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Atopic dermatitis (AD) is a chronic inflammatory skin disorder associated with significant morbidity, including pruritus, recurrent skin lesions, and immune dysregulation. This study aimed to investigate the antioxidative and anti-AD effects of peptides derived from hydrolyzed Sebastes schlegelii (Korea rockfish) tail by-products. Hydrolysates were prepared using various enzymes, including Alcalase, Flavourzyme, Neutrase, and Protamex. Among them, Protamex hydrolysates demonstrated the highest ABTS radical scavenging activity with an RC50 value of 69.69 ± 0.41 µg/mL. Peptides were further isolated from the Protamex hydrolysate using dialysis, fast protein liquid chromatography (FPLC), and high-performance liquid chromatography (HPLC). The most active peptide, STPO-B-II, exhibited a single peak and was identified as a sequence of Glu-Leu-Ala-Lys-Thr-Trp-His-Asp-Met-Lys, designated as MP003. In vivo experiments were conducted using a 2,4-dinitrochlorbenzene (DNCB)-induced AD model in NC/Nga mice. The isolated peptide, MP003, showed significantly reduced AD symptoms, including erythema, lichenification, and collagen deposition. Additionally, MP003 decreased epidermal and dermal thickness, eosinophil, and mast cell infiltration and downregulated the expression of pro-inflammatory cytokines IL-1ß, IL-6, and IgE in serum and skin tissues. These findings suggest that peptides derived from Sebastes schlegelii tail by-products may serve as potential therapeutic agents for AD.
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Antioxidantes , Dermatitis Atópica , Péptidos , Animales , Ratones , Antioxidantes/farmacología , Antioxidantes/química , Dermatitis Atópica/tratamiento farmacológico , Dermatitis Atópica/inducido químicamente , Péptidos/farmacología , Péptidos/química , Péptidos/aislamiento & purificación , Hidrólisis , Modelos Animales de Enfermedad , Peces , Antiinflamatorios/farmacología , Antiinflamatorios/química , MasculinoRESUMEN
The skin is vulnerable to damage from ultraviolet rays and oxidative stress, which can lead to aging and pigmentation issues. This study investigates the antioxidant and whitening efficacy of a decapeptide (DP, KGYSSYICDK) derived from marine fish by-products and evaluates its potential as a new skin-whitening agent. DP demonstrated high antioxidant activity, showing comparable or superior performance to Vitamin C (Vit. C) in ferric reducing antioxidant power (FRAP) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. In hydrogen peroxide (H2O2)-treated HaCaT cells, DP increased cell viability and reduced reactive oxygen species (ROS) generation. Furthermore, DP inhibited tyrosinase activity and decreased melanin production in α-melanocyte stimulating hormone (α-MSH)-induced B16F10 melanoma cells in a dose-dependent manner. Reverse transcription polymerase chain reaction (RT-PCR) analysis revealed that DP reduces the mRNA expression of MITF, tyrosinase, and MC1R, thus suppressing melanin production. DP exhibits strong binding interactions with multiple amino acid residues of tyrosinase, indicating potent inhibitory effects on the enzyme. These results suggest that DP possesses significant antioxidant and whitening properties, highlighting its potential as a skin-whitening agent. Future research should focus on optimizing DP's structure and exploring structure-activity relationships.
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Antioxidantes , Melaninas , Monofenol Monooxigenasa , Preparaciones para Aclaramiento de la Piel , Animales , Humanos , Ratones , alfa-MSH/farmacología , Antioxidantes/farmacología , Antioxidantes/química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Peces , Células HaCaT , Peróxido de Hidrógeno/farmacología , Melaninas/biosíntesis , Melanoma Experimental/tratamiento farmacológico , Melanoma Experimental/metabolismo , Factor de Transcripción Asociado a Microftalmía/metabolismo , Monofenol Monooxigenasa/antagonistas & inhibidores , Monofenol Monooxigenasa/metabolismo , Oligopéptidos/farmacología , Oligopéptidos/química , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Receptor de Melanocortina Tipo 1/metabolismo , Piel/efectos de los fármacos , Piel/metabolismo , Preparaciones para Aclaramiento de la Piel/farmacología , Pigmentación de la Piel/efectos de los fármacosRESUMEN
This study investigated the antioxidant, antimicrobial, and anti-atopic dermatitis (AD) effects of a novel peptide (CP) derived from a Chromis notata by-product hydrolysate. Alcalase, Flavourzyme, Neutrase, and Protamex enzymes were used to hydrolyze the C. notata by-product protein, and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activity was measured. Alcalase hydrolysate exhibited the highest ABTS radical-scavenging activity, leading to the selection of Alcalase for further purification. The CHAO-1-I fraction, with the highest ABTS activity, was isolated and further purified, resulting in the identification of the peptide CP with the amino acid sequence Ala-Gln-Val-Met-Lys-Leu-Pro-His-Arg-Met-Gln-His-Ser-Gln-Ser. CP demonstrated antimicrobial activity against Staphylococcus aureus, inhibiting its growth. In a 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin model in mice, CP significantly alleviated skin lesions, reduced epidermal and dermal thickness, and inhibited mast cell infiltration. Moreover, CP suppressed the elevated levels of interleukin-6 (IL-6) in the plasma of DNCB-induced mice. These findings highlight the potential of CP as a therapeutic agent for AD and suggest a novel application of this C. notata by-product in the fish processing industry.
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Benzotiazoles , Dermatitis Atópica , Perciformes , Ácidos Sulfónicos , Animales , Ratones , Dermatitis Atópica/tratamiento farmacológico , Hidrólisis , Antioxidantes/farmacología , Dinitroclorobenceno , Antibacterianos/farmacología , Péptidos/farmacología , SubtilisinasRESUMEN
Spin-orbit torque (SOT)-driven deterministic control of the magnetic state of a ferromagnet with perpendicular magnetic anisotropy is key to next-generation spintronic applications including non-volatile, ultrafast and energy-efficient data-storage devices. However, field-free deterministic switching of perpendicular magnetization remains a challenge because it requires an out-of-plane antidamping torque, which is not allowed in conventional spin-source materials such as heavy metals and topological insulators due to the system's symmetry. The exploitation of low-crystal symmetries in emergent quantum materials offers a unique approach to achieve SOTs with unconventional forms. Here we report an experimental realization of field-free deterministic magnetic switching of a perpendicularly polarized van der Waals magnet employing an out-of-plane antidamping SOT generated in layered WTe2, a quantum material with a low-symmetry crystal structure. Our numerical simulations suggest that the out-of-plane antidamping torque in WTe2 is essential to explain the observed magnetization switching.
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Epitaxy-the growth of a crystalline material on a substrate-is crucial for the semiconductor industry, but is often limited by the need for lattice matching between the two material systems. This strict requirement is relaxed for van der Waals epitaxy, in which epitaxy on layered or two-dimensional (2D) materials is mediated by weak van der Waals interactions, and which also allows facile layer release from 2D surfaces. It has been thought that 2D materials are the only seed layers for van der Waals epitaxy. However, the substrates below 2D materials may still interact with the layers grown during epitaxy (epilayers), as in the case of the so-called wetting transparency documented for graphene. Here we show that the weak van der Waals potential of graphene cannot completely screen the stronger potential field of many substrates, which enables epitaxial growth to occur despite its presence. We use density functional theory calculations to establish that adatoms will experience remote epitaxial registry with a substrate through a substrate-epilayer gap of up to nine ångströms; this gap can accommodate a monolayer of graphene. We confirm the predictions with homoepitaxial growth of GaAs(001) on GaAs(001) substrates through monolayer graphene, and show that the approach is also applicable to InP and GaP. The grown single-crystalline films are rapidly released from the graphene-coated substrate and perform as well as conventionally prepared films when incorporated in light-emitting devices. This technique enables any type of semiconductor film to be copied from underlying substrates through 2D materials, and then the resultant epilayer to be rapidly released and transferred to a substrate of interest. This process is particularly attractive in the context of non-silicon electronics and photonics, where the ability to re-use the graphene-coated substrates allows savings on the high cost of non-silicon substrates.
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The intrinsic magnetic topological insulators MnBi2Te4 and MnBi2Se4 support novel topological states related to symmetry breaking by magnetic order. Unlike MnBi2Te4, the study of MnBi2Se4 has been inhibited by the lack of bulk crystals, as the van der Waals (vdW) crystal is not the thermodynamic equilibrium phase. Here, we report the layer-by-layer synthesis of vdW MnBi2Se4 crystals using nonequilibrium molecular beam epitaxy. Atomic-resolution scanning transmission electron microscopy and scanning tunneling microscopy identify a well-ordered vdW crystal with septuple-layer base units. The magnetic properties agree with the predicted layered antiferromagnetic ordering but disagree with its predicted out-of-plane orientation. Instead, our samples exhibit an easy-plane anisotropy, which is explained by including dipole-dipole interactions. Angle-resolved photoemission spectroscopy reveals the gapless Dirac-like surface state, which demonstrates that MnBi2Se4 is a topological insulator above the magnetic-ordering temperature. These studies show that MnBi2Se4 is a promising candidate for exploring rich topological phases of layered antiferromagnetic topological insulators.
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Developing efficient and inexpensive electrocatalysts for the hydrogen evolution reaction (HER) in alkaline water electrolysis plays a key role for renewable hydrogen energy technology. The slow reaction kinetics of HER in alkaline solutions, however, has hampered advances in high-performance hydrogen production. Herein, we investigated the trends in HER activity with respect to the binding energies of Ni-based thin film catalysts by incorporating a series of oxophilic transition metal atoms. It was found that the doping of oxophilic atoms enables the modulation of binding abilities of hydrogen and hydroxyl ions on the Ni surfaces, leading to the first establishment of a volcano relation between OH-binding energies and alkaline HER activities. In particular, Cr-incorporated Ni catalyst shows optimized OH-binding as well as H-binding energies for facilitating water dissociation and improving HER activity in alkaline media. Further enhancement of catalytic performance was achieved by introducing an array of three-dimensional (3D) Ni nanohelixes (NHs) that provide abundant surface active sites and effective channels for charge transfer and mass transport. The Cr dopants incorporated into the Ni NHs accelerate the dissociative adsorption process of water, resulting in remarkably enhanced catalytic activities in alkaline medium. Our approach can provide a rational design strategy and experimental methodology toward efficient bimetallic electrocatalysts for alkaline HER using earth-abundant elements.
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OBJECTIVES: Tissue conductivity measurements made with electrical properties tomography (EPT) can be used to define temporal changes in tissue habitats on longitudinal multiparametric MRI. We aimed to demonstrate the added insights for identifying tumor habitats obtained by including EPT with diffusion- and perfusion-weighted MRI, and to evaluate the use of these tumor habitats for determining tumor treatment response in post-treatment glioblastoma. METHODS: Tumor habitats were developed from EPT, diffusion-weighted, and perfusion-weighted MRI in 60 patients with glioblastoma who underwent concurrent chemoradiotherapy. Voxels from EPT, apparent diffusion coefficient (ADC), and cerebral blood volume (CBV) maps were clustered into habitats, and each habitat was serially examined to assess its temporal change. The usefulness of temporal changes in tumor habitats for diagnosing tumor progression and treatment-related change was investigated using logistic regression. The performance of significant predictors was measured using the area under the curve (AUC) from receiver-operating-characteristics analysis with 1000-fold bootstrapping. RESULTS: Five tumor habitats were identified, and of these, the hypervascular cellular habitat (odds ratio [OR] 5.45; 95% CI, 1.75-31.42; p = .02), hypovascular low conductivity habitat (OR 2.00; 95% CI, 1.45-3.05; p < .001), and hypovascular intermediate habitat (OR 1.57; 95% CI, 1.18-2.30; p = .006) were predictive of tumor progression. Low EPT and low CBV reflected a unique hypovascular low conductivity habitat that showed the highest diagnostic performance (AUC 0.86; 95% CI, 0.76-0.96). The combined habitats showed high performance (AUC 0.90; 95% CI, 0.82-0.98) in the differentiation of tumor progression from treatment-related change. CONCLUSION: EPT reveals low conductivity habitats that can improve the diagnosis of tumor progression in post-treatment glioblastoma. KEY POINTS: ⢠Electrical properties tomography (EPT) demonstrated lower conductivity in tumor progression than in treatment-related change. ⢠EPT allowed identification of a unique hypovascular low conductivity habitat when combined with cerebral blood volume mapping. ⢠Tumor habitats with a hypovascular low conductivity habitat, hypervascular cellular habitat, and hypovascular intermediate habitat yielded high diagnostic performance for diagnosing tumor progression.
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Neoplasias Encefálicas , Glioblastoma , Imágenes de Resonancia Magnética Multiparamétrica , Neoplasias Encefálicas/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética , Glioblastoma/diagnóstico por imagen , Glioblastoma/terapia , Humanos , Angiografía por Resonancia Magnética , Imagen por Resonancia MagnéticaRESUMEN
We demonstrate nondecaying, steplike electrical switching of tristate Néel order in Pt/α-Fe_{2}O_{3} bilayers detected by the spin-Hall induced anomalous Hall effect. The as-grown Pt/α-Fe_{2}O_{3} bilayers exhibit sawtooth switching behavior generated by current pulses. After annealing by a high pulse current, the Hall signals reveal single-pulse saturated, nondecaying, steplike switching. Together with control experiments, we show that the sawtooth switching is due to an artifact of Pt while the actual spin-orbit torque induced antiferromagnetic switching is steplike. Our Monte Carlo simulations explain the switching behavior of α-Fe_{2}O_{3} Néel order among three in-plane easy axes.
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Interfacial magnetic anisotropy in magnetic insulators has been largely unexplored. Recently, interface-induced skyrmions and electrical control of magnetization have been discovered in insulator-based heterostructures, which demand a thorough understanding of interfacial interactions in these materials. We observe a substantial, tunable interfacial magnetic anisotropy between Tm_{3}Fe_{5}O_{12} epitaxial thin films and fifteen nonmagnetic materials spanning a significant portion of the periodic table, which we attribute to Rashba spin-orbit coupling. Our results show a clear distinction between nonmagnetic capping layers from the d block and the p block. This work offers a new path for controlling magnetic phases in magnetic insulators for low-loss spintronic applications.
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The tight-binding model has been spectacularly successful in elucidating the electronic and optical properties of a vast number of materials. Within the tight-binding model, the hopping parameters that determine much of the band structure are often taken as constants. Here, using ABA-stacked trilayer graphene as the model system, we show that, contrary to conventional wisdom, the hopping parameters and therefore band structures are not constants, but are systematically variable depending on their relative alignment angle between h-BN. Moreover, the addition or removal of the h-BN substrate results in an inversion of the K and K^{'} valley in trilayer graphene's lowest Landau level. Our work illustrates the oft-ignored and rather surprising impact of the substrates on band structures of 2D materials.
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The topological Hall effect has been a primary indicator of nontrivial spin textures in magnetic materials. We observe the evidence of the topological Hall effect in Pt/Cr_{2}O_{3} bilayers grown on Al_{2}O_{3}(0001) and Al_{2}O_{3}(112[over ¯]0), where the Cr_{2}O_{3} epitaxial film is an antiferromagnetic insulator. The Pt/Cr_{2}O_{3} bilayers exhibit topological Hall resistivity for Cr_{2}O_{3} thicknesses below 6 nm near and above room temperature, which is above the Néel temperature of Cr_{2}O_{3}, revealing the key role of thermal fluctuations in the formation of spin textures. The similarity of topological Hall signals in (0001)- and (112[over ¯]0)-oriented Cr_{2}O_{3} films indicates that the emergence of spin textures is insensitive to crystalline orientation.
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OBJECTIVES: To compare the ability of diffusion-weighted imaging (DWI) parameters acquired from three different models for the diagnosis of hepatic fibrosis (HF). METHODS: Ninety-five patients underwent DWI using nine b values at 3 T magnetic resonance. The hepatic apparent diffusion coefficient (ADC) from a mono-exponential model, the true diffusion coefficient (D t ), pseudo-diffusion coefficient (D p ) and perfusion fraction (f) from a biexponential model, and the distributed diffusion coefficient (DDC) and intravoxel heterogeneity index (α) from a stretched exponential model were compared with the pathological HF stage. For the stretched exponential model, parameters were also obtained using a dataset of six b values (DDC#, α#). The diagnostic performances of the parameters for HF staging were evaluated with Obuchowski measures and receiver operating characteristics (ROC) analysis. The measurement variability of DWI parameters was evaluated using the coefficient of variation (CoV). RESULTS: Diagnostic accuracy for HF staging was highest for DDC# (Obuchowski measures, 0.770 ± 0.03), and it was significantly higher than that of ADC (0.597 ± 0.05, p < 0.001), D t (0.575 ± 0.05, p < 0.001) and f (0.669 ± 0.04, p = 0.035). The parameters from stretched exponential DWI and D p showed higher areas under the ROC curve (AUCs) for determining significant fibrosis (≥F2) and cirrhosis (F = 4) than other parameters. However, D p showed significantly higher measurement variability (CoV, 74.6%) than DDC# (16.1%, p < 0.001) and α# (15.1%, p < 0.001). CONCLUSIONS: Stretched exponential DWI is a promising method for HF staging with good diagnostic performance and fewer b-value acquisitions, allowing shorter acquisition time. KEY POINTS: ⢠Stretched exponential DWI provides a precise and accurate model for HF staging. ⢠Stretched exponential DWI parameters are more reliable than D p from bi-exponential DWI model ⢠Acquisition of six b values is sufficient to obtain accurate DDC and α.
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Cirrosis Hepática/patología , Adulto , Anciano , Imagen de Difusión por Resonancia Magnética/métodos , Métodos Epidemiológicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos BiológicosRESUMEN
This prime objective of this study was to explore the anti-cancer activity of fermented Asterina pectinifera with Cordyceps militaris mycelia (FACM) in B16F10 murine melanoma cells. The effect of FACM on cell viability was assessed using MTT assay. Furthermore, the effect of FACM was compared with unfermented A. pectinifera on cell viability. The results demonstrated that the fermented FACM extract has a higher inhibitory activity on the proliferation of B16F10 murine melanoma cells than unfermented A. pectinifera. In addition, FACM also promoted the expression of pro-apoptotic protein Bax leading to stimulate apoptosis in B16F10 cells. Therefore the present study demonstrates that the FACM might be a potential effective anti-cancer agent, as a result of its stronger anti-proliferative effect and apoptosis inducing effect than A. pectinifera or C. militaris on melanoma cells.
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Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Asterina , Cordyceps , Melanoma Experimental , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Fermentación , Ratones , MicelioRESUMEN
We investigated the antioxidant activity of taurine rich water extract from the cephalothorax of Fenneropenaeus chinensis (FCC). The antioxidant potency of water extract from FCC was assessed using various assay methods, such as DPPH (1,1-diphenyl-2-picrylhydrazyl), alkyl radical scavenging activity, ABTS (2,2'-azinobis (3-ethylbenzothiazoline 6-sulfonic acid ammonium salt)) radical scavenging activity and Ferric reducing antioxidant power (FRAP) assay. The DPPH and alkyl radical scavenging activities of FCC were dose-dependently increased. The lipid peroxidation was estimated using ferric thiocyanate (FTC) assay and thiobarbituric acid (TBA) methods. However, a higher lipid peroxidation activity was observed in TBA method than FTC method. The results of the present study suggested that the FCC extract potentially scavenged the free radical and reduced oxidative stress. Therefore, the present study is concluded that the FCC extract could be a potential source of antioxidant activity.