Objective: Hydrogen sulfide (H 2 S) has been reported to be a gasotransmitter which regulates cardiovascular homeostasis. The present study aims to examine the hypothesis that hydrogen sulfide is able to promote angiogenesis. Methods: Angiogenesis was assessed using in vitro parameters (i.e. endothelial cell proliferation, adhesion, transwell migration assay, scratched wound healing and formation of tube-like structure) and in vivo by assessing neovascularization in mice. Phosphorylation of Akt was measured using Western blot analysis. Results: Exogenously administered NaHS (H 2 S donor) concentration-dependently (10-20 μmol/l) increased cell growth, migration, scratched wound healing and tube-like structure formation in cultured endothelial cells. These effects of NaHS on endothelial wound healing and tube-like structure formation were prevented by either the phosphatidylinositol 3-kinase (PI3K) inhibitor LY 294002 (5 μmol/l) or transfection of a dominant-negative mutant of Akt. NaHS increased Akt phosphorylation and this effect was also blocked by either LY 294002 or wortmannin (25 nmol/l). NaHS did not significantly alter the levels of vascular endothelial growth factor, mRNA expression of fibroblast growth factor and angiopoietin-1, or nitric oxide metabolites. NaHS treatment (10 and 50 μmol kg − 1 day − 1 ) significantly promoted neovascularization in vivo in mice. Conclusion:The present study reports a novel proangiogenic role of H 2 S which is dependent on activation of Akt.

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A bioleaching process to extract rare-earth elements (REE) from fluidized catalytic cracking (FCC) catalysts was optimized using a heterotrophic bacterium Gluconobacter oxydans to produce organic acids from glucose. Parameters optimized included agitation intensity, oxygen levels, glucose concentrations, and nutrient additions. Biolixiviants from the optimized batch process demonstrated REE leaching efficiencies up to 56%. A continuous bioreactor system was subsequently developed to feed a leach process and demonstrated leaching efficiencies of 51%. A techno-economic analysis showed glucose to be the single largest expense for the bioleach process, constituting 44% of the total cost. The bioleaching plant described here was found profitable, although the margin was small. Lower cost carbon and energy sources for producing the biolixiviant, sourcing FCC catalysts with higher total REE content (>1.5% by mass), and improved leaching efficiencies would significantly increase the overall profit. A life cycle analysis showed that electricity and glucose required for the bioreactor had the largest potential for environmental impacts.

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There are many more apoptotic cells in muscle atrophied as a result of brachial plexus injury than in healthy muscle, and apoptosis plays an important role in the pathogenesis of atrophy. The apoptotic signal may be transmitted from Fas to FADD to Caspase-8, with a decrease in Bcl-2 expression aggravating the process.