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   10130篇
  免费   1007篇
  国内免费   21篇
耳鼻咽喉   62篇
儿科学   328篇
妇产科学   202篇
基础医学   1291篇
口腔科学   223篇
临床医学   1141篇
内科学   1936篇
皮肤病学   98篇
神经病学   753篇
特种医学   540篇
外国民族医学   1篇
外科学   1970篇
综合类   332篇
一般理论   12篇
预防医学   941篇
眼科学   171篇
药学   588篇
  1篇
中国医学   15篇
肿瘤学   553篇
  2023年   84篇
  2022年   102篇
  2021年   227篇
  2020年   144篇
  2019年   210篇
  2018年   253篇
  2017年   194篇
  2016年   167篇
  2015年   207篇
  2014年   298篇
  2013年   417篇
  2012年   543篇
  2011年   576篇
  2010年   356篇
  2009年   296篇
  2008年   444篇
  2007年   501篇
  2006年   467篇
  2005年   415篇
  2004年   394篇
  2003年   380篇
  2002年   363篇
  2001年   229篇
  2000年   219篇
  1999年   201篇
  1998年   152篇
  1997年   138篇
  1996年   112篇
  1995年   126篇
  1994年   115篇
  1993年   91篇
  1992年   186篇
  1991年   174篇
  1990年   168篇
  1989年   163篇
  1988年   150篇
  1987年   134篇
  1986年   166篇
  1985年   138篇
  1984年   111篇
  1983年   96篇
  1982年   73篇
  1981年   69篇
  1980年   64篇
  1979年   94篇
  1978年   92篇
  1976年   65篇
  1975年   65篇
  1973年   71篇
  1972年   70篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
New community-based preventive initiatives are required if a reduction in deliberate self-poisoning is to be achieved. Local epidemiological data can be used in a health education approach, directed at professionals who have the most contact with potential cases of deliberate self-poisoning and also to those people falling within identified high-risk groups. Such initiatives require defined outcome measures and a number are proposed. The implications for data collection on deliberate self-poisoning are discussed.  相似文献   
63.
OBJECTIVES: This study determined the effect of provider (nurse or teacher) and training method (workshop or self-preparation) on outcomes of a social influences smoking prevention program. METHODS: One hundred elementary schools were stratified by school risk score (high risk = high smoking rate among senior students) and assigned randomly to conditions: (1) teacher/self-preparation, (2) teacher/workshop, (3) nurse/self-preparation, (4) nurse/workshop, and (5) control. Intervention occurred in grades 6 to 8. Smoking status at the end of grade 8 was the primary endpoint variable. RESULTS: Intervention reduced grade 8 smoking rates in high-risk schools (smoking rates of 26.9% in control vs 16.0% in intervention schools) but not in low-risk schools. There were no significant differences in outcome as a function of training method and no significant differences in outcome between teacher-provided and nurse-provided interventions in high- and medium-risk schools. Although nurses achieved better outcomes than did teachers in low-risk schools, neither provider type achieved outcomes superior to the control condition in those schools. CONCLUSIONS: Workshop training did not affect outcomes. Teachers and nurses were equally effective providers. Results suggest that programming should target high-risk schools.  相似文献   
64.
Psychological influences on the perception of immune function   总被引:5,自引:0,他引:5  
BACKGROUND: Perception of deficiencies in immunity are common in a number of patient complaints. However, little is known about the way in which individuals form perceptions about the competence of their immune system. In two studies we examined the relationship between subjects' perceptions of their immune functioning, physical symptoms, mood and measures of immunity. METHODS: In Study 1, 20 healthy volunteers completed global ratings of their immune system functioning, as well as mood and symptom reports, twice a week for 5 weeks. At the same time, blood samples were taken to assess serum IgA, IgG, and IgM antibodies. In Study 2, another sample of 58 subjects completed the same measures weekly for 5 weeks and their blood was tested for concentrations of CD3, CD4, CD8, and CD16 lymphocytes. RESULTS: We found perceptions of immune functioning to be unrelated to the concentrations of serum antibodies or blood lymphocytes. Immune perceptions were strongly related to mood and in particular, feelings of fatigue and vigour. The experience of recent physical symptoms, while not as strong as mood variables, was also important in perceptions of immune functioning. CONCLUSIONS: Mood seems to be an important determinant in the perception of immune function, and complaints about immune dysfunction in clinical situation should be investigated with this possibility in mind.  相似文献   
65.
Penetrating cardiac trauma can result in a wide range of injuries to intracardiac structures. Missile injury, in particular, can cause damage in more than one cardiac chamber that may be difficult to identify at initial emergent operation. We report a case of late repair of traumatic ventricular septal defect and tricuspid valve perforation from gunshot wound. This case illustrates the importance of thorough examination of intracardiac anatomy during emergent and delayed repair for penetrating cardiac trauma.  相似文献   
66.
OBJECTIVES: To investigate outcome in children with mild traumatic head injury (THI) at 1 week and 3 months postinjury and to identify factors associated with persisting problems. DESIGN: Postconcussional symptomatology, behavior ratings, and neuropsychological test performance were examined at 1 week and 3 months postinjury. SETTING: Participants were recruited from successive presentations to emergency departments of two major hospitals. PARTICIPANTS: 130 Children with mild THI were compared with 96 children having other minor injuries as controls. RESULTS: Children with mild THI experienced headaches, dizziness, and fatigue but exhibited no cognitive impairments, relative to controls, at 1 week postinjury. By 3 months, symptoms had resolved. However, 17% of children showed significant ongoing problems. They were more likely to have a history of previous head injury, learning difficulties, neurological or psychiatric problems, or family stressors. CONCLUSIONS: Persisting problems following mild head injury in children are more common in those with previous head injury, preexisting learning difficulties, or neurological, psychiatric, or family problems. These "at-risk" children should be identified in the emergency department and monitored.  相似文献   
67.
Sertoli cells enhance the survival of co-transplanted dopamine neurons   总被引:5,自引:0,他引:5  
One of the major issues in neural transplantation is the low survival rate (<5%) of transplanted dopamine (DA) neurons [3]. Recently it has been shown that it is possible to enhance the survival of these neurons, which in turn may decrease the amount of tissue that is required for each transplantation patient. The present paper demonstrates a novel approach for enhancing neuronal survival by co-transplantation of neuronal tissue with Testis-derived Sertoli cells (SC). This strategy could improve neuronal survival through the provision of trophic support.  相似文献   
68.
BACKGROUND: Percutaneous renal biopsy, based on the use of an aspiration needle and the patient in the sitting position, was first described by Iversen and Brun in 1951. In 1954, Kark and Muehrcke described the use of the cutting Vim-Silverman needle on patients in the prone position, with a substantial improvement in the rate of success. The 1961 CIBA Foundation Symposium on renal biopsy marked the coming of age of this technique. During the 1950s in Italy, several individuals played a part in promoting and developing percutaneous renal biopsy. Because this pioneer work has received insufficient attention, we describe the contributions of Italians to the early introduction of this technique. METHODS: The Italian and international literature about percutaneous renal biopsy of the period 1951 through 1965 was reviewed. In addition, structured interviews with surviving members of the Italian researchers who first used renal biopsy were conducted. RESULTS: The first renal biopsies in Italy were performed in 1951 in Pisa by the group of Ernico Fiaschi (1913-1989). In their hands, renal biopsy became a tool to investigate the pathogenesis of renal diseases in particular, while simultaneously using the early application of immunofluorescence and electron microscopy. In 1954, Pietro Leonardi (1914-1991) and Arturo Ruol (born 1924) introduced renal biopsy in Padova; they used this technique extensively and published one of the first monographs on the subject. In 1957, Vittorio Bonomini (born 1928) introduced renal biopsy in Bologna, and in subsequent years used this technique to focus on the study of pyelonephritis. CONCLUSIONS: Our historical research shows that Italian groups were among the first to use and develop percutaneous renal biopsy both as a clinical tool and an investigative tool. This article gives international credit to their work.  相似文献   
69.
70.
In April 1998 an outbreak of salmonellosis amongst guests at a wedding feast was investigated. Of the 58 attendees interviewed 38 (66%) subsequently developed gastrointestinal symptoms. Stool cultures from 7 cases grew Salmonella Typhimurium RDNC A045. Food samples were culture-negative for Salmonella spp. A cohort study implicated spatchcock (RR 2.5, 95% CI 1.09-5.77) and scampi (RR 2.0, 95% CI 1.05-3.89). Temperature abuse and cross-contamination within the kitchen during preparation and cooking are likely to have been the main contributing factors to this outbreak. Control measures included staff education in safe food handling and improvements in poultry processing methods to minimise carcass contamination.  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