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   2998681篇
  免费   218039篇
  国内免费   5120篇
耳鼻咽喉   41202篇
儿科学   98980篇
妇产科学   81674篇
基础医学   439234篇
口腔科学   83673篇
临床医学   272050篇
内科学   576976篇
皮肤病学   66657篇
神经病学   237421篇
特种医学   113090篇
外国民族医学   768篇
外科学   449561篇
综合类   64899篇
现状与发展   12篇
一般理论   1162篇
预防医学   236310篇
眼科学   70065篇
药学   221682篇
  13篇
中国医学   5876篇
肿瘤学   160535篇
  2019年   24041篇
  2018年   33359篇
  2017年   25306篇
  2016年   28473篇
  2015年   32034篇
  2014年   45130篇
  2013年   68221篇
  2012年   92950篇
  2011年   98925篇
  2010年   59005篇
  2009年   55645篇
  2008年   92882篇
  2007年   98861篇
  2006年   99836篇
  2005年   96773篇
  2004年   93010篇
  2003年   89519篇
  2002年   86682篇
  2001年   135708篇
  2000年   139284篇
  1999年   117225篇
  1998年   34121篇
  1997年   30142篇
  1996年   30361篇
  1995年   28871篇
  1994年   26646篇
  1993年   25102篇
  1992年   91661篇
  1991年   89600篇
  1990年   87617篇
  1989年   84402篇
  1988年   77465篇
  1987年   76473篇
  1986年   71608篇
  1985年   68865篇
  1984年   51457篇
  1983年   43702篇
  1982年   26146篇
  1979年   47464篇
  1978年   34054篇
  1977年   28447篇
  1976年   27248篇
  1975年   29050篇
  1974年   35045篇
  1973年   33391篇
  1972年   31194篇
  1971年   29521篇
  1970年   27202篇
  1969年   25846篇
  1968年   23771篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
922.
923.
An endoscopic endonasal approach was performed to remove an intra-suprasellar Rathke's cleft cyst. Rathke's cleft cyst are benign lesions, rarely diagnosed because they are often asymptomatic. To the best of our knowledge, at least 475 cases of Rathke's cleft cysts have been reported. They seem to arise from remnants of Rathke's pouch, an invagination of the stomodeum. A 52-year-old woman, complaining of bilateral frontal headaches, was operated on by using an endoscopic endonasal approach, for an intra-suprasellar tumor. The pre-operative diagnosis was non-functioning pituitary adenoma. Intra-operatively a creamy-coloured viscous tissue was found. After the removal of the cyst contents and of the capsule, the suprasellar structures were seen well. The chiasmatic cistern, the chiasm, the pituitary stalk and the pituitary gland were visualized with 0 and 30 degree endoscopes. The pathological findings showed a well-differentiated cuboidal epithelium. The diagnosis was Rathke's cleft cyst. No post-operative complications were observed. The endoscopic technique was particularly suitable in this case, both for the Rathke's cleft features and for an excellent outcome. The Rathke's cleft cyst was easily removed by suction and the cyst wall was entirely removed with curettes and pituitary punches. The hypophysis was distinguished from the cyst and was preserved. The surgical manoeuvres were all done under direct visual control. The absence of nasal packing and of breathing difficulties made comfortable the post-operative outcome. Thus, the endoscopic endonasal approach can be considered the favourite technique in case of either intra- and/or suprasellar Rathke's cleft cysts.  相似文献   
924.
925.
OBJECTIVE: Traditional assessments of the microbial flora associated with acute bacterial rhinosinusitis have relied on maxillary sinus punctures (taps) and culture. These taps are now considered the gold standard for obtaining cultures and are used as the method of identifying bacterial pathogens in antimicrobial trials. Maxillary sinus taps are limited by discomfort to the patients and technical concerns. Because of these factors, the standard of performing taps has limited antibiotic trials and microbial surveillance. Alternatives to maxillary sinus taps have been explored. STUDY DESIGN: We conducted a retrospective, systematic review of the literature from 1950 to 2000 of articles comparing culture techniques in the nose and paranasal sinuses for acute bacterial rhinosinusitis. RESULTS: Nasal cultures have poor correlation to maxillary sinus cultures, whereas there is 60% to 85% concordance between endoscopically guided middle meatal cultures and maxillary sinus cultures. These studies, however, are all limited by small sample sizes and therefore are inadequate to make any concrete recommendations regarding the relative role of endoscopically guided middle meatal cultures as a formal method of pathogen identification in acute bacterial rhinosinusitis. CONCLUSION: A formal prospective study with sufficient sample size to assess the concordance between the microbial flora of the maxillary sinus punctures and middle meatal cultures in acute rhinosinusitis is recommended.  相似文献   
926.
BACKGROUND: Gastric cancer (GC) is the leading cause of cancer deaths in China. Our study prospectively evaluated the impact of repeated endoscopic screens on GC mortality in a high-risk population in China. METHODS: Between 1989 and 1999, a population-based gastroscopic screening was conducted in 4,394 residents of Linqu County, China, a region with the highest rates of GC worldwide. Residents ages 35 to 64 years received initial gastroscopies with biopsies in 1989. Repeated endoscopies were performed in 1994 and 1999. Cancer occurrences and deaths were actively monitored throughout the entire period until July 2000. Mortality from GC was compared with expected values based on mortality rates obtained for Linqu in the 1990-1992 Chinese Cancer Mortality Survey. RESULTS: Between March 1989 and July 2000, 39,303 person-years were accumulated; 85 new GCs occurred, 29 (34.5%) were in early stage. Fifty-eight cases (68%) were identified at one of the screens. The number of observed deaths from GC (37) was close to the expected (36.8). The standardized mortality ratio was 1.01 (95% CI 0.72-1.37) for the entire cohort, 1.13 (95% CI 0.77-1.57) for males, and 0.65 (95% CI 0.26-1.32) for females. CONCLUSIONS: Despite high population coverage with repeated screens, no reduction in GC mortality was observed in this high-risk population in China.  相似文献   
927.
THE BASIC SCIENCE OF PSYCHOLOGY HAS IDENTIFIED specific ingrained responses that are fundamental elements of human nature, underpin common influence strategies and may apply in medical settings. People feel a sense of obligation to repay a perceived debt. A request becomes more attractive when preceded by a marginally worse request. The drive to act consistently will persist even if demands escalate. Peer pressure is intense when people face uncertainty. The image of the requester influences the attractiveness of a request. Authorities have power beyond their expertise. Opportunities appear more valuable when they appear less available. These 7 responses were discovered decades ago in psychology research and seem intuitively understood in the business world, but they are rarely discussed in medical texts. An awareness of these principles can provide a framework for physicians to help patients change their behaviour and to understand how others in society sometime alter patients' choices.  相似文献   
928.
929.
A consecutive series of patients (1978–1981) comprising all patients with acute leukaemia from a population of 475000 inhabitants was reviewed. Thus, 94 patients were diagnosed as having acute leukaemia. No patients were lost from follow-up. The incidence figures of ALL and AML differed significantly from those of Sweden as a whole. 9 patients were < 15 years old. The median age of adult patients was 64 years, 60.8% being ≥ 60 years old. Of adult patients with AML, 20% had a preleukaemic history (chronic myeloproliferative disorders, myelodysplastic syndromes and others). None of 6 patients with leukaemia as a metamorphosis of a chronic myeloproliferative disorder achieved a complete remission. The overall remission rate of the remaining adult patients was 25%. Treated patients, 15–39 years old, with AML without any preleukaemic history, had a complete remission rate of 80% compared to 12% for patients ≥ 60 years old with the same diagnosis. Of 60 patients with ‘primary’ AML, 14 were not treated, mainly because of advanced age and complicating diseases. Most of these patients died within a week of admission.  相似文献   
930.
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