Elastin-Like Polypeptides as Thermosensitive Polymer System

2014 ◽  
Vol 898 ◽  
pp. 296-299
Author(s):  
Xin Tang
Keyword(s):  
Phase Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Body Temperature ◽  
Chain Length ◽  
Polymer System ◽  
The Body ◽  
Thermosensitive Polymer ◽  
Inverse Transition Cycling ◽  
Inverse Transition

Thermo-responsive elastin-like polypeptides (ELPs) were successfully obtained by inverse transition cycling (ITC) and recursive directional ligation (RDL). Six ELPs displayed thermal properties, depending on their sequence and chain length. It was found that the ELP[KV8F-4 and ELP[KV8F-8 were effective as thermosensitive materials at the body temperature with phase transition temperature from 35 to 45oC.

scholarly journals Variation of thermal conductivity of DPPC lipid bilayer membranes around the phase transition temperature

2017 ◽  
Vol 14 (130) ◽  
pp. 20170127 ◽  
Author(s):  
Sina Youssefian ◽  
Nima Rahbar ◽  
Christopher R. Lambert ◽  
Steven Van Dessel
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Lipid Bilayer ◽  
Lipid Bilayers ◽  
Phase Transition Temperature ◽  
Temperature Gradients ◽  
Phase Behaviour ◽  
Gel Phase

Given their amphiphilic nature and chemical structure, phospholipids exhibit a strong thermotropic and lyotropic phase behaviour in an aqueous environment. Around the phase transition temperature, phospholipids transform from a gel-like state to a fluid crystalline structure. In this transition, many key characteristics of the lipid bilayers such as structure and thermal properties alter. In this study, we employed atomistic simulation techniques to study the structure and underlying mechanisms of heat transfer in dipalmitoylphosphatidylcholine (DPPC) lipid bilayers around the fluid–gel phase transformation. To investigate this phenomenon, we performed non-equilibrium molecular dynamics simulations for a range of different temperature gradients. The results show that the thermal properties of the DPPC bilayer are highly dependent on the temperature gradient. Higher temperature gradients cause an increase in the thermal conductivity of the DPPC lipid bilayer. We also found that the thermal conductivity of DPPC is lowest at the transition temperature whereby one lipid leaflet is in the gel phase and the other is in the liquid crystalline phase. This is essentially related to a growth in thermal resistance between the two leaflets of lipid at the transition temperature. These results provide significant new insights into developing new thermal insulation for engineering applications.

Preparation and UCST-type phase behavior of glycopolypeptides in alcoholic solvents

RSC Advances ◽  
2015 ◽  
Vol 5 (130) ◽  
pp. 108023-108029 ◽  
Author(s):  
Xi Wang ◽  
Chenglong Ge ◽  
Ying Ling ◽  
Haoyu Tang
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Behavior ◽  
Chain Length ◽  
Main Chain ◽  
Solution Phase ◽  
Side Chain ◽  
Solvent Concentration ◽  
Type Phase ◽  
Chain Composition

Glycopolypeptides with mannose pendants exhibited a reversible UCST-type phase behavior in various alcoholic solvents. The solution phase transition temperature was related to the solvent, concentration, main-chain length, and side-chain composition.

Synthesis of Nanogels of Poly Methyacrylic Acid Using Methyl Cellulose as a Template

2014 ◽  
Vol 787 ◽  
pp. 401-406
Author(s):  
Jun Li Zhang ◽  
Peng Wang ◽  
Dong An ◽  
Xue Ting Li ◽  
Qian Wu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Methacrylic Acid ◽  
Aqueous Media ◽  
Polymer System ◽  
Methyl Cellulose ◽  
Solution Temperature ◽  
Lower Phase ◽  
Lower Temperature

In recent decades, thermo sensitive polymer system has been intensively studied due to significant importance in fundamental studies and various applications. Methyl cellulose (MC) is a thermo sensitive natural polymer, having a phase transition temperature or a lower critical solution temperature of about 65 °C. When methacrylic acid (MAA) was added to the MC solution, the phase transition of MC occurred at a lower temperature less than 65°C, and a higher concentration of MAA leds to a lower phase transition temperature of MC. Based on the phase transition of MC solution triggered by MAA, the surfactant-free poly (methacrylic acid) nanogels were synthesized by using methyl cellulose as a template in an aqueous media. The resulting PMAA nanogels characterized by using dynamic light scattering (DLS) and Fourier Transform Infrared Spectroscopy (FTIR). The nanogels of poly methyacrylic acid (PMAA) were affected by the concentration of both MC and MAA. A higher concentration of MAA led to a higher polymerization rate, and the higher concentration of MC resulted in the formation of the samller size of PMAA nanogels.

EPB MODEL OF DNA AND THERMODYNAMIC EFFECTIVE BIO TIME

2011 ◽  
Vol 25 (12n13) ◽  
pp. 1151-1155
Author(s):  
V. THANH NGO ◽  
N. A. VIET
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Body Temperature ◽  
Low Temperature ◽  
Real Time ◽  
Phase Transition Temperature ◽  
Microscopic Model ◽  
Dna Melting ◽  
Combined Model ◽  
Pendulum Model

Using the simple EPB model1 of DNA (the combined model of the pendulum model of Englander,2 and Peyrard–Bishop microscopic model3), we propose a bio (DNA) time measured by EPB pendulum. We have shown that the effective bio time has a thermodynamic origin which equals the ordinary (real) time in the range of room-body temperature. Furthermore, it flows slower at low temperature and much faster near the DNA melting phase transition temperature than real time.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

Antipyretic Plants: An Updated Review

2020 ◽  
Vol 16 (1) ◽  
pp. 4-12
Author(s):  
Vandana Garg ◽  
Rohit Dutt
Keyword(s):  
Side Effects ◽  
Body Temperature ◽  
Medicinal Plants ◽  
Inflammatory Mediators ◽  
Review Paper ◽  
The Body ◽  
Hypothalamic Area ◽  
Antipyretic Activity ◽  
Disease States ◽  
Elevated Body Temperature

Background: Fever, is known as pyrexia, may occur due to infection, inflammation, or any tissue damage and disease states. Normally, the infected or damaged tissue initiates the enhanced formation of pro-inflammatory mediators like cytokines which further increases the synthesis of prostaglandin E2 (PgE2) near the hypothalamic area and thereby trigger the hypothalamus to elevate the body temperature. Objective: Antipyretics are the agents which reduce the elevated body temperature. The most commonly used antipyretic agent, paracetamol, may be fatal due to its side effects. Methods: In this review paper, Chemical Abstracts, Google Scholar, PubMed, and Science Direct were the sources for the published article to collect information regarding antipyretic activity. Results: This review compiles the antipyretic plants that may be useful to treat fever due to various diseases. Conclusion: These medicinal plants could be good alternatives for traditional allopathic antipyretics.

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