Analysis of Strain State in the Subcutaneous Tissue with Shear of Skin Surface for Porcine Hind Feet

2017 ◽  
Vol 2017 (0) ◽  
pp. OS1113
Author(s):  
Hiroshi YAMADA ◽  
Yutaro SHIOTSUKI
1986 ◽  
Vol 1 (3) ◽  
pp. 159-169 ◽  
Author(s):  
P. Haselbach ◽  
U. Vollenweider ◽  
G. Moneta ◽  
A. Bollinger

Fluorescence video microscopy after intravenous injection of Na-fluorescein was used to study capillary morphology, pericapillary halo diameters, microvascular flow distribution and transcapillary diffusion of the dye in 15 healthy controls and 15 patients with severe chronic venous insufficiency (CVI). The recordings were made in the medial ankle region. Transcapillary diffusion was monitored within a densitometer window encompassing 3.2 mm2 of skin surface. Microangiopathy known from previous studies was documented in the patients with severe CVI. The number of skin capillaries within the field of observation was not reduced. In some cases inhomogeneous microvascular flow distribution and probable microthrombosis were detected. Mean halo size averaged 81 — 15 μm in the controls and 146 ± 47 μm in the patients (P < 0.001). Unexpectedly, transcapillary diffusion of Na-fluorescein was not significantly increased in the field of measurement. Possible explanations include asynchronous inflow of the dye, the presence of thrombosed and therefore not perfused capillaries, a pericapillary fibrin layer limiting diffusion and redistribution of flow in favour of the subcutaneous tissue.


Author(s):  
DB Gurung

This paper deals with thermo-regulation in human dermal part in a cold atmosphere with significant air flow. The mathematical model involving bio-heat equation has been solved using finite element method and Crank-Nicolson technique to numerically investigate two dimensional temperature distributions. The natural three layers of dermal part – epidermis, dermis, and subcutaneous tissue are considered for the study. The important parameters like blood mass flow rate, metabolic heat generation rate and thermal conductivity are taken distinct in each layer according to their distinct sub-regional activities. The human subject is assumed in static condition. The wind speed is considered in the range from the start of forced convection (? 0.2 m/s) and up to 5 m/s. The loss of heat from the skin surface to the environment is taken due to convection, radiation, and insensible perspiration. Kathmandu University Journal of Science, Engineering and Technology Vol. 8, No. II, December, 2012, 11-24 DOI: http://dx.doi.org/10.3126/kuset.v8i2.7320


2021 ◽  
Author(s):  
Bo Zhang ◽  
Shan Huang ◽  
Hanrui Zhang ◽  
Haiyan Tu

Abstract Background: Moxibustion has been widely used in Chinese medicine treatment and health care, it is necessary to study the mechanism and characteristics of moxibustion treatment. The warm effect of moxibustion is closely related to the therapeutic effect. Studying the distribution and change of thermal field is an effective way to understand the mechanism of moxibustion. Methods: The finite element analysis software COMSOL was used to establish the heat transfer model to simulate the whole moxibustion process. Two kinds of suspended moxibustion methods, including mild moxibustion and sparrow-pecking moxibustion, were used to perform moxibustion trial at Zusanli acupoint (ST36) of volunteers, with Institutional Review Board (IRB) approval, and the thermal field on the skin surface was detected with an infrared thermometer. Results: Moxibustion method and moxibustion distance are the factors that affect the temperature change. The temperature rising speed of mild moxibustion was slower than that of sparrow-pecking moxibustion. When the moxibustion distance changes, the temperature changes obviously. If the moxibustion distance does not change, the body temperature will continue to rise slowly. If the distance increases, the body temperature will show a downward trend. On the contrary, it goes up. The thermal fields of mild moxibustion and sparrow-pecking moxibustion were distributed in concentric circles around Zusanli. After natural cooling, the temperature of subcutaneous tissue was higher than that of epidermis.Conclusion: The speed of skin temperature change is affected by the method of moxibustion. The temperature field characteristics formed on the skin surface and acupoint are affected by the moxibustion distance and the moxibustion duration. Moxibustion will produce warm heat stimulation to the subcutaneous tissue.


Author(s):  
Michael M. Zedelmair ◽  
Abhijit Mukherjee

In this study, the impact of the cannula geometry on the formation of the depot in subcutaneous tissue is investigated when injecting insulin using an insulin pump. The simulations have been conducted using the Computational Fluid Dynamics (CFD) software ANSYS Fluent. The study is focusing on rapid acting insulin analogues typically used in insulin pump therapy, which enter the bloodstream very shortly after administration. A previously developed 2-dimensional simulation has been transferred into a 3-dimensional case in order to simulate cases with non-axisymmetric geometries. The tissue has been modeled as a homogeneous anisotropic porous media by the use of different porosity values in the parallel and perpendicular direction with respect to the skin surface. The process of absorption is implemented into the model by the use of a locally variable species sink term. The basic case, simulated with a solid cannula, has been compared to other cannula geometries in order to evaluate if the delivery of insulin in the tissue can be improved. The geometries under consideration are the addition of circumferential holes in the wall of the cannula as well as using an array of cannulas instead of a single cannula. The depot formation is analyzed simulating a standard bolus injection of 0.05ml of insulin using an injection time of 25 seconds. It is observed that the addition of multiple holes in the wall of the cannula or using an array of cannulas can alter the shape of the depot quite significantly. The impact of the depot shape on the diffusion of insulin in the tissue has been evaluated by measuring the total volume of the depot after injection.


2020 ◽  
Author(s):  
Rocío García-Fonticoba ◽  
Lluis Ferrer ◽  
Olga Francino ◽  
Anna Cusco

Abstract Background. Studies using highly sensitive molecular techniques have detected bacterial communities below the human epidermis. Depending on their abundance and composition, this finding could be clinically relevant. The aim of this study was to determine if bacteria can be detected in the dermis and subcutaneous tissue of dogs without cutaneous disease using two different approaches: traditional cultures and DNA sequencing of the V4 region of bacterial 16S rRNA gene using next-generation sequencing (NGS).Results. Seven healthy dogs were included in the study, and two sets of samples were collected from each subject. Sample sets were composed of a 6-mm abdominal skin biopsy, including epidermis, dermis, and subcutis, a skin surface swab, and an environmental blank sample for contamination control. One set of samples from each dog was submitted for bacterial culture and the other one for bacterial DNA amplification and sequencing. Five different bacterial genera (Staphylococcus, Bacillus, Corynebacterium, Streptococcus, and Enterococcus) were isolated in five out of the seven skin surface swab samples with aerobic microbiological culture methods, while no growth was obtained from the other two samples. Although some DNA could be amplified from epidermal, dermal, and subcutaneous tissue samples, the results of the NGS were similar to those of the blanks.Conclusion. When investigated with aerobic microbiological culture methods, the dermis and subcutaneous tissue of dogs are sterile. NGS techniques lead to the detection of some bacterial DNA, similar to the signal detected in blanks, which does not support the presence of a microbiota in dermis or subcutaneous tissue.


Author(s):  
Abhinav David ◽  
Divyanshu Srivastava

<p>Cutaneous larvae migrans or creeping eruption is a serpiginous cutaneous eruption caused by the accidental penetration and migration of animal hookworm (nematode) larvae through the epidermis and subcutaneous tissue. The infection occurs most frequently in warmer climates and is associated with pruritus and burning sensation<span style="text-decoration: line-through;">s</span>. We report a case of 48 years old farmer with vesicular lesion on left ankle progressing into a serpiginous track on the skin surface without any characteristic symptoms. Treatment with oral and topical drugs led to successful resolution of lesions within 10 days.</p>


2019 ◽  
Vol 6 (8) ◽  
pp. 2988
Author(s):  
Tharun Ganapathy Chitrambalam ◽  
Sidhu Sekhar ◽  
Koshy Mathew Panicker ◽  
Jeyakumar Sundaraj

Mycetoma is a chronic disease, which is endemic in tropical and subtropical countries. Mycetoma is a chronic subcutaneous infection caused by Actinomycetes or fungi. This infection results in a granulomatous inflammatory response in the deep dermis and subcutaneous tissue, which can extend to the underlying bone. Mycetoma is characterized by the formation of grains containing aggregates of the causative organisms that may be discharged onto the skin surface through multiple sinuses. Here we report an unusual presentation of eumycetoma in the thigh of a 41 year old male rural industrial worker hailing from South India.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Rocío García-Fonticoba ◽  
Lluís Ferrer ◽  
Olga Francino ◽  
Anna Cuscó

Abstract Background Studies using highly sensitive molecular techniques have detected bacterial communities below the human epidermis. Depending on their abundance and composition, this finding could be clinically relevant. The aim of this study was to determine if bacteria can be detected in the dermis and subcutaneous tissue of dogs without cutaneous disease using two different approaches: traditional cultures and DNA sequencing of the V4 region of bacterial 16S rRNA gene using next-generation sequencing (NGS). Results Seven healthy dogs were included in the study, and two sets of samples were collected from each subject. Sample sets were composed of a 6-mm abdominal skin biopsy, including epidermis, dermis, and subcutis, a skin surface swab, and an environmental blank sample for contamination control. One set of samples from each dog was submitted for bacterial culture and the other one for bacterial DNA amplification and sequencing. Five different bacterial genera (Staphylococcus, Bacillus, Corynebacterium, Streptococcus, and Enterococcus) were isolated in five out of the seven skin surface swab samples with aerobic microbiological culture methods, while no growth was obtained from the other two samples. Although some DNA could be amplified from epidermal, dermal, and subcutaneous tissue samples, the results of the NGS were similar to those of the blanks. Conclusion When investigated with aerobic microbiological culture methods, the dermis and subcutaneous tissue of dogs are sterile. NGS techniques lead to the detection of some bacterial DNA, similar to the signal detected in blanks, which does not support the presence of a microbiota in dermis or subcutaneous tissue.


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