A Class of Examination of Fiber Orientation Dependency and Failure with Multi-Scale Simulation

This paper examines the mechanical behavior of the short fiber reinforced plastic (SFRP) considering the microstructure using multi-scale simulation. The SFRP, which the microstructure consists of resin and fiver, has a rate, thermal, and fiber orientation dependency. The mechanical property is predicted by matrix and fiber properties. However, the properties by material testing are different from the prediction. Thus, this paper decides each microscopic material parameter on microstructure by the least-square method using the experimental data. Comparing the macro simulation results using homogenized values and the experimental results shows microstructure influences the macroscopic behavior. Moreover, the numerical examples compare the results under two types of tensile speed and three fiber orientation types. The present work completes the multi-scale simulation using a simple microstructure considering fiber orientation and strain rate

Isogeometric Analysis for Vehicle Model in Dynamic Explicit Method

In Isogeometric Analysis, CAD format models can be used for analysis by using BSpline/NURBS, which is used for drawing shapes in CAD, as a shape function of the finite element method. This method can significantly reduce the time required to generate a mesh, which used to take much time. It is necessary to verify the performance of Isogeometric Analysis in the dynamic explicit method for application to automobile analysis. In this study, automobile structural parts were modeled by Isogeometric Analysis method and structural analysis was performed by the dynamic explicit method for evaluation

Age-Correlated Gene Expression in Normal and Neurodegenerative Human Brain Tissues

Human brain aging has received special attention in part because of the elevated risks of neurodegenerative disorders such as Alzheimer's disease in seniors. Recent technological advances enable us to investigate whether similar mechanisms underlie aging and neurodegeneration, by quantifying the similarities and differences in their genome-wide gene expression profiles.We have developed a computational method for assessing an individual's "physiological brain age" by comparing global mRNA expression datasets across a range of normal human brain samples. Application of this method to brains samples from select regions in two diseases--Alzheimer's disease (AD, superior frontal gyrus), frontotemporal lobar degeneration (FTLD, in rostral aspect of frontal cortex ∼BA10)--showed that while control cohorts exhibited no significant difference between physiological and chronological ages, FTLD and AD exhibited prematurely aged expression profiles.This study establishes a quantitative scale for measuring premature aging in neurodegenerative disease cohorts, and it identifies specific physiological mechanisms common to aging and some forms of neurodegeneration. In addition, accelerated expression profiles associated with AD and FTLD suggest some common mechanisms underlying the risk of developing these diseases

Nanostructure and Magnetic Field Ordering in Aqueous Fe3O4 Ferrofluids: A Small-Angle Neutron Scattering Study

Despite the importance of reducing production costs, investigating the hierarchical nanostructure and magnetic field ordering of Fe3O4 ferrofluids is also important to improve its application performance. Therefore, we proposed an inexpensive synthesis method in producing the Fe3O4 ferrofluids and investigated their detailed nanostructure as the effect of liquid carrier composition as well as their magnetic field ordering. In the present work, the Fe3O4 ferrofluids were successfully prepared through a coprecipitation route using a central precursor of natural Fe3O4 from iron sand. The nanostructural behaviors of the Fe3O4 ferrofluids, as the effects of the dilution of the Fe3O4 particles with H2O as a carrier liquid, were examined using a small-angle neutron spectrometer (SANS). The Fe3O4 nanopowders were also prepared for comparison. A single lognormal spherical distribution and a mass fractal model were applied to fit the neutron scattering data of the Fe3O4 ferrofluids. The increasing carrier liquid composition of the fluids during dilution process was able to reduce the fractal dimension and led to a shorter length of aggregation chains. However, it did not change the size of the primary particles or building block (approximately 3.8 nm) of the Fe3O4 particles. The neutron scattering of the Fe3O4 ferrofluids under an external magnetic field in the range of 0 to 1 T exhibited in a standard way of anisotropic phenomenon originating from the nanostructural ordering of the Fe3O4 particles. On the other hand, the Fe3O4 powders did not show anisotropic scattering under an external field in the same range. Furthermore, the magnetization curve of the Fe3O4 ferrofluids and nanopowders exhibited a proper superparamagnetic character at room temperature with the respective saturation magnetization of 4.4 emu/g and 34.7 emu/g

The induction levels of heat shock protein 70 differentiate the vulnerabilities to mutant huntingtin among neuronal subtypes

The reason why vulnerabilities to mutant polyglutamine (polyQ) proteins are different among neuronal subtypes is mostly unknown. In this study, we compared the gene expression profiles of three types of primary neurons expressing huntingtin (htt) or ataxin-1. We found that heat shock protein 70 (hsp70), a well known chaperone molecule protecting neurons in the polyQ pathology, was dramatically upregulated only by mutant htt and selectively in the granule cells of the cerebellum. Granule cells, which are insensitive to degeneration in the human Huntington's disease (HD) pathology, lost their resistance by suppressing hsp70 with siRNA, whereas cortical neurons, affected in human HD, gained resistance by overexpressing hsp70. This indicates that induction levels of hsp70 are a critical factor for determining vulnerabilities to mutant htt among neuronal subtypes. CAT (chloramphenicol acetyltransferase) assays showed that CBF (CCAAT box binding factor, CCAAT/enhancer binding protein zeta) activated, but p53 repressed transcription of the hsp70 gene in granule cells. Basal and mutant htt-induced expression levels of p53 were remarkably lower in granule cells than in cortical neurons, suggesting that different magnitudes of p53 are linked to distinct induction levels of hsp70. Surprisingly, however, heat shock factor 1 was not activated in granule cells by mutant htt. Collectively, different levels of hsp70 among neuronal subtypes might be involved in selective neuronal death in the HD pathology

Magnetic Interactions and Transport in (Ga,Cr)As

The magnetic, transport, and structural properties of (Ga,Cr)As are reported. Zincblende Ga$_{1-x}$Cr$_{x}$As was grown by low-temperature molecular beam epitaxy (MBE). At low concentrations, x$\sim$0.1, the materials exhibit unusual magnetic properties associated with the random magnetism of the alloy. At low temperatures the magnetization M(B) increases rapidly with increasing field due to the alignment of ferromagnetic units (polarons or clusters) having large dipole moments of order 10-10$^2$$\mu_B$. A standard model of superparamagnetism is inadequate for describing both the field and temperature dependence of the magnetization M(B,T). In order to explain M(B) at low temperatures we employ a distributed magnetic moment (DMM) model in which polarons or clusters of ions have a distribution of moments. It is also found that the magnetic susceptibility increases for decreasing temperature but saturates below T=4 K. The inverse susceptibility follows a linear-T Curie-Weiss law and extrapolates to a magnetic transition temperature $\theta$=10 K. In magnetotransport measurements, a room temperature resistivity of $\rho$=0.1 $\Omega$cm and a hole concentration of $\sim10^{20}$ cm$^{-3}$ are found, indicating that Cr can also act as a acceptor similar to Mn. The resistivity increases rapidly for decreasing temperature below room temperature, and becomes strongly insulating at low temperatures. The conductivity follows exp[-(T$_1$/T)$^{1/2}$] over a large range of conductivity, possible evidence of tunneling between polarons or clusters.Comment: To appear in PRB 15 Mar 200

Improvement of the transient expression system for production of recombinant proteins in plants

An efficient and high yielding expression system is required to produce recombinant proteins. Furthermore, the transient expression system can be used to identify the localization of proteins in plant cells. In this study, we demonstrated that combination of a geminiviral replication and a double terminator dramatically enhanced the transient protein expression level in plants. The GFP protein was expressed transiently in lettuce, Nicotiana benthamiana, tomatoes, eggplants, hot peppers, melons, and orchids with agroinfiltration. Compared to a single terminator, a double terminator enhanced the expression level. A heat shock protein terminator combined with an extensin terminator resulted in the highest protein expression. Transiently expressed GFP was confirmed by immunoblot analysis with anti-GFP antibodies. Quantitative analysis revealed that the geminiviral vector with a double terminator resulted in the expression of at least 3.7 mg/g fresh weight of GFP in Nicotiana benthamiana, approximately 2-fold that of the geminiviral vector with a single terminator. These results indicated that combination of the geminiviral replication and a double terminator is a useful tool for transient expression of the gene of interest in plant cells

Study of Non-Standard Neutrino Interactions with Atmospheric Neutrino Data in Super-Kamiokande I and II

In this paper we study non-standard neutrino interactions as an example of physics beyond the standard model using atmospheric neutrino data collected during the Super-Kamiokande I(1996-2001) and II(2003-2005) periods. We focus on flavor-changing-neutral-currents (FCNC), which allow neutrino flavor transitions via neutral current interactions, and effects which violate lepton non-universality (NU) and give rise to different neutral-current interaction-amplitudes for different neutrino flavors. We obtain a limit on the FCNC coupling parameter, varepsilon_{mu tau}, |varepsilon_{mu tau}|<1.1 x 10^{-2} at 90%C.L. and various constraints on other FCNC parameters as a function of the NU coupling, varepsilon_{e e}. We find no evidence of non-standard neutrino interactions in the Super-Kamiokande atmospheric data.Comment: 12 Pages, 14 figures. To be submitted to Phys. Rev.