Anatase Sol Prepared from Peroxotitanium Complex Aqueous Solution Containing Niobium or Vanadium

Niobium- or vanadium-doped anatase sols were prepared by hydrothermal treatment of 0.1 mol/dm³ peroxotitanium complex aqueous solutions dissolving 0–10 mol% niobium or vanadium at 100°C for 8 h. Niobium-doping caused the increase of lattice constants of anatase and the shape change of anatase crystal from spindle-like to cubic-like structure, but no change of the optical absorbance. Vanadium-doping caused the decrease of lattice constant of c -axis, the miniaturization of anatase crystal and the increase of optical absorbance at the wavelength from 350–700 nm.     

Synthesis and surface properties of novel fluoroalkyl end-capped amphiphilic fullerene cooligomers

New fluoroalkyl end-capped fullerene cooligomers were prepared by the reactions of fluoroalkanoyl peroxides with fullerene and comonomers such as acryloylmorpholine, N,N-dimethylacrylamide and acrylic acid. These fluorinated fullerene cooligomers were easily soluble in water and common organic solvents, and were able to reduce the surface tensions of both water and benzene, quite effectively. Additionally, these fullerene cooligomers were found to form a stable monomolecular film at the air-water interface, and the modified polystyrene surface treated with these cooligomers was shown to have a strong hydrophilicity with good oil repellency.     

Organic–silicate hybrid catalysts based on various defined structures for Knoevenagel condensation

Two types of organic–inorganic hybrid base catalysts are prepared. Organic-functionalized molecular sieves (OFMSs), particularly “amine-immobilized porous silicates”, are designed based on common idea to immobilize catalytic active sites on silicate surface. Silicate–organic composite materials (SOCMs), such as “ordered porous silicate–quaternary ammonium composite materials”, are the precursors of ordered porous silicates obtained during the synthesis. Both the OFMS and the SOCM are used as the catalysts for Knoevenagel condensation. Among the OFMSs, there is clear tendency that the use of molecular sieve with larger pore volume and/or surface area gives the product in higher yield. Aminopropylsilyl (AP)-functionalized mesoporous silicates such as AP-MCM-41 gives the product in high yield under mild conditions. No loss of activity is observed after repeated use for three times. The SOCMs are also active for the same reaction. The precursors of the mesoporous silicates are more active than those of microporous silicates. This material can be repeatedly used without significant loss of activity. High activity is not due to the leached species. The active sites of the SOCM catalysts are considered to be SiO⁻ moieties located on the pore-mouth. Activity of the SOCM increases when the reaction is carried out without solvent, whereas decrease in activity of the OFMS is observed in the solvent-free system.     

Aerobic Exercise Ameliorates Cancer Cachexia-Induced Muscle Wasting through Adiponectin Signaling

Cachexia is a multifactorial syndrome characterized by muscle loss that cannot be reversed by conventional nutritional support. To uncover the molecular basis underlying the onset of cancer cachectic muscle wasting and establish an effective intervention against muscle loss, we used a cancer cachectic mouse model and examined the effects of aerobic exercise. Aerobic exercise successfully suppressed muscle atrophy and activated adiponectin signaling. Next, a cellular model for cancer cachectic muscle atrophy using C2C12 myotubes was prepared by treating myotubes with a conditioned medium from a culture of colon-26 cancer cells. Treatment of the atrophic myotubes with recombinant adiponectin was protective against the thinning of cells through the increased production of p-mTOR and suppression of LC3-II. Altogether, these findings suggest that the activation of adiponectin signaling could be part of the molecular mechanisms by which aerobic exercise ameliorates cancer cachexia-induced muscle wasting.     

Effect of inorganic salts,amino acids and proteins on the degradation of pure magnesium in vitro

The possibility of magnesium and its alloys in medical applications is actively investigated in these days for the realization of biodegradable metallic devices. However, the degradation behavior and mechanisms of magnesium and its alloys in physiological environment such as inside the human body have not been elucidated. In this study, we performed 14-d long immersion tests of pure magnesium (3N) in 4 kinds of physiological solutions simulating the body fluids to examine the effects of the chemical components of the body fluids on the degradation of magnesium. The degradation rate of pure magnesium was strongly influenced by the kinds of the solution used. The highest degradation rate was obtained in NaCl, followed by E-MEM, Earle's solution, and E-MEM+FBS. The average degradation rate in NaCl for 8–14 d is about 100 times larger than that in E-MEM+FBS, which is the closest solution to human blood plasma. These results show that protein adsorption and insoluble salt formation retarded magnesium degradation, whereas organic compounds such as amino acids encourage the dissolution of magnesium. Buffering the solution also influenced the degradation rate; buffering NaCl with HEPES increased the degradation rate but buffering with NaHCO₃ decreased it. Based on these results, the use of appropriate solution such as E-MEM+FBS is important for in vitro evaluation of the magnesium degradation rate under the physiological environment simulating inside the human body.     

Fretting fatigue behaviour of Ni-free high-nitrogen stainless steel in a simulated body fluid

Abstract

Fretting fatigue behaviour of Ni-free high-nitrogen steel (HNS) with a yield strength of about 800 MPa, which was prepared by nitrogen gas pressurized electroslag remelting, was studied in air and in phosphate-buffered saline (PBS(-)). For comparison, fretting fatigue behaviour of cold-rolled SUS316L steel (SUS316L(CR)) with similar yield strength was examined. The plain fatigue limit of HNS was slightly lower than that of SUS316L(CR) although the former had a higher tensile strength than the latter. The fretting fatigue limit of HNS was higher than that of SUS316L(CR) both in air and in PBS(-). A decrease in fatigue limit of HNS by fretting was significantly smaller than that of SUS316L(CR) in both environments, indicating that HNS has better fretting fatigue resistance than SUS316L(CR). The decrease in fatigue limit by fretting is discussed taking into account the effect of friction stress due to fretting and the additional influences of wear, tribocorrosion and plastic deformation in the fretted area.     

CO2激光直接钻孔工艺的前后处理

近几年,电子产品朝轻,薄,短,小化迅速发展,印制线路板也随着这股潮流朝向高密度封装方向发展。尤其是积层板总数的增加和导通孔以及连接盘的小径化也日益显著。对于积层线路板而言,用来加工层间连接的盲通孔(BVH)的激光方法取决于导通孔和连接盘径。激光器分为CO2激光和UV-Yag激光两种。导通孔径为60μm以上时,则一般用CO2激光加工。由于铜在CO2激光的波长(9.3μm～10.3μm)领域中的吸收比很低,因此"保形法"(在表面铜箔上,蚀刻出需要的加工孔径(开铜窗),再以激光打掉树脂)成为了现在的主流。然而,由于保形法需要蚀刻开铜窗,因此增加了形成图形的工序,而且导通孔的定位取决于下层的定位标记,容易发生错位。随着积层板层数的增加,导通孔和连接盘的小径化发展,越来越需要提高加工速度和定位精度。因此,同时对铜和树脂进行加工的"直接钻孔法"开始被关注。直接钻孔法是根据格柏数据进行导通孔的定位,因此,即使导通孔/连接盘径越趋小型化,也不会发生错位,是一种能够推进多层化,高密度化的先端技术。本文讲述了以直接钻孔法形成高可靠度导通孔时所需的技术和药品。     

Preparation of mesoporous silica replica using ordered mesoporous carbon by vapor phase transport of silica source

A new vapor phase transport (VPT) technique to prepare an inverse silica replica of an ordered mesoporous carbon was developed. Tetraethyl orthosilicate (TEOS) was infiltrated in mesoporous carbon CMK-3 as the hard template at 180 °C for 48 h under an autogenous pressure in an autoclave in the presence of water. The samples obtained by removal of CMK-3 retained structural regularity of CMK-3 with little shrinkage of framework, which were characterized by SAXRD, N₂ adsorption, TG-DTA, and SEM. Influence of preparation temperature on the loading amount of silica was investigated. The multi-step replication process was monitored by characterizing the replicated materials as well as intermediate composites.     

Formation of the spore clumps during heat treatment increases the heat resistance of bacterial spores

Effects of the clumping of bacterial spores on their heat resistance as a result of heat treatment were investigated. Spore suspensions of Bacillus cereus, Bacillus coagulans and Bacillus licheniformis were heated at 85 degrees C. Survivor curves of the three strains showed tailing in all treatments after 30 min. As the treatment time increased, the formation of spore clumps increased in all strains after 20 min. Relative hydrophobicity of the spore surface increased as a result of heat treatment. The effect of spore concentration on the inactivation of the B. licheniformis spores was investigated, and surviving curves showed no tailing below a concentration of 4.9 log CFU/ml.