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1.
J Hazard Mater ; 477: 135408, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39096641

RESUMO

This study investigates the spatial and temporal dynamics of air quality in Shandong Province from 2016 to 2022. The Air Quality Index (AQI) showed a seasonal pattern, with higher values in winter due to temperature inversions and heating emissions, and lower values in summer aided by favorable dispersion conditions. The AQI improved significantly, decreasing by approximately 39.4 % from 6.44 to 3.90. Coastal cities exhibited better air quality than inland areas, influenced by industrial activities and geographical features. For instance, Zibo's geography restricts pollutant dispersion, resulting in poor air quality. CO levels remained stable, while O3 increased seasonally due to photochemical reactions in summer, with correlation coefficients indicating a strong positive correlation with temperature (r = 0.65). Winter saw elevated NO2 levels linked to heating and vehicular emissions, with an observed increase in correlation with AQI (r = 0.78). PM2.5 and PM10 concentrations were higher in colder months due to heating and atmospheric dust, showing a significant decrease of 45 % and 40 %, respectively, over the study period. Predictive modeling forecasts continued air quality improvements, contingent on sustained policy enforcement and technological advancements. This approach provides a comprehensive framework for future air quality management and improvement.

2.
J Control Release ; 374: 127-139, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39122216

RESUMO

The immunosuppressive tumor microenvironment (TME) in solid tumors often impedes the efficacy of immunotherapy. Bacterial outer membrane vesicles (OMVs), as a promising cancer vaccine that can potently stimulate immune responses, have garnered interest as a potential platform for cancer therapy. However, the low yield of OMVs limits their utilization. To address this limitation, we developed a novel approach to synthesize OMV-like multifunctional synthetic bacterial vesicles (SBVs) by pretreating bacteria with ampicillin and lysing them through sonication. Compared to OMVs, the yield of SBVs increased by 40 times. Additionally, the unique synthesis process of SBVs allows for the encapsulation of bacterial intracellular contents, endowing SBVs with the capability of delivering catalase (CAT) for tumor hypoxia relief and activating the host cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway. To overcome the toxicity of lipopolysaccharide (LPS) on the SBVs surface, we decorated SBVs with a biocompatible polydopamine (PDA) shell, which allowed TME reprogramming using SBVs to be conducted without adverse side effects. Additionally, the photosensitizer indocyanine green (ICG) was loaded into the PDA shell to induce immunogenic cell death and further improve the efficacy of immunotherapy. In summary, the SBVs-based therapeutic platform SBV@PDA/ICG (SBV@P/I) can synergistically elicit safe and potent tumor-specific antitumor responses through combined immunotherapy and phototherapy.

3.
Nat Immunol ; 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39169233

RESUMO

Cancer cells edit gene expression to evade immunosurveillance. However, genome-wide studies of gene editing during early tumorigenesis are lacking. Here we used single-cell RNA sequencing in a breast cancer genetically engineered mouse model (GEMM) to identify edited genes without bias. Late tumors repressed antitumor immunity genes, reducing infiltrating immune cells and tumor-immune cell communications. Innate immune genes, especially interferon-stimulated genes, dominated the list of downregulated tumor genes, while genes that regulate cell-intrinsic malignancy were mostly unedited. Naive and activated CD8+ T cells in early tumors were replaced with exhausted or precursor-exhausted cells in late tumors. Repression of immune genes was reversed by inhibiting DNA methylation using low-dose decitabine, which suppressed tumor growth and restored immune control, increasing the number, functionality and memory of tumor-infiltrating lymphocytes and reducing the number of myeloid suppressor cells. Decitabine induced important interferon, pyroptosis and necroptosis genes, inflammatory cell death and immune control in GEMM and implanted breast and melanoma tumors.

4.
Inorg Chem ; 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39161979

RESUMO

Piezoelectric catalysis could convert mechanical energy into chemical energy, which can combine with solar energy for a high-efficiency piezo-photocatalysis reaction. In this work, NiTiO3 nanorods were synthesized via the sol-gel method and initially employed for the removal of U(VI) from radioactive-contaminated water. The NiTiO3 nanorods will generate an internal electric field in an ultrasonic environment, which could greatly improve the performance of piezo-photocatalysis in reducing U(VI) by promoting the generation of photoexcited electrons and reactive oxygen species (ROS). After exposure to visible light and ultrasound for 3 h, the NTO-R-1 exhibited superb U(VI) degradation efficiency of 93.91%, which was 2.58, 6.15, and 6.68 times greater than those of visible light, ultrasonic irradiation, and dark, respectively. Moreover, photoexcited electrons and oxygen-active species play a decisive role in the piezo-photocatalysis process. Therefore, NiTiO3 with excellent piezo-photocatalysis properties exhibits good potential for the development of efficient wastewater purification catalysts and also helps to probe the possible mechanism of piezo-photocatalysis removal of U(VI) in wastewater.

5.
Poult Sci ; 103(11): 104149, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39154608

RESUMO

Gyrovirus galga1 (GyVg1), formerly known as AGV2, was initially identified in chickens in southern Brazil. The prevalence of GyVg1 from 2021 to 2024 in 28 out of the 63 poultry farms located in Jiangsu, Anhui, Henan, Hunan, Shandong, and Hubei provinces in eastern and central China was detected via PCR. The complete genomes of the 28 strains were sequenced and exhibited a full length of 2,376 bp. Similarity analysis of these strains did not suggest definite correlation with evolutionary branching and geographical distribution. Compared with the reference GyVg1 strains, HN2202 shared the highest similarity of 99.71% with HLJ1511 (chicken-originated) from northeastern China in 2015 to 2016. Recombination analysis revealed that AH2102 was a potential recombinant of peafowl-originated HN2019-PF1 and chicken-originated HLJ1506-2, whereas HN2304 was a recombinant of peafowl-originated HN2019-PF1 and the Hungarian ferret strain G13. Mutation site analysis of the capsid protein revealed that highly mutated regions occurred between sites 288 to 316 and 383 to 419. These results indicate that GyVg1 may have undergone an interspecies transmission, which involved complex mutations and recombination. This study may provide a reference for subsequent investigations targeting the molecular epidemiology and viral evolution of GyVg1.

6.
Vet J ; 306: 106192, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38964602

RESUMO

Bufavirus (BuV) was first identified in feces from children with acute diarrhea, and a genetically related Canine bufavirus (CBuV) was first reported in Italy in 2018. In this study, through the investigation of CBuV in 622 anal swabs from dogs with diarrhea symptoms collected from various provinces in northern, central and eastern China during 2018-2022, 14 samples were detected to be positive. And 5 samples were from dogs co-infected with other canine diarrhea related viruses, which consist of CPV-2, CDV and CCoV. The complete genome sequences (4219 nt) of the fourteen strains were amplified and sequenced. Through comparative analysis with 51 reference BuV strains, six strains might recombinate from the CBuV strains (HUN/2012/22, CaBuV/9AS/2005/ITA and CaBuV/35/2016/ITA) in Hungary and Italy as the parents, and two genetic recombination events from various parents were predicted to occur on the BUV-422 strain. Combined analyzing the phylogenetic tree and sequence alignment, it was found that these CBuVs are highly conserved in the nonstructural protein NS1, but indeed various amino acid mutation sites in the capsid protein VP2, and even some amino acid sites coincide with putative protein plastic regions and potential epitopes. The BUV-422 and BUV-512 strains show sequential mutation sites identical to the divergent strains of CaBuV/9AS/2005/ITA and CaBuV/35/2016/ITA. This study would enrich the molecular data of CBuV in China and provide essential reference for the epidemiological research and vaccine development of CBuV in the future.


Assuntos
Diarreia , Doenças do Cão , Infecções por Parvoviridae , Filogenia , Recombinação Genética , Animais , Cães , Doenças do Cão/virologia , Doenças do Cão/epidemiologia , China/epidemiologia , Diarreia/veterinária , Diarreia/virologia , Diarreia/epidemiologia , Infecções por Parvoviridae/veterinária , Infecções por Parvoviridae/virologia , Infecções por Parvoviridae/epidemiologia , Genoma Viral
7.
ACS Appl Mater Interfaces ; 16(31): 40499-40514, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39051468

RESUMO

Crohn's disease (CD) is a refractory chronic inflammatory bowel disease (IBD) with unknown etiology. Transmural inflammation, involving the intestine and mesentery, represents a characteristic pathological feature of CD and serves as a critical contributor to its intractability. Here, this study describes an oral pyroptosis nanoinhibitor loaded with tumor necrosis factor-α (TNF-α) deoxyribozymes (DNAzymes) (DNAzymes@degradable silicon nanoparticles@Mannose, Dz@MDSN), which can target macrophages at the site of inflammation and respond to reactive oxygen species (ROS) to release drugs. Dz@MDSN can not only break the inflammatory cycle in macrophages by degrading TNF-α mRNA but also reduce the production of ROS mainly from macrophages. Moreover, Dz@MDSN inhibits excessive pyroptosis in epithelial cells through ROS clearance, thereby repairing the intestinal barrier and reducing the translocation of intestinal bacteria to the mesentery. Consequently, these combined actions synergistically contribute to the suppression of inflammation within both the intestine and the mesentery. This study likely represents the first successful attempt in the field of utilizing nanomaterials to achieve transmural healing for CD, which also provides a promising treatment strategy for CD patients.


Assuntos
Doença de Crohn , DNA Catalítico , Piroptose , Fator de Necrose Tumoral alfa , Doença de Crohn/tratamento farmacológico , Doença de Crohn/patologia , Doença de Crohn/metabolismo , Piroptose/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Humanos , Animais , Administração Oral , Camundongos , DNA Catalítico/química , DNA Catalítico/metabolismo , DNA Catalítico/farmacologia , Nanopartículas/química , Espécies Reativas de Oxigênio/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Silício/química , Silício/farmacologia , Manose/química , Manose/farmacologia , Células RAW 264.7 , Masculino
8.
Ecotoxicol Environ Saf ; 281: 116668, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38964058

RESUMO

The study of the fractions and distribution characteristics of organic phosphorus in the sediment of the water level fluctuating zone of Nansi Lake is conducive to revealing the transformation of phosphorus in the lake, and has important scientific significance for controlling the eutrophication of Nansi Lake. Based on the sediment of the water level fluctuation zone of Nansi Lake. The improved Hedley continuous grading extraction, ultraviolet-visible spectroscopy and three-dimensional fluorescence spectroscope were used to characterize the structural characteristics and stability of organic molecules in the sediment, and to reflect the differences in the structure and stability of organophosphate in the water level fluctuating zone. Principal component analysis (PCA), Redundancy analysis (RDA) and correlation heat map analysis were used to analyze the correlation between phosphorus and physicochemical index. The results showed that the alternation between wet-dry conditions was more favorable for the release of phosphorus from sediment, compared to continuous inundation conditions. Moreover, the higher the frequency of wet-dry alternations, the greater the release of phosphorus in different forms from the sediment. Wet-dry alternation resulted in a reduction of substituent on the aromatic rings of sediment DOM (dissolved organic matter), and the continuous drying would increase the molecular weight and humidification degree of DOM in the sediment. Correlation analysis showed that NaOH-Po content in sediment was significantly negatively correlated with TP, IP, OP and various organophosphorus forms, indicating a close transformation relationship between phosphorus forms in sediment. The results can provide a scientific basis for controlling the release of endogenous phosphorus and the risk of eutrophication in Nansi Lake.


Assuntos
Monitoramento Ambiental , Eutrofização , Sedimentos Geológicos , Lagos , Fósforo , Poluentes Químicos da Água , Sedimentos Geológicos/química , Lagos/química , Fósforo/análise , Fósforo/química , Poluentes Químicos da Água/análise , China , Análise de Componente Principal
10.
Nat Nanotechnol ; 19(7): 907-918, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38987649

RESUMO

The exceptional physical properties of two-dimensional (2D) van der Waals (vdW) materials have been extensively researched, driving advances in material synthesis. Epitaxial growth, a prominent synthesis strategy, enables the production of large-area, high-quality 2D films compatible with advanced integrated circuits. Typical 2D single crystals, such as graphene, transition metal dichalcogenides and hexagonal boron nitride, have been epitaxially grown at a wafer scale. A systematic summary is required to offer strategic guidance for the epitaxy of emerging 2D materials. Here we focus on the epitaxy methodologies for 2D vdW materials in two directions: the growth of in-plane single-crystal monolayers and the fabrication of out-of-plane homostructures. We first discuss nucleation control of a single domain and orientation control over multiple domains to achieve large-scale single-crystal monolayers. We analyse the defect levels and measures of crystalline quality of typical 2D vdW materials with various epitaxial growth techniques. We then outline technical routes for the growth of homogeneous multilayers and twisted homostructures. We further summarize the current strategies to guide future efforts in optimizing on-demand fabrication of 2D vdW materials, as well as subsequent device manufacturing for their industrial applications.

11.
Ecol Evol ; 14(7): e11500, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39026954

RESUMO

Many tree species adopt fast seed germination to escape the predation risk by rodents. Physical seed damage and the saliva of rodents on partially consumed seeds may act as cues for seeds to accelerate germination process. However, the impacts of these factors on seed germination rate and speed remain unclear. In this study, we investigated such impacts on the germination rate and speed (reversal of germination time) of four tree species (Quercus variabilis, Q. serrata, Q. acutissima, Q. glauca) after partial consumption by four rodent species (Leopoldamys edwards, Niviventer fulvescens, N. confucianus, Apodemus draco), through a series of experiments. We also examined how seed traits may affect the seed damage degree by rodents by analyzing the relationship between the germination rate and time of rodent-damaged seed and the traits. We found that, artificially- and rodent-damaged seeds exhibited a significantly higher seed germination rate and speed, compared to intact seeds. Also, the rodent saliva on seeds showed no significant effect on seed germination rate and speed. Furthermore, we observed significant positive correlations between several seed traits (including the seed mass, coat thickness, and protein content) and the seed germination rate and speed. These correlations are likely due to their beneficial traits countering seed damage by rodents. Overall, our results highlight the significant role of physical seed damage by rodents (rather than their saliva) in facilitating seed germination of tree species, and potential mutualism between rodents and trees. Additionally, our results may have some implications in forest restoration, such that intentionally sowing or dispersing slightly damaged seeds by humans or drones may increase the likelihood of successful seed regeneration.

12.
Plant J ; 119(3): 1543-1557, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38859560

RESUMO

Aegilops longissima and Ae. sharonensis, being classified into the Sitopsis section of genus Aegilops, are distinct species both taxonomically and ecologically. Nevertheless, earlier observations indicate that the two species are not reproductively isolated to full extent and can inter-bred upon secondary contact. However, the genomic underpinnings of the morpho-ecological differentiation between the two foci species remained unexplored. Here, we resequenced 31 representative accessions of the two species and conducted in-depth comparative genomic analyses. We demonstrate recurrent and ongoing natural hybridizations between Ae. longissima and Ae. sharonensis, and depict features of genome composition of the resultant hybrids at both individual and population levels. We also delineate genomic regions and candidate genes potentially underpinning the differential morphological and edaphic adaptations of the two species. Intriguingly, a binary morphology was observed in the hybrids, suggesting existence of highly diverged genomic regions that remain uneroded by the admixtures. Together, our results provide new insights into the molding effects of interspecific hybridization on genome composition and mechanisms preventing merge of the two species.


Assuntos
Aegilops , Diploide , Genoma de Planta , Hibridização Genética , Genoma de Planta/genética , Aegilops/genética , Genômica , Evolução Molecular , Filogenia
13.
Nat Commun ; 15(1): 4796, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839783

RESUMO

Powdery mildew is a devastating disease that affects wheat yield and quality. Wheat wild relatives represent valuable sources of disease resistance genes. Cloning and characterization of these genes will facilitate their incorporation into wheat breeding programs. Here, we report the cloning of Pm57, a wheat powdery mildew resistance gene from Aegilops searsii. It encodes a tandem kinase protein with putative kinase-pseudokinase domains followed by a von Willebrand factor A domain (WTK-vWA), being ortholog of Lr9 that mediates wheat leaf rust resistance. The resistance function of Pm57 is validated via independent mutants, gene silencing, and transgenic assays. Stable Pm57 transgenic wheat lines and introgression lines exhibit high levels of all-stage resistance to diverse isolates of the Bgt fungus, and no negative impacts on agronomic parameters are observed in our experimental set-up. Our findings highlight the emerging role of kinase fusion proteins in plant disease resistance and provide a valuable gene for wheat breeding.


Assuntos
Aegilops , Ascomicetos , Resistência à Doença , Doenças das Plantas , Proteínas de Plantas , Plantas Geneticamente Modificadas , Triticum , Triticum/microbiologia , Triticum/genética , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Ascomicetos/genética , Ascomicetos/patogenicidade , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Aegilops/genética , Aegilops/microbiologia , Melhoramento Vegetal , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Clonagem Molecular , Regulação da Expressão Gênica de Plantas
14.
Chem Commun (Camb) ; 60(44): 5703-5706, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38738578

RESUMO

A collaborative manipulation strategy of proper heat treatment and self-customized hydrofluoroether-based electrolyte design has been proposed for boosting the sodium-ion storage kinetics of Prussian white cathodes. Improved monoclinic phase stability and electrolyte-cathode compatibility are responsible for an impressive discharge capacity of 148.4 mA h g-1 and excellent electrode reversibility.

15.
Environ Sci Technol ; 58(21): 9456-9465, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38745405

RESUMO

The elimination of uranium from radioactive wastewater is crucial for the safe management and operation of environmental remediation. Here, we present a layered vanadate with high acid/base stability, [Me2NH2]V3O7, as an excellent ion exchanger capturing uranyl from highly complex aqueous solutions. The material possesses an indirect band gap, ferromagnetic characteristic and a flower-like morphology comprising parallel nanosheets. The layered structure of [Me2NH2]V3O7 is predominantly upheld by the H-bond interaction between anionic framework [V3O7]nn- and intercalated [Me2NH2]+. The [Me2NH2]+ within [Me2NH2]V3O7 can be readily exchanged with UO22+. [Me2NH2]V3O7 exhibits high exchange capacity (qm = 176.19 mg/g), fast kinetics (within 15 min), high removal efficiencies (>99%), and good selectivity against an excess of interfering ions. It also displays activity for UO22+ ion exchange over a wide pH range (2.00-7.12). More importantly, [Me2NH2]V3O7 has the capability to effectively remove low-concentration uranium, yielding a residual U concentration of 13 ppb, which falls below the EPA-defined acceptable limit of 30 ppb in typical drinking water. [Me2NH2]V3O7 can also efficiently separate UO22+ from Cs+ or Sr2+ achieving the highest separation factors (SFU/Cs of 589 and SFU/Sr of 227) to date. The BOMD and DFT calculations reveal that the driving force of ion exchange is dominated by the interaction between UO22+ and [V3O7]nn-, whereas the ion exchange rate is influenced by the mobility of UO22+ and [Me2NH2]+. Our experimental findings indicate that [Me2NH2]V3O7 can be considered as a promising uranium scavenger for environmental remediation. Additionally, the simulation results provide valuable mechanistic interpretations for ion exchange and serve as a reference for designing novel ion exchangers.


Assuntos
Urânio , Vanadatos , Urânio/química , Vanadatos/química , Troca Iônica , Poluentes Radioativos da Água/química , Cinética
16.
Science ; 384(6696): 660-665, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38723082

RESUMO

Rapid processing of tactile information is essential to human haptic exploration and dexterous object manipulation. Conventional electronic skins generate frames of tactile signals upon interaction with objects. Unfortunately, they are generally ill-suited for efficient coding of temporal information and rapid feature extraction. In this work, we report a neuromorphic tactile system that uses spike timing, especially the first-spike timing, to code dynamic tactile information about touch and grasp. This strategy enables the system to seamlessly code highly dynamic information with millisecond temporal resolution on par with the biological nervous system, yielding dynamic extraction of tactile features. Upon interaction with objects, the system rapidly classifies them in the initial phase of touch and grasp, thus paving the way to fast tactile feedback desired for neuro-robotics and neuro-prosthetics.


Assuntos
Membros Artificiais , Materiais Biomiméticos , Percepção do Tato , Tato , Humanos , Potenciais de Ação , Força da Mão , Tato/fisiologia , Dispositivos Eletrônicos Vestíveis
17.
PLoS One ; 19(5): e0301788, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38696421

RESUMO

With an increasing number of heterogeneous shareholders participating in corporate governance in reality, the assumption of shareholder homogeneity in agency theory is gradually relaxing in the modern field of corporate governance. The policy of mixed ownership reform in China provides empirical evidence for studying heterogeneous shareholder governance. To fully understand the governance effects of non-state shareholders, we employ the ownership proportion held by non-state shareholders among the top ten shareholders and the appointment of directors as measures for non-state shareholder governance. Using a panel fixed-effect model from the perspective of state-owned enterprises (SOEs) party organizations, we examine the impact of non-state shareholder governance on the governance level of SOEs. The study reveals that non-state shareholder governance positively affects the governance level of SOEs, with board resolutions playing a crucial role in this relationship. When party members serve as directors, the governance effect of non-state shareholders is more significant. Based on the aforementioned research findings, we recommend further refining corporate governance measures for SOEs within the context of SOE reforms. It is advisable to optimize the party organizational governance structure and leverage the synergistic effects of non-state shareholder governance and party organizational governance. Advancing reforms along the Pareto improvement path will contribute to establishing a distinctive corporate governance system for Chinese SOEs.


Assuntos
Conselho Diretor , Propriedade , China , Conselho Diretor/organização & administração , Humanos , Governo Estadual
18.
Inorg Chem ; 63(24): 11369-11380, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38818647

RESUMO

Under xenon lamps, ZnFe2O4 (ZFO) has been shown to be effective in removing uranium through photocatalysis. However, its performance is still inadequate in low-light environments due to low photon utilization and high electron-hole complexation. Herein, S-doped hollow ZnFe2O4 microcubes (Sx-H-ZFO, x = 1, 3, 6, 9) were synthesized using the MOF precursor template method. The hollow morphology improves the utilization of visible light by refracting and reflecting the incident light multiple times within the confined domain. S doping narrows the band gap and shifts the conduction band position negatively, which enhances the separation, migration, and accumulation of photogenerated charges. Additionally, S doping increases the number of adsorption sites, ultimately promoting efficient surface reactions. Consequently, Sx-H-ZFO is capable of removing U(VI) in low-light environments. Under cloudy and rainy weather conditions, the photocatalytic rate of S3-H-ZFO was 100.31 µmol/(g·h), while under LED lamps (5000 Lux) it was 72.70 µmol/(g·h). More interestingly, a systematic mechanistic investigation has revealed that S doping replaces some of the oxygen atoms to enhance electron transfers and adsorption of O2. This process initiates the formation of hydrogen peroxide, which reacts directly with UO22+ to form solid studtite (UO2)O2·2H2O. Additionally, the promising magnetic separation capability of Sx-H-ZFO facilitates the recycling and reusability of the material. This work demonstrates the potential of ZnFe2O4 extraction uranium from nuclear wastewater.

19.
Nature ; 629(8010): 74-79, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38693415

RESUMO

Within the family of two-dimensional dielectrics, rhombohedral boron nitride (rBN) is considerably promising owing to having not only the superior properties of hexagonal boron nitride1-4-including low permittivity and dissipation, strong electrical insulation, good chemical stability, high thermal conductivity and atomic flatness without dangling bonds-but also useful optical nonlinearity and interfacial ferroelectricity originating from the broken in-plane and out-of-plane centrosymmetry5-23. However, the preparation of large-sized single-crystal rBN layers remains a challenge24-26, owing to the requisite unprecedented growth controls to coordinate the lattice orientation of each layer and the sliding vector of every interface. Here we report a facile methodology using bevel-edge epitaxy to prepare centimetre-sized single-crystal rBN layers with exact interlayer ABC stacking on a vicinal nickel surface. We realized successful accurate fabrication over a single-crystal nickel substrate with bunched step edges of the terrace facet (100) at the bevel facet (110), which simultaneously guided the consistent boron-nitrogen bond orientation in each BN layer and the rhombohedral stacking of BN layers via nucleation near each bevel facet. The pure rhombohedral phase of the as-grown BN layers was verified, and consequently showed robust, homogeneous and switchable ferroelectricity with a high Curie temperature. Our work provides an effective route for accurate stacking-controlled growth of single-crystal two-dimensional layers and presents a foundation for applicable multifunctional devices based on stacked two-dimensional materials.

20.
Appl Microbiol Biotechnol ; 108(1): 317, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38700737

RESUMO

Perylenequinones (PQs) are natural photosensitizing compounds used as photodynamic therapy, and heat stress (HS) is the main limiting factor of mycelial growth and secondary metabolism of fungi. This study aimed to unravel the impact of HS-induced Ca2+ and the calcium signaling pathway on PQ biosynthesis of Shiraia sp. Slf14(w). Meanwhile, the intricate interplay between HS-induced NO and Ca2+ and the calcium signaling pathway was investigated. The outcomes disclosed that Ca2+ and the calcium signaling pathway activated by HS could effectively enhance the production of PQs in Shiraia sp. Slf14(w). Further investigations elucidated the specific mechanism through which NO signaling molecules induced by HS act upon the Ca2+/CaM (calmodulin) signaling pathway, thus propelling PQ biosynthesis in Shiraia sp. Slf14(w). This was substantiated by decoding the downstream positioning of the CaM/CaN (calcineurin) pathway in relation to NO through comprehensive analyses encompassing transcript levels, enzyme assays, and the introduction of chemical agents. Concurrently, the engagement of Ca2+ and the calcium signaling pathway in heat shock signaling was also evidenced. The implications of our study underscore the pivotal role of HS-induced Ca2+ and the calcium signaling pathway, which not only participate in heat shock signal transduction but also play an instrumental role in promoting PQ biosynthesis. Consequently, our study not only enriches our comprehension of the mechanisms driving HS signaling transduction in fungi but also offers novel insights into the PQ synthesis paradigm within Shiraia sp. Slf14(w). KEY POINTS: • The calcium signaling pathway was proposed to participate in PQ biosynthesis under HS. • HS-induced NO was revealed to act upon the calcium signaling pathway for the first time.


Assuntos
Ascomicetos , Sinalização do Cálcio , Perileno , Perileno/análogos & derivados , Quinonas , Ascomicetos/metabolismo , Ascomicetos/genética , Ascomicetos/crescimento & desenvolvimento , Quinonas/metabolismo , Perileno/metabolismo , Óxido Nítrico/metabolismo , Resposta ao Choque Térmico , Cálcio/metabolismo , Temperatura Alta
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