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   1757篇
  免费   83篇
耳鼻咽喉   9篇
儿科学   52篇
妇产科学   77篇
基础医学   180篇
口腔科学   30篇
临床医学   205篇
内科学   403篇
皮肤病学   78篇
神经病学   50篇
特种医学   23篇
外科学   236篇
综合类   71篇
一般理论   4篇
预防医学   159篇
眼科学   46篇
药学   188篇
肿瘤学   29篇
  2016年   14篇
  2015年   14篇
  2014年   11篇
  2013年   14篇
  2010年   24篇
  2009年   12篇
  2008年   12篇
  2007年   13篇
  2006年   10篇
  2001年   11篇
  1999年   24篇
  1998年   35篇
  1997年   53篇
  1996年   70篇
  1995年   35篇
  1994年   56篇
  1993年   45篇
  1992年   47篇
  1991年   31篇
  1990年   40篇
  1989年   35篇
  1988年   33篇
  1987年   37篇
  1986年   26篇
  1985年   30篇
  1984年   29篇
  1983年   30篇
  1982年   31篇
  1981年   22篇
  1980年   24篇
  1979年   20篇
  1978年   15篇
  1977年   16篇
  1976年   21篇
  1975年   13篇
  1973年   12篇
  1972年   16篇
  1971年   16篇
  1968年   11篇
  1963年   21篇
  1962年   12篇
  1960年   16篇
  1959年   66篇
  1958年   114篇
  1957年   105篇
  1956年   84篇
  1955年   96篇
  1954年   88篇
  1949年   50篇
  1948年   60篇
排序方式: 共有1840条查询结果,搜索用时 15 毫秒
31.
Two papers have appeared in the literature recently reporting the use of the Severity of Opiate Dependence Questionnaire (SODQ) with American and British samples of opiate addicts. This paper presents the findings of a third study. The SODQ was completed by a further 126 subjects attending the original New York Clinic and the results largely confirmed our earlier findings: first the four main sections of the SODQ each give a strong first factor and secondly when these are combined a strong overall factor emerges. These results are again at variance with those found in the British sample and possible reasons briefly discussed.  相似文献   
32.
TAYLOR G 《Lancet》1963,2(7312):833-834
  相似文献   
33.
34.
The haemodynamic effects of intravenous frusemide (1 mg/kg)were studied in 22 male patients with left ventricular failurefollowing acute myocardial infarction. Radiographic pulmonaryoedema was present in all patients and their average left heartfilling pressure was 20 mmHg. Bolus injection of the drug wasfollowed by immediate increases in systemic arterial pressure(P < 0.05) and heart rate (<0.05); these declined to pre-injectionvalues after 60 min. Following frusemide there were progressivereductions in left heart filling pressure (P < 0.01), thermodilutioncardiac output (P < 0.01) and stroke volume (P < 0.05)and a progressive increase in the derived systemic vascularresistance (P < 0.05). There was an average diuresis of 860ml during the 90 min following the frusemide injection. Theinfluence of frusemide on left ventricular performance was studiedby comparing the circulatory effects of passive leg raisingin the control period with those at 30, 60 and 90 min afterthe drug. In the control period this manoeuvre increased leftheart filling pressure, but not heart rate, cardiac output,stroke volume or systemic vascular resistance. Ninety minutesafter frusemide, but not before, passive leg raising resultedin a significant increase in cardiac output (P < 0.01) andstroke volume at a similar increment in filling pressure anda significant reduction in the systemic vascular resistance(P <0.05). These circulatory actions of intravenous frusemideare compatible with initial arteriolar constriction and venodilatationfollowed by depletion of blood volume with subsequent changein left ventricular pumping performance.  相似文献   
35.
Antibodies are known to be important in mediating malarial immunity, but the influence of the various immunoglobulin isotypes on parasite elimination is unclear. The purpose of this study was to provide basic information on the induction of isotype expression in genetically different mice during primary malaria. Parasitaemias and the serum antimalarial IgM, IgG1, IgG2, IgG3 and IgA antibody titres measured in a radioimmunoassay were followed in outbred and 11 inbred strains of mice infected with 17XNL Plasmodium yoelii. Severity of infection, as judged by length of infection, peak parasitaemias and death, was found to differ between the strains. All strains developed rapid IgM responses, but only 3/11 inbred strains produced significant antimalarial IgG1 levels during primary infection. All strains produced an IgG2 response, which developed slightly more quickly in strains with the least severe courses of malaria. A large variation in the IgG3 response was noted between strains. In general, IgG3 antibodies were the first IgG-isotype to appear in serum. They were detected as early as day 8 in strains that developed mild infections but were not present until around day 20 in strains with the most severe cases of malaria. Only one strain produced detectable antimalarial IgA antibodies. These results show that different patterns of isotype expression are induced in inbred strains of mice during primary P. yoelii infection.  相似文献   
36.
37.
38.
39.
40.
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