Development of a Rapid Temperature Scanning System for Pulsed Magnetic Fields and its Applications

AbstractAn apparatus, which scans temperature in sub-seconds for measuring the temperature dependence of the resistivity, is proposed. This apparatus contains a thermal bath and a sample platform on which a thin-film thermometer and a thin-film heater are sputtered. By thermally isolating the sample platform from surrounding parts, the sample temperature can be scanned at a high sweep rate of 200-300K/s. As a demonstration of the apparatus, the resistivity of a niobium-titanium alloy is measured in a pulsed magnetic field. In addition, as another application of the apparatus, the dielectric polarization measurement of the quantum-paraelectric material SrTiO3 is described

Microstructure of Oxide Insulator Coating before and after Thermal Cycling Test

Erbium oxide (Er2O3) was shown to be a high potential candidate for tritium permeation barrier and electrical insulator coating for advanced breeding blanket systems such as liquid Li, Li-Pb or molten-salt blankets. Recently, we succeeded to form Er2O3 coating layer on large interior surface area of metal pipe using Metal Organic Chemical Vapor Deposition (MOCVD) process. In this paper, we investigated the microstructure of Er2O3 coating layer on stainless steel 316 (SUS 316) plate before and after heat treatments with hydrogen or argon gases. From the results of TEM observations, we confirmed that Er2O3 coating layer with 700 nm thickness was formed on the SUS 316 plate and this layer was identified to poly-crystal phase because the diffraction fleck which was arranged like a ring was observed in the selected electron diffraction pattern. No macroscopic defects such as crack and peeling in Er2O3 coating layer were observed before and after thermal cycling test. The change of microstructure of the Er2O3 coating layer on before and after heat cycling test was reported

Microstructure of Erbium Oxide Thin Film on SUS316 Substrate with Y₂O₃ or CeO₂ Buffer Layers Formed by MOCVD Method

Er2O3 has been known the best candidate material for insulating coating for liquid metal breeding blanket system. The formation of Er2O3 layer by MOCVD method can be succeeded on SUS316 substrate with CeO2 and Y2O3 buffer layers (100 nm and 500 nm) fabricated by RF sputtering, and their microstructures have been confirmed by SEM, TEM and STEM. The surface morphology of their layers was smaller granular structure than the previous study without buffer layer. According to cross sectional TEM (X-TEM) observation, Er2O3, CeO2/Y2O3 buffer, unknown layers and SUS substrate can be confirmed. CeO2 buffer layer has a granular structure, while Y2O3 has a columnar structure. Er2O3 layer formed on each buffer layer had finer structure without buffer layer. It has been also detected that each element does not exist so much in each layer by diffusion during fabrication according to STEM-EDS and HAADF imaging

Gene expression profiling of loss of TET2 and/or JAK2V617F mutant hematopoietic stem cells from mouse models of myeloproliferative neoplasms

AbstractMyeloproliferative neoplasms (MPNs) are clinically characterized by the chronic overproduction of differentiated peripheral blood cells and the gradual expansion of malignant intramedullary/extramedullary hematopoiesis. In MPNs mutations in JAK2 MPL or CALR are detected mutually exclusive in more than 90% of cases [1,2]. Mutations in them lead to the abnormal activation of JAK/STAT signaling and the autonomous growth of differentiated cells therefore they are considered as “driver” gene mutations. In addition to the above driver gene mutations mutations in epigenetic regulators such as TET2 DNMT3A ASXL1 EZH2 or IDH1/2 are detected in about 5%–30% of cases respectively [3]. Mutations in TET2 DNMT3A EZH2 or IDH1/2 commonly confer the increased self-renewal capacity on normal hematopoietic stem cells (HSCs) but they do not lead to the autonomous growth of differentiated cells and only exhibit subtle clinical phenotypes [4,6–8,5]. It was unclear how mutations in such epigenetic regulators influenced abnormal HSCs with driver gene mutations how they influenced the disease phenotype or whether a single driver gene mutation was sufficient for the initiation of human MPNs. Therefore we focused on JAK2V617F and loss of TET2—the former as a representative of driver gene mutations and the latter as a representative of mutations in epigenetic regulators—and examined the influence of single or double mutations on HSCs (Lineage−Sca-1+c-Kit+ cells (LSKs)) by functional analyses and microarray whole-genome expression analyses [9]. Gene expression profiling showed that the HSC fingerprint genes [10] was statistically equally enriched in TET2-knockdown-LSKs but negatively enriched in JAK2V617F–LSKs compared to that in wild-type-LSKs. Double-mutant-LSKs showed the same tendency as JAK2V617F–LSKs in terms of their HSC fingerprint genes but the expression of individual genes differed between the two groups. Among 245 HSC fingerprint genes 100 were more highly expressed in double-mutant-LSKs than in JAK2V617F–LSKs. These altered gene expressions might partly explain the mechanisms of initiation and progression of MPNs which was observed in the functional analyses [9]. Here we describe gene expression profiles deposited at the Gene Expression Omnibus (GEO) under the accession number GSE62302 including experimental methods and quality control analyses