Immobilization of alkaline phosphatase on magnetic particles by site-specific and covalent cross-linking catalyzed by microbial transglutaminase

Bacterial alkaline phosphatase (BAP) was site-specifically and covalently immobilized on magnetic particles (MPs) using the enzymatic reaction of microbial transglutaminase (MTG). Immobilization efficiency was affected by the chemical surface treatment of MPs and immobilized BAP exhibited more than 90% of the initial activity after 10 rounds of recycling.     

Five percent break BWR LOCA/ECC test at ROSA-III without HPCS actuation - two-dimensional core thermal-hydraulic phenomena

The ROSA (Rig of Safety Assessment)-III facility is a volumetrically scaled (1/424) simulated boiling water nuclear reactor (BWR) system with an electrically heated core designed for integral loss-of-coolant accident (LOCA) and emergency core cooling system (ECCS) tests. A recirculation pump suction line break test with a five percent break area was conducted with the assumption of high pressure core spray system (HPCS) failure. The simulated peripheral fuel rods facing the channel box wall had a tendency to be rewetted temporarily at the upper part of the core by falling water from the upper plenum before low pressure core spray system (LPCS) actuation, while the rods in the central region were not rewetted but quenched mainly from the bottom of the core after low pressure coolant injection system (LPCI) actuation. Therefore, the peak cladding temperatures of the simulated high power fuel rods were limited to lower values since they were located in the peripheral region and the temporary rewetting before LPCS actuation occurred mainly in the peripheral region. The ROSA-III five percent break test and a BWR counterpart were analyzed with the RELAP5/MOD1 (cycle 018) code. Similarity between the ROSA-III small break test and a BWR small break LOCA has been confirmed through comparison of the calculated results.     

Electrorheological response of swollen silicone gels containing barium titanate

We have investigated storage moduli of silicone gels containing barium titanate in the presence of dc electric fields. The gels containing barium titanate swollen by silicone oil showed a storage modulus reduction, i.e. negative electrorheological effect. Contrary, no negative electrorheological effect was observed in the unswollen gels and silicon gels without barium titanate. Swollen silicone gels and most of silicone/BaTiO₃ gels obeyed empirical quadratic dependence in electric field strength. Although an apparent phase separation was not observed in the swollen gel, microscopic phase separation may occur due to the difference in electric conductivity between particles (∼10⁻¹⁰ S/cm) and silicone oil (10⁻⁹ S/cm), as a result, the negative electrorheological effect appears. The effects of frequency, degree of swelling, and the field strength have been discussed.     

Scratch behavior of soft thermoplastic olefins: effects of ethylene content and testing rate

Soft thermoplastic olefins (TPOs) consisting of 70 wt.% ethylene–propylene rubber (EPR) and 30 wt.% polypropylene (PP) were subjected to a standardized scratch test (ASTM D7027-05) at three different testing speeds: 1, 10, and 100 mm/s. Two TPO systems were considered for the study: System A having 52 wt.% ethylene in the EPR and System B containing 67 wt.% ethylene. Raising the ethylene content in EPR not only increased the overall blend crystallinity, but also altered the internal morphology of the material. Scratch testing rate appears to impart a significant effect on the scratch behavior of the material. The scratch damage mechanisms and morphology in the above model systems are described and correlated with tensile behavior and mechanical properties to establish a structure–property relationship. Issues regarding scratch properties of the soft TPOs are discussed.     

Involvement of β-Alkylation Machinery and Two Sets of Ketosynthase-Chain-Length Factors in the Biosynthesis of Fogacin Polyketides in Actinoplanes missouriensis

Fogacin and two novel fogacin derivatives, fogacins B and C, were isolated from the rare actinomycete Actinoplanes missouriensis. Biosynthesis of fogacin C apparently requires β alkylation of a polyketide chain. The fogacin biosynthetic type II polyketide synthase (PKS) gene cluster contains a hydroxymethylglutaryl-coenzyme A synthase (HCS) cassette, which is usually responsible for β alkylation in the type I PKS system. Another characteristic of the fog cluster is that it encodes two sets of ketosynthase (KS) and chain-length factor (CLF). Inactivation of either of the two KS genes in A. missouriensis and heterologous expression of the HCS cassette with either of the two KS-CLF genes in Streptomyces albus indicated that each KS-CLF had a different starter substrate specificity: one preferred an unusual β-alkylated starter and the other preferred a normal acetyl starter. This study expands knowledge of HCS cassette-dependent β alkylation into the type II PKS system and provides a natural example of combinatorial biosynthesis for producing diverse polyketides from different starter substrates.     

Sub-100-nm ordered silicon hole arrays by metal-assisted chemical etching

Sub-100-nm silicon nanohole arrays were fabricated by a combination of the site-selective electroless deposition of noble metals through anodic porous alumina and the subsequent metal-assisted chemical etching. Under optimum conditions, the formation of deep straight holes with an ordered periodicity (e.g., 100 nm interval, 40 nm diameter, and high aspect ratio of 50) was successfully achieved. By using the present method, the fabrication of silicon nanohole arrays with 60-nm periodicity was also achieved.     

The COX-2 Selective Blocker Etodolac Inhibits TNFα-Induced Apoptosis in Isolated Rabbit Articular Chondrocytes

Chondrocyte apoptosis contributes to the disruption of cartilage integrity in osteoarthritis (OA). Recently, we reported that activation of volume-sensitive Cl⁻ current (I_Cl,vol) mediates cell shrinkage, triggering apoptosis in rabbit articular chondrocytes. A cyclooxygenase (COX) blocker is frequently used for the treatment of OA. In the present study, we examined in vitro effects of selective blockers of COX on the TNFα-induced activation of I_Cl,vol in rabbit chondrocytes using the patch-clamp technique. Exposure of isolated chondrocytes to TNFα resulted in an obvious increase in membrane Cl⁻ conductance. The TNFα-evoked Cl⁻ current exhibited electrophysiological and pharmacological properties similar to those of I_Cl,vol. Pretreatment of cells with selective COX-2 blocker etodolac markedly inhibited I_Cl,vol activation by TNFα as well as subsequent apoptotic events such as apoptotic cell volume decrease (AVD) and elevation of caspase-3/7 activity. In contrast, a COX-1 blocker had no effect on the decrease in cell volume or the increase in caspase-3/7 activity induced by TNFα. Thus, the COX-2-selective blocker had an inhibitory effect on TNFα-induced apoptotic events, which suggests that this drug would have efficacy for the treatment of OA.     

Charge transporting block copolymer for morphological control in light emitting device based on polymer blends

Bipolar charge transporting block copolymer composing of carbazole and oxadiazole monomers as hole and electron transporting units, respectively, was synthesized by nitroxide mediated radical polymerization. It is found that the current efficiency significantly increased with the addition of the block copolymer in the device based on polymer blend system. AFM measurement revealed that a phase-separated structure in the polymer blend layer changed to suitable morphology in the presence of block copolymer.     

A learning method for dynamic Bayesian network structures using a multi-objective particle swarm optimizer

In this article, we present a multi-objective discrete particle swarm optimizer (DPSO) for learning dynamic Bayesian network (DBN) structures. The proposed method introduces a hierarchical structure consisting of DPSOs and a multi-objective genetic algorithm (MOGA). Groups of DPSOs find effective DBN sub-network structures and a group of MOGAs find the whole of the DBN network structure. Through numerical simulations, the proposed method can find more effective DBN structures, and can obtain them faster than the conventional method.     

Microporous Glass-Ceramics in NASICON-Type Copper(II) Titanium Phosphate

A novel porous glass-ceramic with a skeleton of a NASICON-type copper(II) titanium phosphate was prepared via the controlled crystallization of a glass and the subsequent chemical leaching of the resulting dense glass-ceramic. A volume-crystallized dense glass-ceramic comprised of CuTi₂(PO₄)₃ and Cu₃(PO₄)₂, whose surface was covered by a thin layer of CuO, was prepared by reheating a glass with a nominal composition of 50CuO20TiO₂30P₂O₅ (in mol%) in air. When the resulting glass-ceramic was leached with dilute HCl, the Cu₃(PO₄)₂ and CuO phases were dissolved out selectively, and a cuprous NASICON crystal of CuTi₂(PO₄)₃ was converted to its cupric type, CuTi₄(PO₄)₆, which was left as a skeleton of the porous materials. The specific surface area and the average pore radius of the porous glass-ceramic obtained were ∼70 m²/g and ∼7 nm, respectively. The porous glass-ceramic showed high catalytic activities for the dehydration of 2-propanol.