Ultrasonographic findings of diseases in peripheral lung fields using transtracheobronchial endoscopic ultrasonography (TUS)

Cystic neoplasms of the pancreas constitute about 9% of all cystic lesions of the pancreas and less than 1% of all pancreatic neoplasms. The case of a 70 years-old woman with microcystic cystadenoma is reported. CT-scan of the abdomen diagnosed a 5 cm multilocular septated cyst, with calcifications in the context, localized in the head-uncinate process of the pancreas. The mass was well separated by a sharp cleavage plane with portal vein and superior mesenteric vessels. An ERCP showed cephalic symmetrical stenosis (diameter 3 mm) of the main pancreatic duct (MPD), mildly dilated in the remaining tract (diameter 6 mm). An intraoperative biopsy of the cystic wall was performed. Therefore, it was decided to proceed with a duodenum-preserving resection of the head of the pancreas (DPPHR), including the stenosis tract of the MPD in the surgical specimen. The reconstructive procedure consisted, by i.v. jejunal loop transposition, in a side-to-side pancreatico-jejunostomy, including in the anastomosis both corpocaudal stump and the resection cavity of the pancreatic head, and an end-to-side Roux-en-Y jejuno-jejunostomy. With respect to long-lasting pain relief and preservation of the endocrine and exocrine functions of the pancreas, DPPHR is a highly effective surgical procedure with a low early and late morbidity and mortality due to limited surgical resection. This technique, introduced into surgical practice by Beger, is indicated in patients with chronic pancreatitis with an inflammatory mass in the head of the pancreas. The authors conclude that this procedure can be performed also in case of pancreatic benign tumors, as microcystic cystadenoma. Advantages of this technique makes DPPHR an attractive alternative to Pylorus-Preserving-Pancreatico-Duodenectomy (PPPD).     

Graft copolymerization to cellulose. Effect of sodium thiosulfate on hydrogen peroxide initiator system

The effect of sodium thiosulfate on the graft copolymerization of methyl methacrylate to cellulose in the hydrogen peroxide initiator system was investigated. The addition of sodium thiosulfate in general was effective for decreasing the per cent grafting and the average molecular weight of grafts and increasing the formation of homopolymer, and the effects became pronounced with increasing hydrogen peroxide concentration. Moreover, the addition of sodium thiosulfate slightly suppressed the formation of grafts at a hydrogen peroxide concentration of 3 mmole/l., but greatly promoted it at 20 mmole/l. Traces of metallic ions present in cellulose could not be eliminated sufficiently by treatment with 3N hydrochloric acid. Such ions were found to interact with hydrogen peroxide and thus participate directly in the initiation and termination of the polymerization reaction. EDTA, the chelating agent, was highly effective for suppressing such participation of metallic ions. In the hydrogen peroxide initiator system applied to the EDTA-treated samples, sodium thiosulfate caused an effective initiation of graft formation.     

Cellulose peroxides derived from carbonylated cellulose and hydrogen peroxide

Cellulose peroxides derived from hydrogen peroxide and cellulose derivative into which a ketone group is introduced by reaction with methyl vinyl ketone were investigated. The amount of peroxide formed on the cellulose substrate increased linearly with increasing carbonyl content of the sample, and sulfuric acid activated the formation of peroxide. The cellulose peroxide was gradually decomposed at 60°C in aqueous medium, and the decomposition was accelerated by addition of ferrous salt or irradiation with light of λ > 300nm. Grafting was initiated by adding methyl methacrylate to the thermal decomposition system under nitrogen. The formation, stability, thermal decomposition, and structure of the cellulose peroxide were discussed in comparison with one derived from aldehyde cellulose and hydrogen peroxide.     

Analysis of proton exchange membrane fuel cell catalyst layers for reduction of platinum loading at Nissan

The biggest issue that must be addressed in promoting widespread use of fuel cell vehicles (FCVs) is to reduce the cost of the fuel cell system. Especially, it is of vital importance to reduce platinum (Pt) loading of catalyst layers (CLs) in the membrane electrode assembly (MEA) of a proton exchange membrane fuel cell (PEMFC). In order to lower the Pt loading of the MEA, mass transport of reactants related to the performance in high current density should be enhanced significantly as well as kinetics of the catalyst, which can result in the better Pt utilization and effectiveness. In this study, we summarized our analytical approach and methods for reduction of Pt loading in CLs. Microstructure, mass transport properties of the reactants, and their relation in CLs were elucidated by applying experimental analyses and computational methods. A simple CL model for I–V performance prediction was then established, where experimentally elucidated parameters of the microstructure and the properties in CLs were taken into account. Finally, we revealed the impact of lowering the Pt loading on the transport properties, polarization, and the I–V performance.     

Effects of aging and moisture on the dynamic viscoelastic properties of oriental lacquer (urushi) film

The effects of aging and moisture on the dynamic viscoelastic properties of three oriental lacquer films were investigated. With aging over 1000 days at room temperature, the glass‐transition temperature of the lacquer films (T_α) shifted to higher temperatures, the maximum loss tangent (tanδ_α) decreased, and the storage modulus at 20°C (E) increased. These changes were analogous irrespective of lacquers. With increasing moisture content, E decreased and tanδ increased at room temperature. Although the equilibrium moisture content of the virgin lacquer (sap) film was higher than that of the clear lacquer film, its E and tanδ were more stable with an increase of moisture content. It was speculated that the polysaccharides aggregated in the sap film did not effectively contribute to the mechanical properties of the film, while their hygroscopicity resulted in higher moisture content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2288–2294, 2002     

EFFECT OF FLUIDIZING PARTICLE ON DRYING CHARACTERISTICS OF POROUS MATERIAL IN FLUIDIZED BED

The drying characteristics of porous material in fluidized bed were examined theoretically and experimentally. The brick ball was used as the sample and immersed in the fluidized bed. The glass beads were used as the fluidizing particles and the particle diameters were changed. When the pore diameter of sample was relatively large, the fluidizing particles were adhered on the sample surface. In the theoretical analysis, the heat and mass transfers in adhered particle layer were considered. The fluidizing particles were adhered on the sample surface during the earlier period of drying. The sample temperature largely decreased when the mass of adhered particle decreased. The calculated results are in good agreement with experimental data. The diameter of fluidizing particle had a small effect on the drying time. The excess increments in drying gas temperature hardly contributed to shortening the drying time.     

Microphase-separated structure and mechanical properties of novel polyurethane elastomers prepared with ether based diisocyanate

A diisocyanate baring ether bonds, 1,2-bis(isocyanate)ethoxyethane (TEGDI), was used for the preparation of polyurethane elastomers (PUEs). The PUEs were synthesized with either TEGDI or HDI, poly(oxytetramethylene) glycol (PTMG), and curing agents by a prepolymer method. 1,6-Hexamethylene diisocyanate (HDI) was also used as a control diisocyanate. The TEGDI-based PUEs exhibited highly softened property on account of flexibility of TEGDI itself and weaker phase separation. Another TEGDI-based PUEs were prepared with either poly(oxypropylene) glycol (PPG) or poly(caprolactone) glycol (PCL). Microphase-separated structure of these TEGDI-based PUEs are quite different from those with general diisocyanates and the PUEs were made be greatly softened.     

Surface treatment of ferromagnetic nanoparticle-assembly by UV irradiation with ozone

Fe-Pt nanoparticles of 3.5 nm in average particle diameter are obtained with the simultaneous chemical reduction of platinum acetylacetonate and the thermal decomposition of iron pentacarbonyl. Because the as-synthesized particles are superparamagnetic at room temperature, they must be transformed to L1₀ ordered phase by annealing at temperatures above 773 K to apply to high-density magnetic recording media. However, the annealing at such high temperatures induces the coalescence and inter-particle sintering. In the present paper, to solve the problem caused by the annealing, we use ultraviolet-ozone treatment to modify particle surface. Even after annealing at 773 K, the crystalline size is kept at 4.4 nm. Furthermore, coercivity is higher than that without the ultraviolet-ozone treatment.     

Cathodic pulse breakdown of anodic films on aluminium in alkaline silicate electrolyte – Understanding the role of cathodic half-cycle in AC plasma electrolytic oxidation

Sequential anodic and cathodic pulse voltages were applied on anodised Al micro-electrodes in alkaline silicate electrolyte to explore the role of cathodic pulse in AC or bipolar plasma electrolytic oxidation (PEO) process. SEM observation was carried out to observe the sites of anodic and cathodic breakdown and their morphologies. The prior anodic breakdown accelerated the cathodic breakdown at ?50 V, and the acceleration was associated with the preferential cathodic breakdown at the anodic breakdown sites. However, the succeeding anodic breakdown during applying anodic pulse of 420 V for 2 ms was highly suppressed at the cathodic breakdown sites. This would randomise the anodic breakdown sites. Such role may contribute to the formation of rather uniform coatings on aluminium in this electrolyte without large discharge channels when larger cathodic current is applied with respect to the anodic current in AC PEO.