Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: chemistry

Eindhoven University of Technology researchers found five different phases in mixtures of two substances.

Frozen water can take on up to three forms at the same time when it melts: liquid, ice, and gas. This principle, which states that many substances can occur in up to three phases simultaneously, was explained 150 years ago by the Gibbs phase rule. Today, researchers from Eindhoven University of Technology and University Paris-Saclay are defying this classical theory, with proof of a five-phase equilibrium, something that many scholars considered impossible. This new knowledge yields useful insights for industries that work with complex mixtures, such as in the production of mayonnaise, paint, or LCD’s. The researchers have published their results in the journal Physical Review Letters.

The founder of contemporary thermodynamics and physical chemistry is the American physicist Josiah Willard Gibbs. In the 1870s he derived the phase rule, which describes the maximum number of different phases a substance or mixture of substances can assume simultaneously. For pure substances, the Gibbs Phase Rule predicts a maximum of 3 phases.

Read more | >

CIEQSFTTLFACQTAAEIWRAFGYTVKIMVDNGNCRLHVC: these forty letters are a set of instructions for building a sophisticated medical device designed to recognize the flu virus in your body. The device latches onto the virus and deactivates the part of it that breaks into your cells. It is impossibly tiny—smaller than the virus on which it operates—and it can be manufactured, in tremendous quantities, by your own cells. It’s a protein.

Proteins—molecular machines capable of building, transforming, and interacting with other molecules—do most of the work of life. Antibodies, which defend our cells against invaders, are proteins. So are hormones, which deliver messages within us; enzymes, which carry out the chemical reactions we need to generate energy; and the myosin in our muscles, which contract when we move. A protein is a large molecule built from smaller molecules called amino acids. Our bodies use twenty amino acids to create proteins; our cells chain them together, following instructions in our DNA. (Each letter in a protein’s formula represents an amino acid: the first two in the flu-targeting protein above are cysteine and isoleucine.) After they’re assembled, these long chains crumple up into what often look like random globs. But the seeming chaos in their collapse is actually highly choreographed. Identical strings of amino acids almost always “fold” into identical three-dimensional shapes. This reliability allows each cell to create, on demand, its own suite of purpose-built biological tools. “Proteins are the most sophisticated molecules in the known universe,” Neil King, a biochemist at the University of Washington’s Institute for Protein Design (I.P.D.), told me. In their efficiency, refinement, and subtlety, they surpass pretty much anything that human beings can build.

Today, biochemists engineer proteins to fight infections, produce biofuels, and improve food stability. Usually, they tweak formulas that nature has already discovered, often by evolving new versions of naturally occurring proteins in their labs. But “de novo” protein design—design from scratch—has been “the holy grail of protein science for many decades,” Sarel Fleishman, a biochemist at the Weizmann Institute of Science, in Israel, told me. Designer proteins could help us cure diseases; build new kinds of materials and electronics; clean up the environment; create and transform life itself. In 2018, Frances Arnold, a chemical engineer at the California Institute of Technology, shared the Nobel Prize in Chemistry for her work on protein design. In April, when the coronavirus pandemic was peaking on the coasts, we spoke over video chat. Arnold, framed by palm trees, sat outside her home, in sunny Southern California. I asked how she thought about the potential of protein design. “Well, I think you just have to look at the world behind me, right?” she said. “Nature, for billions of years, has figured out how to extract resources from the environment—sunlight, carbon dioxide—and convert those into remarkable, living, functioning machines. That’s what we want to do—and do it sustainably, right? Do it in a way that life can go on.”

Read more | >

A new study suggests anticholinergic medications may increase the risk of accelerated cognitive decline, especially in older adults at high risk of developing Alzheimer’s disease.

Anticholinergic drugs block the action of acetylcholine, a chemical messenger that controls a range of automatic bodily functions and plays a vital role in memory and attention.

Doctors prescribe these drugs for a variety of conditions, including urinary incontinence, overactive bladder, chronic obstructive pulmonary disorder (COPD), seasonal allergies, and depression.

Read more | >

Discovering chemical substances as possible chemical markers of life existence in Venus’s atmosphere via remote astronomical observations cannot be considered objective evidence of life existence on the planet, says Roscosmos Executive Director for Science and Advanced Programs Alexander Bloshenko. ‘Credible scientific data on that matter can be obtained only via contact explorations of the planet’s surface and atmosphere,’ he added.

Notably, the USSR was the only country to conduct regular explorations of Venus using on-planet stations. The first ever soft landing on another planet’s surface in the Solar system was performed in 1970 by the Venera-7 descent module. Several orbital missions and landings provided detailed data on the Venerian climate, soil and atmosphere composition. The Soviet Venera-13 spacecraft still holds the record as the longest active spacecraft on Venus remaining operational for 127 minutes.

A huge breakaway of the Soviet Union from its competitors in exploration of Venus contributed to the fact that USA called Venus a ‘Soviet planet’. Having recently analyzed the pictures of Venus captured by Soviet missions, scientists of the Russian Academy of Sciences claimed they discovered moving objects and even might be living. And it remains to be seen, whether these guesses are true.

Today, a program of complex exploration of Venus has been developed by Roscosmos in cooperation with the Russian Academy of Sciences. The program consists of several missions. Moreover, a decision was taken to implement the previously planned Venera-D mission including orbital and landing modules, as a national project without involving wide international cooperation. The complex explorations will also include soil and atmosphere samples, as well as exploring evolution processes on Venus that has purportedly suffered a climatic disaster connected with greenhouse effect that is much discussed on Earth today.

Read more | >

Millions of space nerds reacted with joy Monday to a study showing the atmosphere of Venus contains phosphine, a chemical byproduct of biological life. But none would have been more thrilled or less surprised by the discovery than the late, great Carl Sagan — who said this day might come more than 50 years ago.

Now best remembered as the presenter of the most-viewed-ever PBS series Cosmos, the author of the book behind the movie Contact, and the guy who put gold disks of Earth music on NASA’s Voyager missions, Sagan actually got his start studying our closest two planets. He became an astronomer after being inspired as a kid by Edgar Rice Burroughs’ space fantasies, set on Mars and Venus.

‘Cosmos’ presenter Carl Sagan was one of the world’s top experts on Venus, and he saw first what scientists have just announced: possible life on Venus.

Read more | >

Colliding neutron stars were touted as the main source of some of the heaviest elements in the Periodic Table. Now, not so much …

Neutron star collisions do not create the quantity of chemical elements previously assumed, a new analysis of galaxy evolution finds.

The research also reveals that current models can’t explain the amount of gold in the cosmos — creating an astronomical mystery.

Read more | >

In the first experiment to take advantage of a new technology for producing powerful attosecond X-ray laser pulses, a research team led by scientists from the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University showed they can create electronic ripples in molecules through a process called “impulsive Raman scattering.”

Exploiting this unique interaction will allow scientists to study how electrons zipping around kick off key processes in biology, chemistry, materials science and more. The researchers described their results in Physical Review Letters.

Typically, when X-ray pulses interact with matter the X-rays cause the molecules’ innermost “core” electrons to jump to higher energies. These core-excited states are highly unstable, decaying in just millionths of a billionth of a second. In a majority of X-ray experiments, that’s how the story ends: The excited electrons quickly return to their rightful places by transferring their energy to a neighboring electron, forcing it out of the atom and producing a charged ion.

Read more | >

Mid-infrared lasers have been widely used in imaging, detection, diagnostics, environmental monitoring, medicine, industry, defense and others. For mid-infrared laser systems, low phonon energy gain materials are key factors.

Among these mid-infrared materials, Er3+-doped CaF2 transparent ceramics are promising candidate materials because of their ultra-low phonon energy as well as excellent physical, chemical, and , which quickly attract the attention of researchers. However, traditional preparation methods can’t obtain high-quality Er3+-doped CaF2 transparent ceramics.

Recently, a research team led by Prof. Zhang Long from the Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences has developed a high quality Er3+-doped CaF2 transparent ceramics by single crystal ceramization. Their study was published in Journal of the European Ceramic Society.

Read more | >

Scientists at the U.S. Department of Energy’s Ames Laboratory have developed a new computational model that has opened up the potential to make one of their most powerful research tools even more so.

A particularly important tool in a chemist’s arsenal is Nuclear Magnetic Resonance (NMR) spectroscopy. An NMR spectrometer measures the response of atomic nuclei to excitation with radiofrequency waves. This can provide researchers with atomic-level information about the physical, chemical, and electronic properties of materials, including those that are non-crystalline. Dynamic Nuclear Polarization (DNP) NMR is an “ultra” version of NMR, which excites unpaired electrons in radicals and transfers their high spin polarization to the nuclei in the sample being analyzed, resulting in faster, more detailed data. Ames Laboratory has developed DNP-NMR to probe very weak but important chemical signatures, and reduce experimental times from days to minutes.

Computational methods play an important role in experts’ understanding of DNP-NMR, especially for improving the design and execution of experiments using it. Until now, however, the work been limited in scope, and improvements in DNP-NMR techniques have tended to rely on some degree of “serendipity,” according to Fred Perras, an Associate Scientist at Ames Laboratory and a 2020 recipient of a DOE Office of Science Early Career Research Award.

Read more | >