Preparation of uniform titania nanocoating on ZnS-based phosphors by a sol–gel process

A sol–gel process has been developed to coat micron-sized ZnS:Cu,Au,Al phosphors with a smooth and uniform layer of amorphous titania having nanosize thickness. The titania nanocoating is based on the hydrolysis and condensation of titanium tetrabutoxide Ti(OBu)₄. Acetylacetone was used to decrease the reactivity of Ti(OBu)₄. The experimental variables such as water concentration, the amount of ZnS particles, and reaction time were investigated. The thickness of the titania nanocoating was homogeneous and can easily be controlled from 20 to 54 nm by adjusting the experimental variables. The as-prepared titania nanocoating was amorphous phase and could be crystallized to anatase phase upon heating at 500 °C in Ar atmosphere.     

Optimization for removal of ruthenium from nitric acid solution by volatilizing with electrochemical oxidation

Ruthenium is a major fission product element among the platinum group elements (PGEs) in high-level liquid waste (HLLW). Ru tetra-oxide, RuO₄, has high vapor pressure, which is high enough to be run off from its solution even at room temperature. Electrochemical oxidation method, to oxidize nitrosyl ruthenium to the tetra-oxide and then to remove ruthenium from liquid phase to gas phase, was studied to separate Ru from the HLLW. The advantage of this method requires neither additional reagents nor adjustment its valency before the oxidation and disadvantage is necessity of long time for oxidation. In order to improve oxidation rate, we carried out the experiments to clarify the effects following fundamental conditions to the electrochemical oxidation, which are (a) electrolyte temperature, (b) presence of promoter elements, (c) evaporation or reflux of condensed phase, and (d) using or not using of diaphragm at counter electrode. We found the fast oxidation conditions as follows: (1) higher temperature; 95°C, (2) Ce coexistence; 3000 ppm; and (3) usage of a diaphragm for counter electrode. However, evaporation or reflux conditions did not directly affect the electrochemical oxidation efficiency.     

Solution-processed organic crystals for field-effect transistor arrays with smooth semiconductor/dielectric interface on paper substrates

Large surface roughness is a major obstacle for electronic systems fabricated on paper substrates. Here, a mixture solution of organic semiconductor and polymer dielectric was spin-coated on paper substrate with a patterned wettability. This spin-coating process produced organic crystals and a very smooth semiconductor/dielectric interface with a low trap density in well-confined patterns. Despite the large roughness of the paper substrate, the fabricated transistor arrays exhibited high performance with a field-effect mobility reaching 1.3 cm²/V s and an on/off ratio of 10⁸. The presented results offer a simple fabrication method for the current rapidly developing technology of paper electronics.     

Arabidopsis β1,2-xylosyltransferase: substrate specificity and participation in the plant-specific N-glycosylation pathway

β1,2-Xylosyltransferase (XYLT) is a plant-specific glycosyltransferase that contributes to the biosynthesis of N-glycoproteins in plants. However, the specificity of XYLT for N-glycans has not yet been completely clarified. To gain insights into the function of XYLT in the plant N-glycosylation pathway, we examined the acceptor substrate specificity of recombinant Arabidopsis XYLT (AtXYLT) using 2-aminopyridine-labeled N-glycans as the substrates and confirmed the N-glycans of Arabidopsis xylt mutant. Recombinant AtXYLT expressed in insect cells required the β1,2-linked N-acetylglucosamine (GlcNAc) residue at the nonreducing terminus of the α1,3-branched mannose (Man) residue (GlcNAcβ1,2-Manα1,3-Man; GNM3B) for activity. However, AtXYLT showed decreased activity with substrates that contained α1,3-fucose at the chitobiose core-GlcNAc or a terminal GlcNAc at the α1,6-branched Man residue of GlcNAcβ1,2-Man (GlcNAcβ1,2-Manα1,6-Man; GNM3A), whose ratios were 10% and 50% of the optimal substrate, GNM3B, respectively. Moreover, AtXYLT did not show any activity in the transfer of the Xyl residue to N-glycans that contained a mammalian-type β1,4-linked galactose (Gal) residue at the nonreducing terminus of GlcNAcβ1,2-Man. These results indicate that a β1,2-linked GlcNAc residue at the nonreducing terminus of an α1,3-branched Man residue is necessary for AtXYLT activity and that mammalian-type β1,4-linked Gal residue(s) on the same branch completely inhibit(s) the activity. Furthermore, N-glycan analysis showed that approximately 30% of the N-glycans carry the Xyl residue in the wild type. These findings suggest that AtXYLT acts on protein-bound N-glycans prior to α1,3-fucosyltransferase and mannosidase II in planta.     

Instrument for Measuring the Body Mass of Astronauts Under Microgravity Conditions

An improved prototype of the space scale, which has been proposed as a practical and lightweight instrument for measuring the body mass of astronauts under microgravity conditions in the International Space Station (ISS), has been developed. A prominent feature of the proposed instrument is the use of a bungee cord as the source of force. This results in a simple, lightweight, and compact structure of the instrument. It also results in a large displacement during the measurement and then the reduction of the effect of change in subject posture. The feasibility of the prototype design has been evaluated by quantifying the body mass of a human subject in a parabolic flight test. The present and future statuses of the space scale are discussed.     

A novel flavin adenine dinucleotide (FAD) containing d-lactate dehydrogenase from the thermoacidophilic crenarchaeota Sulfolobus tokodaii strain 7: purification, characterization and expression in Escherichia coli

Dye-linked D-lactate dehydrogenase activity was found in the crude extract of a continental thermoacidophilic crenarchaeota, Sulfolobus tokodaii strain 7, and was purified 375-fold through four sequential chromatography steps. With a molecular mass of about 93 kDa, this enzyme was a homodimer comprised of identical subunits with molecular masses of about 48 kDa. The enzyme retained its full activity after incubation at 80 degrees C for 10 min and after incubation at pHs ranging from 6.5 to 10.0 for 30 min at 50 degrees C. The preferred substrate for this enzyme was D-lactate, with 2,6-dichloroindophenol serving as the electron acceptor. Using high-performance liquid chromatography (HPLC), the enzyme's prosthetic group was determined to be flavin adenine dinucleotide (FAD). Its N-terminal amino acid sequence was MLEGIEYSQGEEREDFVGFKIKPKI. Using that sequence and previously reported genome information, the gene encoding the enzyme (ST0649) was identified. It was subsequently cloned and expressed in Escherichia coli and found to encode a polypeptide of 440 amino acids with a calculated molecular weight of 49,715. The amino acid sequence of this dye-linked D-lactate dehydrogenase showed higher homology (39% identity) with that of a glycolate oxidase subunit homologue from Archaeoglobus fulgidus, but less similarity (32% identity) to D-lactate dehydrogenase from A. fulgidus. Taken together, our findings indicate that the dye-linked D-lactate dehydrogenase from S. tokodaii is a novel type of FAD containing D-lactate dehydrogenase.     

Monitoring of lectin-reactive alpha-fetoproteins in patients with hepatocellular carcinoma treated using transcatheter arterial embolization

We investigated hemostatic abnormalities in 37 patients with deep vein thrombosis (DVT) and pulmonary embolism (PE) (PE patients) and in 40 patients with DVT without PE (DVT patients). Plasma fibrinogen, thrombin-antithrombin complex (TAT), plasmin-plasmin inhibitor complex, fibrin-D-dimer, activated protein C (APC)-protein C inhibitor (PCI) complex, von Willebrand factor (vWf), tissue plasminogen activator (t-PA), PA inhibitor-I (PAI-1), and thrombomodulin levels in both PE and DVT patients were significantly increased compared with normal volunteers. Plasma APC-PCI complex, PAI-1, and vWf levels in PE patients were significantly higher than those in DVT patients without PE. These findings indicate that PE patients are more hypercoagulable and hypofibrinolytic than DVT patients. Plasma TAT, APC-PCI complex, PAI-1, and vWf levels were the most sensitive indicators for PE. In these patients, increases in TAT and APC-PCI complex suggest DVT and increased PAI-1 and vWf suggest the risk of onset of PE.     

Magnetic ordering in superconducting YBa2(Cu1−xFex)3Oy oxide

Magnetic susceptibility measurement and the zero-field muon-spin-relaxation experiment have been made for the YBa₂(Cu_1−xFe_x)₃O_y system. The susceptibility has been measured in the field strong enough for the magnetic flux to penetrate the superconductor and the resultant temperature dependence has demonstrated the field cooled effect and a cusp at low temperatures below T_c. The cusp has been observed when the high field has been applied. The dynamical depolarization rate of the muon obtained by the muon-spin-relaxation experiment has shown the maximum at the same temperature as the cusp. The results suggest that the spin glass freezing of localized magnetic moment takes place at the temperature of the cusp, which is consistent with the previous Mössbauer effect experiments. The magnetic phase diagram for the system has been obtained.