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Intermetallic nanomaterials have shown promising potential as high-performance catalysts in various catalytic reactions due to their unconventional crystal phases with ordered atomic arrangements. However, controlled synthesis of intermetallic nanomaterials with tunable crystal phases and unique hollow morphologies remains a challenge. Here, a seeded method is developed to synthesize hollow PdSn intermetallic nanoparticles (NPs) with two different intermetallic phases, that is, orthorhombic Pd2 Sn and monoclinic Pd3 Sn2 . Benefiting from the rational regulation of the crystal phase and morphology, the obtained hollow orthorhombic Pd2 Sn NPs deliver excellent electrocatalytic performance toward glycerol oxidation reaction (GOR), outperforming solid orthorhombic Pd2 Sn NPs, hollow monoclinic Pd3 Sn2 NPs, and commercial Pd/C, which places it among the best reported Pd-based GOR electrocatalysts. The reaction mechanism of GOR using the hollow orthorhombic Pd2 Sn as the catalyst is investigated by operando infrared reflection absorption spectroscopy, which reveals that the hollow orthorhombic Pd2 Sn catalyst cleaves the CC bond more easily compared to the commercial Pd/C. This work can pave an appealing route to the controlled synthesis of diverse novel intermetallic nanomaterials with hollow morphology for various promising applications.
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Nb-modified anatase-supported Pt nanoparticles were synthesized for the efficient conversion of cellulose to light bioalcohols. Characterization confirmed the presence of SMSIs in the catalysts, offering adjacent hydrogenation sites, Brønsted and Lewis acid sites. Treating the catalysts in humid air enhanced the acidic concentration, accelerating the key step during the reaction.
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Celulose , Nanopartículas , Nióbio , CatáliseRESUMO
Given the high energy density and eco-friendly characteristics, lithium-carbon dioxide (Li-CO2) batteries have been considered to be a next-generation energy technology to promote carbon neutral and space exploration. However, Li-CO2 batteries suffer from sluggish reaction kinetics, causing large overpotential and poor energy efficiency. Here, we observe enhanced reaction kinetics in aprotic Li-CO2 batteries with unconventional phase 4H/face-centered cubic (fcc) iridium (Ir) nanostructures grown on gold template. Significantly, 4H/fcc Ir exhibits superior electrochemical performance over fcc Ir in facilitating the round-trip reaction kinetics of Li+-mediated CO2 reduction and evolution, achieving a low charge plateau below 3.61 V and high energy efficiency of 83.8%. Ex situ/in situ studies and theoretical calculations reveal that the boosted reaction kinetics arises from the highly reversible generation of amorphous/low-crystalline discharge products on 4H/fcc Ir via the Ir-O coupling. The demonstration of flexible Li-CO2 pouch cells with 4H/fcc Ir suggests the feasibility of using unconventional phase nanomaterials in practical scenarios.
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Solid polymer electrolytes (SPEs) possess improved thermal and mechanical stability as safe energy storage devices. However, their low ion mobilities and poor electrochemical stabilities still hinder the wide industrial application of SPEs. Herein, we introduce an SPE design that provides an enormous number of electrochemically stable pathways and space for lithium-ion transport, blending polymer (polydopamine) hollow nanospheres with an inactive inorganic template into a poly(ethylene oxide) (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) based SPE. Hollow silica acts as a template for polydopamine processing a large contact area with the polymer electrolyte, and the interface between the polymer electrolyte and hollow composite fillers provides amounts of ion transport channels. In addition, theoretical calculations reveal a strong adsorption between polydopamine and TFSI-, which suppresses the TFSI- motion and meanwhile facilitates the selective Li+ transport. The hollow polydopamine can serve as a versatile platform for anion trapping and has large compatible and stable depression for a well-defined ion transfer interface layer, forming a three-in-one nanocomposite for the enhancement of ionic conductivity with no sacrifice of the mechanical properties. Experimental data confirmed the high mobility of ions within the composite electrolyte with an ionic conductivity of 0.189 mS cm-1 in comparison to the SPE without additives (0.105 mS cm-1) at 60 °C. The mobility of the Li+ increases after adding the polymer-coated inorganic additives, associated with a noticeable enlargement of the electrochemical window. Furthermore, an all-solid-state Li/LiFePO4 battery with a hollow polydopamine nanoparticle-polymer composite electrolyte shows long life, high reversible capacity (134.9 mAh g-1), and high capacity retention (97.2%) after 205 cycles at 0.2 C.
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Electrocatalytic carbon dioxide reduction reaction (CO2 RR) holds significant potential to promote carbon neutrality. However, the selectivity toward multicarbon products in CO2 RR is still too low to meet practical applications. Here the authors report the delicate synthesis of three kinds of Ag-Cu Janus nanostructures with {100} facets (JNS-100) for highly selective tandem electrocatalytic reduction of CO2 to multicarbon products. By controlling the surfactant and reduction kinetics of Cu precursor, the confined growth of Cu with {100} facets on one of the six equal faces of Ag nanocubes is realized. Compared with Cu nanocubes, Ag65 -Cu35 JNS-100 demonstrates much superior selectivity for both ethylene and multicarbon products in CO2 RR at less negative potentials. Density functional theory calculations reveal that the compensating electronic structure and carbon monoxide spillover in Ag65 -Cu35 JNS-100 contribute to the enhanced CO2 RR performance. This study provides an effective strategy to design advanced tandem catalysts toward the extensive application of CO2 RR.
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Myopia is the most common eye condition leading to visual impairment and is greatly influenced by genetics. Over the last two decades, more than 400 associated gene loci have been mapped for myopia and refractive errors via family linkage analyses, candidate gene studies, genome-wide association studies (GWAS), and next-generation sequencing (NGS). Lifestyle factors, such as excessive near work and short outdoor time, are the primary external factors affecting myopia onset and progression. Notably, besides becoming a global health issue, myopia is more prevalent and severe among East Asians than among Caucasians, especially individuals of Chinese, Japanese, and Korean ancestry. Myopia, especially high myopia, can be serious in consequences. The etiology of high myopia is complex. Prediction for progression of myopia to high myopia can help with prevention and early interventions. Prediction models are thus warranted for risk stratification. There have been vigorous investigations on molecular genetics and lifestyle factors to establish polygenic risk estimations for myopia. However, genes causing myopia have to be identified in order to shed light on pathogenesis and pathway mechanisms. This report aims to examine current evidence regarding (1) the genetic architecture of myopia; (2) currently associated myopia loci identified from the OMIM database, genetic association studies, and NGS studies; (3) gene-environment interactions; and (4) the prediction of myopia via polygenic risk scores (PRSs). The report also discusses various perspectives on myopia genetics and heredity.
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We report the synthesis of a tantalum phosphate catalyst with abundant strong acid sites, which is very active for the catalytic conversion of acetone into mesitylene. Characterizations, kinetic studies, and theoretical results show a relationship between the acidic sites and catalytic performance in this reaction.
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With the development of phase engineering of nanomaterials (PEN), construction of noble-metal heterostructures with unconventional crystal phases, including heterophases, has been proposed as an attractive approach toward the rational design of highly efficient catalysts. However, it still remains challenging to realize the controlled preparation of such unconventional-phase noble-metal heterostructures and explore their crystal-phase-dependent applications. Here, various Pd@Ir core-shell nanostructures are synthesized with unconventional fcc-2H-fcc heterophase (2H: hexagonal close-packed; fcc: face-centered cubic) through a wet-chemical seeded method. As a result, heterophase Pd66 @Ir34 nanoparticles, Pd45 @Ir55 multibranched nanodendrites, and Pd68 @Ir22 Co10 trimetallic nanoparticles are obtained via the phase-selective epitaxial growth of fcc-2H-fcc-heterophase Ir-based nanostructures on 2H-Pd seeds. Importantly, the heterophase Pd45 @Ir55 nanodendrites exhibit excellent catalytic performance toward electrochemical hydrogen evolution reaction (HER) under acidic conditions. An overpotential of only 11.0 mV is required to achieve a current density of 10 mA cm-2 on Pd45 @Ir55 nanodendrites, which is lower than those of the conventional fcc-Pd47 @Ir53 counterparts, commercial Ir/C and Pt/C. This work not only demonstrates an appealing route to synthesize novel heterophase nanomaterials for promising applications in the emerging field of PEN, but also highlights the significant role of the crystal phase in determining their catalytic properties.
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In this work, a new type of micromesoporous substance was prepared with fatty alcohol-polyoxyethylene ether (AEO) surfactant freezing penetration and pyrolysis using shells as raw materials. The obtained material exhibited good adsorbability and could be added to oil-contaminated soil to adsorb the pollutant, which resulted in the regeneration of the initially polluted soil. It was determined that the main component of the developed substance was CaCO3. Importantly, the conducted experiments revealed that the obtained mussel micromesoporous material displayed certain adsorption effects toward petroleum hydrocarbons in a diesel solution. Moreover, it was found that chemical adsorption was more optimal than physical adsorption. The soil remediation effect was the best when the content of the mussel micromesoporous material in the soil was 400â g/kg. Under these conditions, the removal rate of petroleum hydrocarbon was established at 49.38%. This study indicated that micromesoporous material has great potential in the application of oil contaminated soil remediation.
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Bivalves , Recuperação e Remediação Ambiental , Poluição por Petróleo , Petróleo , Poluentes do Solo , Animais , Biodegradação Ambiental , Hidrocarbonetos , Porosidade , Solo/química , Poluentes do Solo/análiseRESUMO
Herein, using electron-deficient alkenes embedded with an oxidizing function/leaving group as a rare and nontraditional C1 synthon, we have achieved the redox-neutral Rh(III)-catalyzed chemo- and regioselective [4 + 1] annulation of benzamides for the synthesis of functionalized isoindolinones. This method features broad substrate scope, good to excellent yields, excellent chemo- and regioselectivity, good tolerance of functional groups and mild external-oxidant-free conditions.
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Crystal phase engineering of noble-metal-based alloy nanomaterials paves a new way to the rational synthesis of high-performance catalysts for various applications. However, the controlled preparation of noble-metal-based alloy nanomaterials with unconventional crystal phases still remains a great challenge due to their thermodynamically unstable nature. Herein, we develop a robust and general seeded method to synthesize PdCu alloy nanomaterials with unconventional hexagonal close-packed (hcp, 2H type) phase and also tunable Cu contents. Moreover, galvanic replacement of Cu by Pt can be further conducted to prepare unconventional trimetallic 2H-PdCuPt nanomaterials. Impressively, 2H-Pd67Cu33 nanoparticles possess a high mass activity of 0.87 A mg-1Pd at 0.9 V (vs reversible hydrogen electrode (RHE)) in electrochemical oxygen reduction reaction (ORR) under alkaline condition, which is 2.5 times that of the conventional face-centered cubic (fcc) Pd69Cu31 counterpart, revealing the important role of crystal phase on determining the ORR performance. After the incorporation of Pt, the obtained 2H-Pd71Cu22Pt7 catalyst shows a significantly enhanced mass activity of 1.92 A mg-1Pd+Pt at 0.9 V (vs RHE), which is 19.2 and 8.7 times those of commercial Pt/C and Pd/C, placing it among the best reported Pd-based ORR electrocatalysts under alkaline conditions.
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Spartina alterniflora is an invasive plant from coastal wetlands, and its use in applications has garnered much interest. In this study, a composite photocatalyst (ZnO@BC) was synthesized by preparing zinc oxide (ZnO) nanoparticles with S. alterniflora extracts, S. alterniflora, and one-step carbonization, which was characterized using scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Raman, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy (UV-vis DRS), photoluminescence (PL) and N2 adsorption-desorption isotherm. The degradation capacity and mechanism of malachite green (MG) using ZnO@BC were analyzed under visible irradiation, and the degradation products of malachite green were detected by LC-MS. The results show that ZnO@BC has a larger surface area (83.2 m2/g) and various reactive groups, which enhance its photocatalytic efficiency, with the presence of oxygen vacancy further improving the photocatalytic activity. The total removal rate of malachite green (400 mg/L) using ZnO@BC is up to 98.38%. From the LC-MS analysis, it could be concluded that malachite green is degraded by demethylation, deamination, conjugate structure and benzene ring structure destruction. This study provides a novel idea for the high-value utilization of S. alterniflora.
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Layered 2D materials, such as graphene, transition metal dichalcogenides, transition metal oxides, black phosphorus, graphitic carbon nitride, hexagonal boron nitride, and MXenes, have attracted intensive attention over the past decades owing to their unique properties and wide applications in electronics, catalysis, energy storage, biomedicine, etc. Further reducing the lateral size of layered 2D materials down to less than 10 nm allows for preparing a new class of nanostructures, namely, nanodots derived from layered materials. Nanodots derived from layered materials not only can exhibit the intriguing properties of nanodots due to the size confinement originating from the ultrasmall size, but also can inherit some unique properties of ultrathin layered 2D materials, making them promising candidates in a wide range of applications, especially in biomedicine and catalysis. Here, a comprehensive summary on the materials categories, advantages, synthesis methods, and potential applications of these nanodots derived from layered materials is provided. Finally, personal insights about the challenges and future directions in this promising research field are also given.
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Exploiting internal alkenes embedded with an oxidizing function/leaving group as a rare and unconventional one-carbon unit, a redox-neutral rhodium(III)-catalyzed chemo- and regiospecific [4+1] annulation between indoles and alkenes for the synthesis of functionalized imidazo[1,5-a]indoles has been achieved. Internal alkenes employed here can fulfill an unusual [4+1] annulation rather than normal [4+2] annulation/C-H alkenylation. This method is characterized by excellent chemo- and regioselectivity, broad substrate scope, good functional group tolerance, good to high yields, and redox-neutral conditions.
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Herein, we report the divergent synthesis of alkynylated imidazo[1,5-a]indoles and α,α-difluoromethylene tetrasubstituted alkenes through Rh(III)-catalyzed [4 + 1] annulation/alkyne moiety migration and C-H alkenylation/DG migration, respectively. This protocol features tunable product selectivity, excellent chemo-, regio-, and stereoselectivity, broad substrate scope, moderate to high yields, good tolerance of functional groups, and mild redox-neutral conditions.
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Rechargeable alkali metal-ion batteries (AMIBs) are receiving significant attention owing to their high energy density and low weight. The performance of AMIBs is highly dependent on the electrode materials. It is, therefore, quite crucial to explore suitable electrode materials that can fulfil the future requirements of AMIBs. Herein, a hierarchical hybrid yolk-shell structure of carbon-coated iron selenide microcapsules (FeSe2 @C-3 MCs) is prepared via facile hydrothermal reaction, carbon-coating, HCl solution etching, and then selenization treatment. When used as the conversion-typed anode materials (CTAMs) for AMIBs, the yolk-shell FeSe2 @C-3 MCs show advantages. First, the interconnected external carbon shell improves the mechanical strength of electrodes and accelerates ionic migration and electron transmission. Second, the internal electroactive FeSe2 nanoparticles effectively decrease the extent of volume expansion and avoid pulverization when compared with micro-sized solid FeSe2 . Third, the yolk-shell structure provides sufficient inner void to ensure electrolyte infiltration and mobilize the surface and near-surface reactions of electroactive FeSe2 with alkali metal ions. Consequently, the designed yolk-shell FeSe2 @C-3 MCs demonstrate enhanced electrochemical performance in lithium-ion batteries, sodium-ion batteries, and potassium-ion batteries with high specific capacities, long cyclic stability, and outstanding rate capability, presenting potential application as universal anodes for AMIBs.
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Osteosarcoma is the most frequent bone malignancy in children and adolescents. Despite advances of surgery and chemotherapy in osteosarcoma over the past decades, overall survival rates of osteosarcoma have reached a plateau. The development of multi-drug resistance (MDR) has become the main obstacle in improving chemotherapeutic effects in osteosarcoma treatment. Therefore, understanding detailed mechanisms of chemoresistance and developing novel therapeutic targets to overcome chemoresistance are crucial to improve the prognosis of osteosarcoma patients. Accumulating evidence has proved that multiple noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) play pivotal roles in osteosarcoma progression. Notably, a great number of ncRNAs are abnormally expressed and can regulate chemosensitivity through various mechanisms in osteosarcoma. In this review, we systematically summarize the roles of ncRNAs as well as the molecular mechanisms in modulating drug resistance of osteosarcoma and discuss the potential roles of ncRNAs as biomarkers and novel therapeutic targets for osteosarcoma.
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Neoplasias Ósseas/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Osteossarcoma/patologia , RNA não Traduzido/metabolismo , Antineoplásicos/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/metabolismo , Humanos , MicroRNAs/metabolismo , Osteossarcoma/tratamento farmacológico , Osteossarcoma/metabolismoRESUMO
Chalcogenide-based anodes are receiving increasing attention for rechargeable potassium-ion batteries (PIBs) due to their high theoretical capacities. However, they usually exhibit poor electrochemical performance due to poor structural stability, low conductivity, and severe electrolyte decomposition on the reactive surface. Herein, a method analogous to "blowing bubbles with gum" is used to confine FeS2 and FeSe2 in N-doped carbon for PIB anodes with ultrahigh cyclic stability and enhanced rate capability (over 5000 cycles at 2 A g-1). Several theoretical and experimental methods are employed to understand the electrodes' performance. The density functional theory calculations showed high affinity for potassium adsorption on the FeS2 and FeSe2. The in situ XRD and ex situ TEM analysis confirmed the formation of several intermediate phases of the general formula KxFeS2. These phases have high conductivity and large interlayer distance, which promote reversible potassium insertion and facilitate the charge transfer. Also, the calculated potassium diffusion coefficient during charge/discharge further proves the enhanced kinetics. Furthermore, The FeS2@NC anode in a full cell also exhibits high cyclic stability (88% capacity retention after 120 cycles with 99.9% Coulombic efficiency). Therefore, this work provides not only an approach to overcome several challenges in PIB anodes but also a comprehensive understanding of the mechanism and kinetics of the potassium interaction with chalcogenides.
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Pancreatic cancer is the fourth-leading cause of cancer-related deaths and is expected to be the second-leading cause of cancer-related deaths in Europe and the United States by 2030. The high fatality rate of pancreatic cancer is ascribed to untimely diagnosis, early metastasis and limited responses to both chemotherapy and radiotherapy. Although gemcitabine, 5-fluorouracil and some other drugs can profoundly improve patient prognosis, most pancreatic cancer patients eventually develop drug resistance, leading to poor clinical outcomes. The underlying mechanisms of pancreatic cancer drug resistance are complicated and inconclusive. Interestingly, accumulating evidence has demonstrated that different noncoding RNAs (ncRNAs), such as microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), play a crucial role in pancreatic cancer resistance to chemotherapy reagents. In this paper, we systematically summarize the molecular mechanism underlying the influence of ncRNAs on the generation and development of drug resistance in pancreatic cancer and discuss the potential role of ncRNAs as prognostic markers and new therapeutic targets for pancreatic cancer.
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Antineoplásicos/farmacologia , Neoplasias Pancreáticas/patologia , RNA não Traduzido/genética , Animais , Biomarcadores Tumorais/genética , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , PrognósticoRESUMO
Highly stretchable and transparent ionic conducting materials have enabled new concepts of electronic devices denoted as iontronics, with a distinguishable working mechanism and performances from the conventional electronics. However, the existing ionic conducting materials can hardly bear the humidity and temperature change of our daily life, which has greatly hindered the development and real-world application of iontronics. Herein, we design an ion gel possessing unique traits of hydrophobicity, humidity insensitivity, wide working temperature range (exceeding 100°C, and the range covered our daily life temperature), high conductivity (10-3~10-5 S/cm), extensive stretchability, and high transparency, which is among the best-performing ionic conductors ever developed for flexible iontronics. Several ion gel-based iontronics have been demonstrated, including large-deformation sensors, electroluminescent devices, and ionic cables, which can serve for a long time under harsh conditions. The designed material opens new potential for the real-world application progress of iontronics.