Archive for the ‘chemistry’ category: Page 154

Sep 16, 2020

Proofs of life on Venus can be obtained only through contact explorations

Posted by in categories: alien life, chemistry, climatology, evolution

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.

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Sep 16, 2020

Carl Sagan predicted life on Venus in 1967. We may be close to proving him right

Posted by in categories: alien life, chemistry, media & arts

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.

Sep 15, 2020

Colliding Neutron Stars Generate Just Small Amounts of Gold, Creating an Astronomical Mystery

Posted by in categories: chemistry, evolution, space

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.

Sep 14, 2020

Attosecond pulses reveal electronic ripples in molecules

Posted by in categories: biological, chemistry, particle physics

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.

Sep 12, 2020

Those orange Western skies and the science of light

Posted by in categories: chemistry, physics, science

Sure, it was wildfire smoke that made parts of California and Oregon change hue. But inside that smoke was alchemy — the chemistry and physics of molecules and wavelengths.

Sep 10, 2020

Researchers fabricate high-quality transparent ceramic

Posted by in categories: biotech/medical, chemistry

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.

Sep 10, 2020

New computational model stands to make nuclear magnetic resonance an even more powerful tool for researchers

Posted by in categories: chemistry, materials

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.

Sep 8, 2020

New structural unit simplifies the process of custom-designing proteins

Posted by in categories: biotech/medical, chemistry

The new structure works by mapping the backbones of amino acids to locations of chemicals in the Protein Data Bank involved in interactions with them. The researchers note that only recently has the data bank come to hold enough information to allow for its use in such an application. And they also note that the technique and structure can also be used to produce delivery vehicles based on proteins and also small molecule applications…

A pair of researchers at the University of California, San Francisco, has developed a new protein structure that allows for simplifying the process of custom-designing proteins. In their paper published in the journal Science, Nicholas Polizzi and William DeGrado discuss their structural unit and how they used it. Anna Peacock, with the University of Birmingham, has published a Perspective piece outlining the work by the team in California in the same journal issue.

One of the things that chemists are asked to do is custom design proteins for use in certain special applications. As the researchers note, doing so is considered to be very challenging. It usually involves a considerable amount of trial and error which generally translates to high development costs. In this new effort, the researchers have devised a new unit of to help with such projects. They call it a van der Mer and describe how it can be used to directly map ligand chemical group functionality to peptide residue backbone coordinates.

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Sep 8, 2020

Physicists nudge atoms within less than a trillionth of a second

Posted by in categories: biological, chemistry, particle physics, quantum physics, solar power, sustainability

Scientists from Regensburg and Zurich have found a fascinating way to push an atom with controlled forces so quickly that they can choreograph the motion of a single molecule within less than a trillionth of a second. The extremely sharp needle of their unique ultrafast microscope serves as the technical basis: It carefully scans molecules, similar to a record player. Physicists at the University of Regensburg now showed that shining light pulses onto this needle can transform it into an ultrafast “atomic hand.” This allows molecules to be steered—and new technologies can be inspired.

Atoms and are the constituents of virtually all matter that surrounds us. Interacting with each other according to the rules of quantum mechanics, they form complex systems with an infinite variety of functions. To examine , in a cell, or new ways of solar energy harvesting, scientists would love to not only observe individual molecules, but even control them.

Most intuitively, people learn by haptic exploration, such as pushing, pulling, or tapping. Naturally, we are used to macroscopic objects that we can directly touch, squeeze or nudge by exerting forces. Similarly, atoms and molecules interact via forces, but these forces are extreme in multiple respects. First, the forces acting between atoms and molecules occur at extremely small lengths. In fact, these objects are so small that a special length scale has been introduced to measure them: 1 Ångström (1Å = 0.000,000,000,1 m). Second, at the same time, atoms and molecules move and wiggle around extremely fast. In fact, their motion takes place faster than picoseconds (1 ps = 0.000,000,000,001 s). Hence, to directly steer a molecule during its motion, a tool is required to generate ultrafast forces at the atomic scale.

Sep 8, 2020

Plant protein discovery could reduce need for fertilizer

Posted by in categories: chemistry, climatology, nanotechnology, sustainability

Researchers have discovered how a protein in plant roots controls the uptake of minerals and water, a finding which could improve the tolerance of agricultural crops to climate change and reduce the need for chemical fertilizers.

The research, published in Current Biology, shows that members of the blue copper proteins family, the Uclacyanins are vital in the formation of Casparian strips. These strips are essential structures that control mineral nutrient and water use efficiencies by forming tight seals between cells in plants, blocking nutrients and water leaking between.

This is the first evidence showing the implications of this family in the biosynthesis of lignin, one of the most abundant organic polymers on earth. This study reveals that the required for Casparian strip lignin deposition is highly ordered by forming nano-domains which can have a huge impact on plant nutrition, a finding that could help in the development of crops that are efficient in taking in the nutrients they need.