Kinetic effects of high pressure and the mechanism of thermal transformations of organosilicon peroxides

1985 ◽  
Vol 34 (9) ◽  
pp. 1825-1833
Author(s):  
V. M. Zhulin ◽  
O. B. Rudakov ◽  
G. A. Stashina ◽  
A. V. Ganyushkin ◽  
V. A. Yablokov ◽  
...  
Keyword(s):  
High Pressure ◽  
Thermal Transformations ◽  
Kinetic Effects

Kinetic effects in water and ethylene glycol. Application to high pressure organic synthesis

2000 ◽  
Vol 24 (4) ◽  
pp. 203-207 ◽  
Author(s):  
Ge´rard Jenner ◽  
Ridha Ben Salem
Keyword(s):  
High Pressure ◽  
Ethylene Glycol ◽  
Organic Synthesis ◽  
Kinetic Effects

Effect of high pressure on the activation parameters of thermal transformations of trimethylsilyl(cumyl) peroxide in the liquid phase

1986 ◽  
Vol 35 (10) ◽  
pp. 2013-2018
Author(s):  
V. M. Zhulin ◽  
O. B. Rudakov ◽  
A. V. Ganyushkin ◽  
V. A. Yablokov
Keyword(s):  
High Pressure ◽  
Liquid Phase ◽  
Activation Parameters ◽  
Thermal Transformations

The effects of pressure on the molecular structure and physiological functions of cell membranes

1984 ◽  
Vol 304 (1118) ◽  
pp. 47-68 ◽  
Keyword(s):  
Molecular Structure ◽  
High Pressure ◽  
Lipid Bilayers ◽  
Phase State ◽  
Dynamic Properties ◽  
Membrane Excitability ◽  
Passive Permeability ◽  
Physiological Functions ◽  
Molecular Information ◽  
Kinetic Effects

The effects of high pressure on the phase state and molecular structure of pure lipid bilayers are discussed. T he relations of ΔH, ΔS and Δ∨ in phase transitions are straightforward and are discernible in heterogeneous bilayers in natural membranes. The effects of pressure on the dynamic properties of bilayer constituents are less clearly understood, but order parameters obtained at pressure by different techniques show agreement. The extent and significance of hydration is poorly understood. Four physiological functions are discussed: passive permeability, active transport, membrane excitability and synaptic transmission. It is shown that a full interpretation of the kinetic effects of pressure on these processes requires much more detailed molecular information than is available at present.

Thermal transformations of 2-methylfuran in presence of hydrogen at high pressure

1960 ◽  
Vol 9 (2) ◽  
pp. 311-315
Author(s):  
A. E. Gavrilova ◽  
M. G. Gonikberg
Keyword(s):  
High Pressure ◽  
Thermal Transformations

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Prolonged Fixation Studies For Spaceflight

1973 ◽  
Vol 31 ◽  
pp. 332-333
Author(s):  
Robert Corbett ◽  
Delbert E. Philpott ◽  
Sam Black
Keyword(s):  
High Pressure ◽  
Living Systems ◽  
Prolonged Storage ◽  
Time Intervals ◽  
Early Signs ◽  
Large Numbers

Observation of subtle or early signs of change in spaceflight induced alterations on living systems require precise methods of sampling. In-flight analysis would be preferable but constraints of time, equipment, personnel and cost dictate the necessity for prolonged storage before retrieval. Because of this, various tissues have been stored in fixatives and combinations of fixatives and observed at various time intervals. High pressure and the effect of buffer alone have also been tried.Of the various tissues embedded, muscle, cartilage and liver, liver has been the most extensively studied because it contains large numbers of organelles common to all tissues (Fig. 1).

Cryosectioning plant roots prepared by high-pressure freezing

1987 ◽  
Vol 45 ◽  
pp. 662-663
Author(s):  
R.E. Crang ◽  
M. Mueller ◽  
K. Zierold
Keyword(s):  
High Pressure ◽  
Cell Walls ◽  
Plant Tissues ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Vitreous State ◽  
Radial Depth ◽  
Irregular Topography ◽  
Considerable Depth ◽  
Conventional Freezing

Obtaining frozen-hydrated sections of plant tissues for electron microscopy and microanalysis has been considered difficult, if not impossible, due primarily to the considerable depth of effective freezing in the tissues which would be required. The greatest depth of vitreous freezing is generally considered to be only 15-20 μm in animal specimens. Plant cells are often much larger in diameter and, if several cells are required to be intact, ice crystal damage can be expected to be so severe as to prevent successful cryoultramicrotomy. The very nature of cell walls, intercellular air spaces, irregular topography, and large vacuoles often make it impractical to use immersion, metal-mirror, or jet freezing techniques for botanical material.However, it has been proposed that high-pressure freezing (HPF) may offer an alternative to the more conventional freezing techniques, inasmuch as non-cryoprotected specimens may be frozen in a vitreous, or near-vitreous state, to a radial depth of at least 0.5 mm.

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