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Zinc ion capacitors (ZICs) have shown potential for breaking the energy density ceiling of traditional supercapacitors (SCs) via appropriate device design. Nevertheless, a significant challenge remains in advancing ZIC positive electrode materials with excellent conductivity, high specific capacitance, and reliable cycle stability. A highly attractive option for carbon-based electrode materials is reduced graphene oxide (RGO) due to its vast specific surface area, prominent porosity, and 3D cross-linked frame. However, the tight stacking of RGO sheets driven by van der Waals forces can restrict active sites, decrease specific capacitance, and elevate electrochemical impedance. To overcome these challenges, 3D defective RGO (DRGO) hydrogels were prepared by a metal Co cocatalytic gasification reaction. This method produced mesoporous defects on the surface of RGO hydrogels via a low-temperature hydrothermal self-assembly strategy. The surface of the layer has a wide and uniform distribution, which can offer abundant redox active sites, rich ion transfer channels, and fast reaction kinetics. In this work, 3D DRGO//Zn exhibited a wide operating window (0-1.8 V), high specific capacitance (189.39 F g-1 at 1 A g-1), outstanding energy density (85.23 W h kg-1 at 960.31 W kg-1; 52.36 W h kg-1 at 17454.87 W kg-1), and persistent cycling life (98.86% initial capacitance retention after 10 000 cycles at 10 A g-1). This study emphasizes the device design of ZIC and promising prospects of using 3D DRGO hydrogel as a feasible positive electrode for ZIC.
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Although Ti3C2Tx MXenes have attracted attention in electrochemical energy storage devices due to their excellent electronic conductivity, controllable layer structure, and huge redox active surface area, the application of Ti3C2Tx as supercapacitor (SC) electrode materials is severely limited by the ineffective chemical ion transport kinetics caused by self-restacking. In order to increase the interlayer spacing of Ti3C2Tx, the intercalation method is hailed as an effective process. Herein, polyaniline (PANI) nanorods as intercalators were synthesized by the polymerization of an aniline (ANI) monomer chemisorbed onto Ti3C2Tx wrinkled nanosheets, and the formation of a Ti3C2Tx@PANI heterostructure is conducive to the large interlayer voids. Then, the heterostructure was integrated into a three-dimensional (3D) porous cross-linked framework via a simple graphene oxide (GO)-assisted self-convergence hydrothermal strategy with low temperatures. Due to the synergistic effect among each component and 3D porous interconnected structure, the hierarchical Ti3C2Tx@PANI-reduced graphene oxide (RGO) heterostructure hydrogel possesses the advantages of excellent electrical conductivity, high specific capacitance, repressive aggregation, and large electrochemical active area. Heterostructure hydrogel electrodes (without binders) display excellent electrochemical performance with a specific capacitance as high as 301.0 F g-1 at 1 A g-1, 90.74% capacitance retention over 10 000 cycles, and a maximum energy density of 44.6 W h kg-1 at a power density of 504.7 W kg-1. Our study provides a fresh strategy for constructing a 3D Ti3C2Tx-based framework applicable to other MXenes in the design of hybrid structures for maximizing their potential applications in energy storage.
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The practical application of supercapacitors (SCs) has been known to be restricted by low energy density, and zinc ion capacitors (ZICs) with a capacitive cathode and a battery-type anode have emerged as a unique technology that can effectively mitigate the issue. To this end, the design of electrodes with low electrochemical impedance, high specific capacitance, and outstanding reaction stability represents a critical first step. Herein, we report the synthesis of hierarchical Ti3C2TX@PANI heterostructures by uniform deposition of conductive polyaniline (PANI) polymer nanofibers on the exposed surface of the Ti3C2TX nanosheets, which are then assembled into a three-dimensional (3D) cross-linking framework by a graphene oxide (GO)-assisted self-convergence hydrothermal strategy. This resulting 3D Ti3C2TX@PANI-reduced graphene oxide (Ti3C2TX@PANI-RGO) heterostructure hydrogel shows a large surface area (488.75 F g-1 at 0.5 A g-1), outstanding electrical conductivity, and fast reaction kinetics, making it a promising electrode material. Separately, defective RGO (DRGO) hydrogels are prepared by a patterning process, and they exhibit a broad and uniform distribution of mesopores, which is conducive to ion transport with an excellent specific capacitance (223.52 F g-1 at 0.5 A g-1). A ZIC is subsequently constructed by utilizing Ti3C2TX@PANI-RGO as the anode and DRGO as the cathode, which displays an extensive operating voltage (0-3.0 V), prominent energy density (1060.96 Wh kg-1 at 761.32 W kg-1, 439.87 Wh kg-1 at 9786.86 W kg-1), and durable cycle stability (retaining 67.9% of the original capacitance after 4000 cycles at 6 A g-1). This study underscores the immense prospect of the Ti3C2TX-based heterostructure hydrogel and DRGO as a feasible anode and cathode for ZICs, respectively.
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PURPOSE: Cancer-related expenditures present a lasting economic burden on patients and their families and may exert long-term adverse effects on the patients' life and quality of life. In this study, the comprehensive score for financial toxicity (COST) was used to investigate the financial toxicity (FT) levels and related risk factors in Chinese patients with cancer. METHODS: Quantitative data were collected through a questionnaire covering three aspects: sociodemographic information, economic and behavioral cost-coping strategies, and the COST scale. Univariate and multivariate analyses were performed to identify factors associated with FT. RESULTS: According to 594 completed questionnaires, the COST score ranged 0-41, with a median of 18 (mean±SD, 17.98±7.978). Over 80% of patients with cancer reported at least moderate FT (COST score <26). A multivariate model showed that urban residents, coverage by other health insurance policies, and higher household income and consumption expenditures were significantly associated with higher COST scores, indicative of lower FT. The middle-aged (45-59 years old), higher out-of-pocket (OOP) medication expenditures and hospitalizations, borrowed money, and forgone treatment were all significantly associated with lower COST scores, indicating higher FT. CONCLUSION: Severe FT was associated with sociodemographic factors among Chinese patients with cancer, family financial factors, and economic and behavioral cost-coping strategies. Government should identify and manage the patients with high-risk characteristics of FT and work out better health policies for them.
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Habilidades de Afrontamiento , Costo de Enfermedad , Estrés Financiero , Gastos en Salud , Humanos , Estrés Financiero/psicología , Neoplasias/economía , Neoplasias/epidemiología , Neoplasias/terapia , Calidad de Vida , Factores de Riesgo , Pueblos del Este de Asia/psicología , China/epidemiología , Factores Sociodemográficos , Determinantes Sociales de la Salud , Masculino , Femenino , Persona de Mediana Edad , Habilidades de Afrontamiento/métodosRESUMEN
Asymmetric supercapacitors (ASCs) based on a battery-type anode and a capacitive-type cathode have been attracting extensive interest because of their high energy density. Herein, NiO nanosheets are hydrothermally deposited onto a V4C3TX substrate, which are then assembled into a 3D porous heterostructure hydrogel through a graphene oxide-assisted self-convergence hydrothermal process at low temperatures. The resultant hierarchical V4C3TX@NiO-RGO heterostructure hydrogel exhibits an ultrahigh specific capacitance of up to 1014.5 F g-1 at 1 A g-1. In addition, a defective reduced graphene oxide (DRGO) hydrogel is prepared using a cost-effective hydrothermal procedure followed by cobalt-catalyzed gasification, which shows a higher specific capacitance (258 F g-1 at 1 A g-1) than the untreated RGO hydrogel (176 F g-1). These two electrodes are then assembled into an ASC; the device features a stable operating voltage of 1.8 V, a maximum energy density of 86.22 W h kg-1 at 900 W kg-1, and excellent cycling stability at 96.4% capacitance retention after 10 000 cycles at 10 A g-1. The results from this work highlight the unique potential of MXene-based materials for the construction of high-performance ASCs.
RESUMEN
The rational design of an asymmetric supercapacitor (ASC) with an expanded operating voltage window has been recognized as a promising strategy to maximize the energy density of the device. Nevertheless, it remains challenging to have electrode materials that feature good electrical conductivity and high specific capacitance. Herein, a 3D layered Ti3C2TX@NiO-reduced graphene oxide (RGO) heterostructured hydrogel was successfully synthesized by uniform deposition of NiO nanoflowers onto Ti3C2TX nanosheets, and the heterostructure was assembled into a 3D porous hydrogel through a hydrothermal GO-gelation process at low temperatures. The resultant Ti3C2TX@NiO-RGO heterostructured hydrogel exhibited an ultrahigh specific capacitance of 979 F g-1 at 0.5 A g-1, in comparison to that of Ti3C2TX@NiO (623 F g-1) and Ti3C2TX (112 F g-1). Separately, a defective RGO (DRGO) hydrogel was found to exhibit a drastic increase in specific capacitance, compared to untreated RGO (261 vs 178 F g-1 at 0.5 A g-1), owing to abundant mesopores. These two materials were then used as free-standing anode and cathode to construct an ASC, which displayed a large operating voltage (1.8 V), a high energy density (79.02 Wh kg-1 at 450 W kg-1 and 45.68 Wh kg-1 at 9000 W kg-1), and remarkable cycling stability (retention of 95.6% of the capacitance after 10,000 cycles at 10 A g-1). This work highlights the unique potential of Ti3C2TX-based heterostructured hydrogels as viable electrode materials for ASCs.
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The environmental degradation and physical aging of microplastics (MP) caused by oxidative stress have not been thoroughly elucidated. In this study, we used different oxidative agents (Fe2+-activated peroxymonosulfate and Fenton reagents) that can form free radicals to study the degradation mechanisms of nylon 6 (PA6) and polystyrene (PS) MPs. After 4 cycles of treatment, mass losses of 25.6% and 22.1% were obtained with PA6 and PS MPs, respectively. Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) were employed to confirm the MP oxidation, and polymer chain scissions. FTIR data indicated the existence of oxygen-containing chemical groups resulting from MPs oxidation, and chain scissions, such as CO, C-O, and O-CO. Raman spectroscopy suggested the presence of exposed aromatic groups, and weakening of the relative intensity of C-H related to the oxidation, and chain scission of the MPs. SEM imaging revealed visible morphological changes on the surface of MPs as a result of degradation. XPS indicated that the O/C ratio could be used as an indicator for the degree of MPs oxidation. By analyzing the degradation products with surface-enhanced Raman scattering (SERS) and gas chromatography-mass spectrometry, low-molecular-weight alkanes, alcohols, aldehydes, carboxylic acids derived from the derivatization of alcohols, were detected. These findings confirmed the advantage of using multiple analytic methods in tandem to evaluate the degradation of environmental MPs.
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Microplásticos , Contaminantes Químicos del Agua , Alcoholes , Plásticos , Poliestirenos/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/análisisRESUMEN
Accurate detection of mercury ions (Hg2+) in water is of great importance for environmental protection. Here, a surface-enhanced Raman scattering (SERS) sensor using bovine-serum-albumin-modified gold-silicon nanowire arrays (Au@SiNWAs) is used to detect the ions. The SiNWAs were grown via chemical etching; the addition of modified gold particles on the surface formed Au@SiNWAs to increase the surface activity. The Raman enhancement factor was as large as â¼2.52 × 105, which was also confirmed with finite-difference time-domain simulations. The detection limit for Hg2+ ions in water was as low as â¼10-12 M, which is much lower than that stipulated by the United States Environmental Protection Agency's maximum residue requirements for drinking water. Furthermore, the SERS intensity was linear with the log of the Hg2+ concentration between 1 pM and 100 nM, with a correlation coefficient of 0.992. There was no significant interference when other metal ions were present, which shows the excellent selectivity of the SERS sensor. Unknown Hg2+ concentrations in water can be readily determined in an accurate and reliable manner, with a relative standard deviation of â¼9.21%.
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Mercurio , Nanopartículas del Metal , Animales , Bovinos , Iones , Albúmina Sérica Bovina , Espectrometría Raman , AguaRESUMEN
A previous study revealed that energy cane bagasse (ECB) pretreated with ionic liquid (IL), 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]), exhibited significantly higher enzymatic digestibility than untreated or water-treated ECB due to delignification and reduction of cellulose crystallinity. This study evaluated the effect of multiple recycled IL on the pretreatment of ECB for enzymatic hydrolysis. ECB was pretreated with [EMIM][OAc] (5% (w/w)) at 100 °C or 120 °C for 0.5 h up to 4 h followed by hydrolysis with commercially available enzymes. The post-pretreatment IL-containing liquid was evaporated at 100 °C for 12 h to remove water and then reused during pretreatment without any further purification. The enzymatic digestibility decreased as the number of pretreatment recycles increased. Decreasing pretreatment temperatures from 120 °C to 100 °C and extending the residence times from 0.5 h to 2 h brought significant improvement to the pretreatment efficiency of recycled [EMIM][OAc] on ECB.
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Celulasa/química , Celulosa/química , Líquidos Iónicos/química , Lignina/síntesis química , Reciclaje/métodos , Saccharum/química , HidrólisisRESUMEN
Ionic liquids (ILs) are promising solvents for the pretreatment of lignocellulose as they are thermally stable, environmentally friendly, recyclable, and have low volatility. This study evaluated the effect of 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) for the pretreatment of energy cane bagasse in terms of biomass composition, structural changes and enzymatic digestibility. Energy cane bagasse was pretreated with [EMIM][OAc] (5% (w/w)) at 120 °C for 30 min followed by hydrolysis with commercially available enzymes, Spezyme CP and Novozyme 188. IL-treated energy cane bagasse resulted in significant lignin removal (32.0%) with slight glucan and xylan losses (8.8% and 14.0%, respectively), and exhibited a much higher enzymatic digestibility (87.0% and 64.3%) than untreated (5.5% and 2.8%) or water-treated (4.0% and 2.1%) energy cane bagasse in terms of both cellulose and hemicellulose digestibilities, respectively. The enhanced digestibilities of IL-treated biomass can be attributed to delignification and reduction of cellulose crystallinity as confirmed by FTIR and XRD analyses.
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Biotecnología/métodos , Celulosa/química , Celulosa/metabolismo , Líquidos Iónicos/farmacología , Saccharum/química , Saccharum/efectos de los fármacos , Biomasa , Celulasa/metabolismo , Celulosa/ultraestructura , Cristalización , Hidrólisis/efectos de los fármacos , Imidazoles/farmacología , Líquidos Iónicos/química , Lignina/química , Polisacáridos/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Agua/farmacología , Difracción de Rayos X , beta-Glucosidasa/metabolismoRESUMEN
BACKGROUND: Herba Moslae is a well-known edible and medicinal plant in China, and the essential oil, which is assumed to contain the active components, was isolated by steam distillation method. The aim of this study was to investigate the antimicrobial activity and the antioxidant activity of the essential oil from Herba Moslae. RESULTS: The essential oil from Herba Moslae exhibited antimicrobial activity against all of the tested bacteria and fungi. The minimum inhibitory concentration (MIC) values for bacteria ranged from 118 to 472 microg mL(-1), and the minimum bactericidal concentration (MBC) values were from 236 to 944 microg mL(-1). The oil showed pronounced antibacterial and antifungal activity against Staphylococcus aureus and Aspergillus oryzae, but weak inhibition to Escherichia coli. The antioxidant activity of the essential oil from Herba Moslae was evaluated by using DPPH radical scavenging assay, beta-carotene/linoleic acid bleaching assay and metal chelating activity assay. In addition, the amount of total phenolic content in the oil (386 +/- 1 microg kg(-1)) was determined. CONCLUSION: This study suggests that the essential oil from Herba Moslae could be potentially used as a new potential source of natural antimicrobial, antioxidants and antiputrefactive in food industry.