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   853篇
  免费   82篇
  国内免费   9篇
耳鼻咽喉   4篇
儿科学   108篇
妇产科学   38篇
基础医学   103篇
口腔科学   31篇
临床医学   78篇
内科学   161篇
皮肤病学   22篇
神经病学   25篇
特种医学   129篇
外科学   48篇
综合类   43篇
预防医学   76篇
眼科学   30篇
药学   21篇
肿瘤学   27篇
  2022年   2篇
  2021年   4篇
  2020年   7篇
  2019年   7篇
  2018年   20篇
  2017年   10篇
  2016年   21篇
  2015年   22篇
  2014年   28篇
  2013年   43篇
  2012年   27篇
  2011年   22篇
  2010年   45篇
  2009年   46篇
  2008年   26篇
  2007年   43篇
  2006年   19篇
  2005年   32篇
  2004年   12篇
  2003年   21篇
  2002年   16篇
  2001年   16篇
  2000年   17篇
  1999年   16篇
  1998年   47篇
  1997年   50篇
  1996年   44篇
  1995年   39篇
  1994年   25篇
  1993年   31篇
  1992年   6篇
  1991年   9篇
  1990年   9篇
  1989年   19篇
  1988年   18篇
  1987年   12篇
  1986年   14篇
  1985年   17篇
  1984年   9篇
  1983年   12篇
  1982年   5篇
  1981年   13篇
  1980年   7篇
  1979年   4篇
  1978年   6篇
  1977年   9篇
  1976年   10篇
  1975年   2篇
  1973年   2篇
  1884年   1篇
排序方式: 共有944条查询结果,搜索用时 296 毫秒
81.
Background Anti‐tumour necrosis factors (anti‐TNF) are more and more used, but the rate of skin adverse events is not known. Objective The aim was to assess the number of skin infections and other dermatoses in patients treated with anti‐TNFα. Patients and methods One hundred eighty‐seven patients suffering from rheumatoid arthritis or ankylosing spondylitis underwent a dermatological exam. Patients with anti‐TNF were compared with those without this treatment in a prospective transversal study. Results Among them, 59 patients were treated with anti‐TNFα and steroids were prescribed in 100 cases. There was no difference in the prevalence of skin infections or eczema or tumours. Skin drug reactions were observed in six patients. Infections by dermatophytes appear very frequent, approaching 70% in both groups. Conclusions This study shows that skin infections (or other skin diseases) are not more frequent in these patients. No differences were observed in infections (bacterial fungal, parasital or viral), tumours, psoriasis or the manifestations of atopic dermatitis. Nonetheless, a long‐term survey might be interesting, especially about skin tumours.  相似文献   
82.
Pregnancy outcome was studied in a county in Norway 3 years prior to and 3 years subsequent to the Chernobyl nuclear plant accident on 26th April 1986. More detailed analyses have been performed for the 12 months prior to and subsequent to the accident. A significant increase in the spontaneous abortion rate the first year after the accident was followed by a slight decrease during the second and third years, but figures were still higher than the period prior to the accident. The rate of legal abortions was unchanged. During the entire observation period the number of births increased continuously, with the exception of a decrease in the last 2 months of 1986 and the first month of 1987. A higher incidence of spontaneous abortions was found for pregnancies conceived during the first 3 months after the accident. This increase in the spontaneous abortion rate is noteworthy, and more especially its long-term persistence, which cannot be the result of external radiation. The internal radiation from food polluted by radioactive fallout is a possible explanation. Changes in nutrition in order to avoid polluted food may also be of importance.  相似文献   
83.
Reports on pregnancies in kidney donors are scarce. The aim was to assess pregnancy outcomes for previous donors nationwide. The Medical Birth Registry of Norway holds records of births since 1967. Linkage with the Norwegian Renal Registry provided data on pregnancies of kidney donors 1967–2002. A random sample from the Medical Birth Registry was control group, as was pregnancies in kidney donors prior to donation. Differences between groups were assessed by two-sided Fisher's exact tests and with generalized linear mixed models (GLMM). We identified 326 donors with 726 pregnancies, 106 after donation. In unadjusted analysis (Fisher) no differences were observed in the occurrence of preeclampsia (p = 0.22). In the adjusted analysis (GLMM) it was more common in pregnancies after donation, 6/106 (5.7%), than in pregnancies before donation 16/620 (2.6%) (p = 0.026). The occurrence of stillbirths after donation was 3/106 (2.8%), before donation 7/620 (1.1%), in controls (1.1%) (p = 0.17). No differences were observed in the occurrence of adverse pregnancy outcome in kidney donors and in the general population in unadjusted analysis. Our finding of more frequent preeclampsia in pregnancies after kidney donation in the secondary analysis must be interpreted with caution, as the number of events was low.  相似文献   
84.
85.
86.
Six painful hips in five patients were examined with magnetic resonance (MR) imaging and were found to have diffuse signal abnormalities in the marrow of the femoral head and neck, which extended into the intertrochanteric area in five cases. The abnormal regions were low in signal intensity on images obtained with a short repetition time (TR) and a short echo time (TE) and were isointense or hyperintense on long TR/TE images--findings that have been attributed by others to bone marrow edema. Edema was also seen in marrow just above the acetabulum in two cases. No focal abnormalities characteristic of osteonecrosis were seen. Osteonecrosis was subsequently shown to be present in all six femoral heads at core biopsy (three cases) or by subsequent development of focal MR abnormalities reported to be highly specific for osteonecrosis (three cases). The affected hips had been radiographically normal or subtly osteopenic and had shown intense radionuclide uptake in the femoral head at scintigraphy, with lesser abnormality in the neck and intertrochanteric region. Follow-up MR examinations of five of the six femoral heads showed the diffuse abnormalities to have been transient. Although diffuse MR abnormalities in the proximal femur are not specific, they may indicate the presence of osteonecrosis of the femoral head.  相似文献   
87.
Pregnancy outcome in Norway after Chernobyl   总被引:1,自引:0,他引:1  
Pregnancy outcome has been studied in terms of legal abortions, early spontaneous abortions and total number of pregnancies (in an ad hoc study covering 6 counties) as well as various perinatal health problems (on the basis of routinely recorded data for epidemiological surveillance from the Medical Birth Registry of Norway). Apparently, no effects were observed in terms of an increased occurrence of legal abortions, while spontaneous abortions increased from 7.2% of all pregnancies during the last 12 months before the accident to 8.3% after the accident [corrected]. At the same time, the total number of pregnancies somewhat decreased. Based on monthly measurements in each municipality of external and internal (food-based) doses, dose-response associations were assessed for a number of perinatal health problems. No associations were observed.  相似文献   
88.
In order to describe the British experience of Wegener's granuiomatosisHospital Activity Analysis was used to collect cases diagnosedin England, Wales and Scotland between 1975 and 1985. Wherepossible clinical details, histological material and chest radiographswere obtained. Two hundred and sixty five patients were consideredto have Wegener's granuiomatosis. In 109 a single pathologistconfirmed the diagnosis by finding both granulomas and vasculitisin biopsy material. The diagnosis was made on clinical groundsor clinical grounds together with histological diagnosis inthe local hospital in 156 patients. Wegener's granuiomatosiswas confined to the lung or upper respiratory tract in 22 percent of patients and renal disease occurred in 58 per cent.Laboratory tests showed a pattern of mild anaemia, polymorphleucocytosis, eosinophilia and an elevated ESR and hypergammaglobulinaemia,with no specific pattern of changes. Histological confirmation was most frequently obtained by examinationof nasal biopsy specimens, but multiple biopsies were oftenrequired. Renal biopsies showed focal proliferative glomerulonephritisbut granulomatous glomerulonephritis was uncommon. Of availablechest radiographs 61 per cent were abnormal, large opacitiesbeing most common. Small irregular opacities were found lessoften and other abnormalities were uncommon. Treatment varied widely and 10 per cent of patients receivedno drug therapy. This large series illustrates that even withoutspecific treatment, patients with Wegener's granuiomatosis cansurvive for several years and with modern treatment survivalfor more than a decade is possible. Conclusions about the effectivenessof the various therapies cannot be drawn from this restrospectivestudy. Renal failure and disseminated vasculities were the commonestcauses of death; death was considered to result from complicationsof treatment with cytotoxic drugs or prednisolone in 6 per centof patients.  相似文献   
89.
BACKGROUND: The Kell blood group system comprises 21 antigens residing on a red cell membrane glycoprotein of apparent M(r) 93,000. STUDY DESIGN AND METHODS: Serologic techniques were used to identify a new red cell antigen. The monoclonal antibody-specific immobilization of erythrocyte antigens (MAIEA) assay was used to identify the red cell membrane component carrying that antigen. RESULTS: A new high-frequency red cell antigen was identified and provisionally named RAZ. RAZ is absent from K.o red cells and from red cells treated with 2-amino- ethylisothiouronium bromide and is expressed weakly on McLeod phenotype cells. It differs from all other Kell system antigens, and no depression of other Kell system antigens on RAZ+ red cells was noticed. The RAZ antigen was shown by the MAIEA assay to be located on the Kell glycoprotein. CONCLUSION: RAZ is a new high-frequency antigen located on the Kell glycoprotein. The MAIEA assay is a very effective method of demonstrating the membrane structure carrying a red cell antigen.  相似文献   
90.
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