High-pressure synthesis of cubic BN using Fe–Mo–Al and Co–Mo–Al alloy solvents

The pressure and temperature regions of cubic BN formation were determined using Fe–Mo–Al and Co–Mo–Al ternary alloys as synthetic solvents of cubic BN. The alloy compositions employed in the present study were (in weight percent) Fe60.14–Mo36.86–Al3 and Co57.6–Mo38.4–Al4. The cubic BN was successfully synthesized at minimum pressure of about 4.4 GPa and temperature of about 1250 °C. Pressure and temperature of cubic BN synthesis were decreased drastically by small amount of Al addition into Fe–Mo or Co–Mo alloy solvents. The growth of cubic BN was started at the interface between the molten alloy and the source hexagonal BN. In the present study, we proposed that Fe–Mo and Co–Mo work as solvent of B and N atoms and Al acts as a nucleation agent of cubic BN.     

Identification of fungi using DNA sequences: an approach to identify Fusarium species isolated from domestic unpolished rice

Molecular approaches are being developed to provide for the rapid and objective identification of fungi. We attempted the identification of Fusarium species by a genetic analysis to validate practically the utility of a molecular approach for fungal identification and to reveal its limitations, and sequenced three regions, the 5' end of the 28S rRNA gene (D2 region) and the internal transcribed spacer 1 and 2 (ITS1 and ITS2) regions, in the rRNA genes. The DNA sequences of 38 Fusarium strains isolated from domestic unpolished rice were compared for similarity with entries in the GenBank. Based on this comparison, it was estimated that all these three regions, as a minimum, must be compared with the database to identify Fusaria at the species level. According to the combinations of sequences in the three regions, the 38 isolates were classified into 13 groups. Out of the 13 groups, 6 groups (20 isolates in total) could be identified as definite species based only on the sequence data. For the other 6 groups (17 isolates in total), candidate species were limited on the basis of the sequence similarity, and then the isolates were identified at the species level with the aid of morphology. Only one isolate could not be identified. These results verified that DNA sequence comparison with the GenBank database is useful for the identification of Fusarium species.     

4-Hydroxyderricin,as a PPARγ Agonist,Promotes Adipogenesis,Adiponectin Secretion,and Glucose Uptake in 3T3-L1 Cells

Adipocyte differentiation plays a pivotal role in maintaining the production of small‐size adipocytes with insulin sensitivity, and impaired adipogenesis is implicated in insulin resistance. 4‐Hydroxyderricin (4‐HD), a phytochemical component of Angelica keiskei, possesses diverse biological properties such as anti‐inflammatory, antidiabetic, and antitumor. In the present study, we investigated the effects of 4‐HD on adipocyte differentiation. 4‐HD promoted lipid accumulation in 3T3‐L1 cells, upregulated both peroxisome proliferator‐activated receptor (PPAR)‐γ mRNA and protein expression, and acted as a ligand for PPARγ in the luciferase assay. Moreover, 4‐HD increased the mRNA and protein expression levels of adiponectin. Additionally, it promoted insulin‐dependent glucose uptake into 3T3‐L1 adipocytes and increased Akt phosphorylation and glucose transporter (GLUT) 4 mRNA expression. In summary, these findings suggest that 4‐HD, which promoted adipogenesis and insulin sensitivity in 3T3‐L1 cells, might be a phytochemical with potent insulin‐sensitizing effects.     

Controllable Magnetic Proximity Effect and Charge Transfer in 2D Semiconductor and Double-Layered Perovskite Manganese Oxide van der Waals Heterostructure

Optically generated excitonic states (excitons and trions) in transition metal dichalcogenides are highly sensitive to the electronic and magnetic properties of the materials underneath. Modulation and control of the excitonic states in a novel van der Waals (vdW) heterostructure of monolayer MoSe₂ on double-layered perovskite Mn oxide ((La_0.8Nd_0.2)_1.2Sr_1.8Mn₂O₇) is demonstrated, wherein the Mn oxide transforms from a paramagnetic insulator to a ferromagnetic metal. A discontinuous change in the exciton photoluminescence intensity via dielectric screening is observed. Further, a relatively high trion intensity is discovered due to the charge transfer from metallic Mn oxide under the Curie temperature. Moreover, the vdW heterostructures with an ultrathin h-BN spacer layer demonstrate enhanced valley splitting and polarization of excitonic states due to the proximity effect of the ferromagnetic spins of Mn oxide. The controllable h-BN thickness in vdW heterostructures reveals a several-nanometer-long scale of charge transfer as well as a magnetic proximity effect. The vdW heterostructure allows modulation and control of the excitonic states via dielectric screening, charge carriers, and magnetic spins.     

Effect of sedimentary facies and geological properties on thermal conductivity of Pleistocene volcanic sediments in Tokyo,central Japan

When ground source heat pump systems are installed underground, an estimate of the thermal conductivity is required to determine the desired total length of the heat exchanger (U-tube). Many large cities in Asia are built on Quaternary sediments, but the thermal conductivity of these sediments is not well understood. To measure the thermal conductivity of Pleistocene volcanic sediments in Tokyo, Japan, we discuss methods of measuring thermal conductivity and factors influencing the thermal conductivity of volcanic sediment, which has low quartz content. The results obtained from experiments using a drill core, borehole data and artificial sediment samples are as follows: (1) values of thermal conductivity predicted using water content, porosity or sand content can be underestimated in volcanic sediment or sediments with large amounts of magnetic minerals; (2) magnetic minerals have a higher thermal conductivity than quartz, so there is a relationship between magnetic susceptibility and thermal conductivity: (3) comparison of thermal conductivity measurements performed using box- and needle-type probes showed that the values measured using the former are comparatively larger. This decrease in thermal conductivity is explained by formation of air-filled cracks when the needle penetrates the sediment, as air has a lower thermal conductivity than sediment.