreactive cells, and microglia and astrocyte reactivity in the substantia nigra pars compacta (SNpc) and striatal dopaminergic fibers.

Methods: The animals were supplemented with fish oil for 50 days and subjected to unilateral intrastriatal 6-hydroxydopamine (6-OHDA)-induced lesions as a model of PD.

Results: Fish oil mitigated the loss of SNpc neurons and nerve terminals in the striatum that was caused by 6-OHDA. This protective effect was associated with reductions of the density of iNOS-immunoreactive cells and microglia and astrocyte reactivity.

Discussion: These results suggest that the antioxidant and antiinflammatory properties of fish oil supplementation are closely related to a decrease in dopaminergic damage that is caused by the 6-OHDA model of PD.  相似文献   

16.

Objective and method

The French Obesity Plan enabled the creation of 37 Specialized Obesity Centers (CSOs) in 2012 to ensure a dual mission, the multidisciplinary management of severe or complex obesity and the organization of care channels in the regions. This report takes stock of the first three years of operation of the CSOs, based on the data collected by the National Observatory of CSOs (oNCSO), set up by the General Directorate of Hospitalization and Care.

Results

The overall results were positive for access to paraclinical examinations, although all CSOs did not have a biphotonic absorptiometer (DEXA) or calorimetry. The CSOs were initially developing links with the 12 sectors of care studied by the oNCSO, with some weaknesses including psychiatry. The survey did not make it possible to take stock of the real numbers of the actual workforce of the CSOs, given the large number of outliers. All responding CSOs reported having obese-oriented therapeutic education programs for the medical, surgical, and pediatric sectors. The activities of CSOs in medicine, surgery, gynecology and obstetrics were heterogeneous. In 2014, about 25–30% of all bariatric surgery procedures were performed in the CSOs in France. On average, CSOs received about 2500 severely obese adult patients in day care or in-patient care for the medical sector. The results suggested a certain fragility of the pathways of obstetric gynecology and the pediatric pathways.

Conclusion

This declarative survey, despite many limitations, shows however that CSOs have taken an important place in the French care system.  相似文献   
17.
Abstract:  Introduction:  Peri-implant pathologies consist of an inflammatory process affecting the soft and hard tissues surrounding the implants. Chlorhexidine is considered the gold standard antiseptic, with a large variety of choice in administration. In this study, a protocol for the irrigation of peri-implant pockets with a chlorhexidine gel, using a plastic needle for the delivery of the product into the peri-implant pockets is described. Study participants and methods:  Nine patients with at least one implant presenting peri-implant pathology (inflamed soft tissue associated with bone loss around the implant) were enrolled in this prospective clinical study, and followed-up for 1 year, where clinical parameters such as modified plaque index, modified bleeding index, probing pocket depths, attachment levels were assessed at baseline, 1 month, and 1 year after implementation of the treatment protocol. Results:  Treatment success was achieved in eight of the nine patients (and in 11 of the 13 implants) according to the success criteria adopted by the authors of this study. Discussion:  Infection control lies at the heart of peri-implant treatment. The control of three factors such as optimal diagnosis, removal of the aetiological factor of the disease (proper removal of debris and decontamination of the peri-implant sulcus/pocket) and a good patient's oral hygiene self-care represents the key to success, resulting in good treatment outcomes when managing peri-implant pathologies. The protocol used (irrigation of peri-implant pockets with chlorhexidine gel delivered by a plastic needle) is considered to be of utility.  相似文献   
18.
Flexural strength of provisional crown and fixed partial denture resins   总被引:2,自引:0,他引:2  
STATEMENT OF PROBLEM: Provisional prostheses are subject to flexure under function. Selection of the appropriate material for their fabrication is difficult given the limited evidence-based information on the flexural strength of provisional resins. PURPOSE: This study compared the flexural strength of 5 methacrylate-based resins and 8 bis-acryl resins used to fabricate provisional crowns and fixed partial dentures. MATERIAL AND METHODS: Bar-type specimens were fabricated according to American National Standards Institute/American Dental Association specification 27. After being immersed in artificial saliva at 37 degrees C for 10 days, the specimens were fractured under 3-point loading in a universal testing machine at a crosshead speed of 0.75 mm/min. Maximal loads to fracture in Newtons were recorded. Mean flexural strengths were calculated in MPa (n = 10 per group). Comparisons were made with analysis of variance and Duncan's multiple range test (P<.05). RESULTS: Mean flexural strengths ranged from 56.2 to 123.6 MPa. There were 4 statistically similar groups. The group with the highest strengths consisted of 4 bis-acryl materials (Provipont, Integrity, Protemp 3 Garant, and Luxatemp). CONCLUSION: Within the limitations of this study, flexural strengths were material- rather than category-specific. Some, but not all, bis-acryl resins demonstrated significantly superior flexural strength over traditional methacrylate resins.  相似文献   
19.
This study estimated the lifetime prevalence of toothache at ages 6 and 12 yr, the prevalence of toothache during the last month, and their association with social, behavioural and clinical exposures in the course of life of 339 12-yr-old children from a birth cohort in Pelotas, Brazil. Exploratory variables were collected in the perinatal study and during several follow-up studies. Prevalence ratios were calculated using Poisson regression, following a hierarchical conceptual model. The lifetime prevalence of toothache at ages 6 and 12 yr were 39% [95% confidence interval (CI) = (34;45)] and 63% [95% CI = (58;69)], respectively. Toothache during the last month was reported by 11% [95% CI = (8;15)]. Children who did not live with their biological father at birth, and children with higher dmf-t counts, reported a higher lifetime prevalence of toothache at age 6 yr. Children experiencing poverty between ages 0 and 4 yr, with higher dmf-t and DMF-T indexes presented a greater lifetime prevalence of toothache at 12 yr. Toothache within the last month was more likely to be reported by girls and by children who did not live with their biological father at birth. Preventive strategies should be implemented in early stages of the life cycle, taking into account the socio-economic and family context in which pain mostly occurs.  相似文献   
20.
Progressive systemic sclerosis is a chronic sclerotic disease which causes diffuse, increased deposition of extracellular matrix in connective tissue with vascular abnormalities, resulting in tissue hypoxia. Aesthetic and facial dysfunction are followed by important oral and facial manifestation of disturbances such as xerostomia, the lack of saliva in the mouth, and its associated complications. Most clinical manifestations begin with tongue rigidity. The facial skin changes and bone resorption of mandible angle are often reported. Other systemic changes include the involvement of internal organs which leads to serious complications as well as disorders in the cardiac muscle and Raynaud's phenomenon. The objective of the this paper is to report two cases of systemic sclerosis in patients with oral and facial manifestations of the disease. A brief review of the literature, focusing on deontological alterations is also presented.  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