opinions wanted - Page 4

Retlaw · 12-06-2013, 12:48

Quote:

Originally Posted by Gordon Booth

If that is true how do they freeze sperm and eggs in liquid nitrogen(-196 Centigrade) but still unfreeze them and they are alive and viable?

Because the freezing process is so fast Ice Crystals don't form,
try it with a tomato, it will still be a tomato when defrosted.

MargaretR · 12-06-2013, 12:48

Ego death - Wikipedia, the free encyclopedia

"Some famous examples of people claiming to have had the experience are Ramana Maharshi and U. G. Krishnamurti. In 2000 Eckhart Tolle claimed that he underwent the experience after having suffered from long periods of suicidal depression. He says he woke up in the middle of that night and thought,
“I couldn’t live with myself any longer. And in this a question arose without an answer: who is the ‘I’ that cannot live with the self? What is the self? I felt drawn into a void. I didn’t know at the time that what really happened was the mind-made self, with its heaviness, its problems, that lives between the unsatisfying past and the fearful future, collapsed. It dissolved.”

Tolle recalls going out for a walk in London the next morning, and finding that “everything was miraculous, deeply peaceful. Even the traffic."

I have had a brief experience of the 'void' during a lucid dream - it is difficult to describe 'overwhelming calm'.

PS Judging others is an expression of ego so I really should avoid having any opinion about Less as a person - just saying - he no longer 'rattles' me, which is nice not to experience such negative emotion.

Less · 12-06-2013, 13:34

Oh, dear, not rattled, you?
You live to be rattled you look for the worst things possible in everything.

DaveinGermany · 12-06-2013, 17:24

Quote:

Originally Posted by Less

there is more truth in a little boy being able to stick his finger in a 'Dyke',

He did , but she didn't half crack the little sod!

DtheP47 · 13-06-2013, 12:08

Quote:

Originally Posted by Gordon Booth

If that is true how do they freeze sperm and eggs in liquid nitrogen(-196 Centigrade) but still unfreeze them and they are alive and viable?

Quote:

Originally Posted by DtheP47

Think it's to do with our heads consisting of complex vegetable matter (some of us not so complex Mr B*

) Try freezing a tomato. It all turns to gooey mush when thawed out. Ice crystals form, vessels burst and fluids leak.

*Present company excepted !!

As water freezes, it expands. Since cells are made up of mostly water, freezing expands the “stuff” inside which destroys their cell walls and they die. The cryonics companies need to remove and/or replace this water. They replace it with something called a cryoprotectant. Much like the antifreeze in an car. This glycerol based mixture stops and protects against damage to your organs and tissues by hindering the formation of ice crystals. This process is called “vitrification” and allows cells to live in a sort of suspended animation.

For a tomato to remain a tomato the water would have to be removed in a process similar to the above. And then rehydrated somehow at the thawing stage.
So in essence the tomato would have to be dessicated first, ergo, you are not freezing a tomato really.

Gordon Booth · 13-06-2013, 14:11

Quote:

Originally Posted by DtheP47

As water freezes, it expands. Since cells are made up of mostly water, freezing expands the “stuff” inside which destroys their cell walls and they die. The cryonics companies need to remove and/or replace this water. They replace it with something called a cryoprotectant. Much like the antifreeze in an car. This glycerol based mixture stops and protects against damage to your organs and tissues by hindering the formation of ice crystals. This process is called “vitrification” and allows cells to live in a sort of suspended animation.

For a tomato to remain a tomato the water would have to be removed in a process similar to the above. And then rehydrated somehow at the thawing stage.
So in essence the tomato would have to be dessicated first, ergo, you are not freezing a tomato really.

Thanks, DP, sort of rules out bringing you back to life, full of antifreeze, doesn't it?
Still, if they could do it you'd make a good Antarctic explorer, wouldn't you? No need for all those warm clothes.
Doesn't explain how they freeze sperm and eggs though. I'm sure they're not full of antifreeze, if they are we're pushing evolution hard!

susie123 · 13-06-2013, 14:28

Quote:

Originally Posted by Gordon Booth

Thanks, DP, sort of rules out bringing you back to life, full of antifreeze, doesn't it?
Still, if they could do it you'd make a good Antarctic explorer, wouldn't you? No need for all those warm clothes.
Doesn't explain how they freeze sperm and eggs though. I'm sure they're not full of antifreeze, if they are we're pushing evolution hard!

Gordon, it does seem that the same methods are used for sperm and doesn't seem to stop the little blighters swimming.

Semen cryopreservation - Wikipedia, the free encyclopedia

As for eggs, they are not usually frozen. It is embryos that are frozen, after fertilisation. However, freezzing of eggs is at an experimental stage. The following information is taken from the Macmillan charity website regarding loss of fertility after cancer treatment.

Freezing embryos

This is the most effective way of preserving fertility. After your eggs have been collected, they’re placed in a test tube with your partner’s or a donor’s sperm to see if they fertilise. This is called in vitro fertilisation (IVF). The eggs that are fertilised grow into tiny embryos, which are frozen and then stored.
When you’re ready to try and get pregnant after treatment, the embryos are thawed and placed in the womb to see if they implant. Usually, no more than one or two are placed in at a time. Although pregnancy rates using frozen embryos are lower than when embryos are implanted immediately, lots of babies have been born using this technique.

Freezing eggs

If you don’t have a partner you may want to freeze your eggs and have them fertilised later when you’ve met someone. This is still experimental but techniques are improving. It’s available privately and on the NHS in some units. Eggs are collected as usual (as described above) and are frozen and stored. When you’re ready to try to get pregnant, the eggs are thawed and fertilised by injecting a single sperm directly into an egg. This is called intra-cytoplasmic sperm injection (ICSI).
If any eggs are successfully fertilised, the resulting embryos are placed in the womb to see if a pregnancy develops.
Freezing eggs and ICSI is much less likely to result in a pregnancy than embryo storage, but success rates are improving.

accyman · 13-06-2013, 14:31

Quote:

Originally Posted by Gordon Booth

Thanks, DP, sort of rules out bringing you back to life, full of antifreeze, doesn't it?
Still, if they could do it you'd make a good Antarctic explorer, wouldn't you? No need for all those warm clothes.
Doesn't explain how they freeze sperm and eggs though. I'm sure they're not full of antifreeze, if they are we're pushing evolution hard!

maybe as an egg or a sperm there are a lot less cells to dammage where as a grown product of the combination of both is much more complex and larger and teh risk of dammage greater but thats just pure specualtion

a few years ago a mammoth was found preserved in ice and although they cant revive it if i remember correctly they do think they could clone it in the near future so it may be a case that things like dna can survive freezing and remain viable but larger cells cant.

iv got some juice on ice in manchester from before my radiotherapy treatment that was planned for me if i ever pop back to use it ill ask lol