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Archive for the ‘chemistry’ category: Page 43

Jul 21, 2023

Scientists use chemical mapping to study the spiraling arms of the Milky Way

Posted by in categories: chemistry, evolution, mapping, space

A researcher has used the technique of chemical mapping to study the spiral arms of our home galaxy: the Milky Way. According to Keith Hawkins, assistant professor at The University of Texas at Austin, chemical cartography might help us better grasp the structure and evolution of our galaxy.

“Much like the early explorers, who created better and better maps of our world, we are now creating better and better maps of the Milky Way,” mentioned Hawkins in an official release.


NASA/JPL-Caltech.

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Jul 21, 2023

Hydrogen from sunlight: US researcher set conversion efficiency record

Posted by in categories: chemistry, energy, engineering, transportation

Built using inexpensive semiconductors, the device packs all components to make hydrogen and can be scaled.

A research team led by Aditya Mohite, a professor of chemical and biomolecular engineering at Rice University in the US, has designed a device that can use sunlight to generate hydrogen, with a record efficiency of 20.8 percent, a press release said.

Hydrogen is being touted as the future of clean energy due to its high energy density that could be deployed even to fly large planes. However, the process of generating hydrogen is currently heavily dependent on fossil fuels. For hydrogen to herald a new future in clean energy, it needs to be produced sustainably and without carbon emissions.

Jul 21, 2023

A ‘toolbox of biocatalysts’ improves control over free radicals

Posted by in category: chemistry

One of the central challenges for synthetic chemists is to impose control over free radicals. Highly reactive molecules with an unpaired electron, free radicals, may be familiar to you; these are the type of molecules we take antioxidant supplements for, in an effort to tame oxidative stress.

In the world of synthetic , however, hold a lot of promise.

“Free chemistry is very useful for the synthesis of both bioactive small molecules and everyday polymers,” said UC Santa Barbara chemistry professor Yang Yang, an author of a paper on the matter that appears in Nature Catalysis. “However, imposing stereocontrol over free-radical mediated reactions has eluded the asymmetric catalysis community for decades. We’re trying to develop biocatalytic strategies to further push the boundaries of free radical chemistry.”

Jul 21, 2023

Fueled by new chemistry, algorithm mines fungi for useful molecules

Posted by in categories: biotech/medical, chemistry, computing, food, genetics, information science

A newly described type of chemistry in fungi is both surprisingly common and likely to involve highly reactive enzymes, two traits that make the genes involved useful signposts pointing to a potential treasure trove of biological compounds with medical and chemical applications.

It was also nearly invisible to scientists until now.

In the last 15 years, the hunt for molecules from living organisms—many with promise as drugs, antimicrobial agents, chemical catalysts and even food additives—has relied on trained to search the DNA of bacteria, fungi and plants for genes that produce enzymes known to drive that result in interesting compounds.

Jul 21, 2023

Chemical mapping reveals the Milky Way’s spiral arms

Posted by in categories: chemistry, mapping, space

Identifying regions of the Milky Way’s spiral arms that have previously gone undetected.

Jul 20, 2023

JWST Just Detected Carbon in The Cosmic Dawn… Before We Thought Carbon Was Possible

Posted by in categories: chemistry, cosmology

EMBARGO Wednesday 19 July 1,600 BST | 1,500 GMT | Thursday 20 July 100 AEST

Back when the Universe was still just a wee baby Universe, there wasn’t a lot going on chemically. There was hydrogen, with some helium, and a few traces of other things. Heavier elements didn’t arrive until stars had formed, lived, and died.

Imagine, therefore, the consternation of scientists when, using the James Webb Space Telescope to peer back into the distant reaches of the Universe, they discovered significant amounts of carbon dust, less than a billion years after the Big Bang.

Jul 19, 2023

US scientists discover chemical to reverse aging

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

In a groundbreaking study, researchers have unlocked a new frontier in the fight against aging and age-related diseases. The study, conducted by a team of scientists at Harvard Medical School, has published the first chemical approach to reprogram cells to a younger state. Previously, this was only achievable using a powerful gene therapy.

The team’s findings build upon the discovery that the expression of specific genes, called Yamanaka factors, could convert adult cells into induced pluripotent stem cells (iPSCs). This Nobel Prize-winning discovery raised the question of whether it might be possible to reverse cellular aging without causing cells to become too young and turn cancerous.

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Jul 19, 2023

Scientists use supercomputer to learn how cicada wings kill bacteria

Posted by in categories: biological, chemistry, engineering, nanotechnology, supercomputing

Over the past decade, teams of engineers, chemists and biologists have analyzed the physical and chemical properties of cicada wings, hoping to unlock the secret of their ability to kill microbes on contact. If this function of nature can be replicated by science, it may lead to development of new products with inherently antibacterial surfaces that are more effective than current chemical treatments.

When researchers at Stony Brook University’s Department of Materials Science and Chemical Engineering developed a simple technique to duplicate the cicada wing’s nanostructure, they were still missing a key piece of information: How do the nanopillars on its surface actually eliminate bacteria? Thankfully, they knew exactly who could help them find the answer: Jan-Michael Carrillo, a researcher with the Center for Nanophase Materials Sciences at the Department of Energy’s Oak Ridge National Laboratory.

For nanoscience researchers who seek computational comparisons and insights for their experiments, Carrillo provides a singular service: large-scale, high-resolution molecular dynamics (MD) simulations on the Summit supercomputer at the Oak Ridge Leadership Computing Facility at ORNL.

Jul 18, 2023

Study sheds light on mechanisms underlying H. pylori-induced gastric cancer

Posted by in categories: biotech/medical, chemistry

Helicobacter pylori (H. pylori) infections are commonly associated with abdominal pain, bloating, and acidity. Clinical evidence suggests that infection with H. pylori cagA+ strains dramatically increases the risk of developing gastric cancer.

A specialized protein delivered by H. pylori to the host, oncoprotein “CagA,” has been shown to interact with multiple host proteins and promote gastric carcinogenesis (transformation of normal cells to ). However, the underlying mechanisms associated with its biochemical activity have not been fully determined yet.

A new study published in Science Signaling on 18 July insights into the additional mechanism of oncogenic CagA action.

Jul 18, 2023

Macroscopic photonic single crystals via seeded growth of DNA-coated colloids

Posted by in categories: biotech/medical, chemistry, nanotechnology

DNA-programmed self-assembly leverages the chemical specificity of DNA hybridization to stabilize user-prescribed crystal structures1,2. Pioneering studies have demonstrated that DNA hybridization can guide the self-assembly of a wide variety of nanoparticle crystal lattices, which can grow to micrometer dimensions and contain millions of particles3,4,5,6,7,8,9. Attention has now turned toward the goal of assembling photonic crystals from optical-scale particles (i.e., roughly 100‑1000 nm in diameter)10,11,12 using DNA-programmed interactions. To this end, progress over the past decade has established that DNA can indeed program the self-assembly of bespoke crystalline structures from micrometer-sized colloidal particles13,14,15,16,17,18,19. However, growing single-domain crystals comprising millions of DNA-functionalized, micrometer-sized colloidal particles remains an unresolved barrier to the development of practical technologies based on DNA-programmed assembly. Prior efforts have yielded either single-domain crystals no more than a few dozen micrometers in size13,14,15,16 or larger polycrystalline materials with heterogeneous domain sizes12,15,17,20. These features—small crystal domains, polycrystallinity, and size dispersity—have therefore precluded the use of DNA-coated colloidal crystals in photonic metamaterial applications.

Assembling macroscopic materials from DNA-functionalized, micrometer-sized colloids is challenging due to the vastly different length scales between the DNA molecules and the colloidal particles (Fig. 1a). This combination leads to crystallization kinetics that are extremely sensitive to temperature and prone to kinetic trapping1,21,22,23. The resulting challenges are both practical and fundamental in nature. For example, recent work has shown that crystal nucleation rates can vary by orders of magnitude over a temperature range of only 0.25 °C19. Extremely precise temperature control would therefore be required to self-assemble single-domain crystals from a bulk solution (Fig. 1b). At the same time, annealing polycrystalline materials is difficult due to the combination of the short-range attraction and the friction arising from the DNA-mediated colloidal interactions, which slows the rolling and sliding of colloidal particles at crystalline interfaces15,19,24,25.

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