Formation,characterization, and glucose response in mice to rice starch with low digestibility produced by citric acid treatment

The optimum conditions for producing rice starch enriched in slowly digestible and resistant fractions by citric acid treatment determined by a response surface methodology (RSM) model equation, were: reaction temperature, 128.4 °C; reaction time, 13.8 h; and citric acid, 2.62 mmol/20 g starch. The slowly digestible and resistant starch fractions of the optimally acid-treated rice starch totalled 54.1%, which was 28.1% higher than the control. The slowly digestible and resistant fractions of the acid-treated rice starch did not differ significantly after heat treatment, whereas those of raw rice starch decreased by 49.6–63.8%, depending on the type of heat treatment (cooking at 100 °C or autoclaving). The slowly digestible fraction of the acid-treated starch increased by 8.9–14.2%. After autoclaving, the glucose response of the acid-treated starch was lower than untreated starch, but similar to that of Novelose 330. After heat treatment, the rate of blood glucose decrease was slower for the acid-treated starch than for Novelose 330. Compared to raw rice starch, the acid-treated starch exhibited increases in apparent amylose content, blue value, dextrose equivalent, cold-water solubility and transmittance, and decreases in wavelength of maximum absorbance, viscosity, and gel-forming ability.     

Synthesis of rosinimide modified with polyphenylpyridinylsiloxane and its characteristics

Rosin maleic anhydride adduct (RMA)-bisester was prepared by the esterification of chlorinated RMA with hydroquinone. Phenylpyridinylcyclotrisiloxane (D ₃ ^Ph,Py ) was synthesized from phenylpyridinyldichlorosilane in the presence of zinc oxide catalyst, and amino group terminated polyphenylpyridinylsiloxane prepolymer was prepared by equilibrium polymerization of D ₃ ^Ph,Py with 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. Rosinimide (PSMR) was prepared from the imidization of RMA-bisester with polyphenylpyridinylsiloxane prepolymer at 120°C for 7 h using γ-butyrolactone/pyridine. It showed that PSMR had better thermal stalbility than rosinimide modified with polydimethylsiloxane.     

Preparation of bio-polyurethane using castor oil and antibacterial hybrid films thereof with silver-doped hydroxyapatite

The hybrid films of bio-polyurethane (Bio-PU) and silver-doped hydroxyapatite (HA-Ag) for breathable and antibacterial textile applications. The Bio-PU was synthesized using a mixture of castor oil based polyol with petroleum based poly(ethylene glycol). Silver doping to hydroxyapatite(HA) was carried out through ion exchange mechanism between calcium ion in HA and silver ion (Ag⁺) in aqueous solution of AgNO₃. The concentration of Ag⁺ was controlled to 100-300 ppm. The existence of silver in HA was proved using SEM-EDS while the silver doping amount was estimated by measuring residual concentration of Ag⁺ after doping using ICP-OES. It was found that the hybrid films exhibited excellent antibacterial activity against bacteria of S. aureus and K. pneumonia by showing 99.9 % reduction of bacteria.     

Synaptic protein degradation underlies destabilization of retrieved fear memory

Reactivated memory undergoes a rebuilding process that depends on de novo protein synthesis. This suggests that retrieval is dynamic and serves to incorporate new information into preexisting memories. However, little is known about whether or not protein degradation is involved in the reorganization of retrieved memory. We found that postsynaptic proteins were degraded in the hippocampus by polyubiquitination after retrieval of contextual fear memory. Moreover, the infusion of proteasome inhibitor into the CA1 region immediately after retrieval prevented anisomycin-induced memory impairment, as well as the extinction of fear memory. This suggests that ubiquitin- and proteasome-dependent protein degradation underlies destabilization processes after fear memory retrieval. It also provides strong evidence for the existence of reorganization processes whereby preexisting memory is disrupted by protein degradation, and updated memory is reconsolidated by protein synthesis.     

Image analysis of the luster of fabrics with modified cross-section fibers

We have investigated the luster of modified cross-sectional fiber fabrics as one of the essential quality estimates for clothing development. We have confirmed an objective evaluation method, and have determined the experimental luster characteristics of modified cross-section fibers. The cross-section of the fibers in a fabric affects the appearance of a textile. We used the image analysis method to investigate the luster to determine the critical factors influencing the appearance of modified cross-section fiber fabrics. For similarly structured textiles in a component fabric, clear differences were observed in the fabric weave, density, percentage, and total area of blobs, which is image region. Color played a decisive role in the luster of the textiles, and luster was not significantly influenced by the modified cross-section fabric weave. In addition, the degree of luster did not increase in the order plain to twill to satin for modified cross-sectional fiber fabrics. All the split-type microfibers exhibited higher numerical luster values (percentage of pixels, and number and total area of blobs) than sea-island microfibers did. The degree of luster of the modified cross-sectional fiber fabrics was not high at specular reflection angles.     

Comparative study on fibrid formation models

In Kalb’s theory, the length of fibrid increased with the shear rate increasing and decreased with the viscosity ratio of polymer solution and coagulation bath increasing, however, which were inconsistent to the experimental date when the shear rate was large enough. In this paper, Kalb’s theory was modified, and the simulation results based on the new formation models of fibrid were compared with the actual data. The results indicated that the viscosity ratio, shear rate, coagulation bath were the main factors for effecting the length of fibrid, which fit well with the simulating data in new models.     

Properties of waterborne polyurethane (WBPU) coatings: Effect of alkyl chain length of tertiary amines of carboxylic acid salt groups

Waterborne polyurethane (WBPU) dispersions were prepared via a pre-polymer process using 4,4-dicyclohexylmethane diisocyanate (H₁₂MDI), poly(tetramethyleneoxideglycol) (PTMG), 2,2-dimethylol propionic acid (DMPA), ethylene diamine (EDA), and tertiary amines (TAs) with varying amounts of DMPA and TAs. Three TAs with different alkyl chain lengths were used to neutralize the DMPA carboxylic group: N,N-dimethylbutylamine (DMBA, C4), N,N-dimethylhexylamine (DMHA, C6), and N,N-dimethyloctylamine (DMOA, C8). The structures of the synthesized WBPUs were determined via FT-IR and ¹H NMR spectroscopic techniques. The effects of DMPA and TA content and the TA alkyl chain length on stability of dispersions and properties such as water swelling (%), glass transition temperature (T _g ), tensile strength, binding energy and adhesive strength were investigated. The initial adhesive strength of the intact coatings increased with increasing DMPA and TA content and increasing alkyl chain length of TA. However, after immersion of the coatings in water, the adhesive strength decreased. The maximum adhesive strength under water was observed at a DMPA content of 20.20 mol% with 5.30 wt% DMOA, which has the longest alkyl chain.     

Data transmission textiles for smart clothing using conducting fibers

In this study, electrical properties and data transmission characteristics of 75D PET/silver composite filaments were measured and analyzed in order to explore the feasibility of “digital textiles” in terms of resistance, resonance frequency, dB loss, and Bandwidth. Those characteristics were measured and compared according to measurement length (10～50 cm) and number of strands (1～10) in order to provide a design guide line for smart clothing. According to the measurement results, electrical characteristics of conducting fiber can be enhanced by increasing the number of fiber strand. It was also demonstrated that multiple resonances could occur from conducting fiber when the fiber lengths are varied. Finally, it showed the delay time of conducting fiber reached the saturated value when the number of fiber strand exceeded five.