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   919篇
  免费   34篇
  国内免费   12篇
耳鼻咽喉   4篇
儿科学   29篇
妇产科学   7篇
基础医学   83篇
口腔科学   26篇
临床医学   125篇
内科学   131篇
皮肤病学   23篇
神经病学   27篇
特种医学   127篇
外科学   154篇
综合类   69篇
预防医学   47篇
眼科学   8篇
药学   59篇
  1篇
中国医学   10篇
肿瘤学   35篇
  2023年   5篇
  2022年   23篇
  2021年   20篇
  2020年   16篇
  2019年   13篇
  2018年   18篇
  2017年   16篇
  2016年   11篇
  2015年   49篇
  2014年   63篇
  2013年   38篇
  2012年   46篇
  2011年   51篇
  2010年   40篇
  2009年   30篇
  2008年   38篇
  2007年   38篇
  2006年   39篇
  2005年   19篇
  2004年   24篇
  2003年   30篇
  2002年   20篇
  2001年   16篇
  2000年   13篇
  1999年   16篇
  1998年   14篇
  1997年   16篇
  1996年   19篇
  1995年   25篇
  1994年   26篇
  1993年   13篇
  1992年   7篇
  1991年   6篇
  1990年   6篇
  1989年   13篇
  1988年   12篇
  1987年   9篇
  1986年   13篇
  1985年   26篇
  1984年   9篇
  1983年   9篇
  1982年   3篇
  1981年   11篇
  1980年   8篇
  1979年   6篇
  1978年   7篇
  1977年   8篇
  1976年   3篇
  1974年   1篇
  1957年   1篇
排序方式: 共有965条查询结果,搜索用时 0 毫秒
71.
Management of cerebral ischemia due to Takayasu''''s arteritis   总被引:2,自引:0,他引:2  
Aortoarteritis ,alsocalledTakayasu’sarteritis ,isachronicidiopathicinflammatorydiseasethataffectslargeandmediumsizearteries Clinicalfeaturesreflectlimbororganischemiaresultingfromstenosistoobliterationofinvolvedarteries Thisdisease ,describedbyTakayasuin…  相似文献   
72.
73.
Adverse reactions in blood donors with a history of seizures or epilepsy   总被引:1,自引:0,他引:1  
BACKGROUND: Individuals with epilepsy or seizure disorders are restricted from donating blood because of concern that they are prone to adverse donor reactions such as syncope and convulsions. A study evaluating whether that concern is warranted is reported. STUDY DESIGN AND METHODS: During a 2-year period beginning in 1987, blood donors in Maryland with a history of seizures were actively recruited by the American Red Cross. Adverse donor reactions were classified as "slight", indicating dizziness and nausea without loss of consciousness; "moderate," denoting syncope; and "severe," indicating convulsive syncope. RESULTS: There were 329,143 satisfactory blood donations; 613 individuals reporting a history of seizures donated blood a total of 723 times. Among donors with seizures, 186 (35.7%) were taking antiepileptic medication, and 61 (8.4%) had had one or more seizures in the preceding year. Individuals with seizures had a low incidence of adverse reactions (3.34%). Although this incidence was slightly higher than that in the entire population (2.24%), the difference was not significant. In particular, the risk of syncope with or without convulsive activity was low for people with seizures (0.21%) and not significantly greater than that in other donors (0.28%). CONCLUSION: Individuals with seizures or epilepsy are not at greater risk for adverse reactions after blood donation, and major restrictions on their participation as blood donors are not warranted.  相似文献   
74.
The authors studied the natural history of human immunodeficiency virus (HIV) exposure in 187 hemophiliacs followed for an average of 45 months. Overall, 55 percent developed antibody specific for HIV and 21 percent developed persistent generalized lymphadenopathy. Most patients seroconverted sometime between early 1982 and the end of 1984. Four patients developed acquired immune deficiency syndrome (AIDS) and four seropositive patients developed idiopathic thrombocytopenia (ITP). One of the four patients who developed AIDS and three of the four with ITP had preexisting lymphadenopathy. None of the 10 patients with lymphadenopathy or the 20 asymptomatic patients was seropositive for human T-lymphotropic virus, type I. Although seropositivity and lymphadenopathy have been found in many of the authors' patients, few have developed clinical disease that can be related to HIV infection.  相似文献   
75.
There is no detailed information on clinical and immunopathologic features of immunoglobulin M nephropathy (IgMN) in children with idiopathic nephrotic syndrome (INS) in Pakistan. We reviewed our native renal biopsies over 15 years (July 1995-July 2010) and identified 135 cases of IgMN in nephrotic children (≤17 years). Their demographic, clinical and immunopathologic data were retrieved from biopsy reports and case notes. Mean age of this cohort was 7.6 ± 4.2 years. Males were 92 (68.1%) and females were 43 (31.9%). Steroid-dependent NS was seen in 88 (65.2%) cases and steroid-resistant NS in 47 (34.2%). Hematuria was found in 42 cases (31.2%) and hypertension in 27 (19.5%). The most common morphologic change was glomerular mesangial proliferation, found in 89 (65.9%) biopsies. Minor changes were seen in 46 (34.1%) cases and focal segmental glomerulosclerosis (FSGS) in 37 (27.4%). Immunofluorescence microscopy showed diffuse mesangial positivity of IgM in all cases. C3 and C1q were found in 72 (53.3%) and 40 (29.7%) cases, respectively. Our results show that IgMN is a fairly common cause of INS in children in Pakistan. It shows a spectrum of morphologic changes ranging from minor changes to FSGS.  相似文献   
76.
Purpose  To develop a classification system for all proximal tibial fractures in children that accounts for force of injury and fracture patterns. Methods  At our institution, 135 pediatric proximal tibia fractures were treated from 1997 to 2005. Fractures were classified into four groups according to the direction of force of injury: valgus, varus, extension, and flexion–avulsion. Each group was subdivided into metaphyseal and physeal type by fracture location and Salter–Harris classification. Also included were tibial tuberosity and tibial spine fractures. Results  Of the 135 fractures, 30 (22.2%) were classified as flexion group, 60 (44.4%) extension group, 28 (20.8%) valgus group, and 17 (12.6%) varus group. The most common type was extension-epiphyseal-intra-articular-tibial spine in 52 fractures (38.5%). This study shows that proximal tibial fractures are age-dependent in relation to: mechanism, location, and Salter–Harris type. In prepubescent children (ages 4–9 years), varus and valgus forces were the predominate mechanism of fracture creation. During the years nearing adolescence (around ages 10–12 years), a fracture mechanism involving extension forces predominated. With pubescence (after age 13 years), the flexion–avulsion pattern is most commonly seen. Furthermore, metaphyseal fractures predominated in the youngest population (ages 3–6 years), with tibial spine fractures occurring at age 10, Salter–Harris type I and II fractures at age 12, and Salter–Harris type III and IV physeal injuries occurring around age 14 years. Conclusion  We propose a new classification scheme that reflects both the direction of force and fracture pattern that appears to be age-dependent. A better understanding of injury patterns based on the age of the child, in conjunction with appropriate pre-operative imaging studies, such as computer-aided tomography, will facilitate the operative treatment of these often complex fractures.  相似文献   
77.

Background and purpose:

Chemokines orchestrate neutrophil recruitment to inflammatory foci. In the present study, we evaluated the participation of three chemokines, KC/CXCL1, MIP-2/CXCL2 and LIX/CXCL5, which are ligands for chemokine receptor 2 (CXCR2), in mediating neutrophil recruitment in immune inflammation induced by antigen in immunized mice.

Experimental approach:

Neutrophil recruitment was assessed in immunized mice challenged with methylated bovine serum albumin, KC/CXCL1, LIX/CXCL5 or tumour necrosis factor (TNF)-α. Cytokine and chemokine levels were determined in peritoneal exudates and in supernatants of macrophages and mast cells by elisa. CXCR2 and intercellular adhesion molecule 1 (ICAM-1) expression was determined using immunohistochemistry and confocal microscopy.

Key results:

Antigen challenge induced dose- and time-dependent neutrophil recruitment and production of KC/CXCL1, LIX/CXCL5 and TNF-α, but not MIP-2/CXCL2, in peritoneal exudates. Neutrophil recruitment was inhibited by treatment with reparixin (CXCR1/2 antagonist), anti-KC/CXCL1, anti-LIX/CXCL5 or anti-TNF-α antibodies and in tumour necrosis factor receptor 1-deficient mice. Intraperitoneal injection of KC/CXCL1 and LIX/CXCL5 induced dose- and time-dependent neutrophil recruitment and TNF-α production, which were inhibited by reparixin or anti-TNF-α treatment. Macrophages and mast cells expressed CXCR2 receptors. Increased macrophage numbers enhanced, while cromolyn sodium (mast cell stabilizer) diminished, LIX/CXCL5-induced neutrophil recruitment. Macrophages and mast cells from immunized mice produced TNF-α upon LIX/CXCL5 stimulation. Methylated bovine serum albumin induced expression of ICAM-1 on mesenteric vascular endothelium, which was inhibited by anti-TNF-α or anti-LIX/CXCL5.

Conclusion and implications:

Following antigen challenge, CXCR2 ligands are produced and act on macrophages and mast cells triggering the production of TNF-α, which synergistically contribute to neutrophil recruitment through induction of the expression of ICAM-1.  相似文献   
78.
79.
目的分析乳腺肿物针吸细胞学对乳腺癌早期诊断应用价值。方法用5毫升一次性塑料注射器,对乳腺肿物及乳头溢液患者进行定位针吸细胞学诊断,并与临床病理组织学对照。结果乳腺针吸细胞学不仅对乳腺疾病诊断有重要适用价值,而且对乳腺癌早期诊断有重要价值,总诊断准确率达95.3%。结论乳腺针吸细胞学具有创伤小、简单快速、安全可靠、经济实用、结果准确等优点,各项技术指标明显高于传统诊断方法,是目前任何方法无法取代的,有较高推广实用价值。  相似文献   
80.
生理学是医学高等院校的基础医学主干课程,机能实验教学是其重要组成部分。在生理学技能实验教学中,教学思路必须向开放型转变,在基本教学大纲的要求下充分培养学生自主思维能力,同时加强其严谨科学态度和团队协作精神的培养。  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