Multiscale numerical approximation of morphology formation in ternary mixtures with evaporation : Discrete and continuum models for high-performance computing

We propose three models to study morphology formations in interacting ternary mixtures with the evaporation of one component. Our models involve three distinct length scales: microscopic, mesoscopic, and respectively, macroscopic. The real-world application we have in mind concerns charge transport through the heterogeneous structures arising in the fabrication of organic solar cells. As first model, we propose a microscopic 3-spins lattice dynamics with short-range interactions between the considered species. This microscopic model is approximated numerically via a Monte Carlo Metropolis-based algorithm. We explore the effect of the model parameters (volatility of the solvent, system's temperature, and interaction strengths) on the structure of the formed morphologies. Our second model is built upon the first one, by introducing a new mesoscale corresponding to the size of block spins. The link between these two models as well as between the effects of the model parameters and formed morphologies are studied in detail. These two models offer insight into cross-sections of the modeling box. Our third model encodes a macroscopic view of the evaporating mixture. We investigate its capability to lead to internal coherent structures. We propose a macroscopic system of nonlinearly coupled Cahn-Hilliard equations to capture numerical results for a top view of the modeling box. Effects of effective evaporation rates, effective interaction energy parameters, and degree of polymerization on the wanted morphology formation are explored via the computational platform FEniCS using a FEM approximation of a suitably linearized system. High-performance computing resources and Python-based parallel implementations have been used to facilitate the numerical approximation of the three models

Cerebellar decompensation following a stroke in contralateral posterior parietal cortex

We describe here a patient who exhibited cerebellar hypermetria on the left side following a cerebellar ischemia in left cerebellar hemisphere. She subsequently recovered clinically. However, twenty months after cerebellar ischemia, cerebellar symptoms reappeared suddenly. Moreover, kinematic and electromyographic (EMG) abnormalities during fast movements of left wrist were identical to those detected after the initial cerebellar lesion. Surprisingly, the causal lesion of this cerebellar decompensation was found to be a stroke at the level of the right posterior parietal association area. Copyright (C) 1999 Elsevier Science B.V.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Orthostatic tremor associated with cerebellar ataxia

SCOPUS: le.jinfo:eu-repo/semantics/publishe

Cerebellar ataxia following whooping cough

Bordetella pertussis (BP), the agent of whooping cough, has not been recognized so far as a cause of permanent cerebellar ataxia in human. We describe three patients who developed a disabling and permanent cerebellar syndrome soon after whooping cough. In two patients, diagnosis of BP infection was confirmed by culture of nasopharyngeal secretions. The infection occurred between the age of 13 and 15 years, with neurological symptoms beginning after a delay varying from 3 weeks to 3 months. In our three patients, the cerebellar syndrome was characterized by dysmetria of ocular saccades, scanning speech and ataxic gait. Brain MRI demonstrated a pancerebellar atrophy. The pathogenesis of this cerebellar degeneration is not established. Experimental studies have demonstrated that the cerebellum is particularly vulnerable to lymphocytosis-promoting factor (LPF), one of the exotoxins from BP. The mechanism of this toxicity might be a marked increase in the cellular levels of 3',5'cyclic guanosine monophosphate (cGMP). Since whooping cough is a bacterial exotoxin-mediated disease, this is the first report of a cerebellar syndrome triggered by a bacterial exotoxin. Copyright (C) 1999 Elsevier Science B.V.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Different types of cerebellar hypometria associated with a distinct topography of the lesion in cerebellum

We recorded ballistic wrist flexion movements in fifteen cerebellar patients exhibiting hypometria. The movement and the associated agonist and antagonist-EMG activities were analysed. On the basis of the topography of the cerebellar-lesion, our patients were divided into three groups. In the first group including five patients, lesions involved the efferent dentato- thalamo-cortical pathway and hypometria was associated with an imbalance between the rate of rise of the agonist EMG activity and the rate of rinse of antagonist EMG activity. In the three patients of group II, lesions were located at the level of the middle cerebellar peduncle, disrupting the crossed ponto-cerebellar projections. In these patients, the intensity of the agonist EMG activity was reduced and the duration of the antagonist EMG activity was increased. In the third group including seven patients presenting either a diffuse cerebellar atrophy or a stroke involving a large parenchymatous area, the agonist-antagonist EMG pattern showed a prolongation of the duration of the antagonist burst. Our results show that discrete mechanisms of cerebellar hypometria are associated with different anatomical lesions.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

A mesoscopic lattice model for morphology formation in ternary mixtures with evaporation

We develop a mesoscopic lattice model to study the morphology formation in interacting ternary mixtures with the evaporation of one component. As concrete potential application of our model, we wish to capture morphologies as they are typically arising during the fabrication of organic solar cells. In this context, we consider an evaporating solvent into which two other components are dissolved, as a model for a 2-component coating solution that is drying on a substrate. We propose a 3-spins dynamics to describe the evolution of the three interacting species. As main tool, we use a Monte Carlo Metropolis-based algorithm, with the possibility of varying the system’s temperature, mixture composition, interaction strengths, and evaporation kinetics. The main novelty is the structure of the mesoscopic model – a bi-dimensional lattice with periodic boundary conditions, divided into square cells to encode a mesoscopic range interaction among the units. We investigate the effect of the model parameters on the structure of the resulting morphologies. Finally, we compare the results obtained with the mesoscopic model with corresponding ones based on an analogous lattice model with a short range interaction among the units, i.e. when the mesoscopic length scale coincides with the microscopic length scale of the lattice

Relationship between induced sputum cytology and inflammatory status with lung structural and functional abnormalities in asbestosis

Background Asbestosis is associated with lung cellular and immunological abnormalities. Induced sputum cytology and local and systemic markers of inflammation may be helpful to characterize disease status and progression in these patients. Methods Thirty-nine ex-workers with asbestosis on high-resolution CT (HRCT) and 21 non-exposed controls were evaluated. Sputum cytology and IL-8 in serum and sputum were related to lung function impairment. Results Subjects with asbestosis had reduced sputum cellularity but higher macrophagel neutrophil ratio and % macrophage as compared with controls. Sputum and serum IL-8 were also higher in patients with asbestosis (P < 0.05). In addition, evidence of lung architectural distorption on HRCT was associated with increased levels of serum IL-8. Interestingly, absolute macrophage number was negatively correlated with total lung capacity (r = -0.40; P = 0.04) and serum IL-8 to lung diffiusing capacity (r = -0.45; P = 0.01). Conclusions Occupationally exposed subjects with asbestosis on HRCT have cytologic abnormalities in induced sputum and increased local and systemic pro-inflammatory status which are correlated to functional impairment