Caldwelllundsgaard0452

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These results highlighted that our LPNVPnt system could pave the way for the development of an elaborate drug delivery technology for ER-targeting at the intracellular level.Autonomous active, elastic filaments that interact with each other to achieve cooperation and synchrony underlie many critical functions in biology. The mechanisms underlying this collective response and the essential ingredients for stable synchronization remain a mystery. Inspired by how these biological entities integrate elasticity with molecular motor activity to generate sustained oscillations, a number of synthetic active filament systems have been developed that mimic oscillations of these biological active filaments. Here, we describe the collective dynamics and stable spatiotemporal patterns that emerge in such biomimetic multi-filament arrays, under conditions where steric interactions may impact or dominate the collective dynamics. To focus on the role of steric interactions, we study the system using Brownian dynamics, without considering long-ranged hydrodynamic interactions. check details The simulations treat each filament as a connected chain of self-propelling colloids. We demonstrate that short-range steuck and jammed configurations. Taken together, simulations suggest that short-ranged steric inter-filament interactions could combine with complementary hydrodynamic interactions to control the development and regulation of oscillatory collective patterns. Furthermore, roughness and steric interactions may be critical to the development of jammed spatially periodic states; a spatiotemporal feature not observed in purely hydrodynamically interacting systems.The bare-nosed wombat (Vombatus ursinus) is a fossorial, herbivorous, Australian marsupial, renowned for its cubic feces. However, the ability of the wombat's soft intestine to sculpt flat faces and sharp corners in feces is poorly understood. In this combined experimental and numerical study, we show one mechanism for the formation of corners in a highly damped environment. Wombat dissections show that cubes are formed within the last 17 percent of the intestine. Using histology and tensile testing, we discover that the cross-section of the intestine exhibits regions with a two-fold increase in thickness and a four-fold increase in stiffness, which we hypothesize facilitates the formation of corners by contractions of the intestine. Using a mathematical model, we simulate a series of azimuthal contractions of a damped elastic ring composed of alternating stiff and soft regions. Increased stiffness ratio and higher Reynolds number yield shapes that are more square. The corners arise from faster contraction in the stiff regions and relatively slower movement in the center of the soft regions. These results may have applications in manufacturing, clinical pathology, and digestive health.Precise control over the motion of magnetically responsive particles in fluidic chambers is important for probing and manipulating tasks in prospective microrobotic and bio-analytical platforms. We have previously exploited such colloids as shuttles for the microscale manipulation of objects. Here, we study the rolling motion of magnetically driven Janus colloids on solid substrates under the influence of an orthogonal external electric field. Electrically induced attractive interactions were used to tune the load on the Janus colloid and thereby the friction with the underlying substrate, leading to control over the forward velocity of the particle. Our experimental data suggest that the frictional coupling required to achieve translation, transitions from a hydrodynamic regime to one of mixed contact coupling with increasing load force. Based on this insight, we show that our colloidal microrobots can probe the local friction coefficient of various solid surfaces, which makes them potentially useful as tribological microsensors. Lastly, we precisely manipulate porous cargos using our colloidal rollers, a feat that holds promise for bio-analytical applications.The prototype phonon-liquid electron-crystal β-Cu2Se has been ranked among the best thermoelectric material with its ultralow lattice thermal conductivity (κL). The atomic fluidity, harmonic approximation failure, and the existence of a large number of imaginary phonon modes hinder the atomistic analysis of phonon transport in β-Cu2Se. Thus, the atomistic origins of its ultralow κL remain elusive. In this study, we present a self-consistent phonon (SCPH) calculation of the lattice dynamical properties of β-Cu2Se by including quartic anharmonicity and stiffening imaginary phonon modes in the anharmonic phonon dispersion, aiming to unravel the atomistic origins of ultralow κL. Upon renormalizing harmonic phonon dispersion with quartic anharmonicity, those imaginary phonon modes arising from copper fluidity diminish as temperature increases and anharmonic phonon dispersions are obtained. By solving the Boltzmann transport equation within the relaxation time approximation (BTE-RTA), we predicted ultralow κL which demonstrated an overall agreement with previous experiments. After analyzing the harmonic as well as anharmonic phonon density of states, it was found that the inclusion of quartic anharmonicity induces the suppression of low-lying phonon modes, which coincides with the experimental observation of the selective breakdown of long-wave transverse acoustic phonons. However, for the propagative heat-carriers, the anharmonic scattering enhances and phonon relaxation lifetime decreases as temperature increases, leading to a further reduction of κL. This study provides an extra insight into the atomistic origins of ultralow κL in β-Cu2Se from first-principles anharmonic force constants and helps engineer the lattice dynamical properties for better thermoelectric performance.Monolayer C2N is promising for next-generation electronic and optoelectronic applications due to its appropriate band gap and high carrier efficiency. However, relative studies have been held back due to the lack of high-quality electrode contacts. Here, we comprehensively study the electronic and transport properties of monolayer C2N with a series of electrode materials (Al, Ti, Ni, Cu, Ag, Pt, V2C, Cr2C and graphene) by using the nonequilibrium Green's function (NEGF) method combined with density functional theory (DFT). The monolayer C2N forms Ohmic contacts with the Ti/Cu/Ag electrode material in both armchair and zigzag directions, whereas Ohmic contact is only formed in the zigzag direction of the C2N-Al field effect transistor. However, the C2N-Ni, -Pt, -V2C, -Mo2C, -graphene contact systems form n-type Schottky contacts in either the armchair or zigzag direction owing to the relatively strong Fermi level pinning (the pinning factor S = 0.32 in the armchair direction and S = 0.26 in the zigzag direction).