An active system consisting of many self-spinning dimers is simulated, and a distinct local rotational jamming transition is observed as the density increases. In the low density regime, the system stays in an absorbi...An active system consisting of many self-spinning dimers is simulated, and a distinct local rotational jamming transition is observed as the density increases. In the low density regime, the system stays in an absorbing state,in which each dimer rotates independently subject to the applied torque;while in the high density regime,a fraction of the dimers become rotationally jammed into local clusters, and the system exhibits microphaseseparation like two-phase morphologies. For high enough densities, the system becomes completely jammed in both rotational and translational degrees of freedom. Such a simple system is found to exhibit rich and multiscale disordered hyperuniformities among the above phases: the absorbing state shows a critical hyperuniformity of the strongest class and subcritically preserves the vanishing density fluctuation scaling up to some length scale;the locally jammed state shows a two-phase hyperuniformity conversely beyond some length scale with respect to the phase cluster sizes;the totally jammed state appears to be a monomer crystal, but intrinsically loses large-scale hyperuniformity. These results are inspiring for designing novel phase-separation and disordered hyperuniform systems through dynamical organization.展开更多
We quantify the mean potential energy of a passive colloidal particle harmonically confined in a bacterial solution using optical traps.We find that the average potential energy of the passive particle depends on the ...We quantify the mean potential energy of a passive colloidal particle harmonically confined in a bacterial solution using optical traps.We find that the average potential energy of the passive particle depends on the trap stiffness,in contrast to the equilibrium case where energy partition is independent of the external constraints.The constraint dependence of the mean potential energy originates from the fact that the persistent collisions between the passive particle and the active bacteria are influenced by the particle relaxation dynamics.Our experimental results are consistent with the Brownian dynamics simulations,and confirm the recent theoretical prediction.展开更多
Using colloidal particles with different thermosensitivities,we observe the transition from a crystalline solid to a dis-ordered glass by tuning the size mismatch of the constituent particles in quasi-two-dimensional c...Using colloidal particles with different thermosensitivities,we observe the transition from a crystalline solid to a dis-ordered glass by tuning the size mismatch of the constituent particles in quasi-two-dimensional configurations.The transition is clearly identifiable by the correlation functions of the orientational order parameters and its susceptibilities.Different from typical order-to-disorder transitions such as melting,where the underlying mechanism involves the diffusion of defects,the disordered phase in the crystal-to-glass transition grows via a nucleation process.The disordered clusters grow in size as the particle mismatch increases,and eventually percolate the whole system,which signifies the qualitative change from an ordered crystal to a disordered glass.展开更多
The interaction between cell surface receptors and extracellular ligands is highly related to many physiological processes in living systems.Many techniques have been developed to measure the ligand-receptor binding k...The interaction between cell surface receptors and extracellular ligands is highly related to many physiological processes in living systems.Many techniques have been developed to measure the ligand-receptor binding kinetics at the single-cell level.However,few techniques can measure the physiologically relevant shear binding affinity over a single cell in the clinical environment.Here,we develop a new optical technique,termed single-cell rotational adhesion frequency assay(scRAFA),that mimics in vivo cell adhesion to achieve label-free determination of both homogeneous and heterogeneous binding kinetics of targeted cells at the subcellular level.Moreover,the scRAFA is also applicable to analyze the binding affinities on a single cell in native human biofluids.With its superior performance and general applicability,scRAFA is expected to find applications in study of the spatial organization of cell surface receptors and diagnosis of infectious diseases.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11774393, 11404378, 12274448, 22272040, and T2325027)Youth Innovation Promotion Association of CAS (Grant No. 2017014)the National Key R&D Program of China (Grant Nos. 2022YFF0503504 and 2022YFA1203200)。
文摘An active system consisting of many self-spinning dimers is simulated, and a distinct local rotational jamming transition is observed as the density increases. In the low density regime, the system stays in an absorbing state,in which each dimer rotates independently subject to the applied torque;while in the high density regime,a fraction of the dimers become rotationally jammed into local clusters, and the system exhibits microphaseseparation like two-phase morphologies. For high enough densities, the system becomes completely jammed in both rotational and translational degrees of freedom. Such a simple system is found to exhibit rich and multiscale disordered hyperuniformities among the above phases: the absorbing state shows a critical hyperuniformity of the strongest class and subcritically preserves the vanishing density fluctuation scaling up to some length scale;the locally jammed state shows a two-phase hyperuniformity conversely beyond some length scale with respect to the phase cluster sizes;the totally jammed state appears to be a monomer crystal, but intrinsically loses large-scale hyperuniformity. These results are inspiring for designing novel phase-separation and disordered hyperuniform systems through dynamical organization.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874397,11674365,11774393,and 11774394).
文摘We quantify the mean potential energy of a passive colloidal particle harmonically confined in a bacterial solution using optical traps.We find that the average potential energy of the passive particle depends on the trap stiffness,in contrast to the equilibrium case where energy partition is independent of the external constraints.The constraint dependence of the mean potential energy originates from the fact that the persistent collisions between the passive particle and the active bacteria are influenced by the particle relaxation dynamics.Our experimental results are consistent with the Brownian dynamics simulations,and confirm the recent theoretical prediction.
基金supported by the National Natural Science Foundation of China(11874395 and 12174434)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB3300000).|。
文摘Using colloidal particles with different thermosensitivities,we observe the transition from a crystalline solid to a dis-ordered glass by tuning the size mismatch of the constituent particles in quasi-two-dimensional configurations.The transition is clearly identifiable by the correlation functions of the orientational order parameters and its susceptibilities.Different from typical order-to-disorder transitions such as melting,where the underlying mechanism involves the diffusion of defects,the disordered phase in the crystal-to-glass transition grows via a nucleation process.The disordered clusters grow in size as the particle mismatch increases,and eventually percolate the whole system,which signifies the qualitative change from an ordered crystal to a disordered glass.
基金Y.L.,H.D.,J.L.and Y.Z.acknowledge the financial support of National Institute of General Medical Sciences of the National Institutes of Health.(DP2GM128446)National Science Foundation(ECCS-2001650)X.L.,M.Y.acknowledge the financial support of National Natural Science Foundation of China(No.11874397).
文摘The interaction between cell surface receptors and extracellular ligands is highly related to many physiological processes in living systems.Many techniques have been developed to measure the ligand-receptor binding kinetics at the single-cell level.However,few techniques can measure the physiologically relevant shear binding affinity over a single cell in the clinical environment.Here,we develop a new optical technique,termed single-cell rotational adhesion frequency assay(scRAFA),that mimics in vivo cell adhesion to achieve label-free determination of both homogeneous and heterogeneous binding kinetics of targeted cells at the subcellular level.Moreover,the scRAFA is also applicable to analyze the binding affinities on a single cell in native human biofluids.With its superior performance and general applicability,scRAFA is expected to find applications in study of the spatial organization of cell surface receptors and diagnosis of infectious diseases.
