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   1158篇
  免费   42篇
  国内免费   64篇
耳鼻咽喉   2篇
儿科学   73篇
妇产科学   80篇
基础医学   102篇
口腔科学   19篇
临床医学   123篇
内科学   261篇
皮肤病学   21篇
神经病学   80篇
特种医学   152篇
外科学   113篇
综合类   26篇
预防医学   21篇
眼科学   10篇
药学   78篇
中国医学   3篇
肿瘤学   100篇
  2021年   6篇
  2020年   6篇
  2019年   4篇
  2018年   11篇
  2017年   12篇
  2016年   10篇
  2015年   23篇
  2014年   24篇
  2013年   32篇
  2012年   23篇
  2011年   26篇
  2010年   40篇
  2009年   35篇
  2008年   37篇
  2007年   65篇
  2006年   40篇
  2005年   27篇
  2004年   23篇
  2003年   21篇
  2002年   40篇
  2001年   29篇
  2000年   23篇
  1999年   20篇
  1998年   48篇
  1997年   50篇
  1996年   56篇
  1995年   30篇
  1994年   33篇
  1993年   21篇
  1992年   14篇
  1991年   15篇
  1990年   19篇
  1989年   45篇
  1988年   37篇
  1987年   30篇
  1986年   29篇
  1985年   28篇
  1984年   24篇
  1983年   20篇
  1982年   19篇
  1981年   19篇
  1980年   15篇
  1979年   16篇
  1978年   7篇
  1977年   34篇
  1976年   9篇
  1975年   37篇
  1974年   5篇
  1973年   10篇
  1971年   3篇
排序方式: 共有1264条查询结果,搜索用时 0 毫秒
51.
BACKGROUND: The increased incidence of neurological deviations in preterm infants with chronic lung disease (CLD) has been linked to severe brain haemorrhage (intraventricular haemorrhage (IVH)) and periventricular leucomalacia (PVL) rather than to CLD per se. AIM: To evaluate whether CLD without concomitant brain lesions constitutes a risk factor for adverse developmental outcome. METHOD: Forty three very low birthweight infants with CLD, but without IVH or PVL, and 43 very low birthweight infants without CLD, IVH, or PVL were evaluated at 5 and 10 months of corrected age using the movement assessment of infants (MAI) scale. The Griffiths' developmental test was carried out at 10 months of age. RESULTS: The overall motor assessments (MAI) in infants with CLD and controls were not significantly different. However, differences were observed in the execution of volitional movements (MAI), the total sum, hand and eye coordination, and perception and intelligence (measured by the performance scale of the Griffiths' test). CONCLUSIONS: CLD has a deleterious effect on the control of hand and eye coordination and on perception and intelligence. These results thus re-emphasise the necessity for careful neurodevelopmental follow up of infants with CLD whether or not they suffered IVH or PVL.  相似文献   
52.
E mu-pim-1 transgenic mice are predisposed to develop lymphomas. Due to their low spontaneous tumour incidence and their increased sensitivity towards the lymphomagen ethylnitrosourea these mice may present an interesting model for short-term carcinogenicity testing. Here, we report on the further exploration of this transgenic mouse model with two additional carcinogens known to have, among others, the lymphohaematopoietic system as target, i.e. benzo[a]pyrene (B[a]P) and 12-O-tetradecanoylphorbol-13-acetate (TPA). B[a]P, given three times a week (by gavage) for 13 weeks at 4.3, 13 or 39 mg/kg body weight, resulted in a dose-related increase in lymphomas up to a 90% incidence in E(mu)-pim-1 mice during the observation period of 40 weeks. B[a]P also induced tumours of the forestomach within this observation period, though at a lower incidence and apparently equally effective in wildtype and transgenic mice. TPA, on the other hand, was unable to induce lymphomas (or tumours in any other organ) in either transgenic or wildtype animals within the observation period of 44 weeks, when applied dermally at the maximum tolerated dose of 3 microg/mouse, twice a week for 35 weeks. Molecular analysis showed that B[a]P-induced lymphomas in transgenic mice were of T-cell origin, 80% of which had elevated levels of c-myc expression. None of the lymphomas had increased N-myc expression and mutation analysis of the ras-gene family revealed a K-ras mutation in only one out of eight tumours investigated. Also, none of the lymphomas showed aberrant expression of p53 as determined by immunohistochemistry. It is concluded that the E mu-pim-1 mouse model will not be very suitable for short-term carcinogenicity testing in general: only genotoxic chemicals that have the lymphohaematopoietic system as target for carcinogenesis in wild- type mice, appear to be efficiently identified.   相似文献   
53.
Mucormycosis is a rare fungal infection of childhood, occurring mainly in patients with chronic illnesses such as diabetes and malignancies. The fungus seldom grows in culture and confirmation of the diagnosis depends on histologic examination of infected tissues. To date, the reported natural history of the disease has been rapid progression and a fatal outcome. Therefore, the importance of early diagnosis by tissue biopsy and early treatment with surgical debridement and systemic antifungal therapy cannot be overemphasized. The pulmonary system is the most common site for mucormycosis in patients with leukemia. We report what we believe to be the first successfully treated case of isolated muscular mucormycosis occurring in a child with biphenotypic acute leukemia. The diagnosis was made promptly by tissue examination at the time of surgical debridement. The patient was also given systemic amphotericin-B therapy.   相似文献   
54.
Data on body composition in conjunction with reference centiles are helpful in identifying the severity of growth and nutritional disorders in infancy and for evaluating the adequacy of treatment given during this important period of rapid growth. Total body fat (TBF) and fat-free mass (FFM) were estimated from total body electrical conductivity (TBEC) measurements in 423 healthy term Caucasian infants, aged 14-379 days. Cross sectional age, weight, and length related centile standards are presented for TBF and FFM. Centiles were calculated using Altman's method, based on polynomial regression and modelling of the residual variation. The TBF percentage steeply increased during the first half year of life, and slowly declined beyond this age. Various simple TBEC derived anthropometric prediction equations for TBF and FFM are available to be used in conjunction with these standards. Regression equations for the P50 and the residual SD, depending on age, weight, or length, are provided for constructing centile charts and calculating standard deviation scores.  相似文献   
55.
Of a total number of 643 injured patients admitted during 1986 and 1987, 113 were tested for antibodies against the human immunodeficiency virus (HIV) and hepatitis B surface antigen HBsAg and the concentration of hepatitis B surface antibodies (HBsAb) was determined. Nine patients were HIV positive while HBsAg was detected in two patients and increased levels of HBsAb were found in 19 patients. HIV antibodies were found in 6 (4.8 per cent) of 124 victims of violence, in 3.3 per cent of the patients with penetrating injuries and 1.1 per cent of the patients with multiple, closed injuries. The estimated prevalence for HIV infection in the Norwegian population is 0.08 per cent, thus indicating an over-representation of infected patients among injured patients and victims of violence.  相似文献   
56.
57.
Concepts necessary to an understanding of the basics of quality assurance audits are presented. Included are specific examples that bridged theory and practice by applying the protocol to a real-life diagnostic imaging situation. This method meets the present requirements of the Joint Commission of the Accrediation of Hospitals.  相似文献   
58.
Funktionelle Elektrostimulation anstatt Operation?   总被引:1,自引:0,他引:1  
The aim of this study was to restore the grasp function of a tetraplegic patient with a C5 spinal cord injury (SCI) by means of functional electrical stimulation (FES). Using three pairs of surface electrodes and orthotic wrist stabilisation a simple palmar grasp was realised.The FES was controlled with a switch mounted on a wheelchair or-for the first time-with an EEG-based brain-computer interface (BCI). Application of this stimulation system enabled the patient to drink for the first time after the accident from a glass without any additional help.  相似文献   
59.
60.
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