bluuebunny/crossref_metadata_2025_split huggingface dataset:
New reprocessable branched polyurethane from biorenewable sources
Authors: Platonova E O , Pavlov A A , Polezhaev A V 
Published: August 2021

Abstract
Thermally-remendable and recyclable polyurethane was obtained via Diels-Alder reaction using branched glycol Voranol 3138 (glycerin-derived block-copolymer of polyethylene and polypropylene) as soft segment and toluene-2,4-diisocyanate (TDI) as hard segment subsequently functionalized by terminal difurfurylamine groups. By cross-linking via Diels-Alder reaction with N,N’-bismaleimido-4,4′-diphenylmethane (BMI) new self-healing branched polyurethane was obtained. Polymer structure was characterized by NMR and IR spectroscopy along with thermal analysis methods (DSC and TGA). Resulting material has good processability and opportunity for recycling.
Branched copolylactides: the effect of the synthesis method on their properties
Authors: Istratov V V , Polezhaev A V 
Published: August 2021

Abstract
In this work, L-lactide, acting as a cyclic AB monomer, was copolymerized with various AB2 comonomers. Depending on the nature of the AB2 comonomer, it was either a combination of L-lactide ring-opening polymerization with glycidol polymerization or a combination of L-lactide ring-opening polymerization with 2,2-bis (hydroxymethyl) propionic acid (BHP) polycondensation. Both synthetic methods resulted in branched copolyesters. A number of polymers with varying degrees of branching were obtained by systematically changing the proportion of comonomer AB2. The polymers were characterized using
1H NMR spectroscopy and SEC, and their thermal properties were studied using differential scanning calorimetry and thermogravimetric analysis. Also were investigated the viscosity of the solution and the wettability of the branched copolymers. Although structurally similar macromolecules were formed in both synthesis methods, polymers with BHP as AB2 comonomers have higher melting- and glass transition temperatures, higher thermal stability, solution viscosity and lower wettability than polymers with glycidol as AB2 comonomers.
Recent progress in self-healing polyurethanes based on Diels-Alder reaction
Authors: Borodulin A S , Ponomareva P F , Platonova E O , Pavlova V A 
Published: August 2021

Abstract
This review examines the latest advances in the synthesis and application of polyurethanes that have a self-healing effect due to the thermally reversible Diels-Alder reaction. A classification of strategies for improving the parameters of the final polymers is proposed, which includes the division into polyurethanes with a flexible organic linker, composites with nanoparticles, and systems with a dual self-healing mechanism both due to the Diels-Alder reaction and the reaction of the formation of a disulfide bonds from thiols. The possible applications of the obtained materials and the assumption about the further development of the field are considered.
Modeling of non-Newtonian fluid flows in porous textile structures under RTM technologies
Authors: Dimitrienko Yu I , Shuguang Li 
Published: August 2021

Abstract
In this paper, the investigation is devoted to the application of homogenization methods to the transport theory of non-Newtonian shear-thinning fluids in porous fabric structures. Mathematical model is proposed for describing the local transfer of non-Newtonian shear-thinning fluid over a periodic cell, and the symmetry of the microstructure and periodic boundary conditions are used to significantly reduce the complexity of the problem and the computational burden. Solving local problems allows us to find accurate local distributions of velocities, pressure and viscosity inside a separate pore, and also to evaluate the permeability of the porous medium and the effective viscosity of the fluid when only the geometry of the pore is known. Finally, the numerical results for the local transport of pseudoplastic fluid in porous media are given.
Asymptotic analysis of the two-layer plates bending with nonlinear interlayer friction
Authors: Dimitrienko Yu I , Gubareva E A , Makovskaya M O 
Published: August 2021

Abstracts
The article is devoted to the study of the features of the occurrence of slip between layers of a thin two-layer plate with an initial ideal contact under the influence of critical pressure. A three-dimensional problem of the linear theory of elasticity for a thin two-layer plate with sliding conditions with friction at the interface is considered. To solve this problem, the method of asymptotic averaging is applied. An equation is established for calculating the critical pressure for a two-layer plate at which the layers begin to slip. A numerical example is considered for a two-layer fiberglass for different conditions of fixing at the ends. It is shown that the fixing conditions affect the critical pressure of the beginning of sliding.
Modeling nonlinear dielectric properties of laminated composites
Authors: Dimitrienko Yu I , Gubareva E A , Zubarev K M 
Published: August 2021

Abstracts
The article is devoted to the development of a method for predicting the nonlinear dielectric properties of layered composites with complex dependences of the dielectric constant on the electric field strength, which consider the effects of a sharp increase and subsequent decrease in the dielectric constant with increasing field strength. The method is based on the use of the theory of asymptotic averaging proposed by N.S. Bakhvalov, E. Sanchez-Palencia, in relation to the nonlinear problem of electrostatics in a layered medium. As a result of applying this method, local nonlinear problems of electrostatics on a periodicity cell are formulated, and an algorithm for calculating effective nonlinear dielectric constants is proposed. It is shown that a layered composite is a transversely isotropic nonlinear dielectric material if its layers are isotropic materials. A numerical example of calculating the nonlinear properties of a 2-layer composite based on barium titanate and ferroelectric ceramic varicond VK4 is considered. Calculations have shown that the developed method for calculating the nonlinear-dielectric ratios of composites is quite effective and makes it possible to predict the dielectric properties of composites at various values of the electric field strength, including the regions where the dielectric permittivities of the layer materials are saturated. The developed technique can serve as a basis for designing new nonlinear dielectric composite materials with unusual properties.
3D Finite Element Modeling of Stresses in Filament Wound Structures
Authors: Dimitrienko Y I , Yurin Yu V , Maremshaova A A 
Published: August 2021

Abstracts
A method for calculating stresses in the structure of a pressure cylinder made by winding a composite fibrous material has been developed. A special feature of the proposed method is that the problem is solved within the framework of the 3D formulation of the problem of the theory of elasticity, considering the curvilinear anisotropy of the structure, which changes from point to point. This technique allows one to consider the detailed microstructure of a composite material wound with overlapping tapes. To solve the problem, the 3D finite element method is used, as well as a special algorithm for constructing an additional mesh of elements, which makes it possible to relate the curvilinear anisotropy with the geometry of the thin-walled shell under study.
Numerical methods of Laplace transform inversion in the problem of determination of viscoelastic characteristics of composite materials
Authors: Valishin A A , Tinyaev M A 
Published: August 2021

Abstracts
When designing products made of composite materials intended for operation in difficult conditions of inhomogeneous deformations and temperatures, it is important to consider the viscoelastic properties of the binder and fillers. The article analyzes the relationship between relaxation and creep characteristics. All known creep and relaxation nuclei in the literature are considered. The problem of transformation of creep characteristics into relaxation characteristics and Vice versa is discussed in detail. There is a simple relationship between the creep and relaxation functions in the Laplace image space. However, when returning to the space of the originals, in many cases there are great difficulties in reversing the Laplace transform. Two numerical methods for inverting the Laplace transform are considered: the use of the Fourier series in sine and the method of quadrature formulas. Algorithms and computer programs for realization of these methods are made. It is shown that the operating time of a computer program implementing the Fourier method by sine is almost 2 times less than the operating time of a computer program implementing the quadrature formula method. However, the first method is inferior to the latter method in accuracy of calculations: the relaxation functions and relaxation rates, it is advisable to find the first method, since the computational error is almost indiscernible, and the functions of creep and creep speed, the second way, because for most functions, the result obtained by the second method is much more accurate than the result obtained by the first method.
Application of the ultrajet diagnostic method to assess the damage of carbon fiber-reinforced plastic under cooling conditions
Authors: Papich A , Galinovsky A L , Izotov N A , Zhenyuan Chia 
Published: August 2021

Abstract
This paper considers the possibility of using the ultrajet diagnostic for studying the strength properties of carbon fiber-reinforced plastics after cryogenic temperature impact. The method is based on the interaction of a high-speed liquid jet and a fine-dispersed abrasive with the coating to be diagnosed. Analysis of the experimental data revealed a decrease in the material’s strength after cooling in liquid nitrogen. The deterioration of the composite strength properties is explained by the decrease in the adhesive strength in the “fiber-matrix” system.
Investigation of the properties of carbon fiber reinforced plastics after the seawater exposure
Authors: Vasiliev M D , Komarov I A 
Published: August 2021

Abstract
The results of experimental studies of the mechanical characteristics of carbon fibers (CFRPs) before and after their exposure at seawater are presented. The choice of seawater as an operation medium is due to the fact that this carbon fiber is intended for the manufacture of power elements of a manned underwater vehicle. Carbon fibers were made using vacuum infusion technology based on an epoxy binder, and biaxial carbon fabric was used as a reinforcing material. The prepared samples were kept in seawater for 384 h, which made it possible to estimate the amount of water absorption, as well as the change in mechanical characteristics after exposure to seawater. It has been established that the strength of CFRPs does not change during interlayer shear, decreases by 14% during bending, and the value of the elastic modulus, after exposure to seawater, decreases by 17%.
New ternary intermetallic compound SmRuSn2
Authors: Pavlova V A , Murashova E V , Borodulin A S 
Published: August 2021

Abstract
Ternary intermetallic compound SmRuSn2 was synthesized in the system Sm-Ru-Sn by arc-melting and annealing at 600 °C in field with high content of Sn. Its crystal structure was determined from single crystal X-ray diffraction data (at 240 K) and then confirmed by the powder X-ray diffraction data (at 295 K). The compound crystallizes in with space group Cmcm (No. 63), unit cell unit cell parameters: a=4.3954(19) Å, b=10.3783(13) Å, c=7.417(2) Å, Z=4. The intermetallic compound SmRuSn2 belongs to the structure type MgCuAl2.
Research on Multi-beam Handover Invitation Technology for GEO Mobile Satellite System
Authors: Jiang Yumeng 
Published: August 2021

Abstract
Different from the terrestrial cellular system, the GEO mobile satellite system has its own characteristics, such as the extremely large beams, the long propagation delay and the diversity of the MS (Mobile Station) velocity. Based on these characteristics, a cooperative beam-cluster is constructed, and a handover invitation technology based on the coordinated multi-beam is proposed in the paper. Using the sending mechanism of handover invitation by a variable sliding window, the technology can avoid the occurrence of the phenomenon of “ping pong” handover to realize seamless handover, and make the handover quick, efficient and reliable. Simulation results show that the algorithm significantly increases the handover success rate, prevents the unnecessary handoff and has a favourable adaptability to the high velocity MS.
A-154 Predicting Older Adults’ Subjective Well-Being and Resilience through Executive Functioning
Authors: Kaufman Jack R , Bradford Anna , DelDonno Sophie , Germain Jacob , Hovatta Nathalie , Kim Joseph , Langenecker Scott A , Lorentz Natalie , Patron Victor , Weisenbach Sara , Welsh Robert C 
Published: August 2021

Abstract

Objective
We measured the extent to which sub-domains of executive functioning (EF) associate with resilience and well-being in older adults ranging from minimal to severe in depression symptom severity. We hypothesized that measures of set-shifting ability, problem solving skills, and cognitive flexibility would positively predict resilience and wellness, spanning affective, judgmental and cognitive components.

Methods
56 older adults (27 female, mean age = 67.6, mean education = 16.52) with degrees of depression ranging from minimal to severe completed a behavioral battery. EF measures included the Trail Making Test (TMT) [B score], Delis-Kaplan Executive Function System (D-KEFS) Sorting Task [correct sorts], Controlled Oral Word Association Test (COWA) [total score], and Wisconsin Card Sorting Task (WCST) [Perseverative responses]. Outcome measures included the Ego Resiliency Scale (ERS), the Life Orientation Test – Revised (LOT-R), the Satisfaction With Life Scale (SWLS), and a cumulative well-being scale. Finally, the Hamilton Depression Rating Scale (HAM-D) was used to evaluate depression symptom presence and severity.

Results
A series of multiple regression models were performed with age, sex and education in the first step, depression symptom severity in the second, and executive functioning measure in the third. Final models for the above four outcomes yielded the following R squares: 0.34 (p = 0.08), 0.38 (p = 0.06), 0.35 (p = 0.07), and 0.44 (p = 0.01).

Conclusions
Depression (shown to correlate with our outcomes) accounted for, well-being and resilience were consistently predicted with behavioral measures of executive function. Older adults may want to look toward cognitive resilience and other EF targets to exploit the relationship this has with wellness downstream.
A-1 The Influence of Base Rate and Sample Size on Performance of a Random Forest Classifier for Dementia Prediction: Implications for Recruitment
Authors: Brickell Emily , Whitford Andrew , Boettcher Anneliese , Pereira Carolina , Sawyer R John 
Published: August 2021

Abstract

Objective
Machine learning (ML) classifier performance estimates are affected by sample size and class imbalance in training data, and yet performance is often reported with balanced data. We explore the effect of varying sample size and dementia conversion base rate on the performance of a classifier that predicts future dementia.

Method
Longitudinal data from the National Alzheimer’s Coordination Center (NACC) Uniform Data Set (UDS) were used. All participants had MCI at baseline. A random forest classifier (RFC) was trained to predict dementia at 1, 2, and 3 years. Predictors included baseline neuropsychological test scores, demographics, and health history. Cases were sampled at multiple sample sizes (N = 125, 250, 500, 1000 and 2000) and base rates (0.1, 0.2, 0.3, 0.4, and 0.5). Performance was evaluated using Matthews Correlation Coefficient (MCC).

Results
For balanced data (N = 1000), the classifier predicts conversion to dementia at 3 years with an MCC of 0.54 (sensitivity = 0.79; specificity = 0.75). As expected, means of classifier performance estimates decline as the conversion rate decreases. Likewise, variability of estimates increases with smaller sample sizes. For a conversion rate of 30%, consistent with many memory clinics, classifier performance declines only moderately (MCC = 0.44). In conversion rates of 10% and 20%, performance approaches chance. Performance trends illustrated in Figure 1.

Conclusions
Such classifiers may have clinical utility in memory clinics with higher conversion rates. Expected tradeoffs are observed with respect to diminishing sample size increasing error variance, and higher base rates of positive cases improving overall performance. Results provide potential guidelines for sample size and recruitment targets with RFC designs.
Acetate excretion by a methanotroph,Methylocaldum marinumS8, under aerobic conditions
Authors: Takeuchi Mio , Yoshioka Hideyoshi 
Published: August 2021

ABSTRACTMethane-oxidizing bacteria (methanotrophs) often coexist with methylotrophs that utilize methanol excreted by methanotrophs. Recently, we found that a facultative methylotroph, Methyloceanibacter caenitepidi Gela4T, possibly utilizes acetate rather than methanol in the coculture with a methanotroph, Methylocaldum marinum S8. Here, we examined the effects of oxygen concentrations on growth of and acetate excretion by M. marinum S8 in pure culture and the coculture with M. caenitepidi Gela4T. M. marinum S8 excreted acetate during the exponential growth phase not only under microaerobic (O2 concentrations of 3.5%-6%) but also under aerobic (O2 concentrations of 20%-31%) conditions. RNA-Seq analyses of M. marinum S8 cells grown under aerobic conditions suggested that phosphoketolase and acetate kinase were candidate genes involved in acetate production. Nonmethylotrophic bacteria, Cupriavidus necator NBRC 102504, could grow when cocultured with M. marinum S8, also supporting the existence of methanol-independent cross-feeding from M. marinum S8 under aerobic conditions.
External Validation and Comparison of Clostridioides difficile Severity Scoring Systems
Authors: Perry D Alexander , Shirley Daniel , Micic Dejan , Patel Pratish C , Putler Rosemary , Menon Anitha , Young Vincent B , Rao Krishna 
Published: August 2021

Abstract

Background
Many models have been developed to predict severe outcomes from Clostridioides difficile infection (CDI). These models are usually developed at a single institution and largely are not externally validated. Our aim in this study was to validate previously published risk scores in a multicenter cohort of patients with CDI.

Methods
This was a retrospective study on 4 inpatient cohorts with CDI from 3 distinct sites: the universities of Michigan (2010–2012 and 2016), Chicago (2012), and Wisconsin (2012). The primary composite outcome was admission to an intensive care unit, colectomy, and/or death attributed to CDI within 30 days of positive testing. Both within each cohort and combined across all cohorts, published CDI severity scores were assessed and compared to each other and the Infectious Diseases Society of America (IDSA) guideline definitions of severe and fulminant CDI.

Results
A total of 3646 patients were included for analysis. Including the 2 IDSA guideline definitions, 14 scores were assessed. Performance of scores varied within each cohort and in the combined set (mean area under the receiver operator characteristic curve [AuROC], 0.61; range, 0.53–0.66). Only half of the scores had performance at or better than IDSA severe and fulminant definitions (AuROCs of 0.64 and 0.63, respectively). Most of the scoring systems had more false than true positives in the combined set (mean, 81.5%; range, 0%–91.5%).

Conclusions
No published CDI severity score showed stable, good predictive ability for adverse outcomes across multiple cohorts/institutions or in a combined multicenter cohort.
The conserved long non-coding RNA CARMA regulates cardiomyocyte differentiation
Authors: Kay Maryam , Soltani Bahram M , Nemir Mohamed , Aghagolzadeh Parisa , Pezzuto Iole , Chouvardas Panagiotis , Ruberto Francesco , Movahedi Fatemeh , Ansari Hassan , Baharvand Hossein , Pedrazzini Thierry 
Published: August 2021

Abstract

Aims
Production of functional cardiomyocytes from pluripotent stem cells requires tight control of the differentiation process. Long non-coding RNAs (lncRNAs) exert critical regulatory functions in cell specification during development. In this study, we designed an integrated approach to identify lncRNAs implicated in cardiogenesis in differentiating human embryonic stem cells (ESCs).

Methods and results
We identified CARMA (CARdiomyocyte Maturation-Associated lncRNA), a conserved lncRNA controlling cardiomyocyte differentiation and maturation in human ESCs. CARMA is located adjacent to MIR-1-1HG, the host gene for two cardiogenic miRNAs: MIR1-1 and MIR-133a2, and transcribed in an antisense orientation. The expression of CARMA and the miRNAs are negatively correlated, and CARMA knockdown increases MIR1-1 and MIR-133a2 expression. In addition, CARMA possesses MIR-133a2 binding sites, suggesting the lncRNA could be also a target of miRNA action. Upon CARMA down-regulation, MIR-133a2 target protein-coding genes are coordinately down-regulated. Among those, we found RBPJ, the gene encoding the effector of the NOTCH pathway. NOTCH has been shown to control a binary cell fate decision between the mesoderm and the neuroectoderm lineages, and NOTCH inhibition leads to enhanced cardiomyocyte differentiation at the expense of neuroectodermal derivatives. Interestingly, two lncRNAs, linc1230 and linc1335, which are known repressors of neuroectodermal specification, were found up-regulated upon Notch1 silencing in ESCs. Forced expression of either linc1230 or linc1335 improved ESC-derived cardiomyocyte production. These two lncRNAs were also found up-regulated following CARMA knockdown in ESCs.

Conclusions
Altogether, these data suggest the existence of a network, implicating three newly identified lncRNAs, the two myomirs MIR1-1 and MIR-133a2 and the NOTCH signalling pathway, for the coordinated regulation of cardiogenic differentiation in ESCs.