scholarly journals Equilibrium Volume Change and Elastic Properties of Poly(N-isopropylacrylamide) Gels Containing Latex Particles

2001 ◽  
Vol 33 (8) ◽  
pp. 554-559 ◽  
Author(s):  
Akifumi Ikehata ◽  
Minako Takano ◽  
Hideharu Ushiki
Keyword(s):  
Elastic Properties ◽  
Volume Change ◽  
Latex Particles ◽  
Equilibrium Volume

Dispersion of Latex Particles in a Nematic Solution. 2. Phase Diagram and Elastic Properties

Langmuir ◽  
1996 ◽  
Vol 12 (16) ◽  
pp. 3789-3792 ◽  
Author(s):  
V. A. Raghunathan ◽  
P. Richetti ◽  
D. Roux
Keyword(s):  
Phase Diagram ◽  
Elastic Properties ◽  
Latex Particles

Tapping mode force microscopy imaging of elastic properties of core-shell latex particles

1999 ◽  
Vol 27 (5-6) ◽  
pp. 392-395 ◽  
Author(s):  
I. Stapff ◽  
G. Weidemann ◽  
C. Schellenberg ◽  
M. Regenbrecht ◽  
S. Akari ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Core Shell ◽  
Microscopy Imaging ◽  
Latex Particles ◽  
Tapping Mode ◽  
Force Microscopy

A Freeze Shadow Technique for the Preparation of Soft Paint Latexes for Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 314-315
Author(s):  
Earl R. Walter ◽  
Glen H. Bryant
Keyword(s):  
Sample Preparation ◽  
High Vacuum ◽  
Vacuum System ◽  
Latex Particles ◽  
New Methods ◽  
Diffusion Pump ◽  
Film Forming ◽  
Routine Basis ◽  
Distribution Studies ◽  
Preparation Techniques

With the development of soft, film forming latexes for use in paints and other coatings applications, it became desirable to develop new methods of sample preparation for latex particle size distribution studies with the electron microscope. Conventional latex sample preparation techniques were inadequate due to the pronounced tendency of these new soft latex particles to distort, flatten and fuse on the substrate when they dried. In order to avoid these complications and obtain electron micrographs of undistorted latex particles of soft resins, a freeze-dry, cold shadowing technique was developed. The method has now been used in our laboratory on a routine basis for several years.The cold shadowing is done in a specially constructed vacuum system, having a conventional mechanical fore pump and oil diffusion pump supplying vacuum. The system incorporates bellows type high vacuum valves to permit a prepump cycle and opening of the shadowing chamber without shutting down the oil diffusion pump. A baffeled sorption trap isolates the shadowing chamber from the pumps.

Artifacts caused by dehydration and epoxy embedding in TEM

1991 ◽  
Vol 49 ◽  
pp. 338-339
Author(s):  
Hilton H. Mollenhauer
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Volume Change ◽  
Tissue Damage ◽  
Beam Specimen ◽  
Chemical Fixation ◽  
Resin Impregnation ◽  
Storage Vesicles ◽  
A Cell ◽  
Tissue Shrinkage

Various means have been devised to preserve biological specimens for electron microscopy, the most common being chemical fixation followed by dehydration and resin impregnation. It is intuitive, and has been amply demonstrated, that these manipulations lead to aberrations of many tissue elements. This report deals with three parts of this problem: specimen dehydration, epoxy embedding resins, and electron beam-specimen interactions. However, because of limited space, only a few points can be summarized.Dehydration: Tissue damage, or at least some molecular transitions within the tissue, must occur during passage of a cell or tissue to a nonaqueous state. Most obvious, perhaps, is a loss of lipid, both that which is in the form of storage vesicles and that associated with tissue elements, particularly membranes. Loss of water during dehydration may also lead to tissue shrinkage of 5-70% (volume change) depending on the tissue and dehydrating agent.

Electron Microscopy and image reconstruction reveal the structural basis for spectrin's elastic properties

1992 ◽  
Vol 50 (1) ◽  
pp. 510-511
Author(s):  
Amy M. McGough ◽  
Robert Josephs
Keyword(s):  
Electron Microscopy ◽  
Elastic Properties ◽  
Conformational Changes ◽  
Quaternary Structure ◽  
Three Dimensional ◽  
Membrane Skeleton ◽  
Projection Algorithm ◽  
Structural Basis ◽  
Iterative Approximation ◽  
Membrane Skeletons

The remarkable deformability of the erythrocyte derives in large part from the elastic properties of spectrin, the major component of the membrane skeleton. It is generally accepted that spectrin's elasticity arises from marked conformational changes which include variations in its overall length (1). In this work the structure of spectrin in partially expanded membrane skeletons was studied by electron microscopy to determine the molecular basis for spectrin's elastic properties. Spectrin molecules were analysed with respect to three features: length, conformation, and quaternary structure. The results of these studies lead to a model of how spectrin mediates the elastic deformation of the erythrocyte.Membrane skeletons were isolated from erythrocyte membrane ghosts, negatively stained, and examined by transmission electron microscopy (2). Particle lengths and end-to-end distances were measured from enlarged prints using the computer program MACMEASURE. Spectrin conformation (straightness) was assessed by calculating the particles’ correlation length by iterative approximation (3). Digitised spectrin images were correlation averaged or Fourier filtered to improve their signal-to-noise ratios. Three-dimensional reconstructions were performed using a suite of programs which were based on the filtered back-projection algorithm and executed on a cluster of Microvax 3200 workstations (4).

The buckling of thin EM specimens

1990 ◽  
Vol 48 (4) ◽  
pp. 850-851
Author(s):  
A.R. Thölén
Keyword(s):  
Electron Microscope ◽  
Elastic Properties ◽  
Crystal Surface ◽  
Specimen Surface ◽  
Radius Of Curvature ◽  
Thin Foils ◽  
Thin Electron ◽  
Regular Patterns

Thin electron microscope specimens often contain irregular bend contours (Figs. 1-3). Very regular bend patterns have, however, been observed around holes in some ion-milled specimens. The purpose of this investigation is twofold. Firstly, to find the geometry of bent specimens and the elastic properties of extremely thin foils and secondly, to obtain more information about the background to the observed regular patterns.The specimen surface is described by z = f(x,y,p), where p is a parameter, eg. the radius of curvature of a sphere. The beam is entering along the z—direction, which coincides with the foil normal, FN, of the undisturbed crystal surface (z = 0). We have here used FN = [001]. Furthermore some low indexed reflections are chosen around the pole FN and in our fcc crystal the following g-vectors are selected:

Short-term volume and turgor regulation in yeast

2008 ◽  
Vol 45 ◽  
pp. 147-160 ◽  
Author(s):  
Jörg Schaber ◽  
Edda Klipp
Keyword(s):  
Dynamic Model ◽  
Volume Change ◽  
Volume Regulation ◽  
Time Course ◽  
Osmotic Shock ◽  
Intracellular Concentration ◽  
Short Term ◽  
Hydrodynamic Property ◽  
Turgor Regulation ◽  
Thermodynamic Framework

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.

The Hydrostatic Pressure Effect on Elastic Properties of B2-Phase Single Crystals Ti50Ni48Fe2and Ti50Ni45Fe5Alloys

1995 ◽  
Vol 05 (C8) ◽  
pp. C8-729-C8-734
Author(s):  
A.I. Lotkov ◽  
V.P. Lapshin ◽  
V.A. Goncharova ◽  
H.V Chernysheva ◽  
V.N. Grishkov ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Single Crystals ◽  
Elastic Properties ◽  
Pressure Effect ◽  
B2 Phase

FREE VOLUME CHANGE OF METALLIC GLASSES STUDIED BY THERMAL EXPANSION MEASUREMENTS

1980 ◽  
Vol 41 (C8) ◽  
pp. C8-875-C8-877
Author(s):  
E. Girt ◽  
P. Tomić ◽  
A. Kuršumović ◽  
T. Mihać-Kosanović
Keyword(s):  
Thermal Expansion ◽  
Free Volume ◽  
Volume Change ◽  
Metallic Glasses

Increased Protein Synthesis by Human Platelets during Phagocytosis of Latex Particles in Vitro

1976 ◽  
Vol 35 (02) ◽  
pp. 350-357 ◽  
Author(s):  
Hana Bessler ◽  
Galila Agam ◽  
Meir Djaldetti
Keyword(s):  
Protein Synthesis ◽  
Fold Increase ◽  
Human Platelets ◽  
Polystyrene Latex ◽  
Latex Particles ◽  
The Third ◽  
Platelet Protein ◽  
Dose Dependent ◽  
Phagocytotic Activity

SummaryA three-fold increase of protein synthesis by human platelets during in vitro phagocytosis of polystyrene latex particles was detected. During the first two hours of incubation, the percentage of phagocytizing platelets and the number of latex particles per platelet increased; by the end of the third hour, the first parameter remained stable, while the number of latex particles per cell had decreased.Vincristine (20 μg/ml of cell suspension) inhibited platelet protein synthesis. This effect was both time- and dose-dependent. The drug also caused a decrease in the number of phagocytizing cells, as well as in their phagocytotic activity.

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