RESUMO
Current techniques for identifying and quantifying sulfate radicals (SO4·-) in SO4·--based advanced oxidation processes (SR-AOPs) are unsatisfactory due to their low selectivity, poor reliability, and limited feasibility for real-time quantification. In this study, naproxen (NAP) was employed as a turn-on luminescent probe for real-time quantification of SO4·- in SR-AOPs. The chemiluminescence(CL) yield (ΦCL) of the reaction of NAP with SO4·- was first determined to be 1.49 × 10-5 E mol-1 with the bisulfite activation by cerium(IV) [Ce(IV)/BS] process. Then, the maximum peak concentrations of SO4·- in the Ce(IV)/BS-NAP process was quantified to be â¼10-11 M based on the derived equation. Since ΦCL of the reaction of NAP with SO4·- was much greater than that with other reactive oxidizing species (ROS), the developed CL method worked well in selective quantification of SO4·- in various SR-AOPs (e.g., the activation of peroxymonosulfate and persulfate by iron processes). Finally, the electron transfer from NAP to SO4·- was proposed to be the critical step for CL production. This work provides a novel CL method for real-time quantification of SO4·-, which facilitates the development of SR-AOPs and their application in water and wastewater treatment.
Assuntos
Poluentes Químicos da Água , Purificação da Água , Naproxeno , Reprodutibilidade dos Testes , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Oxirredução , SulfatosRESUMO
Marsupenaeus japonicus is an important marine crustacean species. However, a lack of genomic resources hinders the use of whole genome sequencing to explore their genetic basis and molecular mechanisms for genome-assisted breeding. Consequently, we determined the chromosome-level genome of M. japonicus. Here we determine the chromosome-level genome assembly for M. japonicus with a total of 665.19 Gb genomic sequencing data, yielding an approximately1.54 Gb assembly with a contig N50 size of 229.97 kb and a scaffold N50 size of 38.27 Mb. With the high-throughput chromosome conformation capture (Hi-C) technology, we anchored 18,019 contigs onto 42 pseudo-chromosomes, accounting for 99.40% of the total genome assembly. Analysis of the present M. japonicus genome revealed 24,317 protein-coding genes and a high proportion of repetitive sequences (61.56%). The high-quality genome assembly enabled the identification of genes associated with cold-stress and cold tolerance in kuruma shrimp through the comparison of eyestalk transcriptomes between the low temperature-stressed shrimp (10 °C) and normal temperature shrimp (28 °C). The genome assembly presented here could be useful in future studies to reveal the molecular mechanisms of M. japonicus in response to low temperature stress and the molecular assisted breeding of M. japonicus in low temperature.
Assuntos
Genoma , Genômica , Cromossomos/genética , Sequências Repetitivas de Ácido Nucleico , Temperatura Baixa , FilogeniaRESUMO
Dopamine receptors (DARs) are important transmembrane receptors responsible for receiving extracellular signals in the DAR-mediated signaling pathway, and are involved in a variety of physiological functions. Herein, the D1 DAR gene from Marsupenaeus japonicus (MjDAD1) was identified and characterized. The protein encoded by MjDAD1 has the typical structure and functional domains of the G-protein coupled receptor family. MjDAD1 expression was significantly upregulated in the gills and hepatopancreas after low temperature stress. Moreover, double-stranded RNA-mediated silencing of MjDAD1 significantly changed the levels of protein kinases (PKA and PKC), second messengers (cyclic AMP (cAMP), cyclic cGMP, calmodulin, and diacyl glycerol), and G-protein effectors (adenylate cyclase and phospholipase C). Furthermore, MjDAD1 silencing increased the apoptosis rate of gill and hepatopancreas cells. Thus, following binding to their specific receptors, G-protein effectors are activated by MjDAD1, leading to DAD1-cAMP/PKA pathway-mediated regulation of caspase-dependent mitochondrial apoptosis. We suggest that MjDAD1 is indispensable for the environmental adaptation of M. japonicus.
Assuntos
Receptores Dopaminérgicos , Sistemas do Segundo Mensageiro , Animais , Receptores Dopaminérgicos/metabolismo , Temperatura , AMP Cíclico/metabolismo , Proteínas de Ligação ao GTP/metabolismoRESUMO
Degradation of organic contaminants with simultaneous recycling of Ag+ from silver-containing organic wastewater such as photographic effluents is desired. Although photoelectrocatalysis (PEC) technology is a good candidate for this type of wastewater, its reaction kinetics still needs to be improved. Herein, peroxymonosulfate (PMS) was employed to enhance the PEC kinetics for oxidation of phenol (PhOH) at the anode and reduction of Ag+ at the cathode. The degradation efficiency of phenol (PhOH, 0.1 mmol/L) was increased from 42.8% to 96.9% by adding 5 mmol/L PMS at a potential of 0.25 V. Meanwhile, the Ag (by wt%) deposited on the cathode was 28.1% (Ag2O) in PEC process, while that of Ag (by wt%) was 69.7% (Ag0) by adding PMS. According to the electrochemistry analysis, PMS, as photoelectrons acceptor, enhances the separation efficiency of charges and the direct h+ oxidation of PhOH at the photoanode. Meantime, the increasing cathode potential avoided H2 evolution and strongly alkaline at the surface of cathode, thus enabling the deposition of Ag+ in the form of metallic silver with the help of PMS. In addition, PMS combined with PEC process was effective in treating photographic effluents.
Assuntos
Prata , Águas Residuárias , Eletrodos , Peróxidos , FenóisRESUMO
Total organic carbon (TOC) is a valuable indicator to evaluate the degree of organic pollution in wastewater. Real-time analysis of TOC in wastewater can allow the wastewater treatment plants to manage the treatment process efficiently, avoid violations of the discharge regulations, and eliminate overtreatment. However, traditional methods for TOC determination are time-consuming. Benefitting from the rapid generation of SO4â¢- in the iron(II)-activated peroxymonosulfate (Fe(II)/PMS) system and the high reactivity of SO4â¢- towards naproxen as a chemiluminescence (CL) probe, a surrogate for TOC based on the determination of CL quenching capacity (CLQC) of organics in the Fe(II)/PMS-naproxen system was developed. According to the derived equation by considering both non-fluorescent and fluorescent quenching, the CLQC of organics in the Fe(II)/PMS-naproxen system was highly dependent on their TOC, making it to be a potential surrogate for TOC. The interferences of ubiquitous inorganic ions in wastewater on the determination of CLQC were leveled by adjusting electrical conductivity and adding mercury ions. Finally, the feasibility of CLQC as a surrogate for TOC in two real wastewaters containing different concentrations of inorganic anions was confirmed. This work can provide a TOC value within several seconds by determining the CLQC of wastewater with Fe(II)/PMS-naproxen system.
Assuntos
Mercúrio , Águas Residuárias , Carbono , Compostos Ferrosos , Luminescência , Naproxeno , Oxirredução , PeróxidosRESUMO
Peroxymonosulfate (PMS) was introduced into a photoelectrocatalytic (PEC) system with a bismuth vanadate (BiVO4) photoanode to enhance the PEC oxidation of bisphenol A (BPA). With the addition of 5 mM PMS, the degradation efficiency of 10 mg/L BPA was significantly improved from 24.2% to 100.0% within 120 min and the side reaction of O2 evolution was avoided at a potential as low as 0.25 V. The electron spin resonance and radicals quenching results suggested that photogenerated holes instead of SO4â¢- and OH were primarily responsible for the BPA degradation. To further explore the role of PMS, a photocatalytic fuel cell with the structure of BiVO4 (photoanode)|10 mg/L BPA|proton exchange membrane (separator)|5 mM PMS|Pt (cathode) was constructed and demonstrated that PMS played a key role as electrons acceptor instead of the precursor of SO4â¢-. The PEC tests including open-circuit potential, linear sweep voltammetry and electrochemical impedance spectroscopy indicated that a more efficient separation of photogenerated charges was achieved in the PEC process with the help of PMS, thus generating more photogenerated holes for enhanced BPA degradation. This work may provide a novel way to enhance the separation of photogenerated charges at the photoanode.