Porous Titania Ceramic Prepared by Mimicking Silicified Wood

A porous titania ceramic with a woodlike microstructure that was analogous to silicified wood was prepared. The production of "titanified wood" was performed using the following process: (i) introduction of titanium tetraisopropoxide into wood materials via vacuum infiltration, (ii) hydrolysis of the titanium tetraisopropoxide in the cell structure to form a titania gel, and (iii) firing at a temperature of 600°–1400°C in air. The resulting titania ceramic had the same external and internal forms of the original wood.     

Influence of interparticle forces on selective wet agglomeration

The influence of interparticle forces between primary particles, which include interaction force between dispersed particles in liquid calculated by DLVO theory and two kinds of forces caused by a liquid bridge of bridging liquid between particles, on selective wet agglomeration was investigated on the basis of the relationships between the results of separation efficiency obtained in author’s previous study and these interparticle forces. The first step of selective wet agglomeration is the collision between bridging liquid droplets and objective particles to be agglomerated. This collision is mainly influenced by the interparticle force calculated by DLVO theory. Incorporation of two objective particles, the second step in the agglomeration process, is influenced by liquid bridge force between objective particles. Growth to pellet-type agglomerates, the third step in the agglomeration process, is thought to be influenced mainly by aggregation force in the agglomerates by entry suction potential. The results of this study showed that selective wet agglomeration under the experimental conditions used in this study is influenced greatly by liquid bridge force and entry suction potential, which play major roles in the second step and third step, respectively, of the selective wet agglomeration process.     

Generalized stress intensity factors of V-shaped notch in a round bar under torsion, tension, and bending

In this study, generalized stress intensity factors K_I,λ1, K_II,λ2, and K_III,λ4 are calculated for a V-shaped notched round bar under tension, bending, and torsion using the singular integral equation of the body force method. The body force method is used to formulate the problem as a system of singular integral equations, where the unknown functions are the densities of body forces distributed in an infinite body. In order to analyze the problem accurately, the unknown functions are expressed as piecewise smooth functions using three types of fundamental densities and power series, where the fundamental densities are chosen to represent the symmetric stress singularity and the skew-symmetric stress singularity. Generalized stress intensity factors at the notch tip are systematically calculated for various shapes of V-shaped notches. Normalized stress intensity factors are given by using limiting solutions; they are almost determined by notch depth alone, and almost independent of other geometrical parameters. The accuracy of Benthem-Koiter’s formula proposed for a circumferential crack is also examined through the comparison with the present analysis.     

Effects of triton WR 1339 and orotic acid on lipid metabolism in rats

In order to investigate the effect of hepatic cholesterol flux on biliary bile acids, Triton WR 1339 and orotic acid were administered to rats, and the biliary cholesterol, phospholipids and bile acids were analyzed together with serum lipoproteins and hepatic lipids. Triton, which raised serum very low density lipoprotein and lipid levels and decreased serum high density lipoprotein liver lipid levels, increase the biliary cholic acid group/chenodeoxycholic acid group ratio (CA/CDCA) in the bile without affecting the total amount of bile acids and the other biliary lipids. Orotic acid, which decreased serum lipid and lipoprotein concentrations and increased liver lipid levels, increased the biliary excretion of cholesterol and phospholipids, but produced no significant change in the total amount of bile acids and in the CA/CDCA ratio in bile.     

Characteristics of serum hyaluronate concentrations in patients with alcoholic liver disease

It has been reported that serum hyaluronate [hyaluronic acid (HA)] concentrations are increased in liver diseases, especially in alcoholic liver disease (ALD). However, the characteristics of serum HA concentration in patients with ALD have not been studied. In this study, first, we measured serum HA concentrations in patients with different stages of both ALD and non-ALD to clarify the characteristics of serum HA concentration in patients with ALD. Second, we measured serum HA concentrations in patients with ALD sequentially after abstinence. We also measured serum HA concentrations in patients with chronic type C hepatitis before and after treatment with interferon. Finally, we analyzed the relationship between serum HA concentrations and the contents of type IV collagen and laminin in the livers of both ALD and non-ALD patients. Serum HA concentrations in liver disease were higher than the cut-off value, and increased significantly (p < 0.001) in parallel with the progression of hepatic fibrosis in both ALD and non-ALD patients. Serum HA concentrations in patients actively drinking with ALD were significantly higher (p < 0.001) than those in non-ALD. After 4 weeks of abstinence, these concentrations fell to the levels of non-ALD. Although serum ALT levels were decreased in 80% of patients treated with interferon, serum HA concentrations were not changed or increased. A significant correlation between serum HA concentrations and hepatic type IV collagen and laminin content was present in ALD, but not in non-ALD. These results clearly suggest that the increase of serum HA concentrations in ALD may be associated with not only hepatic fibrosis, but also alcohol drinking.     

Characterization of p–n junction formed at the boundary of facets in cubic-BN using scanning electron microscope

For the application of ultraviolet light emitting diodes, self-organized p–n junctions were formed at the boundaries of facets in cubic boron nitride. The optical and electrical characteristics of these junctions were studied using cathodoluminescence (CL) and electron-beam-induced current (EBIC) in a scanning electron microscope. The p and n regions were clearly distinguished by the variation of CL spectra and monochromatic CL images. A broad band with a peak at 4.0 eV (310 nm) was observed in p-region, but not in n-region. Monochromatic CL image at 4.0 eV showed that the Be impurity distribution in p-region was not uniform. Variation of EBIC profiles indicated the inhomogeneity of diffusion length along p-n junction. The inhomogeneous electroluminescence along the p–n junction under the reverse current condition was clarified by the inhomogeneities revealed by EBIC and CL characterizations.     

Development of atherosclerosis in alloxan diabetic rats

Rats with alloxan-induced diabetes developed severe atherosclerotic lesions when they were maintained on a 0.25% cholesterol diet for one year. The atheromatous changes developed at the aortic arch, appeared as early as 3 months after the start of the experiment, and increased thereafter. The diabetic rats also developed atherosclerosis when they were fed standard rat chow, but the area of the atheromatous lesion was about one tenth of that in rats fed the high-cholesterol diet. Normal rats did not develop atherosclerosis even when fed the high-cholesterol diet for one year. The alloxan diabetic rats showed no increase in body weight, but developed serum glucose levels as high as 600-800 mg/dl as well as high serum cholesterol levels and lower serum HDL-cholesterol levels. The development of atherosclerosis in these rats was significantly related to an increase in the serum cholesterol/phospholipid ratio, the atherogenic index (TC-HDLC/HDLC), and the serum total cholesterol level, but was not related to the serum glucose, HDL-cholesterol, triglyceride, or lipid peroxide levels. These relationships were found as early as B-16 weeks after the start of the experiment. These data suggest that the serum cholesterol/phospholipid ratio, the atherogenic index, and the total cholesterol level are important risk factors for the development of atherosclerosis in rats with alloxan diabetes.