bluuebunny/crossref_metadata_2025 huggingface dataset:
Superhydrophobic and Highly Flexible Artificial Solid Electrolyte Interphase Inspired by Lotus Effect Toward Highly Stable Zn Anode
Authors: Zhou Wanting , Chen Zetao , Zhao Shunshun , Chen Shimou
Published: August 2024

Due to their cost‐effectiveness, high safety, and environmental friendliness, aqueous zinc‐ion batteries (AZIBs) are among the most promising technologies for next‐generation energy storage systems. Nonetheless, dendrite growth, hydrogen evolution, and corrosion at zinc (Zn) anode severely hinder their practical application. In this study, a combination of molecular self‐assembly engineering, squeegee coating, and air spraying process is employed to create a superhydrophobic and highly flexible artificial solid‐electrolyte‐interface layer on Zn anode (denoted as SFM/Zn). Self‐assembled monolayer of triethoxy‐3‐aminopropylsilane optimizes Zn2+ migration kinetics. The superhydrophobic interface, formed by polydimethylsiloxane (PDMS) and trimethoxy(octadecyl)silane (OTS)‐modified nanosilicon dioxide particles, inhibits water‐related side reactions. Furthermore, the highly flexible PDMS serves as a dynamic adaptive interface for Zn anode, effectively alleviating the “tip effect”. Consequently, the SFM/Zn||SFM/Zn symmetrical cells enable reversible and stable Zn plating/stripping at both ultralow current density (0.2 mA cm−2) and ultrahigh current density (45 mA cm−2). The assembled Zn‐vanadium (SFM/Zn||NH4V4O10) cell deliver stable average Coulombic efficiency (nearly 100%) and ultralong cycling stability (135.5 mAh g−1 after 500 cycles at 5 A g−1 and 173.2 mAh g−1 after 1000 cycles at 2 A g−1). This innovative superhydrophobic three‐layered strategy sheds new light on designing highly durable Zn anode for high‐performance AZIBs.
Bi1‐CuCo2O4 Hollow Carbon Nanofibers Boosts NH3 Production from Electrocatalytic Nitrate Reduction
Authors: Lin Hexing , Wei Jinshan , Guo Ying , Li Yi , Lu Xihui , Zhou Chucheng , Liu Shaoqing , Li Ya‐yun
Published: August 2024

Ammonia, as a high‐energy‐density carrier for hydrogen storage, is in great demand worldwide. Electrocatalytic nitrate reduction reaction (NO3RR) provides a green NH3 production process. However, the complex reaction pathways for NO3RR to NH3 and the difficulty in controlling intermediate products limit the reduction process. Herein, by incorporating atomic‐level bismuth (Bi) into CuCo2O4 hollow carbon nanofibers, the catalytic activity of the electrocatalyst for NO3RR is enhanced. The maximum Faradaic efficiency of Bi1‐CuCo2O4 is 95.53%, with an NH3 yield of 448.74 µmol h−1 cm−2 at −0.8 V versus RHE. Density Functional Theory calculations show that the presence of Bi lowers the reaction barrier for the hydrogenation step from *NO2 to *NO2H, while promoting mass transfer on the release of *NH3 and the reactivation of surface‐active sites. Differential charge density calculations also show that after Bi doping, the charge supplied by the catalyst to NO3− increases from 0.62 to 0.72 e‐, thus reasoned for enhanced NO3RR activity. The established nitrate‐Zn battery shows an energy density of 2.81 mW cm−2, thus implying the potential application.
Direct Visualization of Defect‐Controlled Diffusion in van der Waals Gaps
Authors: Thomsen Joachim Dahl , Wang Yaxian , Flyvbjerg Henrik , Park Eugene , Watanabe Kenji , Taniguchi Takashi , Narang Prineha , Ross Frances M.
Published: August 2024

Diffusion processes govern fundamental phenomena such as phase transformations, doping, and intercalation in van der Waals (vdW) bonded materials. Here, the diffusion dynamics of W atoms by visualizing the motion of individual atoms at three different vdW interfaces: hexagonal boron nitride (BN)/vacuum, BN/BN, and BN/WSe2, by recording scanning transmission electron microscopy movies is quantified. Supported by density functional theory (DFT) calculations, it is inferred that in all cases diffusion is governed by intermittent trapping at electron beam‐generated defect sites. This leads to diffusion properties that depend strongly on the number of defects. These results suggest that diffusion and intercalation processes in vdW materials are highly tunable and sensitive to crystal quality. The demonstration of imaging, with high spatial and temporal resolution, of layers and individual atoms inside vdW heterostructures offers possibilities for direct visualization of diffusion and atomic interactions, as well as for experiments exploring atomic structures, their in situ modification, and electrical property measurements of active devices combined with atomic resolution imaging.
Enhancing the Electrical Conductivity and Long‐Term Stability of PEDOT:PSS Electrodes through Sequential Treatment with Nitric Acid and Cesium Chloride
Authors: Adilbekova Begimai , Scaccabarozzi Alberto D. , Faber Hendrik , Nugraha Mohamad Insan , Bruevich Vladimir , Kaltsas Dimitris , Naphade Dipti R. , Wehbe Nimer , Emwas Abdul‐Hamid , Alshareef Husam N. , Podzorov Vitaly , Martín Jaime , Tsetseris Leonidas , Anthopoulos Thomas D.
Published: August 2024

Solution‐processable poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is an important polymeric conductor used extensively in organic flexible, wearable, and stretchable optoelectronics. However, further enhancing its conductivity and long‐term stability while maintaining its superb mechanical properties remains challenging. Here, a novel post‐treatment approach to enhance the electrical properties and stability of sub‐20‐nm‐thin PEDOT:PSS films processed from solution is introduced. The approach involves a sequential post‐treatment with HNO3 and CsCl, resulting in a remarkable enhancement of the electrical conductivity of PEDOT:PSS films to over 5500 S cm−1, along with improved carrier mobility. The post‐treated films exhibit remarkable air stability, retaining over 85% of their initial conductivity even after 270 days of storage. Various characterization techniques, including X‐ray photoelectron spectroscopy, atomic force microscopy, Raman spectroscopy, Hall effect measurements, and grazing incidence wide angle X‐ray scattering, coupled with density functional theory calculations, provide insights into the structural changes and interactions responsible for these improvements. To demonstrate the potential for practical applications, the ultrathin PEDOT:PSS films are connected to an inorganic light‐emitting diode with a battery, showcasing their suitability as transparent electrodes. This work presents a promising approach for enhancing the electrical conductivity of PEDOT:PSS while offering a comprehensive understanding of the underlying mechanisms that can guide further advances.
Intrinsic Out‐Of‐Plane and In‐Plane Ferroelectricity in 2D AgCrS2 with High Curie Temperature
Authors: Xing Jiabao , Tang Yue , Li Jiaxin , Wu Changwei , Gu Yiru , Li Xiaobo , Zhang Hu , Zhang Mingwen , Wang Xiao , Zhou Xing , Gan Xuetao , Wu Di , Zeng Jinghui , Zhai Tianyou , Xu Hua
Published: August 2024

2D ferroelectric materials have attracted extensive research interest due to potential applications in nonvolatile memory, nanoelectronics and optoelectronics. However, the available 2D ferroelectric materials are scarce and most of them are limited by the uncontrollable preparation. Herein, a novel 2D ferroelectric material AgCrS2 is reported that are controllably synthesized in large‐scale via salt‐assist chemical vapor deposition growth. By tuning the growth temperature from 800 to 900 °C, the thickness of AgCrS2 nanosheets can be precisely modulated from 2.1 to 40 nm. Structural and nonlinear optical characterizations demonstrate that AgCrS2 nanosheet crystallizes in a non‐centrosymmetric structure with high crystallinity and remarkable air stability. As a result, AgCrS2 of various thicknesses display robust ferroelectric polarization in both in‐plane (IP) and out‐of‐plane (OOP) directions with strong intercorrelation and high ferroelectric phase transition temperature (682 K). Theoretical calculations suggest that the ferroelectricity in AgCrS2 originates from the displacement of Ag atoms in AgS4 tetrahedrons, which changes the dipole moment alignment. Moreover, ferroelectric switching is demonstrated in both lateral and vertical AgCrS2 devices, which exhibit exotic nonvolatile memory behavior with distinct high and low resistance states. This study expands the scope of 2D ferroelectric materials and facilitates the ferroelectric‐based nonvolatile memory applications.
Microwave Investigation of DMSO‐Doped PEDOT:PSS Patch Resonators Under Varying Relative Humidity
Authors: Dordanihaghighi Marzieh , Arjmand Mohammad , Zarifi Mohammad H.
Published: August 2024

Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a conductive polymer widely used in various microwave sensing components. Enhancing the efficiency of PEDOT:PSS‐based microwave structures relies on improving the polymer's conductivity, achievable by adding secondary solvents such as dimethyl sulfoxide (DMSO), which significantly boosts the electrical conductivity. However, the performance of DMSO‐doped PEDOT:PSS films in microwave regime requires investigations. Herein, patch resonators are fabricated using solution processing of aqueous dispersion of PEDOT:PSS doped with varying concentrations of DMSO from 0 to 8 wt.% to investigate their microwave behavior within the frequency range of 4.5–6.5 GHz. The PEDOT:PSS patch structures are implemented on a glass substrate and their resonant characteristics, including resonant frequency and amplitude, are studied in response to varying relative humidity (RH) levels ranging from 0% to 70%. The significant variations in the microwave responses are observed at the resonant amplitude, confirming the main impact of humidity on the conductivity of the films. According to the measured results, the 2 wt.% doped patch shows greater sensitivity to the changes to the RH in contrast to the 8 wt.% doped patches, where the response shows less sensitivity to the humidity variation. The results indicate that a lower percentage of DMSO enhances sensitivity to the humidity at the cost of increased electromagnetic loss in the resonant patch structures for humidity sensing applications.
Pulsed‐Laser Deposition of Ge‐Doped BiTe Nanofilms and Their Application in Room‐Temperature Long‐Wave Infrared Photodetection
Authors: Wang Wan , Wang Ximiao , Yao Jiandong , Chen Huanjun , Yang Guowei
Published: August 2024

Long‐wave infrared photodetectors play an indispensable role in a variety of fields such as science, technology, engineering, and medicine. However, to date, most conventional long‐wave infrared photodetectors need to be operated under low temperature to meet the performance requirements. This can lead to a series of problems such as large device volume and high operating cost. Therefore, it is urgent to explore novel long‐wave photosensitive materials. In recent years, the development of nanotechnology has opened a new door for long‐wave infrared photodetection. Herein, pulsed‐laser deposition is successfully applied to the preparation of Ge‐doped BiTe (GBT) thin films. Importantly, the corresponding GBT photodetector exhibits excellent long‐wave infrared photosensitivity. Specifically, upon 10.5 µm illumination, the responsivity, external quantum efficiency, and detectivity reach 1.41 mA W−1, 0.017%, and 1.96 × 106 Jones, respectively. Moreover, a fast response rate with the rise/decay time down to 42.5/41.1 µs is realized. On this basis, the GBT photodetector is used as the receiving unit for optical signals to achieve proof‐of‐concept long‐wave optical information transmission application. On the whole, this study provides a new material platform for long‐wave optoelectronic sensing.
Tailoring Co‐Free LiNi0.5Mn1.5O4 Material for High‐Voltage Lithium‐Ion Batteries: Particle Design & Grain Boundary Engineering
Authors: Nisar Umair , Reichel Benedikt , Mundszinger Manuel , Wohlfahrt‐Mehrens Margret , Hölzle Markus , Axmann Peter
Published: August 2024

Cobalt‐free LiNi0.5Mn1.5O4 (LNMO) is a promising cathode material for high‐energy and power‐density lithium‐ion batteries (LIBs). However, its commercial adoption is hindered by rapid capacity degradation due to the unstable LNMO/electrolyte interface caused by LNMO's high operating voltage. Structural degradation from Jahn–Teller distortion and metal‐ion dissolution also contributes to poor cycling stability. Additionally, producing industrial‐grade LNMO with high tap density, low surface area and reduced metal‐ion dissolution is challenging. This study addresses these challenges through a rational material design approach, synthesizing LNMO with large spherical secondary particles (>14.0 µm) and high tap density (>2.0 g cm−3). The primary particles (1.5–6.0 µm) exhibit a truncated‐octahedral shaped morphology that predominantly exposes (111) surface facets, with fewer (100) surfaces, stabilizing the LNMO/electrolyte interface, reducing metal dissolution, and enhancing lithium‐ion kinetics. Silicon infusion into grain boundaries further improves structural integrity by forming a silicon‐rich phase. The tailored LNMO demonstrates exceptional rate capability, cycling stability, and improved interfacial kinetics, significantly advancing the potential for cobalt‐free LNMO in high‐voltage LIBs. This work highlights the importance of tailored cathode material design for achieving the performance and stability required for emerging high‐voltage LIBs applications.
Tailoring the Electrode‐Electrolyte Interface for Reliable Operation of All‐Climate 4.8 V Li||NCM811 Batteries
Authors: Yang Wujie , Zhang Zhenjie , Sun Xinyi , Liu Yiwen , Sheng Chuanchao , Chen Aoyuan , He Ping , Zhou Haoshen
Published: August 2024

Combining high‐voltage nickel‐rich cathodes with lithium metal anodes is among the most promising approaches for achieving high‐energy‐density lithium batteries. However, most current electrolytes fail to simultaneously satisfy the compatibility requirements for the lithium metal anode and the tolerance for the ultra‐high voltage NCM811 cathode. Here, we have designed an ultra‐oxidation‐resistant electrolyte by meticulously adjusting the composition of fluorinated carbonates. Our study reveals that a solid‐electrolyte interphase (SEI) rich in LiF and Li2O is constructed on the lithium anode through the synergistic decomposition of the fluorinated solvents and PF6− anion, facilitating smooth lithium metal deposition. The superior oxidation resistance of our electrolyte enables the Li||NCM811 cell to deliver a capacity retention of 80 % after 300 cycles at an ultrahigh cut–off voltage of 4.8 V. Additionally, a pioneering 4.8 V‐class lithium metal pouch cell with an energy density of 462.2 Wh kg−1 stably cycles for 110 cycles under harsh conditions of high cathode loading (30 mg cm−2), low N/P ratio (1.18), and lean electrolytes (2.3 g Ah−1).
Preparation of thermally conductive polyimide/aluminum oxide/boehmite composite separators for enhancing lithium‐ion battery safety and performance
Authors: Haolin Dong , Cui Weiwei , Yunlong Huang , Xin Chen , Yubo Ding
Published: August 2024

This study endeavors to enhance the safety of lithium‐ion batteries (LIBs) by synthesizing a polyamide acid (PAA)/Al2O3 composite spinning solution using 4,4′‐diaminodiphenyl ether (ODA) and pyromellitic anhydride (PMDA) as monomers, and nano‐Al2O3 as a thermal conductivity filler. Subsequently, the PAA/Al2O3 fiber membrane is fabricated via electrostatic spinning, followed by gradient heating imidization to produce a polyimide (PI)/Al2O3 composite membrane. This membrane is then dipped into a boron nitride (BM) slurry to ultimately yield an organic–inorganic PI/Al2O3/BM composite separator with superior flame‐retardant and thermal conductivity properties. The thermal stability, flame retardancy, electrolyte wettability, mechanical integrity, and cycle rate performance of the composite membranes are rigorously evaluated. The results demonstrate that the PI/5% Al2O3/BM composite membrane exhibits the most favorable overall performance, with no shrinkage observed at 200°C and no significant changes after sustained ignition for 10 s. The incorporation of the thermal conductivity Al2O3 filler significantly enhances the heat transfer properties of the composite separator. The room temperature ionic conductivity reaches 2.786 mS cm−1 after electrolyte absorption, and the initial discharge capacity of the assembled battery is 156.28 mAhg−1. Following 100 charge/discharge cycles at 0.2C, the capacity retention rate is 97.7%, and at a discharge rate of 5C, the capacity retention rate is 74.9%.
Synergistically enhanced dielectric properties and thermal conductivity in percolating flaky copper/poly(vinylidene fluoride) nanocomposites via engineering magnesium oxide as a buffer interlayer
Authors: Chen Xiaolong , Zhou Wenying , Meng Xingxing , Lv Yajuan , Kong Fanrong , Lin Na , Zheng Jian , Han Caian
Published: August 2024

High dielectric constant (ε), thermal conductivity (TC), and breakdown strength (Eb) along with low loss flexible polymeric nanocomposites display multifunctional applications. In this work, to synergistically bolster the TC and Eb while restraining dielectric loss and leakage current in the percolating flaky copper (f‐Cu)/poly(vinylidene fluoride) (PVDF), presenting a giant ε, the core@shell structured f‐Cu@MgO (magnesium oxide) nanosheets were first created via a chemical precipitation method, then incorporated into host PVDF to explore the MgO shell’ impact on the TC and dielectric properties of the resulting nanocomposites. The introduced MgO interlayer strengthens the interfacial interactions and significantly mitigates the interfacial mismatch in both ε and conductivity between the f‐Cu and PVDF, resulting in elevated TC and Eb of the f‐Cu@MgO/PVDF in comparison to pristine f‐Cu/PVDF. Furthermore, the insulating MgO interlayer introduces deep traps and inhibits the long‐distance migration of electrons, leading to remarkably suppressed dielectric loss. More importantly, the TC and dielectric properties of nanocomposites can be optimized by tuning the MgO thickness. The fitting results via the Havriliak‐Negami equation theoretically support the MgO shell's suppression effect on charge migration and reveal the underlying polarization mechanism in the nanocomposites. The developed nanocomposites with currently high ε, Eb and TC but low loss, present promising applications in electrical power systems.
Toward durable polylactic acid/poly(methyl methacrylate) polyblend fibers with high performance
Authors: Zhang Huixian , Sun Tonghui , Xiao Min , Bai Hongwei
Published: August 2024

Polylactic acid/poly(methyl methacrylate) (PLA/PMMA) composite fibers with high performance were fabricated using melt spinning technique. The crystallization, lamellae orientation and physical properties of composite fibers were investigated systematically. The addition of PMMA (0–20 wt%) has improved the hydrolysis resistance of composite fibers by preventing water molecules from penetrating and diffusing through the fibers, but the strength and heat resistance were reduced at the same time. The stereocomplex crystallites (SC) formed before spinning by introducing poly(D‐lactide) (PDLA) (3 wt%) in poly(L‐lactide) (PLLA) matrix and acted as nucleating agents to enhanced the crystallization and lamellae orientation of PLLA matrix, which improved the physical properties of PLA composite fibers resultful. The tensile strength of PLA fibers with 3 wt% PDLA and 5 wt% PMMA was increased 31% as well as the boiling water shrinkage and the hydrolysis rate were decreased 30% and 33% in relation to PLLA fibers. Finally, the hydrolysis resistance was further enhanced on the basis of realizing high strength and heat resistance, which is of great significance for preparing durable PLA fiber materials and expanding their application.
A New Mixture Model With Cure Rate Applied to Breast Cancer Data
Authors: Gallardo Diego I. , Brandão Márcia , Leão Jeremias , Bourguignon Marcelo , Calsavara Vinicius
Published: August 2024

We introduce a new modelling for long‐term survival models, assuming that the number of competing causes follows a mixture of Poisson and the Birnbaum‐Saunders distribution. In this context, we present some statistical properties of our model and demonstrate that the promotion time model emerges as a limiting case. We delve into detailed discussions of specific models within this class. Notably, we examine the expected number of competing causes, which depends on covariates. This allows for direct modeling of the cure rate as a function of covariates. We present an Expectation‐Maximization (EM) algorithm for parameter estimation, to discuss the estimation via maximum likelihood (ML) and provide insights into parameter inference for this model. Additionally, we outline sufficient conditions for ensuring the consistency and asymptotic normal distribution of ML estimators. To evaluate the performance of our estimation method, we conduct a Monte Carlo simulation to provide asymptotic properties and a power study of LR test by contrasting our methodology against the promotion time model. To demonstrate the practical applicability of our model, we apply it to a real medical dataset from a population‐based study of incidence of breast cancer in São Paulo, Brazil. Our results illustrate that the proposed model can outperform traditional approaches in terms of model fitting, highlighting its potential utility in real‐world scenarios.
Exploring a facile preparation method for Co‐Ni/MoS2‐derived nanohybrid from wheat straw extract and its physicochemical properties
Authors: Himanshu Magan , Singh Anjali , Verma Bhawna , Pandey Saurabh Kumar , Syed Asad , Elgorban Abdallah M. , Wong Ling Shing , Mohammad Akbar , Srivastava Neha
Published: August 2024

This study presents a novel approach for the fabrication of a Co,Ni/MoS2‐derived nanohybrid material using wheat straw extract. The facile synthesis method involves a sol–gel process, followed by calcination, showcasing the potential of agricultural waste as a sustainable reducing and chelating reagent. The as‐prepared nanohybrid has been characterized using different techniques to analyse its physicochemical properties. X‐ray diffraction analysis confirmed the successful synthesis of the nanohybrid material, identifying the presence of NiMoO4, CoSO4 and Mo17O47 as its components. Fourier‐transform infrared spectroscopy differentiated the functional groups present in the wheat straw biomass and those in the nanohybrid material, highlighting the formation of metal–oxide and sulphide bonds. Scanning electron microscopy revealed a heterogeneous morphology with agglomerated structures and a grain size of around 70 nm in the nanohybrid. Energy‐dispersive X‐ray spectroscopy analysis shows the composition of elements with weight percentages of (Mo) 9.17%, (S) 6.21%, (Co) 12.48%, (Ni) 12.18% and (O) 50.46% contributing to its composition. Electrochemical analysis performed through cyclic voltammetry showcased the exceptional performance of the nanohybrid material as compared with MoS2, suggesting its possible applications for designing biosensors and related technologies. Thus, the research study presented herein underscores the efficient utilization of natural resources for the development of functional nanomaterials with promising applications in various fields. This study paves a way for manufacturing innovation along with advancement of novel synthesis method for sustainable nanomaterial for future technological developments.
Fostering firm value: Unpacking the effect of circular economy disclosure via social media
Authors: Petruzzella Felice , Giakoumelou Anastasia , L'Abate Vitiana , Raimo Nicola , Vitolla Filippo
Published: August 2024

Growing environmental concerns and the need to address global challenges such as climate change and resource exploitation have highlighted the relevance of the circular economy (CE) and the importance for companies to communicate circular practices externally. While academic literature has examined the dissemination of CE information, the effects of CE disclosure (CED) remain underexplored. This study aims to fill this gap by exploring, through signaling theory, the influence of CED via social media on firm value. The econometric analysis, based on 366 observations (an unbalanced panel of 133 internationally listed companies for the period 2019–2021), demonstrates that CED via Twitter serves as a powerful market signal, positively influencing investor perception and increasing firm value. This study enlarges the literature relating to the association between non‐financial disclosure and firm value, and the effects of CED. Furthermore, it extends the debate on the use of social media as disclosure tools and broadens the scope of signaling theory.
Dual Aliovalent Dopants Cu, Mn Engineered Eco‐Friendly QDs for Ultra‐Stable Anti‐Counterfeiting
Authors: Kokilavani S. , Selopal Gurpreet Singh , Jin Lei , Kumar Pawan , Barba David , Rosei Federico
Published: August 2024

Doping in semiconductor quantum dots (QDs) using optically active dopants tailors their optical, electronic, and magnetic properties beyond what is achieved by controlling size, shape, and composition. Herein, we synergistically modulated the optical properties of eco‐friendly ZnInSe2/ZnSe core/shell QDs by incorporating Cu‐doping and Mn‐alloying into their core and shell to investigate their use in anti‐counterfeiting and information encryption. The engineered “Cu:ZnInSe2/Mn:ZnSe” core/shell QDs exhibit an intense bright orange photoluminescence (PL) emission centered at 606 nm, with better color purity than the undoped and individually doped core/shell QDs. The average PL lifetime is significantly extended to 201 ns, making it relevant for complex encryption and anti‐counterfeiting. PL studies reveal that in Cu:ZnInSe2/Mn:ZnSe, the photophysical emission arises from the Cu state via radiative transition from the Mn 4T1 state. Integration of Cu:ZnInSe2/Mn:ZnSe core/shell QDs into poly(methyl methacrylate) (PMMA) serves as versatile smart concealed luminescent inks for both writing and printing patterns. The features of these printed patterns using Cu:ZnInSe2/Mn:ZnSe core/shell QDs persisted after 10 weeks of water‐soaking and retained 70 % of PL emission intensity at 170 °C, demonstrating excellent thermal stability. This work provides an efficient approach to enhance both the emission and the stability of eco‐friendly QDs via dopant engineering for fluorescence anti‐counterfeiting applications.
Carbon Dots as Bioactive Antifungal Nanomaterials
Authors: Sturabotti Elisa , Camilli Alessandro , Leonelli Francesca , Vetica Fabrizio
Published: August 2024

Nowadays, the widespread diffusion of infections caused by opportunistic fungi represents a demanding threat for global health security. This phenomenon has also worsened by the emergence of contagious events in hospitalisation environments and by the fact that many fungi have developed harsh and serious resistance mechanisms to the traditional antimycotic drugs. Hence, the design of novel antifungal agents is a key factor to counteract mycotic infections and resistance. Within this context, nanomaterials are gaining increasing attention thanks to their biocidal character. Among these, carbon dots (CDs) represent a class of zero‐dimensional, photoluminescent and quasi‐spherical nanoparticles which, for their great and tuneable features, have found applications in catalysis, sensing and biomedicine. Nevertheless, only a few works define and recapitulate their antifungal properties. Therefore, we aim to give an overview about the recent advances in the synthesis of CDs active against infective fungi. We described the general features of CDs and fungal cells, by highlighting some of the most common antimycotic mechanisms. Then, we evaluated the effects of CDs, antimicrobial drugs‐loaded CDs and CDs‐incorporated packaging systems on different fungi and analysed the use of CDs as fluorescent nano‐trackers for bioimaging, showing, to all effects, their promising application as antifungal agents.
Social isolation, depression, and anxiety among young adult cancer survivors: The mediating role of social connectedness
Authors: Li Xiaoyin , Hathaway Cassandra A. , Small Brent J. , Tometich Danielle B. , Gudenkauf Lisa M. , Hoogland Aasha I. , Fox Rina S. , Victorson David E. , Salsman John M. , Gonzalez Brian D. , Jim Heather S. L. , Siegel Erin M. , Tworoger Shelley S. , Oswald Laura B.
Published: August 2024

Background

Social isolation and social connectedness are health determinants and aspects of social well‐being with strong associations with psychological distress. This study evaluated relationships among social isolation, social connectedness, and psychological distress (i.e., depression, anxiety) over 1 year in young adult (YA) cancer survivors 18–39 years old.

Methods

Participants were YAs in a large cohort study that completed questionnaires every 2 months for 1 year. Social isolation, aspects of social connectedness (i.e., companionship, emotional support, instrumental support, and informational support), depression, and anxiety were assessed with Patient‐Reported Outcomes Measurement Information System short form measures. Mixed‐effect models were used to evaluate changes over time. Confirmatory factor analysis and multilevel structural equation modeling were used to define social connectedness as a latent construct and determine whether relationships between social isolation and psychological distress were mediated by social connectedness.

Results

Participants (N = 304) were mean (M) = 33.5 years old (SD = 4.7) and M = 4.5 years (SD = 3.5) post‐initial cancer diagnosis. Most participants were female (67.4%) and non‐Hispanic White (68.4%). Average scores for social well‐being and psychological distress were within normative ranges and did not change (p values >.05). However, large proportions of participants reported at least mild social isolation (27%–30%), depressive symptoms (36%–37%), and symptoms of anxiety (49%–51%) at each time point. Across participants, more social isolation was related to less social connectedness (p values <.001), more depressive symptoms (p < .001), and more symptoms of anxiety (p < .001). Social connectedness mediated the relationship between social isolation and depression (p = .004), but not anxiety (p > .05).

Conclusions

Social isolation and connectedness could be intervention targets for reducing depression among YA cancer survivors.
Ab‐HIDS: An anomaly‐based host intrusion detection system using frequency of N‐gram system call features and ensemble learning for containerized environment
Authors: Joraviya Nidhi , Gohil Bhavesh N. , Rao Udai Pratap
Published: August 2024

Cloud's operating‐system‐level virtualization has introduced a new phase of lightweight virtualization through containers. The architecture of cloud‐native and microservices‐based application development strongly advocates for the use of containers due to their swift and convenient deployment capabilities. However, the security of applications within containers is important, as malicious or vulnerable content could jeopardize the container and the host system. This vulnerability also extends to neighboring containers and may compromise data integrity and confidentiality. The article focuses on developing an intrusion detection system tailored to containerized cloud environments by identifying system call analysis techniques and also proposes an anomaly‐based host intrusion detection system (Ab‐HIDS). This system employs the frequency of N‐grams system calls as distinctive features. To enhance performance, two ensemble learning models, namely voting‐based ensemble learning and XGBoost ensemble learning, are employed for training and testing the data. The proposed system is evaluated using the Leipzig Intrusion Detection Data Set (LID‐DS), demonstrating substantial performance compared to existing state‐of‐the‐art methods. Ab‐HIDS is validated for class imbalance using the imbalance ratio and synthetic minority over‐sampling technique methods. Our system achieved significant improvements in detection accuracy with 4% increase for the voting‐based ensemble model and 6% increase for the XGBoost ensemble model. Additionally, we observed reductions in the false positive rate by 0.9% and 0.8% for these models, respectively, compared to existing state‐of‐the‐art methods. These results illustrate the potential of our proposed approach in improving security measures within containerized environments.
A study of online academic risk prediction based on neural network multivariate time series features
Authors: Wu Yang , Yu Mengping , Huang Huan , Hou Rui
Published: August 2024

Neural networks are becoming increasingly widely used in various fields, especially for academic risk forecasts. Academic risk prediction is a hot topic in the field of big data in education that aims to identify and help students who experience great academic difficulties. In recent years, the use of machine learning algorithms and deep learning algorithms to achieve academic risk prediction has garnered increased attention and development. However, most of these studies use nontime series data as features for prediction, which are slightly insufficient in terms of timeliness. Therefore, this article focuses on time series data features that are more expressive of changes in students' learning status and uses multivariate time series data as predictive features. This article proposes a method based on multivariate time series features and a neural network to predict academic risk. The method includes three steps: first, the multivariate time series feature is extracted from the interaction records of the students' online learning platforms; second, the multivariate time series feature transformation model ROCKET is applied to convert the multivariate time series feature into a new feature; third, the new feature is converted into a final prediction result using a linear classification model. Comparative tests show that the proposed method has high effectiveness.
Enhancing damping of low‐frequency oscillations in power networks through energy storage system‐based controller
Authors: Kumar Rohit , Mohanty Soumya R. , Verma Mitresh Kumar
Published: August 2024

Mitigating inter‐area low‐frequency oscillations is a significant concern in multi‐machine power systems due to their adverse effects on system stability. These oscillations are intricately linked with power oscillations. So appropriate power modulation through the Battery Energy Storage System (BESS) can be an effective strategy for preserving system stability. In this paper, the maximal of all minimal residue indices under variations in power system operating conditions is utilized as the index for identifying the location for installation of the BESS, the damping control loop, and the feedback signal. A fixed‐structure scheme‐based wide‐area damping controller (WADC) is proposed for the BESS, providing sufficient damping of inter‐area oscillation modes. A modified IEEE 39‐bus system is simulated using a real‐time digital simulator as a test system in this work. The simulation results confirmed that the proposed WADC could effectively damp various inter‐area oscillation modes. Furthermore, it offers robust damping performance over contingencies associated with the system's various operating scenarios as well as the uncertainty associated with fixed and variable communication delays in the feedback signal of WADC and the integration of solar photovoltaic systems. Moreover, a comparative analysis of the proposed WADC is carried out with a BESS‐based wide‐area power system stabilizer, which is found to be more effective in mitigating system inter‐area oscillations.
A distributed coordinated control strategy for isolated AC microgrids based on consensus algorithm considering communication delay
Authors: Yan Chaofeng , Li Qirui , Zhang Xiaomeng , Han Yang , Yang Ping , Zalhaf Amr S.
Published: August 2024

In the multi‐paralleled converter microgrid system, the traditional hierarchical control strategy can eliminate the bus voltage amplitude and frequency deviation from the rated value. However, isolated AC microgrids may face extreme scenarios such as communication delays and interruptions in data transmission due to the use of low‐bandwidth communication (LBC) lines. Additionally, the inconsistent line impedance of each distributed generation (DG) unit may result in the inaccurate division of reactive power in multi‐paralleled converter systems, thus affecting system stability. To address these issues, this paper presents a distributed coordinated control strategy for isolated AC microgrids based on the consensus algorithm. The proposed strategy first replaces LBC lines with a filter to alleviate the effects of communication delays. A small‐signal model is established in its state space, and stability of the microgrid system under the proposed control strategy is verified through eigenvalue analysis. Furthermore, based on the above theoretical analysis, a consensus algorithm is introduced, and a distributed control strategy for isolated AC microgrids based on the consensus algorithm is proposed to solve the issue of inaccurate equalization of the system's reactive power. Finally, factors that influence the dynamic convergence performance of the consensus algorithm are analyzed through simulation in PLECS software. Also, the maximum tolerable communication delays of the microgrid system under different communication topologies are also compared, and the system's robustness is evaluated under the condition of sudden communication interruption in a DG unit and sudden weather variation. These analyses confirmed the robustness of the proposed strategy against communication delays, output power fluctuation, and communication interruptions.
Substance Use and Its Relationship With Attachment and Early Maladaptive Schemes in Adolescents in Ecuador
Authors: Olave Leticia , Momeñe Janire , Macía Laura , Macía Patricia , Chávez‐Vera María Dolores , Herrero Marta , Estévez Ana , Iruarrizaga Itziar
Published: August 2024

Given the scarcity of studies addressing substance consumption and its relationship with attachment styles and early maladaptive schemas in adolescents, the present study is proposed. Aims of this study are to analyze the relationship among attachment styles, early maladaptive schemas, and substance use; test the predictive role of attachment styles on substance use; and observe the mediating role of early maladaptive schemas in the relationship between attachment and substance use. The sample consisted of 1533 adolescents from Ecuador (53.9% males) aged between 14 and 18 years (M = 15.76; SD = 1.25). The attachment styles of security, value to parental authority, parental permissiveness, parental interference, self‐sufficiency and resentment against parents, childhood trauma, and family concern predict substance use (tobacco, alcohol, tranquilizers/sedatives or sleeping pills, hashish or marijuana, cocaine, GHB or liquid ecstasy, ecstasy, amphetamines/speed, hallucinogens, heroin, inhalants/volatiles), and the mediating role of early maladaptive schemas is confirmed (explained variance up to 33.33%). Identifying risk or vulnerability factors, such as attachment and early maladaptive schemas related to substance consumption, is especially relevant for designing and implementing preventive interventions in the adolescent population.
Heatwave‐induced functional shifts in zooplankton communities result in weaker top‐down control on phytoplankton
Authors: Huỳnh Thu‐Hương , Horváth Zsófia , Pálffy Károly , Kardos Vivien , Szabó Beáta , Dobosy Péter , Vad Csaba F.
Published: August 2024

Freshwater ecosystems are increasingly affected by rising annual mean temperatures and heatwaves. While heatwaves are expected to have more immediate effects than mean temperature increases on local communities, comparative experimental studies are largely lacking. We conducted a 1‐month mesocosm experiment to test the effect of different warming treatments, constantly raised temperatures (+3°C) and recurring heatwaves (+6°C), on plankton communities. We specifically tested how shifts in zooplankton trait composition and functional groups are reflected in ecosystem function (top‐down control on primary producers). We found that heatwaves had a stronger and more immediate effect on zooplankton trait composition (specifically on body length and body mass) and functional groups. Heatwaves led to the decrease of small‐bodied grazers (i.e., Rotifera) and the dominance of larger omnivorous Copepoda, and these shifts resulted in weaker top‐down control, leading to elevated phytoplankton biomass. Altogether, our results highlight the importance of the indirect effects of heatwaves via inducing shifts in zooplankton functional groups and trait composition, which may lead to algal blooms.
Low‐intensity urbanisation alters community composition across multiple trophic levels on Lipsi Island, Greece
Authors: Hawkins Eleanor R. , Macrina Laura , Malcolm‐McKay Alice , Cotterill Nicola , Miliou Anastasia , O'Gorman Eoin J.
Published: August 2024

Urbanisation has reduced the abundance and diversity of many taxonomic groups, and the effects may be more pronounced on islands, which have a smaller regional species pool to compensate. Green spaces within urban environments may help to safeguard wildlife assemblages, and the associated habitat heterogeneity can even increase species diversity. Here, total abundance and species diversity of butterflies, birds, and vegetation at nine rural and nine urban locations were quantified on Lipsi Island, Greece. Sites were assessed using Pollard walks for butterflies, point‐count surveys for birds, and quadrats for vegetation. There was no significant difference in the abundance or species diversity of butterflies or vegetation among rural and urban locations, which could pertain to the low building density within urbanised areas and the minimal extent of urbanisation on the island. However, urban areas hosted a significantly greater abundance, richness, and diversity of birds compared to rural sites. The community composition of butterflies, birds, and vegetation also differed significantly between urban and rural locations, highlighting the impact of urbanisation on species across a broad range of trophic groups. This study contributes to ecological knowledge on the impacts of urbanisation across multiple trophic levels in island ecosystems, with comparisons across a gradient of island size and urbanisation intensity needed in future research.
A comparison of the large‐scale gene expression patterns in summer and fall migratory Pantala flavescens (Fabricius) in northern China
Authors: Cao Lingzhen , Wang Na
Published: August 2024

Pantala flavescens (Fabricius) is the most well‐known seasonal migratory insect. This research focused on the molecular response of P. flavescens migration in summer and fall. A total of 17,810 assembled unigenes were obtained and 624 differentially expressed genes (DEGs) were identified in summer migration compared to fall migration. A number of DEGs, including cpr49Ae, itm2b, chitinase, cpr11B, laccase2, nd5, vtg2 and so on, had previously been reported to be involved in cold‐ and high‐temperature resistance. Functional enrichment analysis showed three pathways ‘that antibacterial humoral response, response to bacterial, and lipid transporter activity’ were significantly enriched in summer migration while that six pathways ‘structural constituent of cuticle, chitin binding, mitochondrion, propanoate metabolism, citrate cycle, hypertrophic cardiomyopathy’ were significantly enriched in fall migration. These results will provide a valuable baseline for further understanding of the molecular mechanisms of insect adaptation to different climate migrations.
Reduced trophic niche breadth is associated with higher productivity in a recovering apex predator population
Authors: de Gabriel Hernando Miguel , Fernández‐Gil Alberto , Lamas Javier A. , Ansola Luis M. , Román Jacinto , Revilla Eloy
Published: August 2024

Understanding the trophic and demographic dynamics of apex predators is of paramount importance for ecosystem conservation. Apex predators are usually free from predation, and thus, the main driver of population dynamics is the availability of trophic resources, which affects breeding performance. Albeit food habits have been described in many apex species, the effects of changes in the trophic niche on long‐term demographic dynamics are poorly known. We describe the long‐term (N = 25 years) changes in trophic niche breadth of a recovering golden eagle population in a Mediterranean landscape (northern Spain) and search for potential correlates with their productivity (i.e., number of fledged eaglets per controlled pair) as a proxy for their breeding performance (N = 290 pair‐years). We identified a total of 3475 prey items from 77 species; rabbits, hares, and red‐legged partridges were the most frequent prey consumed (overall 51%), followed by roe deer (10%), red‐billed chough, red foxes, and woodpigeons, all of them with >5%. Prey diversity in eagles' diet decreased during the study period. Consumption of rabbits and roe deer increased, while that of hares and partridges decreased; no significant trends were observed in the consumption of foxes, choughs, and woodpigeons. Prey diversity and red‐legged partridge consumption were negatively correlated with productivity at the territory level, while rabbits, corvids, and pigeons showed a strong positive relationship with productivity. The size of the territory showed the strongest positive relationship with productivity, while roughness was negatively correlated. Rabbits and ungulates showed negative and positive correlations with roughness, respectively, while predator consumption exhibited a negative relationship with the size of the territory. Our findings give insights into the potential trophic mechanisms driving the dynamics of recovering apex predator populations; a reduction in the trophic niche breadth toward specific groups of prey, which could be due to a higher availability and individual specificity toward these prey species, might enhance productivity at the territory level and, ultimately, influence population dynamics facilitating the recovery process. The remarkable increase in the consumption of wild ungulates, predators, and other apex consumers suggests that the current population recovery and reduced trophic niche breadth may facilitate this eagle population to exhibit its apex role and contribute to ecosystem functionality.