The European Physical Journal E最新文献_第7页

Optimal escapes in active matter 活性物质中的最佳逃逸

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-28 DOI: 10.1140/epje/s10189-023-00402-7

Luca Angelani

引用次数: 0

Vesicle condensation induced by synapsin: condensate size, geometry, and vesicle shape deformations 突触素诱导的囊泡凝聚：凝聚物的大小、几何形状和囊泡形状变形。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-25 DOI: 10.1140/epje/s10189-023-00404-5

Jette Alfken, Charlotte Neuhaus, András Major, Alyona Taskina, Christian Hoffmann, Marcelo Ganzella, Arsen Petrovic, David Zwicker, Rubén Fernández-Busnadiego, Reinhard Jahn, Dragomir Milovanovic, Tim Salditt

{"title":"Vesicle condensation induced by synapsin: condensate size, geometry, and vesicle shape deformations","authors":"Jette Alfken, Charlotte Neuhaus, András Major, Alyona Taskina, Christian Hoffmann, Marcelo Ganzella, Arsen Petrovic, David Zwicker, Rubén Fernández-Busnadiego, Reinhard Jahn, Dragomir Milovanovic, Tim Salditt","doi":"10.1140/epje/s10189-023-00404-5","DOIUrl":"10.1140/epje/s10189-023-00404-5","url":null,"abstract":"We study the formation of vesicle condensates induced by the protein synapsin, as a cell-free model system mimicking vesicle pool formation in the synapse. The system can be considered as an example of liquid–liquid phase separation (LLPS) in biomolecular fluids, where one phase is a complex fluid itself consisting of vesicles and a protein network. We address the pertinent question why the LLPS is self-limiting and stops at a certain size, i.e., why macroscopic phase separation is prevented. Using fluorescence light microscopy, we observe different morphologies of the condensates (aggregates) depending on the protein-to-lipid ratio. Cryogenic electron microscopy then allows us to resolve individual vesicle positions and shapes in a condensate and notably the size and geometry of adhesion zones between vesicles. We hypothesize that the membrane tension induced by already formed adhesion zones then in turn limits the capability of vesicles to bind additional vesicles, resulting in a finite condensate size. In a simple numerical toy model we show that this effect can be accounted for by redistribution of effective binding particles on the vesicle surface, accounting for the synapsin-induced adhesion zone.","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11233366/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139545048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detachment forces during parallel-plate gap separation mediated by a simple yield-stress fluid 由简单屈服应力流体介导的平行板间隙分离过程中的脱离力。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-23 DOI: 10.1140/epje/s10189-023-00397-1

Vítor Hugo de Oliveira Pereira, Wilson Barros Jr.

引用次数: 0

Scaling regimes for wormlike chains confined to cylindrical surfaces under tension 局限于圆柱表面的蠕虫链在张力作用下的缩放机制。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-22 DOI: 10.1140/epje/s10189-023-00384-6

Greg Morrison, D. Thirumalai

引用次数: 0

Correction: Convective mixing in porous media: a review of Darcy, pore-scale and Hele-Shaw studies 更正：多孔介质中的对流混合：达西、孔隙尺度和赫勒-肖研究综述。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-11 DOI: 10.1140/epje/s10189-023-00401-8

Marco De Paoli

引用次数: 0

Ions and dipoles in electric field: nonlinear polarization and field-dependent chemical reaction 电场中的离子和偶极子：非线性极化和随电场变化的化学反应。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-11 DOI: 10.1140/epje/s10189-023-00398-0

Akira Onuki

引用次数: 0

Physical insights into biological memory using phospholipid membranes 利用磷脂膜对生物记忆的物理洞察。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-11 DOI: 10.1140/epje/s10189-023-00391-7

Dima Bolmatov, C. Patrick Collier, John Katsaras, Maxim O. Lavrentovich

引用次数: 0

Multispherical shapes of vesicles with intramembrane domains 具有膜内结构域的多球形囊泡。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-11 DOI: 10.1140/epje/s10189-023-00399-z

Reinhard Lipowsky

{"title":"Multispherical shapes of vesicles with intramembrane domains","authors":"Reinhard Lipowsky","doi":"10.1140/epje/s10189-023-00399-z","DOIUrl":"10.1140/epje/s10189-023-00399-z","url":null,"abstract":"Phase separation of biomembranes into two fluid phases, a and b, leads to the formation of vesicles with intramembrane a- and b-domains. These vesicles can attain multispherical shapes consisting of several spheres connected by closed membrane necks. Here, we study the morphological complexity of these multispheres using the theory of curvature elasticity. Vesicles with two domains form two-sphere shapes, consisting of one a- and one b-sphere, connected by a closed ab-neck. The necks’ effective mean curvature is used to distinguish positive from negative necks. Two-sphere shapes of two-domain vesicles can attain four different morphologies that are governed by two different stability conditions. The closed ab-necks are compressed by constriction forces which induce neck fission and vesicle division for large line tensions and/or large spontaneous curvatures. Multispherical shapes with one ab-neck and additional aa- and bb-necks involve several stability conditions, which act to reduce the stability regimes of the multispheres. Furthermore, vesicles with more than two domains form multispheres with more than one ab-neck. The multispherical shapes described here represent generalized constant-mean-curvature surfaces with up to four constant mean curvatures. These shapes are accessible to experimental studies using available methods for giant vesicles prepared from ternary lipid mixtures.","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-023-00399-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139416061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A continuum mechanics model of the plant cell wall reveals interplay between enzyme action and cell wall structure 植物细胞壁连续介质力学模型揭示了酶作用与细胞壁结构之间的相互作用。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-01-06 DOI: 10.1140/epje/s10189-023-00396-2

Euan T. Smithers, Jingxi Luo, Rosemary J. Dyson

{"title":"A continuum mechanics model of the plant cell wall reveals interplay between enzyme action and cell wall structure","authors":"Euan T. Smithers, Jingxi Luo, Rosemary J. Dyson","doi":"10.1140/epje/s10189-023-00396-2","DOIUrl":"10.1140/epje/s10189-023-00396-2","url":null,"abstract":"Plant cell growth is regulated through manipulation of the cell wall network, which consists of oriented cellulose microfibrils embedded within a ground matrix incorporating pectin and hemicellulose components. There remain many unknowns as to how this manipulation occurs. Experiments have shown that cellulose reorients in cell walls as the cell expands, while recent data suggest that growth is controlled by distinct collections of hemicellulose called biomechanical hotspots, which join the cellulose molecule together. The enzymes expansin and Cel12A have both been shown to induce growth of the cell wall; however, while Cel12A’s wall-loosening action leads to a reduction in the cell wall strength, expansin’s has been shown to increase the strength of the cell wall. In contrast, members of the XTH enzyme family hydrolyse hemicellulose but do not appear to cause wall creep. This experimentally observed behaviour still awaits a full explanation. We derive and analyse a mathematical model for the effective mechanical properties of the evolving cell wall network, incorporating cellulose microfibrils, which reorient with cell growth and are linked via biomechanical hotspots made up of regions of crosslinking hemicellulose. Assuming a visco-elastic response for the cell wall and using a continuum approach, we calculate the total stress resultant of the cell wall for a given overall growth rate. By changing appropriate parameters affecting breakage rate and viscous properties, we provide evidence for the biomechanical hotspot hypothesis and develop mechanistic understanding of the growth-inducing enzymes.","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-023-00396-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139110591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Motility and swimming: universal description and generic trajectories 运动和游泳：通用描述和通用轨迹。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2023-12-26 DOI: 10.1140/epje/s10189-023-00395-3

Alexander Farutin, Suhail M. Rizvi, Wei-Fan Hu, Te-Sheng Lin, Salima Rafai, Chaouqi Misbah

{"title":"Motility and swimming: universal description and generic trajectories","authors":"Alexander Farutin, Suhail M. Rizvi, Wei-Fan Hu, Te-Sheng Lin, Salima Rafai, Chaouqi Misbah","doi":"10.1140/epje/s10189-023-00395-3","DOIUrl":"10.1140/epje/s10189-023-00395-3","url":null,"abstract":"Autonomous locomotion is a ubiquitous phenomenon in biology and in physics of active systems at microscopic scale. This includes prokaryotic, eukaryotic cells (crawling and swimming) and artificial swimmers. An outstanding feature is the ability of these entities to follow complex trajectories, ranging from straight, curved (circular, helical...), to random-like ones. The non-straight nature of these trajectories is often explained as a consequence of the asymmetry of the particle or the medium in which it moves, or due to the presence of bounding walls, etc... Here, we show that for a particle driven by a concentration field of an active species, straight, circular and helical trajectories emerge naturally in the absence of asymmetry of the particle or that of suspending medium. Our proof is based on general considerations, without referring to an explicit form of a model. We show that these three trajectories correspond to self-congruent solutions. Self-congruency means that the states of the system at different moments of time can be made identical by an appropriate combination of rotation and translation of the coordinate space. We show that these solutions are exhibited by spherically symmetric particles as a result of a series of pitchfork bifurcations, leading to spontaneous symmetry breaking in the concentration field driving the particle motility. Self-congruent dynamics in one and two dimensions are analyzed as well. Finally, we present a simple explicit nonlinear exactly solvable model of fully isotropic phoretic particle that shows the transitions from a non-motile state to straight motion to circular motion to helical motion as a series of spontaneous symmetry-breaking bifurcations. Whether a system exhibits or not a given trajectory only depends on the numerical values of parameters entering the model, while asymmetry of swimmer shape, or anisotropy of the suspending medium, or influence of bounding walls are not necessary.","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139037280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0