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Archive for the ‘chemistry’ category: Page 103

Aug 10, 2023

Researchers discover the ‘ebb & flow’ brain mechanism that drives learning

Posted by in categories: biotech/medical, chemistry, food, neuroscience

Researchers have long thought that rewards like food or money encourage learning in the brain by causing the release of the “feel-good” hormone dopamine, known to reinforce storage of new information. Now, a new study in rodents describes how learning still occurs in the absence of an immediate incentive.

Led by researchers at NYU Grossman School of Medicine, the study explored the relationship between dopamine and the brain chemical acetylcholine, also known to play a role in learning and memory. Past research had shown that these two hormones compete with one another, so that a boost in one causes a decline in the other. Rewards were thought to promote learning by simultaneously triggering an increase in dopamine and a decrease in acetylcholine.

This sudden hormone imbalance is believed to open a window of opportunity for brain cells to adjust to new circumstances and form memories for later use. Known as neuroplasticity, this process is a major feature of learning as well as recovery after injury. However, the question had remained whether food and other external rewards are the only drivers for this memory system, or whether our brains instead are able to create the same conditions that are favorable to learning without outside help.

Aug 10, 2023

Small-molecule autocatalysis may have paved the way for the emergence of evolution by natural selection

Posted by in categories: biological, chemistry, evolution, genetics

The discipline of systems chemistry deals with the analysis and synthesis of various autocatalytic systems and is therefore closely related to the study of the origin of life, since it investigates systems that can be considered as a transition between chemical and biological evolution: more complex than simple molecules, but simpler than living cells.

Tibor Gánti described the theory of self-replicating microspheres as early as 1978. These still lacked , but concealed within their membranes an autocatalytic metabolic network of small molecules, isolated (compartmentalized) within their membranes.

As the autocatalytic process takes place, the membrane-building material is also produced, leading to the division of the sphere. This system may appear to be a , and although it lacks genetic material, this can only be verified experimentally. These microspheres can be considered as “infrabiological” , since they do not reach the level of biological organization, but they exceed the complexity of normal chemical reactions.

Aug 10, 2023

“Quantum Superchemistry” Breakthrough: A Pioneering Discovery by University of Chicago Scientists

Posted by in categories: biotech/medical, business, chemistry, engineering, law, policy, quantum physics

A team from the University of Chicago.

Founded in 1,890, the University of Chicago (UChicago, U of C, or Chicago) is a private research university in Chicago, Illinois. Located on a 217-acre campus in Chicago’s Hyde Park neighborhood, near Lake Michigan, the school holds top-ten positions in various national and international rankings. UChicago is also well known for its professional schools: Pritzker School of Medicine, Booth School of Business, Law School, School of Social Service Administration, Harris School of Public Policy Studies, Divinity School and the Graham School of Continuing Liberal and Professional Studies, and Pritzker School of Molecular Engineering.

Aug 10, 2023

Spatial Interactions in Hydrogenated Perovskite Nickelate Synaptic Networks

Posted by in categories: chemistry, robotics/AI

A key aspect of how the brain learns and enables decision-making processes is through synaptic interactions. Electrical transmission and communication in a network of synapses are modulated by extracellular fields generated by ionic chemical gradients. Emulating such spatial interactions in synthetic networks can be of potential use for neuromorphic learning and the hardware implementation of artificial intelligence. Here, we demonstrate that in a network of hydrogen-doped perovskite nickelate devices, electric bias across a single junction can tune the coupling strength between the neighboring cells. Electrical transport measurements and spatially resolved diffraction and nanoprobe X-ray and scanning microwave impedance spectroscopic studies suggest that graded proton distribution in the inhomogeneous medium of hydrogen-doped nickelate film enables this behavior.

Aug 9, 2023

NASA’s Building a Nuclear Rocket That Would Get Us to Mars in Just 6 Weeks

Posted by in categories: chemistry, nuclear energy, space travel

Deep space is a hostile environment for humans, which makes the long journey to Mars a serious stumbling block for manned missions. A nuclear-powered rocket could slash the journey time, and NASA has announced plans to test the technology by 2027 at the latest.

Most spacecraft to date have used chemical rockets packed with fuel and oxidizer, which rely on combustion to propel them through space. A nuclear-powered rocket would instead use a fission reactor to heat liquid hydrogen to very high temperatures and then blast it out the back of the spacecraft.

These kinds of engines could be up to three times more efficient than those in conventional rockets, and could cut the time to transit from Earth to Mars from roughly seven months to as little as six weeks. NASA has teamed up with DARPA to make the idea a reality, signing a deal with defense contractor Lockheed Martin to launch a working prototype into space as early as 2025.

Aug 8, 2023

Scientists Observe First Evidence of ‘Quantum Superchemistry’ in The Lab

Posted by in categories: chemistry, particle physics, quantum physics

Weird things happen on the quantum level. Whole clouds of particles can become entangled, their individuality lost as they act as one.

Now scientists have observed, for the first time, ultracold atoms cooled to a quantum state chemically reacting as a collective, rather than haphazardly forming new molecules after bumping into each other by chance.

“What we saw lined up with the theoretical predictions,” says Cheng Chin, a physicist at the University of Chicago and senior author of the study. “This has been a scientific goal for 20 years, so it’s a very exciting era.”

Aug 8, 2023

First evidence of ‘quantum superchemistry’ observed in lab

Posted by in categories: chemistry, particle physics, quantum physics

“This has been a scientific goal for 20 years, so it’s a very exciting era.”

In a significant advance, scientists have obtained the first proof of a phenomenon known as “quantum superchemistry.” This effect was previously predicted but never actually observed in the laboratory.

The University of Chicago researchers that led this experiment characterize quantum superchemistry as a “phenomenon where particles in the same quantum state undergo collectively accelerated reactions.”

Continue reading “First evidence of ‘quantum superchemistry’ observed in lab” »

Aug 7, 2023

Single-particle photoacoustic vibrational spectroscopy using optical microresonators

Posted by in categories: biological, chemistry, particle physics

Pythagoras first discovered that the vibrations of strings are drastically enhanced at certain frequencies. This discovery forms the basis of our tone system. Such natural vibrations ubiquitously exist in objects regardless of their size scales and are widely utilized to derive their species, constituents, and morphology. For example, molecular vibrations at a terahertz rate have become the most common fingerprints for the identification of chemicals and the structural analysis of large biomolecules.

Recently, natural vibrations of particles at the mesoscopic scale have received growing interest, since this category includes a wide range of functional particles, as well as most and viruses. However, natural vibrations of these mesoscopic particles have remained hidden from existing technologies.

These particles with sizes ranging from 100 nm to 100 μm are expected to vibrate faintly at megahertz to gigahertz rates. This frequency regime could not be resolved by current Raman and Brillouin spectroscopies, however, due to strong Rayleigh-wing scattering, while the performances of piezoelectric techniques that are widely exploited in macroscopic systems degrade significantly at frequencies beyond a few megahertz.

Aug 7, 2023

New strategy decodes dynamic structure of proteins within cells

Posted by in categories: chemistry, physics

Protein dynamics play a crucial role in diverse functions. The intracellular environment significantly influences protein dynamics, particularly for intrinsically disordered proteins (IDPs).

A research group led Prof. Zhang Lihua from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Assoc. Prof. Gong Zhou from the Precision Measurement Science and Technology Innovation Research Institute of CAS, has proposed a strategy using in-vivo chemical cross-linking and (in-vivo XL-MS) to decode the dynamic structure of proteins within .

In-vivo XL-MS is potential for analyzing the dynamic structure of proteins within cells due to its high throughput, high sensitivity, and low requirements for protein purity.

Aug 7, 2023

Scientists observe first evidence of ‘quantum superchemistry’ in the laboratory

Posted by in categories: chemistry, particle physics, quantum physics

A team from the University of Chicago has announced the first evidence for “quantum superchemistry”—a phenomenon where particles in the same quantum state undergo collective accelerated reactions. The effect had been predicted, but never observed in the laboratory.