Temperature dependence of thermal properties of ex vivo liver tissue up to ablative temperatures

2019 ◽  
Vol 64 (10) ◽  
pp. 105016 ◽  
Author(s):  
V Lopresto ◽  
A Argentieri ◽  
R Pinto ◽  
M Cavagnaro
Keyword(s):  
Thermal Properties ◽  
Temperature Dependence ◽  
Liver Tissue ◽  
Ex Vivo

The temperature dependent thermal properties of ex vivo porcine liver tissue heated from 20°C to 90°C

2012 ◽  
Vol 131 (4) ◽  
pp. 3364-3364 ◽  
Author(s):  
Min Joo Choi ◽  
Sitaramanjaneya Reddy Guntur ◽  
Kang IL Lee ◽  
Dong Guk Paeng ◽  
Andrew Coleman
Keyword(s):  
Thermal Properties ◽  
Liver Tissue ◽  
Ex Vivo ◽  
Temperature Dependent ◽  
Porcine Liver

Temperature Dependence of the Thermal Properties of Optical Memory Materials

2007 ◽  
Vol 46 (6B) ◽  
pp. 3909-3911 ◽  
Author(s):  
Masashi Kuwahara ◽  
Osamu Suzuki ◽  
Yuzo Yamakawa ◽  
Naoyuki Taketoshi ◽  
Takashi Yagi ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Temperature Dependence ◽  
Optical Memory

scholarly journals Characterisation of Ex Vivo Liver Thermal Properties for Electromagnetic-Based Hyperthermic Therapies

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 3004 ◽  
Author(s):  
Nuno P. Silva ◽  
Anna Bottiglieri ◽  
Raquel C. Conceição ◽  
Martin O’Halloran ◽  
Laura Farina
Keyword(s):  
Thermal Properties ◽  
Ex Vivo ◽  
Tissue Perfusion ◽  
Heating Process ◽  
Volumetric Heat Capacity ◽  
Accurate Knowledge ◽  
Different Temperatures ◽  
Treatment Plans ◽  
Specific Tissue ◽  
Tissue Target

Electromagnetic-based hyperthermic therapies induce a controlled increase of temperature in a specific tissue target in order to increase the tissue perfusion or metabolism, or even to induce cell necrosis. These therapies require accurate knowledge of dielectric and thermal properties to optimise treatment plans. While dielectric properties have been well investigated, only a few studies have been conducted with the aim of understanding the changes of thermal properties as a function of temperature; i.e., thermal conductivity, volumetric heat capacity and thermal diffusivity. In this study, we experimentally investigate the thermal properties of ex vivo ovine liver in the hyperthermic temperature range, from 25 °C to 97 °C. A significant increase in thermal properties is observed only above 90 °C. An analytical model is developed to model the thermal properties as a function of temperature. Thermal properties are also investigated during the natural cooling of the heated tissue. A reversible phenomenon of the thermal properties is observed; during the cooling, thermal properties followed the same behaviour observed in the heating process. Additionally, tissue density and water content are evaluated at different temperatures. Density does not change with temperature; mass and volume losses change proportionally due to water vaporisation. A 30% water loss was observed above 90 °C.

scholarly journals Temperature Dependence and Anisotropic Effects in the Thermal Properties of Hen Egg-White Lysozyme Crystals

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1279
Author(s):  
Syou Maki ◽  
Seiji Fujiwara ◽  
Seiichi Tanaka ◽  
Eka Erzalia ◽  
Mizuki Kato ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Properties ◽  
Temperature Dependence ◽  
Superconducting Magnet ◽  
Egg White ◽  
Hen Egg White Lysozyme ◽  
Egg White Lysozyme ◽  
Hen Egg White ◽  
The Difference ◽  
Hen Egg

We measured the thermal conductivity (λ) and thermal diffusivity (α) of tetragonal hen egg-white lysozyme (HEWL) crystals by the transient short-hot wire method. The crystals were grown by two different methods: Magnetically levitated crystals were realized with a superconducting magnet, the c-axis of which was perpendicularly orientated in the direction of the wire, and naturally grown crystals realized by the two-liquid method, grown randomly. We confirmed the temperature dependence in both the λ and α properties by measuring the variations in temperature and by statistical analysis. These properties differed slightly depending on the presence or absence of a magnetic field applied during the crystal growth. We hypothesize that the difference originated from the orientation of the crystals caused by the magnetic field. The statistical analyses demonstrated the possibility that asymmetric thermal conduction in the protein crystals provides anisotropic effects of the thermal properties.

Adenosine Receptor Adora2b Plays a Mechanistic Role in the Protective Effect of the Volatile Anesthetic Sevoflurane during Liver Ischemia/Reperfusion

2016 ◽  
Vol 125 (3) ◽  
pp. 547-560 ◽  
Author(s):  
Tiago F. Granja ◽  
David Köhler ◽  
Jessica Schad ◽  
Claudia Bernardo de Oliveira Franz ◽  
Franziska Konrad ◽  
...  
Keyword(s):  
Adenosine Receptor ◽  
Adenosine Receptors ◽  
Alanine Aminotransferase ◽  
Liver Tissue ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Volatile Anesthetic ◽  
Liver Ischemia ◽  
Cytokine Release ◽  
Wild Type

Abstract Background Liver ischemia/reperfusion (IR) injury is characterized by hepatic tissue damage and an inflammatory response. This is accompanied by the formation and vascular sequestration of platelet–neutrophil conjugates (PNCs). Signaling through Adora2b adenosine receptors can provide liver protection. Volatile anesthetics may interact with adenosine receptors. This study investigates potential antiinflammatory effects of the volatile anesthetic sevoflurane during liver IR. Methods Experiments were performed ex vivo with human blood and in a liver IR model with wild-type, Adora2a−/−, and Adora2b−/− mice. The effect of sevoflurane on platelet activation, PNC formation and sequestration, cytokine release, and liver damage (alanine aminotransferase release) was analyzed using flow cytometry, luminometry, and immunofluorescence. Adenosine receptor expression in liver tissue was analyzed using immunohistochemistry and real-time polymerase chain reaction. Results Ex vivo experiments indicate that sevoflurane inhibits platelet and leukocyte activation (n = 5). During liver IR, sevoflurane (2 Vol%) decreased PNC formation 2.4-fold in wild-type (P < 0.05) but not in Adora2b−/− mice (n ≥ 5). Sevoflurane reduced PNC sequestration 1.9-fold (P < 0.05) and alanine aminotransferase release 3.5-fold (P < 0.05) in wild-type but not in Adora2b−/− mice (n = 5). In Adora2a−/− mice, sevoflurane also inhibited PNC formation and cytokine release. Sevoflurane diminished cytokine release (n ≥ 3) and increased Adora2b transcription and expression in liver tissue of wild-types (n = 4). Conclusions Our experiments highlight antiinflammatory and tissue-protective properties of sevoflurane during liver IR and reveal a mechanistic role of Adora2b in sevoflurane-associated effects. The targeted use of sevoflurane not only as an anesthetic but also to prevent IR damage is a promising approach in the treatment of critically ill patients.

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