Glycerol Electro-Oxidation in Alkaline Medium with Pt-Fe/C Electrocatalysts Synthesized by the Polyol Method: Increased Selectivity and Activity Provided by Less Expensive Catalysts.

We have investigated platinum catalysts containing iron as a modifier to obtain catalysts with superior electrocatalytic activity toward glycerol electro-oxidation in an alkaline medium. The electrocatalysts, supported on carbon Vulcan, were synthesized by the polyol method. The physicochemical characterization data showed that the metals were well distributed on the carbon support and had small particle size (2 nm). The Pt:Fe metal ratio differed from the nominal composition, indicating that reducing iron with platinum was difficult, even though some parameters of the synthesis process were changed. Electrochemical analyses revealed that PtFe/C was more active and stable than commercial Pt/C was, and analysis of the electrolysis by-products showed that iron addition to Pt/C boosted the glycerol conversion and selectivity for glyceric acid formation.

Relationship between Payment for Ecosystem Services Programs and Disasters in Southeast Atlantic Forest region, Brazil.

Ecosystem services significantly contribute to ecosystems resilience and stability. In this sense, payment for ecosystem services can be designed and applied to prevent or decrease environmental disaster risks. This study aimed at verifying whether municipalities taking part in PES programs present higher number of natural disasters (flood, drought, landslide and fire) between 2009 and 2020 in the Paraíba do Sul river basin. We expected that municipalities having more disaster events would take part in more projects, which we found. Programs can be implemented in response to the increase in natural disasters. We also expected PES calls to explicitly target natural disaster prevention measures and actions, which we did not observe. We found actions related to soil conservation and vegetation cover that might prevent risks, but there were no mentions of disasters. It is concerning that PES in Vale do Paraíba Paulista programs have not been addressing natural disaster risk reduction in a landscape, where floods, droughts, anthropogenic fires and erosion problems associated with hilly reliefs have been increasing in the last years.

Carbon Nanotube PtSn Nanoparticles for Enhanced Complete Biocatalytic Oxidation of Ethylene Glycol in Biofuel Cells.

We report a hybrid catalytic system containing metallic PtSn nanoparticles deposited on multiwalled carbon nanotubes (Pt65Sn35/MWCNTs), prepared by the microwave-assisted method, coupled to the enzyme oxalate oxidase (OxOx) for complete ethylene glycol (EG) electrooxidation. Pt65Sn35/MWCNTs, without OxOx, showed good electrochemical activity toward EG oxidation and all the byproducts. Pt65Sn35/MWCNTs cleaved the glyoxilic acid C-C bond, producing CO2 and formic acid, which was further oxidized at the electrode. Concerning EG oxidation, the catalytic activity of the hybrid system (Pt65Sn35/MWCNTs+OxOx) was twice the catalytic activity of Pt65Sn35/MWCNTs. Long-term electrolysis revealed that Pt65Sn35/MWCNTs+OxOx was much more active for EG oxidation than Pt65Sn35/MWCNTs: the charge increased by 65%. The chromatographic results proved that Pt65Sn35/MWCNTs+OxOx collected all of the 10 electrons per molecule of the fuel and was able to catalyze EG oxidation to CO2 due to the associative oxidation between the metallic nanoparticles and the enzymatic pathway. Overall, Pt65Sn35/MWCNTs+OxOx proved to be a promising system to enhance the development of enzymatic biofuel cells for further application in the bioelectrochemistry field.

Evaluation of seeds ethanolic extracts of Triplaris gardneriana Wedd. using in vitro and in vivo toxicological methods.

Triplaris gardneriana Wedd. is a tree used in folk medicine to treat venereal diseases and inflammation as well as a source of biological compounds with antioxidant capacity. In order to assess the safety of these bioactive compounds, the present study aimed to determine the toxicity of an ethanolic extract of T. gardneriana, (EETg). Toxicological tests included hemolytic activity, toxicity toward the brine shrimp Artemia, cytotoxicity against breast cancer cells (MCF7) and acute oral toxicity in rodents. In addition, toxicogenomics techniques were used to determine genome expression in MCF7 cells exposed to EETg. The results showed that the extract exhibits approximately 60% of hemolytic activity at the highest tested concentration (64 µg/ml) and toxicity against nauplii of Artemia sp. (LC50 of 67.85 µg/ml). Further, EETg appears to be cytotoxic to MCF7 (cell viability reduced to 40% at 250 µg/ml after 24 hr). Genomic data demonstrated differential expression of 14 genes. Data analysis indicated possible altered pathways (e.g., xenobiotic metabolism), possible adverse health risks (e.g., hepatotoxicity), and drugs with similar gene expression profile (e.g., antimicrobials). The investigation provides important information on potentially adverse aspects of EETg, which need to be considered prior to the therapeutic utilization of this plant.Abbreviations: EETg: ethanolic extract of T. gardneriana seeds; MCF7: michigan cancer foundation-7 which refers to a human breast cell line (adenocarcinoma); NGS: next-generation sequencing; edgeR: empirical analysis of digital gene expression data in R; Consensus: consensus path database; FDR: false discovery rate; NCBI: national center for biotechnology information; KEGG: kyoto encyclopedia of genes and genomes; Ingenuity: ingenuity pathway analysis software; CMAP: connectivity map; OECD: organization for economic co-operation and development; HL-60: human promyelocytic leukemia cells; PC3: prostate cancer cells.

The potential of commercially available phytotherapeutic compounds as new photosensitizers for dental antimicrobial PDT: A photochemical and photobiological in vitro study.

The present study evaluated the effectiveness of extracts of commercially available Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum as photosensitizers in Antimicrobial Photodynamic Therapy (aPDT). Each photosensitizer (PS) was analyzed in a spectrophotometer between 350 and 750 nm to determine the ideal light source. Once the absorption bands were determined, three light sources were selected. To determine the concentration of use, the compounds were tested at different concentrations on bovine dentin samples to evaluate the risk of staining. Once the concentration was determined, the PSs were evaluated for dark toxicity and phototoxicity on fibroblast and bacteria culture. Each compound was then irradiated with each light source and evaluated for the production of reactive oxygen species (ROS). The bacterial reduction was tested on E. faecalis culture in planktonic form and on biofilm using an energy of 10 J and an Energy Density of 26 J/cm2. The tested compounds exhibited light absorption in three bands of the visible spectrum: violet (405 nm), blue (460 nm) and red (660 nm). At a 1:6 concentration, none of the compounds caused tooth staining as they did not exhibit significant toxicity in the cells or bacterial suspension. Additionally, significant ROS production was observed when the compounds were irradiated at each wavelength. When aPDT was performed on the plactonic and biofilm bacteria, significant microbial reduction was observed in both cases, reaching a reduction of up to 5Logs. In conclusion, extracts of Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum exhibited potential for use as photosensitizing agents in aPDT.

Lantana montevidensis Briq improves the aminoglycoside activity against multiresistant Escherichia coli and Staphylococcus aureus.

OBJECTIVE: In this work, we report the antibacterial and modulatory activity of Lantana montevidensis Briq. MATERIALS AND METHODS: The antibacterial activities of leaf (LELm) and root (RELm) extracts alone or in association with aminoglycosides were determined by a microdilution test. Multiresistant strains of Escherichia coli (Ec 27) and Staphylococcus aureus (Sa 358) were used. RESULTS: The results show the inhibitory activity of LELm against E. coli (minimal inhibitory concentration [MIC] 16 µg/mL) and S. aureus (MIC 128 µg/mL). The synergistic effect of the extracts and aminoglycosides was verified too. The maximum effects were obtained with RELm with gentamicin against E. coli with MIC reduction (312 to 2 µL). CONCLUSION: The data from this study are indicative of the activity antibacterial of extracts of L. montevidensis and its potential in modifying the resistance of aminoglycosides.

WITHDRAWN: Phytochemical screening and modulation of antibiotic activity by Ocimum gratissimum L.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.bionut.2010.09.007. The duplicate article has therefore been withdrawn.