Astronomers make breakthrough discovery in planet formation, conflicting with theoretical predictions

Posted on December 16, 2023 by Igor Mitreski

Recent observations of the young star DG Taurus reveal a smooth protoplanetary disk in which no planets have yet formed, suggesting that it is on the brink of this process. The findings show unexpected dust grain growth patterns and provide new insights into the early stages of planet formation. Credit: SciTechDaily.com

Astronomers have become very good at finding signs of planet formation around stars. However, to fully understand planet formation, it is important to examine cases where this process has not yet begun.

Looking for something and not finding it can sometimes be even more difficult than finding it, but new detailed observations of the young star DG Taurus reveal that the planet is a smooth protoplanet with no signs of planet formation. It was shown that it has a system disk. This lack of detected planet formation may indicate that DG Taurus is on the eve of planet formation.

Image of radio radiation intensity from a disk near DG Taurus observed with ALMA. Rings have not yet formed within the disk, suggesting that planets are about to form.Credit: ALMA (ESO/National Astronomical Observatory/NRAO), S. Obashi et al.

Protoplanetary disk and planet growth

Planets form around protostars, which are young stars that are still forming, in disks of gas and dust known as protoplanetary disks. Planets grow so slowly that it is impossible to observe their evolution in situ. Therefore, astronomers observe many protostars at slightly different stages of planet formation to build theoretical understanding.

This time, an international research team led by Satoshi Ohashi of the National Astronomical Observatory of Japan (NAOJ) has developed the Atacama Large Millimeter/Submillimeter Array (alma telescope) will conduct high-resolution observations of the protoplanetary disk surrounding the relatively young protostar DG Taurus, located 410 light-years away in the direction of Taurus. The researchers found that DG Taurus has a smooth protoplanetary disk and no rings that would indicate planet formation. This led the research team to believe that the DG Taurus system could begin forming planets in the future.

Unexpected discoveries and future research

The researchers found that during this pre-planetary stage, dust particles are within 40 astronomical units (about twice the size of Earth’s orbit). Uranus The radius of the central protostar is still small, but beyond this radius the dust particles begin to grow, which is the first step in planet formation. This goes against the theoretical expectation that planet formation begins inside the disk.

These results provide surprising new information about dust distribution and other conditions at the beginning of planet formation. Studying more examples in the future will further deepen our understanding of planet formation.

Reference: “Dust concentration and particle growth in the smooth disk of a DG tau protostar revealed by ALMA triple-band frequency observations” Satoshi Ohashi, Munetake Momose, Akiraka Kataoka, Aya Higuchi E, Takashi Tsukagoshi, Takahiro Ueda, Claudio Codella, Linda Podio, Tomoyuki Hanawa, Nami Sakai, Hiroshi Kobayashi, Satoshi Okuzumi, Hidekazu Tanaka, August 28, 2023, of astrophysical journal.
DOI: 10.3847/1538-4357/ace9b9

This research was funded by the Japan Society for the Promotion of Science, the German Foundation, and the European Union.

Source: scitechdaily.com

Breakthrough in New Coronavirus Treatment: Discovery of New Antiviral Drug

Posted on December 15, 2023 by Igor Mitreski

The Coronavirus Moonshot Consortium report focuses on the discovery of a new class of inhibitors against the main protease of SARS-CoV-2. This global collaboration has generated promising lead compounds, openly shared thousands of compound designs, and represents significant progress in coronavirus drug development.

The COVID Moonshot breakthrough study introduced new non-peptide inhibitors. SARS-CoV-2showcases global collaboration and open science in advancing coronavirus treatments. Although the group’s results have been freely available since its founding in March 2020, the Coronavirus Moonshot Consortium has finally officially reported its results.

Coronavirus Moonshot – An open science, crowdsourced, patent-free drug discovery campaign targeting SARS-CoV-2 virus – A wealth of data has been obtained about the virus’s major proteases, including insights that may pave the way for the development of new and better treatments. “The main treatments described by [these researchers] “Given drug approval timelines and challenges, we may not be ready in time to make an impact on the current pandemic,” write Brian Shoichet and Charles Craik in a related perspective. “Yet, the compounds and the techniques used to identify them may have implications for human health in the future.”

Global cooperation and drug discovery efforts This novel collaboration involved more than 200 volunteer scientists from 47 academic and industrial organizations across 25 countries. “The coronavirus moonshot provides an example of open science drug discovery that could lead to advances in infectious disease drug discovery. This research area is of great public importance but chronically underfunded from the private sector. “There is a shortage,” Melissa et al. write. SARS-CoVB-2 main protease (Mpro) is an attractive target for antiviral drug development due to its important role in viral replication. Current SARS-CoV-2 Mpro inhibitors, such as those drawn from existing antiviral pipelines such as Paxlovid and Xocova, have shown clinical success. However, the use of these compounds remains relatively limited, and their peptidomimetics and covalent scaffolds pose problems for synthesis and administration.

Impact on innovative drug design and open science Hey, Bobby other. describe the discovery of a novel noncovalent and nonpeptidic inhibitor scaffold that is chemically distinct from current Mpro inhibitors. By leveraging a crowdsourcing approach combined with the expertise of hundreds of individuals around the world, Bobby other. We will explain the open science drug discovery campaign. machine learningutilize molecular simulations, and high-throughput structural biology and chemistry to assemble a detailed structural map of the major proteases of SARS-CoV-2 and their biochemical activities.

From over 18,000 compound designs generated by the COVID Moonshot Consortium, the authors identified several non-covalent, non-peptidomimetic compounds, including lead compounds with promising bioavailability, safety, and antiviral activity. identified sex inhibitors. All compound designs from the project are openly shared, building a rich, open, intellectual property-free knowledge base for future anti-coronavirus drug discovery.

Reference:
DOI: 10.1126/science.abo7201

Source: scitechdaily.com

Discovery of a ‘Quantum Switch’ Controlling Photosynthesis by Scientists

Posted on December 15, 2023 by Igor Mitreski

A new study reveals the quantum switching mechanism of light-harvesting complex II (LHCII), which is critical for efficient photosynthesis. This discovery, achieved through advanced cryo-EM and theoretical calculations, supports a dynamic role for LHCII in regulating energy transfer in plants. Credit: SciTechDaily.com

Photosynthesis is an important process that allows plants to use sunlight to convert carbon dioxide into organic compounds. Light-harvesting complex II (LHCII) consists of dye molecules bound to proteins. It alternates between two main roles. Under strong light, excess energy is dissipated as heat through non-photochemical quenching, and under weak light, light is efficiently transferred to the reaction center.

Recent bioengineering research has revealed that faster switching between these functions can improve photosynthetic efficiency. For example, soybean crops showed yield increases of up to 33%. However, the precise atomic-level structural changes in LHCII that cause this control have not been known until now.

The molecular mechanism of NPQ and acidity-induced changes in several key structural factors cause the LHCII trimer to switch between light-harvesting and energy-quenching states.Credit: Institute of Physics

innovative research approach

In the new study, researchers led by Professor Weng Yuxiang from the Institute of Physics, Chinese Academy of Sciences, in collaboration with Professor Gao Jiali’s group from the Shenzhen Bay Institute, combined single-particle cryo-electron microscopy (cryo-EM) research. Using multistate density functional theory (MSDFT) calculations of energy transfer between photosynthetic pigment molecules, we analyzed the dynamic structure of his LHCII at atomic resolution and identified photosynthetic pigment quantum switches for intermolecular energy transfer. Masu.

As part of the study, they developed a series of six cryogenic states, including energy transfer states with LHCII in solution and energy quenching states with laterally confined LHCII in membrane nanodisks under neutral and acidic conditions. reported the EM structure.

Comparing these different structures shows that LHCII undergoes a structural change upon acidification. This change allosterically changes the interpigment distance of the fluorescence quenching locus lutein 1 (Lut1)-chlorophyll 612 (Chl612) only when LHCII is confined to membrane nanodiscs, leading to the quenching of excited Chl612 by Lut1. cause. Therefore, lateral pressure-confined LHCII (e.g., aggregated LHCII) is a prerequisite for non-photochemical quenching (NPQ), whereas acidThe induced conformational change enhances fluorescence quenching.

Cryo-EM structures of LHCII in nanodiscs and surfactant solutions at pH 7.8 and 5.4. Credit: Institute of Physics

Quantum switching mechanism in photosynthesis

Through cryo-EM structures and MSDFT calculations of known crystal structures in the extinction state and transient fluorescence experiments, an important quantum switching mechanism of LHCII with the Lut1-Chl612 distance as a key factor was revealed.

This distance controls the energy transfer quantum channels in response to lateral pressure and conformational changes to LHCII. That is, a small change in the critical distance of 5.6 Å allows a reversible switch between light collection and excess energy dissipation. This mechanism allows for rapid response to changes in light intensity, achieving both high efficiency and efficiency. photosynthesis Balanced photoprotection using LHCII as a quantum switch.

Fluorescence decay rate, relationship of Lut1–Chl612 electronic bond strength to Lut1–Chl612 separation distance, and plot of Lut1–Chl612 distance versus crossing angle of TM helices A and B in different LHCII structures. Credit: Institute of Physics

Previously, these two research groups collaborated on molecular dynamics simulations and ultrafast infrared spectroscopy experiments to propose that LHCII is an allosterically controlled molecular machine. Their current experimental cryo-EM structure confirms previously theoretically predicted structural changes in his LHCII.

Reference: “Cryo-EM structure of LHCII in photoactive and photoprotected states reveals allosteric control of light harvesting and excess energy dissipation” Meixia Ruan, Hao Li, Ying Zhang, Ruoqi Zhao, Jun Zhang, Yingjie Wang , Jiali Gao, Zhuan Wang, Yumei Wang, Dapeng Sun, Wei Ding, Yuxiang Weng, August 31, 2023, natural plants.
DOI: 10.1038/s41477-023-01500-2

This research was supported by a project of the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the Shenzhen Science and Technology Innovation Committee.

Source: scitechdaily.com

New Discovery May Enhance Fuel Production

Posted on December 3, 2023 by Igor Mitreski

Researchers at Washington State University have discovered self-sustaining oscillations in the Fischer-Tropsch process, an important industrial method for converting coal, natural gas, or biomass into liquid fuels. This breakthrough reveals oscillatory rather than steady-state behavior in reactions, which could lead to more efficient and controlled fuel production. This discovery provides a new knowledge-based approach to catalyst design and process optimization in the chemical industry.

Researchers at Washington State University have made significant progress in understanding the Fischer-Tropsch process, an important industrial method for converting coal, natural gas, or biomass into liquid fuels. They discovered that, unlike many catalytic reactions that maintain a steady state, the Fischer-Tropsch process exhibits self-sustaining oscillations that alternate between high and low activity states.

This insight published in the journal scienceopens the possibility of optimizing the reaction rate and increasing the yield of the desired product, which could lead to more efficient fuel production in the future.

“Velocity fluctuations, usually accompanied by large fluctuations in temperature, are undesirable in the chemical industry due to safety concerns,” said corresponding author Professor Norbert Kruse of the WSU Jean and Linda Voiland School of Chemical Engineering and Bioengineering. (corresponding author) said. “In this case, the oscillations are controlled and mechanistically well understood. With this foundation of understanding, both experimental and theoretical approaches to research and development can be quite different. It really becomes a knowledge-based approach, which is very useful for us.”

Rethinking catalyst design

The Fischer-Tropsch process is commonly used to make fuels and chemicals, but researchers have had little understanding of how the complex catalytic conversion process works. This process uses a catalyst to convert two simple molecules, hydrogen and carbon monoxide, into long chains of molecules, hydrocarbons that are widely used in everyday life.

Research and development in the fuel and chemical industries has used a trial-and-error approach for more than a century, but researchers will now design catalysts more intentionally and use vibrational techniques to tune reactions and improve catalytic reactions. will be able to cause the condition. performance.

The researchers first encountered this oscillation after graduate student Rui Zhang approached Kruse about the problem of not being able to stabilize the reaction temperature. Studying it together, they discovered surprising vibrations.

“It was very interesting,” Kruse said. “He showed it to me and I said, ‘Louis, congratulations, you have a vibration! “And we continued to develop this story.”

The researchers not only discovered that the reaction causes an oscillatory reaction state, but also discovered why this happens. That is, as the reaction temperature increases due to heat generation, the reaction gas loses contact with the catalyst surface, slowing the reaction and decreasing the temperature. When the temperature is low enough, the concentration of reactant gases on the catalyst surface increases and the reaction rate accelerates again. As a result, the temperature increases and the cycle ends.

Fusion of theory and experiment

For this study, the researchers demonstrated the reaction in the lab using a frequently used cobalt catalyst modified by the addition of cerium oxide and modeled how it works.Co-author Pierre Gaspard of the Free University of Brussels developed the reaction scheme and theoretically imposed Change the temperature periodically to reproduce the experimental rate and selectivity of the reaction.

“This is so beautiful that we were able to model it theoretically,” said corresponding author Yong Wang, Regents Professor in the WSU Boyland School and Zhang’s co-supervisor. . “Theoretical and experimental data were in close agreement.”

Kruse has been researching vibrational responses for more than 30 years. The discovery of oscillatory behavior due to the Fischer-Tropsch reaction was quite surprising because the Fischer-Tropsch reaction is mechanistically very complex.

“In our research, we sometimes experience a lot of frustration because things don’t go our way, but sometimes we have moments that we can’t explain,” Kruse said. “It’s very rewarding, but ‘rewarding’ is a weak word to describe the excitement of making this great progress.”

Reference: “Obcillating Fischer-Tropsch Reaction” by Rui Zhang, Yong Wang, Pierre Gaspard, Norbert Kruse, October 5, 2023, science.
DOI: 10.1126/science.adh8463

This research was supported by Chambroad Chemical Industry Research Institute Co., Ltd., the National Science Foundation, and the Department of Energy’s Basic Energy Sciences Catalysis Science Program.

Source: scitechdaily.com

Lucy spacecraft makes a new asteroid discovery, finding another one beyond asteroid Dinkinesh

Posted on November 2, 2023 by Igor Mitreski

Asteroid Dinkinesh and its orbiting asteroids

NASA/Goddard/SwRI/Johns Hopkins University APL/NOAO

NASA’s Lucy spacecraft passed the first asteroid and discovered a second asteroid at the same time. Lucy passed the small asteroid Dinkinesh on November 1, and images sent back to Earth show that Dinkinesh has an even smaller space rock orbiting it, the smallest main-belt asteroid ever observed up close. It became clear that there was.

This finding was not entirely surprising. As Lucy approached Dinkinesh over the past few weeks, the asteroid’s brightness appeared to oscillate over time, often indicating the presence of some type of satellite. But Dinkinesh’s diameter is only about 790 meters (790 meters), making it impossible to spot the satellite from Earth, and until November 1, even spacecraft were too far away to see it clearly.

During a flyby on November 1, Lucy flew just 430 kilometers (430 kilometers) from Dinkinesh at speeds of about 16,000 kilometers per hour, taking photos as it passed. These photos reveal a second, smaller asteroid in the Dinkinesh binary, this one only about 220 meters in diameter.

“We knew this would be the smallest main-belt asteroid ever seen up close.” Keith Knoll at NASA’s Goddard Space Flight Center in Maryland. statement. “The fact that it’s two makes it even more exciting. In some ways, these asteroids are similar to near-Earth asteroids. Binary Didymus and Dimorpho [NASA’s Double Asteroid Redirection Test mission] However, there are some very interesting differences that we will explore further. ”

The main purpose of the flyby was to test Lucy’s scientific equipment, especially the system that keeps it on target as it passes by at high speed, and the fact that nothing is visible in these first images suggests that the tracking system is not properly aligned. It shows that it is functioning. The remaining data from the encounter will be transmitted to Earth over the next week or so for more thorough examination by the mission’s scientists and engineers.

Now that Lucy has passed Dinkinesh and its partner asteroid, its next target is asteroid 52246 Donald Johansson, where it plans to visit in 2025 before accelerating toward Jupiter’s Trojan asteroids. The Trojan horse travels in front of and behind Jupiter as it orbits around the sun, and because it is likely a remnant left over from the formation of the solar system, it provides valuable insight into how the planet formed and evolved over time. May hold insights. Lucy she will reach the Trojans in 2027.

topic:

Source: www.newscientist.com

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Tag Archives: discovery

Astronomers make breakthrough discovery in planet formation, conflicting with theoretical predictions

Protoplanetary disk and planet growth

Unexpected discoveries and future research

Breakthrough in New Coronavirus Treatment: Discovery of New Antiviral Drug

Discovery of a ‘Quantum Switch’ Controlling Photosynthesis by Scientists

innovative research approach

Quantum switching mechanism in photosynthesis

New Discovery May Enhance Fuel Production

Rethinking catalyst design

Fusion of theory and experiment

Lucy spacecraft makes a new asteroid discovery, finding another one beyond asteroid Dinkinesh