bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast and accurate calculation of myocardial T1 and T2 values using deep learning Bloch equation simulations (DeepBLESS)
Authors: Shao Jiaxin , Ghodrati Vahid , Nguyen Kim‐Lien , Hu Peng 
Published: May 2020

PurposeTo propose and evaluate a deep learning model for rapid and accurate calculation of myocardial T1/T2 values based on a previously proposed Bloch equation simulation with slice profile correction (BLESSPC) method.MethodsDeep learning Bloch equation simulations (DeepBLESS) models are proposed for rapid and accurate T1 estimation for the MOLLI T1 mapping sequence with balanced SSFP readouts and T1/T2 estimation for a radial simultaneous T1 and T2 mapping (radial T1‐T2) sequence. The DeepBLESS models were trained separately based on simulated radial T1‐T2 and MOLLI data, respectively. The DeepBLESS T1‐T2 estimation accuracy was evaluated based on simulated data with different noise levels. The DeepBLESS model was compared with BLESSPC in simulation, phantom, and in vivo studies for the MOLLI sequence at 1.5 T and radial T1‐T2 sequence at 3 T.ResultsAfter DeepBLESS was trained, in phantom studies, DeepBLESS and BLESSPC achieved similar accuracy and precision in T1‐T2 estimations for both MOLLI and radial T1‐T2 (P > .05). For in vivo, DeepBLESS and BLESSPC generated similar myocardial T1/T2 values for radial T1‐T2 at 3 T (T1: 1366 ± 31 ms for both methods, P > .05; T2: 37.4 ms ± 0.9 ms for both methods, P > .05), and similar myocardial T1 values for the MOLLI sequence at 1.5 T (1044 ± 20 ms for both methods, P > .05). DeepBLESS generated a T1/T2 map in less than 1 second.ConclusionThe DeepBLESS model offers an almost instantaneous approach for estimating accurate T1/T2 values, replacing BLESSPC for both MOLLI and radial T1‐T2 sequences, and is promising for multiparametric mapping in cardiac MRI.
Optimizing telemedicine to facilitate amyotrophic lateral sclerosis clinical trials
Authors: Govindarajan Raghav , Berry James D. , Paganoni Sabrina , Pulley Michael T. , Simmons Zachary 
Published: May 2020

AbstractAmyotrophic lateral sclerosis (ALS) has the largest drug pipeline among neuromuscular diseases, with over 160 companies actively involved in ALS research. There is a growing need to recruit trial participants, but ALS patients often have limited mobility and most ALS trials are conducted in a small number of major centers. These factors effectively limit patient participation, particularly for those in rural areas. The current coronavirus disease 2019 (COVID‐19) pandemic has necessitated the more widespread use of telemedicine technology for clinical care, and has prompted consideration of its increased use for clinical trials. In this opinion piece, we describe the current state of telemedicine for recruitment, consenting, and screening of participants for clinical trials. We also summarize the available data on remote administration of outcome measures. Current challenges include validation of outcome measures for remote assessment, as well as technological, regulatory, and licensure barriers.
Form factor analysis of the surface electromyographic interference pattern
Authors: Nandedkar Sanjeev D. , Barkhaus Paul E. , Stålberg Erik V. 
Published: May 2020

AbstractIntroductionIn contrast to needle electromyography (EMG), surface EMG recordings are painless. It is of interest to develop methods to analyze surface EMG for diagnostic purposes.MethodsSurface EMG interference pattern (SIP) recordings from the abductor pollicis brevis muscle of healthy subjects and subjects with amyotrophic lateral sclerosis (ALS) were analyzed by measuring root‐mean‐square (RMS) voltage, mean rectified voltage, form factor (FF), and the clustering index (CI). The FF vs SIP area plot was used for analysis.ResultsThe SIP FF was increased and abnormal in ALS subjects, especially when SIP area was less than 200 mVms. Power regression showed a faster FF decline with SIP area in ALS patients than in healthy subjects. The CI and FF showed a strong correlation.DiscussionFF is easy to calculate and demonstrates abnormalities in ALS patients.
Compound muscle action potential scan and MScanFit motor unit number estimation during Wallerian degeneration after nerve transections
Authors: Kesim‐Sahin Ozlem , Sirin Nermin Gorkem , Erbas Bahar , Artug Tugrul , Oguz‐Akarsu Emel , Kocasoy‐Orhan Elif , Baslo Mehmet Baris , Mammadova Nermin , Emekli Ufuk , Oge Ali Emre 
Published: May 2020

AbstractBackgroundCompound muscle action potential (CMAP) scan and MScanFit have been used to understand the consequences of denervation and reinnervation. This study aimed to monitor these parameters during Wallerian degeneration (WD) after acute nerve transections (ANT).MethodsBeginning after urgent surgery, CMAP scans were recorded at 1–2 day intervals in 12 patients with ANT of the ulnar or median nerves, by stimulating the distal stump (DS). Stimulus intensities (SI), steps, returners, and MScanFit were calculated. Studies were grouped according to the examination time after ANT. Results were compared with those of 27 controls.ResultsCMAP amplitudes and MScanFit progressively declined, revealing a positive correlation with one another. SIs were higher in WD groups than controls. Steps appeared or disappeared in follow‐up scans. The late WD group had higher returner% than the early WD and control groups.ConclusionsMScanFit can monitor neuromuscular dysfunction during WD. SIs revealed excitability changes in DS.
Model Reduction Framework with a New Take on Active Subspaces for Optimization Problems with Linearized Fluid‐Structure Interaction Constraints
Authors: Boncoraglio Gabriele , Farhat Charbel , Bou‐Mosleh Charbel 
Published: May 2020

SummaryIn this paper, a new take on the concept of an active subspace for reducing the dimension of the design parameter space in a multidisciplinary analysis and optimization (MDAO) problem is proposed. The new approach is intertwined with the concepts of adaptive parameter sampling, projection‐based model order reduction, and a database of linear, projection‐based reduced‐order models equipped with interpolation on matrix manifolds, in order to construct an efficient computational framework for MDAO. The framework is fully developed for MDAO problems with linearized fluid‐structure interaction constraints. It is applied to the aeroelastic tailoring, under flutter constraints, of two different flight systems: a flexible configuration of NASA's Common Research Model; and NASA's Aeroelastic Research Wing #2 (ARW‐2). The obtained results illustrate the feasibility of the computational framework for realistic MDAO problems and highlight the benefits of the new approach for constructing an active subspace in both terms of solution optimality and wall‐clock time reduction.
Coupled optimization of macroscopic structures and lattice infill
Authors: Geoffroy‐Donders Perle , Allaire Grégoire , Michailidis Georgios , Pantz Olivier 
Published: May 2020

SummaryThis article is concerned with the coupled optimization of the external boundary of a structure and its infill made of some graded lattice material. The lattice material is made of a periodic cell, macroscopically modulated and oriented. The external boundary may be coated by a layer of pure material with a fixed prescribed thickness. The infill is optimized by the homogenization method while the macroscopic shape is geometrically optimized by the Hadamard method of shape sensitivity. A first original feature of the proposed approach is that the infill material follows the displacement on the exterior boundary during the geometric optimization step. A second key feature is the dehomogenization or projection step which build a smoothly varying lattice infill from the optimal homogenized properties. Several numerical examples illustrate the effectiveness of our approach in 2‐d, which is especially convenient when considering design‐dependent loads.
A modified cutting‐plane time integration scheme with adaptive substepping for elasto‐viscoplastic models
Authors: Li Jian , Yin Zhen‐Yu 
Published: May 2020

SummaryIntegration of stress‐strain‐time relationship is a key issue for the application of elasto‐viscoplastic models to engineering practice. This article presents a novel adaptive substepping cutting‐plane time integration scheme for elasto‐viscoplastic models keeping the advantage of original cutting‐plane (OCP) with only the first derivatives of loading surface required. The deficiency of OCP time integration algorithm is first discussed taking a simple overstress theory based elasto‐viscoplastic modified Cam‐Clay model (EVP‐MCC) as example. To overcome this, a new algorithm is developed with three features: (1) an evolution function for the hardening variable of dynamic loading surface is innovatively deduced for the Taylor series approximation, (2) the elastic predictor is modified to account for the initial viscoplastic strain rate with more accuracy, and (3) a new adaptive substepping technique for restricting simultaneously both strain and time incremental sizes based on the overstress distance is proposed. For easy understanding, the proposed algorithm is first presented for one‐dimensional condition, and then extended to three‐dimensional condition. The new integrated EVP‐MCC model using the proposed algorithm is examined by simulating laboratory tests at both levels of integration point and finite element with a good performance in terms of accuracy and convergence.
A semi‐implicit stabilized particle Galerkin method for incompressible free surface flow simulations
Authors: Pan Xiaofei , Wu Cheng‐Tang , Hu Wei 
Published: May 2020

SummaryA new particle Galerkin method is introduced to solve the Naiver‐Stokes equations in a Lagrangian fashion. The present method aims to suppress key numerical instabilities observed in the strong form Lagrangian particle methods such as smoothed particle hydrodynamics (SPH), incompressible SPH, and moving particle semi‐implicit for incompressible free surface flow simulations.It is well‐known that strong form Lagrangian particle methods usually rely on ad hoc particle stabilization techniques based on particle shifting, artificial viscosity, or density‐invariant condition due to some formulation inconsistency issues. In the present method, we introduce a momentum‐consistent velocity smoothing algorithm which is used to combine with the second‐order rotational incremental pressure‐correction scheme to stabilize the pressure field as well as to enforce the consistency of Neumann boundary condition. To further impose slip‐free or nonslip boundary conditions for the fluid flow, a penalty method which is free of ghost or dummy particles is developed. Finally, a particle insertion‐deletion adaptive scheme is proposed when the violent fluid flow is considered. Four numerical examples are studied to validate the accuracy and stability of the present method.
An evidence‐based structured one‐year programme to sustain physical activity in patients with heart failure in primary care: A non‐randomized longitudinal feasibility study
Authors: Nordgren Lena , Söderlund Anne 
Published: May 2020

AbstractAimThe primary objective of this non‐randomized feasibility study was to test a 1‐year model programme for sustaining/increasing patients’ motivation to perform daily physical activity.DesignNon‐randomized longitudinal feasibility study with a one‐group repeated measures design.MethodsThe study took place at a primary care centre in mid‐Sweden in 2017–2018. The model programme included individual and group‐based support, individualized physical activity prescriptions, a wrist‐worn activity tracker and an activity diary. The main outcomes were the participants’ perceptions of programme feasibility and scores on the Exercise Self‐Efficacy Scale.ResultsSeven patients were recruited. Six patients completed the programme that was perceived to imply learning, motivation and support. Compared with baseline, the median score of the Exercise Self‐Efficacy Scale improved 3 months after participants completed the programme.
Two‐grid methods for –P1 mixed finite element approximation of general elliptic optimal control problems with low regularity
Authors: Hou Tianliang , Leng Haitao , Luan Tian 
Published: May 2020

AbstractIn this paper, we present a two‐grid mixed finite element scheme for distributed optimal control governed by general elliptic equations. –P1 mixed finite elements are used for the discretization of the state and co‐state variables, whereas piecewise constant function is used to approximate the control variable. We first use a new approach to obtain the superclose property between the centroid interpolation and the numerical solution of the optimal control u with order h2 under the low regularity. Based on the superclose property, we derive the optimal a priori error estimates. Then, using a postprocessing projection operator, we get a second‐order superconvergent result for the control u. Next, we construct a two‐grid mixed finite element scheme and analyze a priori error estimates. In the two‐grid scheme, the solution of the elliptic optimal control problem on a fine grid is reduced to the solution of the elliptic optimal control problem on a much coarser grid and the solution of a linear algebraic system on the fine grid and the resulting solution still maintains an asymptotically optimal accuracy. Finally, a numerical example is presented to verify the theoretical results.
The effect of polyhedral oligosilsesquioxanes (POSS) on cavitation resistance of hybrid acrylate films
Authors: Kalifa Mustafa , Tomić Nataša Z. , Vuksanović Marija M. , Stevanovic Sanja , Đokić Veljko , Husović Tatjana Volkov , Pavlović Vladimir , Jančić Heinemann Radmila M. , Marinković Aleksandar D. 
Published: May 2020

AbstractCavitation erosion of hybrid acrylate composite films with polyhedral oligosilsesquioxanes (POSS) was investigated in this study. The hybrid films are made with 1, 3 and 5 wt% of POSS reagents containing: (a) hydroxyl (POSS‐M), (b) both hydroxyl and allyl (POSS‐M‐A) and (c) methacryloyl groups (POSS‐M‐Cl). Addition of 5 wt% POSS‐M‐A caused the highest microhardness increase for 49.8%, in comparison to the pure matrix material. Cavitation resistance of hybrid films, estimated as the time‐dependent mass loss, was improved by POSS addition. POSS‐M‐A addition (5 wt%) contributed to 94% lower mass loss comparing to pure Bis‐GMA/TEGDMA film. Scanning electron (SEM) and atomic force microscopy (AFM) showed the lowest surface roughness obtained for composite with POSS‐M‐A. The improved hardness and wear resistance of the composite films indicated that POSS‐M‐A filler enhanced interfacial adhesion and reinforcing of the Bis‐GMA/TEGDMA matrix.
Intermittent absent and reversed umbilical artery flows in appropriately grown monochorionic diamniotic twins in relation to proximate cord insertion: A harmful combination?
Authors: Eschbach Sanne Johanna , Tollenaar Lisanne S. A. , Oepkes Dick , Lopriore Enrico , Haak Monique C. 
Published: May 2020

AbstractObjectiveTo compare the prevalence of intermittent absent or reversed end‐diastolic flow (iAREDF) in the umbilical artery in appropriately grown monochorionic diamniotic (MCDA) pregnancies with and without proximate cord insertion (PCI), and to evaluate pregnancy outcome.MethodsThe prevalence of iAREDF in MCDA pregnancies with PCI (n = 11) was compared with a control group without PCI (n = 33). PCI was defined as a distance between the cord insertions below the fifth percentile. Placental sharing, number, and diameter of anastomoses were assessed by placental examination. Pregnancy outcome was evaluated.ResultsiAREDF was present in 7/11 PCI pregnancies, compared with 0/33 in the control group (P ≤ .01). All PCI pregnancies and 94% of controls had arterioarterial (AA)‐anastomoses (P = .56), the diameter was larger in the PCI group, respectively 3.3 vs 2.1 mm (P = .03). Three cases with iAREDF had adverse outcome, two resulted in fetal death of which one with brain damage in the co‐twin, another underwent early premature emergency section for fetal distress.ConclusioniAREDF occurs in a large proportion of MCDA pregnancies with PCI and is related to the diameter of the AA anastomosis. We hypothesize that iAREDF in appropriately grown MCDA twin pregnancies reflects an unstable hemodynamic balance with an increased risk for fetal deterioration. Whether outcome in these pregnancies can be improved by altered management requires further investigation.
I am all ears: Maximize maize doubled haploid success by promoting axillary branch elongation
Authors: Wu Miin‐Feng , Goldshmidt Alexander , Ovadya Daniel , Larue Huachun 
Published: May 2020

AbstractThe maize doubled haploid (DH) technology plays an important role in accelerating breeding genetic gain. One major challenge in fully leveraging the potential of DH technology to accelerate genetic gain is obtaining a consistent seed return from haploid (DH0) plants after chromosome doubling. Here we demonstrated that DH0 seed production can be increased by increasing the number of mature axillary female inflorescences (ears) at anthesis. To determine the maximum capacity of a maize plant to develop ears, we first characterized the developmental progression of every axillary meristem. We found that all axillary meristems developed to a similar developmental stage before the reproductive transition of the shoot apical meristem (SAM). Upon reproductive transition of the SAM, all axillary meristems are released for reproductive development into ears in a developmental gradient reflective on their positions along the main stem. However, under most circumstances only the top one or two ears can generate silks at anthesis. We found that applying the GA inhibitor paclobutrazol (PAC) during the early reproductive transition of axillary meristems increased the number of silking ears at anthesis, leading to increased success of self‐pollination and seed production. These results provide a blueprint to improve DH efficiency and demonstrate the potential of breeding innovation through understanding crops’ developmental processes.
Interrogating Fractionation and Other Sources of Variability in Shotgun Proteomes Using Quality Metrics
Authors: Kriek Marina , Monyai Koena , Magcwebeba Tandeka U. , Du Plessis Nelita , Stoychev Stoyan H. , Tabb David L. 
Published: May 2020

AbstractThe increasing amount of publicly available proteomics data creates opportunities for data scientists to investigate quality metrics in novel ways. QuaMeter IDFree is used to generate quality metrics from 665 RAW files and 97 WIFF files representing publicly available “shotgun” mass spectrometry datasets. These experiments are selected to represent Mycobacterium tuberculosis lysates, mouse MDSCs, and exosomes derived from human cell lines. Machine learning techniques are demonstrated to detect outliers within experiments and it is shown that quality metrics may be used to distinguish sources of variability among these experiments. In particular, the findings demonstrate that according to nested ANOVA performed on an SDS‐PAGE shotgun principal component analysis, runs of fractions from the same gel regions cluster together rather than technical replicates, close temporal proximity, or even biological samples. This indicates that the individual fraction may have had a higher impact on the quality metrics than other factors. In addition, sample type, instrument type, mass analyzer, fragmentation technique, and digestion enzyme are identified as sources of variability. From a quality control perspective, the importance of study design and in particular, the run order, is illustrated in seeking ways to limit the impact of technical variability.
On the Holton–Lindzen–Plumb model for mean flow reversals in stratified fluids
Authors: Renaud Antoine , Venaille Antoine 
Published: May 2020

AbstractThe Holton–Lindzen–Plumb (HLP) model describes the spontaneous emergence of mean flow reversals in stratified fluids. It has played a central role in understanding the Quasi‐Biennial Oscillation of equatorial winds in Earth's stratosphere and has arguably become a linchpin of wave–mean flow interaction theory in geophysical and astrophysical fluid dynamics. The derivation of the model's equation from primary equations follows from several assumptions, including quasi‐linear approximations, WKB expansion of the wavefield, simplifications of boundary‐layer terms, among others. Starting from the two‐dimensional, non‐rotating, Boussinesq equations, we present in this paper a self‐consistent derivation of the HLP model and show the existence of a distinguished limit for which all approximations remains valid. We furthermore discuss the important role of boundary conditions, and the relevance of this model to describe secondary bifurcations associated with a quasi‐periodic route to chaos.
Texture‐based classification of high‐resolution precipitation forecasts with machine‐learning methods
Authors: Hamidi Yamina , Raynaud Laure , Rottner Lucie , Arbogast Philippe 
Published: May 2020

AbstractObject‐based methods are commonly used for verification and postprocessing of high‐resolution precipitation forecasts. They usually detect objects based on intensity criteria only, without considering the spatial organization of rainfall, known as texture. This article evaluates the performance of several machine‐learning methods to detect “continuous” and “intermittent” rainfall patterns in the forecasts of the French convective‐scale Arome model. A sliding‐window segmentation algorithm, which applies a classification model at each grid point, is implemented. Several classifiers and input textural features are compared. Overall, intermittent precipitation is the most difficult to detect. The random forest classifier is shown to provide the best classification results independently of the predictor used, with a surprising ability to extract a relevant signal from a synthetic descriptor such as the rainfall cumulative distribution function, as well as from the large amount of unprocessed information provided by neighbouring grid points. On the other hand, the logistic regression classifier needs a texture‐oriented predictor, such as the statistics derived from the grey‐level co‐occurrence matrix, to perform well. Global insight into model behaviour is then obtained by examining the importance of input features. Finally, we show that random forests trained on Arome deterministic forecasts can be applied successfully to discriminate between precipitation textures in different Arome configuration outputs and gridded observations.
Rapid and direct identification of the origin of white tea with proton transfer reaction time‐of‐flight mass spectrometry
Authors: Zhang Dandan , Wu Weihua , Qiu Xiaohong , Li Xiaojing , Zhao Feng , Ye Naixing 
Published: May 2020

RationaleWhite tea has become very popular in recent years, but there has been no scientific identification of white tea from different origins. For product authentication and valorization, every kind of white tea must be marked with an indication of its origin.MethodsVolatile profiles of white tea leaf samples from their main origins in China (Fuding City, Zhenghe City and Jianyang City) were analyzed using proton transfer reaction time‐of‐flight mass spectrometry (PTR‐TOFMS). Tentative identifications of the volatile organic compounds (VOCs) were obtained by PTR‐TOFMS of the headspace. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS‐DA) were performed to evaluate the differences among the various origins.ResultsTeas from different origins were shown to have characteristic VOCs and profiles. Thus, white teas from different origins could be separated by characterizing the volatile emissions from the dry tea leaves. The ability of the two classification models to use the volatile fingerprints in origin discrimination was investigated.ConclusionsTwo classification models (PCA and OPLS‐DA) were applied to the PTR‐TOFMS data obtained from the VOCs of various white teas. The classification models were shown to be useful in identifying the origin of white tea samples, providing a reference for white tea identification.