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Category: chemistry – Page 310

The robot seen here can work almost 24–7, carrying out experiments by itself. The automated scientist – the first of its kind – can make its own decisions about which chemistry experiments to perform next, and has already discovered a new catalyst.

With humanoid dimensions, and working in a standard laboratory, it uses instruments much like a human does. Unlike a real person, however, this 400 kg robot has infinite patience, and works for 21.5 hours each day, pausing only to recharge its battery.

This new technology – reported in the journal Nature and featured on the front cover – is designed to tackle problems of a scale and complexity that are currently beyond our grasp. New drug formulations could be autonomously discovered, for example, by searching vast and unexplored chemical spaces.

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The goal of ‘femtochemistry’ is to film and control chemical reactions with short flashes of light. Using consecutive laser pulses, atomic bonds can be excited precisely and broken as desired. So far, this has been demonstrated for selected molecules. Researchers at the University of Göttingen and the Max Planck Institute for Biophysical Chemistry have now succeeded in transferring this principle to a solid, controlling its crystal structure on the surface. The results have been published in the journal Nature.

The team, led by Jan Gerrit Horstmann and Professor Claus Ropers, evaporated an extremely thin layer of indium onto a silicon crystal and then cooled the crystal down to −220 degrees Celsius. While the indium form conductive metal chains on the at room temperature, they spontaneously rearrange themselves into electrically insulating hexagons at such low temperatures. This process is known as the transition between two phases—the metallic and the insulating—and can be switched by laser pulses. In their experiments, the researchers then illuminated the cold surface with two short laser pulses and immediately afterwards observed the arrangement of the indium atoms using an electron beam. They found that the rhythm of the has a considerable influence on how efficiently the surface can be switched to the metallic state.

This effect can be explained by oscillations of the atoms on the surface, as first author Jan Gerrit Horstmann explains: “In order to get from one state to the other, the atoms have to move in different directions and in doing so overcome a sort of hill, similar to a roller coaster ride. A single laser pulse is not enough for this, however, and the atoms merely swing back and forth. But like a rocking motion, a second pulse at the right time can give just enough energy to the system to make the transition possible.” In their experiments the physicists observed several oscillations of the atoms, which influence the conversion in very different ways.

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Clint Brauer’s farm outside of Cheney, Kansas, could be described as Old MacDonald’s Farm plus robots. Along with 5,500 square feet of vegetable-growing greenhouses, classes teaching local families to grow their food, a herd of 105 sheep, and Warren G—a banana-eating llama named after the rapper—is a fleet of ten, 140-pound, battery-operated robots.

Brauer, the co-founder of Greenfield Robotics, grew up a farm kid. He left for the big city tech and digital world, but eventually made his way back to the family farm. Now, it’s the R&D headquarters for the Greenfield Robotics team, plus a working farm.

When Brauer returned to his agricultural roots, he did so with a purpose: to prove that food could be grown without harmful chemicals and by embracing soil- and planet-friendly practices. He did just that, becoming one of the premier farmers growing vegetables in Kansas without pesticides, selling to local markets, grocery store chains, and chefs.

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As the death toll from the COVID-19 pandemic mounts, scientists worldwide continue their push to develop effective treatments and a vaccine for the highly contagious respiratory virus.

University of South Florida Health (USF Health) Morsani College of Medicine scientists recently worked with colleagues at the University of Arizona College of Pharmacy to identify several existing compounds that block replication of the COVID-19 virus (SARS-CoV-2) within grown in the laboratory. The inhibitors all demonstrated potent chemical and structural interactions with a critical to the virus’s ability to proliferate.

The research team’s discovery study appeared June 15 in Cell Research, a high-impact Nature journal.

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NASA is bringing the smell of space to Earth with a new fragrance called Eau de Space. The fragrance was developed by chemist Steve Pearce, who was contracted by NASA in 2008 to recreate the scent of space.

With his knowledge of flavor and fragrance chemistry, Pearce used astronauts’ descriptions of the smell of space to come up with combinations to match what was described as “ozone, hot metal, and fried steak,” CNN reports.

“It’s a bitter kind of smell in addition to being smoky and burned, kind of like a smell from a gun, right after you fire the shot,” astronaut Peggy Whitson told CNN. Eau de Space product manager, Matt Richmond, said he has struggled to accurately describe the fragrance’s scent, adding that astronauts have also likened the smell to “a mix of gunpowder, seared steak, raspberries, and rum.”

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New research from the University of Colorado Boulder has offered some of the clearest evidence to date showing how the gut microbiome produces a metabolite that, over time, contributes to age-related declines in cardiovascular health.

High blood levels of trimethylamine-N-Oxide (TMAO), a metabolic byproduct of digestion, have been strongly linked to negative cardiovascular health. When one eats red meat, eggs or other animal proteins, certain types of gut bacteria feed on chemicals in those foods and produce TMA, or trimethylamine, which is then turned into TMAO in the liver.

A number of studies have linked TMAO to heart disease, however, until now it hasn’t been clear exactly how this metabolite causes cardiovascular damage. A robust new study, published in the journal Hypertension, is offering one of the first thorough mechanistic investigations illustrating how TMAO damages the cardiovascular system.

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Brain-inspired computing paradigms have led to substantial advances in the automation of visual and linguistic tasks by emulating the distributed information processing of biological systems. The similarity between artificial neural networks (ANNs) and biological systems has inspired ANN implementation in biomedical interfaces including prosthetics and brain-machine interfaces. While promising, these implementations rely on software to run ANN algorithms. Ultimately, it is desirable to build hardware ANNs that can both directly interface with living tissue and adapt based on biofeedback. The first essential step towards biologically integrated neuromorphic systems is to achieve synaptic conditioning based on biochemical signalling activity. Here, we directly couple an organic neuromorphic device with dopaminergic cells to constitute a biohybrid synapse with neurotransmitter-mediated synaptic plasticity. By mimicking the dopamine recycling machinery of the synaptic cleft, we demonstrate both long-term conditioning and recovery of the synaptic weight, paving the way towards combining artificial neuromorphic systems with biological neural networks.

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A USC Dornsife chemistry professor’s bet on a student proposal leads to new understanding of what defines a metal — and lands the cover of Science.

Ryan McMullen had never heard of the USC Dornsife College of Letters, Arts and Sciences when he started casting about for a graduate chemistry program. But on the recommendation of one of his professors, he sent an email to the College’s Professor of Chemistry Stephen Bradforth proposing an experiment to tease out what makes a metal really a metal.

The proposal would not only turn into his Ph.D. thesis but a major scientific breakthrough.

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Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic components or the transmission of signals. High-frequency electromagnetic fields can only be shielded with conductive shells that are closed on all sides. Often thin metal sheets or metallized foils are used for this purpose. However, for many applications such a shield is too heavy or too poorly adaptable to the given geometry. The ideal solution would be a light, flexible and durable material with extremely high shielding effectiveness.

Aerogels against electromagnetic radiation

A breakthrough in this area has now been achieved by a research team led by Zhihui Zeng and Gustav Nyström. The researchers are using nanofibers of as the basis for an aerogel, which is a light, highly porous material. Cellulose fibers are obtained from wood and, due to their , enable a wide range of chemical modifications. They are therefore a highly popular research object. The crucial factor in the processing and modification of these cellulose nanofibres is to be able to produce certain microstructures in a defined way and to interpret the effects achieved. These relationships between structure and properties are the very field of research of Nyström’s team at Empa.

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