781 research outputs found

    Neuroprotective effects of mild hypoxia in organotypic hippocampal slice cultures

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    PurposeThe aim of this study was to investigate the potential effects of mild hypoxia in the mature and immature brain.MethodsWe prepared organotypic slice cultures of the hippocampus and used hippocampal tissue cultures at 7 and 14 days in vitro (DIV) to represent the immature and mature brain, respectively. Tissue cultures were exposed to 10% oxygen for 60 minutes. Twenty-four hours after this hypoxic insult, propidium iodide fluorescence images were obtained, and the damaged areas in the cornu ammonis 1 (CA1), CA3, and dentate gyrus (DG) were measured using image analysis.ResultsIn the 7-DIV group compared to control tissue, hypoxia-exposed tissue showed decreased damage in two regions (CA1: 5.59%±2.99% vs. 4.80%±1.37%, P=0.900; DG: 33.88%±12.53% vs. 15.98%±2.37%, P=0.166), but this decrease was not statistically significant. In the 14-DIV group, hypoxia-exposed tissue showed decreased damage compared to control tissues; this decrease was not significant in the CA3 (24.51%±6.05% vs. 18.31%±3.28%, P=0.373) or DG (15.72%±3.47% vs. 9.91%±2.11%, P=0.134), but was significant in the CA1 (50.91%±5.90% vs. 32.30%±3.34%, P=0.004).ConclusionAlthough only CA1 tissues cultured for 14 DIV showed significantly less damage after exposure to hypoxia, the other tissues examined in this study showed a tendency towards less damage after hypoxic exposure. Therefore, mild hypoxia might play a protective role in the brain

    Decreased C-reactive protein induces abnormal vascular structure in a rat model of liver dysfunction induced by bile duct ligation

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    Background/Aims Chronic liver disease leads to liver fibrosis, and although the liver does have a certain regenerative capacity, this disease is associated with dysfunction of the liver vessels. C-reactive protein (CRP) is produced in the liver and circulated from there for metabolism. CRP was recently shown to inhibit angiogenesis by inducing endothelial cell dysfunction. The objective of this study was to determine the effect of CRP levels on angiogenesis in a rat model of liver dysfunction induced by bile duct ligation (BDL). Methods The diameter of the hepatic vein was analyzed in rat liver tissues using hematoxylin and eosin (H&E) staining. The expression levels of angiogenic factors, albumin, and CRP were analyzed by real-time PCR and Western blotting. A tube formation assay was performed to confirm the effect of CRP on angiogenesis in human umbilical vein endothelial cells (HUVECs) treated with lithocholic acid (LCA) and siRNA-CRP. Results The diameter of the hepatic portal vein increased significantly with the progression of cirrhosis. The expression levels of angiogenic factors were increased in the cirrhotic liver. In contrast, the expression levels of albumin and CRP were significantly lower in the liver tissue obtained from the BDL rat model than in the normal liver. The CRP level was correlated with the expression of albumin in hepatocytes treated with LCA and siRNA-CRP. Tube formation was significantly decreased in HUVECs when they were treated with LCA or a combination of LCA and siRNA-CRP. Conclusion CRP seems to be involved in the abnormal formation of vessels in hepatic disease, and so it could be a useful diagnostic marker for hepatic disease

    Neurodevelopmental Outcomes and Brain Volumetric Analysis of Low-Grade Intraventricular Hemorrhage

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    Purpose Extremely preterm infants are prone to brain injury and underdevelopment. Intraventricular hemorrhage (IVH) is the most common cause of brain injury and a significant risk factor for neurodevelopmental delay in preterm infants. Severe IVH is known to have a poor outcome; however, the outcomes of low-grade IVH remain controversial. This study aimed to evaluate neurodevelopmental outcomes and brain segmental volumes of preterm infants with low-grade IVH. Methods This retrospective cohort study included 109 extremely preterm infants who underwent term equivalent age-magnetic resonance imaging and neurodevelopmental evaluation at a corrected age of 18 to 24 months. We compared infants with and without low-grade IVH. Results Among the 109 extremely preterm infants, 25 had low-grade IVH and 84 had no IVH. There were no significant differences in the neurodevelopmental outcomes between the low-grade and no IVH groups. In multivariate analysis, low-grade IVH was associated with a smaller medullary volume (adjusted odds ratio, 0.575; 95% confidence interval, 0.346 to 0.957; P=0.034). Conclusion We found no significant differences in the neurodevelopmental outcomes of extremely preterm infants at a corrected age of 18 to 24 months between those with low-grade IVH and those without IVH. Low-grade IVH was associated with a smaller medullary volume

    Proliferation of Hepatic Oval Cells via Cyclooxygenase-2 and Extracellular Matrix Protein Signaling during Liver Regeneration Following 2-AAF/Partial Hepatectomy in Rats

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    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð„with constraintsð ð ð„ „ ðandðŽð„ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

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    A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

    Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

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    Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (Ό̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ÂŻ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ÂŻ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),Ό̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

    Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at root s=13 TeV

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    Measurements of Higgs boson production cross sections and couplings in events where the Higgs boson decays into a pair of photons are reported. Events are selected from a sample of proton-proton collisions at root s = 13TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137 fb(-1). Analysis categories enriched in Higgs boson events produced via gluon fusion, vector boson fusion, vector boson associated production, and production associated with top quarks are constructed. The total Higgs boson signal strength, relative to the standard model (SM) prediction, is measured to be 1.12 +/- 0.09. Other properties of the Higgs boson are measured, including SM signal strength modifiers, production cross sections, and its couplings to other particles. These include the most precise measurements of gluon fusion and vector boson fusion Higgs boson production in several different kinematic regions, the first measurement of Higgs boson production in association with a top quark pair in five regions of the Higgs boson transverse momentum, and an upper limit on the rate of Higgs boson production in association with a single top quark. All results are found to be in agreement with the SM expectations.Peer reviewe

    Measurement of the top quark mass using events with a single reconstructed top quark in pp collisions at root s=13 TeV

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    Abstract:A measurement of the top quark mass is performed using a data sample en-riched with single top quark events produced in thetchannel. The study is based on proton-proton collision data, corresponding to an integrated luminosity of 35.9 fb−1, recorded at√s= 13TeV by the CMS experiment at the LHC in 2016. Candidate events are selectedby requiring an isolated high-momentum lepton (muon or electron) and exactly two jets,of which one is identified as originating from a bottom quark. Multivariate discriminantsare designed to separate the signal from the background. Optimized thresholds are placedon the discriminant outputs to obtain an event sample with high signal purity. The topquark mass is found to be172.13+0.76−0.77GeV, where the uncertainty includes both the sta-tistical and systematic components, reaching sub-GeV precision for the first time in thisevent topology. The masses of the top quark and antiquark are also determined separatelyusing the lepton charge in the final state, from which the mass ratio and difference aredetermined to be0.9952+0.0079−0.0104and0.83+1.79−1.35GeV, respectively. The results are consistentwithCPTinvariance
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