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DJ-1 was recently reported to mediate the cardioprotection of delayed hypoxic preconditioning (DHP) by suppressing hypoxia/reoxygenation (H/R)-induced oxidative stress, but its mechanism against H/R-induced oxidative stress during DHP is not fully elucidated. Here, using the well-established cellular model of DHP, we again found that DHP significantly improved cell viability and reduced lactate dehydrogenase release with concurrently up-regulated DJ-1 protein expression in H9c2 cells subjected to H/R. Importantly, DHP efficiently improved mitochondrial complex I activity following H/R and attenuated H/R-induced mitochondrial reactive oxygen species (ROS) generation and subsequent oxidative stress, as demonstrated by a much smaller decrease in reduced glutathione/oxidized glutathione ratio and a much smaller increase in intracellular ROS and malondialdehyde contents than that observed for the H/R group. However, the aforementioned effects of DHP were antagonized by DJ-1 knockdown with short hairpin RNA but mimicked by DJ-1 overexpression. Intriguingly, pharmacological inhibition of mitochondria complex I with Rotenone attenuated all the protective effects caused by DHP and DJ-1 overexpression, including maintenance of mitochondria complex I and suppression of mitochondrial ROS generation and subsequent oxidative stress. Taken together, this work revealed that preserving mitochondrial complex I activity and subsequently inhibiting mitochondrial ROS generation could be a novel mechanism by which DJ-1 mediates the cardioprotection of DHP against H/R-induced oxidative stress damage.

We propose a theoretical ground for emissive capacitively coupled radio-frequency plasma sheath under low pressure. The rf sheath is assumed to be collisionless, and oscillates with external source. A known sinusoidal voltage instead of current is taken as prerequisite to derive sheath dynamics. Kinetic studies are performed to determine mean wall potential as a function of secondary emission coefficient and applied voltage amplitude, with which the complete mean DC sheath is resolved. Analytical analyses under homogeneous model and numerical analyses under inhomogeneous model are conducted to deduce real time sheath properties including space potential, capacitance and stochastic heating. Obtained results are validated by a continuum kinetic simulation without ionization. The influences of collisionality and ionization induced by secondary electrons are elucidated with a particle-in-cell simulation, which further formalizes proposed theories and inspires future works.

Two new phenylglycol derivatives, (S)-(+)-2-(3,4-dihydroxy phenyl)-2-ethoxyl- ethanol and (S)-(+)-2-(3,4-dihydroxy phenyl)-2-acetoxy-ethanol, were isolated from the leaves of Syringa reticulata var. mandshurica, along with two known phenethylols, p-hydroxyl phenethanol and 3,4-dihydroxy phenethanol. The planar structures of the new compounds were established on the basis of their spectral data, and their absolute stereochemistry was established by modified Mosher's method. The two known compounds were identified by comparison of spectral data with published references. The two new compounds showed conspicuous antifungal activities by agar medium assay.