In Situ Ambient Pressure Photoelectron Spectroscopy Study of the Plasma-Surface Interaction on Metal Foils.

The plasma-surface interface has sparked interest due to its potential of creating alternative reaction pathways not available in typical gas-surface reactions. Currently, there are a limited number of in situ studies investigating the plasma-surface interface, restricting the development of its application. Here, we report the use of in situ ambient pressure X-ray photoelectron spectroscopy in tandem with an optical spectrometer to characterize the hydrogen plasma's interaction with metal surfaces. Our results demonstrate the possibility to monitor changes on the metal foil surface in situ in a plasma environment. We observed an intermediate state from the metal oxide to an -OH species during the plasma environment, indicative of reactive hydrogen radicals at room temperature. Furthermore, the formation of metal-carbides in the hydrogen plasma environment was detected, a characteristic absent in gas and vacuum environments. These findings illustrate the significance of performing in situ investigations of the plasma-surface interface to better understand and utilize its ability to create reactive environments at low temperature.

Propofol-mediated cardioprotection dependent of microRNA-451/HMGB1 against myocardial ischemia-reperfusion injury.

Administration of propofol at the time of reperfusion has shown to protect the heart from ischemia and reperfusion (I/R) injury. The aim of the present study was to investigate the molecular mechanism underling the cardioprotective effect of propofol against myocardial I/R injury (MIRI) in vivo and in vitro. Rat heart I/R injury was induced by ligation of the left anterior descending (LAD) artery for 30 min followed by 2-hr reperfusion. Propofol pretreatment (0.01 mg/g) was performed 10 min before reperfusion. In vitro MIRI was investigated in cultured cardiomyocytes H9C2 following hypoxia/reoxygenation (H/R) injuries. Propofol pretreatment in vitro was achieved in the medium supplemented with 25 µmol/L propofol before H/R injuries. Propofol pretreatment significantly increased miRNA-451 expression, decreased HMGB1 expression, reduced infarct size, and I/R-induced cardiomyocyte apoptosis in rat hearts undergoing I/R injuries. Knockdown of miRNA-451 48 hr before I/R injury was found to increase HMGB1 expression, infarct size, and I/R-induced cardiomyocyte apoptosis in rat hearts in the presence of propofol pretreatment. These in vivo findings were reproduced in vivo that knockdown of miRNA-451 48 hr before H/R injuries increased HMGB1 expression and H/R-induced apoptosis in cultured H9C2 supplemented with propofol. In addition, luciferase activity assays and gain-of-function studies found that propofol could decrease HMGB1, the target of miRNA-541. Taken together our findings provide a first demonstration that propofol-mediated cardioprotection against MIRI is dependent of microRNA-451/HMGB1. The study provides a novel target to prevent I/R injury during propofol anesthesia.

A dual-response fluorescent probe for Zn2+ and Al3+ detection in aqueous media: pH-dependent selectivity and practical application.

A Schiff base-type fluorescent probe (1) consist of 2-hydroxynaphthaldehyde and glutamide moieties has been designed and synthesized for detection Zn2+ and Al3+. The probe shows pH dependent dual-selectivity for Zn2+ and Al3+ in Tris-HCl buffer, viz. that can selectively recognized Zn2+ at pH 7.4 and Al3+ at pH 6.0, respectively. From Job's plots and MS data, the stoichiometric ratios of the probe with Zn2+ and Al3+ appeared to be 1:1 and 2:1, respectively. The probe can detect as low as 5.5 × 10-8 M-1 Zn2+ and 1.27 × 10-7 M-1 Al3+, whereas respective association constants are 4.27 × 104 M-1 and 3.50 × 109 M-1. Furthermore, it is also confirmed that the probe has good cell-permeability and could thus be used to selectively sense intracellular Zn2+ and Al3+ by bioimaging in different pH environment. Finally the probe has been used successfully for determination of the analytes in real drug samples.

Coordination-induced gelation of an L-glutamic acid Schiff base derivative: the anion effect and cyanide-specific selectivity.

By rational assembly of Zn(2+) and Cu(2+) with G, three metallogels (ZnG, CuG and Zn-CuG) were prepared. The gelation was controlled by the presence of specific anions, with their efficacy linked to the Hofmeister series. Zn-CuG could fluorescently detect CN(-) with specific selectivity over S(2-) and Cys through the competitive coordination of CN(-) and G with Cu(2+).