Influence of Hydrophilic and Hydrophobic Coating on Hydrofoil Performance

International audienceTidal power turbines take advantage of tidal energy to generate renewable hydropower. Since the tidal turbines are fixed in the ocean, it is common to paint the blade and the structure of tidal energy generator with antifouling coating to prevent marine organisms from attaching to them. Therefore, it is important to predict the influence of the coatings on the tidal turbine's performance. In this paper, hydrophilic and hydrophobic coatings which are known to be useful in antifouling were studied from the perspective of flow field and cavitation. Cavitation was visualized with a high-speed video camera and the cavitation characteristics of blades painted with hydrophilic or hydrophobic coatings were compared. With this visualization, it was possible to observe that the hydrophilic foil and hydrophobic foil had distinctive characteristics in cavitation inception and growth. Moreover, the reliability of both coatings was evaluated in order to discuss whether these coatings were useful for long. Immersion tests were carried out to evaluate the deterioration of the coatings in pure water. In addition, magnetostriction vibratory tests were carried out to evaluate the resistance to cavitation erosion of both coatings. From these investigations, a chemical transformation of the hydrophilic coating was observed. Moreover, both coatings were easily removed when they were exposed to strong cavitation impacts

Spin-orbit coupling inactivity of Co2+^{2+} ion in geometrically frustrated magnet GeCo2_2O4_4

We report single-crystal neutron diffraction studies on a spinel antiferromagnet GeCo$_2$O$_4$, which exhibits magnetic order with a trigonal propagation vector and tetragonal lattice expansion ($c/a\simeq1.001$) below $T_{\rm N}=21$ K. For this inconsistency between spin and lattice in symmetry, magnetic Bragg reflections with a tetragonal propagation vector were discovered below $T_{\rm N}$. We discuss spin and orbital states of Co$^{2+}$ ion underlying the new magnetic component.Comment: 3 pages 2 figures, submitted to ICFCM proceeding (Journal of Physics: Conference Series, 2011

Positive Transfer Effect of Amygdaloid Kindling in Developing Rats

To study the hypothesis that seizure susceptibility in the young rat brain is higher than that in the adult brain, positive transfer effect (PTE) in amygdaloid kindling in rats was investigated at varing ages: 15 days, 18 days, 28 days, 40 days and 70 days. Although PTE was observed regardless of age, it was more pronounced in weaning rats than in adult rats

Fermi surface reconstruction due to the orthorhombic distortion in Dirac semimetal YbMnSb2_2

Dirac semi-metal with magnetic atoms as constituents delivers an interesting platform to investigate the interplay of Fermi surface (FS) topology, electron correlation, and magnetism. One such family of semi-metal is YbMn$Pn_2$ ($Pn$ = Sb, Bi), which is being actively studied due to the intertwined spin and charge degrees of freedom. In this Letter, we investigate the relationship between the magnetic/crystal structures and FS topology of YbMnSb$_2$ using single crystal x-ray diffraction, neutron scattering, magnetic susceptibility, magnetotransport measurement and complimentary DFT calculation. Contrary to previous reports, the x-ray and neutron diffraction reveal that YbMnSb$_2$ crystallizes in an orthorhombic $Pnma$ structure with notable anti-phase displacement of the magnetic Mn ions that increases in magnitude upon cooling. First principles DFT calculation reveals a reduced Brillouin zone and more anisotropic FS of YbMnSb$_2$ compared to YbMnBi$_2$ as a result of the orthorhombicity. Moreover, the hole type carrier density drops by two orders of magnitude as YbMnSb$_2$ orders antiferromagnetically indicating band folding in magnetic ordered state. In addition, the Landau level fan diagram yields a non-trivial nature of the SdH quantum oscillation frequency arising from the Dirac-like Fermi pocket. These results imply that YbMnSb$_2$ is an ideal platform to explore the interplay of subtle lattice distortion, magnetic order, and topological transport arising from relativistic quasiparticles.Comment: 11 pages, contains 4 figures and 7 Supplemental Figure

Quantitative monitoring of single nucleotide mutations by allele-specific quantitative PCR can be used for the assessment of minimal residual disease in patients with hematological malignancies throughout their clinical course

BackgroundMonitoring of minimal residual disease (MRD) in patients with hematological malignancies is important for evaluating the patients\u27 therapeutic response and risk of relapse. Single nucleotide mutations associated with leukemogenesis can be considered as applicable MRD markers.MethodsWe developed an allele-specific quantitative polymerase chain reaction (AS-qPCR) for FLT3 2503G > T, KIT 2446G > T, and KIT 2447A > T and compared the change in the expression levels of the FLT3 or KIT mutations assessed by AS-qPCR to those of the RUNX1–RUNX1T1 fusion gene and WT1 by conventional quantitative PCR.ResultsThe AS-qPCR using primers including template-mismatched nucleotide or template-mismatched nucleotide plus locked nucleic acid substituted nucleotide provided higher selectivity for mutant nucleotides. The change in the expression levels of the FLT3 or KIT mutations at the time of relapse and just after hematopoietic stem cell transplantation correlated well with that of the RUNX1–RUNX1T1 fusion gene and WT1. Moreover, during complete remission, only AS-qPCR could detect low-level expression of residual mutations.ConclusionsThe AS-qPCR for analyzing single nucleotide mutations contributes to the monitoring of MRD in patients without recurrent fusion gene throughout the clinical course and thus broadens the spectrum of patients in whom MRD can be monitored

Successful Treatment in a Case of Massive Hepatocellular Carcinoma with Paraneoplastic Syndrome

Paraneoplastic syndromes of hepatocellular carcinoma (HCC) are not uncommon. However, the prognosis is poor and follow-up and improvement of paraneoplastic syndromes with treatment have been reported rarely. We report a successful case in an aged man of a massive HCC with paraneoplastic syndrome, treated by combined intraarterial chemotherapy and hepatic resection. Paraneoplastic syndrome (erythrocytosis and hyperlipidemia) was monitored throughout the treatment and erythropoietin (EPO) mRNA also was analyzed in the resected liver. The hemoglobin level and serum levels of EPO and total cholesterol (T-cho) decreased dramatically with treatment, along with a decrease in serum levels of α-fetoprotein and protein induced by vitamin vitamin K absence II (PIVKA-II). Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) revealed that the residual cancer expressed EPO RNA but the nontumor tissue did not. This was a rare case of paraneoplastic syndrome of HCC that was treated successfully. This case indicates that paraneoplastic syndrome reflected tumor progression and that serum levels of both EPO and T-cho might be used as tumor markers

GWAS of mosaic loss of chromosome Y highlights genetic effects on blood cell differentiation

Abstract: Mosaic loss of chromosome Y (mLOY) is frequently observed in the leukocytes of ageing men. However, the genetic architecture and biological mechanisms underlying mLOY are not fully understood. In a cohort of 95,380 Japanese men, we identify 50 independent genetic markers in 46 loci associated with mLOY at a genome-wide significant level, 35 of which are unreported. Lead markers overlap enhancer marks in hematopoietic stem cells (HSCs, P ≤ 1.0 × 10−6). mLOY genome-wide association study signals exhibit polygenic architecture and demonstrate strong heritability enrichment in regions surrounding genes specifically expressed in multipotent progenitor (MPP) cells and HSCs (P ≤ 3.5 × 10−6). ChIP-seq data demonstrate that binding sites of FLI1, a fate-determining factor promoting HSC differentiation into platelets rather than red blood cells (RBCs), show a strong heritability enrichment (P = 1.5 × 10−6). Consistent with these findings, platelet and RBC counts are positively and negatively associated with mLOY, respectively. Collectively, our observations improve our understanding of the mechanisms underlying mLOY

Elucidating the genetic architecture of reproductive ageing in the Japanese population.

Population studies elucidating the genetic architecture of reproductive ageing have been largely limited to European ancestries, restricting the generalizability of the findings and overlooking possible key genes poorly captured by common European genetic variation. Here, we report 26 loci (all P < 5 × 10-8) for reproductive ageing, i.e. puberty timing or age at menopause, in a non-European population (up to 67,029 women of Japanese ancestry). Highlighted genes for menopause include GNRH1, which supports a primary, rather than passive, role for hypothalamic-pituitary GnRH signalling in the timing of menopause. For puberty timing, we demonstrate an aetiological role for receptor-like protein tyrosine phosphatases by combining evidence across population genetics and pre- and peri-pubertal changes in hypothalamic gene expression in rodent and primate models. Furthermore, our findings demonstrate widespread differences in allele frequencies and effect estimates between Japanese and European associated variants, highlighting the benefits and challenges of large-scale trans-ethnic approaches