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   250篇
  免费   19篇
  国内免费   27篇
耳鼻咽喉   1篇
儿科学   20篇
妇产科学   3篇
基础医学   36篇
口腔科学   18篇
临床医学   45篇
内科学   59篇
皮肤病学   8篇
神经病学   5篇
特种医学   25篇
外科学   20篇
综合类   18篇
预防医学   8篇
药学   14篇
中国医学   1篇
肿瘤学   15篇
  2023年   1篇
  2022年   2篇
  2021年   1篇
  2020年   2篇
  2019年   3篇
  2018年   5篇
  2017年   6篇
  2016年   7篇
  2015年   6篇
  2014年   7篇
  2013年   12篇
  2012年   3篇
  2011年   4篇
  2010年   10篇
  2009年   11篇
  2008年   5篇
  2007年   15篇
  2006年   5篇
  2005年   13篇
  2004年   4篇
  2003年   1篇
  2002年   7篇
  2001年   9篇
  2000年   4篇
  1999年   8篇
  1998年   21篇
  1997年   18篇
  1996年   17篇
  1995年   13篇
  1994年   14篇
  1993年   3篇
  1992年   4篇
  1991年   3篇
  1990年   3篇
  1989年   7篇
  1988年   5篇
  1987年   5篇
  1986年   10篇
  1985年   4篇
  1982年   2篇
  1981年   2篇
  1980年   1篇
  1978年   3篇
  1977年   3篇
  1976年   4篇
  1975年   3篇
排序方式: 共有296条查询结果,搜索用时 15 毫秒
81.
Indium-111 labeled leukocyte imaging was compared with three-phase skeletal scintigraphy as a means of determining whether osteomyelitis was complicating diabetic osteoarthropathy. Three-phase scintigraphy demonstrated increased activity in both infected and noninfected osteopathic bone, with a sensitivity of 75% and a specificity of 56% for osteomyelitis. Leukocyte imaging had the same sensitivity but was most helpful for excluding infection (specificity, 89%) when three-phase imaging could not. Abnormal leukocyte localization was seen at the primary site of infection in all cases within 4 hours after injection. Disadvantages of leukocyte imaging included long preparation time, low count rates resulting in poor spatial resolution, and absence of bone landmarks, which made it difficult to differentiate soft tissue from bone infection.  相似文献   
82.
Objective : To determine the genotype of patients attending the cystic fibrosis clinic at John Hunter Hospital, Newcastle, Australia.
Methodology : Seventy-five of the 76 patients attending the clinic over a 6 month period had blood collected for genetic analysis of 17 of the cystic fibrosis (CF) gene mutations.
Results : Sixty-one per cent of the patients were homozygous for the ΔF508 mutation and all except one child had at least one ΔF508 mutation.
Discussion : Nearly 80% of the CF genes were the ΔF508 mutation. This prevalence suggests that the obligatory false negative rate of a newborn screening programme for CF based on a combination of immunoreactive trypsin and the ΔF508 gene may be as low as 4-5%.  相似文献   
83.
Chan  FK  Ching  JY  Hung  LC  齐文安 《英国医学杂志》2005,8(6):372-373
问题:在有阿司匹林诱发溃疡出血史的患者中,用氯毗格雷预防溃疡出血复发,是否不次于小剂量阿司匹林加埃索美拉唑?[编者按]  相似文献   
84.
85.
86.
Extracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be an interesting model for the analysis of fetal organogenesis. Here we describe a technique for culturing embryonic stem cells (ESCs) in the absence of artificial scaffolds which generated mineralized miromasses. Embryonic stem cells were harvested and osteogenic differentiation was stimulated by the addition of dexamethasone, ascorbic acid, and ß-glycerolphosphate (DAG). After three days of cultivation microspheres were formed. These spherical three-dimensional cell units showed a peripheral zone consisting of densely packed cell layers surrounded by minerals that were embedded in the extracellular matrix. Alizarine red staining confirmed evidence of mineralization after 10 days of DAG stimulation in the stimulated but not in the control group. Transmission electron microscopy demonstrated scorching crystallites and collagenous fibrils as early indication of bone formation. These extracellular structures resembled hydroxyl apatite-like crystals as demonstrated by distinct diffraction patterns using electron diffraction analysis. The micromass culture technique is an appropriate model to form three-dimensional bone-like micro-units without the need for an underlying scaffold. Further studies will have to show whether the technique is applicable also to pluripotent stem cells of different origin.  相似文献   
87.

Introduction

Inhaled mannitol has beneficial effects on lung function, mucociliary clearance, quality of life and sputum properties. This trial examined the efficacy of inhaled mannitol in children with cystic fibrosis (CF).

Methods

The efficacy of inhaled mannitol in children with CF aged 6–17 years was assessed in a phase 2, randomised, placebo-controlled crossover study. Subjects were randomly assigned to mannitol 400 mg every 12 h or matching placebo for 8 weeks, followed by an 8 week washout and an 8 week period with the alternate treatment. The primary endpoint was the absolute change from baseline in ppFEV1 (percent predicted FEV1).

Results

A total of 92 subjects were studied, with a mean age of 12 years and mean baseline ppFEV1 of 72.2%. During mannitol treatment ppFEV1 was 3.42% (p = 0.004) higher compared to placebo or a 4.97% (p = 0.005) relative difference; relative change from baseline FEF25-75 was 10.52% (p = 0.013). During mannitol treatment, acute post-treatment sputum weight was higher (p = 0.012). In pre-specified subgroups (rhDNase use, age, and disease severity), the treatment differences consistently favoured mannitol. The most common AEs were cough and pulmonary exacerbations. Pulmonary exacerbation AEs were approximately 30% lower in the mannitol group.

Conclusions

In children with CF, inhaled mannitol was associated with significant improvements in lung function and sputum weight, irrespective of rhDNase use, age or disease severity. Inhaled mannitol was well tolerated and was associated with a reduced incidence of pulmonary exacerbation AEs. (Clinical Trials.Gov: NCT 01883531)  相似文献   
88.
89.
Two new human myeloma cell lines have been established from a 36-year- old woman with refractory IgG kappa multiple myeloma in whom bilateral malignant pleural effusions developed. The malignant plasma cells from each effusion were set up in a liquid culture using an L-15 medium containing catalase, glutathione, selenous acid, ascorbic acid, insulin, transferrin, additional glutamine hydrocortisone, and 2- mercaptoethanol and designated as M-3 medium. Two IgG kappa cell lines, LB -831 and LB-832, were established and proved to be Epstein-Barr virus negative using the internal repeat sequence DNA probe. Characteristic plasma cell morphology was evident by light and electron microscopy. Immunotyping revealed an IgG kappa , B1+, B2-, Ia (HLA- DR)+, CALLA+ phenotype for each cell line as well as for the original pleural fluid and bone marrow myeloma cells. The supernatants also contained IgG kappa, beta 2 microglobulin, and large amounts of osteoclast-activating factor (indicating bone-resorbing activity). Cytogenetic analysis of the LB-831 cell line revealed a nearly triploid highly abnormal karyotype with numerous clonal chromosomal abnormalities involving chromosomes 1, 3, 5, 7, 13, and 15; several structurally abnormal marker chromosomes; and a putative homogeneously staining region on chromosome 7p at band p22. Analysis of the LB-832 cell line revealed several additional clonal abnormalities. These additional cytogenetic changes suggest that in vivo sequential clonal evolution occurred in this patient. Therefore, two new but related cell lines have been established, which should prove useful for further biological studies.  相似文献   
90.

Background  

Several humoral immune factors are responsible for a successful pregnancy. There are a few studies, which demonstrate the role of antipaternal cytotoxic antibodies (APCA) and mixed lymphocyte reaction blocking factor (MLR-Bf) in the maintenance of pregnancy. However, these factors have not been studied in women with history of recurrent spontaneous abortion (RSA). We designed this study to review the role of APCA and MLR-Bf in normal pregnancy as well as in women with a history of RSA.  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