High-performance and robust high-temperature polymer electrolyte membranes with moderate microphase separation by implementation of terphenyl-based polymers

Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel cells.To overcome these barriers,poly(terphenyl piperidinium)s constructed from the m-and p-isomers of terphenyl were synthesized to regulate the microstructure of the membrane.Highly rigid p-terphenyl units prompt the formation of moderate PA aggregates,where the ion-pair interaction between piperidinium and biphosphate is reinforced,leading to a reduction in the plasticizing effect.As a result,there are trade-offs between the proton conductivity,mechanical strength,and PA retention of the membranes with varied m/p-isomer ratios.The designed PA-doped PTP-20m membrane exhibits superior ionic conductivity,good mechanical strength,and excellent PA retention over a wide range of temperature(80–160°C)as well as satisfactory resistance to harsh accelerated aging tests.As a result,the membrane presents a desirable combination of performance(1.462 W cm^(-2) under the H_(2)/O_(2)condition,which is 1.5 times higher than that of PBI-based membrane)and durability(300 h at 160°C and 0.2 A cm^(-2))in the fuel cell.The results of this study provide new insights that will guide molecular design from the perspective of microstructure to improve the performance and robustness of HT-PEMs.

食管癌生物标志物预测及临床病理特征分析(英文)

Objective:The aim of this study was to explore the expression of manganese superoxide dismutase(MnSOD) in esophageal squamous cell carcinoma and its relationship with clinicopathological characteristics and its biological behavior.Methods:Immunohistochemical method(SP method),reverse transcription-polymerase chain reaction(RT-PCR) and Western blot were combined to detect the MnSOD protein and mRNA expression in 45 cases of esophageal squamous cell carcinoma and the normal tissue that was 5 cm apart from the edge of esophageal cancer lesion and without documented microscopic invasive cancer.Meanwhile,analysis was performed on the relationship between the pathological features of esophageal cancer and its biological behavior.Results:In esophageal squamous cell carcinoma and normal esophageal tissue,MnSOD protein expression was identified in 31.1%(14/45) and 86.7%(31/45)(P = 0.003),respectively,with the relative expression levels of MnSOD mRNA were 0.310 ± 0.036 and 0.482 ± 0.053(P = 0.000).The longer the lesions and the deeper the invasion,the differentiation would become poorer and the expression level of MnSOD would get lower,indicating that the level of MnSOD protein and mRNA expression were closely related to esophageal squamous cell carcinoma in the length of lesion,depth of invasion,and degree of differentiation(P < 0.05).Nevertheless,it showed no association with the presence of the lymph node metastasis,lesion site and the macroscopic classification(P > 0.05).Conclusion:The MnSOD protein and mRNA expression were both decreased in esophageal squamous cell carcinoma tissue.This may be related to the carcinogenesis and development of esophageal cancer.Detection of the expression of MnSOD would be of clinical significance in understanding the prognosis and guiding therapeutic strategy of esophageal cancer.