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Category: chemistry – Page 163

Enzyme-catalyzed replication of nucleic acid sequences is a prerequisite for the survival and evolution of biological entities. Before the advent of protein synthesis, genetic information was most likely stored in and replicated by RNA. However, experimental systems for sustained RNA-dependent RNA-replication are difficult to realise, in part due to the high thermodynamic stability of duplex products and the low chemical stability of catalytic RNAs. Using a derivative of a group I intron as a model for an RNA replicase, we show that heated air-water interfaces that are exposed to a plausible CO2-rich atmosphere enable sense and antisense RNA replication as well as template-dependent synthesis and catalysis of a functional ribozyme in a one-pot reaction. Both reactions are driven by autonomous oscillations in salt concentrations and pH, resulting from precipitation of acidified dew droplets, which transiently destabilise RNA duplexes. Our results suggest that an abundant Hadean microenvironment may have promoted both replication and synthesis of functional RNAs.

© 2023. The Author(s).

Conflict of interest statement.

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Reported here are experiments that show that ribonucleoside triphosphates are converted to polyribonucleic acid when incubated with rock glasses similar to those likely present 4.3−4.4 billion years ago on the Hadean Earth surface, where they were formed by impacts and volcanism. This polyribonucleic acid averages 100–300 nucleotides in length, with a substantial fraction of 3’,-5’-dinucleotide linkages. Chemical analyses, including classical methods that were used to prove the structure of natural RNA, establish a polyribonucleic acid structure for these products. The polyribonucleic acid accumulated and was stable for months, with a synthesis rate of 2 × 10-3 pmoles of triphosphate polymerized each hour per gram of glass (25°C, pH 7.5). These results suggest that polyribonucleotides were available to Hadean environments if triphosphates were. As many proposals are emerging describing how triphosphates might have been made on the Hadean Earth, the process observed here offers an important missing step in models for the prebiotic synthesis of RNA.

Keywords: Impact glasses; Mafic rocks; Nucleoside triphosphates; Origin of life; Prebiotic chemistry; RNA world.

Conflict of interest statement.

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The team developed a cyclical process in which the device is rinsed with water, dried in relatively low heat, and printed on again.

In the electronics industry, placing several layers of components on top of each other to develop complex devices is no easy task. And with printed electronics, the task is more complicated.

“If you’re making a peanut butter and jelly sandwich, one layer on either slice of bread is easy,” Aaron Franklin, the Addy Professor of Electrical and Computer Engineering at Duke, said in a statement. “But if you put the jelly down first and then try to spread peanut butter on top of it, forget it, the jelly won’t stay put and will intermix with the peanut butter.

The current electronics fabrication technology relies on hazardous chemicals and toxic gases. The entire industry has also been flagged for attention by the US Environmental Protection Agency.

Continue reading “Researchers print fully recyclable electronics that replace toxic chemicals with water” | >

Researchers have developed a new way to produce and shape large, high-quality mirrors that are much thinner than the primary mirrors previously used for telescopes deployed in space. The resulting mirrors are flexible enough to be rolled up and stored compactly inside a launch vehicle.

“Launching and deploying space telescopes is a complicated and costly procedure,” said Sebastian Rabien from Max Planck Institute for Extraterrestrial Physics in Germany. “This new approach—which is very different from typical mirror production and polishing procedures—could help solve weight and packaging issues for telescope mirrors, enabling much larger, and thus more sensitive, telescopes to be placed in orbit.”

In the journal Applied Optics, Rabien reports successful fabrication of parabolic membrane mirror prototypes up to 30 cm in diameter. These mirrors, which could be scaled up to the sizes needed in space telescopes, were created by using chemical vapor deposition to grow membrane mirrors on a rotating liquid inside a vacuum chamber. He also developed a method that uses heat to adaptively correct imperfections that might occur after the mirror is unfolded.

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Materials that can conduct negatively charged hydrogen atoms in ambient conditions could pave the way for advanced clean energy storage and electrochemical conversion technologies. A research team from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) demonstrated a technique that enables a room-temperature all-solid-state hydride cell by introducing and exploiting defects in the lattice structure of rare earth hydrides. Their study was published in Nature on April 5.

Solid materials that conduct lithium, sodium and hydrogen cations have been used in batteries and fuel cells. Under certain conditions, some of the materials transition to superionic states where ions move as fast as they do in liquids by skipping through the rigid crystal structure. This phenomenon is advantageous for chemical and energy conversions as it allows ions to move without a liquid or soft membrane to separate the electrodes. However, few can reach this state under ambient conditions.

“Materials that exhibit superionic conduction at ambient conditions would provide huge opportunities for constructing brand new all-solid-state hydride batteries, fuel cells and electrochemical cells for the storage and conversion of clean energy,” said Prof. Chen Ping, study author from DICP.

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c Department of Chemical Biology, Xiamen University, Xiamen, 361,005, China.

The concept of xeno-nucleic acids (XNAs) was first proposed in 2009 in a theoretical paper, referring to additional types of nucleic acids, whose sugar moieties would differ from those in DNA and RNA. However, with the rising popularity of XNAs, the definition of XNAs has been extended to unnatural nucleic acids with chemically modified sugar, nucleobase, or phosphate moieties that are distinct from those found in DNA and RNA. The discovery and engineering of both polymerases and reverse transcriptases to synthesize, replicate and evolve a diverse range of XNAs has attracted significant attention and has enabled the discovery of XNA ligands (aptamers) and XNA catalysts (XNAzymes) as well as the synthesis of XNA nanostructures with potential as novel therapeutics. The field of XNAs continues to grow rapidly towards realizing the potential of XNAs in biotechnology and molecular medicine. This themed issue unites a collection of articles attesting to the rapid progress in the field.

One of the key advantages of XNAs is their generally enhanced resistance to nuclease degradation. This biostability, the affinity and specificity towards a target, and the general lack of immunogenicity of modified nucleic acids are critical for their potential application as therapeutics. Modified sugar moieties such as 2′-modified analogs, conformationally locked analogs, and threose-replaced analogs in particular contribute to the increased biological stability of XNAs against enzymatic degradation. Replacing the phosphodiester linkages with charge-neutral backbones including peptide-like backbones and triazole-linked backbones offers further opportunities to tune the stability, conformation and physicochemical properties of XNAs and enhance the affinity to their targets.

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In an advance they consider a breakthrough in computational chemistry research, University of Wisconsin–Madison chemical engineers have developed model of how catalytic reactions work at the atomic scale. This understanding could allow engineers and chemists to develop more efficient catalysts and tune industrial processes—potentially with enormous energy savings, given that 90% of the products we encounter in our lives are produced, at least partially, via catalysis.

Catalyst materials accelerate without undergoing changes themselves. They are critical for refining petroleum products and for manufacturing pharmaceuticals, plastics, food additives, fertilizers, green fuels, industrial chemicals and much more.

Scientists and engineers have spent decades fine-tuning catalytic reactions—yet because it’s currently impossible to directly observe those reactions at the and pressures often involved in industrial-scale catalysis, they haven’t known exactly what is taking place on the nano and atomic scales. This new research helps unravel that mystery with potentially major ramifications for industry.

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The neuroscience study opens new avenues for understanding the brain’s role in learning and education. As researchers uncover more about the mechanisms underlying acquiring knowledge, educators can implement evidence-based strategies to enhance student outcomes. This blog post delves into the fascinating world of neuroscience, explores how the brain learns, and examines various learning theories and strategies informed by neuroscientific research.

Understanding the Basics of Neuroscience

Neuroscience refers to studying the nervous system, focusing on its role in behavior, cognition, and learning. The human brain, a complex organ, contains billions of neurons that transmit information through electrical and chemical signals. These neurons form networks, and the brain’s organization into different regions allows it to carry out specific functions.

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New research from a team of scientists at the Cornell University Center for Bright Beams has made significant strides in developing new techniques to guide the growth of materials used in next-generation particle accelerators.

The study, published in the Journal of Physical Chemistry C, reveals the potential for greater control over the growth of superconducting Nb3Sn films, which could significantly reduce the cost and size of cryogenic infrastructure required for .

Superconducting accelerator facilities, such as those used for X-ray free-electron laser radiation, rely on niobium superconducting radio frequency (SRF) cavities to generate high-energy beams. However, the associated cryogenic infrastructure, energy consumption, and operating costs of niobium SRF cavities limit access to this technology.

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Researchers at the Laboratory of Organic Electronics, Linköping University, have together with colleagues at the Lawrence Berkeley National Laboratory in Berkeley, California, developed a method that increases the signal strength from microbial electrochemical cells by up to twenty times. The secret is a film with an embedded bacterium: Shewanella oneidensis.

Adding to electrochemical systems is often an environmentally sensitive means to convert chemical energy to electricity. Applications include water purification, bioelectronics, biosensors, and for the harvesting and storage of energy in fuel cells. One problem that miniaturisation of the processes has encountered is that a high requires large electrodes and a large volume of liquid.

Researchers at Linköping University, together with colleagues at the Lawrence Berkeley National Laboratory in Berkeley, California, USA, have now developed a method in which they embed the electroactive Shewanella oneidensis into PEDOT: PSS, an electrically conducting polymer, on a substrate of carbon felt.

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