Reorientation Process Research Articles

Goblet cell interactions reorient bundled mucus strands for efficient airway clearance.

The respiratory tract of larger animals is cleared by sweeping bundled strands along the airway surface. These bundled strands can be millimetric in length and consist of MUC5B mucin. They are produced by submucosal glands, and upon emerging from these glands, the long axis of the bundled strands is oriented along the cilia-mediated flow toward the oral cavity. However, after release, the bundled strands are found to have turned orthogonal to the flow, which maximizes their clearance potential. How this unexpected reorientation is accomplished is presently not well understood. Recent experiments suggest that the reorientation process involves bundled strands sticking to MUC5AC mucus threads, which are tethered to the goblet cells. Such goblet cells are present in small numbers throughout the airway epithelium. Here, we develop a minimal model for reorientation of bundled mucus strands through adhesive interactions with surface goblet cells. Our simulations reveal that goblet cell interactions can reorient the bundled strands within 10 mm of release-making reorientation on the length scale of the tracheal tube feasible-and can stabilize the orthogonal orientation. Our model also reproduces other experimental observations such as strong velocity fluctuations and significant slow-down of the bundled strand with respect to the cilia-mediated flow. We further provide insight into the strand turning mechanism by examining the effect of strand shape on the impulse exerted by a single goblet cell. We conclude that goblet cell-mediated reorientation is a viable route for bundled strand reorientation, which should be further validated in future experiment.

Individual Differences in Spatial Orientation Modulate Perspective Taking in Listeners.

Previous research suggests that individuals exhibit consistent tendencies towards taking their own (an egocentric) or their partner's (an othercentric) spatial perspective. In addition, several factors such as spatial orientation ability, inhibitory control, and social preferences, have been found to mediate these perspective taking tendencies. However, these factors have not been studied together in the context of a single task. The present study explores these individual differences together in spatial perspective taking, using a task of simulated interaction in which listeners can choose to interpret an ambiguous spatial utterance egocentrically or othercentrically. We use a data-driven approach of latent profile analysis to classify participants into subgroups based on their spatial perspective taking tendencies. Our results show that stable subgroups of participants can be identified who differ in their perspective taking tendencies. This behaviour also correlates with a measure of listeners' spatial orientation ability, but not their inhibitory control or social preferences. Our results can be interpreted within a framework that views spatial perspective taking as an embodied cognitive process of a mental reorientation of the self relative to the environment, providing insight on the nature of the mechanisms underlying this operation.

Disorder enhanced dynamical heterogeneity in strain glass alloys.

An open question related to strain-glass (STG) alloys is whether they process similar dynamical behaviors to other glass systems. In the present work, we investigate the reorientation process of martensite domains in both STG and martensitic alloys. Our results show the presence of highly doped point defects can greatly intensify the dynamical heterogeneity and spatiotemporal correlation in ferroelastic or shape memory alloy systems, which are also two main hallmarks of structural glasses. What's more, we find that such dynamic heterogeneity exists in a different range spanning microscopic to mesoscopic scales, indicated by our molecular dynamic (MD) simulations and time-dependent Ginzburg-Landau (TDGL) modeling. Dopant atoms induced transient strain networks, i.e., spatial correlated local lattice distortion, is a response for such heterogeneous dynamics. The present study thus solidifies strain glass as a new state of matter and may provide guidelines for developing new strain glass alloys.&#xD.

Multiscale simulations of surface adsorption characteristics of amino acids on zinc metal anode

Aqueous zinc-ion batteries (ZIBs) are considered promising power sources for grid storage, but they face several issues, including dendrite growth, corrosion, hydrogen evolution, etc., which are related to the Zn metal/liquid electrolyte interface. To address these challenges, many researchers have focused on modifying the Zn anode with surface adsorption. However, the underlying mechanism between the Zn surface and adsorbed/protective molecules has not been thoroughly explored. In this study, we built a multiscale simulation platform that integrates state-of-art simulation methods to comprehensively investigate the adsorption process of amino acids on the Zn metal surface. Our major finding is that adsorption sites, adsorbate–surface angle, and average distance are critical parameters for the stability and strength of surface adsorption. Additionally, ab initio molecular dynamics reveal the kinetics of the surface adsorption and molecule reorientation processes. Specifically, it can be discovered that the amino acids prefer to align parallel to the Zn metal surface, leading to better surface protection against corrosion and preventing dendrite growth. These findings pave the way for an in-depth understanding of the surface adsorption process, as well as providing concrete design principles for stable Zn metal anodes.

Dynamic reorientation of tidally locked bodies: Application to Pluto

Planets and moons reorient in space due to mass redistribution associated with various types of internal and external processes. While the equilibrium orientation of a tidally locked body is well understood, much less explored are the dynamics of the reorientation process (or true polar wander, TPW, used here for the motion of either the rotation or the tidal pole). TPW dynamics can be non-trivial and are important for predicting the patterns of TPW-induced surface fractures, as well as for assessing whether enough time has passed for the equilibrium orientation to be reached. The only existing and relatively complex numerical method for an accurate evaluation of the reorientation dynamics of a tidally locked body was described in a series of papers by Hu et al. (2017a,b, 2019). Here we demonstrate that an identical solution can be obtained with a simpler approach, denoted as oω||mMIA, because during TPW the tidal and the rotation axes closely follow respectively the minor and the major axes of the total, time-evolving inertia tensor of the body. Motivated by the presumed reorientation of Pluto, the use of the oω||mMIA method is illustrated on several test examples. In particular, we vary the load sign and the mass of the host body and analyze whether TPW paths are curved or straight. When tidal forcing is relatively small, the paths of negative anomalies (e.g. basins) towards the rotation pole are highly curved, while positive loads may reach the sub- or anti-host point straightforwardly. The obtained behavior is explained by the relative timing of longitudinal and latitudinal reorientation. Our results suggest that the Sputnik Planitia basin cannot be a negative anomaly at present day, and that the remnant figure of Pluto must have formed prior to the reorientation. Finally, the presented method is complemented with an energy balance that can be used to test the numerical solution and to quantify the changes in orbital distance due to TPW. A new release of the custom written code LIOUSHELL that is used to perform the simulations is made freely available on GitHub.

In-situ high energy X-ray diffraction study of deformation behavior in Nb nanoparticle-martensitic NiTi composite wire

This study investigated the deformation behavior in Nb nanoparticle-martensitic NiTi composite wire during tensile loading by means of in-situ high-energy X-ray diffraction. Compared to Nb nanowires, the dispersedly distributed Nb nanoparticles have little effect on the transformation and deformation behaviors of NiTi matrix, causing the absence of R phase transformation and the occurrence of deformation twinning in NiTi matrix. Meanwhile, the occurrence of deformation twinning in NiTi matrix can reduce the shape strain to be coordinated by the unfavorable orientated martensite variants, and thus decreases the internal stress among NiTi martensite variants generated during martensite reorientation process. In addition, TEM result proved that Nb nanoparticles can achieve exceptionally large elastic strain in B19′-NiTi matrix (∼4%), just as Nb nanowires. However, this large elastic strain (stress) will be released with the occurrence of NiTi deformation twinning.

Investigating the Hydroxyl Reorientation in Hydroxyapatite Using Machine Learning Potentials

The chain or network of hydroxyl groups (OH–) is crucial in determining the structure and function of materials, especially in hydroxyapatite (HAP), a mineral essential for human bones. HAP exhibits a linear arrangement of OH– along the c-axis, which determines its phase transition, dielectric, and piezoelectric properties. However, the mechanism underlying OH– reorientation with temperature remains elusive using traditional experimental and theoretical methods. To address this, we developed a machine learning atomistic potential for HAP using an active learning algorithm, which achieved density functional theory-level accuracy in describing OH– of HAP. The machine learning molecular dynamics simulations revealed that the reorientation of OH– in HAP with temperature occurs through ″flip-flop″ motion, rather than proton transfer. This process starts at about 473 K and accelerates with increasing temperature, consistent with the experimentally observed transformation from the monoclinic to hexagonal phase. At 973 K and above, the rapid “flip-flop” reorientation process leads to an undetermined orientation of OH– along the c-axis. These findings highlight the potential of machine learning-accelerated molecular dynamics simulations in unraveling the microscopic mechanisms underlying the hydrogen bond network in complex multicomponent materials at the atomic level.

A Statistical Mechanics Approach to Describe Cell Reorientation Under Stretch

Experiments show that when a monolayer of cells cultured on an elastic substratum is subject to a cyclic stretch, cells tend to reorient either perpendicularly or at an oblique angle with respect to the main stretching direction. Due to stochastic effects, however, the distribution of angles achieved by the cells is broader and, experimentally, histograms over the interval [0^circ , 90^circ ] are usually reported. Here we will determine the evolution and the stationary state of probability density functions describing the statistical distribution of the orientations of the cells using Fokker–Planck equations derived from microscopic rules for describing the reorientation process of the cell. As a first attempt, we shall use a stochastic differential equation related to a very general elastic energy that the cell tries to minimize and, we will show that the results of the time integration and of the stationary state of the related forward Fokker–Planck equation compare very well with experimental results obtained by different researchers. Then, in order to model more accurately the microscopic process of cell reorientation and to shed light on the mechanisms performed by cells that are subject to cyclic stretch, we consider discrete in time random processes that allow to recover Fokker–Planck equations through classical tools of kinetic theory. In particular, we shall introduce a model of reorientation as a function of the rotation angle as a result of an optimal control problem. Also in this latter case the results match very well with experiments.

Principle of virtual power and drilling degrees of freedom for dynamic modeling of the behavior of liquid crystal elastomer films

In this work, we aim to model the reorientation process of mesogens in nematic liquid crystal elastomers within the context of dynamics. We consider a continuum model with separate mappings for the deformation of the monolithic material and the orientation of the nematic director, where the latter describes the inclination of the mesogens. We achieve the inextensibility of the nematic director through the introduction of drilling degrees of freedom. We combine this approach with the application of the principle of virtual power and a mixed finite element formulation, in order to formulate distinct momentum and angular momentum balance laws for the two separate mappings. Furthermore, we include in our continuum model a volume load and a surface load associated only with the orientation mapping. We show in the presented three numerical examples that our formulation enables the fulfillment of all momentum and angular momentum balance laws.

Outcome analysis on individual health budgets in mental Health: finding from the Friuli Venezia Giulia Region, Italy

Background Individual Health Budget (IHB) is used for social and health integration and to facilitate processes of resource reorientation in healthcare. Despite its increased use in mental health settings, few studies investigated its effectiveness in severe mental disorders. Methods 383 IHB beneficiaries were recruited among Mental Health Departments users of the Italian region Friuli Venezia Giulia. Data involved sociodemographic and clinical variables, IHB type and scores of Health of the Nation Outcome Scale (HoNOS) at admission to IHB programme (T0), after 12 months (T1), and after 24 months (T2). Results The length and the mean number of hospitalisations and healthcare interventions decreased at T1. A significant scores’ reduction from T0 to T1 evaluation was found in HoNOS total score (T-test (P) < 0.05) and in most of its items. An improvement throughout the whole evaluation period (T0 vs. T2) was found in 36% of the IHB beneficiaries, while more than 60% of them remained in the same HoNOS severity category. Conclusions Our results support the use of IHB in patients with severe mental problems, since it may contribute to an improvement in social and clinical functioning, consequently lowering the burden on MHDs.

Perpendicular Alignment of Covalent Organic Framework (COF) Pore Channels by Solvent Vapor Annealing

Covalent organic frameworks (COFs) have showcased great potential in diverse applications such as separation and catalysis, where mass transfer confined in their pore channels plays a significant role. However, anisotropic orientation usually occurs in polycrystalline COFs, and perpendicular alignment of COF pore channels is ultimately desired to maximize their performance. Herein, we demonstrate a strategy, solvent vapor annealing, to reorient COF pore channels from anisotropic orientation to perpendicular alignment. COF thin films are first synthesized to have flexible N-H bonds in their skeletons, thus having structural mobility to enable molecular rearrangement. A solvent with low relative permittivity and a conjugated structure is then identified to have a strong affinity toward the COFs, allowing its vapor to easily penetrate into the COF interlayers. The solvent vapor weakens the π-π interaction and consequently allows the COF monolayers to dissociate. The COF monolayers undergo a reorientation process that converts from random stacking into the face-on stacking fashion, in which the through COF pores are perpendicularly aligned. The aligned COF film exhibits high separation precision toward ions featuring a size difference down to 2 Å, which is 8 times higher than that of the anisotropically oriented counterpart. This work opens up an avenue for COF orientation regulation by solvent vapor annealing and reveals the essential role of the perpendicular alignment of COF pore channels to enable precision separations.

Giant dynamic electromechanical response via field driven pseudo-ergodicity in nonergodic relaxors

Enhanced electromechanical response can commonly be found during the crossover from normal to relaxor ferroelectric state, making relaxors to be potential candidates for actuators. In this work, (Pb0.917La0.083)(Zr0.65Ti0.35)0.97925O3 ceramic was taken as a case study, which shows a critical nonergodic state with both double-like P-E loop and irreversible relaxor-normal ferroelectric phase after poling at room temperature. The low-hysteresis linear-like S-P2 loop, in-situ synchrotron X-ray diffraction and transmission electron microscope results suggest that the nonpolar relaxor state acts as a bridge during polarization reorientation process, accompanying which lattice strain contributes to 61.8% of the total strain. In other words, the transformation from normal ferroelectric to nonergodic relaxor state could be triggered by electric field through polarization contraction, which could change to be spontaneously with slightly increasing temperature in the nonergodic relaxor zone. Therefore, pseudo-ergodicity in nonergodic relaxors (i.e. reversible nonergodic-normal ferroelectric phase transition) driven by periodic electric field should be the main mechanism for obtaining large electrostrain close to the nonergodic-ergodic relaxor boundary. This work provides new insights into polarization reorientation process in relaxor ferroelectrics, especially phase instability in nonergodic relaxor zone approaching to freezing temperature.

РОЛЬ ЯРОСЛАВА ДАШКЕВИЧА У ДОСЛІДЖЕННІ «БІЛИХ ПЛЯМ» УКРАЇНСЬКОЇ ІСТОРІЇ У ПЕРІОД «ПЕРЕБУДОВИ» (1985–1991 РР.)

The author concludes about involving historians during the period of restructuring into the process of conscious reorientation of Ukrainian humanitarians. He speaking with publications in periodicals or at scientific conferences violated important aspects of the historical past of Ukraine, which were distorted or ordered in the scientific sense of Soviet time. First of all, these issues were connected with the opening of the myth of the sovereignty of the Ukrainian nation. And here, according to the historian, the return to the sources of Ukrainian historiography and critical analysis of the sources should not be the last role. However, most of the works of the scientist, in the investigated period were scientifically popular. This is due to the fact that only the first steps were taken in the national science to overcome the communist stereotypes and to study the national history. He demonstrated deep knowledge of the subject, which was based on deep study of scientific works of predecessors and source base. He constantly stressed the great importance of historical science for the formation of national consciousness, therefore demanded from scientists to look at the historical process only from the positions of their own people and prospects of its development. In the days of independence of Ukraine, some of the author’s judgments were changed by the social political circumstances, which require a deep scientific analysis of his creative heritage using comparative analysis.

Favorable dynamics of switching and non-switching polarizations in ⟨001⟩pc oriented Sm:PMN-PT crystal

In this investigation, the dynamic behavior of the switching and the non-switching polarization loops has been studied for ⟨001⟩pc oriented PMN-PT and Sm:PMN-PT crystals. A five-pulse triangular wave sequence was employed to measure the switching and non-switching polarization loops separately as a function of amplitude and frequency of the poling field. Dynamic scaling of the switching loops was performed according to the power law &amp;lt;ASW&amp;gt;∝ Eαfβ. The lower negative value of β for Sm:PMN-PT suggests a shorter response time of crystallographic domains for it as compared to that for PMN-PT. The value of exponent α for PMN-PT was found to be higher in the low-field regime where 180° switching dominates the domain reorientation process. For Sm:PMN-PT, on the other hand, the value of α was found to be higher at high fields, which implies a superior ferroelastic domain reorientation. A similar power law scaling was also performed on the non-switching loops, which suggests a faster dynamic response of intrinsic polarization in Sm:PMN-PT as compared to that for PMN-PT. However, the intrinsic polarization in Sm:PMN-PT was found to be less responsive to the increasing field as compared to that for PMN-PT. We believe that the findings of this investigation would add another dimension to the understanding of the mechanism responsible for the high piezoelectric activity in samarium doped PMN-0.28PT crystal and polycrystalline ceramics.

Dithioester-terminated copolymers with simultaneous high dielectric constant and breakdown strength for energy storage

High-energy storable polymer dielectrics are highly desirable and applicable for compact and efficient power electronic devices. However, existing polymer dielectrics suffer from either a low dielectric constant or a low breakdown strength and exhibit an extremely low energy density. Here, the reversible addition−fragmentation chain transfer polymerization and polyaddition polymerization techniques are combined to create a dithioester-terminated polythiourea (PTU)-based copolymer dielectric with an extraordinarily high energy density of 10.7 J/cm3. The end-group functionalized copolymer significantly increases the dielectric constant from 6.0 to 7.6, which enhances the breakdown strength from 264 to 563 MV/m. The theoretical analysis from the proton nuclear magnetic resonance, atomic force microscope (AFM), and the dynamics of the polarization behaviors demonstrates conformational transitions between the two distinct trans/trans and cis/trans thioureas, along with the formation of polar PTU nanoregions. These result in a flexible polarization reorientation process and increased dielectric constant. Meanwhile, the density functional theory calculations for the electronic structures of the block copolymers indicate that the excellent breakdown strength of the end-group functionalized copolymer is attributed to strong charge trapping from the unique dithioesters. This work proposes a strategy to achieve a simultaneous high dielectric constant and breakdown strength toward excellent energy storage performances by end-group functionalization and composition modifications.

Ground states and magnonics in orthogonally coupled symmetric all-antiferromagnetic junctions

In this paper, the rich ground-state structure of orthogonally coupled symmetric all-antiferromagnetic junctions with easy-plane anisotropy is reported. A spin reorientation process rather than the traditional spin flop (SF) occurs, resulting in a phase in which N\'eel vectors preserve the mirror-reflection symmetry (termed MRS phase). The phase transitions in the ground state between SF and MRS phases can be either first or second order. After disturbed by external stimuli, magnons with different parities emerge. For in-plane dc fields, no couplings between magnons occur. When dc fields become oblique, coherent couplings between magnons with opposite parity emerge, leading to anticrossings in resonance frequencies. However, self-hybridization among magnons with the same parity never happens. More interestingly, spin waves based on MRS phases are linearly polarized and their polarization directions can be fine controlled.

THE MAIN PEDAGOGICAL REQUIREMENTS AND CRITERIA FOR ORGANIZING TRAINING FOR THE DEVELOPMENT OF PUPILS' PROFESSIONAL COMPETENCE USING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES

In the conditions of modern development of education, the training of pupils with the skills and abilities of socio-psychological and professional adaptation in a rapidly changing world comes to the fore. Education becomes not only a means for the most adequate reflection of the requirements of a market economy and a new society, but also a way to achieve, form the creative, spiritual needs of the individual. Changing the foundations of education is accompanied by a global process of reorientation of the result of education. Therefore, the article presents the investigation of the pedagogical requirements and criteria for the organization of training in the development of professional competence of pupils with the usage of multimedia electronic educational resources. The result of the research depicts that multimedia electronic educational resources are valuable source in improving pupils' professional competence. In addition, the presented requirements and criteria are beneficial in organizing training in the development of professional competence of pupils for multimedia electronic educational resources.

A novel radial orientation treatment of nematic liquid crystals using magnetic field lines with permanent magnet and applying the assisted electric field

AbstractRecently, there has been considerable research on optical devices, such as liquid crystal (LC) lenses and special optical plates, using LCs. In such devices, relatively small LC cells are frequently used, or unique LC orientations are required. As an LC orientation process, we focused on the LC director's orientation induced by the magnetic force line distribution of a small neodymium magnet. We propose a simple method for obtaining radial orientation, which is rather difficult to obtain using the ordinary rubbing method. The initial orientation in the LC cell is a vertical orientation cell with almost zero azimuth anchoring. With the proposed method, the reorientation process is performed with an assisting electric field and a small permanent magnet, unlike the conventional magnetic field orientation process that requires a large electromagnet. Furthermore, a polymer stabilization treatment is used to fix the obtained radial orientation pattern in the LC cell. After the treatment, the applying voltage can control the tilt angle of the director in weak polymer treatment, and a completely fixed orientation pattern can be obtained that in strong.

Single-crystalline PbTe film growth through reorientation

Heteroepitaxy enables the engineering of novel properties, which do not exist in a single material. Two principal growth modes are identified for material combinations with a large lattice mismatch, Volmer-Weber, and Stranski-Krastanov. Both lead to the formation of three-dimensional islands, hampering the growth of flat defect-free thin films. This limits the number of viable material combinations. Here, we report a distinct growth mode found in molecular beam epitaxy of PbTe on InP initiated by pregrowth surface treatments. Early nucleation forms islands analogous to the Volmer-Weber growth mode, but film closure exhibits a flat surface with atomic terracing. Remarkably, despite multiple distinct crystal orientations found in the initial islands, the final film is single crystalline. This is possible due to a reorientation process occurring during island coalescence, facilitating high quality heteroepitaxy despite the large lattice mismatch, difference in crystal structures, and diverging thermal expansion coefficients of PbTe and InP. This growth mode offers a new strategy for the heteroepitaxy of dissimilar materials and expands the realm of possible material combinations.

Dynamic Electric Field Alignment Determines the Water Rotational Motion around Protein.

Water rotational dynamics in biomolecular solution is crucial to evaluating and controlling biomolecule stability. In this molecular dynamics simulation (MD) study on lysozyme solutions, we present how the exerted internal electric field determines water rotational dynamics. We find that the relaxation time of water rotation is equivalent to that of the reorientation of the exerted overall electric field for every single water molecule, regardless of its translation mode. Namely, water molecular rotation synchronizes with the exerted field reorientation. We also map the reorientation process of the electric field at fixed points relative to protein in the solution, which displays the local hydration dynamics commensurate with the reported time-dependent fluorescence Stokes shift (TDFSS) measurements. Comparing the spatial distribution of local field reorientation relaxation time with that of rotational relaxation time, we further suggest that water rotation dynamics are subject to the reorientation of the local overall field within the hydration layer. While outside the hydration layer, the relaxation time of the local electric field reorientation is short enough (subpicosecond) to assume the δ function, showing the electric force with randomly changing orientation is applied to each water molecule.