Electrochemical supercapacitor (EC) is a kind of device able to generate and store clean energy, which makes it the object of intense research. This work proposes a double layer capacitance ...combination of electrochemical reduced graphene oxide (rGO) and carbon fiber (CF) in addition to pseudocapacitive behavior of polyaniline (PAni) to produce PAni/rGO/CF ternary composite with high capacitive response. rGO/CF and PAni/rGO/CF are obtained by electrochemical methodology. The morphological and structural analyses by scanning electron microscopy, X-ray diffraction, and Raman spectroscopy show that these nanostructured composite materials can be produced successfully. rGO/CF and PAni/rGO/CF samples are evaluated electrochemically by cyclic voltammetry (CV), electrochemical impedance spectroscopy, and charge/discharge tests. PAni/rGO/CF ternary composite presents a better performance in terms of specific capacitance and electrochemical reversibility than that of rGO/CF composite and CF electrodes. The results show that this ternary composite can be a promising electrode for applications in supercapacitors.
•Simple and inexpensive electrochemical method to produce PAni/rGO/CF composites.•The PAni/rGO/CF showed high specific capacitance and electrochemical reversibility.•Promising candidate to be applied as flexible electrodes in electrochemical capacitor.
Iron and sulfur are key elements in the biogeochemistry of estuarine soils, in which Fe and sulfate reduction (SR) pathways are important for organic matter decomposition. In the semi-arid coast of ...NE Brazil, mangroves are characterized by large seasonal variations in weather and the presence of numerous shrimp farms. The objective was to determine the impacts of shrimp farm effluents on iron and sulfur geochemistry in mangrove soils under the semi-arid climate of NE Brazil. A seasonal study was made of two mangrove forest soils (SF, a mangrove forest that directly receives wastewater from shrimp ponds and CS, a control site). Pyrite Fe, oxyhydroxides Fe, acid volatile sulfide, degree of pyritization (DOP), pH, Eh, total organic carbon (TOC) and total S were determined. There was a clear decrease in pyritic Fe and DOP in the SF soils, which may be related to the anaerobic oxidation of pyrite coupled with nitrate reduction, or to the dominance of denitrification over SR. Lower TOC contents in the SF site suggest that below ground decomposition increased in response to eutrophication. The seasonal variations led to important changes in the semi-arid mangrove soils. During the dry period, both soils experienced oxidizing conditions with remarkable loss of reduced and oxidized forms of Fe, which may have important environmental implications as Fe is biolimiting for marine primary production. The data show that both factors (seasonal weather variations and shrimp effluents) play important roles in the geochemical processes that occur in these soils and, thus, may affect their functioning and maintenance.
► The concentration of TBH was reduced by 90% following electrolysis with BDD/Ti. ► Electrolysis with BDD/Ti electrodes led to the removal of 80% of total organic carbon. ► The reduction and ...formation of the byproducts of TBH could be monitored by HPLC. ► Ion chromatography confirmed that the electrochemical breakdown of TBH with BDD/Ti. ► The least doped BDD was the more efficient.
The thiadiazolylurea derivative tebuthiuron (TBH) is commonly used as an herbicide even though it is highly toxic to humans. While various processes have been proposed for the removal of organic contaminants of this type from wastewater, electrochemical degradation has shown particular promise. The aim of the present study was to investigate the electrochemical degradation of TBH using anodes comprising boron-doped (5000 and 30000ppm) diamond (BDD) films deposited onto Ti substrates operated at current densities in the range 10–200mAcm−2. Both anodes removed TBH following a similar pseudo first-order reaction kinetics with kapp close to 3.2×10−2min−1. The maximum mineralization efficiency obtained was 80%. High-pressure liquid chromatography with UV–VIS detection established that both anodes degraded TBH via similar intermediates. Ion chromatography revealed that increasing concentrations of nitrate ions (up to 0.9ppm) were formed with increasing current density, while the formation of nitrite ions was observed with both anodes at current densities ⩾150mAcm−2. The BDD film prepared at the lower doping level (5000ppm) was more efficient in degrading TBH than its more highly doped counterpart. This unexpected finding may be explained in terms of the quantity of impurities incorporated into the diamond lattice during chemical vapor deposition.
► Electrochemical advanced oxidation process was studied using BDD based anodes with different boron concentrations. ► The difference between the non-active and active anodes for organics ...degradation. ► The influence of morphologic and structural properties of BDD electrodes on the RO-16 dye degradation.
Boron-doped diamond (BDD) films grown on the titanium substrate were used to study the electrochemical degradation of Reactive Orange (RO) 16 Dye. The films were produced by hot filament chemical vapor deposition (HFCVD) technique using two different boron concentrations. The growth parameters were controlled to obtain heavily doped diamond films. They were named as E1 and E2 electrodes, with acceptor concentrations of 4.0 and 8.0
×
10
21
atoms
cm
−3, respectively. The boron levels were evaluated from Mott–Schottky plots also corroborated by Raman's spectra, which characterized the film quality as well as its physical property. Scanning Electron Microscopy showed well-defined microcrystalline grain morphologies with crystal orientation mixtures of (1
1
1) and (1
0
0). The electrode efficiencies were studied from the advanced oxidation process (AOP) to degrade electrochemically the Reactive Orange 16 azo-dye (RO16). The results were analyzed by UV/VIS spectroscopy, total organic carbon (TOC) and high-performance liquid chromatography (HPLC) techniques. From UV/VIS spectra the highest doped electrode (E2) showed the best efficiency for both, the aromaticity reduction and the azo group fracture. These tendencies were confirmed by the TOC and chromatographic measurements. Besides, the results showed a direct relationship among the BDD morphology, physical property, and its performance during the degradation process.
Highlights ► CAPE protects against the dopaminergic neuronal loss induced by 6-OHDA in rats. ► This is the first study to show the protection against 6-OHDA neurotoxicity in vivo. ► The mechanism ...involves ROS scavenging, metals chelation and MPT inhibition. ► CAPE does not affect mitochondrial calcium homeostasis. ► CAPE does not cause mitochondrial dysfunction.
Volcanic soils are unique naturally fertile resources, extensively used for agricultural purposes and with particular physicochemical properties that may result in accumulation of toxic substances, ...such as trace metals. Trace metal contaminated soils have significant effects on soil microbial activities and hence on soil quality. The aim of this study is to determine the soil microbial responses to metal contamination in volcanic soils under different agricultural land use practices (conventional, traditional and organic), based on a three-tier approach: Tier 1 – assess soil microbial activities, Tier 2 – link the microbial activity to soil trace metal contamination and, Tier 3 – integrate the microbial activity in an effect-based soil index (Integrative Biological Response) to score soil health status in metal contaminated agricultural soils. Our results showed that microbial biomass C levels and soil enzymes activities were decreased in all agricultural soils. Dehydrogenase and β-glucosidase activities, soil basal respiration and microbial biomass C were the most sensitive responses to trace metal soil contamination. The Integrative Biological Response value indicated that soil health was ranked as: organic>traditional>conventional, highlighting the importance of integrative biomarker-based strategies for the development of the trace metal “footprint” in Andosols.
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•The studied agricultural Andosols are naturally enriched with trace metals.•Conventional farming in Andosols particularly decreases soil microbial activities.•Dehydrogenase, β-glucosidase, SBR and MB-C are the most sensitive responses.•Farming systems soil health is ranked by IBR as: organic>traditional>conventional.
STING (stimulator of interferon genes) is a cytosolic sensor for cyclic dinucleotides and also an adaptor molecule for intracellular DNA receptors. Although STING has important functions in the host ...defense against pathogens and in autoimmune diseases, its physiological relevance in intestinal homeostasis is largely unknown. In this study, we show that STING
mice presented defective protective mechanisms of intestinal mucosa, including decreased number of goblet cells, diminished mucus production, and lower levels of secretory IgA, when compared with wild-type (WT) mice. Fecal content and microbiota DNA could activate STING, indicating a role of this molecule in gut. Microbiota composition was altered in STING
mice toward a more inflammatory profile, evidencing a reduction in the Allobacolum and Bifidobacterium groups along with increase in Disulfovibrio bacteria. Absence of STING lead to decrease in induced intraepithelial lymphocytes (IEL) and to increase in group 1 innate lymphoid cell (ILC1) as well as ILC3 frequencies and decrease in ILC2 in the colon. Development and function of Foxp3+ and LAP+ regulatory T cells were also compromised in STING
mice. Moreover, these mice were highly susceptible to dextran sodium sulfate-induced colitis, T-cell-induced colitis, and enteric Salmonella typhimurium infection when compared with WT animals. Therefore, our results identify an important role of STING in maintaining gut homeostasis and also a protective effect in controlling gut inflammation.
This work evaluates the effects of coupling Conductive Diamond Electrochemical Oxidation (CDEO) with electrogenerated peroxide (CDEO-H2O2), iron (II) catalyst (electro-Fenton, EF) and UV irradiation ...(photoelectron-Fenton, PEF) techniques for the treatment of wastewater containing a commercial mixture of Diuron and Hexazinone herbicides. Although the techniques employed in this study exhibited significant differences in terms of current charge, energy consumption and amounts of byproducts formed, they have shown to be capable of degrading and mineralizing both herbicides (Diuron and Hexazinone). The application of electrooxidation technique with and without hydrogen peroxide generation led to the oxidation of both herbicides, where removal rates ranging from 74% to 99% and 77%–92% were obtained for Hexazinone and Diuron, respectively. Hexazinone and Diuron were completely removed after 90 min in the EF process. PEF was found to be the most efficient technique for having drastically reduced the time for complete degradation of the herbicides, although 25% of organic carbon remained in solution after 120 min of electrolysis. Higher rates of herbicides degradation were obtained in this order: PEF > EF > CDEO/H2O2/UV > CDEO/H2O2 > CDEO > UV. The result indicates that the production of oxidants is promoted by the hybrid processes, and this leads to an improvement in the oxidation of the pollutants. The synergistic coefficient obtained for the coupled techniques were higher than one in terms of both herbicides degradation and Total Organic Carbon (TOC) removal. Two important sub-products of reaction were identified, and their degradation route is in agreement with the reports published in the literature. Essentially, this work draws attention to the synergistic effect caused by the coupling of techniques involving the treatment of chemical agents in wastewater and sheds light on how to use this coupling technique for the development of more efficient treatment processes.
•Oxidation capacity increases in the following order: UV < CDEO < CDEO-H2O2 < EF < CDEO/H2O2-UV < PEF.•Diuron and Hexazinone are similarly oxidized under bare CDEO techniques.•Higher rates of herbicides decay were obtained in hybrid processes due to the enhancement of oxidants production.•Synergistic coefficients greater than 1 were obtained for the coupling of H2O2, Fe (II) and UV to CDEO.
Chromosomal region maintenance 1 (CRM1 also known as Xpo1 and exportin‐1) is the receptor for the nuclear export controlling the intracellular localization and function of many cellular and viral ...proteins that play a crucial role in viral infections and cancer. The inhibition of CRM1 has emerged as a promising therapeutic approach to interfere with the lifecycle of many viruses, for the treatment of cancer, and to overcome therapy resistance. Recently, selinexor has been approved as the first CRM1 inhibitor for the treatment of multiple myeloma, providing proof of concept for this therapeutic option with a new mode of action. However, selinexor is associated with dose‐limiting toxicity and hence, the discovery of alternative small molecule leads that could be developed as less toxic anticancer and antiviral therapeutics will have a significant impact in the clinic. Here, we report a CRM1 inhibitor discovery platform. The development of this platform includes reporter cell lines that monitor CRM1 activity by using red fluorescent protein or green fluorescent protein‐labeled HIV‐1 Rev protein with a strong heterologous nuclear export signal. Simultaneously, the intracellular localization of other proteins, to be interrogated for their capacity to undergo CRM1‐mediated export, can be followed by co‐culturing stable cell lines expressing fluorescent fusion proteins. We used this platform to interrogate the mode of nuclear export of several proteins, including PDK1, p110α, STAT5A, FOXO1, 3, 4 and TRIB2, and to screen a compound collection. We show that while p110α partially relies on CRM1‐dependent nuclear export, TRIB2 is exported from the nucleus in a CRM1‐independent manner. Compound screening revealed the striking activity of an organoselenium compound on the CRM1 nuclear export receptor.
CRM1 is a nuclear export receptor that has been considered as a promising therapeutic target for the treatment of many types of cancers and viral infections. Here we report the development of a multiplexed platform to analyze the CRM1‐dependence of any protein of interest as shown for the human proteins PDK1, p110α, STAT5A, FOXO1/3/4 and TRIB2. Compound screening revealed the striking inhibitory activity of an organoselenium compound on CRM1 and nuclear export of. endogenous CRM1 substrates.
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