Modification of polylactide upon physical properties by solution-cast blends from polylactide and polylactide-grafted dextran

Polylactide (PLA)-grafted polysaccharides with various lengths and numbers of graft chains were synthesized using a trimethylsilyl protection method. The properties of the cast films prepared from graft-copolymers were investigated through thermal and dynamic mechanical analyses. The graft-copolymer films exhibited a lower glass transition temperature (T_g), melting temperature, and crystallinity, and higher viscosity properties compared to PLA films. Moreover, the usefulness of graft-copolymer as a plasticizer was investigated with 1:4 blend films prepared from the graft-copolymers and PLA. The blend films showed lower T_g and crystallinity, and higher viscosity properties compared to PLA films.     

The effects of pulmonary rehabilitation combined with inspiratory muscle training on pulmonary function and inspiratory muscle strength in elderly patients with chronic obstructive pulmonary disease]

It has been suggested that pulmonary rehabilitation compined with inspiratory muscle training (IMT) might improve pulmonary function and respiratory muscle strength in elderly patients with chronic obstructive pulmonary disease (COPD). To test this hypothesis, inspiratory muscle strength (PImax), expiratory muscle strength (PEmax) and resting pulmonary function were measured in 13 elderly patients with COPD (aged 70.3 +/- 2.7 years). Inspiratory muscle training (IMT) was performed for 15 min twice a day, using a pressure threshold device, for a total of 12 weeks. The inspiratory threshold was set at 15% of maximal inspiratory pressure (PImax) for each individual. Pulmonary rehabilitation was performed for 12-h sessions over a 12-week period. Patients with COPD were assigned randomly to two groups: pulmonary rehabilitation combined with IMT (group A) (n = 7), and conventional pulmonary rehabilitation only (group B) (n = 6). Functional residual capacity (FRC) decreased significantly from 4.3 +/- 0.4 L at baseline to 3.9 +/- 0.4 L after rehabilitation (p < 0.01), Vp significantly increased from 4.6 +/- 0.8 L/sec at baseline to 5.1 +/- 0.7 L/sec after rehabilitation (p < 0.05) and the PImax increased significantly from 51.5 +/- 5.4 cmH2O at baseline to 80.9 +/- 7.0 cmH2O after rehabilitation (p < 0.02) in group A. However, these variables did not change in group B. There was no improvement in the 10-minutes walking distance of group A, but there was a significant increase in that of group B. It can be concluded that pulmonary rehabilitation combined with IMT improves pulmonary function and inspiratory muscle strength in elderly patients with COPD.     

Activity tests of various catalysts for hydrocracking of coal by means of high pressure differential thermal analysis

The activities of fourteen kinds of catalysts for the hydrocracking of Taiheiyo coal were examined by a high pressure differential thermal analytical method. Exothermic peaks appeared at low temperatures (420–430°C) when MoO₃TiO₂, NiY zeolite and CoY zeolite were used as catalysts, indicating that these catalysts are highly active compared with other catalysts including MoO₃CoOAl₂O₃. The qualitative analysis of gas and liquid products revealed that MoO₃TiO₂ and CoY are good catalysts for the liquefaction reaction. The hydrogenation ability of the catalyst is concluded to be more important than its acidic property.     

Relation between fluidity and solvent extraction yield of coals

Four coals with similar ultimate analyses were Soxhlet-extracted with pyridine before and after heat treatment at 400 °C and with quinoline at 350 °C. Pyridine extraction yield tended to be proportional to log maximum fluidity (MF), but with some discrepancies. Quinoline extraction yield was more nearly proportional to log MF. However, the best correlation with log MF was obtained for quinoline extraction yield corrected for inert content.     

Perpendicular magnetic recording with a composite anisotropy film

For a recently proposed perpendicular recording system, a composite anisotropy medium has been developed to improve the recording sensitivity of the perpendicular recording head. The medium is composed of a Fe-Ni soft magnetic film and a Co-Cr perpendicular anisotropy film, which are successively deposited on a base by an r. f. sputtering. By using the new double layer medium, an extremely high recording sensitivity could be obtained, compared with the single layer Co-Cr medium. The recording current needed to saturate the double layer film decreased to one-tenth of that for the single layer Co-Cr film. Although the Fe-Ni layer was soft magnetic material, neither deterioration of the frequency response nor peak shift was observed for the double layer film. The reproduction with a perpendicular head was also investigated, and a high output voltage and a high signal-to-noise ratio were obtained.     

Dissolution of coal with NaOH-alcohol: Effect of alcohol species

Methanol, ethanol, straight-chain propanol, isopropanol, straight-chain butanol, sec-butanol, tert-butanol, straight-chain pentanol, and iso-pentanol were used for the reaction of coal with NaOH-alcohol at 290 °C for 1 h. All the products dissolved in pyridine with an extraction yield > 80 wt%. Straight-chain alcohols are less reactive than the secondary alcohols owing to the differences in hydrogen donating ability.     

Fuel utilization and glucose hyperalimentation after liver resection

Clinical studies and experiments in rats were carried out to elucidate changes in fuel utilization after hepatectomy. In addition, the effect of glucose hyperalimentation on energy metabolism in the liver remnant was studied. Respiratory quotient (RQ) and substrate oxidation rate for fat and glucose were evaluated by indirect calorimetry in eight patients who had undergone liver resection. Patients had a reduced nonprotein RQ of approximately 0.85 and a reduced ratio of glucose to fat oxidation of approximately 2.0 on the 1st and 2nd postoperative days. After 80% hepatectomy, rats received either 30 kcal.kg-1.day-1 (group 1) or 200 kcal.kg-1.day-1 (group 2) of glucose for 48 h. In both rat groups, hepatic mitochondrial ATP synthesis 12 and 24 h after hepatectomy was accelerated when palmitic acid was used as the substrate and suppressed when pyruvate was used compared with sham-operated groups. This suggests that the energy substrate of the remnant liver was principally fatty acids rather than glucose, which seems to occur also in humans. Hepatic energy charge was within normal limits in group 1 (0.862 +/- 0.008) but decreased significantly in group 2 (0.818 +/- 0.006, p < 0.01) 12 h after hepatectomy. An abundance of glucose in the early postoperative period therefore caused a hepatic energy derangement by suppressing endogenous fat oxidation. This suppression was corroborated by the findings of lower immunoreactive glucagon and nonesterified fatty acid concentration in group 2. Therefore, glucose hyperalimentation in the early postoperative period after liver resection is not recommended.     

High-speed InGaP/GaAs transistors with a sidewall base contactstructure

We have fabricated InGaP/GaAs double heterojunction bipolar transistors with a sidewall base contact structure. These transistors operate in both emitter-up and emitter-down modes. Symmetric characteristics of the cutoff frequency f_T=68 GHz and the maximum oscillation frequency f_max=31 GHz were obtained at a base-collector bias V_BC of 0 V. For emitter-down operation, f _T was found to reach a maximum of 78 GHz when the base-collector junction was forward biased at 0.9 V. The product of f _T for emitter-down operation and f_T for emitter-up operation was 5.3×10³ GHz², which is about six times that of previously reported SiGe heterojunction bipolar transistors