Artificial Intelligence-based determination of fracture toughness and bending strength of silicon nitride ceramics

Two mechanical properties, fracture toughness (K_IC) and bending strength (σ), of silicon nitride (Si₃N₄) ceramics were determined from their microstructural images via convolutional neural network (CNN) models. The Si₃N₄ samples used for database were fabricated using various kinds of sintering additives under different process conditions. In total, 330 data sets were prepared and used for building the CNN models for artificial intelligence-bassed determination of the two mechanical properties and testing the determination accuracy of the trained models. The determination coefficients (R²), which were used as accuracy indices, were approximately 0.85 for K_IC and 0.92 for σ. Although both the R² values were relatively high, the lower value for K_IC suggests that it is influenced more by what is little obtained from the microstructural information, such as grain-boundary characteristics. Furthermore, gradient-weighted class activation mapping, which can visualize which parts of the image the CNN models focus on, showed that the trained models determined the two mechanical properties based on correct recognition of the microstructural difference among the images.     

Potential of the Angiotensin Receptor Blockers (ARBs) Telmisartan,Irbesartan, and Candesartan for Inhibiting the HMGB1/RAGE Axis in Prevention and Acute Treatment of Stroke

Stroke is a major cause of mortality and disability worldwide. The main cause of stroke is atherosclerosis, and the most common risk factor for atherosclerosis is hypertension. Therefore, antihypertensive treatments are recommended for the prevention of stroke. Three angiotensin receptor blockers (ARBs), telmisartan, irbesartan and candesartan, inhibit the expression of the receptor for advanced glycation end-products (RAGE), which is one of the pleiotropic effects of these drugs. High mobility group box 1 (HMGB1) is the ligand of RAGE, and has been recently identified as a lethal mediator of severe sepsis. HMGB1 is an intracellular protein, which acts as an inflammatory cytokine when released into the extracellular milieu. Extracellular HMGB1 causes multiple organ failure and contributes to the pathogenesis of hypertension, hyperlipidemia, diabetes mellitus, atherosclerosis, thrombosis, and stroke. This is the first review of the literature evaluating the potential of three ARBs for the HMGB1-RAGE axis on stroke therapy, including prevention and acute treatment. This review covers clinical and experimental studies conducted between 1976 and 2013. We propose that ARBs, which inhibit the HMGB1/RAGE axis, may offer a novel option for prevention and acute treatment of stroke. However, additional clinical studies are necessary to verify the efficacy of ARBs.     

Oil-water interfacial activation of lipase for interesterification of triglyceride and fatty acid

Lipase usually has little interesterification activity in organic solvents, probably owing to the absence of an oil-water interface. Lipases were processed in a two-phase hydrocarbon-water system that had an oil-water interface. Crude lipase (from Rhizopus japonicus) in a buffer and a small volume of aliphatic hydrocarbon as an oil phase were mixed and then lyophilized to remove the aqueous and oil phases. The interfacially processed lipase has a remarkable interesterification activity in n-hexane compared to crude native lipases. We postulate that this activation is caused by the oil-water interface, i.e., the interface between hydrocarbon and water makes the lipase lid open and enables the lipase to work effectively in n-hexane. Several different hydrocarbons were investigated as an oil phase, and n-tetradecane was found to be the best for interesterification. Activated lipase was successfully inactivated in a water suspension without an oil-water interface, and the inactivated lipase could be reactivated. We demonstrated that the oil (hydrocarbon)-water interface induced reversible activation to lipase for interesterification. This work was presented at the Biocatalysis Symposium in April 2000, held at the 91st Annual Meeting and Expo of the American Oil Chemists’ Society, San Diego, CA     

Novel functional polymers: Poly(dimethylsiloxane)‐polyamide multiblock copolymer. IX. Surface properties of blend film of aramid–silicone resins with aramid

A blending technique was studied in order to widen the applications of aramid–silicone multiblock copolymer (PAS). A PAS/aramid blend film was prepared and the characterization of the surfaces was investigated. The two‐phase nature of poly(dimethylsiloxane) (PDMS) and the aromatic polyamide (aramid) multiblock copolymer (PAS) were clarified in part by evaluating the surface enrichment in PAS/aramid blend films. There were no significant differences among the PASs as additives; however, the PASs were able to alter the aramid surface to that of silicone, even though they were used at low concentration. The atomic force microscopy observation suggested that the mobility of the silicone segment that existed on the surface was restricted by the associated aramid segments. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2198–2205, 2000