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Old 2020-04-27, 23:37   #771
Gordon
 
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Quote:
Originally Posted by Chuck View Post
That's what I'm expecting; an annual Corona vaccine. Perhaps it can be combined with the annual flu vaccine.
Or the annual 6 month house arrest?

The general population who seem to have lost the ability to actually think for themselves are all sleep walking into oblivion and being scared like little children into doing what they are told is good for them...
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Old 2020-04-27, 23:56   #772
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Quote:
Originally Posted by ewmayer View Post
https://finance.yahoo.com/news/aytu-...120000824.html

The Healight technology employs proprietary methods of administering intermittent ultraviolet (UV) A light via a novel endotracheal medical device.
Fascinating. The article also says,
Quote:
"Our team has shown that administering a specific spectrum of UV-A light can eradicate viruses in infected human cells (including coronavirus) and bacteria in the area while preserving healthy cells," stated Dr. Pimentel of Cedars-Sinai.
I recall being informed in this very thread, that it was UV-C that killed microbes, and UV-A and UV-B were not all that effective -- at least for microbes on surfaces, as evidenced by a study of what was on the tanning beds in tanning salons.

This claims that the intermittent UV-A kills viruses in infected cells. It also claims it eradicates "bacteria in the area" while "preserving healthy cells."
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Old 2020-04-28, 00:04   #773
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Quote:
Originally Posted by Gordon View Post
155,000 people a day die, none of which are down to this virus.

28,000 a day die from starvation which is ENTIRELY preventable.

Now tell me again why a few thousand dying from a flu virus is the end of the world??
The difference is that starvation only affects the little people, and more specifically the poor people, right? But a virus doesn't respect any political or wealth boundaries so the politicians and "authorities" are now concerned by it. So naturally they get scared and want to stop it. If that means shutting down the planet to protect themselves then they will do it.

We can't have non-authority-respecting things active in the world, right? The politicians don't like it.
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Old 2020-04-28, 00:11   #774
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Originally Posted by kriesel View Post
Science says: It’s time to start easing the lockdowns https://nypost.com/2020/04/26/scienc...rus-lockdowns/
The suggestion of isolating and protecting obviously-at-risk segments of the population (frail and elderly, mostly) while basically letting the younger, apparently less-likely-to-become-seriously-ill folks become infected, then presumably immune, does have a certain appeal. I note that

Quote:
Scott W. Atlas, MD, is the David and Joan Traitel Senior Fellow at Stanford University's Hoover Institution and a former chief of neuroradiology at Stanford Medical Center.
I imagine some folks here would see "Hoover Institution" and roll their eyes.

What got my attention in the description of the author, though, was "neuroradiology." Expertise in one area of medicine does not necessarily carry over to others. We learned from the Terri Schiavo case that, as a neurologist, Bill Frist was a great cardiologist. And it may be here that, as an epidemiologist/infectious disease expert, Dr. Atlas is a great neuroradiologist.
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Old 2020-04-28, 00:14   #775
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UVC is what is used in germicidal lamps. I used them back in the day in the lab. They work quickly. We could sterilize a clean and dry filtering funnel in under 5 minutes. (3 actually at the same time, top and bottom both parts. used 4 lamps ~ 25cm long.)
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Old 2020-04-28, 03:15   #776
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Quote:
The suggestion of isolating and protecting obviously-at-risk segments of the population (frail and elderly, mostly) while basically letting the younger, apparently less-likely-to-become-seriously-ill folks become infected, then presumably immune, does have a certain appeal.
[Dr Sardonicus, this is emphatically not aimed at you. I'm just jumping off from your paraphrase of the quoted material, which I found pithy and evocative.]
https://bgr.com/2020/04/07/coronavir...-19-infection/
Quote:
However, an increasing number of doctors believe that not all COVID-19 patients will show signs of heart damage due to pulmonary failure and inflammation. The virus might infect the heart muscle directly.
Data from China, Italy, and the US shows that this is the case for a subset of patients. KHN explains that an initial study found cardiac damage in as many as 1 in 5 patients, which resulted in heart failure and even death. It happened in patients who didn’t show any signs of respiratory distress, not just in critical cases.
Two studies from China also looked at cardiac problems in COVID-19 patients. The larger of the two looked at 416 hospitalized patients, concluding that 19% showed signs of heart damage, and they were more likely to die. 51% of people with heart damage died, versus 4.5% of those who didn’t. What’s more troubling is that patients who didn’t have any preexisting heart conditions but developed heart damage during the infection were more likely to die than patients with known heart disease but no heart damage due to COVID-19.
I guess a few younger people (along with other age groups) having sudden fatal heart attacks and massive debilitating strokes is a small price to pay for...uh...excuse me, what would it be for?

The point is that severe effects continue to emerge. Strokes seem to involve runaway blood clotting.

Science is still finding its way with this disease. There have been too many impulsive and ill-informed decisions taken already.

We don't have anything within a parsec of proper testing in the US. I heard Gov Pritzker announcing over a hundred testing sites being opened around Illinois, which I commend. I did not catch all of the briefing, so I'm not sure if just anyone can get tested.

Mapping the degree and extent of infection is just a start on knowing how to deal effectively with the pandemic. We need information to rationally manage increased public interaction, and be prepared to deal with the resulting increase of exposure.
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Old 2020-04-28, 03:22   #777
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The atmosphere is an effective filter for blocking solar UVB and UVC https://en.wikipedia.org/wiki/Ultraviolet#Subtypes
Around 264nm UVC is most effective for damaging DNA and RNA. Don't want to give the patient lung cancer as a result of the treatment.
The short wavlength end of UVA somewhat overlaps the long wavelength end of the germicidal effectiveness, and DNA, RNA, and typical protein absorptance spectra.
Analytical spectroscopy for proteins is sometimes done at 280nm, or longer wavelength.
https://en.wikipedia.org/wiki/Ultrav...rcury_lamp.png
https://jascoinc.com/applications/pr...trophotometer/
The lower germicidal effectiveness of longer UV wavelength in the range 275-310nm is offset by the much higher brightness of available LEDs at 300+nm vs 280nm and shorter.
https://cdn.intechopen.com/pdfs/3462...nomedicine.pdf
The history of Ultraviolet Germicidal irradiation for air disinfection https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789813/
I've been interested in UV optics for years, after having spent an extended period researching and applying UV light sources for a microscopy enhancement project, and having been involved somewhat in a UV telescope.
(Shortening the wavelength improves the microscope diffraction limit although it reduces the depth of field considerably.)
(Good UV-VIS-IR lab spectrophotometers typically use deuterium gas lamps for broad spectrum UV sources and switch to another source for visible and near IR.)

Last fiddled with by kriesel on 2020-04-28 at 03:23
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Old 2020-04-28, 03:43   #778
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Quote:
I've been interested in UV optics for years, after having spent an extended period researching and applying UV light sources for a microscopy enhancement project, and having been involved somewhat in a UV telescope.
(Shortening the wavelength improves the microscope diffraction limit although it reduces the depth of field considerably.)
Fascinating! Thanks for that outline. I resonate with depth of field as a photographer, even though visible light is probably focused differently.
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Old 2020-04-28, 03:53   #779
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Quote:
The politicians don't like it.
Many years back on a far more politically oriented site, I coined (I like to think) the term 'prostiticians'. It seemed a more accurate terminology for the role most of them play.
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Old 2020-04-28, 06:51   #780
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Quote:
Originally Posted by kladner View Post
even though visible light is probably focused differently.
Is it? I would have thought that lenses would be used in rather a lot of the UV. We used to use quartz optics at the relatively long wavelengths but I have no experience down towards 100nm ("vacuum UV"), which includes the astronomically important Lyman lines.

Time for me to start to find out.

Last fiddled with by xilman on 2020-04-28 at 06:51
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Old 2020-04-28, 09:10   #781
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Quote:
Originally Posted by kladner View Post
Fascinating! Thanks for that outline. I resonate with depth of field as a photographer, even though visible light is probably focused differently.
Now imagine that the illumination and imaging optical axes are inclined 30 degrees from the surface to be imaged, and much of the optics are in ultra high vacuum (no fingerprints allowed on anything). Some commonly used optical materials are very limiting in the UV https://wp.optics.arizona.edu/optome...ittance_us.pdf One of the candidate lens materials is synthetic fused silica glass. https://www.thorlabs.com/images/TabI...ta%20Sheet.pdf
Also sapphire crystal, which is tough to fabricate, because of its hardness. Its high refractive index is useful for some things, but its birefringence https://en.wikipedia.org/wiki/Birefringence means optical figure must be correctly oriented relative to crystal axis, to minimize split images. https://www.guildoptics.com/sapphire...re-properties/ Calcium fluorite was not allowed due to the issues fluorine could create in the vacuum system. Diameters ranged from 3 to 16mm as I recall. QA of such custom optics is challenging.
Eventually in air as wavelength declines the absorptance of oxygen and other air constituents becomes an issue. Nitrogen fill or evacuation are possibilities for extending to lower wavelength. Lab spectrophotometers reach 190nm without nitrogen fill. http://irina.eas.gatech.edu/EAS8803_SPRING2012/Lec7.pdf
Chromatic aberration is often an issue in optics design. Using an LED light source for limited bandwidth controls that issue. Cameras for imaging are a whole other issue; fused-silica-windowed or windowless sensors. https://www.vision-systems.com/non-f...w-applications Going from incandescent illumination to UV LED allowed ~halving resolvable feature linear size given the allowable project budget. UV absorption of some object material & wavelength combinations is so high, that different LED wavelengths are used.

Last fiddled with by kriesel on 2020-04-28 at 09:41
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