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1.
Proc Natl Acad Sci U S A ; 120(27): e2300625120, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37364101

RESUMO

The dehydrogenation reaction of bioderived ethanol is of particular interest for the synthesis of fuels and value-added chemicals. However, this reaction historically suffered from high energy consumption (>260 °C or >0.8 V) and low efficiency. Herein, the efficient conversion of alcohol to hydrogen and aldehyde is achieved by integrating the thermal dehydrogenation reaction with electrochemical hydrogen transfer at low temperature (120 °C) and low voltage (0.06 V), utilizing a bifunctional catalyst (Ru/C) with both thermal-catalytic and electrocatalytic activities. Specifically, the coupled electrochemical hydrogen separation procedure can serve as electrochemical hydrogen pumps, which effectively promote the equilibrium of ethanol dehydrogenation toward hydrogen and acetaldehyde production and simultaneously purifies hydrogen at the cathode. By utilizing this strategy, we achieved boosted hydrogen and acetaldehyde yields of 1,020 mmol g-1 h-1 and 1,185 mmol g-1 h-1, respectively, which are threefold higher than the exclusive ethanol thermal dehydrogenation. This work opens up a prospective route for the high-efficiency production of hydrogen and acetaldehyde via coupled thermal-electrocatalysis.

2.
Plant J ; 118(6): 1872-1888, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38481350

RESUMO

As a plant-specific transcription factor, lateral organ boundaries domain (LBD) protein was reported to regulate plant growth and stress response, but the functional research of subfamily II genes is limited. SlMYC2, a master regulator of Jasmonic acid response, has been found to exhibit high expression levels in fruit and has been implicated in the regulation of fruit ripening and resistance to Botrytis. However, its role in fruit expansion remains unknown. In this study, we present evidence that a subfamily II member of LBD, namely SlLBD40, collaborates with SlMYC2 in the regulation of fruit expansion. Overexpression of SlLBD40 significantly promoted fruit growth by promoting mesocarp cell expansion, while knockout of SlLBD40 showed the opposite result. Similarly, SlMYC2 knockout resulted in a significant decrease in cell expansion within the fruit. Genetic analysis indicated that SlLBD40-mediated cell expansion depends on the expression of SlMYC2. SlLBD40 bound to the promoter of SlEXPA5, an expansin gene, but did not activate its expression directly. While, the co-expression of SlMYC2 and SlLBD40 significantly stimulated the activation of SlEXPA5, leading to an increase in fruit size. SlLBD40 interacted with SlMYC2 and enhanced the stability and abundance of SlMYC2. Furthermore, SlMYC2 directly targeted and activated the expression of SlLBD40, which is essential for SlLBD40-mediated fruit expansion. In summary, our research elucidates the role of the interaction between SlLBD40 and SlMYC2 in promoting cell expansion in tomato fruits, thus providing novel insights into the molecular genetics underlying fruit growth.


Assuntos
Frutas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Solanum lycopersicum , Fatores de Transcrição , Solanum lycopersicum/genética , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética
3.
Plant J ; 118(2): 373-387, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38159103

RESUMO

Petals in rapeseed (Brassica napus) serve multiple functions, including protection of reproductive organs, nutrient acquisition, and attraction of pollinators. However, they also cluster densely at the top, forming a thick layer that absorbs and reflects a considerable amount of photosynthetically active radiation. Breeding genotypes with large, small, or even petal-less varieties, requires knowledge of primary genes for allelic selection and manipulation. However, our current understanding of petal-size regulation is limited, and the lack of markers and pre-breeding materials hinders targeted petal-size breeding. Here, we conducted a genome-wide association study on petal size using 295 diverse accessions. We identified 20 significant single nucleotide polymorphisms and 236 genes associated with petal-size variation. Through a cross-analysis of genomic and transcriptomic data, we focused on 14 specific genes, from which molecular markers for diverging petal-size features can be developed. Leveraging CRISPR-Cas9 technology, we successfully generated a quadruple mutant of Far-Red Elongated Hypocotyl 3 (q-bnfhy3), which exhibited smaller petals compared to the wild type. Our study provides insights into the genetic basis of petal-size regulation in rapeseed and offers abundant potential molecular markers for breeding. The q-bnfhy3 mutant unveiled a novel role of FHY3 orthologues in regulating petal size in addition to previously reported functions.


Assuntos
Brassica napus , Brassica rapa , Brassica napus/genética , Estudo de Associação Genômica Ampla , Sistemas CRISPR-Cas , Melhoramento Vegetal , Brassica rapa/genética , Mutagênese
4.
Plant Physiol ; 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38478471

RESUMO

During meiotic prophase I, chromosomes undergo large-scale dynamics to allow homologous chromosome pairing, prior to which chromosome ends attach to the inner nuclear envelope and form a chromosomal bouquet. Chromosome pairing is crucial for homologous recombination and accurate chromosome segregation during meiosis. However, the specific mechanism by which homologous chromosomes recognize each other is poorly understood. Here, we investigated the process of homologous chromosome pairing during early prophase I of meiosis in rice (Oryza sativa) using pooled oligo probes specific to an entire chromosome or chromosome arm. We revealed that chromosome pairing begins from both ends and extends towards the center from early zygotene through late zygotene. Genetic analysis of both trisomy and autotetraploidy also showed that pairing initiation is induced by both ends of a chromosome. However, healed ends that lack the original terminal regions on telocentric and acrocentric chromosomes cannot initiate homologous chromosome pairing, even though they may still enter the telomere clustering region at the bouquet stage. Furthermore, a chromosome that lacks the distal parts on both sides loses the ability to pair with other intact chromosomes. Thus, the native ends of chromosomes play a crucial role in initiating homologous chromosome pairing during meiosis and likely have a substantial impact on genome differentiation.

5.
Plant J ; 116(3): 717-727, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37632767

RESUMO

Crossovers (COs) are necessary for generating genetic diversity that breeders can select, but there are conserved mechanisms that regulate their frequency and distribution. Increasing CO frequency may raise the efficiency of selection by increasing the chance of integrating more desirable traits. In this study, we characterize rice FANCM and explore its functions in meiotic CO control. FANCM mutations do not affect fertility in rice, but they cause a great boost in the overall frequency of COs in both inbred and hybrid rice, according to genetic analysis of the complete set of fancm zmm (hei10, ptd, shoc1, mer3, zip4, msh4, msh5, and heip1) mutants. Although the early homologous recombination events proceed normally in fancm, the meiotic extra COs are not marked with HEI10 and require MUS81 resolvase for resolution. FANCM depends on PAIR1, COM1, DMC1, and HUS1 to perform its functions. Simultaneous disruption of FANCM and MEICA1 synergistically increases CO frequency, but it is accompanied by nonhomologous chromosome associations and fragmentations. FANCM interacts with the MHF complex, and ablation of rice MHF1 or MHF2 could restore the formation of 12 bivalents in the absence of the ZMM gene ZIP4. Our data indicate that unleashing meiotic COs by mutating any member of the FANCM-MHF complex could be an effective procedure to accelerate the efficiency of rice breeding.


Assuntos
Oryza , Oryza/genética , DNA Helicases/genética , Melhoramento Vegetal , Meiose/genética , Recombinação Homóloga , Troca Genética
6.
J Am Chem Soc ; 146(22): 14954-14958, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38804682

RESUMO

Copper (Cu) single-atom catalysts (SACs) exhibit great potential for generating multicarbon (C2+) products, but the intrinsic activity of single-atom Cu (Cu1) under realistic conditions remains controversial. Herein, we perform extensive calculations with explicit solvation to investigate the underlying mechanism of Cu SACs, disclosing the absence of C2+ activity in Cu1 sites regardless of the different substrates. The original Cu1 sites (first taking Cu1 stably anchored on carbon nitride as an example) cannot facilitate *CO hydrogenation and CO-CO coupling due to the lack of active sites nearby, and they are unstable under operation, causing leaching and aggregation to form small Cu clusters. The derived Cu clusters composed of at least three Cu atoms can efficiently promote CO-CO coupling, as revealed by kinetic analyses. We extend the modeling to other typical Cu SACs and reveal that all of the Cu1 sites are inactive, while the C2+ performance of the derived Cu-cluster catalysts is substrate-dependent. This study offers mechanistic insights into Cu SACs and provides practical guidance for their rational optimization.

7.
Small ; 20(26): e2309972, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38279615

RESUMO

In this work, novel ternary composite ZIF-67/Ag NPs/NaYF4:Yb,Er is synthesized by solvothermal method. The photocatalytic activity of the composite is evaluated by sulfadiazine (SDZ) degradation under simulated sunlight. High elimination efficiency of the composite is 95.4% in 180 min with good reusability and stability. The active species (h+, ·O2 - and ·OH) are identified. The attack sites and degradation process of SDZ are deeply investigated based on theoretical calculation and liquid chromatography-mass spectrometry analysis. The upconversion mechanism study shows that favorable photocatalytic effectiveness is attributed to the full utilization of sunlight through the energy transfer upconversion process and fluorescence resonance energy transfer. Additionally, the composite is endowed with outstanding light-absorbing qualities and effective photogenerated electron-hole pair separation thanks to the localized surface plasmon resonance effect of Ag nanoparticles. This work can motivate further design of novel photocatalysts with upconversion luminescence performance, which are applied to the removal of sulphonamide antibiotics in the environment.

8.
Plant Physiol ; 192(2): 1063-1079, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-36905369

RESUMO

Centromeres consist of highly repetitive sequences that are challenging to map, clone, and sequence. Active genes exist in centromeric regions, but their biological functions are difficult to explore owing to extreme suppression of recombination in these regions. In this study, we used the CRISPR/Cas9 system to knock out the transcribed gene Mitochondrial Ribosomal Protein L15 (OsMRPL15), located in the centromeric region of rice (Oryza sativa) chromosome 8, resulting in gametophyte sterility. Osmrpl15 pollen was completely sterile, with abnormalities appearing at the tricellular stage including the absence of starch granules and disrupted mitochondrial structure. Loss of OsMRPL15 caused abnormal accumulation of mitoribosomal proteins and large subunit rRNA in pollen mitochondria. Moreover, the biosynthesis of several proteins in mitochondria was defective, and expression of mitochondrial genes was upregulated at the mRNA level. Osmrpl15 pollen contained smaller amounts of intermediates related to starch metabolism than wild-type pollen, while biosynthesis of several amino acids was upregulated, possibly to compensate for defective mitochondrial protein biosynthesis and initiate consumption of carbohydrates necessary for starch biosynthesis. These results provide further insight into how defects in mitoribosome development cause gametophyte male sterility.


Assuntos
Oryza , Oryza/genética , Oryza/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Genes de Plantas , Amido/metabolismo , Pólen/genética , Pólen/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
9.
Cardiovasc Diabetol ; 23(1): 164, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38724987

RESUMO

Dynamin-related protein 1 (Drp1) is a crucial regulator of mitochondrial dynamics, the overactivation of which can lead to cardiovascular disease. Multiple distinct posttranscriptional modifications of Drp1 have been reported, among which S-nitrosylation was recently introduced. However, the detailed regulatory mechanism of S-nitrosylation of Drp1 (SNO-Drp1) in cardiac microvascular dysfunction in diabetes remains elusive. The present study revealed that mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) was consistently upregulated in diabetic cardiomyopathy (DCM) and promoted SNO-Drp1 in cardiac microvascular endothelial cells (CMECs), which in turn led to mitochondrial dysfunction and cardiac microvascular disorder. Further studies confirmed that MAP4K4 promoted SNO-Drp1 at human C644 (mouse C650) by inhibiting glutathione peroxidase 4 (GPX4) expression, through which MAP4K4 stimulated endothelial ferroptosis in diabetes. In contrast, inhibition of MAP4K4 via DMX-5804 significantly reduced endothelial ferroptosis, alleviated cardiac microvascular dysfunction and improved cardiac dysfunction in db/db mice by reducing SNO-Drp1. In parallel, the C650A mutation in mice abolished SNO-Drp1 and the role of Drp1 in promoting cardiac microvascular disorder and cardiac dysfunction. In conclusion, our findings demonstrate that MAP4K4 plays an important role in endothelial dysfunction in DCM and reveal that SNO-Drp1 and ferroptosis activation may act as downstream targets, representing potential therapeutic targets for DCM.


Assuntos
Cardiomiopatias Diabéticas , Dinaminas , Células Endoteliais , Transdução de Sinais , Animais , Humanos , Masculino , Camundongos , Células Cultivadas , Circulação Coronária , Cardiomiopatias Diabéticas/metabolismo , Cardiomiopatias Diabéticas/genética , Cardiomiopatias Diabéticas/fisiopatologia , Cardiomiopatias Diabéticas/patologia , Cardiomiopatias Diabéticas/enzimologia , Cardiomiopatias Diabéticas/etiologia , Modelos Animais de Doenças , Dinaminas/metabolismo , Dinaminas/genética , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Células Endoteliais/enzimologia , Células Endoteliais/efeitos dos fármacos , Ferroptose/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/patologia , Mitocôndrias Cardíacas/enzimologia , Processamento de Proteína Pós-Traducional , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética
10.
Chemistry ; 30(28): e202400414, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38454788

RESUMO

Li-CO2 batteries facilitate renewable energy storage in a cost-effective, eco-friendly manner. However, an inadequate understanding of their reaction mechanism severely impedes their development. Here we outline recent mechanistic advances in the discharge processes of Li-CO2 batteries, particularly in terms of the theoretical aspect. First, the vital factors affecting the formation of discharge intermediates are highlighted, and a surface lithiation mechanism predominantly applicable to catalysts with weak CO2 adsorption is proposed. Subsequently, the modeling of the chemical potential of Li++e-, which is crucial for the evaluation of the theoretical limiting voltage, is detailed. Finally, challenges and future directions pertaining to the further development of Li-CO2 are discussed. In essence, this concept article seeks to inspire future experimental and theoretical studies in advancing the development of Li-CO2 electrochemical technology.

11.
J Org Chem ; 89(8): 5871-5877, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38595315

RESUMO

A palladium-catalyzed iodine-assisted carbonylation reaction of indoles with readily available ClCF2CO2Na and alcohols has been developed. This protocol provides a practical and efficient approach to highly regioselective indole-3-carboxylates via a preiodination strategy of indoles. Different from classic carbonylation using toxic and difficult-to-handle carbon monoxide, this operationally simple and scalable reaction employed difluorocarbene as the carbonyl surrogate.

12.
Cell Mol Biol (Noisy-le-grand) ; 70(1): 207-212, 2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38372095

RESUMO

To investigate whether rosmarinic acid protects cardiomyocytes from inflammatory damage through miRNAs, high-throughput sequencing and bioinformatics analysis were performed to identify TNF-α-induced inflammatory damage in cardiomyocytes and miRNAs differentially expressed in TNF-α-induced inflammatory injury in cardiomyocytes, and the bioinformatics analysis shown that the expression levels of 10 miRNAs were significantly up-regulated, and the expression levels of 6 miRNAs were significantly down-regulated. Among them, the expression level of miR-344a-3p was significantly up-regulated in the experimental group, while the expression level of miR-449c-5p was significantly down-regulated in experimental group of cells. The target genes of miR-344a-3p and miR-449c-5p were CCR1 and ATP2B4 respectively. The luciferase reporter system showed that luciferase activity in the WT-CCR1+miR-344a-3p mimic group was significantly decreased, and the expression of CCR1 was significantly decreased at mRNA and protein level after miR-344a-3p was transfected into H9C2 cells, indicating that TNF-α-induced inflammatory injury in cardiomyocytes, rosmarinic acid may up-regulate the expression of miR-344a-3p, thereby inhibiting the expression of CCR1 and ultimately protecting the cardiomyocytes from inflammatory damage. Thus, we thought that CCR1 might be a new therapeutic target for cardiomyocyte injury.


Assuntos
MicroRNAs , Miócitos Cardíacos , Miócitos Cardíacos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Ácido Rosmarínico , MicroRNAs/genética , MicroRNAs/metabolismo , Luciferases/metabolismo , Apoptose/fisiologia
13.
Cell Mol Biol (Noisy-le-grand) ; 70(4): 196-201, 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38678606

RESUMO

The superiority of drug-coated balloon (DCB) in treating small vessels, branching lesions, and high-risk bleeding lesions in coronary heart disease patients has been confirmed. However, its safety and efficacy in large vessels are still unclear. We aimed to investigate whether the efficacy of DCB in large vessels is not inferior to that of drug-eluting stent (DES). From November 2019 to April 2022, a total of 88 patients in our hospital who underwent coronary angiography for the first time and decided to receive DCB or DES treatment were selected. Indicators including late lumen loss (LLL), major adverse cardiovascular event (MACE) rate, major bleeding and all-cause mortality were evaluated at 9 months and 1-year post percutaneous coronary intervention (PCI) therapy. The primary endpoint of 9-month LLL was -0.07 in the DCB group and 0.19 mm in the DES group (p value<0.001). 1-year cumulative MACE rates were similar in the DCB and DES groups (3.03% vs. 7.23%, P=0.519), TLR rates were similar (3.03% vs. 7.23%, P=0.519), Major bleeding was similar (3.03% vs. 5.45%, P=0.580), and 1 case of Cardiac death in DES group. For LLL, the DCB-only strategy was non-inferior to DES in treating de novo large lesions in the coronary arteries. Furthermore, the efficacy of DCB was comparable to DES at 1 year of follow-up for secondary clinical endpoints.


Assuntos
Angioplastia Coronária com Balão , Angiografia Coronária , Doença da Artéria Coronariana , Vasos Coronários , Stents Farmacológicos , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Stents Farmacológicos/efeitos adversos , Angioplastia Coronária com Balão/métodos , Angioplastia Coronária com Balão/efeitos adversos , Doença da Artéria Coronariana/terapia , Doença da Artéria Coronariana/diagnóstico por imagem , Idoso , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/patologia , Intervenção Coronária Percutânea/métodos , Resultado do Tratamento , Hemorragia/etiologia
14.
Phys Chem Chem Phys ; 26(21): 15120-15124, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38752288

RESUMO

Covalent organic frameworks (COFs) exhibit great potential for electrocatalysis. Here, using DFT calculations and constant-potential modelling, we report the feasibility of a series of COFs toward NO reduction via regulating their central metal atoms and linking ligands. A COF with single-atom Mn is identified to possess superior activity while maintaining high NH3 selectivity.

15.
Neoplasma ; 71(3): 279-288, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38958715

RESUMO

Osteosarcoma (OS) is a common primary bone tumor in children and adolescents. Circular RNA (circRNA)-IARS acts as an oncogene in multiple human tumors. However, the circ-IARS function in OS is unclear. This research aimed to elucidate the roles and mechanisms of circ-IARS in OS. In this study, circ-IARS expressions were raised in OS tissues and cells. circ-IARS expressions were closely related to clinical stage and distant metastasis. Furthermore, overall survival rates were reduced in OS patients with high circ-IARS levels. Also, silencing circ-IARS weakened OS cell proliferation and invasion, yet enhanced cell ferroptosis. Mechanistically, circ-IARS targeted miR-188-5p to regulate RAB14 expressions in OS cells. Moreover, circ-IARS knockdown repressed OS cell proliferation, invasion, and induced ferroptosis, yet these impacts were abolished by co-transfection with anti-miR-188-5p or pcDNA-RAB14. Meanwhile, interference with circ-IARS reduced OS cell proliferation, and decreased RAB14 (a member of the RAS oncogene family), GPX4, and xCT (crucial ferroptosis regulators) expressions in vivo. In conclusion, circ-IARS facilitated OS progression via miR-188-5p/RAB14.


Assuntos
Neoplasias Ósseas , Proliferação de Células , Ferroptose , MicroRNAs , Osteossarcoma , RNA Circular , Proteínas rab de Ligação ao GTP , Humanos , Osteossarcoma/genética , Osteossarcoma/patologia , Osteossarcoma/metabolismo , MicroRNAs/genética , RNA Circular/genética , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo , Ferroptose/genética , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/metabolismo , Masculino , Linhagem Celular Tumoral , Feminino , Progressão da Doença , Camundongos , Animais , Regulação Neoplásica da Expressão Gênica
16.
Biomed Chromatogr ; 38(7): e5870, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38664069

RESUMO

Spleen deficiency can lead to various abnormal physiological functions of the spleen. Atractylodis Macrocephalae Rhizoma (AMR) is a traditional Chinese medicine used to invigorate the spleen and tonify qi. The study aimed to identify the primary active components influencing the efficacy of AMR in strengthening the spleen and replenishing qi through spectrum-effect relationship and chemometrics. Network pharmacology was used to investigate the mechanism by which AMR strengthens the spleen and replenishes qi, with molecular docking utilized for validation purposes. The findings indicated that bran-fried AMR exhibited superior efficacy, with atractylenolides and atractylone identified as the primary active constituents. Atractylenolide II emerged as the most influential component impacting the effectiveness of AMR, while the key target was androgen receptor. Furthermore, crucial pathways implicated included the mitogen-activated protein cascade (MAPK) cascade, RNA polymerase II transcription factor activity, ligand-activated sequence-specific DNA binding, and RNA polymerase II sequence-specific DNA-binding transcription factor binding. In summary, our study has identified the primary active components associated with the efficacy of AMR and has provided an initial exploration of its mechanism of action. This offers a theoretical foundation for future investigations into the material basis and molecular mechanisms underlying the pharmacodynamics of AMR.


Assuntos
Atractylodes , Medicamentos de Ervas Chinesas , Lactonas , Simulação de Acoplamento Molecular , Farmacologia em Rede , Sesquiterpenos , Baço , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Animais , Atractylodes/química , Lactonas/química , Lactonas/farmacologia , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Baço/efeitos dos fármacos , Baço/metabolismo , Rizoma/química , Masculino
17.
Ecotoxicol Environ Saf ; 278: 116354, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38691882

RESUMO

After the resumption of work and production following the COVID-19 pandemic, many cities entered a "transition phase", characterized by the gradual recovery of emission levels from various sources. Although the overall PM2.5 emission trends have recovered, the specific changes in different sources of PM2.5 remain unclear. Here, we investigated the changes in source contributions and the evolution pattern of pollution episodes (PE) in Wuhan during the "transition period" and compared them with the same period during the COVID-19 lockdown. We found that vehicle emissions, industrial processes, and road dust exhibited significant recoveries during the transition period, increasing by 5.4%, 4.8%, and 3.9%, respectively, during the PE. As primary emissions increased, secondary formation slightly declined, but it still played a predominant role (accounting for 39.1∼ 43.0% of secondary nitrate). The reduction in industrial activities was partially offset by residential burning. The evolution characteristics of PE exhibited significant differences between the two periods, with PM2.5 concentration persisting at a high level during the transition period. The differences in the evolution patterns of the two periods were also reflected in their change rates at each stage, which mostly depend on the pre-PE concentration level. The transition period shows a significantly higher value (8.4 µg m-3 h-1) compared with the lockdown period, almost double the amount. In addition to local emissions, regional transport should be a key consideration in pollution mitigation strategies, especially in areas adjacent to Wuhan. Our study quantifies the variations in sources between the two periods, providing valuable insights for optimizing environmental planning to achieve established goals.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Cidades , Monitoramento Ambiental , Material Particulado , China/epidemiologia , COVID-19/epidemiologia , Monitoramento Ambiental/métodos , Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Material Particulado/análise , Humanos , Emissões de Veículos/análise , SARS-CoV-2 , Indústrias , Pandemias
18.
Nano Lett ; 23(3): 1085-1092, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36649599

RESUMO

Curved ultrathin PtPd nanodendrites (CNDs) with long-range compressive strain and highly branched feature are first prepared by a functional surfactant-induced strategy. Precise synthesis realized the construction of both curved and flat PtPd nanodendrites (NDs) with the same atomic ratio, which contributed to exploration of the strain effect on electrocatalytic performance alone. Abundant evidence is provided to confirm that the long-range compressive strain in curved PtPd architectures can effectively tailor the local coordination environment of active sites, lower the position of the d-band center, weaken the adsorption energy of the intermediates (e.g., H* and CO*), and ultimately increase their intrinsic activity. The density functional theory (DFT) calculations further reveal that the introduction of compressive strain weakens the Gibbs free-energy of the intermediate (ΔGH*), which is favorable for accelerating the hydrogen evolution reaction (HER) kinetics. A similar enhanced electrocatalytic performance can also be found in the methanol oxidation reaction (MOR).

19.
Angew Chem Int Ed Engl ; : e202407339, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714494

RESUMO

Two-electron oxidative addition is one of the most important elementary reactions for d-block transition metals but it is uncommon for f-block elements. Here, we report the first examples of intermolecular oxidative addition of E-H (E=C, N) bonds to uranium(II) centers. The transient U(II) species was formed in-situ by reducing a heterometallic cluster featuring U(IV)-Pd(0) bonds with potassium-graphite (KC8). Oxidative addition of C-H or N-H bonds to the U(II) centers was observed when this transient U(II) species was treated with benzene, carbazole or 1-adamantylamine, respectively. The U(II) centers could also react with tetracene, biphenylene or N2O, leading to the formation of arene reduced U(IV) products and uranyl(VI) species via two- or four-electron processes. This study demonstrates that the intermolecular two-electron oxidative addition reactions are viable for actinide elements.

20.
Angew Chem Int Ed Engl ; 63(3): e202317087, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38055225

RESUMO

Electrocatalytic C-N coupling process is indeed a sustainable alternative for direct urea synthesis and co-upgrading of carbon dioxide and nitrate wastes. However, the main challenge lies in the unactivated C-N coupling process. Here, we proposed a strategy of intermediate assembly with alkali metal cations to activate C-N coupling at the electrode/electrolyte interface. Urea synthesis activity follows the trend of Li+

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