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The presence and induced secondary reactions of natural organic matter (NOM) significantly affect the remediation efficacy of in situ chemical oxidation (ISCO) systems. However, it remains unclear how this process relates to organic radicals generated from reactions between the NOM and oxidants. The study, for the first time, reported the vital roles and transformation pathways of carbon-centered radicals (CCRâ¢) derived from NOM in activated persulfate (PS) systems. Results showed that both typical terrestrial/aquatic NOM isolates and collected NOM samples produced CCR⢠by scavenging activated PS and greatly enhanced the dehalogenation performance under anoxic conditions. Under oxic conditions, newly formed CCR⢠could be oxidized by O2 and generate organic peroxide intermediates (ROOâ¢) to catalytically yield additional â¢OH without the involvement of PS. Nuclear magnetic resonance (NMR) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) results indicated that CCR⢠predominantly formed from carboxyl and aliphatic structures instead of aromatics within NOM through hydrogen abstraction and decarboxylation reactions by SO4â¢- or â¢OH. Specific anoxic reactions (i.e., dehalogenation and intramolecular cross-coupling reactions) further promoted the transformation of CCR⢠to more unsaturated and polymerized/condensed compounds. In contrast, oxic propagation of ROO⢠enhanced bond breakage/ring cleavage and degradation of CCR⢠due to the presence of additional â¢OH and self-decomposition. This study provides novel insights into the role of NOM and O2 in ISCO and the development of engineered strategies for creating organic radicals capable of enhancing the remediation of specific contaminants and recovering organic carbon.
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Electrochemical advanced oxidation processes (EAOPs) have shown great promise for treating industrial wastewater contaminated with phenolic compounds. However, the presence of chloride in the wastewater leads to the production of undesirable chlorinated organic and inorganic byproducts, limiting the application of EAOPs. To address this challenge, we investigated the potential of incorporating Fe(II) and Fe(III) into the EAOPs with a boron-doped diamond (BDD) anode under near-neutral conditions. Our findings revealed that both Fe(II) and Fe(III) facilitated the generation of high-valent iron-oxo species (Fe(IV) and Fe(V)) in the anodic compartment, thereby reducing the oxidation contribution of reactive chlorine species. Remarkably, the addition of 1000 µM Fe(II) under high chloride conditions resulted in over a 2.8-fold increase in the oxidation rate of 50 µM phenolic contaminants at pH 6.5. Furthermore, 1000 µM Fe(II) contributed to a reduction of more than 66% in the formation of chlorinated byproducts, consequently enhancing the biodegradability of the treated water. Additionally, transitioning from batch mode to continuous flow mode further amplified the positive effects of Fe(II) on the EAOPs. Overall, this study presents a modified electrochemical approach that simultaneously enhanced the degradation of phenolic contaminants and improved the biodegradability of wastewater with high chloride concentrations.
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Cloretos , Técnicas Eletroquímicas , Ferro , Oxirredução , Fenóis , Águas Residuárias , Poluentes Químicos da Água , Águas Residuárias/química , Fenóis/química , Cloretos/química , Ferro/química , Poluentes Químicos da Água/química , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Eletrodos , Boro/químicaRESUMO
BACKGROUND: Thalamic abnormalities in schizophrenia are recognized, alongside cognitive deficits. However, the current findings about these abnormalities during the prodromal period remain relatively few and inconsistent. This study applied multimodal methods to explore the alterations in thalamic function and structure and their relationship with cognitive function in first-episode schizophrenia (FES) patients and ultra-high-risk (UHR) individuals, aiming to affirm the thalamus's role in schizophrenia development and cognitive deficits. METHODS: 75 FES patients, 60 UHR individuals, and 60 healthy controls (HC) were recruited. Among the three groups, gray matter volume (GMV) and functional connectivity (FC) were evaluated to reflect the structural and functional abnormalities in the thalamus. Pearson correlation was used to calculate the association between these abnormalities and cognitive impairments. RESULTS: No significant difference in GMV of the thalamus was found among the abovementioned three groups. Compared with HC individuals, FES patients had decreased thalamocortical FC mostly in the thalamocortical triple network, including the default mode network (DMN), salience network (SN), and executive control network (ECN). UHR individuals had similar but milder dysconnectivity as the FES group. Furthermore, FC between the left thalamus and right putamen was significantly correlated with execution speed and attention in the FES group. CONCLUSIONS: Our findings revealed decreased thalamocortical FC associated with cognitive deficits in FES and UHR subjects. This improves our understanding of the functional alterations in thalamus in prodromal stage of schizophrenia and the related factors of the cognitive impairment of the disease. TRIAL REGISTRATION: ClinicalTrials.govNCT03965598; https://clinicaltrials.gov/ct2/show/NCT03965598.
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Brain structural abnormality has been observed in the prodromal and early stages of schizophrenia, but the mechanism behind it is not clear. In this study, to explore the association between cortical abnormalities, metabolite levels, inflammation levels and clinical symptoms of schizophrenia, 51 drug-naive first-episode schizophrenia (FES) patients, 51 ultra-high risk for psychosis (UHR), and 51 healthy controls (HC) were recruited. We estimated gray matter volume (GMV), cortical thickness (CT), concentrations of different metabolites, and inflammatory marks among four groups (UHR converted to psychosis [UHR-C], UHR unconverted to psychosis [UHR-NC], FES, HC). UHR-C group had more CT in the right lateral occipital cortex and the right medial orbito-frontal cortex (rMOF), while a significant reduction in CT of the right fusiform cortex was observed in FES group. UHR-C group had significantly higher concentration of IL-6, while IL-17 could significantly predict CT of the right fusiform and IL-4 and IL-17 were significant predictors of CT in the rMOF. To conclude, it is reasonable to speculate that the increased CT in UHR-C group is related to the inflammatory response, and may participate in some compensatory mechanism, but might become exhaustive with the progress of the disease due to potential neurotoxic effects.
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Córtex Cerebral , Imageamento por Ressonância Magnética , Esquizofrenia , Humanos , Esquizofrenia/patologia , Esquizofrenia/diagnóstico por imagem , Masculino , Feminino , Adulto Jovem , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Adulto , Substância Cinzenta/patologia , Substância Cinzenta/diagnóstico por imagem , AdolescenteRESUMO
The electrochemical technology provides a practical and viable solution to the global water scarcity issue, but it has an inherent challenge of generating toxic halogenated byproducts in treatment of saline wastewater. Our study reveals an unexpected discovery: the presence of a trace amount of Br- not only enhanced the electrochemical oxidation of organic compounds with electron-rich groups but also significantly reduced the formation of halogenated byproducts. For example, in the presence of 20 µM Br-, the oxidation rate of phenol increased from 0.156 to 0.563 min-1, and the concentration of total organic halogen decreased from 59.2 to 8.6 µM. Through probe experiments, direct electron transfer and HO⢠were ruled out as major contributors; transient absorption spectroscopy (TAS) and computational kinetic models revealed that trace Br- triggers a shift in the dominant reactive species from Cl2â¢- to Br2â¢-, which plays a key role in pollutant removal. Both TAS and electron paramagnetic resonance identified signals unique to the phenoxyl and carbon-centered radicals in the Br2â¢--dominated system, indicating distinct reaction mechanisms compared to those involving Cl2â¢-. Kinetic isotope experiments and density functional theory calculations confirmed that the interaction between Br2â¢- and phenolic pollutants follows a hydrogen atom abstraction pathway, whereas Cl2â¢- predominantly engages pollutants through radical adduct formation. These insights significantly enhance our understanding of bromine radical-involved oxidation processes and have crucial implications for optimizing electrochemical treatment systems for saline wastewater.
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Águas Residuárias , Águas Residuárias/química , Poluentes Químicos da Água/química , Oxirredução , Halogenação , Técnicas Eletroquímicas , Cinética , Purificação da Água/métodosRESUMO
Background/Objectives: Dyslipidemia is a well-established risk factor for cardiovascular disease (CVD). However, among available drug treatments, only those targeted at lowering LDL-C and consequently TC have demonstrated efficacy in preventing CVD. This is to say that the benefit for those with isolated high TG or low HDL-C is limited. The objective of this study is to examine the overlapping pattern of the four dyslipidemia components in US adult populations, which is important for quantifying the proportion of those who are less likely to benefit from lipid-lowering drugs and for a more precise use of the drug. Methods: A total of 7822 participants aged over 20 with abnormalities in any of the four lipid parameters, excluding those on lipid-lowering medications, were included from the National Health and Nutrition Examination Survey (NHANES) cycles spanning 1999-2000 through 2017-2018. The proportions of different combinations of them were calculated and presented using area-proportional Euler plots. Results: High TC, high LDL-C, high TG, and low HDL-C were seen in 32.8% (95% CI: 31.3%-34.2%), 28.1% (95% CI: 26.6%-29.6%), 26.7% (95% CI: 25.4%-28.0%), and 65.9% (95% CI: 64.0%-67.7%) of the people with dyslipidemia, respectively. The proportions of dyslipidemia cases attributable to "high LDL-C or high TC" (irrespective of HDL-C and TG levels), "normal LDL-C, normal TC, but high TG" (irrespective of HDL-C level), and "normal LDL-C, normal TC, normal TG, but low HDL-C" (i.e., isolated low HDL-C) accounted for 37.5% (95% CI: 35.9%-39.1%), 18.3% (95% CI: 17.2%-19.4%), and 44.2% (95% CI: 42.5%-46.0%), respectively. Conclusions: Some two-thirds of those with dyslipidemia had low HDL-C or high TG but normal LDL-C and normal TC. As these people are less likely to benefit from currently available drug treatments in terms of CVD prevention, it is important to identify other effective strategies or interventions targeted at them in order to achieve more precise and cost-effective management of dyslipidemia.
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BACKGROUND: Obesity can cause structural changes and functional adjustments in growing children's feet. However, there is a lack of continuous observation of changes in feet in children with persistent obesity during important developmental periods. This makes it challenging to provide precise preventive measures. OBJECTIVE: This study aimed to investigate the effects of persistent obesity on gait patterns in children at an important stage in the formation of a robust foot arch. METHODS: The Footscan® plantar pressure system was used for 3 checks over two years. A total of 372 children aged 7-8 years participated in the study, and gait data from 33 children who maintained normal weight and 26 children with persistent obesity were finally selected. Repeated measures ANOVA or Friedman's test were used for longitudinal comparisons. Independent-Sample t-tests or the Mann-Whitney-Wilcoxon tests were used for cross-sectional comparisons. RESULTS: During the important period of development, children with persistent obesity did not exhibit a significant decrease in the arch index and had significantly higher values than the normal group in the third check. The persistently obese children showed increased load accumulation in the lateral rearfoot, first metatarsophalangeal joints, and the great toe regions. Children with persistent obesity had significantly greater medial-lateral displacements in the initial contact phase and forefoot contact phase than normal children in the first check. These differences diminished between the second and third checks. SIGNIFICANCE: Persistent obesity during an important period of foot development leads to slow or abnormal development of arch structure and affects foot loading patterns with heel inverted and forefoot everted. Additionally, the development of gait stability is not limited by persistent obesity.
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Pé , Marcha , Humanos , Criança , Masculino , Feminino , Estudos Longitudinais , Marcha/fisiologia , Pé/fisiopatologia , Pé/fisiologia , Fenômenos Biomecânicos , Obesidade Infantil/fisiopatologia , Estudos TransversaisRESUMO
WEE1 and CHEK1 (CHK1) kinases are critical regulators of the G2/M cell cycle checkpoint and DNA damage response pathways. The WEE1 inhibitor AZD1775 and the CHK1 inhibitor SRA737 are in clinical trials for various cancers, but have not been thoroughly examined in prostate cancer, particularly castration-resistant (CRPC) and neuroendocrine prostate cancers (NEPC). Our data demonstrated elevated WEE1 and CHK1 expressions in CRPC and NEPC cell lines and patient samples. AZD1775 resulted in rapid and potent cell killing with comparable IC50s across different prostate cancer cell lines, while SRA737 displayed time-dependent progressive cell killing with 10- to 20-fold differences in IC50s. Notably, their combination synergistically reduced the viability of all CRPC cell lines and tumor spheroids in a concentration- and time-dependent manner. Importantly, in a transgenic mouse model of NEPC, both agents alone or in combination suppressed tumor growth, improved overall survival, and reduced the incidence of distant metastases, with SRA737 exhibiting remarkable single agent anticancer activity. Mechanistically, SRA737 synergized with AZD1775 by blocking AZD1775-induced feedback activation of CHK1 in prostate cancer cells, resulting in increased mitotic entry and accumulation of DNA damage. In summary, this preclinical study shows that CHK1 inhibitor SRA737 alone and its combination with AZD1775 offer potential effective treatments for CRPC and NEPC.
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Proteínas de Ciclo Celular , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Camundongos , Animais , Proteínas de Ciclo Celular/genética , Proteínas Tirosina Quinases/genética , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Proteínas Nucleares/metabolismo , Pirimidinonas/farmacologia , Dano ao DNA , Linhagem Celular TumoralRESUMO
The bloodâbrain barrier (BBB) acts as a hindrance to drug therapy reaching the brain. With an increasing incidence of neurovascular diseases and brain cancer metastases, there is a need for an ideal in vitro model to develop novel methodologies for enhancing drug delivery to the brain. Here, we established a multicellular human brain spheroid model that mimics the BBB both architecturally and functionally. Within the spheroids, endothelial cells and pericytes localized to the periphery, while neurons, astrocytes, and microglia were distributed throughout. Ultrasound-targeted microbubble cavitation (UTMC) is a novel noninvasive technology for enhancing endothelial drug permeability. We utilized our three-dimensional (3D) model to study the feasibility and mechanisms regulating UTMC-induced hyperpermeability. UTMC caused a significant increase in the penetration of 10 kDa Texas red dextran (TRD) into the spheroids, 100 µm beyond the BBB, without compromising cell viability. This hyperpermeability was dependent on UTMC-induced calcium (Ca2+) influx and endothelial nitric oxide synthase (eNOS) activation. Our 3D brain spheroid model, with its intact and functional BBB, offers a valuable platform for studying the bioeffects of UTMC, including effects occurring spatially distant from the endothelial barrier.
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Barreira Hematoencefálica , Neoplasias Encefálicas , Humanos , Preparações Farmacêuticas , Células Endoteliais , Encéfalo , AstrócitosRESUMO
WEE1 and CHEK1 (CHK1) kinases are critical regulators of the G2/M cell cycle checkpoint and DNA damage response pathways. The WEE1 inhibitor AZD1775 and the CHK1 inhibitor SRA737 are in clinical trials for various cancers, but have not been examined in prostate cancer, particularly castration-resistant (CRPC) and neuroendocrine prostate cancers (NEPC). Our data demonstrated elevated WEE1 and CHK1 expressions in CRPC/NEPC cell lines and patient samples. AZD1775 resulted in rapid and potent cell killing with comparable IC50s across different prostate cancer cell lines, while SRA737 displayed time-dependent progressive cell killing with 10- to 20-fold differences in IC50s. Notably, their combination synergistically reduced the viability of all CRPC cell lines and tumor spheroids in a concentration- and time-dependent manner. Importantly, in a transgenic mouse model of NEPC, both agents alone or in combination suppressed tumor growth, improved overall survival, and reduced the incidence of distant metastases, with SRA737 exhibiting remarkable single agent anticancer activity. Mechanistically, SRA737 synergized with AZD1775 by blocking AZD1775-induced feedback activation of CHK1 in prostate cancer cells, resulting in increased mitotic entry and accumulation of DNA damage. In summary, this preclinical study shows that CHK1 inhibitor SRA737 alone and its combination with AZD1775 offer potential effective treatments for CRPC and NEPC.
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Mixed metal oxide (MMO) anodes are commonly used for electrochlorination of ammonium (NH4+) in wastewater treatment, but they suffer from low efficiency due to inadequate chlorine generation at low Cl- concentrations and sluggish reaction kinetics between free chlorine and NH4+ under acidic pH conditions. To address this challenge, we develop a straightforward wet chemistry approach to synthesize BiOCl-functionalized MMO electrodes using the MMO as an efficient Ohmic contact for electron transfer. Our study demonstrates that the BiOCl@MMO anode outperforms the pristine MMO anode, exhibiting higher free chlorine generation (24.6-60.0 mg Cl2 L-1), increased Faradaic efficiency (75.5 vs 31.0%), and improved rate constant of NH4+ oxidation (2.41 vs 0.76 mg L-1 min-1) at 50 mM Cl- concentration. Characterization techniques including electron paramagnetic resonance and in situ transient absorption spectra confirm the production of chlorine radicals (Cl⢠and Cl2â¢-) by the BiOCl/MMO anode. Laser flash photolysis reveals significantly higher apparent second-order rate constants ((4.3-4.9) × 106 M-1 s-1 at pH 2.0-4.0) for the reaction between NH4+ and Clâ¢, compared to the undetectable reaction between NH4+ and Cl2â¢-, as well as the slower reaction between NH4+ and free chlorine (102 M-1 s-1 at pH < 4.0) within the same pH range, emphasizing the significance of Cl⢠in enhancing NH4+ oxidation. Mechanistic studies provide compelling evidence of the capacity of BiOCl for Cl- adsorption, facilitating chlorine evolution and Cl⢠generation. Importantly, the BiOCl@MMO anode exhibits excellent long-term stability and high catalytic activity for NH4+-N removal in a real landfill leachate. These findings offer valuable insights into the rational design of electrodes to improve electrocatalytic NH4+ abatement, which holds great promise for wastewater treatment applications.
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Compostos de Amônio , Poluentes Químicos da Água , Águas Residuárias , Cloro , Oxirredução , Óxidos/química , Eletrodos , Poluentes Químicos da Água/análise , CloretosRESUMO
Schizophrenia has been associated with abnormal intrinsic brain activity, involving various cognitive impairments. Qualitatively similar abnormalities are seen in individuals at ultra-high risk (UHR) for psychosis. In this study, resting-state fMRI (rs-fMRI) data were collected from 44 drug-naïve first-episode schizophrenia (Dn-FES) patients, 48 UHR individuals, and 40 healthy controls (HCs). The fractional amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo), and functional connectivity (FC), were performed to evaluate resting brain function. A support vector machine (SVM) was applied for classification analysis. Compared to HCs, both clinical groups showed increased fALFF in the central executive network (CEN), decreased ReHo in the ventral visual pathway (VVP) and decreased FC in temporal-sensorimotor regions. Excellent performance was achieved by using fALFF value in distinguishing both FES (sensitivity=83.21%, specificity=80.58%, accuracy=81.37%, p=0.009) and UHR (sensitivity=75.88%, specificity=85.72%, accuracy=80.72%, p<0.001) from HC group. Moreover, the study highlighted the importance of frontal and temporal alteration in the pathogenesis of schizophrenia. However, no fMRI features were observed that could well distinguish Dn-FES from UHR group. To conclude, fALFF in the CEN may provide potential power for identifying individuals at the early stage of schizophrenia and the alteration in the frontal and temporal lobe may be important to these individuals.
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Transtornos Psicóticos , Esquizofrenia , Humanos , Encéfalo , Mapeamento Encefálico , Lobo Temporal , Imageamento por Ressonância MagnéticaRESUMO
The total synthesis of four novel mono-methoxy and hydroxyl substituted ring-A dihydronarciclasine derivatives enabled identification of the 7-hydroxyl derivative as a potent and selective antiviral agent targeting SARSCoV-2 and HSV-1. The concentration of this small molecule that inhibited HSV-1 infection by 50% (IC50), determined by using induced pluripotent stem cells (iPCS)-derived brain organ organoids generated from two iPCS lines, was estimated to be 0.504 µM and 0.209 µM. No significant reduction in organoid viability was observed at concentrations up to 50 mM. Genomic expression analyses revealed a significant effect on host-cell innate immunity, revealing activation of the integrated stress response via PERK kinase upregulation, phosphorylation of eukaryotic initiation factor 2α (eIF2α) and type I IFN, as factors potentiating multiple host-defense mechanisms against viral infection. Following infection of mouse eyes with HSV-1, treatment with the compound dramatically reduced HSV-1 shedding in vivo.
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Alcaloides de Amaryllidaceae , Antineoplásicos , Herpesvirus Humano 1 , Interferon Tipo I , Camundongos , Animais , Antivirais/farmacologia , Alcaloides de Amaryllidaceae/farmacologia , FosforilaçãoRESUMO
BACKGROUND: Herpesviruses alter cognitive functions in humans following acute infections; progressive cognitive decline and dementia have also been suggested. It is important to understand the pathogenic mechanisms of such infections. The complement system - comprising functionally related proteins integral for systemic innate and adaptive immunity - is an important component of host responses. The complement system has specialized functions in the brain. Still, the dynamics of the brain complement system are still poorly understood. Many complement proteins have limited access to the brain from plasma, necessitating synthesis and specific regulation of expression in the brain; thus, complement protein synthesis, activation, regulation, and signaling should be investigated in human brain-relevant cellular models. Cells derived from human-induced pluripotent stem cells (hiPSCs) could enable tractable models. METHODS: Human-induced pluripotent stem cells were differentiated into neuronal (hi-N) and microglial (hi-M) cells that were cultured with primary culture human astrocyte-like cells (ha-D). Gene expression analyses and complement protein levels were analyzed in mono- and co-cultures. RESULTS: Transcript levels of complement proteins differ by cell type and co-culture conditions, with evidence for cellular crosstalk in co-cultures. Hi-N and hi-M cells have distinct patterns of expression of complement receptors, soluble factors, and regulatory proteins. hi-N cells produce complement factor 4 (C4) and factor B (FB), whereas hi-M cells produce complement factor 2 (C2) and complement factor 3 (C3). Thus, neither hi-N nor hi-M cells can form either of the C3-convertases - C4bC2a and C3bBb. However, when hi-N and hi-M cells are combined in co-cultures, both types of functional C3 convertase are produced, indicated by elevated levels of the cleaved C3 protein, C3a. CONCLUSIONS: hiPSC-derived co-culture models can be used to study viral infection in the brain, particularly complement receptor and function in relation to cellular "crosstalk." The models could be refined to further investigate pathogenic mechanisms.
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Infecções por Herpesviridae , Células-Tronco Pluripotentes Induzidas , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Complemento C3/metabolismo , Neurônios/metabolismo , Convertases de Complemento C3-C5/metabolismo , Encéfalo/metabolismo , Infecções por Herpesviridae/metabolismoRESUMO
Electrochemical oxidation has been demonstrated to be a useful method for removing biorefractory organic pollutants in mature landfill leachate but suffers from low efficiency in eliminating ammonium because of its resistance to being oxidized by HO⢠or free chlorine (FC) at decreased pH. Here, we propose a new bipolar membrane-electrochlorination (BPM-EC) process to address this issue. We found that the BPM-EC system was significantly superior to both the undivided and divided reactors with monopolar membranes in terms of elevated rate of ammonium removal, attenuated generation of byproducts (e.g., nitrate and chloramines), increased Faradaic efficiency, and decreased energy consumption. Mechanistic studies revealed that the integration of BPM was helpful in creating alkaline environments in the vicinity of the anode, which facilitated production of surface-bound HO⢠and FC and eventually promoted in situ generation of ClOâ¢, a crucial reactive species mainly responsible for accelerating ammonium oxidation and selective transformation to nitrogen. The efficacy of BPM-EC in treating landfill leachates with different ammonium concentrations was verified under batch and continuous-flow conditions. A kinetic model that incorporates the key parameters was developed, which can successfully predict the optimal number of BPM-EC reactors (e.g., 2 and 5 for leachates containing 589.4 ± 5.5 and 1258.1 ± 9.6 mg L-1 NH4+-N, respectively) necessary for complete removal of ammonium. These findings reveal that the BPM-EC process shows promise in treating ammonium-containing wastewater, with advantages that include effectiveness, adaptability, and flexibility.
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Compostos de Amônio , Poluentes Químicos da Água , Águas Residuárias , Compostos Orgânicos , Nitratos , Oxirredução , NitrogênioRESUMO
The generation of chlorinated byproducts during the electrochemical oxidation (EO) of Cl--laden wastewater is a significant concern. We aim to propose a concept of converting reactive species (e.g., reactive chlorines and HO⢠resulting from electrolysis) into 1O2 via the addition of H2O2, which substantially alleviates chlorinated organic formation. When phenol was used as a model organic compound, the results showed that the H2O2-involving EO system outperformed the H2O2-absent system in terms of higher rate constants (5.95 × 10-2 min-1vs. 2.97 × 10-2 min-1) and a much lower accumulation of total organic chlorinated products (1.42 mg L-1vs. 8.18 mg L-1) during a 60 min operation. The rate constants of disappearance of a variety of phenolic compounds were positively correlated with the Hammett constants (σ), suggesting that the reactive species preferred oxidizing phenols with electron-rich groups. After the identification of 1O2 that was abundant in the bulk solution with the use of electron paramagnetic resonance and computational kinetic simulation, the routes of 1O2 generation were revealed. Despite the consensus as to the contribution of reaction between H2O2 and ClO- to 1O2 formation, we conclude that the predominant pathway is through H2O2 reaction with electrogenerated HO⢠or chlorine radicals (Cl⢠and Cl2â¢-) to produce O2â¢-, followed by self-combination. Density functional theory calculations theoretically showed the difficulty in forming chlorinated byproducts for the 1O2-initiated phenol oxidation in the presence of Cl-, which, by contrast, easily occurred for the Clâ¢-or HOâ¢-initiated phenol reaction. The experiments run with real coking wastewater containing high-concentration phenols further demonstrated the superiority of the H2O2-involving EO system. The findings imply that this unique method for treating Cl--laden organic wastewater is expected to be widely adopted for generalizing EO technology for environmental applications.
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Poluentes Químicos da Água , Purificação da Água , Águas Residuárias/química , Cloro/química , Purificação da Água/métodos , Fenol/química , Peróxido de Hidrogênio/química , Fenóis , Halogênios/química , Oxirredução , Cloretos , Poluentes Químicos da Água/química , Raios UltravioletaRESUMO
Archaea are considered an essential group of gut microorganisms in both humans and animals. However, they have been neglected in previous studies, especially those involving non-ruminants. In this study, we re-analyzed published metagenomic and metatranscriptomic data sequenced from matched samples to explore the composition and the expression activity of gut archaea in ruminants (cattle and sheep) and monogastric animals (pig and chicken). Our results showed that the alpha and beta diversity of each host species, especially cattle and chickens, calculated from metagenomic and metatranscriptomic data were significantly different, suggesting that metatranscriptomic data better represent the functional status of archaea. We detected that the relative abundance of 17 (cattle), 7 (sheep), 20 (pig), and 2 (chicken) archaeal species were identified in the top 100 archaeal taxa when analyzing the metagenomic datasets, and these species were classified as the "active archaeal species" for each host species by comparison with corresponding metatranscriptomic data. For example, The expressive abundance in metatranscriptomic dataset of Methanosphaera cuniculi and Methanosphaera stadtmanae were 30- and 27-fold higher than that in metagenomic abundance, indicating their potentially important function in the pig gut. Here we aim to show the potential importance of archaea in the livestock digestive tract and encourage future research in this area, especially on the gut archaea of monogastric animals.
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The corrosion of Fe(0) in the presence of O2 in nature can lead to the oxidation of organic compounds, but the efficiency is very limited. Herein, attempts were made to establish a galvanic system that separates the anodic Fe(0) oxidation reaction and the cathodic O2 reduction reaction using an air-breathing cathode. Compared with the chemical Fe(0)/O2 system, it exhibited a substantially higher capability of destroying a variety of pollutants, such as organic dyes (12 types), phenol, nitrobenzene, acetaminophen, phenol, and ethylenediaminetetraacetic acid. The degradation rate constant of a model dye (i.e., Rhodamine B) increased from 0.047 min-1 (chemical) to 1.412 min-1 (galvanic) under the passive air-breathing condition. The electric circuit design promoted Fe(0) dissolution to Fe(II) and triggered electron transfer that drives O2 reduction to H2O2, two important species responsible for the generation of HO⢠at high abundance. In addition, the galvanic Fe(0)/O2 system produces electricity while destroying pollutants. Tests with real Ni plating wastewater further demonstrated the capability of the system to oxidize complexed organics and phosphite. This study provides a new strategy for boosting the oxidative capacity of the Fe(0)/O2 system, which shows promise for acid wastewater treatment.
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Poluentes Ambientais , Poluentes Químicos da Água , Eletrodos , Peróxido de Hidrogênio/química , Ferro/química , Oxirredução , Estresse Oxidativo , Fenóis , Poluentes Químicos da Água/químicaRESUMO
The formation of chlorinated byproducts represents a significant threat to the quality of the effluent treated using electrochemical advanced oxidation processes (EAOPs), thus spurring investigation into alleviating their production. This study presents a new strategy to minimize the release of chlorinated intermediates during the electrochemical oxidation of Ni-EDTA by establishing a dual mixed metal oxide (MMO)/Fe anode system. The results indicate that the dual-anode system achieved a substantially higher rate (0.141 min-1) of Ni-EDTA destruction and accordingly allowed a more pronounced removal of aqueous Ni (from 39.85 to 0.63 mg L-1) after alkaline precipitation, compared with its single MMO anode (0.017 min-1 of Ni-EDTA removal, with 14.38 mg L-1 Ni remaining) and single Fe anode (insignificant Ni-EDTA removal, with 38.37 mg L-1 Ni remaining) counterparts. Compared to reactive chlorine species (RCS) produced from the single MMO anode system, Fe(IV) was in situ generated from the dual-anode system and was predominantly responsible for the attenuation of chlorinated byproducts and thus the decrease in the acute toxicity of the treated solution (evaluated using luminescent bacteria). The Fe(IV)-dominated dual-anode system also exhibited superior performance in removing multiple pollutants (including organic ligands, Ni, and phosphite) in the real electroless plating effluent. The findings suggest that the strategy for Fe(II) transition to Fe(IV) by active chlorine paves a new avenue for yielding less chlorinated products with lower toxicity when EAOPs are used to treat chloride-containing organic wastewater.
Assuntos
Cloro , Poluentes Químicos da Água , Cloretos , Cloro/análise , Ácido Edético , Eletrodos , Compostos Ferrosos , Halogênios , Oxirredução , Águas Residuárias , Poluentes Químicos da Água/análiseRESUMO
Encephalitis, the most significant of the central nervous system (CNS) diseases caused by Herpes simplex virus 1 (HSV-1), may have long-term sequelae in survivors treated with acyclovir, the cause of which is unclear. HSV-1 exhibits a tropism toward neurogenic niches in CNS enriched with neural precursor cells (NPCs), which play a pivotal role in neurogenesis. NPCs are susceptible to HSV-1. There is a paucity of information regarding the influence of HSV-1 on neurogenesis in humans. We investigated HSV-1 infection of NPCs from two individuals. Our results show (i) HSV-1 impairs, to different extents, the proliferation, self-renewing, and, to an even greater extent, migration of NPCs from these two subjects; (ii) The protective effect of the gold-standard antiherpetic drug acyclovir (ACV) varies with viral dose and is incomplete. It is also subject to differences in terms of efficacy of the NPCs derived from these two individuals. These results suggest that the effects of HSV-1 may have on aspects of NPC neurogenesis may vary among individuals, even in the presence of acyclovir, and this may contribute to the heterogeneity of cognitive sequelae across encephalitis survivors. Further analysis of NPC cell lines from a larger number of individuals is warranted.