Physical properties of the hybrid lipid POPC on micrometer-sized domains in mixed lipid membranes

2015 ◽  
Vol 17 (32) ◽  
pp. 20882-20888 ◽  
Author(s):  
Naofumi Shimokawa ◽  
Mariko Nagata ◽  
Masahiro Takagi
Keyword(s):  
Physical Properties ◽  
Lipid Membranes ◽  
Ternary Mixture ◽  
Domain Boundary ◽  
The Other ◽  
Component Mixture ◽  
Other Hand ◽  
Liquid Ordered ◽  
Mixed Lipid Membranes ◽  
Chain Ordering

In a DPPC/DOPC/POPC ternary mixture, hybrid lipids are localized at the solid-ordered domain boundary. On the other hand, in a DPPC/DOPC/POPC/Chol four-component mixture, they are included in the liquid-ordered domain and disturb the chain ordering of lipids in the domain.

The Sucrose-Natural Gypsum Makes the Compound Retarder to the Cement and the Concretes Performance Influence Experimental Study

2011 ◽  
Vol 335-336 ◽  
pp. 1219-1222
Author(s):  
Ru Qin Wang
Keyword(s):  
Experimental Study ◽  
Physical Properties ◽  
Experimental Research ◽  
Mixing Time ◽  
The Other ◽  
Positive Correlation ◽  
Other Hand ◽  
Cement And Concrete

By the experimental research to the effect sucrose-natural gypsum as composite retarder on the performance of cement and concrete. This paper analyzes and summarizes the fact that the influence of this kind of composite retarder is more obvious than the slow setting effect of a single sugar or plaster. And the retardation of cement and concrete the mixing time is basically the amount of sugar a positive correlation. And on the other hand, it will not influence other physical properties.

scholarly journals Preparation and Thermal and Anti-UV Properties of Chitosan/Mica Copolymer

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Yih-Sheng Huang ◽  
Sheng-Haur Yu ◽  
Yea-Ru Sheu ◽  
Kuo-Shien Huang
Keyword(s):  
Experimental Data ◽  
Thermal Stability ◽  
Free Radical ◽  
Physical Properties ◽  
Ammonium Persulfate ◽  
Sodium Bisulfite ◽  
The Other ◽  
Other Hand

This experiment aims to produce a free radical while annoying the oxidizing-reducing reagent of the ammonium persulfate and the sodium bisulfite under nitrogen, then trigger copolymerization between modified-mica and chitosan to prepare a variety of copolymers. This experiment also aims to study the related properties of these copolymer materials. The experimental data shows that the copolymer has more thermal stability and better absorption of UV than chitosan. But the above physical properties will be less if the mica ratio in copolymer is more than 8%. On the other hand, the SEM photo of the microstructure also shows that the modified mica distributes homogeneously on the surface of the film of the copolymer.

scholarly journals Isospectral drums and simple groups

2018 ◽  
Vol 15 (04) ◽  
pp. 1850060
Author(s):  
Koen Thas
Keyword(s):  
Physical Properties ◽  
The Other ◽  
Simple Groups ◽  
Finite Simple Groups ◽  
Planar Domains ◽  
Other Hand ◽  
Isospectral Manifolds ◽  
Transplantation Technique ◽  
Rule Out

Nearly every known pair of isospectral but nonisometric manifolds — with as most famous members isospectral bounded [Formula: see text]-planar domains which makes one “not hear the shape of a drum” [M. Kac, Can one hear the shape of a drum? Amer. Math. Monthly 73(4 part 2) (1966) 1–23] — arise from the (group theoretical) Gassmann–Sunada method. Moreover, all the known [Formula: see text]-planar examples (so counter examples to Kac’s question) are constructed through a famous specialization of this method, called transplantation. We first describe a number of very general classes of length equivalent manifolds, with as particular cases isospectral manifolds, in each of the constructions starting from a given example that arises itself from the Gassmann–Sunada method. The constructions include the examples arising from the transplantation technique (and thus in particular the known planar examples). To that end, we introduce four properties — called FF, MAX, PAIR and INV — inspired by natural physical properties (which rule out trivial constructions), that are satisfied for each of the known planar examples. Vice versa, we show that length equivalent manifolds with FF, MAX, PAIR and INV which arise from the Gassmann–Sunada method, must fall under one of our prior constructions, thus describing a precise classification of these objects. Due to the nature of our constructions and properties, a deep connection with finite simple groups occurs which seems, perhaps, rather surprising in the context of this paper. On the other hand, our properties define in some sense physically irreducible pairs of length equivalent manifolds — “atoms” of general pairs of length equivalent manifolds, in that such a general pair of manifolds is patched up out of irreducible pairs — and that is precisely what simple groups are for general groups.

Formation of modulated phases and domain rigidification in fatty acid-containing lipid membranes

2017 ◽  
Vol 19 (20) ◽  
pp. 13252-13263 ◽  
Author(s):  
Naofumi Shimokawa ◽  
Rieko Mukai ◽  
Mariko Nagata ◽  
Masahiro Takagi
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Palmitic Acid ◽  
Elaidic Acid ◽  
Lipid Membranes ◽  
Phytanic Acid ◽  
Domain Boundary ◽  
Line Tension ◽  
Modulated Phases ◽  
Liquid Ordered

A liquid-ordered domain is transformed into a solid-ordered domain by the addition of palmitic acid or elaidic acid. Oleic acid and phytanic acid reduce the line tension at the liquid domain boundary and consequently modulated phases appear.

scholarly journals 1. The Evolution of Asteroids as Meteorite Parent-Bodies

1977 ◽  
Vol 39 ◽  
pp. 265-275 ◽  
Author(s):  
C. R. Chapman
Keyword(s):  
Physical Properties ◽  
Source Region ◽  
The Other ◽  
Asteroid Belt ◽  
Correct Interpretation ◽  
Ordinary Chondrites ◽  
Main Belt ◽  
Compelling Reason ◽  
Other Hand ◽  
Cometary Origin

The hypothesis that the asteroid belt is the source region for nearly all meteorite remains viable and there is no compelling reason to ascribe any meteorites to cometary origin. On the other hand, uncertainties about the true composition of the larger S type asteroids and difficulties in finding plausible main-belt source-bodies for the ordinary chondrites leave room open for further speculation on this question. The scenario for the evolution of asteroids, based on collisional models of two distinct populations of different physical properties, is being criticized and refined. It remains uncertain whether this approach will ultimately prove to be the correct interpretation of the collisional evolution of asteroids.

Properties of Higher Polymers in Solution. III. The Action of Ultra-Violet Light on Dissolved Rubber

1936 ◽  
Vol 9 (4) ◽  
pp. 570-572 ◽  
Author(s):  
Kurt H. Meyer ◽  
Cesare Ferri
Keyword(s):  
Physical Properties ◽  
Wave Length ◽  
Ultra Violet ◽  
The Other ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Ultra Violet Radiation ◽  
Gutta Percha ◽  
Other Hand ◽  
Violet Radiation

Abstract The action of ultra-violet radiation on rubber has been the object of a long series of investigations. According to van Rossem, rubber is depolymerized under the action of light. Asano on the other hand thinks that ultra-violet light, is able to bring about either polymerization or depolymerization according to its wave-length. More recently Dogadkin and Pantschenkov have carried out experiments in an atmosphere of nitrogen, during the course of which they have found a strong diminution in the viscosity. From this fact they have concluded that light is able to cause depolymerization and micellar degradation. We have undertaken a study of the action of ultra-violet light on rubber in order to prove whether the double cis-linkages of rubber undergo a transposition into trans-linkages, for numerous instances are known where light causes these cis-trans-transpositions. In the case of rubber, one should obtain, therefore, either a hydrocarbon of the gutta-percha type or, if light causes a sort of cis-trans-equilibrium, a hydrocarbon with double cis-linkages distributed irregularly. In our experiments we were extremely careful to exclude oxygen, since some years ago Henri proved that ultra-violet light activates greatly the oxidation of rubber. On the other hand it is known that oxidation causes a diminution in the length of the chains which modifies considerably the physical properties, for example, the viscosity, and which may mask the effect produced by light.

Investigating the early phase of the galaxy evolution through high-z damped Lyα absorption systems

2019 ◽  
Vol 15 (S341) ◽  
pp. 294-296
Author(s):  
Kazuyuki Ogura ◽  
Tohru Nagao ◽  
Masatoshi Imanishi ◽  
Nobunari Kashikawa ◽  
Yoshiaki Taniguchi ◽  
...  
Keyword(s):  
Physical Properties ◽  
Galaxy Evolution ◽  
Early Phase ◽  
Luminosity Function ◽  
The Other ◽  
Other Hand ◽  
The Galaxy

AbstractWe present the physical properties of Lyα emitters (LAEs) in a “DLA-concentrated regions” where there are 3 or more DLA within (50 Mpc)3 cubic box. We observed LAEs in a DLA-concentrated region at z = 2.3, the J1230+34 field, with Subaru/Suprime-Cam. In the 50 Mpc scale, we found no deferences in properties of LAEs such as Lyα luminosity function in the DLA-concentrated region compared to other fields at similar redshift. On the other hand, we found a ∼10 Mpc scale LAE overdensity around a strong DLA with NHI = 1021.08 cm−2.

Deformation Characteristics of Granular Materials Under Hydrostatic Compression

1972 ◽  
Vol 9 (4) ◽  
pp. 338-350 ◽  
Author(s):  
M. A. El-Sohby ◽  
K. Z. Andrawes
Keyword(s):  
Physical Properties ◽  
Granular Materials ◽  
Hydrostatic Compression ◽  
The Other ◽  
Deformation Characteristics ◽  
Total Deformation ◽  
Triaxial Apparatus ◽  
Other Hand ◽  
Dense Specimen

The deformation characteristics of sand and other granular materials under hydrostatic compression are studied in the conventional triaxial apparatus using 4 × 4 in. (10 × 10 cm) specimens. Modifications have been made for measuring small axial strains and free end platens were used. The errors in testing have been estimated and their effect was evaluated. Different kinds of granular materials were tested to study the effect of the physical properties of the material on its deformational behavior.The results showed that the total deformation of a mass of sand subjected to a hydrostatic compression is generally not recoverable, and can be divided into elastic (recoverable) and sliding (irrecoverable) components. It has also been found out that for a dense specimen of sand most of the total deformation is recoverable, since the sliding component of deformation represents only a small fraction of the total deformation. The results also showed that for the very dense specimen axial and radial strains were nearly equal which implies that the material behaves isotropically. On the other hand for a loose specimen the sliding component of deformation becomes large and thus the total deformation of the specimen cannot be considered completely elastic. Furthermore axial and radial strains of the loose specimen were not equal.

scholarly journals Using spectral decomposition of the signals from laurdan-derived probes to evaluate the physical state of membranes in live cells

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 763 ◽  
Author(s):  
Serge Mazeres ◽  
Farzad Fereidouni ◽  
Etienne Joly
Keyword(s):  
Spectral Decomposition ◽  
Mammalian Cells ◽  
Lipid Droplets ◽  
Physical State ◽  
The Other ◽  
Live Cells ◽  
Whole Cells ◽  
Mammalian Cell Lines ◽  
Other Hand ◽  
Liquid Ordered

Background: We wanted to investigate the physical state of biological membranes in live cells under the most physiological conditions possible. Methods: For this we have been using laurdan, C-laurdan or M-laurdan to label a variety of cells, and a biphoton microscope equipped with both a thermostatic chamber and a spectral analyser. We also used a flow cytometer to quantify the 450/530 nm ratio of fluorescence emissions by whole cells. Results: We find that using all the information provided by spectral analysis to perform spectral decomposition dramatically improves the imaging resolution compared to using just two channels, as commonly used to calculate generalized polarisation (GP). Coupled to a new plugin called Fraction Mapper, developed to represent the fraction of light intensity in the first component in a stack of two images, we obtain very clear pictures of both the intra-cellular distribution of the probes, and the polarity of the cellular environments where the lipid probes are localised. Our results lead us to conclude that, in live cells kept at 37°C, laurdan, and M-laurdan to a lesser extent, have a strong tendency to accumulate in the very apolar environment of intra-cytoplasmic lipid droplets, but label the plasma membrane (PM) of mammalian cells ineffectively. On the other hand, C-laurdan labels the PM very quickly and effectively, and does not detectably accumulate in lipid droplets. Conclusions: From using these probes on a variety of mammalian cell lines, as well as on cells from Drosophila and Dictyostelium discoideum, we conclude that, apart from the lipid droplets, which are very apolar, probes in intracellular membranes reveal a relatively polar and hydrated environment, suggesting a very marked dominance of liquid disordered states. PMs, on the other hand, are much more apolar, suggesting a strong dominance of liquid ordered state, which fits with their high sterol contents.

scholarly journals Using spectral decomposition of the signals from laurdan-derived probes to evaluate the physical state of membranes in live cells

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 763 ◽  
Author(s):  
Serge Mazeres ◽  
Farzad Fereidouni ◽  
Etienne Joly
Keyword(s):  
Spectral Decomposition ◽  
Mammalian Cells ◽  
Lipid Droplets ◽  
Physical State ◽  
The Other ◽  
Live Cells ◽  
Whole Cells ◽  
Mammalian Cell Lines ◽  
Other Hand ◽  
Liquid Ordered

Background: We wanted to investigate the physical state of biological membranes in live cells under the most physiological conditions possible. Methods: For this we have been using laurdan, C-laurdan or M-laurdan to label a variety of cells, and a biphoton microscope equipped with both a thermostatic chamber and a spectral analyser. We also used a flow cytometer to quantify the 450/530 nm ratio of fluorescence emissions by whole cells. Results: We find that using all the information provided by spectral analysis to perform spectral decomposition dramatically improves the imaging resolution compared to using just two channels, as commonly used to calculate generalized polarisation (GP). Coupled to a new plugin called Fraction Mapper, developed to represent the fraction of light intensity in the first component in a stack of two images, we obtain very clear pictures of both the intra-cellular distribution of the probes, and the polarity of the cellular environments where the lipid probes are localised. Our results lead us to conclude that, in live cells kept at 37°C, laurdan, and M-laurdan to a lesser extent, have a strong tendency to accumulate in the very apolar environment of intra-cytoplasmic lipid droplets, but label the plasma membrane (PM) of mammalian cells ineffectively. On the other hand, C-laurdan labels the PM very quickly and effectively, and does not detectably accumulate in lipid droplets. Conclusions: From using these probes on a variety of mammalian cell lines, as well as on cells from Drosophila and Dictyostelium discoideum, we conclude that, apart from the lipid droplets, which are very apolar, probes in intracellular membranes reveal a relatively polar and hydrated environment, suggesting a very marked dominance of liquid disordered states. PMs, on the other hand, are much more apolar, suggesting a strong dominance of liquid ordered state, which fits with their high sterol contents.

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