Quantification of seven arsenic compounds in seafood products by liquid chromatography/electrospray ionization-single quadrupole mass spectrometry (LC/ESI-MS)

A liquid chromatography/electrospray ionization-single quadrupole mass spectrometry (LC/ESI-MS) method was developed to quantify seven arsenic compounds: arsenate (As(V)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AB), trimethylarsine oxide (TMAO), arsenocholine (AC) and tetramethylarsonium ion (TEMA), widely found in seafood. The arsenicals separated by anion- or cation-exchange LC were all readily identified under the optimized ESI-MS conditions. Linear calibration curves constructed by plotting the peak area counts of molecular ions against the arsenic concentrations were obtained for all seven arsenic compounds. The limits of quantification (S/N = 10) were 800, 600, 50, 10, 5, 5 and 5 ng ml^-1 for As(V), MMA, DMA, AB, TMAO, AC and TEMA, respectively. The LC/ESI-MS method was found to be useful to quantify arsenic compounds in seafood by model experiments using the mid-gut gland and muscle of a shellfish (Buccinid whelks). Spiking experiments verified the accuracy of the method.     

Relationship between cellulase treatment and the dyeability with a direct dye for various kinds of cellulosic fibers

The cellulosic fibers were dyed to equilibrium with Congo Red before and after cellulase treatment. The fibers examined were rayon, polynozic, cupra, flax, and cotton. It was found that the volume term for dyeing (V) was associated with weight loss (WL) caused by the cellulase treatment, for the original fibers. Apparent affinity for dyeing (AF) for the cellulase-treated fibers was calculated using a constant value of V obtained for each kind of the original fibers. The results led to the assumption that there would be two kinds of the regions that could be accessible to dye. One would be the region that was readily digested by the enzymatic hydrolysis. The other would be the region that was additionally developed by the attack of cellulase. The previously dyed fibers were hydrolyzed by cellulase. It was found that the physical bondings that formed between cellulose and Congo Red molecules would block the hydrolysis by cellulase for all the fibers examined. It was also assumed that there would be a region that could be accessible to cellulase but not entirely to Congo Red. © 1993 John Wiley & Sons, Inc.     

A Protease Inhibitor with Induction Therapy with Natural Interferon-β in Patients with HCV Genotype 1b Infection

The restoration of innate immune responses has potential as a novel therapeutic strategy for chronic hepatitis C (CHC). We compared the efficacy and safety of induction therapy (IT) with natural interferon-β (n-IFN-β) followed by pegylated-IFN-α/ribavirin (PR) alone (group A, n = 30) and IT with a protease inhibitor (PI) (simeprevir or vaniprevir)/PR (group B, n = 13) in CHC patients with genotype 1b and high viral loads. During IT with nIFN-β, virologic response rates in group A and group B were 10% and 8% (p = 0.6792) at week 4, 30% and 16% (p = 0.6989) at week 12 and 47% and 20% (p = 0.0887) at week 24 respectively. During and after the treatment with PR alone or PI/PR, virologic response rates in groups A and B were 50% and 82% (p = 0.01535) at week 4, 53% and 91% (p = 0.006745) at week 8, 57% and 91% (p = 0.001126) at week 12, 57% and 100% (p < 0.001845) at the end of the treatment and 57% and 80% (p < 0.005166) after treatment cessation. IT with PI/PR linked to the restoration of innate immune response was tolerated well, overcame virological breakthrough, enhanced early virologic responses, and resulted in a sustained virologic response in difficult-to-treat CHC patients. IT with PI/PR is beneficial for treating difficult-to-treat CHC patients.     

Validation of decay heat calculation results of ORIGEN2.2 and CASMO5 for light water reactor fuel

Comparing with the fission product nuclide (FP) decay heat summation calculation result in MeV/sec/fission based on the JENDL FP decay and yield data files 2011 for the burst fission, FP decay heat calculated by ORIGEN2.2 coupled with JENDL-4.0 base library ORLIBJ40 was verified at the cooling time from 1 sec to 10⁸ sec for ²³⁵U (thermal), ²³⁸U (fast), ²³⁹Pu (thermal) and ²⁴¹Pu (thermal). For these fission nuclides, FP decay heat calculated by CASMO5 at the same cooling time after a short irradiation (10⁴ sec) was also compared with that of ORIGEN2.2. In the analysis of decay heat measurements at the cooling time from 2.3 years to 27 years consisting of four data sets on the fuel assemblies discharged from the US PWRs and BWRs, and the Swedish PWRs and BWRs, the average values of the ratios of the calculated to measured results (C/E's) were from 0.972 to 1.031 for ORIGEN2.2, and from 0.977 to 1.016 for CASMO5. The standard deviations of C/E's for the four data sets were from 0.02 to 0.03 for the both codes except for those of the US BWR fuel assemblies which were from 0.11 to 0.12. The obtained C/E's were similar to those in the precedent study.     

Temperature Dependence of Crystal Structure and THz Absorption Spectra of Organic Nonlinear Optical Stilbazolium Material for High-Output THz-Wave Generation

A stilbazolium material comprising 4-dimethylamino-N′-methyl-4′-stilbazolium tosylate (DAST), which has a large nonlinear optical susceptibility, was studied for application in terahertz (THz)-wave generation. The temperature-dependent structure of the DAST crystal was measured by using powder X-ray diffraction from ?100 to 200 °C, indicating a volume expansion of 4.6 %. The lattice constants show anisotropic thermal expansion. Also, the temperature dependence of THz absorption spectra was measured by terahertz time-domain spectroscopy (THz-TDS) in the temperature range varying from ?80 to 88.1 °C. A strong absorption peak was found at around 1 THz, shifting slightly toward a lower frequency with increasing temperature. The temperature dependence of the THz spectra was compared with that of X-ray diffraction. The shifting of THz-vibrational frequencies of the DAST crystal suggests that the change in its lattice structure is temperature dependent.     

Uranium separation from a simulant fuel debris solution using a benzimidazole-type anion exchange resin

Ion exchange is one of the most useful separation methods. Certain ion exchange resins have been developed for use in reprocessing technology. The purpose of this study is to evaluate the U selectivity of a benzimidazole-type anion exchange resin and its potential for the separation of U from a solution of simulant fuel debris in HCl. The selectivity of the benzimidazole-type anion exchange resin for adsorption of the major elements present in fuel debris in HCl solution (such as in debris from the Fukushima Daiichi nuclear power plant) was analyzed, and the tendencies were discussed from the viewpoint of complexation. Moreover, chromatographic separation of U from the other elements was evaluated using the resin. The results indicate that this type of resin has high U separation selectivity. Consequently, the authors developed a novel strategy involving the use of this resin for U separation in conjunction with chlorination of hardly soluble materials by using atmospheric-pressure nonthermal plasma. This strategy is also proposed to be applicable for stabilizing waste forms and for nuclear fuel material accounting, such as for debris from the Fukushima nuclear power plant and other complex hardly soluble nuclear materials.     

Task‐based FMM for heterogeneous architectures

High performance fast multipole method is crucial for the numerical simulation of many physical problems. In a previous study, we have shown that task‐based fast multipole method provides the flexibility required to process a wide spectrum of particle distributions efficiently on multicore architectures. In this paper, we now show how such an approach can be extended to fully exploit heterogeneous platforms. For that, we design highly tuned graphics processing unit (GPU) versions of the two dominant operators P2P and M2L) as well as a scheduling strategy that dynamically decides which proportion of subsequent tasks is processed on regular CPU cores and on GPU accelerators. We assess our method with the StarPU runtime system for executing the resulting task flow on an Intel X5650 Nehalem multicore processor possibly enhanced with one, two, or three Nvidia Fermi M2070 or M2090 GPUs (Santa Clara, CA, USA). A detailed experimental study on two 30 million particle distributions (a cube and an ellipsoid) shows that the resulting software consistently achieves high performance across architectures. Copyright © 2015 John Wiley & Sons, Ltd.     

Low‐Temperature Synthesis of Calcium Hexaboride Powder via Transient Boron Carbide Formation

Calcium hexaboride (CaB₆) powder was synthesized by carbothermal reduction using a low‐temperature synthesis method for boron carbide (B₄C) powder. A B₄C precursor consisting of boron oxide (B₂O₃) and carbon components was prepared from a condensed boric acid (H₃BO₃)‐poly(vinyl alcohol) (PVA) product by thermal decomposition in air, which was then mixed with calcium carbonate (CaCO₃) powder. CaB₆ was formed via the transient formation of calcium borate (Ca₃B₂O₆) and B₄C, which were in close contact owing to the finely dispersed B₂O₃/carbon structure of the B₄C precursor. CaB₆ powder with fine particles was synthesized by heat treatment at 1400°C for 10 h in an Ar flow.