Archive for the ‘chemistry’ category: Page 7

Dec 12, 2018

Silica paradox: Scientists discover seemingly ‘impossible’ material

Posted by in categories: chemistry, physics, supercomputing

An international team of physicists and materials scientists from NUST MISIS, Bayerisches Geoinstitut (Germany), Linkoping University (Sweden), and the California Institute of Technology (U.S.) has discovered an “impossible” modification of silica-coesite-IV and coasite-V materials, which seems to defy the generally accepted rules for the formation of chemical bonds in inorganic materials formulated by Linus Pauling, who won the 1954 Nobel Prize in Chemistry for that discovery. The research results were published in Nature Communications on November 15th, 2018.

According to Pauling’s rules, the fragments of the atomic lattice in inorganic materials are connected by vertices, because bonding by faces is the most energy-intensive way to form a chemical connection. Therefore, it does not exist in nature. However, scientists have proved, both experimentally and theoretically, using NUST MISIS’ supercomputer, that it is possible to form such a connections if the materials are at ultra-high pressure conditions. The obtained results show that fundamentally new classes of materials exist at extreme conditions.

“In our work, we have synthesized and described metastable phases of high-pressure silica: coesite-IV and coesite-V. Their crystal structures are drastically different from any of the earlier described models,” says Igor Abrikosov, leader of the theoretical research team. “Two newly discovered coesites contain octahedrons SiO6, that, contrary to Pauling’s rule, are connected through common face, which is the most energy-intensive chemical connection. Our results show that the possible silicate magmas in the lower mantle of the Earth can have , which makes these magmas more compressible than predicted before.”

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Dec 11, 2018

Scientists identify vast underground ecosystem containing billions of micro-organisms

Posted by in categories: chemistry, physics

The team combines 1,200 scientists from 52 countries in disciplines ranging from geology and microbiology to chemistry and physics. A year before the conclusion of their 10-year study, they will present an amalgamation of findings to date before the American Geophysical Union’s annual meeting opens this week.

Global team of scientists find ecosystem below earth that is twice the size of world’s oceans.

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Dec 10, 2018

An Oklahoma High Schooler Changed the Rules of Organic Chemistry

Posted by in category: chemistry

We thought we knew everything about carbon. We were wrong.

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Nov 30, 2018

Life on Earth Could Have Started Thanks to a Simple Ingredient We Use Every Day

Posted by in categories: chemistry, energy

If classic monster movies and old science experiments are to be believed, life begins with a spark.

Not everybody is convinced by this kind of origin story, so the search continues for sources of energy capable of transforming a prebiotic soup into a life-generating dish. Maybe the secret ingredient isn’t anything more shocking than a pinch of salt.

A new study led by researchers from the Earth-Life Science Institute (ELSI) at Tokyo Institute of Technology in Japan has turned their attention to common old sodium chloride as a potential conduit for the chemical energy required for early biochemistry.

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Nov 29, 2018

New catalyst material produces abundant cheap hydrogen

Posted by in categories: chemistry, energy, engineering, government, sustainability

QUT chemistry researchers have discovered cheaper and more efficient materials for producing hydrogen for the storage of renewable energy that could replace current water-splitting catalysts.

Professor Anthony O’Mullane said the potential for the chemical storage of renewable energy in the form of hydrogen was being investigated around the world.

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Nov 23, 2018

Meet Dawn Shaughnessy, the Real-Life Alchemist Who Expanded the Periodic Table

Posted by in categories: chemistry, particle physics

The periodic table is chemistry’s holy text. Not only does it list all of the tools at chemists’ disposal, but its mere shape—where these elements fall into specific rows and columns—has made profound predictions about new elements and their properties that later came true. But few chemists on Earth have a closer relationship with the document than Dawn Shaughnessy, whose team is partially responsible for adding six new elements to table’s ranks.

Shaughnessy leads a team of real-life alchemists. You might be familiar with alchemy as a medieval European practice where mystics attempted to transmute elements into more valuable ones. But rather than turn the element lead into gold, Shaughnessy and her team turned plutonium into flerovium.

Shaughnessy’s parents encouraged her to pursue science from a young age—her father was an engineer, and she had an electronics kit as well as a chemistry set as a child. She’d first thought about doing orthopedic research but didn’t want to cut people open, she explained to me, and chemistry was a natural fit. But when she arrived at the University of California, Berkeley as an undergraduate, she learned that chemistry could be more than just mixing liquids in beakers. She could create the atoms themselves.

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Nov 22, 2018

Sir Aaron Klug, OM, scientist who won a Nobel Prize for his work on electron microscopy and chromosomes – obituary

Posted by in categories: biotech/medical, chemistry

Sir Aaron Klug, OM, who has died aged 92, won the 1982 Nobel Prize in Chemistry for his development of crystallographic electron microscopy and his work in charting the infinitely complex structures of chromosomes, the body’s largest molecules.

Human genes are made of nucleic acids such as DNA (deoxyribonucleic acid). The acids are too small to be seen with an ordinary microscope and too large to be studied by examining them under X-rays.

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Nov 20, 2018

We’re going to Jezero!

Posted by in categories: chemistry, climatology, space

At Jezero, Mars 2020’s goal will be “to explore the history of water and chemistry in an ancient crater lake basin and associated river-delta environments to probe early Martian climates and search for life.”

NASA announced this morning the selection of Jezero crater for the landing site of the Mars 2020 mission. Jezero is a 45-kilometer-wide crater that once held a lake, and now holds a spectacular ancient river delta.

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Nov 17, 2018

AI heralds new frontiers for predicting enzyme activity

Posted by in categories: biological, chemistry, engineering, robotics/AI

Researchers from the Departments of Chemistry and Engineering Science at the University of Oxford have found a general way of predicting enzyme activity. Enzymes are the protein catalysts that perform most of the key functions in Biology. Published in Nature Chemical Biology, the researchers’ novel AI approach is based on the enzyme’s sequence, together with the screening of a defined ‘training set’ of substrates and the right chemical parameters to define them.

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Nov 17, 2018

Fisetin—a new senolytic

Posted by in categories: biotech/medical, chemistry, genetics, life extension

More information on the search for natural senolytics (that clear the senescent cells and potentially make us younger)- on ficetin, found in abundance for example in strawberries, a newly published study and discussion in the blog of Josh Mitteldorf. But we still would have to consume around 20 kg strawberries for two consecutive days to reach the dose used in the happy longer living mice!

Senolytic drugs have been the most promising near-term anti-aging therapy since the ground-breaking paper by van Deursen of Mayo Clinic published in 2011 . The body accumulates senescent cells as we age, damaged cells that send out signal molecules that in turn modify our biochemistry in a toxic, pro-inflammatory direction. Though the number of such cells is small, the damage they do is great. Van Deursen showed that just getting rid of these cells could increase lifespan of mice by ~25%. But he did it with a trick, using genetically engineered mice in which the senescent cells had a built-in self-destruct switch.

After that, the race was on to find chemical agents that would do the same thing without the genetically engineered self-destruct. They must selectively kill senescent cells, while leaving all other cells unharmed. It’s a tall order, because even a little residual toxicity to normal cells can be quite damaging. Before last week, the two best candidates were FOXO4-DRI and a combination of quercetin with dasatinib .

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