Influence of temperature gradients on mono- and divalent ion transport in electrodialysis at limiting currents

Temperature gradients in electrodialysis (ED) stacks can potentially enhance the efficiency of charge separation and the selective transport of ions. We have previously investigated temperature gradients in the Ohmic regime but not in the limiting current regime, where diffusion of ions towards the membrane determines the transport rate and temperature gradients potentially have the largest influence. In this research, commercial ion exchange membranes (FAS and FKS, FUMATECH, Germany) are used for the investigation of temperature gradients in the limiting current regime. In contrast to the Ohmic regime, we find that heating the diluted stream increases the current obtained (at a constant applied potential) when compared to heating the concentrate stream in systems containing monovalent KCl and NaCl solutions. For mixtures of mono- and divalent ions, the temperature gradient has a larger influence on the selectivity of the separation. If the desalinated stream is heated, divalent Mg2+ ions show a higher transport than the monovalent K+ and Na+ ions. This is due to the enhanced competitive transport of the mono- and divalent ions under the application of a temperature gradient. These results show the potential application and relevance of temperature gradients to enhance the selective separation of mono- and divalent ions

Influence of temperature gradients on mono- and divalent ion transport in electrodialysis at limiting currents

Data set belonging to publicaton: Desalination, 443, 62-69. DOI: 10.1016/j.desal.2018.05.00

Deregulation of E2-EPF Ubiquitin Carrier Protein in Papillary Renal Cell Carcinoma

Molecular pathways associated with pathogenesis of sporadic papillary renal cell carcinoma (PRCC), the second most common form of kidney cancer, are poorly understood. We analyzed primary tumor specimens from 35 PRCC patients treated by nephrectomy via gene expression analysis and tissue microarrays constructed from an additional 57 paraffin-embedded PRCC samples via immunohistochemistry. Gene products were validated and further studied by Western blot analyses using primary PRCC tumor samples and established renal cell carcinoma cell lines, and potential associations with pathologic variables and survival in 27 patients with follow-up information were determined. We show that the expression of E2-EPF ubiquitin carrier protein, which targets the principal negative regulator of hypoxia-inducible factor (HIF), von Hippel-Lindau protein, for proteasome-dependent degradation, is markedly elevated in the majority of PRCC tumors exhibiting increased HIF1α expression, and is associated with poor prognosis. In addition, we identified multiple hypoxia-responsive elements within the E2-EPF promoter, and for the first time we demonstrated that E2-EPF is a hypoxia-inducible gene directly regulated via HIF1. These findings reveal deregulation of the oxygen-sensing pathway impinging on the positive feedback mechanism of HIF1-mediated regulation of E2-EPF in PRCC