Friday, July 3, 2020

Did a mutation help the coronavirus spread? More evidence, but lingering questions

A scanning electron micrograph of a cell infected with the coronavirus, NIAID image.

For months, scientists have debated whether a variant of the coronavirus that has come to predominate in much of the world did so partly because it is more transmissible than other viruses.

The new report, posted by the journal Cell and led by investigators at Los Alamos National Laboratory, suggested that the variant did have such an advantage. Other researchers said the findings were not yet definitive.

The new paper, led by Bette Korber, a theoretical biologist, presents evidence in the form of lab findings, tests of infected patients and a broad statistical analysis of the pandemic as the D614G variant repeatedly took over in cities, regions and countries.  (Full Story)

New form of coronavirus spreads faster, but doesn't make people sicker

A global study has found clear evidence that a new form of the coronavirus has spread from Europe to the US. The new mutation makes the virus more infectious but does not seem to make people any sicker, an international team of researchers reported Thursday.

“Our global tracking data show that the G614 variant in Spike has spread faster than D614,” theoretical biologist Bette Korber of Los Alamos National Laboratory and colleagues wrote in their report. “We interpret this to mean that the virus is likely to be more infectious,” they add. “Interestingly, we did not find evidence of G614 impact on disease severity.” (Full Story)

This coronavirus mutation has taken over the world. Scientists are trying to understand why

Health-care workers administer coronavirus testing in Tampa. From WaPo.

At least four laboratory experiments suggest that the mutation makes the virus more infectious, although none of that work has been peer-reviewed. Another unpublished study led by scientists at Los Alamos National Laboratory asserts that patients with the G variant actually have more virus in their bodies, making them more likely to spread it to others.

So far, the biggest study of transmission has come from Bette Korber, a computational biologist at Los Alamos National Laboratory who built one of the world’s biggest viral genome databases for tracking HIV.  (Full Story)

The coronavirus has changed since it left Wuhan. Is it more infectious?

3-D model of the novel coronavirus shows the spike proteins in red. From the LA Times.

A version of the coronavirus first seen in Italy four months ago has overtaken the original strain from Wuhan and is now dominant around the world, scientists reported Thursday.

The study authors, led by Bette Korber, a computational biologist at Los Alamos National Laboratory, posted a preliminary version of the work in May that generated substantial controversy by claiming the mutation in the spike protein made the virus more contagious. Korber and her team also warned that the mutation could undermine efforts to develop desperately needed vaccines and treatments for COVID-19. (Full Story)

World's dominant strain of coronavirus is 10 times more infectious

The newer strain G614 (blue) appeared later in the pandemic but, since then, has dominated, LANL image.

A study done by scientists at the University of Sheffield and Los Alamos National Laboratory, New Mexico, found that D614 appeared to have been the virus's original state in humans, and the one found in Wuhan. It made up the vast majority of all Covid-19 infections in China, and Asia as a whole, and also seemed to be the first version of the virus to appear in the countries they studied.

However, the mutated version - G614 - started to appear soon after in Europe and North America in particular, before going on to take over as the dominant virus.  'A clear and consistent pattern was observed in almost every place where adequate sampling was available,' the researchers said. (Full Story)

Also from Genetic Engineering & Biotechnology News

Building better electron sources with graphene

Graphene allows photocathode substrates to be cleaned and reused, LANL image.

Photocathodes that produce electron beams for electron microscopes and advanced accelerators can be refreshed and rebuilt repeatedly without opening the devices that rely on them, provided the electron emitting materials are deposited on single-atom-thick layers of carbon known as graphene, according to a new study published in the journal Applied Physics Letters.

“The machines that rely on these electron emitters typically operate under high vacuum,” said Los Alamos National Laboratory physicist Hisato Yamaguchi. “By choosing graphene over materials like silicon or molybdenum, which tend to degrade during use, we can clean the substrate and redeposit electron-emitting materials without opening the vacuum.  (Full Story)

Quantum dot solar cells get greener

SEM image of electrodes infiltrated with quantum dots, LANL image.

Semiconducting nanocrystals called colloidal quantum dots (CQDs) are ideal for applications such as large-panel displays and photovoltaic cells thanks to their high efficiency and colour purity. Their main drawback is their toxicity, since they have traditionally been made from cadmium or other heavy metals, such as lead. 

Researchers at the Los Alamos National Laboratory in the US have now engineered cadmium-free QD solar cells that reach efficiencies on par with those of their environmentally-unfriendly counterparts. The key to the new devices’ high performance is their tolerance to defects, they say. (Full Story)

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