bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extremely low frequency wave localization via elastic foundation induced metamaterial with a spiral cavity
Authors: Bae Myung Hwan , Choi Wonjae , Ha Jong Moon , Kim Miso , Seung Hong Min 
Published: March 2022

AbstractWe proposed a metamaterial which exhibits elastic wave localization at extremely low frequencies. First, we opened an extremely low bandgap via elastic foundations. Subsequently, we investigated wave localization by imposing normal defect, which is widely used to capture waves in conventional wave localization systems. However, there were limitations: wave localization was not achieved when a weak bandgap is generated, and the operating frequency of localization is still in the upper part of the bandgap. To overcome wave localization via the normal defect, we proposed a novel metamaterial with a spiral cavity which can tune the resonating frequency depending on the length of the spiral path. By imposing on the spiral cavity inside the elastic foundation-induced metamaterial, we can shift the resonating frequency of the cavity down. Finally, we carried out wave simulations, not only to support the previous eigenfrequency study for the supercell, but also to verify that the finite-size metamaterial can also achieve wave localization at the extremely low frequencies. Through wave simulations, we could observe wave localization even at 77.3 Hz, which is definitely the lower part of the extremely low bandgap.
Determining the anatomical site in knee radiographs using deep learning
Authors: Quinsten Anton S. , Umutlu Lale , Forsting Michael , Nassenstein Kai , Demircioğlu Aydin 
Published: March 2022

AbstractAn important quality criterion for radiographs is the correct anatomical side marking. A deep neural network is evaluated to predict the correct anatomical side in radiographs of the knee acquired in anterior–posterior direction. In this retrospective study, a ResNet-34 network was trained on 2892 radiographs from 2540 patients to predict the anatomical side of knees in radiographs. The network was evaluated in an internal validation cohort of 932 radiographs of 816 patients and in an external validation cohort of 490 radiographs from 462 patients. The network showed an accuracy of 99.8% and 99.9% on the internal and external validation cohort, respectively, which is comparable to the accuracy of radiographers. Anatomical side in radiographs of the knee in anterior–posterior direction can be deduced from radiographs with high accuracy using deep learning.
Hemodynamic force analysis is not ready for clinical trials on HFpEF
Authors: Arvidsson Per M. , Nelsson Anders , Magnusson Martin , Smith J. Gustav , Carlsson Marcus , Arheden Håkan 
Published: March 2022

AbstractHemodynamic force analysis has been proposed as a novel tool for early detection of subclinical systolic dysfunction in heart failure with preserved ejection fraction (HFpEF). Here we investigated the ability of hemodynamic forces to discriminate between healthy subjects and heart failure patients with varying degrees of systolic dysfunction. We studied 34 controls, 16 HFpEF patients, and 25 heart failure patients with mid-range (HFmrEF) or reduced ejection fraction (HFrEF) using cardiac magnetic resonance with acquisition of cine images and 4D flow at 1.5 T. The Navier–Stokes equation was used to compute global left ventricular hemodynamic forces over the entire cardiac cycle. Forces were analyzed for systole, diastole, and the entire heartbeat, with and without normalization to left ventricular volume. Volume-normalized hemodynamic forces demonstrated significant positive correlation with EF (r2 = 0.47, p < 0.0001) and were found significantly lower in heart failure with reduced ejection fraction compared to controls (p < 0.0001 for systole and diastole). No difference was seen between controls and HFpEF (p > 0.34). Non-normalized forces displayed no differences between controls and HFpEF (p > 0.24 for all analyses) and did not correlate with EF (p = 0.36). Left ventricular hemodynamic force analysis, whether indexed to LV volumes or not, is not ready for clinical trials on HFpEF assessment.
Copper-catalyzed aerobic benzylic C(sp3)–H lactonization of 2-alkylbenzamides via N-centered radicals
Authors: Nozawa-Kumada Kanako , Ono Kanako , Kurosu Satoshi , Shigeno Masanori , Kondo Yoshinori 
Published: March 2022

We developed a novel copper-catalyzed benzolactone synthesis via 1,5-HAT of amidyl radicals from 2-alkylbenzamides under O2 atmosphere.
How background music of shopping sites affects consumers during festival season
Authors: Chen Dan , Zhang Xiaoran , Jiang Hanyun , Meng Xiao , Zheng Jun , Sun Lingyun , Zhang Kejun 
Published: March 2022

AbstractThis study focusses on the impact of the background music on consumers' shopping experience during the festival seasons. The authors derived a new research model based on the environmental psychology model in the literature and then designed an empirical experiment to examine changes in consumers' non‐behavioural shopping outcomes under different conditions. The authors built a virtual shopping website and chose a traditional Chinese festival, the Mid‐Autumn Festival, as the experimental scenario in which the authors used a questionnaire to measure the differences in dependent variables formed by different treatments. Data from the online experiment showed that consumers' experience is more positive with music than without the background music, and the consumer's emotions play a mediating role. However, there is no significant effect of music with the theme of the Mid‐Autumn Festival compared to ordinary pop music, which proves that the theme of music does not affect consumers' experience in the online shopping scenario. These findings reflect the psychology and behaviour of consumers when using shopping websites and provide suggestions for shopping site design.
Aircraft trajectory filtering method based on Gaussian‐sum and maximum correntropy square‐root cubature Kalman filter
Authors: Bai Jing G. , Ge Quan B. , Li Hong , Xiao Jian M. , Wang Yuan L. 
Published: March 2022

AbstractAiming at meetiing the need to filtering flight trajectory data for aircraft testing, a novel adaptive cubature Kalman filter (CKF) is proposed based on the maximum correntropy and Gaussian‐sum in this paper. Firstly, based on the traditional CKF algorithm, we introduced a Gaussian‐sum method to approximate non‐Gaussian noise to get more accurate filtering results in view of the problem of reduced filtering accuracy caused by the inherent non‐Gaussian nature of the noise and the system non‐linearity. Secondly, the maximum correntropy criterion is introduced to solve further the problem of improving the filtering accuracy of the system in the case of non‐linearity. Simulation results and actual data verification showed that the Square‐root cubature Kalman filter algorithm based on the maximum correntropy and Gaussian‐sum has higher accuracy than traditional filtering algorithms, which verified the algorithm's effectiveness in the application.
Data‐driven consensus control for a class of unknown nonlinear multiagent systems with time delays
Authors: Liu Shida , Li Jiancheng , Wang Li , Hou Zhongsheng , Ji Honghai 
Published: March 2022

AbstractIn this paper, the distributed output consensus tracking problem for a class of unknown heterogeneous discrete‐time single‐input single‐output nonlinear multiagent systems (MASs) with time delays is considered. For this problem, a distributed data‐driven consensus control strategy is proposed by using improved model‐free adaptive control with a time delay. First, the unknown nonlinear multiagent time delay system is transformed into a virtual data model with time‐varying parameters by using a partial form dynamic linearisation method. Then, a controller with model‐free adaptive control and a tracking differentiator are designed. The proposed method uses only the input/output data of neighbouring agents during the control process without mathematically modelling multiple agents. For the time delay system, the boundedness of the closed‐loop tracking error is theoretically proven for both the tracking problem and the regulation problem. Furthermore, this result can be generalised to switching topology structures by a rigorous mathematical proof. Numerical simulations verify the effectiveness of the proposed algorithm.
Active and reactive power control of grid‐connected single‐phase asymmetrical eleven‐level inverter
Authors: Tayyab Mohammad , Sarwar Adil , Murshid Shadab , Tariq Mohd , Al‐Durra Ahmed , Bakhsh Farhad Ilahi 
Published: March 2022

AbstractIn recent times, multilevel inverters (MLIs) have become very popular for commercial and industrial applications. Here, an eleven‐level inverter and its power flow control are presented. The presented topology has a lesser component count than other existing topologies, thus reducing the devices and overall cost of the inverter. This inverter comprises six bidirectional switches, two DC sources, one four‐quadrant switch, and two capacitors for the voltage divider circuit. The conduction modes and corresponding switching states of the presented eleven‐level inverter are shown in detail. Further, the apparent power control of the presented inverter under grid‐connected operation is discussed, which provides simultaneous active and reactive power control over the power injected into the grid. Switching and conduction losses are calculated for 3 and 6 kVA grid injected power at 0.8 power factor lagging. The obtained results show that the total harmonic distortion (THD) of the inverter output voltage and grid current is 12.10% and 0.23%, respectively, under 6 kVA power transfer conditions. The real‐time analysis is also carried out for 3 and 6 kVA power transfer conditions for the presented eleven‐level inverter to validate the active and reactive power flow control.
Translational motion estimation and compensation in distributed inverse synthetic aperture radar imaging of ship target with complex motion
Authors: Zhang Junqiu , Wang Yong 
Published: March 2022

AbstractA translational motion estimation and compensation method is proposed based on the parametric method by multiple stations in the distributed inverse synthetic aperture radar (ISAR) imaging. For ship targets with complex motion, the distributed ISAR increases the cross‐range resolution of the image by expanding the observation angle. However, the translation compensation methods by a single station will destroy the correlation between the echoes, which reduces the image quality, and a more accurate joint translation compensation method is required. Multi‐static observation is obtained in the Distributed system, which we can utilise in the parameter estimation: 1) joint Doppler estimation, 2) station angle estimation, and 3) rotation velocity estimation. Based on the above estimations, the velocity vector and the acceleration vector of the target can be obtained, and then the translational motion compensation can be realised parametrically. The algorithm processing chain is presented in this paper. Finally, the numerical simulations with four stations are presented to verify the effectiveness and the robustness of the proposed algorithm.
MUSE spectroscopic observations of the young massive cluster NGC 1850
Authors: Sollima A. , D’Orazi V. , Gratton R. , Carini R. , Carretta E. , Bragaglia A. , Lucatello S. 
Published: March 2022

Context. The double cluster NGC 1850 in the Large Magellanic Cloud is the nearest young massive cluster of the Local Group with a mass similar to those of Galactic globular clusters. Recent studies have revealed an extended morphology of its main-sequence turn-off (MSTO), which can be interpreted as a spread in either age or internal rotation. In spite of its proximity, an accurate spectroscopic determination of its chemical properties is still missing.
Aims. We aim to investigate the general chemistry and the kinematics of this stellar system to test whether possible signs of multiple populations are observable in this cluster.
Methods. We analysed the spectra obtained with MUSE in adaptive optics mode of 1167 stars in both components of this cluster (NGC 1850A and NGC 1850B). Thanks to this data set, we were able to measure accurate global metallicities, Ba abundances, and radial velocities for a sample of 38 red supergiants and a guess of the oxygen abundance in the brightest turn-off stars belonging to NGC 1850A.
Results. We find an average metallicity of ⟨[M/H]⟩ = −0.31 ± 0.01, a mean Ba abundance of ⟨[Ba/Fe]⟩ = +0.40 ± 0.02, and a systemic radial velocity of ⟨vLOS⟩ = 251.1 ± 0.3 km s−1. The dispersion of the radial velocities suggests a dynamical mass of log(M/M⊙) = 4.84 ± 0.1, while no significant systemic rotation is detected. We detect a significant bimodality in O I line strength among the turn-off stars of NGC 1850A with ∼66% of stars with [O/Fe]∼ − 0.16 and the rest with no detectable line. The majority of O-weak stars preferentially populate the red side of the MSTO and show H lines in emission, suggesting that they are Be stars rotating close to their critical velocity. Among normal MSTO stars, red stars have broader line profiles than blue ones, on average, suggesting a correlation between colour and rotational velocity.
Conclusions. The mean metallicity of this cluster lies at the metal-rich side of the metallicity distribution of the Large Magellanic Cloud following its age-metallicity relation. The Ba and O abundances agree with those measured in the bar of this galaxy. The correlation between line broadening and colour suggests that the observed colour spread among turn-off stars can be due to a wide range in rotational velocity covered by these stars.
Rolle der PET/CT beim multiplen Myelom und anderen Plasmazellerkrankungen
Authors: Derlin Thorsten , Pfob Christian , Lapa Constantin 
Published: March 2022

ZusammenfassungDie 18F-Fluordesoxyglukose (FDG) Positronen-Emissions-Tomografie/Computertomografie (PET/CT) als Verfahren der molekularen Bildgebung erlaubt die simultane Beurteilung morphologischer Charakteristika des mineralisierten Knochens (z. B. Osteolysen) sowie molekularer Parameter (z. B. Stoffwechselaktivität) und bietet damit umfassende (patho)biologische Informationen. Sie hat in den letzten Jahren einen zunehmend wichtigen Stellenwert in der Bildgebung der Plasmazellerkrankungen gefunden, ist zentrales Instrument sowohl in der Differenzialdiagnostik als auch in der Ausbreitungsdiagnostik der einzelnen Entitäten und erlaubt ein Therapiemonitoring im Verlauf. In der Initialdiagnostik leistet die FDG PET/CT einen wertvollen Beitrag in der Differenzialdiagnostik der Plasmazellerkrankungen, insbesondere beim solitären Plasmozytom. Zudem ermöglicht sie eine sensitive Ausbreitungsdiagnostik beim multiplen Myelom durch die Erfassung eines fokalen und diffusen Knochenmarkbefalls sowie para- und extramedullärer Myelommanifestationen. Die FDG PET/CT ist dabei dem konventionellen Röntgenstatus und der low-dose Computertomografie (LDCT) überlegen und der Ganzkörper-Magnetresonanztomografie (GK-MRT) weitestgehend gleichwertig. Sie liefert zudem prognostische Informationen, insbesondere vor Stammzelltransplantation, und ist aufgrund ihres hohen positiv prädiktiven Wertes bildgebender Referenzstandard zur Beurteilung des Therapieansprechens. Zudem kann sie zusammen mit anderen Methoden eingesetzt werden, um eine minimale Resterkrankung (MRD)-Negativität zu definieren. Neue Radiopharmaka und theranostische Ansätze erweitern das Einsatzfeld für die PET bei Plasmazellerkrankungen.
Erworbene Katarakte
Authors: Bisorca-Gassendorf Lukas , Szurman Peter , Wenzel Martin , Januschowski Kai 
Published: March 2022

ZusammenfassungWeitaus seltener und daher weniger bekannt als die altersbedingte Katarakt ist die sekundär erworbene Katarakt, die eine diagnostische und chirurgische Herausforderung darstellen kann.
Dieser Beitrag gibt einen Überblick über die häufigsten Subtypen vor allem bei Erwachsenen und beleuchtet die chirurgischen Besonderheiten einschließlich perioperativer Charakteristika.
Validated, Consensus-Based Second- and Third-Trimester Sonographic Learning Objectives for the Obstetrics Clerkship
Authors: Wade Eleanor , McBride Christina M. , Elling Sara L. , Shvartsman Katerina , Thagard Andrew S. 
Published: March 2022

Objective Currently, there are no established guidelines for obstetric ultrasound training at the core medical student clerkship level. Our objective was to develop practical, consensus-based learning objectives in second- and third-trimester ultrasound and assess the feasibility of implementing these objectives into a clinical curriculum.
Study Design Using the modified Delphi approach, a panel of expert stakeholders (n = 23) was assembled to reach consensus on the proposed learning objectives. A model curriculum was created consisting of a video tutorial, in-person training, and an optional tracker and piloted at two academic medical centers. Participant perception of acquired ultrasound skills and the program were assessed using a modified, previously validated survey. Pre- and postprogram survey responses were compared using the Chi-squared test of association. A p-value of <0.05 was considered statistically significant.
Results The expert panel reached consensus on five learning objectives to include determination of fetal number and presentation, assessment of fetal heart rate, determination of placental location, assessment of amniotic fluid volume, and a general understanding of the biophysical profile and its indications. A total of 26 students participated in the piloted curriculum. On completion, a majority of participants reported improved confidence in understanding and performing prenatal ultrasound in the second and third trimesters (p < 0.05). The majority of participants valued a hands-on ultrasound curriculum.
Conclusion We propose practical, consensus-based learning objectives for second- and third-trimester sonography during the core clerkship with demonstrated feasibility in a two-center pilot program.
Key Points
The Obstetrical Care and Delivery Experience of Women with Epilepsy in the MONEAD Study
Authors: McElrath Thomas F. , Druzin Maurice , Van Marter Linda J. , May Ryan C. , Brown Carrie , Stek Alice , Grobman William , Dolan Mary , Chang Patricia , Flood-Schaffer Kellie , Parker Lamar , Meador Kimford J. , Pennell Page B. ,   for the MONEAD Investigator Group
Published: March 2022

Objective We examined mode of delivery among pregnant women with epilepsy (PWWE) versus pregnant controls (PC). We hypothesize that PWWE are more likely to deliver by cesarean.
Study Design The Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD) study is an observational, prospective, multicenter investigation of pregnancy outcomes funded by the National Institute of Health (NIH). MONEAD enrolled patients from December 2012 through January 2016. PWWE were matched to PC in a case:control ratio of 3:1. This analysis had 80% power to detect a 36% increase in cesarean frequency assuming a baseline rate of 30% among PC at an α = 0.05.
Results This report analyzed 331 PWWE (76%) and 102 PC (24%) who gave birth while enrolled in the study. PWWE and PC had similar rates of cesarean delivery (34.7 vs. 28.6%; p = 0.27). Of women with cesarean, rates of cesarean without labor were similar between groups for those delivering in recruitment hospitals (48.2 vs. 50.0%) but in nonrecruitment hospitals, cesarean rates without labor were over two-fold higher among PWWE than those of PC (68.8 vs. 30.8%; p = 0.023). Receipt of a cesarean after labor did not differ for PWWE compared to PC or by type of antiepileptic drug among the PWWE.
Conclusion These findings suggest that the obstetrical experiences of PWWE and PC are similar. An interesting deviation from this observation was the mode of delivery with higher unlabored cesarean rates occurring among PWWE in nonrecruitment hospitals. As the study recruitment hospitals were tertiary academic centers and nonrecruitment hospitals tended to be community-based institutions, differences in perinatal expertise might contribute to this difference.
Key Points
Viscoelastic Testing in an Obstetric Population at High Risk of Hemorrhage
Authors: Graves Stephen M. , Montemorano Lauren , Rood Kara M. , Costantine Maged M. , Fiorini Kasey , Cackovic Michael 
Published: March 2022

Introduction Rotational thromboelastometry (ROTEM) is a point-of-care viscoelastic test used in trauma for goal-directed transfusion. However, there are limited data on baseline ROTEM parameters in the U.S. obstetric population. Obtaining baseline parameters is a first step in implementing a goal-directed massive transfusion protocol in obstetric hemorrhage.
Objective Our study aimed to establish pre- and postdelivery baseline parameters in a high-risk obstetric population and determine their association with postpartum hemorrhage (PPH).
Study Design Prospective observational study of patients ≥34 weeks' gestation, at high risk of PPH, admitted for delivery. INTEM, EXTEM, FIBTEM, and APTEM assays were performed at the time of admission to labor and delivery and then 2 hours after delivery. Primary outcome was pre- and postdelivery ROTEM parameters among women without PPH. A sample size of 60 women was needed for >90% power to detect at least 50% correlation between pre- and postdelivery assuming a loss of 10% of participants to follow-up.
Results Of 60 women in the study, 10 (17%) had PPH. Baseline characteristics were not different between those with or without PPH. Pre- and postdelivery ROTEM parameters were not significantly different except for APTEM. None of the patients who had PPH, compared with 4 (10%) of those who did not, had shortened clotting time and higher maximum clot firmness in postdelivery APTEM compared with EXTEM, a pattern suggestive of hyperfibrinolysis (p = 0.4).
Conclusion In this study, we describe baseline ROTEM parameters in women at high risk of PPH. The majority of patients did not have a ROTEM pattern that is suggestive of hyperfibrinolysis, for which tranexamic acid is thought to be beneficial. Based on our findings, previously established obstetric transfusion thresholds for goal-directed massive transfusion protocols are likely valid for the majority of the obstetric population regardless of the presence of comorbidities or pregnancy complications.
Key Points