bluuebunny/crossref_metadata_2025 huggingface dataset:
Observer‐based output feedback event‐triggered consensus tracking for linear multi‐agent systems
Authors: Zhang Xuxi , Song Jinbao
Published: February 2024

This paper investigates the consensus tracking of multi‐agent systems (MASs) with general linear dynamics and directed graphs via observer‐based event‐triggered (ET) control. For each follower, a dynamic event‐triggered (DET) unknown input observer (UIO) is constructed to estimate the relative states, which utilizes the discrete relative output information among neighboring agents, and the estimate errors can exponentially converge to zero. Then, an observer‐based DET controller, which has the superiority of reducing the communication burden, is presented. Unlike most existing works, a dual ET mechanism of observer and controller is proposed, whose triggering functions are independent of each other. In addition, the time‐varying item in the triggering functions is further extended to be a class of positive functions, including some existing exponential functions as its special cases. Under the proposed DET UIO and DET control protocol, it is rigorously demonstrated that consensus tracking can be achieved asymptotically, and Zeno behavior is ruled out. Finally, a numerical example is provided to verify the validity of the results.
The impact of paid sick leave mandates on women's employment and economic security
Authors: Slopen Meredith
Published: February 2024

The United States does not guarantee job‐protected paid leave to workers when they or a family member are ill or need to seek medical care. Prior research shows that women are less likely to have access to paid sick leave (PSL) through their employers. I examine the impacts of three recent state‐level paid sick leave policies in California, Massachusetts, and Oregon on women's employment and economic security using data from the American Community Survey. Using difference‐in‐differences and dynamic effects models, I find that PSL mandates increase women's employment by 1.2 percentage points (a 1.7% increase over the pre‐policy baseline mean) with an average increase in income from wages and salary of $2,347, accompanied by steady decreases in poverty in the years after policy implementation. Effects are strongest among mothers and women without college degrees. This study demonstrates that PSL improves women's employment and economic security and may play an essential role in the package of policies supporting women's employment and earnings.
On the Generalized Lemaitre Tolman Bondi Metric: Classical Sensitivities and Quantum Einstein‐Vaz Shells
Authors: Molaei Mohammadreza , Corda Christian
Published: February 2024

In this paper, in the classical framework, the lower bounds for the sensitivities of the generalized Lemaitre Tolman Bondi metric are evaluated. The calculated lower bounds via the linear dynamical systems , , and are , and respectively. The sensitivities and the lower sensitivities via are zero are also shown. In the quantum framework, the properties of the Einstein‐Vaz shells which are the final result of the quantum gravitational collapse arising from the Lemaitre Tolman Bondi discussed by Vaz in 2014 are analyzed. In fact, Vaz showed that continued collapse to a singularity can only be obtained if one combines two independent and entire solutions of the Wheeler‐DeWitt equation. Forbidding such a combination leads naturally to matter condensing on the Schwarzschild surface during quantum collapse. In that way, an entirely new framework for black holes (BHs) has emerged. The approach of Vaz was also consistent with Einstein's idea in 1939 of the localization of the collapsing particles within a thin spherical shell. Here, following an approach of oned of us (CC), we derive the BH mass and energy spectra via a Schrodinger‐like approach, by further supporting Vaz's conclusions that instead of a spacetime singularity covered by an event horizon, the final result of the gravitational collapse is an essentially quantum object, an extremely compact “dark star”. This “gravitational atom” is held up not by any degeneracy pressure but by quantum gravity in the same way that ordinary atoms are sustained by quantum mechanics. Finally, the time evolution of the Einstein‐Vaz shells is discussed.
Dynamic Shear Mechanical Properties and Microscopic Deformation Characteristics of Laser Cladding IN625 Alloy
Authors: Liu Tao , Ding Musen , Bao Hong , Lei Jingfa , Wang Lu
Published: February 2024

To reveal the dynamic shear mechanical properties of laser cladding Inconel 625 (IN625) alloy, dynamic shear mechanical properties experiments are conducted on forged specimens and laser cladding specimens by split Hopkinson press bar experimental device. Optical microscopy, scanning electron microscopy, and electron backscattered diffraction (EBSD) are used to characterize the microscopic morphology, crystal orientation, and grain size of laser cladding specimens before and after dynamic shear deformation. In the results, it is shown that the yield strength and shear strength of both forged and laser clad specimens increase with the increase of shear strain rate, reflecting a remarkable strain‐rate‐strengthening effect, and the shear strength of the laser cladding specimen is higher than that of the forged specimen. After dynamic shear loading, the grains in the shear region of the laser cladding specimen are severely deformed, deformation bands appear, and some dendrites are transformed into equiaxed crystal. After shear deformation, the preferred orientation strength of the crystal increases, the small‐size grain and low‐angle grain boundary increase, and a large number of dislocations are formed in the shear region, which dominates the dynamic shear deformation behavior of the material. Dislocation is an important dominant mechanism of dynamic shear deformation.
Understanding Graphitic Carbon Nitride as Photocatalyst: A Case Study on Thermal Engineering of Physical and Chemical Features
Authors: Memarian Nafiseh , Farahi Ehsan , Tobeiha Nafiseh , You Sujie , Concina Isabella
Published: February 2024

Rationalizing material features according to the adopted synthetic strategy, aiming then to tune them on demand, is among the most relevant purposes of investigation in materials science. Herein, the systematic analysis of the dependence of graphitic carbon nitride (g‐C3N4) physical characteristics on the decomposition temperature of urea, rationalizing the impact of synthetic temperature on several characteristics of the materials (degree of N–H condensation, carbon vs nitrogen content, structural parameters, photoluminescence lifetime, surface area, pores volume), is discussed. g‐C3N4 nanostructures are fabricated by thermal decomposition of urea at different temperatures under ambient atmosphere, obtaining an almost ideal stoichiometry (C/N = 0.72) when setting the temperature at 600 °C. The samples show structural, textural, compositional, and optical differences directly depending on the fabrication temperature: specific surface area, pore volume and size, intralayer distance, and speed of radiative recombination of photogenerated charges are proportionally enhanced by increasing the synthesis temperature. The role played by all the physicochemical features of the prepared samples in promoting the catalytic degradation of Rhodamine B is investigated, highlighting their synergistic role in enhancing the catalytic efficiency. Significant differences in the dye degradation are recorded when using either UV or solar simulated light, demonstrating that Rhodamine B photosensitization rules the process.
Insight into the Grain Refining Mechanism of Al–Ti–C and the Interfacial Properties between the Inoculants and Aluminum
Authors: Zhao Dahong , Xie Cheng , Xiao Zhengbing , Huang Shita
Published: February 2024

The grain refinement mechanism of Al–Ti–C grain refiners used in the casting procedure of aluminum has been studied by first‐principles calculation. Considering the controversy over Al3Ti, TiC, or Al3Ti–TiC as nucleation sites, the adsorption behavior of possible nucleation surfaces for Al atoms, including adsorption energies and adsorption sites, as well as the interfacial properties of Al/Al3Ti/TiC are calculated and compared. In the results, it is shown that the Al3Ti(112) surface has a stronger adsorption capacity for Al than TiC. By using the edge‐to‐edge matching crystallographic model and the calculation of the adsorption energy, it is found that the monolayer Al3Ti(112) can be stabilized on the TiC(100) surface, and the combination of TiC and monolayer Al3Ti can significantly improve the adsorption capacity of Al. Interfacial electronic structure analysis shows stronger chemical bonding between Al and Ti at the Al/Al3Ti/TiC interface compared to Al/Al3Ti, which explains that the monolayer Al3Ti covering the TiC surface has the strongest adsorption capacity for Al atoms. Therefore, it is speculated that TiC with a monolayer of Al3Ti covering the surface will serve as a potential nucleation site during grain refinement, which will provide a theoretical reference for future research work.
Mathematical modeling of lung mechanics and pressure‐controlled ventilation design for barotrauma minimization: A numerical simulation study
Authors: D'Orsi Laura , Borri Alessandro , De Gaetano Andrea
Published: February 2024

Mechanical ventilation represents a fundamental mode of therapy for severely ill patients who cannot breathe autonomously. At the same time, it has the potential of determining Ventilator‐Induced Lung Injury (VILI) and further damaging the patient's respiratory system. In this work we present a model‐based approach for pressure delivery optimization in the context of pressure‐control mechanical ventilation, with the aim of maintaining oxygenation while minimizing barotrauma. A simple compartmental model of respiration describes both mechanical ventilation, alveolar oxygen exchange and blood oxygen transport. Model Predictive Control is used to optimize delivered air pressure at the mouth at each inspiration, optimizing a trade‐off between oxygenation and barotrauma. Numerical simulations with different values of the trade‐off parameter and in two emblematic pulmonary disease scenarios (ARDS and COPD) show the effectiveness of the proposed approach.
Image‐Guided Photothermal and Immune Therapy of Tumors via Melanin‐Producing Genetically Engineered Bacteria
Authors: Song Weijian , He Yaling , Feng Yanan , Wang Yuanyuan , Li Xiaoying , Wu Yingnan , Zhang Shanxin , Zhong Lin , Yan Fei , Sun Litao
Published: February 2024

Photothermal therapy (PTT) is a new treatment modality for tumors. However, the efficient delivery of photothermal agents into tumors remains difficult, especially in hypoxic tumor regions. In this study, an approach to deliver melanin, a natural photothermal agent, into tumors using genetically engineered bacteria for image‐guided photothermal and immune therapy is developed. An Escherichia coli MG1655 is transformed with a recombinant plasmid harboring a tyrosinase gene to produce melanin nanoparticles. Melanin‐producing genetically engineered bacteria (MG1655‐M) are systemically administered to 4T1 tumor‐bearing mice. The tumor‐targeting properties of MG1655‐M in the hypoxic environment integrate the properties of hypoxia targeting, photoacoustic imaging, and photothermal therapeutic agents in an “all‐in‐one” manner. This eliminates the need for post‐modification to achieve image‐guided hypoxia‐targeted cancer photothermal therapy. Tumor growth is significantly suppressed by irradiating the tumor with an 808 nm laser. Furthermore, strong antitumor immunity is triggered by PTT, thereby producing long‐term immune memory effects that effectively inhibit tumor metastasis and recurrence. This work proposes a new photothermal and immune therapy guided by an “all‐in‐one” melanin‐producing genetically engineered bacteria, which can offer broad potential applications in cancer treatment.
An Appraisal for Providing Charge Transfer (CT) Through Synthetic Porous Frameworks for their Semiconductor Applications
Authors: Shahmirzaee Mozhgan , Nagai Atsushi
Published: February 2024

In recent years, there has been considerable focus on the development of charge transfer (CT) complex formation as a means to modify the band gaps of organic materials. In particular, CT complexes alternate layers of aromatic molecules with donor (D) and acceptor (A) properties to provide inherent electrical conductivity. In particular, the synthetic porous frameworks as attractive D–A components have been extensively studied in recent years in comparison to existing D–A materials. Therefore, in this work, the synthetic porous frameworks are classified into conjugated microporous polymers (CMPs), covalent organic frameworks (COFs), and metal–organic frameworks (MOFs) and compare high‐quality materials for CT in semiconductors. This work updates the overview of the above porous frameworks for CT, starting with their early history regarding their semiconductor applications, and lists CT concepts and selected key developments in their CT complexes and CT composites. In addition, the network formation methods and their functionalization are discussed to provide access to a variety of potential applications. Furthermore, several theoretical investigations, efficiency improvement techniques, and a discussion of the electrical conductivity of the porous frameworks are also highlighted. Finally, a perspective of synthetic porous framework studies on CT performance is provided along with some comparisons.
Mechanocatalytic Synthesis of Ammonia by Titanium Dioxide with Bridge‐Oxygen Vacancies: Investigating Mechanism from the Experimental and First‐Principle Approach
Authors: He Chengli , Chen Yang , Hao Zixiang , Wang Linrui , Wang Mingyan , Cui Xiaoli
Published: February 2024

Mechanochemical ammonia (NH3) synthesis is an emerging mild approach derived from nitrogen (N2) gas and hydrogen (H) source. The gas‐liquid phase mechanochemical process utilizes water (H2O), rather than conventional hydrogen (H2) gas, as H sources, thus avoiding carbon dioxide (CO2) emission during H2 production. However, ammonia yield is relatively low to meet practical demand due to huge energy barriers of N2 activation and H2O dissociation. Here, six transition metal oxides (TMO) such as titanium dioxide (TiO2), iron(III) oxide (Fe2O3), copper(II) oxide (CuO), niobium(V) oxide(Nb2O5), zinc oxide (ZnO), and copper(I) oxide (Cu2O) are investigated as catalysts in mechanochemical N2 fixation. Among them, TiO2 shows the best mechanocatalytic effect and the optimum reaction rate constant is 3.6‐fold higher than the TMO‐free process. The theoretical calculations show that N2 molecules prefer to side‐on chemisorb on the mechano‐induced bridge‐oxygen vacancies in the (101) crystal plane of TiO2 catalyst, while H2O molecules can dissociate on the same sites more easily to provide free H atoms, enabling an alternative‐way hydrogeneration process of activated N2 molecules to release NH3 eventually. This work highlights the cost‐effective TiO2 mechanocatalyst for ammonia synthesis under mild conditions and proposes a defect‐engineering‐induced mechanocatalytic mechanism to promote N2 activation and H2O dissociation.
Intermetallic Cobalt Indium Nanoparticles as Oxygen Evolution Reaction Precatalyst: A Non‐Leaching p‐Block Element
Authors: Hausmann J. Niklas , Ashton Marten , Mebs Stefan , Walter Carsten , Selve Sören , Haumann Michael , Sontheimer Tobias , Dau Holger , Driess Matthias , Menezes Prashanth W.
Published: February 2024

Merely all transition‐metal‐based materials reconstruct into similar oxyhydroxides during the electrocatalytic oxygen evolution reaction (OER), severely limiting the options for a tailored OER catalyst design. In such reconstructions, initial constituent p‐block elements take a sacrificial role and leach into the electrolyte as oxyanions, thereby losing the ability to tune the catalyst's properties systematically. From a thermodynamic point of view, indium is expected to behave differently and should remain in the solid phase under alkaline OER conditions. However, the structural behavior of transition metal indium phases during the OER remains unexplored. Herein, are synthesized intermetallic cobalt indium (CoIn3) nanoparticles and revealed by in situ X‐ray absorption spectroscopy and scanning transmission microscopy that they undergo phase segregation to cobalt oxyhydroxide and indium hydroxide. The obtained cobalt oxyhydroxide outperforms a metallic‐cobalt‐derived one due to more accessible active sites. The observed phase segregation shows that indium behaves distinctively differently from most p‐block elements and remains at the electrode surface, where it can form lasting interfaces with the active metal oxo phases.
Synergistic Dual Doping of Sulfur and Copper for Improved Thermoelectric Properties of Silver Selenide Nanomaterials
Authors: Han Yue , Li Xiaohan , Jin Yifang , Wang Xiaolin , Sun Xingnan , An Cheng Jin
Published: February 2024

Research on flexible thermoelectric (TE) materials has typically focused on conducting polymers and conducting polymer‐based composites. However, achieving TE properties comparable in magnitude to those exhibited by their inorganic counterparts remains a formidable challenge. This study focuses on the synthesis of silver selenide (Ag2Se) nanomaterials using solvothermal methods and demonstrates a significant enhancement in their TE properties through the synergistic dual doping of sulfur and copper. Flexible TE thin films demonstrating excellent flexibility are successfully fabricated using vacuum filtration and hot‐pressing techniques. The resulting thin films also exhibited outstanding TE performance, with a high Seebeck coefficient (S = −138.5 µV K−1) and electrical conductivity (σ = 1.19 × 105 S m−1). The record power factor of 2296.8 µW m−1 K−2 at room temperature is primarily attributed to enhanced carrier transport and interfacial energy filtration effects in the composite material. Capitalizing on these excellent TE properties, the maximum power output of flexible TE devices reached 1.13 µW with a temperature difference of 28.6 K. This study demonstrates the potential of Ag2Se‐based TE materials for flexible and efficient energy‐harvesting applications.
Rational Construction of 3D Self‐Supported MOF‐Derived Cobalt Phosphide‐Based Hollow Nanowall Arrays for Efficient Overall Water Splitting At large Current Density
Authors: Kong Dezhi , Xu Qingguo , Chu Ningning , Wang Hui , Lim Yew Von , Cheng Jinbing , Huang Shaozhuan , Xu Tingting , Li Xinjian , Wang Ye , Luo Yongsong , Yang Hui Ying
Published: February 2024

Developing efficient nonprecious bifunctional electrocatalysts for hydrogen and oxygen evolution reactions (HER and OER) in the same electrolyte with a low overpotential and large current density presents an appealing yet challenging goal for large‐scale water electrolysis. Herein, a unique 3D self‐branched hierarchical nanostructure composed of ultra‐small cobalt phosphide (CoP) nanoparticles embedded into N, P‐codoped carbon nanotubes knitted hollow nanowall arrays (CoPʘNPCNTs HNWAs) on carbon textiles (CTs) through a carbonization‐phosphatization process is presented. Benefiting from the uniform protrusion distributions of CoP nanoparticles, the optimum CoPʘNPCNTs HNWAs composites with high abundant porosity exhibit superior electrocatalytic activity and excellent stability for OER in alkaline conditions, as well as for HER in both acidic and alkaline electrolytes, even under large current densities. Furthermore, the assembled CoPʘNPCNTs/CTs||CoPʘNPCNTs/CTs electrolyzer demonstrates exceptional performance, requiring an ultralow cell voltage of 1.50 V to deliver the current density of 10 mA cm−2 for overall water splitting (OWS) with favorable stability, even achieving a large current density of 200 mA cm−2 at a low cell voltage of 1.78 V. Density functional theory (DFT) calculation further reveals that all the C atoms between N and P atoms in CoPʘNPCNTs/CTs act as the most efficient active sites, significantly enhancing the electrocatalytic properties. This strategy, utilizing 2D MOF arrays as a structural and compositional material to create multifunctional composites/hybrids, opens new avenues for the exploration of highly efficient and robust non‐noble‐metal catalysts for energy‐conversion reactions.
Aluminum Halide‐Based Electron‐Selective Passivating Contacts for Crystalline Silicon Solar Cells
Authors: Gao Kun , Xing Chunfang , Xu Dacheng , Lou Xinliang , Wang Xinyu , Li Kun , Li Wenhao , Mao Jie , Zheng Peiting , Zhang Xinyu , Yang Xinbo
Published: February 2024

Extensive research has focused on developing wide‐bandgap metal compound‐based passivating contacts as alternatives to conventional doped‐silicon‐layer‐based passivating contacts to mitigate parasitic absorption losses in crystalline silicon (c‐Si) solar cells. Herein, thermally‐evaporated aluminum halides (AlX)‐based electron‐selective passivating contacts for c‐Si solar cells are investigated. A low contact resistivity of 60.5 and 38.4 mΩ cm2 is obtained on the AlClx/n‐type c‐Si (n‐Si) and AlFx/n‐Si heterocontacts, respectively, thanks to the low work function of AlX. Power conversion efficiencies (PCEs) of 19.1% and 19.6% are achieved on proof‐of‐concept n‐Si solar cells featuring a full‐area AlClx/Al and AlFx/Al passivating contact, respectively. By further implementing an ultrathin SiO2 passivation interlayer and a pre‐annealing treatment, the electron selectivity (especially the surface passivation) of AlX is significantly enhanced. Accordingly, a remarkable PCE of 21% is achieved on n‐Si solar cells featuring a full‐area SiO2/AlFx/Al rear contact. AlFx‐based electron‐selective passivating contacts exhibit good thermal stability up to ≈400 °C and better long‐term environmental stability. This work demonstrates the potential of AlFx‐based electron‐selective passivating contact for solar cells.
Epitaxially Grown Mechanically Robust 2D Thin Film of Secondary Interactions Led Molecularly Woven Material
Authors: Marvaniya Karan , Dobariya Priyanka , Maurya Ashish , Patel Ketan , Kushwaha Shilpi
Published: February 2024

Molecularly woven materials with striking mechanical resilience, and 2D controlled topologies like textiles, fishing nets, and baskets are highly anticipated. Molecular weaving exclusively apprehended by the secondary interactions expanding to laterally grown 2D self‐assemblies with retained crystalline arrangement is stimulating. The interlacing entails planar molecules screwed together to form 2D woven thin films. Here, secondary interactions led 2D interlaced molecularly woven material (2°MW) built by 1D helical threads of organic chromophores twisted together via end‐to‐end CH···O connections, held strongly at inter‐crossing by multiple OH···N interactions to prevent slippage is presented. Whereas, 1D helical threads with face‐to‐face O–H···O connections sans interlacing led the non‐woven material (2°NW). The polarity‐driven directionality in 2°MW led the water‐actuated epitaxial growth of 2D‐sheets to lateral thin films restricted to nano‐scale thickness. The molecularly woven thin film is self‐healing, flexible, and mechanically resilient in nature, while maintaining the crystalline regularity is attributed to the supple secondary interactions (2°).
Enhancing Electrode Performance through Triple Distribution Modulation of Active Material, Conductive Agent, and Porosity
Authors: He Renjie , Cai Chuyue , Li Siwu , Cheng Shijie , Xie Jia
Published: February 2024

The increasing demand for large‐scale energy storage propels the development of lithium‐ion batteries with high energy and high power density. Low tortuosity electrodes with aligned straight channels have proved to be effective in building such batteries. However, manufacturing such low tortuosity electrodes in large scale remains extremely challenging. In contrast, high‐performance electrodes with customized gradients of materials and porosity are possible to be made by industrial roll‐to‐roll coating process. Yet, the desired design of gradients combining materials and porosity is unclear for high‐performance gradient electrodes. Here, triple gradient LiFePO4 electrodes (TGE) are fabricated featuring distribution modulation of active material, conductive agent, and porosity by combining suction filtration with the phase inversion method. The effects and mechanism of active material, conductive agent, and porosity distribution on electrode performance are analyzed by experiments. It is found that the electrode with a gradual increase of active material content from current collector to separator coupled with the distribution of conductive agent and porosity in the opposite direction, demonstrates the best rate capability, the fastest electrochemical reaction kinetics, and the highest utilization of active material. This work provides valuable insights into the design of gradient electrodes with high performance and high potential in application.
A Disposable Thermally Triggered Photonic Crystal Anti‐Counterfeiting Tag with Irreversible Response and Multi‐Step Color Changes
Authors: Wang Jieqiu , Yin Tian , Ge Jianping
Published: February 2024

Thermochromic photonic crystal (PC) is a promising material for anti‐counterfeiting applications, but there are still challenges to further improve the anti‐counterfeiting performance and the practicability in usage. Here, a disposable thermally triggered PC anti‐counterfeiting tag with irreversible response and multi‐step color changes is developed based on the thermochromic Silica/(Polyethylene glycol‐Ethoxylated trimethylolpropane triacrylate) (SiO2/(PEG‐ETPTA)) double‐layer film. The fast and irreversible thermal response come from the quick melting and infiltration of PEG‐ETPTA into the PCs upon heating. The multi‐step color change at different temperatures originated from the regioselective control of the UV curing degree of the PEG‐ETPTA layer and the resulting thermochromic temperature of the double‐layer film. Therefore, the invisible PC pattern on the tag can be revealed part by part upon heating and became invisible again after overheating, which offered diversified visual effects and enhanced anti‐counterfeiting performances.
P‐N Bonds‐Mediated Atomic‐Level Charge‐Transfer Channel Fabricated between Violet Phosphorus and Carbon Nitride Favors Charge Separation and Water Splitting
Authors: Wang Xin , Wang Yan , Ma Ming , Zhao Xuewen , Zhang Jinying , Zhang Fuxiang
Published: February 2024

Heterostructures are widely employed in photocatalysis to promote charge separation and photocatalytic activity. However, their benefits are limited by the linkages and contact environment at the interface. Herein, violet phosphorus quantum dots (VPQDs) and graphitic carbon nitride (g‐C3N4) are employed as model materials to form VPQDs/g‐C3N4 heterostructures by a simple ultrasonic pulse excitation method. The heterostructure contains strong interfacial P‐N bonds that mitigate interfacial charge‐separation issues. P‐P bond breakage occurs in the distinctive cage‐like [P9] VPQD units during longitudinal disruption, thereby exposing numerous active P sites that bond with N atoms in g‐C3N4 under ultrasonic pulse excitation. The atomic‐level interfacial P–N bonds of the Z‐scheme VPQDs/g‐C3N4 heterostructure serve as photogenerated charge‐transfer channels for improved electron‐hole separation efficiency. This results in excellent photocatalytic performance with a hydrogen evolution rate of 7.70 mmol g−1 h−1 (over 9.2 and 8.5 times greater than those of pure g‐C3N4 and VPQDs, respectively) and apparent quantum yield of 11.68% at 400 nm. Using atomic‐level chemical bonds to promote interfacial charge separation in phosphorene heterostructures is a feasible and effective design strategy for photocatalytic water‐splitting materials.
Carbon Dots with Spatially‐Mediated‐N/S‐Co‐Doping Enabling One‐Year Stable Lubricant with Oil Leakage Detection Capability
Authors: Xue Shenghua , Cui Yuhong , Jin Guangkai , Wang Hongyue , Liu Shujuan , Ye Qian , Wang Hongqiang , Zhou Feng , Liu Weimin
Published: February 2024

The dispersion stability of nano‐lubricating additives is crucial for the shelf life of lubricant and its practical applications. Nitrogen–sulfur co‐doped carbon dots (N,S@CDs) via a one‐step hydrothermal method with nitropyrene and thiourea as raw materials are hereby presented. The N and S elements are selectively distributed throughout the entire carbon skeleton with a doping amount of 22.6 at%. The as‐synthesized N,S@CDs exhibit excellent dispersion stability in PEG200 and maintain stability for over one year. The experiment results indicate that N,S@CDs significantly improve the anti‐wear and friction reduction properties of PEG200, while the friction coefficient is reduced from 0.25 to 0.09 with 1.5 wt% N,S@CDs addition, and the wear volume, depth, and width are reduced by 68%, 52%, and 57%, respectively. The good lubrication performance is attributed to N,S@CDs excellent dispersion stability, enhanced filling and polishing effects, and complex tribochemical reactions caused by heteroatom doping to form a stable protective film on the worn surface. Furthermore, the as‐prepared N,S@CDs exhibit intrinsic fluorescence intensity in PEG200 with the photoluminescence quantum yield (PLQY) of 12.5% and remain fluorescent stable during the long‐term friction process, therefore the N,S@CDs have a potential application prospect in non‐destructive detection of oil leakage via fluorescence labeling method.
In‐Plane Topological‐Defect‐Enriched Graphene as an Efficient Metal‐Free Catalyst for pH‐Universal H2O2 Electrosynthesis
Authors: Mou Zhixing , Mu Yuewen , Liu Lijia , Cao Daili , Chen Shuai , Yan Wenjun , Zhou Haiqing , Chan Ting‐Shan , Chang Lo‐Yueh , Fan Xiujun
Published: February 2024

Developing efficient metal‐free catalysts to directly synthesize hydrogen peroxide (H2O2) through a 2‐electron (2e) oxygen reduction reaction (ORR) is crucial for substituting the traditional energy‐intensive anthraquinone process. Here, in‐plane topological defects enriched graphene with pentagon‐S and pyrrolic‐N coordination (SNC) is synthesized via the process of hydrothermal and nitridation. In SNC, pentagon‐S and pyrrolic‐N originating from thiourea precursor are covalently grafted onto the basal plane of the graphene framework, building unsymmetrical dumbbell‐like S─C─N motifs, which effectively modulates atomic and electronic structures of graphene. The SNC catalyst delivers ultrahigh H2O2 productivity of 8.1, 7.3, and 3.9 mol gcatalyst−1 h−1 in alkaline, neutral, and acidic electrolytes, respectively, together with long‐term operational stability in pH‐universal electrolytes, outperforming most reported carbon catalysts. Theoretical calculations further unveil that defective S─C─N motifs efficiently optimize the binding strength to OOH* intermediate and substantially diminish the kinetic barrier for reducing O2 to H2O2, thereby promoting the intrinsic activity of 2e‐ORR.
Biomimetic Nano‐Cancer Stem Cell Scavenger for Inhibition of Breast Cancer Recurrence and Metastasis after FLASH‐Radiotherapy
Authors: Suo Meng , Shen Hanchen , Lyu Meng , Jiang Yi , Liao Xiaoming , Tang Wei , Pan You , Zhang Tianfu , Ning Shipeng , Tang Ben Zhong
Published: February 2024

Compared to conventional radiotherapy (RT), FLASH‐RT delivers ultra‐high dose radiation, significantly reducing damage to normal tissue while guaranteeing the effect of cancer treatment. However, cancer recurrence and metastasis frequently occur after all RT due to the existence of intractable cancer stem cells (CSCs). To address this, a biomimetic nanoplatform (named TAFL) of tumor‐derived exosome fusion liposomes is designed by co‐loading aggregation‐induced emission photothermal agents, TPE‐BBT, and anti‐cancer drugs, aspirin, aiming to clear CSCs for inhibiting cancer recurrence and metastasis after FLASH‐RT therapy . Aspirin released in TAFL system triggered by laser irradiation can induce apoptosis and DNA damage of 4T1 CSCs, comprehensively downregulate their stemness phenotype, and inhibit their sphericity. Furthermore, the TPE‐BBT mediated mild‐photothermal therapy can alleviate the hypoxic tumor microenvironment, inhibit the DNA repair of CSCs, which further amplifies the effect of aspirin against CSCs, therefore reduces the effective dose of aspirin, making TAFL more biologically safe. In vivo experimental results demonstrated that decreased CSCs population mediated by TAFL system treatment significantly inhibited tumor recurrence and metastasis after FLASH‐RT therapy. In summary, this TAFL system   provides a new idea for the future clinical application of FLASH‐RT therapy.
Highly Efficient Solar‐Light‐Driven Photodegradation of Metronidazole by Nickel Hexacyanoferrate Nanocubes Showing Enhanced Catalytic Performances
Authors: Lushaj Edlind , Bordin Matteo , Akbar Kamran , Liccardo Letizia , Barroso‐Martín Isabel , Rodríguez‐Castellón Enrique , Vomiero Alberto , Moretti Elisa , Polo Federico
Published: February 2024

Environmental pollution is a complex problem that threatens the health and life of animal and plant ecosystems on the planet. In this respect, the scientific community faces increasingly challenging tasks in designing novel materials with beneficial properties to address this issue. This study describes a simple yet effective synthetic protocol to obtain nickel hexacyanoferrate (Ni‐HCF) nanocubes as a suitable photocatalyst, which can enable an efficient photodegradation of hazardous anthropogenic organic contaminants in water, such as antibiotics. Ni‐HCF nanocubes are fully characterized and their optical and electrochemical properties are investigated. Preliminary tests are also carried out to photocatalytically remove metronidazole (MDZ), an antibiotic that is difficult to degrade and has become a common contaminant as it is widely used to treat infections caused by anaerobic microorganisms. Under simulated solar light, Ni‐HCF displays substantial photocatalytic activity, degrading 94.3% of MDZ in 6 h. The remarkable performance of Ni‐HCF nanocubes is attributeto a higher ability to separate charge carriers and to a lower resistance toward charge transfer, as confirmed by the electrochemical characterization. These achievements highlight the possibility of combining the performance of earth‐abundant catalysts with a renewable energy source for environmental remediation, thus meeting the requirements for sustainable development.
Atomic Imaging of the Pb Precipitation in Lead‐Halide Perovskites
Authors: Liu Yusheng , Ma Mengmeng , Zhang Xuliang , Song Bin , Chen Xiao , Wei Fei , Yuan Jianyu , Shen Boyuan
Published: February 2024

The lead iodide (PbI2) in lead‐halide perovskite (LHP) is both a positive additive for material properties and a site for the formation of device defects. Therefore, atomic‐level detection of PbI2 and its derived Pb structures are crucial for understanding the performance and stability of the LHP material. In this work, the atomic imaging of the LHP, PbI2, and Pb lattices is achieved using low‐dose integrated differential phase contrast (iDPC) scanning transmission electron microscopy (STEM). Combining it with the traditional high‐angle annular dark field (HAADF)‐STEM, the Pb precipitation in different LHPs (CsPbI3, CsPbBr3, and FAPbI3) and under different conditions (light, air, and heat) can be investigated in real space. Then, the features of Pb precipitation (positions and sizes) are visually revealed under different conditions and the stabilities of different LHPs. Meanwhile, the pathway of Pb precipitation is directly imaged and confirmed by the iDPC‐STEM during an in situ heating process, supporting the detailed mechanism of Pb precipitation. These results provide the visual evidence for analyzing atomic Pb precipitation in LHPs, which helps better understand the structure‐property relation induced by Pb impurity.
Tetradentate Pt(II) Complexes with Bulky Carbazole Moieties for High‐Efficiency and Narrow‐Emitting Blue Organic Light‐Emitting Devices
Authors: Cheong Kiun , Han Seung Won , Lee Jun Yeob
Published: February 2024

Blue tetradentate Pt(II) complexes, Pt‐tBuCz and Pt‐dipCz, are synthesized by introducing carbazoles with bulky substituents for improving the rigidity and inhibiting intermolecular interactions of phosphorescent emitter. tert‐Butyl and 2,6‐diisopropylphenyl groups are substituted as the blocking groups at 3 position of the carbazole in Pt‐tBuCz and Pt‐dipCz, respectively. These new phosphorescent emitters exhibit a narrow full width at half maximum (FWHM) and a high horizontal emitting dipole orientation ratio. Pt‐dipCz demonstrates a small FWHM of 24 nm, a high emitting dipole orientation ratio of 81%, and a high photoluminescence quantum yield value of 94%. As a result, the Pt‐tBuCz and Pt‐dipCz devices exhibited external quantum efficiencies (EQEs) of 23.7% and 25.0% with small FWHMs of 25 and 22 nm, respectively. For the Pt‐dipCz device, the small FWHM and high EQE of >20% are maintained even at a doping concentration of 20 wt%. Furthermore, phosphor‐sensitized organic light‐emitting diodes fabricated using Pt‐dipCz as a sensitizer achieved a high EQE of 31.4% with an FWHM of 18 nm. This result indicates that the 2,6‐diisopropylphenyl group is a effective blocking group for Pt(II) complexes to develop highly efficient, color stable, doping concentration resistant, and efficiently sensitizing blue phosphors.
Effect of Substrate Material Properties on Microstructure and Mechanical Properties of Ni60 Coatings Prepared by Extreme High‐Speed Laser Cladding
Authors: Shen Xiao , Chen Lan , Wu Yue , Chen Chen , Zhang Xinzhou , Zhou Wangfan , Ren Xudong
Published: February 2024

Using extreme high‐speed laser cladding technology, Ni60 coatings are laser cladded onto stainless‐steel, 20# steel, and 45# steel substrates. The effect of substrate material properties on the cracking behavior, microstructure, and tribological properties of the Ni60 coating is systematically studied. The results show that as the difference of the coefficient of thermal expansion between the substrate and cladding material decreases, the tendency for crack generation in the cladding layer is reduced. In addition, the difference of the thermal physical properties of the substrate has an important effect on the temperature gradient during the cooling process of the coating, and then affects the growth rate of the grain in the coating and the overall mechanical properties of the coating. Finer grain size, fewer macroscopic coating cracks, and the evenly distributed hard phase in the Ni60 coating on the 20# steel substrate lead to better wear resistance.
Transformer oil‐based Casson ternary hybrid nanofluid flow configured by a porous rotating disk with hall current
Authors: Paul Ashish , Patgiri Bhagyashri , Sarma Neelav
Published: February 2024

The present work examines the 3D, incompressible, magnetohydrodynamic, mixed convective, and Darcy‐Forchheimer Casson /transformer oil ternary hybrid nanofluid flow configured by a porous rotatory disk. This research work takes into account the influences of hall current, thermophoresis, heat absorption/generation, Brownian motion, joule heating, chemical reaction, thermal radiation, activation energy, and velocity slip condition. The administrative partial differential equations (PDEs) that expound the problem are modified into a set of ordinary differential equations (ODEs) by imposing a similarity conversion, which is further solved numerically by adapting the worthy bvp4c scheme. The velocity, thermal, and mass profiles are delineated through graphs, and the features of skin friction coefficient, heat, and mass transmission are also explicated thoroughly via tables. One significant observation of this research is that the Casson parameter weakens transversal velocity whereas a reverse tendency is noticed against the radial velocity. Our obtained outputs affirm that Casson ternary hybrid nanofluid has respectively 10.93 % and 8.86% higher heat deliverance rate when compared to Casson nanofluid and Casson hybrid nanofluid. Besides, the Casson ternary hybrid nanofluid has respectively 33.68 % and 27.52% higher mass deliverance rate when compared to the Casson nanofluid and Casson hybrid nanofluid. Also, the sturdy values of the Casson parameter lessen the skin friction coefficient. The inferences derived from our research may advantageously be used in rotating types of machinery, medical equipment, gas turbine rotators, etc.
Emerging role of complement in COVID-19 and other respiratory virus diseases
Authors: Xiao Mark T. , Ellsworth Calder R. , Qin Xuebin
Published: February 2024

The complement system, a key component of innate immunity, provides the first line of defense against bacterial infection; however, the COVID-19 pandemic has revealed that it may also engender severe complications in the context of viral respiratory disease. Here, we review the mechanisms of complement activation and regulation and explore their roles in both protecting against infection and exacerbating disease. We discuss emerging evidence related to complement-targeted therapeutics in COVID-19 and compare the role of the complement in other respiratory viral diseases like influenza and respiratory syncytial virus. We review recent mechanistic studies and animal models that can be used for further investigation. Novel knockout studies are proposed to better understand the nuances of the activation of the complement system in respiratory viral diseases.
What makes full artificial agents morally different
Authors: Firt Erez
Published: February 2024

In the research field of machine ethics, we commonly categorize artificial moral agents into four types, with the most advanced referred to as a full ethical agent, or sometimes a full-blown Artificial Moral Agent (AMA). This type has three main characteristics: autonomy, moral understanding and a certain level of consciousness, including intentional mental states, moral emotions such as compassion, the ability to praise and condemn, and a conscience. This paper aims to discuss various aspects of full-blown AMAs and presents the following argument: the creation of full-blown artificial moral agents, endowed with intentional mental states and moral emotions, and trained to align with human values, does not, by itself, guarantee that these systems will have human morality. Therefore, it is questionable whether they will be inclined to honor and follow what they perceive as incorrect moral values. we do not intend to claim that there is such a thing as a universally shared human morality, only that as there are different human communities holding different sets of moral values, the moral systems or values of the discussed artificial agents would be different from those held by human communities, for reasons we discuss in the paper.
Demonstrating the reliability of in vivo metabolomics based chemical grouping: towards best practice
Authors: Viant Mark R. , Amstalden E. , Athersuch T. , Bouhifd M. , Camuzeaux S. , Crizer D. M. , Driemert P. , Ebbels T. , Ekman D. , Flick B. , Giri V. , Gómez-Romero M. , Haake V. , Herold M. , Kende A. , Lai F. , Leonards P. E. G. , Lim P. P. , Lloyd G. R. , Mosley J. , Namini C. , Rice J. R. , Romano S. , Sands C. , Smith M. J. , Sobanski T. , Southam A. D. , Swindale L. , van Ravenzwaay B. , Walk T. , Weber R. J. M. , Zickgraf F. M. , Kamp H.
Published: February 2024

While grouping/read-across is widely used to fill data gaps, chemical registration dossiers are often rejected due to weak category justifications based on structural similarity only. Metabolomics provides a route to robust chemical categories via evidence of shared molecular effects across source and target substances. To gain international acceptance, this approach must demonstrate high reliability, and best-practice guidance is required. The MetAbolomics ring Trial for CHemical groupING (MATCHING), comprising six industrial, government and academic ring-trial partners, evaluated inter-laboratory reproducibility and worked towards best-practice. An independent team selected eight substances (WY-14643, 4-chloro-3-nitroaniline, 17α-methyl-testosterone, trenbolone, aniline, dichlorprop-p, 2-chloroaniline, fenofibrate); ring-trial partners were blinded to their identities and modes-of-action. Plasma samples were derived from 28-day rat tests (two doses per substance), aliquoted, and distributed to partners. Each partner applied their preferred liquid chromatography–mass spectrometry (LC–MS) metabolomics workflows to acquire, process, quality assess, statistically analyze and report their grouping results to the European Chemicals Agency, to ensure the blinding conditions of the ring trial. Five of six partners, whose metabolomics datasets passed quality control, correctly identified the grouping of eight test substances into three categories, for both male and female rats. Strikingly, this was achieved even though a range of metabolomics approaches were used. Through assessing intrastudy quality-control samples, the sixth partner observed high technical variation and was unable to group the substances. By comparing workflows, we conclude that some heterogeneity in metabolomics methods isnotdetrimental to consistent grouping, and that assessing data quality prior to grouping is essential. We recommend development of international guidance for quality-control acceptance criteria. This study demonstrates the reliability of metabolomics for chemical grouping and works towards best-practice.
Identification of key neuronal mechanisms triggered by dimethyl fumarate in SH-SY5Y human neuroblastoma cells through a metabolomic approach
Authors: Araújo Ana Margarida , Marques Sandra I. , Guedes de Pinho Paula , Carmo Helena , Carvalho Félix , Silva João Pedro
Published: February 2024

Dimethyl fumarate (DMF) is an old drug used for psoriasis treatment that has recently been repurposed to treat relapse–remitting multiple sclerosis, mostly due to its neuro- and immunomodulatory actions. However, mining of a pharmacovigilance database recently ranked DMF as the second pharmaceutical most associated with cognitive adverse events. To our best knowledge, the signaling mechanisms underlying its therapeutic and neurotoxic outcomes remain mostly undisclosed. This work thus represents the first-hand assessment of DMF-induced metabolic changes in undifferentiated SH-SY5Y human neuroblastoma cells, through an untargeted metabolomic approach using gas chromatography–mass spectrometry (GC–MS). The endometabolome was analyzed following 24 h and 96 h of exposure to two pharmacologically relevant DMF concentrations (0.1 and 10 μM). None of these conditions significantly reduced metabolic activity (MTT reduction assay). Our data showed that 24 h-exposure to DMF at both concentrations tested mainly affected metabolic pathways involved in mitochondrial activity (e.g., citric acid cycle, de novo triacylglycerol biosynthesis), and the synthesis of catecholamines and serotonin by changing the levels of their respective precursors, namely phenylalanine (0.68-fold decrease for 10 μM DMF vs vehicle), and tryptophan (1.36-fold increase for 0.1 μM DMF vs vehicle). Interestingly, taurine, whose levels can be modulated via Nrf2 signaling (DMF’s primary target), emerged as a key mediator of DMF’s neuronal action, displaying a 3.86-fold increase and 0.27-fold decrease for 10 μM DMF at 24 h and 96 h, respectively. A 96 h-exposure to DMF seemed to mainly trigger pathways associated with glucose production (e.g., gluconeogenesis, glucose-alanine cycle, malate-aspartate shuttle), possibly related to the metabolism of DMF into monomethyl fumarate and its further conversion into glucose via activation of the citric acid cycle. Overall, our data contribute to improving the understanding of the events associated with neuronal exposure to DMF.