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   251篇
  免费   11篇
  国内免费   1篇
耳鼻咽喉   3篇
儿科学   18篇
妇产科学   11篇
基础医学   22篇
口腔科学   12篇
临床医学   17篇
内科学   59篇
皮肤病学   3篇
神经病学   19篇
特种医学   12篇
外科学   25篇
综合类   11篇
预防医学   12篇
眼科学   3篇
药学   15篇
肿瘤学   21篇
  2023年   3篇
  2022年   4篇
  2021年   19篇
  2020年   6篇
  2019年   8篇
  2018年   11篇
  2017年   3篇
  2016年   8篇
  2015年   8篇
  2014年   17篇
  2013年   15篇
  2012年   16篇
  2011年   19篇
  2010年   16篇
  2009年   9篇
  2008年   17篇
  2007年   17篇
  2006年   13篇
  2005年   13篇
  2004年   19篇
  2003年   7篇
  2002年   5篇
  2001年   2篇
  1998年   1篇
  1996年   1篇
  1995年   1篇
  1994年   2篇
  1992年   1篇
  1990年   1篇
  1982年   1篇
排序方式: 共有263条查询结果,搜索用时 15 毫秒
1.
A symptomatic 1,400 g premature triplet underwent successful transcatheter coil embolization of patent arterial duct using the umbilical artery. One 3 mm x 3 cm Flipper coil was used with no angiographic residual shunt. To the best of our knowledge, this is one of the smallest preterm infants to undergo this transcatheter procedure.  相似文献   
2.
3.
4.
Glial fibrillary acidic protein (GFAP) is the principal intermediate filament protein found in mature astrocytes. Although the exact function of GFAP is poorly understood, it is presumed to stabilize the astrocyte’s cytoskeleton and help in maintaining cell shape. Previous studies from our laboratory have shown that when astrocytes were cocultured with primary Schwann cells (pSCs), astrocytes became hypertrophied and fibrous with intensely positive GFAP staining and segregated Schwann cells (SCs) into pockets. In order to understand the functional role of GFAP in this already established astrocyte-SC coculture model, we generated GFAP-negative cell lines from a GFAP-positive astrocytoma cell line and cocultured both the cell lines with pSCs. Our studies demonstrate that the GFAP-positive cell line put out processes toward the SCs, whereas the GFAP-negative cells did not form processes and the majority of the cells remained round. The most significant and interesting finding of this study, however, is the formation of elaborate processes by SCs when grown in coculture with the astrocytoma cells, unlike SCs cultured alone, which showed their typical bipolar spindle-shaped morphology. The extent of processes did not seem to be dependent on GFAP, since SCs cultured with both the cell lines formed similar processes. This coculture model may be useful in elucidating the factor(s) responsible for the formation of processes by SCs and can be further help in our understanding of the mechanism of morphological transformation of SCs.  相似文献   
5.
A series of polycaprolactone and ternary-based (Na(2)O)(0.55-x)(CaO)(x)(P(2)O(5))(0.45) glass composites were created, each containing 20% volume percentage of glass with various calcium compositions. A short-term degradation study was carried out to investigate the physical and ion release behaviour of these composites, utilising analytical techniques such as dynamical mechanical analysis, and ion chromatography. All the composites experienced significant loss of weight and stiffness throughout the study, with the 24 mol% calcium composites losing the greatest amount of weight and stiffness. The pH profile of the aqueous solutions in which the composites were placed were initially acidic, but began to neutralise mid-way through the study, with the 36 mol% solution achieving the most acidic conditions. The ion release behaviour mirrored the mass loss behaviour of the glass component of the composites. The cations (sodium and calcium ions) release was comparable with the initial stages of composite mass degradation, both of which exhibited almost immediate release when placed into solution. The 24 mol% composites underwent rapid rates of cation release, while the 36 mol% experienced the slowest rates of release. By contrast, anion (phosphates and polyphosphates) release showed a dissimilar trend, with rapid release of the P(2)O(7) and P(3)O(10) occurring during the first few hours in solution, whilst the P(3)O(9) structure released steadily during the first 48 h in solution. Finally, PO(4) release was at a constant rate over the duration of the study, releasing up to 300 ppm from the 32 and 36 mol% samples by the end of 200 h. To summarise, these results show that by combining phosphate glasses with biodegradable polymer, it is possible to create composites whose rate of degradation can be controlled to meet the needs of their end application.  相似文献   
6.
AimsWe sought to characterize the direction and associated factors of eGFR change following diagnosis of youth-onset type 1 and type 2 diabetes.MethodsWe assessed the direction of eGFR change at two visits (mean 6.6 years apart) in SEARCH, a longitudinal cohort study of youth-onset type 1 and type 2 diabetes. We used the CKiDCr-CysC equation to estimate GFR and categorized ‘rising’ and ‘declining’ eGFR as an annual change of ≥3 ml/min/1.73 m2 in either direction. Multivariable logistic regression evaluated factors associated with directional change in eGFR.ResultsEstimated GFR declined in 23.8% and rose in 2.8% of participants with type 1 diabetes (N = 1225; baseline age 11.4 years), and declined in 18.1% and rose in 15.6% of participants with type 2 diabetes (N = 160; baseline age 15.0 years). Factors associated with rising and declining eGFR (versus stable) in both type 1 and type 2 diabetes included sex, age at diagnosis, baseline eGFR and difference in fasting glucose between study visits. Additional factors in type 1 diabetes included time from baseline visit, HbA1c and body mass index.ConclusionsOver the first decade of diabetes, eGFR decline is more common in type 1 diabetes whereas eGFR rise is more common in type 2 diabetes.  相似文献   
7.
Increased CD8+ T‐cell precursor frequency (PF) precludes the requirement of CD4+ helper T (Th) cells for primary CD8+ cytotoxic T‐lymphocyte (CTL) responses. However, the key questions of whether unhelped CTLs generated at higher PF are functional effectors, and whether unhelped CTLs can differentiate into functional memory cells at higher PF are unclear. In this study, ovalbumin (OVA) ‐pulsed dendritic cells (DCOVA) derived from C57BL/6, CD40 knockout (CD40?/?) or CD40 ligand knockout (CD40L?/?) mice were used to immunize C57BL/6, Iab?/?, CD40?/? or CD40L?/? mice, whose PF was previously increased with transfer of 1 × 106 CD8+ T cells derived from OVA‐specific T‐cell receptor (TCR) transgenic OTI, OTI(CD40?/?) or OTI(CD40L?/?) mice. All the immunized mice were then assessed for effector and memory CTL responses. Following DC immunization, relatively comparable CTL priming occurred without CD4+ T‐cell help and Th‐provided CD40/CD40L signalling. In addition, the unhelped CTLs were functional effectors capable of inducing therapeutic immunity against established OVA‐expressing tumours. In contrast, the functional memory development of CTLs was severely impaired in the absence of CD4+ T‐cell help and CD40/CD40L signalling. Finally, unhelped memory CTLs failed to protect mice against lethal tumour challenge. Taken together, these results demonstrate that CD4+ T‐cell help at higher PF, is not required for effector CTL priming, but is required for functional memory CTL development against cancer. Our data may impact the development of novel preventive and therapeutic approaches in cancer patients with compromised CD4+ T‐cell functions.  相似文献   
8.
Pectus carinatum or protrusion deformity of chest wall is less frequently occurring anterior chest wall deformity when compared to pectus excavatum. It may be classified as type 1 or chondro-gladiolar and type 2 or chondro-manubrial deformity. Other variations seen are symmetrical and asymmetrical pectus carinatum. Here we present two unique case reports, one with chondro-manubrial deformity (Currarino–Silverman syndrome) and other with asymmetrical pectus carinatum having bifid rib which are some of the rare variations seen in pectus carinatum found during Computerized tomographic examination. Currarino–Silverman syndrome is a type 2 pectus carinatum, a rare deformity with chondro-manubrial involvement and usually associated congenital heart diseases. Early fusion of sternal plates is one of the known theories in producing this deformity. On the other hand, asymmetrical pectus deformity are usually seen due to imbalance or abnormality in growth plates of costal cartilages leading to forked rib or bifid rib, which are accidently seen on radiological examination. To conclude, our reports would help in differential diagnosis from frequently occurring conditions affecting chest like chondro-gladiolar deformity, pectus excavatum, chest wall tumours, rib fractures and intra thoracic ribs.  相似文献   
9.
Extra‐pulmonary tuberculosis is the presence of disease in an organ without obvious involvement of the lungs (World Health Organization, Tuberculosis Fact sheet, 2006). The present article focuses on the incidence of extra‐pulmonary tuberculosis as an emerging and clinically significant disease to be reckoned with in the present era. It also highlights fine‐needle aspiration cytology (FNAC) as an inexpensive, less invasive procedure for early diagnosis of such tuberculosis and timely initiation of specific therapy. All cases of proved tuberculosis presenting to the M.V.J. Medical College and Research Hospital were recorded over a period of two years (2008–2010); and categorized as pulmonary and extra‐pulmonary cases. A total of 96 cases of tuberculosis were observed; extra‐pulmonary tuberculosis was seen in 64 cases. Of these 56 cases were from lymphnodes and 8 from extra‐nodal sites which included tuberculous dactylitis (two cases), tuberculous mastitis (two cases), tuberculous synovial effusion (one case), pericardial effusion (one case), epididymo‐orchitis (one case), and cold abscess (one case). The cytology patterns observed included granulomatous inflammation and necrosis with or without acid fast bacilli. Diagn. Cytopathol. 2013. © 2012 Wiley Periodicals, Inc.  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