You got off lucky. An old friend of mine learned this lesson when on a
particularly sunny day he spent an hour out on a New Zealand glacier in
shorts with no underwear...
On 2020-05-06 16:17, James Holton wrote:
I feel I should correct you on one thing Tim: UV _can_ go around
corners because it scatters. I learned this the hard way as a younger
man after a fine day of skiing. I had put sunscreen everywhere except
the bottom of my nose.
You are right, however, that the intensity after scattering is quite a
bit less than tha main illumination. This is true for all kinds of
light.
-James Holton
MAD Scientist
On 5/5/2020 11:59 PM, Tim Gruene wrote:
Hi James,
for us, the suggestions of cling film / plastic wrap or just swapping
keyboards and mice per person is the simplest - thanks to everyone for
the many suggestions. Especially the latter, since only two people
will
operate the instruments.
UV light does not go around corners. It might be useful for fume
hoods,
but for most places, door handles and other curved surfaces are
probably much more the infecting parts, while they escape the UV
light.
And vira are transported in water droplets, which are larger than 1um.
Best,
Tim
On Tue, 5 May 2020 17:19:56 -0700
James Holton <jmhol...@lbl.gov> wrote:
All joking aside, there has been a furor of attention on UV-based
disinfection of late. Some of it is not entirely crazy. I.E.
Columbia University’s Center for Radiological Research has put
forward the idea of illuminating occupied public areas with
ultra-narrow-band UV-C (222 nm).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552051/
Mind you, UV-C normally covers 100 - 280 nm, and the PPE requirements
for that (at LBNL at least) are extensive: polycarbonate safety
glasses and face shield with a mark U6 (UV protection), long-sleeved
clothing, and gloves. Basically: do not expose skin!
The idea behind using monochromatic 222 nm radiation is that it is at
the edge of a very steep increase in the absorption of water,
protein, and other biologicals. Penetration depths are hard to
estimate because of the steep slope, but they are on the order of 1
micron. So, smaller than a typical mamalian cell, but bigger than a
bacterium or virus. The paper above did not have any human subjects,
nor did it discuss how to deal with all the ozone, but the results
are intruiging. Needs further study.
Personally, I think this would probably fog your corneas and perhaps
burn the thin skin on lips and other exposed mucosa. Hair I'd expect
to embrittle and fall apart eventually. Yes, hair is 40 microns thick
and the penetration depth is 1 micron, but photon's don't "stop" at
the penetration depth. 36% of them go deeper. Plastic in keyboards
too would probably bleach and flake with prolonged exposure. Ever
seen a keyboard left out in the sun for a few weeks? I'd worry a bit
about this micro-damage creating crevices where bugs could hide.
I encourage you to bring this up with your Health and Safety people,
but make sure they are sitting down first.
-James Holton
MAD Scientist
On 4/29/2020 12:41 PM, Andrea Thorn wrote:
Hi Tim!
100% alcohol is less effective than 80%, and in order to completely
be sure, the keyboard needs not only to be wiped. One can buy
keyboards that can be disinfected because they are waterproof, such
as the Cherry JK-1068DE-2 for about 50 €.
We clean the keyboards in our lab occasionally anyway, and have
used 70% alcohol on them without problem. Disinfectant wipes, a
detergent cleaner (such as Viss Glass & Flächen) and cotton swabs
also offer some help. We wipe our mobile phones with a disinfectant
wipe after washing our hands when arriving home/at work.
I would also be really interested in what could be done with a UV
light, if someone knows?
If the computer is used by one person during the shift, individual
keyboards for each person could be a solution. If people sit down,
the desk surface, which may be touched, should likely also be wiped
at the beginning and end of the shift I would say.
Stay save and best wishes,
Andrea.
Am 29/04/2020 um 21:04 schrieb Diana Tomchick:
100% ethanol or isopropanol work really well on the microscopes,
I soak a Kimwipe and then clean the eyepieces and the knobs for
changing magnification and focus, as well as the door handles,
bench tops, etc.
Diana
**************************************************
Diana R. Tomchick
Professor
Departments of Biophysics and Biochemistry
UT Southwestern Medical Center
5323 Harry Hines Blvd.
Rm. ND10.214A
Dallas, TX 75390-8816
diana.tomch...@utsouthwestern.edu
(214) 645-6383 (phone)
(214) 645-6353 (fax)
------------------------------------------------------------------------
*From:* CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of
Diana Tomchick <diana.tomch...@utsouthwestern.edu>
*Sent:* Wednesday, April 29, 2020 2:00 PM
*To:* CCP4BB@JISCMAIL.AC.UK
*Subject:* Re: [ccp4bb] disinfecting keyboards
EXTERNAL MAIL
You could try doing what my technician does with her keyboard;
she wraps it in a clear, thin food wrap that can be taped to the
back of the keyboard. This is usually done to keep food and other
things (liquids) from damaging the keyboard, but you could simply
replace the wrap every time someone else uses it.
Personally I like using a Kimwipe soaked with 100% isopropanol,
I've never yet encountered a keyboard that suffered from having
the writing removed with that or 100% ethanol. Both work and as
long as they are 100% (no water), the keyboard and mouse have no
issues.
Diana
**************************************************
Diana R. Tomchick
Professor
Departments of Biophysics and Biochemistry
UT Southwestern Medical Center
5323 Harry Hines Blvd.
Rm. ND10.214A
Dallas, TX 75390-8816
diana.tomch...@utsouthwestern.edu
(214) 645-6383 (phone)
(214) 645-6353 (fax)
------------------------------------------------------------------------
*From:* CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of
Tim Gruene <tim.gru...@univie.ac.at>
*Sent:* Wednesday, April 29, 2020 1:53 PM
*To:* CCP4BB@JISCMAIL.AC.UK
*Subject:* [ccp4bb] disinfecting keyboards
Dear all,
can you make suggestions for how to disinfect computer keyboards,
and instrument panels?
Our facility is going to reboot next week, with shifts so that
people don't meet. The main interface will be the computer
keyboards, as well as the door of our X-ray diffractometer and the
mounting of the crystals.
The keyboard labels may not like alcohols (and the efficiency of
injecting disinfecting through the USB cable is also under
discussion, so I heard).
One way would be to use individual keyboards, and wearing gloves
for replugging, and to use gloves for mounting crystals.
But maybe there are other ways that won't require gloves?
Best regards,
Tim
-- --
Tim Gruene
Head of the Centre for X-ray Structure Analysis
Faculty of Chemistry
University of Vienna
Phone: +43-1-4277-70202
GPG Key ID = A46BEE1A
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The future of medicine, today.
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--
Dr. Andrea Thorn | group leader
andrea.th...@uni-wuerzburg.de
+49 931 31-83677
Rudolf Virchow Center, University of Wuerzburg
Josef-Schneider-Str. 2 | 97080 Wuerzburg | Germany
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