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Cluster Computing - In this study, a secure and coordinated blockchain based energy trading system for Electric Vehicles (EVs) is presented. The major goals of this study are to provide secure and...  相似文献   
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Gastric cancer is a life-threatening disease; resulting from interaction among genetic, epigenetic, and environmental factors. Aberrant dysregulation and methylation changes in Wnt/β-catenin signaling downstream elements are a prevalent phenomenon encountered in gastric tumorigenesis. Also, viral infections play a role in gastric cancer development. CTNNBIP1 (β-catenin interacting protein 1) gene is an antagonist of Wnt signaling which binds to the β-catenin molecules. The CTNNBIP1 function as tumor suppressor gene or oncogene in different types of cancer is controversial. Moreover, its function and regulatory mechanisms in gastric cancer progression is unknown. In the present study, we examined CTNNBIP1 gene expression, the methylation status of the regulatory region of the gene, and their association with Epstein–Barr virus (EBV), and cytomegalovirus (CMV) and Helicobacter pylori infections in human gastric adenocarcinoma tissues in comparison with their adjacent nontumoral tissues. Our data revealed a significant downregulation of CTNNBIP1 in gastric tumors. Female patients showed lower level of CTNNBIP1 than males (p < 0.05). Also, decreased expression of CTNNBIP1 was markedly associated with well-differentiated tumor grades (p < 0.05). No methylation change was observed between tumoral and nontumoral tissues. Additionally, CTNNBIP1 down regulation was significantly associated with CMV infection (p < 0.05). In the absence of EBV infection, lower expression of CTNNBIP1 was observed. There was no association between H. pylori infection and CTNNBIP1 expression. Our findings revealed the tumor suppressor role for CTNNBIP1 in gastric adenocarcinoma. Interestingly, EBV and CMV infections modulate CTNNBIP1 expression.  相似文献   
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Nowadays, increased use of nanomaterials in industry and biomedicine poses potential risks to human health and the environment. Studying their possible toxicological effects is therefore of great significance. The present investigation was designed to examine the status of oxidative stress induced by nanoparticles (NPs) of ferric oxide (Fe2O 3) and titanium oxide (TiO 2) with their micro-sized counterpart on mouse lung and bone marrow–derived normal tissue cells. We assessed the induction of oxidative stress by measuring its indicators such as antioxidant scavenging activity of superoxide dismutase and catalase as well as malondialdehyde concentration. Moreover, colony formation of bone marrow cells was assayed following induction with colony stimulating factor (CSF) from lung cells. NPs had a more potent stimulatory effect on the oxidative stress status than their micron-sized counterparts. In addition, the highest level of oxidative stress derived from TiO 2 NPs was observed in both tissue types. Cotreatment with NPs and the antioxidant α-tocopherol reduced antioxidant activities and membrane lipid peroxidation (LPO) in the lung cells, but increased CSF-induced colony formation activity of bone marrow cells, suggesting that oxidative stress may be the cause of the cytotoxic effects of NPs. It is concluded that free radicals generated following exposure to NPs resulted in significant oxidative stress in mouse cells, indicated by increased LPO and antioxidant enzyme activity and decreased colony formation.  相似文献   
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Alzheimer''s disease is characterized by the presence of extraneuronal amyloid plaques composed of amyloid-beta (Aβ) fibrillar aggregates in the brains of patients. In mouse models, it has previously been shown that atorvastatin (Ator), a cholesterol-lowering drug, has some reducing effect on the production of cerebral Aβ. A meta-analysis on humans showed moderate effects in the short term but no improvement in the Alzheimer''s Disease Assessment Scale—Cognitive Subscale behavioral test. Here, we explore a potential direct effect of Ator on Aβ42 aggregation. Using NMR-based monomer consumption assays and CD spectroscopy, we observed a promoting effect of Ator in its original form (Ator-calcium) on Aβ42 aggregation, as expected because of the presence of calcium ions. The effect was reversed when applying a CaCO3-based calcium ion scavenging method, which was validated by the aforementioned methods as well as thioflavin-T fluorescence assays and transmission electron microscopy. We found that the aggregation was inhibited significantly when the concentration of calcium-free Ator exceeded that of Aβ by at least a factor of 2. The 1H–15N heteronuclear single quantum correlation and saturation-transfer difference NMR data suggest that calcium-free Ator exerts its effect through interaction with the 16KLVF19 binding site on the Aβ peptide via its aromatic rings as well as hydroxyl and methyl groups. On the other hand, molecular dynamics simulations confirmed that the increasing concentration of Ator is necessary for the inhibition of the conformational transition of Aβ from an α-helix-dominant to a β-sheet-dominant structure.  相似文献   
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In acute infectious mononucleosis (AIM), very large clones of Ag-specific CD8+ effector T cells are generated. Many clones persist as memory cells, although the clone size is greatly reduced. It would be expected that the large number of cell divisions occurring during clonal expansion would lead to shortening of telomeres, predisposing to replicative senescence. Instead, we show that clonally expanded CD8+ T cells in AIM have paradoxical preservation of telomere length in association with marked up-regulation of telomerase. We postulate that this allows a proportion of responding T cells to enter the memory pool with a preserved capacity to continue dividing so that long-term immunological memory can be maintained.  相似文献   
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Background. Low recurrence of gastritis is seen in patients infected with Helicobacter pylori carrying the type II urease B gene, compared with H. pylori carrying types I and III. The underlying mechanism has been studied in terms of the urease activity and interleukin (IL)‐8 production capacity of different strains of H. pylori. Materials and Methods. Forty‐five patients infected with different strains of H. pylori (type I; 15, type II; 15 and type III; 15) were enrolled in the study. H. pylori was isolated from gastric mucosa and cultured in the presence of urea at pH 5.5 to evaluate urease activity. The capacity of different strains of H. pylori to induce IL‐8 mRNA and IL‐8 from a human gastric cancer cell line and human peripheral blood mononuclear cells was evaluated. Results. The urease activity of type II H. pylori[523 ± 228 µg of ammonia/dl/108 colony‐forming units (CFU)/ml] was significantly lower than that of type I (1355 ± 1369 µg of ammonia/dl/108 CFU/ml) and type III (1442 ± 2229 µg of ammonia/dl/108 CFU/ml) (p < .05). Gastric cancer cells cocultured with type II H. pylori produced lower levels of IL‐8 mRNA compared with type I and type III H. pylori. The levels of IL‐8 were also significantly lower in cultures induced by type II H. pylori compared with those induced by type I and type III H. pylori. Peripheral blood mononuclear cells also produced lower levels of IL‐8 when cocultured with type II compared with type I H. pylori. Conclusions. These results indicate that both the lower level of urease activity and the low IL‐8‐inducing capacity of type II H. pylori might underlie the lower recurrence rate of gastritis caused by type II H. pylori.  相似文献   
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Docosahexaenoic acid (22:6n-3, DHA) is highly enriched in neuronal membranes and is considered to be essential for proper brain function. We have previously demonstrated in Neuro 2A cells that DHA as a membrane component protects cells from apoptotic death induced by serum deprivation (Kim et al. 2000). In the present study we demonstrate that staurosporine (ST) induces apoptosis in Neuro 2A cells and DHA enrichment prior to the ST treatment significantly inhibits the apoptotic cell death, as evidenced by the reduction of caspase-3 activity, cleavage of pro-caspase-3 to active caspase-3, DNA strand-breaking and laddering. Enrichment of cells with other fatty acids such as oleic and arachidonic acids did not exert such an effect, indicating that the antiapoptotic effect was specific to DHA enrichment. Among the several protein kinase inhibitors, only phosphatidylinositol 3-kinase (PI3-K) inhibitors, wortmanin, and LY-294002 abolished the protective effect of DHA in ST-induced apoptosis. Concurrently, ST-treatment significantly decreased the phosphorylation status of Akt at Ser-473 and Thr-308 as well as Akt activity, and this reduction was partially prevented by DHA enrichment. The extent of the antiapoptotic effect of DHA correlated with a time-dependent increase in the phosphatidylserine (PS) content upon DHA enrichment. When cells were enriched with DHA in serine-free medium, the PS increase diminished and the DHA effect on caspase-3 activation as well as Akt phosphorylation in ST-induced apoptosis was no longer apparent, suggesting that DHA's role in accumulating membrane PS is an important component for the observed protection. In summary, DHA enrichment uniquely protects ST-induced apoptosis in a PS- and PI3-K-dependent manner. From these data, we suggest that the antiapoptotic effect of DHA is mediated at least in part through the PI3-K/Akt pathway, facilitated by DHA-induced PS accumulation.  相似文献   
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