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   78篇
  免费   8篇
  国内免费   1篇
  2024年   1篇
  2023年   1篇
  2022年   2篇
  2021年   4篇
  2020年   8篇
  2019年   14篇
  2018年   2篇
  2017年   6篇
  2016年   5篇
  2015年   1篇
  2014年   2篇
  2013年   8篇
  2012年   4篇
  2011年   4篇
  2008年   1篇
  2007年   2篇
  2006年   2篇
  2005年   1篇
  2003年   1篇
  2001年   4篇
  1991年   1篇
  1987年   1篇
  1985年   1篇
  1982年   2篇
  1981年   2篇
  1979年   1篇
  1978年   3篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
排序方式: 共有87条查询结果,搜索用时 15 毫秒
51.
Here, we report a Chinese case of Creutzfeldt–Jakob disease (CJD) with a rare mutation in the prion protein gene (PRNP) leading to an exchange of amino acid from valine (Val) to isoleucine (I) at codon 203 (V203I). The 80-y-old male presented with sudden memory loss, rapid loss of vocabulary, inattention and slow responses, accompanied by dizziness, blurred vision and ataxia. Two weeks after admission, he exhibited tremor, myoclonus and bilateral Babinski signs. At the end of the clinical course, he developed severe akinetic mutism. The cerebrospinal fluid (CSF) was positive for 14-3-3 protein. Increased bilateral signal intensity in the frontal and parietal lobes was seen on diffusion-weighted imaging (DWI); periodic activity was recorded on an electroencephalogram (EEG). There was no family history of similar symptoms. The total clinical course was approximately two months.  相似文献   
52.
目的:近年来研究表明,关节软骨细胞凋亡在骨关节炎发病过程中起到了重要的作用,本文旨在探讨microma-15a模拟物对于原代人膝关节软骨细胞增殖与凋亡的影响。方法:取人外伤性截肢后的膝关节软骨,采用双酶消化法分离获得人膝关节软骨细胞,并进行体外培养,通过甲苯胺蓝染色和II型胶原免疫细胞化学染色进行软骨细胞鉴定。将培养的软骨细胞传代后取第l代细胞,分为实验组和对照组,实验组采用mir.15a模拟物(has.mir-15amimics)转染软骨细胞,上调软骨细胞内mir-15a的表达量;对照组分为阴性对照组、空白对照组。采用MTT法测定细胞增殖曲线,流式细胞仪测定细胞凋亡率。结果:原代细胞中细胞呈多角形、圆形与梭型,贴壁生长;甲苯胺蓝染色胞质呈深蓝色,II型胶原染色胞质呈黄褐色,为特异性染色。经统计学分析,实验组与对照组相比增殖速率明显下降(P〈0.05)。实验组凋亡率(7.13%±0.57)与阴性对照组凋亡率(2.66%±0.15)相比明显增高(P〈0.05)。结论:采用双酶消化法成功分离并培养具有生物学特性的原代人膝关节软骨细胞,通过转染mir-15a模拟物外源性增加关节软骨细胞内mir.15a表达量可显著促进其凋亡并抑制其增殖,为阐明骨关节炎发病机制提供了新的理论依据,为’临床治疗提供了新的靶点。  相似文献   
53.
The molecular mechanisms controlling the differentiation of human basal keratinocyte stem cells towards the epidermis are well characterized, whereas the earliest process leading to the specification of embryonic stem cells into keratinocytes is still not well understood. MicroRNAs are regulators of many cellular events, but evidence for microRNA acting on the differentiation of human embryonic stem cells into a specific lineage has been elusive. By using our recent protocol for obtaining functional keratinocytes from hESC, we attempted to analyze the role of microRNAs in the early stages of epidermal differentiation. Thus, we identified a set of 5 microRNAs, namely miR-200a, miR-200b, miR-203, miR-205 and miR-429, that are specifically overexpressed during the early stages of the differentiation process. Interestingly, our functional analyses revealed an instrumental role of miR-203, which had been previously shown to play a key role during the formation of the pluristratified epidermis by basal keratinocyte stem cells, in the early keratinocyte commitment. These results highlight the determinant and unique role of miR-203 during the entire process of epidermal development by extending its spectrum of action from the early commitment of embryonic stem cells to ultimate differentiation of the organ.  相似文献   
54.
55.
We report a Japanese patient with Creutzfeldt-Jakob disease (CJD) with a V203I homozygous mutation of the prion protein gene (PRNP). A 73-year-old woman developed rapidly progressive gait disturbance and cognitive dysfunction. Four months after the onset, she entered a state of an akinetic mutism. Gene analysis revealed a homozygous V203I mutation in the PRNP. Familial CJD with a V203I mutation is rare, and all previously reported cases had a heterozygous mutation showing manifestations similar to those of typical sporadic CJD. Although genetic prion diseases with homozygous PRNP mutations often present with an earlier onset and more rapid clinical course than those with heterozygous mutations, no difference was found in clinical phenotype between our homozygous case and reported heterozygous cases.  相似文献   
56.
Esophageal squamous cell carcinoma (ESCC) is one of the most common digestive tumors worldwide. The Mucin 1 (MUC1) heterodimeric protein has been confirmed that is overexpressed in ESCC and induced adverse outcomes. However, the detailed mechanism(s) remained challenging. So, we investigated the relationship between MUC1-C and metabolism in ESCC cells. In the results, TP53-induced glycolysis and apoptosis regulator (TIGAR) was overexpressed and correlative with MUC1-C positively in ESCC tissue. Targeting MUC1-C inhibits AKT–mTORC–S6K1 signaling and blocks TIGAR translation. We found that the inhibitory effect of GO-203 on TIGAR was mediated by inhibition of AKT–mTOR–S6K1 pathway. The findings also demonstrated that the suppressive effect of GO-203 on TIGAR is related to the decrease of glutathione level, the increase of reactive oxygen species and the loss of mitochondrial transmembrane membrane potential. In xenograft tissues, GO-203 inhibited the growth of ESCC cells and lead to the low expression of transmembrane C-terminal subunit (MUC1-C) and TIGAR. This evidence supports the contention that MUC1-C is significant for metabolism in ESCC and indicated that MUC1-C is a potential target for the treatment of ESCC.  相似文献   
57.
The supernatant fluids from activated lymphocytes or from herpes simplex virus-infected cells agglutinated EA but not E. The effect of preincubation of various “Fc receptornegative” cells with these supernatant fluids on the formation of EA rosettes was investigated. Following such preincubation lymphoblasts, brain cells, and cells from methyl-cholanthrene-induced murine sarcoma formed EA rosettes.  相似文献   
58.
High fructose intake is a risk factor for liver fibrosis. Polydatin is a main constituent of the rhizome of Polygonum cuspidatum, which has been used in traditional Chinese medicine to treat liver fibrosis. However, the underlying mechanisms of fructose‐driven liver fibrosis as well as the actions of polydatin are not fully understood. In this study, fructose was found to promote zinc finger E‐box binding homeobox 1 (ZEB1) nuclear translocation, decrease microRNA‐203 (miR‐203) expression, increase survivin, activate transforming growth factor β1 (TGF‐β1)/Smad signalling, down‐regulate E‐cadherin, and up‐regulate fibroblast specific protein 1 (FSP1), vimentin, N‐cadherin and collagen I (COL1A1) in rat livers and BRL‐3A cells, in parallel with fructose‐induced liver fibrosis. Furthermore, ZEB1 nuclear translocation‐mediated miR‐203 low‐expression was found to target survivin to activate TGF‐β1/Smad signalling, causing the EMT in fructose‐exposed BRL‐3A cells. Polydatin antagonized ZEB1 nuclear translocation to up‐regulate miR‐203, subsequently blocked survivin‐activated TGF‐β1/Smad signalling, which were consistent with its protection against fructose‐induced EMT and liver fibrosis. These results suggest that ZEB1 nuclear translocation may play an essential role in fructose‐induced EMT in liver fibrosis by targeting survivin to activate TGF‐β1/Smad signalling. The suppression of ZEB1 nuclear translocation by polydatin may be a novel strategy for attenuating the EMT in liver fibrosis associated with high fructose diet.  相似文献   
59.
This research was determined to unearth the diagnostic values and the effects of microRNA (miR)-130a and miR-203 on cell proliferation and apoptosis of papillary thyroid carcinoma (PTC). Expression of miR-130a and miR-203 were evaluated and were subjected to correlation analysis. The diagnostic values of miR-130a and miR-203 and their associations with clinicopathological characteristics of patients with PTC were measured. The expression levels of miR-130a and miR-203 in K1, IHH4, TPC-1, and BCPAP cells together with Nthy-ori 3-1 cells were measured. Cells were transfected with miR-130a mimics, miR-203 mimics, and coordinate of miR-130a mimics and miR-203 mimics. Cell growth, colony formation, and apoptosis were detected by cell counting kit-8 (CCK-8) assay, colony formation assay, and flow cytometry. PTC tissues had decreased miR-130a and miR-203 relative to adjacent normal tissues and normal thyroid tissue (both P < .05). miR-130a was in positive correlation with miR-203 (r = 0.754, P < .01). miR-130a was related with tumor infiltration and tumor stage while miR-203 was implicated in tumor stage and lymph-node metastasis. The area under the curve (AUC), sensitivity, as well as specificity for miR-130 in predicting PTC was 0.839, 74.5%, and 85.0% and those for miR-203 were 0.818, 73.7%, and 84.0%, respectively. PTC cells had lower expression of miR-130a and miR-203 than that in Nthy-ori 3-1 cells. After transfected miR-130a and miR-203 mimics in BCPAP and TPC-1 cells, both cells had increased miR-130a and miR-203, promoted cell apoptosis rate and decreased cell growth rate, and colony formation ability. After coordinately transfected with miR-130a mimics and miR-203 mimics, the cell growth and colony formation ability of PTC cells were restrained, and apoptosis of PTC cells was elevated (all P < .05). This study highlights that miR-130a and miR-203 have satisfactory diagnostic value in PTC and upregulated miR-130a and miR-203 can inhibit PTC cell growth and promote cell apoptosis.  相似文献   
60.
许多研究表明,miRNAs在肿瘤中失活与特定的遗传和表观遗传机制改变有关,hsa-miR-203在膀胱癌组织和细胞中表达下调并扮演着抑癌基因的角色。为了验证hsa-miR-203在膀胱癌细胞中是否受DNA甲基化抑制,采用去甲基化抑制剂5-Aza-CdR(5-氮-2'-脱氧胞苷)处理5637和BIU-87膀胱癌细胞,MSP和RT-PCR检测表明,hsa-miR-203的启动子在5637和BIU-87细胞中存在完全的甲基化,而5-Aza-CdR能逆转hsa-miR-203启动子的甲基化状态,恢复hsa-miR-203的表达。MTT法测定显示,5-Aza-CdR使5637和BIU-87膀胱癌细胞增殖受到明显抑制,并呈时间和剂量依赖性。同时,流式细胞仪检测显示,5-Aza-CdR使5637和BIU-87膀胱癌细胞周期阻滞于G_0/G_1期。因此,5-Aza-CdR能抑制膀胱癌细胞5637和BIU-87增殖并干扰其细胞周期。hsa-miR-203启动子异常甲基化是其在膀胱癌细胞中低表达的重要机制,5-Aza-CdR能逆转hsa-miR-203基因的甲基化,恢复hsa-miR-203的表达,为hsa-miR-203作为膀...  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