Base de dados : MEDLINE
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  1 / 22577 MEDLINE  
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[PMID]:28455252
[Au] Autor:Kwak HW; Shin M; Lee JY; Yun H; Song DW; Yang Y; Shin BS; Park YH; Lee KH
[Ad] Endereço:Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea.
[Ti] Título:Fabrication of an ultrafine fish gelatin nanofibrous web from an aqueous solution by electrospinning.
[So] Source:Int J Biol Macromol;102:1092-1103, 2017 Sep.
[Is] ISSN:1879-0003
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Electrospinning of aqueous gelatin solution obtained from bovine or porcine sources has been difficult to achieve without additional facilities, such as a temperature control oven or heating cover. Gelatin from cold-water fish has low contents of proline (Pro) and hydroxyproline (Hyp) compared with mammalian-derived gelatin. For this reason, the fish-derived gelatin maintains a sol state without showing gelation behavior at room temperature. In the present study, we prepared an ultrafine fish gelatin nanofibrous web by electrospinning from aqueous solutions without any additive polymers or temperature control facilities. The concentration and viscosity of fish gelatin are the most important factor in determining the electrospinnability and fiber diameter. Electrospinning of aqueous fish gelatin has the highest nanofiber productivity compared to other organic solvent systems. Using glutaraldehyde vapor (GTA), the water stability was improved and substantial enhancement was achieved in the mechanical properties. Finally, the cytotoxicity of a fish gelatin nanofibrous scaffold was evaluated based on a cell proliferation study by culturing human dermal fibroblasts (HDFs) compared with a fish gelatin film and nanofibrous mat from mammalian gelatin. The result shows better initial cell attachment and proliferation compared with the fish gelatin film and no significant difference compared with mammalian-derived gelatin nanofibrous mat. We expect that electrospinning of aqueous fish gelatin could be an effective alternative mammalian gelatin source.
[Mh] Termos MeSH primário: Eletricidade
Peixes
Gelatina/química
Nanofibras/química
Nanotecnologia
Água/química
[Mh] Termos MeSH secundário: Animais
Materiais Biocompatíveis/química
Materiais Biocompatíveis/farmacologia
Bovinos
Adesão Celular/efeitos dos fármacos
Proliferação Celular/efeitos dos fármacos
Fibroblastos/citologia
Fibroblastos/efeitos dos fármacos
Gelatina/farmacologia
Glutaral/química
Seres Humanos
Hidrólise
Reologia
Soluções
Viscosidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biocompatible Materials); 0 (Solutions); 059QF0KO0R (Water); 9000-70-8 (Gelatin); T3C89M417N (Glutaral)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170430
[St] Status:MEDLINE


  2 / 22577 MEDLINE  
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[PMID]:28450249
[Au] Autor:Kurt A; Toker OS; Tornuk F
[Ad] Endereço:Department of Food Engineering, Engineering Faculty, Ondokuz Mayis University, 55139, Samsun, Turkey; Department of Food Engineering, Engineering and Architecture Faculty, Bitlis Eren University, 13000 Bitlis, Turkey. Electronic address: abdullahkurt48@gmail.com.
[Ti] Título:Effect of xanthan and locust bean gum synergistic interaction on characteristics of biodegradable edible film.
[So] Source:Int J Biol Macromol;102:1035-1044, 2017 Sep.
[Is] ISSN:1879-0003
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The present study was aimed to use different combinations of xanthan (XG) and locust bean gum (LBG) in the biodegradable edible film preparation by benefitting from their synergistic interactions for the first time. Concentrations of LBG, XG and glycerol of the optimized film sample were found to be 89.6%, 10.4% and 20%, respectively. At the optimum point the WVP, TS, E% and EM values of film were found 0.22gmmh m kPa, 86.97MPa, 33.34% and 177.25MPa, respectively. The optimized film was characterized for its physical, thermal and structural behavior. The scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR) analyses exhibited miscibility and presence of interaction between polymers. In conclusion, XG and LBG interaction was used successfully to get biodegradable films and coatings with improved characteristics.
[Mh] Termos MeSH primário: Materiais Biocompatíveis/química
Galactanos/química
Mananas/química
Gomas Vegetais/química
Polissacarídeos Bacterianos/química
Embalagem de Produtos
[Mh] Termos MeSH secundário: Materiais Biocompatíveis/metabolismo
Composição de Medicamentos
Glicerol/química
Fenômenos Mecânicos
Permeabilidade
Reologia
Vapor
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biocompatible Materials); 0 (Galactans); 0 (Mannans); 0 (Plant Gums); 0 (Polysaccharides, Bacterial); 0 (Steam); PDC6A3C0OX (Glycerol); TTV12P4NEE (xanthan gum); V4716MY704 (locust bean gum)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE


  3 / 22577 MEDLINE  
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[PMID]:29318229
[Au] Autor:Gjerde N; Zhu K; Nyström B; Knudsen KD
[Ad] Endereço:Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. bo.nystrom@kjemi.uio.no.
[Ti] Título:Effect of PCL end-groups on the self-assembly process of Pluronic in aqueous media.
[So] Source:Phys Chem Chem Phys;20(4):2585-2596, 2018 Jan 24.
[Is] ISSN:1463-9084
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Understanding self-assembly of amphiphilic copolymers in aqueous solution is an important issue in many areas, e.g., in order to tailor-make carriers for drugs and genes. We have synthesized modified versions of the copolymer of type PEO-PPO-PEO (Pluronic, F127), with short (PCL(5)) or long (PCL(11)) PCL blocks at both ends. Turbidity, dynamic light scattering (DLS), small angle neutron scattering (SANS), and rheology measurements were carried out on dilute aqueous solutions of these polymers to investigate their self-assembly behavior. The DLS results clearly show that both micellization and inter-micellization can be controlled by polymer concentration, temperature, and length of the PCL block. The interplay between unimers, micelles, and clusters of micelles could be monitored and the size and size distribution of the species were determined. The SANS data could be portrayed by a spherical core-shell model at all considered conditions of temperature and concentration for F127 and PCL(5) apart from F127 at the lowest temperature measured. The SANS data for PCL(11) were described by a spherical core-shell model at low temperatures, whereas at elevated temperatures asymmetric sub-structures appeared and a cylindrical core-shell model was employed in the analysis of the data. The appearance of pronounced correlation peaks at elevated temperatures signalizes marked intermicellar interactions. The shear viscosity data revealed a minor shear thinning effect, suggesting that the interchain structures are rather stable and not easily disrupted. The work shows that PCL-modification of Pluronic has a large influence on the self-assembly process and on the final structure of the assemblies.
[Mh] Termos MeSH primário: Poloxâmero/química
Poliésteres/química
Água/química
[Mh] Termos MeSH secundário: Difusão Dinâmica da Luz
Espectroscopia de Ressonância Magnética
Nefelometria e Turbidimetria
Difração de Nêutrons
Reologia
Espalhamento a Baixo Ângulo
Resistência ao Cisalhamento
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Polyesters); 059QF0KO0R (Water); 106392-12-5 (Poloxamer); 24980-41-4 (polycaprolactone)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180226
[Lr] Data última revisão:
180226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180111
[St] Status:MEDLINE
[do] DOI:10.1039/c7cp07240f


  4 / 22577 MEDLINE  
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[PMID]:29284779
[Au] Autor:Dumanskiy YV; Stoliarova OY; Syniachenko OV; Giulmamedova MF; Potapov YA
[Ad] Endereço:Donetsk National Medical University, Lyman 84400, Ukraine.
[Ti] Título:Adsorption-rheological properties of blood serum in lung cancer patients.
[So] Source:Exp Oncol;39(4):304-307, 2017 Dec.
[Is] ISSN:1812-9269
[Cp] País de publicação:Ukraine
[La] Idioma:eng
[Ab] Resumo:The aim and objectives of the study were to investigate the state of adsorption-rheological properties of blood (ARPB) in patients with different clinical course of lung cancer (LC), the detection of violations of surface-active, viscoelastic and relaxation properties of blood serum, their association with tumor markers, the evaluation of the prognostic value of initial indexes in the development of complications from radiochemotherapy. PATIENTS AND METHODS: The study included 115 patients with LC at the age from 24 to 80 years (average age 58 years), among whom there were 78% men and 22% women. The parameters of surface (interfacial) viscosity, elasticity, viscoelasticity module, tension and relaxation of blood serum were studied by the oscillating drop method using a computer tensiometer "PAT2-Sinterface", and its volumetric viscosity was investigated using a Low-Shear-30 rotational viscometer. ARPB parameters were also studied in a control group composed from 50 healthy donors. RESULTS: Increased levels of volumetrical viscosity, surface tension, surface elasticity and the relaxation time of the blood are typical for patients with LC and depended on the localization of the tumor, its histological variant, differentiation grade, severity of the course of the disease, the number of metastases in the lymph nodes, distant organs and skeleton, involvement of the pleura and ribs, the development of compression pulmonary syndrome, metastasis into the spine, adrenals, brain, and pancreas. The surface-active, viscoelastic and relaxation properties of the blood correlated with the levels of tumor markers (TGFß1, VEGF, C-reactive protein, α -macroglobulin). CONCLUSIONS: Integral changes of ARPB observed in every fifth patient with LC are involved in the pathogenesis of the disease, have predictive value in relation to the clinical course of disease (volumetric viscosity) and the development of complications from radiochemotherapy (surface viscosity).
[Mh] Termos MeSH primário: Neoplasias Pulmonares/sangue
Soro/química
[Mh] Termos MeSH secundário: Adsorção
Adulto
Idoso
Idoso de 80 Anos ou mais
Feminino
Seres Humanos
Neoplasias Pulmonares/patologia
Masculino
Meia-Idade
Reologia
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180223
[Lr] Data última revisão:
180223
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171230
[St] Status:MEDLINE


  5 / 22577 MEDLINE  
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[PMID]:29394010
[Au] Autor:Kleinen J; Venzmer J
[Ti] Título:Streaming potential measurements to understand the rheological properties of surfactant formulations containing anionic and zwitterionic surfactant.
[So] Source:J Cosmet Sci;67(2):59-70, 2016 Mar-Apr.
[Is] ISSN:1525-7886
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Surfactant formulations are often based on an anionic primary surfactant combined with an amphoteric secondary surfactant. One popular option is the combination of lauryl ether sulfate and cocamidopropyl betaine, because such formulations are not only mild but also easy to thicken. Changes in the molecular structure of the betaine in terms of alkyl chain length distribution and headgroup structure do have dramatic effects on the viscosity of these formulations, as can be explained in terms of properties of rod-like micelles and exchange kinetics by oscillatory rheological measurements. The root cause of the effect of the different betaine derivatives on the micellar structure, however, remains unclear when considering rheology only. Although the streaming potential of colloidal objects is typically determined to forecast the stability of dispersions, we have used the streaming potential to characterize micellar solutions of different betaine surfactant structures. It could be shown that (a) the hydrophilicity of the surfactants can be nicely probed by this method and (b) there is a good correlation of these values with the rheological properties of binary mixtures of the betaines with anionic surfactant. Also, the chemical structure of the headgroups has a significant influence on both the isoelectric point and the magnitude of the streaming potential of the zwitterionic surfactants. These effects have again a dramatic influence on the interaction with anionic surfactants, as becomes obvious when looking at the rheology of such mixtures. Therefore, the findings obtained can be utilized to better understand and design surfactant formulations of a desired viscosity profile.
[Mh] Termos MeSH primário: Betaína/análogos & derivados
Polietilenoglicóis/química
Tensoativos/química
Água/química
[Mh] Termos MeSH secundário: Betaína/química
Técnicas Eletroquímicas
Interações Hidrofóbicas e Hidrofílicas
Micelas
Estrutura Molecular
Reologia
Viscosidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Micelles); 0 (Surface-Active Agents); 059QF0KO0R (Water); 26183-44-8 (dodecyl polyoxyethylene sulfuric acid); 30IQX730WE (Polyethylene Glycols); 3SCV180C9W (Betaine); 5OCF3O11KX (cocamidopropyl betaine)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180203
[St] Status:MEDLINE


  6 / 22577 MEDLINE  
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[PMID]:28468922
[Au] Autor:Herzog H; Klein B; Ziegler A
[Ad] Endereço:Institut für Zoologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany hendrik.herzog@uni-bonn.de.
[Ti] Título:Form and function of the teleost lateral line revealed using three-dimensional imaging and computational fluid dynamics.
[So] Source:J R Soc Interface;14(130), 2017 May.
[Is] ISSN:1742-5662
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Fishes sense weak water motion using the lateral line. Among the thousands of described fish species, this organ may differ in size, shape and distribution of individual mechanoreceptors or lateral line canals. The reasons for this diversity remain unclear, but are very likely related to habitat preferences. To better understand the performance of the organ in natural hydrodynamic surroundings, various three-dimensional imaging datasets of the cephalic lateral line were gathered using as representative freshwater teleost. These data are employed to simulate hydrodynamic phenomena around the head and within lateral line canals. The results show that changes in canal dimensions alter the absolute stimulation amplitudes, but have little effect on the relation between bulk water flow and higher frequency signals. By contrast, depressions in the skin known as epidermal pits reduce bulk flow stimulation and increase the ratio between higher-frequency signals and the background flow stimulus.
[Mh] Termos MeSH primário: Peixes
Imagem Tridimensional
Sistema da Linha Lateral
Modelos Biológicos
Reologia
[Mh] Termos MeSH secundário: Animais
Peixes/anatomia & histologia
Peixes/fisiologia
Sistema da Linha Lateral/anatomia & histologia
Sistema da Linha Lateral/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180220
[Lr] Data última revisão:
180220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE


  7 / 22577 MEDLINE  
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[PMID]:28470532
[Au] Autor:Dakhil H; Wierschem A
[Ad] Endereço:Institute of Fluid Mechanics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstr. 4, Erlangen, 91058, Germany.
[Ti] Título:Average Rheological Quantities of Cells in Monolayers.
[So] Source:Methods Mol Biol;1601:257-266, 2017.
[Is] ISSN:1940-6029
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Measuring rheological properties of cells in monolayers enables quantifying average cell properties in single experimental runs despite large cell-to-cell variations. Here, we describe how to modify a commercial rotational rheometer to accomplish the necessary precision for a monolayer rheometer and we delineate the steps for setting up experiments detecting average viscoelastic cell properties.
[Mh] Termos MeSH primário: Reologia/instrumentação
Análise de Célula Única/instrumentação
[Mh] Termos MeSH secundário: Adesão Celular
Células Cultivadas
Elasticidade
Fibroblastos/química
Corantes Fluorescentes/química
Células HeLa
Seres Humanos
Estresse Mecânico
Viscosidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Fluorescent Dyes)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180219
[Lr] Data última revisão:
180219
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE
[do] DOI:10.1007/978-1-4939-6960-9_20


  8 / 22577 MEDLINE  
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[PMID]:29394015
[Au] Autor:Gillece T; McMullen RL; Fares H; Senak L; Ozkan S; Foltis L
[Ti] Título:Probing the textures of composite skin care formulations using large amplitude oscillatory shear.
[So] Source:J Cosmet Sci;67(3):121-59, 2016 May-Jun.
[Is] ISSN:1525-7886
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Identifying meaningful and measurable rheological parameters that shadow the dynamic shear stresses sustained in the initial application and subsequent spreading of structured cosmetic formulations onto the skin is quite challenging. When applied to non-Newtonian soft solids, traditional oscillatory rheological testing tends to best correlate with the "at-rest" state, or, more fundamentally, with the initial and thermodynamically reversible perturbations in the physiochemical networking that binds components of the amalgamated microstructure. In addition, after yielding, as an applied film is further thinned while spreading on the skin surface, shear rates during flow processes may rapidly and dynamically increase to 104 s⁻¹ , which is a magnitude that is not practically simulated with a standard rotational rheometer. Realistically speaking, it is rare that a single rheological measurement or resultant parameter predicts the sensorial appeal of a complex fluid during the entire scope of a spreading process. Large amplitude oscillatory shear (LAOS) methodology is an augmentation of standard oscillatory rheology, or small amplitude oscillatory shear (SAOS), and delivers a means to dynamically probe the deforming microstructure of a soft solid as it rheologically transitioned from a viscoplastic material to a structured fluid. LAOS rheology was performed on four different prototypes having different skincare textures to produce Bowditch­Lissajous plots (henceforth truncated to Lissajous in the remainder of the document) for subsequent association with previously measured sensorial properties. Insights into the shapes of the curves and their relation to paralleled sensorial analyses are primarily based on the performance of the composite prototypes rather than speculating on the individual contribution of each constituent to the dynamics of the adapting microstructure. Therefore, transitions in the Lissajous trajectories may be used to visually describe changes in the bulk rheology as the physical components of the local viscoelastic environment are controllably sheared. In this work, Lissajous profiles are amassed with smooth and rough surfaces data utilizing standard rheological techniques, including oscillatory SAOS, stress ramps, Brookfield viscometry, and the manifestation of interfacial or complex flow properties, such as wall-slip and shear-banding phenomena. Practical influences on the human stratum corneum, including thermal softening and electrostatic shielding, are also considered. Additionally, outcomes from texture profile analysis are reported and contrasted with the accompanying results. Ultimately, the objective is to make meaningful connections between trends in Lissajous trajectories and paralleled sensorial analyses conducted by a trained expert panel. For the reader, a basic level of rheological knowledge is assumed.
[Mh] Termos MeSH primário: Cosméticos/química
[Mh] Termos MeSH secundário: Composição de Medicamentos
Seres Humanos
Reologia
Higiene da Pele
Fenômenos Fisiológicos da Pele
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cosmetics)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180215
[Lr] Data última revisão:
180215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180203
[St] Status:MEDLINE


  9 / 22577 MEDLINE  
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[PMID]:29251503
[Au] Autor:Ge S; Li M; Ji N; Liu J; Mul H; Xiong L; Sun Q
[Ad] Endereço:College of Food Science and Engineering and ‡Central Laboratory, Qingdao Agricultural University Qingdao, Shandong Province 266109, China.
[Ti] Título:Preparation of a Strong Gelatin-Short Linear Glucan Nanocomposite Hydrogel by an in Situ Self-Assembly Process.
[So] Source:J Agric Food Chem;66(1):177-186, 2018 Jan 10.
[Is] ISSN:1520-5118
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Gelatin hydrogels exhibit excellent biocompatibility, nonimmunogenicity, and biodegradability, but they have limited applications in the food and medical industries because of their poor mechanical properties. Herein, we first developed an in situ self-assembly process for the preparation of gelatin-short linear glucan (SLG) nanocomposite hydrogels with enhanced mechanical strength. The microstructure, dynamic viscoelasticity, compression behavior, and thermal characteristics of the gelatin-SLG nanocomposite hydrogels were determined using scanning electron microscopy (SEM), dynamic rheological experiments, compression tests, and texture profile analysis tests. The SEM images revealed that nanoparticles were formed by the in situ self-assembly of SLG in the gelatin matrix and that the size of these nanoparticles ranged between 200 and 600 nm. The pores of the nanocomposite hydrogels were smaller than those of the pure gelatin hydrogels. Transmission electron microscopy images and X-ray diffraction further confirmed the presence of SLG nanoparticles with spherical shapes and B-type structures. Compared with pure gelatin hydrogels, the nanocomposite hydrogels exhibited improved mechanical behavior. Notably, the hardness and maximum values of the compressive stress of gelatin-SLG nanocomposites containing 5% SLG increased by about 2-fold and 3-fold, respectively, compared to the corresponding values of pure gelatin hydrogels.
[Mh] Termos MeSH primário: Gelatina/química
Glucanos/química
Hidrogéis/química
Nanocompostos/química
[Mh] Termos MeSH secundário: Varredura Diferencial de Calorimetria
Difusão Dinâmica da Luz
Dureza
Microscopia Eletrônica de Varredura
Microscopia Eletrônica de Transmissão
Nanocompostos/ultraestrutura
Nanopartículas/química
Reologia
Espectroscopia de Infravermelho com Transformada de Fourier
Viscosidade
Difração de Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Glucans); 0 (Hydrogels); 9000-70-8 (Gelatin)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180215
[Lr] Data última revisão:
180215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171219
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jafc.7b04684


  10 / 22577 MEDLINE  
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[PMID]:29253848
[Au] Autor:McFadden WM; McCall PM; Gardel ML; Munro EM
[Ad] Endereço:Biophysical Sciences Program, University of Chicago, Chicago, Illinois, United States of America.
[Ti] Título:Filament turnover tunes both force generation and dissipation to control long-range flows in a model actomyosin cortex.
[So] Source:PLoS Comput Biol;13(12):e1005811, 2017 12.
[Is] ISSN:1553-7358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Actomyosin-based cortical flow is a fundamental engine for cellular morphogenesis. Cortical flows are generated by cross-linked networks of actin filaments and myosin motors, in which active stress produced by motor activity is opposed by passive resistance to network deformation. Continuous flow requires local remodeling through crosslink unbinding and and/or filament disassembly. But how local remodeling tunes stress production and dissipation, and how this in turn shapes long range flow, remains poorly understood. Here, we study a computational model for a cross-linked network with active motors based on minimal requirements for production and dissipation of contractile stress: Asymmetric filament compliance, spatial heterogeneity of motor activity, reversible cross-links and filament turnover. We characterize how the production and dissipation of network stress depend, individually, on cross-link dynamics and filament turnover, and how these dependencies combine to determine overall rates of cortical flow. Our analysis predicts that filament turnover is required to maintain active stress against external resistance and steady state flow in response to external stress. Steady state stress increases with filament lifetime up to a characteristic time τm, then decreases with lifetime above τm. Effective viscosity increases with filament lifetime up to a characteristic time τc, and then becomes independent of filament lifetime and sharply dependent on crosslink dynamics. These individual dependencies of active stress and effective viscosity define multiple regimes of steady state flow. In particular our model predicts that when filament lifetimes are shorter than both τc and τm, the dependencies of effective viscosity and steady state stress on filament turnover cancel one another, such that flow speed is insensitive to filament turnover, and shows a simple dependence on motor activity and crosslink dynamics. These results provide a framework for understanding how animal cells tune cortical flow through local control of network remodeling.
[Mh] Termos MeSH primário: Actomiosina/fisiologia
[Mh] Termos MeSH secundário: Citoesqueleto de Actina/química
Citoesqueleto de Actina/fisiologia
Actomiosina/química
Animais
Fenômenos Biomecânicos
Biologia Computacional
Simulação por Computador
Citoesqueleto/fisiologia
Modelos Biológicos
Proteínas Motores Moleculares/química
Proteínas Motores Moleculares/fisiologia
Morfogênese
Reologia
Estresse Fisiológico
Viscosidade
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Molecular Motor Proteins); 9013-26-7 (Actomyosin)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180210
[Lr] Data última revisão:
180210
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171219
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pcbi.1005811



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