In this study, different fluorescent constituents of dissolved organic matter (DOM) with terrestrial sources and their membrane fouling potentials were tracked in the hybrid ultrafiltration (UF) ...processes adopting UV photooxidation with TiO2 nanoparticles (NPs) as a form of pretreatment via fluorescence excitation emission matrix coupled with parallel factor analysis (EEM-PARAFAC). The photocatalytic oxidation processes consistently resulted in enhanced removal rates of DOM and membrane fouling mitigation regardless of DOM sources. EEM-PARAFAC decomposed bulk DOM into four different fluorescent DOM (FDOM) components including three humic-like components (C1, C2, and C3) and one protein/polyphenol-like component (C4). The results showed that direct hole oxidation was primarily involved in attacking large sized humic-like C1 on TiO2 surfaces, while indirect oxidation with hydroxyl radicals was responsible for the removal of the small sized humic-like C3 and C4. Under a short irradiation period of 30min, the intermediate-sized humic-like C2 was released into solutions from adsorbed C1. Among the FDOM components, C4 was the most associated with reversible fouling of the hybrid UF system, while C1 contributed most of the fouling of the UF system without the photocatalysis. Meanwhile, C3 was the most important FDOM component responsible for irreversible fouling, and the contribution was more pronounced at longer irradiation. This study revealed the great applicability of EEM-PARAFAC in probing the extent of membrane fouling in TiO2/UV-UF hybrid systems. Considering the unique characteristics of the individual FDOM components, EEM-PARAFAC can provide valuable information providing further insight into system optimization as well as predictions of the treated water quality.
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•TiO2/UV oxidation resulted in enhanced removal of DOM and reduced membrane fouling.•Large sized FDOM was removed by direct hole oxidation.•Protein/polyphenol-like FDOM was highly associated with reversible fouling in hybrid systems.•EEM-PARAFAC successfully tracked the fate and fouling behavior of FDOM in hybrid systems.
Health and environmental risks regarding perfluorooctanoic acid, a well-known perfluorinated compound, are still a subject of great concern. Ubiquitous exposure and disparity of results make it ...difficult to determine the underlying mechanism of action, especially at the cellular level. This study proposes an experimental design to assess the reversibility of adverse effects after a one-time exposure to the compound, in comparison with other more conventional timings. Complementary endpoints including total protein content, neutral red uptake and MTT reduction tests along with division rates and microscopic observations were evaluated in HeLa cells. In addition, PFOA quantification inside the cells was performed. The cellular effects exerted after 24 h exposure to perfluorooctanoic acid are non-reversible after a 48 h recovery period. In addition, we describe for the first time the induction of plasma membrane blebbing and the activation of membrane repair mechanisms after recovery from non-cytotoxic treatments with the compound. This experimental design has provided relevant information regarding the toxicity of this perfluorinated compound, relating all the adverse effects detected to its interaction with the plasma membrane.
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•PFOA exposure produces non-reversible effects on HeLa cells.•PFOA increases mitotic index after 24 h and 24 + 48 h treatments.•Exposure to PFOA induces plasma membrane blebbing and membrane-repair mechanisms.•Uptake of PFOA and interaction with plasma membrane mediate cellular injuries.
PFOA induces membrane blebbing and repair mechanisms.
Amyloid fibrils are supramolecular protein assemblies represented by a cross-β structure and fibrous morphology, whose structural architecture has been previously investigated. While amyloid fibrils ...are basically a main-chain-dominated structure consisting of a backbone of hydrogen bonds, side-chain interactions also play an important role in determining their detailed structures and physicochemical properties. In amyloid fibrils comprising short peptide segments, a steric zipper where a pair of β-sheets with side chains interdigitate tightly is found as a fundamental motif. In amyloid fibrils comprising longer polypeptides, each polypeptide chain folds into a planar structure composed of several β-strands linked by turns or loops, and the steric zippers are formed locally to stabilize the structure. Multiple segments capable of forming steric zippers are contained within a single protein molecule in many cases, and polymorphism appears as a result of the diverse regions and counterparts of the steric zippers. Furthermore, the β-solenoid structure, where the polypeptide chain folds in a solenoid shape with side chains packed inside, is recognized as another important amyloid motif. While side-chain interactions are primarily achieved by non-polar residues in disease-related amyloid fibrils, the participation of hydrophilic and charged residues is prominent in functional amyloids, which often leads to spatiotemporally controlled fibrillation, high reversibility, and the formation of labile amyloids with kinked backbone topology. Achieving precise control of the side-chain interactions within amyloid structures will open up a new horizon for designing useful amyloid-based nanomaterials.
Tremendous attention has been paid to the water-associated side reactions and zinc (Zn) dendrite growth on the electrode-electrolyte interface. However, the Zn pulverization that can cause continuous ...depletion of active Zn metal and exacerbate hydrogen evolution is severely neglected. Here, we disclose that the excessive Zn feeding that causes incomplete crystallization is responsible for Zn pulverization formation through analyzing the thermodynamic and kinetics process of Zn deposition. On the basis, we introduce 1-ethyl-3-methylimidazolium cations (EMIm
) into the electrolyte to form a Galton-board-like three-dimensional inert-cation (3DIC) region. Modeling test shows that the 3DIC EMIm
can induce the Zn
flux to follow in a Gauss distribution, thus acting as elastic sites to buffer the perpendicular diffusion of Zn
and direct the lateral diffusion, thus effectively avoiding the local Zn
accumulation and irreversible crystal formation. Consequently, anti-pulverized Zn metal deposition behavior is achieved with an average Coulombic efficiency of 99.6% at 5 mA cm
over 2,000 cycles and superb stability in symmetric cell over 1,200 h at -30 °C. Furthermore, the Zn||KVOH pouch cell can stably cycle over 1,200 cycles at 2 A g
and maintain a capacity of up to 12 mAh.
Developing high‐capacity conversion‐type anodes with superior durability substituting conventional graphite anodes is urgently desired to improve the energy density of lithium‐ion batteries (LIBs). ...However, fatal capacity decay during cycling of the conversion‐type anodes, which is primarily due to their inevitable structural degradation and continuous solid‐electrolyte interphase reformation induced by drastic volume change, has highly restricted their commercialization. And, the interrelated effects of phase transformation, structural evolution, and electrochemical characteristics of the conversion‐type anodes during cycling remain poorly understood. Herein, the findings on the fabrication and understanding of a previously unexplored entropy‐stabilized spinel oxide, (Co0.2Mn0.2V0.2Fe0.2Zn0.2)3O4 as a promising conversion anode for LIBs, exhibiting not only moderate volume change character but also highly reversible capacities of ≈900 mAh g−1 for 500 cycles at 0.2 A g−1 and ≈500 mAh g−1 for 2000 cycles at 3 A g−1, respectively, are reported. Evidenced by in situ transmission electron microscopy coupled with theoretical calculations, its underlying mechanism underpinning highly reversible Li storage is explicitly revealed, which originates from reversible phase transformation and domain reconstruction during cycling. Moreover, the origin of small volume change is also clearly clarified. This work provides renewed mechanistic insights into designing high‐capacity and durable conversion‐type electrode materials for high‐performance LIBs.
In this work, a new entropy‐stabilized spinel oxide, (Co0.2Mn0.2V0.2Fe0.2Zn0.2)3O4, is identified as a promising conversion anode for Li‐ion batteries, exhibiting moderate volume change character, highly reversible capacities and stable cycling performance. Its underlying mechanism underpinning highly reversible Li storage is explicitly clarified through in situ transmission electron microscopy coupled with theoretical calculation analysis.
Wettability patterns have significant application potential in liquid transportation and water collection. Plasma hydrophilization is high-efficient and less-destructive, and has been widely used for ...preparing wettability patterns. However, the plasma-treated surfaces tend to recover to its original wettability, causing invalidation of the patterns. As a green treatment method, boiled water treatment could construct nanostructures, which is favorable for hydrophilicity-retaining; while the hydrophilization effect of plasma treatment would promote the reaction. Therefore, it should be possible to combine plasma and boiled water treatments to prepare long-lasting wettability patterns. In this paper, superhydrophobic aluminum surfaces were modified by plasma jet followed by boiled water treatment. The time stability, microstructures and chemical compositions of the treated surfaces were investigated by testing contact angles, scanning electron microscope, X-ray diffractometer, and X-ray photoelectron spectroscopy. The surfaces treated by plasma jet and boiled water could retain superhydrophilicity for a long time under various storage conditions, including normal ambient, high temperature or high humidity. On the basis of this technique, long-lasting patterns could be prepared on different metal substrates. The green method proposed is expected to have promising application potential in fabricating wettability patterns and lab-on-chip devices, especially for those used in severe conditions.
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•Long-lasting water/oil wettability patterns are prepared on metal substrates.•The patterns show good time stability under high temperature/humidity.•The patterns are obtained by using plasma and boiled water to modify substrates.•The modification method is reversible.
The metabolites of gut microbiome are important host-health regulating factors and can be interrupted when the host is exposed to environmental pollutant via ingestion route. Arsenic contaminated ...drinking water is one of the most serious environmental health problems worldwide. Therefore, the arsenic-induced alterations of gut microbiome and metabolome, especially the persistence and reversibility of the alterations after the long-term arsenic exposure will be interesting to know. In this study, we investigated the relationship between gut microbiota and metabolites in male rats both after the 30-days arsenic treatment and 30-days recovery duration. The composition and diversity of gut microbiota were affected significantly by the treatment, but they presented partial improvement in recovery duration. Moreover, arsenic exposure induced the significant changes of 73 metabolites, which involved in the metabolism of glycerophospholipid, linoleic acid, as well as the biosynthesis of phenylalanine, tyrosine and tryptophan. Although it had a persistent effect, the restoration of glycerophospholipid metabolism was observed in the 30-days recovery. Integration analysis further correlated the arsenic impacting microbes with some important differential metabolites. Lactobacillus associated with the decreases of phosphatidylethanolamine(34:1), 16alpha-hydroxydehydroepiandrosterone 3-sulfate, seryltryptophan and alanyltyrosine in recovery duration. Lactobacillus strains have potential to work as protective agents against arsenic toxicity by restoring perturbed glycerophospholipid metabolism. In summary, arsenic significantly disrupted gut microbiome and metabolome, but the disruptions are reversible to some extent after a 30-days recovery.
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•An integrated approach was used to investigate arsenic significantly affected gut microbiome and its metabolite profiles.•Arsenic-induced disruptions of gut microbiome and metabolome are reversible to some extent after a 30-days recovery.•Lactobacillus strains may work as protective agents against arsenic-induced health damage.
This study presents the development of green and sustainable supercapacitor electrodes using activated carbons derived from industrial waste from red pepper (RPW) via conventional chemical activation ...using ZnCl2 at various carbonization/activation temperatures. The activated carbon samples were subjected to various analytical techniques, including elemental analysis, N2 adsorption-desorption, Raman, FT-IR, and SEM-EDS. The resulting carbon samples were then used to prepare standard coin-sized supercapacitor cells, which were tested using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques with a 6 M KOH electrolyte. The BET surface area and surface functionality of the samples decreased as the temperature increased. The material produced at the highest temperature (AC800) exhibited the lowest gravimetric capacitance value (131 F/g). However, it demonstrated perfectly reversible electrochemical behavior with the highest capacitance retention of 50 % (between 0.5 A/g and 10 A/g) and cyclic stability (>96 %) over 10,000 cycles among all the other materials. Conversely, the electrode material produced at the lowest temperature (AC600) had the highest gravimetric capacitance value of 175 F/g but the lowest electrochemical stability due to the contribution of pseudo faradaic processes in the storage mechanism.
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•Activated carbons (ACs) were derived from RPW with ZnCl2 at various temperatures.•ACs were examined as supercapacitor electrodes materials.•The temperature had significant impact on the textural properties and capacitive behavior of ACs.•AC600 had the highest gravimetric capacitance thanks to the contribution of pseudo capacitance.•AC800 showed best reversibility, cyclic stability, and capacitance retention as the electrode material.
•Ce doped nickel ferrite was developed as a novel solid state reference electrode.•Doping of Ce in nickel ferrite was successfully achieved.•Stability of fabricated SSREs was studied in different pH ...solutions.•Fabricated Ce doped SSREs attributed strong stability and high reversibility.
In this study, we fabricated a solid-state reference electrode (SSRE) using cerium (Ce) doping in nickel ferrite (NiFe2O4) nanoparticles (NPs) to monitor the corrosion of steel rebar in concrete. The process for synthesis of NPs was sol-gel combustion. The NPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) probed with energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). These techniques confirmed that the Ce doping was achieved successfully. The electrochemical stability of the fabricated SSRE was studied in buffer solution at different pH (7, 9, and 12) as well as in synthetic concrete pore solution (SCPS) and 3% NaCl-contaminated SCPS. Chloride ions do not affect the property of Ce-doped NiFe2O4. The stability of Ce-doped SSREs in different solutions as well as in concrete was constant throughout the exposure periods. The reversibility test results of Ce-doped NiFe2O4 in SCPS solution for NiCe0.1Fe1.9O4 (NFC1) and NiCe0.5Fe1.5O4 (NFC5) showed 20 and 15mV, respective differences in potential between the forward and reverse scan. This result indicates that Ce-doped NiFe2O4 SSREs have better reversibility behavior than NiFe2O4 in SCPS. The reliability of NFC5 SSRE is excellent in SCPS and a concrete environment, and the maximum difference in both conditions was 5mV, which is within the range of acceptable values. This indicates that Ce-doped NiFe2O4 SSRE can be used as a reliable embeddable sensor in concrete structures.
The tremendous progress in deep learning has enabled to extract soft-biometric attributes from faces, which raises privacy concerns over images collected for face recognition. Advances toward ...attribute privacy have been able to conceal multiple attributes while preserving identity information but suffer from limitations: they 1) only consider a few soft-biometric attributes and 2) fail to support reversibility for attribute privacy preservation. To break these limitations, we design a reversible privacy-preserving scheme for various face attributes, called reversible attribute privacy preservation (RAPP). RAPP benefits from two modules: 1) The attribute obfuscator introduces a stream cipher to determine that special attributes have to be concealed with the user-defined password, which also supports recovering original attributes. 2) The attribute adversarial network is proposed to generate perturbed images that conceal various attributes while retaining the utility of face verification. In addition, when a wrong password is provided, the returned image with wrong attribute classification results still keeps realistic, which confuses an attacker to know whether the recovery is correct. Extensive experiments demonstrate that RAPP enables to conceal various attributes and recover original images while facilitating face verification.
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