6 research outputs found

    Characteristics of a self-assembled fibrillar gel prepared from red stingray collagen

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    A translucent collagen gel was formed from a transparent acidic solution of red stingray collagen by adjusting to physiological ionic strength and pH in phosphate buffer and then incubating at 25?37°C. During fibril formation from red stingray collagen, the turbidity increased when the NaCl concentration was increased at constant pH and the rate of fibril formation was accelerated by higher pH or lower NaCl concentration. The T m of red stingray collagen fibrillar gel was estimated as 44.3 ± 3.5°C, which was higher than that of the collagen solution, 33.2°C. In addition, red stingray collagen gel maintained its shape without melting and was suitable for culture of mouse stromal cells at 37°C

    A serine proteinase from the sarcoplasmic fraction of red sea bream Pagrus major is possibly derived from blood

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    Collagen degradation is known to be involved in the post mortem tenderization of fish muscle. A serine proteinase that is assumed to be related to collagen degradation after fish death was purified from the sarcoplasmic fraction of red sea bream Pagrus major by ammonium sulfate fractionation and column chromatography on Sephacryl S-300, Q Sepharose and Phenyl Sepharose CL-4B. The enzyme hydrolyzed gelatin and was obtained as a protein band of approximately 38 kDa upon sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing conditions. The N-terminal amino acid sequence of the enzyme was determined for 32 residues. A protein that had the same N-terminal amino acid sequence as the enzyme for ten residues was purified from the serum of red sea bream and showed the same characteristics as the enzyme. Therefore, it is suggested that the serine proteinase migrates from the blood to muscle and degrades muscle proteins after the death of the fish

    3D PEEK Objects Fabricated by Fused Filament Fabrication (FFF)

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    PEEK (poly ether ether ketone) materials printed using FFF 3D printing have been actively studied on applying electronic devices in satellites owing to their excellent light weight and thermal resistance. However, the PEEK FFF process generated cavities inside due to large shrinkage has degraded both mechanical integrity and printing reliability. Here, we have investigated the correlations between nozzle temperatures and PEEK printing behaviors such as the reliability of printed line width and surface roughness. As the temperature increased from 360 to 380 °C, the width of the printed line showed a tendency to decrease. However, the width of PEEK printed lines re-increased from 350 to 426 μm at the nozzle temperatures between 380 and 400 °C, associated with solid to liquid-like phase transition and printed out distorted and disconnected lines. The surface roughness of PEEK objects increased from 49 to 55 μm as the nozzle temperature increased from 380 to 400 °C, where PEEK is melted down and quickly solidified based on more energy and additional heating time at higher printing temperatures at 400 °C. Based on these printing trends, a reliability analysis of the printed line was performed. The printed line formed the most uniform width at 380 °C and had a highest Weibull coefficient of 28.6 using the reliability analysis technique called Weibull modulus

    The development of digital histopathology platform using quantitative phase imaging and artificial intelligence

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    Here, we propose a portable, multimodal, fully-automated digital histopathology platform based on quantitative phase imaging (QPI) and artificial intelligence (AI). Our system clearly visualized cells and tissues of histology slides without labeling at various magnifications up to 40x. It was also built as small form factor and operated by wireless control of the custom-built Android application considered mobility and user-interface. Moreover, our system equipped AI guidance which converted quantitative phase images to conventional H&E stained brightfield images with high accuracy. With validation tests on several tissues, we confirmed that our device has competitive performance over traditional methods in histopathologic works

    Reactive Disperse Dyes Bearing Various Blocked Isocyanate Groups for Digital Textile Printing Ink

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    Wastewater management is of considerable economic and environmental importance for the dyeing industry. Digital textile printing (DTP), which is based on sublimation transfer and does not generate wastewater, is currently being explored as an inkjet-based method of printing colorants onto fabric. It finds wide industrial applications with most poly(ethylene terephthalate) (PET) and nylon fibers. However, for additional industrial applications, it is necessary to use natural fibers, such as cotton. Therefore, to expand the applicability of DTP, it is essential to develop a novel reactive disperse dye that can interact with the fabric. In this study, we introduced a blocked isocyanate functional group into the dye to enhance binding to the fabric. The effect of sublimation transfer on fabrics as a function of temperature was compared using the newly synthesized reactive disperse dyes with different blocking groups based on pyrazole derivatives, such as pyrazole (Py), di-methylpyrazole (DMPy), and di-tert-butylpyrazole (DtBPy). Fabrics coated with the new reactive disperse dyes, including PET, nylon, and cotton, were printed at 190 °C, 200 °C, and 210 °C using thermal transfer equipment. In the case of the synthesized DHP-A dye on cotton at 210 °C, the color strength was 2.1, which was higher than that of commercial dyes and other synthesized dyes, such as DMP-A and DTP-A. The fastness values of the synthesized DHP-A were measured on cotton, and it was found that the washing and light fastness values on cotton are higher than those of commercial dyes. This study confirmed the possibility of introducing isocyanate groups into reactive disperse dyes
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