Macroscopic Models for the Bioelectronic Interface of Engineered Artificial Membranes

2018 ◽  
pp. 287-314
Author(s):  
William Hoiles ◽  
Vikram Krishnamurthy
Keyword(s):  
Artificial Membranes ◽  
Macroscopic Models

Video real-time imaging of artificial membranes during freeze-drying by cryo-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 16-17
Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price
Keyword(s):  
Real Time ◽  
Self Assembly ◽  
Freeze Drying ◽  
Video Capture ◽  
Drying Process ◽  
Artificial Membranes ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Spherical Structures ◽  
Capture Techniques

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.

Stochastic homogenization and macroscopic modelling of composites and flow through porous media

2002 ◽  
pp. 337-378 ◽  
Author(s):  
Jozef Telega ◽  
Wlodzimierz Bielski
Keyword(s):  
Porous Medium ◽  
Random Distribution ◽  
Flow Through Porous Media ◽  
Macroscopic Models ◽  
Linear Elastic ◽  
Multi Scale ◽  
Convergence Method ◽  
Flow Through ◽  
The Mean ◽  
Random Porous Medium

The aim of this contribution is mainly twofold. First, the stochastic two-scale convergence in the mean developed by Bourgeat et al. [13] is used to derive the macroscopic models of: (i) diffusion in random porous medium, (ii) nonstationary flow of Stokesian fluid through random linear elastic porous medium. Second, the multi-scale convergence method developed by Allaire and Briane [7] for the case of several microperiodic scales is extended to random distribution of heterogeneities characterized by separated scales (stochastic reiterated homogenization). .

scholarly journals Omp35, a New Enterobacter aerogenes Porin Involved in Selective Susceptibility to Cephalosporins

2004 ◽  
Vol 48 (6) ◽  
pp. 2153-2158 ◽  
Author(s):  
Charléric Bornet ◽  
Nathalie Saint ◽  
Lilia Fetnaci ◽  
Myrielle Dupont ◽  
Anne Davin-Régli ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Outer Membrane ◽  
Antibiotic Susceptibility ◽  
Enterobacter Aerogenes ◽  
Artificial Membranes ◽  
Specific Location ◽  
Outer Membrane Permeability ◽  
Constriction Region ◽  
High Conductance

ABSTRACT In Enterobacter aerogenes, β-lactam resistance often involves a decrease in outer membrane permeability induced by modifications of porin synthesis. In ATCC 15038 strain, we observed a different pattern of porin production associated with a variable antibiotic susceptibility. We purified Omp35, which is expressed under conditions of low osmolality and analyzed its pore-forming properties in artificial membranes. This porin was found to be an OmpF-like protein with high conductance values. It showed a noticeably higher conductance compared to Omp36 and a specific location of WNYT residues in the L3 loop. The importance of the constriction region in the porin function suggests that this organization is involved in the level of susceptibility to negative large cephalosporins such as ceftriaxone by bacteria producing the Omp35 porin subfamily.

scholarly journals Ranking the critical sections of railway networks

2020 ◽  
pp. 095440972092568
Author(s):  
Ratthaphong Meesit ◽  
John Andrews
Keyword(s):  
Network Flow ◽  
Topological Analysis ◽  
Preventive Strategy ◽  
Railway Network ◽  
Macroscopic Models ◽  
Railway Systems ◽  
Railway Networks ◽  
Network Simulation Model ◽  
The Impact ◽  
Critical Sections

Railway systems are now facing an increasing number of threats such as aging infrastructures and climate changes. The identification of critical network sections provides infrastructure managers with the ability to understand the impact of a disruption and creates a suitable preventive strategy to counter such threats. To this end, various vulnerability analysis methods have been proposed for railway networks. Two main types of methods, network topological analysis and network flow-based analysis, have been developed. Both approaches are constructed based on macroscopic models, which take only some railway properties such as network structure, train and passenger flow into account. Thus, the results obtained are high level approximations. This study proposes a new analysis method, which is developed based on the stochastic-microscopic railway network simulation model. The method can be applied to identify the critical sections of a railway network. The effect of impact levels and occurrence times of a disruption on the network section criticality is presented. An application of the proposed model is demonstrated using the Liverpool railway network in the UK.

Binding of tumor-promoting and biologically inactive phorbol esters to artificial membranes

1982 ◽  
Vol 17 (2) ◽  
pp. 135-140 ◽  
Author(s):  
Michel Deleers ◽  
Willy J. Malaisse
Keyword(s):  
Phorbol Esters ◽  
Artificial Membranes

Monitoring of lung tumour cell growth in artificial membranes

2004 ◽  
Vol 20 (3) ◽  
pp. 442-447 ◽  
Author(s):  
Ying Yang ◽  
Josep Sulé-Suso ◽  
Alicia J El Haj ◽  
Paul R Hoban ◽  
RuiKang Wang
Keyword(s):  
Cell Growth ◽  
Tumour Cell ◽  
Lung Tumour ◽  
Artificial Membranes ◽  
Tumour Cell Growth

scholarly journals Investigation of representing hysteresis in macroscopic models of two-phase flow in porous media using intermediate scale experimental data

2017 ◽  
Vol 53 (1) ◽  
pp. 199-221 ◽  
Author(s):  
Abdullah Cihan ◽  
Jens Birkholzer ◽  
Luca Trevisan ◽  
Ana Gonzalez-Nicolas ◽  
Tissa Illangasekare
Keyword(s):  
Experimental Data ◽  
Porous Media ◽  
Two Phase Flow ◽  
Flow In Porous Media ◽  
Phase Flow ◽  
Two Phase ◽  
Intermediate Scale ◽  
Macroscopic Models

Kinetic behavior of enzymes in artificial membranes. Inhibition and reversibility effects

Biochemistry ◽  
1974 ◽  
Vol 13 (14) ◽  
pp. 2995-3000 ◽  
Author(s):  
Daniel Thomas ◽  
Catherine Bourdillon ◽  
Georges Broun ◽  
Jean P. Kernevez
Keyword(s):  
Kinetic Behavior ◽  
Artificial Membranes

Atomistic Aspects of Fracture Modelling in the Framework of Continuum Mechanics

1998 ◽  
Vol 538 ◽  
Author(s):  
F. Cleri
Keyword(s):  
Continuum Mechanics ◽  
Constitutive Relations ◽  
Point Of View ◽  
Atomic Scale ◽  
Continuum Models ◽  
Cohesive Law ◽  
Macroscopic Models ◽  
Scale Models ◽  
Level Information ◽  
Set Up

AbstractThe validity and predictive capability of continuum models of fracture rests on basic informations whose origin lies at the atomic scale. Examples of such crucial informations are, e.g., the explicit form of the cohesive law in the Barenblatt model and the shear-displacement relation in the Rice-Peierls-Nabarro model. Modem approaches to incorporate atomic-level information into fracture modelling require to increase the size of atomic-scale models up to millions of atoms and more; or to connect directly atomistic and macroscopic, e.g. finite-elements, models; or to pass information from atomistic to continuum models in the form of constitutive relations. A main drawback of the atomistic methods is the complexity of the simulation results, which can be rather difficult to rationalize in the framework of classical, continuum fracture mechanics. We critically discuss the main issues in the atomistic simulation of fracture problems (and dislocations, to some extent); our objective is to indicate how to set up atomistic simulations which represent well-posed problems also from the point of view of continuum mechanics, so as to ease the connection between atomistic information and macroscopic models of fracture.

Specific Interactions of Mycosubtilin with Cholesterol-Containing Artificial Membranes

Langmuir ◽  
2011 ◽  
Vol 27 (17) ◽  
pp. 10785-10792 ◽  
Author(s):  
Mehmet Nail Nasir ◽  
Françoise Besson
Keyword(s):  
Specific Interactions ◽  
Artificial Membranes
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