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Volume 50, Issue 6
Displaying 1-11 of 11 articles from this issue
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Hiroshi EBATO, Yoshio OKAHATA, Takehisa MATSUDA1993 Volume 50 Issue 6 Pages 463-469
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSInteraction between bovine epithelial cells and cell adhesion protein, fibronectin, was measured by using a quartz crystal microbalance (QCM) in buffer solution at 37°C. QCMs are well known to detect a mass change on an electrode at a nanogram level from the resonance frequency change. The fibronectin-coated QCM was soaked into an aqueous solution, bovine epitheliums cells were then put on the QCM, and the frequency change was followed with time. The frequency of the QCM decreased with time after putting cells on the electrode. The time-course of the frequency decrease seems to reflect the strength of the cell adhesion onto fibronectin on the QCM. This was confirmed by the observation of the cell adhesion behavior by using electron microscopy, interference reflection microscopy, and fluorescence microscopy.View full abstractDownload PDF (2192K) -
Osamu HARADA, Masami SUGITA, Tohei YAMAMOTO1993 Volume 50 Issue 6 Pages 471-475
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSOn photo-irradiation of a solubilized collagen film in methyl methacrylate (MMA) solution, polymerization of MMA took place in the film efficiently, and a poly (MMA) -grafted collagen film was easily obtained. Although the film contained a large amount of PMMA, one of the surfaces contained no grafted PMMA up to 0.4μm. The film was hydrophilic and showed higher wet-strength than glutaraldehyde closslinked-collagen films.View full abstractDownload PDF (677K) -
Satoru MATSUSHITA, Masayuki KISHIBE, Sumiharu ARIMA, Masami SUGITA1993 Volume 50 Issue 6 Pages 477-484
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSTo characterize the thermal denaturation behavior of solubilized collagen solution, the temperature dependence of the helix fraction (X) and the differentiated curve (dX/dT) of X established by optical rotation measurements were investigated. On the dX/dT curve of the pepsin-solubilized collagen (PC1) solution, the small thermal denaturation peak (component L) was found at a lower temperature (TL) along with the main thermal denaturation peak (component H) at a higher temperature (TH). Thus, the effects of experimental conditions on TL, TH, and the ratio (L/H) of the amount of component L to that of component H were examined. The effects of the heating rate and the concentration of collagen on TL and TH were small. TH decreased with the increase of the concentration of acetic acid or sodium chloride, and reached minimum at pH 3.5 to 4.5. L/H ratio was unchanged. However, as the irradiation time of ultraviolet rays increased, TL and THdecreased slightly and L/H increased. For commercially available collagens and solubilized collagens prepared from hides, the thermal denaturation behavior of their solutions and their patterns of the sodium dodecyl sulphate-polyacrylamide gel slab electrophoresis (SDS-PAGE) indicated that collagens, with large L/H values, had many bands without sub-units. The component L of each collagen was probably damaged due to crushing and solubilization.View full abstractDownload PDF (1465K) -
Yukio FUJIMORI, Takashi KANEKO, Hiroyuki NISHIDE, Eishun TSUCHIDA1993 Volume 50 Issue 6 Pages 485-488
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSPhotoreaction of camphorquinone (CQ) and dimethylaminoethyl methacrylate (DMAEMA) and its initiation capability of MMA polymerization was studied as a model system for visible light-cured dental composite resins. The photo-sensitizer (CQ) produced CQ radical anion by irradiation in the presence of the reducing agent (DMAEMA) under N2. ESR signal intensity and the IR and UV-Vis absorption spectra of CQ carbonyl group decreased during irradiation, and the polymerization rate of MMA depended on the decrease in the CQ carbonyl group. The hydrogen abstraction reaction by CQ radical seemed to promote the polymerization of MMA. Atmospheric oxygen inactivated the CQ radical and reduced the polymerization.View full abstractDownload PDF (646K) -
Shinichi SATO, Hisao NOJIRI, Toshinao OKITSU, Tohru WAINAI1993 Volume 50 Issue 6 Pages 489-496
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSA homogeneous liquid with good storage-stability was obtained by heating the mixture of N, N'-4, 4'-diphenylmethane-bismaleimide (BMI), bisphenol A type epoxy resin (Ep828), and phenol (PhOH) or hydroquinone (HQ). For studying the mechanism of this reaction, N-phenylmaleimide (PMI) and phenyl glycidyl ether (PGE) were used as model compounds for BMI and Ep828, respectively. Main reaction was the the radical polymerization initiated by the charge-transfer complex formed between PMI and PhOH. The product {- (BMI) -n} of this reaction had good compatibility with unreacted Ep828 and thus the mixture existed as a homogeneous liquid. The reaction products of BMI/Ep828/PhOH or HQ were cured with 2-ethyl-4-methyl imidazole (2E4MZ) and 4, 4'-diaminodiphenylmethane (DDM). The heat-resistance of the cured resins modified with HQ was higher than that of the cured systems modified with PhOH.View full abstractDownload PDF (1219K) -
Katsutoshi TANAKA, Kazuo NAKAYAMA1993 Volume 50 Issue 6 Pages 497-505
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSDynamic mechanical properties of immiscible, compatibilized polymer blend were investigated by using a Rheovibron. Specimens were prepared from extruded sheets of Orgalloy (R) (PA6/PP), blend of polyamide-6 (PA6) andpolypropylene (PP). Both the as-peaks of PA6 and PP were observed in the temperature dependences of loss modulus (E'') and tanδ. The as-peak of PA6 in the PA6/PP specimen kept in water shifted to lower temperature by 95°C and overlapped with that of PP. The dynamic storage moduli (E') of water-adsorbed specimens increased in thetemperature range of below-40°C, and E' at higher temperatures were rather small in comparison with those of dried specimens. When the water-adsorbed specimen was dried again under vacuum, δE' of the specimen reached to the same level of the original dried specimen. Also, effects of aging of PA6/PP at 200°C were investigated. The crystallization of PA6 phases was promoted and the PP phase recrystallized after melting. The temperature dependence of E' of the aged specimen was affected by changes of morphology of PA6 and PP phase. The aa-peak of PA6 phase in E''-temperature curve shifted to higher temperatures.View full abstractDownload PDF (1913K) -
Akira TAKAHASHI, Ken TATEBE, Makoto ONISHI, Yukio SEITA, Kazuaki TAKAH ...1993 Volume 50 Issue 6 Pages 507-513
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSMicroporous hollow fiber membranes were prepared by extraction of liquid paraffin (LP) after melt-spinning of a polypropylene (PP) /LP mixture. Relationship between melt viscosity of PP and porous structure, and effects of a crystalline nucleating agent (NA) on membrane structure, properties and performance were investigated. The diameter of PP micro-sphere crystals decreased as melt viscosity of PP decreased, because of improved miscibility between PP and LP, and NA makes the diameter of micropores small and uniform. As a result, the elongation at break and permeability decreased, while the strength at break was retained. The resulting microporous hollow fiber membranes show the structure useful for artificial lungs.View full abstractDownload PDF (2810K) -
Akira TAKAHASHI, Ken TATEBE, Makoto ONISHI, Yukio SEITA, Kazuaki TAKAH ...1993 Volume 50 Issue 6 Pages 515-521
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSEffects of specific heat, viscosity, and solubility to liquid paraffin (LP) of a coolant on the surface structure, porosity, and gas permeability of PP hollow fiber membranes were studied. A porous surface was not obtained with a coolant of higher specific heat. If the coolant is a good solvent for LP, surface pore diameter of PP hollow fibers becomes too large, and pore density at the inner surface of PP hollow fibers decreases. When LP is used as coolant, surface pore diameter becomes too large for artificial lungs in spite of enough pore density at the inner surface. Appropriate pore density at inner surface, surface pore diameter and gas permeability could be obtained with a coolant of preferable specific heat, viscosity, and solubility to LP.View full abstractDownload PDF (3226K) -
Akira TANAKA, Yuji KOJIMA1993 Volume 50 Issue 6 Pages 523-527
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSA 7-ray sensor has been fabricated which uses the plastic scintillating optical-fiber and-plate doped with organic fluorescent materials and a photon counting module with a silicon avalanche photo-diode or the optical power meter. The 137Cs was used as γ-ray source. The output power from the scintillating fiber was measured under the dose rate from 0.1 mR/h to 10 R/h. The experimental results show that this sensor can detect the dose rate above 10 mR/h for the scintillatng fiber and above 1.0 mR/h for the combination of scintillating-fiber and-plate. This sensor does not need electric power source for sensing the 7-rays and is not affected by electromagnetic interference. So this can be expected to performas radioactive sensor.View full abstractDownload PDF (923K) -
Takao ANDO, Yukio ZENITANI, Masahumi OISI1993 Volume 50 Issue 6 Pages 529-531
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSIn the reaction of 4, 4'-diisocyanatodiphenylmethane with a diol mixture (Mn=700) of polyethylene adipate (Mn=2000) and ethylene glycol in N, N-Dimethylformamide, the effects of monomer concentration and mixing method on the rate of polyurethane formation were studied. With increasing molecular weight of the intermediate polyurethane, the increment of the molecular weight decresed. When the molecular weight of the intermediate polyurethane was higher than 8×104 and the initial monomer concentration was higher than 70wt%, the increment of the molecular weight decreased with increasing the initial monomer concentration. The apparent rate constant decreased with decreasing mixing efficiency.View full abstractDownload PDF (433K) -
Michiko TAZAKI, Akiko ONODERA, Terutake HOMMA1993 Volume 50 Issue 6 Pages 533-536
Published: June 25, 1993
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSThermoreversible gels were obtained from the solutions of highly crystalline PVDF in acetone (Actn), methyl ethyl ketone (MEK), and ethyl acetate (EA). The gel forming rate was comparatively slow. SEM observation of the gel showed that the gel was consisted of aggregated crystallites having petal-like thin leaves which were quite similar to the shape of an LHDPE gel obtained from organic solvents. Further observation of the crystallites by TEM indicated that the crystallites were constituted of gathered oriented fibrins. The microstructure was also similar to that of an LHDPE gel obtained in organic solution.View full abstractDownload PDF (1364K)
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