Graft polymerization of vinyl monomers initiated by peroxycarbonate groups introduced onto silica surface by Michael addition

The introduction of peroxycarbonate groups onto a silica surface and the graft polymerization of vinyl monomers initiated by peroxycarbonate groups introduced onto a silica surface were investigated. The introduction of peroxycarbonate groups onto a silica surface was achieved by Michael addition of amino groups introduced onto the silica surface to t‐butylperoxy‐2‐methacryloyloxyethylcarbonate (HEPO). The amount of peroxycarbonate groups was determined to be 0.17 mmol/g. The graft polymerization of various vinyl monomers such as styrene (St), N‐vinyl‐2‐pyrrolidinone (NVPD), and 2‐hydroxyethyl methacrylate (HEMA) was initiated by peroxycarbonate groups introduced onto the silica surface to give the corresponding polymer‐grafted silicas. The percentage of poly(St)‐grafting reached about 120% after 5 h. This means that 1.20 g of poly(St) is grafted onto 1.0 g of silica. The surface of poly(St)‐grafted silica shows a hydrophobic nature, but the surfaces of poly(NVPD) and poly(HEMA)‐grafted silica show a hydrophilic nature. Furthermore, the poly(St)‐grafted silica was found to give a stable colloidal dispersion in a good solvent for the grafted polymer. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1491–1497, 1999     

Proteomic profiling of differential display analysis for human oral squamous cell carcinoma: 14-3-3 σ Protein is upregulated in human oral squamous cell carcinoma and dependent on the differentiation level

Oral squamous cell carcinoma (OSCC) has an absolute majority of all oral cancer. We used proteomic technology to analyze the protein expression profile in OSCC tissues and accompanying surrounding normal tissues in four oral locations (buccal mucosa, gingival mucosa, oral floor, and tongue). Ten protein spots were overexpressed more strongly in cancer tissues than normal ones, and were identified as proliferating cell nuclear antigen, 14-3-3 ε, 14-3-3 σ, proteasome subunit α type 5, translationally controlled tumor protein, eukaryotic translation initiation factor 3 subunit, macrophage capping protein, and mitochondrial isocitrate dehydrogenase subunit α. Macrophage capping protein and mitochondrial isocitrate dehydrogenase subunit α had two spots. Especially, we focused on 14-3-3 σ protein, one of the eight identified proteins, and assessed its expression level in four oral locations of OSCC by using differential display methods. The expression level of 14-3-3 σ protein was upregulated in four locations of oral cavity. Eight proteins which we identified in this study may play an important role in OSCC carcinogenesis and progression and could be used as diagnostic biomarkers of OSCC.     

Why Are “Others” So Polarized? Perceived Political Polarization and Media Use in 10 Countries

This study tests the associations between news media use and perceived political polarization, conceptualized as citizens' beliefs about partisan divides among major political parties. Relying on representative surveys in Canada, Colombia, Greece, India, Italy, Japan, South Korea, Norway, the United Kingdom, and the United States, we test whether perceived polarization is related to the use of television news, newspaper, radio news, and online news media. Data show that online news consumption is systematically and consistently related to perceived polarization, but not to attitude polarization, understood as individual attitude extremity. In contrast, the relationships between traditional media use and perceived and attitude polarization is mostly country dependent. An explanation of these findings based on exemplification is proposed and tested in an experimental design.     

Three-dimensional object recognition using laser range sensor

Image information provided by cameras is strongly affected by environmental influence of an object’s circumjacent and circumference. In order to reduce environmental influence, a system which was integrated distance information provided from a laser range sensor (LRS) and image information provided by a camera was developed, and consisted of an object extraction section and a recognition processing section. In this paper the effectiveness of the system was inspected by performing an object extraction experiment using the combined integrated distance information and image information. From these results, this system could remove a background and a floor surface by using the distance information, and simpler object extraction was enabled. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

A human-machine cooperative system for generating sign language animation using thermal image

We propose a new approach aimed at sign language animation by skin region detection on an infrared image. To generate several kinds of animations expressing personality and/or emotion appropriately, conventional systems require many manual operations. However, a promising way to realize a lower workload is to manually refine an animation made automatically with a dynamic image of real motion. In the proposed method, a 3D CG model corresponding to a characteristic posture in sign language is made automatically by pattern recognition on a thermal image, and then a person’s hand in the CG model is set. The hand part is made manually beforehand. If necessary, the model can be replaced manually by a more appropriate model corresponding to training key frames and/or the model can be refined manually. In our experiments, a person experienced in using sign language recognized the Japanese sign language of 71 words expressed as animation with 88.3% accuracy, and three persons experienced in using sign language also recognized the sign language animation representing three emotions (neutral, happy and angry) with 88.9% accuracy. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Temperature Dependence of Toluene Decomposition Behavior in the Discharge–Catalyst Hybrid Reactor

The temperature dependence of toluene decomposition behavior was investigated with a two-stage discharge and ozone-decomposition-catalyst hybrid reactor. Toluene conversion jumped by four times by adding catalyst to the discharge at ambient temperature. This synergistic effect diminished with an increase in temperature, and no synergy was observed at higher than 200degC. In the hybrid reactor, CO_x formation was promoted compared to discharge alone irrespective of temperature, and toluene was completely oxidized to CO_x at higher than 100degC. Ozone acts as the precursor of the key oxidants in the toluene decomposition.     

Effect of sequence distribution of poly(vinyl alcohol-vinyl acetate) on the coloring reaction with iodine

Red complex formation between poly(vinyl alcohol-vinyl acetate) with iodine was investigated from the standpoint of its application as a measure of sequence distribution in the copolymer. Defining a parameter Y which means a ratio of the bound triiodide ion to the VAc unit in a copolymer, we could relate the Y value to the sequence probabilities. Sequence probabilities have also been evaluated by differential thermal analysis. Comparing the probabilities obtained from both methods, the iodine complexation method is concluded to be a complementary method with thermal analysis, that is, the iodine complexation method is applicable to the VAc unit-rich copolymers, in which the melting point cannot be measured by the thermal analysis.     

Papain immobilization onto porous poly(λ-methyl L-glutamate) beads

Water-insoluble papain was prepared by immobilizing papain onto the surface of porous poly(λ-methyl L -glutamate) (PMLG) beads with and without spacer. The mode of the immobilization between papain and porous PMLG beads was covalent fixation. The relative activity and the stability of the immobilized papain was investigated. The retained activity of the papain covalently immobilized by the azide method was found to be excellent toward a small ester substrate, N-benzyl L -arginine ethyl ester (BAEE), compared with that of the peptide binding method. The values of the Michaelis constant K_m and the maximum reaction velocity V_m for free and immobilized papain on the PMLG beads were estimated. The apparent K_m was larger for immobilized papain than for the free enzyme, while V_m was smaller for the immobilized papain. The thermal stability of the covalently immobilized papain was higher than that of the free papain. The initial enzymatic activity of the covalently immobilized papain remained approximately unchanged with storage time, when the batch enzyme reaction was performed repeatedly, indicating the excellent durability.     

A new class of magnetic fluids: bmim[FeCl/sub 4/] and nbmim[FeCl/sub 4/] ionic liquids

The responses to a magnet of two room-temperature ionic liquids containing tetrachloroferrate(III) ions, 1-butyl-3-methylimidazolium tetrachloroferrate (bmim[FeCl/sub 4/]) and 1-butyronitrile-3-methylimidazolium tetrachloroferrate (nbmim[FeCl/sub 4/]) are compared. Although their magnetic susceptibilities are similar, the observed responses are distinct from each other, suggesting that the response is determined not only by the magnetic susceptibility but also by the other factors including density, viscosity, and surface tension. The two magnetic ionic liquids constitute a new class of magnetic fluids that hold many attractive physical properties for practical applications.