Radiophotoluminescence phenomenon in copper-doped aluminoborosilicate glass

Radiophotoluminescence phenomena have been widely investigated on various types of materials for dosimetry applications. We report that an aluminoborosilicate glass containing 0.005 mol% copper exhibits intense photoluminescence in the visible region induced by X-ray and γ-ray irradiation. The luminescence is assigned to the 3d⁹4s¹ → 3d¹⁰ transition of Cu⁺. The proportionality of the intensity of the induced photoluminescence to the irradiation dose was confirmed up to 0.5 kGy using ⁶⁰Co γ-ray irradiation. Based on the spectroscopic results, a potential mechanism was proposed for the enhancement of the photoluminescence. The exposure to the ionizing radiation generates electron-hole pairs in the glass, and the electrons are subsequently captured by the Cu²⁺ ions, which are converted to Cu⁺ and emit the luminescence. For the glass containing 0.01 mol% copper, the pronounced enhancement of the photoluminescence was not observed because the reverse reaction, ie, the capture of the holes by the Cu⁺ ions, becomes prominent. The photoluminescence induced by the irradiation was stably observed for the glasses kept at room temperature and even for the glasses heat-treated at 150°C. However, the induced photoluminescence could be eliminated by the heat treatment at a temperature at 500°C, and the glass returned to the initial pre-irradiation state. The Cu-doped aluminoborosilicate glass is a potential candidate for use in dosimetry applications.     

Real-Time Duplex Applications of Loop-Mediated AMPlification (LAMP) by Assimilating Probes

Isothermal nucleic-acid amplification methods such as Loop-Mediated isothermal AMPlification (LAMP) are increasingly appealing alternatives to PCR for use in portable diagnostic system due to the low cost, weight, and power requirements of the instrumentation. As such, interest in developing new probes and other functionality based on the LAMP reaction has been intense. Here, we report on the development of duplexed LAMP assays for pathogen detection using spectrally unique Assimilating Probes. As proof of principle, we used a reaction for Salmonella enterica as a model coupled with a reaction for λ-phage DNA as an internal control, as well as a duplexed assay to sub-type specific quarantine strains of the bacterial wilt pathogen Ralstonia solanacearum. Detection limits for bacterial DNA analyzed in individual reactions was less than 100 genomic equivalents in all cases, and increased by one to two orders of magnitude when reactions were coupled in duplexed formats. Even so, due to the more robust activity of newly available strand-displacing polymerases, the duplexed assays reported here were more powerful than analogous individual reactions reported only a few years ago, and represent a significant advance for incorporation of internal controls to validate assay results in the field.     

Mechanical properties of SiNxCx ceramic films prepared by plasma CVD

The mechanical properties of Si₃N₄-SiC, SiN_x and SiC_y films prepared at a low temperature of 400 °C by plasma chemical vapour deposition are reported. Microhardness, internal stress of the film and adhesive strength between the film and glass or stainless steel substrate were evaluated as principal mechanical properties. Microhardness was measured to be about 10 to 20 G Pa dependent on the film composition in each system. Internal stress of the films on borosilicate glass substrates extensively varied from tensile to compressive with the film composition change from Si₃N₄ to SiC. Adhesive strength, as ascertained by the scratch test, was about 580 to 800 MPa for crown glass substrates, and about 210 to 310 M Pa for 316 stainless steel substrates. It is pointed out that tensile stress in these films brought about more abrupt decreases of the adhesive strength than did compressive stress.     

[110]-surface strained-SOI CMOS devices

We have newly developed [110]-surface strained-silicon-on-insulator (SOI) n- and p-MOSFETs on [110]-surface relaxed-SiGe-on-insulator substrates with the Ge content of 25%, fabricated by applying the Ge condensation technique to SiGe layers grown on [110]-surface SOI wafers. We have demonstrated that the electron and the hole mobility enhancement of [110]-surface strained-SOI devices amounts to 23% and 50%, respectively, against the mobilities of [110]-surface unstrained MOSFETs. As a result, the electron and the hole mobility ratios of [110]-surface strained-SOI MOSFETs to the universal mobility of (100)-surface bulk-MOSFETs increase up to 81% and 203%, respectively. Therefore, the current drive imbalance between n- and p-MOS can be reduced. Moreover, both the electron and the hole mobilities of the [110]-surface strained-SOIs strongly depend on the drain current flow direction, which is qualitatively explained by the anisotropic effective mass characteristics of the carriers on a [110]-surface Si. As a result, the [110]-surface strained-SOI technology with optimization of the current flow directions of n- and p-MOS is promising for realizing higher speed scaled CMOS.     

Hepatitis GB virus C genome in the serum of aplastic anaemia patients receiving frequent blood transfusions

GB virus C (GBV-C) RNA was detected in five of 18 patients with aplastic anaemia who had received blood transfusions, whereas it was not detected in eight patients who had not received any transfusions. Antibody against hepatitis C virus (anti-HCV) was detected in nine patients in the transfusion group, compared with one of eight who had not received any transfusions. Therefore, the route of transmission of both GBV-C and HCV in these patients appeared to have been multiple blood transfusion. Since all of the GBV-C RNA-positive patients harboured anti-HCV, GBV-C seems to frequently superinfect with HCV. Neither GBV-C nor HCV is likely to have been a causative agent of the anaemia in the cases examined.     

Electron acceleration by single and double laser beams

The longitudinal electric field of single and double Gaussian laser beams are used to accelerate electrons. The longitudinal field of the single beam is concentrated on the axis and is favourable for acceleration. A set of two beams is considered. Beams run parallel, collinearly, overlap partially and have a phase difference iπ in between. As a result, the transverse components of fields cancel each other while the longitudinal components are double-fold. In both schemes, the electrons are accelerated in lengths of the Rayleigh range, which is common to the plasma-based accelerators.     

Comparative study on the assay for IgE antibodies specific for Chamaecyparis obtusa pollen between AlaSTAT and CAP-RAST

Titers of IgE antibody specific for the pollen of Chamaecyparis obtusa (C. obtusa) were determined by AlaSTAT and CAP-RAST in 221 patients with Japanese cedar pollinosis. IgE antibody to C. obtusa tested positive by CAP-RAST at a higher rate (80.5%) than by AlaSTAT (52.6%). The results obtained from the two assays were compared with those from intradermal skin test. CAP-RAST had a higher sensitivity than that of AlaSTAT. Because the two methods showed no differences in the determination of IgE antibody specific for Cryptomeria japonica, the above differences between AlaSTAT and CAP-RAST are surmised to be ascribable to the differences of C. obtusa antigen used in the both assays.     

Screening of Inhibitors Targeting Heat Shock Protein 47 Involved in the Development of Idiopathic Pulmonary Fibrosis

Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is causally related to fibrotic diseases, including idiopathic pulmonary fibrosis. The identification of Compounds that interfere with the HSP47-collagen interaction is essential for the development of relevant therapeutics. Herein, we prepared human HSP47 as a soluble fusion protein expressed in E. coli and established an assay system for HSP47 inhibitor screening. We screened a natural and synthetic Compound library established at Nagasaki University. Among 1023 Compounds, 13 exhibited inhibitory activity against human HSP47, of which three inhibited its function in a dose-dependent manner. Epigallocatechin-3-O-gallate, one of these three Compounds, is a typical polyphenol Compound derived from tea leaves. Structurally related Compounds were synthesized and examined for their activity, revealing a hydroxyl group at A-ring position 5 as important for its activity. The present findings provide valuable insight for the development of natural product-derived therapeutics for fibrotic diseases, including idiopathic pulmonary fibrosis.     

Chemical Modification of Phage-Displayed Helix-Loop-Helix Peptides to Construct Kinase-Focused Libraries

Conformationally constrained peptides hold promise as molecular tools in chemical biology and as a new modality in drug discovery. The construction and screening of a target-focused library could be a promising approach for the generation of de novo ligands or inhibitors against target proteins. Here, we have prepared a protein kinase-focused library by chemically modifying helix-loop-helix (HLH) peptides displayed on phage and subsequently tethered to adenosine. The library was screened against aurora kinase A (AurA). The selected HLH peptide Bip - 3 retained the α-helical structure and bound to AurA with a K_D value of 13.7 μM. Bip - 3 and the adenosine-tethered peptide Bip - 3 - Adc provided IC₅₀ values of 103 μM and 7.7 μM, respectively, suggesting that Bip - 3 - Adc bivalently inhibited AurA. In addition, the selectivity of Bip - 3 - Adc to several protein kinases was tested, and was highest against AurA. These results demonstrate that chemical modification can enable the construction of a kinase-focused library of phage-displayed HLH peptides.