Nonaqueous rechargeable lithium–oxygen batteries (LOBs) are one of the most promising candidates for future electric vehicles and wearable/flexible electronics. However, their development is severely ...hindered by the sluggish kinetics of the ORR and OER during the discharge and charge processes. Here, we employ MOF-assisted spatial confinement and ionic substitution strategies to synthesize Ru single atoms riveted with nitrogen-doped porous carbon (Ru SAs-NC) as the electrocatalytic material. By using the optimized Ru0.3 SAs-NC as electrocatalyst in the oxygen-breathing electrodes, the developed LOB can deliver the lowest overpotential of only 0.55 V at 0.02 mA cm–2. Moreover, in-situ DEMS results quantify that the e–/O2 ratio of LOBs in a full cycle is only 2.14, indicating a superior electrocatalytic performance in LOB applications. Theoretical calculations reveal that the Ru–N4 serves as the driving force center, and the amount of this configuration can significantly affect the internal affinity of intermediate species. The rate-limiting step of the ORR on the catalyst surface is the occurrence of 2e– reactions to generate Li2O2, while that of the OER pathway is the oxidation of Li2O2. This work broadens the field of vision for the design of single-site high-efficiency catalysts with maximum atomic utilization efficiency for LOBs.
NiOOH nanosheet/graphene hydrogels (H–NiOOH/GS), with mesoporous NiOOH nanosheets uniformly dispersed within the highly interconnected 3D graphene network, are constructed and studied for the first ...time by a mixed solvothermal and hydrothermal reaction. The effect of solvent composition on the morphology, phase, dispersibility of nanocrystal and hydrogel strength is systematically studied. As binder-free electrodes of supercapacitors, H–NiOOH/GS delivers high capacitance of 1162Fg−1 at 1Ag−1 with excellent rate capability (981Fg−1 at 20Ag−1). The charge-storage mechanisms of H–NiOOH/GS are in-depth investigated by quantifying the kinetics of charge storage, which reveals that NiOOH exhibits both capacitive effects and diffusion-controlled battery-type behavior during charge storage. Additionally, solvothermal-induced pure graphene hydrogels (H-GS) are also prepared and used as the negative electrode for the first time, which show an impressive specific capacitance of 425 and 368Fg−1 at 5 and 40mVs−1, respectively. Benefitting from the synergistic contribution of both positive and negative electrodes, the assembled H–NiOOH/GS//H-GS asymmetric supercapacitors achieve a remarkable energy density of 66.8Whkg−1 at a power density of 800Wkg−1, and excellent cycling stability with 85.3% capacitance retention after 8000 cycles, holding great promise for energy storage applications.
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•A new material, NiOOH nanosheet/GS hydrogel, was prepared for the first time.•The charge-storage mechanisms of the hydrogels were in-depth investigated.•NiOOH/GS hydrogels delivered high specific capacitances and good rate capability.•The assembled H-NiOOH/GS//H-GS achieved a remarkable energy density of 66.8 Wh kg-1.
3D macroscopic tin oxide/nitrogen-doped graphene frameworks (SnO2/GN) were constructed by a novel solvothermal-induced self-assembly process, using SnO2 colloid as precursor (crystal size of 3–7 nm). ...Solvothermal treatment played a key role as N,N-dimethylmethanamide (DMF) acted both as reducing reagent and nitrogen source, requiring no additional nitrogen-containing precursors or post-treatment. The SnO2/GN exhibited a 3D hierarchical porous architecture with a large surface area (336 m2g‑1), which not only effectively prevented the agglomeration of SnO2 but also facilitated fast ion and electron transport through 3D pathways. As a result, the optimized electrode with GN content of 44.23% exhibited superior rate capability (1126, 855, and 614 mAh g‑1 at 1000, 3000, and 6000 mA g‑1, respectively) and extraordinary prolonged cycling stability at high current densities (905 mAh g‑1 after 1000 cycles at 2000 mA g‑1). Electrochemical impedance spectroscopy (EIS) and morphological study demonstrated the enhanced electrochemical reactivity and good structural stability of the electrode.
As an efficient and facile access to linear or branched allylic compounds, transition metal‐catalyzed allylic C(sp3)–H functionalization reaction via η3‐allylmetal intermediates has gained increasing ...interest in recent years. Pd, Rh, Ru, Ir, Fe and Co‐catalyzed systems have all been successfully achieved, affording various allylic compounds bearing a diverse set of functionalities. Herein, we provide a comprehensive review of this burgeoning field according to different transition metal catalysts.
Abstract
A self-supporting Co
3
O
4
/graphene hybrid film has been constructed via vacuum filtration of Co(OH)
2
nanosheet and graphene, followed by a two-step thermal treatment. Within the hybrid ...film, Co
3
O
4
nanoparticles with size of 40~60 nm uniformly
in-situ
grew on the surface of graphene, forming a novel porous and interleaved structure with strong interactions between Co
3
O
4
nanoparticles and graphene. Such fascinating microstructures can greatly facilitate interfacial electron transportation and accommodate the volume changes upon Li ions insertion and extraction. Consequently, the binder-less hybrid film demonstrated extremely high reversible capacity (1287.7 mAh g
−
1
at 0.2 A g
−
1
), excellent cycling stability and rate capability (1110 and 800 mAh g
−
1
at 0.5 and 1.0 A g
−
1
, respectively).
Sugar beet is vulnerable to years of continuous cropping, and allelopathy is one of the important factors leading to continuous cropping disorder. To explore the physiological and molecular ...mechanisms behind continuous cropping obstacles on sugar beet, this study combined transcriptomics and metabolomics to analyze the effects of different years of continuous cropping on metabolite changes, differential gene expression, and root exudate regulation in sugar beet. We collected sugar beet’s root samples from 1–, 3–, and 5-year continuous cropping systems for metabolome and transcriptome analyses. Our data revealed that T3 and T5 had 50 and 33 metabolites significantly different from T1, respectively. The autotoxic substance salicylaldehyde was found to continuously accumulate in root exudates with increasing years of continuous cropping. Sucrose was highly reduced in T3 (4.05-fold decrease) and T5 (2.01-fold decrease) compared to T1. Respectively, 2,660 and 3,515 differentially expressed genes (DEGs) were significantly regulated in T3 and T5 compared to T1. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that metabolic pathways and biosynthesis of secondary metabolites were perturbed in T3 and T5 vs. T1. Integrated metabolomics analyses identified 73 DEGs involved in enriched metabolic pathways, all of which were the oxidation-reduction process pathways. In conclusion, this study provides evidence that continuous cropping obstacles can change the metabolome and transcriptome of sugar beet, affecting its growth and quality.
The inducible nitric oxide synthase (iNOS) is associated with more aggressive solid tumors, including hepatocellular carcinoma (HCC). Notch signaling in cancer stem cells promotes cancer progression ...and requires Notch cleavage by ADAM (a disintegrin and metalloprotease) proteases. We hypothesized that iNOS/NO promotes Notch1 activation through TACE/ADAM17 activation in liver cancer stem cells (LCSCs), leading to a more aggressive cancer phenotype. Expression of the stem cell markers CD24 and CD133 in the tumors of patients with HCC was associated with greater iNOS expression and worse outcomes. The expression of iNOS in CD24⁺CD133⁺ LCSCs, but not CD24⁻CD133⁻ LCSCs, promoted Notch1 signaling and stemness characteristics in vitro and in vivo, as well as accelerating HCC initiation and tumor formation in the mouse xenograft tumor model. iNOS/NO led to Notch1 signaling through a pathway involving the soluble guanylyl cyclase/cGMP/PKG-dependent activation of TACE/ADAM17 and up-regulation of iRhom2 in LCSCs. In patients with HCC, higher TACE/ADAM17 expression and Notch1 activation correlated with poor prognosis. These findings link iNOS to Notch1 signaling in CD24⁺CD133⁺ LCSCs through the activation of TACE/ADAM17 and identify a mechanism for how iNOS contributes to progression of CD24⁺CD133⁺ HCC.
Abstract This study aims to further understand the changes in physical activity level(PAL) and mental health among adolescents before and after the outbreak of COVID-19 and explore the protective ...role of physical activity (PA) on the mental health of adolescents during major disasters. A convenient sampling method was used to conduct a cross-sectional survey. The cross-sectional data from 2838 Chinese middle school students (mean age = 14.91 ± 1.71 years, 49.54% female) were used, of which 1,471 and 1,367 were in 2021 and 2022, respectively. The PAL was collected using the Physical Activity Questionnaire for Children (PAQ-CN), mental health status was collected using the Mental Health Inventory of Middle School Students (MMHI-60), sociodemographic information was collected using a self-reported questionnaire. Before and after the outbreak of COVID-19, the PAL of adolescents was 2.36 ± 0.74 and 2.50 ± 0.66, respectively, with a significant difference ( p < 0.01, 95% CI: 0.09, 0.19). The mental health scores were 1.71 ± 0.60 and 1.86 ± 0.73, respectively, with a significant difference ( p < 0.01, 95% CI: − 0.20, − 0.10). The detection rates of mental health problems were 27.50% and 35.50%, respectively. The rates of achieving PAL standards were 30.20% and 18.00% among adolescents, while the rates of not achieving PAL standards were 39.60% and 18.00%. PA is a protective factor for the mental health of adolescents during major disasters.
Circular RNAs (circRNAs) are demonstrated to play vital roles in human diseases, including rheumatoid arthritis (RA). Therefore, this research aimed to explore the effects of hsa_circRNA_0025908 ...(circ_0025908) on RA.
RNA expression of circ_0025908, microRNA-650 (miR-650), and Signal peptide-CUBepidermal growth factor-like containing protein 2 (SCUBE2) were assessed by real-time quantitative polymerase chain reaction; protein expression of SCUBE2, apoptosis- and invasion-related proteins was evaluated by western blot assay. Functional assays were performed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide, 5-ethynyl-2'-deoxyuridine, transwell, flow cytometry, and enzyme linked immunosorbent assay assays. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays confirmed the interaction relationship among circ_0025908, miR-650, and SCUBE2.
Circ_0025908 was overexpressed in synovial tissues and fibroblast-like synoviocytes (FLS) from RA patients. Inhibition of circ_0025908 repressed proliferation, migration, invasion, inflammation, and cell cycle progression, while induced apoptosis in the FLS isolated from RA patients (FLS-RA), accompanied with increased Bax, cleaved caspase-3 and E-cadherin, but declined Bcl-2, N-cadherin and Vimentin. MiR-650 was a target of circ_0025908, and SCUBE2 was a target for miR-650. Silencing of miR-650 could overturned above effects of circ_0025908 knockdown in FLS-RA, whereas its overexpression could mimic those effects by downregulating SCUBE2. Additionally, SCUBE2 expression could be positively regulated by circ_0025908 and inversely regulated by miR-650. Notably, Pearson's correlation analysis confirmed the linear correlation among circ_0025908, miR-650 and SCUBE2 in these RA tissues.
Circ_0025908 inhibition can suppress FLS-RA dysfunctions through targeting miR-650/SCUBE2 axis, suggesting a new potential therapeutic clue for RA patients.
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