Vitrification


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vitrification

[‚vi·trə·fə′kā·shən]
(engineering)
Heat treatment of a material such as a ceramic to produce a glazed surface.
(geology)
Formation of a glassy or noncrystalline material.
(medicine)
An experimental procedure for preserving human organs in which chemicals are added prior to cooling to prevent crystallization of water within and outside the cells, so that with coolings the molecules essentially become fixed in place.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Vitrification

 

change of a liquid into a glasslike state when the temperature is lowered. Vitrification occurs in plants and animals as well as in their isolated organs and tissues when they are abruptly chilled (below -20° C). Tissue thus frozen in an amorphous glasslike mass remains viable a long time; if carefully thawed, the vital activity of tis-sues and whole organisms can be restored.


Vitrification

 

the transition of a liquid to a solid glassy state as it is supercooled. In contrast to crystallization, where the liquid-crystal transition occurs in jumps at the melting point (Tmp) vitrification involves the conversion of melts of certain inorganic and organic substances (quartz, silicates, phosphates, borates, sulfur), which are undergoing cooling and a gradual increase in viscosity, to a solid state at the vitrification temperature (Tv). Upon vitrification, a liquid retains (inherits) the structural elements that characterized the liquid at temperatures above Tv.

With an increase in viscosity from 108to 1012newtons·sec/m2(l newton·sec/m2 = 10 poises) in the Tmp – Tv range, there is a continuous change in other physicochemical properties of the liquid being cooled. For example, the specific volume and conductivity in this range have smooth curves when plotted against temperature; the coefficient of thermal expansion and the index of refraction undergo changes in jumps.

Table 1. Anomalous ranges of certain types of glass
GlassTVTmp
Window ...............550700
Household glassware ...............530630
Optical F2 ...............430570
Vitreous silica ...............12501250

Because of the peculiarities of the changes in properties in the interval between Tmp and Tv, this range is described as anomalous. The plastic state is characteristic of various types of glass within this range (see Table 1), while the brittle state characterizes glass at temperatures below Tv.

N. M. PAVLUSHKIN

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

vitrification

Of a clay product, the condition resulting when kiln temperatures are sufficient to fuse grains and close the surface pores, making the mass impervious.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
Vitrification and warming: Oocytes (n=160 oocyte) were vitrified by cryotop method described by Kuwayama (45).
In this case, the absence of satisfactory results may be due to the lack of adequate procedures for vitrification, combined with the wrongly rewarming of encapsulated explants at room temperature.
Vitrification significantly decreased the viability of MSCs using either DMSO (VD, 54.93 [+ or -] 13.07%) or EG (VE, 87.31 [+ or -] 4.36%) as penetrating cryoprotectants compared to that of the nonvitrified control group (VC, 98.83 [+ or -] 1.03%), and compared to EG, DMSO showed less cryoprotection of cells (Figure 2(a), P < 0.05).
On the other hand, the contact between cryopreserved samples and L[N.sub.2] is not avoided in most devices used for vitrification. The main challenge is therefore combating the pathogens in larger volumes of L[N.sub.2] and in the containers where it is stored as well as developing or optimizing vitrification devices to ensure hermetical cryostorage of oocytes and embryos after vitrification.
The pH value and osmotic pressure of all vitrification solutions were measured by a pH meter (Mettler Toledo, USA) and an Osmometer (OSMOMAT030 Cryoscopic Osmometer, Germany), respectively.
The vitrification and warming procedure was essentially followed as described previously (Bang et al., 2014).
Vitrification protocols are based on dehydrating material in cryoprotective glycerol based solutions such as PVS2 and PVS3 (SAKAI and ENGELMANN, 2007).
Cryopreservation procedures: The vitrification protocol used in this study was based on Sakai, Kobayashi and Oiyama (1990).
When construction started on the vitrification plant in 2002, the largest building--standing 12 stories high and covering an area larger than a football field--was the Pretreatment Facility.
Besides, well studies have been done to investigate the gelation and vitrification mechanisms that affect membrane morphologies.
Dr Herrid says his protocol differs from all other methods of vitrification because sucrose, used in the thawing process for other species, has proven toxic to camel embryos and has therefore been replaced with other sugars.