Jeff Gilchrist

Scientists Trace Lupus to One of The World's Most Common Viruses One of the world's most common viral infections could underlie virtually every case of lupus, according to a recent study providing the strongest evidence yet for a link.

New article here ( www.sciencealert.com/scientists-t... ). 3/

Epstein-Barr virus reprograms autoreactive B cells as antigen-presenting cells in systemic lupus erythematosus Epstein-Barr virus reprograms autoreactive B cells as antigen-presenting cells to promote pathogenic antinuclear T and B cell responses in lupus.

The study is here ( www.science.org/doi/10.1126/... ). 2/

Thread @virusesimmunity.bsky.social "A ground breaking paper by Shady Younis et al. @stanfordimmunology.bsky.social provides an answer to the long-standing question about how EBV infections are linked to lupus. A short thread to explain the key findings." ( threadreaderapp.com/thread/19891... )

After some finagling to get the assembly procedure just right we are finally releasing the aluminum bodied POLARIS air purifier, made-in-Canada and based on the open-source design by Zack Deis.

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#airpurifier #indoorairquality #covidisairborne

Bar chart titled “Equivalent Exposure Time to Unmasked Person.” The chart compares how long different masks/respirators extend the equivalent exposure time relative to being unmasked. The x-axis shows unmasked infection times of 1, 5, and 10 minutes. The y-axis shows equivalent masked exposure time, ranging up to 5000 minutes. Seven mask types are represented by colored bars: - Procedure mask (loose fit, FF=2) - Ear loop mask (tight fit, FF=6) - Vertical bifold headband mask (FF=30) - N95 headband masks with fit factors of 100, 200, and 500 Key pattern: higher fit factor masks dramatically increase equivalent exposure time. For example, at 10 minutes unmasked, a procedure mask extends exposure to 20 minutes, while an N95 with FF=400 extends it to 5000 minutes.

How does various mask fit compare to filter the air and protect you or others?

Most masks, even baggy blue procedure masks use filtering material that can filter 95%+ of particles that pass through it, but the key is "pass through it". Continue to learn more... 🧪🧵1/

Here's what life before vaccines was really like The morning of August 2nd 1852 promised a lovely summer’s day in London. But not for 8 year old George Williams.

What was life really like before vaccines? The story of what happened to 8-year old George Williams in August 1852 gives us a glimpse.

open.substack.com/pub/epiellie...

It is possible that a specific headband respirator may have a worse fit on a person than a specific earloop respirator but in general the two straps around the head tend to pull better in the required direction to make and keep a better fit.

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But many earloops look more like this where the fit factor is more in the <6 range ( www.testtheplanet.org?pgid=kcyqfc6... ). 3/

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For example here is the Breatheteq KN95 small which is all over the place ranging from 1.6 to 500 depending on the person ( www.testtheplanet.org?pgid=kcyqfc6... ). 2/

Test The Planet | Adversarial Quantitative Fit Test Data TestThePlanet an open source movement aggregating and displaying live updates of motion resilience tests of all available respirators with adversarial protocols such as Crash2.5 for a growing communit...

Although fit it very specific to each individual there is some fit test data from multiple people for a variety of different masks/respirators that you can check out here ( www.testtheplanet.org ). 1/

They could be, some fit better than others and lots do not have very high fit factor on many people, especially when moving/talking. Unless tested, would be more cautious with an ear loop no matter what the standard they conform to.

Thread by jeffgilchrist: Fit Testing to ensure a good seal on your mask [Pa... - PingThread Fit Testing to ensure a good seal on your mask [Part 2] This thread describes my quantitative fit testing experience with some real-world results of various types of #masks including #NIOSH #N95 and ...

* Fit Testing to ensure a good seal on your mask [Part 2]: ( pingthread.com/thread/16553... ) 23/

Thread by jeffgilchrist: Fit Testing to ensure a good seal on your mask [Pa... - PingThread Fit Testing to ensure a good seal on your mask [Part 1] This thread explains what mask fit testing is (qualitative and quantitative), why it is important, and my testing experience with some real-wor...

* Fit Testing to ensure a good seal on your mask [Part 1]: ( pingthread.com/thread/16523... ) 22/

* Why can you still smell things wearing an effective mask? ( bsky.app/profile/jeff... ). 21/

How respirators actually work and which type is best? How respirators & filters actually work and which type is best? Written by: Jeff Gilchrist, PhD Link to this document: https://tinyurl.com/HowMasksActuallyWork Last updated: February 2, 2025 I see ma...

People who are interesting in learning more about how respirators work and what is fit testing and fit factors, the following resources are available:
* How respirators actually work and which type is best? ( docs.google.com/document/d/1... ) 20/

The other tab is "Fit Factor Calculator" lets you enter your own results from a fit testing exercise and calculates the overall fit factor score which can be used for a comparison with other fit factors. 19/

The main point is that there is a huge different in exposure time going from no mask or a baggy blue procedure mask to a head band N95, even if it just passes fit testing, while many like myself can get a much higher fit factor than the pass rate. 18/

This is just one set of scenarios, you can adjust it to whatever you want to compare. 17/

When I had my 3M Aura fit tested, I got over 500 for the fit factor which would boost that time to 2500 minutes (41 hours) before equivalent exposure assuming that fit factor stayed constant throughout the time period. 16/

If you jump to an N95 respirator with a headband that just passes a fit test so the fit factor is 100, that would increase the time to 500 minutes (8.3 hours) before equivalent exposure to an unmasked person. 15/

Some ear loop respirators get a fit factor of about 6 which means it would be 30 minutes before a similar exposure, and other ear loop respirators can be higher or lower depending on the fit for your face. 14/

Procedure masks (baggy blue) on many people will only filter about 50% of particles so if it only takes 5 minutes for an unmasked person to become infected, then that time doubles to 10 minutes to get an equivalent exposure of virus with a baggy blue. 13/

Bar chart titled “Equivalent Exposure Time to Unmasked Person.” The chart compares how long different masks/respirators extend the equivalent exposure time relative to being unmasked. The x-axis shows unmasked infection times of 1, 5, and 10 minutes. The y-axis shows equivalent masked exposure time, ranging up to 5000 minutes. Seven mask types are represented by colored bars: - Procedure mask (loose fit, FF=2) - Ear loop mask (tight fit, FF=6) - Vertical bifold headband mask (FF=30) - N95 headband masks with fit factors of 100, 200, and 500 Key pattern: higher fit factor masks dramatically increase equivalent exposure time. For example, at 10 minutes unmasked, a procedure mask extends exposure to 20 minutes, while an N95 with FF=400 extends it to 5000 minutes.

The graph shows a fictitious high COVID concentration example of 3 scenarios where someone without a mask could get infected from COVID within 1, 5, and 10 minutes along with various fit factors (FF). 12/

There are two tabs, "Equivalent Exposure Time Calculator" that lets you compare multiple # minutes to infection time scenarios against multiple fit factors which you can adjust for the scenarios you are interested in comparing. 11/

Fit Factor & Impact Calculator

The calculator is available here ( docs.google.com/spreadsheets... ). 10/

A fit factor of 100 is the minimum pass rate for a fit test which means there are 100x less particles inside the mask than outside. A fit factor of 2 means there is 2x less particles inside or you could also say that 50% of particles are being filtered. 9/

...and it will show you how much longer it would be to have an equivalent exposure for various fit factors of masks based on how much filtration they are performing. You can adjust the # of minutes, and also input different fit factors. Some example fit factors are provided to get you started. 8/

To make things more flexible so that you can look at various scenarios for the specific situations you are interested in comparing, I have created a couple of calculators that let you input and decide how many minutes it would take to become infected without a mask... 7/

Quantitative fit-test concordance of a pair of similar-fit 3M Aura respirator models, 3M 9320A+ and 3M 1870+: A randomized crossover study Some manufacturers provide information on similar-fit model pairings of filtering facepiece respirators (FFRs), suggesting that fit-test outcome of one model helps predict the other. This guidance may be useful during crisis capacity when FFR ...

The popular 3M Aura 1870+ for example had an 88.9% pass rate for women and 97.6% pass rate for men in this study so for personal use it is very likely to be better than a baggy blue procedure mask even without a fit test ( pmc.ncbi.nlm.nih.gov/articles/PMC... ). 6/

It is also important to note, that while getting a fit test done is the best way to ensure a specific respirator fits well on your face, there are certain brands of respirators like the 3M Aura that have very high fit testing pass rates. 5/