By Reuters Staff
SHANGHAI (Reuters) - The number of
people who have been infected with COVID-19 in the Chinese city of Wuhan, where
the virus was first identified, could be around three times the official
figure, according to a study by Chinese researchers based in the city.
The paper, published by the PLOS
Neglected Tropical Diseases journal on Thursday, analysed blood samples from
more than 60,000 healthy individuals taken from locations across China from
March to May 2020.
It found that 1.68% of those from
Wuhan contained antibodies for SARS-CoV-2, the virus that causes COVID-19,
compared to 0.59% in surrounding Hubei province and 0.38% in the rest of China.
With the city’s total population at
more than 10 million, the researchers estimated that as many as 168,000 Wuhan
residents were infected with the virus, compared to the official number of
50,340 hospitalised cases.
The study suggested at least two
thirds of the total number were asymptomatic, and thousands could have been
infected after the “elimination” of clinical cases, raising the possibility the
virus could exist in a community for a long period without causing
hospitalisations.
A separate study published by the
Chinese Center for Disease Control and Prevention (CDC) late last month put the
“seroprevalence” rate in Wuhan, the percentage of the population with
antibodies, even higher at 4.43%, implying that around half a million people in
the city could have been infected.
More
https://www.reuters.com/article/us-health-coronavirus-china-wuhan/china-study-says-wuhan-covid-infections-3-times-higher-than-official-figure-idUSKBN29D0CW
Chinese city of 11 million stops
people leaving in bid to contain COVID January 7, 2021 12:49 AM By Reuters Staff
SHANGHAI (Reuters) -The capital and largest
city in northern China’s Hebei province barred people from leaving on Thursday
in an effort to curb the spread of the coronavirus as the country reported the
biggest rise in daily infections in more than five months.
Hebei accounted for 51 of the 52
local cases reported by the National Health Commission on Thursday. This
compared with 20 cases reported in the province, which surrounds Beijing, a day
earlier.
Authorities in Shijiazhuang, home to
11 million people, have launched mass testing drives and banned gatherings to
reduce the spread of the coronavirus.
In addition to barring people from
leaving the city, people and vehicles from areas of the city considered
high-risk were not allowed to leave their district, authorities said.
Hebei entered a “wartime mode” on
Tuesday, meaning investigation teams would be set up at provincial, city and
district levels to trace the close contacts of those who have tested positive.
Chinese state television earlier
reported that Shijiazhuang had banned passengers from entering its main railway
station. The city had previously required travellers to present a negative
nucleic acid COVID-19 test result taken within 72 hours before boarding a train
or a plane in the province.
Total new COVID-19 cases for all of
mainland China stood at 63, compared with 32 reported a day earlier, marking
the biggest rise in daily cases since 127 cases were reported on July 30.
The number of asymptomatic carriers,
who have been infected with the SARS-CoV-2 virus that causes the disease but
have yet to develop any symptoms, also rose, to 79 from 64 a day earlier.
The total number of confirmed
COVID-19 cases in mainland China since the outbreak first started in the city
of Wuhan in late 2019 now stands at 87,278, while the death toll remained
unchanged at 4,634.
In the city of Dalian in Liaoning
province in China’s northeast, which has reported local infections in recent
days, residents in medium or high-risk areas have been barred from leaving the
city. Residents in other areas were told to refrain from unnecessary trips out
of Dalian.
More
https://uk.reuters.com/article/uk-health-coronavirus-china/chinese-city-of-11-million-stops-people-leaving-in-bid-to-contain-covid-idUKKBN29C02U?il=0
US and UK diverge over critical
COVID-19 vaccine dose strategy By Rich Haridy January 06, 2021
Health
authorities in the United Kingdom have recommended extending dosing schedules
for approved COVID-19 vaccines, suggesting one dose offers enough short-term
protection despite clinical trials only testing two-dose regimes. Authorities
in the United States, however, claim this dosing change is unproven, risky and
premature.
Two
COVID-19 vaccines have been approved for emergency use in the UK. Both were
trialed using a two-dose schedule, with the second dose administered three to
four weeks after the first.
New advice from the Joint Committee on Vaccination and
Immunisation (JCVI) is now suggesting the second dose of both approved vaccines
can be delayed for up to 12 weeks. While clinical trial data is not clear on
how this change to the tested dosing schedule will affect long-term immunity,
the JCVI advice presents a utilitarian solution to the current wave of virus
transmission spreading across the UK.
“The four UK Chief Medical Officers agree with the JCVI
that at this stage of the pandemic prioritising the first doses of vaccine for
as many people as possible on the priority list will protect the greatest
number of at risk people overall in the shortest possible time and will have
the greatest impact on reducing mortality, severe disease and hospitalisations
and in protecting the NHS and equivalent health services,” declares a UK government statement .
In response to the UK government decision, the US Food
& Drug Administration (FDA) released a statement claiming it does not recommend changes
to currently approved COVID-19 vaccine dosing schedules, and called any changes
to dosing schedules, “premature and not rooted solidly in the available
evidence.”
The FDA’s statement claims there is no data from clinical
trials to suggest anything definitive about the depth or duration of protection
one would receive from a single vaccine dose.
“We know that some of these discussions about changing the
dosing schedule or dose are based on a belief that changing the dose or dosing
schedule can help get more vaccine to the public faster,” the FDA statement notes . “However, making such changes that are
not supported by adequate scientific evidence may ultimately be counterproductive
to public health.”
Anthony Fauci, director of the National Institute of
Allergy and Infectious Diseases, said in an interview with CNN the US will not be following the
UK in delaying a second dose for COVID-19 vaccines. He added that while he
understood the argument for delaying a second dose, there simply is no clear
evidence from clinical trials that one dose generates effective protection.
A joint statement from Pfizer and BioNTech, the developers
of one of the COVID-19 vaccines approved for use in the UK and UK, affirms
Fauci’s sentiment. The statement says since the clinical trial investigated a
two-dose schedule, there is no evidence as to whether a single dose offers any
level of protection past three weeks.
“The safety and efficacy of the vaccine has not been
evaluated on different dosing schedules as the majority of trial participants
received the second dose within the window specified in the study design,” the Pfizer/BioNTech
statement says. “There is no data to demonstrate that protection after the
first dose is sustained after 21 days.”
Although it is true that no COVID-19
vaccine clinical trial investigating two-dose regimes can report clear data on
the long-term protection generated by one dose, not all experts are against the
idea of delaying the second dose. Stephen Evans, from the London School of
Hygiene and Tropical Medicine, says the UK is currently in a crisis scenario
due to its current wave of infections, and this factor must be taken into
account when considering vaccine scheduling decisions.
“The trials did not compare
different dose spacing or compare one versus two doses, so we simply do not
know what is ‘optimal’,” says Evans. “So, the information directly from the
trials is lacking. We have to utilize what we know from science generally. We
know that vaccinating only half of a vulnerable population will lead to a
notable increase in cases of COVID, with all which that entails including
deaths. When resources of doses and people to vaccinate are limited, then
vaccinating more people with potentially less efficacy is demonstrably better
than a fuller efficacy in only half.”
More
https://newatlas.com/health-wellbeing/us-uk-disagree-critical-coronavirus-vaccine-dose-schedule/
Next, some vaccine links
kindly sent along from a LIR reader in Canada. The links come from a most
informative update from Stanford Hospital in California.
World
Health Organization - Landscape of COVID-19 candidate vaccines . https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines
NY
Times Coronavirus Vaccine Tracker . https://www.nytimes.com/interactive/2020/science/coronavirus-vaccine-tracker.html
Stanford
Website . https://racetoacure.stanford.edu/clinical-trials/132
Regulatory
Focus COVID-19 vaccine tracker . https://www.raps.org/news-and-articles/news-articles/2020/3/covid-19-vaccine-tracker
Some other useful Covid links.
Johns Hopkins Coronavirus
resource centre
https://coronavirus.jhu.edu/map.html
Rt Covid-19
https://rt.live/
Covid19info.live
https://wuflu.live/
Centers for Disease Control
Coronavirus
https://www.cdc.gov/coronavirus/2019-ncov/index.html
The Spectator
https://data.spectator.co.uk/city/national
Technology Update.
With events happening
fast in the development of solar power and graphene, I’ve added this section.
Updates as they get reported.
A high order for a low dimension Novel crystal
confines electrons to one dimension for spintronic applications Date: January 4, 2021
Source: University of Tokyo
Summary: Spintronics refers to a suite of physical
systems which may one day replace many electronic systems. To realize this
generational leap, material components that confine electrons in one dimension
are highly sought after. For the first time, researchers created such a
material in the form of a special bismuth-based crystal known as a high-order
topological insulator.
To create spintronic devices, new
materials need to be designed that take advantage of quantum behaviors not seen
in everyday life. You are probably familiar with conductors and insulators,
which permit and restrict the flow of electrons, respectively. Semiconductors
are common but less familiar to some; these usually insulate, but conduct under
certain circumstances, making them ideal miniature switches.
For spintronic applications, a new
kind of electronic material is required and it's called a topological
insulator. It differs from these other three materials by insulating throughout
its bulk, but conducting only along its surface. And what it conducts is not
the flow of electrons themselves, but a property of them known as their spin or
angular momentum. This spin current, as it's known, could open up a world of
ultrahigh-speed and low-power devices.
However, not all topological
insulators are equal: Two kinds, so-called strong and weak, have already been
created, but have some drawbacks. As they conduct spin along their entire surface,
the electrons present tend to scatter, which weakens their ability to convey a
spin current. But since 2017, a third kind of topological insulator called a
higher-order topological insulator has been theorized. Now, for the first time,
one has been created by a team at the Institute for Solid State Physics at the
University of Tokyo.
"We created a higher-order
topological insulator using the element bismuth," said Associate Professor
Takeshi Kondo. "It has the novel ability of being able to conduct a spin
current along only its corner edges, essentially one-dimensional lines. As the
spin current is bound to one dimension instead of two, the electrons do not
scatter so the spin current remains stable."
To create this three-dimensional
crystal, Kondo and his team stacked two-dimensional slices of crystal one atom
thick in a certain way. For strong or weak topological insulators, crystal
slices in the stack are all oriented the same way, like playing cards face down
in a deck. But to create the higher-order topological insulator, the
orientation of the slices was alternated, the metaphorical playing cards were
faced up then down repeatedly throughout the stack. This subtle change in
arrangement makes a huge change in the behavior of the resultant three-dimensional
crystal.
The crystal layers in the stack are
held together by a quantum mechanical force called the van der Waals force.
This is one of the rare kinds of quantum phenomena that you actually do see in
daily life, as it is partly responsible for the way that powdered materials
clump together and flow the way they do. In the crystal, it adheres the layers
together.
"It
was exciting to see that the topological properties appear and disappear
depending only on the way the two-dimensional atomic sheets were stacked,"
said Kondo. "Such a degree of freedom in material design will bring new
ideas, leading toward applications including fast and efficient spintronic
devices, and things we have yet to envisage."
https://www.sciencedaily.com/releases/2021/01/210104114119.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fmatter_energy%2Fgraphene+%28Graphene+News+--+ScienceDaily%29
Another weekend,
and hopefully a peaceful weekend in America as we get close to a handover of
power on the 20th. But will President Trump resign this weekend? Have a great
weekend everyone.
No comments:
Post a Comment