A high performance pMOSFET with two-step recessed SiGe-S/D structure for 32 nm node and beyond

A novel SiGe-S/D structure for high performance pMOSFET called two-step recessed SiGe-source/drain (S/D) is developed with careful optimization of recessed SiGe-S/D structure. With this method, hole mobility, short channel effect and S/D resistance in pMOSFET are improved compared with conventional recessed SiGe-S/D structure. To enhance device performance such as drain current drivability, SiGe region has to be closer to channel region. Then, conventional deep SiGe-S/D region with carefully optimized shallow SiGe SDE region showed additional device performance improvement without SCE degradation. As a result, high performance 24 nm gate length pMOSFET was demonstrated with drive current of 451 μA/μm at V_dd of 0.9 V and I_off of 100 nA/μm (552 μA/μm at V_dd of 1.0 V). Furthermore, by combining with V_dd scaling, we indicate the extendability of two-step recessed SiGe-S/D structure down to 15 nm node generation.     

Exogenous ANP Treatment Ameliorates Myocardial Insulin Resistance and Protects against Ischemia–Reperfusion Injury in Diet-Induced Obesity

Increasing evidence suggests natriuretic peptides (NPs) coordinate interorgan metabolic crosstalk. We recently reported exogenous ANP treatment ameliorated systemic insulin resistance by inducing adipose tissue browning and attenuating hepatic steatosis in diet-induced obesity (DIO). We herein investigated whether ANP treatment also ameliorates myocardial insulin resistance, leading to cardioprotection during ischemia–reperfusion injury (IRI) in DIO. Mice fed a high-fat diet (HFD) or normal-fat diet for 13 weeks were treated with or without ANP infusion subcutaneously for another 3 weeks. Left ventricular BNP expression was substantially reduced in HFD hearts. Intraperitoneal-insulin-administration-induced Akt phosphorylation was impaired in HFD hearts, which was restored by ANP treatment, suggesting that ANP treatment ameliorated myocardial insulin resistance. After ischemia–reperfusion using the Langendorff model, HFD impaired cardiac functional recovery with a corresponding increased infarct size. However, ANP treatment improved functional recovery and reduced injury while restoring impaired IRI-induced Akt phosphorylation in HFD hearts. Myocardial ultrastructural analyses showed increased peri-mitochondrial lipid droplets with concomitantly decreased ATGL and HSL phosphorylation levels in ANP-treated HFD, suggesting that ANP protects mitochondria from lipid overload by trapping lipids. Accordingly, ANP treatment attenuated mitochondria cristae disruption after IRI in HFD hearts. In summary, exogenous ANP treatment ameliorates myocardial insulin resistance and protects against IRI associated with mitochondrial ultrastructure modifications in DIO. Replenishing biologically active NPs substantially affects HFD hearts in which endogenous NP production is impaired.     

Synthesis of well-defined graft copolymer with oligodimethylsiloxane and polyvinylalcohol branches

Summary Polyvinylalcohol macromer of well controlled molecular weight and molecular weight distribution, whose hydroxyl groups being protected as silyl ethers, was synthesized by Lewis acid catalyzed sequential silyl aldol condensation. Copolymerization of p-oligodimethylsiloxanylstyrene with the macromer, followed by the removal of the hydroxyl protective groups, gave the well-defined title graft copolymer.     

Emulation and behavior understanding through shared values

Neurophysiology has revealed the existence of mirror neurons in the brain of macaque monkeys that activate when the monkey executes a goal directed behavior and also when it observes the same behavior performed by another. The concept of the mirror neurons/systems (Oztop and Kawato, 2006) [19] suggests that behavior acquisition and understanding of others’ behavior are related.We propose a method not only to learn and execute a variety of behaviors but also to understand observed behavior, supposing that the observer has already acquired the utilities (state values in reinforcement learning scheme) of all kinds of behavior the observed agent can do. The method does not need a precise world model or a coordinate transformation system to deal with a view difference caused by different viewpoints. This paper shows that an observer can understand/recognize behaviors shown by a demonstrator based not on a precise object trajectory in allocentric/egocentric coordinate space but rather on an estimated utility transition during the observed behavior.Furthermore, it is shown that the loop of the behavior acquisition and recognition of observed behavior accelerates the learning and improves the recognition performance. The state value updates can be accelerated by the observation without real trial and error while the learned values enrich the recognition system, since it is based on estimation of the state value of the observed behavior. The validity of the proposed method is shown by applying it to a dynamic environment where two robots play soccer.     

Syntheses of polyamide-poly(methyl methacrylate) graft copolymers by polycondensation reactions of macromonomers

Summary Dicarboxyl-terminated macromolecular monomers (macromonomers) were synthesized by radical polymerization of methyl methacrylate in the presence of thiomalic acid as a chain transfer agent. This macromonomer and sebacic acid were condensed with diamines (p,p-diaminodiphenyl ether, p,p-diaminodiphenylmethane and m-phenylenediamine) by triphenylphosphitepyridine system. Thus, graft copolyamides of well-defined structure and composition were readily prepared. This is the first example of the polycondensation reactions of macromonomers.     

Enhancement of oxygen permselectivity of polydimethylsiloxane-b-polycarbonate film by the surface modification with fluorine-containing polymer

Summary Both oxygen permeability coefficient(^PO₂) and separation factor ( = ^PO₂/^PN₂) through polydimethylsiloxane-b-polycarbonate(PDMS/PC) film were improved by the addition of small amounts(1.0 wt%) of the fluorine-containing polymer. This improvement was considered to be caused by the selective solubilization of oxygen in the surfaceaccumulated fluorine polymer domain.     

A Novel α-Glucosidase of the Glycoside Hydrolase Family 31 from Aspergillus sojae

We characterized an α-glucosidase belonging to the glycoside hydrolase family 31 from Aspergillus sojae. The α-glucosidase gene was cloned using the whole genome sequence of A. sojae, and the recombinant enzyme was expressed in Aspergillus nidulans. The enzyme was purified using affinity chromatography. The enzyme showed an optimum pH of 5.5 and was stable between pH 6.0 and 10.0. The optimum temperature was approximately 55 °C. The enzyme was stable up to 50 °C, but lost its activity at 70 °C. The enzyme acted on a broad range of maltooligosaccharides and isomaltooligosaccharides, soluble starch, and dextran, and released glucose from these substrates. When maltose was used as substrate, the enzyme catalyzed transglucosylation to produce oligosaccharides consisting of α-1,6-glucosidic linkages as the major products. The transglucosylation pattern with maltopentaose was also analyzed, indicating that the enzyme mainly produced oligosaccharides with molecular weights higher than that of maltopentaose and containing continuous α-1,6-glucosidic linkages. These results demonstrate that the enzyme is a novel α-glucosidase that acts on both maltooligosaccharides and isomaltooligosaccharides, and efficiently produces oligosaccharides containing continuous α-1,6-glucosidic linkages.     

An artificial nonradiative recombination center model created by use of a Si1 − xGex/Si quantum-well-inserted pseudomorphic superlattice

An attempt is made to mimic a system under the influence of nonradiative recombination (NR) by use of a Si_1 − xGe_x quantum well (QW) embedded in a Si_1 − xGe_x/Si strained-layer superlattice. Carrier transfer mediates the coupling between the first miniband of superlattice barrier and QW ground state, which is useful in setting up an artificial NR center based only on radiative channels. Steady-state and transient photoluminescence (PL) reproduces spectroscopic features shared by NR systems at large such as quadratic dependence of PL intensity on excitation power and prolonged decay time at increased pumping, which are quite opposite to radiative recombination.     

Chronic effects of methylmercury in rats. I. Biochemical aspects

The effect of a pre-coronary angioplasty education and counselling program on knowledge and psychological status of patients and on knowledge and quality of life/coping status of their spouses was evaluated. Forty patients and their spouses participated in a pre-coronary angioplasty education and counselling program and 40 served as controls. Knowledge, psychological status and quality of life/coping status were assessed prior to coronary angioplasty and at a mean of four and 11 months post-coronary angioplasty. At four months, improved knowledge and reduced anxiety were found for patients in the experimental group. At 11 months, spouses in the experimental group showed continued improvement in quality of life compared to those in the control group. It was concluded that pre-coronary angioplasty education and counselling can impact favourably upon knowledge in patients and quality of life in spouses.     

Thermal and photo-induced surface damage in paratellurite

Long-term operation of TeO2 acousto-optical device is limited by the formation of surface damage caused by the He–Cd laser irradiation. Similar surface damage occurs during the heat treatment of the TeO2 crystal at 350°C. In this study, TeO2 specimens after various surface treatments have been observed by electron microscopy and X-ray photoelectron spectroscopy. The variation of the transmittance for mechanically polished specimens has been measured in situ during heat treatments. It was found that the thermal surface damage at 350°C was formed in the surface layer damaged by mechanical polishing. The mechanically damaged layer was amorphous and deficient in oxygen in the as-polished state. The electron microscopic observation revealed that the surface damage layer induced by heat treatments or by the ultraviolet light irradiation contained tellurium particles (20–40 nm) in diameter dispersed in the TeO2 matrix. On annealing the TeO2 specimen at 500°C in air, however, the particles disappeared because of the melting, evaporation and oxidation of tellurium which restores the transmittance of the crystal. Based on the results, combined with the observation of surface damage induced by the visible light irradiation, a possible mechanism of the surface damage formation has been briefly discussed. This revised version was published online in November 2006 with corrections to the Cover Date.