Synthesis of chloromethylstyrene‐tetraethyleneglycol dimethacrylate copolymer beads having various phenolic derivatives immobilized via amide bond and their antioxidation activity

Resins having phenolic derivatives were prepared by treating a resin (RAS‐4G), having benzylamino groups, with benzoic acids containing phenolic hydroxyl groups. The RAS‐4G was prepared by treating macroreticular chloromethylstyrene‐tetraethyleneglycol dimethacrylate (4G) copolymer beads with potassium phthalimide in N,N‐dimethylformamide, followed by reflux in an ethanol/hydrazine monohydrate mixture. 4‐Hydroxy benzoic acid, (2,4‐, 3,4‐, and 3,5‐)dihydroxy benzoic acids, 3,4,5‐trihydroxy benzoic acid, etc., were used as benzoic acids with phenolic hydroxyl groups. The antioxidation ability of the resins having phenolic derivatives was investigated against the generation of 1,4‐dioxane hydroperoxide. The resins showed high inhibition ability against the generation of hydroperoxide. In particular, the resin (RAS‐4G‐3,4‐DHBA) having two phenolic hydroxyl groups had the highest inhibition ability. The resins were found to act as radical scavengers during the generation of 1,4‐dioxane hydroperoxide by UV irradiation in the presence of oxygen. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2097–2104, 2005     

Electrochemical window of molten LiCl-KCl-CaCl2 and the Ag/Ag reference electrode

The electrochemical window of an LiCl-KCl-CaCl₂ eutectic melt (52.3:11.6:36.1 mol%) was determined by cyclic voltammetry and open-circuit potentiometry at 723-873 K. The reaction at the anodic limit was confirmed to be Cl₂ gas evolution. The reaction at the cathodic limit was found to be a liquid Ca-Li alloy formation on the basis of ICP analysis of the deposits. An Ag⁺/Ag reference electrode separated with a Pyrex membrane showed good stability for more than 1 week. The standard electrode potential of Ag⁺/Ag was determined in the temperature range of 723-823 K by measuring the potential of a silver electrode in different concentrations of Ag⁺ ions.     

An Efficient Synthesis of Chiral Alcohols via Catalytic Hydrogenation of Esters

A ruthenium complex was found to catalyze the hydrogenation of chiral esters without the loss of their optical purities under mild and neutral conditions. This method can avoid a violent quench step and an extraction step which accompany conventional reduction using metal hydride reagents such as sodium borohydride and lithium aluminum hydride.     

The effect of polystyrene as a porogen on the fluoride ion adsorption of Zr(IV) surface-immobilized resin

A novel adsorbent, Zr(IV)-immobilized resin, was prepared by surface template polymerization. This adsorbent, prepared by adding polystyrene (PS) to resin, has a high adsorption capacity for the removal of fluoride ion from aqueous solutions. The adsorption capacity increased with rising PS concentration, since the specific surface area can be effectively increased by adding polystyrene as a porogen. The adsorption isotherm has been modeled by the Langmuir and Freundlich equations. The adsorption isotherms were well described by the Langmuir equation. The removal of fluoride was also carried out using a column method. The presence of PS in the resin exerted a remarkable influence on the uptake of fluoride ion. The fluoride adsorbed on the resin was quantitatively eluted with 0.1 M NaOH.     

Drying processes for preparation of titania aerogel using supercritical carbon dioxide

Supercritical carbon dioxide drying was performed for the preparation of titania aerogels from sol–gel routes. The conditions of supercritical carbon dioxide drying were 313–323 K and 7.8–15.5 MPa. The solvents in titania wet gels obtained from the sol–gel routes were replaced by acetone. The titania aerogels obtained from supercritical carbon dioxide drying form needle-like structures. In supercritical carbon dioxide drying, the extraction rates of acetone from the wet gels were measured by using an on-line Fourier transform infrared spectroscope. It was found that the titania aerogels with lower cohesion were induced from the formations of homogenous phase for carbon dioxide + acetone system and the lower extraction rates of acetone. Furthermore, titania films were prepared by the depositions of the titania aerogels on ITO-coated PET substrates. The needle-like aerogels with lower cohesion derive the titania film with high surface area.     

Entropic effect on creep in nanocrystalline metals

We report a significant entropic effect on creep of nanocrystalline metal using molecular dynamics. Our simulations reveal that the activation entropy may contribute a multiplicative factor of many orders of magnitude to the steady-state creep rate. The relationship between activation entropy and enthalpy obeys an empirical Meyer–Neldel compensation rule. The activation volume is found to decrease with increasing temperature for dislocation nucleation creep, which agrees well with experimental results. The study opens up an avenue for quantitatively discussing the entropic effects on various thermally activated deformations in nanocrystals.     

Synthesis of poly[2-(N,N-dimethyl)aminoethyl methacrylate-co-acrylonitrile]

Summary Radical copolymerization of 2-(N,N-dimethyl)aminoethyl methacrylate (1) and acrylonitrile (2) initiated by 2,2-azobis(2-methylpropionitrile) was carried out. The sequence distributions of the copolymers were investigated by ¹³C NMR spectroscopy. A terminal model was used to interpret the propagation process in the copolymerization. The monomer reactivity ratios in the bulk copolymerization at 45°C were evaluated as r₁=1.06 and r₂=0.07. Radical reactivity indices and frontier electron densities for 1 and 2 were calculated.     

Computer Supported Social Networking For Augmenting Cooperation

The exploration of social networks is essential for finding capable cooperators who can help problem-solving and for augmenting cooperation between workers in an organization. This paper describes PeCo-Mediator-II to seek capable cooperators through a chain of personal connections (PeCo) in a networked organization. Moreover, this system helps to gather, explore, and visualize social networks in an organization. The experimental results show that the system facilitates users' encounters with cooperators and develops new helpful connections with the cooperators.     

Large-scale atomistic modeling of nanoelectronic structures

Large-scale molecular-dynamics simulations are performed on parallel computers to study critical issues on ultrathin dielectric films and device reliability in next-decade semiconductor devices. New interatomic-potential models based on many-body, reactive, and quantum-mechanical schemes are used to study various atomic-scale effects: growth of oxide layers; dielectric properties of high-permittivity oxides; dislocation activities at semiconductor/dielectric interfaces; effects of amorphous layers and pixellation on atomic-level stresses in lattice-mismatched nanopixels; and nanoindentation testing of thin films. Enabling technologies for 10 to 100 million-atom simulations of nanoelectronic structures are discussed, which include multiresolution algorithms for molecular dynamics, load balancing, and data management. In ten years, this scalable software infrastructure will enable trillion-atom simulations of realistic device structures with sizes well beyond μm on petaflop computers     

Muc-1 core protein is expressed on multiple myeloma cells and is induced by dexamethasone

Monoclonal antibodies (MoAbs) that selectively identify Muc-1 core protein (MoAbs DF3-P, VU-4H5) determinants were used to identify the Muc-1 glycoform present on 7 multiple myeloma (MM) cell lines, 5 MM patient plasma cells, 12 MM patient B cells, as well as 32 non-MM cell lines and normal hematopoietic cells. Flow cytometry studies demonstrated that all MM cell lines, MM patient plasma cells, and MM patient B cells expressed Muc-1 core protein epitopes. Circulating B cells from 4 normal donors also expressed Muc-1 core protein. In contrast, Muc-1 core protein was absent on 28 of 32 non-MM neoplastic cell lines, 17 of which expressed Muc-1. Splenic and tonsillar B cells, CD34(+) stem cells, resting T cells, and bone marrow plasma cells obtained from normal donors both lacked Muc-1 glycoforms. We next studied the effects of estrogen, progesterone, and glucocorticoid receptor agonists and antagonists on Muc-1 expression, because consensus sequences for the response elements of these steroids are present on the Muc-1 gene promoter. These studies showed that dexamethasone (Dex) induced Muc-1 expression on MM cell lines, as determined by both flow cytometry and Western blot analyses. Dex also induced upregulation of Muc-1 on prostate and ovarian cancer cell lines. Time and dose-response studies demonstrated that Dex induced maximal cell surface Muc-1 expression by 24 hours at concentrations of 10(-8) mol/L. Dex induced Muc-1 upregulation could be blocked with a 10-fold excess of the glucocorticoid receptor antagonist RU486, confirming that Dex was acting via the glucocorticoid receptor. No changes in Muc-1 expression were observed on MM cells treated with estrogen and progesterone receptor agonists and antagonists or with RU486. These studies provide the framework for targeting Muc-1 core protein in vaccination and serotherapy trials in MM. In addition, the finding that Muc-1 expression on MM cells can be augmented by Dex at pharmacologically achievable levels suggests their potential utility in enhancing treatments targeting Muc-1 in MM.