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   5439篇
  免费   453篇
  国内免费   21篇
耳鼻咽喉   21篇
儿科学   194篇
妇产科学   91篇
基础医学   788篇
口腔科学   53篇
临床医学   595篇
内科学   1225篇
皮肤病学   92篇
神经病学   533篇
特种医学   139篇
外科学   639篇
综合类   56篇
一般理论   1篇
预防医学   558篇
眼科学   80篇
药学   410篇
中国医学   15篇
肿瘤学   423篇
  2024年   6篇
  2023年   76篇
  2022年   87篇
  2021年   230篇
  2020年   146篇
  2019年   203篇
  2018年   201篇
  2017年   149篇
  2016年   176篇
  2015年   191篇
  2014年   220篇
  2013年   291篇
  2012年   424篇
  2011年   455篇
  2010年   240篇
  2009年   200篇
  2008年   374篇
  2007年   331篇
  2006年   378篇
  2005年   333篇
  2004年   300篇
  2003年   271篇
  2002年   195篇
  2001年   38篇
  2000年   21篇
  1999年   40篇
  1998年   43篇
  1997年   35篇
  1996年   23篇
  1995年   34篇
  1994年   20篇
  1993年   15篇
  1992年   17篇
  1991年   17篇
  1990年   19篇
  1989年   22篇
  1988年   10篇
  1987年   10篇
  1986年   9篇
  1985年   6篇
  1984年   7篇
  1983年   12篇
  1982年   7篇
  1981年   2篇
  1978年   2篇
  1977年   6篇
  1976年   2篇
  1967年   3篇
  1966年   3篇
  1906年   1篇
排序方式: 共有5913条查询结果,搜索用时 218 毫秒
1.
2.
Risk is a concept inherent in every medical procedure. It can be defined as the probability of an adverse event in a defined population over a specified period of time. In the frame of food allergy management, it might be related to a diagnostic procedure, a treatment, or the consumption of foods. The risk of an adverse event can also be augmented by individual factors. This rostrum article discusses various aspects faced by children with food allergies in the light of risk, and their practical implications. Identifying personal risks for severe reaction, such as unstable asthma, and correcting them whenever possible also contribute to a reduction of the risk inherent to food allergy. Among the facets discussed, oral food challenges (OFC) are the most common diagnostic procedures implying an inherent risk. The risk of OFCs can be minimized by correct indication and timing of the test, a safe setting, as well as by ensuring that the patient is otherwise well without potential stressor potentially increasing the risk of a more severe reaction. Oral immunotherapy (OIT) has been studied as a potential treatment for increasing the threshold dose for reaction, and thus reducing the risk of accidental reaction. Nevertheless, the procedure is not devoid of risk as the patients may and do often react during the course of the procedure. Ingestion of trace amounts in processed foods, mainly in community settings such as restaurants, schools, or day care, represents a potential risk of reactions, although for a minority of patients. Precautionary allergen labeling (PAL) is a widespread strategy to reduce the potential risk of reactions due to traces. However, PAL is currently inefficient due to inconsistent labeling, also not indicating a clear maximum amount possibly present in the manufactured food. Finally, cost-effectiveness needs to be considered in risk management, as many risk reduction procedures are clearly not cost-effective.  相似文献   
3.
Inherited single gene defects have been identified in both humans and mice that lead to loss of developmental control over the left-right asymmetry of the heart and viscera. In mice the recessively inherited mutation iv leads to such apparent loss of control over situs: 50% of iv/iv mice exhibit situs inversus and 50% exhibit normal situs. The affected gene product has not been identified in these animals. To study the normal function of iv, we have taken an approach directed to the gene itself. As a first step, we have mapped iv genetically, by examining its segregation in backcrosses with respect to markers defined by restriction fragment length polymorphisms. The iv locus lies 3 centimorgans (cM) from the immunoglobulin heavy-chain constant-region gene complex (Igh-C) on chromosome 12. A multilocus map of the region suggests the gene order centromere-Aat (alpha 1-antitrypsin gene complex)-(11 cM)-iv-(3 cM)-Igh-C-(1 cM)-Igh-V (immunoglobulin heavy-chain variable-region gene complex).  相似文献   
4.

Background  

Although training and education have long been accepted as integral to disaster preparedness, many currently taught practices are neither evidence-based nor standardized. The need for effective evidence-based disaster training of healthcare staff at all levels, including the development of standards and guidelines for training in the multi-disciplinary health response to major events, has been designated by the disaster response community as a high priority. We describe the application of systematic evidence-based consensus building methods to derive educational competencies and objectives in criteria-based preparedness and response relevant to all hospital healthcare workers.  相似文献   
5.
To determine whether polymorphisms of platelet surface glycoprotein associated with arterial thrombosis are risk factors for branch retinal vein occlusion. A case-control study in which 69 patients with branch retinal vein occlusion and 147 controls who attended the eye clinic for nonvascular complications participated. DNA was extracted from whole blood and analyzed for genotyping of platelet glycoprotein polymorphisms by polymerase chain reactions and specific restricted enzymes. No relationship was found between the four platelet glycoprotein polymorphisms i.e. GPIa C807T, VNTR and Kozak of glycoprotein Ibalpha, the HPA-1 of glycoprotein IIIa and the occurrence of branch retinal vein occlusion. The HPA-2 polymorphism was found in 18 out 60 (30%) patients with branch retinal vein occlusion in comparison with 27 out 142 (19%) of controls, with an estimated odds ratio of 1.8 (95% confidence interval, 0.91-3.65). The four platelet glycoprotein polymorphisms are not risk factors for branch retinal vein occlusion and therefore it seems unnecessary to screen those patients for it. A larger study is required, however, to determine whether HPA-2 is a novel risk factor for branch retinal vein occlusion.  相似文献   
6.
Aim:  To present an evidence-based framework to improve the quality of occupational therapy expert opinions on work capacity for litigation, compensation and insurance purposes.
Methods:  Grounded theory methodology was used to collect and analyse data from a sample of 31 participants, comprising 19 occupational therapists, 6 medical specialists and 6 lawyers. A focused semistructured interview was completed with each participant. In addition, 20 participants verified the key findings.
Results:  The framework is contextualised within a medicolegal system requiring increasing expertise. The framework consists of (i) broad professional development strategies and principles, and (ii) specific strategies and principles for improving opinions through reporting and assessment practices.
Conclusions:  The synthesis of the participants' recommendations provides systematic guidelines for improving occupational therapy expert opinion on work capacity.  相似文献   
7.
8.
9.
We describe the clinical and pathological findings of the hemolytic uremic syndrome (HUS) in two children with human immunodeficiency virus (HIV) infection. Both patients presented with microangiopathic hemolytic anemia, thrombocytopenia, and subsequently developed renal failure. The diagnosis of HUS was confirmed by renal histopathology in both patients. None of these children presented with bloody diarrhea, evidence of circulating antibody response to Escherichia coli O157 lipopolysaccharide, or other known risk factors for HUS, except for the presence of HIV infection. Each patient was treated with intravenous plasma infusion and renal replacement therapy. Their clinical course was characterized by non-oliguria and lack of significant hypertension throughout the acute phase of the disease. Despite these favorable clinical parameters, both patients developed end-stage renal failure. The etiology of this atypical HUS characterized by poor renal survival remains unknown and the role of HIV infection in its pathogenesis, although possible, is unclear. Received March 5, 1996; received in revised form and accepted October 15, 1996  相似文献   
10.
Seminal analysis was performed within 2 months of orchiectomy on 97 patients with clinical Stage I malignant testicular teratoma managed by surveillance following orchiectomy. Relapse of malignant disease occurred in 28% of 47 patients with a sperm count less than 10 X 10(6)/ml and in 32% of 50 patients with a sperm count greater than or equal to 10 X 10(6)/ml. Of 11 patients with azoospermia, 4 relapsed and 1 developed contralateral testicular germ cell tumour. Of 35 patients with malignant teratoma undifferentiated the relapse rate was 68% in 16 patients with a sperm count less than 10 X 10(6)/ml and 42% in 19 patients with a sperm count greater than or equal to 10 X 10(6)/ml. It was concluded that sperm count analysis is non-contributory in estimating the risk of relapse in clinical Stage I teratoma.  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