Consumption of lily bulb modulates fecal ratios of firmicutes and bacteroidetes phyla in rats fed a high-fat diet

Food Science and Biotechnology - Different ascorbic acid (AA) concentrations of 0.16, 0.20, and 0.24% (w/v) were added to pear juice from the new cultivar Pyrus pyrifolia Nakai cv....     

A complex cell-like receptive field obtained by information maximization

The energy model (Pollen & Ronner, 1983; Adelson & Bergen, 1985) for a complex cell in the visual cortex is investigated theoretically. The energy model describes the output of a complex cell as the squared sum of outputs of two linear operators. An information-maximization problem to determine the two linear operators is investigated assuming the low signal-to-noise ratio limit and a localization term in the objective function. As a result, two linear operators characterized by a quadrature pair of Gabor functions are obtained as solutions. The result agrees with the energy model, which well describes the shift-invariant and orientation-selective responses of actual complex cells, and thus suggests that complex cells are optimally designed from an information-theoretic viewpoint.     

A 65-nm SoC Embedded 6T-SRAM Designed for Manufacturability With Read and Write Operation Stabilizing Circuits

In the sub-100-nm CMOS generation, a large local Vth variability degrades the 6T-SRAM cell stability, so that we have to consider this local variability as well as the global variability to achieve high-yield SRAM products. Therefore, we need to employ some assist circuits to expand the SRAM operating margin. We propose a variability-tolerant 6T-SRAM cell layout and new circuit techniques to improve both the read and the write operating margins in the presence of a large Vth variability. By applying these circuit techniques to a 0.494-mum² SRAM cell with a beta ratio of 1, which is an extremely small cell size, we can achieve a high-yield 8M-SRAM for a wide range of Vth values using a 65-nm low stand-by power (LSTP) CMOS technology     

Improvement of Porous Si Luminescence Intensity Durability by Nitrogen Ion Irradiation Using an ECR Ion Source

We have investigated the effects of the porous Si surface passivation by oxygen or nitrogen ion processing on the photoluminescence (PL) intensity and its stability using an electron cyclotron resonance ion source. The results indicate that an anneal before exposure to ion beam causes a PL intensity enhancement upon exposure to oxygen or nitrogen ion beam. A combination of an anneal and a passivation by exposure to nitrogen ion beam enhances the PL intensity by a factor of 2.5 compared to the intensity of the initial as-anodized PS and the enhanced intensity is stabilized for more than 180 min under Ar⁺-laser illumination while oxygen-ion-exposed PS exhibits an enhancement in PL intensity only by 1.4 and a decay in PL intensity by 20% after 180 min Ar⁺-laser illumination. The results suggest that the reaction of nitrogen with a PS surface plays a key role for the PL intensity enhancement and stability.     

Regio- and stereoselective propranolol metabolism by 15 forms of purified cytochromes P-450 from rat liver

Regio- and stereoselectivity of cytochrome P-450-mediated propranolol metabolism (4-, 5- and 7-hydroxylations and N-desisopropylation) was studied using 15 purified cytochrome P-450 species. With each purified cytochrome P-450 species, the regioselectivity was distinct and different between the two optical isomers used as substrates. The stereoselectivity was different depending on the position of propranolol to be metabolized. The regio- and stereoselectivity was altered when substrate concentration was altered, suggesting that the kinetics of the reactions are different depending on the positions of propranolol to be metabolized. Furthermore, the selectivity and its manner of alterations with substrate concentrations were different among all cytochrome P-450 species used. Propranolol, with its multiple metabolic pathways and optical isomers, is an extremely interesting substrate for characterization of cytochrome P-450 species.     

Dependence of thin-oxide films quality on surface microroughness

The effects of silicon surface microroughness on electrical properties of thin-oxide films, such as breakdown electric field intensity (E_BD) and time-dependent dielectric breakdown (Q_BD), have been studied, where the microroughnesses of silicon and silicon dioxide surfaces are evaluated by the scanning tunneling microscope (STM) and the atomic force microscope (AFM), respectively. An increase of surface microroughness has been confirmed to severely degrade the E_BD and Q_BD characteristics of thin-oxide films with thicknesses of 8-10 nm and to simultaneously decrease channel electron mobility. An increase of surface microroughness has been demonstrated to originate mainly from wet chemical cleaning processing based on the RCA cleaning concept, particularly the ammonium-hydrogen-peroxide cleaning step. In order to keep the surface microroughness at an initial level, the content ratio of NH₄OH/H₂O₂/H₂ O solution has been set at 0.05:1:5 and the room-temperature DI water rinsing has been introduced right after the NH₄OH/H₂O₂/H₂O cleaning step in conventional RCA cleaning procedure     

Human organ phantoms for catheterization using the radiation crosslinking technique

An artificial organ based on polyvinyl alcohol (PVA) hydrogel was developed to train medical staff to improve their ablation therapy skills, by using the radiation cross-linking technique. The aqueous PVA solution was irradiated with γ-rays or electron beams to produce a highly transparent, high-strength, and flexible crosslinked hydrogel without using a crosslinking agent. Physical properties of the hydrogel, such as, gel fraction, swelling, and elastic modulus, were controlled by changing the radiation dose. The catheter ablation region on the surface of the cardiac phantom produced from PVA hydrogel with temperature-responsive pigment inks can be visually identified by the color change. The tumor organ phantom consists of the PVA hydrogel with the purple pigment ink (healthy organ site) and red PVA hydrogel with cellulose (the tumor sites) was developed by applying this radiation crosslinking technique. The positions of the tumor hydrogel and the ablation electrode needle can be confirmed through ultrasound echography. It is possible to practice ablation on the tumor site while observing the echo images under conditions similar to the actual treatment. These novel human organ phantoms are created as a means for ablation training for treating cardiac arrhythmia and liver cancer using the radiation crosslinking technology.     

Characterization of Light-Enhanced Respiration in Cyanobacteria

In eukaryotic algae, respiratory O₂ uptake is enhanced after illumination, which is called light-enhanced respiration (LER). It is likely stimulated by an increase in respiratory substrates produced during photosynthetic CO₂ assimilation and function in keeping the metabolic and redox homeostasis in the light in eukaryotic cells, based on the interactions among the cytosol, chloroplasts, and mitochondria. Here, we first characterize LER in photosynthetic prokaryote cyanobacteria, in which respiration and photosynthesis share their metabolisms and electron transport chains in one cell. From the physiological analysis, the cyanobacterium Synechocystis sp. PCC 6803 performs LER, similar to eukaryotic algae, which shows a capacity comparable to the net photosynthetic O₂ evolution rate. Although the respiratory and photosynthetic electron transports share the interchain, LER was uncoupled from photosynthetic electron transport. Mutant analyses demonstrated that LER is motivated by the substrates directly provided by photosynthetic CO₂ assimilation, but not by glycogen. Further, the light-dependent activation of LER was observed even with exogenously added glucose, implying a regulatory mechanism for LER in addition to the substrate amounts. Finally, we discuss the physiological significance of the large capacity of LER in cyanobacteria and eukaryotic algae compared to those in plants that normally show less LER.     

Microstructure and Faraday effect of Tb2O3-Al2O3-SiO2-B2O3 glasses for fiber-based magneto-optical applications

For the fiber-based magneto-optical (MO) devices, like Faraday optical isolator, the target MO glasses are supposed to strike a balance among the following properties: high Verdet constant, chemical and physical stabilities, compatibility with the fiber drawing process, and the connectivity to the silica glass fiber networks. In this work, we report on the MO application of Tb₂O₃-Al₂O₃-SiO₂-B₂O₃ (TASB) glasses as a derivative of the yttrium aluminum silicate (YAS) glass fiber systems which have been intensively studied for their huge potential in the context of all-fiber lasers. We found that MO properties of the obtained TASB glasses vary systematically with the B₂O₃ contents. The effects of B₂O₃ on the local glass structures and the valence state of Tb ions were clarified via nuclear magnetic resonance, electron spin resonance, X-ray photoemission spectroscopy, and Raman spectroscopy. B₂O₃ content in TASB glasses leads to a certain degree of depolymerization in glass network and most of Tb⁴⁺ ions from the raw material of Tb₄O₇ are reduced to Tb³⁺ ions even in air, resulting in an improved MO properties. Due to the relatively high Verdet constant (∼70 rad/T/m) and suitable rheology of the glass melt speculated from the thermal analysis, TASB glass system in this work is adaptable to stable fiber-based Faraday effect devices.     

Rate dependence on mechanical properties of unsaturated cohesive soil with stress-induced anisotropy

The strain rate during shearing has been shown in experimental studies to strongly affect the mechanical behaviour of soil. For saturated soil, sufficient knowledge has been obtained to achieve equilibrium conditions for the pore water pressure. Nevertheless, little is known about unsaturated soil. Therefore, this study used a hollow cylindrical torsional shear apparatus to investigate the rate dependence on the deformation and strength properties of unsaturated soil. First, unsaturated specimens were anisotropically consolidated with different directions of major principal stress to assess the rate dependence of the anisotropic behaviour. Then, the shear stress was removed to produce an isotropic stress state. Shearing was applied using the specimens to evaluate the strain rate effects on the mechanical properties of unsaturated cohesive soil. The results indicate that the secant shear modulus increased with the strain rate in both constant suction (CS) and constant water content (CW) conditions. The shear strength did not change with the strain rate under a CW condition, but it decreased with the strain rate under a CS condition.