Faculty Profiles - UCHIDA Tetsuya

Papers - UCHIDA Tetsuya

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One-Pot Preparation of Aromatic Poly(azomethine ester) Fibrillar Crystals Using Reaction-Induced Crystallization Reviewed

Jin Gong, Yasuhide Yakushi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY 49 ( 1 ) 127 - 137 2011.1

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

Polymerizations of 4-(4-acetoxybenzylideneamino)-benzoic acid were performed in dibenzyltoluene (DBT) and a mixture of DBT and liquid paraffin at 350 degrees C for 6 h. Fibrillar crystals of poly[4-(4-oxybenzylideneamino)benzoyl] (POAB) having the width of 50-450 nm and the length of over 15 pm were obtained by the crystallization during the polymerization. The fibrillar crystals possessed high crystallinity and the molecular chains aligned perpendicular to the long axis of the fibrillar crystals. Plate-like crystals were initially formed by the crystallization of oligomers, and then they changed to the fibrillar crystals via the formation of bundle-like crystals after 1 h. Molecular weight increased by the further polymerization in the crystals. Based on these results, one-pot preparation of the fibrillar POAB crystals was examined by the polymerization of 4-acetoxybenzaldehyde and 4-aminobenzoic acid. The polymerization at 180 degrees C for 2 h and then at 350 degrees C for 6 h afforded the fibrillar crystals with a small amount of the ribbon-like crystals. Although the side-reaction to generate the p-benzamide sequences was not completely depressed, the sequence of heating in which 180 degrees C for the formation of the azomethine linkage and then 350 degrees C for the formation of the ester linkage was preferable to prepare the fibrillar POAB crystals. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 127-137, 2011

DOI： 10.1002/pola.24427

Denaturation temperature of dried lens tissue rises with trehalose pretreatment Reviewed

Jianan Sun, Toshihiko Matsuo, Tetsuya Uchida

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY 103 ( 1 ) 387 - 391 2011.1

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Trehalose, a non-reducing disaccharide, is known as an exceptional protector against desiccation and heat stress. Differential scanning calorimetry is a simple tool to determine thermodynamic parameters concerning the structural state of proteins. In this study, we measured denaturation temperature (or melting temperature) of dried lenses to know the effect of trehalose pretreatment. Isolated porcine lenses were incubated in wells without any solution or with saline, 100 mM trehalose, or 100 mM cyclic tetrasaccharide in saline at room temperature for 150 min. The solutions were removed, and all lens samples were dried at room temperature and in room humidity until the weight showed no change. The nucleus of each sample was taken out and placed on a measuring platform for differential scanning calorimetry. The denaturation temperature of the dried lenses significantly rose by about 10 degrees C with 100 mM trehalose pretreatment, compared to no pretreatment, pretreatment with saline or 100 mM cyclic tetrasaccharide (P < 0.05, analysis of variance, P < 0.05, Student-Newman-Keuls tests, n = 7). The denaturation temperature showed no difference among the dried lenses with no pretreatment or pretreatment by saline or cyclic tetrasaccharide. In conclusion, pretreatment with trehalose raises denaturation temperature of the dried porcine lens. Trehalose might stabilize the dried tissue structure to get a higher denaturation temperature.

DOI： 10.1007/s10973-010-0906-6

Preparation of Poly(p-phenylenepyromelliteimide) Microspheres with Rugged Surfaces Using Crystallization During Isothermal Polymerization Reviewed

Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULAR CHEMISTRY AND PHYSICS 212 ( 2 ) 159 - 167 2011.1

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Preparation of discrete PPPI microspheres was examined using the crystallization of oligomers during isothermal polymerization of PMDA and p-phenylene diisocyanate, and that of pyromellitic dithioanhydride and PPDA in poor solvents. In contrast to PPPI microspheres with smooth surfaces that were previously prepared by phase-separation during the polymerization of PPDA and PMDA, the microspheres obtained here consisted of flake-like lamellae with rugged surfaces. The diameters of the microspheres ranged from 0.5 to 6.7 mu m. They exhibited excellent thermal stability depending on the monomers. These results provide a new preparative procedure of the PPPI microsphere with a rugged surface.

DOI： 10.1002/macp.201000510

Poly[2,6-(1,4-phenylene)-benzobisimidazole] Nanofiber Networks Reviewed

Jin Gong, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULAR CHEMISTRY AND PHYSICS 211 ( 20 ) 2226 - 2232 2010.10

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

The preparation of poly[2,6-(1,4-phenylene)-benzobisimidazole] (PPBI) nanofibers was examined using the crystallization of oligomers during isothermal polymerization of self-polymerizable 2-(1,4-carbophenoxyphenyl)-5,6-diaminobenzimidazole. The polymerization was carried out at 350 degrees C at a concentration of 1w-t.-% for 6 h in three kinds of solvent. The solvent influenced the morphology of PPBI precipitates significantly, and PPBI nanofiber networks were successfully formed in DBT, of which the width ranged from 30 to 110 nm. Molecules were aligned along the long axis of nanofibers. A fibrillar morphology with molecular orientation is ideal for high performance materials such as reinforcements, non-woven fabrics and so on. The nanofiber networks exhibit the highest thermal stability.

DOI： 10.1002/macp.201000306

Poly(2,5-benzimidazole) nanofibers prepared by reaction-induced crystallization Reviewed

Kazuya Kimura, Jin Gong, Shin-ichiro Kohama, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

POLYMER JOURNAL 42 ( 5 ) 375 - 382 2010.5

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP

Morphological control of poly(2,5-benzimidazole) (PBI) was examined by reaction-induced phase separation of oligomers during polymerization to prepare nanofibers. Three monomers, 3,4-diaminobenzoic acid (DABA), 3,4-diacetoamidebenzoic acid (DAcBA) and phenyl 3,4-diaminobenzoate (PDAB), were used to synthesize PBI. Polymerizations were carried out at 350 degrees C in a mixture of dibenzyltoluene isomers. Polymerization of DABA yielded spheres with plate-like crystals on their surface. Polymerization of DAcBA yielded almost no precipitates because of the high solubility of DAcBA oligomers. By contrast, polymerization of PDAB yielded aggregates of PBI nanofibers (of which the average diameter was similar to 60 nm), which resembled nonwoven fabrics. These fibers were formed by precipitation of (2,5-benzimidazole) oligomers and their subsequent polymerization into a developing crystal structure. The structure of the monomer significantly influenced the morphology of the PBI product, and PDAB was preferable for the preparation of PBI nanofibers. The temperature of 10% N-2 weight loss in these nanofibers was in the range of 634-644 degrees C and they were thermally stable. Polymer Journal (2010) 42, 375-382; doi:10.1038/pj.2010.20; published online 17 March 2010

DOI： 10.1038/pj.2010.20

Safety, efficacy, and quality control of a photoelectric dye-based retinal prosthesis (Okayama University-type retinal prosthesis) as a medical device Reviewed

Toshihiko Matsuo, Tetsuya Uchida, Kenichi Takarabe

JOURNAL OF ARTIFICIAL ORGANS 12 ( 4 ) 213 - 225 2009.12

Language：English Publisher：SPRINGER TOKYO

Patients with retinitis pigmentosa lose photoreceptor cells as a result of genetic abnormalities and hence become blind. Neurons such as bipolar cells and ganglion cells remain alive even in the retina of these patients, and ganglion cells send axons to the brain as the optic nerve. The basic concept of retinal prostheses is to replace dead photoreceptor cells with artificial devices to stimulate the remaining neurons with electric currents or potentials. Photodiode arrays and digital camera-type electrode arrays are the two main approaches for retinal prostheses to stimulate retinal neurons, but these arrays have the problems of poor biocompatibility, low sensitivity, and low output of electric currents, and hence have a requirement for external electric sources (batteries). To overcome these problems, we are developing photoelectric dye-based retinal prostheses that absorb light and convert photon energy to generate electric potentials. The prototype, using a photoelectric dye-coupled polyethylene film, could induce intracellular calcium elevation in photoreceptor-lacking embryonic retinal tissues and cultured retinal neurons. The subretinal implantation of the prototype in the eyes of Royal College of Surgeons (RCS) rats led to vision recovery as proved by a behavior test. The photoelectric dye that was chosen for the prototype did not exhibit any cytotoxicity. The surface potentials of the photoelectric dye-coupled film showed a rapid on-and-off response to illumination with a threshold for light intensity as measured by a Kelvin probe system. Photoelectric dye-based retinal prostheses are thin and soft, and therefore, a sheet of the film of large size, corresponding to a large visual field, could be inserted into the vitreous and then to the subretinal space through a small opening by rolling up the film. Clinical studies of photoelectric dye-based retinal prostheses in patients with retinitis pigmentosa who lose sight will be planned after the manufacturing control and the quality control had been established for the medical device.

DOI： 10.1007/s10047-009-0471-6

Direct Synthesis of Wholly Aromatic Polyamides by Using Reaction-Induced Crystallization Reviewed

Kazufumi Kobashi, Kentaro Kobayashi, Haruki Yasuda, Kentaro Arimachi, Testuya Uchida, Kanji Wakabayashi, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULES 42 ( 16 ) 6128 - 6135 2009.8

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Direct synthesis of rigid-rod aromatic polyamides was studied without condensation reagents by using reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of p-aminobenzoic acid were carried out in an aromatic solvent at a polymerization concentration of 20% at 350 degrees C. High molecular weight poly(p-benzamide) (PBA) was obtained in the form of plate-like crystals, and the highest molecular weight was 11.6 x 10(3). In this polymerization, the oligomers were formed in the solution by the condensation reaction with the elimination of water. When the molecular weight of oligomers exceeded the critical value, the oligomers were precipitated by crystallization via supersaturated state to form the plate-like crystals. The molecular weight increased by the polymerization between the oligomers on and in the crystals. Poly(p-phenylene isophthalamide) (PPIA) was also obtained in the form of plate-like crystals by the polymerization of p-phenylene diamine (PPDA) and isophthalic acid (IPA) under the same condition as that of PBA. These results exhibited the thermally direct synthesis of infusible aromatic polyamides. Sequential addition of monomers into this heterogeneous polymerization was examined to increase the molecular weight. In the step-growth polymerization, the addition of monomers into the homogeneous polymerization could not increase the molecular weight because it was determined by the extent of reaction and reshuffled by the transamidation reaction. However, the addition of PPDA and IPA during the polymerization resulted in the increase in the molecular weight of PPIA. This result gave possibly a novel procedure for the preparation of high molecular weight condensation-type polymers.

DOI： 10.1021/ma9009033

Preparation of Poly(4 '-oxy-4-biphenylcarbonyl) Needlelike Crystals with the Aid of Copolymerization Reviewed

Naomi Yoshida, Yasuhiro Kurihara, Shin-ichiro Kohama, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULES 41 ( 20 ) 7571 - 7578 2008.10

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Preparation of poly(4'-oxy-4-biphenylcarbonyl) (POBP) needlelike crystals was examined by using reaction-induced crystallization of oligomers during copolymerization of 4-(4-aceloxypheilyl)benzoic acid (APBA) and 4-acetoxybenzoic acid (ABA). Polymerizations were carried out in aromatic solvent at various ABA molar ratios in feed (chi(f)). When they chi(f) was 20-10 mol %, starlike aggregates of needlelike crystals and fibrillated slablike crystals were separately formed, exhibiting similar morphology to poly(4-oxybenzoyl) and POPB crystals. 4-(Oxyphenyl)benzoyl (OPB) homo-oligomers and co-oligomers rich in OPB moiety were more rapidly precipitated due to the lower solubility, and the slablike crystals were formed. Afterward, 4-oxybenzoyl (013) homo-oligomers and the co-oligomers rich in OB moiety were precipitated to form spindlelike crystals. The OPB homo-oligomers and the co-oligomers rich in OPB moiety were continuously crystallized on both crystals due to the high degree of supersaturation. and the spindlelike crystals grew to the needlelike crystals mainly comprised of POBP. Copolymerization of 4-(4-acetoxybenzoyloxy)benzoic acid and APBA at chi(f) of 10 mol % yielded the needlelike crystals without coexisting fibrillated slablike crystals. This result provides a new methodology for morphology control with the aid of copolymerization.

DOI： 10.1021/ma800029n

Preparation of poly(4-phthalimide) nanoribbon by reaction-induced crystallization Reviewed

Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULES 41 ( 13 ) 4607 - 4614 2008.7

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

The morphology of poly(4-phthalimide) (PPI) crystals was examined by using reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of alkyl 4-aminophthalates such as I-ethyl 4-aminophthalate (1EAP), 2-ethyl 4-aminophthalate, 1-hexyl 4-aminophthalate, and 2-hexyl 4-aminophthalate were carried out at 330 degrees C in a mixture of isomers of dibenzyltoluene without stirring. Nanoscale PPI ribbons having smooth surface were formed by the polymerizations of these monomers. The ribbons prepared from 1EAP at a concentration of 2.0% for 24 h were averagely 12 mu m in length, 150 urn in width, and 8 nm in thickness, in which the molecular chains aligned along the long axis of the ribbon. The phase-separated oligomers were fully cyclized imide oligomers, and this is of great importance for the formation of the ribbon. The obtained ribbons possessed high crystallinity and exhibited excellent thermal stability.

DOI： 10.1021/ma800874w

Morphology control of poly(2,2'-phenylene-5,5'-bibenzimidazole) by reaction-induced crystallization during polymerization Reviewed

Shin-ichiro Kohama, Jin Gong, Kazuya Kimura, Shinichi Yamazaki, Tetsuya Uchida, Kaoru Shimamura, Kunio Kimura

POLYMER 49 ( 7 ) 1783 - 1791 2008.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Morphology control of polybenzimidazoles was examined by reaction-induced phase separation during polymerization. Polymerizations of 3,3'-diaminobenzidine with terephthalic acid or diphenyl terephthalate were carried out in poor solvents. The morphology of the precipitated poly[2,2'-(1,4-phenylene)-5,5'-bibenzimidazole] (PpBBI) was significantly influenced by the polymerization conditions, and the aggregates of nano-scale PpBBl fibers were obtained by the polymerization at a concentration of 3-5% and 320-350 degrees C in dibenzyltoluene. The average diameter of the fibers was ca. 50 mn and inherent viscosities of the precipitates were 0.35-0.58 dL g(-1). They possessed high crystallinity and thermal stability. The oligomers were precipitated first by the reaction-induced crystallization to form the highly crystalline lath-like crystals at an initial stage of polymerization. Then the lath-like crystals were split into disentangled aggregates of fine fibers with maintaining the high crystallinity. The polymerization mainly proceeded when the oligomers were registered into the crystals. The obtained aggregates of nano-scale fibers could be recognized as nonwoven fabrics. Morphology control of poly [2,2'-(1,3-phenylene)-5,5'-bibenzimidazole] was also examined and particles were mainly formed. (c) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2008.02.016

Glial reaction to photoelectric dye-based retinal prostheses implanted in the subretinal space of rats Reviewed

Takayuki Tamaki, Toshihiko Matsuo, Osamu Hosoya, Kimiko M. Tsutsui, Tetsuya Uchida, Kazuo Okamoto, Akihito Uji, Hiroshi Ohtsuki

JOURNAL OF ARTIFICIAL ORGANS 11 ( 1 ) 38 - 44 2008.4

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER TOKYO

We have designed a new type of retinal prosthesis using polyethylene films coupled with photoelectric dye molecules that absorb light and convert photon energy to electric potentials. An extruded-blown film of high-density polyethylene was used as the original polyethylene film. Recrystallized film was made by recrystallization from the melting of the original polyethylene film. A photoelectric dye,2-[2-[4-(dibutylamino)phenyl]ethenyl]-3-carboxymethylbenzothiazolium bromide, was coupled to the two types of polyethylene films through amide linkages. Samples of the original dye-coupled film, the dye-coupled recrystallized film, and the dye-uncoupled plain film were implanted in the subretinal space of normal adult rats. Frozen sections were cut from the eyes enucleated at 1 week or 1 month and were either stained with hematoxylin and eosin, stained immunohistochemically for glial fibrillary acidic protein (GFAP), or processed for in situ apoptosis detection. The results revealed that retinal tissue damage was negligible with no inflammatory cells and few apoptotic cells. GFAP was significantly up-regulated in retinal sites with the implantation of all types of polyethylene films at 1 week, compared with the adjacent retinal sites (P < 0.005, analysis of variance). The GFAP up-regulation was also present at 1 month for the plain film and dye-coupled recrystallized film (P < 0.05). Glial cell encirclement around the films increased significantly between 1 week and 1 month (P = 0.023, two-factor analysis of variance) but was not significantly different among the three types of polyethylene films (P = 0.4531). These results showed evidence of glial reactions to the photoelectric dye-coupled polyethylene films implanted into the subretinal space of rat eyes and also proved their basic biological safety.

DOI： 10.1007/s10047-007-0398-8

Fabrication of nanoribbon of high-performance polyimide

K. Wakabayashi, S. Yamazaki, T. Uchida, K. Kimura

American Chemical Society, Polymer Preprints, Division of Polymer Chemistry 49 ( 1 ) 331 - 332 2008

Fabrication of particles and crystals of poly(p-phenylene pyromelliteimide) and the study on crystal structure Reviewed

Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura, Kaoru Shimamura

MACROMOLECULES 40 ( 2 ) 239 - 246 2007.1

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Morphologies of poly(p-phenylene pyromelliteimide) (PPPI) were investigated by using phase separation during polymerization of pyromellitic dianhydride (PMDA) and p-phenylene diamine (PPDA). Polymerizations were carried out at 330 degrees C for 6 h. PPDA was added to the solution of PMDA in an aromatic solvent at various temperatures after PMDA was entirely dissolved. The morphology of the precipitates was drastically changed with the temperature of PPDA addition (Tad). When Tad was 240 degrees C, the fine particles were formed through the formation of droplets via liquid-liquid phase separation. On the contrary, when Tad was higher than 280 degrees C, the mixture of lozenge-shaped crystals and starlike aggregates of needlelike crystals were formed by the crystallization of oligomers. Tad influenced the degree of imidization of oligomers, resulting in the variation in the morphology of PPPI. Crystal structure and molecular chain orientation of the lozenge-shaped crystals were also investigated by high-resolution transmission electron microscope.

DOI： 10.1021/ma062032y

Light-induced electron transfer on the single wall carbon nanotube surrounded in anthracene dendron in aqueous solution Reviewed

Atula S. D. Sandanayaka, Yutaka Takaguchi, Tetsuya Uchida, Yuuki Sako, Yu Morimoto, Yasuyuki Araki, Osamu Ito

CHEMISTRY LETTERS 35 ( 10 ) 1188 - 1189 2006.10

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Light illumination of single-wall carbon nanotubes (SWCNTs) dispersed with anthracene (An) dendrons afforded the accumulation of the reduced form of methyl viologen in the presence of a hole shifter. With the helps of the fluorescence lifetime and transient absorption measurements, the charge-separation process from the excited state of the hybrides of An dendrimer to SWCNT was confirmed.

DOI： 10.1246/cl.2006.1188

Intracellular calcium response and adhesiveness of chick embryonic retinal neurons to photoelectric dye-coupled polyethylene films as prototypes of retinal prostheses Reviewed

Akihito Uji, Toshihiko Matsuo, Tetsuya Uchida, Kaoru Shimamura, Hiroshi Ohtsuki

ARTIFICIAL ORGANS 30 ( 9 ) 695 - 703 2006.9

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

Photoelectric dyes, which absorb light and convert photon energy to electric potentials, were shown to stimulate retinal neurons in culture. One of these dyes coupled with polyethylene film surface, as a prototype of retinal prostheses, could induce intracellular calcium elevation in chick embryonic retinal tissues. In this study, we used retinal cells from chick embryos in which no photoreceptor outer segments yet developed, and assessed cell adhesiveness and response to the original and modified types of our retinal prostheses. Extruded-blown film of high density polyethylene was used as the original polyethylene film. Polyethylene film surface was modified either by coupling with type 1 collagen or by crystallization from the melt of the original polyethylene film. A photoelectric dye, 2-[2-[4-(dibutylamino)phenyl]ethenyl]-3-carboxymethylbenzothiazolium bromide, was coupled to these different types of polyethylene films through amide linkage. Retinal cells from chick embryos at the 12-day embryonic stage were cultured on the surface of dye-coupled films. The response of retinal cells to the dye-coupled films was observed by calcium imaging. Cell types, either neurons or glial cells, were detected by immunocytochemical staining and also observed by scanning electron microscopy (SEM). Intracellular calcium elevation was observed in cells, including both neurons and glial cells, on the surface of the original dye-coupled film, collagen-coated dye-coupled film, and dye-coupled recrystallized film, in contrast with no response of cells cultured on the dye-uncoupled plain film. Retinal neurons grew upon colonies of glial cells settling on the surface of all different types of the films. The number of retinal neurons on the collagen-coated dye-coupled film and dye-coupled recrystallized film was significantly larger than the number of neurons on the dye-uncoupled plain film (P = 0.0004, analysis of variance; P < 0.05, Tukey-Kramer test). With SEM, Muller cell-like large cells covered the original dye-coupled film and collagen-coated dye-coupled film, while neuron-like small cells settled directly on the dye-coupled recrystallized film and also formed large colonies on Muller-like cells. Retinal neurons and glial cells were cultured directly on the different types of dye-coupled polyethylene films. Photoelectric dye-coupled polyethylene films could be used as prototypes of retinal prostheses.

DOI： 10.1111/j.1525-1594.2006.00286.x

Morphology and modulus of vapor grown carbon nano fibers Reviewed

Tetsuya Uchida, David P. Anderson, Marilyn L. Minus, Satish Kumar

JOURNAL OF MATERIALS SCIENCE 41 ( 18 ) 5851 - 5856 2006.8

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Two types of morphologies have been observed in vapor grown carbon nano fibers (CNFs) using transmission electron microscopy (TEM). In one case, a truncated cone microstructure was observed, with outer and inner diameters of 60 and 25 nm, respectively. In this type of CNF, graphite sheets were oriented at about 15 degrees to the fiber axis. The second type of fiber was a double-layer CNF with outer and inner diameters of 83 and 20 nm, respectively. A truncated cone structure was also observed in the double-layer CNF. Graphite sheets in the outer layer of the double-layer fibers were oriented along the nano fiber axis. Tensile modulus for the first type of nano fiber along its axis was calculated to be 50 GPa, and for the second type of fiber the calculated modulus value was in the 100-775 GPa range, depending on the outer layer orientation. Modulus calculations based on these two morphologies explain the wide ranging experimental CNF modulus values reported in the literature.

DOI： 10.1007/s10853-006-0324-0

Electrooxidation of alcohols in an N-oxyl-immobilized rigid network polymer particles/water disperse system Reviewed

J Kubota, T Ido, M Kuroboshi, H Tanaka, T Uchida, K Shimamura

TETRAHEDRON 62 ( 20 ) 4769 - 4773 2006.5

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The electrooxidation of alcohols in an aqueous disperse system with N-oxyl-immobilized poly(p-phenylene benzobisthiazole) network polymer particles (PBZT(NT)-N-Oxyl) as a disperse phase was performed successfully in a simple beaker-type undivided cell tinder a constant current condition to afford the corresponding ketones, aldehydes, and/or carboxylic acid in moderate to good yields. Recycle use of both the PBZT(NT)-N-Oxyl particles and the aqueous media could be achieved successfully by immobilization of additional N-oxyl moiety on the polymer particles in an appropriate interval. Notably, the shape and the particle size of PBZT(NT)-N-Oxyl were not appreciably changed even after 60 times recycle use. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2006.03.020

Atomic force microscopic observation of trehalose-treated and dried corneal epithelial surface Reviewed

Yuko Izawa, Toshihiko Matsuo, Tetsuya Uchida, Kaoru Shimamura, Hiroshi Ohtsuki

Cell Preservation Technology 4 ( 2 ) 117 - 122 2006

Language：English Publishing type：Research paper (scientific journal) Publisher：MARY ANN LIEBERT INC

To search for the mechanism of the effect of trehalose on the ocular surface applied as eye drops, we observed trehalose-treated and dried corneal epithelial surfaces of porcine eyes with atomic force microscopy. Full-thickness corneal pieces, 5 × 5 mm in size, were cut out from enucleated porcine eyes. Three kinds of disaccharides, trehalose, maltose, and sucrose, dissolved in saline at 100 mM concentration, and saline as a control, were applied to the epithelial surface of the full-thickness corneal pieces for 1 min. Excess fluid was then absorbed by cotton tips at the epithelial edge of the pieces, and the corneal pieces were dried naturally at room temperature and in room humidity for 72 h. The dried corneal epithelial surfaces were observed first with a dissecting microscope and then fixed on the observation platform for atomic force microscopy. With dissecting microscopy, trehalose-treated corneal epithelial surfaces appeared smoother than saline-, maltose-, or sucrose-treated surfaces. With atomic force microscopy in a tapping mode, saline-, maltose-, and sucrose-treated corneal epithelial surfaces had a larger number of pits in greater sizes than trehalose-treated surfaces. The number of pits measuring 0.14 μm or larger was significantly less in trehalose-treated corneal epithelial surfaces than in saline-treated surfaces (p = 0.0326, analysis of variance [ANOVA], p &lt
0.05, Tukey-Kramer test). No significant difference was found in the number of pits between maltose- or sucrose-treated surfaces and saline-treated surfaces. Mean roughness, an indicator for surface roughness, was significantly lower in trehalose-treated surfaces than in sucrose-treated surfaces (p = 0.0181, ANOVA, p &lt
0.05, Tukey-Kramer test). Trehalose-treated corneal epithelial surfaces are smoother than saline-, maltose-, or sucrose-treated surfaces. One effect of trehalose on the ocular surface is to keep the corneal epithelial surface smooth in drying condition. © Mary Ann Liebert, Inc.

DOI： 10.1089/cpt.2006.4.117

Fractionation of rigid polymer 2

Manabu Hirao, Masaru Hamada, Jin Gong, Tetsuya Uchida, Kaoru Shimamara, Shun-Ichi Nakamura

Polymer Preprints, Japan 55 ( 1 ) 1113 2006

Language：Japanese Publishing type：Research paper (international conference proceedings)

Column fractionation of the rigid polymer, poly(p-phenylene benzobisthiazole)(PBZT), was carried out in dilute solution in cone, methane sulfuric acid using silica gels as packing material. In the process, the rigid polymer concentration in the elute was measured by using visible light absorption spectrum, hence molecular weight distribution in the pristine PBZT.

Fullerodendron-assisted dispersion of single-walled carbon nanotubes via noncovalent functionalization Reviewed

Y Takaguchi, M Tamura, Y Sako, Y Yanagimoto, S Tsuboi, T Uchida, K Shimamura, S Kimura, T Wakahara, Y Maeda, T Akasaka

CHEMISTRY LETTERS 34 ( 12 ) 1608 - 1609 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Single-walled carbon nanotubes (SWNTs) were well dispersed in both water and organic solvent by the use of fullero-dendron as a dispersant. A C-60 moiety at the focal point of dendron plays a crucial role in the dispersing process, because dendron having an anthracene unit at the focal point can not disperse SWNTs in THE The dispersions of SWNTs were characterized by UV-vis-NIR spectroscopy, Raman spectroscopy, SEM, HRTEM, and AFM.

DOI： 10.1246/cl.2005.1608

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