bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Chemistry of a Halogenated Borazine: From Supramolecular Assemblies to a Random Covalent BN‐Substituted Carbon Network
Authors: Sena Tömekce Birce , Cuxart Marc G. , Caputo Laura , Poletto Daniele , Charlier Jean‐Christophe , Bonifazi Davide , Auwärter Willi 
Published: September 2024

AbstractThe on‐surface synthesis strategy has emerged as a promising route for fabricating well‐defined two‐dimensional (2D) BN‐substituted carbon nanomaterials with tunable electronic properties. This approach relies on specially designed precursors and requires a thorough understanding of the on‐surface reaction pathways. It promises precise structural control at the atomic scale, thus complementing chemical vapor deposition (CVD). In this study, we investigated a novel heteroatomic precursor, tetrabromoborazine, which incorporates a BN core and an OH group, on Ag(111) using low temperature scanning tunnelling microscopy/spectroscopy (LT‐STM/STS) and X‐ray photoelectron spectroscopy (XPS). Through sequential temperature‐induced reactions involving dehalogenation and dehydrogenation, distinct tetrabromoborazine derivatives were produced as reaction intermediates, leading to the formation of specific self‐assemblies. Notably, the resulting intricate supramolecular structures include a chiral kagomé lattice composed of molecular dimers exhibiting a unique electronic signature. The final product obtained was a random covalent carbon network with BN‐substitution and embedded oxygen heteroatoms. Our study offers valuable insights into the significance of the structure and functionalization of BN precursors in temperature‐induced on‐surface reactions, which can help future rational precursor design. Additionally, it introduces complex surface architectures that offer a high areal density of borazine cores.
Anchoring Pt Single‐Atom Sites on Vacancies of MgO(Al) Nanosheets as Bifunctional Catalysts to Accelerate Hydrogenation‐Cyclization Cascade Reactions
Authors: Xie Deqiong , Xue Ruifang , Dou Kecan , Song Yaping , Fu Yanghe , Zhang Fumin , Chen De‐Li , Zhu Weidong 
Published: September 2024

AbstractThe direct hydrogenation of 2‐nitroacylbenzene to 2,1‐benzisoxazole presents a significant challenge in the pharmaceutical and fine chemicals industries. In this study, a defect engineering strategy is employed to create bifunctional single‐atom catalysts (SACs) by anchoring Pt single atoms onto metal vacancies within MgO(Al) nanosheets. The resultant Pt1/MgO(Al) SAC displays an exceptional catalytic activity and selectivity in the hydrogenation‐cyclization of 2‐nitroacylbenzene, achieving a 97.5 % yield at complete conversion and a record‐breaking turnover frequency of 458.8 h−1 under the mild conditions. The synergistic catalysis between the fully exposed single‐atom Pt sites within a unique Pt‐O−Mg/Al moiety and the abundant basic sites of the MgO(Al) support is responsible for this outstanding catalytic performance. The current work, therefore, paves the way for developing bifunctional or multifunctional SACs that can enhance efficient organocatalytic conversions.
Highly Twisted Fenestrindane‐Based Porous Nanographenes
Authors: Sun Xiao‐Qing , Li Yuke , Kuck Dietmar , Chow Hak‐Fun 
Published: September 2024

AbstractTwo fenestrindane‐based porous nanographenes containing four polyaromatic macrocycles in a highly twisted, basically S4–symmetric conformation were synthesized and characterized by NMR spectroscopy and mass spectrometry. Stepwise π‐extension at the periphery of the fenestrindane core by a sequence of eightfold Suzuki‐Miyaura cross‐coupling, fourfold Scholl cyclodehydrogenation and another eightfold Suzuki‐Miyaura reaction affords the porous nanographene precursors in good yields. In the last step, fourfold intramolecular Yamamoto coupling generates the porous nanographenes in 17‐18 %‐yield. Their optical and electronic properties were studied by UV/Vis and fluorescence spectroscopy and cyclic voltammetry. DFT calculations revealed structural details of the macrocycles. The surprisingly weak binding of these porous structures with chloride ions (K≈10 M−1) is attributed to their highly twisted conformation. The title compounds represent the first porous nanographenes based on the [5.5.5.5]fenestrane motif and, at the same time, they consist of a fenestrane‐like polyarylene network.
Molecular Aggregation to and from Disaggregation of an Organic Emitter for Strategic Emission Modulation
Authors: Paul Provakar , Samanta Saikat , Chatterjee Arunavo , Mondal Bibhas , Kanti Roy Ujjal , Majumdar Tapas , Mallick Arabinda 
Published: September 2024

Abstract“Aggregation‐caused fluorescence quenching” is a well‐established phenomenon by now. The procedure from aggregation to disaggregation usually causes a revival of emission signals, and thus affords an interesting new path to design “turn‐on” optical probes. For this purpose, the photophysics, energetics and dynamics of supra‐molecular encapsulation induced disaggregation of a self‐assembled bis‐indole derivative, 3,3’‐bisindolyl(phenyl)methane (BIPM), and its further reaggregation are reported herein. Compared to disaggregation strategies, its reverse process, reaggregation, has received much less attention so far. The gamma‐cyclodextrin (γ‐CD) molecules were found to be effective in disaggregating the BIPM associations and emission enhancement, whereas, the incorporation of guanidine hydrochloride (Gnd‐HCl) into the aqueous solution of disaggregated BIPM monomers in γ‐CD environment resulted in probe reaggregation leading to quenching of the restored emission. Here, γ‐CD and Gnd‐HCl can be considered as the molecular modulators of BIPM fluorescence based on the disaggregation–reaggregation mechanisms. The spectroscopic and thermodynamic findings associated with the disaggregation‐reaggregation processes might be insightful in reversible controlling of molecular aggregation and the associated optical properties for diverse applications.
Ruthenium Clusters Modification Carbon Layer‐Encapsulated NiCoP Nanoneedles as Advanced Electrocatalyst for Efficient Seawater Splitting Application
Authors: Liu Zhiwei , Ning Xueer , Hao Aize , Khan Muhammad Farooq , Rehman Shania 
Published: September 2024

AbstractDeveloping efficient and durable electrocatalyst for seawater splitting is crucial in hydrogen production. Herein, a multi‐scale design strategy was employed to fabricate ruthenium clusters modification carbon layer‐encapsulated nickel‐cobalt‐phosphorus (Ru/C/NiCoP) nanoneedles electrocatalyst supported on nickel foam (NF). We demonstrated that Ru/C/NiCoP/NF exhibited exceptional oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performances, with low overpotential, Tafel slope and superior stability. Furthermore, the electrocatalytic mechanism of Ru/C/NiCoP was elucidated through the combination of ex‐situ and in‐situ characterizations, along with comprehensive electrochemical tests. Strikingly, Ru clusters and the NiCoP with carbon layer engendered robust electronic interaction reaction, accelerated the charge transfer rate, provided more active sites, and enhanced intrinsic catalytic activity, thus substantially promoting the OER kinetics and HER reaction steps as well as stability. In addition, the two‐electrode system constructed with Ru/C/NiCoP/NF achieved current density of 10 mA cm−2 in both pure water and seawater at ultra‐low potential of 1.46/1.47 V, with Faraday efficiency close to 100 %. Even at higher current density of 100 mA cm−2, the required driving voltage remained low at 1.75/1.77 V, maintaining stable operation for 150 h, outperforming most reported non‐noble catalysts. This innovative strategy provides facile and versatile approach for developing advanced electrocatalysts in seawater electrolysis application.
High Young′s Modulus LixTiO2 Layer Suppressing the Pulverization and Deactivation of Lithiophilic Ag Nanoparticles
Authors: Dai Wangqi , Lu Jia , Wang Yuke , Cheng Xinyu , Yu Le , Wang Chungeng , Fu Zhengwen 
Published: September 2024

AbstractAnode‐free Lithium metal batteries, with their high energy density (>500 Wh/kg), are emerging as a promising solution for high‐energy‐density rechargeable batteries. However, the Coulombic Efficiency and capacity often decline due to interface side reactions. To address this, a lithiophilic layer is introduced, promoting stable and uniform Li deposition. Despite its effectiveness, this layer often undergoes electrochemical deactivation over time. This work investigates lithiophilic silver (Ag), prepared via magnetron sputtering on a copper (Cu) current collector. Finite element simulations identify stress changes from alloying reactions as a key cause of Ag particle pulverization and deactivation. A high Young′s modulus coating layer is proposed to mitigate this. The Ag2TiO3@Ag@TiO2@Cu composite electrode, designed with multi‐layer structures, demonstrates a slower deactivation process through galvanostatic electrochemical cycling. Characterization methods such as SEM, AFM, and TEM confirm the suppression of Ag particle pulverization, while uncoated Ag fractures and deactivates. This work uncovers a potential failure mechanism of lithiophilic metallic nanoparticles and proposes a strategy for deactivation suppression using an artificial coating layer.
Implementation of Electromagnetic Theory: Improved Analysis and Design for Class F Power Amplifier
Authors: Rahaman Syed Enamur , Dwari Santanu , Mandal Mirnal Kanti 
Published: September 2024

ABSTRACTThe general electromagnetic (EM) theory has not yet been applied to the analysis of Class F (CF) power amplifier (PA). In this paper, an alternative approach for CF PA is presented based on the EM theory. Theoretical analysis shows that the CF PA can be divided into two broad categories, forward voltage gain, and reflected voltage gain PA. The existing CF PA belongs to the reflected voltage gain PA. Even though both the CF PAs have the same voltage gain, the PA with forward voltage gain provides higher fundamental power Ps,1@F and drain efficiency PAE@F than that CF PA with reflected voltage gain and Class B PA. This important conclusion is obtained as a result of this analysis, which cannot be explained by available theory in the literature. The theoretical analysis is validated at 2.2 GHz by fabrication and measurements. According to the results, Ps,1@B = 31.8 dBm and PAE@B = 53.27% in Class B PA. In CF PA with reflected voltage gain, Ps,1@F = 30.20 dBm and PAE@F = 48.6%. Both cases have lower power and PAE as compared to new category of CF PA. This new CF PA with forward voltage gain has, Ps,1@F = 33.04 dBm and PAE@F = 63.7%.
Design and Control of DVR Based on Adaptive Bateman Polynomial for Power Quality Improvement
Authors: Rai Kanchan Bala , Kumar Narendra , Singh Alka 
Published: September 2024

ABSTRACTPower quality issues encompass a spectrum of disturbances that affect the stability and reliability of the power supply. This study explores voltage‐related anomalies, including sags, surges, flickers, unbalances, harmonics, interruptions, and swells, examining their origins, characteristics, and repercussions. These issues arise from a myriad of sources, such as load fluctuations, equipment malfunctions, and grid dynamics. The ramifications of these disturbances extend to equipment malfunctions, reduced operational efficiency, and financial losses. Dynamic voltage restorer (DVRs) are series custom power devices for mitigating these voltage‐related anomalies and use real‐time monitoring and control to quickly inject exact voltages into the grid during disruptions, restoring voltage levels to acceptable levels. This study demonstrates the capacity of DVRs to successfully alleviate power quality concerns, hence improving equipment dependability and system stability by analyzing case studies and simulation findings. The control system used to supply switching signals to the voltage source converter (VSC) of the DVR is based on adaptive Bateman polynomial (ABMP). Traditional DVR control techniques often rely on fixed or linear control strategies, which may not adequately handle varying load conditions and disturbances. ABMP offers an adaptive approach where the control parameters can adjust dynamically based on real‐time system conditions. This adaptive capability enhances the accuracy of voltage restoration, ensuring that the DVR responds optimally to varying loads and disturbances. During voltage sag and swell conditions at the grid side, the VSC injects the compensating voltage in series with the feeder with a constant switching frequency. A battery energy‐supported system (BESS) based DVR is considered for the proposed system. The supply is connected to the critical and sensitive loads. The proposed control scheme is validated through extensive simulation and experimental results.
Coordination Behaviors Between Aryl Diamide Amine Ligands and Trivalent Lanthanides: A Spectroscopic and Structural Study
Authors: Fang Dong , Gao Fengxin , Yang Xiaofan , Miao YuJie , Xiao Chengliang 
Published: September 2024

AbstractInvestigating the complexation of organic ligands with trivalent lanthanides (Ln(III)) is crucial in various fields, particularly in the separation of actinides from lanthanides for spent fuel reprocessing. While alkyl diamide amine ligands have been extensively studied, aryl‐functionalized ligands are rarely reported. To understand the effect of substituents on the coordination mode of diamide amine ligands with Ln(III), two aryl‐substituted diamide amine ligands, 2,2′‐(p‐tolylazanediyl)bis(N‐ethyl‐N‐(p‐tolyl)acetamide) (L1) and 2,2′‐((2‐ethylhexyl)azanediyl)bis(N‐ethyl‐N‐(p‐tolyl)acetamide) (L2), were synthesized and systematically studied. 1H NMR titration showed that metal ion coordination affected the electron density of methylene groups near coordinating atoms more than that of aromatic rings, while fluorescence titration and single‐crystal analysis confirmed 1 : 1 ligand‐Ln(III) complexes. Compared to alkyl diamide amine ligands, aryl groups increased steric hindrance, enhancing torsional strain and preventing amine nitrogen from participating in complexation, leading to weaker coordination as only two carbonyl oxygen atoms coordinated with Ln(III) in a bidentate mode. This work provides insight into how substituents influence the complexation properties of diamide amine ligands with f‐elements, aiding in the design of new ligands with improved performance.
Clinical outcome of salvage surgery in patients with recurrent oral cavity cancer: A systematic review and meta‐analysis
Authors: Lee Oh‐Hyeong , Bang Jooin , Kim Geun‐Jeon , Sun Dong‐il , Kim Sang‐Yeon 
Published: September 2024

AbstractThis systematic review and meta‐analysis investigated the impact of salvage surgery on 5‐year overall survival (OS) and prognostic factors in recurrent oral cavity cancer (rOCC) patients. Relevant literature before May 2022 was reviewed, including retrospective cohort studies and observational studies comparing salvage surgery to other treatments. Risk‐of‐bias assessments were conducted using the Newcastle–Ottawa scale. Statistical and subgroup analyses assessed the impact of salvage surgery on 5‐year OS and prognostic factors. 3036 documents were initially retrieved, with 14 retrospective cohort studies (2069 participants) included. Meta‐analysis of 5‐year OS in salvage surgery patients yielded a rate of 43.0%. Subgroup analysis showed higher OS in Asians (49.9% vs. 36.9%, p = 0.003) and late‐relapse (63.8% vs. 30.0%, p = 0.004) groups. Prognostic factors revealed hazards associated with nodal recurrence, extranodal extension, and perineural invasion. Salvage surgery is a viable option for rOCC patients, showing favorable 5‐year OS outcomes. Low publication bias enhances study reliability, but its single‐arm design limits conclusions on salvage surgery superiority over other treatments.
Research on the mechanism of HOPX‐HDAC2 interaction inducing differentiation blockage in acute myeloid leukemia
Authors: He Fang , Tu Yan , Ni Lihong 
Published: September 2024

AbstractHomeodomain‐only protein homeobox (HOPX) mainly exerts its transcriptional repression by physically sequestering the serum co‐repressor and recruiting histone deacetylase (HDAC), possessing important potential as a prognostic gene in acute myeloid leukemia (AML). HDACs play crucial roles in cell growth, gene regulation, and metabolism, and they are also important factors in promoting AML progression. Therefore, this project attempts to investigate whether HOPX affects AML progression by interacting with HDAC2 protein. Bioinformatics analysis was employed to identify potential prognostic genes in AML. Flow cytometry and MTT assays were performed to analyze the cellular biological functions of the AML prognostic marker HOPX. The interaction network of HOPX was analyzed using the Search Tool for the Retrieval of Interacting Genes database, and the interaction between HOPX and HDAC2 was observed using endogenous and exogenous immunoprecipitation. HOPX is highly expressed in AML cells. Further research uncovered that low expression of HOPX can repress the proliferation activity, anti‐apoptotic ability, and differentiation blockage of AML cells. Moreover, mechanistically, HOPX induced AML differentiation blockage and malignant progression through interaction with HDAC. HOPX can serve as a prognostic marker for AML and can interact with HDAC2 to induce AML differentiation blockage and malignant progression.
A Proposal for Model‐Based Systems Engineering Method for Creating Secure Cyber‐Physical Systems
Authors: Larsen Martin Haug , Kokkula Satyanarayana , Muller Gerrit 
Published: September 2024

AbstractRising levels of risk as cyber‐attackers look to exploit system vulnerabilities threatens the Air Traffic Control industry. Attacks on Air Navigation Service Providers' communications systems may lead to airspace closure and even cause safety issues. This paper presents a novel Model‐Based Systems Engineering method that enables systems engineers, in collaboration with system security and software engineers, to perform threat‐modeling analysis of cyber‐physical systems early in the system development process and incorporate mitigation strategies into the system design. The proposed model‐based method covers few security concepts, including misuse cases, system assets, threats, risks, vulnerabilities, and security control identification. The study found that the proposed method is suitable for conducting security analysis for complex cyber‐physical systems early in the system development process.
Modeling Cybersecurity Operations to Improve Resilience
Authors: Taylor Ivan W. , Willett Keith D. 
Published: September 2024

AbstractIn this paper, we explore the concept of operational resilience of a network or system of computer systems, focusing on the processes of a cybersecurity team within the multi‐disciplinary network security operations center. The computer system under examination has faced a cyber‐attack that has reduced its capability. The organization's reputation is damaged temporarily but can be restored if the network security operations center can quickly restore the organization's ability to produce desired results. After a cyber‐attack, we examine the processes for restoring the system's capability to its original level. These processes will happen sequentially and require close coordination of the cybersecurity team members. We examine a balanced and adaptive assignment policy within the cybersecurity organization to the various processes, showing how these policies can impact the speed with which the system's capability can be restored. Our findings reveal that the adaptive assignment policy among the team members can increase the system restoration rate even though recovering the complete capability of the system may be the same.
Enabling FuSE Security Objectives by Leveraging Cyber Survivability Methods
Authors: Papke Barry , Kratzke Ron , Span Martin (Trae) , Shevchenko Nataliya (Natasha) 
Published: September 2024

AbstractThe importance of system security continues to grow as systems become more complex, more connected, and more vulnerable. The INCOSE Vision 2035 sets goals for systems engineering (SE) as a discipline in enabling engineering solutions for a better world: “By 2035, cybersecurity will be as foundational a perspective in systems design as system performance and safety are today” (INCOSE, 2024). A key objective of the INCOSE Future of Systems Engineering (FuSE) Security Foundations Roadmap is to recognize system security as a fundamental part of the mission, integrated into the system architecture, and not “bolted‐on” as a separate subsystem or set of features in the detailed design. To achieve this, systems engineering must address system security early in the system lifecycle, during the mission analysis and concept development phase and ensure it is addressed as a functional requirement throughout the systems engineering lifecycle. System security needs must be treated as fundamental system capability.The INCOSE FuSE Security foundations roadmap identifies six (6) objectives and eleven (11) foundational concepts necessary to achieve the FuSE vision for system security (Dove, et al., 2021). Five of the objectives and five of the foundational concepts are directly related to systems acquisition and engineering lifecycle processes. The five key foundational concepts are: Stakeholder Alignment, Security as a Capability, Security as a Functional Requirement, Loss Driven Engineering and Modeled Trustworthiness.The Operational Test and Evaluation (OT&E) community has extensive cyber assessment and execution processes mandated through numerous Department of Defense (DoD) and individual service policies, directives and guidebooks. This paper studies several of the cybersecurity assessment and process guidebooks, analyzing the processes and methods to identify areas where systems engineering should be responsible, and which SE activities and outputs are needed to enable the requirements of each guidebook.This paper examines six OT&E cyber security guidebooks, and the methods and processes they describe to achieve system security in relation to the five foundation concepts. In addition to their test and evaluation processes, each describes systems engineering processes, activities and outputs that could be used to form the initial foundation of a system security technical process.While the original INCOSE vision statement uses the term “cybersecurity,” the FuSE Security initiative is adopting the term “system security” to emphasize that this is a system engineering responsibility as opposed to software engineering or information technology task. As a result, the analysis of the cybersecurity guidebooks will be in the context of “system security.”
Theoretical Underpinnings to Establish Fidelity Conditions for Defining Verification Models
Authors: Wach Paul , Salado Alejandro 
Published: September 2024

AbstractThe current state of the discipline suggests that the desired fidelity of verification models is defined based on qualitative statements, that is, using heuristics, at the onset of an engineering endeavor. While the use of heuristics in systems engineering is well known, many heuristics have not been validated, and therefore there may be errors in judgement that could lead to systems being engineered that are ultimately not fit‐for‐purpose. This bears the question, based on what conditions should we formally define verification models? In this article, we provide insights from our research to discover the sufficient conditions for defining verification models, taking a science‐based approach that leverages the richness of systems‐theoretic constructs.