Thermal conductivity of uranium dioxide by nonequilibrium Molecular dynamics simulation

金沢大学理学部The thermal conductivity of UO2 pellet, which is used as nuclear fuel, was calculated using the nonequilibrium classical molecular dynamics method by Evans and Morriss. The result of calculation from 300–3000 K obtained presents the same tendency as experiments below 2400 K. Above 2400 K, a different tendency was observed in which the electron conduction was not negligible. The thermal conductivity using the nonequilibrium molecular dynamics method was calculated with about 1/10 number of simulation steps compared with the equilibrium molecular dynamics simulation. It was found that the nonequilibrium molecular dynamics simulation is quite effective

In Vitro Studies to Define the Cell-Surface and Intracellular Targets of Polyarginine-Conjugated Sodium Borocaptate as a Potential Delivery Agent for Boron Neutron Capture Therapy

Boron neutron capture therapy (BNCT) requires pharmaceutical innovations and molecular-based evidence of effectiveness to become a standard cancer therapeutic in the future. Recently, in Japan, 4-borono-L-phenylalanine (BPA) was approved as a boron agent for BNCT against head and neck (H&N) cancers. H&N cancer appears to be a suitable target for BPA-BNCT, because the expression levels of L-type amino acid transporter 1 (LAT1), one of the amino acid transporters responsible for BPA uptake, are elevated in most cases of H&N cancer. However, in other types of cancer including malignant brain tumors, LAT1 is not always highly expressed. To expand the possibility of BNCT for these cases, we previously developed poly-arginine peptide (polyR)-conjugated mercaptoundecahydrododecaborate (BSH). PolyR confers the cell membrane permeability and tumor selectivity of BSH. However, the molecular determinants for the properties are not fully understood. In this present study, we have identified the cluster of differentiation 44 (CD44) protein and translational machinery proteins as a major cell surface target and intracellular targets of BSH-polyR, respectively. CD44, also known as a stem cell-associated maker in various types of cancer, is required for the cellular uptake of polyR-conjugated molecules. We showed that BSH-polyR was predominantly delivered to a CD44(High) cell population of cancer cells. Once delivered, BSH-polyR interacted with the translational machinery components, including the initiation factors, termination factors, and poly(A)-biding protein (PABP). As a proof of principle, we performed BSH-polyR-based BNCT against glioma stem-like cells and revealed that BSH-polyR successfully induced BNCT-dependent cell death specifically in CD44(High) cells. Bioinformatics analysis indicated that BSH-polyR would be suitable for certain types of malignant tumors. Our results shed light on the biochemical properties of BSH-polyR, which may further contribute to the therapeutic optimization of BSH-BNCT in the future

General Survey of Tohoku Hybrid Magnet System(Part I. Establishment and Tests of Hybrid Magnet System at HFLSM)

Outline of Tohoku Hybrid Magnet system is briefly described. High Field Laboratory was established in the Research Institute for Iron, Steel and Other Metals, Tohoku University, in 1981, for accelerating research and development of high field superconducting materials. Three hybrid magnets generating magnetic fields more than 20 T have been constructed as its main apparatuses. The strongest hybrid magnet, HM-1, could produce 31.1 T in November, 1986, which was the world record as this kind of hybrid magnet. Several important features of the hybrid magnet system are introduced which will be also useful to understand the following papers

Paradoxical expression of IL-28B mRNA in peripheral blood in human T-cell leukemia virus Type-1 mono-infection and co-infection with hepatitis C Virus

<p>Abstract</p> <p>Background</p> <p>Human T-cell leukemia virus type-1 (HTLV-1) carriers co-infected with and hepatitis C virus (HCV) have been known to be at higher risk of their related diseases than mono-infected individuals. The recent studies clarified that IL-28B polymorphism rs8099917 is associated with not only the HCV therapeutic response by IFN, but also innate immunity and antiviral activity. The aim of our research was to clarify study whether IL-28B gene polymorphism (rs8099917) is associated with HTLV-1/HCV co-infection.</p> <p>Results</p> <p>The genotyping and viral-serological analysis for 340 individuals showed that IL-28B genotype distribution of rs8099917 SNP did not differ significantly by respective viral infection status. However, the IL-28B mRNA expression level was 3.8 fold higher in HTLV-1 mono-infection than HTLV-1/HCV co-infection. The high expression level was associated with TT (OR, 6.25), whiles the low expression was associated with co-infection of the two viruses (OR, 9.5). However, there was no association between down-regulation and ATL development (OR, 0.8).</p> <p>Conclusion</p> <p>HTLV-1 mono-infection up-regulates the expression of IL-28B transcripts in genotype-dependent manner, whiles HTLV-1/HCV co-infection down-regulates regardless of ATL development.</p

Physical Properties of Clay Minerals and Water : By means Molecular Dynamics Simulations

An interatomic potential model and a parameter set are presented for the molecular simulations of systems relating to clay. MD simulations of water and ice-Ih showed the validity of this model by reproducing structures and physical properties for the wide range of temperatures. The swelling properties of beidellite were simulated for various hydration numbers. The step-wise increase of basal spacing was shown with increasing hydration numbers, which are assigned to zero-, one-, two- and three-layer hydrations. The slope of internal energy of interlayer water for the increasing hydration number also shows step-wise behavior. MD simulations of clay molecule-water and aqueous solution systems were performed. Structural and physical properties of the interface were investigated as local properties. Electrical double layer and the diffusion layer were investigated for both systems

Micro/Macro-Behavior of Water Flow and Diffusion in Clay : Multiscale Homogenization Analysis

Clay is a micro-inhomogeneous material. For bentonite clay we present here a unified numerical scheme to treat its molecular characteristics and micro/macro-continuum behavior. Note that we commonly use a macro-phenomenological model for analyzing material behavior. However, existing models are not sufficiently effective under extreme conditions such as deeply located clay. We try to resolve this difficulty. Properties of saturated bentonite are characterized by hydrated montmorillonite, the major clay mineral of bentonite. Since the crystalline structure of clay minerals determines fundamental properties, we analyze its molecular behavior by applying a molecular dynamics (MD) simulation and inquire into physicochemical properties of the clay hydrate system such as diffusivity of chemical species. To extend the microscopic characteristics of constituent materials to the macroscopic diffusion behavior of the micro-inhomogeneous material we develop a multiscale homogenization analysis (HA) to treat adsorption behavior at a micro-level

Transport Phenomena in Porous Media: Aspects of MicroMacro Behaviour

This monograph presents an integrated perspective of the wide range of phenomena and processes applicable to the study of transport of species in porous materials. In order to formulate the entire range of porous media and their uses, this book gives the basics of continuum mechanics, thermodynamics, seepage and consolidation and diffusion, including multiscale homogenization methods. The particular structure of the book has been chosen because it is essential to be aware of the true properties of porous materials particularly in terms of nano, micro and macro mechanisms.  This book is of pedagogical and practical importance to the fields covered by civil, environmental, nuclear and petroleum engineering and also in chemical physics and geophysics as it relates to radioactive waste disposal, geotechnical engineering, mining and petroleum engineering and chemical engineering