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   244篇
  免费   26篇
  国内免费   13篇
儿科学   12篇
妇产科学   1篇
基础医学   31篇
口腔科学   5篇
临床医学   40篇
内科学   54篇
皮肤病学   2篇
神经病学   4篇
特种医学   80篇
外科学   8篇
综合类   2篇
预防医学   10篇
眼科学   2篇
药学   17篇
中国医学   1篇
肿瘤学   14篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   6篇
  2016年   1篇
  2015年   2篇
  2014年   1篇
  2013年   3篇
  2012年   2篇
  2011年   3篇
  2010年   6篇
  2009年   2篇
  2008年   2篇
  2007年   9篇
  2006年   1篇
  2005年   7篇
  2004年   1篇
  2003年   2篇
  2002年   5篇
  2001年   4篇
  2000年   3篇
  1999年   6篇
  1998年   22篇
  1997年   19篇
  1996年   16篇
  1995年   14篇
  1994年   11篇
  1993年   10篇
  1991年   1篇
  1990年   4篇
  1989年   14篇
  1988年   21篇
  1987年   9篇
  1986年   9篇
  1985年   4篇
  1984年   6篇
  1983年   4篇
  1982年   12篇
  1981年   5篇
  1980年   6篇
  1979年   4篇
  1978年   3篇
  1977年   8篇
  1976年   6篇
  1975年   5篇
排序方式: 共有283条查询结果,搜索用时 15 毫秒
41.
张辉  尹宗生  张胜权  陈斌  王伟  华兴一  胡勇  李光武 《医学争鸣》2005,26(22):F0002-F0002
1 材料和方法 1.1 材料 KM小鼠,孕13.5 d,安徽省实验动物中心提供. 大肠杆菌JM109由安徽医科大学分子生物学教研室提供. Trizol试剂盒、pSecTag2/Hygro B质粒(Invitrogen). 质粒小量提取试剂盒、 RT-PCR试剂盒(Promega);Ex Taq DNA聚合酶、T4 DNA连接酶,DNA Marker, pMD18-T Vector,限制性内切酶(TaKaRa).  相似文献   
42.
43.
BACKGROUND: Specific immunotherapy (SIT) is a valuable treatment for respiratory allergy, and the use of chemically modified allergens (allergoids) has improved its safety, as testified by several studies. We evaluated the effects of a SIT course with an allergoid extract of Parietaria pollen in a double-blind, placebo-controlled trial. METHODS: The study was double-blind in the first year; then it was prolonged up to 3 years with all patients on active treatment. Clinical effectiveness, safety, skin reactivity, systemic immunologic parameters, and subjective assessment were evaluated. We also had available a self-evaluation recorded in a follow-up visit 4 years after the discontinuation of SIT. RESULTS: A significant reduction of the symptoms plus drug intake scores during the pollen seasons was observed in the patients receiving active SIT. The placebo patients, after switching to active SIT, also showed significant clinical improvement. The clinical efficacy persisted during years 2 and 3 of treatment. After year 1, the actively treated patients reported a significant subjective improvement (frequency of symptoms, P = 0.001; duration of symptoms, P = 0.024; physical performance, P = 0.043) compared with the placebo group. The self-evaluation by visual analog scale showed that all patients maintained a significant clinical improvement up to 4 years after discontinuing SIT (year 1: active=+31.6%, placebo=-15.7%; year 7: active=+35.8%, placebo=+31.3%). The systemic immunologic changes after active SIT paralleled those described elsewhere (IgE decreased from 22 to 9 and from 21 to 8 IU/ml; IgG4 increased from 43 to 87 and from 18 to 60 IU/ml). A significant decrease in skin reactivity to three different allergen concentrations was observed at year 3 compared with pretreatment values (P<0.05). CONCLUSIONS: The investigational SIT with Parietaria appeared to be effective and safe; a 3-year course of treatment achieved a long-lasting efficacy.  相似文献   
44.
食管癌的诊断和治疗   总被引:12,自引:8,他引:4  
1诊断 1.1普查由于食管早期癌的疗效明显好于进展期癌,加之,内镜下食管粘膜切除术用于无淋巴结转移的表浅食管癌的根治已取得良好疗效,并已逐渐被医患双方所接受,因而普查仍是目前改善食管癌(EC)疗效的肯定手段.我国北方尤其是太行山地区及伊朗里海沿岸居民、有头颈癌肿史者是EC的高发人群.  相似文献   
45.
The aim of this paper is to detail the experience obtained in implementing an image-guided radiation therapy program at the Northern Sydney Cancer Centre. This required retrofitting a Varian Clinac 21EX with an on-board imager. The commissioning and quality assurance procedures, organisation of a multidisciplinary image guided radiation therapy group, and the development of clinical protocols for orthogonal kV and cone beam computed tomography implementation are described. Reassessment of the image-guided radiation therapy program has continued as new equipment and software versions were made available in the department.  相似文献   
46.
47.
To determine the prevalence of small lung nodules on low‐dose helical computed tomography (CT) in a Western Australian cohort of asymptomatic long‐term cigarette smokers and to compare this with a large, similarly derived cohort of North Americans from the Mayo Clinic Lung Cancer Screening Trial. Forty‐nine asymptomatic long‐term cigarette smokers of minimum age 50 years underwent a low‐dose 64‐slice helical CT of the lungs. Images were viewed on a soft copy reporting station with thin section axial and coronal images, maximum intensity projection images, and advanced image manipulation tools. The prevalence of all nodules was 39%, significantly lower than the Mayo Clinic cohort prevalence of 51% (P < 0.01, Fisher's exact test), despite the use of more advanced imaging technology and image manipulation designed to increase the sensitivity for nodules. The prevalence of small nodules in asymptomatic long‐term cigarette smokers in Western Australia is high, though significantly less than that found in a large study in North America. The authors postulate this is due to the relatively low rates of mycobacterium tuberculosis and soil‐derived fungal pulmonary infections in Western Australia, as well as a lower degree of urban air pollution.  相似文献   
48.
49.
Prostatic evaluation by transrectal endosonography: detection of carcinoma   总被引:1,自引:0,他引:1  
Transrectal endosonography is one of the most sensitive techniques to evaluate prostatic disease and is far more accurate than conventional sonography. A retrospective review of sonographic characteristics of the prostate was made in an attempt to define the ability of the technique to distinguish benign from malignant disease. Analysis included evaluation of the capsule (smoothness, regularity, and/or invasion), abnormal foci (echogenicity, margination, brightness, thickness, and symmetry), and presence of acoustic shadowing and/or enhancement from the abnormal foci. Evaluation of 443 pathologically proved cases (the majority being large lesions) showed that differentiation between benign and large and/or invasive malignant disease may be suggested by results of transrectal endosonography. However, there is still great overlap of the sonographic appearances.  相似文献   
50.
This prospective study compared images obtained with a photostimulable imaging plate with matched images obtained with a conventional screen-film combination in 26 patients undergoing intraoperative arteriography. Diagnostic accuracy of the two techniques was assessed objectively, and image quality was assessed subjectively. In 16 patients (62%), the radiation exposure was reduced by 50% for the imaging plate technique by decreasing the mAs level generally used for the screen-film combination. Because of the dynamic range of the imaging plate system, no repeat examinations were necessary, while 12% of the screen-film studies had to be repeated because of over- or under-penetration. Imaging plate studies required 6% more time for processing than screen-film studies. Receiver-operating-characteristic analysis indicated no difference in diagnostic accuracy between the two imaging techniques. Subjective evaluation also revealed no difference in observer preference for imaging plate or screen-film studies. The imaging plate technique is an excellent alternative to screen-film studies in the operating room.  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