Display omitted
•The ZnO/C@(Ni,Co)Se2 core–shell nanostructure is fabricated by MOF derivatives.•The performance is optimized by specific surface area and synergistic effect.•The electrode displays ...the specific capacity of 164.18 mA h g−1 at 1 A g−1.•The ASC device shows a high energy density of 65.67 W h kg−1 at 800 W kg−1.
To achieve a high energy density of nickel cobalt bimetallic selenide electrode materials, the key points are on the construction of porous materials and control of the appropriate proportion of active materials. Here, a well-design structure MOF derived ZnO/C@(Ni,Co)Se2 core–shell nanostructure on carbon cloth was prepared for the first time. The ZnO/C@(Ni,Co)Se2 core–shell nanostructure electrode exhibits the ascendant specific capacity of 164.18 mA h g−1 at 1 A g−1. The as-obtained ZnO/C@(Ni,Co)Se2//AC asymmetric supercapacitor shows the superior energy density of 65.67 W h kg−1 at 800 W kg−1, with 97.87% capacitance retention after 10,000 cycles. The stable self-supporting MOF derived porous carbon material as the core not only provides a strong support structure for thin shell nanosheets but also enhances the specific surface area. An appropriate proportion of Ni/Co and the existence of weak electronegative Se is profitable to improve the electronic structure of the (Ni,Co)Se2 thin nanosheet shell. Besides, the synergistic effect between the active materials can also optimize the electrochemical performance of the electrode materials. Thus, our work offers a new strategy for MOF derived porous carbon to construct flexible electrode materials with high electrochemical performance.
This paper presents analytical solutions for full-field radiation in magnetoelectric (ME) antennas, considering a fully magneto-elastic coupled constitutive relation. A nonlinear converse ME coupling ...model is established, incorporating mechanical, electric, and magnetic variables with generalized Maxwell equations. This model emphasizes the essence of ME antennas, where radiation is achieved through strain/stress-mediated coupling between different phases. The magnetic flux density and electric displacement obtained from the model are used as sources to solve the full-field radiations of ME antennas. The proposed model is validated through existing experiments and simulations, demonstrating that the radiation performance of ME antennas is strongly influenced by nonlinear magneto-elastic coupling. The material parameters and magnetic bias significantly impact the magnetic flux density and far-field radiation due to the nonlinear magnetization process. The study reveals the mechanisms behind enhanced working bandwidth and frequency tuning by examining the frequency response of the radiation impedance with material parameters. By adjusting the initial magnetization rate, saturation magnetostriction, and saturation magnetization, the radiation efficiency/gain can be increased by 340%, 108%, and 112% respectively. This model enhances our understanding of the full-field radiation of ME antennas and provides a foundation for designing tunable ME antennas.
This paper presents an analytical model for the near-field radiation of acoustically actuated magnetoelectric (ME) antennas considering a fully magneto-elastic coupled magnetostrictive constitutive ...relation. The nonlinearity of the magnetostrictive phase is introduced into the governing equation of the ME antennas using the equivalent parameter method, resulting in analytical expressions of the near-field radiation. The strain distribution in the ME antenna is calculated first and then extracted as a source for solving the magnetic flux density, energies, average radiated power, and radiation impedance. The predictions for the admittance and impedance show good agreement with simulation and experimental data, respectively. The effects of the external stimuli on the radiation performance are investigated, to theoretically evaluate the ME antennas operated in complex magnetic and stress conditions. The required magnetic bias corresponding to the maximum radiation of the ME antennas is determined, which is changed with the pre-stress. In addition, the radiation power can be improved by tensile stress before the required magnetic bias or by compressive stress after the required magnetic bias. The present model may provide a basis for the evaluation and regulation of acoustically actuated ME antenna.
Leptin binds to receptors in multiple hypothalamic nuclei to increase sympathetic nerve activity; however, the neurocircuitry is unclear. Here, using anesthetized male Sprague-Dawley rats, we ...investigated the role of the paraventricular nucleus of the hypothalamus. Intracerebroventricular injection of leptin slowly increased lumbar sympathetic nerve activity (LSNA), heart rate, mean arterial pressure, and baroreflex control of LSNA and heart rate. Inhibition of the paraventricular nucleus with muscimol completely reversed leptin's effects. Blockade of paraventricular melanocortin 3/4 receptors with SHU9119 or ionotropic glutamate receptors with kynurenate, alone or together, each partially reversed the effects of leptin, implicating increased activation of glutamate and melanocortin 3/4 receptors. Conversely, although blockade of neuropeptide Y Y1 receptors in the paraventricular nucleus increased LSNA, mean arterial pressure, and heart rate, these responses were prevented by intracerebroventricular or arcuate nucleus injections of leptin, suggesting that, at least in part, leptin also increases sympathetic nerve activity by suppression of tonic neuropeptide Y inhibitory inputs from the arcuate nucleus. Injection of the melanocortin 3/4 receptor agonist melanotan-II into the paraventricular nucleus increased LSNA, mean arterial pressure, and heart rate only after blockade of neuropeptide Y Y1 receptors. Therefore, we conclude that leptin increases LSNA in part via increased glutamatergic and α-melanocyte-stimulating hormone drive of paraventricular sympathoexcitatory neurons, the latter of which requires simultaneous withdrawal of tonic neuropeptide Y inhibition.
The point of care testing (POCT) of telomerase activity is critical for early diagnosis of cancer. Herein, a colorimetric method was developed for visual detection of telomerase activity via hydrogen ...peroxide test strip. It is based on the telomerase-controlled in-situ formation of hydrogen peroxide. Firstly, biotinylated telomerase substrate (TS) primer was attached on the surface of magnetic beads (MBs) via the streptavidin-biotin reaction to form MB-TS complex. Then, TS primers were elongated by telomerase to form long telomere elongated products (TEP) which contains TTAGGG repeat units. The in-situ formed MB-TEP complex specifically hybridized with glucose oxidase modified cDNA (GOD-cDNA). After magnetic separation and washing, the MB-TEP/GOD-cDNA complex incubated with glucose solution to in-situ produce hydrogen peroxide which was detected by hydrogen peroxide test strip. One long TEP hybridized with multiple GOD-cDNAs, which enriched GOD to highly efficiently catalyze glucose for generating hydrogen peroxide. Thus, the visual assay achieved sensitive detection of telomerase activity, and the limit of detection (LOD) reached as low as 10 HeLa cells/μL by naked eyes and 4.5 HeLa cells/μL by absorbance measurements. Therefore, it offers a sensitive and low-cost method for visual detection of telomerase activity, which also, widens the application of commercial hydrogen peroxide test strip in the development of non-H2O2 biosensors.
•A visual POC approach was developed for detecting telomerase activity via hydrogen peroxide test strip.•The utilization of hydrogen peroxide test strip led to a facile and low-cost POC assay.•The activity of telomerase in serum was reliably and visually detected.
Stimuli-sensitive hydrogels are ideal candidates for biomedical and bioengineering purposes, although applications of hydrogels may be limited, due in part to the limited choice of suitable materials ...for constructing hydrogels, the complexity in the synthesis of the source materials, and the undesired fast-then-slow drug-release behaviors of usual hydrogels. Herein, we describe the fabrication of a new supramolecular guanosine (G)-quadruplex hydrogel by multicomponent self-assembly of endogenous guanosine (G), 2-formylboronic acid (2-FPBA), and tris(2-aminoethyl)amine (TAEA) in the presence of KCl in an easy and convenient way. The features of the G-quadruplex hydrogel include (1) versatility and commercial availability of building blocks with different functions, (2) dynamic iminoboronate bonds with pH and glucose responsiveness, and (3) zero-order drug-release behavior because of the superficial peel-off of the hydrogel in response to stimuli. The structure, morphology, and properties of the G-quadruplex hydrogel were well-characterized, and satisfactory zero-order drug release was successfully achieved. This kind of supramolecular G-quadruplex hydrogels may find applications in biological fields.
This paper presents an analytical model to evaluate the self-bias magnetoelectric (ME) effect of magnetization-graded ME composites under extensional-bending coupled vibration. The distribution of ...the self-bias magnetic field produced inside ME composites is quantitatively analyzed based on the molecular current model. Sequentially, a multi-field coupled ME model is developed using equivalent nonlinear constitutive relations, extensional-bending coupled equations, and Maxwell’s equations simultaneously. The developed ME theory is highlighted with a direct comparison with experiments that shows their close agreement. The results indicate that an available self-bias magnetic field is produced in the magnetization-graded composites, which in turn induces a self-bias ME coupling at zero bias magnetic field. It is also demonstrated that, with applying tensile stress or appropriately increasing the thickness of the high-permeability layer, the self-bias ME coefficient can be enhanced and account for more than 55% of the maximum one, and the resonance frequency is regulated in a wide range. In addition, the competitive relationship between the influence of mechanical and magnetic properties of high-permeability materials on self-bias ME coupling is revealed. Given the significance of this study, it may be utilized in the development of high-performance self-bias ME devices.
Recognizing and quantifying enantiomers of chiral molecule is of great importance in chemical, biological and pharmaceutical fields. Herein, we presented one simple-yet-efficient method of sensing ...tyrosine (Tyr) enantiomers. In this sensing, silver triangular nanoplates (AgTNPs) were used as colorimetric probes. L-Tyr quickly induced the color of AgTNPs solution to change from dark blue to light gray, whereas D-Tyr induced no change of the AgTNPs solution color. The obvious color change enables the naked eye to recognize Tyr enantiomer. The visual method was used to detect the enantiometric excess value of L-Tyr in the whole range (-100 % ∼ 100 %). This chiral sensing can be finished within 5 min using one simple ultraviolet-visible spectrometer or naked eye. Furthermore, the mechanism of this chiral sensing was explored. It was confirmed that this chiral sensing was based on AgTNPs' intrinsic chirality. This chiral sensing is rapid, simple, and low-cost, and has great potential for chiral determination of Tyr.
Introduction
Amyotrophic lateral sclerosis (ALS) is a fatal progressive neurodegenerative disease resulting in the dysfunction of upper and lower motor neurons. Biomarkers in fluid have been used to ...monitor the disease and its progression. Milk fat globule-EGF factor 8 (MFG-E8) is an inflammation modulator, which is involved in the pathogenesis of neurodegenerative diseases. We here took this study to evaluate the predictive value of MFG-E8 in ALS.
Methods
This study consisted of 19 patients with ALS and 15 healthy controls. Cerebrospinal fluid (CSF) were collected from all participants and tested for the levels of MFG-E8, neurofilament light (NFL), and heavy chain (NFH). The correlations between MFG-E8 and NFL, NFH, ALS severity, cognitive status, and forced vital capacity (FVC) were analyzed.
Results
We found that MFG-E8 performs well in distinguishing ALS from controls, with relatively higher level of MFG-E8 in ALS subjects, than controls. Moreover, MFG-E8 negatively correlated with the revised ALS function rating scale (ALS-FRS), but not with the levels of NFL and NFH, disease duration, progression rate, mini-mental state examination (MMSE), and FVC.
Conclusions
The study proved that CSF MFG-E8 helps distinguish ALS from controls. However, the protein in CSF negatively predicted disease severity.
PDF
