A simulation study of short channel effects with a QET model based on Fermi–Dirac statistics and nonparabolicity for high-mobility MOSFETs

In this paper, the quantum confinement and short channel effects of Si, Ge, and \(\hbox {In}_{0.53}\hbox {Ga}_{0.47}\)As n-MOSFETs are evaluated. Both bulk and double-gate structures are simulated using a quantum energy transport model based on Fermi–Dirac statistics. Nonparabolic band effects are further considered. The QET model allows us to simulate carrier transport including quantum confinement and hot carrier effects. The charge control by the gate is reduced in the Ge and \(\hbox {In}_{0.53}\hbox {Ga}_{0.47}\)As bulk n-MOSFETs due to the low effective mass and high permittivity. This charge control reduction induces the degradation of short channel effects. In double-gate structures, different improvements of drain induced barrier lowering (DIBL) and subthreshold slope (SS) are seen. The double-gate structure is effective in the suppression of DIBL for all channel materials. The SS degradation depends on channel materials even in double-gate structure.     

Fabrication of Aluminum Foam/Dense Steel Composite by Friction Stir Welding

Aluminum foam/dense steel composites were fabricated by friction stir welding (FSW). It is expected that both mixing a blowing agent into aluminum and bonding the aluminum precursor to steel can be conducted simultaneously by FSW. It was shown that although heat treatment of the precursor evolved a brittle intermetallic compound layer, the bonding strength of the interface consisting of the intermetallic compound layer was relatively high compared with the fracture strength of the aluminum foam itself.     

Effect of substrate temperature on the structure and magnetic properties of CoPt/AlN multilayer films

The effect of substrate temperature on the structure and magnetic properties of CoPt/AlN multilayer films has been investigated.The crystallinity of CoPt has been improved with increasing substrate temperature from room temperature to 400 ℃.After post-annealing process,L1_0 CoPt structure transformation has also been promoted.However,since the easy magnetic axis of L1_0 CoPt is in[001]orientation,the promotion of L1_0 CoPt transformation causes the change of easy magnetic axis in(111) textured CoPt layers,which impairs the perpendicular magnetic anisotropy.The optimum substrate temperature should be room temperature to obtain the strongest perpendicular magnetic anisotropy according to the results of the present work.     

Availability of bone marrow stromal cells in three-dimensional coculture with hepatocytes and transplantation into liver-damaged mice

Rat bone marrow stromal cells (BMSCs) were cultured in porous hydroxyapatite (HA) disks for 2 weeks to form a cell layer on the surface. Freshly isolated hepatocytes were then inoculated into both BMSC-cultured and non-treated HA disks. Hepatocytes cocultured with BMSCs secreted significantly more albumin than those in monoculture in vitro. The cell-packed HA disks were implanted into the peritoneal cavity of Nagase analbuminemia rats (NARs), and 4 weeks later, blood samples were collected to measure the albumin concentration. The cotransplantation of BMSCs with hepatocytes significantly increased the serum albumin concentration in NARs. The HA disks coculturing mice hepatocytes and BMSCs were also implanted into mice, in which liver damage had been induced using carbon tetrachloride and phenobarbital. The decreased serum albumin level in liver-damaged mice was completely recovered by the transplantation of hepatocytes and BMSCs. The serum level of IL-6 in liver-damaged mice was also increased by the cotransplantation of BMSCs and hepatocytes. Thus, the transplantation of BMSCs appears to have a systemic effect on recipients through the increase in the serum cytokine level as well as a local effect on cotransplanted hepatocytes.     

Transition of mechanical property of porous alginate scaffold with cells during culture period

The rupture forces of porous alginate scaffolds seeded with hepatocytes or fibroblast-like cells increased during 3 d of culture and then decreased. The phenomenon was independent of the number of viable cells within the scaffolds, but dependent on protein adsorption to the alginate as well as a reduction in the degree of crosslinks of the calcium-alginate gel.     

Functional expression of streptococcal galactosyltransferase in baculovirus/insect cell expression system

The cpsIaJ gene of Streptococcus agalactiae type Ia codes for beta-1,4-galactosyltransferase. In this study, the functional expression of His-tagged CpsIaJ in a baculovirus expression system was performed, because the efficient functional expression of this enzyme in Escherichia coli had been unsuccessful. Using a partially purified enzyme preparation, we found that the enzyme had a restricted substrate specificity and that the entire structure of the substrate GlcNAc beta1-3Gal beta1-4Glc was required for the activity. Furthermore, mutations in a conserved DXD motif caused the loss of the enzyme's activity.     

Maintenance of hepatocyte functions by coculture with bone marrow stromal cells

Rat hepatocytes and bone marrow stromal cells (BMSCs) were cocultured with the aim of maintaining differentiated hepatocyte functions. After BMSCs were expanded to a confluent monolayer, freshly isolated hepatocytes were cultured with them, separated by a semipermeable membrane. The BMSCs significantly increased the urea synthesis and albumin secretion activities of the hepatocytes. Conditioned medium prepared from a BMSC monoculture had the same effect. Further study showed that interleukin-6 was involved in the maintenance of urea synthesis and another factor in the maintenance of albumin secretion.