The structures and gas-sorption properties of l-tyrosine films prepared by the Knudsen effusion method

l-tyrosine (L-Tyr) films with an oblique columnar structure were prepared by the Knudsen cell effusion method. The L-Tyr films were formed at a Knudsen cell temperature that was sufficiently lower than the decomposition temperature of L-Tyr. As the heating rate controlled by DC current is increased, the molecular network constructed of hydrogen bonds tends to collapse, and the film density and surface hydrophobicity tend to decrease. Higher DC currents are likely to induce a decarboxylation reaction. L-Tyr films prepared at a higher heating rate have enhanced gas sorption capabilities for a wide range of volatile organic compounds (VOCs). The sorption capabilities are particularly enhanced for linear hydrocarbons. The gas sorption characteristics for VOCs suggest that the adsorption in the vicinity of the film surface is dominant rather than diffusion into the film, which corresponds with the densified surface morphology.     

A spatial evaluation of forest biomass usage using GIS

We conducted a spatial evaluation of forest biomass usage using a geographic information system (GIS) for the Japanese town of Yusuhara. In Japan, over 60% of the land is covered with forest, of which at least 40% is artificial forest. However, because of high labor costs, the profitability of forestry is decreasing, so timber cultivation is not done to the extent that it could be, and thinning has to be subsidized. Under these circumstances, much of the forest is deteriorating. Most of the thinning is accounted for by throwaway thinning, in which the resulting wood is not used. However, with the steep rise in oil prices and the intensification of global warming concerns, expectations are rising for the use of biomass energy from thinned timber that has previously been discarded. If thinned timber, logging residues, and offcuts are utilized for biomass energy and their economic value becomes apparent, profitability will improve for both final cutting and thinning. And in addition to forestry activities being invigorated, it will be possible for some of the deteriorating forests (which have associated dangers such as landslides) to recover. However, using thinned timber and logging residues is problematic in that profitability is affected by harvesting costs. Harvesting costs are largely determined by geographic factors and are higher for more distant stands. Accordingly, in this article, operational costs for different stands are calculated using GIS and matched with total demand in the subject region. In addition, stands with lower operational costs are identified and an investigation of a highly feasible use of forest biomass is carried out.     

Structural analysis of coating film with ultra-small-angle x-ray scattering

The structure of magnetic coating films was analyzed by the ultra-small-angle X-ray scattering (USAXS) technique. Small-angle X-ray scattering (SAXS) has been used to investigate the size, shape, and correlation of the nm sized structure. USAXS, with a measurable range extending to the μm order, can be used to analyze the submicron sized structure of paints and coating films. Preliminary USAXS experiments for a magnetic paint and magnetic coating films revealed that USAXS is useful to evaluate the structure of the particles in the paint and the films. Combined with other experimental methods, USAXS will provide a new kind of information about the structural analysis. Yokohama Research Center, 1000 Kamoshida, Aoba-ku, Yokohama, 227-8502, Japan. Department of Polymer Chemistry, Kyoto, 606-8501, Japan.     

Simple low-vacuum coating of paraffin wax on carbonaceous gas sensing layers

A simple low-vacuum coater has been fabricated by using a vacuum resin degassing chamber, in which an aluminum effusion cell is heated by a soldering iron. Our developed vacuum coater presents the versatile methods for depositing paraffin wax for skin-coating the sensing layers of quartz crystal microbalance (QCM). As the increase of the cell temperature, the thickness and inhomogeneity of the wax films were increased. Impedance analyses revealed that the energy dissipation of the QCM was remarkably enhanced with the amount of wax. It was also revealed that the as-deposited wax was fluidic until coagulation by heat radiation. This surface skin coating enhanced the ethyl acetate (EA) sorption capabilities of the polyethylene-sputtered QCM sensor, whereas, it reduced the EA sorption capacity of the d-phenylalanine-sputtered QCM sensor.     

Association of atherosclerosis and cardiac cell dysfunction

It is recognized that heart failure in patients with atherosclerotic lesion is the result of ischemia. However, there may also be cardiac cell dysfunction independent of ischemia, as factors advancing both of atherosclerosis and heart failure are discovered. The renin-angiotensin system is one of factor and angiotensin-converting enzyme inhibitor (ACEi) prevents progression of atherosclerotic lesion and heart failure. To elucidate the association of atherosclerosis and cardiac cell dysfunction, we investigated the effects of ACEi on cultured cardiac myocytes. Captopril increased beta-receptor density of myocytes and augmented the response to isoproterenol. CV-3480, a ACEi, also up-regulated beta-receptors but angiotensin I, angiotensin II and angiotensin type I receptor antagonist did not. Bradykinin B2 receptor blocker, HOE140, suppressed the effect of captopril on cultured cells. The results suggest that ACEi up-regulated beta-receptors and augmented the response to beta-receptor agonist through BK potentiation.     

Preparation of flame-retardant polyethylene foam of open-cell type by radiation grafting of vinyl phosphonate oligomer

Flame-retardant polyethylene foam was successfully obtained by grafting a vinyl phosphonate oligomer onto polyethylene foam of an open-cell type using a simultaneous radiation grafting technique. The foam was impregnated with the oligomer and irradiated in a nitrogen atmosphere with an electron beam. The grafted foam thus obtained was found to pass the three most severe flammability tests that have to be cleared when the foam is to be used for materials where high flame-retardant property is required. No hydrogen cyanide was detected in burning exhaust gas of the grafted foam. © 1994 John Wiley & Sons, Inc.     

Portal-hypertensive gastropathy develops less in patients with cirrhosis and fundal varices

BACKGROUND/AIMS: The aim of this prospective study was to examine the association of portal-hypertensive gastropathy and fundal varices in patients with cirrhosis. METHODS: We carried out an endoscopic observation in 476 patients with cirrhosis (study 1), including 62 patients undergoing endoscopic obliteration of esophageal varices (study 2). In study 1, patients were classified into five subgroups: no esophagofundal varices (n=119), small esophagofundal varices (n=127), dominant esophageal varices (n=177), dominant fundal varices (n=27), and large esophagofundal varices (n=26). The severity of liver dysfunction was assessed by Pugh-Child classification: class A (n=222), class B (n=200), and class C (n=54). In study 2, two groups, poorly developed fundal varices (n=50) and well developed fundal (n=12), were distinguished and the follow-up endoscopic examinations were performed on the basis of 3-month intervals for 2 years. In each study, the severity of portal-hypertensive gastropathy was scored: 0 (absent), 1 (mild), 2 (severe), and 3 (bleeding). RESULTS: Study 1: One-way ANOVA showed that both variceal pattern and Pugh-Child class significantly influenced portal-hypertensive gastropathy score. However, two-way ANOVA indicated that variceal pattern was the only significant variable. Portal-hypertensive gastropathy score was significantly higher in patients with dominant esophageal varices than in either patients with no esophagofundal varices or patients with small esophagofundal varices. In contrast, portal-hypertensive gastropathy score in patients with dominant fundal varices was similar to that in patients with no esophagofundal varices and was significantly lower compared with that in patients with dominant esophageal varices. Furthermore, portal-hypertensive gastropathy score was significantly lower in patients with large esophagofundal varices than in patients with dominant esophageal varices. Study 2: After the obliteration of esophageal varices, portal-hypertensive gastropathy score in patients with poorly developed fundal varices became significantly higher at 3-, 6-, 9-months while it was not modified in patients with well developed fundal varices during the follow-up period. Furthermore, the integrated incremental change in portal-hypertensive gastropathy score during the first 1-year follow-up period was significantly lower in patients with well developed fundal varices than in patients with poorly developed fundal varices. CONCLUSIONS: These results indicate that both spontaneous and obliteration-induced portal-hypertensive gastropathy lesions develop less in patients with cirrhosis and fundal varices.     

Preparation of hydrophilic polyethylene foam of open cell type by radiation grafting of acrylic acid

Hydrophilic polyethylene foam was synthesized by radiation grafting of acrylic acid onto polyethylene foam of open cell type using monomer solution containing Mohr's salt which inhibits homopolymerization of the monomer. The graft foam was easily dyed by cationic dyes and showed excellent moisture regain. The wicking properties were also excellent and were almost the same as those of commercially available PVA foam. The surface resistivity of 10¹⁶ ohm of the original foam decreased to 10⁶ ohm and half decay time of surface charge decreased from 8000 s to 1 s by the grafting, indicating that the grafted foam has excellent antistatic properties.