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   446篇
  免费   22篇
  国内免费   5篇
耳鼻咽喉   9篇
儿科学   6篇
妇产科学   6篇
基础医学   83篇
口腔科学   6篇
临床医学   34篇
内科学   63篇
皮肤病学   13篇
神经病学   42篇
特种医学   11篇
外科学   53篇
综合类   2篇
预防医学   72篇
眼科学   4篇
药学   21篇
肿瘤学   48篇
  2023年   5篇
  2022年   28篇
  2021年   26篇
  2020年   10篇
  2019年   14篇
  2018年   20篇
  2017年   17篇
  2016年   13篇
  2015年   13篇
  2014年   13篇
  2013年   28篇
  2012年   36篇
  2011年   46篇
  2010年   27篇
  2009年   25篇
  2008年   25篇
  2007年   15篇
  2006年   24篇
  2005年   20篇
  2004年   11篇
  2003年   15篇
  2002年   11篇
  2001年   3篇
  2000年   3篇
  1999年   4篇
  1998年   2篇
  1997年   1篇
  1995年   1篇
  1993年   2篇
  1992年   2篇
  1991年   6篇
  1988年   5篇
  1986年   1篇
  1962年   1篇
排序方式: 共有473条查询结果,搜索用时 15 毫秒
41.

Background

Medulloepithelioma is a rare primitive neuroectodermal tumor of the central nervous system, usually developing in childhood. Due to its rarity, the optimal management is still unknown. The prognosis is poor, especially when resection is incomplete. Adjuvant radiochemotherapy is often indicated.

Case presentation

We report a rare case of infratentorial medulloepithelioma in a 3 year old girl. She presented symptoms of increased intracranial pressure. On examination, she had coordination problems, ptosis and exotropia of the right eye. Magnetic resonance imaging demonstrated a large cerebellar vermix tumor. Immuno-histochemistry revealed a diffuse positivity for Vimentin and focal positivity for the epithelial membrane antigen, but Glial Fibrillary Acidic Protein and Synaptophysin were negative, the MIB-1 antibody was very high. She received postoperative craniospinal irradiation and died 7 months later.

Conclusion

We describe the features (epidemiological, clinical, histological, immunohistochemical and therapeutic outcomes) of our case and confront it to literature data.
  相似文献   
42.
We have previously screened thirteen medicinal mushrooms for their potential anti-cancer activities in eleven different cell lines and found that the extract of Amauroderma rude exerted the highest capacity in inducing cancer cell death. The current study aimed to purify molecules mediating the anti-cancer cell activity. The extract of Amauroderma rude was subject to fractionation, silica gel chromatography, and HPLC. We purified a compound and identified it as ergosterol by EI-MS and NMR, which was expressed at the highest level in Amauroderma rude compared with other medicinal mushrooms tested. We found that ergosterol induced cancer cell death, which was time and concentration dependent. In the in vivo experiment, normal mice were injected with murine cancer cell line B16 that is very aggressive and caused mouse death severely. We found that treatment with ergosterol prolonged mouse survival. We found that ergosterol-mediated suppression of breast cancer cell viability occurred through apoptosis and that ergosterol up-regulated expression of the tumor suppressor Foxo3. In addition, the Foxo3 down-stream signaling molecules Fas, FasL, BimL, and BimS were up-regulated leading to apoptosis in human breast cancer cells MDA-MB-231. Our results suggest that ergosterol is the main anti-cancer ingredient in Amauroderma rude, which activated the apoptotic signal pathway. Ergosterol may serve as a potential lead for cancer therapy.  相似文献   
43.
ObjectivesProteolytic degradation of aggrecan is a hallmark of the pathology of osteoarthritis. The aim of this study was to develop enzyme-linked immunosorbent assay (ELISA) to quantify the serum levels of specific aggrecan fragments generated by aggrecanases-mediated cleavage. We investigated the relationships between these two aggrecan degradations fragments and urinary CTX-II levels.MethodsThe competitive ELISAs employ a polyclonal antibody raised against the aggrecan fragments containing two neoepitopes NITEGE373 and 374ARGSVI. We measured serum levels of ARGSV and NITEGE in 125 women with knee osteoarthritis (mean ± SD age of 53.6 ± 7.6 years, mean ± SD disease duration of 3.6 ± 3.8 years), and 57 women age-matched controls.ResultsAggrecan neoepitopes assays showed an intra- and inter-assay imprecision (CV) lower than 20% for both tests and good linearity. Median serum ARGSVI (by 18%; P = 0.002), and NITEGE (36.4%; P < 0.001) levels were significantly decreased in patients with knee osteoarthritis compared with controls. Minimal joint space width was negatively correlated with ARGSVI (r = –0.368, P = 0.04) and NITEGE (r = –0.274, P = 0.038) in knee osteoarthritis patients. Median urinary CTX-II levels were significantly increased by 39.5% (P = 0.001) in knee OA patients compared with controls.ConclusionMarkers of degradation aggrecan were analyzed for the first time in an African osteoarthritis population. These markers can be used to monitor aggrecanase activity in human joint disease. Their combination with CTX-II can improve clinical investigation of patients with osteoarthritis patients.  相似文献   
44.
45.
Primary hepatic vipoma   总被引:1,自引:0,他引:1  
Vipoma is a rare neuroendocrine tumor most frequently localized in the pancreas. When it is extrapancreatic, it is most often neurogenic. We report a case of primary extrapancreatic vipoma that is non neurogenic localized in the right liver in a patient with severe diarrhea and hypokaliema. Computed tomography, magnetic resonance imaging, intraoperative tomography and surgical exploration did not show any other extrahepatic primary lesion. The diagnosis was performed by immunochemistry, tumorous cells were positives with anti-VIP antibody. Forty two months after right hepatectomy, the patient was asymptomatic.  相似文献   
46.
47.
48.
49.
Cervical spondylolysis is defined as a corticated cleft between the superior and inferior articular facets of the articular pillar, the cervical equivalent of the pars interarticularis in the lumbar spine. Of primary importance is its recognition to avoid confusion with more clinically significant abnormalities such as fracture or dislocation. This case report describes bilateral spondylolysis and associated dysplasia of C5 in a 31-year-old female. We describe the radiographic presentation of this anomaly, stressing the importance of computed tomography for correct diagnosis. A review of the literature on this interesting abnormality and a complete differential diagnosis are presented.  相似文献   
50.
Breast cancer in Tunisia is characterized by a much higher incidence of aggressiveness compared with Western countries. The pattern of allelic loss at the BRCA1 locus in Tunisian women with breast carcinoma has not been studied. Therefore, the aim of this present preliminary study was mainly focused on loss of heterozygosity (LOH) analysis of the BRCA1 gene to determine if this tumor suppressor gene is involved in sporadic breast carcinoma among Tunisian women. We investigate allelic losses by analyzing three microsatellite markers in the BRCA1 region, in a panel of 21 human breast tumors. D17S1322 marker had the highest frequency of LOH (59%), followed by the D17S1323 (35%), and EDH-17B (20%). Collectively out of 21 informative cases 13 (62%) showed LOH at at least one BRCA1 locus. This data provides evidence that allelic loss at BRCA1 is a frequent event in sporadic breast tumorigenesis among Tunisian women, and suggests that the BRCA1 gene might play an important role as a tumor suppressor gene.  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