Tuesday, May 21, 2019
Cryonics Cryogenics
cryogenics refers to the branches of physics and engineering that study very low temperatures, how to produce them, and how materials behave at those temperatures. Cryogenics is wholly about temperatures below -150C or 123 K. One of the most amazing applications of cryogenic processing is cryonics where the kind-hearted individualify is exposed to cryogenic treatment in order to preserve it after death. In the fall in States of America, there are, currently, two organizations that offer cryogenic treatment for human bodies The Cryonics Institute in Clinton Township, Michigan and Alcor in Scottsdale, Arizona.Once death sets in, the patients bodies are preserved in chemicals de sign(a) to theoretically protect cellular structure, before being lowered into steel tubes of silver-tongued nitrogen, called dewars. Here they will be kept in cold storage at 196C in the hope that someday in the future they may be brought back to life. There are currently 147 people in cryogenic suspen sion, with another 1,000 members signed up for the deep freeze. History of Human CryogenicsIn 1940, pioneer biologist Basil Luyet make a work titled Life and Death at Low Temperatures in which he detect that while many organisms underwent serious damages at very low temperatures. However, in some cases, he reported that he managed to restore normal function when organisms were rewarmed after freezing. Luyets work led to a satisfying new area of science called cryobiology. British scientists found that by soaking cells in a resultant role of glycerol, red blood cells and bull semen could be frozen and then their functions could be completely restored on rewarming.The main disc all overy is that through human cryogenics, life can, in f dissemble, be stopped and restarted under controlled conditions. In the United States, Robert Ettinger through his book The Prospect of Immortality (1964) promoted the idea that a person frozen after efficacious death might rationally hope to be re suscitated at some time in the far future when medicine has advanced enough to cure most diseases, bring eat the aging process, and determine any residual damage caused by freezing (Klein, 2004). This came to be known as Ettingers concept.Many scientists avoid the idea of manipulating life and death conditions of the body and hence there has not been much progress in this field since the 1960s. Cryonics is an unproven theory. There are scientific obstacles that, some would say, are insurmountable. One of the success stories in this realm is that of Gregory Fahy and his team. They have succeeded in cryopreserving a rabbit kidney, reversed the procedure and successfully re-implanted it without losing the ability to incur the life of the recipient (Fahy, 2006). Challenges in Cryonics Cryonic aspirants may choose to have their entire body stored or only their head frozen.The thinking behind the latter option is that an old person would not pauperism to come back alive in his old b ody. Cryonics is an expensive option. Alcor currently charges the equivalent of ? 80,000 for the full body option and ? 42,000 for the head only (Cryonics Cryogenics, 2006). The long-term storage of biological materials, including human organs, requires very low temperatures, which typically are achieved with liquid nitrogen (LN2). While LN2 provides suitable ultralow temperatures, general storage environments have been less than o.k. and this is an obstacle in cryonics (Lehr, 2006).Another major challenge facing cryonics is that the current technique of full-body preservation with cryoprotectant chemicals causes extensive molecular(a) damage to the body. To successfully bring a patient back to life, cryonics would not only need to reverse this damage, but would overly have to cure the original illness the patient died from. Apart from this, the process of cryonics also raises a lot of legal and ethical issues such as How can a legally fallen person have a valid contract for cryo preservation? Is euthanasia an option for cryonicists? Are cryonics organizations right in selling an unproven technology? (Best, 2006) Cryopreservation Procedure As soon as a patient dies, the persons brain cells are the first to die. Hence the first step would be to stop cellular decomposition caused by oxygen deprivation. This is done by cooling the body. For every 10C downslope in temperature there is a 50% reduction in metabolic demand which means it takes twice as long for damage to occur. The body should be kept just above freezing and then, a mechanical chest compressor is used to temporarily restore circulation before injecting medications to stop the blood clotting.Then, the patients blood is rinse out and replaced with a temporary protective fluid. Now, there is a surgical process that begins by hatchway the chest cavity to allow plastic cannulation tubes to be sewn into the heart to provide compliance and exit points for the cryoprotectant fluid. These tubes are c onnected to a by-pass machine that circulates the cryopreservation fluid approximately the body. The process called vitrification involves replacing over 60% of the water in the body with, potentially toxic, preservation chemicals.When exposed to cryogenic temperatures of below -120C they react by turning tissue to a glass-like solid. Throughout the procedure the body is kept jam-packed in ice inside a perspex covering. Liquid nitrogen vapor is regularly pumped around the body to keep the temperature at -3C. After the surgery, the body is transferred to an insulated holding chamber for the rapid cool down stage. Liquid nitrogen vapor is pumped inside and probes will monitor the bodys core temperature. The temperature will be dropped rapidly to just above the glass transition point.The body is then placed in a sleeping-bag and put into a pod which is the permanent storage container where it will be cooled very slowly to liquid nitrogen temperature (Cryonics Cryogenics, 2006). Conclu sion It has been mans inherent nature to search for eternity and eternal youth. So, it is no wonder that the science of cryonics has captivated the interests of mankind. Cryonics is a science that is still in the nascent stage. It is a disputable science that is countered by seemingly unanswerable questions.Yet, the fascination for conquering age and death keeps research in cryonics advancing. Bibliography Platt, Charles (2006). Cryonics A Short History The Impossible Dream. http//www. imminst. org/forum/index. php? s=&act=ST&f=61&t=860 Best, Ben (2006). Cryonics The Issues. http//www. benbest. com/cryonics/cryiss. html Lehr, A. Valentine (2006). Precision, flexibility critical in long-term, ultra- low-temperature storage of biological materials. Control Considerations for Cryogenic Storage Facilities. HPAC Engineering. rattling(a) 2006. http//www. hpac.com/member/feature/2006/0806/0806_lehr. htm Cryonics, Cryogenics (2006). Death in the deep freeze. http//www. mymultiplesclerosis . co. uk/stranger-than-fiction/cryogenics. html Fahy, M. Gregory (2006). Cryopreservation of Complex Systems The Missing conjoin in the Regenerative Medicine Supply Chain. Rejuvenation Research. Jun 2006, Vol. 9, No. 2 279-291. http//www. liebertonline. com/doi/abs/10. 1089/rej. 2006. 9. 279? journalCode=rej= Klein, Bruce (2004). Robert Ettinger, Father of Cryonics. http//www. imminst. org/forum/index. php? act=ST&f=67&t=4112
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment