Analysis of the diffracting centers of a complex 3-dimensional structure

2002 ◽  
Author(s):  
I. De Leeneer ◽  
E. Schweicher ◽  
A. Barel
Keyword(s):  
Dimensional Structure ◽  
3 Dimensional

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

Structure and Interaction of Protamine by Dark Field Electron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 160-161
Author(s):  
D.P. Bazett-Jones ◽  
F.P. Ottensmeyer
Keyword(s):  
Electron Microscopy ◽  
Dark Field ◽  
Amino Acid Sequences ◽  
Dimensional Structure ◽  
3 Dimensional ◽  
Field Electron ◽  
Proposed Model ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Positively Charged

It has been shown for some time that it is possible to obtain images of small unstained proteins, with a resolution of approximately 5Å using dark field electron microscopy (1,2). Applying this technique, we have observed a uniformity in size and shape of the 2-dimensional images of pure specimens of fish protamines (salmon, herring (clupeine, Y-l) and rainbow trout (Salmo irideus)). On the basis of these images, a model for the 3-dimensional structure of the fish protamines has been proposed (2).The known amino acid sequences of fish protamines show stretches of positively charged arginines, separated by regions of neutral amino acids (3). The proposed model for protamine structure (2) consists of an irregular, right-handed helix with the segments of adjacent arginines forming the loops of the coil.

High resolution spot scan imaging of frozen, hydrated actin bundles with 400kV electrons

1992 ◽  
Vol 50 (1) ◽  
pp. 512-513
Author(s):  
J. Jakana ◽  
M.F. Schmid ◽  
P. Matsudaira ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Binding Proteins ◽  
Actin Binding ◽  
Eukaryotic Cells ◽  
Dimensional Structure ◽  
Structural Basis ◽  
Actin Bundle ◽  
Actin Bundles ◽  
3 Dimensional ◽  
Macromolecular Assembly

Actin is a protein found in all eukaryotic cells. In its polymerized form, the cells use it for motility, cytokinesis and for cytoskeletal support. An example of this latter class is the actin bundle in the acrosomal process from the Limulus sperm. The different functions actin performs seem to arise from its interaction with the actin binding proteins. A 3-dimensional structure of this macromolecular assembly is essential to provide a structural basis for understanding this interaction in relationship to its development and functions.

scholarly journals 3-Dimensional Structure-Imitation Model of Evolution of Microstructure of Powder Body During Sintering

1999 ◽  
Vol 32 (1-4) ◽  
pp. 221-233
Author(s):  
I. G. Kamenin ◽  
R. M. Kadushnikov ◽  
V. M. Alievsky ◽  
D. M. Alievsky ◽  
S. V. Somina
Keyword(s):  
Powder Compact ◽  
3D Structure ◽  
Particle Interaction ◽  
Spherical Particles ◽  
Dimensional Structure ◽  
3 Dimensional ◽  
Powder Body ◽  
Time Dependencies ◽  
Growth Laws ◽  
Evolution Of Microstructure

This paper describes a 3D structure-imitation computer model of evolution of the powder compact during sinteringand recrystallization without nucleation. At the initial stages of the evolution processes (sintering until a mosaic structure of boundaries is formed) the model particles are spheres, and two-particle interaction laws control their evolution. During sintering the degree of mutual penetration of the particles increases, regions where spherical particles are wholly facetted by contacts with neighboring particles are formed and grow. These particles are described using the formalism of Voronoi radical polyhedra, and grain growth laws govern their evolution. The model predicts the time dependencies of the following structure parameters of the polyhedra: average polyhedron size and dispersion, total surface of the facets of the polyhedra and total lenght of the edges of the polyhedra.

Prediction of Ridging by 3-Dimensional Texture in Ferritic Stainless Steels

2014 ◽  
Vol 622-623 ◽  
pp. 72-76
Author(s):  
Yang Jin Chung ◽  
Deok Chan Ahn ◽  
Frédéric Barlat ◽  
Myoung Gyu Lee
Keyword(s):  
Crystal Plasticity ◽  
Stainless Steels ◽  
Rolling Direction ◽  
Single Layer ◽  
Experimental Result ◽  
Dimensional Structure ◽  
Ferritic Stainless Steels ◽  
3 Dimensional ◽  
Crystal Plasticity Fem ◽  
Constitutive Parameters

Experimental and numerical investigations of the ridging in ferritic stainless steels were presented in this paper. Two kinds of ferritic stainless steels exhibiting different levels of ridging were selected as model materials. The measured roughness of the uniaxially elongated specimens up to 15% in rolling direction (RD) was compared to the prediction using a rate-dependent crystal plasticity FEM (CPFEM). Initial textures of the two materials on 5 equi-spaced sequential RD planes were obtained by EBSD measurement. The initial textures were utilized as input data for the constitutive parameters of the crystal plasticity. Measured respective single planar textures were collected all together so that the 5-layer textures complete 3-dimensional structure and they were mapped onto the FE mesh. Ridging profiles predicted by the CPFEM using both every single layer texture and multilayer texture were compared to the experimental results. Predicted ridging profile of a material exhibiting weak ridging by using 5-layer EBSD mapping was in good agreement with the experimental result. On the other hand, prediction by using only single layer texture was efficient to estimate the ridging in a material exhibiting severe ridging due to the elongated cluster of analogous orientations along RD.

scholarly journals Curved or linear? Predicting the 3‐dimensional structure of α ‐helical antimicrobial peptides in an amphipathic environment

FEBS Letters ◽  
2020 ◽  
Vol 594 (6) ◽  
pp. 1062-1080
Author(s):  
Glen Bergen ◽  
Martin Stroet ◽  
Bertrand Caron ◽  
David Poger ◽  
Alan E. Mark
Keyword(s):  
Antimicrobial Peptides ◽  
Dimensional Structure ◽  
3 Dimensional
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