Structural basis for the conformational protection of nitrogenase from O.

The low reduction potentials required for the reduction of dinitrogen (N) render metal-based nitrogen-fixation catalysts vulnerable to irreversible damage by dioxygen (O). Such O sensitivity represents a major conundrum for the enzyme nitrogenase, as a large fraction of nitrogen-fixing organisms are either obligate aerobes or closely associated with O-respiring organisms to support the high energy demand of catalytic N reduction. To counter O damage to nitrogenase, diazotrophs use O scavengers, exploit compartmentalization or maintain high respiration rates to minimize intracellular O concentrations.

Studies on Shielding and Activation Levels in a Concrete-Iron-Concrete Sandwich Structure Wall in the CMUH Proton Therapy Facility.

The shielding performance and activation susceptibility of a sandwich wall in the proton therapy facility of China Medical University Hospital were investigated in an integrated manner using FLUKA Monte Carlo simulations. The 2-m-thick partition wall between two adjoining treatment rooms had a three-layered structure, which comprised a 0.2-m-thick iron layer sandwiched between two layers of 0.

Oncogenic RARγ isoforms promote head and neck cancer proliferation through vinexin-β-mediated cell cycle acceleration and autocrine activation of EGFR signal.

Results of retinoid-based therapies in head and neck cancer (HNC) are generally disappointing, indicating a lack of understanding of retinoic acid signaling. The role of retinoic acid receptor gamma (RARγ) and its isoforms in HNC is yet to be established. In this study, we found that RARγ1, 2, 4 are the predominant RARγ isoforms expressed in various types of human cancers, including HNC.