Simple evaluation of aortic arch calcification by chest radiography in hemodialysis patients

Vascular calcification is associated with a poor prognosis in dialysis patients. It can be assessed with computed tomography but simple inoffice techniques may provide useful information. We compared the results obtained with a simple noninvasive technique with those obtained using multidetector computed tomography for aortic arch calcification volume (AoACV) in chronic hemodialysis (HD) patients. The enrolled study subjects were 63 (32 men and 31 women) maintenance HD patients. Calcification of the aortic arch was semiquantitatively estimated with a AoAC score (AoACS) on plain chest radiology. The AoACV was increased, with a mean value of 6.6 ranging from 0% to 36.5%. The coefficient of intraobserver variation was less than 2.5%. Aortic arch calcification score was highly correlated with AoACV (r=0.635, P<0.001). Multiple regression analysis showed age (F value=12.62, P<0.001) and pulse pressure (F value=4.54, P=0.037) to be significant independent determinants of AoACS. In conclusion, a simple measurement of AoACS may be useful for inoffice imaging to choose a therapeutic regimen in HD patients.     

Properties of Sodium-Lithium Niobate Solid Solution Ceramics with Small Lithium Concentrations

The structural, dielectric, and piezoelectric properties of the solid solution (Na_1-x,Li_x,)NbO₂ were studied. Solid solution ceramics with x values up to 0.14 occur as a single phase. The phase diagram from 0° to 600°C is given. The low-temperature phase has a perovskite pseudo-monoclinic structure and inverts to a pseudotetragonal structure at a temperature that decreases with increasing x. The high-temperature phase is pseudocubic, and the minimum transition temperature from the pseudotetragonal to the pseudocubic structure is 350° C near x = 0.04. Anomalies in the dielectric constant vs. temperature curve agree well with the transition temperatures, although no anomaly was observed at the temperature of transition from the pseudotetragonal to the pseudocubic phase when x was less than 0.06. Lithium ions in the system facilitate the transformation from the antiferro-electric to the ferroelectric state produced by applying an electric field. A new ferroelectric phase becomes stable when x is greater than 0.07. Poled ferroelectric specimens had a planar coupling coefficient of 0.232, a dielectric constant of 220, and a frequency constant of 3352 kc-mm. The piezoelectric properties disappear not at the transition temperature but at the temperature at which strain exhibits an anomaly when x is greater than 0.07. A perovskite phase with a pseudorhombohedral subcell exists as an intermediate phase for x greater than 0.10, the exact value depending on the preparation method. The phase can be easily converted to pseudomonoclinic when the ceramic is fired at 1180° to 1220°C.     

Visualization of BrdU-labelled DNA in cyanobacterial cells by Hilbert differential contrast transmission electron microscopy

We have attempted to observe the native shape of DNA in rapidly frozen whole cyanobacterial cells through 5-bromo-2-deoxyuridine (BrdU) incorporation and visualization with a Hilbert differential contrast transmission electron microscopy (HDC TEM). The incorporation of BrdU into the DNA of Synechococcus elongatus PCC 7942 was confirmed with fluorescently labelled anti-BrdU antibodies and through EDX analysis of ultra-thin sections. HDC TEM observed cells that had incorporated BrdU into their DNA exhibited electron dense areas at the location corresponding to fluorescently labelled BrdU. Since various strings and strands were observed in high contrast with the HDC TEM, we conclude that the method promises to allow us to identify and understand bulk structural changes of the in vivo DNA and the nucleoid through observation at high resolution.     

Improvement of impact strength and hydrolytic stability of PC/ABS blend using reactive polymer

Polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) blends have been used widely for specific applications such as in automotive interior and exterior parts, and for office automation equipment parts. This study was conducted to investigate the effects of a reactive polymer as a modifier on properties such as the impact strength of PC/ABS blends. A reaction between PC and maleic anhydride group cannot usually be expected because the end hydroxyl group of PC is capped with an end‐capping agent such as t‐butylphenol to improve PC properties such as fluidity, thermal resistance, and impact strength. However, a reactive polymer that has a maleic anhydride group reacts with the end hydroxyl group of PC hydrolyzed with metal salts. Results show that PC/ABS with a reactive polymer exhibits improved impact strength. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44550.     

Formation, Microstructure, and Properties of Barium Zirconium Sulfide Ceramics

The preparation, microstructure, and properties of BaZrS₃ ceramics are described. The compound was prepared by heating either an equimolar mixture of BaS and ZrS₂ or BaZrO₃ alone in CS₂ gas. The reaction of the BaZrO₃−CS₂ system was extremely rapid, as would be expected in an autocatalytic reaction caused by very strong reduction by CS₂. Well-sintered bodies were obtained only by the BaZrO₃−CS₂ reaction. The time dependence of grain growth was affected considerably when reaction and sintering occurred above 1250° C. Non-uniform grain growth which occurs when an excess of Ba is present can be interpreted in terms of secondary recrystallization resulting from segregation of BaS at the grain boundary during sintering. The BaZrS₃ ceramic was stable in air up to 550°C and was oxidized above that temperature.     

Phenolic rigid organic filler/isotactic polypropylene composites. II. Tensile properties

A novel phenolic rigid organic filler (KT) was used to modify isotactic polypropylene (iPP). The influence of KT particles on the tensile properties of PP/KT microcomposites was studied by uniaxial tensile test and the morphological structures of the stretched specimens were observed by scanning electron microscopy (SEM) and polarized optical microscopy (POM). We found that the Young’s modulus of PP/KT specimens increased with filler content, while the yield and break of the specimens are related to the filler particles size. The yield stress, the breaking stress and the ultimate elongation of PP/KT specimens were close to those of unfilled iPP specimens when the maximal filler particles size is less than a critical value, which is 7 μm at a crosshead speed of 10 mm/min and 3 μm at 200 mm/min, close to that of glass bead but far more than those of other rigid inorganic filler particles. The interfacial interaction was further estimated from yield stress, indicating that KT particles have a moderate interfacial interaction with iPP matrix. Thus, the incorporation of small KT particles can reinforce iPP matrix and simultaneously cause few detrimental effects on the other excellent tensile properties of iPP matrix, due to their organic nature, higher specific area, solid true-spherical shape and the homogenous dispersion of the ROF particles in microcomposites.     

Phenolic rigid organic filler/isotactic polypropylene composites. I. Preparation

A novel phenolic rigid organic filler (KT) was melt-mixed with an isotactic polypropylene (iPP) to prepare a series of PP/KT composites, with or without maleic anhydride grafted polypropylene (MAPP) as compatilizer. The evolution of filler morphology during melt-mixing and melt-pressure processes was monitored by scanning electron microscope (SEM) and polarized optical microscope (POM). The influences of shear force, pressure time, filler content and MAPP concentration on the final filler dispersion were studied. We found that this rigid organic filler readily melted and dispersed homogenously into the iPP matrix through a fission-fusion process during the melt-mixing process. Thus a balanced dispersion, which was closely related to shear force and MAPP concentration, can be achieved. During the melt-pressure process, parts of the filler particles combined gradually through a coalescence process. However, the incorporation of MAPP can effectively inhibit the tendency to coalesce and refine the filler particles sizes into nanoscale. Thus, a series of PP/KT composites with controllable filler particles size and narrow size distribution can be obtained just by adjusting process conditions and MAPP concentration. In addition, due to the in-situ formation mechanism, the filler phase possessed a typical solid true-spherical shape.     

Antioxidant properties of rare sugar D-allose: Effects on mitochondrial reactive oxygen species production in Neuro2A cells

The anti-oxidative activity of the rare sugar D-allose has recently been reported, but the mechanism is largely unclear. In this study, we evaluated the reactive oxygen species (ROS) scavenging activities of D-allose and then examined the effects of D-allose on ROS production in mitochondria to clarify the antioxidant properties of D-allose. While D-allose did not scavenge hydrogen peroxide and superoxide anions, it eliminated hydroxyl radicals to the same extent as D-glucose. Rotenone, an uncoupler of mitochondrial respiratory complex I, induces ROS production in mouse neuroblastoma Neuro2A cells in the presence of D-glucose. However, in the presence of D-allose, there was no change in the ROS levels in Neuro2A cells following rotenone treatment. Furthermore, treatment with D-allose attenuated the D-glucose-dependent ROS generation induced by rotenone. Whereas treatment with D-glucose enhanced ATP synthesis in Neuro2A cells, D-allose was less effective in producing intracellular ATP than D-glucose. Treatment with D-allose inhibited the ATP synthesis stimulated by D-glucose. These results suggest that D-allose suppresses ROS production in the mitochondria due to competition with D-glucose at the cellular level.     

Sintering of ZnS with a Small Amount of Ba2ZnS3

The effects of alkali and alkali-earth chloride additives on the sintering of ZnS powder compacts in H₂S have been examined. BaCl₂ was found to promote the sintering of ZnS. BaCl₂ reacts with ZnS to form Ba₂ZnS₃, which acts as a flux for sintering.