bluuebunny/crossref_metadata_2025 huggingface dataset:
A Stress‐Driven Double‐Phase–Field Framework for Tensile Fracturing Processes in Transversely Isotropic Rocks
Authors: Yuan Weihong , Zhao Yang , Zhang Bingyin
Published: September 2024

We present a double‐phase–field framework for tensile fracturing processes in transversely isotropic rocks. Two distinct phase‐field variables are introduced to represent smeared approximations of tensile fractures along the weak bedding planes and through the anisotropic rock matrix, respectively. Driving forces that control fracture propagation in the phase‐field framework are constructed as a stress‐based formula with a recently developed tensile failure criterion that distinguishes the two failure modes in transversely isotropic rocks. For numerical implementation, we adopt a staggered integration scheme and decouple the governing equations so that the displacement field and phase‐field variables can be updated in sequence for a given loading step. The finite element formulation of the proposed framework is introduced in detail in this paper and is implemented in an in‐house finite element code. The numerical implementation is then validated by reproducing the uniaxial tension test results of Lyons sandstone. After that, we conduct simulations on a pre‐notched square plate loaded in tension to demonstrate the features of the proposed framework. Finally, we conduct simulations of three‐point bending tests of Pengshui shale and show that the proposed model can reproduce the force–displacement curves and failure patterns of specimens with different bedding plane orientations observed in laboratory experiments.
Semi‐Analytical Solution for One‐Dimensional Nonlinear Consolidation of Multilayered Soil Considering Self‐Weight and Boundary Time Effect
Authors: Zong Mengfan , Zhang Jing , Wu Wenbing , Yu Ziye , Zhang Yi , Mei Guoxiong
Published: September 2024

The self‐weight stress in multilayered soil varies with depth, and traditional consolidation research seldom takes into account the actual distribution of self‐weight stress, resulting in inaccurate calculations of soil consolidation and settlement. This paper presents a semi‐analytical solution for the one‐dimensional nonlinear consolidation of multilayered soil, considering self‐weight, time‐dependent loading, and boundary time effect. The validity of the proposed solution is confirmed through comparison with existing analytical solutions and finite difference solution. Based on the proposed semi‐analytical solution, this study investigates the influence of self‐weight, interface parameter, soil properties, and nonlinear parameters on the consolidation characteristics of multilayered soil. The results indicate that factoring in the true distribution of self‐weight leads to a faster dissipation rate of excess pore water pressure and larger settlement and settlement rate, compared to not considering self‐weight. Both boundary drainage performance and soil nonlinearity have an impact on consolidation. If the boundary drainage capacity is inadequate, the influence of soil nonlinearity on consolidation diminishes.
The effect of silane‐modified carbon black and nano‐silica, individually and in combination, on the performance of ethylene–propylene–diene monomer rubber
Authors: Jaberi Mofrad Farzaneh , Ahmadpour Ali , Ostad Movahed Saeed
Published: September 2024

This study assesses the effectiveness of a specially developed surface‐modified carbon black, both on its own and in combination with nano‐silica, as a hybrid filler for ethylene–propylene–diene monomer (EPDM) rubber compounds. The modification process, which included treatment with a silane coupling agent, resulted in enhanced curing characteristics. The ∆Torque values for compounds incorporating the modified carbon black exceeded those of other formulations by 25.85%. Scanning electron microscopy (SEM) analysis demonstrated improved filler dispersion and better compatibility between rubber and filler due to the surface modification. The silane‐modified carbon black showed considerable enhancements in mechanical properties, particularly in tear resistance, with increases in tensile and tear strength of 22.46% and 34.86%, respectively, following surface treatment. Dynamic mechanical analysis (DMA) indicated the influence of both surface modification and filler type, revealing that the combination of modified carbon black and nano‐silica achieved a reduction in rolling resistance of 20.41% and enhanced ice and wet grip performance by 7.95%. Additionally, modified carbon black displayed varying effects on the glass transition temperature. Thermal gravimetric analysis (TGA) confirmed that the thermal stability of the compounds was consistent, while solvent resistance improved with surface modification, as shown by swelling ratios. Thermodynamic analysis indicated that the surface modification of carbon black positively influences the elasticity and chain mobility of the rubber compounds studied. In conclusion, the careful selection and optimization of filler materials and their modifications are essential for customizing the properties of rubber compounds to satisfy specific performance criteria and applications.

Highlights

Promising EPDM compounds were prepared with Silane‐Modified CB and Nano‐Silica.

Silane‐modified CB effectively improved the curing properties of the EPDM compound.

The ΔTorque and cross‐link density of modified CB/EPDM show the highest value.

Modified CB/Nano‐Silica/EPDM exhibited significant improvement in tear strength.

Modified CB/Nano‐silica/EPDM have lower rolling resistance and higher wet grip.
Synergistic effects of sisal/glass fiber hybridization and eggshell powder filler on the performance of eco‐friendly polymer composites
Authors: Hadlahalli chandrashekar Priya , Nagarajachari Upendra , Thyavihalli Girijappa Yashas Gowda , Byrapura Chandregowda Hemaraju , Kalappa Prashantha
Published: September 2024

In recent years, there has been a significant emphasis on the development of composite materials that are both high‐performing and environmentally friendly. Hybrid polymer composites that are reinforced by both sisal and glass fibers are introduced in this study. Investigation was conducted to evaluate the combined influence of hybrid reinforcements and Egg Shell Powder (ESP) on the mechanical properties of the composites. The hand layup technique was employed to create hybrid laminates by incorporating variable amounts of ESP (0–15 wt%) and employing various stacking sequences. Various mechanical testing was administered to the composites that had been prepared. The results indicated that the glass/sisal hybrid laminates exhibited superior mechanical properties in comparison to the non‐hybrid sisal laminates, which was attributed to the synergistic benefits of incorporating both sisal and glass fibers. The incorporation of Egg Shell Powder significantly improved the material's mechanical properties. The glass/sisal hybrid laminates with 15% ESP laminate demonstrated the maximum tensile strength (195.23 MPa), flexural strength (150.02 MPa), and ILSS (7.55 MPa). Scanning electron microscopy enabled a comprehensive analysis of the hybrid composites' interfacial adhesion and microstructure. This investigation verified that the ESP was effectively dispersed and had a substantial effect on the interface between the matrix and the fibers. The hybrid composites that are generated are environmentally friendly and exhibit extraordinary potential for a variety of applications, offering a sustainable and high‐performing alternative to conventional synthetic composites. These discoveries promote the utilization of bio‐based resources in the composites industry and advance the development of sustainable materials.

Highlights

The glass/sisal hybrid laminates with 15% ESP laminate showed highest tensile strength of 195.23 MPa

Hybrid composites exhibited superior mechanical properties.

ESP addition significantly improved interfacial adhesion and strength

Water absorption decreased with increasing ESP content up to 15%

Development of Eco‐friendly composites suitable for automotive and aerospace applications
Magnetic elastomer composites with tunable magnetization behaviors for flexible magnetic transducers
Authors: Wang Yue , Wang Zihan , Liu Xiayu , Zhang Luodan , Li Qingxin , Abdallaha Duaa , Song Xiaoli , Zhang Lifeng , Sun Hui , Liu Junliang
Published: September 2024

Magnetic elastomer composites are extending the field of soft robotics by integrating the flexibility of elastomers with the versatile performance of magnetic materials. In this work, a series of magnetic elastomers (BaCoxTixFe12–2xO19/PDMS) with tunable magnetic response have been successfully synthesized. In this composite, the magnetic component consists of Co‐Ti co‐doped barium hexaferrite (BaCoxTixFe12–2xO19, BCTF) nano powders, and the matrix is made of polydimethylsiloxane (PDMS). The coercivity (Hc) of BCTF can be reduced from 3950 Oe to 70 Oe, which bestow on the magnetic elastomer different magnetic response behavior. These magnetic elastomer composites obtained by blending have low Young's modulus, approximately 1.5 MPa. Furthermore, when applying the same external magnetic field, BaCo1.2Ti1.2Fe9.6O19/PDMS the magnetic deformation Angle can be as high as 60°. These magnetic elastomers exhibit different magnetic‐induced deformation owing to the adjustable permeability of the magnetic nanoparticles. This research significantly advances the design of applications with specific magnetic characteristics, such as sensors and transducers, thus opening new horizons for innovation in soft robotics and related fields.

Highlights

All elastomer composite exhibit a low modulus of approximately 1.5 MPa.

These composites exhibit different magnetic response behaviors.

This research provides a solution for the innovation of transducers.
A perspective on the time‐dependent structure and properties of amorphous polymer
Authors: Juska Thomas
Published: September 2024

A molecular mechanism of viscoelastic deformation is presented. Amorphous polymers are characterized as a heterogeneous network of nanoscale cells. A “cell” is a homogeneous region within the network. Each cell phase fluctuates between the glassy and elastomer states with a period τ. The values of τ vary from cell to cell over several orders of magnitude and are strong functions of temperature. Whether a given cell responds as glassy or elastomeric depends on the ratio between its period of phase fluctuation (τj) and the period of observation (1/f), where f is the test frequency. We express this ratio, the Deborah number, as (τj × f), and present equations for modulus and energy loss as functions of (τj × f). The condition (τj × f) = 1 defines the glass transition of a cell, which arises cell‐by‐cell over a range of temperature, or over a range of time under stress. Viscoelastic deformation occurs if a cell changes phase while under stress. Energy stored during glassy state deformation is lost if the cell fluctuates to the elastomeric state. Stress is out of phase with strain, because strain rate controls the level of stress in glassy cells between phase fluctuations.

Highlights

A molecular mechanism of viscoelasticity is presented that does not involve viscous flow.

Amorphous polymer is a heterogeneous network of nanoscale cells.

Cells fluctuate in phase between glassy and elastomeric states due to their size.

Time‐dependent properties are caused by time‐dependent structure.

Energy is lost when glass phase cells under stress fluctuate to the elastomer phase.
Interpretable machine learning‐assisted strategy for predicting the mechanical properties of hydroxyl‐terminated polyether binders
Authors: Han Ruohan , Fu Xiaolong , Guo Hongwei
Published: September 2024

Hydroxy‐terminated polyether (HTPE) binders are attractive in the weapons materials and equipment industry for their insensitive properties and flexibility. We propose an interpretable machine learning‐assisted modeling strategy to predict the mechanical properties of HTPE binders for the first time using machine learning methods. In this strategy, the effects of formulation composition, multiscale characterization, preparation conditions, and mechanical experimental conditions are evaluated on the mechanical properties of HTPE binders. As part of the study, three different techniques were used to predict material properties: bag‐based methods (Extra Random Tree, Random Forest), boosting‐based methods (XGBoost, CatBoost, and Gradient Boosted Regression), and Artificial Neural Networks (MLPs), all of which were highly accurate in predicting material properties. Based on this, SHAP analysis is used to explain how these influencing factors influence the material properties. An efficient method for examining HTPE binders formulations is provided by this strategy.
N‐heterocyclic carbene copper complexes catalyze the C1 polymerization of substituted diazomethanes
Authors: Kang Songsu , Lu Sherilyn J. , Cho Minyeong , Cho Youngsang , Sultane Prakash R. , Bielawski Christopher W.
Published: September 2024

The C1 polymerization of substituted diazomethanes, including diazoethane and 2,2,2‐trifluoromethyl diazomethane, are reported. N‐heterocyclic carbene copper complexes were employed as catalysts for the polymerization reactions and afforded the corresponding persubstituted polymers containing methyl or trifluoromethyl units along the backbones of the polymer products. The polymers were characterized using size exclusion chromatography, a variety of spectroscopic and thermal techniques, and contact angle measurements. Polymers prepared using the C1 polymerization methodology described herein are more hydrophobic than related polymers that were obtained using a standard C2 polymerization method and the fluorinated polymers were determined to be more hydrophobic than their hydrogenated analogues. The relationship between fluorine content and wettability of persubstituted polymers was quantified.
A DFT Analysis of Structural and Electronic Features of [Mo(CO)6‐n(SiX)n] (n=1, 2 and 3, and X=O, S, Se and Te) Complexes
Authors: Sivan Akhil K. , Thomas Jisha Mary , Christopher Jeyakumar Thayalaraj
Published: September 2024

DFT was used to analyze the molecular and electronic structures of the mono, di‐ and tri‐substituted isomers of [Mo(CO)6‐n(SiX)n] (where, X=O, S, Se, Te) and they were compared to the Mo(CO)6 complex. The total energy of all the complexes indicates that the trans isomer is slightly more stable than the cis isomer, but the stability of the fac and mer isomers is comparable. The HOMO‐LUMO energy gap of the complexes was determined and it indicated that the energy gap of the newly designed complexes is smaller than that of the parent complex Mo(CO)6 (1), ranging from 3.45–5.08 eV for the complexes 2–21. The FMO analysis of 2–21 showed that they are more reactive than complex 1. Insights on the bonding nature of these complexes are provided by the NPA, NBO, and EDA studies. The bond contribution from the Si atom in the Mo−Si bond is greater than that from the Mo atom, based on the NBO study. However, the C atom contributes more to the Mo−CO bond as well. Atomic charges on the Mo atom have a higher negative charge and the Si atom shows a positive charge in all the complexes. This study provides valuable information about the isolobal and isoelectronic nature of different substitutions of Si−X bonds at different positions instead of CO molecule in [Mo(CO)6].
Synthetic and Natural Xanthones as Antibacterial Agents—Review
Authors: Prathiksha Joyline , Murali Thokur Sreepathy , Nayak Roopa
Published: September 2024

Xanthones, a class of polyketide derivatives characterized by a dibenzo‐γ‐pyrone core structure, are aromatic oxygenated cyclic compounds extensively found in nature. They are known for their diverse biological activities, including anti‐Alzheimer, antitumor, and antidiabetic properties, which have spurred extensive research into their therapeutic potential. One of the most significant challenges facing mankind currently is the development of antibiotic resistance in pathogenic microbes making microbial infections increasingly difficult to treat. The formation of biofilms enhances bacterial resistance to antibiotics, immune defenses, and environmental stresses. In this review, we have categorized xanthones, both of biological origin and synthesized, based on their structure and summarized the recent studies on their ability to inhibit Gram‐positive and ‐negative bacteria as well as the various underlying mechanisms that contribute to their microbicidal activity. These mechanisms include inhibition of virulence factors and biofilm formation, interaction with cell membranes, and interference with cell wall synthesis and DNA replication. In addition, we have listed the various methods involved in biofilm inhibition and the structure‐activity relationship of various xanthone molecules, highlighting how xanthone derivatives exhibit increased antibacterial activity. With the growing concern of antibiotic resistance, exploring natural compounds like xanthones to study their interaction with bacterial cells is crucial for identifying new treatment options.
Fast Horizon Approximation: Impacts on Integrated Photovoltaic Irradiation Simulations
Authors: Sovetkin Evgenii , Gerber Andreas , Pieters Bart E.
Published: September 2024

In applications that utilize detailed solar resource assessments with high‐resolution topography data, calculating the topographic horizon is critical for accurate shading calculations. In particular, the horizon calculation significantly influences the time needed to model solar irradiation in integrated photovoltaic applications. The new approximate horizon algorithm was developed to balance accuracy and computation time. This study evaluates the algorithm's performance in modeling vehicle‐ and building‐integrated photovoltaics, considering the impact of surface orientation and elevation. It is demonstrated that the proposed horizon algorithm achieves the same level of accuracy four times faster than previously known approaches for vehicle‐integrated applications. Moreover, for building‐integrated applications, the proposed approach performs better at elevations higher than 10 m on facades and roofs. Finally, the impact of maximum sampling distance on irradiation for high‐ and low‐resolutions topography is studied.
Role of innovative behaviour as a missing linchpin in artificial intelligence adoption to enhancing job security and job performance
Authors: Ghorbanzadeh Davood , Espinosa‐Cristia Juan Felipe , Abdelrasheed Nasser Said Gomaa , Mostafa Sanaa Soliman Saeed , Askar Shavan , Almufti Saman M.
Published: September 2024

Building upon the sociotechnical system theory, the present study contributes by examining the relationship between artificial intelligence (AI) adoption, employees' innovative behaviour on employee performance and job security (JS). The primary data is collected from 340 employees from firms located in the industrial hub of a developing economy using a simple random technique, and data is analysed using Smart‐PLS 3 from the manufacturing sector. The study evidences that employees' adoption and utilization of AI technologies positively influence their innovative behaviour, job performance (JP), and security. Moreover, the study finds a mediating role of innovative behaviour to connect the dots. Organizations can prioritize using AI‐driven training programmes so employees can use AI tools efficiently. Study findings also encourage employees to engage in innovative work behaviours like investigating novel concepts and experimenting with AI technologies to improve JP. This study invalidates that AI will replace employees at the workplace, as we can safely conclude that AI adoption enhances JP and JS.
Multidimensional Approach for the Assessment of Environmental Pollution and Health Risk Associated With V, Ni, Cr, Cu, and Zn in the Recent Sediments of Kabini Interstate River, Southeastern Western Ghats, India
Authors: Gupta Himanshi , Krishnakumar Appukuttanpillai , Krishnan Krishnan Anoop
Published: September 2024

The present work intends to study the variation of heavy metals (HMs) to scrutinize the scenario of pollution index and associated environmental risk, as well as source weathering conditions along the Kabini River. The decreasing order of concentration of HMs along the basin is Cr > V > Ni > Zn > Cu. The paper spotlights the pollution grade in sediments, assessed by the geo‐accumulation index (Igeo), contamination factor (Cf), pollution load index (PLI), and enrichment factor (Ef). The assessment of ecological risk is studied as potential ecological risk index (RI), toxic risk index (TRI), and modified hazard quotients (mHQs). As per the Igeo and Cf, V and Cr concentrations are higher in the region. Further, PLI confirmed that 35% of samples exceeded the limits of sediment quality guidelines. The RI and TRI values show that a higher ecological risk is associated with Ni, V, and Cr and with Cu and Cr, respectively. Additionally, the 23% Ni and 20% Cu samples from mHQ indicate the severity of pollution in the aquatic environment. The inputs from anthropogenic and natural sources change the concentration of these HMs along the region. Moreover, the study of CIA and plagioclase index of alteration plots confirmed the low to intense weathering conditions. The statistical approach shows the linkage between Cr–V, Cu–Zn, and principal component analysis–derived prominent sources: industrial and agricultural runoff, as well as higher silicate weathering, contribute to the HMs concentration in the region. The Kabini River passes through different climatic and land‐use domains of Kerala and Karnataka, which eventually regulate the HM concentration and geo‐environmental processes in the region and affect the health risk to humans in one or the other way. The reference data generated from the present work are absolutely new and would be significant in the future for deriving sustainable development plans for the well‐being of human beings and precious natural resources.
Extreme low‐level wind jets in Storm Ciarán
Authors: Gray Suzanne L. , Volonté Ambrogio
Published: September 2024

Satellite imagery of Storm Ciarán as it approached the UK early on 1 November 2023 showed characteristic banding that fuelled media reports that Ciarán could contain a sting jet, with enhanced likelihood of damaging surface winds and gusts. Here operational numerical weather prediction model output is used with trajectory analysis to reveal the existence of at least two wind speed maxima attributed to sting jets. The small‐scale sting jets are located beneath, and likely affected by, far broader overrunning strong wind regions attributed to a deeply descending dry intrusion, thus highlighting the likely interaction of these airstreams at low levels.
Revisiting the self‐supply model: A foundational, not a complimentary model for water supply in rural households
Authors: Wainaina George Kiambuthi , Barbosa Helen
Published: September 2024

In this opinion article, we propose that self‐supply, as a model for household‐managed water supply in rural areas, is the foundational model for water supply in rural households. Any other model is only complementary while it lasts. Therefore, self‐supply needs more emphasis in research and intentional exposure and support in practice. This is underscored by the fact that despite the use of taxes, transfers, and tariffs that fund other service models, major water service gaps still exist in rural households forcing them to invest directly in self‐supply. Over 2.2 billion people globally still lack access to safe water. Our argument is not that other models such as communal or government models are irrelevant; rather, it is that self‐supply is the foundational and often preferred model for rural households due to reliability, predictability, control, and flexibility. Yet it is overlooked often. Therefore, we call for investing in research informing self‐supply policy, practice, and funding especially where it links with other models to be prioritized. This will likely accelerate the achievement of SDG 6.
Artificial Intelligence Methods for Evaluating Mitochondrial Dysfunction: Exploring Various Chemical Notations Suitable for Neural Language Processing Models
Authors: Viganò Edoardo Luca , Colombo Erika , Ballabio Davide , Roncaglioni Alessandra
Published: September 2024

In recent years, the integration of Artificial Intelligence and Machine Learning methods, such as Neural Language Processing (NLP), with biochemical and biomedical research has revolutionized the field of toxicology defining a profound advancement in our understanding of the toxicological effects of diverse chemical compounds on biological systems.

Among various toxic effects, mitochondrial dysfunction has emerged as a crucial endpoint due to its role in various diseases related to the liver, heart brain, and more in general related to different physiological processes. Indeed, mitochondria are indispensable organelles in cells that serve as the primary hub for energy production, and they are responsible for critical functions in cell metabolism, signaling, and cellular demise. Traditional methods for assessing chemical hazards and their impact on mitochondrial function have relied heavily on experimental assays and animal studies, which are often time-consuming, resource-intensive, and limited in scalability. To overcome these limitations, in silico methods have emerged as indispensable tools in toxicological research to reduce the need for traditional in vivo testing and saving valuable resources in terms of time and money.

This study utilized NLP models to explore diverse chemical notations utilized to encode chemical information such as Simplified Molecular Input Line Entry System (SMILES), DeepSMILES and Self-Referencing Embedded Strings (SELFIES), with the aim of evaluating toxic interactions between chemicals and specific biological targets, achieving high predictivity performance.
Balancing Imbalanced Toxicity Models: Using MolBERT with Focal Loss
Authors: Masood Muhammad Arslan , Kaski Samuel , Ceulemans Hugo , Herman Dorota , Heinonen Markus
Published: September 2024

Drug-induced liver injury (DILI) presents a multifaceted challenge, influenced by interconnected biological mechanisms. Current DILI datasets are characterized by small sizes and high imbalance, posing difficulties in learning robust representations and accurate modeling. To address these challenges, we trained a multi-modal multi-task model integrating preclinical histopathologies, biochemistry (blood markers), and clinical DILI-related adverse drug reactions (ADRs). Leveraging pretrained BERT models, we extracted representations covering a broad chemical space, facilitating robust learning in both frozen and fine-tuned settings. To address imbalanced data, we explored weighted Binary Cross-Entropy (w-BCE) and weighted Focal Loss (w-FL) . Our results demonstrate that the frozen BERT model consistently enhances performance across all metrics and modalities with weighted loss functions compared to their non-weighted counterparts. However, the efficacy of fine-tuning BERT varies across modalities, yielding inconclusive results. In summary, the incorporation of BERT features with weighted loss functions demonstrates advantages, while the efficacy of fine-tuning remains uncertain.
Revisiting the fermion-field nontopological solitons
Authors: Xie Ke-Pan
Published: September 2024

Abstract

Nontopological fermionic solitons exist across a diverse range of particle physics models and have rich cosmological implications. This study establishes a general framework for calculating fermionic soliton profiles under arbitrary scalar potentials, utilizing relativistic mean field theory to accurately depict the interaction between the fermion condensate and the background scalar field. Within this framework, the conventional “fermion bound states” are revealed as a subset of fermionic solitons. In addition, we demonstrate how the analytical formulae in previous studies are derived as special cases of our algorithm, discussing the validity of such approximations. Furthermore, we explore the phenomenology of fermionic solitons, highlighting new formation mechanisms and evolution paths, and reconsidering the possibility of collapse into primordial black holes.
Indirect constraints on third generation baryon number violation
Authors: Beneke Martin , Finauri Gael , Petrov Alexey A.
Published: September 2024

Abstract

The non-observation of baryon number violation suggests that the scale of baryon-number violating interactions at zero temperature is comparable to the GUT scale. However, the pertinent measurements involve hadrons made of the first-generation quarks, such as protons and neutrons. One may therefore entertain the idea that new flavour physics breaks baryon number at a much lower scale, but only in the coupling to a third generation quark, leading to observable baryon-number violating b-hadron decay rates. In this paper we show that indirect constraints on the new physics scale ΛBNV from the existing bounds on the proton lifetime do not allow for this possibility. For this purpose we consider the three dominant proton decay channels p → $$ {\ell}^{+}{\nu}_{\ell}\overline{\nu} $$

ℓ
+

ν
ℓ

ν
¯

, p → $$ {\pi}^{+}\overline{\nu} $$

π
+

ν
¯

and p → π0ℓ+ mediated by a virtual bottom quark.
On the absence of the chiral magnetic effect in equilibrium QCD
Authors: Brandt B. B. , Endrődi G. , Garnacho-Velasco E. , Markó G.
Published: September 2024

Abstract

In this paper we investigate the chiral magnetic effect (CME): the generation of an electric current due to a homogeneous background magnetic field and a homogeneous chiral imbalance in QCD. We demonstrate that the leading coefficient describing the CME vanishes in equilibrium, both for free fermions as well as in full QCD. Our full QCD results are based on continuum extrapolated lattice simulations using dynamical staggered quarks with physical masses as well as quenched Wilson quarks. We show that it is crucial that a gauge invariant ultraviolet regularization is used to compute the CME and elaborate on why some of the existing in-equilibrium calculations of this effect gave a nonzero result. We stress that our findings imply the absence of a time-independent CME current flowing in equilibrium QCD, but do not concern the CME as an out-of-equilibrium, time-dependent effect.
Normalization of ZZ instanton amplitudes in type 0B minimal superstring theory
Authors: Chakrabhavi Vivek , Eniceicu Dan Stefan , Mahajan Raghu , Murdia Chitraang
Published: September 2024

Abstract

We study ZZ instanton corrections in the (2, 4k) $$ \mathcal{N} $$
N
= 1 minimal superstring theory with the type 0B GSO projection, which becomes the type 0B $$ \mathcal{N} $$
N
= 1 super-JT gravity in the k → ∞ limit. Each member of the (2, 4k) family of theories has two phases distinguished by the sign of the Liouville bulk cosmological constant. The worldsheet method for computing the one-loop normalization constant multiplying the instanton corrections gives an ill-defined answer in both phases. We fix these divergences using insights from string field theory and find finite, unambiguous results. Each member of the (2, 4k) family of theories is dual to a double-scaled one-matrix integral, where the double-scaling limit can be obtained starting either from a unitary matrix integral with a leading one-cut saddle point, or from a hermitian matrix integral with a leading two-cut saddle point. The matrix integral exhibits a gap-closing transition, which is the same as the double-scaled Gross-Witten-Wadia transition when k = 1. We also compute instanton corrections in the double-scaled matrix integral for all k and in both phases, and find perfect agreement with the string theory results.
Rigid iatrogenic hallux varus: a decades’ worth experience with arthrodesis of the metatarsophalangeal joint
Authors: Belfiore S. , Vaggi S. , Vitali F. , Zanirato A. , Quarto E. , Formica M.
Published: September 2024

Purpose

Arthrodesis of the first ray metatarsophalangeal joint (MPJ) is the gold standard in iatrogenic hallux varus (IHV) in the presence of stiffness and osteoarthritis. The purpose of this study is to collect clinical and radiographic results and complications of MPJ arthrodesis in rigid iatrogenic HV.

Methods

A retrospective evaluation of rigid iatrogenic HV undergoing arthrodesis with a minimum follow-up (FU) of two years was performed. The clinical parameters assessed were visual analog scale (VAS), the AOFAS Hallux Metatarsophalangeal-Interphalangeal Scale score and the satisfaction scale. The radiological parameters evaluated the first to second metatarsal angle (IMA) and the angle of hallux valgus (HVA). Complications were also analysed.

Result

A total of 18 patients (19 procedures) with a mean FU of 5.5 ± 2.5 years were included. The mean VAS improved from 7.3 ± 1.6 to 1.3 ± 1.2 (p < 0.05) at the last FU. Similarly, the AOFAS Hallux Metatarsophalangeal-Interphalangeal scale score significantly improved to 82 ± 9.2 (p < 0.05). Radiological evaluation demonstrated a 1–2 IMA improvement from 4.4 ± 2.2° preoperatively to 8.9 ± 2.4° at 3 months post-operatively. Similarly, there was a significant (p < 0.05) improvement of the HVA from − 22.7 ± 4.1° to 13.1 ± 4.1° at three months post-operative (p < 0.05). No signification loss of correction was noted at the last follow-up (p > 0.05). In one case, a delayed fusion at the arthrodesis site required surgical revision to promote fusion. No patient experienced pain with stress from the first MTP joint arthrodesis site or identified the arthrodesis site as a source of pain. No patient required implant removal. Re-operation and revision rates were 5.3%. The overall complications rate was 15.8%.

Conclusions

MPJ fusion effectively corrects Iatrogenic Hallux Varus in cases of rigid and fixed deformities in the medium- to long-term follow-up, with lasting improvements in AOFAS and VAS scores. The procedure is characterised by a non-negligible risk of complications, reoperations and revisions.

Level of evidence

Level IV, case series.
Catalysing Environmental Action: a Governance Framework for Enhancing Individual Participation in Sub-Saharan Africa’s Plastic Circular Economy
Authors: Ambituuni Ambisisi , Ajala Olubunmi , Schroeder Patrick , Oyinlola Muyiwa
Published: September 2024

Plastic waste poses a significant challenge to achieving sustainable production and consumption of resources, particularly in sub-Saharan Africa where effective governance and waste management systems are lacking. In this paper, we develop an empirical understanding of the influence of public governance system on promoting circular economy (CE) for plastic actions among individuals. Through a survey of 1475 participants across five sub-Saharan African countries, we tested five hypotheses drawing on New Governance Theory and CE Action Recipe to explore the relationship between governance and individual’s actions supporting CE for plastic. We found that a governance system that supports CE practices and exhibits governance efficiency is positively associated with individuals’ actions supporting CE for plastic. The awareness of government policies, laws and regulations, institutions, processes, and programmes have a significant impact on individuals’ engagement in plastic circularity practices. The paper’s theoretical and governance implications highlight the relevance of public governance in shaping action towards a CE for plastic at the individual level.
Delayed Shift in Microbiota Composition in a Marine Microcosm Pollution Experiment
Authors: Ramirez Luis Yndy Ariem , Angell Inga Leena , Nilsen Tonje , Rudi Knut
Published: September 2024

Benthic habitats are the largest habitats on Earth, being essential for marine ecosystem functioning. Benthic habitats are particularly vulnerable towards pollution and anthropogenetic influence due to general oligotrophic nature. We, therefore, simulated pollution events involving nitrate and sulphate, in combination with organic carbon. We then observed the microbiota composition the following month. Surprisingly, upon nitrate addition, an abrupt response was observed between two and three weeks after the pollution event. We observed a threefold reduction in species richness, with a dominance of the genus Pseudarchobacter within the Campylobacteriota phylum, concurring with a decrease in nitrification potential and an increase in Dissimilatory Nitrate Reduction to Ammonium (DNRA) and a regain in denitrification. Likewise, addition of sulphate contributed to a delayed response with reduction in species richness albeit weaker than for nitrate, leading to a shift towards potential spore-forming Firmicutes. There was also an increase in DNRA, but only for the oxic conditions, concurring with a regain in sulphate reductio and denitrification. For the nitrate addition experiments, the delay in response could potentially be attributed to the genus Pseudarchobacter which rely on sulphides for denitrification, while for the sulphate addition experiments, the delayed response might be explained by the germination of spores. The late increase of DNRA may indicate a shift towards a different metabolic regime for nitrogen. In conclusion, our microcosm experiments revealed delayed abrupt microbiota shifts resembling tipping points that can potentially be overlooked in natural ecosystems.
Suboptimal osteoporosis care in hospitalized patients: a retrospective analysis of vertebral compression fractures detected on computed tomography
Authors: Minalyan Artem , Li Terrence , D’Anna Kathleena , Alfraji Nasam , Gabrielyan Lilit , Downey Christina
Published: September 2024

Vertebral compression fractures (VCFs) are the most common osteoporotic fractures. Only 1/3 of patients with VCFs are clinically diagnosed. In our institution, the Fracture Liaison Service (FLS) was launched in 2017 to improve osteoporosis management for hospitalized patients. (1) To assess osteoporosis awareness among medical providers for emergency department (ED)/hospitalized patients aged 50 or greater; (2) To estimate the rate of FLS consults or referrals to primary care providers (FLS/PCP) by primary teams. A centralized radiology system was used to examine all thoracic and lumbar computed tomography (CT) scans conducted between June 1, 2017 and June 1, 2022. 449 studies were identified with the radiologic impression “compression fracture”. 182 studies were excluded after manual chart review. 267 hospitalizations/ED visits with lumbar and/or thoracic spine CT scans were included. Referrals to FLS (26) or PCP (27) were made in 53 cases (~ 20% of the total). In the ED subgroup (131 hospitalizations), only 17 patients had FLS/PCP referrals. The “compression fracture” was mentioned in 227 (85%) discharge notes (any part), while “osteoporosis” was mentioned in only 74 (28%) hospitalizations. A statistically significant difference was found between the two groups when “osteoporosis” was mentioned in the “assessment and plan” section (p = 0.02). Our data show that the overall osteoporosis care for affected patients is suboptimal. Medical providers often overlook the presence of osteoporosis, leading to a lack of consultation with the FLS of referral to PCPs for further evaluation and treatment.
Incremental prognostic value of left atrial strain in apical hypertrophic cardiomyopathy: a cardiovascular magnetic resonance study
Authors: Tang Yun , Ma Xuan , Wang Jiaxin , Yang Shujuan , Dong Zhixiang , Chen Xiuyu , Zhao Kankan , Wei Zhuxin , Xu Jing , Song Yanyan , Xiang Xiaorui , Cui Chen , Zhu Yanjie , Yang Kai , Zhao Shihua
Published: September 2024

Objectives

This study aimed to evaluate the prognostic value of left atrial (LA) strain in patients with apical hypertrophic cardiomyopathy (ApHCM), as assessed by cardiac magnetic resonance (CMR) imaging.

Methods

Four hundred and five consecutive patients with ApHCM who underwent CMR examination were retrospectively included. The study endpoint included all-cause death, heart transplant, aborted sudden cardiac death, hospitalization for heart failure, stroke, and new-onset atrial fibrillation (AF).

Results

After a median follow-up of 97 months, 75 patients (18.5%) reached the endpoint. Patients were divided into two groups based on the median LA reservoir strain of 29.4%. The group with lower LA reservoir strain had thicker maximum wall thickness, greater late gadolinium enhancement extent, and smaller end-diastolic volume index, stroke volume index, and cardiac index (all p < 0.02). For LA parameters, this subgroup showed greater diameter and volume index and worse ejection fraction, reservoir, conduit, and booster strain (all p < 0.001). In the multivariable model, age (HR 1.88, 95% CI: 1.06–3.31, p = 0.030), baseline AF (HR 2.95, 95% CI: 1.64–5.28, p < 0.001), LA volume index (LAVi) (HR 2.07, 95% CI: 1.21–3.55, p = 0.008) and LA reservoir strain (HR 2.82, 95% CI: 1.51–5.26, p = 0.001) were all associated with the outcome. Adding LAVi and LA reservoir strain in turn to the multivariable model (age and baseline AF) resulted in significant improvements in model performance (p < 0.001).

Conclusion

In ApHCM patients, LA reservoir strain is independently associated with cardiovascular risk events and has an incremental prognostic value.

Clinical relevance statement

Left atrial reservoir strain measured by cardiac magnetic resonance is highly correlated with the prognosis of apical hypertrophic cardiomyopathy and has potential incremental value in the prognosis of major adverse cardiac events.

Key Points

Left atrial (LA) strain parameters may be useful for risk stratification and treatment of apical hypertrophic cardiomyopathy (ApHCM).

Apical hypertrophic cardiomyopathy (ApHCM) is independently associated with LA morphology and function.

Cardiac MR examination, especially its feature-tracking technology, provides the possibility to prognosticate ApHCM at an early stage.

Graphical Abstract
Deep learning reconstruction algorithm and high-concentration contrast medium: feasibility of a double-low protocol in coronary computed tomography angiography
Authors: Caruso Damiano , De Santis Domenico , Tremamunno Giuseppe , Santangeli Curzio , Polidori Tiziano , Bona Giovanna G. , Zerunian Marta , Del Gaudio Antonella , Pugliese Luca , Laghi Andrea
Published: September 2024

Objective

To evaluate radiation dose and image quality of a double-low CCTA protocol reconstructed utilizing high-strength deep learning image reconstructions (DLIR-H) compared to standard adaptive statistical iterative reconstruction (ASiR-V) protocol in non-obese patients.

Materials and methods

From June to October 2022, consecutive patients, undergoing clinically indicated CCTA, with BMI < 30 kg/m2 were prospectively included and randomly assigned into three groups: group A (100 kVp, ASiR-V 50%, iodine delivery rate [IDR] = 1.8 g/s), group B (80 kVp, DLIR-H, IDR = 1.4 g/s), and group C (80 kVp, DLIR-H, IDR = 1.2 g/s). High-concentration contrast medium was administered. Image quality analysis was evaluated by two radiologists. Radiation and contrast dose, and objective and subjective image quality were compared across the three groups.

Results

The final population consisted of 255 patients (64 ± 10 years, 161 men), 85 per group. Group B yielded 42% radiation dose reduction (2.36 ± 0.9 mSv) compared to group A (4.07 ± 1.2 mSv; p < 0.001) and achieved a higher signal-to-noise ratio (30.5 ± 11.5), contrast-to-noise-ratio (27.8 ± 11), and subjective image quality (Likert scale score: 4, interquartile range: 3–4) compared to group A and group C (all p ≤ 0.001). Contrast medium dose in group C (44.8 ± 4.4 mL) was lower than group A (57.7 ± 6.2 mL) and B (50.4 ± 4.3 mL), all the comparisons were statistically different (all p < 0.001).

Conclusion

DLIR-H combined with 80-kVp CCTA with an IDR 1.4 significantly reduces radiation and contrast medium exposure while improving image quality compared to conventional 100-kVp with 1.8 IDR protocol in non-obese patients.

Clinical relevance statement

Low radiation and low contrast medium dose coronary CT angiography protocol is feasible with high-strength deep learning reconstruction and high-concentration contrast medium without compromising image quality.

Key Points

Minimizing the radiation and contrast medium dose while maintaining CT image quality is highly desirable.

High-strength deep learning iterative reconstruction protocol yielded 42% radiation dose reduction compared to conventional protocol.

“Double-low” coronary CTA is feasible with high-strength deep learning reconstruction without compromising image quality in non-obese patients.
A probability model for estimating age in young individuals relative to key legal thresholds: 15, 18 or 21-year
Authors: Heldring Nina , Rezaie Ali-Reza , Larsson André , Gahn Rebecca , Zilg Brita , Camilleri Simon , Saade Antoine , Wesp Philipp , Palm Elias , Kvist Ola
Published: September 2024

Age estimations are relevant for pre-trial detention, sentencing in criminal cases and as part of the evaluation in asylum processes to protect the rights and privileges of minors. No current method can determine an exact chronological age due to individual variations in biological development. This study seeks to develop a validated statistical model for estimating an age relative to key legal thresholds (15, 18, and 21 years) based on a skeletal (CT-clavicle, radiography-hand/wrist or MR-knee) and tooth (radiography-third molar) developmental stages. The whole model is based on 34 scientific studies, divided into examinations of the hand/wrist (15 studies), clavicle (5 studies), distal femur (4 studies), and third molars (10 studies). In total, data from approximately 27,000 individuals have been incorporated and the model has subsequently been validated with data from 5,000 individuals. The core framework of the model is built upon transition analysis and is further developed by a combination of a type of parametric bootstrapping and Bayesian theory. Validation of the model includes testing the models on independent datasets of individuals with known ages and shows a high precision with separate populations aligning closely with the model’s predictions. The practical use of the complex statistical model requires a user-friendly tool to provide probabilities together with the margin of error. The assessment based on the model forms the medical component for the overall evaluation of an individual’s age.