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1.
Int J Mol Sci ; 25(9)2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38731817

RESUMEN

MCPH1 has been identified as the causal gene for primary microcephaly type 1, a neurodevelopmental disorder characterized by reduced brain size and delayed growth. As a multifunction protein, MCPH1 has been reported to repress the expression of TERT and interact with transcriptional regulator E2F1. However, it remains unclear whether MCPH1 regulates brain development through its transcriptional regulation function. This study showed that the knockout of Mcph1 in mice leads to delayed growth as early as the embryo stage E11.5. Transcriptome analysis (RNA-seq) revealed that the deletion of Mcph1 resulted in changes in the expression levels of a limited number of genes. Although the expression of some of E2F1 targets, such as Satb2 and Cdkn1c, was affected, the differentially expressed genes (DEGs) were not significantly enriched as E2F1 target genes. Further investigations showed that primary and immortalized Mcph1 knockout mouse embryonic fibroblasts (MEFs) exhibited cell cycle arrest and cellular senescence phenotype. Interestingly, the upregulation of p19ARF was detected in Mcph1 knockout MEFs, and silencing p19Arf restored the cell cycle and growth arrest to wild-type levels. Our findings suggested it is unlikely that MCPH1 regulates neurodevelopment through E2F1-mediated transcriptional regulation, and p19ARF-dependent cell cycle arrest and cellular senescence may contribute to the developmental abnormalities observed in primary microcephaly.


Asunto(s)
Puntos de Control del Ciclo Celular , Senescencia Celular , Inhibidor p16 de la Quinasa Dependiente de Ciclina , Ratones Noqueados , Microcefalia , Animales , Ratones , Senescencia Celular/genética , Microcefalia/genética , Microcefalia/metabolismo , Microcefalia/patología , Puntos de Control del Ciclo Celular/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/deficiencia , Factor de Transcripción E2F1/genética , Factor de Transcripción E2F1/metabolismo , Fibroblastos/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo
2.
Int J Mol Sci ; 25(9)2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38731970

RESUMEN

Malaria is a severe disease that presents a significant threat to human health. As resistance to current drugs continues to increase, there is an urgent need for new antimalarial medications. Aminoacyl-tRNA synthetases (aaRSs) represent promising targets for drug development. In this study, we identified Plasmodium falciparum tyrosyl-tRNA synthetase (PfTyrRS) as a potential target for antimalarial drug development through a comparative analysis of the amino acid sequences and three-dimensional structures of human and plasmodium TyrRS, with particular emphasis on differences in key amino acids at the aminoacylation site. A total of 2141 bioactive compounds were screened using a high-throughput thermal shift assay (TSA). Okanin, known as an inhibitor of LPS-induced TLR4 expression, exhibited potent inhibitory activity against PfTyrRS, while showing limited inhibition of human TyrRS. Furthermore, bio-layer interferometry (BLI) confirmed the high affinity of okanin for PfTyrRS. Molecular dynamics (MD) simulations highlighted the stable conformation of okanin within PfTyrRS and its sustained binding to the enzyme. A molecular docking analysis revealed that okanin binds to both the tyrosine and partial ATP binding sites of the enzyme, preventing substrate binding. In addition, the compound inhibited the production of Plasmodium falciparum in the blood stage and had little cytotoxicity. Thus, okanin is a promising lead compound for the treatment of malaria caused by P. falciparum.


Asunto(s)
Antimaláricos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Plasmodium falciparum , Tirosina-ARNt Ligasa , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/enzimología , Tirosina-ARNt Ligasa/antagonistas & inhibidores , Tirosina-ARNt Ligasa/metabolismo , Humanos , Antimaláricos/farmacología , Antimaláricos/química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/química , Sitios de Unión , Unión Proteica , Animales , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/parasitología
3.
Food Funct ; 15(8): 4614-4626, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38590249

RESUMEN

The role of vitamin D (VD) in non-alcoholic fatty liver disease (NAFLD) remains controversial, possibly due to the differential effects of various forms of VD. In our study, Sod1 gene knockout (SKO) mice were utilized as lean NAFLD models, which were administered 15 000 IU VD3 per kg diet, or intraperitoneally injected with the active VD analog calcipotriol for 12 weeks. We found that VD3 exacerbated hepatic steatosis in SKO mice, with an increase in the levels of Cd36, Fatp2, Dgat2, and CEBPA. However, calcipotriol exerted no significant effect on hepatic steatosis. Calcipotriol inhibited the expression of Il-1a, Il-1b, Il-6, Adgre1, and TNF, with a reduction of NFκB phosphorylation in SKO mice. No effect was observed by either VD3 or calcipotriol on hepatocyte injury and hepatic fibrosis. Co-immunofluorescence stains of CD68, a liver macrophage marker, and VDR showed that calcipotriol reduced CD68 positive cells, and increased the colocalization of VDR with CD68. However, VD3 elevated hepatocyte VDR expression, with no substantial effect on the colocalization of VDR with CD68. Finally, we found that VD3 increased the levels of serum 25(OH)D3 and 24,25(OH)2D3, whereas calcipotriol decreased both. Both VD3 and calcipotriol did not disturb serum calcium and phosphate levels. In summary, our study found that VD3 accentuated hepatic steatosis, while calcipotriol diminished inflammation levels in SKO mice, and the difference might stem from their distinct cellular selectivity in activating VDR. This study provides a reference for the application of VD in the treatment of lean NAFLD.


Asunto(s)
Calcitriol , Calcitriol/análogos & derivados , Colecalciferol , Ratones Noqueados , Enfermedad del Hígado Graso no Alcohólico , Animales , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/genética , Calcitriol/farmacología , Ratones , Colecalciferol/farmacología , Masculino , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismo , Hígado/metabolismo , Hígado/efectos de los fármacos , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Inflamación/tratamiento farmacológico , Ratones Endogámicos C57BL , Humanos , Modelos Animales de Enfermedad
4.
Discov Nano ; 19(1): 66, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38619656

RESUMEN

Effective treatment of oily wastewater, which is toxic and harmful and causes serious environmental pollution and health risks, has become an important research field. Membrane separation technology has emerged as a key area of investigation in oil-water separation research due to its high separation efficiency, low costs, and user-friendly operation. This review aims to report on the advances in the research of various types of separation membranes around emulsion permeance, separation efficiency, antifouling efficiency, and stimulus responsiveness. Meanwhile, the challenges encountered in oil-water separation membranes are examined, and potential research avenues are identified.

5.
Sci Bull (Beijing) ; 2024 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-38627135

RESUMEN

The advancement of flexible electronics demands improved components, necessitating heat dissipation membranes (HDMs) to exhibit high thermal conductivity while maintaining structural integrity and performance stability even after extensive deformation. Herein, we have devised a laser-modulated reduction technique for graphene oxide (GO), enabling the fabrication of high-quality, large-scale, low-defect graphene, which yields high-performance HDMs after orderly deposition. The work underscores the crucial role of the laser wavelength and dispersion liquid's coupling intensity in influencing the morphology and properties of graphene. Optimal coupling effect and energy conversion are realized when a laser of 1064 nm wavelength irradiates a triethylene glycol (TEG)/N,N-Dimethylformamide (DMF) dispersion. This unique synergy generates high transient energy, which facilitates the deprotonation process and ensures a swift, comprehensive GO reduction. In contrast to conventional water-based laser reduction methods, the accelerated reaction magnifies the size of the graphene sheets by mitigating the ablation effect. After membrane construction with an ordered structure, the corresponding membrane exhibits a high thermal conductivity of 1632 W m-1 K-1, requiring only ∼1/10 of the total preparation time required by other reported methods. Remarkably, the resulting HDM demonstrates superior resilience against creasing and folding, maintaining excellent smoothness and negligible reduction in thermal conductivity after violent rubbing. The combination of exceptional flexibility and thermal conductivity in HDMs paves the way for long-term practical use in the flexible electronics industry.

6.
J Phys Act Health ; : 1-9, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38684209

RESUMEN

BACKGROUND: To assess the associations of replacing sedentary behavior with different types of physical activity with mortality among the US adults of varying diabetes statuses. METHODS: This prospective cohort study included 21,637 participants (mean age, 48.5 y) from the National Health and Nutrition Examination Survey 2007-2018. Physical activity including leisure-time moderate-vigorous-intensity activity (MVPA), walking/bicycling, worktime MVPA, and sedentary behavior. We conducted an isotemporal substitution analysis using Cox regression to estimate the associations between replacements and mortality risks. RESULTS: We found significant protective associations between replacing 30 minutes per day sedentary behavior with 3 types of physical activity and all-cause, cardiovascular disease (CVD) mortality risk (except worktime MVPA for CVD mortality) among total participants, with hazard ratio (HR; 95% confidence interval [CI]) ranging from 0.86 (0.77-0.95) to 0.96 (0.94-0.98). Among participants with diagnosed diabetes, replacing sedentary behavior with leisure-time MVPA was associated with a lower all-cause mortality risk (HR 0.81, 95% CI, 0.70-0.94), which was also observed in other subgroups, with HRs (95% CI) ranging from 0.87 (0.80-0.94) to 0.89 (0.81-0.99). Among those with prediabetes/undiagnosed diabetes, replacing sedentary behavior with walking/bicycling was associated with lower CVD mortality risk, and replacement to work-time MVPA was associated with lower all-cause and CVD mortality risk, with HRs (95% CI) ranging from 0.72 (0.63-0.83) to 0.96 (0.92-0.99). CONCLUSIONS: Replacing sedentary behaviors with 30 minutes per day leisure-time MVPA was associated with lower all-cause mortality, regardless of diabetes statuses. Among people with prediabetes/undiagnosed diabetes, walking/bicycling was additionally associated with lower CVD mortality, and worktime MVPA was associated with lower all-cause and CVD mortality.

7.
Front Genet ; 15: 1359579, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38586585

RESUMEN

Background: Systemic inflammatory regulators have been associated with preeclampsia (PE) during pregnancy; however, there is inconsistent evidence from animal models and observational results. Methods: Using summary data from genome-wide association studies (GWASs), we performed a bidirectional Mendelian randomization (MR) analysis of two samples of systemic inflammatory regulators (n = 8,186) and PE (n = 267,242) individuals of European ancestry. As our primary analysis, we used the random-effects inverse-variance weighted (IVW) approach. Sensitivity and pleiotropy analyses were conducted using the MR-Egger method, weighted median, MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and Cochran's Q test. Results: The results indicate that there is a correlation between a higher circulating level of tumor necrosis factor alpha (TNF-α) and interleukin-9 (IL-9) and an increased risk of PE (odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.09-1.60, p = 0.004 and OR = 1.28, 95% CI: 1.02-1.62, p = 0.033, respectively). Conversely, lower levels of stem cell growth factor beta (SCGF-ß) (OR = 0.89, 95% CI: 0.80-0.99, p = 0.027) and interleukin-5 (IL-5) (OR = 0.80, 95% CI: 0.65-0.98, p = 0.030) are linked to an increased risk of PE. The macrophage migration inhibitory factor (MIF) is the downstream inflammatory regulator of PE, according to reverse magnetic resonance imaging studies. Conclusion: Our study suggests that SCGF-ß, IL-5, IL-9, and TNF-α causally affect the PE risk, while PE is causally associated with MIF. Further studies are needed to validate these biomarkers in managing PE.

8.
Nat Mater ; 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38548900
9.
Proc Natl Acad Sci U S A ; 121(13): e2317192121, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38507451

RESUMEN

Photothermal heating and photocatalytic treatment are two solar-driven water processing approaches by harnessing NIR and UV-vis light, respectively, which can fully utilize solar energy if integrated. However, it remains a challenge to achieve high performance in both approaches when integrated in a material due to uncontrollable heat diffusion. Here, we report a demonstration of heat confinement on photothermal sites and fluid cooling on photocatalysis sites at the nanoscale, within a well-designed heat and fluid confinement nanofiber reactor. Photothermal and photocatalytic nanostructures were alternatively aligned in electrospun nanofibers for on-demand nanofluidic thermal management as well as easy folding into 3D structures with enhanced light utilization and mass transfer. Such a design showed simultaneously high photothermal evaporation rate (2.59 kg m-2 h-1, exceeding the limit rate) and efficient photocatalytic upcycling of microplastics pollutant into valued products. Enabled by controlled photothermal heating, the valued main product (i.e., methyl acetate) can be evaporated out with 100% selectivity by in situ separation.

10.
Nanomaterials (Basel) ; 14(5)2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38470730

RESUMEN

Polydimethylsiloxane (PDMS) has emerged as a promising candidate for the dielectric layer in implantable sensors due to its exceptional biocompatibility, stability, and flexibility. This study introduces an innovative approach to produce graphene-reinforced PDMS (Gr-PDMS), where graphite powders are exfoliated into mono- and few-layer graphene sheets within the polymer solution, concurrently forming cross-linkages with PDMS. This method yields a uniformly distributed graphene within the polymer matrix with improved interfaces between graphene and PDMS, significantly reducing the percolation threshold of graphene dispersed in PDMS from 10% to 5%. As-synthesized Gr-PDMS exhibits improved mechanical and electrical properties, tested for potential use in capacitive pressure sensors. The results demonstrate an impressive pressure sensitivity up to 0.0273 kpa-1, 45 times higher than that of pristine PDMS and 2.5 times higher than the reported literature value. The Gr-PDMS showcases excellent pressure sensing ability and stability, fulfilling the requirements for implantable intracranial pressure (ICP) sensors.

11.
Angew Chem Int Ed Engl ; 63(15): e202400621, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38334221

RESUMEN

Photo-assisted ion batteries utilize light to boost capacity but face cycling instability due to complex charge/ion transfer under illumination. This study identified photo-induced proton transfer (photo-induced PT) as a significant process in photo-(dis)charging of widely-used V2O5-based zinc-ion batteries, contributing to enhanced capacity under illumination but jeopardizing photo-stability. Photo-induced PT occurs at 100 ps after photo-excitation, inducing rapid proton extraction into V2O5 photoelectrode. This process creates a proton-deficient microenvironment on surface, leading to repetitive cathode dissolution and anode corrosion in each cycle. Enabling the intercalated protons from photo-induced PT to be reversibly employed in charge-discharge processes via the anode-alloying strategy achieves high photo-stability for the battery. Consequently, a ~54 % capacity enhancement was achieved in a V2O5-based zinc-ion battery under illumination, with ~90 % capacity retention after 4000 cycles. This extends the photo-stability record by 10 times. This study offers promising advancements in energy storage by addressing instability issues in photo-assisted ion batteries.

12.
Small ; : e2305764, 2024 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-38368252

RESUMEN

Photothermal therapy (PTT) is a new treatment modality for tumors. However, the efficient delivery of photothermal agents into tumors remains difficult, especially in hypoxic tumor regions. In this study, an approach to deliver melanin, a natural photothermal agent, into tumors using genetically engineered bacteria for image-guided photothermal and immune therapy is developed. An Escherichia coli MG1655 is transformed with a recombinant plasmid harboring a tyrosinase gene to produce melanin nanoparticles. Melanin-producing genetically engineered bacteria (MG1655-M) are systemically administered to 4T1 tumor-bearing mice. The tumor-targeting properties of MG1655-M in the hypoxic environment integrate the properties of hypoxia targeting, photoacoustic imaging, and photothermal therapeutic agents in an "all-in-one" manner. This eliminates the need for post-modification to achieve image-guided hypoxia-targeted cancer photothermal therapy. Tumor growth is significantly suppressed by irradiating the tumor with an 808 nm laser. Furthermore, strong antitumor immunity is triggered by PTT, thereby producing long-term immune memory effects that effectively inhibit tumor metastasis and recurrence. This work proposes a new photothermal and immune therapy guided by an "all-in-one" melanin-producing genetically engineered bacteria, which can offer broad potential applications in cancer treatment.

13.
Phys Chem Chem Phys ; 26(7): 6396-6409, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38315565

RESUMEN

Two-dimensional (2D) MBenes have enormous potential in energy applications. Vanadium metal, with its versatile and tunable electronic states, can further enhance the electrochemical performance of MBenes. However, most MBenes are composed of a few atomic layers as the metal boron (MB) block, e.g., M2B2, which might lead to instability and poor mechanical response. Herein, we designed and predicted 2D V4B6 associated with different terminations (T = Cl, O, S) using a top-down method and global search for parental V4AB6. Among the A element candidates, the P-glued MAB phase exhibited high stability and easy synthesizability. Moreover, 2D V4B6 was feasibly formed and easily exfoliated owing to its weak V-P bonding. Most of the surface functionalization could improve both the mechanical and electrochemical properties of the V4B6 monolayer. In particular, 2D V4B6S2 exhibited a high potential as an anode material for lithium-ion batteries (LIBs) with high theoretical capacity (297 mA h g-1), low diffusion barrier (0.166 eV), and low open circuit voltage (0.136 V), outperforming a majority of MXenes and transition metal sulfide layers. This work offers a new strategy for designing desirable 2D layers from parental materials, and tuning their properties via composition and surface functionalization, which could shed light on the development of other 2D metal-ion anodes.

14.
Biomed Opt Express ; 15(1): 59-76, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38223179

RESUMEN

Hypoxia is a critical tumor microenvironment (TME) component. It significantly impacts tumor growth and metastasis and is known to be a major obstacle for cancer therapy. Integrating hypoxia modulation with imaging-based monitoring represents a promising strategy that holds the potential for enhancing tumor theranostics. Herein, a kind of nanoenzyme Prussian blue (PB) is synthesized as a metal-organic framework (MOF) to load the second near-infrared (NIR-II) small molecule dye IR1061, which could catalyze hydrogen peroxide to produce oxygen and provide a photothermal conversion element for photoacoustic imaging (PAI) and photothermal therapy (PTT). To enhance stability and biocompatibility, silica was used as a coating for an integrated nanoplatform (SPI). SPI was found to relieve the hypoxic nature of the TME effectively, thus suppressing tumor cell migration and downregulating the expression of heat shock protein 70 (HSP70), both of which led to an amplified NIR-II PTT effect in vitro and in vivo, guided by the NIR-II PAI. Furthermore, label-free multi-spectral PAI permitted the real-time evaluation of SPI as a putative tumor treatment. A clinical histological analysis confirmed the amplified treatment effect. Hence, SPI combined with PAI could offer a new approach for tumor diagnosing, treating, and monitoring.

15.
Plant Cell Rep ; 43(1): 28, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38177567

RESUMEN

KEY MESSAGE: The weighted gene co-expression network analysis and antisense oligonucleotide-mediated transient gene silencing revealed that CsAAP6 plays an important role in amino acid transport during tea shoot development. Nitrogen transport from source to sink is crucial for tea shoot growth and quality formation. Amino acid represents the major transport form of reduced nitrogen in the phloem between source and sink, but the molecular mechanism of amino acid transport from source leaves to new shoots is not yet clear. Therefore, the composition of metabolites in phloem exudates collected by the EDTA-facilitated method was analyzed through widely targeted metabolomics. A total of 326 metabolites were identified in the phloem exudates with the richest variety of amino acids and their derivatives (93), accounting for approximately 39.13% of the total metabolites. Moreover, through targeted metabolomics, it was found that the content of glutamine, glutamic acid, and theanine was the most abundant, and gradually increased with the development of new shoots. Meanwhile, transcriptome analysis suggested that the expression of amino acid transport genes changed significantly. The WGCNA analysis identified that the expression levels of CsAVT1, CsLHTL8, and CsAAP6 genes located in the MEterquoise module were positively correlated with the content of amino acids such as glutamine, glutamic acid, and theanine in phloem exudates. Reducing the CsAAP6 in mature leaves resulted in a significant decrease in the content of glutamic acid, aspartic acid, alanine, leucine, asparagine, glutamine, and arginine in the phloem exudates, indicating that CsAAP6 played an important role in the source to sink transport of amino acids in the phloem. The research results will provide the theoretical basis and genetic resources for the improvement of nitrogen use efficiency and tea quality.


Asunto(s)
Aminoácidos , Glutamina , Aminoácidos/metabolismo , Glutamatos/metabolismo , , Perfilación de la Expresión Génica , Nitrógeno/metabolismo
16.
Nanoscale ; 16(6): 3043-3052, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38235520

RESUMEN

Due to limited mass loading, high-capacity electrode materials such as transition metal oxides (TMOs) are essential for microscale Li-ion batteries (LIBs) integrated in nano-/micro-electromechanical systems (N/MEMS). Unfortunately, their electrochemical performances are largely plagued by severe mechanical degradation and slow electron transport. Therefore, it is crucial to develop strategies that can improve the structural stability and electronic conductivity of TMO electrodes. In this work, double-carbon (carbon nanotubes and ketjen black) microsphere (DCMS) supported Co3O4 electrodes are fabricated simply through a spray drying and solvothermal method, which are designed to have a mesoporous three-dimensional (3D) hierarchical heterostructure containing well-dispersed Co3O4 nanoparticles within the DCMS framework. An in situ transmission electron microscopy (TEM) study reveals that the DCMS framework can not only provide facile strain accommodation, but also good electronic conductivity, leading to a much improved Li-storage performance compared to other Co3O4-based anodes. The hierarchical electrode exhibits maximum charge capacities of 1205.2 and 678.1 mA h g-1 at current densities of 0.1 and 2 A g-1, respectively, as well as a capacity retention of 92.2% at 0.3 A g-1 after 100 cycles. This study provides a low-cost, simple and general method for developing advanced high-capacity electrodes.

17.
Nanoscale Horiz ; 9(2): 254-263, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38014510

RESUMEN

Tension-compression asymmetry is a topic of current interest in nanostructures, especially in strain engineering. Herein, we report a novel on-chip microelectromechanical system (MEMS) that can realize in situ quantitative mechanical testing of nanostructures under tension-compression functions. The mechanical properties of three kinds of nanostructures fabricated by focused ion beam (FIB) techniques were systematically investigated with the presented on-chip testing system. The results declare that both Pt nanopillars and C nanowires exhibit plastic deformation behavior under tension testing, with average Young's moduli of 70.06 GPa and 58.32 GPa, respectively. However, the mechanical deformation mechanisms of the two nanostructures changed in compression tests. The Pt nanopillar exhibited in-plane buckling behavior, while the C nanowire displayed 3D twisting behavior with a maximum strain of 25.47%, which is far greater than the tensile strain. Moreover, asymmetric behavior was also observed in the C nanospring during five loading-unloading tension-compression deformation tests. This work provides a novel insight into the asymmetric mechanical properties of nanostructures, with potential applications in nanotechnology research.

19.
Nanoscale Horiz ; 9(1): 162-173, 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-37991927

RESUMEN

Recently, two-dimensional (2D) FeSe-like anti-MXenes (or XMenes), composed of late d-block transition metal M and p-block nonmetal X elements, have been both experimentally and theoretically investigated. Here, we select three 2D borides FeB, CoB and IrB for a deeper investigation by including strong correlation effects, as a fertile ground for understanding and applications. Using a combination of Hubbard corrected first-principles calculations and Monte Carlo simulations, FeB and CoB are found to be ferro- and anti-ferro magnetic, contrasting with the non-magnetic nature of IrB. The metallic FeB XMene monolayer, superior to most of the MXenes or MBenes, exhibits robust ferromagnetism, driven by intertwined direct-exchange and super-exchange interactions between adjacent Fe atoms. The predicted Curie temperature (TC) of the FeB monolayer via the Heisenberg model reaches an impressive 425 K, with the easy-axis oriented out-of-plane and high magnetic anisotropic energy (MAE). The asymmetry in the spin-resolved transmission spectrum induces a thermal spin current, providing an opportunity for spin filtration. This novel 2D FeB material is expected to hold great promise as an information storage medium and find applications in emerging spintronic devices.

20.
Nanomaterials (Basel) ; 13(20)2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37887907

RESUMEN

ß-Ga2O3 nanostructures are attractive wide-band-gap semiconductor materials as they exhibit promising photoelectric properties and potential applications. Despite the extensive efforts on ß-Ga2O3 nanowires, investigations into ß-Ga2O3 nanotubes are rare since the tubular structures are hard to synthesize. In this paper, we report a facile method for fabricating ß-Ga2O3 nanotubes using pre-synthesized GaSb nanowires as sacrificial templates. Through a two-step heating-treatment strategy, the GaSb nanowires are partially oxidized to form ß-Ga2O3 shells, and then, the residual inner parts are removed subsequently in vacuum conditions, yielding delicate hollow ß-Ga2O3 nanotubes. The length, diameter, and thickness of the nanotubes can be customized by using different GaSb nanowires and heating parameters. In situ transmission electron microscopic heating experiments are performed to reveal the transformation dynamics of the ß-Ga2O3 nanotubes, while the Kirkendall effect and the sublimation process are found to be critical. Moreover, photoelectric tests are carried out on the obtained ß-Ga2O3 nanotubes. A photoresponsivity of ~25.9 A/W and a detectivity of ~5.6 × 1011 Jones have been achieved with a single-ß-Ga2O3-nanotube device under an excitation wavelength of 254 nm.

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