Dr. Ali Nouri Profile picture
Teaching @Princeton. Fmr Deputy Director @WhiteHouse; Fmr Assistant Secretary @Energy; Fmr President @Scientistsorg. Tweeting about Science and Technology.
28 subscribers
Dec 3 5 tweets 2 min read
🧵 1/5 New @NatureMicrobiol study reveals H5N1 bird flu evolution: Scientists measured infectious virus particles in air from infected ferrets, finding recent strains show low but increased ability to be expelled into air compared to older variants. Image 2/5 Key finding: While 2005 H5N1 showed no infectious virus in air samples, recent strains from a European polecat (2022) and US dairy worker (2024) showed limited infectious virus shedding in air from single ferrets. This matches their observed limited transmission patterns.
Aug 27 5 tweets 2 min read
1/New study on how Clade 2b Mpox spreads between people👇

Note: this is a different clade (subtype) from more recent outbreak caused by Clade 1b which is more lethal (more on clade 1b later)

Now back to Clade 2b: from 2022-24 it spread to >100 nations
wwwnc.cdc.gov/eid/article/30… 2/The outbreak was driven by human-to-human transmission via close contact with infected persons; most cases among men who have sex with men.

However: the new study (albeit small sample size) points to infection from contact with skin lesions as higher risk than from semen.
Nov 6, 2022 5 tweets 3 min read
According to CDC 1 out of 5 who are infected with SARS-COV-2 develop Long Covid.

New report by @zalaly using @DeptVetAffairs data found taking Paxlovid is associated with a 25% decrease in #LongCovid: rb.gy/vnwitj

A thread on how Paxlovid💊neutralizes the virus👇 1/5 2/The SARS-CoV-2 virus is made up of components (proteins, RNA, lipids) that come together and give rise to functional virus particles. Paxlovid blocks the ability of some of the proteins to function, resulting in a defective virus. Here's how…
Oct 31, 2022 22 tweets 8 min read
Big news from @ENERGY:

Electric Vehicle battery & grid battery supply chains are coming to the USA 🇺🇸

$2.8 Billion in awards to support 20 companies to manufacture domestically

This is 1st of set of investments to build out battery manufacturing

A thread on projects👇1/22 2/22

Albemarle: project objective to construct new, commercial-scale U.S.-
based lithium materials processing plant at Kings Mountain, North
Carolina that uses sustainably extracted minerals from the site’s lithium mine.
Aug 15, 2022 6 tweets 2 min read
The Inflation Reduction Act Congress just passed includes a historic $369 billion investment to 1) lower energy costs; 2) revitalize US manufacturing; 3) slash greenhouse gasses by 40%; and 4) address environmental justice. Here are a few highlights from this bill🧵 Princeton REPEAT Project 1. Lowers energy costs for consumers:

Includes rebates to install electric & low emission appliances in homes

Also includes tax credits to make homes energy efficient, install solar, geothermal, etc...

$7,500 consumer credit to purchase clean cars like EVs; $4K for used🚘
Jul 18, 2022 4 tweets 2 min read
1/Early diagnosis, isolation & contact tracing of close contacts are key to controling the Monkeypox outbreak.

Here are the European Union health authority's recommendations for who should be contact traced during this outbreak: the four categories of "close contacts" include:🧵 Image 2/

🔹️Sexual partners: those with any type of sexual contact with MPX cases from the onset of symptoms

🔹️Household contacts: those living in same household (inc. overnight camping/stay) with MPX cases; those sharing clothing, bedding, utensils; or caregivers of MPX cases Image
Jul 9, 2022 5 tweets 2 min read
1/Monkeypox is a member of the Poxviridae family. These are large viruses with large DNA genomes (∼200 thousand bases🧬). By comparison, sars-cov-2 has ~30 thousand. And since its genome is made of RNA it mutates more than monkeypox. Nice review article:rb.gy/higk98🧵 2/Monkeypox is closely related to the infamous smallpox. After smallpox was eradicated through a global vaccination campaign we rightly stopped vaccinating against it. But that allowed monkeypox, once confined to remote areas, to spread more.
Dec 30, 2021 4 tweets 3 min read
1/📌What if we had the ability to stop #SARSCoV2—and all its variants—from infecting us?

We do. It's called an N95 mask. When worn properly it catches over 95% of airborne particles—mechanicaly & electrostatically.

It's excellent against #Omicron. A thread on how it works🧵 2/N95 respirators are made of polypropylene material that go through a "melt blowing" process where it's melted & extruded through small-diameter holes into hundreds of tiny fibers (like spaghetti) that are tangled together. They block incoming particles. rb.gy/nz3vgx
Dec 23, 2021 4 tweets 3 min read
1/How does #Paxlovid, the new COVID-19 pill💊work?

The virus is made up of components (proteins, RNA...) that come together and give rise to functional virus particles.

Paxlovid blocks the ability of some of the proteins to function, resulting in a defective virus🧵 Image 2/After the virus infects cells, it replicates its RNA genome, turns that RNA into proteins, & assembles proteins into new viruses (virions)

During the RNA to protein step, some proteins are first strung together but need to be freed from one another in order to do their job Image Source: https://www.r...
Dec 2, 2021 4 tweets 3 min read
1/Big discovery during the pandemic was that the Coronavirus is #airborne: hitches ride in respiratory aerosols that can float a long time & infect from afar. But what do these tiny things look like? Using Supercomputer @ORNL, scientists are finding out nyti.ms/3xNoORm🧵 2/researchers created a model of the virus in aerosols from billions of 'virtual atoms'. They also included other molecules & proteins found in these aerosols. They ran simulations using Summit: one of world's fastest Supercomputers @ORNL, a Department of Energy National Lab.
Aug 7, 2021 4 tweets 2 min read
📌1/Study on SARS-COV-2 patients shows that 85% of total *viral load they emitted was on respiratory aerosols 5µm or smaller.

Small aerosols defy gravity, float on air for hours & accumulate indoors, necessitating room ventilation & masks.

*Viral RNA used as proxy for virus🧵 2/"Our results demonstrate the
potential for fine respiratory aerosols to play role in community transmission of SARS-CoV-2...suggesting that SARS-CoV-2 transmission events are driven by the airborne route and could explain the difficulty in containing the virus"
Aug 1, 2021 5 tweets 3 min read
1/How SARS-COV-2 infects cells: ~24-40 Spike proteins stick out of the surface of the virus. They're key to the virus attaching itself to human cells. SARS-CoV-2 spikes are flexible & flop around, making it easier for multiple Spikes to grab cells. @Nature piece by @Scudellari 🧵 2/ The variants of concern have mutations in the S1 subunit of Spike protein, which includes RBD — the part of Spike that grabs the human ACE2 receptor. The Delta variant has multiple mutations in the S1 subunit, including some in RBD that may improve its ability to bind ACE2.
Feb 20, 2021 4 tweets 2 min read
📌CDC Report: Confirmed reinfection w/variant containing E484K mutation that's been associated with escape from several neutralizing antibodies. 45-year-old w/ no underlying conditions reinfected, 2nd episode more severe, higher viral load, though didn't require hospitalization🧵 Viruses from both episodes were sequenced to confirm reinfection w/ distinct variant, as opposed to a single prolonged infection. The 2nd episode contained the E484K which @jbloom_lab has shown to be less susceptible to some antibodies 2/3
Jan 16, 2021 8 tweets 8 min read
📌1/Infectious #SARSCoV2 in the air of a car 2 hrs after unmasked driver w/mild #COVID exited vehicle. Researchers found the virus in tiny air samples (0.25-0.5 um) and showed the virus retained ability to infect cells in a lab. H/T @UniversalMaski2 1/8🧵
rb.gy/odlbap 2/In July study found the virus to be stable in air. Mechanically generated aerosols/airborne #SARSCoV2 retained ability to infect cells for at least 16 hrs. Hardier in aerosols than SARS-1 or MERS. Helps explain why #airborne route is a major culprit: rb.gy/jxh0oh 2/8
Jan 7, 2021 7 tweets 3 min read
1/📌Concerning case of reinfection: healthy 45 year old was reinfected with the genetically distinct SARS-CoV-2 variant that harbors the E484K mutation - this is the variant that was recently reported to escape neutralizing antibodies 1/6🧵 Image 2/Second infection was more severe. Given the infections were 5 months apart its hard to know whether the immune response against the 1st infection simply waned, or, alternatively, if the variant virus managed to evade the immune response 2/6
preprints.org/manuscript/202… Image
Jan 5, 2021 5 tweets 2 min read
1/📌BREAKING on #SARS_CoV_2 variants: the emerging variants in South Africa and Brazil that harbor the E484K mutation have "greatly reduced susceptibility" to neutralization by polyclonal serum antibodies derived from some individuals. This may have consequences for vaccines🧵 2/The "Receptor Binding Domain" on the Spike protein of the virus is a critical site for antibodies to bind to because those antibodies can block the virus from binding the ACE2 receptor on our cells. Mutations at that site are allowing the virus to escape antibodies.
Dec 30, 2020 5 tweets 3 min read
1/The #oxfordvaccine just approved in the UK is a version of an adenovirus (common cold virus) that instructs our cells to make the Spike protein of coronavirus. This trains our immune system so when we encounter #SARSCoV2, we can mount a defense. Here's how the vaccine works🧵 2/#SARSCoV2 is covered w/Spike proteins that help the virus grab human cells. To make the vaccine, researchers first isolated the gene that is responsible for making the Spike protein. They 'snipped' it from the rest of the genetic material of the coronavirus.
Dec 29, 2020 7 tweets 3 min read
1/📌NIH Study: COVID-19 severity could depend on route of infection: Infection through inhaling #Airborne virus could lead to more severe disease than infection from fomites (contact w/ contaminated objects.) To test it, hamsters were infected via the different routes. 1/7🧵 2/Intranasal (I.N) and aerosol inoculation caused more severe respiratory pathology, higher viral loads and increased weight loss. Fomite exposure led to milder disease. Here's weight loss👇Black lines are control animals in each group. 2/7
Dec 28, 2020 5 tweets 3 min read
1/📌In order to limit the importation of the variant coronavirus from the UK, CDC now requires travelers to be tested before boarding a flight. The strategy is insufficient because it's overly reliant on diagnostic tests that can't detect the virus in early stages of infection🧵 2/CDC requires a negative test up to 3 days prior to flight. One problem is you can test negative but catch the virus in intervening days. Another is that tests, even the gold standard PCR test, misses the virus in the early stages of infection & provides a false sense of safety.
Dec 28, 2020 6 tweets 4 min read
1/📌Next US Vaccine💉:@Novavax began Phase 3 Trial. KEY difference: While Moderna/Pfizer deliver genetic material (mRNA) that our cells subsequently turn into Spike protein, #Novavax delivers the Spike protein directly. To do that, they first have to make Spike protein in a lab🧵 2/That's done by taking the Spike DNA🧬and splicing it into a larger piece of DNA that is used to deliver genes into cells that are growing in a lab. Those cells "read" the DNA, turn it into RNA, and then into proteins. The Spike proteins are then harvested and purified.
Dec 24, 2020 4 tweets 3 min read
1/📌Evidence of #Airborne #SARSCoV2 traveling 12 floors of an apt building through the drainage system: 200+ residents in a wing of a high-rise were tested, revealing 9 infections. Those families lived in 3 vertically aligned flats connected by drainage pipes in the bathrooms🧵 Image 2/To confirm apt units are indeed connected, tracer gas was released into drainage system of one unit and shown to come out of the other. Evidence for alternative mechanisms of transmission (e.g. use of public spaces, elevators, etc..) could not be found. Image