Open circuit voltage (OCV) hold tests were conducted to clarify the effect of interim diagnoses, which are necessary to determine if the tests should be terminated, in OCV durability testing of a polymer electrolyte fuel cell. The tests were implemented by the method described in the protocol of the ''Cell Evaluation Project'' that is compatible with the FCCJ protocol. Based on the results, we demonstrated that frequent interim IV measurements might accelerate the degradation of electrolyte membranes. Therefore, we should reduce the frequency of the interim IV measurements and explore the appropriate interval of interim diagnoses to avoid damages by the diagnosis itself.

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To understand the effect of Diesel Exhaust Particles (DEP) on the mechanisms of exacerbation of inflammation in airway smooth muscle, we analyzed the comprehensive gene expression of bronchial smooth muscle cells (BSMC) treated with DEP. As a result, we found that DEP upregulated the expression of genes related to the activation of inflammatory cells and the constriction of smooth muscle cells in BSMC. The results suggested the possibility that BSMC have an important role in the exacerbation of inflammation induced by DEP.

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To investigate the effects of particulate matter on permeability of cultured human airway epithelial cells (Calu-3), we evaluated the barrier functional analysis as measured by Trans Epithelial Electric Resistance (TEER), and gene expression analysis of cell adhesion molecules. In addition, we observed morphological changes in tight junctions (TJ) of Calu-3 cells by transmission electron microscopy (TEM). As a result, diesel exhaust particles (DEP) reduced TEER of Calu-3 cells, and the result was supported by gene expression of some adhesion molecules. On the other hand, we could not identify DEP in the intercellular space of TJ or cytoplasm by TEM observation.

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