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   373篇
  免费   34篇
耳鼻咽喉   4篇
儿科学   33篇
妇产科学   3篇
基础医学   48篇
口腔科学   17篇
临床医学   33篇
内科学   84篇
神经病学   25篇
特种医学   5篇
外科学   30篇
预防医学   65篇
眼科学   13篇
药学   29篇
肿瘤学   18篇
  2023年   2篇
  2022年   3篇
  2021年   2篇
  2019年   6篇
  2018年   8篇
  2017年   2篇
  2016年   4篇
  2015年   5篇
  2014年   6篇
  2013年   14篇
  2012年   11篇
  2011年   12篇
  2010年   9篇
  2009年   14篇
  2008年   15篇
  2007年   19篇
  2006年   20篇
  2005年   21篇
  2004年   21篇
  2003年   18篇
  2002年   22篇
  2001年   7篇
  2000年   8篇
  1999年   14篇
  1998年   3篇
  1997年   7篇
  1996年   9篇
  1995年   11篇
  1994年   6篇
  1993年   2篇
  1992年   11篇
  1991年   6篇
  1990年   5篇
  1989年   7篇
  1988年   10篇
  1987年   6篇
  1986年   8篇
  1985年   11篇
  1984年   3篇
  1983年   3篇
  1982年   4篇
  1981年   5篇
  1980年   5篇
  1979年   4篇
  1977年   4篇
  1976年   5篇
  1975年   2篇
  1968年   1篇
  1967年   2篇
  1961年   1篇
排序方式: 共有407条查询结果,搜索用时 31 毫秒
1.
Localized pleural plaques and lung cancer.   总被引:1,自引:0,他引:1  
In a mass chest radiography survey conducted in 1971 for 7,986 residents of three Finnish communities, 604 subjects (7.6%) with pleural plaques but not other asbestos-related radiographic signs were identified. The same number of referents, each individually matched to each plaque carrier on sex, birth year, and community, was selected from among persons in the same source population with no pleural plaques. The two groups were followed for investigation of incidence of lung cancer during 1972-1989. Twenty-eight of those with plaques and 25 referents contracted lung cancer (crude conditional RR = 1.1; CL95 = 0.7, 1.9). The application of the proportional hazards model, with adjustment for sex, age, and residence, resulted in a hazard ratio of 1.1 (CL = 0.6, 1.8). The risk ratio estimate may be biased; hence, the result is inconclusive in regard to the predictive assessment of lung cancer risk among carriers of pleural plaques.  相似文献   
2.
In an examination of the possible harmful effects of work in an office environment and the use of a video display terminal (VDT) on the course of pregnancy, the experience of 1,475 reference mothers from a Finnish case-referent study of birth defects was analyzed. The study was based on the national Register of Congenital Malformations, whose data were supplemented with special interviews on mothers' work conditions. The group which worked in an office environment consisted of 239 women, of whom 60 had worked with video display terminals; 805 mothers had not worked in an office. Only mothers who had worked during most of their pregnancy and who had a singleton birth were included; hence 431 women were excluded from the analysis. The information on threatened abortion, length of gestation, birthweight, placental weight, and maternal blood pressure was analyzed. Office work involved no elevated risk of threatened abortion when compared with nonoffice work, and among the VDT users the proportion with symptoms related to an impending early termination of pregnancy was similar to that of other office workers. No unfavorable effects on the length of gestation were observed between the compared groups, and there were no differences in the birthweight of the babies when adjustment was made for gestational age or the other aspects under consideration. Thus the results did not suggest that office employment or work with video display terminals would be harmful for pregnancy.  相似文献   
3.
Centrally administered thyrotropin-releasing hormone exerts a well documented hypertensive effect. In this study, the possible physiological role of thyrotropin-releasing hormone in the central cardiovascular regulation was evaluated in spontaneously hypertensive rats receiving long-term (8-14 days) intracerebroventricular infusion of a heterologous antiserum to thyrotropin-releasing hormone. The effect of this passive immunization on the blood pressure was monitored from conscious animals by the tail-cuff method. Thyrotropin-releasing hormone antiserum significantly decreased the systolic arterial pressure in adult rats with established hypertension. No alterations in serum thyroid hormone status were observed indicating that the antihypertensive effect of immunological blockade of thyrotropin-releasing hormone was not due to changes in the serum thyroid hormone levels. These results provide evidence for a role of endogenous brain thyrotropin-releasing hormone in the maintenance of hypertension in spontaneously hypertensive rats.  相似文献   
4.
In this retrospective study 103 serum samples from 16 females with systemic lupus erythematosus (SLE), obtained during a mean follow-up time of 2 years, were investigated for the presence of anti-denatured [single-stranded (ss)] DNA antibodies of the IgG, IgM, and IgA classes. The anti-ssDNA antibodies were determined by an enzyme-linked immunosorbent assay (ELISA), and the results were expressed in three ways: as units derived from a single serum dilution and as two parameters,E andA, calculated from the dose-response curve,E being an estimate of the effective amount of antibodies andA a function of the reaction constant between the antigen and the antibody. The simultaneous occurrence of anti-ssDNA antibodies of all three immunoglobulin classes was seen most often in the patients with the shortest duration of the disease. Clinically active disease was found to correlate with high reaction constants of the IgA anti-ssDNA antibodies. There was also an association between the IgA anti-ssDNA antibody levels and the presence of nephritis. Great fluctuations in the amounts of effective antibodies of the IgG class were seen in seven patients, in six of whom changes in the disease activity also were seen. Changes in the disease activity were unaccompanied by fluctuations in the IgG anti-ssDNA levels in four patients; two of these patients were positive for antibodies against extractable nuclear antigens. We conclude that it is of value to express the results of the anti-ssDNA ELISA as a function of the dose-response curve when monitoring patients with SLE and that immunoglobulin class-specific determinations of anti-ssDNA antibodies may provide information about the disease activity in many patients with SLE.  相似文献   
5.
Antigenic properties of Chlamydia trachomatis lipopolysaccharide.   总被引:5,自引:8,他引:5       下载免费PDF全文
The antigenic properties of the lipopolysaccharide (LPS) of Chlamydia trachomatis L2 were investigated. By means of passive hemolysis, passive hemolysis inhibition, and absorption experiments, it was shown that antiserum raised against chlamydial elementary bodies contained at least two different antibody specificities which reacted with different antigenic determinants of chlamydial LPS. One of these antibodies cross-reacted with enterobacterial Re LPS, recognizing a structure which is shared by both LPSs, whereas the reactivity of the second antibody was restricted to chlamydial LPS. The former antibody could be absorbed with Salmonella minnesota Re LPS, whereas the latter was not affected by this absorption. Therefore, chlamydial LPS possesses two distinct antigenic determinants, one of which is C. trachomatis specific, the other of which is responsible for the cross-reactivity with enterobacterial Re-type LPS. Both antigenic determinants were destroyed during mild acid-catalyzed hydrolysis. It was further shown that free chlamydial lipid A exhibits antigenicity that cross-reacts with free enterobacterial lipid A. This antigenicity, however, as in enterobacterial LPS, is present in a cryptic form, i.e., it is unmasked only after acid hydrolysis of LPS.  相似文献   
6.
A hypertensive patient with left cardiac enlargement developed marked hypertension under general anaesthesia, during which time a tourniquet was applied around his thigh. When the tourniquet was released, severe hypotension ensued which responded to therapy. The patient, however, died 16 h later of a myocardial infarction. Because of this incident, the anaesthetic and haemodynamic data of 699 patients who underwent limb surgery with a pneumatic tourniquet inflated for at least an hour were retrospectively examined using multivariate analysis. A 30% increase in systolic and/or diastolic arterial blood pressure occurred in 27% of the total patient material and in 67% of those who had had a general anaesthetic. There was a higher frequency of the occurrence of "tourniquet hypertension" with older age, longer operations and the operation site being the lower rather than the upper limb. Tourniquet hypertension rarely occurred in patients with spinal anaesthesia (2.7%) and brachial plexus blockade (2.5%), while those with intravenous regional anesthesia had a higher incidence (19%) of hypertension.  相似文献   
7.
Malaria prophylaxis and self-therapy in airline crews   总被引:2,自引:0,他引:2  
The risk of malaria infection in airline crews is estimated to be 0.5 per 1,000 persons per night in areas with high levels of malaria transmission. Routine chemoprophylaxis for years is not recommended because of possible side effects. Airline crews should therefore use appropriate measures to prevent mosquito bites. In addition, they may need to carry "standby" medication with them to be used for presumptive treatment of a febrile illness if medical attention is not readily available.  相似文献   
8.
9.
10.
Marjatta Repo 《Aphasiology》2013,27(6):571-572
Abstract

Maria Pachalska's approach to aphasia rehabilitation is from a holistic perspective. Traditionally, aphasia therapists have tried to promote communicative ability using several methods. Pachalska has combined the most important approaches and created a model which she calls the Complex Aphasia Rehabilitation Model (CARM). She offers this model as an example of a holistic approach to aphasia rehabilitation. It stresses the importance of taking into account both psychological and social factors in aphasia rehabilitation.  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