Development of surface tension model with manybody potential force

A new approach to calculate surface tension in a particle method is proposed. In particle methods, one way to calculate surface tension is introducing pairwise potential force, which is long-range attractive and short-range repulsive. However, the potential force acts not only on the surface but also inside the fluid bulk, which causes unrealistic pressure increase in the droplet or shrinkage of the droplet. In this study, a many-body potential is introduced for surface tension calculation instead of the pairwise potential. The new approach is tested in the droplet oscillation calculation, capillary pressure calculation and capillary rise calculation. The surface tension could be estimated consistently in these calculations

Numerical analysis of the eutectic melting and relocation of the b4c control rod materials by the MPFI-MPS method

Eutectic melting and subsequent relocation of the boron-carbide (B4C) control rod materials were simulated by a particle method. In the past, it was difficult to simulate the eutectic melting by a particle method because the melting starts at the interface between two different materials, which leads to the instability of the particle motion due to the small amount of fluid particles and lack of the thermodynamic consistency of the particle system. Thus, the Moving Particle Full Implicit (MPFI)-Moving Particle Semi-implicit (MPS) method was developed and introduced in the current study. Specifically, the MPFI method was introduced for the momentum transfer calculation, and the MPS method was introduced for the heat and mass transfer calculation. The MPFIMPS method realized the simulation of the eutectic melting and subsequent relocation behaviour

Artificial Extracellular Matrix Proteins Containing Phenylalanine Analogues Biosynthesized in Bacteria Using T7 Expression System and the PEGylation

In vivo incorporation of phenylalanine (Phe) analogues into an artificial extracellular matrix protein (aECM-CS5-ELF) was accomplished using a bacterial expression host that harbors the mutant phenylalanyl-tRNA synthetase (PheRS) with an enlarged binding pocket. Although the Ala294Gly/Thr251Gly mutant PheRS (PheRS**) under the control of T5 promoter allows incorporation of some Phe analogues into a protein, the T5 system is not suitable for material science studies because the amount of materials produced is not sufficient due to the moderate strength of the T5 promoter. This limitation can be overcome by using a pair of T7 promoter and T7 RNA polymerase instead. In the T7 expression system, it is difficult, however, to achieve a high incorporation level of Phe analogues, due to competition of Phe analogues for incorporation with the residual Phe that is required for synthesis of active T7 RNA polymerase. In this study, we prepared the PheRS** under T7 promoter and optimized culture condition to improve both the incorporation level of recombinant aECM protein and the incorporation level of Phe analogues. Incorporation and expression levels tend to increase in the case of p-azidophenylalanine, p-iodophenylalanine, and p-acetylphenylalanine. We evaluated the lower critical transition temperature, which is dependent on the incorporation ratio and the turbidity decreased when the incorporation level increased. Circular dichromism measurement indicated that this tendency is based on conformational change from random coil to β-turn structure. We demonstrated that polyethylene glycol (PEG) can be conjugated at reaction site of Phe analogues incorporated. We also demonstrated that the increased hydrophilicity of elastin-like sequences in the aECM-CS5-ELF made by PEG conjugation could suppress nonspecific adhesion of human umbilical vein endothelial cells (HUVEC)

Observation of the Fano-Kondo Anti-Resonance in a Quantum Wire with a Side-Coupled Quantum Dot

We have observed the Fano-Kondo anti-resonance in a quantum wire with a side-coupled quantum dot. In a weak coupling regime, dips due to the Fano effect appeared. As the coupling strength increased, conductance in the regions between the dips decreased alternately. From the temperature dependence and the response to the magnetic field, we conclude that the conductance reduction is due to the Fano-Kondo anti-resonance. At a Kondo valley with the Fano parameter $q\approx 0$, the phase shift is locked to $\pi/2$ against the gate voltage when the system is close to the unitary limit in agreement with theoretical predictions by Gerland {\it et al.} [Phys. Rev. Lett. {\bf 84}, 3710 (2000)].Comment: 4 pages, 4 figure

Significance of genomic instability in breast cancer in atomic bomb survivors: analysis of microarray-comparative genomic hybridization

<p>Abstract</p> <p>Background</p> <p>It has been postulated that ionizing radiation induces breast cancers among atomic bomb (A-bomb) survivors. We have reported a higher incidence of <it>HER2 </it>and <it>C-MYC </it>oncogene amplification in breast cancers from A-bomb survivors. The purpose of this study was to clarify the effect of A-bomb radiation exposure on genomic instability (GIN), which is an important hallmark of carcinogenesis, in archival formalin-fixed paraffin-embedded (FFPE) tissues of breast cancer by using microarray-comparative genomic hybridization (aCGH).</p> <p>Methods</p> <p>Tumor DNA was extracted from FFPE tissues of invasive ductal cancers from 15 survivors who were exposed at 1.5 km or less from the hypocenter and 13 calendar year-matched non-exposed patients followed by aCGH analysis using a high-density oligonucleotide microarray. The total length of copy number aberrations (CNA) was used as an indicator of GIN, and correlation with clinicopathological factors were statistically tested.</p> <p>Results</p> <p>The mean of the derivative log ratio spread (DLRSpread), which estimates the noise by calculating the spread of log ratio differences between consecutive probes for all chromosomes, was 0.54 (range, 0.26 to 1.05). The concordance of results between aCGH and fluorescence in situ hybridization (FISH) for <it>HER2 </it>gene amplification was 88%. The incidence of <it>HER2 </it>amplification and histological grade was significantly higher in the A-bomb survivors than control group (P = 0.04, respectively). The total length of CNA tended to be larger in the A-bomb survivors (P = 0.15). Correlation analysis of CNA and clinicopathological factors revealed that DLRSpread was negatively correlated with that significantly (P = 0.034, r = -0.40). Multivariate analysis with covariance revealed that the exposure to A-bomb was a significant (P = 0.005) independent factor which was associated with larger total length of CNA of breast cancers.</p> <p>Conclusions</p> <p>Thus, archival FFPE tissues from A-bomb survivors are useful for genome-wide aCGH analysis. Our results suggested that A-bomb radiation may affect the increased amount of CNA as a hallmark of GIN and, subsequently, be associated with a higher histologic grade in breast cancer found in A-bomb survivors.</p

High resolution X-ray computed tomographic (CT) images of chondrites and a chondrule

In order to study internal textures of meteorites, images were obtained by X-ray computer tomography (CT). This combined high resolution X-ray radiography and computer tomography system belongs to the so-called third generation type with a micro-focus X-ray source and a linear CCD detector with 2048 elements. This allows a spacial resolution of a few μm in the images. Samples examined include the Moorabie meteorite (L3), Allende meteorite (CV3), and a chondrule removed from Allende meteorite. In images, Fe-Ni alloy, troilite, and silicates can be distinguished clearly, and chondrules can be resolved from their Fe-rich rims in Moorabie meteorite. In Allende Fe-Ni alloy, pentlandite, and silicates can be distinguished, and chondrules, CAI\u27s, and matrix can be recognized. Many euhedral crystals, probably olivine and/or pyroxene, were identified in a chondrule, suggesting that the chondrule has a porphyritic texture. In addition to minerals or their assemblages, holes can be identified by the X-ray CT method and were found in chondrules in Allende

Local tentative bonding method to maintain alignment accuracy in bonding process using resin as an adhesive material

The authors proposed a novel method to maintain the alignment accuracy in the wafer-bonding process, which uses a resin as an adhesive material. Recently, the resin has received attention as an adhesive material for wafer bonding in microelectromechanical system device fabrication because of its multiple advantageous material properties. However, because of its inherent material viscosity, the alignment accuracy cannot be easily maintained, particularly when two wafers are bonded with a thick resin after alignment. To solve this problem, they proposed a local tentative bonding method. After aligning the two wafers, they irradiated the adhesive resin layer between the wafers using a near-infrared (NIR) spotlight (wavelength = 1020 nm), which is transparent to Si wafers. Using several NIR irradiation spots aimed at the resin layer after aligning the wafers, the resin layer was bonded locally and tentatively, which was sufficiently secure to avoid wafer shifting in the subsequent process. The local tentative bonded areas acted as anchors, which held the wafers during the bonding process. They performed experiments to demonstrate the effectiveness of their method using resins, such as polyimide, benzocyclobutene and SU-8. Consequently, they achieved an alignment accuracy <5 µm, which is a significant improvement compared with the typical bonding results