Symmetric Ones Research Articles

General strategies for IgG-like bispecific antibody purification.

Bispecific antibodies (bsAbs) can simultaneously bind two different antigens or epitopes. Their dual-targeting capability enables novel mechanisms of action, gaining therapeutic advantages over conventional monospecific mAbs. In recent years, the number of bsAbs grows rapidly and bsAbs under development are available in diverse formats. In particular, Fc-containing IgG-like bsAbs, which represent the major group, can be constructed in asymmetric or symmetric format. For asymmetric ones, whose assembly requires multiple distinct chains, although numerous strategies have been developed to promote desired chain pairing, product-related variants such as free chains, half molecules and mispaired species are usually present at various levels. For symmetric ones, increased level of aggregates and truncating variants is often associated with their production. In general, bsAbs pose greater challenges to the downstream team than regular mAbs. In the past few years, our team successfully developed the downstream process for over 70 bsAbs in greater than 30 different formats and accumulated substantial experience. This review introduces general strategies that we have used while purifying these challenging molecules.

Aerodynamic study of a leading-edge rotating cylinder in a cambered aerofoil (NACA2412)

PurposeFlow separation over an aircraft’s wing beyond a specific angle of attack is challenging. Flow boundary layer manipulation has been investigated to improve aerofoil lift and mitigate flow separation difficulties including stall and drag. This is solved via active or passive flow control. Active flow control method moving surface boundary (MSB) enhances shear flow momentum, making it effective. MSB is easier than suction and blowing. Asymmetrical airfoils, which generate lift in aircraft wings, have received less MSB research than symmetrical ones. The purpose of this study is to asses the design efficacy of MSB’s NACA 2412 aerofoil.Design/methodology/approachTo observe the performance of MSB in NACA 2412, a computational model has been created, and aerodynamical performance has been analyzed.FindingsThe study results show that the NACA 2412 with MSB has better aerodynamic efficiency than the NACA 2412 base design. It works best when it reaches its optimal speed and the delay in flow separation works well.Research limitations/implicationsLimitations may include specific aerofoil applicability, external factors and simulation constraints. Implications guide future research for broader insights and applications.Practical implicationsImproving asymmetrical aerofoil performance, mitigating stall effects, reducing drag and optimizing designs with moving surface boundary. Insights gained can enhance overall aircraft efficiency and flow control techniques.Originality/valueThe MSB flow control in a chambered aerofoil is less explored and not explored enough in wing-based aerofoils, and the optimal cylinder speed ratio trend has been discussed at each angle of attack studied.

Investigation of Vertical-axis Tidal Turbine Mechanical Strength using FSI Analysis based on Blade Profile

Abstract Tidal energy, as a renewable energy source harnessed from the ocean, holds substantial promise owing to its heightened energy density, reliability, and longevity. An investigation encompassing the deployment of tidal stream electricity from 2003 through August 2020 revealed that blade malfunction was identified as the primary reason for system failures, with generator and monitoring system failures occurring subsequently. The majority of the research that has been done on the design of vertical-axis tidal turbine blades has focused on how well the blade performs in terms of power output without taking into account the generation of mechanical force. This force can potentially shorten the blade’s lifetime when implemented in a real-world scenario. By modelling a steady-state fluid-structure interaction (FSI) configuration, this study examines how the shape of the turbine blades affects the amount of mechanical force they generate, particularly in vertical-axis tidal turbines. The type of blade profile is the variable under consideration, and the stress levels experienced by a structure are influenced by the type of blade profile used. When comparing symmetrical and asymmetrical NACA straight blade types under similar climatic conditions, it has been found that the blade profile plays a significant role. Asymmetrical blade profiles, in particular, generate a higher lift force compared to symmetrical ones, thereby affecting stress levels more noticeably.

Thermoelastic damping in asymmetric vibrations of nonlocal circular plate resonators with Moore-Gibson-Thompson heat conduction

Precise estimation of the amount of thermoelastic damping (TED) in small-sized resonators is one of the crucial issues in their optimal design. According to several experimental, numerical and theoretical findings, the behavior of structures with such small dimensions in structural and thermal domains does not follow classical elasticity theory and the Fourier law of heat conduction. The objective of this work is to develop a nonclassical formulation for computing TED in asymmetric vibrations of circular nanoplates according to nonlocal theory (NT) and Moore-Gibson-Thompson (MGT) heat transfer model. To do so, first, the coupled equations of motion and heat are derived in the purview of NT and MGT model. Then, the real and imaginary parts of the system frequency are extracted from the frequency equation affected by thermoelastic coupling. Finally, by means of the existing definition for TED, a mathematical expression including nonlocal parameter of NT and nonclassical constants of MGT model is obtained to make an estimate of TED value. In the numerical examples section, to ensure the credibility of the provided formulation, the results obtained through this model are compared with those reported in the literature in the context of simpler models. Then, by presenting various graphical data, the type and extent of the role of different factors in TED changes are appraised. The obtained results indicate that employing NT and MGT model can substantially impact the amount of TED compared to the estimations of the classical formulation. Furthermore, the comparison of results reveals that the magnitude of TED in asymmetric vibration modes surpasses that in symmetric ones, and consequently incorporating asymmetric vibration modes is crucial for thorough analysis of TED in circular nanoplates. Thus, the formulation presented in this article can aid in achieving an optimal design for such plates, particularly in terms of minimizing energy loss.

Grain boundaries are Brownian ratchets.

We demonstrate that grain boundaries (GBs) behave as Brownian ratchets, exhibiting direction-dependent mobilities and unidirectional motion under oscillatory driving forces or cyclic thermal annealing. We observed these phenomena for nearly all nonsymmetric GBs but not for symmetric ones. Our observations build on molecular dynamics and phase-field crystal simulations for a wide range of GB types and driving forces in both bicrystal and polycrystalline microstructures. We corroborate these simulation results through in situ experimental observations. We analyze these results with a Markov chain model and explore the implications of GB ratchet behavior for materials processing and microstructure tailoring.

Adaptive Fixed-Time Safety Concurrent Control of Vehicular Platoons with Time-Varying Actuator Faults under Distance Constraints

This paper investigates the fault-tolerant control problem for vehicular platoons with time-varying actuator fault directions and distance constraints. A bias constraint function is introduced to convert the asymmetric constraints into symmetric ones, based on which a unified barrier Lyapunov function (BLF) method is proposed to ensure distance constraints. Further, an adaptive fixed-time fault-tolerant controller in the context of a sliding mode control technique is proposed, wherein a new Nussbaum function is adopted to address the effects of unknown time-varying actuator fault directions. It is proved that both individual vehicle stability and string stability can all be guaranteed, and the effectiveness of the proposed algorithm is verified through numerical simulations.

Characterising galaxy clusters’ completeness function in Planck with hydrodynamical simulations

Galaxy cluster number counts are an important probe with which to constrain cosmological parameters. One of the main ingredients of the analysis, along with accurate estimates of cluster masses, is the selection function, and in particular the completeness associated with the cluster sample under consideration. Incorrectly characterising this function can lead to biases in cosmological constraints. In this work, we want to study the completeness of the Planck cluster catalogue, estimating the probability of cluster detection in a realistic setting using hydrodynamical simulations. In particular, we probe the case in which the cluster model assumed in the detection method differs from the shapes and profiles of true galaxy clusters. We created around 9000 images of the Sunyaev–Zel’dovich effect from galaxy clusters from the IllustrisTNG simulation, and used a Monte Carlo injection method to estimate the completeness function. We studied the impact of having different cluster pressure profiles and complex cluster morphologies on the detection process. We find that the cluster profile has a significant effect on completeness, with clusters with steeper profiles producing a higher completeness than ones with flatter profiles. We also show that cluster morphology has a small impact on completeness, finding that elliptical clusters have a slightly lower probability of detection with respect to spherically symmetric ones. Finally, we investigate the impact of a different completeness function on a cosmological analysis with cluster number counts, showing a shift in the constraints on Ωm and σ8 that lies in the same direction as the shift driven by the mass bias.

Study on the Impact of Tail Wing Profiles on the Resistance Characteristics of Amphibious Vehicles

The resistance performance of amphibious vehicles can be improved by installing underwater tail hydrofoils. The research on the impact of different hydrofoil profiles on the resistance characteristics of amphibious vehicles can provide a reference for the vehicle’s design. For an amphibious vehicle model, five shapes of symmetrical hydrofoils, NACA0012, NACA0015, NACA0016, and asymmetric hydrofoils NACA23012, NACA66-209, were selected as the underwater tail wing of the vehicle body, respectively. Based on the RANS method and overset grid technology, the resistance performance of the vehicle body was numerically calculated, and the resistance variation in the amphibious vehicle equipped with different tail hydrofoils at 0.43 < Fr∇ < 1.3 speed was obtained. The basic shape of amphibious vehicle tail wings can be determined by comparing the effects of symmetrical hydrofoils and asymmetric hydrofoils on body resistance. The results show that the asymmetric hydrofoils have a better resistance reduction effect on amphibious vehicles than the symmetrical ones. Among them, an amphibious vehicle installing the asymmetric hydrofoil NACA66-209 as an underwater tail wing can reduce resistance by 44.3%. Chord length is an important factor affecting the resistance reduction performance of tail wings. When Fr∇ = 1.3, the asymmetric hydrofoil optimized based on chord length has a 21.2% higher resistance reduction effect on amphibious vehicles.

On the role of asymmetric molecular geometry in high-performance organic solar cells

Although asymmetric molecular design has been widely demonstrated effective for organic photovoltaics (OPVs), the correlation between asymmetric molecular geometry and their optoelectronic properties is still unclear. To access this issue, we have designed and synthesized several symmetric-asymmetric non-fullerene acceptors (NFAs) pairs with identical physical and optoelectronic properties. Interestingly, we found that the asymmetric NFAs universally exhibited increased open-circuit voltage compared to their symmetric counterparts, due to the reduced non-radiative charge recombination. From our molecular-dynamic simulations, the asymmetric NFA naturally exhibits more diverse molecular interaction patterns at the donor (D):acceptor (A) interface as compared to the symmetric ones, as well as higher D:A interfacial charge-transfer state energy. Moreover, it is observed that the asymmetric structure can effectively suppress triplet state formation. These advantages enable a best efficiency of 18.80%, which is one of the champion results among binary OPVs. Therefore, this work unambiguously demonstrates the unique advantage of asymmetric molecular geometry, unveils the underlying mechanism, and highlights the manipulation of D:A interface as an important consideration for future molecular design.

Subsonic aeroelastic behaviors of a composite plate with embedded MFC actuators under hygrothermal environment

Subsonic aeroelastic effects of train-body skin structures have been intensely attractive among researchers due to the improvement of high-speed train speed. In this article, the aeroelastic behaviors of a laminated composite plate with embedded Macro Fiber Composite (MFC) actuators in hygrothermal environment under the subsonic airflow has been investigated. The Von Karman large deflection theory and the subsonic aerodynamic model based on the Bernoulli's equation are applied in the formulation. The principle of virtual work is adopted to obtain the nonlinear aeroelastic equations of the laminated composite panel with embedded MFC actuators. Subsequently, the Newmark method and Newton-Raphson method are combined to solve the framework in order to capture the nonlinear aeroelastic response of the subsonic laminated panel in time domain. Since the presence of moisture concentrations, temperature rises and applied voltages of the embedded MFC actuators will result in additional stiffness effects on composite panels by inducing prestress, thus change the aeroelastic behaviors of the composite panel, the influences of these main parameters on aeroelastic performance are analyzed. The results show that the aeroelastic flutter velocity of the composite panel gets remarkably deteriorated due to the adverse hygrothermal environment and can be strengthened through the applied voltages and appropriate lamination angles of embedded MFC actuators. Besides, the main findings of this study are the anti-symmetric laminate buckles then changes to an periodic oscillation like the limit-cycle-oscillation while there is no such phenomenon for the symmetric ones.

Tracking and classification performances in the bio-inspired asymmetric and symmetric networks

Abstract Machine learning, deep learning and neural networks are extensively applied for the development of many fields. Though their technologies are improved greatly, they are often said to be opaque in terms of explainability. Their explainable neural functions will be essential to realization in the networks. In this paper, it is shown that the bio-inspired networks are useful for the explanation of tracking and classification of features. First, the asymmetric network with nonlinear functions is created based on the bio-inspired retinal network. They have orthogonal properties useful for the tracking of features compared with the conventional symmetric networks, which is also proposed on the biological functions. Next, the analysis for the independence of the subspaces between the Fourier bases and the asymmetric network bases is performed. It was that the asymmetric networks have better performances in the classification compared with the symmetric ones. Further, the layered asymmetric networks generate the higher dimensional orthogonal bases that improve the classification accuracies by the replacements of bases. Finally, we classified Reuters collections data applying the explainable processing steps, which consist of the linear discriminations and the sparse coding with nearest neighbor relation for classification.

The nonlinear evolution of two surface quasi-geostrophic vortices

We investigate numerically the evolution of a baroclinic vortex in a two-level surface quasi-geostrophic model. The vortex is composed of two circular patches of uniform buoyancy, one located at each level. We vary the vortex radii, the magnitude of buoyancy, and the vertical distance between the two levels. We also study different radial profiles of buoyancy for each vortex. This article considers two main situations: firstly, initially columnar vortices with like-signed buoyancies. These vortices are contra-rotating, are linearly unstable and may break. Secondly, we consider initially tilted vortices with opposite-signed buoyancies, which may align vertically. Numerical experiments show that (1) identical contra-rotating vortices break into hetons when initially perturbed by low azimuthal modes; (2) unstable, vertically asymmetric, contra-rotating vortices can stabilise nonlinearly more often than vertically symmetric ones, and can form quasi-steady baroclinic tripoles; (3) co-rotating vortices can align when the two levels are close to each other vertically, and when the vortices are initially horizontally distant from each other by less than three radii; (4) for initially more distant vortices, two such vortices rotate around the plane center; and(5) in all cases, the vortex boundaries are disturbed by Rossby waves. These results compare favorably to earlier results with internal quasi-geostrophic vortices. Further modelling efforts may extend the present study to fully three-dimensional ocean dynamics.

The usefulness of the open surgical technique of sternocostal elevation for asymmetric pectus excavatum: a retrospective study.

The Nuss procedure is currently the mainstream of pectus excavatum (PE) surgery; however, it is considered to be more difficult for asymmetric cases than for symmetric ones. Sternocostal elevation (SCE), which was performed at our hospital, is a surgical method that determines the extent of resection of the costal cartilage while comparing the left and right balance during surgery; thus, it is highly useful for correcting rib cage with strong asymmetry. Of the 256 patients who underwent SCE at our hospital between July 2014 and July 2022, 58 (22.7%) with asymmetric PE were retrospectively examined. However, patients with advanced scoliosis having a Cobb angle of 25° or higher were excluded; therefore, 51 (19.9%) patients were analyzed. Two indices and other measurements were evaluated to determine the success of correction for asymmetry using computed tomography (CT). The difference between the left and right thoraxes, the Haller index, and the sternal torsion angle significantly improved. Furthermore, we herein set a new numerical index as an indicator of asymmetry improvement and to be used for a more standard thorax morphology; the difference between the left and right thoraxes/the average of the left and right thoraxes. That new index also significantly improved. SCE is considered a highly useful surgical method for asymmetric PE.

Peptide translocation across asymmetric phospholipid membranes

The transport of molecules across cell membranes is vital for proper cell function and effective drug delivery. While most cell membranes naturally possess an asymmetric lipid composition, research on membrane transport predominantly uses symmetric lipid membranes. The permeation through the asymmetric membrane is then calculated as a sum of the inverse permeabilities of leaflets from symmetric bilayers. In this study, we examined how two types of amphiphilic molecules translocate across both asymmetric and symmetric membranes. Using computer simulations with both coarse-grained and atomistic force fields, we calculated the free energy profiles for the passage of model amphiphilic peptides and a lipid across various membranes. Our results consistently demonstrate that while the free energy profiles for asymmetric membranes with a small differential stress concur with symmetric ones in the region of lipid headgroups, the profiles differ around the center of the membrane. In this region, the free energy for the asymmetric membrane transitions between the profiles for two symmetric membranes. In addition, we show that peptide permeability through an asymmetric membrane cannot always be predicted from the permeabilities of the symmetric membranes. This indicates that using symmetric membranes falls short in providing an accurate depiction of peptide translocation across asymmetric membranes.

Analysis of Coil Systems with Non-Symmetrical Fe Backings for Electrical Vehicle Wireless Charging Applications

Wireless power transfer is a widely applied technology whose market and application areas are growing rapidly. It is considered to be a promising supplement to the conductive charging of electrical vehicles (EVs). Wireless charging provides safety, convenience, and reliability in terms of mitigating issues related to wiring, risk of tearing, trip hazards, and contact wear inherent to the conductive charging. A variety of coil structures have been researched for EV charging applications; however, most of them were of the symmetrical type. This work analyzes systems of coils possessing ferromagnetic backing with non-symmetrical geometries and compares them with the conventional symmetrical ones. Numerical FEM simulation was applied in the research. The numerical models were verified analytically and experimentally. The impact of air-gap length, longitudinal displacement, number of turns, and width of the ferrite bars on coupling factor was investigated. The results suggest that coil systems with non-symmetrical structures of ferromagnetic backings are a good alternative to the conventional symmetrical structures for wireless electrical vehicle charging applications.

Simulating asymmetric membranes using P21 periodic boundary conditions.

Molecular dynamics (MD) simulations of symmetric lipid bilayers are now well established, while those of asymmetric ones are considerably less developed. This disjunction arises in part because the surface tensions of leaflets in asymmetric bilayers can differ (unlike those of symmetric ones), and there is no simple way to determine them without assumptions. This chapter describes the use of P21 periodic boundary conditions (PBC), which allow lipids to switch leaflets, to generate asymmetric bilayers under the assumption of equal chemical potentials of lipids in opposing leaflets. A series of examples, ranging from bilayers with one lipid type to those with peptides and proteins, provides a guide for the use of P21 PBC. Critical properties of asymmetric membranes, such as spontaneous curvature, are highly sensitive to differences in the leaflet surface tensions (or differential stress), and equilibration with P21 PBC substantially reduces differential stress of asymmetric bilayers assembled with surface area-based methods. Limitations of the method are discussed. Technically, the nonstandard unit cell is difficult to parallelize and to incorporate restraints. Inherently, the assumption of equal chemical potentials, and therefore the method itself, is not applicable to all target systems. Despite these limitations, it is argued that P21 simulations should be considered when designing equilibration protocols for MD studies of most asymmetric membranes.

Cobalt-catalyzed dithiolation of unactivated alkenes with thiols: facile access to diverse vicinal dithioethers.

Direct dithiolation of alkenes with thiols has been rarely reported. Herein, a simple cobalt-catalyzed aerobic approach has been developed to realize this transformation. With the aid of HFIP, diverse vicinal dithioethers including symmetric and unsymmetric ones could be obtained from readily available substrates. Gram-scale synthesis and late-stage modification of complex molecules highlight the practicability of this approach.

Экспериментальное исследование осциллирующего течения в трубном пучке

Oscillating reciprocating flows are found in a variety of engineering applications. The mechanisms of oscillating flows have not been sufficiently studied. Oscillating flows can be created artificially to increase heat transfer equipment by intensifying heat transfer. Thus, this paper studies the flow and heat transfer characteristics of a tube bundle under the influence of oscillating flow. The assessment of heat transfer and the hydrodynamic flow pattern in a tube bundle during flow oscillations is carried out on the basis of experimental studies. Flow oscillations have been created by a pneumatic system that drove a pulsator. The time characteristic of the pressure drop of the tube bundle has been recorded using an oscilloscope and pressure drop sensors. To assess the dynamics of flow velocity, the high-speed shooting method is used. The heat exchange of a tube bundle has been determined by the electrical power expended to maintain a constant temperature on the tube side of the bundle. For the first time, heat transfer and the hydrodynamic flow pattern with asymmetrical flow oscillations in an inline tube bundle are studied experimentally. It is shown that the shape of oscillations of flow velocity and pressure drop depend on frequency. It has been found that with increasing frequency there is an increase in the values of flow velocity and pressure drop. It has been determined that for certain moments of time, the flow velocity and pressure drop during asymmetrical oscillations exceed symmetrical ones. It has been established that the heat transfer rate of a bundle increases by 1,7 times with an increase in frequency. It has been shown that asymmetrical oscillations are more effective in intensifying heat transfer than symmetrical ones by an average of 1,1 times. Analysis of the results obtained has showed the possibility of intensifying heat transfer in a tube bundle using oscillating flows. Thus, oscillating flows can be used to increase the efficiency of heat exchange equipment. The results obtained on the hydrodynamic flow pattern can be used in mathematical modeling of oscillating flows, which are necessary to expand the operating parameters of the study and determine the most effective ones.

Theoretical model of random freight flow distribution in the conveyor transport line of the coal mine

Purpose. Increasing the efficiency of the conveyor transport system of the mine due to the application of rational parameters, which are calculated objectively on the basis of the reliable output data of random freight flow in the conveyor transport line, taking into account the velocity of minerals transportation, including a perfect theoretical model application of the freight flow distribution. Methodology. Complex research: - statistical studies on the actual distribution of random freight flow in the highly productive stages of the PSU Mine “n.a Heroiv Kosmosu” PJSC “DTEK Pavlohradvuhillia”; - description of histograms of the distribution of random freight flow by various indicative algebraic functions, normal and gamma distribution of a random variable and a specially constructed function with separately defined parameters of its branches; - analysis of research results regarding the correctness of the theoretical model of the distribution of random freight flow according to various criteria of genuineness, a center of grouping, amplitude, velocity of rise and fall, and deviation. Findings. A perfect theoretical model was built in the form of an indicative algebraic function, whose branches are described by the normal distribution law of a random variable with separately determined parameters. It describes well the distribution of random freight flow in the conveyor transport line of the mine and ensures the determination of its parameters by the methods of probability theory. Originality. A theoretical model of the distribution of random freight flow in the conveyor transport line of the mine has been obtained for the first time, which describes well various cases of its distribution, including symmetric and asymmetric ones, and provides the determination of the freight flow parameters by the methods of probability theory. Practical value. The actual value of the coefficient of nonuniformity of the freight flow in the conveyor transport line of the mine, which was determined by a perfect theoretical model, exceeds, by almost a quarter, the value inherent in the model accepted in practice, the normal law of the distribution of a random variable. The coefficient of nonuniformity of the freight flow in the highly productive longwalls of only the specified mine reaches a value of 2.012, which already exceeds the normative value limit for conveyor transport lines along horizontal and inclined preparatory workings of mining areas (2.0). Reliable initial data on the variation of the random freight flow in the conveyor transport line of the mine, which is substantiated by a perfect theoretical model of its distribution, have a positive effect on the calculation of its parameters and contribute to increasing the efficiency and reliability of the functioning of the conveyor transport system.

Experimental investigation on low-velocity impact behavior of glass, Kevlar, and hybrid composites with an elastomeric polyurethane matrix

Low-velocity impacts represent a critical dynamic condition for engineering structures. Combining two reinforcing fibers in a single matrix, i.e., hybridization, is considered a feasible way to improve composite performance. In this context, this paper presents an experimental work on composites with Kevlar and glass fabrics and a novel thermoset polyurethane matrix. The coupons are manufactured by vacuum infusion technique and low-velocity impact tests are carried out. First, the impact behavior of Kevlar and glass laminates of different thicknesses is assessed, and then impact tests are performed on different configurations of hybrid laminates, both symmetric and non-symmetric. For the non-symmetric specimens, impact tests were conducted on both sides of the stack. Load vs displacement curves are reported along with absorbed energy. To investigate the damage mechanism, the front, back, and cross-section views of the specimens are analyzed, and features related to the stacking sequences are discussed. Thermographic analyses are carried out on the impacted specimens to further analyze damage. The failure mechanisms are different from traditional epoxy composites and a hybridization effect is reported. The results evidence that the hybrid coupons are viable for structural applications, being capable of absorbing high-impact energies, in particular, non-symmetric hybrid laminates outperformed the Kevlar, glass, and symmetric ones, absorbing roughly 15% less energy for the highest energy impact.