2,330 research outputs found

    511 keV galactic line from first-order phase transitions and primordial black holes

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    Hawking evaporation of primordial black hole (PBH), with mass 3×1017MPBH/M7×10173\times 10^{-17} \lesssim M_{\rm PBH}/M_\odot \lesssim 7\times 10^{-17} and fractional abundance 0.01fPBH0.50.01 \lesssim f_{\rm PBH} \lesssim 0.5, well reproduces 511 keV gamma-ray excess from galaxy center. In this work, we investigated the production mechanism of PBHs base on the first-order phase transition induced by quartic effective thermal potential of a scalar field in dark sector. We found the phase transition with vacuum energy, O(1)B1/4/MeVO(100)\mathcal{O}(1)\lesssim B^{1/4}/{\rm MeV} \lesssim \mathcal{O}(100), produces the desired PBH mass and abundance fraction. Correlated signatures of gravitational wave and extragalactic gamma-ray from phase transition and black hole evaporation, respectively, are within μ\muAres and AMEGO/e-ASTROGAM projected sensitivities

    Performance evaluation on the implementation of Pre-established Medical Processes for nurse practitioners in the hospitals

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    In 2015, Taiwan announced the establishment of “Pre-established Medical Processes” and related regulations to assist nurse practitioners in the clinical tasks, maintain medical quality and patient safety, and provide protection in clinical practice. However, the effectiveness of implementation still needs to be improved and strengthened. This study adopts the TAM and the TTF as the research framework, and a cross-sectional design. The questionnaires are administered to the professional nurse practitioners in the hospitals of central Taiwan. A total of 300 questionnaires were distributed, and Smart PLS 3.0 and SPSS 24.0 were both applied to verify interpretability. The questionnaire recovery rate was 88.3%, and the overall predictive power was 65.2%. Technological characteristics and TTF had a significant impact on perceived usefulness

    AMP-Activated Protein Kinase Activation during Cardioplegia-Induced Hypoxia/Reoxygenation Injury Attenuates Cardiomyocytic Apoptosis via Reduction of Endoplasmic Reticulum Stress

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    Cardioplegic-induced H/R injury results in cardiomyocytic apoptosis. AMPK has been shown to reduce ER stress and the unfolded protein response (UPR). Whether AMPK activation can attenuate cardiomyocytic apoptosis after cardioplegia-induced H/R injury is unknown. Cardiomyocytes were exposed to simulated ischemia by incubation in a hypoxic chamber with intermittent cold cardioplegia solution infusion at 20-minute intervals and subsequently reoxygenated in a normoxic environment. Various doses of AMPK activators (AICAR or metformin) were given 2 days before H/R injury. The cardiomyocytes were harvested after reoxygenation for subsequent examination. With both AMPK activators, the antiapoptotic genes of ER stress and UPR, the subsequent production of proapoptotic proteins was attenuated, and the antiapoptotic proteins were elevated. The activity of the apoptotic effectors of ER stress was also reduced with AMPK activation. Moreover, TUNEL staining showed that AMPK activation significantly reduced the percentage of apoptotic cardiomyocytes after cardioplegia-induced H/R injury. Our results revealed that AMPK activation during cardioplegia-induced H/R injury attenuates cardiomyocytic apoptosis, via enhancement of antiapoptotic and reduction of proapoptotic responses, resulting from lessening ER stress and the UPR. AMPK activation may serve as a future pharmacological target to reduce H/R injury in the clinical setting

    Measuring cash flow and overdraft for fuzzy project networks with overlapping activities

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    Overlapping activities with imprecise durations to accelerate schedules has an impact on scheduling a con­struction project. The project may need to be rescheduled to suit the available overdraft limitation rather than to adopt the least total cost schedule. However, past research has seldom conducted a risk analysis on the project cash flow and overdraft requirements for projects with overlapping activities in a fuzzy environment. This research uses fuzzy DSM-based scheduling and proposes an algorithm to calculate the cash flow and overdraft at different risk levels. A numerical example is illustrated to demonstrate the algorithm’s effectiveness

    The impact of luxury housing on neighborhood housing prices: an application of the spatial difference-in-differences method

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    This study investigated the spatial spillover effects of luxury housing during and after construction, in regards to increases in housing prices in neighboring areas as well as the spatial dependence of neighboring housing. This study focused on already completed luxury housing in Taipei, Taiwan. First, the nearest-neighbor matching approach of propensity score matching was used to overcome the problem of data heterogeneity. The difference-in-differences (DD) method and spatial econometrics were used for analysis. The empirical results indicated that the spatial error model had the best goodness of fit. This indicated that housing prices increased by 13.0% during construction of luxury housing nearby. This indicated that housing prices increased by 5.8% after the construction of luxury housing nearby. The empirical results showed that the ongoing and completed construction of luxury housing had spillover effects on housing prices. The effect of ongoing construction of luxury housing was particularly large in scope, indicating its role as a predictor of psychological reaction in the market

    Necrotizing fasciitis in liver cirrhosis

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    SummaryBackgroundNecrotizing fasciitis (NF) is associated with a high mortality rate. Hepatitis is endemic in Taiwan, and liver cirrhosis is associated with the development of NF. The characteristics of these patients, however, have not been well documented or the predictors of mortality clearly identified. The purpose of this study is to identify predictors of mortality in patients with liver cirrhosis and necrotizing fasciitis.MethodsThis study was conducted at the Chi-Mei Medical Center in southern Taiwan. Demographic data, clinical characteristics, and the microorganisms responsible for NF in patients with liver cirrhosis were recorded. To identify independent predictors associated with mortality, univariate analysis followed by multivariate logistic regression modeling was performed.ResultsDuring the period 2003–2011, a total of 55 patients with liver cirrhosis and NF were treated at the Chi-Mei Medical Center. Most patients had infections by monomicrobial Gram-negative bacilli. Univariate analysis revealed that severity of liver cirrhosis, shock, band polymorphonuclear neutrophil (>10%), international normalized ratio (>1.5), serum creatinine (>2.0 mg/dL), serum albumin (<2.5 g/dL), and activated partial thromboplastin time (>60 seconds) were significantly associated with mortality. However, multivariate logistic regression analysis revealed that serum albumin of <2.5 g/dL was the only independent predictor of mortality in patients with liver cirrhosis and NF.ConclusionNF in the vast majority of cirrhotic patients was caused by Gram-negative bacilli. Hypoalbuminemia (serum albumin <2.5 g/dL) was associated with mortality in patients with liver cirrhosis and NF. Further studies are needed to assess whether resuscitation with albumin-containing solutions lowers the mortality rate in such patients

    An earthquake slip zone is a magnetic recorder

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    International audienceDuring an earthquake, the physical and the chemical transformations along a slip zone lead to an intense deformation within the gouge layer of a mature fault zone. Because the gouge contains ferromagnetic minerals, it has the capacity to behave as a magnetic recorder during an earthquake. This constitutes a conceivable way to identify earthquakes slip zones. In this paper, we investigate the magnetic record of the Chelungpu fault gouge that hosts the principal slip zone of the Chi-Chi earthquake (Mw 7.6, 1999, Taiwan) using Taiwan Chelungpu-fault Drilling Project core samples. Rock magnetic investigation pinpoints the location of the Chi-Chi mm-thick principal slip zone within the 16-cm thick gouge at ~1 km depth. A modern magnetic dipole of Earth magnetic field is recovered throughout this gouge but not in the wall rocks nor in the two other adjacent fault zones. This magnetic record resides essentially in two magnetic minerals; magnetite in the principal slip zone, and neoformed goethite elsewhere in the gouge. We propose a model where magnetic record: 1) is preserved during inter-seismic time, 2) is erased during co-seismic time and 3) is imprinted during post-seismic time when fluids cooled down. We suggest that the identification of a stable magnetic record carried by neoformed goethite may be a signature of friction-heating process in seismic slip zone
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