Search results
Results from the WOW.Com Content Network
The frozen section procedure as practiced today in medical laboratories is based on the description by Dr Louis B. Wilson in 1905. Wilson developed the technique from earlier reports at the request of Dr William Mayo, surgeon and one of the founders of the Mayo Clinic [3] Earlier reports by Dr Thomas S. Cullen at Johns Hopkins Hospital in Baltimore also involved frozen section, but only after ...
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. Slow programmable freezing was developed during the early 1970s, and eventually resulted in the first human frozen embryo birth in 1984. Since then, machines that ...
Damage from freezing cold injury occurs through direct freezing of tissue, disrupted blood flow to affected skin, and rewarming injury. [8] [11] [3] Freezing causes ice crystal formation in tissue that disrupts cell membranes and surrounding blood vessels. [11]
Similar to the frozen section procedure employed in medicine, cryosectioning is a method to rapidly freeze, cut, and mount sections of tissue for histology. The tissue is usually sectioned on a cryostat or freezing microtome. [12] The frozen sections are mounted on a glass slide and may be stained to enhance the contrast between different tissues.
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]
Freezing is a phase transition in which a liquid turns into a solid when its temperature is lowered below its freezing point. [ 1 ] [ 2 ] For most substances, the melting and freezing points are the same temperature; however, certain substances possess differing solid-liquid transition temperatures.
Example of a periglacial landscape with both pingos and polygon wedge ice near Tuktoyaktuk, Northwest Territories, Canada. Periglaciation (adjective: "periglacial", referring to places at the edges of glacial areas) describes geomorphic processes that result from seasonal thawing and freezing, very often in areas of permafrost. The meltwater ...
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 ...