SiO_(2) Induces Iron Overload and Ferroptosis in Cardiomyocytes in a Silicosis Mouse Model

Objective The aim of this study was to explore the role and mechanism of ferroptosis in SiO_(2)-induced cardiac injury using a mouse model.Methods Male C57BL/6 mice were intratracheally instilled with SiO_(2) to create a silicosis model.Ferrostatin-1(Fer-1)and deferoxamine(DFO)were used to suppress ferroptosis.Serum biomarkers,oxidative stress markers,histopathology,iron content,and the expression of ferroptosis-related proteins were assessed.Results SiO_(2) altered serum cardiac injury biomarkers,oxidative stress,iron accumulation,and ferroptosis markers in myocardial tissue.Fer-1 and DFO reduced lipid peroxidation and iron overload,and alleviated SiO_(2)-induced mitochondrial damage and myocardial injury.SiO_(2) inhibited Nuclear factor erythroid 2-related factor 2(Nrf2)and its downstream antioxidant genes,while Fer-1 more potently reactivated Nrf2 compared to DFO.Conclusion Iron overload-induced ferroptosis contributes to SiO_(2)-induced cardiac injury.Targeting ferroptosis by reducing iron accumulation or inhibiting lipid peroxidation protects against SiO_(2) cardiotoxicity,potentially via modulation of the Nrf2 pathway.

Lithium Sulfur Batteries:Insights from Solvation Chemistry to Feasibility Designing Strategies for Practical Applications

Rechargeable lithium-sulfur(Li-S)batteries,featuring high energy density,low cost,and environmental friendliness,have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li-ion batteries.However,their practical deployment has long been plagued by the infamous“shuttle effect”of soluble Li polysulfides(LiPSs)and the rampant growth of Li dendrites.Therefore,it is important to specifically elucidate the solvation structure in the Li-S system and systematically summarize the feasibility strategies that can simultaneously suppress the shuttle effect and the growth of Li dendrites for practical applications.This review attempts to achieve this goal.In this review,we first introduce the importance of developing Li-S batteries and highlight the key challenges.Then,we revisit the working principles of Li-S batteries and underscore the fundamental understanding of LiPSs.Next,we summarize some representative characterization techniques and theoretical calculations applied to characterize the solvation structure of LiPSs.Afterward,we overview feasible designing strategies that can simultaneously suppress the shuttle effect of soluble LiPSs and the growth of Li dendrites.Finally,we conclude and propose personal insights and perspectives on the future development of Li-S batteries.We envisage that this timely review can provide some inspiration to build better Li-S batteries for promoting practical applications.

DC active power filter based on model predictive control for DC bus overvoltage suppression of accelerator grid power supply

The China Fusion Engineering Test Reactor plans to build a 200 k V/25 A acceleration grid power supply(AGPS)for the negative-ion-based neutral beam injector prototype system.The AGPS uses a rectifier-inverter-isolated step-up structure.There is a DC bus between the rectifier and the inverter.In order to limit DC bus voltage ripple and transient fluctuations,a large number of capacitors are used,which degrades the reliability of the power supply and occupies a large amount of space.This work finds that due to the difference in the turn-off time of the rectifier and the inverter,the capacitance mainly depends on the rectifier current when the inverter is turned off.On this basis,an active power filter(APF)scheme is proposed to absorb the current.To enhance the dynamic response ability of the APF,model predictive control is adopted.In this paper,the circuit structure of the APF is introduced,the prediction model is deduced,the corresponding control strategy and signal detection method are proposed,and the simulation and experimental results show that APF can track the transient current of the DC bus and reduce the voltage fluctuation significantly.

Fusion power supply advances by the J-TEXT engineering team

To meet the stringent requirements of the fusion power supply for large-scale fusion devices,the J-TEXT engineering team has carried out key technology research and applications in several important directions of fusion power supply.This article presents the advances made by the J-TEXT engineering team in recent years in the following areas:(1) a high-voltage power supply for an auxiliary heating system;(2) a breakdown protection device for an auxiliary heating power supply;(3) magnetic field compatibility;(4) a high-voltage pulsed power supply for a fieldreversed configuration;(5) a large physics experimental facility control system.The research backgrounds,technical progress,test results,applications,summaries and prospects are described in detail in each part.These innovative research results and valuable engineering experience can promote the progress of fusion power supply technology,and also lay a foundation for the development of power supplies with higher parameters in the future.

Fault diagnosis algorithm for 3-phase passive rectifiers based on frequency-domain analysis for acceleration grid power supply in CFETR NBI system

The acceleration grid power supply(AGPS) is a crucial part of the Negative-ion Neutral Beam Injection system in the China Fusion Engineering Test Reactor,which includes a 3-phase passive(diode) rectifier.To diagnose and localize faults in the rectifier,this paper proposes a frequencydomain analysis-based fault diagnosis algorithm for the rectifier in AGPS.First,time-domain expressions and spectral characteristics of the output voltage of the TPTL-NPC inverter-based power supply are analyzed.Then,frequency-domain analysis-based fault diagnosis and frequency-domain analysis-based sub-fault diagnosis algorithms are proposed to diagnose open circuit(OC) faults of diode(s),which benefit from the analysis of harmonics magnitude and phase-angle of the output voltage.Only a fundamental period is needed to diagnose and localize exact faults,and a strong Variable-duration Fault Detection Method is proposed to identify acceptable ripple from OC faults.Detailed simulations and experimental results demonstrate the effectiveness,quickness,and robustness of the proposed algorithms,and the diagnosis algorithms proposed in this article provide a significant method for the fault diagnosis of other rectifiers and converters.

Perovskite Cathode Materials for Low‑Temperature Solid Oxide Fuel Cells:Fundamentals to Optimization

Acceleration of the oxygen reduction reaction at the cathode is paramount in the development of low-temperature solid oxide fuel cells.At low operating temperatures between 450 and 600℃,the interactions between the surface and the bulk of the cathode materials greatly impact the electrode kinetics and consequently determine the overall efficacy and long-term stability of the fuel cells.This review will provide an overview of the recent progress in the understanding of surface-bulk interactions in perovskite oxides as well as their impact on cathode reactivity and stability.This review will also summarize current strategies in the development of cathode materials through bulk doping and surface functionalization.In addition,this review will highlight the roles of surface segregation in the mediation of surface and bulk interactions,which have profound impacts on the properties of cathode surfaces and the bulk and therefore overall cathode performance.Although trade-offs between reactivity and stability commonly exist in terms of catalyst design,opportunities also exist in attaining optimal cathode performance through the modulation of both cathode surfaces and bulk using combined strategies.This review will conclude with future research directions involving investigations into the role of oxygen vacancy and mobility in catalysis,the rational modulation of surface-bulk interactions and the use of advanced fabrication techniques,all of which can lead to optimized cathode performance.

Controlling disorder in host lattice by hetero-valence ion doping to manipulate luminescence in spinel solid solution phosphors

Phosphor materials have been rapidly developed in the past decades. Developing phosphors with desired properties including strong luminescence intensity and long lifetime has attracted widespread attention. Herein, we show that hetero-valence ion doping can serve as a potent strategy to manipulate luminescence in persistent phosphors by controlling disorder in the host lattice. Specifically, spinel phosphor Zn(Ga_(1-x)Zn_x)(Ga_(1-x)Ge_x)O_4:Cr is developed by doping ZnGa_2O_4:Cr with tetravalent Ge^(^(4+)).Compared to the original ZnGa_2O_4:Cr, the doped Zn(Ga_(1-x)Zn_x)(Ga_(1-x)Ge_x)O_4:Cr possesses significantly enhanced persistent luminescence intensity and prolonged decay time. Rietveld refinements show that Ge^(4+)enters into octahedral sites to substitute Ga^(3+), which leads to the co-substitution of Ga^(3+) by Zn^(2+) for charge compensation. The hetero-valence substitution of Ga^(3+) by Ge^(4+)and Zn^(2+) enriches the charged defects in Zn(Ga_(1-x)Zn_x)(Ga_(1-x)Ge_x)O_4:Cr, making it possible to trap large amounts of charge carriers within the defects during excitation. Electron paramagnetic resonance measurement further confirms that the amount of Cr^(3+) neighboring charged defects increases with Ge^(4+)doping. Thus charge carriers released from defects can readily combine with the neighboring Cr^(3+) to produce bright persistent luminescence after excitation ceases. The hetero-valence ion doping strategy can further be employed to develop many other phosphors and contributes to lighting, photocatalysis and bioimaging.

Copper-catalyzed asymmetric propargylic substitution of anthrones and propargylic esters

Anthrones are key structural motifs in many natural products, bioactive compounds and pharmaceutical chemicals. Earth-abundant-metal-catalyzed asymmetric functionalization of anthrones has not proved to be viable. Herein, we disclosed a highly enantioselective propargylic substitution of anthrones with propargylic esters using copper salts with chiral N, N, P-ligand. This strategy is amenable to a broad range of substrates, uses readily available starting materials, provides excellent yields with remarkable enantioselectivity under mild conditions, and enables attractive products diversification routes.

Room-Temperature Persistent Luminescence in Metal Halide Perovskite Nanocrystals for Solar-Driven CO_(2)Bioreduction

The rapid crystal growth of metal halide perovskite(MHP)nanocrystals inevitably leads to the generation of abundant crystal defects in the lattice.Here,defects-mediated long-lived charges and accompanying room-temperature persistent luminescence are demonstrated to be a general phenomenon in MHP nanocrystals.Density functional theory calculations suggest that the collaboration of Schottky and point defects enables upward cascading depletion for electron transfer in MHP nanocrystals,leading to the generation of long-lived photoexcited charges with lifetimes over 30 min.The excellent optical properties including the presence of long-lived charges,high charge separation efficiency,and broad absorption in the visible region make MHPs ideal candidates for both photocatalysis and photobiocatalysis.The MHPs were further integrated with enzymes to construct a light-driven biosynthetic system for the selective production of fine chemicals from CO_(2)with solar energy.The biosynthetic system can produce formate with a quantum yield of 3.24%,much higher than that of plants(∼0.2-1.6%).These findings will benefit the understanding of the optoelectronic properties of MHPs and further provide opportunities for the development of biosynthetic systems for solar-to-chemical synthesis.

Phytolith evidence reveals the origin of angiosperm leaf eating habits among ancient Cretaceous birds

Recently,Nature Communications published a study on the feeding habits of an ancient extinct bird called Jeholornis from the Early Cretaceous Jehol Biota of China led by researchers from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences.1 Jeholornis and its closely related species are regarded as part of the second most primitive lineage in the family tree of birds,retaining a long bony dinosaurian tail,small teeth,and large claws on the wings.Adopting an interdisciplinary approach,the scientific team discovered hundreds of phytoliths originated from the leaves of the basal angiosperm group called magnoliids(which includes living magnolias,cinnamon,and avocadoes),while investigating the stomach residues contents of a well-preserved 120-million-year-old juvenile Jeholornis fossil.These fossil phytoliths are the first confirmation that help point to the origin and evolution of leaf eating in ancient birds and further sketch an interesting scientific story about the early interactions between birds and flowering plants(Figure 1).