bluuebunny/crossref_metadata_2025 huggingface dataset:
DFT Insights into FEBID Stability: Condensed Study of Gold(I) Complexes with Phosphine Ligands
Authors: Afaneh Akef T. , Alshhadat Mohanad , Marashdeh Ali , Almatarneh Mansour H. , Helal Wissam
Published: March 2024

This work examines the durability and responsiveness of XAuL precursors in the context of synthesizing Au‐nanomaterials. The study used density functional theory (DFT) simulations to look at the shapes, bond dissociation energies, and thermodynamic properties of a number of XAuL precursors. Within this framework, X denotes halogens Cl, Br, or I, whereas L denotes ligands such as PH3, PF3, PMe3, P(OMe)3, and P(NH2)3. Our investigations indicate that there is no discernible relationship between the lengths of XAuL bonds and binding energies. Small changes in bond dissociation free energy (▵BDG) serve as indicators of neutral precursors with low stability. The aforementioned precursors are essential for chemical vapor deposition. There are clear patterns that depend on the size of the halogen and the type of ligand when the ▵BDG values and interatomic distances in the XAuL precursors are looked at. Adding an electron to the precursor changes the length of the XAuL bond, which makes the ΔBDG values of anionic precursors lower than those of neutral precursors. The study is mostly about looking at how ligands L and XAu fragments interact with each other by looking at frontier molecular orbitals (FMOs). It has been shown that higher energy gap (ΔBDG) values lead to better interaction between the HOMO and LUMO orbitals of ligand L and XAu fragments. Furthermore, the research of electrophilicity emphasizes the significance of π‐back donation and the covalent energy involved in the bonding between XAu‐PR3. Thermodynamic study indicates that the dissociation processes exhibit more spontaneity under elevated temperatures and reduced pressures. The size of halogens affects spontaneity, with larger halogens exhibiting higher negative ▵BDG values. The study shows that IAuPMe3, BrAuPMe3, and ClAuPMe3 are stable starting materials for making gold nanoparticles using focused electron beam‐induced deposition (FEBID) in normal situations. This extensive study enhances our understanding of precursor design for Au‐nanofabrication by providing valuable insights into the stability, reactivity, and thermodynamic characteristics of XAuL precursors.
A Defective Disc‐Like Cu1.96S Anode Material with the Efficient Cu Vacancies for High‐Performance Sodium‐Ion Storage
Authors: Wang Zhihao , Lu Yongyi , Zhang Guangdi , Quan Lingfeng , Liu Mingzu , Liu Haimei , Wang Yonggang
Published: March 2024

Due to their significant capacity and reliable reversibility, transition metal sulphides (TMSs) have received attention as potential anode materials for sodium‐ion batteries (SIBs). Nonetheless, a prevalent challenge with TMSs lies in their significant volume expansion and sluggish kinetics, impeding their capacity for rapid and enduring Na+ storage. Herein, a Cu1.96S@NC nanodisc material enriched with copper vacancies is synthesised via a hydrothermal and annealing procedure. Density functional theory (DFT) calculations reveal that the incorporation of copper vacancies significantly boosts electrical conductivity by reducing the energy barrier for ion diffusion, thereby promoting efficient electron/ion transport. Moreover, the presence of copper vacancies creates ample active sites for the integration of sodium ions, streamlines charge transfer, boosts electronic conductivity, and, ultimately, significantly enhances the overall performance of SIBs. This novel anode material, Cu1.96S@NC, demonstrates a reversible capacity of 339 mAh g−1 after 2000 cycles at a rate of 5 A g−1. In addition, it maintains a noteworthy reversible capacity of 314 mAh g−1 with an exceptional capacity retention of 96% even after 2000 cycles at 20 A g−1. The results demonstrate that creating cationic vacancies is a highly effective strategy for engineering anode materials with high capacity and rapid reactivity.
Heterostructured Graphene@Silica@Iron Phenylphosphinate for Fire‐Retardant, Strong, Thermally Conductive Yet Electrically Insulated Epoxy Nanocomposites
Authors: Chen Qiang , Huo Siqi , Lu Yixia , Ding Mingmei , Feng Jiabing , Huang Guobo , Xu Hang , Sun Ziqi , Wang Zhengzhou , Song Pingan
Published: March 2024

The portfolio of extraordinary fire retardancy, mechanical properties, dielectric/electric insulating performances, and thermal conductivity (λ) is essential for the practical applications of epoxy resin (EP) in high‐end industries. To date, it remains a great challenge to achieve such a performanceportfolio in EP due to their different and even mutually exclusive governing mechanisms. Herein, a multifunctional additive (G@SiO2@FeHP) is fabricated by in situ immobilization of silica (SiO2) and iron phenylphosphinate (FeHP) onto the graphene (G) surface. Benefiting from the synergistic effect of G, SiO2 and FeHP, the addition of 1.0 wt% G@SiO2@FeHP enables EP to achieve a vertical burning (UL‐94) V‐0 rating and a limiting oxygen index (LOI) of 30.5%. Besides, both heat release and smoke generation of as‐prepared EP nanocomposite are significantly suppressed due to the condensed‐phase function of G@SiO2@FeHP. Adding 1.0 wt% G@SiO2@FeHP also brings about 44.5%, 61.1%, and 42.3% enhancements in the tensile strength, tensile modulus, and impact strength of EP nanocomposite. Moreover, the EP nanocomposite exhibits well‐preserved dielectric and electric insulating properties and significantly enhanced λ. This work provides an integrated strategy for the development of multifunctional EP materials, thus facilitating their high‐performance applications.
In Situ Growth Strategy to Construct “Four‐In‐One” Separators with Functionalized Polyphosphazene Coatings for Safe and Stable Lithium–Sulfur Batteries
Authors: Dong Xinxin , Gu Weiwen , Tong Xin , Liu Guoqing , Sun Jun , Li Huihui , Gu Xiaoyu , Zhu Tao , Zhang Sheng
Published: March 2024

Lithium–sulfur batteries (LSBs) are facing many challenges, such as the inadequate conductivity of sulfur, the shuttle effect caused by lithium polysulfide (LiPSs), lithium dendrites, and the flammability, which have hindered their commercial applications. Herein, a “four‐in‐one” functionalized coating is fabricated on the surface of polypropylene (PP) separator by using a novel flame‐retardant namely InC‐HCTB to meet these challenges. InC‐HCTB is obtained by cultivating polyphosphazene on the surface of carbon nanotubes with an in situ growth strategy. First, this unique architecture fosters an enhanced conductive network, bolstering the bidirectional enhancement of both ionic and electronic conductivities. Furthermore, InC‐HCTB effectively inhibits the shuttle effect of LiPSs. LSBs exhibit a remarkable capacity of 1170.7 mA h g−1 at 0.2 C, and the capacity degradation is a mere 0.0436% over 800 cycles at 1 C. Third, InC‐HCTB coating serves as an ion migration network, hindering the growth of lithium dendrites. More importantly, InC‐HCTB exhibits notable flame retardancy. The radical trapping action in the gas phase and the protective effect of the shielded char layer in the condensed phase are simulated and verified. This facile in situ growth strategy constructs a “four‐in‐one” functional separator coating, rendering InC‐HCTB a promising additive for the large‐scale production of safe and stable LSBs.
Bromine Atoms Decorated Pyene‐based Covalent Organic Frameworks for Accelerated Photocatalytic H2 Production
Authors: Deng Xile , Gao Nan , Bai Lianyang
Published: March 2024

Designing materials with low exciton binding energy is an efficient way of improving the hydrogen production performance of COFs（Covalent Organic Frameworks. Here, it is demonstrated that the strategy of decorating bromine atoms on Pyene‐based COFs can achieve elevated photocatalytic H2 evolution rates (HER = 13.61 mmol g−1h−1). Low‐temperature fluorescence and time‐resolved fluorescence spectroscopy (TRPL) indicate that the introduction of bromine atoms can significantly suppress charge recombination. DFT (Density Functional Theory) calculation clarified that the C atoms adjacent to Br are the active sites with a reduced energy barrier in the process of formatting H intermediate species (H*). The modification strategy of Br atoms in COF furnishes a new medium for exploiting exquisite photocatalysts.
Mixed‐Transducer Micro‐Origami for Efficient Motion and Decoupled Sensing
Authors: Zhu Yi , Ghrayeb Anan , Yu Joonyoung , Yang Yiwei , Filipov Evgueni T. , Oldham Kenn R.
Published: March 2024

This work introduces a mixed‐transducer micro‐origami to achieve efficient vibration, controllable motion, and decoupled sensing. Existing micro‐origami systems tend to have only one type of transducer (actuator/sensor), which limits their versatility and functionality because any given transducer system has a narrow range of advantageous working conditions. However, it is possible to harness the benefit of different micro‐transducer systems to enhance the performance of functional micro‐origami. More specifically, this work introduces a micro‐origami system that can integrate the advantages of three transducer systems: strained morph (SM) systems, polymer based electro‐thermal (ET) systems, and thin‐film lead zirconate titanate (PZT) systems. A versatile photolithography fabrication process is introduced to build this mixed‐transducer micro‐origami system, and their performance is investigated through experiments and simulation models. This work shows that mixed‐transducer micro‐origami can achieve power efficient vibration with high frequency, large vibration ranges, and little degradation; can produce decoupled folding motion with good controllability; and can accomplish simultaneous sensing and actuation to detect and interact with external environments and small‐scale samples. The superior performance of mixed‐transducer micro‐origami systems makes them promising tools for micro‐manipulation, micro‐assembly, biomedical probes, self‐sensing metamaterials, and more.
Phase Engineering via Aluminum Doping Enhances the Electrochemical Stability of Lithium‐Rich Cobalt‐Free Layered Oxides for Lithium‐Ion Batteries
Authors: De Sloovere Dries , Mylavarapu Satish Kumar , D'Haen Jan , Thersleff Thomas , Jaworski Aleksander , Grins Jekabs , Svensson Gunnar , Stoyanova Radostina , Jøsang Leif Olav , Prakasha Kunkanadu Rajappa , Merlo Maximiliano , Martínez Elías , Nel‐lo Pascual Marc , Jacas Biendicho Jordi , Van Bael Marlies K. , Hardy An
Published: March 2024

Lithium‐rich, cobalt‐free oxides are promising potential positive electrode materials for lithium‐ion batteries because of their high energy density, lower cost, and reduced environmental and ethical concerns. However, their commercial breakthrough is hindered because of their subpar electrochemical stability. This work studies the effect of aluminum doping on Li1.26Ni0.15Mn0.61O2 as a lithium‐rich, cobalt‐free layered oxide. Al doping suppresses voltage fade and improves the capacity retention from 46% for Li1.26Ni0.15Mn0.61O2 to 67% for Li1.26Ni0.15Mn0.56Al0.05O2 after 250 cycles at 0.2 C. The undoped material has a monoclinic Li2MnO3‐type structure with spinel on the particle edges. In contrast, Al‐doped materials (Li1.26Ni0.15Mn0.61‐xAlxO2) consist of a more stable rhombohedral phase at the particle edges, with a monoclinic phase core. For this core‐shell structure, the formation of Mn3+ is suppressed along with the material's decomposition to a disordered spinel, and the amount of the rhombohedral phase content increases during galvanostatic cycling. Whereas previous studies generally provided qualitative insight into the degradation mechanisms during electrochemical cycling, this work provides quantitative information on the stabilizing effect of the rhombohedral shell in the doped sample. As such, this study provides fundamental insight into the mechanisms through which Al doping increases the electrochemical stability of lithium‐rich cobalt‐free layered oxides.
Enhancing Nitrate Reduction to Ammonia Through Crystal Phase Engineering: Unveiling the Hydrogen Bonding Effect in δ‐FeOOH Electrocatalysis
Authors: Qu Kaiyu , Zhu Xiaojuan , Zhang Yu , Song Leyang , Wang Jing , Gong Yushuang , Liu Xiang , Wang An‐Liang
Published: March 2024

Crystal phase engineering has emerged as a powerful tool for tailoring the electrocatalytic performance, yet its impact on nitrate reduction to ammonia (NRA) remains largely uncharted territory. Herein, density functional theory (DFT) calculations are performed to unravel the influence of the crystal phase of FeOOH on the adsorption behavior of *NO3. Inspiringly, FeOOH samples with four distinct crystal phases (δ, γ, α, and β) are successfully synthesized and deployed as electrocatalysts for NRA. Remarkably, among all FeOOH samples, δ‐FeOOH demonstrates the superior NRA performance, achieving a NH3 Faradic efficiency () of 90.2% at –1.0 V versus reversible hydrogen electrode (RHE) and a NH3 yield rate () of 5.73 mg h−1 cm−2 at –1.2 V. In‐depth experiments and theoretical calculations unveil the existence of hydrogen bonding interaction between δ‐FeOOH and *NOx, which not only enhances the adsorption of *NOx but also disrupts the linear relationships between the free energy of *NO3 adsorption and various parameters, including limiting potential, d‐band center (εd) and transferred charge from FeOOH to *NO3, ultimately contributing to the exceptional NRA performance.
A lightweight Intrusion Detection for Internet of Things‐based smart buildings
Authors: Murthy Amith , Asghar Muhammad Rizwan , Tu Wanqing
Published: March 2024

The integration of Internet of Things (IoT) devices into commercial or industrial buildings to create smart environments, such as Smart Buildings (SBs), has enabled real‐time data collection and processing to effectively manage building operations. Due to poor security design and implementation in IoT devices, SB networks face an array of security challenges and threats (e.g., botnet malware) that leverage IoT devices to conduct Distributed Denial of Service (DDoS) attacks on the Internet infrastructure. Machine Learning (ML)‐based traffic classification systems aim to automatically detect such attacks by effectively differentiating attacks from benign traffic patterns in IoT networks. However, there is an inherent accuracy‐efficiency tradeoff in network traffic classification tasks. To balance this tradeoff, we develop an accurate yet lightweight device‐specific traffic classification model. This model classifies SB traffic flows into four types of coarse‐grained flows, based on the locations of traffic sources and the directions of traffic transmissions. Through these four types of coarse‐grained flows, the model can extract simple yet effective flow rate features to conduct learning and predictions. Our experiments find the model to achieve an overall accuracy of 96%, with only 32 features to be learned by the ML model.
Vinyl Polymers as Key Materials in Contact Lens Design: A Review of Progress and Future Directions
Authors: Shaker Lina M. , Al‐Amiery Ahmed , Isahak Wan Nor Roslam Wan , Al‐Azzawi Waleed Khalid
Published: March 2024

Vinyl polymers, crucial in contemporary contact lens design, present unique attributes with promising implications for vision correction. This comprehensive review navigates the trajectory and future trajectories of vinyl polymer‐based contact lenses. The introduction underscores the vital role of contact lenses in vision correction and positions vinyl polymers as ideal materials due to their exceptional properties. Delving into material specifics—high oxygen permeability, optical clarity, surface wettability, and mechanical strength—the analysis emphasizes their influence on corneal health, comfort, and durability. The versatility of manufacturing techniques, encompassing spin casting, molding processes, polymerization, and surface modification, underscores their feasibility in crafting high‐quality lenses. Examining clinical applications, encompassing daily disposables, extended wear, silicone hydrogel, and specialty lenses, alongside biocompatibility assessments and user feedback, provides a nuanced understanding of vinyl polymer‐based lens effectiveness. The article candidly addresses challenges—dehydration, deposits, mechanical stability, and durability—alongside regulatory considerations. Future prospects involve novel formulations, smart materials, bioinspired designs, and noninvasive technologies to amplify comfort and performance. In conclusion, this review distills progress, acknowledges challenges, and charts a sanguine course for vinyl polymer materials in advancing contact lens design, envisioning a future marked by enhanced vision correction technologies.
Effect of Particle Diameter on Water Sorption by Rice Grains
Authors: Nagahama Tamaki , Adachi Shuji , Watanabe Yoshiyuki
Published: March 2024

Water sorption of non‐glutinous Uruchi and sticky Mochi rice grains of different diameters is kinetically analyzed using linear driving force and autocatalytic models. Water‐sorption curves are classified into two types based on their shape and according to the state of rice grains below and above the gelatinization temperature. Below the gelatinization temperature, the apparent activation energy and the frequency factor decrease with increasing rice‐particle diameter. The water sorption mechanisms of both types of rice appear to be the same in terms of the enthalpy–entropy compensation effect. Above the gelatinization temperature, it appears that the gelatinizable areas of starch granules contribute to the equilibrium moisture content, whereas the non‐gelatinizable areas affect the rate constant.
SafeNet: Towards mitigating replaceable unsafe Rust code via a recommendation‐based approach
Authors: Dong Yan , Zhang Zhicong , Cui Mohan , Xu Hui
Published: March 2024

Rust is a system‐level programming language with advantages in memory safety. It ensures that any Rust programs without unsafe code should not incur undefined behaviours. However, unsafe code still plays an essential role in Rust to achieve low‐level control. Therefore, a major design pattern of Rust programs is interior unsafe, which wraps unsafe code as safe APIs and handles all undefined behaviours internally. Rust standard library already provides a rich set of safe APIs to facilitate Rust code development. Nevertheless, due to unfamiliarity with these APIs, developers may misuse unnecessary unsafe code and suffer memory‐safety risks. In this paper, we investigate an approach to mitigate replaceable unsafe code. We first analyse unsafe APIs of the Rust standard library and summarize their common usage patterns. Each pattern corresponds to one or several code samples in our knowledge base. Then, we develop an approach to automatically recognize the usage pattern and recommend corresponding code samples. Our approach leverages dataflow analysis to exclude impossible patterns and employs a BERT‐based machine learning model to find the most similar pattern among the rest. We have conducted evaluation experiments with 472 unsafe code snippets collected from GitHub projects and successfully recognized the pattern of 394 snippets. We hope our approach can assist developers in detecting unnecessary unsafe code and suggesting safe alternatives.
Effectiveness of an ecological flow regime to assure successful recruitment of anadromous Coregoninae populations in the Rupert River (northern Quebec, Canada)
Authors: Belzile Louis , Guay Jean-Christophe
Published: March 2024

Objective

As part of a large-scale hydroelectric project, the mean annual flow of the Rupert River (northern Quebec, Canada) was reduced by 52% at its mouth in 2009. To protect fish habitat, an ecological flow regime that was modulated according to the biological seasons was implemented downstream from the diversion point. An 8-year monitoring program, including 2 years before partial diversion, was carried out to verify the effectiveness of this mitigation measure on the total annual abundance of anadromous Coregoninae (Cisco Coregonus artedi and Lake Whitefish C. clupeaformis) larvae, which was used as biological indicator of recruitment success. The monitoring also aimed to determine the effects of flow modification on the timing of the larval drift and the spatial distribution of larvae in a river cross section.

Methods

Each year, sampling consisted of installing drift nets during the entire downstream larval migration in a river cross section of the lower Rupert River. Drift nets were systematically placed to ensure representative sampling of the river section.

Result

Prior to flow reduction, the estimated total number of larvae varied between 1.8 and 8.6 million. Over the following 6 years, the estimated larval population has remained steady at 3–4 million. Otherwise, larval drift characteristics have not changed since the flow reduction, as (1) the duration of the larval drift is the same as before, about 1 month in May and early June, with a peak period of about 8 days; (2) rise in water temperature in spring is a determining factor in the timing of larval drift; and (3) the larvae drift mainly near the surface of the water.

Conclusion

The monitoring results indicate that the ecological flow regime implemented in the Rupert River was adequate to maintain anadromous coregonine populations.
It's not just a science thing: Educating future STEM professionals through mis/disinformation responsive instruction
Authors: Herman Benjamin C. , Poor Sarah , Clough Michael P. , Rao Asha , Kidd Aaron , De Jesús Daniel , Varghese Davis
Published: March 2024

Informed scientific thinking is a vital component of engaging all socioscientific issues (SSI) such as climate change and the COVID‐19 pandemic. However, socioscientific engagement may be influenced by sociocultural factors and mis/disinformation efforts to the widespread detriment of human and environmental well‐being. The purpose of this mixed‐methods study was to determine how 506 post‐secondary life science majors' COVID‐19 related nature science (NOS) views and COVID‐19 vaccine acceptance/support and conspiracy resistance changed through pandemic responsive instruction on COVID‐19 science, viral biology, and vaccines with integrated focus on NOS and mis/disinformation. This investigation also sought to reveal factors (e.g., sociocultural group membership, NOS views) that associated with changes in those students' COVID‐19 vaccine acceptance/support and conspiracy resistance. After experiencing the pandemic responsive instruction, the students' COVID‐19 vaccine acceptance/support and conspiracy resistance and trust in COVID‐19 science and cognizance of its reliable and revisionary character (i.e., NOS) significantly improved from a small to large extent. Through the pandemic responsive instruction, the students' development of NOS views significantly associated with their development of higher levels of vaccine acceptance and conspiracy resistance and increases in students' vaccine conspiracy resistance significantly associated with increases in vaccine acceptance. Changes in students' vaccine acceptance and conspiracy resistance from before to after the pandemic responsive instruction also varied significantly based on sociocultural grouping (e.g., race/ethnicity and political orientation). Despite the promising impact demonstrated by the pandemic responsive instruction, vaccine conspiracy views and resistance appeared to linger among the students who notably were entering fields that deal with viruses, vaccines, and public health. Implications discussed include the importance for helping students to understand NOS relevant to SSI and analyze how sociocultural membership, motivated and identity protective reasoning processes, mis/disinformation, and trust in science influence socioscientific decision‐making.
Enhancing river floodplain management with nature‐based solutions: Overcoming barriers and harnessing enablers
Authors: Christopher Nikita , Vachette Astrid , Horne Avril , Kosovac Anna
Published: March 2024

Floodplains are regularly inundated areas of land that provide ecosystem benefits for the entire catchment area, along with numerous benefits for communities making them ideal for human settlement. The management of floodplains involves an ongoing dilemma; how best to balance the need to protect urban settlements from significant flood events with the benefits that inundation brings to the environmental and cultural values of the floodplain. These flood events have been traditionally addressed using technical flood protection measures. However, nature‐based solutions (NbS), provide a potential alternative approach. In this research, we analyze 29 global case studies centered on river floodplain management to investigate the barriers and enablers that affect the implementation of NbS, including floodplain restoration, mangroves, riparian forest restoration, wetland green infrastructure, among other strategies. The aim of this paper is to gain insights into improving floodplain management through the assessment of barriers and enablers evident in these case studies. The barriers and enablers were divided into six categories: social, technical, financial, political, institutional and economic and further into several sub‐divided categories. Social and technical categories were the most commonly described barriers and enablers closely followed by the institutional category. The discussion is centered around four topics: understanding community and decision‐maker risk perceptions, increased focus on stakeholders, managing multiple conflicting objectives, and consideration of multiple spatial scales. Further research on the uptake of NbS needs to focus on addressing risk communication and modeling, managing trade‐offs, and demonstration of delayed benefits.

This article is categorized under:

Water and Life > Conservation, Management, and Awareness

Science of Water > Water and Environmental Change
Reflection of plane waves in a nonlocal double poroelastic semiconducting medium with variable thermal conductivity and mass diffusivity
Authors: Sheokand Parmender , Deswal Sunita , Choudhary Suman , Jangra Amit
Published: March 2024

The present investigation is concerned with the reflection phenomena of plane waves in a homogeneous, isotropic, nonlocal, photothermoelastic semiconducting medium under the effects of double porosity, variable thermal conductivity and mass diffusivity. The formulation is applied to generalized thermoelasticity based on the Lord–Shulman theory. The problem is solved analytically and it is shown that there exist six coupled longitudinal waves in addition to an independent transverse wave in the considered medium. The amplitude ratios and energy ratios of these reflected waves have been calculated analytically and computed numerically for a specific material with the help of MATLAB programming. The numerical results of reflection coefficients are presented graphically to show the effects of double porosity, photothermal transport process, nonlocality, variable thermal conductivity and mass diffusivity. It is verified that during reflection phenomena, the sum of energy ratios is equal to unity at each angle of incidence and there is no energy dissipation at the boundary surface. Some special cases of interest have also been inferred from the current investigation.
Perturbative RG flows in AdS. An étude
Authors: Lauria Edoardo , Milam Michael N. , van Rees Balt C.
Published: March 2024

Abstract

We discuss general properties of perturbative RG flows in AdS with a focus on the treatment of boundary conditions and infrared divergences. In contrast with flat-space boundary QFT, general covariance in AdS implies the absence of independent boundary flows. We illustrate how boundary correlation functions remain conformally covariant even if the bulk QFT has a scale. We apply our general discussion to the RG flow between consecutive unitary diagonal minimal models which is triggered by the ϕ(1,3) operator. For these theories we conjecture a flow diagram whose form is significantly simpler than that in flat-space boundary QFT. In several stand-alone appendices we discuss two-dimensional BCFTs in general and the minimal model BCFTs in particular. These include both an extensive review as well as the computation of several new BCFT correlation functions.
Gravitational p → ∆+ transition form factors in chiral perturbation theory
Authors: Alharazin H. , Sun B.-D. , Epelbaum E. , Gegelia J. , Meißner U.-G.
Published: March 2024

Abstract

The gravitational form factors of the transition from the proton to the ∆+ resonance are calculated to leading one-loop order using a manifestly Lorentz-invariant formulation of chiral perturbation theory. We take into account the leading electromagnetic and strong isospin-violating effects. The loop contributions to the transition form factors are found to be free of power-counting violating pieces, which is consistent with the absence of tree-level diagrams at the considered order. In this sense, our results can be regarded as predictions of chiral perturbation theory.
The centaur-algebra of observables
Authors: Aguilar-Gutierrez Sergio E. , Bahiru Eyoab , Espíndola Ricardo
Published: March 2024

Abstract

This letter explores a transition in the type of von Neumann algebra for asymptotically AdS spacetimes from the implementations of the different gravitational constraints. We denote it as the centaur-algebra of observables. In the first part of the letter, we employ a class of flow geometries interpolating between AdS2 and dS2 spaces, the centaur geometries. We study the type II∞ crossed product algebra describing the semiclassical gravitational theory, and we explore the algebra of bounded sub-regions in the bulk theory following $$ T\overline{T} $$
T

T
¯

deformations of the geometry and study the gravitational constraints with respect to the quasi-local Brown-York energy of the system at a finite cutoff. In the second part, we study arbitrary asymptotically AdS spacetimes, where we implement the boundary protocol of an infalling observer modeled as a probe black hole proposed by [1] to study modifications in the algebra. In both situations, we show how incorporating the constraints requires a type II1 description.
Molecular hallmarks of ageing in amyotrophic lateral sclerosis
Authors: Jagaraj Cyril Jones , Shadfar Sina , Kashani Sara Assar , Saravanabavan Sayanthooran , Farzana Fabiha , Atkin Julie D.
Published: March 2024

Amyotrophic lateral sclerosis (ALS) is a fatal, severely debilitating and rapidly progressing disorder affecting motor neurons in the brain, brainstem, and spinal cord. Unfortunately, there are few effective treatments, thus there remains a critical need to find novel interventions that can mitigate against its effects. Whilst the aetiology of ALS remains unclear, ageing is the major risk factor. Ageing is a slowly progressive process marked by functional decline of an organism over its lifespan. However, it remains unclear how ageing promotes the risk of ALS. At the molecular and cellular level there are specific hallmarks characteristic of normal ageing. These hallmarks are highly inter-related and overlap significantly with each other. Moreover, whilst ageing is a normal process, there are striking similarities at the molecular level between these factors and neurodegeneration in ALS. Nine ageing hallmarks were originally proposed: genomic instability, loss of telomeres, senescence, epigenetic modifications, dysregulated nutrient sensing, loss of proteostasis, mitochondrial dysfunction, stem cell exhaustion, and altered inter-cellular communication. However, these were recently (2023) expanded to include dysregulation of autophagy, inflammation and dysbiosis. Hence, given the latest updates to these hallmarks, and their close association to disease processes in ALS, a new examination of their relationship to pathophysiology is warranted. In this review, we describe possible mechanisms by which normal ageing impacts on neurodegenerative mechanisms implicated in ALS, and new therapeutic interventions that may arise from this.
Systematic and quantitative analysis of stop codon readthrough in Rett syndrome nonsense mutations
Authors: Lebeda Dennis , Fierenz Adrian , Werfel Lina , Rosin-Arbesfeld Rina , Hofhuis Julia , Thoms Sven
Published: March 2024

Rett syndrome (RTT) is a neurodevelopmental disorder resulting from genetic mutations in the methyl CpG binding protein 2 (MeCP2) gene. Specifically, around 35% of RTT patients harbor premature termination codons (PTCs) within the MeCP2 gene due to nonsense mutations. A promising therapeutic avenue for these individuals involves the use of aminoglycosides, which stimulate translational readthrough (TR) by causing stop codons to be interpreted as sense codons. However, the effectiveness of this treatment depends on several factors, including the type of stop codon and the surrounding nucleotides, collectively referred to as the stop codon context (SCC). Here, we develop a high-content reporter system to precisely measure TR efficiency at different SCCs, assess the recovery of the full-length MeCP2 protein, and evaluate its subcellular localization. We have conducted a comprehensive investigation into the intricate relationship between SCC characteristics and TR induction, examining a total of 14 pathogenic MeCP2 nonsense mutations with the aim to advance the prospects of personalized therapy for individuals with RTT. Our results demonstrate that TR induction can successfully restore full-length MeCP2 protein, albeit to varying degrees, contingent upon the SCC and the specific position of the PTC within the MeCP2 mRNA. TR induction can lead to the re-establishment of nuclear localization of MeCP2, indicating the potential restoration of protein functionality. In summary, our findings underscore the significance of SCC-specific approaches in the development of tailored therapies for RTT. By unraveling the relationship between SCC and TR therapy, we pave the way for personalized, individualized treatment strategies that hold promise for improving the lives of individuals affected by this debilitating neurodevelopmental disorder.

Key messages

The efficiency of readthrough induction at MeCP2 premature termination codons strongly depends on the stop codon context.

The position of the premature termination codon on the transcript influences the readthrough inducibility.

A new high-content dual reporter assay facilitates the measurement and prediction of readthrough efficiency of specific nucleotide stop contexts.

Readthrough induction results in the recovery of full-length MeCP2 and its re-localization to the nucleus.

MeCP2 requires only one of its annotated nuclear localization signals.
Construction of relatedness matrices in autopolyploid populations using low-depth high-throughput sequencing data
Authors: Bilton Timothy P. , Sharma Sanjeev Kumar , Schofield Matthew R. , Black Michael A. , Jacobs Jeanne M. E. , Bryan Glenn J. , Dodds Ken G.
Published: March 2024

Key message

An improved estimator of genomic relatedness using low-depth high-throughput sequencing data for autopolyploids is developed. Its outputs strongly correlate with SNP array-based estimates and are available in the package GUSrelate.

High-throughput sequencing (HTS) methods have reduced sequencing costs and resources compared to array-based tools, facilitating the investigation of many non-model polyploid species. One important quantity that can be computed from HTS data is the genetic relatedness between all individuals in a population. However, HTS data are often messy, with multiple sources of errors (i.e. sequencing errors or missing parental alleles) which, if not accounted for, can lead to bias in genomic relatedness estimates. We derive a new estimator for constructing a genomic relationship matrix (GRM) from HTS data for autopolyploid species that accounts for errors associated with low sequencing depths, implemented in theRpackage GUSrelate. Simulations revealed that GUSrelate performed similarly to existing GRM methods at high depth but reduced bias in self-relatedness estimates when the sequencing depth was low. Using a panel consisting of 351 tetraploid potato genotypes, we found that GUSrelate produced GRMs from genotyping-by-sequencing (GBS) data that were highly correlated with a GRM computed from SNP array data, and less biased than existing methods when benchmarking against the array-based GRM estimates. GUSrelate provides researchers with a tool to reliably construct GRMs from low-depth HTS data.
Pathogen lifestyle determines host genetic signature of quantitative disease resistance loci in oilseed rape (Brassica napus)
Authors: Jacott Catherine N. , Schoonbeek Henk-jan , Sidhu Gurpinder Singh , Steuernagel Burkhard , Kirby Rachel , Zheng Xiaorong , von Tiedermann Andreas , Macioszek Violetta K. , Kononowicz Andrzej K. , Fell Heather , Fitt Bruce D. L. , Mitrousia Georgia K. , Stotz Henrik U. , Ridout Christopher J. , Wells Rachel
Published: March 2024

Key message

Using associative transcriptomics, our study identifies genes conferring resistance to four diverse fungal pathogens in crops, emphasizing key genetic determinants of multi-pathogen resistance.

Crops are affected by several pathogens, but these are rarely studied in parallel to identify common and unique genetic factors controlling diseases. Broad-spectrum quantitative disease resistance (QDR) is desirable for crop breeding as it confers resistance to several pathogen species. Here, we use associative transcriptomics (AT) to identify candidate gene loci associated with Brassica napus constitutive QDR to four contrasting fungal pathogens: Alternaria brassicicola, Botrytis cinerea, Pyrenopeziza brassicae, and Verticillium longisporum. We did not identify any shared loci associated with broad-spectrum QDR to fungal pathogens with contrasting lifestyles. Instead, we observed QDR dependent on the lifestyle of the pathogen—hemibiotrophic and necrotrophic pathogens had distinct QDR responses and associated loci, including some loci associated with early immunity. Furthermore, we identify a genomic deletion associated with resistance to V. longisporum and potentially broad-spectrum QDR. This is the first time AT has been used for several pathosystems simultaneously to identify host genetic loci involved in broad-spectrum QDR. We highlight constitutive expressed candidate loci for broad-spectrum QDR with no antagonistic effects on susceptibility to the other pathogens studies as candidates for crop breeding. In conclusion, this study represents an advancement in our understanding of broad-spectrum QDR in B. napus and is a significant resource for the scientific community.
Modelling and simulation of heat flow in indexable insert drilling
Authors: Andersson Tobias , Svensson Daniel , Andersson Lassila Andreas
Published: March 2024

In machining, the heat generated during the process deforms the components and the final shape might not meet specified tolerances. There is therefore a need for a compensation strategy which requires knowledge of the workpiece temperature field and the associated thermal distortions. In this work, a methodology is presented for the determination of the heat load for indexable insert drilling of AISI 4140. Compared to previous research, this work has introduced a varying heat load. The heat load is extracted from thermo-mechanical finite element simulations for different nominal chip thicknesses and cutting speeds using the coupled Eulerian-Lagrangian formulation of an orthogonal turning process. The heat load is then transferred to a simplified 2D axisymmetric heat transfer model where the in-process temperature field in the workpiece is predicted. To verify the methodology, the predicted temperatures are compared to the experimentally measured temperatures for various feed rates. It is found that the model is capable of predicting the workpiece temperatures reasonably well. However, the methodology needs to be further explored to validate its applicability.
Prescriptions of homeopathic remedies at the expense of the German statutory health insurance from 1985 to 2021: scientific, legal and pharmacoeconomic analysis
Authors: Leemhuis Hauke , Seifert Roland
Published: March 2024

The prescription of homeopathic remedies at the expense of the statutory health insurance (SHI) system in Germany has been criticized for years due to a lack of evidence. Now, on the planned abolition of the reimbursement of homeopathic medicines in Germany, the debate on this topic has been reignited. The aim of this paper is to show the costs and their development over time incurred by homeopathic remedies in the healthcare system from 1985 to 2021. For this purpose, 15 selected homeopathic medicines were chosen from the drug prescription report (Arzneiverordnungsreport) and analyzed with regard to their development of DDD (Defined Daily Dose) using data from the Wissenschaftliches Institut der Ortskrankenkassen (WidO, Scientific Institute of the General Local Health Insurance Funds) and compared with their respective rational pharmacological alternatives. The price comparison was based on the DDD costs and the pharmacy retail price of the smallest packaging in each case. The clinical study situation for the preparations was also analyzed. For this purpose, the clinical studies provided by the manufacturer and those on PubMed were divided into evidence levels and analyzed. In addition, the presentation of homeopathic remedies on company websites, in online pharmacies, in specialist information and package leaflets was analyzed with regard to side effects, interactions, indication, and information on the alleged effect/proof of efficacy. In many media, information on homeopathic medicines remained incomplete, and non-compliance with the Therapeutic Product Advertising Act (Heilmittelwerbegesetz) was noted. Naming of the products if often very suggestive, too. Manufacturers’ claims of efficacy go far beyond what can be considered proven in terms of evidence-based medicine and the quality of most clinical studies is poor. Homeopathic remedies are on average significantly more expensive than their rational pharmacological alternatives. Furthermore, DDD costs have continued to rise over the years analyzed. In aggregate, from a pharmacoeconomic, legal, and scientific perspective, abolition of reimbursement of homeopathic medicines in Germany at the expense of the SHI system is well justified.
Changes in distinct brain systems identified with fMRI during smoking cessation treatment with varenicline: a review
Authors: Panagopoulos Vassilis N. , Bailey Alexis , Kostopoulos George K. , Ioannides Andreas A.
Published: March 2024

Background

Varenicline is considered one of the most effective treatment options for smoking cessation. Nonetheless, it is only modestly effective. A deeper comprehension of the effects of varenicline by means of the in-depth review of relevant fMRI studies may assist in paving the development of more targeted and effective treatments.

Methodology

A search of PubMed and Google Scholar databases was conducted with the keywords “functional magnetic resonance imaging” or “fMRI”, and “varenicline”. All peer-reviewed articles regarding the assessment of smokers with fMRI while undergoing treatment with varenicline and meeting the predefined criteria were included.

Results

Several studies utilizing different methodologies and targeting different aspects of brain function were identified. During nicotine withdrawal, decreased mesocorticolimbic activity and increased amygdala activity, as well as elevated amygdala-insula and insula-default-mode-network functional connectivity are alleviated by varenicline under specific testing conditions. However, other nicotine withdrawal-induced changes, including the decreased reward responsivity of the ventral striatum, the bilateral dorsal striatum and the anterior cingulate cortex are not influenced by varenicline suggesting a task-dependent divergence in neurocircuitry activation. Under satiety, varenicline treatment is associated with diminished cue-induced activation of the ventral striatum and medial orbitofrontal cortex concomitant with reduced cravings; during the resting state, varenicline induces activation of the lateral orbitofrontal cortex and suppression of the right amygdala.

Conclusions

The current review provides important clues with regard to the neurobiological mechanism of action of varenicline and highlights promising research opportunities regarding the development of more selective and effective treatments and predictive biomarkers for treatment efficacy.
Upper bounds for the critical values of homology classes of loops
Authors: Rademacher Hans-Bert
Published: March 2024

In this short note we discuss upper bounds for the critical values of homology classes in the based and free loop space of compact manifolds carrying a Riemannian or Finsler metric of positive Ricci curvature. In particular it follows that a shortest closed geodesic on a compact and simply-connected n-dimensional manifold of positive Ricci curvature $$\text {Ric}\ge n-1$$

Ric
≥
n
-
1

has length $$\le n \pi .$$

≤
n
π
.

This improves the bound $$8\pi (n-1)$$

8
π
(
n
-
1
)

given by Rotman (Positive Ricci curvature and the length of a shortest periodic geodesic. arXiv:2203.09492, 2022).
Combination of IL-33 with PD-1 blockade augment mILC2s-mediated anti-tumor immunity
Authors: Yue Jiawei , Guo Hui , Xu Peng , Ma Jinhong , Shi Weifeng , Wu Yumin
Published: March 2024

Background

Group 2 innate lymphoid cells (ILC2s) represent one of the main tissue-specific innate lymphoid cell populations, which are key drivers of cytokine secretion in their occupational niche. However, the precise involvement of ILC2s in cancer immunity and their potential impact on immunotherapeutic approaches remain poorly understood.

Methods

The proportion of ILC2s originating from various tissue sources were quantified through flow cytometry, along with the determination of CD4+ T cell and CD8+ T cell percentages. Flow cytometry was also employed to assess IFN-γ production and programmed cell death protein-1 (PD-1) expression in T cells. Immunohistochemistry was utilized to detect IL-33 expression in tumor tissues, while immunofluorescence was employed to confirm the infiltration of ILC2s in both murine and human tumor tissues.

Results

In this study, we provide evidence that intra-tumoral ILC2s in lung adenocarcinoma (LUAD) exist in a quiescent state. However, the activation of intra-tumoral ILC2s is induced by IL-33 specifically in a natural ILC2s (nILC2, ST2+KLRG1−) phenotype. Considering the pivotal role of PD-1 in cancer immunotherapy and its immunoregulatory functions, we investigated the synergistic effects of IL-33 and anti-PD-1 and found that their combination enhances anti-tumor immunity and improves the efficacy of immunotherapy. Moreover, this combination leads to the upregulation of activated mature ILC2s (mILC2, ST2+KLRG1+) phenotype, thereby highlighting the activated ILC2s as a novel enhancer of the immunoregulatory properties of anti-PD-1.

Conclusions

Collectively, these findings underscore the significance of ILC2s and their contribution to the anti-tumor response in the context of cancer immunotherapy. Consequently, the simultaneous targeting of ILC2s and T cells represents a potentially promising and widely applicable strategy for immunotherapeutic interventions.