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BACKGROUND: Uveitis and posterior scleritis are sight-threatening diseases with undefined pathogenesis and accurate diagnosis remains challenging. METHODS: Two plasma-derived extracellular vesicle (EV) subpopulations, small and large EVs, obtained from patients with ankylosing spondylitis-related uveitis, Behcet's disease uveitis, Vogt-Koyanagi-Harada syndrome, and posterior scleritis were subjected to proteomics analysis alongside plasma using SWATH-MS. A comprehensive bioinformatics analysis was performed on the proteomic profiles of sEVs, lEVs, and plasma. Candidate biomarkers were validated in a new cohort using ELISA. Pearson correlation analysis was performed to analyze the relationship between clinical parameters and proteomic data. Connectivity map database was used to predict therapeutic agents. RESULTS: In total, 3,668 proteins were identified and over 3000 proteins were quantified from 278 samples. When comparing diseased group to healthy control, the proteomic profiles of the two EV subgroups were more correlated with disease than plasma. Comprehensive bioinformatics analysis highlighted potential pathogenic mechanisms for these diseases. Potential biomarker panels for four diseases were identified and validated. We found a negative correlation between plasma endothelin-converting enzyme 1 level and mean retinal thickness. Potential therapeutic drugs were proposed, and their targets were identified. CONCLUSIONS: This study provides a proteomic landscape of plasma and EVs involved in ankylosing spondylitis-related uveitis, Behcet's disease uveitis, Vogt-Koyanagi-Harada syndrome, and posterior scleritis, offers insights into disease pathogenesis, identifies valuable biomarker candidates, and proposes promising therapeutic agents.
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Síndrome de Behçet , Vesículas Extracelulares , Esclerite , Espondilite Anquilosante , Uveíte , Síndrome Uveomeningoencefálica , Humanos , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/complicações , Síndrome Uveomeningoencefálica/diagnóstico , Síndrome Uveomeningoencefálica/complicações , Esclerite/etiologia , Espondilite Anquilosante/complicações , Proteômica , Uveíte/complicaçõesRESUMO
Uranium detection and extraction are necessary for the ecological environment as the growing demand for nuclear energy. Hence, exploring stable materials with excellent performance in uranium extraction and detection is highly desired. Herein, by amidoxime-functionalizing tetrafluoroterephthalonitrile (TFTPN) crosslinked hydroquinone (bP), phloroglucinol (tP), and 4,4',4â³-trihydroxytriphenylmethane (tBP), three covalent organic polymers (COPs) bPF-AO, tPF-AO, and tBPF-AO with different crosslinked architectures are fabricated. Uranium extraction and detection related to the difference in molecule construction were systemically investigated, giving some reference for the rational design and fabrication of advanced materials for the removal and monitoring of uranium in the environment. The tPF-AO with a compact steric structure achieves the highest theoretical maximum adsorption capacity of 578.9 ± 15.2 mg g-1 and the best recyclability. The scattering electron center and U(VI) selective binding sites endow tBPF-AO with excellent capability in selective detection for U(VI), with a limit of detection of 24.2 nmol L-1, which is well below the standard for U(VI) in drinking water of the World Health Organization (WHO). Moreover, the COPs possess prominent physicochemical stability and recyclability, and more importantly, the PAE-based COPs are derived from inexpensive industry materials with easy processing methods, providing an efficient and economical way for the detection and adsorption of uranium.
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Urânio , Floroglucinol , Adsorção , Sítios de Ligação , Elétrons , PolímerosRESUMO
PURPOSE: To report the clinical profile and outcomes of acute Vogt-Koyanagi-Harada disease with a strict immunosuppression regimen and investigate the risk factors for a prolonged disease course. METHODS: A total of 101 patients with acute Vogt-Koyanagi-Harada (202 eyes) with more than 24 months of follow-up were recruited from January 2011 to June 2020. They were divided into two groups according to the interval between the onset of Vogt-Koyanagi-Harada and treatment. Oral prednisone was gradually tapered off by a diminished dose according to a relatively strict protocol. Patient responses to the treatment regimen were classified as long-term drug-free remission or chronic recurrent. RESULTS: Ninety-six patients (95.0%) achieved long-term drug-free remission without recurrence, while 5 (5.0%) had chronic recurrence. Most patients achieved good best-corrected visual acuity (90.6% â§20/25). A generalized estimation equation model demonstrated that time of visit, ocular complications, and cigarette smoking were independent risk factors for a longer disease course, and smokers required a higher drug dose and longer treatment course than nonsmokers. CONCLUSION: An immunosuppressive regimen with an appropriate tapering speed can lead to long-term drug-free remission in patients with acute Vogt-Koyanagi-Harada. Cigarette smoking significantly affects ocular inflammation.
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Síndrome Uveomeningoencefálica , Humanos , Síndrome Uveomeningoencefálica/diagnóstico , Síndrome Uveomeningoencefálica/tratamento farmacológico , Glucocorticoides , Doença Aguda , Imunossupressores/uso terapêutico , Prednisona/uso terapêutico , Progressão da Doença , Estudos RetrospectivosRESUMO
BACKGROUND: VogtâKoyanagiâHarada (VKH) disease is a multifactorial systemic autoimmune disorder against melanocytes that is characterized by panuveitis. Familial occurrence of VKH disease is rare. Here, we report two cases of a father and his son with characteristic manifestations of VKH disease. CASE PRESENTATION: A 53-year-old male with typical clinical symptoms of VKH disease was referred to Tangshan Eye Hospital. Examination showed the presence of ciliochoroidal effusion and exudative retinal detachment in both eyes. The patient was given intravenous methylprednisolone 120 mg for 2 days and intravenous methylprednisolone 80 mg for 1 day followed by 48 mg (1 mg/kg/day) oral methylprednisolone daily, accompanied by oral azathioprine 50 mg daily. Cycloplegic agent (0.5% tropicamide three times daily [TID]) was added. The patient was free of symptoms and recurrence within more than 1-year-follow-up period, the best corrected visual acuity (BVCA) was increased and maintained in both eyes with complete resolution of subretinal fluid. One year and nine months later, case 2 (his son) also presented with the typical clinical symptoms of VKH disease at 29 years of age. The son also recovered from VKH disease after routine and standard treatment. CONCLUSIONS: To the best of our knowledge, this is the first VKH disease case report of a father-son relationship. Although genetic factors have been demonstrated to be involved in the pathogenesis of VKH disease, the different inheritance modes of VKH patients need to be further explored and studied.
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Glucocorticoides , Metilprednisolona , Síndrome Uveomeningoencefálica , Humanos , Masculino , Pessoa de Meia-Idade , Pai , Glucocorticoides/uso terapêutico , Metilprednisolona/uso terapêutico , Núcleo Familiar , Síndrome Uveomeningoencefálica/diagnóstico , Síndrome Uveomeningoencefálica/tratamento farmacológico , Síndrome Uveomeningoencefálica/complicações , Adulto , Acuidade Visual , Resultado do TratamentoRESUMO
Aqueous hexavalent chromium (Cr(VI)) treatment and chromium resource recovery toward Cr-containing wastes are of significant importance and necessity to both wastewater remediation and resource recovery. Herein, via mild photoreaction conditions with isopropanol (IPA) as an electron donor, a catalyst-free strategy for aqueous Cr(VI) extraction to form an insoluble polyhydroxy Cr(V) complex is developed for the first time. Aqueous Cr(VI) with concentration from 5 to 150 ppm can be efficiently extracted with high selectivity even in the presence of coexisting ions, and the total Cr concentration in residue solution can be as low as 0.5 ppm. The Cr resource could be efficiently recovered as pure Cr2O3 by calcinating the resulting Cr(V) precipitate. Outstanding extraction efficiency could be realized with various IPA concentrations (1.3-12.0 mol/L) by coordinately tuning the pH value to promote the formation of Cr(VI)-IPA ester. The formed ester undergoes intramolecular electron transition under visible light irradiation, resulting in a polyhydroxy solid-state Cr(V) intermediate complex. The controlled pH value blocks further reduction of Cr(V) to soluble Cr(III); thus the insoluble Cr(V) intermediate complex is stabilized thermodynamically under ambient conditions. Because of its electric neutrality property and the strong intermolecule interaction via hydrogen bonds, a dioxo-bridged di-nuclear Cr(V) complex {Cr2(µ-O)2(OH)4[OCH(CH3)2]2} is finally precipitated as the main product. Satisfactory extraction and recovery of Cr from chromium-plating wastewater and discarded stainless steel verify that this approach is ideal for both one-step purification of Cr(VI)-containing wastewater and selective resource recovery from Cr-containing solid wastes in practical application.
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Recuperação e Remediação Ambiental , Águas Residuárias , 2-Propanol , Cromo/química , Ésteres , Concentração de Íons de Hidrogênio , Resíduos Sólidos , Aço Inoxidável , Água/químicaRESUMO
BACKGROUND: Vogt-Koyanagi-Harada (VKH) disease is a common type of uveitis that leads to blindness. The clinical manifestations and treatment solutions are different between initial-onset and recurrent VKH. Therefore, identifying the microRNA (miRNA) profiles from initial-onset and recurrent VKH patients may shed light on the molecular mechanisms underlying the pathogenesis of VKH disease. METHODS AND RESULTS: RNAs isolated from peripheral blood mononuclear cells (PBMCs) from patients with initial-onset VKH, recurrent VKH, and healthy individuals were subjected to high-throughput miRNA sequencing. Pairwise analysis of miRNA sequencing data between groups was conducted to identify differentially expressed miRNAs (DEMs), which were verified using real-time quantitative polymerase chain reaction. After receiver operating characteristic analyses, we found that hsa-miR-4664-3p, hsa-miR-7704, hsa-miR-4504, and hsa-miR-206 may serve as biomarkers of different VKH stages. DEMs were classified into three groups based on their differential expression: DEMs in initial-onset stage, DEMs in recurrent stage, and DEMs common between both VKH stages (shared DEMs). Pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes identified the mitogen-activated protein kinase, tumor necrosis factor, and mechanistic target of rapamycin kinase pathways as significantly enriched among the target genes of recurrent stage and shared DEMs. Furthermore, we mapped a network of competing endogenous RNAs for hsa-miR-206, which we used to identify putative targets for VKH treatment. CONCLUSION: Hsa-miR-4664-3p, hsa-miR-7704, hsa-miR-4504, and hsa-miR-206 may serve as biomarkers for different stages of VKH. Additionally, our competing endogenous RNA network of hsa-miR-206 provides a new direction for VKH treatment.
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MicroRNAs , Síndrome Uveomeningoencefálica , Humanos , Síndrome Uveomeningoencefálica/genética , Síndrome Uveomeningoencefálica/metabolismo , Síndrome Uveomeningoencefálica/patologia , Leucócitos Mononucleares/metabolismo , MicroRNAs/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Biomarcadores/metabolismoRESUMO
Aluminosilicate clay mineral (ACM) is a kind of typical raw materials that used widely in manufacturing industry owing to the abundant reserve and low-cost exploring. In past two decades, in-depth understanding on unique layered structure and abundant surface properties endows ACM in the emerging research and application fields. In field of solar-chemical energy conversion, ACM has been widely used to support various semiconductor photocatalysts, forming the composites and achieving efficient conversion of reactants under sunlight irradiation. To date, classic ACM such as kaolinite and montmorillonite, loaded with semiconductor photocatalysts has been widely applied in photocatalysis. This review summaries the recent works on ACM-based composites in photocatalysis. Focusing on the properties of surface and layered structure, we elucidate the different features in the composition with various functional photocatalysts on two typical kinds of ACM, i.e., type 1:1 and type 2:1. Not only large surface area and active surface hydroxyl group assist the substrate adsorption, but also the layered structure provides more space to enlarge the application of ACM-based photocatalysts. Besides, we overview the modifications on ACM from both external surface and the inter-layer space that make the formation of composites more efficiently and boost the photo-chemical process. This review could inspire more upcoming design and synthesis for ACM-based photocatalysts, leading this kind of economic and eco-friendly materials for more practical application in the future.
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Caulim , Semicondutores , Silicatos de Alumínio , Argila , MineraisRESUMO
Turbulence has significant influences on the growth rate and community structure of phytoplankton in large shallow lakes. Phytoplankton in moving water may be influenced by turbulence and nutrient concentration gradients on a short time scale. To assess this issue, our research used an ensemble water quality and ecological model by internally coupling the three-dimensional hydrodynamic model, the Environmental Fluid Dynamics Code (EFDC), and the one-dimensional ecosystem model, PCLake. The results showed that turbulence dramatically inhibited phytoplankton growth, while nutrients had the opposite effect. In addition, turbulence was the key factor contributing to phytoplankton growth. However, the effects of turbulence on phytoplankton correlated with nutrient concentrations. For lower nutrient concentrations, phytoplankton growth was controlled by nutrients. Logistic regression models were established with the modeled chlorophyll a, total nitrogen (TN), total phosphorus (TP) and turbulent kinetic energy (Ke). The results also showed that turbulence could improve nutrient uptake by phytoplankton, especially at low nutrient levels. The effects of turbulence on phytoplankton may imply that energy transfer occurs between water turbulence and phytoplankton. Our study will provide insight into management and remediation strategies of ecosystems based on energy processes in the future.
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Lagos , Fitoplâncton , Clorofila A , Ecossistema , Transferência de Energia , Monitoramento Ambiental , Eutrofização , Nitrogênio , Fósforo , Qualidade da ÁguaRESUMO
To enhance the electron-hole separation and boost the practical performance of commercial titania (Degussa P25) under natural solar light, in this work, P25 was modified with Co(II) species (CoP25) through post-treatment with decomposition of Co-ethylenediaminetetraacetic acid precursors in a wet chemical anchoring process. With appropriate Co(II) loading amount as molecular cocatalyst, the resulted CoP25-4 showed significantly improved photocatalytic performance for Cr(VI) reduction and bisphenol A (BPA) oxidation under UV-light irradiation. The coexistence of Cr(VI) and BPA promoted mutually the degradation of both pollutants. Under simulated solar light (AM 1.5G) illumination, the Cr(VI) reduction rate over CoP25-4 was 8.5 times enhanced compared with that over P25, whereas the simultaneous degradation rate of BPA over CoP25-4 was 8 times higher than that over P25. Further investigations indicated that the covalent atomic Co(II) anchoring on P25 significantly promoted the photogenerated electron-hole separation and facilitated Cr(VI) reduction via the formation of a Co(I) intermediate and simultaneously boosted BPA oxidation. Our results demonstrated a facile strategy to modify P25 with remarkably improved performance for the practical application in environmental pollution management under natural light excitation.
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Highly efficient removal of metal ion pollutants, such as toxic and nuclear waste-related metal ions, remains a serious task from the biological and environmental standpoint because of their harmful effects on human health and the environment. Recently, highly porous metal-organic frameworks (MOFs), with excellent chemical stability and abundant functional groups, have represented a new addition to the area of capturing various types of hazardous metal ion pollutants. This review focuses on recent progress in reported MOFs and MOF-based composites as superior adsorbents for the efficient removal of toxic and nuclear waste-related metal ions. Aspects related to the interaction mechanisms between metal ions and MOF-based materials are systematically summarized, including macroscopic batch experiments, microscopic spectroscopy analysis, and theoretical calculations. The adsorption properties of various MOF-based materials are assessed and compared with those of other widely used adsorbents. Finally, we propose our personal insights into future research opportunities and challenges in the hope of stimulating more researchers to engage in this new field of MOF-based materials for environmental pollution management.
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Poluição Ambiental/análise , Estruturas Metalorgânicas/química , Metais/isolamento & purificação , Poluentes Radioativos/isolamento & purificação , Resíduos Radioativos , Adsorção , Monitoramento Ambiental , Íons/química , Íons/isolamento & purificação , Íons/toxicidade , Metais/química , Metais/toxicidade , Poluentes Radioativos/química , Poluentes Radioativos/toxicidadeRESUMO
Photosynthetic biocatalysts are emerging as a new class of materials, with their sophisticated and intricate structure, which promise improved remarkable quantum efficiency compared to conventional inorganic materials in artificial photosynthesis. To break the limitation of efficiency, the construction of bioconjugated photo-electrochemical conversion devices has garnered substantial interest and stood at the frontier of the multidisciplinary research between biology and chemistry. Herein, a biohybrid photoanode of a photosynthetic membrane protein (Photosystem II (PS II)), extracted from fresh spinach entrapped on mesoporous WO3 film, is fabricated on fluorine-doped tin oxide. The PS II membrane proteins are observed to communicate with the WO3 electrode in the absence of any soluble redox mediators and sacrificial reagents under the visible light of the solar spectrum, even to 700 nm. The biohybrid electrode undergoes electron transfer and generates a significantly enhanced photocurrent compared to previously reported PS II-based photoanodes with carbon nanostructures or other semiconductor substrates for solar water oxidation. The maximum incident photon-to-current conversion efficiency reaches 15.24% at 400 nm in the visible light region. This work provides some insights and possibilities into the efficient assembly of a future solar energy conversion system based on visible-light-responsive semiconductors and photosynthetic proteins.
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Luz , Proteínas de Membrana/metabolismo , Óxidos/química , Fotossíntese , Tungstênio/química , Água/química , Eletricidade , Eletrodos , Flúor/química , Oxirredução , Complexo de Proteína do Fotossistema II/metabolismo , Porosidade , Spinacia oleracea , Compostos de Estanho/químicaRESUMO
l-cysteine intercalated Mg/Al layered double hydroxide (Cys-LDH) composites were fabricated and applied for treating the U(VI) contaminated wastewater under various conditions. Interaction mechanisms and adsorption properties were investigated by using batch experiments with spectroscopy analysis. The adsorption isotherms and kinetics were fitted perfectly with the Langmuir isotherm and the pseudo-second-order model, respectively. The significant maximum adsorption capacity of Cys-LDH (211.58â¯mg/g) compared to LDH was attributed to the larger number of functional groups on Cys-LDH. The presence of humic acid (HA) decreased U(VI) elimination on Cys-LDH at high pH but increased U(VI) removal at low pH. Typically, the presence of various anions (such as NO3-, Cl-, ClO4- and SO42-) did not obviously affect U(VI) adsorption on Cys-LDH, while the coexisted CO32- significantly affected U(VI) elimination. The predominate adsorption were determined to be the formation of Cys-U(VI)-Cys complexes with cysteine in the Cys-LDH interlayers. The results demonstrated that the Cys-LDH are promising adsorbents for efficient elimination and extraction of radionuclides in actual environmental contamination management.
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Cisteína/química , Poluentes Químicos da Água/química , Adsorção , Substâncias Húmicas , Hidróxidos , SoluçõesRESUMO
Planarians are an ideal model organism for regeneration research due to their amazing ability to regenerate. DNA replication is crucial for genome stability. Replication factor C (RFC), which is a replication factor C-like complex and plays an important role during DNA replication in eukaryotes, has been reported as a wound response factor during planarian regeneration. However, how RFC controls regeneration in planarians by regulating DNA replication remains to be explained. Here, we used a two-dimensional electrophoresis (2-DE) proteomic approach to identify differentially expressed proteins in intact and regenerated planarians. Approximately 132 protein spots showed differences between intact and regenerative tissues. We selected 21 significantly expressed protein spots and processed them using TOF MS analysis. Finally, we cloned three of these candidate genes (Djhsp70, Djrfc2, Djfaim), focusing on the function of Djrfc2 during regeneration. We found that the distribution of Djrfc2 tends toward the wound site. RNA interference (RNAi) of Djrfc2 increases the number of dividing cells and the expression level of planarian neoblast marker genes, which may result in hyper-proliferation. Our studies use an available approach to directly study the regeneration dynamic at the protein level and provide further evidence to support a function of Djrfc2 in planarian regeneration.
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Planárias/fisiologia , Regeneração/fisiologia , Proteína de Replicação C/genética , Animais , Proliferação de Células , Eletroforese em Gel Bidimensional , Regulação da Expressão Gênica , Planárias/genética , Proteômica , Interferência de RNA , Proteína de Replicação C/metabolismoRESUMO
The photoreduction of CO2 is attractive for the production of renewable fuels and the mitigation of global warming. Herein, we report an efficient method for CO2 reduction over elemental boron catalysts in the presence of only water and light irradiation through a photothermocatalytic process. Owing to its high solar-light absorption and effective photothermal conversion, the illuminated boron catalyst experiences remarkable self-heating. This process favors CO2 activation and also induces localized boron hydrolysis to inâ situ produce H2 as an active proton source and electron donor for CO2 reduction as well as boron oxides as promoters of CO2 adsorption. These synergistic effects, in combination with the unique catalytic properties of boron, are proposed to account for the efficiency of the CO2 reduction. This study highlights the promise of photothermocatalytic strategies for CO2 conversion and also opens new avenues towards the development of related solar-energy utilization schemes.
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Water splitting represents a promising technology for renewable energy conversion and storage, but it is greatly hindered by the kinetically sluggish oxygen evolution reaction (OER). Here, using Au-nanoparticle-decorated Ni(OH)2 nanosheets [Ni(OH)2-Au] as catalysts, we demonstrate that the photon-induced surface plasmon resonance (SPR) excitation on Au nanoparticles could significantly activate the OER catalysis, specifically achieving a more than 4-fold enhanced activity and meanwhile affording a markedly decreased overpotential of 270 mV at the current density of 10 mA cm(-2) and a small Tafel slope of 35 mV dec(-1) (no iR-correction), which is much better than those of the benchmark IrO2 and RuO2, as well as most Ni-based OER catalysts reported to date. The synergy of the enhanced generation of Ni(III/IV) active species and the improved charge transfer, both induced by hot-electron excitation on Au nanoparticles, is proposed to account for such a markedly increased activity. The SPR-enhanced OER catalysis could also be observed over cobalt oxide (CoO)-Au and iron oxy-hydroxide (FeOOH)-Au catalysts, suggesting the generality of this strategy. These findings highlight the possibility of activating OER catalysis by plasmonic excitation and could open new avenues toward the design of more-energy-efficient catalytic water oxidation systems with the assistance of light energy.
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A series of rod-like porous graphitic-carbon nitrides (short as CNs) with enhanced in-plane ordering have been fabricated through self-assembled heptazine hydrate precursors for the first time. By controlling the calcination of the preformed precursors with different temperature-rising rates, the resulted CNs (SAHEP-CNs-1) with the most ordered and least stacked graphitic planar are showing a tremendously improved hydrogen evolution rate of 420 µmol h-1 under visible light and a remarkable apparent quantum efficiency of 8.9% at 420 nm, which is among the highest values for C3 N4 -related photocatalysts in the literature. This work discloses that enhancing in-plane ordering is one critical factor for improving the photocatalytic H2 evolution of carbon nitride, which is an effective solution to prolong the lifetime of charge carriers by accelerating the charge transport and separation within the graphitic planar. This finding would present a facial strategy for the designing of efficient organic semiconductors for photocatalysis.
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Modular optimization of metal-organic frameworks (MOFs) was realized by incorporation of coordinatively unsaturated single atoms in a MOF matrix. The newly developed MOF can selectively capture and photoreduce CO2 with high efficiency under visible-light irradiation. Mechanistic investigation reveals that the presence of single Co atoms in the MOF can greatly boost the electron-hole separation efficiency in porphyrin units. Directional migration of photogenerated excitons from porphyrin to catalytic Co centers was witnessed, thereby achieving supply of long-lived electrons for the reduction of CO2 molecules adsorbed on Co centers. As a direct result, porphyrin MOF comprising atomically dispersed catalytic centers exhibits significantly enhanced photocatalytic conversion of CO2 , which is equivalent to a 3.13-fold improvement in CO evolution rate (200.6â µmol g-1 h-1 ) and a 5.93-fold enhancement in CH4 generation rate (36.67â µmol g-1 h-1 ) compared to the parent MOF.
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To assess the environmental behavior and impact of graphene oxide (GO) on living organisms more accurately, the aggregation of GO and its deposition on Al2O3 particles were systematically investigated using batch experiments across a wide range of solution chemistries. The results indicated that the aggregation of GO and its deposition on Al2O3 depended on the solution pH and the types and concentrations of electrolytes. MgCl2 and CaCl2 destabilized GO because of their effective charge screening and neutralization, and the presence of NaH2PO4 and poly(acrylic acid) (PAA) improved the stability of GO with the increase in pH values as a result of electrostatic interactions and steric repulsion. Specifically, the dissolution of Al2O3 contributed to GO aggregation at relatively low pH or high pH values. Results from this study provide critical information for predicting the fate of GO in aquatic-terrestrial transition zones, where aluminum (hydro)oxides are present.
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Óxido de Alumínio/química , Grafite/química , Resinas Acrílicas/química , Ânions , Cátions , Meio Ambiente , Concentração de Íons de Hidrogênio , Solubilidade , Soluções , Água/químicaRESUMO
In light of the widespread use of fossil fuels and the resulting environmental pollution, it is crucial to develop efficient photocatalysts for renewable energy applications that utilize visible light. Organic photocatalysts based on ß-ketoenamine offer several advantages, including facile preparation, high stability, structural controllability, and excellent photovoltaic properties. However, in previous studies, the synthesis of porous organic polymers (POPs) often involved long, high-temperature processes. In this study, POPs with donor (D)-acceptor (A) structure were constructed by utilizing various branched bridging groups and 2,4,6-triformylphloroglucinol, across multiple temperature gradients. Through adjustments in hydrothermal temperature, we successfully synthesized a series of POPs with varying enol-keto structure ratios. Among these POPs, the dimethoxybenzidine-POPs (DMDPOPs) with methoxy electron-rich branched chains exhibited superior photovoltaic performance, electron transfer rate, and photocatalytic activity compared to the dihydroxybenzidine-POPs (DHDPOPs) with electron-deficient hydroxyl branched chains. Notably, DMDPOP-30 demonstrated outstanding performance, achieving a conversion rate of 98% within 3 h. Additionally, other POPs exhibited favorable conversions (90%), further confirming the feasibility of this synthetic approach. Moreover, the synthesis of DMDPOP-30 was achieved under mild conditions at room temperature, highlighting its significant potential for practical applications.
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Developing bifunctional electrocatalysts based on non-precious metals for overall water splitting, while maintaining high catalytic activity and stability under high current densities, remains challenging. Herein, we successfully constructred trace iron-doped nickel-cobalt selenide with abundant CoSe2 (210)-Ni3Se4 (202) heterointerfaces via a simple one-step selenization reaction. The synthesized Fe-NiCoSex/NCFF (NCFF stands for nickel-cobalt-iron foam) exhibits outstanding hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity with low overpotentials of 328 mV for HER and 345 mV for OER at a high current density of 1000 mA cm-2, while maintaining stability for over 20 h. Additionally, the Fe-NiCoSex/NCFF exhibits the lowest Tafel slope values for both HER (33.7 mV dec-1) and OER (55.92 mV dec-1), indicating the fastest kinetics on its surface. The Fe-NiCoSex/NCFF features uniformly distributed micrometer-sized selenide particles with dense nanowires on their surface, providing a large reactive surface area and abundant active sites. Moreover, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analyses reveal that the catalyst is composed of nickel, cobalt, and iron, forming micrometer-sized particles with both crystalline and amorphous phases, thereby enhancing HER and OER performance under high current density. Density functional theory (DFT) calculations demonstrate that the heterostructure CoSe2 (210)-Ni3Se4 (202), with high electron density and suitable adsorption capacity for reaction intermediates, and low energy barriers for HER (-0.384 eV) and OER (ΔG1st: 0.243 eV, ΔG2nd: 0.376 eV), serves as an active center for both HER and OER.