Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 203
Filtrar
1.
J Inflamm Res ; 17: 2839-2850, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38751687

RESUMO

Purpose: Acupoint autohemotherapy (A-AHT) has been proposed as an alternative and complementary treatment for atopic dermatitis (AD), yet the exact role of its blood component in terms of therapeutic efficacy and mechanism of action is still largely unknown. Methods: This study aimed to evaluate the therapeutic efficacies and action mechanisms of intramuscular injections of autologous whole blood (AWB) and mouse immunoglobulin G (IgG) (autologous or heterologous) at acupoints on 2,4-dinitrochlorobenzene (DNCB)-induced AD mouse models. Serum levels of total immunoglobulin E (IgE), IgG, interleukin-10 (IL-10), and interferon-gamma (IFN-γ) were measured, as well as mRNA expression levels of Forkhead box P3 (FoxP3), IL-10 and IFN-γ in dorsal skin lesions, and IL-10+, IFN-γ+ and FoxP3+CD4+T cells in murine spleen. Results: It showed that repeated acupoint injection of AWB, autologous total IgG (purified from autologous blood in AD mice) or heterologous total IgG (purified from healthy blood in normal mice) effectively reduced the severity of AD symptoms and decreased epidermal and dermal thickness as well as mast cells in skin lesions. Additionally, AWB acupoint injection was found to upregulate FoxP3+, IL-10+ and IFN-γ+ CD4+T cells in murine spleen, suppressing the production of IgE antibodies and increasing that of IgG antibodies in the serum. Furthermore, both AWB and autologous total IgG administrations significantly elevated FoxP3 expression, mRNA levels of IL-10 and IFN-γ in dorsal skin lesions. However, acupoint injection of heterologous total IgG had no effect on regulatory T (Treg) and Th1 cells modulation. Conclusion: These findings suggest that the therapeutic effects of A-AHT on AD are mediated by IgG-induced activation of Treg cells.

2.
Psychoradiology ; 4: kkae008, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38715747

RESUMO

Whereas autism spectrum condition is known for its social and communicative challenges, some autistic children demonstrate unusual islets of abilities including those related to mathematics, the neurobiological underpinnings of which are increasingly becoming the focus of research. Here we describe an 8-year-old autistic boy with intellectual and language challenges, yet exceptional arithmetic ability. He can perform verbal-based multiplication of three- and even four-digit numbers within 20 seconds. To gain insights into the neural basis of his talent, we investigated the gray matter in the child's brain in comparison to typical development, applying voxel-based morphometry to magnetic resonance imaging data. The case exhibited reduced gray matter volume in regions associated with arithmetic, which may suggest an accelerated development of brain regions with arithmetic compared to typically developing individuals: potentially a key factor contributing to his exceptional talent. Taken together, this case report describes an example of the neurodiversity of autism. Our research provides valuable insights into the potential neural basis of exceptional arithmetic abilities in individuals with the autism spectrum and its potential contribution to depicting the diversity and complexity of autism.

3.
Aesthet Surg J ; 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38567442

RESUMO

BACKGROUND: Macrophage-mediated inflammatory response in the early post-grafting period restricts fat graft retention. Pyroptosis is a novel type of programmed cell death that extensively participates in inflammatory pathologies. OBJECTIVES: This study sought to determine whether macrophage pyroptosis is activated during the inflammatory phase after fat grafting and to investigate the efficacy of a pyroptosis inhibitor, disulfiram (DSF) in fat graft retention. METHODS: We established a C57BL/6 mice fat grafting model and then analyzed macrophage pyroptosis. DSF (50 mg/kg, every other day) was intraperitoneally injected started from 1 h prior to fat grafting and continued for 14 days. An in vitro co-culture system was established in which mouse RAW264.7 macrophages were co-cultured with apoptotic adipocytes to further validate the findings of the in vivo studies and to explore the underlying mechanisms. RESULTS: Here we reported that macrophage pyroptosis was activated in both fat grafts and in vitro co-culture models. DSF was found to be a potent pyroptosis inhibitor to promote M2 macrophage polarization. In addition, DSF was demonstrated to enhance vascularization and graft retention. CONCLUSIONS: Our results suggested that pyroptosis plays a crucial role in the inflammatory cascade within fat grafts. DSF, being a clinically available drug could be translated into a clinically effective drug for improving fat graft survival via inhibiting macrophage pyroptosis, thereby inducing M2 macrophage polarization and promoting neovascularization.

4.
Adv Mater ; : e2402232, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684179

RESUMO

Recently, the real topology has been attracting widespread interest in two dimensions (2D). Here, based on first-principles calculations and theoretical analysis, the monolayer Cr2Se2O (ML-CrSeO) is revealed as the first material example of a 2D antiferromagnetic (AFM) real Chern insulator (RCI) with topologically protected corner states. Unlike previous RCIs, it is found that the real topology of the ML-CrSeO is rooted in one certain mirror subsystem of the two spin channels, and cannot be directly obtained from all the valence bands in each spin channel as commonly believed. In particular, due to antiferromagnetism, the corner modes in ML-CrSeO exhibit strong corner-contrasted spin polarization, leading to spin-corner coupling (SCC). This SCC enables a direct connection between spin space and real space. Consequently, large and switchable net magnetization can be induced in the ML-CrSeO nanodisk by electrostatic means, such as potential step and in-plane electric field, and the corresponding magnetoelectric responses behave like a sign function, distinguished from that of the conventional multiferroic materials. This work considerably broadens the candidate range of RCI materials, and opens up a new direction for topo-spintronics and 2D AFM materials research.

5.
Front Neurosci ; 18: 1371418, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38650621

RESUMO

As an excellent single-stage object detector based on neural networks, YOLOv5 has found extensive applications in the industrial domain; however, it still exhibits certain design limitations. To address these issues, this paper proposes Efficient Scale Fusion YOLO (ESF-YOLO). Firstly, the Multi-Sampling Conv Module (MSCM) is designed, which enhances the backbone network's learning capability for low-level features through multi-scale receptive fields and cross-scale feature fusion. Secondly, to tackle occlusion issues, a new Block-wise Channel Attention Module (BCAM) is designed, assigning greater weights to channels corresponding to critical information. Next, a lightweight Decoupled Head (LD-Head) is devised. Additionally, the loss function is redesigned to address asynchrony between labels and confidences, alleviating the imbalance between positive and negative samples during the neural network training. Finally, an adaptive scale factor for Intersection over Union (IoU) calculation is innovatively proposed, adjusting bounding box sizes adaptively to accommodate targets of different sizes in the dataset. Experimental results on the SODA10M and CBIA8K datasets demonstrate that ESF-YOLO increases Average Precision at 0.50 IoU (AP50) by 3.93 and 2.24%, Average Precision at 0.75 IoU (AP75) by 4.77 and 4.85%, and mean Average Precision (mAP) by 4 and 5.39%, respectively, validating the model's broad applicability.

6.
Mikrochim Acta ; 191(4): 201, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38489138

RESUMO

Nowadays, the frequent occurrence of food adulteration makes glucose detection particularly important in food safety and quality management. The quality and taste of honey are closely related to the glucose content. However, due to the drawbacks of expensive equipment, complex operating procedures, and time-consuming processes, the application scope of traditional glucose detection methods is limited. Hence, this study developed a photoelectric chemical (PEC) sensor, which is composed of a photoactive material of bismuth tungstate (Bi2WO6) with titanium dioxide (TiO2) and glucose oxidase (GOD), for simple and rapid detection of glucose. Notably, the composites' absorption prominently increased in the visible light region, and the photo-generated electron-hole pairs were efficiently separated by virtue of the unique nanostructure system, thus playing a crucial role in facilitating PEC activity. In the presence of dissolved oxygen, the photocurrent intensity was enhanced by H2O2 generated from glucose under electro-oxidation specifically catalyzed by GOD fixed on the modified electrode. When the working potential was 0.3 V, the changes of photocurrent response indicated that the PEC enzyme biosensor provides a low detection limit (3.8 µM), and a wide linear range (0.008-8 mM). This method has better selectivity in honey samples and broad application prospects in clinical diagnosis for future.


Assuntos
Técnicas Biossensoriais , Nanoestruturas , Peróxido de Hidrogênio , Técnicas Biossensoriais/métodos , Luz , Glucose , Glucose Oxidase/química
7.
Langmuir ; 40(13): 7021-7028, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38501919

RESUMO

Photodynamic therapy (PDT) stands as an efficacious modality for the treatment of cancer and various diseases, in which optimization of the electron transfer and augmentation of the production of lethal reactive oxygen species (ROS) represent pivotal challenges to enhance its therapeutic efficacy. Empirical investigations have established that the spontaneous initiation of redox reactions associated with electron transfer is feasible and is located in the gas-liquid interfaces. Meanwhile, nanobubbles (NBs) are emerging as entities capable of furnishing a plethora of such interfaces, attributed to their stability and large surface/volume ratio in bulk water. Thus, NBs provide a chance to expedite the electron-transfer kinetics within the context of PDT in an ambient environment. In this paper, we present a pioneering exploration into the impact of nitrogen nanobubbles (N2-NBs) on the electron transfer of the photosensitizer levofloxacin (LEV). Transient absorption spectra and time-resolved decay spectra, as determined through laser flash photolysis, unequivocally reveal that N2-NBs exhibit a mitigating effect on the decay of the LEV excitation triplet state, thereby facilitating subsequent processes. Of paramount significance is the observation that the presence of N2-NBs markedly accelerates the electron transfer of LEV, albeit with a marginal inhibitory influence on its energy-transfer reaction. This observation is corroborated through absorbance measurements and offers compelling evidence substantiating the role of NBs in expediting electron transfer within the ambit of PDT. The mechanism elucidated herein sheds light on how N2-NBs intricately influence both electron-transfer and energy-transfer reactions in the photosensitizer LEV. These findings not only contribute to a nuanced understanding of the underlying processes but also furnish novel insights that may inform the application of NBs in the realm of photodynamic therapy.


Assuntos
Levofloxacino , Fármacos Fotossensibilizantes , Fármacos Fotossensibilizantes/farmacologia , Levofloxacino/farmacologia , Processos Fotoquímicos , Oxirredução , Transporte de Elétrons
8.
J Med Biochem ; 43(1): 36-42, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38496025

RESUMO

Background: Cerebral haemorrhage is a critical condition that often requires surgical treatment, and postoperative intracranial infection can significantly impact patient outcomes. The aim of the study was to examine the relationship between the levels of lactic acid and glucose in cerebrospinal fluid (CSF) of patients with cerebral haemorrhage and their postoperative intracranial infection and clinical prognosis. Methods: The study selected the clinical data of 324 patients with cerebral haemorrhage who underwent surgical treatment in our hospital from March 2020 to March 2022 for retrospective analysis and divided these patients into the intracranial infection group (Group A, n=22, leukocyte values in CSF>5×106/L) and the non-intracranial infection group (Group B, n=302, leukocyte values in CSF 5×106/L) according to the occurrence of postoperative intracranial infection in patients to detect the levels of lactic acid and glucose in CSF at different times in the two groups. Pearson method was adopted to analyze the correlation of the levels of lactic acid and glucose in CSF of patients with intracranial infection, and the Glasgow Outcome Scale (GOS) was used to assess the clinical prognosis of patients. According to their scores, these patients were divided into the good prognosis group (GPG, scores of 4-5 points, n=178) and the poor prognosis group (PPG, scores of 1-3 points, n=146). The levels of lactic acid and glucose in the CSF of patients in the two groups were measured, and the Pearson method was adopted to analyze the relationship between these levels and clinical prognosis.

9.
BMC Musculoskelet Disord ; 25(1): 198, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443916

RESUMO

BACKGROUND: This meta-analysis aims to investigate the efficacy of early rehabilitation on patients who have undergone surgery for distal radius fractures (DRFs) with palmar plating, focusing on multiple outcome measures including upper limb function, wrist function, back extension mobility, pain levels, and complications. METHODS: A rigorous search strategy adhering to the PRISMA guidelines was employed across four major databases, including PubMed, Embase, Web of Science, and the Cochrane Library. Studies were included based on stringent criteria, and data extraction was performed independently by two reviewers. Meta-analysis was conducted employing both fixed-effect and random-effects models as dictated by heterogeneity, assessed by the I2 statistic and chi-square tests. A total of 7 studies, encompassing diverse demographic groups and timelines, were included for the final analysis. RESULTS: The meta-analysis disclosed that early rehabilitation yielded a statistically significant improvement in upper limb function (SMD -0.27; 95% CI -0.48 to -0.07; P < 0.0001) and back extension mobility (SMD 0.26; 95% CI 0.04 to 0.48; P = 0.021). A notable reduction in pain levels was observed in the early rehabilitation group (SMD -0.28; 95% CI -0.53 to -0.02; P = 0.03). However, there were no significant differences in wrist function (SMD -0.13; 95% CI -0.38 to 0.12; P = 0.36) and complications (OR 0.99; 95% CI 0.61 to 1.61; P = 0.96). CONCLUSIONS: Early rehabilitation post-DRF surgery with palmar plating has been found to be beneficial in enhancing upper limb functionality and back extension mobility, and in reducing pain levels. Nevertheless, no significant impact was observed regarding wrist function and complications.


Assuntos
Fraturas do Punho , Humanos , Dor , Extremidade Superior , Punho , Fraturas do Punho/reabilitação , Articulação do Punho
10.
J Environ Sci (China) ; 142: 204-214, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38527885

RESUMO

Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity. However, its inadequate catalytic activity results in difficulty in effectively degrading pollutants in the catalytic degradation system that it constitutes. Thus, we constructed a photochemical system composed of hematite with {001} facet of high activity facet and low-cost and non-toxic oxalic acid (OA) for the removal of various types of pollutants. The removal rate for the degradation of metronidazole, tetracycline hydrochloride, Rhodamine B, and hexavalent chromium by hematite nanoplate with the exposed {001} facet activating OA under visible light irradiation was 4.75, 2.25, 2.33, and 2.74 times than that by the exposed {110} facet, respectively. Density functional theory (DFT) calculation proved that the OA molecule was more easily adsorbed on the {001} facet of hematite than that on the {110} facet, which would favor the formation of the more Fe(III)-OA complex and reactive species. In addition, the reactive site of metronidazole for the attraction of radicals was identified on the basis of the DFT calculation on the molecular occupied orbitals, and the possible degradation pathway for metronidazole included carbon chain fracture, hydroxyethyl-cleavage, denitrogenation, and hydroxylation. Thus, this finding may offer a valuable direction in designing an efficient iron-based catalyst based on facet engineering for the improved activity of Fenton-like systems such as OA activation.


Assuntos
Poluentes Ambientais , Nanopartículas , Compostos Férricos/química , Ácido Oxálico , Metronidazol , Luz , Peróxido de Hidrogênio/química , Catálise
11.
Nat Commun ; 15(1): 1472, 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38368437

RESUMO

Understanding how plants alter their development and architecture in response to ambient temperature is crucial for breeding resilient crops. Here, we identify the quantitative trait locus qMULTIPLE INFLORESCENCE BRANCH 2 (qMIB2), which modulates inflorescence branching in response to high ambient temperature in tomato (Solanum lycopersicum). The non-functional mib2 allele may have been selected in large-fruited varieties to ensure larger and more uniform fruits under varying temperatures. MIB2 gene encodes a homolog of the Arabidopsis thaliana transcription factor SPATULA; its expression is induced in meristems at high temperature. MIB2 directly binds to the promoter of its downstream gene CONSTANS-Like1 (SlCOL1) by recognizing the conserved G-box motif to activate SlCOL1 expression in reproductive meristems. Overexpressing SlCOL1 rescue the reduced inflorescence branching of mib2, suggesting how the MIB2-SlCOL1 module helps tomato inflorescences adapt to high temperature. Our findings reveal the molecular mechanism underlying inflorescence thermomorphogenesis and provide a target for breeding climate-resilient crops.


Assuntos
Arabidopsis , Solanum lycopersicum , Inflorescência , Solanum lycopersicum/genética , Vernalização , Melhoramento Vegetal , Meristema/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
12.
J Invest Dermatol ; 144(5): 1148-1160.e15, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38242315

RESUMO

Long noncoding RNAs are pivotal contributors to the development of human diseases. However, their significance in the context of diabetic wound healing regulated by human umbilical cord mesenchymal stem cells (hUCMSCs) remains unclear. This study sheds light on the involvement of lncCCKAR5 in this process. We found that hUCMSCs exposed to high glucose conditions exhibited a significant downregulation of lncCCKAR5 expression, and lncCCKAR5 played a critical role in modulating autophagy, thus inhibiting apoptosis in hUCMSCs. In addition, the reduction of lncCCKAR5 in cells exposed to high glucose effectively thwarted cellular senescence and facilitated filopodium formation. Mechanistically, lncCCKAR5 served as a scaffold that facilitated the interaction between MKRN2 and LMNA, a key regulator of cytoskeletal function and autophagy. The lncCCKAR5/LMNA/MKRN2 complex played a pivotal role in promoting the ubiquitin-mediated degradation of LMNA, with this effect being further augmented by N6-adenosine methylation of lncCCKAR5. Consequently, our findings underscore the critical role of lncCCKAR5 in regulating the autophagic process in hUCMSCs, particularly through protein ubiquitination and degradation. This intricate regulatory network presents a promising avenue for potential therapeutic interventions in the context of diabetic wound healing involving hUCMSCs.


Assuntos
Adenosina , Adenosina/análogos & derivados , Autofagia , Lamina Tipo A , Células-Tronco Mesenquimais , RNA Longo não Codificante , Cordão Umbilical , Cicatrização , Humanos , Autofagia/efeitos dos fármacos , Adenosina/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Cordão Umbilical/citologia , RNA Longo não Codificante/metabolismo , RNA Longo não Codificante/genética , Lamina Tipo A/metabolismo , Lamina Tipo A/genética , Camundongos , Células Cultivadas , Animais , Apoptose/efeitos dos fármacos , Glucose/metabolismo , Glucose/farmacologia , Senescência Celular/efeitos dos fármacos
13.
Phys Chem Chem Phys ; 26(4): 3092-3100, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38180442

RESUMO

Kagome lattices may have numerous exotic physical properties, such as stable ferromagnetism and topological states. Herein, combining the particle swarm structure search method with first-principles calculations, we identify a two-dimensional (2D) kagome Mo2Se3 crystal structure with space group P6/mmm. The results show that 2D kagome Mo2Se3 is a 100% spin-polarized topological nodal line semimetal and exhibits excellent ambient stability. The band crossing points form two nodal loops around the high-symmetry points Γ and K. On the other hand, Mo2Se3 shows intrinsic ferromagnetism with a large magnetic moment of 3.05 µB per Mo atom and magnetic anisotropy energy (MAE) of 4.78 meV. Monte Carlo simulations estimate that Mo2Se3 possesses a high Curie temperature of about 673 K. In addition, its ferromagnetic ground state can be well preserved under external strain, and the MAE can be improved by increasing the strain. More importantly, the position of each nodal line can be adjusted to the Fermi level through hole doping. This multifunctional 2D magnetic material that combines spin and topology has great potential in the field of nanoscale spintronic devices.

14.
Comput Biol Med ; 170: 107968, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38244472

RESUMO

When performing stent intervention for iliac vein compression syndrome, the operator selects the appropriate stent and determines its implantation depth according to the type and severity of iliac vein stenosis in the patient. However, there is still uncertainty regarding how the structure of the stent and its implantation depth affect hemodynamics at the site of lesion. In this paper, we analyzed three commonly used stents (Vena stent from Venmedtch, Venovo from Bard, and Smart stent from Cordis) with different implantation depths (0, 10, 20 mm) using computational fluid dynamics (CFD). We focused on evaluating hemorheological parameters such as time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), etc., within one pulsatile cycle after stent implantation. The correlation between geometric parameters of the stents and hemodynamic indicators was assessed using Pearson correlation coefficient (r), which was further validated through PIV velocity measurement experiment. The results revealed that an increase in implantation depth led to a more pronounced disturbance effect on blood flow at bifurcation for densely arranged support body-type stents. This effect was particularly significant during periods of smooth blood flow. On the other hand, crown-shaped Vena stents exhibited relatively less disruption to blood flow post-implantation. Implantation depth showed a strong negative correlation with TAWSS but a strong positive correlation with OSI and RRT. These findings suggest an increased risk of thrombosis at iliac vein bifurcation following stent placement. Amongst all three tested stents, Vena Stent demonstrated more favorable periodic parameters after implantation compared to others. These results provide valuable theoretical insights into understanding contralateral circulation thrombosis associated with iliac vein stenting.


Assuntos
Veia Ilíaca , Trombose , Humanos , Veia Ilíaca/cirurgia , Hemodinâmica , Stents/efeitos adversos
15.
IEEE Trans Cybern ; 54(5): 3265-3274, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37028390

RESUMO

The exchange of information is a crucial factor in achieving consensus among agents. However, in real-world scenarios, nonideal information sharing is prevalent due to complex environmental conditions. Consider the information distortions (data) and stochastic information flow (media) during state transmission both caused by physical constraints, a novel model of transmission-constrained consensus over random networks is proposed in this work. The transmission constraints are represented by heterogeneous functions that reflect the impact of environmental interference in multiagent systems or social networks. A directed random graph is applied to model the stochastic information flow where every edge is connected probabilistically. Using stochastic stability theory and the martingale convergence theorem, it is demonstrated that the agent states will converge to a consensus value with probability 1, despite information distortions and randomness in information flow. Numerical simulations are presented to validate the effectiveness of the proposed model.

16.
Nucleic Acids Res ; 52(3): 1258-1271, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38048302

RESUMO

Progression through the mitotic and meiotic cell cycle is driven by fluctuations in the levels of cyclins, the regulatory subunits controlling the localization and activity of CDK1 kinases. Cyclin levels are regulated through a precise balance of synthesis and degradation. Here we demonstrate that the synthesis of Cyclin B1 during the oocyte meiotic cell cycle is defined by the selective translation of mRNA variants generated through alternative cleavage and polyadenylation (APA). Using gene editing in mice, we introduced mutations into the proximal and distal polyadenylation elements of the 3' untranslated region (UTR) of the Ccnb1 mRNA. Through in vivo loss-of-function experiments, we demonstrate that the translation of mRNA with a short 3' UTR specifies Cyclin B1 protein levels that set the timing of meiotic re-entry. In contrast, translation directed by a long 3' UTR is necessary to direct Cyclin B1 protein accumulation during the MI/MII transition. These findings establish that the progression through the cell cycle is dependent on the selective translation of multiple mRNA variants generated by APA.


Assuntos
Ciclina B1 , Meiose , Poliadenilação , Animais , Camundongos , Regiões 3' não Traduzidas/genética , Ciclo Celular/genética , Ciclina B1/genética , Ciclina B1/metabolismo , Ciclinas/genética , Ciclinas/metabolismo , Oócitos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
17.
Adv Sci (Weinh) ; 11(6): e2307297, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38044294

RESUMO

When spin-orbit coupling (SOC) is absent, all proposed half-metals with twofold degenerate nodal points at the K (or K') point in 2D materials are classified as "Dirac half-metals" owing to the way graphene is utilized in the earliest studies. Actually, each band crossing point at the K or K' point is described by a 2D Weyl Hamiltonian with definite chirality; hence, it should be a Weyl point. To the best of its knowledge, there have not yet been any reports of a genuine (i.e., fourfold degenerate) 2D Dirac point half-metal. In this work, using first-principles calculations, it proposes for the first time that the 2D d0 -type ferromagnet Mg4 N4 is a genuine 2D Dirac half-metal candidate with a fourfold degenerate Dirac point at the S high-symmetry point, intrinsic magnetism, a high Curie temperature, 100% spin polarization, topology robust under the SOC and uniaxial and biaxial strains, and spin-polarized edge states. This work can serve as a starting point for future predictions of intrinsically magnetic materials with genuine 2D Dirac points, which will aid the frontier of topo-spintronics research in 2D systems.

18.
Sci Rep ; 13(1): 22909, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38129472

RESUMO

The grey wolf optimizer is an effective and well-known meta-heuristic algorithm, but it also has the weaknesses of insufficient population diversity, falling into local optimal solutions easily, and unsatisfactory convergence speed. Therefore, we propose a hybrid grey wolf optimizer (HGWO), based mainly on the exploitation phase of the harris hawk optimization. It also includes population initialization with Latin hypercube sampling, a nonlinear convergence factor with local perturbations, some extended exploration strategies. In HGWO, the grey wolves can have harris hawks-like flight capabilities during position updates, which greatly expands the search range and improves global searchability. By incorporating a greedy algorithm, grey wolves will relocate only if the new location is superior to the current one. This paper assesses the performance of the hybrid grey wolf optimizer (HGWO) by comparing it with other heuristic algorithms and enhanced schemes of the grey wolf optimizer. The evaluation is conducted using 23 classical benchmark test functions and CEC2020. The experimental results reveal that the HGWO algorithm performs well in terms of its global exploration ability, local exploitation ability, convergence speed, and convergence accuracy. Additionally, the enhanced algorithm demonstrates considerable advantages in solving engineering problems, thus substantiating its effectiveness and applicability.

19.
Brain Sci ; 13(12)2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38137136

RESUMO

Oxytocin is well known for its role in relationships and social cognition and has more recently been implicated in pain relief and pain perception. Connections between prosocial feelings and pain relief are also well documented; however, the effects of exogenous oxytocin on social cognition and pain have not been explored. The current study tested whether intranasally delivered oxytocin affects pain perception through prosocial behaviors. Additionally, moderation of the effects of oxytocin by life history or genetic polymorphisms is examined. Young adults (n = 43; 65% female) were administered intranasal oxytocin (24 IU) or placebo in a crossover design on two visits separated by a one-week washout period. Pain was delivered via cold pressor. Baseline measures for decision-making and social cognition were collected, as well as pain sensitivity and medication history. Saliva samples were collected for analysis of genetic markers, and urine samples were collected to assess oxytocin saturation. Following oxytocin administration, participants reported increased prosocial cognition and decision-making. Pain perception appeared to be adaptive, with procedural order and expectation affecting perception. Finally, behavioral trust and cooperation responses were significantly predicted by genetic markers. Oxytocin may increase a patient's trust and cooperation and reduce pain sensitivity while having fewer physiological side effects than current pharmaceutical options.

20.
Dalton Trans ; 52(40): 14613-14620, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37786378

RESUMO

As a pseudocapacitor electrode material, molybdenum disulfide (MoS2) usually shows inferior capacity, rate capability and cyclability. Structural regulation and heteroatom doping are the available methods to ameliorate the electrochemical properties of MoS2. Herein, phosphorus doped molybdenum disulfide regulated by sodium chloride (SP-MoS2) is successfully synthesized using phosphomolybdate acid as a molybdenum source and an in situ dopant and sodium chloride (NaCl) as a structural regulator. Under the structural regulation of NaCl, the SP-MoS2 nanosheets exhibit an interweaved architecture with a large interlayer spacing of 0.68 nm. Owing to the in situ P doping and large specific surface area (21.0 m2 g-1), the SP-MoS2 electrode possesses a maximum capacity of 564.8 F g-1 at 1 A g-1 and retains 56.3% of the original capacity at 20 A g-1. Density functional theory (DFT) calculations indicate that SP-MoS2 displays a high K+ average adsorption energy of -3.636 eV. In addition, the fabricated SP-MoS2//AC asymmetric supercapacitor device displays an energy density of 22.8 W h kg-1 at 759 W kg-1.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...