Identification of a helix–turn–helix motif for high temperature dependence of vanilloid receptor TRPV2

2021 ◽  
Author(s):  
Beiying Liu ◽  
Feng Qin
2017 ◽  
Vol 114 (7) ◽  
pp. 1589-1594 ◽  
Author(s):  
Beiying Liu ◽  
Feng Qin

Thermal transient receptor potential (TRP) channels, a group of ion channels from the transient receptor potential family, play important functions in pain and thermal sensation. These channels are directly activated by temperature and possess strong temperature dependence. Furthermore, their temperature sensitivity can be highly dynamic and use-dependent. For example, the vanilloid receptor transient receptor potential 3 (TRPV3), which has been implicated as a warmth detector, becomes responsive to warm temperatures only after intensive stimulation. Upon initial activation, the channel exhibits a high-temperature threshold in the noxious temperature range above 50 °C. This use dependence of heat sensitivity thus provides a mechanism for sensitization of thermal channels. However, how the channels acquire the use dependence remains unknown. Here, by comparative studies of chimeric channels between use-dependent and use-independent homologs, we have determined the molecular basis that underlies the use dependence of temperature sensitivity of TRPV3. Remarkably, the restoration of a single residue that is apparently missing in the use-dependent homologs could largely eliminate the use dependence of heat sensitivity of TRPV3. The location of the region suggests a mechanism of temperature-dependent gating of thermal TRP channels involving an intracellular region assembled around the TRP domain.


Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.


1996 ◽  
Vol 442 ◽  
Author(s):  
J.-M. Spaeth ◽  
S. Greulich-Weber ◽  
M. März ◽  
E. N. Kalabukhova ◽  
S. N. Lukin

AbstractThe electronic structure of nitrogen donors in 6H-, 4H- and 3C-SiC is investigated by measuring the nitrogen hyperfine (hf) interactions with electron nuclear double resonance (ENDOR) and the temperature dependence of the hf split electron paramagnetic resonance (EPR) spectra. Superhyperfine (shf) interactions with many shells of 13C and 29Si were measured in 6H-SiC. The hf and shf interactions are discussed in the framework of effective mass theory. The temperature dependence is explained with the thermal occupation of the lowest valley-orbit split A1 and E states. It is proposed that the EPR spectra of P donors observed previously in neutron transmuted 6H-SiC at low temperature (<10K) and high temperature (>60K) are all due to substitutional P donors on the two quasi-cubic and hexagonal Si sites, whereby at low temperature the E state is occupied and at high temperature the A1 state. The low temperature spectra are thus thought not to be due to P-vacancy pair defects as proposed previously.


1992 ◽  
Vol 105-110 ◽  
pp. 477-484 ◽  
Author(s):  
C.S. Sundar ◽  
A. Bharathi ◽  
Yan Ching Jean ◽  
W.Y. Ching ◽  
X. Lu ◽  
...  

1988 ◽  
Vol 21 (4) ◽  
pp. 1174-1176 ◽  
Author(s):  
C. De Rosa ◽  
G. Guerra ◽  
V. Petraccone ◽  
R. Centore ◽  
P. Corradini

1978 ◽  
Vol 32 (5) ◽  
pp. 489-493 ◽  
Author(s):  
D. B. Olson ◽  
W. G. Mallard ◽  
W. C. Gardiner

Absorptivity measurements for the 3.39 µm He-Ne laser line are reported for methane, acetylene, ethylene, ethane, propane, n-butane, and n-pentane over the temperature range 300 < T < 2000°K. Shock-heated mixtures containing formaldehyde and methyl iodide showed no absorption or transient absorption at any temperature that could be attributed to formaldehyde or methyl radicals. The temperature dependence of the absorptivities of the C2 and higher hydrocarbons was much weaker than for methane. Comparison with simple theoretical expectations and broad-band absorptivities showed that the higher hydrocarbon absorptions include quite large numbers of absorbing states.


2021 ◽  
Vol 10 (1) ◽  
pp. 586-595
Author(s):  
Ruzhuan Wang ◽  
Dingyu Li ◽  
Weiguo Li

Abstract Hardness is one of the important mechanical properties of high-temperature structural ceramics and their composites. In spite of the extensive use of the materials in high-temperature applications, there are few theoretical models for analyzing their temperature-dependent hardness. To fill this gap in the available literature, this work is focused on developing novel theoretical models for the temperature dependence of the hardness of the ceramics and their composites. The proposed model is just expressed in terms of some basic material parameters including Young’s modulus, melting points, and critical damage size corresponding to plastic deformation, which has no fitting parameters, thereby being simple for materials scientists and engineers to use in the material design. The model predictions for the temperature dependence of hardness of some oxide ceramics, non-oxide ceramics, ceramic–ceramic composites, diamond–ceramic composites, and ceramic-based cermet are presented, and excellent agreements with the experimental measurements are shown. Compared with the experimental measurements, the developed model can effectively save the cost when applied in the material design, which could be used to predict at any targeted temperature. Furthermore, the models could be used to determine the underlying control mechanisms of the temperature dependence of the hardness of the materials.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1922 ◽  
Author(s):  
Lunzhi Li ◽  
Lisheng Zhong ◽  
Kai Zhang ◽  
Jinghui Gao ◽  
Man Xu

There is a long-standing puzzle concerning whether polyethylene blends are a suitable substitution for cable-insulation-used crosslinking polyethylene (XLPE) especially at elevated temperatures. In this paper, we investigate temperature dependence of mechanical, electrical properties of blends with 70 wt % linear low density polyethylene (LLDPE) and 30 wt % high density polyethylene (HDPE) (abbreviated as 70 L-30 H). Our results show that the dielectric loss of 70 L-30 H is about an order of magnitude lower than XLPE, and the AC breakdown strength is 22% higher than XLPE at 90 °C. Moreover, the dynamic mechanical thermal analysis (DMA) measurement and hot set tests suggest that the blends shows optimal mechanical properties especially at high temperature with considerable temperature stability. Further scanning electron microscope (SEM) observation and X-ray diffraction (XRD) analysis uncover the reason for the excellent high temperature performance and temperature stability, which can be ascribed to the uniform fine-spherulite structure in 70 L-30 H blends with high crystallinity sustaining at high temperature. Therefore, our findings may enable the potential application of the blends as cable insulation material with higher thermal-endurance ability.


2011 ◽  
Vol 79 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Divina D Kaombe ◽  
Yanhong Du ◽  
Michael J Lewis

The soluble phase of milk was separated at 20 and 80°C using ultrafiltration. The resulting permeates were then subjected to further ultrafiltration and dialysis at close to these two temperatures. It was found that pH, Ca2+ and soluble Ca decreased as the separation temperature increased both in original UF permeates and in dialysates obtained from these permeates, but P decreased only slightly. The major reason for these changes was due to the precipitation of calcium phosphate/citrate complexes onto the casein micelle with concomitant release of H+. The pH of both permeates and dialysates from milk at 20°C were slightly higher than for milk. When UF permeates collected at 20 and 80°C, were each dialysed at both these temperatures, the dialysate collected at 80°C showed much less temperature dependence for pH and ionic calcium compared with that collected at 20°C. This is in contrast to milk, which shows considerable temperature dependence for pH and ionic calcium. Further experiments revealed that the pH and Ca2+ concentration of permeates showed high temperature dependence above the temperature at which they were separated, but a much lower temperature dependence below that temperature. These findings suggest that dialysis and UF of milk at high temperature provide the best means yet for estimating the pH and ionic calcium of milk at that temperature.


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