Designing bifunctional electrocatalysts to boost oxygen redox reactions is critical for high-performance lithium-oxygen batteries (LOBs). In this work, high-entropy spinel (CoMnNiFeCr)O (HEOS) is fabricated by modulating the internal configuration entropy of spinel and studied as the oxygen electrode catalyst in LOBs. Under the high-entropy atomic environment, the Co-O octahedron in spinel undergoes asymmetric deformation, and the reconfiguration of the electron structure around the Co sites leads to the upward shift of the d-orbital centers of the Co sites toward the Fermi level, which is conducive to the strong adsorption of redox intermediate LiO on the surface of the HEOS, ultimately forming a layer of a highly dispersed LiO thin film.
View Article and Find Full Text PDFLithium-oxygen (Li-O) battery possesses high theoretical energy density of ∼ 3500 Wh kg, yet the sluggish kinetics of oxygen redox reactions hinder its practical application. Herein, TiVC bimetallic MXene solid solution is prepared as the efficient electrocatalyst for Li-O battery. The results of experiment and theoretical calculations reveal that through the formation of Ti-C-V bond in TiVC, electrons transfer from V site to Ti site enhances electron delocalization of V sites, which causes the upshift of d band center of V site and strengthens the adsorption of intermediate products (LiO) on TiVC electrode surface.
View Article and Find Full Text PDFSichuan Da Xue Xue Bao Yi Xue Ban
January 2023
Objective: To evaluate with 7T cardiac magnetic resonance tissue tracking imaging (CMR-TT) the ameliorative effect of Cang-ai volatile oil (CAVO) on left ventricular remodeling (LVR) in rats induced by isoproterenol (ISO), and to make preliminary investigation into CAVO's effects on endothelial dysfunction in LVR.
Methods: A total of 35 healthy male Sprague-Dawley (SD) rats were randomly assigned to two groups, the experimental group ( =27) and the normal control group ( =8). The rat model of LVR was established by subcutaneous injection of ISO solution at 10 mg·kg ·d at multiple sites for 10 consecutive days.
Rationally designing efficient catalysts is the key to promote the kinetics of oxygen electrode reactions in lithium-oxygen (Li-O ) battery. Herein, nitrogen-doped Ti C MXene prepared via hydrothermal method (N-Ti C (H)) is studied as the efficient Li-O battery catalyst. The nitrogen doping increases the disorder degree of N-Ti C (H) and provides abundant active sites, which is conducive to the uniform formation and decomposition of discharge product Li O .
View Article and Find Full Text PDFAqueous Zn batteries with ideal energy density and absolute safety are deemed the most promising candidates for next-generation energy storage systems. Nevertheless, stubborn dendrite formation and notorious parasitic reactions on the Zn metal anode have significantly compromised the Coulombic efficiency (CE) and cycling stability, severely impeding the Zn metal batteries from being deployed in the proposed applications. Herein, instead of random growth of Zn dendrites, a guided preferential growth of planar Zn layers is accomplished via atomic-scale matching of the surface lattice between the hexagonal close-packed (hcp) Zn(002) and face-centered cubic (fcc) Cu(100) crystal planes, as well as underpotential deposition (UPD)-enabled zincophilicity.
View Article and Find Full Text PDFBackground: Despite that estradiol can reduce the risk of cardiovascular diseases in ovariectomized animals in the plains, its effect on animals at high altitude has seldom been reported. We hypothesize that estradiol can ameliorate cardiac damage to ovariectomized rats induced by chronic exposure to hypobaric hypoxia at high altitude.
Purpose: This study was intended to investigate whether cardiovascular magnetic resonance (CMR) imaging could reveal cardioprotective effect of estradiol on ovariectomized rats under chronic exposure to hypobaric hypoxia at high altitude.
Lithium-oxygen batteries (LOBs) with ultra-high theoretical energy density (≈3500 Wh kg ) are considered as the most promising energy storage systems. However, the sluggish kinetics during the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) can induce large voltage hysteresis, inferior roundtrip efficiency and unsatisfactory cyclic stability. Herein, hydrangea-like NiO@Ni P heterogeneous microspheres are elaborately designed as high-efficiency oxygen electrodes for LOBs.
View Article and Find Full Text PDFElectronic structural engineering plays a key role in the design of high-efficiency catalysts. Here, to achieve optimal electronic states, introduction of exotic Fe dopant and Co vacancy into CoSe nanosheet (denoted as Fe-CoSe-V) is presented. The obtained Fe-CoSe-V demonstrates excellent catalytic activity as compared to CoSe.
View Article and Find Full Text PDFCationic defect engineering is an effective strategy to optimize the electronic structure of active sites and boost the oxygen electrode reactions in lithium-oxygen batteries (LOBs). Herein, Ni-Fe layered double oxides enriched with cationic nickel vacancies (Ni-Fe LDO-V ) are first designed and studied as the electrocatalysts for LOBs. Based on the density functional theory calculation, the existence of nickel vacancy in Ni-Fe LDO-V significantly improves its intrinsic affinity toward intermediates, thereby fundamentally optimizing the formation and decomposition pathway of Li O .
View Article and Find Full Text PDFDeveloping effective electrocatalyst and fundamentally understanding the corresponding working mechanism are both urgently desired to overcome the current challenges facing lithium-oxygen batteries (LOBs). Herein, a series of NiFe-based bimetal-organic frameworks (NiFe-MOFs) with certain internal tensile strain are fabricated via a simple organic linker scission strategy, and served as cathode catalysts for LOBs. The introduced tensile strain broadens the inherent interatomic distances, leading to an upshifted d-band center of metallic sites and thus the enhancement of the adsorption strength of catalysts surface towards intermediates, which is contributed to rationally regulate the crystallinity of discharge product LiO.
View Article and Find Full Text PDFGlaucoma, the second leading cause of blindness, is an irreversible optic neuropathy. The mechanism of optic nerve injury caused by glaucoma is undefined at present. There is no effective treatment method for the injury.
View Article and Find Full Text PDFThis study was performed to explore other potential mechanisms underlying hemolysis in addition to pore-formation of tentacle extract (TE) from the jellyfish Cyanea capillata. A dose-dependent increase of hemolysis was observed in rat erythrocyte suspensions and the hemolytic activity of TE was enhanced in the presence of Ca2+, which was attenuated by Ca2+ channel blockers (Diltiazem, Verapamil and Nifedipine). Direct intracellular Ca2+ increase was observed after TE treatment by confocal laser scanning microscopy, and the Ca2+ increase could be depressed by Diltiazem.
View Article and Find Full Text PDFThe delayed jellyfish envenomation syndrome (DJES) with serious multiple organ dysfunction or systemic damages, generally developed 2 h after jellyfish stings, deserves special attention for it is very meaningful to the clinical interventions. To set up a DJES model as well as to obtain more details about its process, an integrative approach, including clinical chemistry, pathology and immunohistochemistry, was conducted to simultaneously monitor the effects of tentacle extract (TE) from the jellyfish Cyanea capillata on the vital target organs (heart, lung, liver and kidney). Our results showed that the TE from C.
View Article and Find Full Text PDFPrevious studies in our laboratory have shown that the cardiotoxicity is the main reason for rat death caused by tentacle-only extract from jellyfish Cyanea capillata. However, the direct cardiotoxicity in vitro and its mechanisms of toxic action remain unclear. The current studies were performed by using the Langendorff-perfused isolated heart model, which showed a dose-dependent hemodynamic and electrocardiogram changes.
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