scholarly journals The Use of Core Warming as a Treatment for Coronavirus Disease 2019 (COVID-19): an Initial Mathematical Model

2020 ◽  
Vol 33 (1) ◽  
pp. 6-15 ◽  
Author(s):  
Marcela Mercado-Montoya ◽  
Nathaniel Bonfanti ◽  
Emily Gundert ◽  
Anne Meredith Drewry ◽  
Roger Bedimo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Viral Entry ◽  
Therapeutic Option ◽  
Blood Perfusion ◽  
Skin Surface ◽  
The Body ◽  
Hospital Environment ◽  
Body Region ◽  
Temperature Sensitive ◽  
Available Technology

Background: Increasing data suggest that elevated body temperature may be helpful in resolving a variety of diseases, including sepsis, acute respiratory distress syndrome (ARDS), and viral illnesses. SARS-CoV-2, which causes coronavirus disease 2019 (COVID-19), may be more temperature sensitive than other coronaviruses, particularly with respect to the binding affinity of its viral entry via the ACE2 receptor. A mechanical provision of elevated temperature focused in a body region of high viral activity in patients undergoing mechanical ventilation may offer a therapeutic option that avoids arrhythmias seen with some pharmaceutical treatments. We investigated the potential to actively provide core warming to the lungs of patients with a commercially available heat transfer device via mathematical modeling, and examine the influence of blood perfusion on temperature using this approach. Methods: Using the software Comsol Multiphysics, we modeled and simulated heat transfer in the body from an intraesophageal warming device, taking into account the airflow from patient ventilation. The simulation was focused on heat transfer and warming of the lungs and performed on a simplified geometry of an adult human body and airway from the pharynx to the lungs. Results: The simulations were run over a range of values for blood perfusion rate, which was a parameter expected to have high influence in overall heat transfer, since the heat capacity and density remain almost constant. The simulation results show a temperature distribution which agrees with the expected clinical experience, with the skin surface at a lower temperature than the rest of the body due to convective cooling in a typical hospital environment. The highest temperature in this case is the device warming water temperature, and that heat diffuses by conduction to the nearby tissues, including the air flowing in the airways. At the range of blood perfusion investigated, maximum lung temperature ranged from 37.6°C to 38.6°C. Conclusions: The provision of core warming via commercially available technology currently utilized in the intensive care unit, emergency department, and operating room can increase regional temperature of lung tissue and airway passages. This warming may offer an innovative approach to treating infectious diseases from viral illnesses such as COVID-19, while avoiding the arrhythmogenic complications of currently used pharmaceutical treatments.

scholarly journals Solving bio-heat transfer multi-layer equation using Green’s Functions method

2021 ◽  
Vol 2090 (1) ◽  
pp. 012150
Author(s):  
de Oliveira Eduardo Peixoto ◽  
Gilmar Guimaräes
Keyword(s):  
Heat Transfer ◽  
Green's Functions ◽  
Green’S Functions ◽  
Transfer Problem ◽  
Blood Perfusion ◽  
The Body ◽  
Mathematical Background ◽  
Number Of Layers ◽  
Pennes Equation ◽  
Transfer Problems

Abstract An analytical method using Green’s Functions for obtaining solutions in bio-heat transfer problems, modeled by Pennes’ Equation, is presented. Mathematical background on how treating Pennes’ equation and its μ2T term is shown, and two contributions to the classical numbering system in heat conduction are proposed: inclusion of terms to specify the presence of the fin term, μ2T, and identify the biological heat transfer problem. The presentation of the solution is made for a general multi-layer domain, deriving and showing general approaches and Green’s Functions for such n number of layers. Numerical examples are presented to simplify human skin as a two-layer domain: dermis and epidermis, accounting metabolism as a heat source, and blood perfusion only at the dermis. Time-independent summations in the series-solution are written in closed forms, leading to better convergence along the boundaries. Details on obtaining the two-layer solution and its eigenvalues are presented for boundary conditions of prescribed temperature inside the body and convection at the surface, such as its intrinsic verification.

Numerical Simulation of Enhanced Skin Thermal Signature of Female Breast Tumor Subjected to Forced Convection

2003 ◽  
Author(s):  
A. Gupta ◽  
L. Hu ◽  
J. P. Gore ◽  
L. X. Xu
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Skin Temperature ◽  
Forced Convection ◽  
Infrared Imaging ◽  
Transfer Problem ◽  
Blood Perfusion ◽  
Skin Surface ◽  
Temperature Distributions ◽  
Thermal Signature

Early detection is considered to be the best defense against breast cancer and imaging plays a very important role in screening and in the diagnosis of symptomatic women. Infrared thermal imaging of skin temperature changes caused by a malignant tumor in breast is a rapidly developing detection modality with potential for functional detection. Knowledge and control of environmental factors which affect the skin temperature can reduce misinterpretations and false diagnosis associated with infrared imaging. A bio heat transfer based numerical model was utilized to study the energy balance in healthy and malignant breasts subjected to low velocity forced convection in a wind tunnel. Existing estimates of metabolic heating rates and previous measurements of temperature distributions along the radial direction in a region intersecting a known tumor and a comparable region in the healthy breast of the same patient were used to estimate the blood perfusion rates for the tumor. A simplified structural and thermal model was used for representing the changes within and around the tumor. Steady state temperature distributions on the skin surface of the breasts were obtained by numerically solving the conjugate heat transfer problem. Parametric studies on the influences of the airflow on the skin thermal expression of tumors were performed. It was found that the presence of tumor may not be clearly shown due to the irregularity of the skin temperature distribution induced by the flow field. Image processing techniques could be employed to eliminate the effects of the flow field and thermal noise and significantly improve the thermal signature of the tumor on the skin surface.

scholarly journals Numerical investigation of heat transfer in a garment convective cooling system

2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Yijie Zhang ◽  
Juhong Jia ◽  
Ziyi Guo
Keyword(s):  
Heat Transfer ◽  
Thermal Comfort ◽  
Cooling System ◽  
Three Dimensional ◽  
Skin Surface ◽  
Air Gap ◽  
The Body ◽  
Three Dimensional Model ◽  
Cooling Air ◽  
Eddy Flow

AbstractA personal microclimate management system is designed to maintain thermal comfort which allows people to overcome a harsh environment. It consists of several micro-fans placed in the garment side seam to provide cooling air. The computational fluid dynamics method was used to simulate the three-dimensional model and analysis the influence of fan’s number and air gap distance. The obtained results depict that the introduced cool airflow will find its way along paths with flow resistance minimized and exhaust through several separated exit. The body heat flux is taken away at the same time. The convection effect is enhanced by the increase in the fans’ numbers, but the fans’ cooling effect varies a lot because of various air gap distances. When the air gap is small enough, the cooling air impact the body surface directly and causes fierce heat loss. While the air gap distance is large enough, the heat transfer along the skin surface could be enhanced by the eddy flow which is existed in the air gap between body and garment. These phenomena can maintain the body’s thermal comfort in a suitable range.

scholarly journals Emperor penguin body surfaces cool below air temperature

2013 ◽  
Vol 9 (3) ◽  
pp. 20121192 ◽  
Author(s):  
D. J. McCafferty ◽  
C. Gilbert ◽  
A.-M. Thierry ◽  
J. Currie ◽  
Y. Le Maho ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Loss ◽  
Thermal Imaging ◽  
Skin Surface ◽  
The Body ◽  
Emperor Penguin ◽  
Emperor Penguins ◽  
Heat Transfer Theory ◽  
Terre Adélie ◽  
Sky Conditions

Emperor penguins Aptenodytes forsteri are able to survive the harsh Antarctic climate because of specialized anatomical, physiological and behavioural adaptations for minimizing heat loss. Heat transfer theory predicts that metabolic heat loss in this species will mostly depend on radiative and convective cooling. To examine this, thermal imaging of emperor penguins was undertaken at the breeding colony of Pointe Géologie in Terre Adélie (66°40′ S 140° 01′ E), Antarctica in June 2008. During clear sky conditions, most outer surfaces of the body were colder than surrounding sub-zero air owing to radiative cooling. In these conditions, the feather surface will paradoxically gain heat by convection from surrounding air. However, owing to the low thermal conductivity of plumage any heat transfer to the skin surface will be negligible. Future thermal imaging studies are likely to yield further insights into the adaptations of this species to the Antarctic climate.

Theory and Experiment for the Effect of Vascular Microstructure on Surface Tissue Heat Transfer—Part II: Model Formulation and Solution

1984 ◽  
Vol 106 (4) ◽  
pp. 331-341 ◽  
Author(s):  
L. M. Jiji ◽  
S. Weinbaum ◽  
D. E. Lemons
Keyword(s):  
Heat Transfer ◽  
Analytic Solution ◽  
Blood Perfusion ◽  
Skin Surface ◽  
Quantitative Model ◽  
Number Density ◽  
Model Formulation ◽  
Physiological Conditions ◽  
Vascular Geometry ◽  
Theory And Experiment

In this paper the conceptual three-layer representation of surface tissue heat transfer proposed in Weinbaum, Jiji and Lemons [I], is developed into a detailed quantitative model. This model takes into consideration the variation of the number density, size and flow velocity of the countercurrent arterio-venous vessels as a function of depth from the skin surface, the directionality of blood perfusion in the transverse vessel layer and the superficial shunting of blood to the cutaneous layer. A closed form analytic solution for the boundary value problem coupling the three layers is obtained. This solution is in terms of numerically evaluated integrals describing the detailed vascular geometry, a capillary bleed-off distribution function and parameters describing the shunting of blood to the cutaneous layer. Representative heat transfer results for typical physiological conditions are presented.

A Potential Role of Coenzyme Q10 Deficiency in Severe SARS-CoV2 Infection

2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Vasilios M. Polymeropoulos ◽  
Keyword(s):  
Viral Entry ◽  
Coenzyme Q10 ◽  
Severe Infection ◽  
The Body ◽  
Therapeutic Options ◽  
Severe Illness ◽  
Infected People ◽  
Inflammatory State ◽  
Exogenous Compounds ◽  
Obesity Hypertension

There is a dramatic need for extensive research into the predictors of severe infection with SARS-CoV2 and therapeutic options for infected people. People who suffer from severe illness and higher mortality display a pattern of having specific co-morbidities (diabetes, obesity, hypertension) and are of higher age. Recent research has described methods of viral entry via receptors (ACE2, TMPRSS2) and the hyper-inflammatory state often associated with severe illness (increase in interleukins, increase in TNF-alpha). These discoveries have led to the research of currently available and developing therapies, that are helpful to patients. Deficiencies of specific vitamins and other endogenous molecules of the body should be examined to understand if a pattern exists among the people most severely affected. Coenzyme Q10 (CoQ10) is a fat-soluble substance ubiquitously expressed throughout the body that is important for the generation of ATP and mediation of inflammatory disease. CoQ10 faces a decline with increasing age, genetic predispositions, and ingestion of exogenous compounds that could reduce the level of CoQ10. Deficiencies and subsequent supplementation with CoQ10 recently has displayed encouraging results for the improvement of a wide variety of diseases. This manuscript is significant as it points to a potential relationship of CoQ10 and the population suffering from severe illness of COVID-19, and further encourages the need for research into measuring the levels of CoQ10 and vitamins to understand if levels predict severe illness and mortality. This could offer new avenues into research in combating this pandemic and potentially future therapeutic options.

scholarly journals A genetic screen for temperature-sensitive morphogenesis-defectiveCaenorhabditis elegansmutants

2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Molly C Jud ◽  
Josh Lowry ◽  
Thalia Padilla ◽  
Erin Clifford ◽  
Yuqi Yang ◽  
...  
Keyword(s):  
Cell Shape ◽  
The Body ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Fundamental Biological Process ◽  
Embryonic Morphogenesis ◽  
Cell Shape Changes ◽  
Development Temperature ◽  
Multicellular Organisms ◽  
Shape Changes

AbstractMorphogenesis involves coordinated cell migrations and cell shape changes that generate tissues and organs, and organize the body plan. Cell adhesion and the cytoskeleton are important for executing morphogenesis, but their regulation remains poorly understood. As genes required for embryonic morphogenesis may have earlier roles in development, temperature-sensitive embryonic-lethal mutations are useful tools for investigating this process. From a collection of ∼200 such Caenorhabditis elegans mutants, we have identified 17 that have highly penetrant embryonic morphogenesis defects after upshifts from the permissive to the restrictive temperature, just prior to the cell shape changes that mediate elongation of the ovoid embryo into a vermiform larva. Using whole genome sequencing, we identified the causal mutations in seven affected genes. These include three genes that have roles in producing the extracellular matrix, which is known to affect the morphogenesis of epithelial tissues in multicellular organisms: the rib-1 and rib-2 genes encode glycosyltransferases, and the emb-9 gene encodes a collagen subunit. We also used live imaging to characterize epidermal cell shape dynamics in one mutant, or1219ts, and observed cell elongation defects during dorsal intercalation and ventral enclosure that may be responsible for the body elongation defects. These results indicate that our screen has identified factors that influence morphogenesis and provides a platform for advancing our understanding of this fundamental biological process.

scholarly journals Surgical excision: an effective initial therapeutic option in the management of giant macrocystic lymphatic malformations in children

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Moaied A. Hassan ◽  
Hasan K. Gatea ◽  
Thura K. Ja’afar
Keyword(s):  
Therapeutic Option ◽  
Surgical Excision ◽  
Functional Results ◽  
The Body ◽  
Lymphatic Malformations ◽  
Therapeutic Modalities ◽  
Complete Surgical Excision ◽  
Cystic Tumors ◽  
Cystic Cavity ◽  
Embryologic Development

Abstract Background Lymphatic malformations are rare benign cystic tumors that result from localized disordered embryologic development of the lymphatic system and can develop anywhere in the body, predominantly in the head and neck. These lesions are classified according to the diameter of the largest cystic cavity within the lesion into microcystic and macrocystic types. Historically, surgical excision has been considered the mainstay of treatment and still remains the first therapeutic option of choice for many surgeons particularly for giant macrocystic lesions. Several alternative therapeutic modalities emerged including intralesional sclerotherapy and laser therapy with encouraging results. The study is designed to assess the effectiveness and safety of surgical excision as an initial therapeutic option in the management of these malformations. Results Asymptomatic mass with parental cosmetic and functional concerns was the mode of presentation in six (66.7%) patients. Seven (77.8%) patients were presented before the age of 2 years. Six (66.7%) of the patients had their lesions in the neck. Complete surgical excision was achieved in eight (88.9%) patients without any evident significant injury to vital neurovascular structures. None of the patients had any difficulties with breathing, swallowing, or phonation and cosmetic results were satisfactory in the majority (88.9%) of them. Conclusion Radical surgical excision of giant macrocystic lymphatic malformations in children is possible in experienced hands. It is an effective and safe initial therapeutic option and gives satisfactory esthetic and functional results.

scholarly journals Dealing with PET radiometabolites

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Krishna Kanta Ghosh ◽  
Parasuraman Padmanabhan ◽  
Chang-Tong Yang ◽  
Sachin Mishra ◽  
Christer Halldin ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Distribution Patterns ◽  
The Body ◽  
Analysis Process ◽  
Pet Tracer ◽  
Positron Emission ◽  
Structural Identity ◽  
Available Technology ◽  
Living Organisms ◽  
Entire Amount

Abstract Positron emission tomography (PET) offers the study of biochemical, physiological, and pharmacological functions at a cellular and molecular level. The performance of a PET study mostly depends on the used radiotracer of interest. However, the development of a novel PET tracer is very difficult, as it is required to fulfill a lot of important criteria. PET radiotracers usually encounter different chemical modifications including redox reaction, hydrolysis, decarboxylation, and various conjugation processes within living organisms. Due to this biotransformation, different chemical entities are produced, and the amount of the parent radiotracer is declined. Consequently, the signal measured by the PET scanner indicates the entire amount of radioactivity deposited in the tissue; however, it does not offer any indication about the chemical disposition of the parent radiotracer itself. From a radiopharmaceutical perspective, it is necessary to quantify the parent radiotracer’s fraction present in the tissue. Hence, the identification of radiometabolites of the radiotracers is vital for PET imaging. There are mainly two reasons for the chemical identification of PET radiometabolites: firstly, to determine the amount of parent radiotracers in plasma, and secondly, to rule out (if a radiometabolite enters the brain) or correct any radiometabolite accumulation in peripheral tissue. Besides, radiometabolite formations of the tracer might be of concern for the PET study, as the radiometabolic products may display considerably contrasting distribution patterns inside the body when compared with the radiotracer itself. Therefore, necessary information is needed about these biochemical transformations to understand the distribution of radioactivity throughout the body. Various published review articles on PET radiometabolites mainly focus on the sample preparation techniques and recently available technology to improve the radiometabolite analysis process. This article essentially summarizes the chemical and structural identity of the radiometabolites of various radiotracers including [11C]PBB3, [11C]flumazenil, [18F]FEPE2I, [11C]PBR28, [11C]MADAM, and (+)[18F]flubatine. Besides, the importance of radiometabolite analysis in PET imaging is also briefly summarized. Moreover, this review also highlights how a slight chemical modification could reduce the formation of radiometabolites, which could interfere with the results of PET imaging. Graphical abstract

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