Estimation of interaction between polyanions and bovine serum albumin by means of affinity chromatography

The ligand binding of some polyanions to bovine serum albumin immobilized on Sepharose 4B has been studied by column affinity chromatography. Frontal chromatography using a polyanion of low concentration on an affinity adsorbent gave the dissociation constant K_d of the polyanion-immobilized ligand complex. K_d values determined under various concentrations enabled us to discuss in detail the interactions of bovine serum albumin and polyanions.     

Polystyrene-supported aluminium silver chloride as selective ethylene adsorbent

Polystyrene-supported aluminium silver chloride was prepared as a solid and selective adsorbent for ethylene by refluxing silver chloride, aluminium chloride, and macroreticular-type polystyrene resin in carbon disulfide, followed by removal of the solvent in vacuo. The adsorbent rapidly adsorbed ethylene about equimolar to aluminium silver chloride under 1 atm at 20°C. Almost all the ethylene adsorbed was released by subjecting the adsorbent to a reduced pressure 8 mm Hg at 20°C for 10 min. The adsorbent, however, showed no adsorption of carbon monoxide under 1 atm at 20°C.     

Selective ethylene adsorbent composed of copper(I) chloride and polystyrene resin having tertiary amino groups

Selective adsorbent for ethylene is prepared from copper(I) chloride and a macroreticular type polystyrene resin having tertiary amino groups. The adsorbent rapidly adsorbs ethylene at 20°C under 1 atm. The adsorbed ethylene is readily desorbed by subjecting the adsorbent to a reduced pressure (3 mm Hg) at 20°C. The ethylene adsorbing capacity of the adsorbent is 5.5 times as large as the adsorbing capacity for ethane. The present adsorbent exhibits no measurable adsorptions of nitrogen and hydrogen at 20°C under 1 atm, and thus is applicable to selective separation of ethylene from mixtures containing these gases and ethane.     

Anisotropy in Superconductivity and Magnetism of PrFeAsO1−δ Single Crystal

The magnetic torque of a high-quality PrFeAsO_1?δ single crystal has been investigated at temperatures from 2 to 200 K in 1 and 5 T. The superconducting anisotropy in PrFeAsO_1?δ can well be approximated by the single-band Kogan torque theory. The superconducting anisotropy of PrFeAsO_1?δ determined by analyzing the torque curve is weakly dependent upon changing temperature. The magnetism contribution to the torque from magnetic Pr ions becomes appreciable compared to the superconducting component. We argue that the Pr ions in the superconducting PrFeAsO_1?δ single crystal show an antiferromagnetic spin ordering at 14 K. The spin structure thus reduced from the torque measurements is different from what neutron diffraction measurements predicted using polycrystalline specimen.     

Analysis of possible introduction of PV systems considering output power fluctuations and battery technology,employing an optimal power generation mix model

This paper presents an evaluation of the impact of extensive introduction of photovoltaic (PV) systems and stationary battery technology into the optimal power generation mix in the Kanto and Kinki regions. The introduction of solar PV systems is expected to be extensively deployed in the Japanese household sector and utility companies in order to address the concerns of energy security and climate change. Considering this expected large‐scale deployment of PV systems in electric power systems, it is necessary to investigate the optimal power generation mix which is technologically capable of controlling and accommodating the intermittent output‐power fluctuations inherent in PV systems. Against this background, we develop both a solar photovoltaic power generation model and an optimal power generation mix model, including stationary battery technology, which can be used to explicitly analyze the impact of PV output fluctuations at a detailed time interval resolution such as 10 minutes for 365 consecutive days. Simulation results reveal that PV introduction does not necessarily increase battery technology due to the cost competitiveness of thermal power plants in the load‐following requirement caused by PV systems. Additionally, on the basis of sensitivity analysis on PV system cost, dramatic cost reduction proves to be indispensable for PV to supply bulk electricity similarly to thermal and nuclear power plants. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(2): 9–19, 2013; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22329     

Site‐Specific Modification of the 6‐Amino Group of Adenosine in RNA by an Interstrand Functionality‐Transfer Reaction With an S‐Functionalized 4‐Thiothymidine

Non‐natural RNA modifications have been widely used to study the function and structure of RNA. Expanding the study of RNA further requires versatile and efficient tools for site‐specific RNA modification. We recently established a new strategy for the site‐specific modification of RNA based on a functionality‐transfer reaction between an oligodeoxynucleotide (ODN) probe and an RNA substrate. 2′‐Deoxy‐6‐thioguanosine was used to anchor the transfer group, and the 4‐amino group of cytosine or the 2‐amino group of guanine was specifically modified. In this study, 2′‐deoxy‐4‐thiothymidine was adopted as a new platform to target the 6‐amino group of adenosine. The (E)‐pyridinyl vinyl keto transfer group was attached to the 4‐thioT in the ODN probe, and it was efficiently and specifically transferred to the 6‐amino group of the opposing adenosine in RNA in the presence of CuCl₂. This method expands the available RNA target sites for specific modification.     

Effects of Helioxanthin Derivative-Treated Human Dental Pulp Stem Cells on Fracture Healing

Bone defects affect patients functionally and psychologically and can decrease quality of life. To resolve these problems, a simple and efficient method of bone regeneration is required. Human dental pulp stem cells (DPSCs) have high proliferative ability and multilineage differentiation potential. In our previous study, we reported a highly efficient method to induce osteogenic differentiation using DPSC sheets treated with a helioxanthin derivative (4-(4-methoxyphenyl)pyrido[40,30:4,5]thieno[2,3-b]pyridine-2-carboxamide (TH)) in a mouse calvarial defect model. However, the localization of the DPSCs after transplantation remains unknown. Therefore, in this study, we investigated the localization of transplanted DPSCs in a mouse fracture model. DPSCs were collected from six healthy patients aged 18–29 years, cultured in normal medium (NM), osteogenic medium (OM), or OM with TH, and fabricated them into cell sheets. To evaluate the efficacy of fracture healing using DPSCs treated with OM+TH, and to clarify the localization of the transplanted DPSC sheets in vivo, we transplanted OM+TH-treated DPSC sheets labeled with PKH26 into mouse tibiae fractures. We demonstrated that transplanted OM+TH-treated DPSCs sheets were localized to the fracture site and facilitated bone formation. These results indicated that transplanted OM+TH-treated DPSCs were localized at fracture sites and directly promoted fracture healing.     

Design and Preparation of Impregnated Catalysts

Solid catalysts in common use are typically in the form of small metal crystallites dispersed on the internal surface of the porous support. Advantages of these supported-metal catalysts lie in their high surface-to-volume ratio and the high thermal stability endowed by the dispersion. Such catalysts are commonly produced by liquid-phase impregnation in which a dry or wet pellet of the porous support is impregnated with a solution of a compound of the desired catalytic constituent. During impregnation and subsequent drying, small crystallites of the catalyst precursors are deposited on the internal surface of the support material. The impregnation and drying steps involve mass and /or heat transfer processes which often do not reach equilibrium, resulting in nonuniform concentration profiles of impregnant, or “impregnation profiles” along the radius of the support pellet.     

Simultaneous Removal of NOx and SOx from Flue Gas of a Glass Melting Furnace using a Combined Ozone Injection and Semi-dry Chemical Process

In this study, we propose a plasma-chemical hybrid NO_x removal process using nonthermal plasma for the treatment of flue gases emitted from glass melting furnaces; the process is demonstrated through a laboratory-scale model experiment conducted using a semi-dry desulfurization apparatus. The performance of the system for simultaneous removal of SO₂ and NO_x is investigated. As a result, NO is effectively oxidized to NO₂ by injecting ozone into the spray region and the removal efficiencies of 90% and 50% were obtained for NO and NO_x, respectively. In addition, the SO₂ removal efficiency of 84% was achieved.     

Evolution of the photoresponse time of the GaAs/AlGaAs cyclotron resonance quantum Hall effect detector

The photoresponse time of the cyclotron resonance detector to terahertz radiation under integer quantum Hall effect conditions in the GaAs/AlGaAs heterostructure is shown to have a deep minimum at the Hall plateau center and two sharp maxima at the plateau edges. The minimum at the plateau center is associated with the fundamental property of vanishing of the random impurity potential screening under quantum Hall effect conditions. The decrease in the response time outside the plateau is related to the equilibrium population of the Landau level above (under) the Fermi level by electrons (holes), respectively, which increases the probability of photoexcited carrier recombination. It is shown that, under conditions of background radiation (300 K), relaxation times decrease by two orders of magnitude while retaining the characteristic magnetic field dependence.