Time Dependent Mathematical Model of Thermoregulation in Human Dermal Parts During Sarcopenia

2021 ◽  
Vol 4 (1) ◽  
pp. 41-53
Author(s):  
Dev Chandra Shrestha ◽  
Saraswati Acharya
Keyword(s):  
Body Weight ◽  
Muscle Mass ◽  
Vital Role ◽  
Time Dependent ◽  
The Finite Element Method ◽  
Bioheat Equation ◽  
One Dimensional ◽  
Metabolic Heat ◽  
Human Body Temperature ◽  
Weight Impact

Sarcopenia is an illness characterized by the loss of skeletal muscle mass, and its strength occurs in aging after 50 years. Muscle mass plays a vital role in body weight and metabolism. The loses in body weight impact reducing the basal metabolic rate (BMR). The BMR affects the human body temperature due to lower metabolic heat production during sarcopenia. The present study deals with time dependent temperature variation in human dermal parts during sarcopenia. The finite element method is used to solve a one-dimensional bioheat equation. In this model, the thickness of the epidermis, dermis layers, and the BMR of different aging, are estimated. The results show the nodal temperature of the epidermis and dermis layers increases due to reducing the thickness. Further, the subcutaneous nodal temperature slightly decreases due to the cause of BMR.

Isoleucine increases muscle mass through promoting myogenesis and intramyocellular fat deposition

2021 ◽  
Author(s):  
Shuge Liu ◽  
Yunmei Sun ◽  
Rui Zhao ◽  
Yingqian Wang ◽  
Wanrong Zhang ◽  
...  
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Mass ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vital Role ◽  
Fat Deposition ◽  
Branched Chain Amino Acid ◽  
Branched Chain

Isoleucine (Ile), as a branched-chain amino acid (BCAA), has a vital role in regulating body weight and muscle protein synthesis.

scholarly journals Analytical solution of one-dimensional Pennes’ bioheat equation

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 1084-1092
Author(s):  
Hongyun Wang ◽  
Wesley A. Burgei ◽  
Hong Zhou
Keyword(s):  
Analytical Solution ◽  
Radiofrequency Energy ◽  
Bioheat Equation ◽  
Surface Cooling ◽  
One Dimensional ◽  
The Fourier Transform ◽  
The One ◽  
Parameter Values ◽  
Mathematical Derivation ◽  
Effect Of Surface

Abstract Pennes’ bioheat equation is the most widely used thermal model for studying heat transfer in biological systems exposed to radiofrequency energy. In their article, “Effect of Surface Cooling and Blood Flow on the Microwave Heating of Tissue,” Foster et al. published an analytical solution to the one-dimensional (1-D) problem, obtained using the Fourier transform. However, their article did not offer any details of the derivation. In this work, we revisit the 1-D problem and provide a comprehensive mathematical derivation of an analytical solution. Our result corrects an error in Foster’s solution which might be a typo in their article. Unlike Foster et al., we integrate the partial differential equation directly. The expression of solution has several apparent singularities for certain parameter values where the physical problem is not expected to be singular. We show that all these singularities are removable, and we derive alternative non-singular formulas. Finally, we extend our analysis to write out an analytical solution of the 1-D bioheat equation for the case of multiple electromagnetic heating pulses.

scholarly journals Hamiltonian Approach to Magnetic Fields with Toroidal Surfaces

1985 ◽  
Vol 40 (10) ◽  
pp. 959-967
Author(s):  
A. Salat
Keyword(s):  
Magnetic Field ◽  
Hamiltonian System ◽  
Magnetic Fields ◽  
Constant Pressure ◽  
Time Dependent ◽  
Hamiltonian Approach ◽  
One Dimensional ◽  
Mhd Equilibrium ◽  
Magnetic Surfaces ◽  
Rotational Transform

The equivalence of magnetic field line equations to a one-dimensional time-dependent Hamiltonian system is used to construct magnetic fields with arbitrary toroidal magnetic surfaces I = const. For this purpose Hamiltonians H which together with their invariants satisfy periodicity constraints have to be known. The choice of H fixes the rotational transform η(I). Arbitrary axisymmetric fields, and nonaxisymmetric fields with constant η(I) are considered in detail.Configurations with coinciding magnetic and current density surfaces are obtained. The approach used is not well suited, however, to satisfying the additional MHD equilibrium condition of constant pressure on magnetic surfaces.

scholarly journals Skeletal muscle mass is associated with erythropoietin response in hemodialysis patients

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Tomoaki Takata ◽  
Yukari Mae ◽  
Kentaro Yamada ◽  
Sosuke Taniguchi ◽  
Shintaro Hamada ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Linear Regression Analysis ◽  
Transferrin Saturation ◽  
Resistance Index ◽  
Hemodialysis Patients ◽  
Maintenance Hemodialysis ◽  
Weekly Dose

Abstract Background Hyporesponsiveness to erythropoietin stimulating agent (ESA) is associated with poor outcomes in patients with chronic kidney disease. Although ESA hyporesponsiveness and sarcopenia have a common pathophysiological background, clinical evidence linking them is scarce. The purpose of the study was to investigate the relationship between ESA responsiveness and skeletal muscle mass in hemodialysis patients. Methods This cross-sectional study analyzed 70 patients on maintenance hemodialysis who were treated with ESA. ESA responsiveness was evaluated by erythropoietin resistance index (ERI), calculated as a weekly dose of ESA divided by body weight and hemoglobin (IU/kg/week/dL), and a weekly dose of ESA/hemoglobin (IU/week/dL). A dose of ESA is equivalated to epoetin β. Correlations between ESA responsiveness and clinical parameters including skeletal muscle mass were analyzed. Results Among the 70 patients, ERI was positively correlated to age (p < 0.002) and negatively correlated to height (p < 0.001), body weight (p < 0.001), BMI (p < 0.001), skeletal muscle mass (p < 0.001), transferrin saturation (TSAT) (p = 0.049), and zinc (p = 0.006). In the multiple linear regression analysis, TSAT, zinc, and skeletal muscle mass were associated with ERI and weekly ESA dose/hemoglobin. Conclusions Skeletal muscle mass was the independent predictor for ESA responsiveness as well as TSAT and zinc. Sarcopenia is another target for the management of anemia in patients with hemodialysis.

A time-dependent model for high-pressure discharges in narrow ablative capillaries

1993 ◽  
Vol 50 (1) ◽  
pp. 51-70 ◽  
Author(s):  
D. Zoler ◽  
S. Cuperman ◽  
J. Ashkenazy ◽  
M. Caner ◽  
Z. Kaplan
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Time Dependent ◽  
Dimensional Model ◽  
Plasma Sources ◽  
One Dimensional ◽  
Space And Time ◽  
Dependent Model ◽  
Energy Equations ◽  
Time Dependent Model

A time-dependent quasi-one-dimensional model is developed for studying high- pressure discharges in ablative capillaries used, for example, as plasma sources in electrothermal launchers. The main features of the model are (i) consideration of ablation effects in each of the continuity, momentum and energy equations; (ii) use of a non-ideal equation of state; and (iii) consideration of space- and time-dependent ionization.

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