258 research outputs found

    Dynamical Generation of the Baryon Asymmetry from a Scale Hierarchy

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    We propose a novel baryogenesis scenario where the baryon asymmetry originates directly from a hierarchy between two fundamental mass scales: the electroweak scale and the Planck scale. Our model is based on the neutrino-portal Affleck-Dine (AD) mechanism, which generates the asymmetry of the AD sector during the radiation-dominated era and subsequently transfers it to the baryon number before the electroweak phase transition. The observed baryon asymmetry is then a natural outcome of this scenario. The model is testable as it predicts the existence of a Majoron with a keV mass and an electroweak scale decay constant. The impact of the relic Majoron on ΔNeff\Delta N_{\rm eff} can be measured through near-future CMB observations.Comment: 5+5 pages, 2+1 figures. v2:references added, discussion extende

    Assessment of satellite rainfall nowcasting based on extrapolation technique

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    Póster presentado en: 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019

    THE EFFECT OF GAS TEMPERATURE AND VELOCITY ON COAL DRYING IN FLUIDIZED BED DRYER

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    The objective of this research work is to develop fluidized bed coal dryer to overcome the disadvantages of low rank coal with high moisture such as low calorific values, costly transportation, high emissions of pollutants, and operational problem. In this paper, laboratory scale bubbling fluidized bed was used to dry high moisture, low-rank Indonesian coal to produce low moisture, high-rank coal. The effects of temperature, gas velocity and bed height to diameter ratio (L/D) on drying rate were studied to obtain information relating to optimum operating conditions. Coal characterizations (proximate analysis, ultimate analysis, Thermogravimetric Analysis (TGA), BET, Higher Heating Value (HHV), Lower Heating Value (LHV)) were performed to identify the effect of the change of moisture content. This investigation aims to study the drying process under moderated heating conditions. As a result of the experiments the conclusion is that the thermal fluidized bed process can be successfully applied to reducing moisture in Indonesian coal. Results also indicate that about 80~90% of total moisture could be reduced, including some of the inherent moisture, yielding high heating value product. The drying rate of coal in a fluidized bed is increased by increasing the temperature and velocity of the drying gas. However gas temperature had limitations causing from the spontaneous combustion and gas velocity has to be decided considering energy efficiency

    Grape seed proanthocyanidin extract inhibits glutamate-induced cell death through inhibition of calcium signals and nitric oxide formation in cultured rat hippocampal neurons

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    <p>Abstract</p> <p>Background</p> <p>Proanthocyanidin is a polyphenolic bioflavonoid with known antioxidant activity. Some flavonoids have a modulatory effect on [Ca<sup>2+</sup>]<sub>i</sub>. Although proanthocyanidin extract from blueberries reportedly affects Ca<sup>2+ </sup>buffering capacity, there are no reports on the effects of proanthocyanidin on glutamate-induced [Ca<sup>2+</sup>]<sub>i </sub>or cell death. In the present study, the effects of grape seed proanthocyanidin extract (GSPE) on glutamate-induced excitotoxicity was investigated through calcium signals and nitric oxide (NO) in cultured rat hippocampal neurons.</p> <p>Results</p> <p>Pretreatment with GSPE (0.3-10 μg/ml) for 5 min inhibited the [Ca<sup>2+</sup>]<sub>i </sub>increase normally induced by treatment with glutamate (100 μM) for 1 min, in a concentration-dependent manner. Pretreatment with GSPE (6 μg/ml) for 5 min significantly decreased the [Ca<sup>2+</sup>]<sub>i </sub>increase normally induced by two ionotropic glutamate receptor agonists, N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). GSPE further decreased AMPA-induced response in the presence of 1 μM nimodipine. However, GSPE did not affect the 50 mM K<sup>+</sup>-induced increase in [Ca<sup>2+</sup>]<sub>i</sub>. GSPE significantly decreased the metabotropic glutamate receptor agonist (<it>RS</it>)-3,5-Dihydroxyphenylglycine-induced increase in [Ca<sup>2+</sup>]<sub>i</sub>, but it did not affect caffeine-induced response. GSPE (0.3-6 μg/ml) significantly inhibited synaptically induced [Ca<sup>2+</sup>]<sub>i </sub>spikes by 0.1 mM [Mg<sup>2+</sup>]<sub>o</sub>. In addition, pretreatment with GSPE (6 μg/ml) for 5 min inhibited 0.1 mM [Mg<sup>2+</sup>]<sub>o</sub>- and glutamate-induced formation of NO. Treatment with GSPE (6 μg/ml) significantly inhibited 0.1 mM [Mg<sup>2+</sup>]<sub>o</sub>- and oxygen glucose deprivation-induced neuronal cell death.</p> <p>Conclusions</p> <p>All these data suggest that GSPE inhibits 0.1 mM [Mg<sup>2+</sup>]<sub>o</sub>- and oxygen glucose deprivation-induced neurotoxicity through inhibition of calcium signals and NO formation in cultured rat hippocampal neurons.</p

    The Effectiveness of Budesonide Nasal Irrigation After Endoscopic Sinus Surgery in Chronic Rhinosinusitis With Asthma

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    Objectives Budesonide nasal irrigation was introduced recently for postoperative management of patients with chronic rhinosinusitis. The safety and therapeutic effectiveness of this procedure is becoming accepted by many physicians. The objective of this study was to evaluate the efficacy of postoperative steroid irrigation in patients with chronic rhinosinusitis and asthma. Methods This prospective study involved 12 chronic rhinosinusitis patients with nasal polyps and asthma who received oral steroid treatment for recurring or worsening disease. The 22-item Sinonasal Outcomes Test (SNOT-22) and Lund-Kennedy endoscopy scores were checked before nasal budesonide irrigation, and 1, 2, 4, and 6 months after irrigation. We also calculated the total amount of oral steroids and inhaled steroids in the 6 months before irrigation and the 6 months after it. Results The mean SNOT-22 score improved from 30.8±14.4 before irrigation to 14.2±8.7 after 6 months of irrigation (P=0.030). The endoscopy score also improved from 7.4±4.7 before irrigation to 2.2±2.7 after 6 months (P<0.001). The total amount of oral steroid was decreased from 397.8±97.6 mg over the 6 months before irrigation to 72.7±99.7 mg over the 6 months after irrigation (P<0.001). Conclusion Nasal irrigation with budesonide is an effective postoperative treatment for chronic rhinosinusitis with asthma, which recurs frequently, reducing the oral steroid intake

    Letter of Intent: Search for sub-millicharged particles at J-PARC

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    We propose a new experiment sensitive to the detection of millicharged particles produced at the 3030 GeV proton fixed-target collisions at J-PARC. The potential site for the experiment is B2 of the Neutrino Monitor building, 280280 m away from the target. With NPOT=1022\textrm{N}_\textrm{POT}=10^{22}, the experiment can provide sensitivity to particles with electric charge 3×104e3\times10^{-4}\,e for mass less than 0.20.2 GeV/c2\textrm{GeV}/\textrm{c}^2 and 1.5×103e1.5\times10^{-3}\,e for mass less than 1.61.6 GeV/c2\textrm{GeV}/\textrm{c}^2. This brings a substantial extension to the current constraints on the charge and the mass of such particles

    The refit model for end-stage liver disease-Na is not a better predictor of mortality than the refit model for end-stage liver disease in patients with cirrhosis and ascites

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    Background/AimsThe modification of the Model for End-Stage Liver Disease (MELD) scoring system (Refit MELD) and the modification of MELD-Na (Refit MELDNa), which optimized the MELD coefficients, were published in 2011. We aimed to validate the superiority of the Refit MELDNa over the Refit MELD for the prediction of 3-month mortality in Korean patients with cirrhosis and ascites.MethodsWe reviewed the medical records of patients admitted with hepatic cirrhosis and ascites to the Konkuk University Hospital between January 2006 and December 2011. The Refit MELD and Refit MELDNa were compared using the predictive value of the 3-month mortality, as assessed by the Child-Pugh score.ResultsIn total, 530 patients were enrolled, 87 of whom died within 3 months. Alcohol was the most common etiology of their cirrhosis (n=271, 51.1%), and the most common cause of death was variceal bleeding (n=20, 23%). The areas under the receiver operating curve (AUROCs) for the Child-Pugh, Refit MELD, and Refit MELDNa scores were 0.754, 0.791, and 0.764 respectively; the corresponding values when the analysis was performed only in patients with persistent ascites (n=115) were 0.725, 0.804, and 0.796, respectively. The significant difference found among the Child-Pugh, Refit MELD, and Refit MELDNa scores was between the Child-Pugh score and Refit MELD in patients with persistent ascites (P=0.039).ConclusionsRefit MELD and Refit MELDNa exhibited good predictability for 3-month mortality in patients with cirrhosis and ascites. However, Refit MELDNa was not found to be a better predictor than Refit MELD, despite the known relationship between hyponatremia and mortality in cirrhotic patients with ascites

    Enhancement of hole injection using ozone treated Ag nanodots dispersed on indium tin oxide anode for organic light emitting diodes

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    The authors report the enhancement of hole injection using an indium tin oxide (ITO) anode covered with ultraviolet (UV) ozone-treated Ag nanodots for fac tris (2-phenylpyridine) iridium Ir(ppy)3-doped phosphorescent organic light-emitting diodes (OLEDs). X-ray photoelectron spectroscopy and UV-visible spectrometer analysis exhibit that UV-ozone treatment of the Ag nanodots dispersed on the ITO anode leads to formation of Ag2O nanodots with high work function and high transparency. Phosphorescent OLEDs fabricated on the Ag2O nanodot-dispersed ITO anode showed a lower turn-on voltage and higher luminescence than those of OLEDs prepared with a commercial ITO anode. It was thought that, as Ag nanodots changed to Ag2O nanodots by UV-ozone treatment, the decrease of the energy barrier height led to the enhancement of hole injection in the phosphorescent OLEDs.This work was supported by Korea Research Foundation grant funded by Korean Government (MOEHRD: Basic Research Promotion Fund)(KRF-2006-003-D00243) and Ministry of Commerce, Industry, and Energy

    Transparent Conducting Indium Zinc Tin Oxide Anode for Highly Efficient Phosphorescent Organic Light Emitting Diodes

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    The preparation and characteristics of a transparent conducting indium zinc tin oxide (IZTO) anode for highly efficient phosphorescent organic light emitting diodes (OLEDs) is described. The resistivity and transmittance of the IZTO anode are comparable to reference In2O3 (ITO) anode films even though it was prepared at room temperature. In addition, the work function of the ozone-treated amorphous IZTO anode (5.12±0.02 eV) is much higher than that of ozone-treated reference ITO anodes (4.94±0.02 eV). The current-voltage-luminance characteristics and efficiencies of OLEDs prepared on the IZTO anode are critically dependent on the sheet resistance of the IZTO anode. Furthermore, both the quantum efficiency and power efficiency of the OLED fabricated on the amorphous IZTO anode are much higher than those of an OLED with the reference ITO anode due to the higher work function of the IZTO anode than those of conventional ITO anode. This indicates that IZTO is an alternative material for conventional ITO anodes used in OLEDs and flexible displays.This work was supported by a Korea Research Foundation Grant funded by the Korea Government MOEHRD: Basic Research Promotion Fund grant no. KRF-2006-331-D00243 and the Ministry of Commerce, Industry, and Energy

    Polyphenolic compounds, antioxidant and anti-inflammatory effects of <i>Abeliophyllum distichum</i> Nakai extract

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    The present study was conducted to evaluate the antioxidant and anti-inflammatory activities of crude methanolic extract of Abeliophyllum distichum Nakai, and those of its partitioned fractions, including hexane, ethyl acetate, n-butanol, and aqueous. The antioxidant activities were analyzed by DPPH free radical scavenging and oxygen radical antioxidant capacity assay. Results showed that the BuOH fraction possessed a strong antioxidant activity through a hydrogen atom transfer reaction-based mechanism and a single electron transfer reaction-based mechanism. In lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, the BuOH fraction of A. distichum methanol extract exhibited a strong inhibitory effect on the nitric oxide production and inhibited the expression of pro-inflammatory mediators, including COX-2, TNF-α, and IL-6, through the inhibition of the MEK/ERK signaling pathway. In addition, the BuOH fraction inhibited the LPS-induced ROS level through the NADPH oxidase-independent mechanism. Furthermore, HPLC analysis identified chlorogenic acid, caffeic acid, gentisic acid, rutin, ferulic acid, and quercetin, and suggested that the antioxidant and anti-inflammatory activities of the BuOH fraction should be mediated by the presence of higher amounts of caffeic acid, rutin, and ferulic acid than other fractions. Taken together, these results suggest that A. distichum extract is a source of antioxidant and anti-inflammatory compounds, and could be developed as a potential source for functional food and dietary health supplement
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