. Scientific Frontline

Monday, January 16, 2023

Early humans: Annual cycles in tooth enamel provide insights into life histories

Jülide Kubat and Wolfgang Müller load the LA-ICPMS with a thin section of tooth for analysis.
Photo Credit: Jülide Kubat

An interdisciplinary team of scientists, led by Goethe University Frankfurt and the Senckenberg Research Institute and Natural History Museum Frankfurt, has discovered – by analyzing their teeth – what our ancestors of the species Homo erectus ate hundreds of thousands of years ago on the island of Java in Southeast Asia: over the course of a year, these early humans switched from a plant-based diet to a mixed one, but were far less dependent on seasonal food supply than, for example, orangutans, which also inhabited the island.

If you take a magnifying glass and a torch and look at your teeth very carefully in the mirror, in places you can spot a pattern of fine, parallel lines running across your teeth. These correspond to the striae of Retzius that mark the growth of our tooth enamel. Enamel starts forming in the womb and continues to mineralize until adolescence, when the last milk teeth fall out and are replaced by permanent ones. Like in all land-dwelling vertebrates, tooth enamel mineralizes gradually in microscopically thin layers in humans too, represented by the striae of Retzius. The speed with which a human develops can be read from these Retzius lines. Physiological changes, such as birth, weaning or illness, for example, leave distinctive traces. The striae of Retzius also form the chronological framework for the chemical composition of tooth enamel, which in turn reflects changes in the diet of that individual.

Highly accurate test for common respiratory viruses uses DNA as ‘bait’

Doctor examining a patient
Photo Credit: Thirdman

The test uses DNA ‘nanobait’ to detect the most common respiratory viruses – including influenza, rhinovirus, RSV and COVID-19 – at the same time. In comparison, PCR (polymerase chain reaction) tests, while highly specific and highly accurate, can only test for a single virus at a time and take several hours to return a result.

While many common respiratory viruses have similar symptoms, they require different treatments. By testing for multiple viruses at once, the researchers say their test will ensure patients get the right treatment quickly and could also reduce the unwarranted use of antibiotics.

In addition, the tests can be used in any setting, and can be easily modified to detect different bacteria and viruses, including potential new variants of SARS-CoV-2, the virus which causes COVID-19. The results are reported in the journal Nature Nanotechnology.

The winter cold, flu and RSV season has arrived in the northern hemisphere, and healthcare workers must make quick decisions about treatment when patients show up in their hospital or clinic.

Mucosal antibodies in the airways provide durable protection against SARS-CoV-2

Charlotte Thålin, M.D. and associate professor at the Department of Clinical Sciences, Danderyd Hospital
Photo Credit: Ludvig Kostyal

Researchers hope that a nasal vaccine may generate mucosal immune responses that protect against SARS-CoV-2 infection.

High levels of mucosal IgA antibodies in the airways protect against SARS-CoV-2 infection for at least eight months. Omicron infection generates durable mucosal antibodies, reducing the risk of re-infection. These are the findings of a study published in The Lancet Infectious Diseases by researchers at Karolinska Institutet and Danderyd Hospital in Sweden. The results raise further hope for the feasibility of future nasal vaccine platforms to protect against infection.

“Antibodies in the blood protect from severe disease, but if we aim to limit infection, viral transmission and the emergence of new SARS-CoV-2 variants, we need to reinforce our immunity at the mucosal surface, which is the viral point of entry”, says Charlotte Thålin, M.D. and associate professor at the Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet who led the study. “This is not achieved by currently employed intramuscularly-delivered vaccines. But the hope is that a nasal vaccine may generate mucosal immune responses similar to those seen after infection, and thereby block the transmission chain”.

Deflecting lightning with a laser lightning rod

During tests carried out on the summit of the Säntis by Jean-Pierre Wolf and Aurélien Houard's team, the scientists noted that the discharge could follow the laser beam of the "LLR" for several dozen meters before reaching the tower of the operator Swisscom (in red and white).
Photo Credit: Xavier Ravinet - UNIGE

A European consortium led by UNIGE, École Polytechnique (Paris), EPFL, hes-so and TRUMPF has managed to guide lightning using a high-power laser installed at the top of Mount Säntis in Switzerland.

Forest fires, power cuts and damaged infrastructure…lightning fascinates and destroys in equal measure, causing as many as 24,000 deaths a year worldwide not to mention widespread destruction. Even today, the lightning rod invented by Benjamin Franklin is the best form of protection. And yet, these rods do not always provide optimal protection for sensitive sites. A European consortium consisting of the University of Geneva (UNIGE), École Polytechnique (Paris), EPFL, hes-so and TRUMPF scientific lasers (Munich) has developed a promising alternative: the Laser Lightning Rod or LLR. After testing the LLR on the summit of Säntis (in Switzerland), the researchers now have proof of its feasibility. The rod can deflect lightning over several dozen meters even in poor weather. The results of this research are published in the journal Nature Photonics.

Sandia work at the heart of next generation nuclear reactor

A team of Sandia National Laboratories researchers is testing materials to make the next generation of fusion reactors. This container is used to expose the samples to nuclear fusion. It holds seven samples of innovative tungsten alloys, post exposure.
Photo Credit: Jonathan Coburn

A team of Sandia National Laboratories researchers working on the reactor at the DIII-D National Fusion Facility is testing materials to make the next generation of fusion reactors, in the quest to develop more carbon-free energy sources.

These magnetic confinement fusion reactors, called tokamaks, use magnetic fields to shape plasma into a donut shape that generates power from nuclear fusion. DIII-D is the largest such facility currently operating in the Department of Energy complex. Tokamaks create high heat and particle fluxes that can cause significant erosion of the reactor wall materials. If these materials contaminate the core plasma, it could make it impossible to bring the reactor to a temperature high enough to start stable, safe fusion.

Jonathan Coburn is one such researcher, part of a team of Sandians that collaborates with DIII-D to test and develop much needed specialized fusion materials for the hot fusion plasma environment.

By detecting tiny flashes of heat, scientist pave way for more stable quantum computers

Measuring the heat of a phase slip in a Josephson junction is a significant step forward for quantum thermodynamics toward better quantum technologies.
Photo Credit: Kuan Yen Tan/Aalto University

An international collaboration between quantum scientists resulted in a new way to measure heat dissipation in superconducting quantum circuits – crucial building blocks for quantum technologies such as computers. The discovery represents a step forward for experimental quantum thermodynamics, the field investigating the interaction of the quantum world and heat, and paves the way for improved quantum devices.

As heat sets limits for traditional computing, so it does for quantum computers. Detecting and controlling the heat dissipation of quantum computers is central for developing better and more stable machines. Researchers at Aalto, the Universitét Grenoble Alpes and University of Konstanz worked together to test a theory about heat dissipation in a so-called phase slip in a quantum device. The result was a reliable and efficient way to measure dissipation that could be scaled to cover a range of quantum applications. The discovery was recently published in Nature Physics.

Multi-layered ‘space skin’ can help future satellites and spacecraft harvest energy

Credit: NASA

A 'space skin' could help protect spacecraft and satellites from harsh solar radiation while also harvesting energy for future use in the craft's mission, according to a study from the University of Surrey and Airbus Defense and Space.

The research team has shown that their innovative nano-coating, called the Multifunctional Nanobarrier Structure (MFNS), can reduce the operating temperatures of space-qualified structures from 120°C to 60°C.

Thanks to its custom-built, room temperature application system, researchers were able to show that it is possible to use the MFNS alongside a craft's sensors and advanced composite materials.

Professor Ravi Silva, corresponding author of the study and Director of the Advanced Technology Institute at the University of Surrey, said:

"Space is a wondrous but dangerous place for us humans and other human-made structures. While solutions already on the market offer protection, they are bulky and can be restrictive when it comes to thermal control.

Rapid cognitive decline uncommon in ageing people with HIV on stable treatment

We need to determine whether people with HIV may require additional care as a result of mental and cognitive health changes as they reach their 60s.
Photo Credit: Sabine van Erp

As with all chronic conditions, a focus on cognitive and mental health should be part of ongoing care.

With successful treatment, HIV has become a chronic health condition which can be managed with life-long care.

Treatment reduces the amounts of HIV in the blood to an undetectable level and most people with the infection who take their medication live as long as people without HIV.

While there have been successful developments in treating the virus, it’s important to understand how it may impact the long-term cognitive function of those ageing with HIV.

Associate Professor Lucette Cysique at the School of Psychology, UNSW Sydney, and her team conducted a long-term study of cognitive function in people who are ageing with chronic stable HIV infection, from 17 care facilities across Australia, published in eClinicalMedicine.

Tens of thousands of possible catalysts on the diameter of a hair

The results of the sputtering process can be seen under the light microscope.
Image Credit: © Lars Banko

New methods make it possible to produce countless new materials in one step and to examine them quickly.

When looking for catalysts for the energy transition, materials made from at least five elements are particularly promising. Only there are theoretically millions of them - how do you find the most powerful? A Bochum research team led by Prof. Dr. Alfred Ludwig, head of the Materials Discovery and Interfaces chair, MDI, managed to accommodate all possible combinations of five elements on one carrier in a single step. In addition, the researchers developed a method to analyze the electrocatalytic potential of each of the combinations in this micromaterial library in high throughput. In this way, they want to speed up the search for potential catalysts many times over. The team at the Ruhr University Bochum reports in the journal Advanced Materials.

Monday, January 9, 2023

Controlling quantum states in individual molecules with two-dimensional ferroelectrics

Researchers used electricity to control the internal states of molecules.
Illustration Credit: Jose Lado/Aalto University

Researchers demonstrated how to control the quantum states of individual molecules with an electrically controllable substrate.

Controlling the internal states of quantum systems is one of the biggest challenges in quantum materials. At the deepest level, single molecules can display different quantum states, even while possessing the same number of electrons. These states are associated with different electron configurations, which can lead to dramatically different properties.

The capability of controlling the electronic configuration of single molecules could lead to major developments in both fundamental science and technology. On the one hand, controlling the internal states of molecules may allow for the development of new artificial materials with exotic properties. On the other hand, it might also make possible the ultimate miniaturization of classical computer memories, with the two configurations could make it possible to encode a 0 and a 1 in a classical memory unit at the molecular level. However, controlling the internal states of molecules still remains a challenge, and realistic, scalable strategies for overcoming it have not been proposed.

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