Oxidation behavior characteristics of an aluminized Ni-based single crystal superalloy CM186LC between 900 °C and 1100 °C in air

Oxidation behavior of an aluminized Ni-based single crystal superalloy CM186LC was performed between 900 °C and 1100 °C in air. The oxidation kinetics approximately followed a parabolic oxidation law at 900 °C and 1100 °C. The mass gains were significantly increased owing to the formation of θ-Al₂O₃ during initial oxidation stage. After 100 h oxidation, the mass gain rates were then decreased due to the transformation from θ-Al₂O₃ to α-Al₂O₃. The microstructures after 500 h oxidation at all temperatures generally consisted of scale, coating layer, interdiffusion zone (IDZ), substrate diffusion zone (SDZ) accompanied with the topologically close-packed (TCP) and substrate.     

Resveratrol-Encapsulated Mitochondria-Targeting Liposome Enhances Mitochondrial Respiratory Capacity in Myocardial Cells

The development of drug delivery systems for use in the treatment of cardiovascular diseases is an area of great interest. We report herein on an evaluation of the therapeutic potential of a myocardial mitochondria-targeting liposome, a multifunctional envelope-type nano device for targeting pancreatic β cells (β-MEND) that was previously developed in our laboratory. Resveratrol (RES), a natural polyphenol compound that has a cardioprotective effect, was encapsulated in the β-MEND (β-MEND (RES)), and its efficacy was evaluated using rat myocardioblasts (H9c2 cells). The β-MEND (RES) was readily taken up by H9c2 cells, as verified by fluorescence-activated cell sorter data, and was observed to be colocalized with intracellular mitochondria by confocal laser scanning microscopy. Myocardial mitochondrial function was evaluated by a Seahorse XF Analyzer and the results showed that the β-MEND (RES) significantly activated cellular maximal respiratory capacity. In addition, the β-MEND (RES) showed no cellular toxicity for H9c2 cells as evidenced by Premix WST-1 assays. This is the first report of the use of a myocardial mitochondria-targeting liposome encapsulating RES for activating mitochondrial function, which was clearly confirmed based on analyses using a Seahorse XF Analyzer.     

Retrograde Axonal Transport of Liposomes from Peripheral Tissue to Spinal Cord and DRGs by Optimized Phospholipid and CTB Modification

Despite recent advancements in therapeutic options for disorders of the central nervous system (CNS), the lack of an efficient drug-delivery system (DDS) hampers their clinical application. We hypothesized that liposomes could be optimized for retrograde transport in axons as a DDS from peripheral tissues to the spinal cord and dorsal root ganglia (DRGs). Three types of liposomes consisting of DSPC, DSPC/POPC, or POPC in combination with cholesterol (Chol) and polyethylene glycol (PEG) lipid were administered to sciatic nerves or the tibialis anterior muscle of mature rats. Liposomes in cell bodies were detected with infrared fluorescence of DiD conjugated to liposomes. Three days later, all nerve-administered liposomes were retrogradely transported to the spinal cord and DRGs, whereas only muscle-administered liposomes consisting of DSPC reached the spinal cord and DRGs. Modification with Cholera toxin B subunit improved the transport efficiency of liposomes to the spinal cord and DRGs from 4.5% to 17.3% and from 3.9% to 14.3% via nerve administration, and from 2.6% to 4.8% and from 2.3% to 4.1% via muscle administration, respectively. Modification with octa-arginine (R8) improved the transport efficiency via nerve administration but abolished the transport capability via muscle administration. These findings provide the initial data for the development of a novel DDS targeting the spinal cord and DRGs via peripheral administration.     

Fabrication of Porous SiO2·RO/SUS Composite Body for DPF （Diesel Particulate Filter） and Microwave Heating Behavior

Glass/stainless steel porous composite body were prepared by the polyurethane sponge replica method using slurries containing mixture of SiO₂-RO/30 vol%SUS.Sintered porous samples were obtained which consists of well-distributed stainless steel particles within the glass matrix.Such a microstructure is desired for the purpose as a soot particulate filters（DPF）utilizing microwave rapid heating in cold start phase.Heating ability of the fabricated porous composite body was carried out placing the specimen in the maximum H-field of a 2.45 GHz single mode applicator.Heating behavior of the samples was mainly influenced by the volume fraction of stainless steel.Higher heating rate was observed for samples with higher stainless steel fraction.Due to the different microwave absorbability of the materials,stainless steel particle in the porous matrix structure was firstly heated up by microwave and transferred the heat energy throughout the whole sample.Increasing of the fraction of the stainless steel particle in the matrix structure led the better heating;however the strength of the samples decreased.     

Optimum design of formable CFRP sheets by generic algorithm and FE analysis by homogenization of multilayered structure with macroscopic anisotropy

A new method for designing carbon-fiber-reinforced plastic (CFRP) sheets with a suitable ply structure for stamping is proposed. This method combines a generic algorithm with a three-dimensional finite element method (FEM) to reproduce a layered structure by homogenizing the fiber structure with elastic-plastic anisotropy of each layer. The maximum strain is used as a fracture index to evaluate the severity of sheet deformation under stamping. The ply structure of the CFRP is optimized for elliptic cup drawing, and the optimized ply structure is validated experimentally. Through the experimental validation, it is proven that the proposed method gives acceptable results for the optimization of the ply structure of thermosetting CFRP sheets for cold/warm stamping.     

Evaporation of Distilled Water in a Fluidized Bed of Various Types of Fluidizing Particles Under Reduced Pressure

An objective of this study is to continuously obtain dispersed, dry, fine powders from a dilute suspension of heat-sensitive materials at a low temperature and high drying rate. A fluidized bed under reduced pressure was used in this study and, as a first step, only distilled water (without solid powders) was used as a sample. Drying characteristics were examined for various types of fluidizing particles. The diameter of fluidizing particle varied for inert particles (glass beads). Three kinds of hygroscopic porous particles (silica gel beads; 3A, 4B, and 5D) were also used as fluidizing particles. Under reduced pressures, the maximum drying rate was found to be higher than that at atmospheric pressure, while the bed temperature became lower with an increase in the maximum drying rate (i.e., drying at lower temperature with a higher drying rate is possible under reduced pressures. As diameter of the fluidizing particle was increased, the maximum drying rate became higher, although the amount of gas required for fluidization also increased. The maximum drying rates for silica gel beads were found to be almost equal to those of glass beads, with the exception of 3A silica gel beads (having a smaller pore diameter). The bed temperature was lower for silica gel beads compared to glass beads at the same maximum drying rate (i.e., silica gel beads (hygroscopic porous particles) are superior to glass beads (inert particles) with regard to drying at low temperatures at a high drying rate).     

Food protective property of new liquid food container PID (Pouch in Dispenser) for microbes

We examined the content protection characteristics of the PID (Pouch in Dispenser) when it was used in the usual manner and when it was polluted artificially. When the PID was used in the usual manner, the nozzle was opened, and experiments were carried out with and without air-blowing. The invasion of bacteria into the PID was not detected. Also, no bacteria were detected in the material poured from the nozzle of the PID. When 3 strains of bacteria suspensions were intentionally smeared on the nozzle of the PID, invasion of bacteria was observed. When the PID was wiped with a dirty cloth, no invasion of bacteria into the PID was detected. It may be necessary to label the PID with the instruction that the nozzle should not be touched. The effected of changes in the water activity and pH, and the preservatives used, may also need to be considered, depending on the contents in the PID.     

A novel prototype of auxiliary edge resonant bridge leg link snubber‐assisted soft‐switching sine‐wave PWM inverter

This paper proposes a new circuit topology of the three‐phase soft‐switching PWM inverter and PFC converter using IGBT power modules, which has the improved active auxiliary switch and edge resonant bridge leg‐commutation‐link soft‐switching snubber circuit with pulse current regenerative feedback loop as compared with the typical auxiliary resonant pole snubber discussed previously. This three‐phase soft‐switching PWM double converter is more suitable and acceptable for a large‐capacity uninterruptible power supply, PFC converter, utility‐interactive bidirectional converter, and so forth. In this paper, the soft‐switching operation and optimum circuit design of the novel type active auxiliary edge resonant bridge leg commutation link snubber treated here are described for high‐power applications. Both the main active power switches and the auxiliary active power switches achieve soft switching under the principles of ZVS or ZCS in this three‐phase inverter switching. This three‐phase soft‐switching commutation scheme can effectively minimize the switching surge‐related electromagnetic noise and the switching power losses of the power semiconductor devices; IGBTs and modules used here. This three‐phase inverter and rectifier coupled double converter system does not need any sensing circuit and its peripheral logic control circuits to detect the voltage or the current and does not require any unwanted chemical electrolytic capacitor to make the neutral point of the DC power supply voltage source. The performances of this power conditioner are proved on the basis of the experimental and simulation results. Because the power semiconductor switches (IGBT module packages) have a trade‐off relation in the switching fall time and tail current interval characteristics as well as the conductive saturation voltage characteristics, this three‐phase soft‐switching PWM double converter can improve actual efficiency in the output power ranges with a trench gate controlled MOS power semiconductor device which is much improved regarding low saturation voltage. The effectiveness of this is verified from a practical point of view. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(4): 64–76, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20207     

Chorioamnionitis Precipitates Perinatal Alterations of Heme-Oxygenase-1 (HO-1) Homeostasis in the Developing Rat Brain

Chorioamnionitis (CHORIO), placental insufficiency, and preterm birth are well-known antecedents of perinatal brain injury (PBI). Heme-oxygenase-1 (HO-1) is an important inducible enzyme in oxidative and inflammatory conditions. In the brain, HO-1 and the iron regulatory receptor, transferrin receptor-1 (TfR1), are known to be involved in iron homeostasis, oxidative stress, and cellular adaptive mechanisms. However, the role of HO pathway in the pathophysiology of PBI has not been previously studied. In this study, we set out to define the ontogeny of the HO pathway in the brain and determine if CHORIO changed its normal developmental regulation. We also aimed to determine the role of HO-1/TfR1 in CHORIO-induced neuroinflammation and peripheral inflammation in a clinically relevant rat model of PBI. We show that HO-1, HO-2, and TfR1 expression are developmentally regulated in the brain during the perinatal period. CHORIO elevates HO-1 and TfR1 mRNA expression in utero and in the early postnatal period and results in sustained increase in HO-1/TfR1 ratios in the brain. This is associated with neuroinflammatory and peripheral immune phenotype supported by a significant increase in brain mononuclear cells and peripheral blood double negative T cells suggesting a role of HO-1/TfR1 pathway dysregulation in CHORIO-induced neuroinflammation.     

Catalytic Activity of Noble Metals for Metal-Assisted Chemical Etching of Silicon

ABSTRACT: Metal-assisted chemical etching of silicon is an electroless method that can produce porous silicon by immersing metal-modified silicon in a hydrofluoric acid solution without electrical bias. We have been studying the metal-assisted hydrofluoric acid etching of silicon using dissolved oxygen as an oxidizing agent. Three major factors control the etching reaction and the porous silicon structure: photoillumination during etching, oxidizing agents, and metal particles. In this study, the influence of noble metal particles, silver, gold, platinum, and rhodium, on this etching is investigated under dark conditions: the absence of photogenerated charges in the silicon. The silicon dissolution is localized under the particles, and nanopores are formed whose diameters resemble the size of the metal nanoparticles. The etching rate of the silicon and the catalytic activity of the metals for the cathodic reduction of oxygen in the hydrofluoric acid solution increase in the order of silver, gold, platinum and rhodium.