Pressure-dependent hydrogen permeability extended for metal membranes not obeying the square-root law.

Hydrogen permeability of metal membranes is generally defined by the square-root law, as the proportional coefficient of permeation flux to the square-root difference of the pressures on both sides of the membrane. However, deviation from the law has been widely reported for palladium, niobium, etc. Although n-th power instead of the square root has often been employed to determine permeability for these membranes, it has no theoretical base. These approaches do not consider concentration dependency of hydrogen diffusivity in the membrane. This study theoretically extended the definition of permeability by taking it into account, where square root of pressure was used throughout. The resultant permeability depended on pressure. This approach had the following four characteristics. First, the permeability could be qualitatively linked with pressure-dependent solution and diffusion coefficients. For this purpose, the solution coefficient was also extended from Sieverts' law. Second, the permeability could be easily evaluated from permeation flux dependent on feed-side pressure, usually measured in membrane study. Third, this approach enabled comparison of permeation ability irrespective of obeying permeation law. Fourth, permeation flux could be estimated for any pressure conditions visually and analytically. Thus, analytically estimated values were more precise than those using the conventional square-root law. These characteristics are successfully demonstrated using experimental results obtained not only for a palladium membrane in this study but also for palladium and niobium membranes in the literature.

Thin and defect-free Pd-based composite membrane without any interlayer and substrate penetration by a combined organic and inorganic process.

A novel combined organic and inorganic process for preparing thin supported membrane was developed, using which a thin and defect-free Pd membrane with uniform thickness of 5 microm was directly coated onto porous alpha-Al2O3 hollow fiber without any interlayer and substrate penetration; at the same time, there existed a small interstice between membrane and substrate, which led to higher hydrogen permeance, infinite selectivity, and better membrane stability.

Quick Preparation of Moisture-Saturated Carbon Fiber-Reinforced Plastics and Their Accelerated Ageing Tests Using Heat and Moisture.

A quick method involving the control of heat and water vapor pressure for preparing moisture-saturated carbon fiber-reinforced plastics (CFRP, 8 unidirectional prepreg layers, 1.5 mm thickness, epoxy resin) has been developed. The moisture-saturated CFRP sample was obtained at 120 °C and 0.2 MPa water vapor in 72 h by this method using a sterilizer (autoclave). The bending strength and viscoelastic properties measured by a dynamic mechanical analysis (DMA) remained unchanged during repetitive saturation and drying steps. No degradation and molecular structural change occurred. Furthermore an accelerated ageing test with two ageing factors, i.e., heat and moisture was developed and performed at 140⁻160 °C and 0.36⁻0.62 MPa water vapor pressure by using a sealed pressure-proof stainless steel vessel (autoclave). The bending strength of the sample decreased from 1107 to 319 MPa at 160 °C and 0.63 MPa water vapor pressure in 9 days. Degraded samples were analyzed by DMA. The degree of degradation for samples was analyzed by DMA. CFRP and degraded CFRP samples were analyzed by using a surface and interfacial cutting analysis system (SAICAS) and an electron probe micro-analyzer (EPMA) equipped in a scanning electron microscope.

Current therapies and investigational drugs for peripheral arterial disease.

Peripheral artery disease (PAD) is associated with elevated morbidity and mortality with cardiovascular (CV) disease. The guideline recommends smoking cessation and antiplatelet/antithrombotic drugs for asymptomatic and symptomatic PAD patients. It also recommends that PAD patients with critical limb ischemia (CLI) should be considered to receive endovascular and open surgical treatment for limb salvage. Although PAD patients with CLI receive these treatments, they are sometimes unable to deliver sufficient blood flow to eliminate their symptoms. Thus specific strategies are needed to promote enough blood flow. To establish the effective method, many investigations have been performed using cell-based therapy. Endothelial progenitor cells, mononuclear cells and mesenchymal stem cells have been well investigated in clinical settings. To induce angiogenesis, vascular endothelial growth factor, fibroblast growth factor and hepatocyte growth factor (HGF) have also been transfected in PAD patients. Among them, HGF is the most promising factor because it can induce angiogenesis without the induction of vascular inflammation and increased permeability. In this review article, we summarize current treatments and investigational drugs of PAD.

High-resolution MALDI-TOF MS study on analysis of low-molecular-weight products from photo-oxidation of poly(3-hexylthiophene).

High-resolution matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOF MS) was used for the analysis of the low-molecular-weight products from the photo-oxidation of poly(3-hexylthiophene) (P3HT) in solution and thin film. Eight new peak series were observed in the low-mass range of the mass spectra of the products degraded in solution, and the formulas of the eight components were determined from the accurate mass. From SEC/MALDI-TOF MS, two components were identified as the degraded products, and the other six components were derived from the fragmentation of the degraded products during the MALDI process. A mechanism for the formation of these components was proposed on the basis of the results of MALDI-TOF MS. For the thin film degradation, a part of products in the solution degradation were observed, which supports that the oxidation of P3HT in solution and thin film proceeded in the same mechanism. This study shows that high-resolution MALDI-TOF MS is effective for the analysis of the low-molecular-weight products from P3HT photo-oxidation and expected to be feasible for the degradation analyses of other polymers. Copyright © 2015 John Wiley & Sons, Ltd.

Beperminogene perplasmid for the treatment of critical limb ischemia.

Therapeutic angiogenesis for the treatment of ischemic disease can be attained through the delivery of recombinant growth factor proteins, through gene transfer or cell transplantation. Gene transfer associated with adenovirus or naked plasmid DNAs has been extensively studied in clinical trials. An investigational product, beperminogene perplasmid, is the naked plasmid DNA encoding the cDNA of human HGF, which has potent angiogenic activity. In several clinical trials, beperminogene perplasmid showed favorable safety and efficacy profile in the treatment of critical limb ischemia. This article reviews the results of pre-clinical and clinical studies of beperminogene perplasmid in the treatment of critical limb ischemia caused by peripheral arterial disease and Buerger's disease.