670 research outputs found

    Top quark FCNC couplings at future circular hadron electron colliders

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    A study of single top quark production via flavor changing neutral current interactions at tqγtq\gamma vertices is performed at future circular hadron electron collider. The signal cross sections for the processes epeW±q+Xe^{-}p\to e^{-}W^{\pm}q+X and epeW±bq+Xe^{-}p\to e^{-}W^{\pm}bq+X in the collision of electron beam with energy Ee=E_e= 60 GeV and proton beam with energy Ep=E_p= 50 TeV are calculated. In the analysis, the invariant mass distributions of three jets reconstructing top quark mass, requiring one b-tagged jet and other two jets reconstructing the WW mass are used to count signal and background events after all selection cuts. The upper limits on the anomalous flavor changing neutral current tqγtq\gamma couplings are found to be λq<\lambda_q < 0.01 at future circular hadron electron collider for Lint=100L_{int}=100 fb1^{-1} with the fast simulation of detector effects. Signal significance depending on the couplings λq\lambda_q is analyzed and an enhanced sensitivity is found to the branching ratio BR(tqγt\to q\gamma) at the future circular hadron electron collider when compared to the current experimental results.Comment: 11 pages, 4 Figures, 4 Tables, to appear in Phys. Rev.

    TURKISH FATHERS' PLAY ATTITUDE WITH CHILDREN DURING COVID-19 LOCKDOWN

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    To investigate how the role of fathers has changed with regards to play as a result of the current Covid-19 pandemic, a number of fathers were asked to complete an online survey designed by the researchers that questioned how they felt their activities with their children had changed over the last three months. In total, 128 participants were recruited (128 males), from a wide range of socio-economic backgrounds, aged between 26-58 years old (mean age 38) with children aged between 3-6 years (mean age 4,8) with all being married for 9.5 years. The result of the analysis will be a resource for the literature. Article visualizations

    Multislice/multidetector-row computed tomography findings of a rare coronary anomaly: the first septal perforator branch originating from the left main coronary artery

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    Multislice/multidetector-row computed tomography (MDCT) is now widely used for noninvasive assessment of coronary arteries, and it may sometimes reveal coronary anomalies. Detection of such anomalies may be relevant both during follow-up and for planning cardiac or coronary surgical/interventional procedures. These anomalies may be missed unless carefully sought. In this paper, we present the MDCT images of a first septal perforator branch originating from the left main coronary artery, which represents an extremely rare coronary anomaly. To the bestof our knowledge, this is the first case in the literature where MDCT images are presented

    Review of Linac-Ring Type Collider Proposals

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    There are three possibly types of particle colliders schemes: familiar (well known) ring-ring colliders, less familiar however sufficiently advanced linear colliders and less familiar and less advanced linac-ring type colliders. The aim of this paper is two-fold: to present possibly complete list of papers on linac-ring type collider proposals and to emphasize the role of linac-ring type machines for future HEP research.Comment: quality of figures is improved, some misprints are correcte

    Thermodynamic Assessment of the La-Fe-O System

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    The La-Fe and the La-Fe-O systems are assessed using the Calphad approach, and the Gibbs energy functions of ternary oxides are presented. Oxygen and mutual La and Fe solubilities in body-centered cubic (bcc) and face-centered cubic (fcc) structured metallic phases are considered in the modeling. Oxygen nonstoichiometry of perovskite-structured La1±x Fe1±y O3−δ is modeled using the compound energy formalism (CEF), and the model is submitted to a defect chemistry analysis. The contribution to the Gibbs energy of LaFeO3 due to a magnetic order-disorder transition is included in the model description. Lanthanum-doped hexaferrite, LaFe12O19, is modeled as a stoichiometric phase. Δf,elements°H 298K (LaFe12O19)=−5745kJ/mol, °S 298K (LaFe12O19)=683J/mol·K, and Δf,oxides°G (LaFe12O19)=4634−37.071T (J/mol) from 1073 to 1723K are calculated. The liquid phase is modeled using the two-sublattice model for ionic liquids. The calculated La-Fe phase diagram, LaO1.5-FeO x phase diagrams at different oxygen partial pressures, and phase equilibria of the La-Fe-O system at 873, 1073, and 1273K as a function of oxygen partial pressures are presente

    Project PROMETHEUS: Design and Construction of a Radio Frequency Quadrupole at TAEK

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    The PROMETHEUS Project is ongoing for the design and development of a 4-vane radio frequency quadrupole (RFQ) together with its H+ ion source, a low energy beam transport (LEBT) line and diagnostics section. The main goal of the project is to achieve the acceleration of the low energy ions up to 1.5 MeV by an RFQ (352 MHz) shorter than 2 meter. A plasma ion source is being developed to produce a 20 keV, 1 mA H+ beam. Simulation results for ion source, transmission and beam dynamics are presented together with analytical studies performed with newly developed RFQ design code DEMIRCI. Simulation results shows that a beam transmission 99% could be achieved at 1.7 m downstream reaching an energy of 1.5 MeV. As the first phase an Aluminum RFQ prototype, the so-called cold model, will be built for low power RF characterization. In this contribution the status of the project, design considerations, simulation results, the various diagnostics techniques and RFQ manufacturing issues are discussed.Comment: 4 pages, 8 figures, Proceedings of the 2nd International Beam Instrumentation Conference 2013 (IBIC'13), 16-19 Sep 2013, WEPC02, p. 65

    Knockdown of Indy/CeNac2 extends Caenorhabditis elegans life span by inducing AMPK/aak-2

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    Reducing the expression of the Indy (Acronym for 'I'm Not Dead, Yet') gene in lower organisms promotes longevity and leads to a phenotype that resembles various aspects of caloric restriction. In C. elegans, the available data on life span extension is controversial. Therefore, the aim of this study was to determine the role of the C. elegans INDY homolog CeNAC2 in life span regulation and to delineate possible molecular mechanisms. siRNA against Indy/CeNAC2 was used to reduce expression of Indy/CeNAC2. Mean life span was assessed in four independent experiments, as well as whole body fat content and AMPK activation. Moreover, the effect of Indy/CeNAC2 knockdown in C. elegans with inactivating variants of AMPK (TG38) was studied. Knockdown of Indy/CeNAC2 increased life span by 22±3 % compared to control siRNA treated C. elegans, together with a decrease in whole body fat content by ~50%. Indy/CeNAC2 reduction also increased the activation of the intracellular energy sensor AMPK/aak2. In worms without functional AMPK/aak2, life span was not extended when Indy/CeNAC2 was reduced. Inhibition of glycolysis with deoxyglucose, an intervention known to increase AMPK/aak2 activity and life span, did not promote longevity when Indy/CeNAC2 was knocked down. Together, these data indicate that reducing the expression of Indy/CeNAC2 increases life span in C. elegans, an effect mediated at least in part by AMPK/aak2

    Graphene oxide integrated sensor for electrochemical monitoring ofmitomycin C–DNA interaction

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    WOS: 000302308600025PubMed ID: 22439135We present a graphene oxide (GO) integrated disposable electrochemical sensor for the enhanced detection of nucleic acids and the sensitive monitoring of the surface-confined interactions between the anticancer drug mitomycin C (MC) and DNA. Interfacial interactions between immobilized calf thymus double-stranded (dsDNA) and anticancer drug MC were investigated using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. Based on three repetitive voltammetric measurements of 120 mu g mL(-1) DNA immobilized on GO-modified electrodes, the RSD % (n = 3) was calculated as 10.47% and the detection limit (DL) for dsDNA was found to be 9.06 mu g mL(-1). EIS studies revealed that the binding of the drug MC to dsDNA leads to a gradual decrease of its negative charge. As a consequence of this interaction, the negative redox species were allowed to approach the electrode, and thus increase the charge transfer kinetics. On the other hand, DPV studies exploited the decrease of the guanine signal due to drug binding as the basis for specifically probing the biointeraction process between MC and dsDNA.Royal Society through Joint Project Scheme [1212R0168]; Turkish Academy of Sciences (TUBA)Turkish Academy of SciencesThis work was supported by the Royal Society through Joint Project Scheme (Project No. 1212R0168). A.E. acknowledges the Turkish Academy of Sciences (TUBA) as an Associate member for its partial support. Authors would like to thank Dr. M. McMullan for the assistance on the synthesis of graphene oxide

    Peripheral microcirculatory alterations are associated with the severity of acute respiratory distress syndrome in COVID-19 patients admitted to intermediate respiratory and intensive care units

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    COVID-19; Endothelial dysfunction; MicrocirculationCOVID-19; Disfunción endotelial; MicrocirculaciónCOVID-19; Disfunció endotelial; MicrocirculacióBackground COVID-19 is primarily a respiratory disease; however, there is also evidence that it causes endothelial damage in the microvasculature of several organs. The aim of the present study is to characterize in vivo the microvascular reactivity in peripheral skeletal muscle of severe COVID-19 patients. Methods This is a prospective observational study carried out in Spain, Mexico and Brazil. Healthy subjects and severe COVID-19 patients admitted to the intermediate respiratory (IRCU) and intensive care units (ICU) due to hypoxemia were studied. Local tissue/blood oxygen saturation (StO2) and local hemoglobin concentration (THC) were non-invasively measured on the forearm by near-infrared spectroscopy (NIRS). A vascular occlusion test (VOT), a three-minute induced ischemia, was performed in order to obtain dynamic StO2 parameters: deoxygenation rate (DeO2), reoxygenation rate (ReO2), and hyperemic response (HAUC). In COVID-19 patients, the severity of ARDS was evaluated by the ratio between peripheral arterial oxygen saturation (SpO2) and the fraction of inspired oxygen (FiO2) (SF ratio). Results Healthy controls (32) and COVID-19 patients (73) were studied. Baseline StO2 and THC did not differ between the two groups. Dynamic VOT-derived parameters were significantly impaired in COVID-19 patients showing lower metabolic rate (DeO2) and diminished endothelial reactivity. At enrollment, most COVID-19 patients were receiving invasive mechanical ventilation (MV) (53%) or high-flow nasal cannula support (32%). Patients on MV were also receiving sedative agents (100%) and vasopressors (29%). Baseline StO2 and DeO2 negatively correlated with SF ratio, while ReO2 showed a positive correlation with SF ratio. There were significant differences in baseline StO2 and ReO2 among the different ARDS groups according to SF ratio, but not among different respiratory support therapies. Conclusion Patients with severe COVID-19 show systemic microcirculatory alterations suggestive of endothelial dysfunction, and these alterations are associated with the severity of ARDS. Further evaluation is needed to determine whether these observations have prognostic implications. These results represent interim findings of the ongoing HEMOCOVID-19 trial. Trial registration ClinicalTrials.gov NCT04689477. Retrospectively registered 30 December 2020.The study has received funding from Fundació CELLEX Barcelona, Fundació Mir-Puig, Ajuntament de Barcelona, Agencia Estatal de Investigación (PHOTOMETABO, PID2019-106481RB-C31/10.13039/501100011033), the "Severo Ochoa" Programme for Centers of Excellence in R&D (CEX2019-000910-S), the Obra social “La Caixa” Foundation (LlumMedBcn), Generalitat de Catalunya (CERCA, AGAUR-2017-SGR-1380, RIS3CAT-001-P-001682 CECH), European Commission Horizon 2020 (FEDER, 688303/LUCA, 101016087/VASCOVID, 87114/LASERLAB-EUROPE V). We also acknowledge the collaboration and an instrument loan from Artinis (Netherlands)

    Neighbor Discovery Using Galois Fields and Its Hardware Implementation

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    Neighbor discovery is essential in all channel ac- cess protocols based on transmission scheduling, whether such protocols are topology-dependent or topology-independent. We propose a novel approach to neighbor discovery based on relative GPS coordinates (RGPS), extending the work by Chlamtac and Farago on topology-transparent transmission scheduling. The proposed approach attains neighbor discovery with timing guarantees, which yields greater scalability and requires smaller transmission compared to neighbor discovery mechanisms based on probabilistic methods. We further present the design and implementation of a hardware accelerator for evaluating the Galois field polynomials used in the proposed neighbor-discovery scheme
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