Wednesday, June 16, 2021

Barbara McClintock is the only woman to be awarded an unshared Nobel Prize in Physiology or Medicine.

McClintock discovered 'jumping genes' in corn, and proved that chunks of genetic code can change position on a chromosome, affecting genetic expression.


Born in Hartford Connecticut, McClintock's family had little money, so her interest in research was viewed with skepticism. It was more important for her to marry, her family thought. Despite this, with her father's support, Barbara began studying at Cornell's College of Agriculture in 1919, and her studies are where her interest remained. She was shy and anything but a careerist, but at the same time, she also realized the importance of what she had achieved, not least of all in her role as an example for other women.




World's oldest football

This is the World's oldest football from 1540. It was made from cowhide with a pig bladder used to inflate the ball. Half the size of a modern football.





The ball was made in Stirling, Scotland, and discovered behind the paneling of the Queen's Chamber in Stirling Castle, which was decorated in the 1540s. Mary Queen of Scots was there at this time and later in life was known to have an interest in all sports but especially golf and football. She recorded a game of football in her diaries while at Carlisle Castle. The ball could have been used in the courtyards within the castle or taken to the royal gardens below the walls. Everyone from the castle, including kings and queens would have been involved. Football was a game for all just as it is today. Was this personal item, belonging to Mary, deliberately placed behind the paneling to act as a protection from witchcraft, a practice common at the time or was it somehow lost. We will never answer that question but we do know that this little ball is the beginning of a sport that now involves a sixth of the population of the world.


Credit: BBC, Peter C. Kjærgaard


Tuesday, June 15, 2021

The photocatalytic system mimics sunflowers by bending towards the light

Scientists have designed a photosensitive hydrogel that can orient towards a light source. The hydrogel mimics phototropism in plants and was used to maximize the energy-harvesting ability of a photocatalyst. 

Phototropism allows plants and other organisms to adapt to changing light conditions and maximize energy harvesting throughout the day. Man-made photocatalytic systems, however, typically require direct irradiation from a light source. There are only a few examples of scientists achieving artificial phototropism that are independent of external control and automatically track the direction of light.




Now, a team led by Feili Lai of KU Leuven in Belgium and Tinaxi Liu of Jiangnan University in China has devised a system that combines artificial phototropism with photocatalytic hydrogen peroxide production. Modelled on a sunflower, the system contains two poly(N-isopropyl acrylamide)-based hydrogels. One hydrogel is temperature-sensitive and forms a stem. It also contains reduced graphene oxide (rGO) to absorb light. On top of the stem sits the second hydrogel, which mimics a flower head. It contains a photocatalyst for generating hydrogen peroxide that is made from cadmium sulfide and reduced graphene oxide composite.


When light is shone on the stem, it bends and tracks the light source. This orientates the floral disk towards the light to maximize light absorption so it can maintain a high photocatalytic efficiency regardless of the incidence of light.

The team compared their hydrogen peroxide yield rate to a system without phototropism and saw that while the light-responsive system’s yield remained constant, the yield of the control decreased as the incident angle increased from 0° to 90°.


References

J Qin et al, Energy Environ. Sci., 2021, DOI: 10.1039/d1ee00587a



Saturday, June 12, 2021

Extraordinary new material shows zero heat expansion from 4 to 1,400 K

 Australian researchers have created what may be one of the most thermally stable materials ever discovered. This new zero thermal expansion (ZTE) material made of scandium, aluminum, tungsten and oxygen did not change in volume at temperatures ranging from 4 to 1400 Kelvin (-269 to 1126 °C, -452 to 2059 °F).

That's a wider range of temperatures, say scientists from the University of New South Wales (UNSW), than any other material demonstrated to date, and it could make orthorhombic Sc1.5Al0.5W3O12 (catchy name, eh?) a very handy tool for anyone engineering something that needs to work in extremely varied thermal environments.



Examples of where this might come in handy include things like aerospace design, where components are exposed to extreme cold in space and extreme heat at launch or on re-entry. Famously, the SR-71 Blackbird was designed to expand so much at its Mach 3.4 top speed that it would liberally drizzle fuel on the runway at ground temperatures; the fuel tanks wouldn't even fully seal until they heated up. This new material stays exactly the same volume from close to absolute zero all the way up to comfortably over the heat you'd expect to get on the wing of a hypersonic aircraft traveling at Mach 5.

Or there's things like medical implants, where the range of expected temperatures isn't so varied but even a small amount of thermal expansion can cause critical issues.

The UNSW team made the discovery more or less by accident: "We were conducting experiments with these materials in association with our batteries-based research, for unrelated purposes, and fortuitously came across this singular property of this particular composition," says Associate Professor Neeraj Sharma.

 After measuring the material using the Echidna high-resolution powder diffractometer at ANSTO's Australian Synchrotron and the Australian Centre for Neutron Scattering, the team found an incredible degree of thermal stability. At the molecular level, materials usually expand because an increase in temperature leads directly to an increase in the length of the atomic bonds between elements. Sometimes it also causes atoms to rotate, resulting in more spacious structures that affect the overall volume.

Not with this stuff, which the team observed across that huge temperature spectrum demonstrating "only minute changes to the bonds, position of oxygen atoms and rotations of the atom arrangements." The team says the exact mechanism behind this extreme thermal stability isn't totally clear, but that perhaps bond lengths, angles and oxygen atom positions are changing in concert with one another to preserve the overall volume.

"Which part's acting at which temperature, well, that's the next question," says Sharma, who adds, “the scandium is rarer and more costly, but we are experimenting with other elements that might be substituted, and the stability retained,”

The other ingredients, however, are widely available, and bond together using a "relatively simple synthesis," so the team believes this material should present no impediments to large-scale manufacturing.

Source:https://lnkd.in/g-QqTDw


📢Spreading the Word!📢 Williams evolves composites-intensive EV platform!

 
Williams Advanced Engineering introduced its FW-EVX electric vehicle (EV) platform in 2017, designed to give vehicle manufacturers a modular system with which to develop new vehicles. 

''WAE reports that it is applying this innovative modular platform for use in a series of EVs with the top hats engineered for the vehicles by Italdesign, one of the leading transportation design and body engineering companies in the world.'' 





''The company's approach is, like many EV platforms being developed, skateboard-like in that the rolling chassis is integrated into a flat structure. However, what is different about the Williams solution is that the battery is housed in a molded composite case that is part of the vehicle load structure: front and rear chassis elements are attached to it. Crash loads are transferred through internal reinforcements that are within the side sills.'' 

To build this structure WAE is using both recycled composite material and aluminum; the company claims that the structure “sets new standards for static and torsional stiffness.” 

Source:Managing Composites

Friday, June 11, 2021

REGISTER -LEAN SIX SIGMA GREEN BELT TRAINING & CERTIFICATION

 Is Six Sigma still relevant today?

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Organizations want their employees to know how to make processes more efficient, how to increase the quality of products, and how to save time and money that can ultimately be reinvested back into the organization.

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Hints that century-old TB vaccine offers an immune boost against Covid-19

 There are indications that BCG revaccination might protect against Covid-19. The latest results come from a Greek study published as an as yet un-peer reviewed preprint on medRxiv.

BCG – Bacillus Calmette–Guérin – celebrates its 100th anniversary this summer and remains the only approved vaccine against tuberculosis. Developed by French bacteriologists Albert Calmette and Camille Guérin from a bovine relative of Mycobacterium tuberculosis, it was first given to an infant in a Parisian hospital in July 1921.

It was recognized early on that BCG vaccination appeared to reduce death from diseases beyond just tuberculosis. Immunologists have long suspected that this live vaccine primes the immune system to better fight infection. Last year, it was hypothesized that BCG vaccination may protect against Covid-19.


The Greek preprint – yet to be peer-reviewed – reported that BCG revaccination resulted in a 68% risk reduction for Covid-19 infection, clinically or virologically confirmed. Five patients receiving placebo developed the severe disease but just one in the BCG vaccine group. However, the trial was relatively small with only around 300 volunteers. ‘It is interesting data, but a small study with high loss to follow-up,’ says Frederik Schaltz-Buchholzer, an epidemiologist at the University of Southern Denmark, who is involved in the Danish BCG trials. ‘We shouldn’t be opening champagne bottles just yet. We have a lot of trials still going on.’

Data from large trials of BCG revaccination in healthcare workers are now in the works. However, in January, a Dutch study of 6132 patients drew attention to initial findings that the vaccine did not offer protection against Covid-19 symptoms in elderly people.

Immunologist Mihai Netea, who was involved in the Greek and Dutch study, says an important difference between them may be that older Greeks received the BCG vaccine as children, whereas people in countries such as Italy, the Netherlands and Belgium never received one. ‘It might be that the T cell response is different in those who have previously been exposed to BCG, and that the innate immune response is also boosted further by a second administration,’ says Netea, who led studies showing how BCG re-programs immune cells.

Large BCG trials for Covid are underway

Most of the BCG trials worldwide for Covid-19 are in healthcare workers, with more than 2500 volunteers in Brazil. These are part of the Brace trial, which has recruited over 7500 healthcare workers at 34 sites in Brazil, the Netherlands, Spain, the UK and Australia. This study is led by Nigel Curtis, a vaccine scientist at the Murdoch Children’s Research Institute and University of Melbourne, Australia, with support from the Bill & Melinda Gates Foundation. The main question posed is whether the off-target effects of BCG boosts innate immunity and thereby lessens the severity of Covid-19, says Curtis.

A trial of over 1200 healthcare workers is also underway in Denmark and a trial with older volunteers is still recruiting there. The former trial was stopped early because healthcare workers began receiving Covid-19 vaccines. This is an issue with other BCG trials carried out in Europe and the US, where trial participants became eligible for Sars-CoV-2 vaccines. Epidemiologists at the University Medical Centre Utrecht, the Netherlands, have now invited BCG trials to take part in a meta-analysis. The aim is to increase the statistical power by combining the data from all ongoing trials now, rather than waiting until the trials are finished, explains immunologist Henri van Werkhoven at Utrecht.

BCG is not the only existing live vaccine under evaluation. The Washington University School of Medicine in St Louis is coordinating an international trial to investigate if the measles, mumps, and rubella (MMR) vaccine protects healthcare workers from Sars-CoV-2. Also, a recent observational study from India suggests that an immune therapy with killed mycobacterium reduced hospitalizations from Covid-19.

‘BCG revaccination in countries with high-pressure load may be useful in countries where classical vaccines are not available. Of course, larger studies from developing countries would be needed to definitively prove that,’ comments Netea. Production of BCG would also need to be ramped up.

These results will be important for future pandemics ‘in order to get even a partial protection from the beginning, so you don’t have to close economies and have so much suffering’, Netea says. He adds that thankfully ‘we have other vaccines that are much more effective [for Covid-19], so the efforts should be put in there.

Source:MedRxiv/Chemistry world

Today's KNOWLEDGE Share : Electron Paramagnetic Resonance

Today's KNOWLEDGE Share Electron Paramagnetic Resonance (EPR), also known as Electron Spin Resonance (ESR) , is a spectroscopic techniqu...