Ability Of OH Research Articles

NiC2O4 nanorods embellished NiCo layered double hydroxide nanoflowers with enhanced electrochemical performances for hybrid supercapacitor

Designing and constructing a high performance and multi-component nickel-based material is preferable for efficient energy storage devices. In this study, we reasonably designed a composite material, NiC2O4/NiCo layered double hydroxide (LDH), composed of 1D NiC2O4 nanorods and 3D NiCo-LDH nanoflowers self-assembled from nanosheets via a hydrothermal method. This causes NiCo-LDH nanoflowers to stretch out, increasing the specific surface area (up to 47 m2 g−1), improving contact with the electrolyte and providing abundant active sites, speeding up the transfer of protons. The excellent double redox reactions of NiC2O4 and NiCo-LDH expedite the reaction kinetics and boost electrochemical activities, resulting in high energy densities of 37.6 Wh kg−1 and high power densities of 809.8 W kg−1 for the NiC2O4/NiCo-LDH||AC hybrid supercapacitor devices. Furthermore, DFT calculations indicate NiC2O4/NiCo-LDH enhance the adsorption ability of OH−. And the improved electrochemical performance of NiC2O4/NiCo-LDH is due to partial electrons transfer through the interface.

A reductive strategy with ultrahigh selectivity for sequential recovery of uranium from radioactive wastewater

Uranium is valuable metal, and it is of great significance to develop a simultaneous separation process of uranium and cesium from radioactive wastewater. Herein, a process was designed to separate sequentially uranium and cesium from wastewater. By comparing the limiting ability of OH− and CO32− to Co2+, Cd2+, and Sr2+ ions, it was found that CO32− could effectively limit the above ions to the solid phase. The result of X-ray photoelectron spectroscopy (XPS) and species analysis revealed that the restriction was achieved through complexation. Through this property, more than 99.9 % of cobalt and cadmium were limited in the solid phase, and U-Cs co-separation was realized. Furthermore, the results of cyclic voltammetry and XPS indicated that U(VI) could be reduced in the liquid phase, but Cs(I) could not, which was the basis for uranium and cesium separation. And more than 99.5 % of uranium was separated from cesium by the electrochemical separation process. Simultaneously, effective separation of uranium and cesium under different pHs has been achieved via selective uranium leaching using carbonate. The co-separation combined with electrochemical separation realized the recovery of pure uranium products, indicating a large potential for realizing uranium resources in wastewater.

A Highly-Efficient Boron Interstitially Inserted Ru Anode Catalyst for Anion Exchange Membrane Fuel Cells.

Developing high-performance electrocatalysts for alkaline hydrogen oxidation reaction (HOR) is crucial for the commercialization of anion exchange membrane fuel cells (AEMFCs). Here, boron interstitially inserted ruthenium (B-Ru/C) is synthesized and used as an anode catalyst for AEMFC, achieving a peak power density of 1.37W cm-2 , close to the state-of-the-art commercial PtRu catalyst. Unexpectedly, instead of the monotonous decline of HOR kinetics with pH as generally believed, an inflection point behavior in the pH-dependent HOR kinetics on B-Ru/C is observed, showing an anomalous behavior that the HOR activity under alkaline electrolyte surpasses acidic electrolyte. Experimental results and density functional theory calculations reveal that the upshifted d-band center of Ru after the intervention of interstitial boron can lead to enhanced adsorption ability of OH and H2 O, which together with the reduced energy barrier of water formation, contributes to the outstanding alkaline HOR performance with a mass activity of 1.716mA µgPGM -1 , which is 13.4-fold and 5.2-fold higher than that of Ru/C and commercial Pt/C, respectively.

Characterization and anti-inflammatory effect of selenium-enriched probiotic Bacillus amyloliquefaciens C-1, a potential postbiotics

A patented strain of Bacillus amyloliquefaciens C-1 in our laboratory could produce functional sodium selenite (Na2SeO3) under optimized fermentation conditions. With the strong stress resistance and abundant secondary metabolites, C-1 showed potential to be developed as selenium-enriched postbiotics. C-1 has the ability to synthesize SeNPs when incubated with 100 μg/ml Na2SeO3 for 30 h at 30 °C aerobically with 10% seeds-culture. The transformation rate from Na2SeO3 into SeNPs reached to 55.51%. After selenium enrichment, there were no significant morphology changes in C-1 cells but obvious SeNPs accumulated inside of cells, observed by scanning electron microscope and transmission electron microscope, verified by energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. SeNPs had antioxidant activity in radical scavenge of superoxide (O2−), Hydroxyl radical (OH−) and 1,1-diphenyl-2-picryl-hydrazine (DPPH), where scavenging ability of OH− is the highest. Selenium-enriched C-1 had obvious anti-inflammatory effect in protecting integrity of Caco-2 cell membrane destroyed by S. typhimurium; it could preventing inflammatory damage in Caco-2 stressed by 200 μM H2O2 for 4 h, with significantly reduced expression of IL-8 (1.687 vs. 3.487, P = 0.01), IL-1β (1.031 vs. 5.000, P < 0.001), TNF-α (2.677 vs. 9.331, P < 0.001), increased Claudin-1 (0.971 vs. 0.611, P < 0.001) and Occludin (0.750 vs. 0.307, P < 0.001). Transcriptome data analysis showed that there were 381 differential genes in the vegetative growth stage and 1674 differential genes in the sporulation stage of C-1 with and without selenium-enrichment. A total of 22 ABC transporter protein-related genes at vegetative stage and 70 ABC transporter protein-related genes at sporulation stage were founded. Genes encoding MsrA, thiol, glutathione and thioredoxin reduction were significantly up-regulated; genes related to ATP synthase such as atpA and atpD genes showed down-regulated during vegetative stage; the flagellar-related genes (flgG, fliM, fliL, and fliJ) showed down-regulated during sporulation stage. The motility, chemotaxis and colonization ability were weakened along with synthesized SeNPs accumulated intracellular at sporulation stage. B. amyloliquefaciens C-1 could convert extracellular selenite into intracellular SeNPs through the oxidation–reduction pathway, with strong selenium-enriched metabolism. The SeNPs and selenium-enriched cells had potential to be developed as nano-selenium biomaterials and selenium-enriched postbiotics.

Facile one-pot hydrothermal synthesis of reticulated porous tobermorite for fast phosphorus recovery

Phosphorus, a depletable resource in nature, has been constantly consumed. Its recovery still remains difficult to be solved. Tobermorite (Ca5Si6O16(OH)2) with chemical stability is an efficient adsorbent for phosphorus. Herein, the reticulated porous tobermorite (CSH) was successfully synthesized through a facile one-step hydrothermal process and its adsorption performance for phosphorus was evaluated. The adsorption reached the equilibrium within 5 min. The kinetic study demonstrated that the adsorption followed the pseudo-second-order model, indicating the adsorption involved the chemisorption. The adsorption perfectly fitted the Langmuir isotherm. The calculated maximum adsorption capacity is 152.46 mg·g−1 at room temperature. Its excellent adsorption performance for phosphorus is attributed to its reticulated porous structure and larger specific surface area. The adsorption is mainly affected by the electrostatic interaction and the releasing ability of OH- and Ca2+ from the CSH. Reticulated porous CSH is a potential efficient adsorbent for phosphorus recovery owing to its facile synthesis, fast adsorption rate, high adsorption capacity and excellent reusability, which provide a feasible alternative for phosphorus recovery.

Design of Oxygen‐doped Co3S4 Hollow Nanosheets by Suppressed Sulfurization for Supercapacitors

AbstractCobalt sulfides can be considered as auspicious electrode materials for supercapacitors due to the good electrical conductivity and high reversible redox capability. In this study, the O‐doped Co3S4 hollow nanosheets supported on carbon paper (O−Co3S4/CP) are facilely prepared through a suppressed sulfurization method by using CP‐supported Co‐ZIF as the precursor and methanol as the solvent. The hollow nanosheets not only offer fast transport pathways but also provide abundant redox active sites. Furthermore, theoretical calculations indicate that the O doping can enhance the adsorption ability of OH− on O−Co3S4 with electrochemical activity and electrical conductivity improvement. Owing to the advantages of the appropriate composition and unique structure, the as‐made hollow structure O−Co3S4/CP shows a remarkable specific capacitance of 755 F g−1 at a current density of 1 A g−1, while a good rate performance of 65 % capacitance retention at 10 A g−1 can be reached. Moreover, the asymmetric supercapacitors assembled by O−Co3S4/CP and activated carbon electrodes yield an energy density of 21.3 Wh kg−1 with power density of 0.75 kW kg−1. The present work can offer a useful guidance for the exploitation of O doped cobalt sulfides hollow nanosheets for supercapacitors.

Effect of low-dose sodium nitrite treatment on the endogenous antioxidant capacity of yak meat during wet curing: Pros and cons

This study aimed to investigate the effects of sodium nitrite treatment on antioxidant enzyme activity and free radical changes in yak meat during wet curing. The effect on superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and nitric oxide synthase (iNOS, TNOS) activity; superoxide anion (O2−) content and production rate; hydrogen peroxide (H2O2) content; nitric oxide (NO) content; and meat hydroxyl radical (OH) inhibition ability were determined. The results showed that NaNO2 treatment effectively increased the activity of CAT, GSH-Px, and NOS (TNOS, iNOS) over the first 3, 5, and 7 days (P < 0.01) following application, respectively, while simultaneously inhibiting the activity of SOD (P < 0.01). In addition, NaNO2 treatment resulted in an increase in O2− content and rate of O2− production in meat, as well as a decrease (P < 0.01) in H2O2 content on the third day of curing. With the addition of NaNO2, the inhibition ability of OH first increased and then decreased, and the NO content in meat increased (P < 0.01). The preliminary study showed that low-dose sodium nitrite could improve the endogenous antioxidant capacity of yak meat during the wet curing process, although it also had negative effects.

Effective separation of prolyl endopeptidase from Aspergillus Niger by aqueous two phase system and its characterization and application

Aspergillus niger prolyl endopeptidase (An-PEP) has become a research focus because of its advantages in specifically cleaving the C-terminal peptide bond of proline residues, especially it was an industrial food-grade acidic PEP. Aqueous two-phase system (ATPS) was first applied for separating An-PEP from fermentation broth. Via response surface method (RSM) experiment, an effectively separation of An-PEP was achieved by ATPS containing27% (w/w) ethanol and 14.5% (w/w) (NH4)2SO4 at pH 6.0 with the recovery of 90.29 ± 0.23% and purification coefficient of 15.35 ± 0.30. The purified An-PEP was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE), fourier transform infrared (FTIR) and fluorescence spectrometry. The optimum temperature and pH of An-PEP were 40 °C and 4.5–5.0, respectively. An-PEP was activated and stabilized by Ca2+ but inhibited by Fe3+. The enzymatic application of purified An-PEP was evaluated by hydrolyzing egg white protein (EWP) to prepare bioactive peptides. The obtained hydrolysates had good scavenging ability of OH and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals, angiotensin converting enzyme (ACE) inhibitory activity and anti-gout activity. This research realized a low-cost, high-efficiency and simple separation technology of An-PEP and provided a broader idea for the preparation of bioactive peptides and the application of An-PEP.

1-Hydroxydodecylidene-1,1-diphosphonic acid flotation of bastnäsite: Performance and mechanism

To separate and enrich rare-earth elements (REE) minerals from their ores through flotation process has become an attracting topic for REE’s strategic position. In the present investigation, the floatability of bastnäsite [(Ce,La)CO3F] was explored by using 1-hydroxydodecylidene-1,1-diphosphonic acid (HDDPA) as a collector. The micro-flotation results showed that bastnäsite displayed an eminent floatability under pH 7.0–10.0, and HDDPA realized an efficient separation of bastnäsite from calcite at pH around 8.0. Zeta potential and solution chemistry inferred that at pH 7.5–9.3, HDDPA3− anions were glad to replace the CO32- ions of Ce(Ⅲ) carbonates in/on bastnäsite interface, resulting in a high flotation recovery of bastnäsite. With increasing OH- concentration, the competition ability of OH- against HDDPA anion intensified, gradually the surface Ce(III) hydroxide species increased, and the floatability of bastnäsite reduced. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) recommended that the surface Ce(III) of bastnäsite interacted with the O atoms of HDDPA’s OP(O)O group to generate a four membered ring configuration, which hydrophobized bastnäsite particles.

Missing OH reactivity in the global marine boundary layer

Abstract. The hydroxyl radical (OH) reacts with thousands of chemical species in the atmosphere, initiating their removal and the chemical reaction sequences that produce ozone, secondary aerosols, and gas-phase acids. OH reactivity, which is the inverse of OH lifetime, influences the OH abundance and the ability of OH to cleanse the atmosphere. The NASA Atmospheric Tomography (ATom) campaign used instruments on the NASA DC-8 aircraft to measure OH reactivity and more than 100 trace chemical species. ATom presented a unique opportunity to test the completeness of the OH reactivity calculated from the chemical species measurements by comparing it to the measured OH reactivity over two oceans across four seasons. Although the calculated OH reactivity was below the limit of detection for the ATom instrument used to measure OH reactivity throughout much of the free troposphere, the instrument was able to measure the OH reactivity in and just above the marine boundary layer. The mean measured value of OH reactivity in the marine boundary layer across all latitudes and all ATom deployments was 1.9 s−1, which is 0.5 s−1 larger than the mean calculated OH reactivity. The missing OH reactivity, the difference between the measured and calculated OH reactivity, varied between 0 and 3.5 s−1, with the highest values over the Northern Hemisphere Pacific Ocean. Correlations of missing OH reactivity with formaldehyde, dimethyl sulfide, butanal, and sea surface temperature suggest the presence of unmeasured or unknown volatile organic compounds or oxygenated volatile organic compounds associated with ocean emissions.

Efficient oxidation of macro-crude oil in soil using oil-absorbing Fe catalyzing H2O2

This study investigated the oxidizing ability of OH for macro-crude oil in soil using oil-absorbing Fe catalyzing H2O2. Two types of oil-contaminated soil were tested: (i) macro long-chain crude oil-contaminated soil (LO-soil) was dominated by long-chain alkanes, and (ii) macro common crude oil-contaminated soil (CO-soil) was dominated by both short- and long-chain alkanes. LO-soil contained 38% (C30 – C27: 1490 mg/kg) macro-crude oil, and CO-soil contained 38% (C30, C29, C15 and C14: 1473 mg/kg) macro-crude oil. The results showed that the greatest removal of macro-crude oil (LO-soil: 938 mg/kg, CO-soil: 821 mg/kg) was observed by H2O2/oil-absorbing Fe, an increase of twofold compared with by H2O2/non oil-absorbing Fe. In addition, the removal of macro-crude oil by per unit iron species in H2O2/oil-absorbing Fe was as high as 0.25–0.35 mg oil/mg Fe, twice that (0.13–0.17 mg oil/mg Fe) achieved by H2O2/non oil-absorbing Fe. The utilization efficiency of OH is improved by H2O2/oil-absorbing Fe. Further analysis found that the oil-absorbing Fe could bind with hydrophobic humic-like acid and fulvic-like acid, increasing the hydrophobicity of oil-absorbing Fe. Thus, macro-crude oil could be efficiently oxidized in soil by oil-absorbing Fe catalyzing H2O2.

Total mineralization of mixtures of Tartrazine, Ponceau SS and Direct Blue 71 azo dyes by solar photoelectro-Fenton in pre-pilot plant

Mixtures of monoazo Tartrazine, diazo Ponceau SS and triazo Direct Blue 71 dyes with 105 mg L−1 of total organic carbon (TOC) in 0.050 M Na2SO4 at pH 3.0 have been treated by solar photoelectro-Fenton (SPEF). Experiments were carried out in a 2.5 L pre-pilot plant with a Pt/air-diffusion cell coupled to a solar planar photoreactor. Comparative trials were made by anodic oxidation with electrogenerated H2O2 (AO-H2O2) and electro-Fenton (EF) to better understand the role of oxidizing agents. AO-H2O2 gave poor degradation due to the low oxidation ability of OH formed at the Pt anode and H2O2 produced at the cathode. Similar color removal was achieved in EF and SPEF because the main oxidant was OH formed in the bulk from Fenton's reaction. EF yielded partial mineralization by formation of molecules with high stability against OH. In contrast, these by-products were rapidly photolyzed under sunlight irradiation in SPEF, which was the most powerful treatment. Up to 8 linear final carboxylic acids were detected, along with the release of sulfate and ammonium ions. The effect of Fe2+ and azo dye concentrations, and current density over the SPEF performance was assessed. Total mineralization of azo dyes mixtures occurred when operating up to 105 mg L−1 TOC with 0.50 mM Fe2+ at 100 mA cm−2.

Needle-like Co[sbnd]Mo[sbnd]O with multi-modal porosity for pseudocapacitors

The needle-like CoMoO with multi-modal porosity was synthesized via simple strategy of chemical coprecipitation in hydrothermal condition. The resulted products were characterized with SEM, EDXS, XPS, XRD, Raman, BET, FTIR and electrochemical techniques. The needle-like CoMoO exhibited excellent electrochemical performance as supercapacitor. A large capacitance value of 1180 F/g was obtained with good cycle life from the CV plots at 5 mV/s or 302 F/g was calculated from the discharge curve at 1 A/g. The good electrochemical performance may be attributed to the multi-modal microstructure of the needle-like CoMoO with the combination of microporosity, mesoporosity and macroporosity which leads to the large surface area and the excellent contact probability, diffusion efficiency and storage ability of OH− ions. It’s observed for the first time that MoO3 in the needle-like CoMoO gradually flows away with the charge-discharge. The presence of Mo may not directly contribute to the electrochemcal capacitance of the materials but it helps to form the structure of the obtained needle-like CoMoO and thus indirectly affect the electrochemical performance of the needle-like CoMoO.

Incineration of acidic aqueous solutions of dopamine by electrochemical advanced oxidation processes with Pt and BDD anodes

The degradation of 1.04mM of the drug dopamine hydrochloride (100mgL−1 of dissolved organic carbon (DOC)) solutions of pH3.0 has been comparatively studied by electrochemical advanced oxidation processes (EAOPs) like anodic oxidation (AO) with a Pt anode and AO, electro-Fenton (EF) and photoelectro-Fenton (PEF) with a boron-doped diamond (BDD) anode. The AO processes were performed with a stainless steel cathode, whereas EF and PEF used an air-diffusion cathode that produced H2O2·AO with a Pt anode led to very poor mineralization because of the low oxidizing ability of OH formed at the Pt surface. The use of a BDD anode in AO yielded faster incineration due to the much greater oxidation of OH generated by BDD. The production of OH in the bulk from Fenton's reaction enhanced largely the mineralization process in EF, which was upgraded in PEF by the photodecomposition of some intermediates by UVA light. Almost total mineralization with 97% DOC removal was found after 360min of EF and 240min of the most powerful PEF at 100mAcm−2. The rise in current density from 16.7 to 100mAcm−2 caused increasing DOC reduction for all EAOPs. The change in mineralization current efficiency and specific energy consumption per unit DOC mass was also discussed. Generated short-linear carboxylic acids like maleic, tartronic, glycolic, acetic, oxalic, oxamic and formic were identified by ion-exclusion HPLC. These acids were quickly removed in EF and more rapidly in PEF due to the photolysis of their Fe(III) complexes. Ion chromatography revealed the pre-eminent generation of NH4+ ion along with a lower proportion of NO3− ion. This technique also confirmed the oxidation of the starting Cl− ion at both Pt and BDD anodes with high ClO4− production using BDD.

Optimizing the Volmer Step by Single-Layer Nickel Hydroxide Nanosheets in Hydrogen Evolution Reaction of Platinum

Hydrogen is considered by many to be a promising energy currency, particularly for the transportation sector and for mobile devices. To realize a hydrogen-based fuel economy, hydrogen must be produced in an efficient and sustainable manner. In this article, single-layer nickel hydroxide (Ni(OH)2)-nanosheet-assisted Pt/C catalysis for the hydrogen evolution reaction (HER) in an alkaline environment was investigated. The HER activity trajectories of the hybrid catalysts in correlation with the composition and morphology of Ni(OH)2 were explored in depth. By optimizing the Volmer step through addition of single-layer Ni(OH)2 into Pt/C catalysis, this hybrid catalyst manifests a 110% increase of the HER activity by using only 20 wt % single-layer Ni(OH)2 with a lithium ion additive as compared to the state-of-the-art Pt/C catalyst. Density functional theory calculations revealed that the single-layer Ni(OH)2 behaves superior in adsorption ability of OH– when compared with multilayer Ni(OH)2. The single-layer ...

Incorporation of Al at ZSM-5 hydrothermal synthesis. Tuning of Al pairs in the framework

The effect of Si- (TEOS, Tixosil and Na-silicate), Al- (AlCl3, Al(NO3)3, NaAlO2, Al(OH)3 and metallic Al) and Na-reactants (NaCl, NaOH, Na3PO4, NaAlO2) in the presence of TPAOH was investigated with regard to the networking of Si and Al atoms in gels and incorporation of Al atoms and their distribution in the hydrothermally synthesized ZSM-5 framework. At Si/Alprod from 12 to 60 the Al–Si–Si–Al sequences (Al pairs) in one 6MR and single Al atoms located in different rings were the most populated (>99% of total Al), reaching 4–70% of the Al atoms in Al pairs in 6MRs adjacent to TPA+. It has been shown that Na+ ions stabilize single SiAlO4− units in Si–Al gels network and lead to a high relative degree of Al incorporation and high population of single Al atoms charge-balanced by TPA+ and Na+ ions. The occurrence of Al pairs in 6MRs is suggested to be controlled by the positive charge on the N atom of TPA+ resulting from its polarization by OH− and other anions present. The decreasing polarization ability of OH−>Cl−∼PO43−>NO3− anions present next to OH− reduces the charge on N+ and results in a decreasing population of Al pairs and increasing population of single Al atoms located in the vicinity of TPA+ ions.

Degradation of 2,4-D herbicide in a recirculation flow plant with a Pt/air-diffusion and a BDD/BDD cell by electrochemical oxidation and electro-Fenton process

Here, 2.5L of solutions of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide of pH 3.0 have been degraded by electrochemical oxidation (EO) and electro-Fenton (EF) using a recirculation flow plant equipped with a single Pt/air-diffusion or BDD/BDD cell containing electrodes of 20cm2 area. In EO, organics were mainly oxidized by OH formed at the anode surface from water oxidation, whereas in EF they were also destroyed in the bulk by OH generated from Fenton’s reaction between added Fe2+ and H2O2 produced at the cathode. In both treatments, the use of a single BDD/BDD cell always allowed larger decontamination due to the higher ability of OH at the BDD surface to mineralize organic intermediates. The most potent EF process with this cell gave 59% mineralization with 23% efficiency and 0.42kWhg−1 TOC specific energy after 300min at 0.5A. The coupling of Pt/air-diffusion and BDD/BDD cells with equal individual current in EF led to similar mineralization degree to that found for the Pt/air-diffusion one at the same total current, but in much shorter time. The effect of current on the mineralization rate, mineralization current efficiency and specific energy of each method was examined. The influence of herbicide concentration on the EF performance of the coupled cell at 2.0A/2.0A was also studied and 83% mineralization was obtained as maximal for 276mgL−1 2,4-D. The herbicide decay always obeyed a pseudo-first-order reaction. A mixture of short-linear carboxylic acids was detected in all final electrolyzed solutions, which were the major organic by-products generated using the single BDD/BDD cell but formed in minor proportion in the EF processes with the Pt/air-diffusion and coupled ones.

Identification of Surface Basic Sites and Acid–Base Pairs of Hydroxyapatite

The Lewis and Bronsted basic properties of a stoichiometric hydroxyapatite (HAp) were investigated by infrared spectroscopy following the adsorption and desorption processes of a Lewis acidic molecule, CO2, and a Bronsted acidic molecule, C2H2. CO2 interacts with basic OH– and O2– of PO43– groups to form hydrogenocarbonates and surface carbonates, respectively. It also generates surface type A carbonates and related water upon substitution of two neighboring structural OH– groups. Water modifies the basic properties of the HAp by decreasing the surface carbonatation and enhancing the formation of hydrogenocarbonates, and promotes the substitution ability of OH– by carbonates. Due to the affinity of HAp for carbonatation, the thermodesorption experiment of CO2 accounts for the thermal decomposition of bulk type A and B carbonates rather than for the lone surface basicity. As for the acetylene probe, three nondissociative adsorption modes of acetylene on the HAp surface are observed: a π complex interaction...

Effects of oxidative stress on apoptosis in manganese-induced testicular toxicity in cocks

Manganese (Mn) is a trace element known to be essential for maintaining the proper function and regulation of many biochemical and cellular reactions. However, little is known about the reproductive toxicity of Mn in birds. To investigate the toxicity of Mn on male reproduction in birds, 50-day-old cocks were fed either a commercial diet or a Mn-supplemented diet containing 600, 900, and 1800 mg/kg MnCl₂. After being treated with Mn for 30, 60, and 90 d, the following were determined: Mn content; histological and ultrastructural changes in the testes, apoptosis; the malondialdehyde (MDA) level; the activities of superoxide dismutase (SOD); the inhibition ability of hydroxyl radicals (OH); the levels of nitric oxide (NO), nitric oxide synthase (NOS), and protein carbonyl in the testes; the DNA-protein crosslinks (DPC); and the activity of the ATP enzyme. Exposure to Mn significantly lowered the activity of SOD and glutathione peroxidase (GPx) and the inhibition ability of OH. Mn exposure also increased the levels of MDA, NO, NOS, DPC, and protein carbonyl; the number of apoptotic cells; and the Mn content and caused obvious histopathological changes in the testes. These findings suggested that Mn exposure resulted in the oxidative damage of cock testicular tissue by altering radical formation, ATP enzyme systems, apoptosis, and DNA damage, which are possible underlying reproductive toxicity mechanisms induced by Mn exposure.

Electro-Fenton and photoelectro-Fenton degradation of the antimicrobial sulfamethazine using a boron-doped diamond anode and an air-diffusion cathode

The degradation of sulfamethazine was tested by electro-Fenton (EF) and photoelectro-Fenton (PEF) using a cell with a boron-doped diamond (BDD) anode and an air-diffusion cathode. The main oxidant of this antimicrobial was hydroxyl radical (OH) formed at the BDD surface from water oxidation and in the bulk from Fenton’s reaction between added Fe2+ and generated H2O2 at the cathode. Optimum conditions for both treatments were pH 3.0 and 0.5mM Fe2+. PEF with UVA radiation was more powerful, allowing an almost total mineralization. EF also gave a large mineralization by the high oxidation ability of OH. The increase in current density enhanced the degradation rate of both processes, but consuming more specific charge and lowering mineralization current efficiency. Higher drug contents yielded greater efficiencies. Sulfamethazine decayed following a pseudo-first-order kinetics, more rapidly in PEF, and its constant rate rose at higher current density and lower drug content. 4,6-Dimethyl-2-pyrimidinamine, catechol, resorcinol, hydroquinone and p-benzoquinone were detected as aromatic intermediates. Oxalic, oxamic and mainly formic acids were accumulated in EF, disappearing more rapidly in PEF due to the additional photolysis of their Fe(III) complexes by UVA light. Organic N was mineralized as NH4+ ion, along with a smaller proportion of NO3- ion.