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Cryonics (from Greek: κρύος kryos, meaning "cold") is the low-temperature freezing (usually at −196 °C or −320.8 °F or 77.1 K) and storage of human remains in the hope that resurrection may be possible in the future. [1] [2] Cryonics is regarded with skepticism by the mainstream scientific community.
A tank of liquid nitrogen, used to supply a cryogenic freezer (for storing laboratory samples at a temperature of about −150 °C or −238 °F) Controlled-rate and slow freezing, also known as slow programmable freezing (SPF), [18] is a technique where cells are cooled to around -196 °C over the course of several hours.
Nitrogen is a liquid under −195.8 °C (77.3 K).. In physics, cryogenics is the production and behaviour of materials at very low temperatures.. The 13th International Institute of Refrigeration's (IIR) International Congress of Refrigeration (held in Washington DC in 1971) endorsed a universal definition of "cryogenics" and "cryogenic" by accepting a threshold of 120 K (−153 °C) to ...
There are two common techniques of cryopreservation: slow freezing and vitrification. Slow freezing helps eliminate the risk of intracellular ice crystals. [16] If ice crystals form in the cells, there can be damage or destruction of genetic material. Vitrification is the process of freezing without the formation of ice crystals. [17]
Cryogenic grinding of plant and animal tissue is a technique used by microbiologists. Samples that require extraction of nucleic acids must be kept at −80 °C or lower during the entire extraction process. For samples that are soft or flexible at room temperature, cryogenic grinding may be the only viable technique for processing samples. [2]
Created Date: 8/30/2012 4:52:52 PM
At least six major areas of cryobiology can be identified: 1) study of cold-adaptation of microorganisms, plants (cold hardiness), and animals, both invertebrates and vertebrates (including hibernation), 2) cryopreservation of cells, tissues, gametes, and embryos of animal and human origin for (medical) purposes of long-term storage by cooling to temperatures below the freezing point of water.
The ultimate objective is to freeze the specimen so rapidly (at 10 4 to 10 6 K per second) that ice crystals are unable to form, or are prevented from growing big enough to cause damage to the specimen's ultrastructure. The formation of samples containing specimens in amorphous ice is the "holy grail" of biological cryomicroscopy. [citation needed]