bluuebunny/crossref_metadata_2025 huggingface dataset:
Strong tribo-piezoelectric effect in bilayer indium nitride (InN)
Authors: Islam Md. Sherajul , Zamil Md. Yasir , Mojumder Md. Rayid Hasan , Stampfl Catherine , Park Jeongwon
Published: September 2021

The high electronegativity between the atoms of two-dimensional (2D) group-III nitrides makes them attractive to demonstrating a strong out-of-plane piezo-electricity effect. Energy harvesting devices can be predicted by cultivating such salient piezoelectric features. This work explores the tribo-piezoelectric properties of 2D-indium nitride (InN) as a promising candidate in nanogenerator applications by means of first-principles calculations. In-plane interlayer sliding between two InN monolayers leads to a noticeable rise of vertical piezoelectricity. The vertical resistance between the InN bilayer renders tribological energy by the sliding effect. During the vertical sliding, a shear strength of 6.6–9.7 GPa is observed between the monolayers. The structure can be used as a tribo-piezoelectric transducer to extract force and stress from the generated out-of-plane tribo-piezoelectric energy. The A–A stacking of the bilayer InN elucidates the highest out-of-plane piezoelectricity. Any decrease in the interlayer distance between the monolayers improves the out-of-plane polarization and thus, increases the inductive voltage generation. Vertical compression of bilayer InN produces an inductive voltage in the range of 0.146–0.196 V. Utilizing such a phenomenon, an InN-based bilayer compression-sliding nanogenerator is proposed, which can tune the generated tribo-piezoelectric energy by compressing the interlayer distance between the InN monolayers. The considered model can render a maximum output power density of ~ 73 mWcm−2 upon vertical sliding.
Impact of exercise capacity on the long-term incidence of atrial arrhythmias in heart failure
Authors: Sakai Tetsuri , Yagishita Atsuhiko , Morise Masahiro , Sakama Susumu , Ijichi Takeshi , Ayabe Kengo , Amino Mari , Ikari Yuji , Yoshioka Koichiro
Published: September 2021

We sought to demonstrate the impact of improved peak exercise oxygen consumption (V̇O2) during maximal exercise testing after cardiac rehabilitation (CR) on the incidence of arrhythmias in patients with heart failure (HF). The present study comprised of 220 patients with HF, and peak V̇O2 was examined at 2 and 5 months after CR. Of the 220 patients, 110 (50%) had a low peak V̇O2 of < 14 mL/min/kg at 2 months. The peak V̇O2 improved in 86 of these 110 (78%) patients at 5 months after CR. During a median follow-up of 6 years, the patients with improvement in peak V̇O2, compared to those without peak V̇O2 improvement, had a lower rate of mortality (4% vs. 29%, log-rank, P < 0.001) and HF hospitalization (6 vs. 17%, log-rank, P = 0.044) and a lower incidence of new-onset atrial arrhythmias (9 vs. 27%, log-rank, P = 0.013), with no difference in the incidence of ventricular arrhythmias between groups (1 vs. 4%, log-rank, P = 0.309). The majority of deaths in the patients without an improved peak V̇O2 were because of cardiovascular events (73%), particularly progressive HF (55%). Early detection and management of atrial arrhythmias may improve outcomes in patients without peak V̇O2 improvement after CR.
Prenylcysteine oxidase 1, an emerging player in atherosclerosis
Authors: Banfi C. , Baetta R. , Barbieri S. S. , Brioschi M. , Guarino A. , Ghilardi S. , Sandrini L. , Eligini S. , Polvani G. , Bergman O. , Eriksson P. , Tremoli E.
Published: September 2021

The research into the pathophysiology of atherosclerosis has considerably increased our understanding of the disease complexity, but still many questions remain unanswered, both mechanistically and pharmacologically. Here, we provided evidence that the pro-oxidant enzyme Prenylcysteine Oxidase 1 (PCYOX1), in the human atherosclerotic lesions, is both synthesized locally and transported within the subintimal space by proatherogenic lipoproteins accumulating in the arterial wall during atherogenesis. Further, Pcyox1 deficiency in Apoe-/- mice retards atheroprogression, is associated with decreased features of lesion vulnerability and lower levels of lipid peroxidation, reduces plasma lipid levels and inflammation. PCYOX1 silencing in vitro affects the cellular proteome by influencing multiple functions related to inflammation, oxidative stress, and platelet adhesion. Collectively, these findings identify the pro-oxidant enzyme PCYOX1 as an emerging player in atherogenesis and, therefore, understanding the biology and mechanisms of all functions of this unique enzyme is likely to provide additional therapeutic opportunities in addressing atherosclerosis.
Kinetic magnetoelectric effect in topological insulators
Authors: Osumi Ken , Zhang Tiantian , Murakami Shuichi
Published: September 2021

The kinetic magnetoelectric effect is an orbital analog of the Edelstein effect and offers an additional degree of freedom to control magnetization via the charge current. Here we theoretically propose a gigantic kinetic magnetoelectric effect in topological insulators and interpret the results in terms of topological surface currents. We construct a theory of the kinetic magnetoelectric effect for a surface Hamiltonian of a topological insulator, and show that it well describes the results by direct numerical calculation. This kinetic magnetoelectric effect depends on the details of the surface, meaning that it cannot be defined as a bulk quantity. We propose that Chern insulators and Z2 topological insulators can be a platform with a large kinetic magnetoelectric effect, compared to metals by 5–8 orders of magnitude, because the current flows only along the surface. We demonstrate the presence of said effect in a topological insulator, identifying Cu2ZnSnSe4 as a potential candidate.
Synthesis and ex vivo biological evaluation of gallium-68 labelled NODAGA chelates assessing cardiac uptake and retention
Authors: Osborne Bradley E. , Yue Thomas T. C. , Waters Edward C. T. , Baark Friedrich , Southworth Richard , Long Nicholas J.
Published: September 2021

A series of TAP-functionalised NODAGA chelates synthesised report on mitochondrial function in myocardial tissue.
New lanthanoid biphenolate complexes, their further reactivity with trimethylaluminium and catalytic activity for the polymerisation ofrac-lactide
Authors: Shephard Angus C. G. , Ali Safaa H. , Wang Jun , Guo Zhifang , Davies Murray S. , Deacon Glen B. , Junk Peter C.
Published: September 2021

A series of rare earth biphenolate complexes of the general form [Ln(mbmp)(mbmpH)(thf)3] have been synthesised by redox transmetallation/protolysis (RTP) and assessed for ROP activity ofrac-lactide.
Multifunctional luminescence sensing and white light adjustment of lanthanide metal–organic frameworks constructed from the flexible cyclotriphosphazene-derived hexacarboxylic acid ligand
Authors: Wang Meng , Gao Hong Wei , Li Jin Xiao , Bai Feng Ying , Xing Yong Heng , Shi Zhan
Published: September 2021

Four novel metal–organic frameworks (MOFs) were synthesized; Tb-MOF exhibits outstanding photophysical properties for the detection of NACs and white light adjustment.
On the nature of recurrent Au⋯π motifs in tris(2,2′-bipyridine)M(ii) (M = Fe, Co and Ni) dicyanoaurate(i) salts: X-ray analysis and theoretical rationalization
Authors: Priola Emanuele , Giordana Alessia , Mazzeo Paolo P. , Mahmoudi Ghodrat , Gomila Rosa M. , Zubkov Fedor I. , Pokazeev Kuzma M. , Valchuk Karina S. , Bacchi Alessia , Zangrando Ennio , Frontera Antonio
Published: September 2021

This manuscript provides new physical insight into the nature of recurrent Au⋯π motifs in tris(2,2′-bipyridine)M(ii) (M = Fe, Co and Ni) dicyanoaurate(i) salts by X-ray analysis and theoretical rationalization.
Synthesis of a full range Fe-doped ZnFexCo2−xO4 and its application as anode material for lithium-ion battery
Authors: Wu You , Zhang Jun , Duan He , Zhao Yanming , Dong Youzhong
Published: September 2021

A full range (0 ≤ x ≤ 2) ZnFexCo2−xO4 solid solution phase was obtained. Benefiting from the increased lithium ion diffusion coefficient and improved electronic conductivity, ZnFe0.33Co1.67O4 presents an excellent electrochemical property.
Introduction to the Forum: Increasing Diversity in the Communication Sciences and Disorders Workforce, Part 1
Authors: Fannin Danai Kasambira , Mandulak Kerry Callahan
Published: September 2021

Purpose

This introduction provides background information about this forum of the
American Journal of Speech-Language Pathology
and a preview of articles published in this first installment of the forum.
η Carinae with Fermi-LAT: two full orbits and the third periastron
Authors: Martí-Devesa G. , Reimer O.
Published: September 2021

Context. Colliding-wind binaries are massive stellar systems featuring strong, interacting winds. These binaries may be actual particle accelerators, making them variable γ-ray sources due to changes in the wind collision region along the orbit. However, only two of these massive stellar binary systems have been identified as high-energy sources. The first and archetypical system of this class is η Carinae, a bright γ-ray source with orbital variability peaking around its periastron passage.

Aims. The origin of the high-energy emission in η Carinae is still unclear, with both lepto-hadronic and hadronic scenarios being under discussion. Moreover, the γ-ray emission seemed to differ between the two periastrons previously observed with the Fermi-Large Area Telescope. Continuing observations might provide highly valuable information for understanding the emission mechanisms in this system.

Methods. We have used almost 12 yr of data from the Fermi-Large Area Telescope. We studied both low- and high-energy components, searching for differences and similarities between both orbits, and we made use of this large dataset to search for emission from nearby colliding-wind binaries.

Results. We show how the energy component above 10 GeV of η Carinae peaks months before the 2014 periastron, while the 2020 periastron is the brightest one to date. Additionally, upper limits are provided for the high-energy emission in other particle-accelerating colliding-wind systems.

Conclusions. Current γ-ray observations of η Carinae strongly suggest that the wind collision region of this system is perturbed from orbit to orbit, affecting particle transport within the shock.
Deriving the bulk properties of solar wind electrons observed by Solar Orbiter
Authors: Nicolaou G. , Wicks R. T. , Owen C. J. , Kataria D. O. , Chandrasekhar A. , Lewis G. R. , Verscharen D. , Fortunato V. , Mele G. , DeMarco R. , Bruno R.
Published: September 2021

Context.We demonstrate the calculation of solar wind electron bulk parameters based on recent observations by Solar Wind Analyser – Electron Analyser System on board Solar Orbiter. We use our methods to derive the electron bulk parameters in a time interval spanning several hours. We attempt a preliminary examination of the polytropic behavior of the electrons by analyzing the derived electron density and temperature. Moreover, we discuss the challenges in analyzing the observations due to the spacecraft charging and photo-electron contamination in the energy range below 10 eV.

Aims.We derived bulk parameters for thermal solar wind electrons by analyzing Solar Orbiter observations and we investigated whether there is any typical polytropic model that is applicable to the electron density and temperature fluctuations.

Methods.We used the appropriate transformations to convert the observations to velocity distribution functions in the instrument frame. We then derived the electron bulk parameters by: (a) calculating the statistical moments of the constructed velocity distribution functions and (b) fitting the constructed distributions with analytical expressions. We first tested our methods by applying them to an artificial data set, which we produced by using the forward modeling technique.

Results.The forward model validates the analysis techniques we use to derive the electron bulk parameters. The calculation of the statistical moments and the fitting method determines bulk parameters that are identical (within the uncertainty limits) to the input parameters that we use to simulate the plasma electrons in the first place. An application of our analysis technique to the data reveals a nearly isothermal electron “core”. The results are affected by the spacecraft potential and the photo-electron contamination, which should be characterized in detail as part of future analyses.
Amplification and generation of turbulence during self-gravitating collapse
Authors: Hennebelle Patrick
Published: September 2021

Context. The formation of astrophysical structures, such as stars, compact objects, and also galaxies, entail an enhancement of densities by many orders of magnitude, which occurs through gravitational collapse.

Aims. The role played by turbulence during this process is important. Turbulence generates density fluctuations, exerts a support against gravity, and possibly delivers angular momentum. How exactly turbulence behaves and is amplified during the collapse remains a matter of investigation and is the aim of the present paper.

Methods. We carried out spherical averaging of the fluid equations, leading to 1D fluid equations that describe the evolution of mean quantities in particular the mean radial velocity as well as the mean radial and transverse turbulent velocities. These equations differ from the ones usually employed in the literature. We then performed a series of 3D numerical simulations of collapsing clouds for a wide range of thermal and turbulent supports with two polytropic equations of state, P ∝ ρΓ, with Γ = 1 and 1.25. For each 3D simulation, we performed a series of 1D simulations using the spherically averaged equations and the same initial conditions.

Results. By performing a detailed comparison between 3D and 1D simulations, we can analyse the observed behaviours in great detail. Altogether, we find that the two approaches agree remarkably well, demonstrating the validity of the inferred equations; although, when turbulence is initially strong, major deviations from spherical geometry certainly preclude quantitative comparisons. The detailed comparisons lead us to an estimate of the turbulent dissipation parameter, which, when the turbulence is initially low, is found to be in good agreement with previous estimates of non self-gravitating supersonic turbulence. When turbulence is initially dynamically significant, larger values of the dissipation appear necessary for the 1D simulations to match the 3D ones. We find that the behaviour of turbulence depends on the cloud thermal support. If it is high, initial turbulence is amplified, as proposed earlier in the literature. However, if thermal support is low, turbulence is also generated by the development of local non-axisymmetric gravitational instabilities reaching values several times larger and in equipartition with gravitational energy.

Conclusions. The inferred 1D equations offer an easy way to estimate the level reached by turbulence during gravitational collapse. Depending on the cloud thermal support, turbulence is either amplified or locally generated.
First detection of C2H5NCO in the ISM and search of other isocyanates towards the G+0.693-0.027 molecular cloud
Authors: Rodríguez-Almeida L. F. , Rivilla V. M. , Jiménez-Serra I. , Melosso M. , Colzi L. , Zeng S. , Tercero B. , de Vicente P. , Martín S. , Requena-Torres M. A. , Rico-Villas F. , Martín-Pintado J.
Published: September 2021

Context. Little is known about the chemistry of isocyanates (compounds with the functional group R-N=C=O) in the interstellar medium (ISM), as only four of them have been detected so far: isocyanate radical (NCO), isocyanic acid (HNCO), N-protonated isocyanic acid (H2NCO+), and methyl isocyanate (CH3NCO). The molecular cloud G+0.693-0.027, located in the Galactic Centre, represents an excellent candidate to search for new isocyanates since it exhibits high abundances of the simplest ones, HNCO and CH3NCO.

Aims. After CH3NCO, the next most complex isocyanates are ethyl isocyanate (C2H5NCO) and vinyl isocyanate (C2H3NCO). Their detection in the ISM would enhance our understanding of the formation of these compounds in space.

Methods. We have searched for C2H5NCO, H2NCO+, C2H3NCO, and cyanogen isocyanate (NCNCO) in a sensitive unbiased spectral survey carried out in the 2 mm and 7 mm radio windows using the IRAM 30m and Yebes 40m radio telescopes, respectively.

Results. We have detected C2H5NCO and H2NCO+ towards G+0.693-0.027 (the former for the first time in the ISM) with molecular abundances of (4.7–7.3) × 10−11 and (1.0–1.5) × 10−11, respectively. A ratio of CH3NCO/C2H5NCO = 8 ± 1 is obtained; therefore, the relative abundance determined for HNCO:CH3NCO:C2H5NCO is 1:1/55:1/447, which implies a decrease by more than one order of magnitude, going progressively from HNCO to CH3NCO and to C2H5NCO. This is similar to what has been found for alcohols and thiols, for example, and suggests that C2H5NCO is likely formed on the surface of dust grains. In addition, we have obtained column density ratios of HNCO/NCO > 269, HNCO/H2NCO+ ∼ 2100, and C2H3NCO/C2H5NCO < 4. A comparison of the methyl/ethyl ratios for isocyanates (-NCO), alcohols (-OH), formiates (HCOO-), nitriles (-CN), and thiols (-SH) is performed and shows that ethyl derivatives may be formed more efficiently for the N-bearing molecules than for the O- and S-bearing molecules.
Neural network model of decision making in electric power facilities under conditions of uncertainty
Authors: Siddikov Isomiddin , Porubay Oksana
Published: September 2021

The article is devoted to the issue of creating a mathematical model of the problem of making management decisions in electric power facilities based on modern intelligent technologies, which makes it possible to take into account the influence of various factors on the operating modes of the power system. A systematic approach to describing processes in the mathematical language of the theory of fuzzy sets is proposed. To solve the problem of controlling the operating modes of the power system, a neurofuzzy network has been developed that combines the algorithms of Takagi-Sugeno fuzzy inference, as well as a recurrent neural network. An adaptive learning algorithm based on the Frechet method is proposed for training a neural network. The analysis of the efficiency of the fuzzy control model under the conditions of various modes of functioning of the local power system is carried out.
Seed Reproduction technology of the Magnolia grandiflora from seeds
Authors: Bakhramov Ruziboy , Yuldashev Xamza , Tokhtaboeva Feruza , Ro'zimatov Ergashali , Ergasheva Gulmira , Mirzaeva Saodat
Published: September 2021

This article highlights the results obtained on the basis of scientific research carried out in 2019-2020 on the technology of reproduction from the seeds of Magnolia grandiflora plant in the farmer’s farm named “Saydullo Temirov” specialized in the cultivation of landscape trees and shrubs located in the Uighur village of Pakhtaobod District of Andijan region. As a result of the study, determination of seed stratification time, planting time and methods, as well as maintenance work were determined, and conclusions were made.
Substantiation the technology and parameters of the “paraplau” type soil dredger for a two-tier plow
Authors: Маmatov Farmon , Temirov Isroil , Оchilov Samar , Chorieva Dilsabo , Rakhmatov Doniyor , Murtazaeva Gulnoza
Published: September 2021

The purpose of the study was to substantiate the technology and parameters of the “paraplau” type soil dredger for a two-tier plow. The basic principles and methods of classical mechanics, mathematical analysis and statistics were used in this study. Sub-tillage loosening of the most compacted layers of the soil of the fields from under the cotton must be carried out in a strip way along the line of the middle of the irrigation furrows between the rows. It is established that for the implementation of strip loosening of the subarable soil layers of fields from under cotton, the width of the two-tier plow should be a multiple of the width of the row spacing. At the same time, for loosening the compacted subsurface layers of the middle of the row spacing of cotton with one working body, the soil dredgers are installed behind each even lower body in the plane of the field edges of the odd bodies. In the case of subtillage loosening of the middle of the row spacing by two soil dredgers with an inclined stand, one soil dredger is installed behind each lower body. An analytical relationship is obtained to justify the relative position of the plow bodies and the soil dredgers, as well as their parameters. Experimental studies have established that the resistivity of a two-tier plow decreases (in comparison with continuous loosening) when the most compacted layers of the middle of the row are loosened with a pointed paw by 17.56%, two soil dredgers with inclined posts by 24.04%, and one soil dredger with an inclined post by 23.24%.
Effect of cadmium metal on barley (Hordeum vulgare) growth and development
Authors: Abdikulov Zafar , Ergashev Marufjon
Published: September 2021

In this study, the effect of cadmium metal ion to 7, 14 and 21day after germination (DAG) autumn barley samples under laboratory condition is investigated. We determined the biomass of plant organs and the amount of cadmium accumulation in above-ground organs at germination (7 DAG), 2-leaf (14 DAG), 3-leaf (21DAG) stages. The results showed that the dry mass of 7, 14 and 21 DAG barley plant was decreased under cadmium metal treatment. However, the root biomass did not change compared with control plant. It is also observed that the 21 DAG plant accumulated around 2.4 and 5.6 times more cadmium than the 14 DAG and 7 DAG plants respectively.
Development of the saw cylinder for gins and linters with use of new elements of the design
Authors: Sultonov Azamat , Agzamov Mirsolikh , Rakhmatov Mashkhur , Agzamov Mirkhosil , Nosirov Khasan
Published: September 2021

Article issues of decrease in amplitude of dynamic fluctuations of saw cylinders of gins and linter for the purpose of reduction of a deviation of saws from the plane of rotation and contact with saws of grates are consecrated. Mathematical models for calculation of flexural fluctuations of a shaft of a saw cylinder, taking into account intensity of placement of the mass moments of inertia, a technique of the solution of the equation of flexural fluctuations of a saw cylinder with variable intensity of weight and flexural rigidity of sections are given. Data on a new design of saw cylinders with use between the saw laying made on a polymeric basis and equipped with steel pins.
Pre-sowing activation of seeds by ultraviolet (UV) radiation
Authors: Anarbaev Anvar , Tursunov Obid , Kodirov Dilshod , Khudaev Ibrokhim , Isakhodjayev Khayrulla , Islikov Sayid
Published: September 2021

The mechanism of influence the UV- radiation biological processes into seeds of agricultural plants is considered. The technical parameters of installation for pre-sowing treatment seeds with ultraviolet radiation lamps for increasing the permeability of biological membranes of cells in seed are defined. The results of experimental researches on have established that for processing of seeds cotton pre-sowing treated with ultraviolet rays, increasing of their germination and productivity of agricultural crops are shown.
A note on the paper “Necessary and sufficient optimality conditions using convexifactors for mathematical programs with equilibrium constraints”
Authors: Gadhi Nazih Abderrazzak
Published: September 2021

In this work, some counterexamples are given to refute some results in the paper by Kohli [RAIRO:OR 53 (2019) 1617–1632]. We correct the fault in some of his results.
3D MRI of the Rheumatic Diseases
Authors: Ezzati Fatemeh , Chalian Majid , Pezeshk Parham
Published: September 2021

Magnetic resonance imaging (MRI) is commonly used to evaluate musculoskeletal pathologies due to its high spatial resolution and excellent tissue contrast. The diagnosis of rheumatic diseases can often be challenging. Investigation with conventional two-dimensional MRI is helpful for diagnosis and monitoring treatment. In the past few years, three-dimensional (3D) MRI has been more commonly used to assess joint pathologies including inflammatory and rheumatic diseases. This review discusses the techniques and protocols of 3D MRI and its diagnostic yield in the assessment of rheumatic diseases, along with different examples.
3D MRI: Technical Considerations and Practical Integration
Authors: Del Grande Filippo , Hinterholzer Natalie , Nanz Daniel
Published: September 2021

One of the main advantages of three-dimensional (3D) magnetic resonance imaging (MRI) is the possibility of isotropic voxels and reconstructed planar cuts through the volumetric data set in any orientation with multiplanar reformation software through real-time evaluation. For example, reformats by the radiologist during reporting allows exploitation of the full potential of isotropic 3D volumetric acquisition or through standardized retrospective reformats of thicker predefined slices of an isotropic volumetric data set by technologists. The main challenges for integrating 3D fast spin echo (FSE) and turbo spin-echo (TSE) MRI in clinical practice are a long acquisition time and some artifacts, whereas for integrating 3D gradient-recalled echo protocols, the main challenges are lower signal-to-noise ratios (SNRs) and the inability to produce intermediate, and T2-weighted contrast. The implementation of bidirectional parallel imaging acquisition and random undersampling acceleration strategies of 3D TSE pulse sequences substantially shortens the examination time with only minor SNR reductions. This article provides an overview of general technical considerations of 3D FSE and TSE sequences in musculoskeletal MRI. It also describes how these sequences achieve efficient data acquisition and reviews the main advantages and challenges for their introduction to clinical practice.
Evaluation and Comparison of Self-Made and Commercial Calibration Markers for Radiographic Magnification Correction in Veterinary Digital Radiography
Authors: Klever Julius , de Motte Anastasia , Meyer-Lindenberg Andrea , Brühschwein Andreas
Published: September 2021

Objective Magnification error is always present in radiography and calibration is necessary, if high accuracy is required in pre-surgical planning. The goal of this study was to verify the use of self-made markers and calibration techniques and to establish guidelines for magnification correction.

Study Design We evaluated and compared spherical and linear markers of different sizes with focus on practicability, accuracy and precision. Markers were placed on foam pads or attached to flexible arms.

Results Vertical marker deviation of 1 cm from the anatomical reference point corresponded to ∼1% of magnification error in our setting. Marker placement along the horizontal plane showed no significant magnification in the periphery of the radiograph. All markers showed good accuracy and the commercial spherical marker with a flexible segment arm had the best results regarding practicability.

Conclusion Our study suggests that marker type is not solely responsible for usability and accuracy but also the type of fixation. In the absence of a calibration marker, calculation of the magnification factor using a measurement tape during radiography is equally reliable. Use of a fixed averaged calculated calibration factor showed poor agreement compared with the marker calibration, probably due to variability in size of the animals. In conclusion, if precision matters, use of a calibration marker, which could be purchased or self-made, is advised.
Contemporary Pattern of Pediatric Infective Endocarditis from Tertiary Care Centre of Northern India: A Single Centre Experience
Authors: Kumar Dinesh , Garg Shikha , Bhatt Dheeraj D.
Published: September 2021

With an increasing number of children with congenital heart disease (CHD) undergoing corrective treatments, improved pediatric intensive care, better antimicrobial treatments, and a relative decrease in rheumatic heart disease over the years, the epidemiology of pediatric infective endocarditis in India may be undergoing a change. The study was done in the department of pediatrics of a tertiary care teaching hospital of North India. A retrospective analysis of case records of children (<12 years) admitted with a diagnosis of infective endocarditis (IE) from January 2013 to April 2019 was performed. Modified Duke's criteria were used to diagnose IE. There were 21 children diagnosed with infective endocarditis during this period. The mean age at presentation was 70 months (range: 2.5–144 months). CHD (n = 13/21, 61.9%) was the most common predisposing condition. A total of 28% (6/21) patients had no preexisting structural heart disease. Nine percent (2/21) had rheumatic heart disease. Staphylococcus aureus was the most common etiological agent in those with a structurally normal heart. Most patients had blood culture–negative infective endocarditis (n = 12, 57.1%). Only one patient fulfilled Duke's major microbiological criteria. Six patients (28.57%) died during the hospital stay. Increasingly younger children are being diagnosed with infective endocarditis in India and a significant number of them are in the setting of a structurally normal heart. In view of high percentage of culture-negative endocarditis, the Duke criteria may need to be revised to retain their sensitivity in such settings.
Nutritional Intake in Children with Septic Shock: A Retrospective Single-Center Study
Authors: Kirk Angela H. P. , Ong Chengsi , Wong Judith J.-M. , Loh Sin Wee , Mok Yee Hui , Lee Jan Hau
Published: September 2021

Nutritional practice in children with severe sepsis or septic shock remains poorly described. We aimed to describe nutrition received by children with severe sepsis or septic shock and explore the association of nutritional intake with clinical outcomes. This study was a retrospective study of children who required pediatric intensive care unit (PICU) admission from 2009 to 2016. Outcomes were mortality, ventilator-free days (VFDs), and PICU-free days (IFDs). A total of 74 patients with septic shock or severe sepsis were identified. Forty-one (55.4%) patients received enteral nutrition (EN) only, 6 (8.1%) patients received parental nutrition (PN) only, 15 (20.3%) patients received both EN and PN, and 12 (16.2%) patients received intravenous fluids alone. Eight of 74 (10.8%) and 4 of 74 (5.4%) had adequate energy and protein intake, respectively. Patients who received early EN had lower odds of 28-day mortality (adjusted hazard ratio [HR] = 0.09, 95% confidence interval [CI]: 0.02, 0.45, p = 0.03) more 28-day VFDs (adjusted β-coefficient = 18.21 [95% CI: 11.11, 25.32], p < 0.001), and IFDs (adjusted ß-coefficient = 16.71 [95% CI: 9.86, 23.56], p < 0.001) than patients who did not receive EN. Late EN was also associated with lower odds of mortality, more VFDs, and IFDs compared with no EN (HR = 0.06, 95% CI: 0.02, 0.23; p < 0.001; adjusted β coefficient = 15.66, 95% CI: 9.31, 22.02; p < 0.001; and 12.34 [95% CI: 6.22, 18.46], p < 0.001; respectively). Inadequate calories and protein were not associated with mortality. EN in children with septic shock or severe sepsis was associated with improved clinical outcomes. Future prospective studies are required to explore the impact of EN timing and optimal nutritional intake in these children.
Bored by bothering? A cost-value approach to pandemic boredom
Authors: Martarelli Corinna S. , Wolff Wanja , Bieleke Maik
Published: September 2021

In an effort to mitigate the impact of the COVID-19 pandemic, countries around the world have employed non-pharmaceutical containment measures. The effectiveness of such mitigation efforts relies on individual compliance (e.g., avoiding to travel or to gather). Crucially, adhering to the required behavioral recommendations places substantial burdens on those who are asked to follow them. One particularly likely outcome of adherence should be the experience of boredom. Thus, people might get bored by bothering. Drawing from research and theorizing on reward-based decision making, we conducted a high-powered study (N = 1553 US participants) to investigate whether the value and effort people ascribe to adherence to containment measures directly and indirectly (i.e., mediated by adherence) affects their experience of boredom. As expected, structural equation modeling revealed that high value and low effort predicted compliance with behavioral recommendations. Moreover, higher compliance was linked to more boredom, meaning that high value and low effort increased boredom via compliance. In contrast, high value and low effort had direct effects on boredom in the opposite direction (i.e., decreasing boredom). Attesting to their robustness and generalizability, these findings held for both prospective (with respect to upcoming winter holidays) and retrospective behavior (with respect to previous thanksgiving holidays), across US states, which had or had not enforced behavioral restrictions, individual differences in boredom proneness, and demographic variables. Taken together, our results provide evidence that people can indeed get bored by bothering: Complying with nonpharmacological containment measures like avoiding to travel and to gather can come at the cost of getting bored, an experience that was strongly linked to negative affect in our study.
Charged dielectric spheres interacting in electrolytic solution: A linearized Poisson–Boltzmann equation model
Authors: Siryk Sergii V. , Bendandi Artemi , Diaspro Alberto , Rocchia Walter
Published: September 2021

We present an analytical theory of electrostatic interactions of two spherical dielectric particles of arbitrary radii and dielectric constants, immersed into a polarizable ionic solvent (assuming that the linearized Poisson–Boltzmann framework holds) and bearing arbitrary charge distributions expanded in multipolar terms. The presented development entails a novel two-center re-expansion analytical theory that expands upon and improves the existing ones, bypassing the conventional expansions in modified Bessel functions. On this basis, we develop a specific matrix formalism that facilitates the construction of asymptotic expansions in ascending order of Debye screening terms of potential coefficients, which are then employed to find exact closed-form expressions for the total electrostatic energy. In particular, this work allows us to explicitly and precisely quantify the k-screened terms of the potential coefficients and mutual interaction energy. Specific cases of monopolar and dipolar distributions are described in particular detail. Comprehensive numerical examples and tests of series convergence and the relative balance of leading and higher-order terms of the mutual interaction energy are presented depending on the inter-particle distance and particles’ radii. The results of this work find application in soft matter modeling and, in particular, in computational biophysics and colloid science, where the availability of increasingly larger experimental structures at the atomic-level resolution makes numerical treatment challenging and calls for more efficient expressions and an increased range of validity.
Multiphase continuum modeling of thrombosis in aneurysms and recirculation zones
Authors: Bouchnita Anass , Belyaev Aleksey V. , Volpert Vitaly
Published: September 2021

Aneurysms of saccular shape are usually associated with a slow, almost stagnant blood flow, as well as a consequent emergence of blood clots. Despite the practical importance, there is a lack of computational models that could combine platelet aggregation, precise biorheology, and blood plasma coagulation into one efficient framework. In the present study, we address both the physical and biochemical effects during thrombosis in aneurysms and blood recirculation zones. We use continuum description of the system and partial differential equation-based model that account for fluid dynamics, platelet transport, adhesion and aggregation, and biochemical cascades of plasma coagulation. The study is focused on the role of transport and accumulation of blood cells, including contact interactions between platelets and red blood cells (RBCs), coagulation cascade triggered by activated platelets, and the hematocrit-dependent blood rheology. We validated the model against known experimental benchmarks for in vitro thrombosis. The numerical simulations indicate an important role of RBCs in spatial propagation and temporal dynamics of the aneurysmal thrombus growth. The local hematocrit determines the viscosity of the RBC-rich regions. As a result, a high hematocrit slows down flow circulation and increases the presence of RBCs in the aneurysm. The intensity of the flow in the blood vessel associated with the aneurysm also affects platelet distribution in the system, as well as the steady shape of the thrombus.
Photovoltaic characterizing method of degradation of polymer light-emitting diodes based on ideality factor and density of states
Authors: Kim Jaehoon , Lee Taesoo , Kwak Jeonghun , Lee Changhee
Published: September 2021

Polymer light-emitting diodes (PLEDs) possess several unique advantages over competitive technologies, including solution processability, broad applicability, and low-cost fabrication. However, their commercialization is delayed due to the relatively low operation stability compared to current display techniques. To provide fundamental insight into the degradation mechanism and enhance the stability, we discuss unique analysis methods of PLEDs' degradation using photovoltaic impedance characteristics. In particular, we report the method to determine the energetic disorder or density of states (DOS) of PLEDs using light intensity (Plight)-dependent open-circuit voltage (VOC) and Cole–Cole plot measurement. Based on the method, it was found that PLED degradation results in a shift of the center of DOS rather than broadening. Furthermore, we extrapolated equivalent ideality factor (n) values from the Plight-dependent VOC and dark current density–voltage (J–V) characteristics, which implied trap-assisted recombination throughout the degradation process. Thus, we believe that the results will provide helpful and comprehensive insight into understanding the degradation of PLEDs.
Catalyst-coated proton exchange membrane for hydrogen production with high pressure water electrolysis
Authors: Zhang Xinrong , Zhang Wei , Yang Weijing , Liu Wen , Min Fanqi , Mao Samuel S. , Xie Jingying
Published: September 2021

Green hydrogen is currently enjoying a worldwide momentum due to its potential in supporting the United Nations Sustainable Development Goals. It is one of key technologies toward the establishment of a global low-carbon energy infrastructure. As a viable solution to achieve green hydrogen from renewable sources such as wind and solar powers, the process of proton exchange membrane (PEM) water electrolysis enables scalable stacked devices and systems for high pressure hydrogen production. By developing a catalyst-coated proton exchange membrane, we constructed membrane electrode assemblies (MEAs) and assembled them into a five-cell stack device to optimize the materials and components. After device characterization and optimization, a 20 kW PEM water electrolysis system was built, which, under high pressure operating conditions, exhibited favorable hydrogen production performance with 82.9% energy efficiency at the current density of 1000 mA/cm2 and reaction temperature of 70 °C. The resulting hydrogen production rate of the system with catalyst-coated membranes reached 3.09 N m3/h, while the power consumption for hydrogen production was 4.39 kWh/N m3. The results indicate the feasibility of PEM water electrolysis technology for green hydrogen production, for which we envision development into commercial applications in the near future.
Modeling the spatial characteristics of extrusion flow instabilities for styrene-butadiene rubbers: Investigating the influence of molecular weight distribution, molecular architecture, and temperature
Authors: Georgantopoulos Christos K. , Esfahani Masood K. , Botha Carlo , Pollard Michael A. , Naue Ingo F. C. , Causa Andrea , Kádár Roland , Wilhelm Manfred
Published: September 2021

The extrusion flow instabilities of three commercial styrene-butadiene rubbers (SBR) are investigated as a function of molecular weight distribution (MWD); molecular architecture (linear, branched); and temperature. The samples have multimodal MWD, with the main component being SBR and a low amount, less than 10 wt. %, of low-molecular weight hydrocarbons. Deviation from the Cox–Merz rule at high angular frequencies/shear rates becomes intense as the amount of medium-molecular weight component increases. Optical analysis is used to identify and quantify spatial surface distortions, specifically wavelength (λ) and height (h), of the different types of extrusion flow instabilities. Qualitative constitutive models are reviewed and used to fit the experimental data for the spatial characteristics of extrusion flow instability. The fitting parameters as obtained by the models are correlated with molecular properties of the materials. It is found that the characteristic spatial wavelength (λ) increases as the extrusion temperature decreases. Hence, the influence of temperature on the spatial characteristic wavelength is investigated and an Arrhenius behavior is observed.
Body-caudal fin fish-inspired self-propulsion study on burst-and-coast and continuous swimming of a hydrofoil model
Authors: Gupta Siddharth , Thekkethil Namshad , Agrawal Amit , Hourigan Kerry , Thompson Mark C. , Sharma Atul
Published: September 2021

The present study examines the energy efficiency of self-propelled hydrofoils for various modes and kinematics of swimming adopted by various body-caudal fin fish. In particular, this work considers the intermittent burst-and-coast (B&C) and continuous swimming modes, and examines the effect of the undulating and/or pitching swimming kinematics, adopted by the undulating body of anguilliform fish and pitching caudal fin of carangiform and thunniform fish. Notably, B&C swimming is adopted in nature mostly by the latter class but rarely by the former. This fact forms the basis of our study on the hydrodynamics and propulsion performance for both classes of fish-inspired swimming using a NACA0012 hydrofoil model. This analysis explores a large parameter space covering undulation wavelength, 0.8≤λ*<∞, Reynolds number, 50≤Ref≤1500, and duty cycle (DC), 0.1≤DC≤1, with the DC representing the fraction of time in B&C swimming. The fluid–structure dynamics-based vortex-shedding-process is investigated, where B&C swimming results in either an asymmetric reverse von Karman (RVK) or forward von Karman vortex street, rather than a symmetric RVK vortex street observed during continuous swimming. It is demonstrated that the B&C swimming results in an energy saving, although there is a concomitant increase in the travel time. Moreover, our results show that B&C swimming is effective for carangiform and thunniform tail-like kinematics but not for anguilliform body-like kinematics of the hydrofoil. Thus, the predictions are consistent with the observed swimming behavior adopted by a fish in nature and provide input into the efficient design of unmanned underwater vehicles.
Accelerated photoelectrochemical oxygen evolution over a BaTaO2N photoanode modified with cobalt-phosphate-loaded TiO2 nanoparticles
Authors: Takagi Fumiaki , Taguchi Suzuna , Kageshima Yosuke , Teshima Katsuya , Domen Kazunari , Nishikiori Hiromasa
Published: September 2021

Because the oxygen evolution reaction (OER) involves a complicated four-electron process, reducing the overpotential for the OER by loading cocatalysts at as high a concentration as possible is critical for achieving efficient photoelectrochemical (PEC) water oxidation. However, such surface modifications should also be designed to not interfere with the bandgap photoexcitation of the light-absorbing materials. In the present study, cobalt-phosphate-loaded TiO2 (CoPi/TiO2) nanoparticles were used to modify a particulate BaTaO2N (BTON) photoanode, resulting in an improvement in the photoanode PEC OER performance. The TiO2 nanoparticles functioned as a transparent and conductive support with a high specific surface area to immobilize CoPi on the photoanode surface. Electrochemical measurements revealed that the CoPi/TiO2 modification led to improved reaction kinetics and that the electrochemically active surface area of the CoPi cocatalysts deposited on the electrode surface substantially increased by a factor of 7.45 as a result of the TiO2 modification. The CoPi/TiO2 modification increased the number of active sites on the surface of the particulate BTON photoanode and minimized the harmful influence of light shielding, thereby accelerating the OER kinetics.
Interplay of chordwise stiffness and shape on performance of self-propelled flexible flapping plate
Authors: Wang Wenjiang , Huang Haibo , Lu Xi-Yun
Published: September 2021

The locomotion of a flapping flexible plate with different shapes and non-uniform chordwise stiffness distribution in a stationary fluid is studied numerically. The normalized effective bending stiffness K∗ for three-dimensional plates with arbitrary stiffness distribution and shape parameters is proposed, and the overall bending stiffness of non-uniform plates with different shapes is reasonably characterized. It is found that the propulsion performance in terms of cruising speed and efficiency of the self-propelled flapping plate mainly depends on the effective bending stiffness. Plates with moderate flexibility K∗ show better propulsion performance. Meanwhile, both a large area moment of the plate and a flexible anterior are favorable to significantly improve their propulsive performance. The evolution of vortical structures and the pressure distribution on the upper and lower surfaces of the plate are analyzed, and the inherent mechanism is revealed. These findings are of great significance to the optimal design of propulsion systems with different fins or wings.
Fatty acid profile, oxidative stability of lipids and sensory attributes of water restricted Xhosa goat meat supplemented with vitamin C
Authors: Akinmoladun O. F. , Fon F. N. , Mpendulo C. T. , Hugo A. , Falowo A. B. , Nantapo C. T. W.
Published: September 2021

Context Water scarcity often accompanied by limited water intake (WI) in livestock may result in pre-slaughter stress, thereby affecting meat quality parameters. Aims This study was conducted to determine the effect of vitamin C (VC) supplementations on fatty acid (FA), lipids oxidation and sensory attributes of Longissimus lumborum muscles of Xhosa goats subjected to different watering regimen. Methods In total, 42 goats were randomly assigned into seven treatments: without water restriction, WR (W0, control); WR of 70% of ad libitum WI (W70); WR of 50% ad libitum WI (W50); WR of 70% of ad libitum WI + 3 g VC daily (W70+); WR of 50% of ad libitum WI intake + 3 g VC daily (W50+); WR of 70% of ad libitum WI + 3 g VC and extra 5 g VC given every 8 days (W70++); WR of 50% of ad libitum WI + 3 g VC and extra 5 g VC given every 8 days (W50++). The goats were fed for 75 days and killed following standard procedures. Bodyweight changes, thaw loss, ultimate pH (pHu), thiobarbituric acid reactive substance (TBARS), moisture and fat content, sensory attributes and FA profile of the meat were evaluated. Key results Results indicated that the decreased final weight in the untreated groups (W70 and W50) was reduced (P > 0.05) in the treated groups (W70+, W50+, W70++, W50++). The treatment effect was not significant (P > 0.05) on pHu, thaw loss and TBARS values. The moisture and fat content in the water-restricted groups were lower (P < 0.05) than in W0. The meat sensory appearance was affected (P < 0.05) by WR. Regardless of VC concentration, vaccenic and docosahexaenoic acid increased (P < 0.05), while linolenic acid decreased as the WR levels increased. Conclusions WR of 70% and 50% of ad libitum WI, with or without VC, did not negatively affect the meat’s lipid oxidation and FA profile. Implications Limited WI reduces body weight. However, a daily dose of VC could help reduce body weight loss during water scarcity.