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Bibaswan Dey

Publications and source records attributed to Bibaswan Dey.

3 recordsLinked to original sources

A Two-Phase Model of Early Atherosclerotic Plaque Development with LDL Toxicity Effects

Atherosclerosis is a chronic inflammatory cardiovascular disease in which fatty plaque is built inside an artery wall. Early atherosclerotic plaque development is typically characterized by inflammatory tissues primarily consisting of foam cells and macrophages. We present a biphasic model that explores early plaque growth to emphasize the role of cytokines (particularly, Monocyte Chemoattractant Protein-1) and oxidized low-density lipoprotein (oxLDL) in monocyte recruitment and foam cell production, respectively. The plaque boundary is assumed to move at the same speed as the inflammatory tissues close to the periphery. This study discusses the oxLDL cholesterols recruitment inside intima and their internalization by the inflammatory cells. Excessive intracellular cholesterol accumulation becomes toxic to macrophage foam cells, leading to cell death beyond a threshold. Our findings reveal that initially, the plaque evolves rapidly, and the growth rate eventually reduces because of the cholesterol-induced toxicity. The present study manifests that higher oxLDL cholesterol flux reduces plaque growth rate, while elevated cytokines flux promotes the corresponding plaque growth behaviour. Between oxLDL cholesterol and intracellular cholesterol, the second one is much more effective towards the growth of inflammatory tissue. The cholesterol-based toxicity-induced cell death parameters are crucial in flattening the plaque growth profile. A detailed analysis of the model presented in this article provides critical insights into the various biochemical and cellular mechanisms behind early plaque development.

q-bio.TO

The Role of Biomarkers on Haemodynamics in Atherosclerotic Artery

Atherosclerosis, a chronic inflammatory cardiovascular disease, leads to arterial constriction caused by the accumulation of lipids, cholesterol, and various substances within artery walls. Such plaque can rupture, resulting in a blood clot that obstructs major arteries and may initiate myocardial infarction, ischemic stroke, etc. Atherosclerotic plaque formation begins with the accumulation of foam cells and macrophages within the intima layer of the arterial wall. At the latter stage, the smooth muscle cells migrated from deeper artery wall layers, contributing to the fibrous cap formation and plaque stabilizing. A developed plaque gradually enters the lumen and narrows down the lumen to impede blood flow. We introduce a two-phase and macroscopic model to investigate the progression of plaque growth in its advanced stage and analyze the minimum gap (Lumen Clearance) within an atherosclerotic artery so that blood cells can pass through. Cardiac troponin, a high specificity and sensitivity biomarker, facilitates early detection of elevated myocardial infarction, Ischemic stroke, etc. risks. This study aims to establish a relationship between the troponin concentration in atherosclerotic arteries and their internal clearance, which could significantly improve our understanding of disease progression. Our observations show that the plaque undergoes rapid evolution in its initial stages, gradually slowing down over time to reach a steady state. At the same time, the lumen clearance exhibits an opposite behavior, decreasing slowly over time. Our study finds a positive correlation between plaque depth and troponin concentration in the blood and a negative relationship between troponin concentrations and lumen clearance in atherosclerotic arteries.

q-bio.TO

Two-phase Modeling of Fluid Injection Inside Subcutaneous Layer of Skin

Being motivated by the delivery of drugs and vaccines through subcutaneous (SC) injection in human bodies, a theoretical investigation is performed using a two-dimensional mathematical model in the cartesian coordinate. In general, a large variety of biological tissues behave as deformable porous material with anisotropic hydraulic conductivity. Consequently, one can adopt the field equations of mixture theory to describe the behavior of the interstitial fluid and adipose cell present in the subcutaneous layer of skin. During the procedure, a medical person takes a big pinch of the skin of the injection application area between the thumb and index finger and holds. This process pulls the fatty tissue away from the muscle and makes the injection process easier. In this situation, the small aspect ratio (denoted as $δ$) of the subcutaneous layer (SCL) i.e., $δ^2\sim0.01$ would simplify the governing equation for tissue dynamics as it becomes a perturbation parameter. This study highlights the issue of the mechanical response of the adipose tissue in terms of the anisotropic hydraulic conductivity variation, the viscosity of the injected drug, the mean depth of subcutaneous tissue, etc. In particular, the computed stress fields can measure the intensity of pain to be experienced by a patient after this procedure. Also, this study discusses the biomechanical impact of the creation of one or more eddy structures (s) near the area of applying injection, which is due to high pressure developed there, increased tissue anisotropy, fluid viscosity, etc.

physics.flu-dyn