Relation between passive smoking at home and dietary intake

Recent attempts to protect hematopoietic progenitor cells from cytarabine (ara-C)-induced toxicity by transfer of the cytidine deaminase (CDD) gene resulted in efficient in vitro inducibility of ara-C resistance. Another enzyme involved in intracellular ara-CTP inactivation is the deoxycytidylate deaminase (dCMPD). We therefore transfected the human dCMPD cDNA gene into murine fibroblasts and investigated the relationship of forced dCMPD expression and resistance induction to ara-C. Several cell lines were established which demonstrated a 1.7-3.5-fold increase in cellular dCMPD activity and an up to 2-fold increase in the IC50 value of ara-C. However, increases in dCMPD activities did not show a positive linear correlation with the induction of ara-C resistance. In addition, CD34 + hematopoietic progenitor cells revealed the highest endogenous dCMPD enzyme levels among different human hematopoietic cells. Thus, despite the documented role for dCMPD in ara-CTP inactivation of certain cell types, these results suggest that the dCMPD gene may prove less useful than the CDD gene as a therapeutic target in attempts to attenuate ara-C-induced bone marrow toxicity.     

Factors affecting the nocturnal decrease in blood pressure: a community-based study in Ohasama

OBJECTIVE: To investigate factors affecting the nocturnal decrease in blood pressure. DESIGN: A cross-sectional study of 823 community-based untreated subjects aged > 20 years. Screening and ambulatory blood pressures were measured and the effects of age and the ambulatory blood pressure on the nocturnal decrease were examined. RESULTS: The magnitude of the decrease and the percentage decrease in the nocturnal blood pressure increased with increasing daytime ambulatory blood pressure and decreased with increasing night-time ambulatory blood pressure. Although the magnitude of the nocturnal decrease in blood pressure increased with increasing daytime blood pressure, the nocturnal blood pressure levels in hypertensives were still higher than those in normotensive subjects. The magnitude decreased with increasing age for men but not for women, whereas the percentage decrease decreased with increasing age both for men and for women. The SD of the 24 h blood pressure correlated strongly to the magnitude of the nocturnal decrease (systolic blood pressure r = 0.62, P < 0.0001; diastolic blood pressure r = 0.52, P < 0.0001), suggesting that the SD of the 24 h blood pressure is representative of the nocturnal decrease. A minimal nocturnal decrease was observed frequently in elderly normotensive men but infrequently in hypertensive individuals from the general population. A marked nocturnal decrease was observed frequently in hypertensive women aged > 70 years. CONCLUSION: Although the magnitude of the nocturnal decrease in blood pressure increased with increasing daytime blood pressure, the nocturnal blood pressure levels increased with increasing daytime ambulatory blood pressure. Therefore, the blood pressure in hypertensive subjects should essentially be lowered throughout the 24 h period. A marked nocturnal decrease in blood pressure in some elderly hypertensive women was observed without treatment. The nocturnal blood pressure levels of such subjects should be considered during treatment.     

Amorphous Pd---Si alloys for hydrogen-permeable and catalytically active membranes

Amorphous Pd_xSi_1-x(x=0.8,0.825,0.85) in the form of ribbon was prepared by a single-roller melt spinning technique to examine hydrogen permeability and catalytic activity for dehydrogenation. As a result, it was found that the amorphous specimens had higher tenacity and higher permeability of hydrogen than its crystallized form. Also, the surface of the amorphous specimen showed a catalytic activity for dehydrogenation of cyclohexane, while no activity was observed in the untreated. Taking advantage of both hydrogen permeability and catalytic activity, the amorphous Pd_xSi_1-x would be expected to be a candidate for a catalytic membrane.     

Protective Role of Glutathione in the Hippocampus after Brain Ischemia

Stroke is a major cause of death worldwide, leading to serious disability. Post-ischemic injury, especially in the cerebral ischemia-prone hippocampus, is a serious problem, as it contributes to vascular dementia. Many studies have shown that in the hippocampus, ischemia/reperfusion induces neuronal death through oxidative stress and neuronal zinc (Zn²⁺) dyshomeostasis. Glutathione (GSH) plays an important role in protecting neurons against oxidative stress as a major intracellular antioxidant. In addition, the thiol group of GSH can function as a principal Zn²⁺ chelator for the maintenance of Zn²⁺ homeostasis in neurons. These lines of evidence suggest that neuronal GSH levels could be a key factor in post-stroke neuronal survival. In neurons, excitatory amino acid carrier 1 (EAAC1) is involved in the influx of cysteine, and intracellular cysteine is the rate-limiting substrate for the synthesis of GSH. Recently, several studies have indicated that cysteine uptake through EAAC1 suppresses ischemia-induced neuronal death via the promotion of hippocampal GSH synthesis in ischemic animal models. In this article, we aimed to review and describe the role of GSH in hippocampal neuroprotection after ischemia/reperfusion, focusing on EAAC1.     

Microwave-hydrothermal synthesis of nano-sized Sn<Superscript>2+</Superscript>-doped BaTiO<Subscript>3</Subscript> powders and dielectric properties of corresponding ceramics obtained by spark plasma sintering method

Ternary oxides containing Sn²⁺ are rare and difficult to prepare using solid state reaction due to disproportionation of Sn²⁺ at high temperature. In this paper, nanoparticles of barium titanate doped with different amounts of Sn²⁺ consisting of single phase perovskite structure were successfully synthesized for the first time by using a microwave-assisted solvothermal reaction. The particle sizes were about 20–40 nm in diameter and increased with increasing the amount of doped tin. Solidified ceramic bodies were obtained using a spark plasma sintering method under argon atmosphere avoiding the disproportionation and oxidation of Sn²⁺ in the air. The grain size and dielectric constant of the sintered body decreased with increasing the amount of doped tin.     

Preparation and characterization of lanthanum carbide encapsulated carbon nanocapsule/lanthanum hexaboride nanocomposites

LaC₂@CNC/LaB₆ nanocomposites were prepared using a spark plasma sintering system, and their mechanical properties and the intensity of characteristic La X-rays from the composites were characterized for application as X-ray target material. Using LaB₆ as a binder, we succeeded in producing LaC₂@CNC/LaB₆ nanocomposites with a bulk density (2.91 g/cm³) and specific electric resistance (3.12 × 10^− 4 Ω cm) through solidification at 2123 K. The fracture bending strength of LaC₂@CNC/LaB₆ nanocomposites (224 MPa) was 1.5 times larger than that observed for graphite/LaB₆ composites. The most emitted characteristic La Lα X-ray from LaC₂@CNC/LaB₆ nanocomposites was 7743 counts/mm²/s in comparison with 6372 counts/mm²/s for graphite/LaB₆ composites.     

Using Simultaneous Deposition and Rapid Growth to Produce Nanostructured Composite Films of AIN/TiN by Chemical Vapor Deposition

Brittleness has been the major obstacle in using ceramics. Previous research has shown, however, that ceramic materials that have small grain size show plasticity. We therefore propose two methods to produce nanostructured ceramic films by chemical vapor deposition (CVD): (1) high-speed deposition and (2) simultaneous deposition of insoluble materials (contained in a mixture of insoluble solids). These methods were successfully applied to aluminum nitride/ titanium nitride (AlN/TiN) films produced by CVD. The AlN/TiN nanostructured composite films were synthesized by atmospheric-pressure CVD (APCVD), using aluminum chloride (AlC1₃), titanium chloride (TiCl₄), and ammonia (NH₃) as reactant gases at temperatures ranging from 923 to 1123 K in a horizontal tubular reactor. For the highspeed deposition strategy, we obtained growth rates as high as 1.2 mm/h. Using either method, we were able to attain AlN/TiN composite films that had a grain size of 8 nm (AlN crystals) and 6 nm (TIN crystals), showing that these methods are effective in producing nanostructured composite films by CVD. Measurements of the fracture toughness of the prepared materials indicated that these strategies can be used to improve the ductility of ceramics.     

Effect of ball-milling and shot-peening on Zr55Al10Ni5Cu30 alloys

Effect of ball-milling and shot-peening on a metallic glass Zr₅₅Al₁₀Ni₅Cu₃₀, which possesses a large supercooled liquid region, has been investigated by means of differential scanning calorimetry, x-ray diffractometry and transmission electron microscopy. Metallic glassy ribbons, powders and plates were prepared by melt-spinning, gas-atomizing and mold-clamp casting techniques, respectively. No structural changes were observed in both the ribbon and powder specimens by ball-milling for around 100 h; however, the powder specimens were crystallized by Fe contamination when they were ball-milled for 540 h. No structural evolution was also observed when the plate specimens were subjected to shot-peening, while crystallized plate specimens were easily amorphized by mild and short period shot-peening. These results imply high phase stability of the Zr₅₅Al₁₀Ni₅Cu₃₀ metallic glass against deformation.     

Dual phase metallic glassy composites with large-size and ultra-high strength fabricated by spark plasma sintering

Two-phase bulk metallic glasses (BMGs) have attracted increasing interest since phase separation might produce metallic glasses with new physical and mechanical properties. In this study, we fabricated the dual phase glassy BMG composites by a spark plasma sintering process using a mixed powder of the gas-atomized Ni-based and Fe-based metallic glassy alloy powders. The thermal stability, microstructure, mechanical and magnetic properties of the obtained dual-phase glassy composites were investigated. The dual-phase glassy composites exhibited ultra-high strength and good soft magnetic properties which satisfy large-size requirements.     

Nanoscale patterning of Zr-Al-Cu-Ni metallic glass thin films deposited by magnetron sputtering

Completely glassy thin films of Zr-Al-Cu-Ni exhibiting a large super-cooled liquid region (deltaTx = 95 K), very smooth surface (Ra = 0.65 nm), and an extremely high value of Vicker's hardness (Hv = 940), as compared to bulk Zr-Al-Cu-Ni metallic glass, were deposited by radiofrequency magnetron sputtering. Nanoscale patterning ability of Zr-Al-Cu-Ni metallic glass thin films was demonstrated by a focused ion beam etching. The capability to write nanometer-scale patterns (line width approximately 12 nm) opens up a variety of possibilities for fabricating nanomolds for imprint lithography, and a wide range of two- or three-dimensional components for future nanoelectromechanical systems.