bluuebunny/crossref_metadata_2025 huggingface dataset:
FATP4 inactivation in cultured macrophages attenuates M1- and ER stress-induced cytokine release via a metabolic shift towards triacylglycerides
Authors: Zhang Yuling , Wu Ning , Gan-Schreier Hongying , Xu Feng , Tuma-Kellner Sabine , Staffer Simone , Seeßle Jessica , Merle Uta , Chamulitrat Walee
Published: April 2021

Fatty acid transport protein 4 (FATP4) belongs to a family of acyl-CoA synthetases which activate long-chain fatty acids into acyl-CoAs subsequently used in specific metabolic pathways. Patients with FATP4 mutations and Fatp4-null mice show thick desquamating skin and other complications, however, FATP4 role on macrophage functions has not been studied. We here determined whether the levels of macrophage glycerophospholipids, sphingolipids including ceramides, triacylglycerides, and cytokine release could be altered by FATP4 inactivation. Two in vitro experimental systems were studied: FATP4 knockdown in THP-1-derived macrophages undergoing M1 (LPS + IFNγ) or M2 (IL-4) activation and bone marrow-derived macrophages (BMDMs) from macrophage-specific Fatp4-knockout (Fatp4M−/−) mice undergoing tunicamycin (TM)-induced endoplasmic reticulum stress. FATP4-deficient macrophages showed a metabolic shift towards triacylglycerides and were protected from M1- or TM-induced release of pro-inflammatory cytokines and cellular injury. Fatp4M−/− BMDMs showed specificity in attenuating TM-induced activation of inositol-requiring enzyme1α, but not other unfolded protein response pathways. Under basal conditions, FATP4/Fatp4 deficiency decreased the levels of ceramides and induced an up-regulation of mannose receptor CD206 expression. The deficiency led to an attenuation of IL-8 release in THP-1 cells as well as TNF-α and IL-12 release in BMDMs. Thus, FATP4 functions as an acyl-CoA synthetase in macrophages and its inactivation suppresses the release of pro-inflammatory cytokines by shifting fatty acids towards the synthesis of specific lipids.
C21 preserves endothelial function in the thoracic aorta from DIO mice: role for AT2, Mas and B2 receptors
Authors: González-Blázquez Raquel , Alcalá Martín , Fernández-Alfonso María S. , Steckelings Ulrike Muscha , Lorenzo M. Paz , Viana Marta , Boisvert William A. , Unger Thomas , Gil-Ortega Marta , Somoza Beatriz
Published: April 2021

Compound 21 (C21), a selective agonist of angiotensin II type 2 receptor (AT2R), induces vasodilation through NO release. Since AT2R seems to be overexpressed in obesity, we hypothesize that C21 prevents the development of obesity-related vascular alterations. The main goal of the present study was to assess the effect of C21 on thoracic aorta endothelial function in a model of diet-induced obesity (DIO) and to elucidate the potential cross-talk among AT2R, Mas receptor (MasR) and/or bradykinin type 2 receptor (B2R) in this response.

Five-week-old male C57BL6J mice were fed a standard (CHOW) or a high-fat diet (HF) for 6 weeks and treated daily with C21 (1 mg/kg p.o) or vehicle, generating four groups: CHOW-C, CHOW-C21, HF-C, HF-C21. Vascular reactivity experiments were performed in thoracic aorta rings. Human endothelial cells (HECs; EA.hy926) were used to elucidate the signaling pathways, both at receptor and intracellular levels.

Arteries from HF mice exhibited increased contractions to Ang II than CHOW mice, effect that was prevented by C21. PD123177, A779 and HOE-140 (AT2R, Mas and B2R antagonists) significantly enhanced Ang II-induced contractions in CHOW but not in HF-C rings, suggesting a lack of functionality of those receptors in obesity. C21 prevented those alterations and favored the formation of AT2R/MasR and MasR/B2R heterodimers. HF mice also exhibited impaired relaxations to acetylcholine (ACh) due to a reduced NO availability. C21 preserved NO release through PKA/p-eNOS and AKT/p-eNOS signaling pathways.

In conclusion, C21 favors the interaction among AT2R, MasR and B2R and prevents the development of obesity-induced endothelial dysfunction by stimulating NO release through PKA/p-eNOS and AKT/p-eNOS signaling pathways.
Intact Correction for Self-Produced Vowel Formant Variability in Individuals With Cerebellar Ataxia Regardless of Auditory Feedback Availability
Authors: Parrell Benjamin , Ivry Richard B. , Nagarajan Srikantan S. , Houde John F.
Published: April 2021

Purpose

Individuals with cerebellar ataxia (CA) caused by cerebellar degeneration exhibit larger reactive compensatory responses to unexpected auditory feedback perturbations than neurobiologically typical speakers, suggesting they may rely more on feedback control during speech. We test this hypothesis by examining variability in unaltered speech. Previous studies of typical speakers have demonstrated a reduction in formant variability (centering) observed during the initial phase of vowel production from vowel onset to vowel midpoint. Centering is hypothesized to reflect feedback-based corrections for self-produced variability and thus may provide a behavioral assay of feedback control in unperturbed speech in the same manner as the compensatory response does for feedback perturbations.

Method

To comprehensively compare centering in individuals with CA and controls, we examine centering in two vowels (/i/ and /ɛ/) under two contexts (isolated words and connected speech). As a control, we examine speech produced both with and without noise to mask auditory feedback.

Results

Individuals with CA do not show increased centering compared to age-matched controls, regardless of vowel, context, or masking. Contrary to previous results in neurobiologically typical speakers, centering was not affected by the presence of masking noise in either group.

Conclusions

The similar magnitude of centering seen with and without masking noise questions whether centering is driven by auditory feedback. However, if centering is at least partially driven by auditory/somatosensory feedback, these results indicate that the larger compensatory response to altered auditory feedback observed in individuals with CA may not reflect typical motor control processes during normal, unaltered speech production.
Steady‐state power operation region of a modular multilevel converter connecting to an AC grid
Authors: Wang Jiecong , Liu Chongru , Annakkage Udaya D. , Li Xiao , Su Chenbo
Published: April 2021

The modular multilevel converter (MMC) has become a widely used topology for voltage source converter–based high‐voltage direct current transmission projects. To calculate the power operation region of an MMC directly and efficiently, we propose a novel steady‐state phasor model of the MMC. The model is expressed as an equivalent capacitance in series with a voltage source, where parameters are independent of alternating current (AC) electrical quantity. Based on the model, we propose an open‐loop approach to determine the operation region boundary of MMC by calculating the envelopes of the P–Q curves. The effect of MMC parameters, the circulating current control, and the short‐circuit ratio of the AC grid to the power operation region can be determined by the size and position of the power operation region. The proposed approach and analysis results were verified by an MMC/AC simulation model built in PSCAD/EMTDC.
Mitigation measures of the electric field in the medium‐voltage power module: Effect of voltage types and recommendations for designers
Authors: Huang Zhizhao , Chen Cai , Kang Yong , Munk‐Nielsen Stig , Uhrenfeldt Christian
Published: April 2021

In the medium‐voltage silicon carbide device power module, the higher voltage level will induce higher electric field stress in critical internal points such as the edge of the conductor on the direct bonded copper (DBC) substrate. This can lead to partial discharge and subsequently accelerated ageing of the insulating medium in the module. Therefore, it is important to reduce the high electric field strength. Herein, the related technical methods of electric field control are reviewed and compared by combining the ease of implementation in real power module and the field control effect. In addition, systematic explanations of the electric field drift and influencing factors of the electric field strength under different voltage types within different module structures are presented. Finally, for half‐bridge power modules with different substrates structures, suggestions on how to implement non‐linear field‐dependent materials to reduce the electric field strength are given.
Phase response reconstruction for non‐minimum phase systems using frequency‐domain magnitude values
Authors: Boland Taco , Naus Rik , Zwamborn Peter
Published: April 2021

It is often more complicated to measure the phase response of a large system than the magnitude. In that case, one can attempt to use the Kramers–Kronig (KK) relations for magnitude and phase, which relates magnitude and phase analytically. The advantage is that then only the magnitude of the frequency response needs to be measured. It is shown that the KK relations for magnitude and phase may yield invalid results when the transfer function has zeros located in the right half of the complex s‐plane, that is, the system is non‐minimum phase. In this paper, a method which enables to determine these zeros is proposed, by using specific excitation signals and measuring the resulting time responses of the system. The method is verified using blind tests among the authors. When the locations of the zeros in the right half of the complex s‐plane are known, modified KK relations can be successfully applied to non‐minimum phase systems. This is demonstrated by computing the phase response of the electric field, excited by a point dipole source inside a closed cavity with Perfect Electrically Conducting (PEC) walls. Also, the effects of simulated measurement noise are considered for this example.
The growth of super-Earths
Authors: Savvidou Sofia , Bitsch Bertram
Published: April 2021

The conditions in the protoplanetary disk are determinant for the various planet formation mechanisms. We present a framework that combines self-consistent disk structures with the calculations of the growth rates of planetary embryos via pebble accretion, in order to study the formation of super-Earths. We first perform 2D hydrodynamical simulations of the inner disks, considering a grain size distribution with multiple chemical species and their corresponding size and composition dependent opacities. The resulting aspect ratios are almost constant with orbital distance, resulting in radially constant pebble isolation masses, the mass where pebble accretion stops. This supports the “peas-in-a-pod” constraint from the Kepler observations. The derived pebble sizes are used to calculate the growth rates of planetary embryos via pebble accretion. Disks with low levels of turbulence (expressed through the α-viscosity) and/or high dust fragmentation velocities allow larger particles, hence lead to lower pebble isolation masses, and the contrary. At the same time, small pebble sizes lead to low accretion rates. We find that there is a trade-off between the pebble isolation mass and the growth timescale; the best set of parameters is an α-viscosity of 10−3 and a dust fragmentation velocity of 10 m s−1, mainly for an initial gas surface density (at 1 AU) greater than 1000 g cm−2. A self-consistent treatment between the disk structures and the pebble sizes is thus of crucial importance for planet formation simulations.
Blue supergiants as tests for stellar physics
Authors: Georgy Cyril , Saio Hideyuki , Meynet Georges
Published: April 2021

Context. Massive star evolution is still poorly understood, and observational tests are required to discriminate between different implementations of physical phenomena in stellar evolution codes.

Aims. By confronting stellar evolution models with observed properties of blue supergiants, such as pulsations, the chemical composition, and position in the Hertzsprung-Russell diagram, we aim to determine which of the criteria used for convection (Schwarzschild or Ledoux) is best able to explain the observations.

Methods. We computed state-of-the-art stellar evolution models with either the Schwarzschild or the Ledoux criterion for convection. Models are for 14 to 35 M⊙ at solar or Large Magellanic Cloud metallicity. For each model, we computed the pulsation properties to know when radial modes are excited. We then compared our results with the position of blue supergiants in the Hertzsprung-Russell diagram, with their surface chemical composition and with their variability.

Results. Our results at Large Magellanic Cloud metallicity shows only a slight preference for the Ledoux criterion over the Schwarzschild one in reproducing, at the same time, the observed properties of blue supergiants, even if the Schwarzschild criterion cannot be excluded at this metallicity. We checked that changing the overshoot parameter at solar metallicity does not improve the situation. We also checked that our models are able to reproduce the position of Galactic blue supergiants in the flux-weighted-gravity–luminosity relation.

Conclusions. We confirm that overall, models computed with the Ledoux criterion are slightly better in matching observations. Our results also support the idea that most Galactic α Cyg variables are blue supergiants from group 2, that is stars that have been through a previous red supergiant phase where they have lost a large amount of mass.
Extreme adaptive optics astrometry of R136
Authors: Khorrami Z. , Langlois M. , Vakili F. , Clark P. C. , Buckner A. S. M. , Gonzalez M. , Crowther P. , Wünsch R. , Palouš J. , Boccaletti A. , Lumsden S. , Moraux E.
Published: April 2021

We compared high-contrast near-infrared images of the core of R136 taken by VLT/SPHERE, in two epochs separated by 3.06 years. For the first time we monitored the dynamics of the detected sources in the core of R136 from a ground-based telescope with adaptive optics. The aim of these observations was to search for High prOper Motion cAndidates (HOMAs) in the central region of R136 (r < 6″) where it has been challenging for other instruments. Two bright sources (K < 15 mag and V < 16 mag) are located near R136a1 and R136c (massive WR stars) and have been identified as potential HOMAs. These sources have significantly shifted in the images with respect to the mean shift of all reliable detected sources and their neighbours, and six times their own astrometric errors. We calculate their proper motions to be 1.36 ± 0.22 mas yr−2 (321 ± 52 km s−1) and 1.15 ± 0.11 mas yr−2 (273 ± 26 km s−1). We discuss different possible scenarios to explain the magnitude of such extreme proper motions, and argue for the necessity to conduct future observations to conclude on the nature of HOMAs in the core of R136.
A deep XMM–Newton observation of the X-Persei-like binary system CXOU J225355.1+624336
Authors: La Palombara N. , Sidoli L. , Esposito P. , Israel G. L. , Rodríguez Castillo G. A.
Published: April 2021

We report on the follow-up XMM–Newton observation of the persistent X-ray pulsar CXOU J225355.1+624336, which was discovered with the CATS@BAR project on archival Chandra data. The source was detected at fX(0.5−10 keV) = 3.4 × 10−12 erg cm−2 s−1, a flux level that is fully consistent with previous observations performed with ROSAT, Swift, and Chandra. When compared with previous measurements, the measured pulse period P = 46.753(3) s implies a constant spin down at an average rate of Ṗ = 5.3 × 10−10 s s−1. The pulse profile is energy dependent, showing three peaks at low energy and a less structured profile above about 3.5 keV. The pulsed fraction slightly increases with energy. We described the time-averaged EPIC spectrum with four different emission models: a partially covered power law, a cutoff power law, and a power law with an additional thermal component (either a black body or a collisionally ionised gas). In all cases we obtained equally good fits, so it was not possible to prefer or reject any emission model on a statistical basis. However, we disfavour the presence of thermal components since their modeled X-ray flux, resulting from a region larger than the neutron star surface, would largely dominate the X-ray emission from the pulsar. The phase-resolved spectral analysis showed that a simple flux variation cannot explain the source variability and proved that there is a spectral variability along the pulse phase. The results of the XMM–Newton observation confirmed that CXOU J225355.1+624336 is a Be X-ray binary (BeXB) with a low luminosity (LX ∼ 1034−35 erg s−1), limited variability, and a constant spin down. Therefore, these results reinforce its source classification as a persistent BeXB.
The Nature of CVC Nonlinearity in Low-Voltage Scanning Tunneling Spectroscopy of Semiconductors
Authors: Loskutov A.I. , Mandel A.M. , Karpova E.E. , Oshurko V.B. , Veselko S.G. , Sharts A.A. , Loskutov S.A.
Published: April 2021

A new model of field emission in a scanning tunnelling microscope was developed. The model describes the tunnelling current from a surface of semiconductor (semimetal) and allows estimating the preexponential factor in the expression for the tunneling probability. It is shown that this factor is directly related to the degree of localization of the electron density and determines the shape of the local tunnel current-voltage characteristics (LTCVCs) at low voltages. The model allows separating the contributions of surface electronic states of different symmetry (dimension) of the tunnelling current. The practical application of the model is demonstrated by the example of mathematical processing of the LTCVCs of HOPG surface containing different structural defects.
Gradient-Based Algorithm for Tracking the Activity of Neural Network Weights Changing
Authors: Starodub Anton , Eliseeva Natalia , Georgiev Milen
Published: April 2021

The research conducted in this paper is in the field of machine learning. The main object of the research is the learning process of an artificial neural network in order to increase its efficiency. The algorithm based on the analysis of retrospective learning data. The dynamics of changes in the values of the weights of an artificial neural network during training is an important indicator of training efficiency. The algorithm proposed in this work is based on changing the weight gradients values. Changing of the gradients weights makes it possible to understand how actively the network weights change during training. This knowledge helps to diagnose the training process and makes an adjusting the training parameters. The results of the algorithm can be used to train an artificial neural network. The network will help to determine the set of measures (actions) needed to optimize the learning process by the algorithm results.
Computer Visualization of Julia Sets for Maps beyond Complex Analyticity
Authors: Toporensky Alexey , Stepanyan Ivan
Published: April 2021

Using the computer program creating Julia sets for two-dimensional maps we have made computer animation showing how Julia sets for the Peckham map alters when the parameter of the map is changing. The Peckham map is a one-parameter map which includes the complex map z=z^2+c, and is nonanalytical for other values of the parameter. Computer animation of Julia fractal sets allows seeing how patterns typical for complex maps gradually destroy.
Transmutation Operator Method for Solving Heat Conduction Problem
Authors: Yaremko Oleg , Yaremko Natalia
Published: April 2021

The transmutation operator method is extended to the case of functions of two variables. The transmutation operator flattens the function, i.e. the transmutation operator replaces a function with discontinuous partial derivatives on the coordinate axes by a continuously differentiable function. The work reveal the properties of the transmutation operator, and prove the commutativity of the transmutation operator and the Laplace operator. It was found that the Cauchy problem for the Laplace equation with internal conjugations in an unbounded domain can be replaced with the model Cauchy problem for the twodimensional Laplace equation. As a result, a new analytical method for solving initial-boundary value problems for a two-dimensional heat equation has been developed. The factorization of the transmutation operator is established as a product of two one-dimensional transmutation operators. The form of the transmutation operator establishing the isomorphism of two mathematical models of heat conduction in unbounded media with different physical characteristics was found and descrfibed.
Investigation of the Stress-Strain State of the Cavity Profiles for Osteosynthesis Screw Heads
Authors: Balova Daria , Rechenko Denis
Published: April 2021

In the modern world, taking into account the active lifestyle of people, the dynamics of growth of complex fractures is observed. Their treatment is associated with rigid fixation of fragments with plates and screws, that is, with the help of osteosynthesis. In the surgical operating room during osteosynthesis is not possible to use auxiliary tools, which can be used to fix the screw with the required screw-in force. As a result, the screw breaks either during surgery or during further operation. This can be avoided by examining the stress-strain state of the screw head for osteosynthesis. By simulating the screw turning process, it is possible to determine the maximum stresses appearing in the screw heads with different profiles, and to choose or develop the profile of the recess under the key, which will be optimal in terms of stress-strain state and manufacturability .
Analysis of Positioning Adjustment Approaches for Cutting Inserts of Thread Cutters
Authors: Grechishnikov Vladimir , Isaev Alexander , Kozochkin Mikhail , Aung Pyae Phyo
Published: April 2021

The inclination angle of cutting inserts of thread cutters should be adjustable to provide the required geometry when machining threads. In serial production, this adjustment is realized by changing the carbide shims. In the present paper, the analysis of relationships between geometric parameters and positioning accuracy errors for thread cutters with inserts is presented.
Models for Managing Production Systems of Machine-Building Enterprises Based on the Development and Using of Their Digital Twins
Authors: Dolgov Vitalii A. , Nikishechkin Petr. A. , Arkhangelskii Vladimir E. , Umnov Pavel I. , Podkidyshev Alexey A.
Published: April 2021

The paper discusses the goals and objectives of creating digital twins of the production system of a machine-building enterprise. The data structure of the information model of the production system of a machine-building enterprise, which is the basis for building a digital twin, is presented. The paper shows the main approaches to managing a production system based on the construction of its digital twin. It is revealed that along with traditional approaches to PS management by forming recommendations in terms of PS engineering and its operation, the choice of the most rational PS management algorithms that take into account the peculiarities of the production process organization and ensure the formation of production schedules that take into account PS reliability indicators has a great potential. It is proposed to use a specialized language of DPML to describe the information model of the PS through the “product-process-resource” paradigm, which ensures the coordination of the processes of forming recommendations in terms of engineering and operation of the PS, as well as the choice of the most rational algorithm for managing the PS.
A comparative study of soil-water characteristic curves for compacted lateritic soil – bacillus coagulans mixtures
Authors: Osinubi Kolawole Juwonlo , Yohanna Paul , Eberemu Adrian Oshioname , Ijimdiya Thomas Stephen
Published: April 2021

A comparative study of soil-water characteristic curves (SWCCs) for compacted lateritic soil ̶ Bacillus coagulans (B. coagulans) mixtures for municipal solid waste (MSW) application was studied. Soil treatment was performed at approximately about one-third pore volume of the microbes (i.e., B. coagulans) for suspension densities of 0, 1.5×108, 6.0×108, 1.2×109, 1.8×109 and 2.4×109cells/ml, correspondingly. Soil specimens were prepared at optimum moisture content (OMC) of British Standard light (BSL) compaction energy. Cementation reagent was applied on the compacted soil and permitted to penetrate until partial saturation was achieved. A set-up of pressure plate extractor was employed to measure the volumetric water content, θ (VWC) in the laboratory for varying matric suctions with a minimum of 10 kPa up to a maximum of 1,500 kPa. The unsaturated hydraulic conductivity (UHC) and VWC were assessed using Brooks - Corey (BC) and Fredlund - Xing (FX) models. Largely, BC and FX models overrated the VWC. Also, the VWC decreased with higher matric suction for the two models considered and the laboratory measured values. The UHC predicted for matric suctions of 500 and 1,500 kPa initially decreased for B. coagulans suspension density up to 1.2×109 cells/ml for BC and FX models, with the exception of a few cases, but thereafter increased with increase in microbial density. For FX model at 1,500 kPa, UHC values of 2.42×10–9, 2.02×10–9, 9.31×10–10, 8.09×10–10 , 1.29×10–9 and 2.27×10–9m/s were recorded at 0, 1.5×108, 6.0×108, 1.2×109, 1.8×109 and 2.4×109cells/ml, respectively. In the case of BC model, values of 2.26×10–17, 1.41×10–14, 2.2×10–14, 4.6×10–19 , 3.25×10–17 and 2.45×10–14m/s were recorded at 0, 1.5×108, 6.0×108, 1.2×109, 1.8×109 and 2.4×109cells/ml, respectively. Thus, the FX model met the design maximum hydraulic conductivity value of 1 x 10–9 m/s requirement for MSW system when lateritic soil was treated with B. coagulans suspension density of 1.2×109 cells/ml, while the BC model satisfied the requirement for all the microbial densities considered and it is recommended for modelling of UHC of lateritic soil admixed with B. coagulans for MSW containment application.
Soil-water retention of highly expansive clay stabilized with a bio-polymer
Authors: Manzanal Diego , Orlandi Sandra , Fernandez Mariano , Laskowski Cecilia , Barría Juan Cruz , Codevila Mauro , Piqué Teresa
Published: April 2021

The unpredictable expansiveness of clayey soils due to the change of water content can be responsible for significant pathologies on civil infrastructure. This behaviour depends mainly on the physical and chemical characteristics of the clayey soil and the stress-suction state of the soil. Extensive research has been carried out to control the swelling potential of clayey soils with traditional inorganic additives such as lime and cement. However, the use of these stabilizers presents adverse implications in terms of cost and environmental impact. Bio-products and waste by-products are an environmentally friendly alternative for geotechnical soil stabilization. In this article, we assess the effect of lignin on the hydro-mechanical behaviour of highly expansive clay. The research focuses on the behaviour upon wetting and the soil-water retention properties of clay and lignin-treated clay with different percentages. Suction measurements were made by using the filter paper technique. Particular emphasis on the mercury intrusion porosimetry analysis of the untreated and treated CR-Clay is done. Results of CR-Clay with lignin-based stabilizer show significant reduction of swelling upon wetting for the higher percentage of addition. Increase of the aggregation is observed with the growth of lignin percentage. An analysis of the soil-water retention properties with the van-Genutchen model is presented.
Thermal and hydraulic effects on the mechanical behavior of coarse-grained soils used as heat storage media
Authors: Hailemariam Henok , Wuttke Frank
Published: April 2021

Assessing the mechanical stability of soils used as heat storage media is vital in the design and wellbeing of sensible heat storage systems, which are typically designed below ground level or as part of the sub-structure of buildings with load bearing capabilities and subjected to frequent water table fluctuations. Nevertheless, considering the importance that moisture and temperature factors have in building a mechanically sound heat storage media, a careful study of such effects has not been given adequate attention in past studies. On this basis, the mechanical performance of two heat storage sandy soils at different moisture contents and temperature conditions is studied in this research. The results show a significant dependence of the mechanical behavior of the investigated soils on moisture content and temperature, which when unaccounted for can result in the inaccurate design of the overall storage system.
Comparison of numerical modeling results from laboratory and field obtained unsaturated flow parameters
Authors: Ahmed Asif , Alam Md Jobair Bin , Islam Md Azijul , Hossain MD Sahadat
Published: April 2021

Moisture and suction variation beneath pavement contribute significantly to the volumetric deformation of expansive subgrade in response to climatic loading. In order to quantify the damage due to climatic loading, estimation of moisture, and suction variation in pavement subgrade is of paramount importance. The objective of the current study is to investigate the moisture and suction variation in response to precipitation events with the aid of numerical modeling in the unsaturated pavement subgrade. In unsaturated soils where the voids are filled with both water and air, the SWCC describes the volume of the voids that remain filled with water as the soil drains pore water. The SWCC has been identified as the vital soil information required to analyze seepage, stability, and volume change problems involved in unsaturated soils. However, the selection of unsaturated flow parameters is typically laboratory-based which represents specific conditions rather than a dynamic scenario of the field. In this study, an attempt was undertaken to conduct numerical modeling using field generated unsaturated flow parameters along with five other predictive models. Results indicated the distinct variation of moisture and suction distribution in subgrade from the same rainfall event while using laboratory versus field generated SWCC unsaturated flow parameters. In addition, predicted model yielded output was also varying with the field generated parameters’ output. Instead of using laboratory-generated static parameters, it was found that field generated dynamic unsaturated flow parameters were able to capture better suction variation at the pavement subgrade.
Evaluation of settlement of shallow foundations laid on unsaturated soils
Authors: Lopes Elis Ferreira , Moreira Marcela Moreira da Rocha , Leme Rosiel Ferreira , da Silva Filho Francisco Chagas
Published: April 2021

The study presents an experimental and numerical study on an unsaturated, non-plastic and poorly graded sand, originated from Fortaleza-CE, Brazil. The numerical analyses used the Finite Element Method (FEM), were performed using the UNSTRUCT software to simulate the curve stress versus strain, considering the effect of suction on soil stiffness. Characterization and determination of the retention curve were performed through filter paper tests, which were used to determine the stress versus strain curve in a double-oedometer test. Suction was considered constant along the entire test. From the numerical analyses done with UNSTRUCT software presented satisfactory results, especially in the presence of suction profiles, that show the variation of suction along of the depth. It can be concluded that higher suction values (and soil stiffness) generate lower settlements.
Transient unsaturated shaft resistance of a single pile during water flow
Authors: Santos Daniel Batista , Lemos Moisés Antônio da Costa , Cavalcante André Luís Brasil
Published: April 2021

The pile foundations’ design is commonly based on the soil’s initial in situ condition during field investigations or the assumption of its saturated condition. However, for some regions in tropical weather, a significant part of the pile shaft remains above the groundwater table (i.e., unsaturated condition) during the structure’s lifespan. Only considering a constant moisture condition in the soil (unsaturated or saturated) can overestimate or underestimate the pile design. The soil shear strength governs the shaft resistance of a pile and depends on the soil matric suction, which is significant in the unsaturated zone. In this study, an analytical model is proposed to estimate piles’ unsaturated shaft resistance and encourage the use of unsaturated soil mechanics in engineering practice. The mathematical equation involves well-known parameters from unsaturated soil mechanics theory and simulates the pile shaft resistance variation with its length and time, considering a unidimensional infiltration downwards (e.g., during a rainfall event).
Deformation analysis of an unsaturated geosynthetic reinforced soil wall subjected to infiltration
Authors: Portelinha Fernando H. M. , Zornberg Jorge G. , Vilar Orencio M.
Published: April 2021

Geosynthetic-reinforced soil walls are structures typically constructed with compacted and thus unsaturated soils. The use of local fine-grained soils as backfill material has been a common practice in view of the significant cost reduction in comparison to granular backfills. This is especially applicable in tropical areas where lateritic soils are found as these material scan exhibit outstanding geotechnical properties mainly under unsaturated conditions. Thus, it is possible to optimize the design and construction of geosynthetic-reinforced soil walls considering soil unsaturation, however it is not known to what extent infiltration can reduce soil suction impairing the safety of the structure. To address the influence of suction on the behavior of geosynthetic structures, a full-scale geotextile-reinforced wall was subjected to infiltration and instrumented to capture the distribution of moisture and soil suction along the reinforced zone, as well as reinforcements strains. This paper presents and discuss the influence of geotextile reinforcement acting as capillary barrier coupled with the wall performance. Results demonstrate that the advancement of infiltration front has a more pronounced effect on deformation as the changes on water contents. Capillary barriers were found to occur retarding infiltration, but not affecting the overall performance of the structure. The average of monitored suction values along the wall height, herein called as “global suction”, was found to be strictly related to maximum reinforcement strains behavior.
Obtaining resistance parameters in iron ore tailing from field (SPT and CPTu) and laboratory tests
Authors: Costa Giovani , Villar Lúcio Flávio
Published: April 2021

Understanding the behaviour of materials resulting from mineral exploration is important in the current scenery of exploration and processing, with high mining waste generation and consequent catastrophic disasters. In this context, this paper presents the results of a geotechnical investigation carried out at an iron ore tailing in Minas Gerais – Brazil aimed at obtaining the shear strength parameters. The methodology is based on a large bibliographic review of field and laboratory tests, and based on obtaining geotechnical correlations, followed by both field and laboratory data analysis resulting from CPTu, SPT and laboratory tests (triaxial). Geotechnical parameters of the presented iron ore tailing enhance knowledge of this material disposed in dams, whose stability and integrity are directly related to the effect of these parameters interaction and mobilization.
Asymptotic behavior of a BAM neural network with delays of distributed type
Authors: Othmani S. , Tatar N.-E. , Khemmoudj A.
Published: April 2021

In this paper, we examine a Bidirectional Associative Memory neural network model with distributed delays. Using a result due to Cid [J. Math. Anal. Appl.281(2003) 264–275], we were able to prove an exponential stability result in the case when the standard Lipschitz continuity condition is violated. Indeed, we deal with activation functions which may not be Lipschitz continuous. Therefore, the standard Halanay inequality is not applicable. We will use a nonlinear version of this inequality. At the end, the obtained differential inequality which should imply the exponential stability appears ‘state dependent’. That is the usual constant depends in this case on the state itself. This adds some difficulties which we overcome by a suitable argument.
The foresight forecasting of social development in rural areas of the region
Authors: Stovba Eugene , Gorbunova Olesya , Stovba Andrey , Kolonskikh Natalya , Sharafutdinov Aidar
Published: April 2021

The article reveals the necessity to use a foresight when designing strategic plans and programs for the socio-economic development of rural municipalities in the present conditions of spatial and harmonious development of rural territories. A phased algorithm for forecasting the social development in rural areas. The article presents the results of foreseeing the social development of rural territories of the Non-chernozem zone of the Republic of Bashkortostan. The proposed unified foresight research methodology that makes it possible to provide a realistic target setting and precise «targeting» of strategic planning for the social development in rural areas. Summing up that the foresight technologies should be used as a system tool for developing a strategy for sustainable development of rural territorial systems.
The modern science of acmeology: integration of psychology and pedagogy in education
Authors: Pautova L. Ye. , Zharinova Ye. N.
Published: April 2021

The purpose of this study is to analyse and define the structural and substantive characteristics of acmeological categories (terms) with regard to fundamental education. The authors carried out theoretic and historical, methodological, systemic and logical analysis of acmeological, psychological and pedagogical studies on efficiency of education system and conceptual framework of creative professional and educational activities. Results of studying and substantiating of acmeological categories (terms) of creative activities within the system of fundamental education are presented in detail. Their structural and substantive features are identified and classified. The study presents categorization of acmeological concepts that integrate psychology and pedagogy. Results of this study can be used 1) as a scientific and methodological basis of fundamental education, particularly for vocational creative activities and for teaching the acme of productivity and professionalism; 2) for classification of acmeological categories and their incorporation into the conceptual framework of the Russian fundamental education.
Chirurgische Behandlung der Refluxkrankheit
Authors: Thalheimer Andreas
Published: April 2021

Als Goldstandard für die chirurgische Antirefluxtherapie gilt nach wie vor die laparoskopische Fundoplicatio. Jedoch wurden in den letzten Jahren weitere interventionelle und chirurgische Techniken entwickelt. Unser Autor erläutert, welche Kriterien bei der Indikation für eine OP wichtig sind und stellt die unterschiedlichen operativen Verfahren vor.
Nicht-ST-Hebungsmyokardinfarkt: Invasive Diagnostik und interventionelle Therapie nach aktueller ESC-Leitlinie
Authors: Burianek Franziska Stephanie , Mehilli Julinda
Published: April 2021

Die 2020 neu erschienenen ESC-Leitlinien zum akuten Koronarsyndrom ohne ST-Hebungen überholen die alten Empfehlungen zur invasiven Diagnostik und Therapie aus 2018 in verschiedenen Aspekten. In Bezug auf die initiale Risikostratifizierung wird aktuell nun insbesondere zwischen Patienten mit sehr hohem Risiko sowie hohem Risiko unterschieden, die sofort (< 2 Stunden) oder früh (< 24 Stunden) invasiv diagnostiziert werden sollen. Extern erfolgreich wiederbelebte Patienten mit stabiler Hämodynamik und ohne ST-Hebungen müssen nicht mehr einer sofortigen invasiven Diagnostik zugeführt werden, sollten aber weiterhin im kurzfristigen Abstand invasiv abgeklärt werden. Hinsichtlich technisch-prozeduraler Aspekte wurde die bisherige Empfehlung zur kompletten Revaskularisierung bei stabilen Patienten mit Mehrgefäßerkrankung weiter aufgewertet. Insgesamt sollte eine komplette Revaskularisierung stattfinden – dies kann, muss aber nicht während der Index-Prozedur
erfolgen. Ferner kann eine FFR-Messung von Nicht-Culprit-Läsionen während der Index-Prozedur durchgeführt werden. Standardmäßig sollte nun auch für NSTE-ACS-Patienten der radiale Zugangsweg gewählt werden.
Echokardiografische Untersuchung klinisch gesunder Frettchen ohne Sedation
Authors: Hildebrandt Nicolai , Henrich Estelle , Schneider Matthias
Published: April 2021

Gegenstand und Ziel Herzerkrankungen, in erster Linie Klappeninsuffizienzen und Kardiomyopathien, spielen auch beim Frettchen eine wichtige Rolle. Ziel dieser Studie war, am wachen gesunden Frettchen gewichtsbezogene Referenzintervalle für echokardiografische Routineparameter im B- und M-Mode zu etablieren, insbesondere des linken Vorhofs.

Material und Methoden Bei 18 gesunden, unsedierten Frettchen erfolgte eine echokardiografische Untersuchung in rechter Seitenlage. In 3 M-Mode-Schnitten (linker Ventrikel, Mitralklappenspitze, Aortenwurzel) aus der rechtsparasternalen Längsachse wurden 3 Herzzyklen mit guter Wandbegrenzung ausgewertet und der Mittelwert ermittelt. Im zweidimensionalen B-Mode-Bild wurden aus dem rechtsparasternalen Kurzachsenblick auf Höhe der Aortenklappe der linke Vorhof (LA) sowie die Aorta (Ao) gemessen und der Quotient LA/Ao errechnet.

Ergebnisse Die 9 männlichen und 9 weiblichen Frettchen (jeweils kastriert) hatten ein mittleres Alter von 2,6 ± 1,3 Jahren und ein mittleres Gewicht von 1,04 ± 0,31 kg. Die M-Mode-Messungen auf Ventrikelebene bzw. Aortenwurzel ließen sich bei allen Tieren durchführen. Es zeigten sich signifikante Effekte des Körpergewichts auf den Durchmesser des Ventrikels in Diastole und Systole sowie Aorta und Vorhof. Die Messung im B-Bild war oftmals nur an einem Standbild ausreichend möglich. Auch hier ergab sich eine signifikante Abhängigkeit von Ao und LA vom Gewicht. Errechnete Parameter wie die Verkürzungsfraktion und der Quotient LA/Ao waren unabhängig vom Gewicht.

Schlussfolgerung und klinische Relevanz Die Echokardiografie im B- und M-Mode stellt am wachen Frettchen eine praxistaugliche Untersuchungstechnik zur Ermittlung von Standardparametern für die morphologische Beurteilung des Herzens dar. Das Körpergewicht muss hierbei jeweils berücksichtigt werden.
Essstörungen im Kindes- und Jugendalter
Authors: Herpertz-Dahlmann Beate
Published: April 2021

Essstörungen sind ein häufiger Vorstellungsanlass in der pädiatrischen Praxis. Die Störung mit Vermeidung oder Einschränkung der Nahrungsaufnahme wurde neu in die ICD-11 aufgenommen. Sie betrifft in vielen Fällen das Klein- oder Schulkind und tritt vor allem bei Patienten mit zugrunde liegenden gastrointestinalen, neurologischen oder entwicklungsneurologischen Erkrankungen auf. Die wichtigste Differenzialdiagnose ist die kindliche Anorexia nervosa. Die jugendliche Anorexia nervosa ist eine der häufigsten chronischen Erkrankungen der Adoleszenz. Der Artikel stellt die Einteilung nach ICD-11 sowie neue Erkenntnisse zu deren Ätiologie, Diagnostik und Therapie dar. Dabei gelten neue Empfehlungen für die Realimentation. Eltern sind intensiv in die Behandlung einzubeziehen und übernehmen zu Beginn der Behandlung die Kontrolle über Essensmenge und Bewegungsverhalten. Lange vollstationäre Aufenthalte sind zu vermeiden. Die Bulimia nervosa und die Binge-Eating-Störung sind durch Heißhungerattacken gekennzeichnet. Dabei ist Binge Eating vielfach mit einer ausgeprägten Adipositas und psychischen Störungen wie Depressionen und Angststörungen assoziiert.
Dicas para reconstrução artroscópica do cruzado anterior sem o garrote
Authors: Datti Iberê Pereira
Published: April 2021

A reconstrução artroscópica do ligamento cruzado anterior é uma cirurgia comum realizada pelos cirurgiões ortopédicos dispostos a restaurar a estabilidade do joelho de pacientes fisicamente ativos. Apesar de ser geralmente um procedimento sem intercorrências, os cirurgiões devem sempre procurar melhores resultados pós-operatórios; neste cenário, a reconstrução artroscópica do ligamento anterior sem torniquete é uma alternativa promissora. O objetivo deste artigo é compartilhar com outros cirurgiões ortopédicos ao redor do mundo nossa experiência com este procedimento e algumas dicas técnicas que podem ser úteis.
Impacto das estratégias adotadas para enfrentar a pandemia de COVID-19 em um Instituto Brasileiro de referência em cirurgia de alta complexidade em Ortopedia e Traumatologia
Authors: Motta Filho Geraldo da Rocha , Leal Ana Carolina , Amaral Marcus Vinicius Galvão do , Maia Phelippe Augusto Valente , Duarte Maria Eugênia Leite , Bähr Germana Lyra
Published: April 2021

A pandemia de COVID-19 exigiu reorganização e adaptação substanciais dos serviços de saúde em todo o mundo. Este estudo tem como objetivo analisar o efeito das estratégias operacionais implementadas no Brasil em resposta à pressão extra imposta aos serviços de saúde pela pandemia de COVID-19 de 2020. Esta pesquisa examina principalmente a estratégia de conversão de um instituto especializado em procedimentos ortopédicos eletivos de alta complexidade em uma unidade de trauma para todos os pacientes com traumatismo musculoesquelético de toda uma unidade federativa. Um estudo retrospectivo comparou as variáveis hospitalares no período de pico da pandemia (de 16 de março de 2020 a 30 de junho de 2020) com o mesmo período de 2019, que representou os valores basais. As variáveis analisadas foram número de profissionais afastados do trabalho, cirurgias realizadas, atendimento ambulatorial, transferências, tempo de internação, número de pacientes com diagnóstico de COVID-19 e mortalidade dos pacientes. Durante o período de pico de COVID-19, houve uma redução de 48,5% na produtividade cirúrgica e de 72,4% no atendimento ambulatorial em comparação ao mesmo período de 2019. O número de transferências aumentou de maneira substancial (124,5%), com relato de 94 casos confirmados e 77 casos suspeitos de COVID-19. A taxa de mortalidade aumentou 245%. Este estudo destacou o efeito da COVID-19 em um hospital ortopédico terciário. Apesar das mudanças dramáticas no funcionamento do hospital devido à instituição de protocolos em resposta à pandemia, os resultados demonstraram a viabilidade e a eficiência de tais protocolos em priorizar a qualidade e a segurança dos pacientes e dos profissionais de saúde.
High-performance resistive switching memory with embedded molybdenum disulfide quantum dots
Authors: Yu Xinna , Chang Ke , Dong Anhua , Gan Zhikai , Jiang Kang'an , Ling Yibin , Niu Yiru , Zheng Diyuan , Dong Xinyuan , Wang Renzhi , Li Yizhen , Zhao Zhuyikang , Bao Peng , Liu Binbin , Cao Yuhong , Hu Su , Wang Hui
Published: April 2021

With the advent of the big-data era, conventional memory technologies and devices are facing enormous challenges. Resistive random access memory (RRAM) is an emerging memory technology that has aroused widespread interest for its immense potential. However, there remain some problems in resistive switching devices, such as high switching voltages, random voltages distribution, wide variation in resistance states, and poor endurance. In this work, molybdenum disulfide quantum dots are applied to resistive switching devices. The resulting devices exhibit improved performance. They have ultra-low and centralized switching voltages, uniformly distributed resistance states, good endurance, and extremely large on/off ratios. This performance optimization may derive from the convergence of electric field distribution around molybdenum disulfide quantum dots, which enhances the formation of localized conductive filaments. In this Letter, we propose an approach for improving resistive switching properties, significantly facilitating the development of data storage and related applications.