We developed a tandem electrocatalyst for CO2‐to‐CO conversion comprising the single Cu site co‐coordinated with N and S anchored carbon matrix (Cu‐S1N3) and atomically dispersed Cu clusters (Cux), ...denoted as Cu‐S1N3/Cux. The as‐prepared Cu‐S1N3/Cux composite presents a 100 % Faradaic efficiency towards CO generation (FECO) at −0.65 V vs. RHE and high FECO over 90 % from −0.55 to −0.75 V, outperforming the analogues with Cu‐N4 (FECO only 54 % at −0.7 V) and Cu‐S1N3 (FECO 70 % at −0.7 V) configurations. The unsymmetrical Cu‐S1N3 atomic interface in the carbon basal plane possesses an optimized binding energy for the key intermediate *COOH compared with Cu‐N4 site. At the same time, the adjacent Cux effectively promotes the protonation of *CO2− by accelerating water dissociation and offering *H to the Cu‐S1N3 active sites. This work provides a tandem strategy for facilitating proton‐coupled electron transfer over the atomic‐level catalytic sites.
A tandem catalyst composed of single Cu sites co‐coordinated with N and S and atomically dispersed Cu clusters (Cu‐S1N3/Cux) was developed for CO2‐to‐CO conversion. The Cu‐S1N3/Cux exhibited a 100 % Faradaic efficiency for CO formation (FECO), outperforming the single‐atomic Cu‐N4 analogue (FECO=54 %).
Abstract
In this paper, we model the dynamics and radiation physics of the rarity event GRB 221009A afterglow in detail. By introducing a top-hat jet that propagates in an environment dominated by ...stellar winds, we explain the publicly available observations of afterglow associated with GRB 221009A over the first week. It is predicted that GRB 221009A emits a luminous very high energy afterglow based on the synchrotron self-Compton (SSC) process in our model. We show the broadband spectral energy distribution (SED) analysis results of GRB 221009A and find that the SSC radiation component of GRB 221009A is very bright in the 0.1–10 TeV band. The integrated SED shows that the SSC emission in the TeV band has detection sensitivity significantly higher than that of LHASSO, MAGIC, and CTA. However, since the release of further observations, deviations from the standard wind environment model have gradually shown up in data. For example, the late-time multiband afterglow cannot be consistently explained under the standard wind environment scenario. It may be necessary to consider modeling with a structured jet with complex geometry or a partial revision of the standard model. Furthermore, we find that the inclusion of GeV observations could break the degeneracy between model parameters, highlighting the significance of high-energy observations in determining accurate parameters for GRB afterglows.
China is currently the world's largest carbon emitter. As a large agricultural country, understanding the relationship between carbon emissions, economic growth and energy consumption in the ...agricultural sector can contribute to achieving the sustainable development of agriculture. Hence, this paper aims to investigate the relationship between carbon emissions, energy consumption and economic growth in the agricultural sector using a time series of data from China's main grain-producing areas during the period between 1996 and 2015. We first estimate the agricultural carbon emissions. And then based on the estimated results, we employ the autoregressive distributed lag (ARDL) model, the Granger causality test based on the vector error correction model (VECM), and impulse response and variance decomposition to test the relationship between carbon emissions, energy consumption and economic growth in the agricultural sector. The estimated results support the environmental Kuznets curve (EKC) hypothesis for agricultural carbon emissions in China's main grain-producing areas. Furthermore, agricultural energy consumption has both the short-run and the long-run negative impacts on agricultural carbon emissions. In addition, we find that there is a bidirectional causality between agricultural carbon emissions and agricultural economic growth in both the short-run and the long-run, and the unidirectional causalities are found to exist from agricultural energy consumption to agricultural carbon emissions and agricultural economic growth. Finally, several policy recommendations are offered to promote the sustainable development of agriculture in China's main grain-producing areas.
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•The environment-energy-economy nexus is examined for agricultural sector.•The study confirms the existence of the EKC for agricultural carbon emissions.•Bidirectional causality between carbon emissions and economic growth is found.•Unidirectional causalities from energy use to carbon emissions and economic growth.•Energy consumption contributes the most to carbon emission.
The advancement of a naturally rich and effective bifunctional substance for hydrogen and oxygen evolution reaction is crucial to enhance hydrogen fuel production efficiency via the electrolysis ...process. Herein, facile and scalable hydrothermal synthesis of bifunctional electrocatalyst of polyoxometalate anchored zinc cobalt sulfide nanowire on Ni‐foam (NF) for overall water splitting is reported for the first time. The electrochemical analysis of POM@ZnCoS/NF displays significantly low HER and OER overpotentials of 170/337 and 200/300 mV to attain a current density of 10/40 and 20/50 mA cm−2, respectively, demonstrating the notable performance of POM@ZnCoS/NF toward H2 and O2 evolution reaction in alkaline medium. Additionally, the electrolyzer consisting of the POM@ZnCoS/NF anode and cathode shows an appealing potential of 1.56 V to deliver 10 mA cm−2 current density for overall water splitting. The high electrocatalytic activity of the POM@ZnCoS/NF is attributed to modulation of the electronic and chemical properties, increment of the electroactive sites and electrochemically active surface area of the zinc cobalt sulfide nanowires due to the anchorage of polyoxometalate nanoparticles. These results demonstrate the advantage of the polyoxometalate incorporation strategy for the design of cost‐effective and highly competent bifunctional catalysts for complete water splitting.
The present investigation demonstrates a facile route for the fabrication of POM@ZnCoS nanowires for electrocatalytic water splitting via a hydrothermal process. Impressively, POM@ZnCoS nanowires deliver outstanding electrocatalytic behavior with a large number of electroactive sites, very low overpotential, and high durability for the overall water splitting process.
In the last decade, the functionally graded carbon nanotube reinforced composites (FG-CNTRCs) have attracted considerable interest due to their excellent mechanical properties, and the structures ...made of FG-CNTRCs have found broad potential applications in aerospace, civil and ocean engineering, automotive industry, and smart structures. Here we review the literature regarding the mechanical analysis of bulk CNTR nanocomposites and FG-CNTRC structures, aiming to provide a clear picture of the mechanical modeling and properties of FG-CNTRCs as well as their composite structures. The review is organized as follows: (1) a brief introduction to the functionally graded materials (FGM), CNTRCs and FG-CNTRCs; (2) a literature review of the mechanical modeling methodologies and properties of bulk CNTRCs; (3) a detailed discussion on the mechanical behaviors of FG-CNTRCs; and (4) conclusions together with a suggestion of future research trends.
Long noncoding RNAs (lncRNA) play important roles in the tumorigenesis and progression of cancers. However, the clinical significance of lncRNAs and their regulatory mechanisms in nasopharyngeal ...carcinogenesis (NPC) are largely unknown. Here, based on a microarray analysis, we identified 384 dysregulated lncRNAs, of which,
was one of the most upregulated lncRNAs in NPC.
significantly associated with poor survival in NPC. N(6)-Methyladenosine (m6A) was highly enriched within
and enhanced its RNA stability.
functioned as an oncogenic lncRNA that promoted NPC cell proliferation, migration, invasion, tumor growth, and metastasis. Mechanistically,
functioned as a competing endogenous RNA (ceRNA) for sponging miR-590-3p and miR-1275, leading to the upregulation of their target
(
), and the activation of FAK/PI3K/Akt signaling to promote NPC cell proliferation and invasion. In summary, our study reveals a potential ceRNA regulatory pathway in which
modulates
expression by binding to miR-590-3p and miR-1275, ultimately promoting tumorigenesis and metastasis in NPC. SIGNIFICANCE: These findings demonstrate the clinical significance of the lncRNA
in nasopharyngeal carcinoma (NPC) and the regulatory mechanism involved in NPC development and progression, providing a novel prognostic indicator and promising therapeutic target.
Abstract
Gamma-ray bursts (GRBs) 201015A and 201216C are valuable cases where very-high-energy (VHE) gamma-ray afterglows have been detected. By analyzing their prompt emission data, we find that GRB ...201216C is an extremely energetic, long GRB with a hard gamma-ray spectrum, while GRB 201015A is a relative subenergetic, soft-spectrum GRB. Attributing their radio–optical–X-ray afterglows to the synchrotron radiation of the relativistic electrons accelerated in their jets, we fit their afterglow lightcurves with the standard external shock model and infer their VHE afterglows from the synchrotron self-Compton scattering process of the electrons. It is found that the jet of GRB 201015A is midrelativistic (Γ
0
= 44), surrounded by a very dense medium (
n
= 1202 cm
−3
), and the jet of GRB 201216C is ultrarelativistic (Γ
0
= 331), surrounded by a moderate dense medium (
n
= 5 cm
−3
). The inferred peak luminosity of the VHE gamma-ray afterglows of GRB 201216C is approximately 10
−9
erg cm
−2
s
−1
at 57–600 s after the GRB trigger, making it detectable with the MAGIC telescopes at a high confidence level, even though the GRB is at a redshift of 1.1. Comparing their intrinsic VHE gamma-ray lightcurves and spectral energy distributions with GRBs 180720B, 190114C, and 190829A, we show that their intrinsic peak luminosity of VHE gamma-ray afterglows at 10
4
s after the GRB trigger is variable from 10
45
to 5 × 10
48
erg s
−1
, and their kinetic energy, initial Lorentz factor, and medium density are diverse among bursts.
Nitrogen-doped carbon-decorated CoP@FeCoP yolk-shelled micro-polyhedras derived from MOF composites exhibited excellent HER and OER activity in the alkaline media.
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•Yolk-shelled ...CoP@FeCoP/NC micro-polyhedras were controllably prepared.•CoP@FeCoP/NC exhibited excellent HER and OER activity in the alkaline media.•The yolk-shelled construction can increase the specific surface area and active sites.•N-doped cabron can optimize electronic structure to enhance electrocatalytic activity.
Designing efficient non-precious electrocatalysts to facilitate overall water splitting is crucial and highly desirable but remains challenging. In this study, we synthesized nitrogen-doped carbon-decorated CoP@FeCoP yolk-shelled micro-polyhedras (denoted as CoP@FeCoP/NC YSMPs) via the phosphorization of ZIF-67@Co-Fe Prussian blue analogues YSMPs. The yolk-shelled construction and nitrogen-doped carbon matrix can effectively reduce the degree of CoP agglomeration, which is beneficial for increasing the specific surface area and active sites of the catalysts. The synergistic effect of yolk-shelled structure and nigtrogen-doped carbon matrix also optimizes the electronic structure and enhances the electrocatalytic activity of CoP@FeCoP/NC YSMPs. In an alkaline electrolyte, the overpotentials of hydrogen evolution reaction and oxygen evolution reaction only need 141 and 238 mV, respectively, to drive the current density of 10 mA cm−2. When a two-electrode water splitting device was conducted with the as-prepared catalyst, it required only a low cell voltage of 1.68 V to achieve a current density of 10 mA cm−2 and displayed outstanding stability over 20 h. This work offers insights into the facile, controllable synthesis strategy of various non-precious metal nanomaterials for high-efficiency water splitting electrocatalysis.
Mesenchymal stem cells (MSCs) can suppress dendritic cells (DCs) maturation and function, mediated by soluble factors, such as indoleamine 2,3-dioxygenase (IDO), prostaglandin E(2) (PGE(2)), and ...nitric oxide (NO). Interleukin-10 (IL-10) is a common immunosuppressive cytokine, and the downstream signaling of the JAK-STAT pathway has been shown to be involved with DCs differentiation and maturation in the context of cancer. Whether IL-10 and/or the JAK-STAT pathway play a role in the inhibitory effect of MSCs on DCs maturation remains controversial. In our study, we cultured MSCs and DCs derived from rat bone marrow under different culturing conditions. Using Transwell plates, we detected by ELISA that the level of IL-10 significantly increased in the supernatants of MSC-DC co-cultures at 48 hours. The cell immunofluorescence assay suggested that the MSCs secreted more IL-10 than the DCs in the co-cultures. Adding exogenous IL-10 to the DCs monoculture or MSC-DC co-cultures stimulated IL-10 and led to a decrease in IL-12, and lower expression of the DCs surface markers CD80, CD86, OX62, MHC-II and CD11b/c. Supplementing the culture with an IL-10 neutralizing antibody (IL-10NA) showed precisely the opposite effect of adding IL-10. Moreover, we demonstrated that the JAK-STAT signaling pathway is involved in inhibiting DCs maturation. Both JAK1 and STAT3 expression and IL-10 secretion decreased markedly after adding a JAK inhibitor (AG490) to the co-culture plate. We propose that there is an IL-10 positive feedback loop, which may explain our observations of elevated IL-10 and enhanced JAK1 and STAT3 expression. Overall, we demonstrated that MSCs inhibit the maturation of DCs through the stimulation of IL-10 secretion, and by activating the JAK1 and STAT3 signaling pathway.
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