A simulation study of the e+/e－ sensitivity of a low resistive phosphate glasselectrode in a RPC using GEANT MC

The resistivity of conventional glass is quite high and is unacceptable in a high rate environment. Low resistive glass-electrodes could be a solution for this problem. The present study reports the e^＋/e^- simulation results of an RPC detector made from low resistive phosphate glass electrodes. The detailed geometrical configuration of the content materials which are the essential components of the glass of the RPC detector have been created with the GEANT4 simulation code. Two different types of particle sources, i.e. for e^＋/e^- , have been located on the detectors surface to evaluate the performance of the phosphate glass RPC. Both of the particles have been simulated as a function of their respective energies in the range of 0.1 MeV 1.0 GeV. The present simulation work has shown that the resistive electrode plays an important role for the particle production in the RPC configuration.     

Measurement of a Nearly Friction-Free Stress–Strain Curve of Silicone Rubber up to a Large Strain in Compression Testing

Nominal stress–strain curves of a silicone rubber specimen with a range of length-to-diameter (L/D) ratios have been measured via compression testing. The curves are highly dependent on the L/D ratio. The contact area has been measured using stamp ink applied to the sidewall of the specimen to determine the optimal L/D ratio which yields the stress–strain curve closest to the curve of the friction-free specimen. Traces of ink appear on the platen after the compression test, indicating that the phenomenon of rollover takes place. When the L/D ratio is less than 1.0, the contact area is less than that of the friction-free specimen although the phenomenon of rollover supplements the contact area. When the L/D ratio increases up to 1.0, the contact area increases toward that of the ideal specimen that deforms uniformly under the friction-free condition; the stress–strain curve of the specimen with the L/D ratio of 1.0 can be regarded as the nearly friction-free property of silicone rubber.     

A comparative simulation study on three lattice systems for the phase separation of polymer-dispersed liquid crystals

This article reports a comparative study of the phase separation process in a polymer-dispersed liquid crystal, based on a Metropolis Monte Carlo simulation study of three lattice systems. We propose a model for the different processes occurring in the formation of polymer-dispersed liquid crystals (PDLCs). The mechanism of PDLC is studied as a function of quench temperature, concentration and degree of polymerization of liquid crystals and polymers. The obtained resultant phase diagrams of the three systems are approximated and compared with the Flory-Huggins theory, and show a good agreement. It has been observed in the simulation results that among all the three systems, the 40 × 40 × 40 lattice showed the most accurate, reliable and stable results.      

Mitochondrial pyruvate dehydrogenase phosphatase 1 regulates the early differentiation of cardiomyocytes from mouse embryonic stem cells

Mitochondria are crucial for maintaining the properties of embryonic stem cells (ESCs) and for regulating their subsequent differentiation into diverse cell lineages, including cardiomyocytes. However, mitochondrial regulators that manage the rate of differentiation or cell fate have been rarely identified. This study aimed to determine the potential mitochondrial factor that controls the differentiation of ESCs into cardiac myocytes. We induced cardiomyocyte differentiation from mouse ESCs (mESCs) and performed microarray assays to assess messenger RNA (mRNA) expression changes at differentiation day 8 (D8) compared with undifferentiated mESCs (D0). Among the differentially expressed genes, Pdp1 expression was significantly decreased (27-fold) on D8 compared to D0, which was accompanied by suppressed mitochondrial indices, including ATP levels, membrane potential, ROS and mitochondrial Ca²⁺. Notably, Pdp1 overexpression significantly enhanced the mitochondrial indices and pyruvate dehydrogenase activity and reduced the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate compared to a mock control. In confirmation of this, a knockdown of the Pdp1 gene promoted the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate. In conclusion, our results suggest that mitochondrial PDP1 is a potential regulator that controls cardiac differentiation at an early differentiation stage in ESCs.     

Magnesium ion conducting solid polymer blend electrolyte based on biodegradable polymers and application in solid-state batteries

Ionics - Magnesium ion conducting solid polymer blend electrolyte based on biodegradable polymers polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) mixed with different molecular weight...     

A rapid,simple and reliable HPLC‐triple quadrupole tandem mass spectrometer method for a simultaneous quantification of irinotecan and its active metabolite 7‐ethyl‐10‐hydroxycamptothecin (SN38) in mouse plasma

A simple, fast and reliable high‐performance liquid chromatography–triple quadrupole mass spectrometry method (HPLC‐MS/MS method) was developed, validated and used for the simultaneous quantification of irinotecan and 7‐ethyl‐10‐hydroxycamptothecin (SN38) in heparinized mouse plasma. Camptothecin was used as the internal standard. A single‐step protein precipitation without evaporation and reconstitution steps was adopted as sample processing method. Our bioanalytical method was validated in compliance with the guidelines from the European Medicines Agency. The lower limit of quantification for both irinotecan and SN38 was 5 ng/mL. The calibration curves for both analytes fitted to a 1/x² weighted linear regression model and ranged from 5 to 1000 ng/mL. The intra‐run and inter‐run precisions were within 8.6%, and the intra‐run and inter‐run accuracies were within 96.4?103.9%. Our validated bioanalytical method was successfully applied to the pharmacokinetic study in mice, in which 4 mg/kg irinotecan was intraperitoneally injected. Copyright © 2014 John Wiley & Sons, Ltd.     

Characteristics of charged and metastable species in micro-discharges of AC- plasma display panel

The temporal effects of charged and metastable particles in the micro-discharges of an AC plasma display panel (AC-PDP) were investigated under actual driving conditions. The discharge gas used in the 4-in PDP was Neon + 4% Xenon. The discharge characteristics in terms of the time scale related to the space-charge decay, wall charge decay, metastable decay, and charge accumulation were investigated using a pulse technique. For Neon + 4% Xenon gas-mixture discharges of 500 torr, 4 /spl mu/s was related to the time scale of the space-charge decay and wall-charge accumulation time. The minimum sustain voltage started to dramatically increase at 20 /spl mu/s, which was related to the time scale of the metastable particles. Whereas, after 40 /spl mu/s, the minimum sustain voltage slowly increased with a slope of 0.01581, which was related to the inverse of the time scale of the wall charge decay.     

Effect of surface oxyfluorination on the dyeability of polyethylene film

The effect of surface oxyfluorination on low-density polyethylene (LDPE) film was studied in terms of surface functionality and surface energetics of the film surfaces, which can be attributed to improvement of the dyeability. The growth of functional groups and surface free energy was confirmed by FTIR-ATR, XPS, and contact angle methods. As a result, the total surface free energy was increased with oxyfluorination time, as a progressive increase of the polar component together with a small decrease of the dispersive component of surface free energy. From the dyeability test using the Kubelka-Munk equation, it was found that the oxyfluorination treatment plays an important role in the growth of oxygen-containing functional groups of LDPE film, resulting in improving the dyeability with a basic dyeing agent. A direct linear relationship is shown between the specific component of surface free energy and the K/S value for this work.