scholarly journals Structure of Gel Phase DPPC Determined by X-Ray Diffraction

2019 ◽  
Vol 116 (3) ◽  
pp. 225a
Author(s):  
John F. Nagle ◽  
Pierre Cognet ◽  
Fernando G. Dupuy ◽  
Stephanie A. Tristram-Nagle
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Gel Phase

Direct X-Ray Study of the Molecular Tilt in Dipalmitoyl Lecithin Bilayers

1980 ◽  
Vol 35 (6) ◽  
pp. 643-644 ◽  
Author(s):  
M. Hentschel ◽  
R. Hosemann ◽  
W. Helfrich
Keyword(s):  
Multilayer System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dipalmitoyl Lecithin ◽  
Gel Phase

Direction and angle of molecular tilt in an ordered multilayer system of dipalmitoyl lecithin and water were directly determined by X-ray diffraction as a function of temperature in the gel phase with ca. 20 wt. % of water

Influence of NaCl on Mechanical Properties and Microstructure of Cement Stone

2013 ◽  
Vol 700 ◽  
pp. 136-139
Author(s):  
Xin Tang ◽  
Jin Huang
Keyword(s):  
Mechanical Properties ◽  
Sodium Chloride ◽  
Crystalline Phase ◽  
The Other ◽  
Cement Stone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Main Crystalline Phase ◽  
Gel Phase ◽  
Scanning Electron

The mechanical properties and microstructure of cement stone containing different sodium chloride (NaCl) have been investigated. Uni-axial compression experiments were used to study mechanical properties. The main crystalline phase composition of cement specimens was determined by means of X-ray diffraction (XRD). Surface morphology of cement stone was observed by using scanning electron microscopy (SEM). The obtained results showed that compared with the other samples, the sample incorporated 14% sodium chloride was quite different, whose compressive strength was higher and microstructure was denser. The sodium chloride crystalline phase and the hydration (C-S-H) gel phase co-existed.

Novel Tri-Cholesteryl Derivatives-Based Low Molecular Mass Organic Gelators with Multi-Stimuli Responsive Properties

2015 ◽  
Vol 68 (5) ◽  
pp. 836
Author(s):  
Min Xue ◽  
Chunmeng Yu ◽  
Gang Wang ◽  
Hang Yu ◽  
Yu Fang
Keyword(s):  
Electron Microscopy ◽  
Molecular Mass ◽  
Driving Force ◽  
Sol Gel ◽  
Stimuli Responsive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hcl Gas ◽  
Gel Phase ◽  
Scanning Electron

Two novel tri-cholesteryl derivatives 1 and 2 have been designed and prepared. Gelation tests in 30 liquids revealed that 1 is a more efficient gelator than 2. Interestingly, the gel of 1/cyclohexane shows a reversible sol–gel phase transition in response to a variety of disparate stimuli such as temperature, stress, and HCl gas. In particular, a fully reversible thixotropic property was observed, which has been rarely reported before. Fourier transform infrared spectroscopy and 1H NMR measurements revealed that hydrogen bonding is an important driving force for the formation of the gel networks. The network structures of 1 and 2 in their cyclohexane gels were studied by scanning electron microscopy and X-ray diffraction analyses, and possible packing models were proposed accordingly. The findings demonstrated in the present work suggest that there is a big potential for developing tri-cholesteryl derivatives into extraordinary low molecular mass gelators.

scholarly journals Structure of gel phase DPPC determined by X-ray diffraction

2019 ◽  
Vol 218 ◽  
pp. 168-177 ◽  
Author(s):  
John F. Nagle ◽  
Pierre Cognet ◽  
Fernando G. Dupuy ◽  
Stephanie Tristram-Nagle
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Gel Phase

scholarly journals Structure of Gel Phase DMPC Determined by X-Ray Diffraction

2002 ◽  
Vol 83 (6) ◽  
pp. 3324-3335 ◽  
Author(s):  
Stephanie Tristram-Nagle ◽  
Yufeng Liu ◽  
Justin Legleiter ◽  
John F. Nagle
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Gel Phase

scholarly journals Gel phase phospholipid in the plasma membrane of sterol-depleted mouse LM cells. Analysis by fluorescence polarization and x-ray diffraction.

1981 ◽  
Vol 256 (14) ◽  
pp. 7528-7535 ◽  
Author(s):  
R. Welti ◽  
D.A. Rintoul ◽  
F. Goodsaid-Zalduondo ◽  
S. Felder ◽  
D.F. Silbert
Keyword(s):  
Plasma Membrane ◽  
Fluorescence Polarization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Phase

scholarly journals Original polymorphism in a naphthalene bisimide π-conjugated organogelator: a complex interplay between hydrogen bonding and heterocycle π-stacking

2019 ◽  
Vol 7 (42) ◽  
pp. 13120-13129 ◽  
Author(s):  
Morgane Diebold ◽  
Elliot Christ ◽  
Laure Biniek ◽  
Lydia Karmazin ◽  
Benoît Heinrich ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Supramolecular Assemblies ◽  
X Ray Diffraction ◽  
Complex Interplay ◽  
X Ray ◽  
Solid States ◽  
Π Stacking ◽  
Gel Phase

A naphthalene bisimide organogelator forms different supramolecular assemblies in the gel phase and in the solid states; the structures of these different polymorphs have been uncovered by electron and X-ray diffraction, UV and FTIR spectroscopies.

STUDY OF THE SWELLING OF THE PHOSPHOLIPID BILAYER, DEPENDING ON THE ANGLE BETWEEN THE INCLINATION OF THE DIPOLE FRAGMENTS AND THE PLANE OF THE LAMELLA

2018 ◽  
Vol 52 (3 (247)) ◽  
pp. 217-221
Author(s):  
M.A. Stepanyan
Keyword(s):  
Dipole Interaction ◽  
Phospholipid Bilayer ◽  
Bilayer Thickness ◽  
X Ray Diffraction ◽  
Minimum Thickness ◽  
X Ray ◽  
Van Der Waals Attraction ◽  
Swelling Coefficient ◽  
Gel Phase ◽  
Repulsive Forces

Using computer simulations and simultaneous X-ray diffraction at large and small angles, the dependence of the swelling coefficient of the phospholipid bilayer on the angle between the inclination of dipole fragments and the plane of the lamella was investigated. It was shown that in this case the balance between electrostatic, repulsive and van der Waals attraction forces is a particular importance. As the dipole angle increases, the repulsive forces of the electrostatic dipole-dipole interaction increase, resulting the increase of the bilayer thickness as a function of the number of –CH-groups in the phospholipid. At a certain angle the bilayer is destroyed. It is also shown that at certain small angles the bilayer takes a minimum thickness. In this case a phase transformation takes place and the system enters the “gel”-phase.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

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