RESUMEN
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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Aguas Residuales , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Oxidación-Reducción , Halogenación , Técnicas Electroquímicas , Cinética , Purificación del Agua/métodosRESUMEN
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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Carbono , Carbono/química , Oxidación-Reducción , Sulfatos/químicaRESUMEN
Coprecipitation of Fe/Cr hydroxides with natural organic matter (NOM) is an important pathway for Cr immobilization. However, the role of NOM in coprecipitation is still controversial due to its molecular heterogeneity and diversity. This study focused on the molecular selectivity of NOM toward Fe/Cr coprecipitates to uncover the fate of Cr via Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS). The results showed that the significant effects of Suwannee River NOM (SRNOM) on Cr immobilization and stability of the Fe/Cr coprecipitates did not merely depend on the adsorption of SRNOM on Fe/Cr hydroxides. FT-ICR-MS spectra suggested that two pathways of molecular selectivity of SRNOM in the coprecipitation affected Cr immobilization. Polycyclic aromatics and polyphenolic compounds in SRNOM preferentially adsorbed on the Fe/Cr hydroxide nanoparticles, which provided extra binding sites and promoted the aggregation. Notably, some specific compounds (i.e., polyphenolic compounds and highly unsaturated phenolic compounds), less unsaturated and more oxygenated than those adsorbed on Fe/Cr hydroxide nanoparticles, were preferentially incorporated into the insoluble Cr-organic complexes in the coprecipitates. Kendrick mass defect analysis revealed that the insoluble Cr-organic complexes contained fewer carbonylated homologous compounds. More importantly, the spatial distribution of insoluble Cr-organic complexes was strongly related to Cr immobilization and stability of the Fe/Cr-NOM coprecipitates. The molecular information of the Fe/Cr-NOM coprecipitates would be beneficial for a better understanding of the transport and fate of Cr and exploration of the related remediation strategy.
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Nanopartículas , Fenoles , Espectrometría de Masas , Nanopartículas/química , AdsorciónRESUMEN
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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Compuestos de Amonio , Contaminantes Químicos del Agua , Aguas Residuales , Cloro , Oxidación-Reducción , Óxidos/química , Electrodos , Contaminantes Químicos del Agua/análisis , ClorurosRESUMEN
Amoebae are protists that are commonly found in water, soil, and other habitats around the world and have complex interactions with other microorganisms. In this work, we investigated how host-endosymbiont interactions between amoebae and bacteria impacted the retention behavior of amoeba spores in porous media. A model amoeba species, Dictyostelium discoideum, and a representative bacterium, Burkholderia agricolaris B1qs70, were used to prepare amoeba spores that carried bacteria. After interacting with B. agricolaris, the retention of D. discoideum spores was enhanced compared to noninfected spores. Diverse proteins, especially proteins contributing to the looser exosporium structure and cell adhesion functionality, are secreted in higher quantities on the exosporium surface of infected spores compared to that of noninfected ones. Comprehensive examinations using a quartz crystal microbalance with dissipation (QCM-D), a parallel plate chamber, and a single-cell force microscope present coherent evidence that changes in the exosporium of D. discoideum spores due to infection by B. agricolaris enhance the connections between spores in the suspension and the spores that were previously deposited on the collector surface, thus resulting in more retention compared to the uninfected ones in porous media. This work provides novel insight into the retention of amoeba spores after bacterial infection in porous media and suggests that the host-endosymbiont relationship regulates the fate of biocolloids in drinking water systems, groundwater, and other porous environments.
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Amoeba , Dictyostelium , Amoeba/microbiología , Dictyostelium/metabolismo , Dictyostelium/microbiología , Porosidad , Esporas Bacterianas , SimbiosisRESUMEN
Young children with liver cirrhosis have a significantly high risk of mortality. However, there are few studies regarding early childhood-onset cirrhosis. This study aims to explore the causes, clinical findings and prognosis of biopsy-proven cirrhosis in infants, toddlers and preschoolers. We enroled young children with biopsy-proven cirrhosis from January 2010. Till January 2020, the study has been going on for 10 years. A total of 139 cirrhotic children were enrolled, including 87 boys and 52 girls. The median age at initially histological diagnosis of cirrhosis was 2 years old (range: 1 month-6 years). Sixty-two patients reported yellowish discoloration of sclera and/or skin as an initial symptom. Ninety-three patients had definite aetiologies while 46 had indeterminate causes. Among the confirmed cases, 31 had hepatitis B virus (HBV) infection, accounting for 33.3%. Subsequently, glycogen storage disease was diagnosed in 16 cases and Wilson disease in 14 cases. In these patients with HBV infection, nine finally achieved hepatitis B surface antigen (HBsAg) loss (29.0%) after effective antiviral therapy during the follow-up. Logistic regression revealed that baseline alanine aminotransferase (odds ratio 1.008, p = 0.028) was the independent predictor of HBsAg loss. Furthermore, one patient who underwent second biopsies showed histological reverse. HBV infection is an important cause of paediatric cirrhosis in our study. The pathogenesis of HBV-related cirrhosis in early childhood deserves further studies.
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Hepatitis B Crónica , Biopsia , Niño , Preescolar , Estudios de Cohortes , ADN Viral , Femenino , Antígenos de Superficie de la Hepatitis B , Virus de la Hepatitis B/genética , Humanos , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/epidemiología , MasculinoRESUMEN
The long-term benefits of interferon-α (IFN-α) treatment in children with chronic hepatitis B (CHB) remain unclear. We conducted a retrospective and real-world study to evaluate the safety and long-term clearance rates of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) in CHB children who received IFN-α monotherapy for 72 weeks and were with 13-year follow-up visit. Participants treated with IFN-α (n = 316) were more likely to become HBeAg negatve (39.87% vs. 27.37%; p < .05) and HBsAg negative (11.08% vs. 3.16%; p < .05) by the end of the treatment period than untreated participants (n = 95). Treated participants also had higher cumulative rates of HBeAg loss (74.13% vs. 59.27%; p < .05) and HBsAg loss (46.95 vs. 33.11%; p < 0.05) than untreated participants in parallel by the end of 13-year follow-up. In particular, the cumulative rate of HBsAg loss was higher in treated children aged 1-7 years than in those aged 8-17 years (71.40% vs. 39.0%; p < .01). Children who were HBeAg-negative at the end of IFN-α treatment or who had serum alanine aminotransferase levels of ≥80 IU/L at baseline were likely to have higher cumulative HBsAg loss rates. Accordingly, HBeAg loss at 72 weeks was positively associated with the cumulative HBsAg loss rate in untreated children. There were no serious adverse events of IFN-α therapy for the treated patients throughout the study period. Overall, IFN-α therapy was effective in obtaining higher long-term cumulative rates of HBeAg and HBsAg loss in children with HBeAg-positive immune-active CHB, especially among those aged 1-7 years.
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Antígenos e de la Hepatitis B , Hepatitis B Crónica , Antivirales/efectos adversos , Niño , ADN Viral , Antígenos de Superficie de la Hepatitis B , Hepatitis B Crónica/tratamiento farmacológico , Humanos , Interferón-alfa/efectos adversos , Polietilenglicoles/uso terapéutico , Proteínas Recombinantes/uso terapéutico , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: Diagnosis of rare diseases possesses a great challenge in pediatric hepatology because expert knowledge in the field is extremely insufficient. The study aims to explore new findings and collect diagnostic experience from pediatric rare liver diseases. METHODS: The large-sample case analysis study included pediatric patients who had liver-involved rare diseases. All cases underwent liver biopsy and/or gene sequencing. RESULTS: A total of 1158 pediatric patients were identified. Liver-based genetic diseases were most frequent (737 cases), followed by liver damages involved in extrahepatic or systemic disorders (151 cases) and cryptogenic hepatobilliary abnormalities (123 cases). Of note, diagnoses of 16 patients were re-evaluated according to genetic results combined with clinical pointers. In addition, 101 patients who underwent gene sequencing remained undiagnosed. Of them, 55 had negative genetic findings, 30 harbored mutations that failed to meet their typically pathogenic condition, and 16 had detected variants that were inconsistent with clinical pointers. CONCLUSIONS: As a study involving known largest number of children with rare hepatobiliary disorders, it allows us to accumulate information (especially new findings) on the etiology and diagnosis of these disorders. The results can help to improve the diagnostic quality in the population. IMPACT: Liver-based genetic diseases were most frequent in clinical profiles of pediatric rare liver diseases. Some novel variants in cases with genetic diseases (for example, two variants of c.3638G>T and c.1435G>C in a patient with progressive familial intrahepatic cholestasis type 2) were identified. As a study involving known largest number of pediatric cases with rare hepatobiliary disorders, it allows us to accumulate information on the etiology and diagnosis of these disorders. The study can help to optimize the diagnostic process and significantly improve the diagnostic quality in the field of pediatric hepatology. Given that clinical variability often exists within rare genetic disease entities and not all rare disorders are genetic, clinicians should not over-depend on the genetic results in the diagnosis.
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Enfermedades del Sistema Digestivo/diagnóstico , Secuenciación del Exoma , Hígado/patología , Enfermedades Raras/diagnóstico , Adolescente , Biopsia , Niño , Preescolar , Enfermedades del Sistema Digestivo/genética , Enfermedades del Sistema Digestivo/patología , Enfermedades del Sistema Digestivo/terapia , Femenino , Predisposición Genética a la Enfermedad , Humanos , Lactante , Masculino , Fenotipo , Valor Predictivo de las Pruebas , Pronóstico , Enfermedades Raras/genética , Enfermedades Raras/patología , Enfermedades Raras/terapia , Reproducibilidad de los Resultados , Estudios RetrospectivosRESUMEN
A nonradical mechanism involved in peroxymonosulfate (PMS) activation in carbonaceous materials (CMs) is still controversial. In this study, we prepared N-doped CMs, including hollow carbon spheres (NHCSs) and carbon nanotubes (N-CNTs), to probe the crucial intermediates during PMS activation. The results suggested that the higher efficiency and lower activation energy (13.72 kJ mol-1) toward phenol (PN) degradation in an NHCS/PMS system than PMS alone (â¼24.07 kJ mol-1) depended on a typical nonradical reaction. Persistent free radicals (PFRs) with a g factor of 2.0033-2.0045, formed as crucial metastable intermediates on NHCS or N-CNT in the presence of PMS, contribute largely to the organic degradation (â¼73.4%). Solid evidence suggested that the formation of PFRs relied on the attack of surface-bonded â¢OH and SO4â¢- or peroxides in PMS, among which surface-bonded SO4â¢- was most thermodynamically favorable based on theoretical calculations. Electron holes within PFRs on NHCSs shifted the Fermi level to the positive energy with the valance band increasing from 1.18 to 1.98 eV, promoting the reactivity toward nucleophilic substances. The degradation intermediates of aromatic compounds (e.g., PN) and electron rearrangement triggered the evolution of PFRs from oxygen-centered to carbon-centered radicals. Moreover, due to the specific electron configuration, graphitic N on NHCS was critical for stabilizing the PFRs. This study provides insightful understanding of the fate of organic contaminants and the structure-activity relationship of reactivity of CMs toward PMS activation.
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Nanotubos de Carbono , Radicales Libres , Compuestos Orgánicos , PeróxidosRESUMEN
Persulfate (PS) activation on biochar (BC) is a promising technology for degrading the aqueous organic contaminants. However, the complexity of activation mechanisms and components in biomass that used to produce BC makes it difficult to predict the performance of PS activation. In this study, we employed eight sludges as the representative biomass that contained absolutely different organic or inorganic components. Results showed that the elemental composition, surface properties, and structures of the sludge-derived BCs (SBCs) clearly depended on the inherent components in the sludges. The intensities of persistent free radicals (PFRs) in the electron paramagnetic resonance (EPR) correlated positively with N-containing content of sludges as electron shuttle, but negatively with the metal content as electron acceptor. Linking with PFRs as crucial sites of triggering a radical reaction, a poly-parameter relationship of predicting PS activation for organic degradation using the sludge components was established (kobs,PN = 0.004 × Cprotein + 0.16 × CM-0.895 -0.118). However, for the PS activation on those SBCs without PFRs, this redox process only relied on the sorption or conductivity-related characteristics, not correlating with the content of intrinsic components in biomass but with pyrolysis temperatures. This study provided insightful information of predicting the remediation efficiency of PS activation on BCs and further understanding the fate of contaminants and stoichiometric efficiency of oxidants in a field application.
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Carbón Orgánico , Instinto , Biomasa , Radicales Libres , Oxidación-Reducción , Aguas del AlcantarilladoRESUMEN
Ubiquitous oxygen vacancies (Vo) existing in metallic compounds can activate peroxymonosulfate (PMS) for water treatment. However, under environmental conditions, especially oxygenated surroundings, the interactions between Vo and PMS as well as the organics degradation mechanism are still ambiguous. In this study, we provide a novel insight into the PMS activation mechanism over Vo-containing Fe-Co layered double hydroxide (LDH). Experimental results show that Vo/PMS is capable of selective degradation of organics via a single-electron-transfer nonradical pathway. Moreover, O2 is firstly demonstrated as the most critical trigger in this system. Mechanistic studies reveal that, with abundant electrons confined in the vacant electron orbitals of Vo, O2 is thermodynamically enabled to capture electrons from Vo to form O2â¢- under the imprinting effect and start the activation process. Simultaneously, Vo becomes electron-deficient and withdraws the electrons from organics to sustain the electrostatic balance and achieve organics degradation (32% for Bisphenol A without PMS). Different from conventional PMS activation, under the collaboration of kinetics and thermodynamics, PMS is endowed with the ability to donate electrons to Vo as a reductant other than an oxidant to form 1O2. In this case, 1O2 and O2â¢- act as the indispensable intermediate species to accelerate the circulation of O2 (as high as 14.3 mg/L) in the micro area around Vo, and promote this nano-confinement electron-recycling process with 67% improvement of Bisphenol A degradation. This study provides a brand-new perspective for the nonradical mechanism of PMS activation over Vo-containing metallic compounds in natural environments.
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Oxígeno , Peróxidos , Electrones , HidróxidosRESUMEN
Amoebas are protists that are widespread in water and soil environments. Some species are pathogenic, inducing potentially lethal effects on humans, making them a major threat to public health. Nonpathogenic amoebas are also of concern because they have the potential to carry a mini-microbiome of bacteria, either transiently or via more long-term stable transport. Due to their resistance to disinfection processes, the physical removal of amoeba by filtration is necessary to prevent their propagation throughout drinking water distribution networks and occurrence in tap water. In this study, a model amoeba species Dictyostelium discoideum was used to study the transport and retention behavior of amoeba spores in porous media. The key factors affecting the transport behavior of amoeba spores in fully saturated media were comprehensively evaluated, with experiments performed using a quartz crystal microbalance with dissipation monitoring (QCM-D) and parallel plate chamber system. The effects of ionic strength (IS) on the deposition of spores were found to be in contrast to the predicted Derjaguin-Landau-Verwey-Overbeek (DLVO) theory that more deposition is observed under lower-IS conditions. The presence of extracellular polymeric substances (EPS) was found to be the main contributor to deposition behavior. Overall, these results provide plausible evidence for the presence of amoeba in tap water. Furthermore, this is one of the first studies to examine the mechanisms affecting the fate of amoeba spores in porous media, providing a significant baseline for future research to minimize the safety risk presented by amoeba in drinking water systems.
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Amoeba , Dictyostelium , Matriz Extracelular de Sustancias Poliméricas , Humanos , Porosidad , Esporas ProtozoariasRESUMEN
To date, studies that focus on treatment of e antigen-negative chronic hepatitis B virus-infected children with advanced fibrosis are extremely limited. This puts these patients at risk of rapid disease progression. Our study aimed to investigate the efficacy of combination antiviral therapy in this population. We prospectively enrolled treatment-naiÌve paediatric patients between 1 year and 12 years of age who had e antigen-negative chronic hepatitis B and histologically proven advanced fibrosis. All patients received de novo combination therapy with lamivudine (LAM) and interferon-α (IFN) for 12 months and then were clinically followed up. The main outcome measure was rate of serum hepatitis B surface antigen (HBsAg) loss at month 12 of treatment. A total of 14 paediatric patients were enrolled, including 9 boys and 5 girls. All patients achieved undetectable HBV DNA levels at month 9 of treatment. A total of 5 patients (35.7%) achieved HBsAg loss at month 12 and finally developed HBsAg seroconversion. Four patients who did not clear HBsAg underwent second liver biopsy, and histological evaluation revealed significant improvements in all of them. As a serum fibrosis marker, aspartate aminotransferase-to-platelet ratio index after 12-month treatment in the 14 patients showed a significant improvement compared with that at baseline (P = .0021). No serious adverse events were observed during the study. Combination antiviral therapy is beneficial to e antigen-negative chronic hepatitis B virus-infected paediatric patients with advanced fibrosis. Further studies with larger cohorts are required.
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Antígenos e de la Hepatitis B , Hepatitis B Crónica , Antivirales/uso terapéutico , Niño , ADN Viral , Femenino , Fibrosis , Antígenos de Superficie de la Hepatitis B , Virus de la Hepatitis B/genética , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/tratamiento farmacológico , Humanos , Recién Nacido , Interferón-alfa/uso terapéutico , Lamivudine/uso terapéutico , Masculino , Resultado del TratamientoRESUMEN
Redox processes mediated by biochar(BC) enhanced the transformation of Cr(VI), which is largely dependent on the presence of PFRs as electron donors. Natural or artificial dopants in BC's could regulate inherent carbon configuration and PFRs. Until recently, the modulation of PFRs and transformation of Cr(VI) in BC by nonmetal-heterocyclic dopants was barely studied. In this study, changes in PFRs introduced by various nitrogen-dopants within BC are presented and the capacity for Cr(VI) transformation without light was investigated. It was found N-dopants were effectively embedded in carbon lattices through activated-Maillard reaction thus altering their charge and PFRs. Transformation of Cr(VI) in N doped biochar relied on mediated direct reduction by surface modulatory PFRs. The kinetic rate of transformation of Cr(VI) was increased 1.4-5 fold in N-BCs compared to nondoped BCs. Theortical calculation suggested a deficiency in surface electrons induced Lewis acid-base bonding which could acted as a bridge for electron transfer. Results of PCA and orbital energy indicated a colinear relationship between PFRs and pyrrolic N, as well as its dual-mode transformation of Cr(VI). This study provides an improved understanding of how N-doped BC contributes to the evolution of PFRs and their corresponding impacts on the transformation of Cr(VI) in environments.
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Carbón Orgánico , Nitrógeno , Adsorción , Cromo , Radicales LibresRESUMEN
BACKGROUND & AIM: There is a paucity of data regarding antiviral therapy in hepatitis B virus (HBV)-infected infants aged <1â¯year who have elevated alanine aminotransferase. This study aims to assess the efficacy and safety of antiviral therapy initiated in infancy. METHODS: A real-world cohort study was conducted from January 2010 to December 2017. HBV-infected infants under 1â¯year of age, with persistent elevation of alanine aminotransferase and high viral load, were recruited and divided into 2 groups. Group I included 18 infants whose parents chose to initiate antiviral therapy with lamivudine before 1â¯year of age. Group II included 11 infants whose parents chose to initiate antiviral therapy with interferon-α after 1â¯year of age and not to receive any antiviral therapies before 1â¯year of age. The main outcome measure was rate of serum HBV surface antigen (HBsAg) loss at month 12 of treatment. RESULTS: There were no statistical differences between Groups I and II regarding baseline characteristics. No infants in Group II developed spontaneous HBsAg loss before 1â¯year of age. In Group I, the cumulative rates of HBsAg loss at month 3, 6, 9 and 12 of treatment were 39%, 67%, 78% and 83%, respectively. In Group II, the cumulative rates of HBsAg loss at month 3, 6, 9 and 12 of treatment were 18%, 27%, 27% and 36%, respectively. Statistical differences existed in the cumulative rates of HBsAg loss between the 2 groups (log-rank test, pâ¯=â¯0.0023). No serious adverse events occurred in the study. CONCLUSION: Early initiation of antiviral therapy for infantile-onset hepatitis B contributes to a rapid and significant loss of HBsAg. Further trials with larger cohorts are needed to verify our results. LAY SUMMARY: Chronicity is a serious threat to infants infected with hepatitis B. However, no treatment measure has been recommended for infantile-onset hepatitis B in current guidelines. In order to evaluate the benefit and safety of antiviral therapy in infantile-onset hepatitis B, a real-world cohort study was conducted. Long-term follow-up results showed that early initiation of antiviral therapy with lamivudine safely led to a rapid and significant loss of serum hepatitis B surface antigen in the present subset of infants with alanine aminotransferase ≥2× upper limit of normal. Further trials with larger cohorts are needed.
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Antivirales/administración & dosificación , Antígenos de Superficie de la Hepatitis B/sangre , Virus de la Hepatitis B/genética , Hepatitis B/tratamiento farmacológico , Interferón-alfa/administración & dosificación , Lamivudine/administración & dosificación , Tiempo de Tratamiento , Alanina Transaminasa/sangre , Preescolar , ADN Viral/sangre , Femenino , Estudios de Seguimiento , Hepatitis B/virología , Antígenos e de la Hepatitis B/sangre , Humanos , Lactante , Masculino , Estudios Prospectivos , Resultado del Tratamiento , Carga Viral/efectos de los fármacosRESUMEN
Minerals and transitional metal oxides of earth-abundant elements are desirable catalysts for in situ chemical oxidation in environmental remediation. However, catalytic activation of peroxydisulfate (PDS) by manganese oxides was barely investigated. In this study, one-dimension manganese dioxides (α- and ß-MnO2) were discovered as effective PDS activators among the diverse manganese oxides for selective degradation of organic contaminants. Compared with other chemical states and crystallographic structures of manganese oxide, ß-MnO2 nanorods exhibited the highest phenol degradation rate (0.044 min-1, 180 min) by activating PDS. A comprehensive study was conducted utilizing electron paramagnetic resonance, chemical probes, radical scavengers, and different solvents to identity the reactive oxygen species (ROS). Singlet oxygen (1O2) was unveiled to be the primary ROS, which was generated by direct oxidation or recombination of superoxide ions and radicals from a metastable manganese intermediate at neutral pH. The study dedicates to the first mechanistic study into PDS activation over manganese oxides and provides a novel catalytic system for selective removal of organic contaminants in wastewater.
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Compuestos de Manganeso , Oxígeno Singlete , Catálisis , Oxidación-Reducción , ÓxidosRESUMEN
BACKGROUND & AIM: Chronic infection with hepatitis B virus (HBV) in children is a serious health problem worldwide. How to treat children with immune-tolerant chronic hepatitis B infection, commonly characterized by hepatitis B e antigen (HBeAg) positivity, high viral load, normal or mildly elevated alanine aminotransferase and no or minimal inflammation in liver histology, remains unresolved. This trial aims to study the benefits of antiviral therapy in children with these characteristics. METHODS: This is a pilot open-label randomized controlled study. From May 2014 to April 2015, 69 treatment-naive chronically HBV-infected children, aged 1 to 16â¯years, who had immune-tolerant characteristics were recruited to this trial and randomly assigned, in a 2:1 ratio, to treatment group and control group. Patients in the treatment group received either interferon-α (IFN) monotherapy or consecutively received IFN monotherapy, combination therapy of IFN and lamivudine (LAM), and LAM therapy alone. All patients were observed until week 96. RESULTS: At baseline, epidemiological, biochemical, serological, virological and histological indices were consistent across the treatment and control groups. Of the 46 patients in the treatment group, 73.91% had undetectable serum HBV DNA, 32.61% achieved HBeAg seroconversion and 21.74% lost hepatitis B surface antigen (HBsAg) at the endpoint. No LAM resistance emerged at week 96. In the control group, only one (4.35%) patient underwent spontaneous HBeAg seroconversion and had undetectable serum HBV DNA during observation, and moreover, none developed HBsAg clearance. For all patients, no serious adverse events were observed. CONCLUSION: Antiviral treatment with a sequential combination of IFN and LAM resulted in a significant improvement in the rates of undetectable serum HBV DNA, HBeAg seroconversion and HBsAg loss in children with chronic HBV infection and immune-tolerant characteristics. LAY SUMMARY: There is a lack of data regarding treatment of immune-tolerant chronic hepatitis B (CHB). It remains unresolved how children with immune-tolerant CHB should be treated. This paper reports the outcomes from a pilot open-label randomized controlled trial on antiviral therapy in children with immune-tolerant characteristics. It shows that a sequential combination of interferon-α and lamivudine was beneficial.
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Antivirales/uso terapéutico , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/inmunología , Adolescente , Alanina Transaminasa/sangre , Antivirales/administración & dosificación , Niño , Preescolar , ADN Viral/sangre , Quimioterapia Combinada , Femenino , Anticuerpos contra la Hepatitis B/sangre , Antígenos e de la Hepatitis B/sangre , Hepatitis B Crónica/virología , Humanos , Tolerancia Inmunológica , Lactante , Interferón-alfa/administración & dosificación , Interferón-alfa/uso terapéutico , Lamivudine/administración & dosificación , Lamivudine/uso terapéutico , Masculino , Proyectos Piloto , SeroconversiónRESUMEN
Environmentally friendly and low-cost catalysts are important for the rapid mineralization of organic contaminants in powerful advanced oxidation processes (AOPs). In this study, we reported N-doped graphitic biochars (N-BCs) as low-cost and efficient catalysts for peroxydisulfate (PDS) activation and the degradation of diverse organic pollutants in water treatment, including Orange G, phenol, sulfamethoxazole, and bisphenol A. The biochars at high annealing temperatures (>700 °C) presented highly graphitic nanosheets, large specific surface areas (SSAs), and rich doped nitrogen. In particular, N-BC derived at 900 °C (N-BC900) exhibited the highest degradation rate, which was 39-fold and 6.5-fold of that on N-BC400 and pristine biochar, respectively, and the N-BC900 surpassed most popular metal or nanocarbon catalysts. Different from the radical-based oxidation in N-BC400/PDS via the persistent free radicals (PFRs), singlet oxygen and nonradical pathways (surface-confined activated persulfate-carbon complexes) were discovered to dominate the oxidation processes in N-BC900/PDS. Moreover, the adsorption of organics was determined to be the key step determining reaction rate, revealing that the pre-adsorption of reactants significantly accelerated the nonradical oxidation pathway. This study not only provides robust and cheap carbonaceous materials for environmental remediation but also enables the first insight into the graphitic biochar-based nonradical catalysis.
Asunto(s)
Grafito , Adsorción , Catálisis , Carbón OrgánicoRESUMEN
Phragmites australis (Cav.) Trin. ex Steud. has been reported to form a symbiosis with arbuscular mycorrhizal fungus (AMF). However, the tolerance mechanism for AMF symbiosis on cadmium (Cd) phytotoxicity still remains unclear. In this study, we investigated the effects of Rhizophagus irregularis inoculation on Cd-stressed (0, 1, and 20mgL-1) roots, stems, and leaves of P. australis with regard to subcellular Cd distribution and chemical forms of Cd. In addition, transmission electron microscopy and Fourier transform infrared spectroscopy were used to investigate variations in subcellular structures and functional groups in plant organs. The results showed that AMF inoculation could induce selective Cd distribution at subcellular levels, depending on different Cd treatments. The investigation of the chemical forms illustrated that AMF inoculation could alleviate Cd toxicity in all organs. Increases were observed in the ratios of undissolved Cd (FHAc) and oxalate Cd (FHCl), while decreases were observed in pectates and protein-integrated Cd (FNaCl) as well as water soluble Cd (FW). Hydroxyl (-OH), amide (-NH), carboxyl (C=O), and phosphate (P=O) groups as well as C-O and C-N stretching played predominant roles for the enhancement of Cd tolerance in response to AMF inoculation. These results provide instructive evidence for the mechanisms by which AMF inoculation enhances the Cd tolerance of P. australis via Cd uptake and distribution.
Asunto(s)
Cadmio/análisis , Contaminantes Ambientales/análisis , Glomeromycota/crecimiento & desarrollo , Micorrizas/fisiología , Poaceae/efectos de los fármacos , Biodegradación Ambiental , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/microbiología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/microbiología , Poaceae/química , Poaceae/microbiología , SimbiosisRESUMEN
Arbuscular mycorrhizal (AM) fungi have been reported to play a central role in improving plant tolerance to cadmium (Cd)-contaminated sites. This is achieved by enhancing both the growth of host plants and the nutritive elements in plants. This study assessed potential regulatory effects of AM symbiosis with regard to nutrient uptake and transport, and revealed different response strategies to various Cd concentrations. Phragmites australis was inoculated with Rhizophagus irregularis in the greenhouse cultivation system, where it was treated with 0-20 mg L-1 of Cd for 21days to investigate growth parameters, as well as Cd and nutritive element distribution in response to AM fungus inoculation. Mycorrhizal plants showed a higher tolerance, particularly under high Cd-level stress in the substrate. Moreover, our results determined the roots as dominant Cd reservoirs in plants. The AM fungus improved Cd accumulation and saturated concentration in the roots, thus inhibiting Cd uptake to shoots. The observed distributions of nutritive elements and the interactions among these indicated the highest microelement contribution to roots, Ca contributed maximally in leaves, and K and P contributed similarly under Cd stress. In addition, AM fungus inoculation effectively impacted Mn and P uptake and accumulation while coping with Cd toxicity. This study also demonstrated translocation factor from metal concentration (TF) could be a good parameter to evaluate different transportation strategies induced by various Cd stresses in contrast to the bioconcentration factor (BCF) and translocation factor from metal accumulation (TF').