Despite the progress in use of hyperthermia in clinical practice, the thermosensitivity of cancer cells is poorly understood. In a previous study, we found that sensitivity to hyperthermia varied among ovarian cancer cell lines. Upon hyperthermia, glycolytic enzymes decreased in hyperthermia-resistant SKOV3 cells. However, the mechanisms of glycolysis inhibition and their relationship with thermoresistance remain to be explored. In this study, metabolomic analysis indicated downregulation of glycolytic metabolites in SKOV3 cells after hyperthermia. Proteomic and pathway analyses predicted that the ubiquitin pathway was specifically activated in resistant SKOV3 cells, compared with hyperthermia-sensitive A2780 cells, and STUB1, a ubiquitin ligase, potentially targeted PKM, a glycolytic rate-limiting enzyme. PKM was found to be degraded via ubiquitination upon hyperthermia. Although glycolysis was inactivated by hyperthermia, ATP production was maintained. We observed that oxygen consumption and mitochondrial membrane potential were activated in SKOV3 cells but suppressed in A2780 cells. The activation of mitochondria could compensate for the ATP production lost due to suppression of glycolysis by hyperthermia. Although the physiological significance has not yet been elucidated, our results demonstrated that metabolomic adaptation from the Warburg effect to mitochondrial oxidative phosphorylation could contribute to thermoresistance in ovarian cancer cells.

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The thermoelectric materials can convert electricity and heat directly. The practical use is expected at a point to reuse unused heat. In the thermoelectric module made from many thermoelectric materials, the erformance evaluation in large temperature difference is very important. The output power, the heat flow, the conversion efficiency, and so on, can be evaluated by the measurement in large temperature difference. The heat flow is evaluated by the temperature gradient method or the flow calorimeter. ADVANCE RIKO Inc. manufactured evaluation instruments (Mini-PEM, PEM-2, F-PEM). The conversion efficiency is calculated from the output power and the heat flow. In this article, we introduce the theory, the description of equipment, the evaluation of the heat flow, the measurement example, and the present condition.

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Thermoregulation is essential for homeothermic animals including mammals. In mammals, heat production, known as an adaptive mechanism for low temperature environments, is thought to mainly occur in specific tissues such as brown adipose tissue. However, there are yet many unclear aspects regarding the intracellular heat production and its mechanism. One of the main reasons is the lack of thermosensors that can measure the temperature inside the cell or in living animals. Recently, various types of fluorescent thermosensors, each based on distinct physical properties, that are able to visualize the intracellular temperature change in live cells have been developed. Among them, genetically-encoded (i.e. protein-based) fluorescent thermosensors especially possess high potentials as intracellular thermosensors, because these sensors can be easily targeted to the subcellular organelle directly where the heat production occurs. Importantly, using the protein-based thermosensors, existence of the heterogeneity of the intracellular temperature has been unveiled. In this review, we describe recent progress regarding the development of fluorescent thermosensors and the visualization of intracellular thermal dynamics in live cells.

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Xanthan is a double helical polysaccharide which is used as a viscosity enhancer for foods and cosmetics. The helices of xanthan are unwound by heating (denaturation) and rewound by cooling (renaturation) the solution. Circular dichroism spectrum of renatured xanthan was essentially identical to that of native xanthan, which suggests renatured xanthan recovered the original local structure. However, the molar mass distribution and solution viscosity of renatured xanthan were not identical to those of native ones. This discrepancy is explained by that renatured xanthan recovered the local structure (helical structure), but its global structure was changed during the denaturation and renaturation. The changes in the global structure induced by the denaturation and renaturation were investigated mainly by static light scattering, size exclusion chromatography, and intrinsic viscosity measurements.

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In this paper, an overview of the current state of the study of the heat capacity of carbon nanotubes (CNTs), both pure and with adsorbed gas impurities, is presented. The structural features of CNTs, which determine their thermal properties, are considered, as well as the possibility of the formation of one-dimensional chains of adsorbates on the outer surface of the bundles. The temperature dependence of the heat capacity of multi-walled carbon nanotubes and bundles of single-walled carbon nanotubes as the quasi-low dimensional systems are analyzed. Ferromagnetic catalyst particles lead for the term Cnuc~T−2 in the heat capacity of the carbon nanotubes at temperatures below 1 K. Above 1 K, the contribution of electrons and nuclear hyperfine contribution is negligibly small in comparison with the phonon contribution. For MWCNTs with the increase of temperature from 2 to 300 K, a changing behavior of temperature dependence of heat capacity from the 3D through 2D to 1D was observed. Particular attention is focused on studies of the heat capacity of one-dimensional chains of atomic and molecular chains of adsorbates located in the outer grooves of bundles of single-walled carbon nanotubes. Heat capacity of 1D chains of atoms of inert gases Xe, Kr, Ar, Ne, and CH4 molecules adsorbed in grooves (G) on the outer surface of the c-SWCNT bundles was investigated both theoretically and experimentally. The frequencies of longitudinal phonon modes at the edge of the Brillouin zone were determined. The contributions of phonons and thermal vacancies to the heat capacity of xenon and the contributions of phonons and orientation vibrations to the heat capacity of nitrogen were analyzed. The contribution of orientation vibrations (librations) to the heat capacity of nitrogen chains is significant above 15 K. Comparison of the experimental and theoretical phonon curves of the heat capacity for 1D chains of methane indicates a significant contribution of the rotational motion of CH4 molecules in the all temperature range of experiment.

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