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   206074篇
  免费   4647篇
  国内免费   529篇
耳鼻咽喉   2858篇
儿科学   7701篇
妇产科学   6075篇
基础医学   26746篇
口腔科学   6078篇
临床医学   16140篇
内科学   38266篇
皮肤病学   4700篇
神经病学   12703篇
特种医学   10958篇
外国民族医学   97篇
外科学   30927篇
综合类   1129篇
一般理论   5篇
预防医学   16819篇
眼科学   4450篇
药学   14116篇
  2篇
中国医学   178篇
肿瘤学   11302篇
  2018年   3841篇
  2017年   4111篇
  2016年   3440篇
  2015年   5186篇
  2014年   4740篇
  2013年   3977篇
  2012年   10770篇
  2011年   5633篇
  2010年   2726篇
  2009年   4322篇
  2008年   2836篇
  2007年   3555篇
  2006年   3782篇
  2005年   11854篇
  2004年   13296篇
  2003年   8752篇
  2002年   3978篇
  2001年   4420篇
  2000年   1774篇
  1999年   5932篇
  1998年   624篇
  1996年   459篇
  1992年   6914篇
  1991年   7152篇
  1990年   7380篇
  1989年   6979篇
  1988年   6496篇
  1987年   6255篇
  1986年   5969篇
  1985年   5260篇
  1984年   3625篇
  1983年   2944篇
  1982年   1025篇
  1981年   792篇
  1980年   851篇
  1979年   3839篇
  1978年   2372篇
  1977年   1792篇
  1976年   1573篇
  1975年   2486篇
  1974年   3117篇
  1973年   2747篇
  1972年   2762篇
  1971年   2750篇
  1970年   2559篇
  1969年   2467篇
  1968年   2238篇
  1967年   2164篇
  1966年   1900篇
  1965年   1131篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
Attachment is a behavioral and physiological system, which enables individual’s dynamic adaptation to its environment. Attachment develops in close interaction between an infant and his/her mother, plays an important role in the development of the infant’s brain, and influences the quality of interpersonal relationships throughout life.Security of attachment is believed to influence individual response to stress, exposing insecurely organized individuals to deregulated autonomic nervous system and exaggerated hypothalamic-pituitary-adrenal activity, which, in turn, produces increased and prolonged exposure to stress-hormones. Such stress responses may have considerable implications for the development of diverse health-risk conditions, such as insulin resistance and hyperlipidemia, shown by numerous studies.Although the mechanisms are not yet fully understood, there is compelling evidence highlighting the role of psychological stress in the development of type 1 diabetes (T1D). One of the possible contributing factors for the development of T1D may be the influence of attachment security on individual stress reactivity. Thus, the suggestion is that insecurely attached individuals are more prone to experience increased and prolonged influence of stress hormones and other mechanisms causing pancreatic beta-cell destruction.The present paper opens with a short overview of the field of attachment in children, the principal attachment classifications and their historic development, describes the influence of attachment security on individual stress-reactivity and the role of the latter in the development of T1D. Following is a review of recent literature on the attachment in patients with T1D with a conclusion of a proposed role of attachment organization in the etiology of T1D.  相似文献   
8.
Background. Haemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterized by fever, hepatosplenomegaly, cytopenia, and progressive multiple-organ failure. HLH in adults is often secondary to autoimmune diseases, cancer, or infections in contrast to familial HLH. Treatment of secondary HLH is directed against the triggering disease in addition to immunosuppressive therapy, the latter commonly according to the HLH-2004 protocol.Methods. We conducted a retrospective study to identify triggering diseases, disease-specific and immunosuppressive therapy administered, and prognosis in adult patients with secondary HLH. Patient data were collected from October 2010 to January 2015.Results. Ten adult patients with secondary HLH were identified. Seven were men, and the median age at diagnosis was 62 years. Five cases were triggered by malignant disease and five by infection. The median patient fulfilled five of the eight HLH-2004 diagnostic criteria. All patients fulfilled the criteria fever, cytopenia, and ferritin >500 µg/L. Median time from hospital admission to HLH diagnosis was 20 days. Four patients received immunosuppressive therapy according to the HLH-2004 protocol. The prognosis was dismal, especially for the patients with malignancy-associated HLH, of whom all died.Conclusion. HLH should be suspected in patients who present with fever, cytopenia, and ferritin >500 µg/L. Secondary HLH has a dismal prognosis. None of the patients with HLH triggered by malignancy survived. Achieving remission of the triggering disease seems to be important for a favourable outcome as, in all surviving patients, the haemophagocytic syndrome resolved after remission of the underlying infection.  相似文献   
9.
Background:Workplace hazards are a significant source of health impairment for workers and of financial losses for firms. EU directives on workers’ health and safety standards significantly contributed to reduce reported occupational injuries, yet the incidence and prevalence of work-related mental illness is still very high.Objectives:We investigated the association between work-related hazards and individuals’ perceived mental health. We reviewed the existing evidence on the channels through which task-related factors, adverse agents and psychosocial factors are expected to affect workers’ health, with specific regard to mental health.Methods:We used data from the fifth wave of the European Working Conditions Survey, covering over 40,000 face-to-face interviews with workers in 34 countries, which includes information on socio-demographic characteristics, firms and jobs attributes, employment status, as well as working conditions and health status. We carried out an empirical analysis with multivariate regression models in order to estimate the relationship between workers’ mental health problems and workplace risk factors.Results:21,020 interviews were used in the multivariate analysis. We found strong correlations between hazards and various indicators of mental health. Among hazardous agents, low temperatures (β=0.0287) and contact with infectious materials (β=0.0394) were positively associated with mental health outcomes. Among task/sequence-related factors, tiring or painful positions (β=0.0713), repetitive hand/arm movements (β=0.0255), working with VDUs (β=0.0301), repetitive tasks <10 min (β=0.0859) and working in evenings (β=0.00754) were positively associated with mental health. Various psychosocial risk factors related to both the content of the job (for example, frequent disruptive interruptions: β=0.219, working in free time: β=0.0759, poor work-life balance: β=0.228) as well as the job context (for example, bad employment prospects: β=0.177, low decisional autonomy: β=0.245, bad social relations: β=0.186, workplace violence: β=0.411) were positively associated with mental health. The main results of the decomposition show that an important contribution to workers’ overall mental distress at work is associated with psychosocial risk factors (up to 60% for depression/anxiety symptoms and sleep disorders), while the contribution of somatic factors is on average lower (up to 20% for overall fatigue).Conclusions:We argue that action is needed to improve workers’ mental well-being, and reduce the economic costs for both the national health system and employers. Regulations and traditional economic measures are unlikely to prove successful in providing adequate standards of primary and secondary preventive measures in the work place without an appropriate and reliable Risk Assessment Procedure.Key words: Work hazards, risk assessment, job content, mental health  相似文献   
10.
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