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   208140篇
  免费   4770篇
  国内免费   546篇
耳鼻咽喉   2898篇
儿科学   7718篇
妇产科学   6189篇
基础医学   26688篇
口腔科学   6116篇
临床医学   16134篇
内科学   39408篇
皮肤病学   4889篇
神经病学   12729篇
特种医学   10845篇
外国民族医学   97篇
外科学   31095篇
综合类   1174篇
一般理论   9篇
预防医学   17165篇
眼科学   4554篇
药学   14226篇
  2篇
中国医学   172篇
肿瘤学   11348篇
  2021年   771篇
  2019年   707篇
  2018年   4159篇
  2017年   4246篇
  2016年   3535篇
  2015年   5196篇
  2014年   4897篇
  2013年   4085篇
  2012年   11086篇
  2011年   6004篇
  2010年   2843篇
  2009年   4439篇
  2008年   2989篇
  2007年   3696篇
  2006年   3811篇
  2005年   11885篇
  2004年   13310篇
  2003年   8749篇
  2002年   3996篇
  2001年   4388篇
  2000年   1735篇
  1999年   5896篇
  1992年   6879篇
  1991年   7107篇
  1990年   7354篇
  1989年   6951篇
  1988年   6475篇
  1987年   6239篇
  1986年   5955篇
  1985年   5242篇
  1984年   3600篇
  1983年   2917篇
  1982年   1010篇
  1981年   776篇
  1980年   846篇
  1979年   3833篇
  1978年   2362篇
  1977年   1783篇
  1976年   1563篇
  1975年   2484篇
  1974年   3108篇
  1973年   2741篇
  1972年   2759篇
  1971年   2750篇
  1970年   2560篇
  1969年   2466篇
  1968年   2242篇
  1967年   2167篇
  1966年   1901篇
  1965年   1132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.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
6.
7.
8.
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   
9.
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   
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