Collagen thermal denaturation study for thermal angioplasty based on modified kinetic model: relation between the artery mechanical properties and collagen denaturation rate

2010 ◽  
Author(s):  
N. Shimazaki ◽  
T. Hayashi ◽  
M. Kunio ◽  
T. Arai
Keyword(s):  
Mechanical Properties ◽  
Kinetic Model ◽  
Thermal Denaturation ◽  
Collagen Denaturation ◽  
Thermal Denaturation Study ◽  
Model Relation ◽  
Denaturation Rate

Kinetics of Tropomyosin Denaturation as a Predictive Model for Verifying Thermal Processing of Beef Products

2006 ◽  
Vol 69 (10) ◽  
pp. 2447-2453 ◽  
Author(s):  
FUR-CHI CHEN ◽  
Y.-H. PEGGY HSIEH ◽  
ROGER C. BRIDGMAN ◽  
AGNES KILONZO-NTHENGE
Keyword(s):  
Kinetic Model ◽  
Thermal Denaturation ◽  
Mathematic Model ◽  
Heating Time ◽  
Enzyme Linked Immunosorbent Assay ◽  
Meat Industry ◽  
Dot Blot ◽  
Quality Control Tool ◽  
Beef Products ◽  
The Impact

An enzyme-linked immunosorbent assay (ELISA) was developed to study thermal denaturation of tropomyosin (Tm) using the time-temperature requirements for cooked beef. The ELISA employed a monoclonal antibody (MAb 2C9) raised against bovine Tm for quantifying residual Tm in muscle extracts. The specificity of MAb 2C9 to bovine Tm was demonstrated by Western blot and the analytical validity of ELISA was confirmed by dot blot. Thermal denaturation of Tm, in the temperature range between 54.4 and 70.0°C, showed first-order dependency. Kinetic parameters of Tm denaturation were derived from isothermal heating of beef muscle extract at 54.4, 57.2, 60.0, and 62.8°C. Temperature dependency of the rate constant (k) was demonstrated by Arrhenius plot; the activation energy (Ea) of Tm denaturation was determined to be 484 kJ·mol−1.A mathematic model describing the impact of the heating time-temperature on Tm denaturation was developed. Predicted Tm from the integrated time-temperature model agreed closely with the measured Tm in dynamically heat-processed beef samples. Percent errors between the measured and the predicted values ranged from −5.1 to 5.3%. The kinetic model provides an accurate and reproducible prediction of the impact of actual heating time-temperature on residual Tm in cooked beef. The MAb-based ELISA and kinetic model developed in this study have the potential to be adapted by the meat industry as a quality control tool.

Solid-phase synthesis and thermal denaturation study of cyclic PNAs targeting the HIV-1 TAR RNA loop

2007 ◽  
Vol 17 (21) ◽  
pp. 6026-6030 ◽  
Author(s):  
Gregory Upert ◽  
Mohamed Mehiri ◽  
Audrey Di Giorgio ◽  
Roger Condom ◽  
Nadia Patino
Keyword(s):  
Thermal Denaturation ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Phase Synthesis ◽  
Thermal Denaturation Study ◽  
Tar Rna ◽  
Hiv 1

scholarly journals Relaxation of ceramic tile stresses generated by fast drying: a kinetic model

2018 ◽  
Author(s):  
J. L. Amorós ◽  
V. Cantavella ◽  
E. Blasco
Keyword(s):  
Mechanical Properties ◽  
Stress Relaxation ◽  
Kinetic Model ◽  
Moisture Content ◽  
Mechanical Strength ◽  
Ceramic Tile ◽  
Drying Process ◽  
Ceramic Tiles ◽  
Relaxation Kinetic ◽  
Dry Conditions

Abstract Unfired tile mechanical properties are very important in the ceramic tile manufacturing process. Inadequate mechanical properties lead to rejects (both in unfired and fired tiles). Unfired tile mechanical strength changes significantly after the tiles exit the industrial dryer. This behaviour can be explained by assuming that the fast-drying process generates stresses in the tile, which subsequently relax. A kinetic model has been derived, based on Maxwell’s viscoelastic elements, which explains the development of dried tile mechanical strength. This increases asymptotically when the dried tiles are stored in dry conditions. However, if tiles adsorb humidity (upon exiting the dryer), tile mechanical strength rises and then decreases. This is the result of two opposing phenomena: stress relaxation raises mechanical strength while the concurrent rise in moisture content lowers mechanical strength. The developed model successfully describes this joint mechanical behaviour. Keywords: ceramic tiles, fast drying, stress relaxation, kinetic model

scholarly journals KINETIC ANALYSIS OF SECONDARY PRECIPITATION IN A HP40-Nb ALLOY

2019 ◽  
Vol 25 (4) ◽  
pp. 223
Author(s):  
Matías Humberto Sosa Lissarrague ◽  
Alfredo Juan ◽  
César Lanz ◽  
Bruno La Rocca ◽  
Alberto Picasso
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Corrosion Resistance ◽  
Kinetic Model ◽  
Kinetic Analysis ◽  
Nucleation And Growth ◽  
Austenitic Matrix ◽  
Heat Resistant Alloy ◽  
Secondary Precipitation ◽  
Secondary Carbides

<p class="AMSmaintext1">The HP40-Nb heat resistant alloy (35Ni-25Cr-Nb) was analysed by means of optical microscopy after aging treatments at 1073 and 1173 K for different times, in order to apply the classic Johnson – Mehl - Avrami – Kolmogorov kinetic model (JMAK), and thus calculate the activation energy of secondary M<sub>23</sub>C<sub>6 </sub>precipitation, which occurs during thermal aging. The relevance of this theoretical analysis is to infer the mechanism that controls the nucleation and growth of M<sub>23</sub>C<sub>6</sub> secondary carbides, since the amount and morphology of these phase influences the mechanical properties as well as the corrosion resistance in service. After performing the kinetic analysis using the JMAK model, the activation energy was found to be 208 kJ/mol, which would indicate that the secondary precipitation in this alloy is controlled by the Cr-diffusion phenomenon along the austenitic matrix.</p>

scholarly journals The effect of Na+ and K+ on the thermal denaturation of Na+ and + K+-dependent ATPase

1983 ◽  
Vol 211 (3) ◽  
pp. 771-774 ◽  
Author(s):  
T H Fischer
Keyword(s):  
Thermal Denaturation ◽  
Elevated Temperatures ◽  
Physical Nature ◽  
Pronounced Increase ◽  
Activation Free Energy ◽  
Dependent Atpase ◽  
Slow Pulse ◽  
Effective Stabilizer ◽  
Enthalpy And Entropy ◽  
Denaturation Rate

To increase our understanding of the physical nature of the Na+ and K+ forms of the Na+ + K+-dependent ATPase, thermal-denaturation studies were conducted in different types of ionic media. Thermal-denaturation measurements were performed by measuring the regeneration of ATPase activity after slow pulse exposure to elevated temperatures. Two types of experiments were performed. First, the dependence of the thermal-denaturation rate on Na+ and K+ concentrations was examined. It was found that both cations stabilized the pump protein. Also, K+ was a more effective stabilizer of the native state than was Na+. Secondly, a set of thermodynamic parameters was obtained by measuring the temperature-dependence of the thermal-denaturation rate under three ionic conditions: 60 mM-K+, 150 mM-Na+ and no Na+ or K+. It was found that ion-mediated stabilization of the pump protein was accompanied by substantial increases in activation enthalpy and entropy, the net effect being a less-pronounced increase in activation free energy.

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