Computational Analysis of Adhesion Dynamics in the Eustachian Tube During Inflammatory Otitis Media

2011 ◽  
Author(s):  
Francis J. Sheer ◽  
Samir N. Ghadiali
Keyword(s):  
Otitis Media ◽  
Computational Models ◽  
Viral Infections ◽  
Morphological Data ◽  
Adhesion Forces ◽  
Tissue Stiffness ◽  
Normal Children ◽  
Multi Scale ◽  
The Cost ◽  
Adhesive Forces

Otitis Media (OM) is an inflammation of the middle ear (ME) that is the most commonly diagnosed childhood illness and the cost of treating OM has been estimated at four billion dollars annually. [1] The onset of OM is typically due to bacterial/viral infections that cause tissue swelling, rapid ME gas exchange and painful sub-ambient ME pressures. Normally, periodic openings of the ET are used to relieve ME pressures. However, the up-regulation of various adhesion proteins within the ET lumen make it difficult for the surrounding muscles to open the ET. The goal of this study is to use computational models to investigate how changes in adhesion dynamics during inflammation influence ET function in three different patient populations: healthy adults, normal children, and CP infants. We have developed a multi-scale computational models of the ET based on histo-morphological data obtained in each population. Adhesive forces within the lumen are modeled as non-linear, reputable spring elements. These models indicate that tissue morphology and mechanics can significantly influence the ET’s response to inflammatory adhesion forces. Specifically, changes in mucosal tissue stiffness and TVP muscle forces are most effective in overcoming inflammatory adhesion forces.

Otitis Media

PEDIATRICS ◽  
1984 ◽  
Vol 74 (5) ◽  
pp. 948-949
Author(s):  
Charles M. Ginsburg
Keyword(s):  
Otitis Media ◽  
Viral Infections ◽  
Otitis Media With Effusion ◽  
Acute Otitis Media ◽  
Medical Personnel ◽  
Medical Attention ◽  
Common Symptom ◽  
Upper Respiratory Tract ◽  
Primary Responsibility ◽  
Printed Materials

Earache, a common symptom in children, causes many parents to seek medical attention. Aside from trauma and the discomfort that often accompanies viral infections of the upper respiratory tract, acute otitis media with effusion is the commonest cause of otalgia in infants and children. Proper management requires a team effort between the physician and the child's parents or caretaker. The physician must transmit to the parents a concise but thorough overview of the problem and a plan for management. This should include information on the pathophysiology of ear disease, its incidence, therapy and the potential adverse effects, and any measures that the parents may take to prevent recurrence. The primary responsibility for transmittal of this information lies with the physician. Ancillary medical personnel and communication aids (videotapes, computers, printed materials) should be utilized, if available, to reinforce the physician's "message.'

scholarly journals Multi-scale dynamic mean field model (MDMF) relates resting-state brain dynamics with local cortical excitatory–inhibitory neurotransmitter homeostasis

2021 ◽  
pp. 1-55
Author(s):  
Amit Naskar ◽  
Anirudh Vattikonda ◽  
Gustavo Deco ◽  
Dipanjan Roy ◽  
Arpan Banerjee
Keyword(s):  
Resting State ◽  
Computational Models ◽  
Field Model ◽  
Diffusion Tensor ◽  
Brain Activity ◽  
Mean Field ◽  
Clustering Coefficient ◽  
Brain Dynamics ◽  
Mean Field Model ◽  
Multi Scale

Abstract Previous computational models have related spontaneous resting-state brain activity with local excitatory−inhibitory balance in neuronal populations. However, how underlying neurotransmitter kinetics associated with E-I balance governs resting state spontaneous brain dynamics remains unknown. Understanding the mechanisms by virtue of which fluctuations in neurotransmitter concentrations, a hallmark of a variety of clinical conditions relate to functional brain activity is of critical importance. We propose a multi-scale dynamic mean field model (MDMF) – a system of coupled differential equations for capturing the synaptic gating dynamics in excitatory and inhibitory neural populations as a function of neurotransmitter kinetics. Individual brain regions are modelled as population of MDMF and are connected by realistic connection topologies estimated from Diffusion Tensor Imaging data. First, MDMF successfully predicts resting-state functionalconnectivity. Second, our results show that optimal range of glutamate and GABA neurotransmitter concentrations subserve as the dynamic working point of the brain, that is, the state of heightened metastability observed in empirical blood-oxygen-level dependent signals. Third, for predictive validity the network measures of segregation (modularity and clustering coefficient) and integration (global efficiency and characteristic path length) from existing healthy and pathological brain network studies could be captured by simulated functional connectivity from MDMF model.

Comparisons of Pins/Dimples/Protrusions Cooling Concepts for a Turbine Blade Tip-Wall at High Reynolds Numbers

2010 ◽  
Author(s):  
Gongnan Xie ◽  
Bengt Sunde´n ◽  
Weihong Zhang
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Computational Models ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Gas Leakage ◽  
Leakage Flows ◽  
Blade Tip ◽  
High Reynolds ◽  
The Cost

The blade tip region encounters high thermal loads because of the hot gas leakage flows, and it must therefore be cooled to ensure a long durability and safe operation. A common way to cool a blade tip is to design serpentine passages with 180° turn under the blade tip-cap inside the turbine blade. Improved internal convective cooling is therefore required to increase blade tip lifetime. Pins, dimples and protrusions are well recognized as effective devices to augment heat transfer in various applications. In this paper, enhanced heat transfer of an internal blade tip-wall has been predicted numerically. The computational models consist of a two-pass channel with 180° turn and arrays of circular pins or hemispherical dimples or protrusions internally mounted on the tip-wall. Inlet Reynolds numbers are ranging from 100,000 to 600,000. The overall performance of the two-pass channels is evaluated. Numerical results show that the heat transfer enhancement of the pinned tip is up to a factor of 3.0 higher than that of a smooth tip while the dimpled-tip and protruded-tip provide about 2.0 times higher heat transfer. These augmentations are achieved at the cost of an increase of pressure drop by less than 10%. By comparing the present cooling concepts with pins, dimples and protrusions, it is shown that the pinned-tip exhibit best performance to improve the blade tip cooling. However, when disregarding the added active area and considering the added mechanical stress, it is suggested that the usage of dimples is more suitable to enhance blade tip cooling, especially at low Reynolds numbers.

Global properties for an age-structured within-host model with Crowley–Martin functional response

2017 ◽  
Vol 10 (02) ◽  
pp. 1750030 ◽  
Author(s):  
Shaoli Wang ◽  
Xinyu Song
Keyword(s):  
Functional Response ◽  
Viral Infections ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Positive Equilibrium ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Multi Scale ◽  
Global Properties ◽  
Age Structured

Based on a multi-scale view, in this paper, we study an age-structured within-host model with Crowley–Martin functional response for the control of viral infections. By means of semigroup and Lyapunov function, the global asymptotical property of infected steady state of the model is obtained. The results show that when the basic reproductive number falls below unity, the infection dies out. However, when the basic reproductive number exceeds unity, there exists a unique positive equilibrium which is globally asymptotically stable. This model can be deduced to different viral models with or without time delay.

Antibiotic or Myringotomy, or Both, for Acute Otitis Media

1983 ◽  
Vol 92 (6_suppl) ◽  
pp. 32-33
Author(s):  
J. S. Supance ◽  
P. H. Kaleida ◽  
M. L. Casselbrant ◽  
M. M. Blatter ◽  
K. S. Reisinger ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Otitis Media ◽  
Acute Otitis Media ◽  
Drug Efficacy ◽  
Pharmacokinetic Studies ◽  
Controlled Clinical Trials ◽  
Randomized Controlled Clinical Trials ◽  
Surgical Methods ◽  
Potential Benefits ◽  
The Cost

Prevention and safe and effective treatment of otitis media are two of our ultimate research goals. Both of these require that a variety of medical and surgical methods of management be evaluated. The most frequent medical management of otitis media is the administration of antibiotics, decongestants, and antihistamines; therefore, several studies that are either randomized placebo-controlled clinical trials or drug efficacy studies have been undertaken. Also, pharmacokinetic studies either have been performed or are underway to determine the ability of drugs to achieve appropriate blood and middle ear levels. The most common methods of surgical management are myringotomy with or without tympanostomy tube insertion, and adenoidectomy with or without tonsillectomy. Randomized controlled clinical trials are being conducted to determine the efficacy and risk/benefit of these procedures at various stages and levels of severity of otitis media in children. In addition, we are attempting to address the problem of the cost of these methods in relation to their potential benefits.

scholarly journals Symptomatic and Asymptomatic Respiratory Viral Infections in the First Year of Life: Association With Acute Otitis Media Development

2014 ◽  
Vol 60 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tasnee Chonmaitree ◽  
Pedro Alvarez-Fernandez ◽  
Kristofer Jennings ◽  
Rocio Trujillo ◽  
Tal Marom ◽  
...  
Keyword(s):  
Otitis Media ◽  
Viral Infections ◽  
Acute Otitis Media ◽  
First Year ◽  
Media Development ◽  
Respiratory Viral Infections ◽  
First Year Of Life

Adhesion Forces for Sub-10 nm Flying-Height Magnetic Storage Head Disk Interfaces

2004 ◽  
Vol 126 (2) ◽  
pp. 334-341 ◽  
Author(s):  
Sung-Chang Lee ◽  
Andreas A. Polycarpou
Keyword(s):  
Flying Height ◽  
Magnetic Storage ◽  
Adhesion Forces ◽  
Force Measurements ◽  
Lubricant Thickness ◽  
Magnetic Disks ◽  
Atomic Force ◽  
Adhesion Model ◽  
Different Levels ◽  
Adhesive Forces

A quasi-dynamic adhesion model is used to calculate the intermolecular adhesion forces present in ultra low flying Head Disk Interfaces (HDI’s). The model is a continuum-based micromechanics model that accounts for realistic surfaces with roughness, molecularly thin lubricants, and is valid under both static and dynamic sliding conditions. Several different levels of surface roughness are investigated ranging from extremely smooth surfaces having a standard deviation of surface heights σ=2 Å to rougher interfaces with several nanometer roughness. It is found that when the flying-height is greater than 5 nm, there are no significant adhesive forces, whereas for flying-heights less than 5 nm, adhesion forces increase sharply, which can be catastrophic to the reliability of low flying HDI’s. In addition to roughness, the apparent area of contact between the flying recording slider and the magnetic disk is also found to significantly affect the magnitude of the adhesion forces. The adhesion model is validated by direct comparisons with adhesion “pull-off” force measurements performed using an Atomic Force Microscope with controlled probe tip areas and magnetic disks having different lubricant thickness.

scholarly journals Erratum: Tuneable resolution as a systems biology approach for multi-scale, multi-compartment computational models

2014 ◽  
Vol 6 (4) ◽  
pp. 344-344
Author(s):  
Denise E. Kirschner ◽  
C. Anthony Hunt ◽  
Simeone Marino ◽  
Mohammad Fallahi-Sichani ◽  
Jennifer J. Linderman
Keyword(s):  
Systems Biology ◽  
Computational Models ◽  
Multi Scale
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