Cationic Graft Polymerization of 2-Oxazolines on Poly(vinyl alcohol) Derivatives

The graft polymerization of various monomers onto PVA has been studied by radical polymerization mechanism. Successful grafting of acrylonitrile (AN), acrylamide (AAm), acrylic acid, methyl methacrylate, and vinyl acetate was reported by using chemical (Minoet al., 1959; Ide, 1961; Maskimov et al., 1965) and radiation (Misra et al., 1987) methods. On the other hand, less attention has been paid to ionic graft polymerization. Sasson and Zilkha reported on grafting formaldehyde onto potassium-metallated PVA (Sasson and Zilkha, 1969). Galin studied grafting of AN and propane sulfone onto sodium-metallated PVA (Galin, 1971). We used the same anionic system for the polymerization of AAm (Ikeda and Suzuki, 1980).     

Correlations of Hepatic Hemodynamics,Liver Function,and Fibrosis Markers in Nonalcoholic Fatty Liver Disease: Comparison with Chronic Hepatitis Related to Hepatitis C Virus

The progression of chronic liver disease differs by etiology. The aim of this study was to elucidate the difference in disease progression between chronic hepatitis C (CHC) and nonalcoholic fatty liver disease (NAFLD) by means of fibrosis markers, liver function, and hepatic tissue blood flow (TBF). Xenon computed tomography (Xe-CT) was performed in 139 patients with NAFLD and 152 patients with CHC (including liver cirrhosis (LC)). The cutoff values for fibrosis markers were compared between NAFLD and CHC, and correlations between hepatic TBF and liver function tests were examined at each fibrosis stage. The cutoff values for detection of the advanced fibrosis stage were lower in NAFLD than in CHC. Although portal venous TBF (PVTBF) correlated with liver function tests, PVTBF in initial LC caused by nonalcoholic steatohepatitis (NASH-LC) was significantly lower than that in hepatitis C virus (C-LC) (p = 0.014). Conversely, the liver function tests in NASH-LC were higher than those in C-LC (p < 0.05). It is important to recognize the difference between NAFLD and CHC. We concluded that changes in hepatic blood flow occurred during the earliest stage of hepatic fibrosis in patients with NAFLD; therefore, patients with NAFLD need to be followed carefully.     

High-efficiency GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy

We report the initial results of GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy (MBE) technique. For GaAs single-junction solar cell, with the application of AlInP as the window layer and GaInP as the back surface field layer, the photovoltaic conversion efficiency of 26% at one sun concentration and air mass 1.5 global (AM1.5G) is realized. The efficiency of 16.4% is also reached for GaInP solar cell. Our results demonstrate that the MBE-grown phosphide-contained III-V compound semiconductor solar cell can be quite comparable to the metal-organic-chemical-vapor-deposition-grown high-efficiency solar cell.     

A theoretically reproduced phase diagram for vinylidene fluoride and trifluoroethylene copolymers

The phase diagram of ferroelectric copolymers of vinylidene fluoride and trifluoroethylene is reproduced theoretically using a simple model for ferroelectric polymers. The copolymerization ratio dependencies of the intramolecular interaction and the intermolecular interaction are induced to reproduce the phase diagram. These interactions have the following effects on the ferroelectric phase transition of the copolymers. The intermolecular interaction between vinylidene fluoride segments is dominant in the ferroelectric phase transition. The intramolecular interaction, discriminating between different chain conformations, gives the phase transition a variety of characters, including first and second order phase transitions. The copolymerization ratio dependence of the intermolecular interaction is also numerically estimated by summing the interaction energy between all atoms. Comparing these two results, we discuss the size of a segment carrying an elementary process of the phase transition.     

Monomer recycling for vulcanized silicone rubbers in the form of cyclosiloxane monomers. Role of acid buffers

The KOH-catalyzed depolymerization of vulcanized silicone rubbers to reproduce cyclosiloxane monomers was studied. First, the depolymerization was carried out in toluene with varying amounts of KOH to find that the yield of monomers first increased and then decreased with the increment of KOH, the highest yield was 65% at the molar ratio KOH/(Si–O) UNITS=0.08. At the molar ratio 0.13 in the absence of solvent, the monomers yield was 46%. However, when an acid buffer such as KH₂PO₄ and KCOOC₆H₄COOH was added after the KOH-catalyzed depolymerization was over, the product yield was increased remarkably to more than 80%.     

Recovery of monomers and fillers from high-temperature-vulcanized silicone rubbers—combined effects of solvent, base and fillers

The depolymerization of high-temperature-vulcanized (HTV) silicone rubbers containing filler silica and alumina into cyclosiloxane monomers and spontaneous recovery of fillers were studied. First, HTV silicone rubber was treated with different types of solvents in the presence of KOH to find that a triad mixture of diethylamine, methanol and hexane was appropriate not only to dissolve the silicone rubber to a suspension but also to separate fillers completely by filtration. The filtrate was distilled to remove solvent first and then give pure cyclosiloxane monomers in 76–84% yields. Second, the rubbers were treated with other types of triad mixture of solvents and bases, e.g. tetramethylammonium hydroxide, hexane and diethylamine. After filtration, residue was again treated with the amine and hexane to recover clean fillers in 83–93% yields. Cyclosiloxane monomers were also obtained from the combined filtrates in 67–78% yields.     

新型Gemini阳离子表面活性剂的合成和性能（1）：从长链烷基二甲基胺及其盐酸盐和环氧氯丙烷合成双烷基双季铵盐阳离子

概述了从长链烷基二甲基叔胺及其盐酸盐和环氧氯丙烷或其他连接剂在温和条件下合成新型双烷基双季铵盐型阳离子表面活性剂的方法,产品的表面活性以及烷基链长、连接基团结构对产物表面活性的影响。     

CeO2–ZrO2 Solid Solution Catalyst for Selective Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide

CeO₂–ZrO₂ solid solution catalysts are very effective for the selective synthesis of dimethyl carbonate from methanol and CO₂. The activity was much dependent on the calcination temperature. The higher the calcination temperature, the higher the activity of the catalyst for DMC formation, though the BET surface area is lower on the catalyst calcined at higher temperature.     

Effects of dietary defatted squid on cholesterol metabolism and hepatic lipogenesis in rats

Male Sprague-Dawley rats were fed a cholesterol-free (Exp. 1) or cholesterol-supplemented (Exp. 2) diet containing 20% casein (control group) or 15% defatted squid and 5% casein (defatted squid group), as protein, for 14 d. Serum and hepatic cholesterol concentrations were lower in rats fed defatted squid than in those fed casein in both cholesterol-free (−20%, P<0.05 and −15%, P<0.05, respectively) and cholesterol-supplemented (−25%, P<0.05 and −15%, P<0.05, respectively) diets. Hepatic triglyceride concentration was lower in the defatted squid than in the control groups in both cholesterol-free (−51%, P<0.05) and cholesterol-supplemented diets (−38%, P<0.01). The activities of cytosolic fatty acid synthase and the NADPH-generating enzymes, malic enzyme and glucose-6-phosphate dehydrogenase, in the liver were lower in the defatted squid than in the control groups in both cholesterol-free (−21%, P<0.01, −33%, P<0.05, and −33%, P<0.01, respectively) and cholesterol-supplemented diets (−34%, P<0.05, −57%, P<0.05, and −67%, P<0.05, respectively). The activity of mitochondrial carnitine palmitoyltransferase in the liver was comparable between the control and defatted squid groups. The activity of Mg²⁺-dependent phosphatidate phosphohydrolase in the liver cytosol was lower in the defatted squid (−9%, P<0.05) than in the control groups only in the cholesterol-free diet. Fecal excretion of total steroids was stimulated by the feeding of defatted squid in both cholesterol-free (+77%, P<0.005) and cholesterol-supplemented diets (+29%, P<0.01). These results suggest that the nonlipid fraction of squid exerts a hypocholesterolemic effect by increasing the excretion of total steroids in feces. The fraction also induces a triglyceride-lowering activity in the liver by decreasing hepatic lipogenesis.