Effects of amino compounds on the formation of γ-tocopherol reducing dimers in autoxidizing linoleate

The effects of various amino compounds trimethylamine oxide (TMAO), tri-n-octylamine (TOA), phosphatidyl choline (PC), and phosphatidyl ethanolamine (PE) on the oxidative decomposition of γ-tocopherol (γ-Toc) and on the formation of its reducing dimers were investigated during the autoxidation of methyl linoleate (ML). In general, γ-Toc diphenyl ether dimer (γ-TED) was formed in preference to two atropisomers of γ-Toc biphenyl dimers [γ-TBD(H) and (L)] in autoxidizing ML. This relationship, however, was reversed when TMAO was added. As the presence of TOA, PC, or PE did not promote the formation of γ-TBD, the preferential formation of γ-TBD was believed to be based on the interaction between TMAO and oxidation products formed from γ-Toc. Effects of TMAO and TOA on the interconversion of γ-Toc reducing dimers were investigated. γ-TED was found to be converted into γ-Toc and γ-TBD(L) in autoxidizing ML. But γ-TBD(H) could not be detected, and the amount of γ-TBD(L) formed was very small. γ-TBD(H) and (L) were formed from their respective atropisomers. In this case, the formations of γ-Toc and γ-TED could not be detected. Therefore, it was concluded that the conversion of γ-TED into γ-TBD and vice versa can be neglected in any event.     

Fundamental Limits of Organic Packages and Boards and the Need for Novel Ceramic Boards for Next Generation Electronic Packaging

The system-on-a-package (SOP) paradigm proposes a package level integration of digital, RF/analog and opto-electronic functions to address future convergent microsystems. Two major components of SOP fabrication are sequential build-up of multiple layers (4–8) of conducting copper patterns with interlayer dielectrics on a board and multiple ICs flip-chip bonded on the top layer. A wide range of passives, wave-guides and other RF and opto-electronic components buried within the dielectric layers provide the multiple functions on a single microminiaturized platform.The routing of future nanoscale ICs with 10,000+ I/Os require multiple build-up layers of ultra fine board feature sizes of 10 m lines/space widths and 40 m pad diameters. Current FR4 boards cannot achieve this build-up technology because of dimensional instability during processing. These boards also undergo high warpage during the sequential build-up process which limits the fine-line lithography and also causes misalignment between the vias and their corresponding landing pads. In addition, the CTE mismatch between the silicon die and the board leads to IC-package interconnect reliability concerns, particularly in future fine-pitch assemblies where underfilling becomes complicated and expensive.This work reports experimental and analytical work comparing the performance of organic and novel ceramic boards for SOP requirements. The property requirements as deduced from these results indicate that a high stiffness and tailorable CTE from 2–4 ppm/C is required to enable SOP microminiaturized board fabrication and assembly without underfill. A novel ceramic board technology is proposed to address these requirements.     

Evidence that activation of Src family kinase is not required for fertilization-associated [Ca2+]i oscillations in mouse eggs

Recent evidence in marine invertebrate, frog, and zebrafish eggs suggests the involvement of a Src family kinase (SFK) in fertilization-induced Ca2+ release. In the present study, we have investigated whether activation of an SFK is required for initiation of intracellular Ca2+ ([Ca2+]i) oscillations in mouse fertilization. We detected a Hck-like protein and tyrosine-phosphorylated proteins in soluble and insoluble sperm fractions, respectively. However, the presence of these proteins did not correspond to the active fractions of porcine sperm extracts (pSE). Moreover, [Ca2+]i oscillations induced by pSE in mouse eggs were unaltered by pre-incubation of pSE with specific SFK inhibitors such as 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazol[3,4-d]-pyrimidine (PP2) or lavendustin A, despite the fact that the inhibitors were shown to be active both in vivo and in vitro. Another SFK inhibitor, peptide A, blocked oscillations when incubated with pSE prior to injection into eggs, but this inhibition required more than ten times the concentration reportedly required to inhibit SFK activity. In addition, pre-injection or pre-incubation of eggs with these inhibitors did not affect the ability of pSE to trigger [Ca2+]i oscillations in mouse eggs. Microinjection of a recombinant c-Src protein or mRNAs encoding constitutively active Src proteins did not induce [Ca2+]i release. Finally, when sperm and eggs, both of which were pre-treated with PP2, were fertilized, [Ca2+]i oscillations occurred normally. We can therefore conclude that activation of an SFK is neither necessary nor sufficient for triggering fertilization-induced [Ca2+]i oscillations.     

Utilization of sludge in building material.

Several thermal solidification processes have been developed mainly in Japan. They are lightweight aggregates, brick, interlocking tile, char, and slag. A full-scale plant of them has been successfully operated for more than 10 years. The quality of the end products is better than the traditional ones. They are all substitutive to existing ones. The Japanese experience proves that all the processes are technically feasible, but not economically. Their manufacturing cost is always higher than market price. In addition, they consume large amounts of energy. However, if they are identified for a process of sludge disposal, all of them are worth considering for a big city where there is no place for the sludge to go. The end products can be reused inside the city. A new alternative is "Portland cement". A Portland cement manufacturer accepts sewage sludge, if being paid some amount of money. An average payment is US$100 each 1,000 kg of ash or sludge cake. The Portland cement manufacturer accepts either cake or ash at the same price. It is about 50 to 30% of the energy cost of thermal solidification. The question is which is the better, dewatered cake or incinerated ash, for the Portland cement application. The answer is "it depends on the distance between the sewage plant and the Portland cement plant."     

Microdosimetry of neutron field for boron neutron capture therapy at Kyoto university reactor

Microdosimetric single event spectrum in a human body simulated by an acrylic phantom has been measured for the clinical BNCT field at the Kyoto University Reactor (KUR). The recoil particles resulting from the initial reaction and subsequent interactions, namely protons, electrons, alpha particles and carbon nuclei are identified in the microdosimetric spectrum. The relative contributions to the neutron dose from proton, alpha particles and carbon are estimated to be about 0.9, 0.07 and 0.3, respectively, four depths between 5 and 41 mm. We estimate that the dose averaged lineal energy, yD decreased with depth from 64 to 46 keV microm(-1). Relative biological effectiveness (RBE) of this neutron field using a response function for the microdosimetric spectrum was estimated to decrease from 3.6 to 2.9 with increasing depth.     

Grazing exit electron probe microanalysis of submicrometer inclusions in metallic materials

Grazing exit electron probe microanalysis (GE-EPMA) is a new method of EPMA in which characteristic X-rays emitted from only near-surface regions of a specimen are detected at extremely low exit angles near 0 degrees (the grazing exit condition). This technique requires the analytical objects exist on a flat surface. Therefore, the GE-EPMA analysis has been used only for the analysis of particles or a thin film on a flat substrate so that there were only few applications for practical analysis. As a new application, we have carried out GE-EPMA analysis of approximately 0.2-microm inclusions on stainless steel, which appeared to be a projection on the specimen surface with chemical etching. The GE-EPMA quantitative results were in excellent agreement with those of inclusions that were extracted from the stainless steel and analyzed by EPMA with conventional exit condition (30 degrees). This method could be, therefore, applied to the analysis of the submicrometer inclusion in a wide variety of metallic materials if the inclusion appears to be a projection with chemical etching treatment.     

On-demand droplet spotter for preparing pico- to femtoliter droplets on surfaces

A droplet spotter for on-demand generation of pico- to femtoliter droplets was developed to meet the requirement for high-density spotting of chemicals on a surface. Our droplet spotter involves applying a approximately 1000-V and approximately 10-ms pulse voltage to the tip of a capillary tube (o.d. approximately 18 microns; i.d. approximately 11 microns) supplied with water or a dye solution. The capability of the spotter was demonstrated by preparing a microarray of dye molecules. The microarray was prepared by spotting approximately 30-fL droplets of a dye solution on a surface at the density of one spot per 20 x 20 micron 2.     

Cryogenic properties of Si-Ti-C-O fibre-bonded ceramic using satin weave

Mechanical and thermophysical characteristics of Si-Ti-C-O fibre-bonded ceramic produced by hot-pressing the laminated material of oxidized satin-woven Si-Ti-C-O fibre have been investigated at room and cryogenic temperatures. The fibre element (diameter: 8 m, fibre volume fraction: 85 ± 1%) constructing the Si-Ti-C-O fibre-bonded ceramic showed a close-packed structure of the oxidized Si-Ti-C-O fibre mainly composed of fine SiC crystals, amorphous SiO₂-based phase and turbostratic carbon. The Si-Ti-C-O fibre-bonded ceramic with lightweight (density: 2.45 × 10³kg/m³) and low porosity (<1 vol%) showed a markedly higher fracture energy (notched, cross-plied specimen: approximately 10kJ/m²) and lower thermal conductivity (1/10 the value of stainless steel). The reason why the fibre- bonded ceramic showed such a low thermal conductivity in spite of very high thermal conductivity of a pure SiC and carbon could be attributed to the complicated microstructure of Si-Ti-C-O fibre-bonded ceramics.