RESUMO
Metallic bismuth (Bi) has been widely explored as remarkable anode material in alkali-ion batteries due to its high gravimetric/volumetric capacity. However, the huge volume expansion up to ≈406% from Bi to full potassiation phase K3 Bi, inducing the slow kinetics and poor cycling stability, hinders its implementation in potassium-ion batteries (PIBs). Here, facile strategy is developed to synthesize hierarchical bismuth nanodots/graphene (BiND/G) composites with ultrahigh-rate and durable potassium ion storage derived from an in situ spontaneous reduction of sodium bismuthate/graphene composites. The in situ formed ultrafine BiND (≈3 nm) confined in graphene layers can not only effectively accommodate the volume change during the alloying/dealloying process but can also provide high-speed channels for ionic transport to the highly active BiND. The BiND/G electrode provides a superior rate capability of 200 mA h g-1 at 10 A g-1 and an impressive reversible capacity of 213 mA h g-1 at 5 A g-1 after 500 cycles with almost no capacity decay. An operando synchrotron radiation-based X-ray diffraction reveals distinctively sharp multiphase transitions, suggesting its underlying operation mechanisms and superiority in potassium ion storage application.
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Adenanthin, a natural ent-kaurane diterpenoid extracted from the herb Isodon adenantha, has been reported to increase intracellular reactive oxygen species in leukemic and hepatocellular carcinoma cells. However, the function and mechanism of the compound in adipogenesis and the development of obesity is still unknown. In this study, we demonstrated that adenanthin inhibited adipogenesis of 3T3-L1 and mouse embryonic fibroblasts, and the underlying mechanism included two processes: a delayed mitotic clonal expansion via G0/G1 cell cycle arrest by inhibiting the RB-E2F1 signaling pathway and a reduced C/EBPß signaling by inhibiting the expression and activity of C/EBPß during mitotic clonal expansion. Furthermore, adenanthin significantly reduced the growing body weight and adipose tissue mass during high-fat diet-inducing obesity of mice, indicating the beneficial effects of adenanthin as a potential agent for prevention of obesity.
Assuntos
Adipogenia/efeitos dos fármacos , Diterpenos do Tipo Caurano/isolamento & purificação , Diterpenos do Tipo Caurano/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Isodon/química , Obesidade/metabolismo , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Dieta Hiperlipídica , Diterpenos do Tipo Caurano/química , Medicamentos de Ervas Chinesas/química , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Masculino , Camundongos , Obesidade/tratamento farmacológico , Obesidade/etiologia , Obesidade/patologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Global navigation satellite systems (GNSS) are well suited for attitude determination. In this study, we use the rotation matrix method to resolve the attitude angle. This method achieves better performance in reducing computational complexity and selecting satellites. The condition of the baseline length is combined with the ambiguity function method (AFM) to search for integer ambiguity, and it is validated in reducing the span of candidates. The noise error is always the key factor to the success rate. It is closely related to the satellite geometry model. In contrast to the AFM, the LAMBDA (Least-squares AMBiguity Decorrelation Adjustment) method gets better results in solving the relationship of the geometric model and the noise error. Although the AFM is more flexible, it is lack of analysis on this aspect. In this study, the influence of the satellite geometry model on the success rate is analyzed in detail. The computation error and the noise error are effectively treated. Not only is the flexibility of the AFM inherited, but the success rate is also increased. An experiment is conducted in a selected campus, and the performance is proved to be effective. Our results are based on simulated and real-time GNSS data and are applied on single-frequency processing, which is known as one of the challenging case of GNSS attitude determination.
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The development of noninvasive approaches to precisely control neural activity in mammals is highly desirable. Here, we used the ion channel transient receptor potential ankyrin-repeat 1 (TRPA1) as a proof of principle, demonstrating remote near-infrared (NIR) activation of endogenous neuronal channels in mice through an engineered nanoagonist. This achievement enables specific neurostimulation in nongenetically modified mice. Initially, target-based screening identified flavins as photopharmacological agonists, allowing for the photoactivation of TRPA1 in sensory neurons upon ultraviolet A/blue light illumination. Subsequently, upconversion nanoparticles (UCNPs) were customized with an emission spectrum aligned to flavin absorption and conjugated with flavin adenine dinucleotide, creating a nanoagonist capable of NIR activation of TRPA1. Following the intrathecal injection of the nanoagonist, noninvasive NIR stimulation allows precise bidirectional control of nociception in mice through remote activation of spinal TRPA1. This study demonstrates a noninvasive NIR neurostimulation method with the potential for adaptation to various endogenous ion channels and neural processes by combining photochemical toolboxes with customized UCNPs.
Assuntos
Raios Infravermelhos , Nanopartículas , Canal de Cátion TRPA1 , Animais , Canal de Cátion TRPA1/metabolismo , Canal de Cátion TRPA1/agonistas , Camundongos , Nanopartículas/química , Células Receptoras Sensoriais/metabolismo , Células Receptoras Sensoriais/fisiologia , Células Receptoras Sensoriais/efeitos dos fármacos , Canais Iônicos/metabolismo , Nociceptividade/efeitos dos fármacosRESUMO
To explore transition metal-based electrocatalysts with remarkable energy storage and conversion performance, the rational design and synthesis of electrodes with rich active sites and favorable electrical conductivity are crucial. Herein, using fluoroethylene carbonate (FEC) additive in electrochemical conversion reaction (electrolyte modification method) is proposed as an effective strategy to enhance the catalytic activity of FeOx/NF. The optimal sample FeOx/NF-Li-FEC1 shows optimized HER activity with remarkably low overpotential of 222 mV at a current density of 200 mA cm-2. By employing FeOx/NF-Li-FEC1 as bifunctional electrocatalysts, the overall water-splitting device reaches a current density of 10 mA cm-2 at a low cell voltage of 1.56 V. The outstanding performance is mainly attributed to the atomic arrangement to offer rich active sites as well as the evolved electronic structure and the thin SEI layer to accelerate charge transfer process. This study opens up a novel avenue to rationally design and synthesize low-cost and high-performance electrode materials for electrochemical energy conversion and storage devices.
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Borneol has been used successfully for the treatment of itchy skin in traditional Chinese medicine. However, the antipruritic effect of borneol has rarely been studied, and the mechanism is unclear. Here, we showed that topical application of borneol on skin substantially suppressed pruritogen chloroquine- and compound 48/80-induced itching in mice. The potential targets of borneol, including transient receptor potential cation channel subfamily V member 3 (TRPV3), transient receptor potential cation channel subfamily A member 1 (TRPA1), transient receptor potential cation channel subfamily M member 8 (TRPM8), and gamma-aminobutyric acid type A (GABAA) receptor were pharmacologically inhibited or genetically knocked out one by one in mouse. Itching behavior studies demonstrated that the antipruritic effect of borneol is largely independent of TRPV3 and GABAA receptor, and TRPA1 and TRPM8 channels are responsible for a major portion of the effect of borneol on chloroquine-induced nonhistaminergic itching. Borneol activates TRPM8 and inhibits TRPA1 in sensory neurons of mice. Topical co-application of TRPA1 antagonist and TRPM8 agonist mimicked the effect of borneol on chloroquine-induced itching. Intrathecal injection of a group II metabotropic glutamate receptor antagonist partially attenuated the effect of borneol and completely abolished the effect of TRPM8 agonist on chloroquine-induced itching, suggesting that a spinal glutamatergic mechanism is involved. In contrast, the effect of borneol on compound 48/80-induced histaminergic itching occurs through TRPA1-and TRPM8-independent mechanisms. Our work demonstrates that borneol is an effective topical itch reliever, and TRPA1 inhibition and TRPM8 activation in peripheral nerve terminals account for its antipruritic effect.
Assuntos
Canais de Cátion TRPM , Canais de Potencial de Receptor Transitório , Camundongos , Animais , Antipruriginosos/farmacologia , Antipruriginosos/uso terapêutico , Canal de Cátion TRPA1 , Canais de Cátion TRPM/fisiologia , Prurido/induzido quimicamente , Prurido/tratamento farmacológico , Células Receptoras Sensoriais , Cloroquina/farmacologia , Nervos Periféricos , Canais de Cátion TRPVRESUMO
BACKGROUND AND PURPOSE: Melanogenesis is essential for pigmentation and deregulated melanogenesis causes pigmentary diseases. Psoralen and ultraviolet A (PUVA) therapy strongly stimulates pigmentation, but the underlying molecular mechanisms are elusive. EXPERIMENTAL APPROACH: Melanin content of cultured human melanocytes was spectrophotometrically measured. Patch-clamp recordings were made in human melanocytes or HEK 293 cells transiently expressing wild type or mutant human TRPV1 and TRPA1 channels. Endogenous expression of TRPV1 and TRPA1 in melanocytes was analysed by western blotting and was knocked down with siRNA. In vivo pigmentary responses were measured by a colorimeter in mouse ear skin. The expression of TRPV1 and TRPA1 in human pigmented lesions was examined by immunohistochemical staining. KEY RESULTS: PUVA strongly stimulated melanogenesis and PUVA-induced TRPV1 and TRPA1 channel activation in melanocytes and the resulting Ca2+ influx were required for the stimulated melanogenesis both in vitro and in vivo. Agonists-induced TRPV1 and TRPA1 activation alone did not stimulate melanogenesis, but it synergized UVA or intrinsic cAMP and NO signalling pathways to stimulate UV-dependent or UV-independent melanogenesis. Moreover, the expressions of TRPV1 and TRPA1 were increased in human melanocytic lesions and inhibition of both channels decreased melanin content in melanoma cells. CONCLUSION AND IMPLICATIONS: TRPV1 and TRPA1 are key molecular sensors and enhancers of extrinsic and intrinsic melanogenic signals in both physiological and pathological conditions, and activation of both channels in melanocytes contributes to PUVA therapy-induced pigmentation. Our work provides a common mechanism of melanogenic regulation and highlights TRPV1 and TRPA1 as potential therapeutic targets for pigmentary disorders.
Assuntos
Canais de Potencial de Receptor Transitório , Animais , Células HEK293 , Humanos , Melaninas/metabolismo , Melanócitos/metabolismo , Camundongos , Canal de Cátion TRPA1/metabolismo , Canais de Cátion TRPV/metabolismo , Canais de Potencial de Receptor Transitório/metabolismoRESUMO
Two-dimensional (2D) antimonene is a promising anode material in sodium-ion batteries (SIBs) because of its high theoretical capacity of 660 mAh g-1 and enlarged surface active sites. However, its Na storage properties and sodiation/desodiation mechanism have not been fully explored. Herein, we propose the sodiation/desodiation reaction mechanism of 2D few-layer antimonene (FLA) based on results acquired by in situ synchrotron X-ray diffraction, ex situ selected-area electron diffraction, and theoretical simulations. Our study shows that the FLA undergoes anisotropic volume expansion along the a/b plane and exhibits reversible crystalline phase evolution (Sb â NaSb â Na3Sb) during cycling. Density-functional theory calculations demonstrate that the FLA has a small Na-ion diffusion barrier of 0.14 eV. The FLA delivers a larger capacity of 642 mAh g-1 at 0.1 C (1 C = 660 mA g-1) and a high rate capability of 429 mAh g-1 at 5 C and maintains a stable capacity of 620 mA g-1 at 0.5 C with 99.7% capacity retention from the 10th to the 150th cycle. Considering the 660 mAh g-1 theoretical capacity of Sb, the electrochemical utilization of Sb atoms of FLA is as high as 93.9% at a rate of 0.5 C for over 150 cycles, which is the highest capacity and Sb utilization ratio reported so far. Our study discloses the Na storage mechanism of 2D FLA, boosting promising applications of 2D materials for advanced SIBs.
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The predictive factors associated with neck pain remain unclear. We conducted a cross-sectional study to assess predictive factors, especially Modic changes (MCs), associated with the intensity and duration of neck pain in patients with cervical disc degenerative disease.We retrospectively reviewed patients in our hospital from January 2013 to December 2016. Severe neck pain (SNP) and persistent neck pain (PNP) were the 2 main outcomes, and were assessed based on the numerical rating scale (NRS). Basic data, and also imaging data, were collected and analyzed as potential predictive factors. Univariate analysis and multiple logistic regression analysis were performed to assess the predictive factors for neck pain.In all, 381 patients (193 males and 188 females) with cervical degenerative disease were included in our study. The number of patients with SNP and PNP were 94 (24.67%) and 109 (28.61%), respectively. The NRS of neck pain in patients with type 1 MCs was significantly higher than type 2 MCs (4.8â±â0.9 vs 3.9â±â1.1; Pâ=â.004). The multivariate logistic analysis showed that kyphosis curvature (odds ratio [OR] 1.082, 95% confidence interval [CI] 1.044-1.112), spondylolisthesis (OR 1.339, 95% CI 1.226-1.462), and annular tear (OR 1.188, 95% CI 1.021-1.382) were factors associated with SNP, whereas kyphosis curvature (OR 1.568, 95% CI 1.022-2.394), spondylolisthesis (OR 1.486, 95% CI 1.082-2.041), and MCs (OR 1.152, 95% CI 1.074-1.234) were associated with PNP.We concluded that kyphosis curvature, spondylolisthesis, and annular tear are associated with SNP, whereas kyphosis curvature, spondylolisthesis, and MCs are associated with PNP. This study supports the view that MCs can lead to a long duration of neck pain.
Assuntos
Vértebras Cervicais , Degeneração do Disco Intervertebral/complicações , Cervicalgia/etiologia , Adulto , Fenômenos Biomecânicos , Estudos Transversais , Feminino , Humanos , Cifose/complicações , Modelos Logísticos , Lordose/complicações , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Medição da Dor , Estudos Retrospectivos , Fatores de Risco , Doenças da Coluna Vertebral/complicações , Espondilolistese/complicaçõesRESUMO
Hybrid carbon films composed of graphene film and porous carbon film may give full play to the advantages of both carbon materials, and have great potential for application in energy storage and conversion devices. Unfortunately, there are very few reports on fabrication of hybrid carbon films. Here we demonstrate a simple approach to fabricate free-standing sandwich-structured hybrid carbon film composed of porous amorphous carbon film and multilayer graphene film by chemical vapor deposition in a controllable and scalable way. Hybrid carbon films reveal good electrical conductivity, excellent flexibility, and good compatibility with substrate. Supercapacitors assembled by hybrid carbon films exhibit ultrahigh rate capability, wide frequency range, good capacitance performance, and high-power density. Moreover, this approach may provide a general path for fabrication of hybrid carbon materials with different structures by using different metals with high carbon solubility, and greatly expands the application scope of carbon materials.