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The rocking-chair lithium-ion capacitors (RLICs), composed of a battery-type cathode and capacitive-type anode, alleviates the issue of increased internal resistance caused by electrolyte consumption during the cycling process of the lithium-ion capacitors (LICs). However, the poor conductivity of cathode materials and the mismatch between the cathode and anode are the key issues that hinder its commercial application. In this work, a modification simplification strategy is proposed to tailor the conductivity of the cathode and matching characteristic with the anode. The in situ grown lithium manganate (LMO) is featured with a three-dimensional conductive network constructed by reduced graphene oxide (rGO). The optimized LMO/rGO composite cathode demonstrates an excellent rate performance, lithium-ion diffusion rate, and cycling performance. After assembling an RLICs with activated carbon (AC), the RLICs exhibits an energy density of as high as 239.11 Wh/kg at a power density of 400 W/kg. Even at a power density of 200 kW/kg, its energy density can maintain at 39.9 Wh/kg. These excellent electrochemical performances are mainly attributed to the compounding of LMO with rGO, which not only improves the conductivity of the cathode but also realizes a better matching with the capacitive-type anode. This modification strategy provides a reference for the further development of energy storage devices suitable for actual production conditions and application scenarios.
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Modern Mars is bipolar, cold, and oxidizing, while early Mars was characterized by icy highlands, episodic warmth and reducing atmosphere. The timing and association of the climate and redox transitions remain inadequately understood. Here we examine the spatiotemporal distribution of the low surface iron abundance in the ancient Martian terrains, revealing that iron abundance decreases with elevation in the older Noachian terrains but with latitude in the younger Noachian terrains. These observations suggest: (a) low-temperature conditions contribute to surface iron depletion, likely facilitated by anoxic leaching through freeze-thaw cycles under a reducing atmosphere, and (b) temperature distribution mode shifted from elevation-dominant to latitude-dominant during the Noachian period. Additionally, we find iron leaching intensity decreases from the Early to Late Noachian epoch, suggesting a gradual atmospheric oxidation coupled with temperature mode transition during the Noachian period. We think atmospheric oxidation led to Mars becoming cold and bipolar in its early history.
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Air filtration has become a desirable route for collecting airborne microbes. However, the potential biotoxicity and sterilization of current air filtration membranes often lead to undesired inactivation of captured microbes, which greatly limits microbial non-traumatic transfer and recovery. Herein, we report a gel-confined phase separation strategy to rationally fabricate a fully bio-based filtration membrane (SGFM) using soluble soybean polysaccharide and gelatin. The versatile SGFM features fascinating honeycomb micro-nano architecture and hierarchical interconnected porous structures for microbial capture, and achieves a lower pressure drop, higher interception efficiency (99.3%), and superior microbial survivability than commercial gelatin filtration membranes. Particularly, the water-dissolvable SGFM can greatly simplify the elution and extraction process after bioaerosol sampling, thereby bringing about maximum sample transfer and vigorous recovery of collected microbes. Meanwhile, green capture coupled with ATP bioluminescence endows the SGFM with rapid and quantitative detection capability for airborne microbes. This work may pave the way for designing green protocols for the detection of bioaerosols.
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Microbiología del Aire , Filtración , Membranas Artificiales , Gelatina/química , Glycine max/química , Glycine max/microbiología , Tamaño de la Partícula , Geles/química , Tecnología Química Verde , Propiedades de Superficie , PorosidadRESUMEN
Cuticular waxes play important roles in plant development and the interaction between plants and their environment. Researches on wax biosynthetic pathways have been reported in several plant species. Also, wax formation is closely related to environmental condition. However, the regulatory mechanism between wax and environmental factors, especially essential mineral elements, is less studied. Here we found that nitrogen (N) played a negative role in the regulation of wax synthesis in apple. We therefore analysed wax content, composition and crystals in BTB-TAZ domain protein 2 (MdBT2) overexpressing and antisense transgenic apple seedlings and found that MdBT2 could downregulate wax biosynthesis. Furthermore, R2R3-MYB transcription factor 16-like protein (MdMYB106) interacted with MdBT2, and MdBT2 mediated its ubiquitination and degradation through the 26S proteasome pathway. Finally, HXXXD-type acyl-transferase ECERIFERUM 2-like1 (MdCER2L1) was confirmed as a downstream target gene of MdMYB106. Our findings reveal an N-mediated apple wax biosynthesis pathway and lay a foundation for further study of the environmental factors associated with wax regulatory networks in apple.
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Arabidopsis , Malus , Arabidopsis/genética , Malus/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Aciltransferasas/metabolismo , Ceras/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Both fulvic acid (FA) and nitrogen (N) play important roles in agricultural production in China. Plants typically show a higher nitrogen utilization efficiency (NUE) under FA application. However, the role of FA application in apple growth and NUE remains unclear. A hydroponic culture experiment was performed, and M9T337 seedlings (a dwarf apple rootstock) were used as the experimental subjects. The biomass, photosynthesis, accumulation, and distribution of photosynthates, N absorption and assimilation, and relative gene expression in the seedlings were examined after treatment with five different concentrations of FA (0, 60, 120, 180, and 240 mg·L-1, represented by CK, FA1, FA2, FA3, FA4, respectively). The results showed that the seedling dry weight and 15NUE were enhanced by FA, and both were highest under the FA2 (the concentration of fulvic acid is 120 mg·L-1) treatment. Further analysis revealed that under the FA2 treatment, the root morphology was optimized, and the root activity was relatively high. Compared with CK (control, the concentration of fulvic acid is 0 mg·L-1), the FA2 treatment strengthened photosynthesis, elevated the key enzyme activities related to C metabolism, upregulated the gene expression of sugar transport proteins, and increased the root sorbitol and sucrose contents, which suggested that the FA2 treatment optimally affected the root growth and N absorption because it enhanced photosynthate synthesis and the leaf-to-root translocation of photoassimilates. The seedlings in the FA2 treatment group also showed a significantly higher NO3- influx rate and NRT (nitrate transporter) gene expression in the roots. Moreover, relatively high N metabolism-related enzyme activities in the leaves and roots were also observed under the FA2 treatment. The isotope labeling results showed that the optimal FA2 supply not only promoted seedling 15N absorption but also optimized the distribution of C and N in the seedlings. These results suggested that an optimal FA supply (120 mg·L-1) enhanced seedling NUE by strengthening photoassimilate synthesis and transport from leaves to roots, regulating N absorption, assimilation, and distribution.
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The inert C(sp3)-H bond and easy overoxidation of toluene make the selective oxidation of toluene to benzaldehyde a great challenge. Herein, we present that a photocatalyst, constructed with a small amount (1 mol %) of amorphous BiOCl nanosheets assembled on TiO2 (denoted as 0.01BOC/TiO2), shows excellent performance in toluene oxidation to benzaldehyde, with 85% selectivity at 10% conversion, and the benzaldehyde formation rate is up to 1.7 mmol g-1 h-1, which is 5.6 and 3.7 times that of bare TiO2 and BOC, respectively. In addition to the charge separation function of the BOC/TiO2 heterojunction, we found that the amorphous structure of BOC endows its abundant surface oxygen vacancies (Ov), which can further promote the charge separation. Most importantly, the surface Ov of amorphous BOC can efficiently adsorb and activate O2, and amorphous BOC makes the product, benzaldehyde, easily desorb from the catalyst surface, which alleviates the further oxidation of benzaldehyde, and results in the high selectivity. This work highlights the importance of the microstructure based on heterojunctions, which is conducive to the rational design of photocatalysts with high performance in organic synthesis.
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The robust and scalable oxygen evolution electrocatalysts that can deliver high current densities at low applied potential is a great challenge for the large-scale industrial application in hydrogen production. Here, the preparation of a grain-boundary-rich Ni-Fe (oxy)hydroxide catalyst on Ni foam is reported using a scalable coating approach followed by a chemical precipitating treatment. This facile method effectively assembles the hierarchical Ni-Fe (oxy)hydroxide nanosheet in the ultrasmall crystalline domains (<4 nm) with rich grain boundaries. The hierarchical nanosheet structure with the grain boundaries provides more accessible catalytic sites, facile charge, and mass transfer. Benefiting from the abundant grain boundaries in the hierarchical nanosheets, the as-prepared Ni-Fe (oxy)hydroxide electrodes deliver current densities of 500 and 1000 mA cm-2 at overpotentials of only 278 and 296 mV for the oxygen evolution reaction. The prepared electrode also exhibits long-term durability at a high current density in alkaline conditions.
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Introduction: High salinity significantly hampers global agricultural productivity. Plants typically undergo lower nitrogen utilization efficiency (NUE) under salt stress. As an active byproduct from brassinolide biosynthesis, 24-epibrassinolide (EBR) is involved in regulating the stress-treated plant N absorption and assimilation. However, the exogenous EBR application effects' on N absorption and assimilation in apple exposed to the salt-stressed condition remains unclear. Methods: We sprayed exogenous EBR (0.2 mg L-1) on apple dwarf rootstock (M9T337) seedlings (growing hydroponically) under salt (NaCl) stress in a growth chamber. We analyzed the seedling development, photosynthesis and its-mediated C fixation, N ( NO 3 - ) absorption and assimilation in reponse to exogenous EBR application under salt stress. Results: The findings demonstrated that NaCl stress greatly hampered seedlings' root growth and that exogenous EBR application obviously alleviated this growth suppression. Exogenous EBR-treated plants under NaCl stress displayed the more ideal root morphology and root activity, stronger salt stress tolerance and photosynthetic capacity as well as higher C- and N-assimilation enzyme activities, NO 3 - ion flow rate and nitrate transporter gene expression level than did untreated plants. Furthermore, the results of isotope labeling noted that exogenous EBR application also enhanced 13C-photoassimilate transport from leaves to roots and 15 NO 3 - transport from roots to leaves under NaCl stress. Conclusion: Our findings imply that exogenous EBR application, through strengthening photosynthesis, C- and N-assimilation enzyme activities, nitrate absorption and transport as well as synchronized optimizing the distribution of seedlings' C and N, has a fundamental role in improving NUE in apple rootstock seedlings under salt stress.
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To improve the availability of inorganic phosphorus (P) in soil, we investigated the role of three macromolecular organic acids (MOAs), including fulvic acid (FA), polyaspartic acid (PA), and tannic acid (TA), in reducing the fixation of inorganic P fertilizer in the soil. AlPO4, FePO4, and Ca8H2(PO4)6·5H2O crystals were chosen as insoluble phosphate representatives in the soil to simulate the solubilization process of inorganic P by MOAs. The microstructural and physicochemical properties of AlPO4, FePO4, and Ca8H2(PO4)6·5H2O were determined by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) before and after treatment of MOAs. In addition, the amounts of leached P and fixed inorganic P in Inceptisols and Alfisols affected by MOAs combined with superphosphate (SP) fertilizer were determined by soil leaching experiments. The presence of the three MOAs significantly increased the concentration of leached P and reduced the contents of insoluble inorganic phosphate formed with iron, aluminum, and calcium fixed in the soil, in which PA combined with SP had the most significant effect. Furthermore, the less inorganic P fixation in the combination treatment of MOAs and SP resulted in a greater wheat yield and P uptake. Therefore, MOAs could be a synergistic material for increasing P fertilizer utilization.
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Identifying electrocatalysts with functions of easy dissociation of water, rapid transformation of hydroxyl and facile hydrogen-hydrogen bond formation are indispensable while challenge for realizing efficient alkaline hydrogen evolution reaction (HER). Herein, we presented the design of Ni3 Sn2 -NiSnOx nanocomposites towards addressing this challenge. We showed that Ni3 Sn2 possessed ideal hydrogen adsorption and low hydroxyl adsorption abilities and NiSnOx facilitated water dissociation and hydroxyl transfer process, respectively. Consequently, the fine-tuned interplay of the two functional parts realized the mutual coordination among the multiple functions and led to significantly boosted HER kinetics. Current densities of 10 and 1000â mA cm-2 were obtained at overpotentials of 14 and 165â mV on the optimized catalyst. This work highlights the significance of considering intrinsic interactions between active sites and all pertinent intermediates on obtaining promising electrocatalysts.
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Involving eight electron transfer process and multiple intermediates of nitrate (NO3 - ) reduction reaction leads to a sluggish kinetic and low Faradaic efficiency, therefore, it is essential to get an insight into the reaction mechanism to develop highly efficient electrocatalyst. Herein, a series of reduced-graphene-oxide-supported RuCu alloy catalysts (Rux Cux /rGO) are fabricated and used for the direct reduction of NO3 - to NH3 . It is found that the Ru1 Cu10 /rGO shows the ammonia formation rate of 0.38 mmol cm-2 h-1 (loading 1 mg cm-2 ) and the ammonia Faradaic efficiency of 98% under an ultralow potential of -0.05 V versus Reversible Hydrogen Electode (RHE), which is comparable to Ru catalyst. The highly efficient activity of Ru1 Cu10 /rGO can be attributed to the synergetic effect between Ru and Cu sites via a relay catalysis, in which the Cu shows the exclusively efficient activity for the reduction of NO3 - to NO2 - and Ru exhibits the superior activity for NO2 - to NH3 . In addition, the doping of Ru into Cu tunes the d-band center of alloy and effectively modulates the adsorption energy of the NO3 - and NO2 - , which promotes the direct reduction of NO3 - to NH3 . This synergetic electrocatalysis strategy opens a new avenue for developing highly efficient multifunctional catalysts.
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Hydrogen peroxide (H2O2), as a main component of reactive oxygen species (ROS), serves as a key signaling molecule relevant to plant stress response and health status. Many strategies have been developed for detecting or quantifying H2O2 concentration. However, reports on simply, visibly tracking H2O2 fluctuation in vivo are limited. Here, for visibly tracking the plant H2O2 wave, a green fluorescent phenotypic probe was designed by merging a H2O2-sensitive tertiary amine moiety with the core fluorophore tetraphenylethene skeleton. The green fluorescence emission is quenched up to 52% by H2O2 with good sensitivity, selectivity, and reversibility within the plant physiological range of 10-100 µM H2O2. In response to various abiotic stresses, including mechanical damage, high salt, strong light and drought, fluorescence fluctuations, response to H2O2 concentration alterations in vivo was visible to the naked eye under irradiation of commercially available UV light (365 nm) after simple injection of this H2O2 probe solution into seedling leaves. This phenotypic fluorescent H2O2 probe illustrates great potential as early sensors of plant health under stress without the aid of skillful operation and specialized equipment.
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Colorantes Fluorescentes , Peróxido de Hidrógeno , Sequías , Estado de Salud , Especies Reactivas de OxígenoRESUMEN
An appropriate pretreatment process is an important part of the preparation of biomass energy from agricultural and forestry waste. Compared to physical and chemical pretreatments alone, the combined ammoniated fiber explosion (AFEX) + hydrogen peroxide (H2O2) pretreatment process can significantly improve the lignin degradation rate and saccharification efficiency, thus improving the hydrogen production capacity during medium-temperature dark fermentation. This study showed that the combined pretreatment increased the saccharification efficiency of herbaceous, hardwood, and softwood biomass by 58.7, 39.5, and 20.6% and the corresponding gas production reached 145.49, 80.75, and 57.52 mL/g, respectively. In addition, X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy showed that AFEX + H2O2 disrupted the structure of the feedstock and was more favorable for lignin removal. Soluble metabolites indicated that AFEX + H2O2 pretreatment enhanced the butyrate metabolic pathway of the substrate and biohydrogen generation and increased the levels of extracellular polymers and microbial community structure.
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The most essential issue facing the world today is the provision of energy and sustainable consumption of natural resources. Pretreatment is an essential step to produce biofuels from lignocellulosic biomass. In this study, ammonia fiber explosion (AFEX) combined with NaOH (A-NaOH) pretreatment effects on the characteristics of Pennisetum sinese (herbaceous), oak (hardwood), and camphor wood (softwood) were assessed using enzymatic efficiency analysis, thereby identifying the composition properties of subsequent bio-H2 production. The results show that the lignin removal (84.2%, 59.7%, and 36.7%, respectively) at 5%A-NaOH conditions and enzymatic efficiency (36.2%, 9.7%, and 6.5%, respectively) of Pennisetum sinese (P. sinese), oak, and camphor wood were significantly increased under 4% A-NaOH conditions. Further A-NaOH pretreatment significantly promoted dark fermentation bio-H2 production (152.3, 99.1, and 76.9 mL/g TS, respectively) and volatile acid production (4660.2, 3720.2, and 3496.2 mg/L, respectively) of P. sinese, oak, and camphor wood. These findings show that A-NaOH pretreatment is an effective means of utilization of lignocellulose resources.
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SignificanceThere is a common consensus that lode gold deposits mostly precipitated from metamorphic fluids via fluid boiling and/or fluid-rock interaction, but whether magmatic hydrothermal fluids and the mixing of such fluids with an external component have played a vital role in the formation of lode gold deposits remains elusive. We use garnet secondary ion mass spectrometry oxygen isotope analysis to demonstrate that the world-class Dongping lode gold deposit has been formed by multiple pulses of magmatic hydrothermal fluids and their mixing with large volumes of meteoric water. This study opens an opportunity to tightly constrain the origin of lode gold deposits worldwide and other hydrothermal systems that may have generated giant ore deposits in the Earth's crust.
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To prolong the shelf life of perishable food with a simple and environmentally friendly postharvest preservation technology is one of the global concerns. This study aimed to explore the application value of biological macromolecule natural cellulose nanofibers (CNFs) in extending the postharvest fruit shelf life. In this study, 0.5% (wt%) CNFs were prepared from natural wood and coated on the surface of early-ripening apple fruits. After 10 days of storage at room temperature, the results revealed that the shelf life of apple fruits with CNF coating was significantly prolonged, and the fruit appearance quality improved. The invisible network structure of CNFs in the fruit epidermis was observed under an atomic force microscope (AFM). The gas chromatography and mass spectrometry (GC-MS) analysis showed that CNFs significantly promoted the formation of epidermal wax, especially fatty alcohols, during storage. In addition, the CNFs remarkably promoted the upregulation of genes related to the synthesis of cuticular wax of apple. In conclusion, this study provides an environmentally sustainable nanomaterial for post-harvest preservation of horticultural products, and also provides a new insight into the effect of CNFs on postharvest storage of apple fruits.
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Photoelectrocatalytic (PEC) degradation of organic pollutants into CO2 and H2O is a promising strategy for addressing ever-growing environmental problems. Titanium dioxide (TiO2) has been widely studied because of its good performance and environmental benignancy; however, the PEC activity of TiO2 catalyst is substantially limited due to its fast electron-hole recombination. Herein, we report a TiO2 nanocone-based photoelectrocatalyst with superior degradation performance and outstanding durability. The unique conical catalyst can boost the PEC degradation of 4-chlorophenol (4-CP) with 99% degradation efficiency and higher than 55% mineralization efficiency at a concentration of 20 ppm. The normalized apparent rate constant of a nanocone catalyst is 5.05 h-1 g-1 m2, which is 3 times that of a nanorod catalyst and 6 times that of an aggregated particle catalyst, respectively. Further characterizations reveal that the conical morphology of TiO2 can make photogenerated charges separate and transfer more efficiently, resulting in outstanding PEC activity. Moreover, computational fluid dynamics simulations indicate that a three-dimensional conical structure is beneficial for mass transfer. This work highlights that tuning the morphology of a photoelectrocatalyst at the nanometer scale not only promotes the charge transfer but also facilitates the mass transportation, which jointly enhance the PEC performance in the degradation of persistent pollutants.
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KEY MESSAGE: MdBZR1 directly binds to the promoter of MdABI5 and suppresses its expression to mediate ABA response. The plant hormones brassinosteroids (BRs) and abscisic acid (ABA) antagonistically regulate various aspects of plant growth and development. However, the association between BR and ABA signaling is less clear. Here, we identified MdBZR1 in apple (Malus domestica) and demonstrated that it was activated by BRs and could respond to ABA treatment. Overexpression of MdBZR1 in apple calli and Arabidopsis reduced ABA-hypersensitive phenotypes, suggesting that MdBZR1 negatively regulates ABA signaling. Subsequently, we found that MdBZR1 directly bound to the promoter region of MdABI5 and suppressed its expression. MdABI5 was significantly induced by ABA treatment. And overexpression of MdABI5 in apple calli increased sensitivity to ABA. Ectopic expression of MdABI5 in Arabidopsis inhibited seed germination and seedling growth. In addition, overexpression of MdBZR1 partially attenuated MdABI5-mediated ABA sensitivity. Taken together, our data indicate that MdBZR1 directly binds to the promoter of MdABI5 and suppresses its expression to antagonistically mediate ABA response. Our work contributes to the functional studies of BZR1 and further broadens the insight into the between BR and ABA signaling.
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Ácido Abscísico/metabolismo , Malus/genética , Proteínas de Plantas/genética , Ácido Abscísico/farmacología , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Malus/efectos de los fármacos , Malus/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Estrés Salino/genéticaRESUMEN
Nitrate is essential for plant growth and development. When nitrate availability is low, plants produce more lateral roots (LRs) to seek nitrate from the soil. In this study, by DNA electrophoretic mobility shift and luciferase assays, it was showed that NIN-like protein 7 (NLP7) transcription factor activated expression of TAR2 by directly binding to its promoter. Finally, through genetic analysis, it was speculated that NLP7 regulated LR development through TAR2. In conclusion, NLP7 binds to the TAR2 promoter and activates TAR2 expression, thereby promoting nitrate-dependent LR development.
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Proteínas de Arabidopsis/fisiología , Arabidopsis/crecimiento & desarrollo , Raíces de Plantas/crecimiento & desarrollo , Factores de Transcripción/fisiología , Triptófano-Transaminasa/fisiología , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Clorofila/metabolismo , Inmunoprecipitación de Cromatina , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos/metabolismo , Malus/crecimiento & desarrollo , Malus/metabolismo , Nitratos/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal , Factores de Transcripción/metabolismo , Triptófano-Transaminasa/metabolismoRESUMEN
Bentonite was modified by introducing humic acid (HA) into interlayer space of bentonite. The structural and physicochemical properties of modified bentonite were determined by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray powder diffraction (XRD) and thermogravimetric analysis (TGA). The results showed that HA could enter the bentonite interlayer and increase the interlayer distance. Moreover, we were also investigated the high adsorption capacity and thermodynamics of modified bentonite to NH4+ cations in solutions. Under the same conditions, the NH4+ adsorption efficiency of modified bentonite (96.4%) was 69.2% higher compared with the natural bentonite (57.0%). The pseudo-second order kinetic model well fit the adsorption kinetics of NH4+ on modified bentonite, indicating that the adsorption type was chemical adsorption or chemisorptions. The isotherms fit well with Langmuir model, and the separation factor revealed that NH4+ on modified bentonite belonged to favorable adsorption. Compared with the natural bentonite, the modified bentonite exhibited a much lower leaching loss of NH4+-N and NO3--N in soil. Meanwhile, the loss of nitrogen caused by NH3 volatilization and N2O emission from soil could also be significantly attenuated by the combined application of modified bentonite and urea. The slower nitrogen release in the treatment combining modified bentonite and urea resulted in a greater yield and nitrogen uptake of wheat. Collectively, the modified bentonite could be used as nitrogen fertilizer synergist to enhance the nitrogen use efficiency.