bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyelectrolyte‐Functionalized NanoMOFs for Highly Efficient Aqueous Lubrication and Sustained Drug Release
Authors: Wu Wei , Liu Jianxi , Tian Lejie , Lin Xiao , Xue Huidan , Gong Peiwei , Zhou Feng , Liu Weimin 
Published: March 2023

AbstractThis study demonstrates the hybridization of polyelectrolyte brushes with anti‐inflammatory drug‐loaded nanoMOFs that can achieve highly efficient aqueous lubrication and sustained drug release for the synergistic therapy of osteoarthritis (OA). Poly(3‐sulfopropyl methacrylate potassium salt) (PSPMK) brushes are grown on the surface of the UiO‐66‐NH2 via one‐pot grafting polymerization, which served as a general surface modification method of NH2‐MOFs to grow the polymer brushes. The growth of the PSPMK brushes greatly enhance the stability, dispersity, and swollen property of the AS‐UiO‐66‐NH2@PSPMK in aqueous media. Using as lubricating additives, the UiO‐66‐NH2@PSPMK achieves not only reductions in both coefficient of friction and wear volume over 70% and 99% but also supports high load‐carrying capacity and long‐term durability. The PSPMK brushes can be served as an universal interfacial modification soft layer that can significantly improve the aqueous lubricating performance of other types of NH2‐MOFs. After encapsulating the anti‐inflammatory aspirin (AS), the AS‐UiO‐66‐NH2@PSPMK shows both sustained drug release and good biocompatibility toward the human normal chondrocytes. This work establishes anti‐inflammatory drug‐loaded UiO‐66‐NH2@PSPMK as a potential multifunctional joint lubricant for OA treatment.
Lack of Causal Associations of Inflammatory Bowel Disease with Parkinson's Disease and Other Neurodegenerative Disorders
Authors: Zeng Ruijie , Wang Jinghua , Zheng Chunwen , Jiang Rui , Tong Shuangshuang , Wu Huihuan , Zhuo Zewei , Yang Qi , Leung Felix W. , Sha Weihong , Chen Hao 
Published: March 2023

AbstractBackgroundObservational studies have indicated associations between inflammatory bowel disease (IBD) and neurodegenerative diseases, including Parkinson's disease (PD).ObjectiveTo evaluate the causal associations of IBD with PD and other selected neurodegenerative disorders using updated data.MethodsBidirectional two‐sample Mendelian randomization studies using genome‐wide association studies summary statistics of IBD and PD.ResultsWe found a lack of evidence for the causal association of IBD on PD (odds ratio [OR], 1.014; 95% confidence interval [CI], 0.967–1.063; P = 0.573). Reverse analysis also indicated no evidence of a causal effect for PD on IBD (OR, 0.978; 95% CI, 0.910–1.052; P = 0.549). The causality between IBD and Alzheimer's disease, amyotrophic lateral sclerosis, and multiple sclerosis was unfounded (all P > 0.05).ConclusionsThe updated analyses provide no clear evidence for causal associations of IBD with PD or the other three neurodegenerative diseases. Potential confounders might contribute to the previously observed associations, and further investigations are warranted. © 2023 International Parkinson and Movement Disorder Society.
Kaiser Permanente grant will bolster NAMI California's statewide reach
Authors: Enos Gary 
Published: March 2023

The family‐focused efforts of the California state operation of the National Alliance on Mental Illness (NAMI California) have received a major boost from integrated health care company Kaiser Permanente. A $2.3 million grant from Kaiser Permanente will allow NAMI California to extend its family programming and advocacy training activities into parts of the state that have not had a local affiliate or any full‐time staff presence.
A novel dose fall‐off index and preliminary application in brain and lung stereotactic radiotherapy
Authors: Shen Zhengwen , Luo Huanli , Li Shi , Tan Xia , Tian Xiumei , Liu Qiang , Jin Fu 
Published: March 2023

AbstractBackgroundStereotactic radiotherapy (SRT) has been widely used for the treatment of brain metastases and early stage non‐small‐cell lung cancer (NSCLC). Excellent SRT plans are characterized by steep dose fall‐off, making it critical to accurately and comprehensively predict and evaluate dose fall‐off.PurposeA novel dose fall‐off index was proposed to ensure high‐quality SRT planning.MethodsThe novel gradient index (NGI) had two different modes: NGIx V for three‐dimensions and NGIx r for one‐dimension. NGIx V and NGIx r were defined as the ratios of the decreased percentage dose (x%) to the corresponding isodose volume and equivalent sphere radii, respectively. A total of 243 SRT plans at our institution between April 2020 and March 2022 were enrolled, including 126 brain and 117 lung SRT plans. Measurement‐based verifications were performed using SRS MapCHECK. Ten plan complexity indexes were calculated. Dosimetric parameters related to radiation injuries were also extracted, including the normal brain volume exposed to 12 Gy (V12) and 18 Gy (V18) during single‐fraction SRT (SF‐SRT) and multi‐fraction SRT (MF‐SRT), respectively, and the normal lung volume exposed to 12 Gy (V12). The performance of NGI and other common dose fall‐off indexes, gradient index (GI), R50% and D2cm were evaluated using Spearman correlation analysis to explore their correlations with the PTV size, gamma passing rate (GPR), plan complexity indexes, and dosimetric parameters.ResultsThere were statistically significant correlations between NGI and PTV size (r = ‐0.98, P < 0.01 for NGI50 V and r = ‐0.93, P < 0.01 for NGI50 r), which were the strongest correlations compared with GI (r = 0.11, P = 0.13), R50% (r = ‐0.08, P = 0.19) and D2cm (r = 0.84, P < 0.01). The fitted formulas of NGI50 V = 23.86V−1.00 and NGI50 r = 113.5r−1.05 were established. The GPRs of enrolled SRT plans were 98.6 ± 1.7%, 94.2 ± 4.7% and 97.1 ± 3.1% using the criteria of 3%/2 mm, 3%/1 mm, and 2%/2 mm, respectively. NGI50 V achieved the strongest correlations with various plan complexity indexes (|r| ranged from 0.67 to 0.91, P < 0.01). NGI50 V also showed the highest r values with V12 (r = ‐0.93, P < 0.01) and V18 (r = ‐0.96, P < 0.01) of the normal brain during SF‐SRT and MF‐SRT, respectively, and V12 (r = ‐0.86, P < 0.01) of the normal lung during lung SRT.ConclusionsCompared with GI, R50% and D2cm, the proposed dose fall‐off index, NGI, had the strongest correlations with the PTV size, plan complexity and V12/V18 of the normal tissues. These correlations established on NGI are more helpful and reliable for SRT planning, quality control, and reducing the risk of radiation injuries.
Understanding aliasing effects and their removal in SPEN MRI: A k‐space perspective
Authors: Zhong Sijie , Chen Minjia , Wei Xiaokang , Dai Ke , Chen Hao , Frydman Lucio , Zhang Zhiyong 
Published: March 2023

PurposeTo characterize the mechanism of formation and the removal of aliasing artifacts and edge ghosts in spatiotemporally encoded (SPEN) MRI within a k‐space theoretical framework.MethodsSPEN's quadratic phase modulation can be described in k‐space by a convolution matrix whose coefficients derive from Fourier relations. This k‐space model allows us to pose SPEN's reconstruction as a deconvolution process from which aliasing and edge ghost artifacts can be quantified by estimating the difference between a full sampling and reconstructions resulting from undersampled SPEN data.ResultsAliasing artifacts in SPEN MRI reconstructions can be traced to image contributions corresponding to high‐frequency k‐space signals. The k‐space picture provides the spatial displacements, phase offsets, and linear amplitude modulations associated to these artifacts, as well as routes to removing these from the reconstruction results. These new ways to estimate the artifact priors were applied to reduce SPEN reconstruction artifacts on simulated, phantom, and human brain MRI data.ConclusionA k‐space description of SPEN's reconstruction helps to better understand the signal characteristics of this MRI technique, and to improve the quality of its resulting images.
Prevalence of Subclinical Hearing Loss in the United States
Authors: Dragon Jacqueline M. , Grewal Maeher R. , Irace Alexandria L. , Garcia Morales Emmanuel , Golub Justin S. 
Published: March 2023

AbstractObjectiveCurrent definitions of hearing loss (HL) may be insufficiently strict, as subclinical hearing loss (SCHL; >0 and ≤25 dB hearing level) has been associated with deleterious age‐related conditions. SCHL prevalence and mean age of HL onset in the United States has not been characterized.Study DesignA cross‐sectional epidemiologic prevalence study.SettingUS Community.MethodsWe analyzed cross‐sectional audiometric data in the US National Health and Nutrition Examination Survey (2005‐2012, 2015‐2018, n = 15,649). Results were scaled to the current population using weighting.Results79.6% of participants (227.32 million Americans) had SCHL. The mean age of HL onset at thresholds of 25, 20, and 15 dB was 74, 66, and 55 years, respectively, for the 4‐frequency pure‐tone average, and 48, 44, and 35 years for the high‐frequency pure‐tone average.ConclusionWe present SCHL prevalence and define HL onset by various sensitive definitions. These results inform ongoing public health efforts to increase hearing aid utilization, particularly given the arrival of over‐the‐counter hearing aids.
Fatigue Phase‐field Modeling for Elastomeric Materials
Authors: Yin Bo , Kaliske Michael 
Published: March 2023

AbstractFatigue failure prediction of elastomeric materials plays a crucial role in engineering applications, e.g., rolling tires. Experimental investigations, as a straightforward evaluation of fatigue failure, do not enable an efficient insight due to significant time consumption. Therefore, several numerical approaches are developed to model fatigue fracture or damage behavior of material components subjected to cyclic loading. Inspired by [1], the work at hand incorporates a degrading fracture toughness into a promising phase‐field method. As a smeared crack representation, the phase‐field model does not depend upon any explicit criterion for crack evolution, e.g., crack initiation and propagation. Furthermore, this work proposes a novel algorithm, which is based on a post‐processing technique, to evaluate the energy release rate for PARIS' parameters during the stable crack propagation regime. The methodology is implemented into the Finite Element framework and a demonstrative numerical example is simulated.
Phase‐field Fracture Based on Representative Crack Elements (RCE): Inelastic Materials, Friction, Finite Deformations, Multi‐physics
Authors: Storm Johannes , Kaliske Michael 
Published: March 2023

AbstractThe concept of representative crack elements has been successfully introduced to phase‐field fracture in previous publications, where anisotropic elasticity [1], visco‐elasticity [2], elasto‐plasticity and crack surface friction [3] are considered at small deformations. This framework allows to overcome unrealistic predictions for the crack kinematics, reported e.g. in Strobl and Seelig [4], and Steinke and Kaliske [5], known from phase‐field models with approximations for the crack closure behaviour based on volumetric‐deviatoric, spectral or similar splits of stress or strain tensors.In the current contribution to the method of phase‐field fracture, the framework for representative crack elements is shown for finite deformations and fully coupled thermo‐mechanics. The iterative solution scheme for the representative crack element and the variational homogenisation method are sketched. Applications to elasto‐plasticity, crack surface friction, finite deformations and thermo‐mechanics with heat radiation through the crack demonstrate the flexibility of the framework.
Parameter identification and uncertainty quantification of the thermal conductivity tensor for transversely isotropic composite materials
Authors: Tröger Jendrik-Alexander , Hartmann Stefan 
Published: March 2023

AbstractThe identification of material parameters with a nonlinear least‐squares approach and finite elements is an established task in solid mechanics. There, full‐field experimental data can be employed in the material parameter identification procedure. The focus of this contribution is on the application of full‐field temperature data, measured with infrared thermography, to identify the coefficients of the thermal conductivity tensor of unidirectional fiber‐reinforced composites. Because of the unidirectional fiber reinforcement, transversely isotropic thermal behavior is assumed and the corresponding two thermal conductivities are identified from full‐field data. Beforehand performing the experiments, numerical re‐identifications are used to optimize the experimental procedure in a sensitivity analysis. Further, the uncertainties of the identified material parameters as well as the uncertainties of subsequent simulations are computed with the Gaussian error propagation concept.
FEM‐Modeling of thermal and viscous effects in piezoelectric MEMS loudspeakers
Authors: Hassanpour Guilvaiee Hamideh , Toth Florian , Kaltenbacher Manfred 
Published: March 2023

AbstractLoudspeakers based on piezoelectric micro‐electro‐mechanical system (PMEMS) are attracting an increasing interest due to their small size, low electronic power consumption, and easy assembly. These aspects are particularly advantageous in applications like earphones, mobile phones, and in‐ear hearing aid devices. However, creating sufficiently high sound pressure levels challenges many existing MEMS loudspeakers. Furthermore, their small dimensions require the consideration of additional physical phenomena like thermoviscous losses, which are often negligible in large loudspeakers. We model and characterize a 3D piezoelectric MEMS loudspeaker in this work using our open‐source finite element method (FEM) program openCFS. We use the linearized conservation of mass, momentum, and energy (thermoviscous acoustic PDEs) for a compressible Newtonian fluid (air) and describe the linear elastic solid using the linearized balance of momentum. The coupling between flow and solid fields is then applied using a non‐conforming FEM formulation. The standard acoustic partial differential equation (PDE) is used in the far‐field, where the thermal and viscous effects are negligible. We study the viscous effects on the displacement and the sound pressure levels (SPLs) of the loudspeaker by parameter studies. These results indicate that at a distance of 13 mm, an SPL of 55 dB at 5 kHz is achieved by a single PMEMS loudspeaker with a footprint of 1.7×1.7 mm2 under a low driving voltage of only 1 V, which is promising considering its dimensions.
Existence results for the higher order linear Cosserat shell model
Authors: Bîrsan Mircea , Ghiba Ionel-Dumitrel , Neff Patrizio 
Published: March 2023

AbstractWe derive the linear elastic Cosserat shell model of order O(h5) in the shell thickness h. To this aim, we linearise the geometrically nonlinear elastic Cosserat shell model established previously. Using Korn‐type inequalities for shells, the coercivity of the energy functional and the Lax‐Milgram theorem, we prove the existence and uniqueness of weak solutions to the equilibrium equations.
Analysis of solitons structure of the damped KdV equation arising in superthermal plasmas: Application of homotopy analysis method
Authors: Kumar Mahesh , Kumar Jana Ranjan 
Published: March 2023

AbstractThe aim of the proposed work is to analyze the soliton structures of dust‐ion acoustic waves obtained in the framework of the Korteg‐de Vries (KdV) equation with the presence of a damping term. The concept of electron acoustic solitary wave in an unmagnetized plasma consisting of superthermal electrons has been taken into consideration. The KdV equation with the presence of a damping term has been derived with the help of the reductive perturbation technique and solved by using the well‐known homotopy analysis method. The considered method approximates all problems in a straightforward and simplified manner. The method computes the series solution efficiently and provides a simple way to ensure its convergence. The approximate analytical solution obtained from the present analysis is compared with available results in the literature for a different choice of pertinent parameters. The upshots specified that the amplitude of solitary waves increases for increasing values of the damping parameter. This study would in a way to demonstrate the potential and effectiveness of the homotopy analysis method to evaluate the various kinds of nonlinear equations arising in the soliton theory.
Tikhonov regularization in general form with Chebfun
Authors: Alqahtani Abdulaziz , Mach Thomas , Reichel Lothar 
Published: March 2023

AbstractLinear ill‐posed problems often are analyzed in function spaces using tools from functional analysis, while their numerical solution typically is computed by first discretizing the problem and then applying tools from finite‐dimensional linear algebra. The Chebfun package makes it possible to solve linear ill‐posed problems without explicit discretization. This work discusses the use of Tikhonov regularization with a fairly general linear regularization operator within the Chebfun framework.
Goal‐oriented adaptivity based on a model hierarchy of mean‐field and full‐field homogenization methods in elasto‐plasticity
Authors: Tchomgue Simeu Arnold , Mahnken Rolf 
Published: March 2023

AbstractMaterials such as composites are heterogeneous at the micro scale, where several constituents with different material properties can be distinguished like elastic inclusions and an elasto‐plastic matrix. One has to deal with these heterogeneities on the micro scale and then perform a scale transition to obtain the overall behavior on the macro scale, which is often referred to as homogenization. The present contribution deals with an efficient combination of numerically low cost mean‐field and numerically high cost full‐field homogenization methods in elasto‐plasticity. To this end, model adaptivity is a promising methodology as it has been well‐established for linear elastic composite models [1]. Quite similarly to the adaptive FEM, it starts with an affordable homogenization method, and then through a loop wise error control, a local switch to accurate homogenization methods is performed to enhance the accuracy (referred to as model refinement). Like hierarchical FE structures for adaptive FEM, hierarchical model structures are established for model adaptivity. Additionally, the model adaptivity is coupled to the well established adaptive finite element method (FEM), such that both macro model and macro discretization errors are controlled. The proposed adaptive procedure is driven by a goal‐oriented a posteriori error estimator based on duality techniques. Finally, two numerical examples illustrate the effectiveness of the proposed adaptive approach.
Analysis of strut‐based lattice cores in sandwich panels using homogenization and dehomogenization methods
Authors: Georges Hussam , Mittelstedt Christian , Becker Wilfried 
Published: March 2023

AbstractThe design freedom provided by additive manufacturing offers new opportunities to fabricate novel structures with a high lightweight potential, such as strut‐based lattice structures. These lattice structures consist of periodically repeated unit cells and can be used in several applications due to their outstanding mechanical performance. One of the possible applications are cores of sandwich panels since the strut‐based lattices offer comparable mechanical properties to conventional honeycomb structures. Moreover, multifunctional use of the sandwich core is enabled by allowing the heat and fluid transfer through the sandwich due to the open‐celled lattice structure. However, strut‐based lattices are rarely utilized as cores in sandwich panels in engineering practice. One of the main reasons for that is the unknown mechanical behavior of lattice cores. In particular, when the sandwich is subjected to concentrated loads, localized stresses and deformations occur in the sandwich core, leading to core damage. In this work, we present a novel analytical model to determine stresses and deformations in the struts of lattice cores of sandwich panels using homogenization and dehomogenization methods. The local core compression caused by localized transverse forces can also be determined by the derived model.
A thermodynamic framework for the phase‐field approach considering carbide precipitation during phase transformations
Authors: Westermann Hendrik , Mahnken Rolf 
Published: March 2023

AbstractMicrostructure evolution during recrystallization annealing affects the macroscopic material properties for various steels. The phenomena include phase transformations and carbide precipitation. The requirements for most engineering components are both, high strength and sufficient residual ductility to withstand the mechanical burden and to offer preferable manufacturing conditions. In the present work a thermodynamic framework is proposed to combine two phase‐field approaches for the investigation of bimodal grain sizes. The developed prototype model studies phase transformations, diffusion of the carbon concentration and precipitation of carbides. Recystallization annealing enables the transformation of the purely martensitic microstructure into ferrite accompanied by carbide precipitation. The grain boundary movement is described by grain orientation and microstructure crystallinity. An adopted phase‐field approach describes the microstructure evolution driven by temperature and stored energy. The model is extended to capture carbide precipitation based on the diffusion kinetics of carbon atoms. Fractions of ferrite and carbide phases are depicted by the order parameters of a multiphase‐field model tied to the thermodynamic framework, thus yielding a novel constitutive framework capable of describing the complex material behavior of metals during thermo‐mechanical processing. Subsequently, a suitable algorithm for the presented phase‐field plasticity model in two dimensions is proposed. The evolution of phase fractions and carbide precipitation is illustrated in numerical examples by conclusive finite element simulations.
3D FEM Simulation of Titanium Alloy (Ti6Al4V) Machining with Harmonic Endmill Tools
Authors: Kalu-Uka Abraham , Ozoegwu Chigbogu , Eberhard Peter 
Published: March 2023

AbstractUsually, end milling operations have been carried out using conventional uniform helix tools with fixed helix angles. Thus, many studies have been conducted to study the effects of these tools on the thermomechanical properties of a milling process. Recently, there have been works that point to the benefits of using harmonic endmills. Harmonic endmills consist of cutting edge profiles that have continuously harmonically varying helix angles. The variation is described using a harmonic function of axial position (elevation) of points on the cutting edge. In this work, a 3D finite element simulation using ABAQUS, is carried out for the complex milling process of Titanium alloy Ti6Al4V. The envelope of the harmonic tool is first generated using a set of MATLAB codes and stored in a Standard Triangle Language (.stl) format. The machine tool is introduced into an FEM program which has been designed to provide for dynamic effects, thermo‐mechanical coupling, material damage law and the criterion for contact associated with the milling process. A Johnson‐Cook material constitutive equation which combines the effects of strain hardening, strain softening, and temperature softening is used. To account for the chip separation criterion, the Johnson Cook damage evolution equation is used. The milling process simulation for Ti6Al4V is then carried out. In the end, the stress distribution and the cutting forces are obtained.