239 research outputs found

    Probe R-parity violating stop resonance at the LHeC

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    We investigate the possibility of detecting single sqaurk production at the proposed LHeC collider, in the framework of R-parity violating supersymmetry. Taking advantage of the enhancement of the direct resonance production of squark and the distinctive kinematics distributions of q~lq\tilde{q}\rightarrow l q two body decay final states, the LHeC provides excellent opportunities of probing R-violating L^Q^D^\hat{L}\hat{Q}\hat{D} interactions at unprecedented level compared to all the knowledge derived from indirect low energy nucleon measurements. If no apparent deviation from SM predictions on high invariant mass of muon and b-quark final states at the LHeC with 1fb1fb^{-1} data, the sensitivities on L^Q^D^\hat{L}\hat{Q}\hat{D} coupling constant λ131×λ233\lambda^{'}_{131} \times \lambda^{'}_{233} can be improved by nearly four orders, at energy scale about 100 GeV.Comment: 9 pages, 8 figure

    Biomass Smoke Exposure Is Associated With Gastric Cancer and Probably Mediated Via Oxidative Stress and DNA Damage: A Case-Control Study.

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    PURPOSE: We investigated the association between gastric cancer and environmental and dietary exposures. In addition, we explored probable mechanistic pathways for the influence of biomass smoke on gastric carcinogenesis. PATIENTS AND METHODS: The study was conducted in Lusaka, Zambia. Questionnaires were used to collect data on risk factors, whereas enzyme-linked immunosorbent assays and high-performance liquid chromatography were used to measure biologic exposures. Study data were analyzed using contingency tables and logistic regression. RESULTS: We enrolled 72 patients with gastric adenocarcinoma and 244 controls. Gastric cancer was positively associated with rural residence (odds ratio [OR], 2.9; 95% CI, 1.5 to 5.3), poverty (OR, 4.2; 95% CI, 1.9 to 9.1), and daily consumption of processed meat (OR, 6.4; 95% CI, 1.3 to 32) and negatively associated with consumption of green vegetables (OR, 0.2; 95% CI, 0.1 to 0.5). Gastric cancer was also associated with biomass smoke exposure (OR, 3.5; 95% CI, 1.9 to 6.2; P < .0001), an association that was stronger for intestinal-type cancers (OR, 3.6; 95% CI, 1.5 to 9.1; P = .003). Exposure to biomass smoke in controls was associated with higher urinary levels of 8-isoprostane (P < .0001), 8-hydroxydeoxyguanosine (P = .029), and 1-hydroxypyrene (P = .041). Gastric cancer was not associated with biochemical measures of current exposure to aflatoxins or ochratoxins. CONCLUSION: In Zambia, exposure to biomass smoke, daily consumption of processed meat, and poverty are risk factors for gastric cancer, whereas daily consumption of green vegetables is protective against gastric cancer. Exposure to biomass smoke was associated with evidence of oxidative stress and DNA damage, suggesting mechanistic plausibility for the observed association, and the association was restricted to intestinal-type gastric cancer

    Clinicopathologic characteristics and treatment outcomes of hepatoid adenocarcinoma of the stomach, a rare but unique subtype of gastric cancer

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    <p>Abstract</p> <p>Background</p> <p>Gastric hepatoid adenocarcinoma (HAC) is a special type of gastric cancer that morphologically mimics hepatocellular carcinoma. In this study, we performed an evaluation of clinicopathologic characteristics, treatment outcome, and prognosis in patients with gastric HAC.</p> <p>Methods</p> <p>We consecutively enrolled patients with pathologically proven gastric HAC at Seoul National University Hospital between January 1996 and December 2008 and conducted a retrospective review. Among 15,253 patients with gastric cancer, 26 patients (0.17%) were diagnosed as gastric HAC.</p> <p>Results</p> <p>Among 26 patients, 22 were male and the median age was 63. Stage at diagnosis was stage IB in 3 patients, stage II in 6 patients, stage III in 7 patients, and stage IV in 10 patients. Eight patients out of 18 patients with stage IB, II, III, and IV relapsed after curative surgery. Relapse-free survival for these patients was 16.67 months. The most common metastatic site was intraabdominal lymph nodes (n = 9), followed by the liver (n = 8). Thirteen patients received palliative chemotherapy. The most commonly used regimen was a combination of fluoropyrimidine and platinum. Partial response was observed in one patient and stable disease in 5 patients. Median overall survival and progression free survival of these patients were 8.03 (95% CI: 6.59-9.47) and 3.47 months (95% CI: 0.65-6.29), respectively.</p> <p>Conclusions</p> <p>Gastric HAC is a very rare but unique type of stomach cancer. Early detection of this type of cancer is of critical importance to patient prognosis. Additional studies to reveal the biology of this tumor are warranted.</p

    Isgur-Wise function in a QCD inspired potential model with confinement as parent in the Variationally Improved Perturbation Theory (VIPT)

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    We have recently reported the calculation of slope and curvature of Isgur-Wise function based on Variationally Improved Perturbation Theory (VIPT) in a QCD inspired potential model. In that work, Coulombic potential was taken as the parent while the linear one as the perturbation.In this work, we choose the linear one as the parent with Coulombic one as the perturbation and see the consequences. Keywords: VIPT,Isgur-Wise function, charge radii and convexity pa- rameter

    Clioquinol Inhibits Zinc-Triggered Caspase Activation in the Hippocampal CA1 Region of a Global Ischemic Gerbil Model

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    Background: Excessive release of chelatable zinc from excitatory synaptic vesicles is involved in the pathogenesis of selective neuronal cell death following transient forebrain ischemia. The present study was designed to examine the neuroprotective effect of a membrane-permeable zinc chelator, clioquinol (CQ), in the CA1 region of the gerbil hippocampus after transient global ischemia. Methodology/Principal Findings: The common carotid arteries were occluded bilaterally, and CQ (10 mg/kg, i.p.) was injected into gerbils once a day. The zinc chelating effect of CQ was examined with TSQ fluorescence and autometallography. Neuronal death, the expression levels of caspases and apoptosis inducing factor (AIF) were evaluated using TUNEL, in situ hybridization and Western blotting, respectively. We were able to show for the first time that CQ treatment attenuates the ischemia-induced zinc accumulation in the CA1 pyramidal neurons, accompanied by less neuronal loss in the CA1 field of the hippocampus after ischemia. Furthermore, the expression levels of caspase-3,-9, and AIF were significantly decreased in the hippocampus of CQ-treated gerbils. Conclusions/Significance: The present study indicates that the neuroprotective effect of CQ is related to downregulation o

    Biocleavable Polycationic Micelles as Highly Efficient Gene Delivery Vectors

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    An amphiphilic disulfide-containing polyamidoamine was synthesized by Michael-type polyaddition reaction of piperazine to equimolar N, N′-bis(acryloyl)cystamine with 90% yield. The polycationic micelles (198 nm, 32.5 mV), prepared from the amphiphilic polyamidoamine by dialysis method, can condense foreign plasmid DNA to form nanosized polycationic micelles/DNA polyelectrolyte complexes with positive charges, which transfected 293T cells with high efficiency. Under optimized conditions, the transfection efficiencies of polycationic micelles/DNA complexes are comparable to, or even higher than that of commercially available branched PEI (Mw 25 kDa)

    Global gene expression profile progression in Gaucher disease mouse models

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    <p>Abstract</p> <p>Background</p> <p>Gaucher disease is caused by defective glucocerebrosidase activity and the consequent accumulation of glucosylceramide. The pathogenic pathways resulting from lipid laden macrophages (Gaucher cells) in visceral organs and their abnormal functions are obscure.</p> <p>Results</p> <p>To elucidate this pathogenic pathway, developmental global gene expression analyses were conducted in distinct <it>Gba1 </it>point-mutated mice (V394L/V394L and D409 V/null). About 0.9 to 3% of genes had altered expression patterns (≥ ± 1.8 fold change), representing several categories, but particularly macrophage activation and immune response genes. Time course analyses (12 to 28 wk) of INFγ-regulated pro-inflammatory (13) and IL-4-regulated anti-inflammatory (11) cytokine/mediator networks showed tissue differential profiles in the lung and liver of the <it>Gba1 </it>mutant mice, implying that the lipid-storage macrophages were not functionally inert. The time course alterations of the INFγ and IL-4 pathways were similar, but varied in degree in these tissues and with the <it>Gba1 </it>mutation.</p> <p>Conclusions</p> <p>Biochemical and pathological analyses demonstrated direct relationships between the degree of tissue glucosylceramides and the gene expression profile alterations. These analyses implicate IFNγ-regulated pro-inflammatory and IL-4-regulated anti-inflammatory networks in differential disease progression with implications for understanding the Gaucher disease course and pathophysiology.</p

    Caspase involvement in autophagy

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    Caspases are a family of cysteine proteases widely known as the principal mediators of the apoptotic cell death response, but considerably less so as the contributors to the regulation of pathways outside cellular demise. In regards to autophagy, the modulatory roles of caspases have only recently begun to be adequately described. In contrast to apoptosis, autophagy promotes cell survival by providing energy and nutrients through the lysosomal degradation of cytoplasmic constituents. Under basal conditions autophagy and apoptosis cross-regulate each other through an elaborate network of interconnections which also includes the interplay between autophagyrelated proteins (ATGs) and caspases. In this review we focus on the effects of this crosstalk at the cellular level, as we aim to concentrate the main observations from research conducted so far on the fine-tuning of autophagy by caspases. Several members of this protease-family have been found to directly interact with key ATGs involved in different tiers across the autophagic cascade. Therefore, we firstly outline the core mechanism of macroautophagy in brief. In an effort to emphasize the importance of the intricate cross-regulation of ATGs and caspases, we also present examples drawn from Drosophila and plant models regarding the contribution of autophagy to apoptotic cell death during normal development
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