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Long-term performance testes by CRIEPI (Central Research Institute for Electric Power Industry) on six industrial stacks have revealed an interesting correlation between cathode polarization loss and ohmic loss. To make clear the physicochemical meaning of this correlation, detailed analyses were made on the conductivity degradation of YSZ electrolyte in button cells and then on the ohmic losses in the industrial cells in terms of time constants which are determined from speed of the tetragonal transformation through the Y diffusion from the cubic phase to the tetragonal phase. In some cases, shorter time constants (faster degradations) were detected than those expected from the two-time-constant (with and without NiO reduction effects) model, suggesting that additional ohmic losses after subtracting the contribution from the tetragonal transformation must be caused from other sources such as cathode-degradation inducing effects. Main cathode degradations can be ascribed to sulfur poisoning due to contamination in air in the CRIEPI test site. An important feature was extracted as this cathode degradations became more severe when the gadolinium-doped ceria (GDC) interlayers were fabricated into dense film. Plausible mechanisms for cathode degradations were proposed based on the Sr/Co depletion on surface of lanthanum strontium cobalt ferrite (LSFC) in the active area. Peculiar cathode degradations found in stacks are interpreted in term of changes in surface concentration by reactions with sulfur oxide, electrochemical side reactions for water vapor emission or Sr volatilization, and diffusion of Sr/Co from inside LSCF.

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Dickkopf3 (DKK3) is a secretory protein that belongs to the DKK family, but exhibits structural divergence from other family members, and its corresponding receptors remain to be identified. Although DKK3 has been shown to have oncogenic functions in certain cancer types, the underlying mechanism by which DKK3 promotes tumorigenesis remains to be clarified. We show here that DKK3 stimulates esophageal cancer cell proliferation via cytoskeleton-associated protein 4 (CKAP4), which acts as a receptor for DKK3. DKK3 was expressed in approximately 50% of tumor lesions of esophageal squamous cell carcinoma (ESCC) cases; simultaneous expression of DKK3 and CKAP4 was associated with poor prognosis. Anti-CKAP4 antibody inhibited both binding of DKK3 to CKAP4 and xenograft tumor formation induced by ESCC cells. p63, a p53-related transcriptional factor frequently amplified in ESCC, bound to the upstream region of the gene. Knockdown of decreased DKK3 expression in ESCC cells, and reexpression of DKK3 partially rescued cell proliferation in -depleted ESCC cells. Expression of ΔNp63α and DKK3 increased the size of tumor-like esophageal organoids, and anti-CKAP4 antibody inhibited growth of esophageal organoids. Taken together, these results suggest that the DKK3-CKAP4 axis might serve as a novel molecular target for ESCC. In esophageal cancer, findings identify DKK3 as a poor prognostic indicator and demonstrate CKAP4 inhibition as an effective therapeutic strategy. .

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