Hyperbaric oxygen protects against myocardial ischemia­reperfusion injury through inhibiting mitochondria dysfunction and autophagy.

Our previous study demonstrated that hyperbaric oxygen (HBO) improves heart function predominantly through reducing oxygen stress, modulating energy metabolism and inhibiting cell apoptosis. The present study aimed to investigate the protective effects of HBO on mitochondrial function and autophagy using rats with a ligated left anterior descending artery. The cardioprotective effects of HBO were mainly evaluated using ELISA, fluorescent probes, transmission electron microscopy and reverse transcription­quantitative PCR (RT­qPCR). HBO pretreatment for 14 days (once a day) using a 0.25 MPa chamber improved mitochondrial morphology and decreased the number of autophagic vesicles, as observed using a transmission electron microscope. HBO pretreatment significantly increased the levels of ATP, ADP, energy charge and the opening of the mitochondrial permeability transition pore, but decreased the levels of AMP, cytochrome c and reactive oxygen species. Moreover, HBO pretreatment significantly increased the gene or protein expression levels of eIF4E­binding protein 1, mammalian target of rapamycin (mTOR), mitochondrial DNA, NADH dehydrogenase subunit 1, mitofusin 1 and mitofusin 2, whereas it decreased the gene or protein expression levels of autophagy­related 5 (Atg5), cytochrome c, dynamin­related protein 1 and p53, as determined using RT­qPCR or immunohistochemistry. In conclusion, HBO treatment was observed to protect cardiomyocytes during myocardial ischemia­reperfusion injury (MIRI) by preventing mitochondrial dysfunction and inhibiting autophagy. Thus, these results provide novel evidence to support the use of HBO as a potential agent for the mitigation of MIRI.

Hierarchically porous and heteroatom self-doped graphitic biomass carbon for supercapacitors.

Here we report a simple, low-cost and environment friendly method, in which Black locust seed dregs and potassium ferrate (K2FeO4) are used as starting raw materials and activation agent. The hierarchically porous carbons (BDPC) with high special surface area and abundant mesopores (SBET = 2010.1 m2 g-1 and Vmeso = 1.457 cm3 g-1) are obtained through hydrothermal treatment and chemical activation. The BDPC electrode exhibits excellent electrochemical performances by virtue of unique architecture and heteroatoms pseudocapacitance contribution. In the three-electrode system, the optimized carbon material (BDPC-2) achieves a high specific capacitance of 333 F g-1 at 1 A g-1 and displays the high rate capability (81.1% capacitance retention at 100 A g-1) in 6 M KOH electrolyte. The symmetric supercapacitor based BDPC-2 exhibits energy density as high as 26.2 Wh kg-1 (at a power density of 0.79 kW kg-1) and excellent long-term cycling stability (only 8% decrease after 10,000 cycles) in 6 M KOH.