Next-Generation Polymer-Electrolyte-Membrane Fuel Cells Using Titanium Foam as Gas Diffusion Layer

In spite of their high conversion efficiency and no emission of greenhouse gases, polymer electrolyte membrane fuel cells (PEMFCs) suffer from prohibitively high cost and insufficient life-span of their core component system, the membrane electrode assembly (MEA). In this paper, we are proposing Ti foam as a promising alternative electrode material in the MEA. Indeed, it showed a current density of 462 mA cm^–2, being ca. 166% higher than that with the baseline Toray 060 gas diffusion layer (GDL) (278 mA cm^–2) with 200 ccm oxygen supply at 0.7 V, when used as the anode GDL, because of its unique three-dimensional strut structure promoting highly efficient catalytic reactions. Furthermore, it exhibits superior corrosion resistance with almost no thickness and weight changes in the accelerated corrosion test, as opposed to considerable reductions in the weight and thickness of the conventional GDL. We believe that this paper suggests profound implications in the commercialization of PEMFCs, because the metallic Ti foam provides a longer-term reliability and chemical stability, which can reduce the loss of Pt catalyst and, hence, the cost of PEMFCs

Low-Temperature and Gram-Scale Synthesis of Two-Dimensional Fe–N–C Carbon Sheets for Robust Electrochemical Oxygen Reduction Reaction

The Fe–N–C-based carbon materials, which are generally formed by high-temperature annealing, have been highlighted as a promising alternative to expensive Pt electrocatalysts for oxygen reduction reaction. However, the delicate formation of active sites remains an issue because of decomposition and transformation of the macrocycle during heat treatment. Accordingly, we developed a low-temperature and gram-scale approach to synthesizing iron phthalocyanine (Pc)-embedded two-dimensional carbon sheets by annealing at 450 °C. The low-temperature annealing process, which is motivated by the synthesis of carbon nanoribbons, is suitable for maintaining the Fe–N–C structure while enhancing coupling with carbon. Our two-dimensional carbon sheets show higher ORR activity than commercial Pt catalyst in alkaline media. Furthermore, the feasibility of real application to alkaline membrane electrolyte fuel cell is verified by superior volumetric current density. In durability point of view, the initial activity is retained up to 3000 potential cycles without appreciable activity loss; this excellent performance is attributed to the structural stabilization and electron donation from the carbon sheet, which occurs via strong electronic coupling. We believe that this low-temperature and large-scale synthesis of a carbon structure will provide new possibilities for the development of electrochemical energy applications

DEXA analysis of rosiglitazone-treated mice.

<p>DEXA analysis of rosiglitazone-treated mice.</p

Time dependent effects of rosiglitazone on osteoblast differentiation.

<p>Primary bone marrow cells were treated with rosiglitazone (10 μM) at the indicated times in the presence of DAG. Extents of osteoblast differentiation were determined by Alizarin red staining (A) and western blotting (B). Experiments were carried out three times and representative results are shown. Densitometric analysis was conducted using UN-SCAN-IT gel ver. 5.1 software (Silk Scientific) and is expressed as means ± SEMs of three experiments. #<i>P</i><0.05 vs differentiated (D). D, differentiated in DAG medium; DR, DAG in the presence of rosiglitazone.</p

Effects of PHD knockdown on the rosiglitazone-induced inhibition of osteoblast differentiation.

<p>The PHD1, 2, and 3 isoforms were knocked down by transfecting in primary bone marrow cells with isoform-specific shRNAs or siRNA on day 0 and day 4 of a 12-day differentiation period. Extents of knockdown were determined by RT-PCR (A), and osteoblast differentiation was monitored by Alizarin red staining (B). The protein levels of Runx2 were determined by western blotting (C). Experiments were conducted twice and representative results are shown. Densitometric analysis was conducted using UN-SCAN-IT gel ver. 5.1 software (Silk Scientific) and is expressed as means ± SEMs of two experiments. *<i>P</i><0.05 vs control shRNA in the absence of rosiglitazone, #<i>P</i><0.05 vs control shRNA in the presence of rosiglitazone.</p

Effects of PHD inhibitors on rosiglitazone-induced anti-osteoblast differentiation.

<p>Primary bone marrow cells were treated with either DMOG (1 mM) or EDHB (20 μM) in the presence or absence of rosiglitazone (10 μM) for 12 days (media were changed every 48 h). Extents of osteoblast differentiation were monitored by Alizarin red staining (A), and the mRNA levels of the PHD 1–3 and osteomarker marker genes were determined by RT-PCR (B). The protein levels of Runx2 and levels of Runx-2 ubiquitination were determined by western blotting (C) and by immunoprecipitation using polyubiquitination antibody (D). The effect of MG-132 (5 μM; an inhibitor of proteasomal degradation) on Runx-2 expression was examined by western blotting (E). Experiments were conducted three times and representative results are shown. Densitometric analysis was conducted using UN-SCAN-IT gel ver. 5.1 software (Silk Scientific) and is expressed as means ± SEMs of three experiments. *<i>P</i><0.05 vs control (C), #<i>P</i><0.05 vs differentiated (D), ✝<i>P</i><0.05 vs DR. C, control (no differentiation); D, differentiated in DAG medium; DR, DAG in the presence of rosiglitazone; DM, DMOG; ED, EDHB; MG, MG-132.</p

Realization of Both High-Performance and Enhanced Durability of Fuel Cells: Pt-Exoskeleton Structure Electrocatalysts

Core–shell structure nanoparticles have been the subject of many studies over the past few years and continue to be studied as electrocatalysts for fuel cells. Therefore, many excellent core–shell catalysts have been fabricated, but few studies have reported the real application of these catalysts in a practical device actual application. In this paper, we demonstrate the use of platinum (Pt)-exoskeleton structure nanoparticles as cathode catalysts with high stability and remarkable Pt mass activity and report the outstanding performance of these materials when used in membrane-electrode assemblies (MEAs) within a polymer electrolyte membrane fuel cell. The stability and degradation characteristics of these materials were also investigated in single cells in an accelerated degradation test using load cycling, which is similar to the drive cycle of a polymer electrolyte membrane fuel cell used in vehicles. The MEAs with Pt-exoskeleton structure catalysts showed enhanced performance throughout the single cell test and exhibited improved degradation ability that differed from that of a commercial Pt/C catalyst

<i>In vivo</i> effects of rosiglitazone in female ICR mice.

<p>Rosiglitazone (10 mg/kg once daily) was administered orally to ICR mice (6 weeks old) for eight weeks. Primary bone marrow cells were isolated from the femora of both vehicle and rosiglitazone-treated animals, and extents of osteoblast differentiation were determined by Alizarin red staining (A). PHD expression and ubiquitinated Runx2 levels were determined by western blotting and immunoprecipitation, respectively (B). Immunohistochemistry of the PHD isoforms (C), and quantification of PHD1, PHD2, and PHD3 signal intensity in bone marrow section (D). Runx2 expression was determined by immunohistochemistry (E). Red arrow indicates each PHD and Runx2 expression. Experiments were conducted three times and representative results are shown. *<i>P</i><0.05 vs vehicle.</p

Concentration dependent effects of rosiglitazone on osteoblast differentiation.

<p>Primary bone marrow cells were treated with the indicated concentrations of rosiglitazone for 12 days in the presence of DAG and extents of osteoblast differentiation were determined by Alizarin red staining (A) and western blotting (B). Experiments were conducted three times and representative results are shown. Densitometric analysis was conducted using UN-SCAN-IT gel ver. 5.1 software (Silk Scientific), and is expressed as means ± SEMs of three experiments. *<i>P</i><0.05 vs control (C), #<i>P</i><0.05 vs differentiated (D). C, control (no differentiation); D, differentiated in DAG medium; R, rosiglitazone.</p

Effects of PPARγ antagonists on rosiglitazone-induced adipocyte differentiation.

<p>Primary bone marrow cells were treated with BADGE (20 μM) or GW9662 (1 μM) in the presence of rosiglitazone (10 μM) for 12 days. Osteoblast differentiation was determined by Alizarin red staining (A), and the mRNA levels of PHD1, 2, and 3, and osteogenic marker genes were analyzed by RT-PCR (B). Densitometric analysis was conducted using UN-SCAN-IT gel ver. 5.1 software (Silk Scientific) and is expressed as means ± SEMs. *<i>P</i><0.05 vs control (C), #<i>P</i><0.05 vs differentiated (D), ✝<i>P</i><0.05 vs DR. Experiments were conducted three times and representative results are shown. C, control (no differentiation); D, differentiated in DAG medium; DR, DAG in the presence of rosiglitazone; BD, BADGE; GW, GW9662.</p