Simulation of running impact using a viscoelastic model considering contact phase

AbstractThe purposes of this study were to develop and validate a new viscoelastic model which can consider the contact phases of running. For these purposes, a simple mechanical model of the human body including two contact points was developed. Three healthy male performed barefoot running at different speeds. The simulated values during the passive phase using this model were well estimated. It was shown that this new model may be useful to analyze the impact force during running

Effect of the Plasma Impedance on the Time Variation of the Inverse Pinch

The effect of the plasma impedance on the transient behavior of the inverse pinch is investigated. The initial value problem of the ordinary differential equation is formulated with respect to the electric current, the magnetic cavity radius, the shock front radius and the density behind the shock front within the frame work of reasonable assumptions. The present treatment is a refinement of the acoustic treatment by the senior author (T.S.) and affords qualitatively reasonable results even for cases where the acoustic treatment breaks down. The solution is obtained numerically by the standard method and the existense of a new type damped oscillation is clarified

Numerical Solution of Two-dimensional Channel Flow of Viscous Incompressible Fluid past an Elliptic Cylinder

We studied a two-dimensional flow of viscous incompressible fluid past a thin elliptic cylinder in a rectilinear channel. The major axis of the cylinder has the same length as the channel width, and the center of the cylinder is placed on the midplane of the channel. Reynolds number R and the angle of attack θ of the cylinder range, respectively, between 50 and 1000 and between 0° and 40°. The new upwind difference scheme by Kawamura Kuwahara (1984) is applied to the stream function-vorticity formalism of the Navier-Stokes equations. The boundary-fitted curvilinear coordinate systems by Thompson et al (1976) are used to transform the physical plane onto a simple calculation plane. The line-Jacobi method of iteration is applied to the solution of the Poisson type equation of the stream function. The Euler explicit method of solution is applied to the solution of the vorticity equation

The Steady Two-dimensional Flow of Viscous Incompressible Fluid Past an Elliptic Valve of Zero Angle of Attack Placed in a Rectilinear Channel : As a Model of a Flow Past a Fully Open Butterfly Valve

We studied the steady two-dimensional flow of a viscous incompressibe fluid past an elliptic valve of zero angle of attack placed in a rectilinear channel. We apply generalized curvilinear coordinates, by which the channel walls and the valve surface are mapped onto corresponding coordinate lines, to the solution of the stream function-vorticity formulation of the Navier-Stokes equations. The ADI and the Euler explicit method of solution are applied to solve the transformed basic equations. Flow patterns, pressure distributions and drag coefficients are obtained for several values of Reynolds number between 0 and 40

Role of p53 mutation in the effect of boron neutron capture therapy on oral squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>Boron neutron capture therapy (BNCT) is a selective radiotherapy, being effective for the treatment of even advanced malignancies in head and neck regions as well as brain tumors and skin melanomas. To clarify the role of p53 gene, the effect of BNCT on oral squamous cell carcinoma (SCC) cells showing either wild- (SAS/neo) or mutant-type (SAS/mp53) p53 was examined.</p> <p>Methods</p> <p>Cells were exposed to neutron beams in the presence of boronophenylalanine (BPA) at Kyoto University Research Reactor. Treated cells were monitored for modulations in colony formation, proliferation, cell cycle, and expression of cell cycle-associated proteins.</p> <p>Results</p> <p>When SAS/neo and SAS/mp53 cells were subjected to BNCT, more suppressive effects on colony formation and cell viability were observed in SAS/neo compared with SAS/mp53 cells. Cell cycle arrest at the G1 checkpoint was observed in SAS/neo, but not in SAS/mp53. Apoptotic cells increased from 6 h after BNCT in SAS/neo and 48 h in SAS/mp53 cells. The expression of p21 was induced in SAS/neo only, but G2 arrest-associated proteins including Wee1, cdc2, and cyclin B1 were altered in both cell lines.</p> <p>Conclusion</p> <p>These results indicate that oral SCC cells with mutant-type are more resistant to BNCT than those with wild-type p53, and that the lack of G1 arrest and related apoptosis may contribute to the resistance. At a physical dose affecting the cell cycle, BNCT inhibits oral SCC cells in p53-dependent and -independent manners.</p

Prophylactic effects of isomaltodextrin in a Balb/c mouse model of egg allergy

The aim of this study was to evaluate the potential effects of isomaltodextrin (IMD), a dietary saccharide polymer derived from enzymatically produced from starch, on the ability to alter immune response (IR) bias to hen egg ovalbumin (Ova) induced allergic inflammation in mice. Groups of Balb/c mice were pre-treated with various doses of IMD in drinking water (1.0, 2.5, and 5.0% w/v) for 6 weeks and subsequently sensitized to the Ova together with continuous administration of IMD. To evaluate changes in immune response bias, immunoglobulin isotype-associated antibody activity, concentrations of type 1 and 2 cytokines and the percentage of T-regulatory cells (T-regs) in blood were measured. Clinical signs of allergy were assessed after oral challenge with Ova. Treatment with IMD did not significantly alter the frequency of clinical signs, however there was a trend in the overall reduction of clinical signs. Effect on IR bias was observed in the treatment groups as reflected by reduction in a type 1-biased phenotype as evident by decrease in isotype-specific IgE, IgG and increase in IL-12 cytokine production and a high proportion of Tregs. This study revealed that IMD could be a useful prophylactic candidate for alteration of allergic IR bias in mice and an immunestimulator for reducing egg induced allergic reactions

Effects of titanium concentration on microstructure and mechanical properties of high-purity vanadium alloys

Effects of Ti concentration on microstructure and mechanical properties of high-purity V-4Cr-xTi alloys have been studied by means of scanning electron microscopy, transmission electron microscopy, Vickers hardness and tensile tests. Results show that precipitation occurs with 1 wt% Ti addition and above, whose diameter gradually increases as Ti concentration rises. Vickers hardness and tensile strength increase with increasing Ti concentration. Moreover, strengthening mechanisms consisting of solid solution strengthening (σSS), grain boundary strengthening (σGB), and precipitation strengthening (σP) are theoretically estimated. The strength contribution sequence is σSS > σGB > σP. Solid solution strengthening from Ti increases with increasing Ti concentration, and precipitation strengthening is not significantly dependent on Ti concentration. Additionally, 1 wt% Ti is probably sufficient to scavenge the interstitial impurities and provide comparable precipitation strengthening with V-4Cr-4Ti alloy

Copy Number Variations Due to Large Genomic Deletion in X-Linked Chronic Granulomatous Disease

Mutations in genes for any of the six subunits of NADPH oxidase cause chronic granulomatous disease (CGD), but almost 2/3 of CGD cases are caused by mutations in the X-linked CYBB gene, also known as NAD (P) H oxidase 2. Approximately 260 patients with CGD have been reported in Japan, of whom 92 were shown to have mutations of the CYBB gene and 16 to have chromosomal deletions. However, there has been very little detailed analysis of the range of the deletion or close understanding of the disease based on this. We therefore analyzed genomic rearrangements in X-linked CGD using array comparative genomic hybridization analysis, revealing the extent and the types of the deletion genes. The subjects were five Japanese X-linked CGD patients estimated to have large base deletions of 1 kb or more in the CYBB gene (four male patients, one female patient) and the mothers of four of those patients. The five Japanese patients were found to range from a patient exhibiting deletions only of the CYBB gene to a female patient exhibiting an extensive DNA deletion and the DMD and CGD phenotype manifested. Of the other three patients, two exhibited CYBB, XK, and DYNLT3 gene deletions. The remaining patient exhibited both a deletion encompassing DNA subsequent to the CYBB region following intron 2 and the DYNLT3 gene and a complex copy number variation involving the insertion of an inverted duplication of a region from the centromere side of DYNLT3 into the deleted region

High Levels of Copper, Zinc, Iron and Magnesium, but not Calcium, in the Cerebrospinal Fluid of Patients with Fahr's Disease

Patients with marked calcification of the basal ganglia and cerebellum have traditionally been referred to as having Fahr's disease, but the nomenclature has been criticized for including heterogeneous etiology. We describe 3 patients with idiopathic bilateral striatopallidodentate calcinosis (IBSPDC). The patients were a 24-year-old man with mental deterioration, a 57-year-old man with parkinsonism and dementia, and a 76-year-old woman with dementia and mild parkinsonism. The former 2 patients showed severe calcification of the basal ganglia and cerebellum, and the latter patient showed severe calcification of the cerebellum. We found significantly increased levels of copper (Cu), zinc (Zn), iron (Fe) and magnesium (Mg), using inductively coupled plasma mass spectrometry in the CSF of all these 3 patients. The increased levels of Cu, Zn, Fe and Mg reflect the involvement of metabolism of several metals and/or metal-binding proteins during the progression of IBSPDC. More numerous patients with IBSPDC should be examined in other races to clarify the common mechanism of the disease and to investigate the specific treatment

Fabp7 Maps to a Quantitative Trait Locus for a Schizophrenia Endophenotype

Deficits in prepulse inhibition (PPI) are a biological marker for schizophrenia. To unravel the mechanisms that control PPI, we performed quantitative trait loci (QTL) analysis on 1,010 F2 mice derived by crossing C57BL/6 (B6) animals that show high PPI with C3H/He (C3) animals that show low PPI. We detected six major loci for PPI, six for the acoustic startle response, and four for latency to response peak, some of which were sex-dependent. A promising candidate on the Chromosome 10-QTL was Fabp7 (fatty acid binding protein 7, brain), a gene with functional links to the N-methyl-D-aspartic acid (NMDA) receptor and expression in astrocytes. Fabp7-deficient mice showed decreased PPI and a shortened startle response latency, typical of the QTL's proposed effects. A quantitative complementation test supported Fabp7 as a potential PPI-QTL gene, particularly in male mice. Disruption of Fabp7 attenuated neurogenesis in vivo. Human FABP7 showed altered expression in schizophrenic brains and genetic association with schizophrenia, which were both evident in males when samples were divided by sex. These results suggest that FABP7 plays a novel and crucial role, linking the NMDA, neurodevelopmental, and glial theories of schizophrenia pathology and the PPI endophenotype, with larger or overt effects in males. We also discuss the results from the perspective of fetal programming