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Harris DH, Torres-Díaz I. Directed assembly of small binary clusters of magnetizable ellipsoids. SOFT MATTER 2024; 20:6411-6423. [PMID: 39083371 DOI: 10.1039/d4sm00300d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2024]
Abstract
We report the effect of shape anisotropy and material properties on the directed assembly of binary suspensions composed of magnetizable ellipsoids. In a Monte Carlo simulation, we implement the ellipsoid-dipole model to calculate the pairwise dipolar interaction energy as a function of position and orientation. The analysis explores dilute suspensions of paramagnetic and diamagnetic ellipsoids with different aspect ratios in a superparamagnetic medium. We analyze the local order of binary structures as a function of particle aspect ratio, medium permeability, and dipolar interaction strength. Our results show that local order and symmetry are tunable under the influence of a uniform magnetic field when one component of the structure is dilute with respect to the other. The simulation results match previously reported experiments on the directed assembly of binary suspension of spheres. Additionally, we report the conditions on particle aspect ratios and medium properties for various structures with rotational symmetries, as well as open and enclosed structures under the influence of a uniform magnetic field.
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Affiliation(s)
- David H Harris
- Department of Chemical and Materials Engineering, The University of Alabama in Huntsville, Huntsville, AL 35899, USA.
| | - Isaac Torres-Díaz
- Department of Chemical and Materials Engineering, The University of Alabama in Huntsville, Huntsville, AL 35899, USA.
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2
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Sun Y, Wang C, Yang J, Shi W, Pang Q, Wang Y, Li J, Hu B, Xia C. Evident structural anisotropies arising from near-zero particle asphericity in granular spherocylinder packings. Phys Rev E 2024; 110:014903. [PMID: 39161035 DOI: 10.1103/physreve.110.014903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 07/02/2024] [Indexed: 08/21/2024]
Abstract
With magnetic resonance imaging experiments, we study packings of granular spherocylinders with merely 2% asphericity. Evident structural anisotropies across all length scales are identified. Most interestingly, the global nematic order decreases with increasing packing fraction, while the local contact anisotropy shows an opposing trend. We attribute this counterintuitive phenomenon to a competition between gravity-driven ordering aided by frictional contacts and a geometric frustration effect at the marginally jammed state. It is also surprising to notice that such slight particle asphericity can trigger non-negligible correlations between contact-level and mesoscale structures, manifested in drastically different nonaffine structural rearrangements upon compaction from that of granular spheres. These observations can help improve statistical mechanical models for the orientational order transformation of nonspherical granular particle packings, which involves complex interplays between particle shape, frictional contacts, and external force field.
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Affiliation(s)
| | | | | | | | | | - Yujie Wang
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, China
- Department of Physics, College of Mathematics and Physics, Chengdu University of Technology, Chengdu 610059, China
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de Anda J, Kuchma SL, Webster SS, Boromand A, Lewis KA, Lee CK, Contreras M, Medeiros Pereira VF, Schmidt W, Hogan DA, O’Hern CS, O’Toole GA, Wong GCL. How P. aeruginosa cells with diverse stator composition collectively swarm. mBio 2024; 15:e0332223. [PMID: 38426789 PMCID: PMC11005332 DOI: 10.1128/mbio.03322-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 12/20/2023] [Indexed: 03/02/2024] Open
Abstract
Swarming is a macroscopic phenomenon in which surface bacteria organize into a motile population. The flagellar motor that drives swarming in Pseudomonas aeruginosa is powered by stators MotAB and MotCD. Deletion of the MotCD stator eliminates swarming, whereas deletion of the MotAB stator enhances swarming. Interestingly, we measured a strongly asymmetric stator availability in the wild-type (WT) strain, with MotAB stators produced at an approximately 40-fold higher level than MotCD stators. However, utilization of MotCD stators in free swimming cells requires higher liquid viscosities, while MotAB stators are readily utilized at low viscosities. Importantly, we find that cells with MotCD stators are ~10× more likely to have an active motor compared to cells uses the MotAB stators. The spectrum of motility intermittency can either cooperatively shut down or promote flagellum motility in WT populations. In P. aeruginosa, transition from a static solid-like biofilm to a dynamic liquid-like swarm is not achieved at a single critical value of flagellum torque or stator fraction but is collectively controlled by diverse combinations of flagellum activities and motor intermittencies via dynamic stator utilization. Experimental and computational results indicate that the initiation or arrest of flagellum-driven swarming motility does not occur from individual fitness or motility performance but rather related to concepts from the "jamming transition" in active granular matter.IMPORTANCEIt is now known that there exist multifactorial influences on swarming motility for P. aeruginosa, but it is not clear precisely why stator selection in the flagellum motor is so important. We show differential production and utilization of the stators. Moreover, we find the unanticipated result that the two motor configurations have significantly different motor intermittencies: the fraction of flagellum-active cells in a population on average with MotCD is active ~10× more often than with MotAB. What emerges from this complex landscape of stator utilization and resultant motor output is an intrinsically heterogeneous population of motile cells. We show how consequences of stator recruitment led to swarming motility and how the stators potentially relate to surface sensing circuitry.
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Affiliation(s)
- Jaime de Anda
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, California, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, California, USA
| | - Sherry L. Kuchma
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Shanice S. Webster
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Arman Boromand
- Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut, USA
| | - Kimberley A. Lewis
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Calvin K. Lee
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, California, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, California, USA
| | - Maria Contreras
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, California, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, California, USA
| | | | - William Schmidt
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, California, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, California, USA
| | - Deborah A. Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Corey S. O’Hern
- Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut, USA
| | - George A. O’Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Gerard C. L. Wong
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, California, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, California, USA
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4
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Xie Z, Atherton TJ. Jamming on convex deformable surfaces. SOFT MATTER 2024; 20:1070-1078. [PMID: 38206105 DOI: 10.1039/d2sm01608g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Jamming is a fundamental transition that governs the behavior of particulate media, including sand, foams and dense suspensions. Upon compression, such media change from freely flowing to a disordered, marginally stable solid that exhibits non-Hookean elasticity. While the jamming process is well established for fixed geometries, the nature and dynamics of jamming for a diverse class of soft materials and deformable substrates, including emulsions and biological matter, remains unknown. Here we propose a new scenario, metric jamming, where rigidification occurs on a surface that has been deformed from its ground state. Unlike classical jamming processes that exhibit discrete mechanical transitions, surprisingly we find that metric jammed states possess mechanical properties continuously tunable between those of classically jammed and conventional elastic media. The compact and curved geometry significantly alters the vibrational spectra of the structures relative to jamming in flat Euclidean space, and metric jammed systems also possess new types of vibrational mode that couple particle and shape degrees of freedom. Our work provides a theoretical framework that unifies our understanding of solidification processes that take place on deformable media and lays the groundwork to exploit jamming for the control and stabilization of shape in self-assembly processes.
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Affiliation(s)
- Zhaoyu Xie
- Department of Physics & Astronomy, Tufts University, 574 Boston Ave, Medford, MA 02155, USA.
| | - Timothy J Atherton
- Department of Physics & Astronomy, Tufts University, 574 Boston Ave, Medford, MA 02155, USA.
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5
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de Anda J, Kuchma SL, Webster SS, Boromand A, Lewis KA, Lee CK, Contreras M, Pereira VFM, Hogan DA, O'Hern CS, O'Toole GA, Wong GCL. How individual P. aeruginosa cells with diverse stator distributions collectively form a heterogeneous macroscopic swarming population. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.10.536285. [PMID: 37090636 PMCID: PMC10120709 DOI: 10.1101/2023.04.10.536285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Swarming is a macroscopic phenomenon in which surface bacteria organize into a motile population. The flagellar motor that drives swarming in Pseudomonas aeruginosa is powered by stators MotAB and MotCD. Deletion of the MotCD stator eliminates swarming, whereas deletion of the MotAB stator enhances swarming. Interestingly, we measured a strongly asymmetric stator availability in the WT strain, with MotAB stators produced ∼40-fold more than MotCD stators. However, recruitment of MotCD stators in free swimming cells requires higher liquid viscosities, while MotAB stators are readily recruited at low viscosities. Importantly, we find that cells with MotCD stators are ∼10x more likely to have an active motor compared to cells without, so wild-type, WT, populations are intrinsically heterogeneous and not reducible to MotAB-dominant or MotCD-dominant behavior. The spectrum of motility intermittency can either cooperatively shut down or promote flagellum motility in WT populations. In P. aeruginosa , transition from a static solid-like biofilm to a dynamic liquid-like swarm is not achieved at a single critical value of flagellum torque or stator fraction but is collectively controlled by diverse combinations of flagellum activities and motor intermittencies via dynamic stator recruitment. Experimental and computational results indicate that the initiation or arrest of flagellum-driven swarming motility does not occur from individual fitness or motility performance but rather related to concepts from the 'jamming transition' in active granular matter. Importance After extensive study, it is now known that there exist multifactorial influences on swarming motility in P. aeruginosa , but it is not clear precisely why stator selection in the flagellum motor is so important or how this process is collectively initiated or arrested. Here, we show that for P. aeruginosa PA14, MotAB stators are produced ∼40-fold more than MotCD stators, but recruitment of MotCD over MotAB stators requires higher liquid viscosities. Moreover, we find the unanticipated result that the two motor configurations have significantly different motor intermittencies, the fraction of flagellum-active cells in a population on average, with MotCD active ∼10x more often than MotAB. What emerges from this complex landscape of stator recruitment and resultant motor output is an intrinsically heterogeneous population of motile cells. We show how consequences of stator recruitment led to swarming motility, and how they potentially relate to surface sensing circuitry.
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Huang Z, Deng W, Yuan Y, Liu L, Wang Y, Li S. Determining the equivalent packing diameter of two-dimensional shapes. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2021.11.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Wang D, Treado JD, Boromand A, Norwick B, Murrell MP, Shattuck MD, O'Hern CS. The structural, vibrational, and mechanical properties of jammed packings of deformable particles in three dimensions. SOFT MATTER 2021; 17:9901-9915. [PMID: 34697616 PMCID: PMC9118367 DOI: 10.1039/d1sm01228b] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We investigate the structural, vibrational, and mechanical properties of jammed packings of deformable particles with shape degrees of freedom in three dimensions (3D). Each 3D deformable particle is modeled as a surface-triangulated polyhedron, with spherical vertices whose positions are determined by a shape-energy function with terms that constrain the particle surface area, volume, and curvature, and prevent interparticle overlap. We show that jammed packings of deformable particles without bending energy possess low-frequency, quartic vibrational modes, whose number decreases with increasing asphericity and matches the number of missing contacts relative to the isostatic value. In contrast, jammed packings of deformable particles with non-zero bending energy are isostatic in 3D, with no quartic modes. We find that the contributions to the eigenmodes of the dynamical matrix from the shape degrees of freedom are significant over the full range of frequency and shape parameters for particles with zero bending energy. We further show that the ensemble-averaged shear modulus 〈G〉 scales with pressure P as 〈G〉 ∼ Pβ, with β ≈ 0.75 for jammed packings of deformable particles with zero bending energy. In contrast, β ≈ 0.5 for packings of deformable particles with non-zero bending energy, which matches the value for jammed packings of soft, spherical particles with fixed shape. These studies underscore the importance of incorporating particle deformability and shape change when modeling the properties of jammed soft materials.
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Affiliation(s)
- Dong Wang
- Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520, USA.
| | - John D Treado
- Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520, USA.
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut 06520, USA
| | - Arman Boromand
- Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520, USA.
| | - Blake Norwick
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Michael P Murrell
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut 06520, USA
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut 06520, USA
- Systems Biology Institute, Yale University, West Haven, Connecticut, 06516, USA
| | - Mark D Shattuck
- Benjamin Levich Institute and Physics Department, The City College of New York, New York, New York 10031, USA
| | - Corey S O'Hern
- Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520, USA.
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut 06520, USA
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
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Zhao C, Gao Q, Chen Y, Li C. Application of parametric function in construction of particle shape and discrete element simulation. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.04.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Chen Y, Yuan M, Wang Z, Zhao Y, Li J, Hu B, Xia C. Structural characterization and statistical properties of jammed soft ellipsoid packing. SOFT MATTER 2021; 17:2963-2972. [PMID: 33595009 DOI: 10.1039/d0sm01699c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The jamming transition and jammed packing structures of hydrogel soft ellipsoids are studied using magnetic resonance imaging techniques. As the packing fraction increases, the fluctuation of local free volume decreases and the fluctuation of particle deformation increases. Effective thermodynamic quantities are obtained by characterizing these fluctuations using k-gamma distributions based on an underlying statistical model for granular materials. Surprisingly, the two granular temperatures measuring the relative fluctuations of both free volume and particle deformation remain basically unchanged as the packing fraction increases. The total configurational entropy is also approximately constant for packing with different packing fractions. The significantly different behaviors of these effective thermodynamic quantities compared with hard sphere systems are further attributed to a statistically affine structural transformation of the packing structures along with particle deformations when the packing fraction changes.
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Affiliation(s)
- Yinfei Chen
- Shanghai Key Laboratory of Magnetic Resonance, Institute of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, P. R. China.
| | - Ming Yuan
- Shanghai Key Laboratory of Magnetic Resonance, Institute of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, P. R. China.
| | - Zhichao Wang
- Shanghai Key Laboratory of Magnetic Resonance, Institute of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, P. R. China.
| | - Yu Zhao
- Shanghai Key Laboratory of Magnetic Resonance, Institute of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, P. R. China.
| | - Jianqi Li
- Shanghai Key Laboratory of Magnetic Resonance, Institute of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, P. R. China.
| | - Bingwen Hu
- Shanghai Key Laboratory of Magnetic Resonance, Institute of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, P. R. China.
| | - Chengjie Xia
- Shanghai Key Laboratory of Magnetic Resonance, Institute of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, P. R. China.
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Voggenreiter M, Roller J, Geiger J, Ebner L, Zumbusch A, Meijer JM. Preparation and Tracking of Oblate Core-Shell Polymethyl-Methacrylate Ellipsoids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13087-13095. [PMID: 33085481 DOI: 10.1021/acs.langmuir.0c02597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Although single-particle level studies on prolate ellipsoidal colloids are relatively abundant, similar studies on oblate ellipsoids are rare because suitable model systems are scarcely available. Here, we present the preparation of monodisperse hard core-shell oblate ellipsoids that can be imaged and tracked in 3D with confocal laser scanning microscopy. Using a thermomechanical squeezing method, we transform spherical core-shell polymethyl-methacrylate (PMMA) particles into oblate ellipsoids. We show how the shape polydispersity as well as the aspect ratio of the obtained oblate ellipsoids can be controlled. In addition, we discuss how the core-shell geometry limits the range of aspect ratios because of the different viscoelastic properties of the cross-linked PMMA core and linear PMMA shell. We further demonstrate imaging of the core-shell oblate dispersions on a single-particle level in real space and time and the tracking of position and orientation using our recently developed tracking algorithm for anisotropic core-shell colloids. Our results thus provide the tools for the future investigation of the behavior of oblate ellipsoids, especially in dense suspensions.
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Affiliation(s)
- Markus Voggenreiter
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Jörg Roller
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - John Geiger
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Lukas Ebner
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Andreas Zumbusch
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Janne-Mieke Meijer
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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Yuan Y, Deng W, Li S. Structural universality in disordered packings with size and shape polydispersity. SOFT MATTER 2020; 16:4528-4539. [PMID: 32356543 DOI: 10.1039/d0sm00110d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We numerically investigate disordered jammed packings with both size and shape polydispersity, using frictionless superellipsoidal particles. We implement the set Voronoi tessellation technique to evaluate the local specific volume, i.e., the ratio of cell volume over particle volume, for each individual particle. We focus on the average structural properties for different types of particles binned by their sizes and shapes. We generalize the basic observation that the larger particles are locally packed more densely than the smaller ones in a polydisperse-sized packing into systems with coupled particle shape dispersity. For this purpose, we define the normalized free volume vf to measure the local compactness of a particle and study its dependency on the normalized particle size A. The definition of vf relies on the calibrated monodisperse specific volume for a certain particle shape. For packings with shape dispersity, we apply the previously introduced concept of equivalent diameter for a non-spherical particle to define A properly. We consider three systems: (A) linear superposition states of mixed-shape packings, (B) merely polydisperse-sized packings, and (C) packings with coupled size and shape polydispersity. For (A), the packing is simply considered as a mixture of different subsystems corresponding to monodisperse packings for different shape components, leading to A = 1, and vf = 1 by definition. We propose a concise model to estimate the shape-dependent factor αc, which defines the equivalent diameter for a certain particle. For (B), vf collapses as a function of A, independent of specific particle shape and size polydispersity. Such structural universality is further validated by a mean-field approximation. For (C), we find that the master curve vf(A) is preserved when particles possess similar αc in a packing. Otherwise, the dispersity of αc among different particles causes the deviation from vf(A). These findings show that a polydisperse packing can be estimated as the combination of various building blocks, i.e., bin components, with a universal relation vf(A).
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Affiliation(s)
- Ye Yuan
- Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China.
| | - Wei Deng
- Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China.
| | - Shuixiang Li
- Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China.
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