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.     

Driving voltage reduction in a two-phase CCD by suppression ofpotential pockets in inter-electrode gaps

This study reports an optimum design for a two-phase charge-coupled device (CCD) and limitations on its driving voltage reduction. The two-phase CCD to be used as a horizontal-CCD (H-CCD) in a CCD image sensor requires low-voltage and high-speed operation. Reducing the driving voltage, however, may induce potential pockets in the channel under the inter-electrode gaps which results in a fatal decrease in charge-transfer efficiency. In this case it is necessary to optimize the CCD design to be free of pocket generation. For this requirement, we conducted two-dimensional (2-D) device simulations for the two-phase CCD, whose potential barriers are formed by boron ion-implantation. Our simulations indicated that the edge position of the potential barrier region and the dose of boron-ion implantation would be important parameters for controlling the size of potential pockets. At an optimum edge position and a boron dose, the minimum driving voltage appears to be reducible to 1.1 V. Characteristics of potential pockets and methods of their suppression are also discussed     

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.     

New low-noise output amplifier for high-definition CCD image sensor

A new low-noise charge-coupled-device (CCD) output amplifier, the RJG detector, has been developed. The RJG detector incorporates a JFET which has an electrically floating ring-junction gate (RJG). The operating principle of the amplifier is that signal charges, transferred from the CCD into the RJG, directly modulate the drain current in the detection JFET. The performance of the detector was evaluated by operating test devices under a 37-MHz clock frequency, which is the same frequency as that for the horizontal CCD operation in the recently developed 2-million-pixel high-definition CCD image sensor. It was found that 1/f noise was reduced by introducing the JFET and that reset noise was completely eliminated by achieving complete charge transfer through the reset operation. As a result, input referred noise equivalent electrons within the 18.5-MHz baseband were reduced to 17 (electrons)     

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.     

Influence of ash composition on heavy metal emissions in ash melting process

Two kinds of fly ash, discharged in the combustion of either refused derived fuel (RDF) or car shredder dust (SD), were examined for the emission of heavy metals in melting process under oxidizing and reducing conditions. The residual fractions of heavy metal in slag were experimentally estimated. As a result, it was confirmed that several volatile heavy metals were readily emitted during melting process. The type of atmosphere provided for the melting process was found to affect the emission of some volatile metals in RDF ash, but not in SD ash. The emission of volatile heavy metals in RDF ash under oxidizing conditions was lower than under any other conditions in this study. The emission behavior of iron and heavy metals in RDF ash under reducing conditions was similar to that in SD ash. These facts indicated that phosphorous in RDF ash had the property of fixing the volatile metals in the slag only under oxidizing conditions. Then the mixture of SD ash with phosphorous oxide powder was also tested in a melting process, and the result was consistent with the above inference of the effect of phosphorous.     

The Failure of the Strong Pumping Lemma for Multiple Context-Free Languages

Seki et al. (Theor. Comput. Sci. 88(2):191–229, 1991) showed that every m-multiple context-free language L is weakly 2m-iterative in the sense that either L is finite or L contains a subset of the form \(\{ u_{0} w_{1}^{i} u_{1} \cdots w_{2m}^{i} u_{2m} \mid i \in \mathbb {N}\}\) , where w ₁?w _2n ≠ε. Whether every m-multiple context-free language L is 2m-iterative, that is to say, whether all but finitely many elements z of L can be written as z=u ₀ w ₁ u ₁?w _2m u _2m with w ₁?w _2m ≠ε and \(\{ u_{0} w_{1}^{i} u_{1} \cdots w_{2m}^{i} u_{2m} \mid i \in \mathbb {N}\} \subseteq L\) , has been open. We show that there is a 3-multiple context-free language that is not k-iterative for any k.     

Distribution of carbon black in SBR

The distribution of HAF carbon black in SBR was studied with the electron microscope and Fraunhofer diffraction. The interparticle distance between black aggregates is 8000 Å at 20 phr and 7000 Å at 40 phr, but above 60 phr it spreads broadly in the vicinity of 4000 Å. The size of black aggregates at 20 phr extends from 300 Å to 3000 Å, and the average diameter is 1200 Å. At 40 phr and 60 phr, black trends to aggregate more than at 20 phr and the average diameter is about 1500–1600 Å; the maximum diameter exceeds 5000 Å. In a black aggregate, there are about 40 spherical particles independently of filler concentration. From the relation between the size and interparticle distance, the connection of black aggregates initiates at 40 phr level and affects the physical properties of filled rubber.     

Reaction products of α-tocopherol with methyl linoleate-peroxyl radicals

α-Tocopherol was reacted with methyl linoleateperoxyl radicals at 37°C. The peroxyl radicals were generated by the reaction of methyl linoleate with a free radical initiator, 2,2′-azobis(2,4-dimethylvaleronitrile). The primary products of α-tocopherol with methyl linoleate-peroxyl radicals were isolated by reversephase and normal-phase high performance liquid chromatography (HPLC), and their structures were characterized by ultraviolet (UV), infrared (IR),¹H and¹³C nuclear magnetic resonance (NMR) and mass spectrometry (MS). There were four stereoisomers of methyl 13-(8a-peroxy-α-tocopherone)-9(Z),11(E)-octadecadienoate and four stereoisomers of methyl9-(8a-peroxy-α-tocopherone)-10(E),12(Z)-octadecadienoate.