bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fitting metabolic models to dissolved oxygen data: The estuarine Bayesian single‐station estimation method
Authors: Beck Marcus W. , Arriola Jill M. , Herrmann Maria , Najjar Raymond G. 
Published: April 2024

AbstractContinuous measurements of dissolved oxygen (DO) are useful for quantifying ecosystem metabolism, which is critical for understanding estuarine biogeochemistry and ecology, but current methods applied to these data may lead to estimates that are physically impossible and poorly constrained errors. Here, we present a new approach for estimating estuarine metabolism: Estuarine BAyesian Single‐station Estimation (EBASE). EBASE applies a Bayesian framework to a simple process‐based model and DO observations, allowing the estimation of critical model parameters, specifically light efficiency and respiration, as informed by a set of prior distributions. EBASE improves upon the stream‐based model from which it was derived by accommodating missing DO data and allowing the user to set the time period over which parameters are estimated. We demonstrate that EBASE can recover known metabolic parameters from a synthetic time series, even in the presence of noise (e.g., due to tidal advection) and when prior distributions are uninformed. Optimization periods of 7 and 30 d are more preferable than 1 d. A comparison with the more‐conventional method of Odum reveals the ability of EBASE to avoid unphysical results (such as negative photosynthesis and respiration) and improves when the DO data are detided. EBASE is available using open‐source software (R) and can be readily applied to multiple years of long‐term monitoring data that are available in many estuaries. Overall, EBASE provides an accessible method to parameterize a simple metabolic model appropriate for estuarine systems and will provide additional understanding of processes that influence ecosystem status and condition.
Long‐Term Follow‐Up of the LEAP Study: Early Versus Delayed Levodopa in Early Parkinson's Disease
Authors: Frequin Henrieke L. , Verschuur Constant V.M. , Suwijn Sven R. , Boel Judith A. , Post Bart , Bloem Bastiaan R. , van Hilten Johannes J. , van Laar Teus , Tissingh Gerrit , Munts Alexander G. , Dijk Joke M. , Lang Anthony E. , Dijkgraaf Marcel G.W. , Hoogland Jeroen , de Bie Rob M.A. ,   for the LEAP Study Group
Published: April 2024

AbstractBackground and ObjectiveThe Levodopa in EArly Parkinson's disease study showed no effect of earlier versus later levodopa initiation on Parkinson's disease (PD) progression over 80 weeks. We now report the effects over 5 years.MethodsThe Levodopa in EArly Parkinson's disease study randomly assigned patients to levodopa/carbidopa 300/75 mg daily for 80 weeks (early start) or to placebo for 40 weeks followed by levodopa/carbidopa 300/75 mg daily for 40 weeks (delayed start). Follow‐up visits were performed 3 and 5 years after baseline. We assessed the between‐group differences in terms of square root transformed total Unified Parkinson's Disease Rating Scale score at 3 and 5 years with linear regression. We compared the prevalence of dyskinesia, prevalence of wearing off, and the levodopa equivalent daily dose.ResultsA total of 321 patients completed the 5‐year visit. The adjusted square root transformed total Unified Parkinson's Disease Rating Scale did not differ between treatment groups at 3 (estimated difference, 0.17; standard error, 0.13; P = 0.18) and 5 years (estimated difference, 0.24; standard error, 0.13; P = 0.07). At 5 years, 46 of 160 patients in the early‐start group and 62 of 161 patients in the delayed‐start group experienced dyskinesia (P = 0.06). The prevalence of wearing off and the levodopa equivalent daily dose were not significantly different between groups.ConclusionsWe did not find a difference in disease progression or in prevalence of motor complications between patients with early PD starting treatment with a low dose of levodopa 40 weeks earlier versus 40 weeks later over the subsequent 5 years. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
AAPM Task Group 334: A guidance document to using radiotherapy immobilization devices and accessories in an MR environment
Authors: Hobson Maritza A. , Hu Yanle , Caldwell Barrett , Cohen Gil'ad N. , Glide‐Hurst Carri , Huang Long , Jackson Paul D. , Jang Sunyoung , Langner Ulrich , Lee Hannah J. , Levesque Ives R. , Narayanan Sreeram , Park Justin C. , Steffen John , Wu Q. Jackie , Zhou Yong 
Published: April 2024

AbstractUse of magnetic resonance (MR) imaging in radiation therapy has increased substantially in recent years as more radiotherapy centers are having MR simulators installed, requesting more time on clinical diagnostic MR systems, or even treating with combination MR linear accelerator (MR‐linac) systems. With this increased use, to ensure the most accurate integration of images into radiotherapy (RT), RT immobilization devices and accessories must be able to be used safely in the MR environment and produce minimal perturbations. The determination of the safety profile and considerations often falls to the medical physicist or other support staff members who at a minimum should be a Level 2 personnel as per the ACR. The purpose of this guidance document will be to help guide the user in making determinations on MR Safety labeling (i.e., MR Safe, Conditional, or Unsafe) including standard testing, and verification of image quality, when using RT immobilization devices and accessories in an MR environment.
Effect of MR head coil geometry on deep‐learning‐based MR image reconstruction
Authors: Dubljevic Natalia , Moore Stephen , Lauzon Michel Louis , Souza Roberto , Frayne Richard 
Published: April 2024

AbstractPurposeTo investigate whether parallel imaging‐imposed geometric coil constraints can be relaxed when using a deep learning (DL)‐based image reconstruction method as opposed to a traditional non‐DL method.Theory and MethodsTraditional and DL‐based MR image reconstruction approaches operate in fundamentally different ways: Traditional methods solve a system of equations derived from the image data whereas DL methods use data/target pairs to learn a generalizable reconstruction model. Two sets of head coil profiles were evaluated: (1) 8‐channel and (2) 32‐channel geometries. A DL model was compared to conjugate gradient SENSE (CG‐SENSE) and L1‐wavelet compressed sensing (CS) through quantitative metrics and visual assessment as coil overlap was increased.ResultsResults were generally consistent between experiments. As coil overlap increased, there was a significant (p
< 0.001) decrease in performance in most cases for all methods. The decrease was most pronounced for CG‐SENSE, and the DL models significantly outperformed (p < 0.001) their non‐DL counterparts in all scenarios. CS showed improved robustness to coil overlap and signal‐to‐noise ratio (SNR) versus CG‐SENSE, but had quantitatively and visually poorer reconstructions characterized by blurriness as compared to DL. DL showed virtually no change in performance across SNR and very small changes across coil overlap.ConclusionThe DL image reconstruction method produced images that were robust to coil overlap and of higher quality than CG‐SENSE and CS. This suggests that geometric coil design constraints can be relaxed when using DL reconstruction methods.
Physiology of the weight‐loss plateau in response to diet restriction, GLP‐1 receptor agonism, and bariatric surgery
Authors: Hall Kevin D. 
Published: April 2024

AbstractObjectiveThe objective of this study was to investigate why different weight‐loss interventions result in varying durations of weight loss prior to approaching plateaus.MethodsA validated mathematical model of energy metabolism and body composition dynamics was used to simulate mean weight‐ and fat‐loss trajectories in response to diet restriction, semaglutide 2.4 mg, tirzepatide 10 mg, and Roux‐en‐Y gastric bypass (RYGB) surgery interventions. Each intervention was simulated by adjusting two model parameters affecting energy intake to fit the mean weight‐loss data. One parameter represented the persistent shift of the system from baseline equilibrium, and the other parameter represented the strength of the feedback control circuit relating weight loss to increased appetite.ResultsRYGB surgery resulted in a persistent intervention magnitude more than threefold greater than diet restriction and about double that of tirzepatide and semaglutide. All interventions except diet restriction substantially weakened the appetite feedback control circuit, resulting in an extended period of weight loss prior to the plateau.ConclusionsThese preliminary mathematical modeling results suggest that both glucagon‐like peptide 1 (GLP‐1) receptor agonism and RYGB surgery interventions act to weaken the appetite feedback control circuit that regulates body weight and induce greater persistent effects to shift the body weight equilibrium compared with diet restriction.
Green synthesis of gold nanoparticles using macroalgae Halimeda macroloba extract and their photocatalytic degradation of methylene blue and methyl orange
Authors: Lavanya G. , Anandaraj K. , Selvam K. , Gopu M. , Selvankumar T. , Govarthanan M. , Kumar P. 
Published: April 2024

AbstractGreen synthesis of gold nanoparticles (AuNPs) is gaining attention of researchers because of their varieties of biomedical and environmental applications. This study reported the novel eco‐friendly synthesis of AuNPs using green macroalgae Halimeda macroloba (HM) extract and evaluate their photocatalytic potential. The green synthesized H. macroloba mediated gold nanoparticles (HM‐AuNPs) was characterized using UV–visible spectrophotometry, Fourier‐transform infrared (FT‐IR) spectroscopy, transmission electron microscope (TEM), scanning electron microscope‐energy dispersive spectroscopy, x‐ray photoelectron spectroscopy (XPS), and particle size distribution (PSD) anlaysis. The UV–visible spectrum shows a sharp intense plasmonic resonance peak at 543 nm. The bioactive compounds present in HM were primarily responsible for the biological reduction of gold ions validated by FT‐IR analysis. XRD analysis proved the crystalline face centered cubic structure of the HM‐AuNPs. The average particle size of 18.72 nm and morphological evidences were obtained from the images from TEM. The metallic form of biosynthesised HM‐AuNPs was confirmed by XPS results with a distinctive binding energy. The photocatalytic degradation ability of the green synthesized HM‐AuNPs was investigated against the methylene blue (MB) and methylene orange (MO) dyes under sunlight irradiation. The HM‐AuNPs exhibited 97.23% and 89.91% photocatalytic activity against MB and MO after 90 min of exposure to sunlight, respectively. The overall results of this research indicate that H. macroloba mediated HM‐AuNPs can be used as an effective option for the degradation of industrial dyes.
Reversible polymer networks based on polylactide with tetraphenylethane thermally dissociating groups in crosslinks
Authors: Bednarek Melania , Grabowski Mateusz , Lipińska Magdalena , Pawlak Andrzej 
Published: April 2024

AbstractPolylactide (PLA)‐based reversible/dynamic polymer networks were synthesized by coupling 4‐arm PLA stars containing reversible tetraphenylethane (TPE) groups in the core using diisocyanate. Star‐shaped PLAs with molecular weights of 3200 and 6400 g/mol were obtained by the original method involving UV coupling of linear PLAs containing benzophenone moieties in the chain middle. The efficient formation of networks with gel content close to 100% was confirmed by FTIR spectroscopy. Networks with different densities of reversible groups exhibited tensile strength in the range of 35–50 MPa. Their reversible character was demonstrated by stress relaxation measurements performed at different temperatures (120–150°C). The prepared networks were capable of very fast stress relaxation due to radical exchange reactions between TPE groups placed in crosslinks, in contrast to a reference network without TPE groups. It was shown in the repairing experiment that networks were capable of processing.
Polyester networks based on Tulipalin A and ε‐caprolactone and activation of the Thioether groups by incorporation of trialkylsulfonium salts
Authors: Ismael Islam , Mrlík Miroslav , Vykydalová Anna , Annušová Adriana , Halahovets Yuriy , Mosnáček Jaroslav , Danko Martin 
Published: April 2024

AbstractLinear and star‐shaped poly(ε‐caprolactone‐co‐α‐methylene‐γ‐butyrolactone) P(CL‐co‐MBL) copolyesters with a pendant functional double bond of α‐methylene‐γ‐butyrolactone (MBL) comonomer were used as polymeric precursor for organo‐gels formation. Crosslinking was carried out by light‐initiated thia‐Michael reaction using 1,5‐pentanedithiol (PDT) and pentaerythritol tetrakis(3‐mercaptopropionate) (PETK). Double bond conversion and the content of free thiol groups in the obtained networks was followed and rationally estimated using confocal Raman spectroscopy. The gel content and the crosslinking density varied based on MBL comonomer and crosslinker content and were highest for slight thiol to double bond excess (SH/vinyl; 2/1 molar ratio) while decreasing with further thiol excess. These parameters were more pronounced by the replacement of linear PDT with the star‐shaped PETK crosslinker. The thermal and rheological properties investigation of the obtained materials was performed employing DSC, TGA and using frequency and temperature sweeps rheological measurements. Shear moduli in the range 0.14 up to 0.93 MPa were obtained due to different content of MBL in pre‐polymer and crosslinker in network formation. The strength was caused by the crystalline phase of the PCL segments up to a temperature of 50°C. Formed thioether bond within the network were not reversible up to 150°C as it was found based on temperature sweep rheology. Following, the activation and conversion of thioether bonds within the obtained materials into trialkylsulfonium salts was attained through the alkylation using butyl brosylate. The dynamic nature of the transalkylation at elevated temperature 150°C allowed network rearrangement, which was proved by stress relaxation experiment and investigation of the self‐healing capabilities.
Functionalization of polyketone (PK) with 1‐(3‐aminopropyl)piperidine for the preparation of anion exchange membranes
Authors: Benzahia Ghrissi , Ferahi Mohammed Issam , Magnani Eleonora , Giovanelli Andrea , Pucci Andrea , Meghabar Rachid 
Published: April 2024

AbstractIn this work, we report the synthesis of a new anion exchange membrane based on a Polyketone (PK) functionalized with 1‐(3‐aminopropyl)piperidine through a solvent‐less Paal‐Knorr reaction with a carbonyl (CCO %) conversion of 36%. A one‐step cast‐quaternization process by using 1,4‐diiodobutane was performed that yielded a homogeneous membrane in a highly reproducible way. The obtained membranes showed good performances in terms of thermal resistance (up to 250°C), water uptake of 21% and ion exchange capacity of 2 meq/g, which support their use as anion exchange membranes for water electrolysers (AEM‐WE).
Extramedullary infiltration in pediatric acute myeloid leukemia: Results from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative
Authors: Li Weiya , Shi Mingyue , Zhou Pan , Liu Ying , Liu Xiaobo , Xiao Xingjun , Zuo Suqiong , Bai Yanliang , Sun Kai 
Published: April 2024

AbstractBackgroundThe outcome of extramedullary infiltration (EMI) in pediatric acute myeloid leukemia (AML) is controversial, and little is known about the implications of stem cell transplantation (SCT) and gemtuzumab ozogamicin (GO) treatment on patients with EMI.MethodsWe retrieved the clinical data of 713 pediatric patients with AML from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset, and analyzed the clinical and prognostic characteristics of patients with EMI at diagnosis and relapse.ResultsA total of 123 patients were identified to have EMI at diagnosis and 64 presented with EMI at relapse. The presence of EMI was associated with age ≤2 years, M5 morphology, abnormal karyotype, and KMT2A rearrangements. Hyperleukocytosis and complex karyotype were more prevalent in patients with EMI at relapse. Additionally, patients with EMI at diagnosis had a reduced incidence of FLT3 ITD−/NPM1+, whereas those with EMI at relapse displayed a lower frequency of FLT3 ITD+. Patients with EMI at diagnosis exhibited a lower complete remission (CR) rate at the end of Induction Course 1 and higher relapse incidence. Importantly, EMI at diagnosis independently predicted both shorter event‐free survival (EFS) and overall survival (OS). Regarding relapse patients, the occurrence of EMI at relapse showed no impact on OS. However, relapse patients with myeloid sarcoma (MS)/no central nervous system (CNS) exhibited poorer OS compared to those with CNS/no MS. Furthermore, regarding patients with EMI at diagnosis, SCT failed to improve the survival, whereas GO treatment potentially enhanced OS.ConclusionEMI at diagnosis is an independent adverse prognostic risk factor for pediatric AML, and GO treatment potentially improves survival for patients with EMI at diagnosis.
The effects of ply clustering positions and orientations on multi‐directional composite laminates' low velocity impact resistance
Authors: Tang Ziruo , Ren Rui , Zhao Changfang , Liu Yangzuo , Zhong Jianlin , Zhou Kedong 
Published: April 2024

AbstractIn this paper, nine different carbon fiber laminates containing clusters are designed using the ant colony ACO algorithm, which have similar equivalent bending stiffnesses and B‐matrices, with the differences being the fiber orientation of the clusters and the position of the clusters in the laminates. The dynamic mechanical characterization of laminates for low velocity impact (LVI) at three different energies was carried out by means of a falling weight impact experiment. The experimental results show that the main form of failure of the laminate is delamination failure at low energy impacts, and shear fracture becomes more and more obvious with the elevation of the impact energy, which was observed in detail by the stereo microscope and electron microscope. The damage area of the laminate and the force and displacement curves after 30 J energy impact were compared by x‐ray scanning to derive the effects of the angle of the ply cluster fibers and the different positions of the ply clusters in the laminate on the impact resistance of the laminate. In conclusion, when designing the laminate, consideration should be given to designing 45° clusters on the impacted side and 90° clusters in the middle layer of the laminate to obtain the best impact resistance.Highlights
Designed 9 types of laminates with different laminate structures based on ACO algorithm.
Different laminates have similar equivalent bending stiffnesses and the B matrix as close to 0 as possible.
LVI tests at three energies were performed on 9 types of laminates.
The effects of different orientations of the clusters and the position of the clusters in the laminate on the impact resistance of the laminate were investigated.
Effect of varying core density and material on the quasi‐static behaviors of sandwich structure with 3D‐printed hexagonal honeycomb core
Authors: Ainin F. Nur , Azaman M. D. , Majid M. S. Abdul , Ridzuan M. J. M. 
Published: April 2024

AbstractAdditive manufacturing (AM) involves the development of complex, lightweight sandwich structures for the automotive and aerospace industries. These structures are essential for load bearing and impact resistance. Nevertheless, there is a significant obstacle of failure under compressive loading, e.g. through brittle fractures and crushing. To address this issue, this study evaluates the compressive properties, energy absorption and failure damage in quasi‐static tests (flatwise, in‐plane, and flexural) of sandwich composites with 3D‐printed hexagonal honeycomb cores of different unit cells (6, 8 and 10 mm) and materials (polylactic acid (PLA), PLA‐Carbon and PLA‐Wood). The results show that increasing the core density enhances compressive strength, modulus, and energy absorption. An 8 mm unit cell absorbs energy optimally for lightweight structures. In PLA flatwise testing, the 8 mm unit cell absorbed 419.49 J more energy than the 10 mm unit cell. Additionally, PLA‐Wood has better mechanical performance than PLA‐Carbon due to the better filler with the PLA‐ matrix. In flatwise testing with an 8 mm unit, PLA‐Wood absorbs 214.01 J, while PLA‐Carbon absorbs 122.49 J. The failure modes vary depending on tests performed. The study highlights the potential of 3D‐printed honeycomb core structures for load‐bearing applications in various industries, including aerospace and automotive.Highlights
Quasi‐static loading behavior of 3D‐printed hexagonal honeycomb cores.
Increased core density improves compressive stress, modulus, and absorbed energy.
An optimal unit cell size for lightweight 3D printed core structures is 8 mm.
PLA‐Wood performs better in energy absorption due to filler compatibility.
The failure modes are related to the type of quasi‐static loads applied.
Inspection of microwave self‐healing efficiency in carbon nanotube reinforced polymer composites for aerospace applications
Authors: Irez Alaeddin Burak 
Published: April 2024

AbstractThe aerospace industry is evolving very rapidly every day, and due to the low operational and maintenance costs, unmanned aerial vehicles (UAVs) are utilized for many duties, including imaging, patrol, surveillance, and delivery. Flying platforms prioritize effective load‐carrying capacity and light weight. To achieve this, lightweight materials with sufficient strength are utilized, and design optimizations are implemented. This study investigates material development for a UAV propeller, taking into account the possible consequences of a bird strike or hard landing such as micro damage occurrence. In this study, a twin‐screw extruder was used to produce hybrid composites by blending a thermoplastic, polyamide‐6 (PA6) with olefin block copolymers (OBC) and carbon nanotubes (CNT). After manufacturing test specimens by injection molding, tensile and Charpy impact tests were performed. OBC increased the elongation capacity and impact resistance of the PA6 through maleic anhydride (MAH) grafting while reducing the tensile strength. CNT incorporation compensated for this drop, but it rendered the composites more brittle. More importantly, due to the CNT's microwave (MW) absorption capacity, the hybrid composites have gained self‐healing properties. Extended MW exposure time and high MW powers may cause localized burning of the material, resulting in a decrease in its self‐healing efficiency. Following the failure of the examined composites, SEM microscopy revealed various toughening mechanisms in the composites. The use of a modified Halpin‐Tsai model to estimate the elastic characteristics of CNT‐reinforced composites revealed promising results, with minimal discrepancies when compared to experimental data.Highlights
CNTs were found efficient for the self‐healing behavior which is critical for improving the lifetime and planning maintenance for UAV propellers.
CNT content, MW power & exposure time all impact the self‐healing efficiency.
Extended MW exposure time and high MW powers can cause localized burning of the material, resulting in a decrease in its self‐healing efficiency.
CNTs created bridge effects, ultimately leading to an enhancement in the strength of the composites.
The use of a modified Halpin‐Tsai model yielded good accuracy with experimental data.