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   1005篇
  免费   26篇
耳鼻咽喉   12篇
儿科学   97篇
妇产科学   13篇
基础医学   93篇
口腔科学   14篇
临床医学   152篇
内科学   258篇
皮肤病学   31篇
神经病学   46篇
特种医学   6篇
外科学   132篇
综合类   15篇
一般理论   1篇
预防医学   61篇
眼科学   8篇
药学   73篇
肿瘤学   19篇
  2016年   9篇
  2015年   11篇
  2014年   19篇
  2013年   22篇
  2011年   8篇
  2010年   18篇
  2009年   35篇
  2008年   7篇
  2007年   11篇
  2006年   10篇
  2003年   10篇
  2001年   10篇
  2000年   6篇
  1999年   23篇
  1998年   23篇
  1997年   44篇
  1996年   42篇
  1995年   32篇
  1994年   28篇
  1993年   33篇
  1992年   17篇
  1991年   32篇
  1990年   30篇
  1989年   18篇
  1988年   19篇
  1987年   25篇
  1986年   21篇
  1985年   17篇
  1984年   15篇
  1983年   12篇
  1982年   15篇
  1981年   12篇
  1980年   13篇
  1979年   14篇
  1978年   12篇
  1977年   10篇
  1973年   7篇
  1971年   11篇
  1970年   14篇
  1969年   12篇
  1967年   6篇
  1960年   6篇
  1959年   21篇
  1958年   41篇
  1957年   38篇
  1956年   44篇
  1955年   33篇
  1954年   29篇
  1949年   11篇
  1948年   7篇
排序方式: 共有1031条查询结果,搜索用时 15 毫秒
41.
42.
In recent years, sleep medicine has evolved into a full-grown discipline, featuring a multidisciplinary approach to diagnosis and treatment of patients with sleep disorders. Sleep medicine cuts across the boundaries of different conventional disciplines and is therefore open to medical and non-medical professionals with different specialty backgrounds. The aim of the current paper is to introduce a qualification for those professionals whose main occupation is to practice sleep medicine in the setting of a sleep medicine centre. The drafting of guidelines dealing with requirements for such qualification was entrusted to a task force by the European Sleep Research Society. The guidelines are the result of a progressive consensus procedure in which standards were defined for education, training, and evaluation. The final step along this pathway is a theoretical and practical examination, providing proof of proficiency in the field of sleep medicine. This paper describes the object of specific competences, the scope of sleep medicine, and the qualification procedures that pertain to three professional categories: medical specialists, non-medical professionals with a university master degree (such as psychologists and biologists), and nurses and technologists. Indices of preceding practical experience and theoretical knowledge are presented in Appendices 1 and 2 . These guidelines are a European standard. They may be adapted in the future according to new scientific insights. National certification programs that comply with these guidelines may be subject to homologation by the ESRS.  相似文献   
43.
44.
45.
46.
47.
48.
OBJECTIVE: The interactions between non‐steroidal anti‐inflammatory drugs and Helicobacter pylori have not been sufficiently documented to date. The aim of this study was to investigate the possible effects of aspirin and indometacin on the growth of H. pylori and to determine the effects of aspirin on the susceptibility of H. pylori to some antimicrobials. METHODS: Kinetic studies were performed by inoculating strains of H. pylori in brucella broth with different concentrations of aspirin and indometacin. Growth of bacteria in the broth was assessed spectrophotometrically and by viable colony counts after incubation for 24 and 48 h. Bacterial morphology was determined by Gram stain under light microscopy. The minimal inhibitory concentration (MIC) of aspirin and indometacin was determined by the standard agar dilution method. The MIC of amoxicillin, clarithromycin and metronidazole was measured in the presence and absence of aspirin by the E‐test method. RESULTS: Kinetic studies revealed that aspirin and indometacin inhibited the growth of H. pylori in a dose‐dependent manner. The bactericidal activity of these agents was expressed by cell lysis. Aspirin at 400 µg/mL produced an almost 2‐log decrease in the number of CFU/mL at 48 h. Similar inhibitory effects were obtained when 100 µg/mL indometacin was tested. The MIC at which 90% of H. pylori was inhibited was 512 µg/mL and 128 µg/mL for aspirin and indometacin, respectively. Increased susceptibility of H. pylori to amoxicillin, clarithromycin and metro­nidazole was found in the presence of aspirin. CONCLUSIONS: Aspirin and indometacin could significantly inhibit the growth of H. pylori when incubated in brucella broth in vitro. A subinhibitory concentration of aspirin enhanced the susceptibility of H. pylori to some antimicrobial agents.  相似文献   
49.
The proto-oncogene Bcl-2 encodes a protein that protects cells from programmed cell death (apoptosis). The protein is expressed in the proliferative compartment of several normal tissues, including normal colonic crypts. The aim of this study was to test Bcl-2 expression in colorectal neoplasms, assuming that, as a regulator of apoptosis, it might be involved in the progression from adenoma to carcinoma. To this end, Bcl-2 reactivity was tested by immunohistochemistry in hyperplastic polyps, colonic adenomas, and carcinomas and its expression was compared with staining for the proliferation-associated Ki-67 antigen, using the MIB-1 antibody. Bcl-2 expression occurred in 2 out of 10 hyperplastic polyps and in 31 out of 35 (tubular, villous, and tubulovillous) adenomas, irrespective of their degree of dysplasia. Of ten carcinomas, only three were focally Bcl-2-positive, all moderately to well differentiated. In two of four carcinomas in Bcl-2-positive adenomas, no Bcl-2 staining was observed. High numbers of MIB-1-positive cells were found in all hyperplastic and neoplastic lesions, without apparent correlation between proliferation and Bcl-2 expression. These findings suggest that in the pathogenesis of hyperplastic polyps, increased crypt cell proliferation is primarily involved, but in some lesions decreased apoptosis may play a role. Furthermore, the increased Bcl-2 expression in adenomas but not in the majority of the carcinomas suggests either that decreased apoptosis is not usually involved in the pathogenesis of these lesions or that the regulation of apoptosis in colorectal epithelia involves additional regulatory factors.  相似文献   
50.
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