Long noncoding RNAs (lncRNA) have been recognized as significant regulators in the progression of atherosclerosis (AS). Oxidized low‐density lipoprotein (ox‐LDL) can induce macrophage inflammation ...and oxidative stress, that serves important roles in AS. However, the exact function of lncRNA NEAT1 and its possible molecular mechanism in AS remain unclear. Here, we concentrated on the roles and molecular mechanisms of NEAT1 in AS development. In our current study, we observed that NEAT1 was elevated by ox‐LDL in a dose‐dependent and time‐dependent manner. RAW264.7 cell survival was greatly enhanced, and cell apoptosis was significantly inhibited by LV‐shNEAT1 transfection. In addition, knockdown of NEAT1 in RAW264.7 cells repressed CD36 expression and foam cell formation while NEAT1 overexpression shown an opposite process. Moreover, NEAT1 downregulation inhibited inflammation molecules including IL‐6, IL‐1β, and TNF‐α. Meanwhile, silencing of NEAT1 can also suppress reactive oxygen species (ROS) and malondialdehyde (MDA) levels with an enhancement of superoxide dismutase (SOD) activity in RAW264.7 cells. MicroRNAs are some short RNAs, and they can regulate multiple biological functions in many diseases including AS. Here, we found that miR‐128 expression was remarkably decreased in ox‐LDL‐incubated RAW264.7 cells. Interestingly, miR‐128 mimics was able to reverse AS‐correlated events induced by overexpression of NEAT1. By using bioinformatics analysis, miR‐128 was predicted as a target of NEAT1 and the correlation between them was validated in our study. Taken these together, it was implied that NEAT1 participated in ox‐LDL‐induced inflammation and oxidative stress in AS development through sponging miR‐128.
Our data suggested that NEAT1 can induce atherosclerosis (AS) pathogenesis via inhibiting miR‐128 in vitro. We found that downregulation of NEAT1 can repress AS development by regulating RAW264.7 cell proliferation, apoptosis, inflammation, and oxidative stress process. Meanwhile, miR‐128 served as a direct target of NEAT1 and we confirmed the correlation between them in vitro.
Supramolecular hydrogels assembled from amino acids and peptide‐derived hydrogelators have shown great potential as biomimetic three‐dimensional (3D) extracellular matrices because of their merits ...over conventional polymeric hydrogels, such as non‐covalent or physical interactions, controllable self‐assembly, and biocompatibility. These merits enable hydrogels to be made not only by using external stimuli, but also under physiological conditions by rationally designing gelator structures, as well as in situ encapsulation of cells into hydrogels for 3D culture. This review will assess current progress in the preparation of amino acids and peptide‐based hydrogels under various kinds of external stimuli, and in situ encapsulation of cells into the hydrogels, with a focus on understanding the associations between their structures, properties, and functions during cell culture, and the remaining challenges in this field. The amino acids and peptide‐based hydrogelators with rationally designed structures have promising applications in the fields of regenerative medicine, tissue engineering, and pre‐clinical evaluation.
Interest in amino acids and peptide‐based supramolecular hydrogels for 3D cell culture is increasing. This review assesses current progress in the preparation of these hydrogels under external stimuli and in situ cell encapsulation into the hydrogels, with a focus on understanding the associations between their structures, properties, and functions during cell culture and the remaining challenges.
Cu1.8S is a promising thermoelectric material with characteristics of superionic conductors. This study has been focused on the effect of Ti4+ doping on both electron and phonon transport properties ...of TixCu1.8-xS (x = 0, 0.04, 0.07, 0.10). The thermoelectric figure of merit (ZT) was greatly enhanced when 0.07 ≤ x ≤ 0.10, mainly due to a decreased thermal conductivity (0.62–0.77 Wm−1K−1) caused by the formation of the lower-conductive Cu4(TiS4) and Cu1.96S second phases, and the introduced point defects. Along with an improved Seebeck coefficient, a peak ZT value of 0.54 at 673 K was obtained in the Ti0.07Cu1.73S composition, which is twice as large as that of the undoped one. A maximum efficiency of about 3.7% at Th = 673 K with a proper output power density (Pd∼0.56 Wcm−2) was obtained. Our results indicate that the introduction of Ti4+ in copper sulfide thermoelectric materials is an effective and convenient strategy to improve ZT by decreasing thermal conductivity.
•An improved α and low κ (0.62–0.77 Wm−1K−1) produced by the second phases by adding Ti4+ in Cu1.8S.•The highest ZT up to 0.54 at 673 K is twice as large as that of the undoped one.•A maximum efficiency of 3.7% at Th = 673 K with a proper Pd∼0.56 Wcm−2 was obtained.
Nanostructure engineering has been extensively applied to ZnO in an effort to improve its performance in thermoelectric material, solar cell, and nanogenerator applications. Nano-structured ZnO bulks ...are limited by their inherently low mobility caused by the high density of grain boundaries and interfaces. In this study, a hybrid micro/nano structure composed of nearly coherent grain boundaries with a low misorientation degree among the nanograins was successfully fabricated in Zn
1−
x
Al
x
O (
x
= 0, 0.01, 0.02, 0.03, 0.04 mol) bulks
via
hydrothermal synthesis and spark plasma sintering. Despite the large amount of nanograin boundaries and interfaces in the resulting material, a high carrier mobility value (50.7 cm
2
V
−1
s
−1
) was obtained in the
x
= 0.2 sample - close to the level shown by ZnO single crystals and far higher than that of its ordinary nano-structured counterparts (<15 cm
2
V
−1
s
−1
). A reduced thermal conductivity value of 2.1 W m
−1
K
−1
at 1073 K was also obtained in the micro/nano-structured
x
= 0.02 bulk due to extremely effective scattering at boundaries and interfaces also present in the nano-structured counterparts. After the simultaneous optimization of both electrical and thermal transport properties, the micro/nano-structured
x
= 0.02 sample showed a high
ZT
value (up to 0.36) at 1073 K. The proposed micro/nano-structure may also be applicable to other thermoelectric materials for further
ZT
enhancement.
We obtained a high thermoelectric figure of merit (
ZT
) in this simple ZnO by adopting a hybrid micro/nano structuring approach.
Direct methanol fuel cells (DMFCs) are among the most promising portable power supplies because of their unique advantages, including high energy density/mobility of liquid fuels, low working ...temperature, and low emission of pollutants. Various metal‐based anode catalysts have been extensively studied and utilized for the essential methanol oxidation reaction (MOR) due to their superior electrocatalytic performance. At present, especially with the rapid advance of nanotechnology, enormous efforts have been exerted to further enhance the catalytic performance and minimize the use of precious metals. Constructing multicomponent metal‐based nanocatalysts with precisely designed structures can achieve this goal by providing highly tunable compositional and structural characteristics, which is promising for the modification and optimization of their related electrochemical properties. The recent advances of metal‐based electrocatalytic materials with rationally designed nanostructures and chemistries for MOR in DMFCs are highlighted and summarized herein. The effects of the well‐defined nanoarchitectures on the improved electrochemical properties of the catalysts are illustrated. Finally, conclusive perspectives are provided on the opportunities and challenges for further refining the nanostructure of metal‐based catalysts and improving electrocatalytic performance, as well as the commercial viability.
Efficient catalysts are critical for the electrocatalytic oxidation reaction of methanol. Metal‐based anode catalysts with well‐defined nanoarchitectures and optimal chemical compositions can provide superior performance with lower costs. The possible effects, challenges, and future development are elaborately discussed to shed light on the further design of metal‐based anode catalysts for the methanol electro‐oxidation reaction, leading to a renewable energy supply future.
Direct detection of circularly polarized light (CPL) is a challenging task due to limited materials and ambiguous structure–property relationships that lead to low distinguishability of the light ...helicities. Perovskite ferroelectric semiconductors incorporating chirality provide new opportunities in dealing with this issue. Herein, a pair of 2D chiral perovskite ferroelectrics is reported, which have enhanced CPL detection performance due to interplays among lattice, photon, charge, spin, and orbit. The chirality‐transfer‐induced chiral&polar ferroelectric phase enhances the asymmetric nature of the photoactive sublattice and achieves a switchable self‐powered detection via the bulk photovoltaic effect. The single‐crystal‐based device exhibits a CPL‐sensitive detection performance under 430 nm with an asymmetric factor of 0.20 for left‐ and right‐CPL differentiation, about two times that of the pure chiral counterparts. The enhanced CPL detection performance is ascribed to the Rashba–Dresselhaus effect that originates from the bulk inversion asymmetry and strong spin–orbit coupling, shown with a large Rashba coefficient, which is demonstrated by density functional theory calculation and circularly polarized light excited photoluminescence measurement. These results provide new perspectives on chiral Rashba ferroelectric semiconductors for direct CPL detection and ferroelectrics‐based chiroptics and spintronics.
A pair of 2D chiral perovskite Rashba ferroelectric semiconductors is reported. The fabricated single‐crystal device responds to circularly polarized light (CPL) under 430 nm with an anisotropy factor of 0.20 for the left‐ and right‐CPL differentiation, about two times of reported pure chiral counterparts. The enhanced performance is ascribed to the Rashba–Dresselhaus effect with a large Rashba coefficient of 0.93 eV Å.
The success of Li–air/O2 batteries has brought extensive attention to the development of various promising non‐Li metal–O2 batteries, such as Zn–O2, Al–O2, Mg–O2 batteries, etc., which have exhibited ...unique advantages, such as low production cost, high energy density, and much enhanced safety. The versatile non‐Li metal–O2 batteries provide a better opportunity for meeting the practical requirements for sustainable energy supplies in various applications. A high‐performance cathode in non‐Li metal–O2 batteries that can effectively trigger both oxygen reduction and evolution reactions and thus boost the overall battery performance is of great research interest. In this article, a comprehensive review on the development of Li‐free metal–O2 batteries and particularly focusing on the oxygen catalytic cathodes for both primary and secondary non‐Li metal–O2 batteries is carefully performed. The current challenges and potential solutions are also outlined and proposed. Through carefully selecting and rationally designing promising catalytic cathodes, a series of non‐Li metal–oxygen batteries toward practical energy storage applications are highly anticipated.
Non‐Li metal–O2 batteries show great potential for future practical energy storage solutions. Current status, challenges, and perspectives in developing high‐performance cathode catalysts (e.g., noble metals, non‐noble metals, metal and nonmetal hybrids, and metal‐free catalysts) are studied for designing emerging non‐Li metal–O2 batteries.
Hierarchical hollow CoP and carbon composites were obtained through a facile synthetic method, where carbonization and phosphorization of the precursor were completed within one single step. The ...composites are composed of hollow CoP@C spheres, which are further made up of CoP nanoparticles with a thin outer carbon layer. Electrochemical performances of the prepared CoP@C composites as anodes for sodium and potassium storage were evaluated and compared. In situ TEM, in situ synchrotron XRD, and DFT calculations were conducted to study the structural evolution and the interaction between Na/K and CoP during cycling processes. Benefiting from the synergistic effect of conductive carbon layer and hierarchical hollow structure, the as‐prepared CoP@C composites demonstrate superior sodium and potassium storage capability as anode materials for rechargeable batteries.
Hierarchical hollow CoP and carbon composites were obtained through a facile one‐step synthesis. Benefiting from the synergistic effect of conductive carbon layer and hierarchical hollow structure, the as‐prepared CoP@C composites demonstrate superior sodium and potassium storage capability as anode materials for rechargeable batteries.
Applications of room‐temperature–sodium sulfur (RT‐Na/S) batteries are currently impeded by the insulating nature of sulfur, the slow redox kinetics of sulfur with sodium, and the dissolution and ...migration of sodium polysulfides. Herein, a novel micrometer‐sized hierarchical S cathode supported by FeS2 electrocatalyst, which is grown in situ in well‐confined carbon nanocage assemblies, is presented. The hierarchical carbon matrix can provide multiple physical entrapment to polysulfides, and the FeS2 nanograins exhibit a low Na‐ion diffusion barrier, strong binding energy, and high affinity for sodium polysulfides. Their combination makes it an ideal sulfur host to immobilize the polysulfides and achieve reversible conversion of polysulfides toward Na2S. Importantly, the hierarchical S cathode is suitable for large‐scale production via the inexpensive and green spray‐drying method. The porous hierarchical S cathode offers a high sulfur content of 65.5 wt%, and can deliver high reversible capacity (524 mAh g−1 over 300 cycles at 0.1 A g−1) and outstanding rate capability (395 mAh g−1 at 1 A g−1 for 850 cycles), holding great promise for both scientific research and real application.
A novel sulfiphilic host, consisting of FeS2 nanograins grown in nitrogen‐doped hierarchical carbon microspheres, is utilized to realize a highly efficient S cathode. The combination of micro‐/nanoarchitectures and FeS2 nanograins with multiple physical entrapment to immobilize the polysulfides and achieve reversible conversion of polysulfides toward Na2S holds great promise for both scientific research and real application.
The electrochemical nitrogen reduction reaction (NRR) is a promising energy‐efficient and low‐emission alternative to the traditional Haber–Bosch process. Usually, the competing hydrogen evolution ...reaction (HER) and the reaction barrier of ambient electrochemical NRR are significant challenges, making a simultaneous high NH3 formation rate and high Faradic efficiency (FE) difficult. To give effective NRR electrocatalysis and suppressed HER, the surface atomic structure of W18O49, which has exposed active W sites and weak binding for H2, is doped with Fe. A high NH3 formation rate of 24.7 μg h−1 mgcat−1 and a high FE of 20.0 % are achieved at an overpotential of only −0.15 V versus the reversible hydrogen electrode. Ab initio calculations reveal an intercalation‐type doping of Fe atoms in the tunnels of the W18O49 crystal structure, which increases the oxygen vacancies and exposes more W active sites, optimizes the nitrogen adsorption energy, and facilitates the electrocatalytic NRR.
More vacancies: Both high NH3 formation rate (24.7 μg h−1 mgcat−1) and Faradic efficiency (20.0 %) are achieved on Fe‐doped W18O49 nanowires@carbon fiber papers at −0.15 V (vs. reversible hydrogen electrode). Fe atoms not only efficiently increase the number of oxygen vacancies of W18O49, but optimize the nitrogen adsorption energy, and facilitate the electrocatalytic nitrogen reduction reaction (NRR).
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