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Archive for the ‘chemistry’ category: Page 121

Jul 7, 2022

Researchers build longest, highly conductive molecular nanowire

Posted by in categories: chemistry, nanotechnology

As our devices get smaller and smaller, the use of molecules as the main components in electronic circuitry is becoming ever more critical. Over the past 10 years, researchers have been trying to use single molecules as conducting wires because of their small scale, distinct electronic characteristics, and high tunability. But in most molecular wires, as the length of the wire increases, the efficiency by which electrons are transmitted across the wire decreases exponentially. This limitation has made it especially challenging to build a long molecular wire—one that is much longer than a nanometer—that actually conducts electricity well.

Columbia researchers announced that they have built a nanowire that is 2.6 nanometers long, shows an unusual increase in conductance as the wire length increases, and has quasi-metallic properties. Its excellent conductivity holds great promise for the field of molecular electronics, enabling electronic devices to become even tinier.

The study is published in Nature Chemistry (“Highly conducting single-molecule topological insulators based on mono-and di-radical cations”).

Jul 6, 2022

CRISPR-Cas9 Genome Editing Technology

Posted by in categories: bioengineering, biotech/medical, chemistry, internet

We’ve learned about a few techniques in biotechnology already, but the CRISPR-Cas9 system is one of the most exciting ones. Inspired by bacterial immune response to viruses, this site-specific gene editing technique won the Nobel prize in chemistry in 2020, going to Jennifer Doudna and Emmanuelle Charpentier. How did they develop this method? What can it be used for? Let’s get the full story!

Select images provided by BioRender.com.

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Jul 5, 2022

A liquefied gas electrolyte to create temperature-resilient lithium-metal batteries

Posted by in categories: chemistry, military

Lithium Ion-based batteries are among the most effective and widely used battery technologies. However, the batteries’ electrolytes mainly contain organic carbonated solvents, which are considered highly flammable with a narrow temperature window. To ensure that they don’t catch fire while operating at extreme temperatures, engineers must design safer electrolytes that are not only non-flammable, but also able to operate at a wide temperature range.

Researchers in the University of California San Diego’s Shirley Meng group and at the Army Research Laboratory have recently developed new liquefied gas electrolytes that could be used to produce lithium-metal batteries that can operate safely from-60 to 55 o C. These electrolytes have a unique structure, outlined in a paper published in Nature Energy, which make them capable of extinguishing fire.

“The liquefied gas electrolyte (LGE) was firstly conceptualized by our research group in a paper published in Science in 2017 and has been developed over five years,” Yijie Yin, one of the researchers who are working in this field from Prof. Meng’s lab, told TechXplore. “It consists of a variety of fluorocarbon gases, that when put under pressure, liquefies to form a chemically stable, low-freezing point, low-cost electrolyte.”

Jul 5, 2022

IBM Builds an AI-Powered Electronic Tongue

Posted by in category: chemistry

The tongue, called Hypertaste, can detect and analyze a liquid’s chemical composition.

Jul 5, 2022

Photonic synapses with low power consumption and high sensitivity

Posted by in categories: chemistry, information science, robotics/AI

Neuromorphic photonics/electronics is the future of ultralow energy intelligent computing and artificial intelligence (AI). In recent years, inspired by the human brain, artificial neuromorphic devices have attracted extensive attention, especially in simulating visual perception and memory storage. Because of its advantages of high bandwidth, high interference immunity, ultrafast signal transmission and lower energy consumption, neuromorphic photonic devices are expected to realize real-time response to input data. In addition, photonic synapses can realize non-contact writing strategy, which contributes to the development of wireless communication.

The use of low-dimensional materials provides an opportunity to develop complex brain-like systems and low-power memory logic computers. For example, large-scale, uniform and reproducible transition metal dichalcogenides (TMDs) show great potential for miniaturization and low-power biomimetic device applications due to their excellent charge-trapping properties and compatibility with traditional CMOS processes. The von Neumann architecture with discrete memory and processor leads to high power consumption and low efficiency of traditional computing. Therefore, the sensor-memory fusion or sensor-memory-processor integration neuromorphic architecture system can meet the increasingly developing demands of big data and AI for and high performance devices. Artificial synaptic devices are the most important components of neuromorphic systems. The performance evaluation of synaptic devices will help to further apply them to more complex artificial neural networks (ANN).

Chemical vapor deposition (CVD)-grown TMDs inevitably introduce defects or impurities, showed a persistent photoconductivity (PPC) effect. TMDs photonic synapses integrating synaptic properties and optical detection capabilities show great advantages in neuromorphic systems for low-power visual information perception and processing as well as brain memory.

Jul 4, 2022

New Artificial Photosynthesis Method Grows Food With No Sunshine

Posted by in categories: chemistry, food, solar power, sustainability

Photosynthesis uses a series of chemical reactions to convert carbon dioxide, water, and sunlight into glucose and oxygen. The light-dependent stage comes first, and relies on sunlight to transfer energy to plants, which convert it to chemical energy. The light-independent stage (also called the Calvin Cycle) follows, when this chemical energy and carbon dioxide are used to form carbohydrate molecules (like glucose).

A research team from UC Riverside and the University of Delaware found a way to leapfrog over the light-dependent stage entirely, providing plants with the chemical energy they need to complete the Calvin Cycle in total darkness. They used an electrolysis to convert carbon dioxide and water into acetate, a salt or ester form of acetic acid and a common building block for biosynthesis (it’s also the main component of vinegar). The team fed the acetate to plants in the dark, finding they were able to use it as they would have used the chemical energy they’d get from sunlight.

They tried their method on several varieties of plants and measured the differences in growth efficiency as compared to regular photosynthesis. Green algae grew four times more efficiently, while yeast saw an 18-fold improvement.

Jul 3, 2022

Jennifer Doudna | Four ways that CRISPR will revolutionize healthcare

Posted by in categories: bioengineering, biotech/medical, chemistry, food, health, policy

Hear from Nobel laureate Jennifer Doudna on the four ways that CRISPR gene editing technologies will revolutionize healthcare.

In her 31 March talk at the Frontiers Forum, Prof Jennifer Doudna outlined how CRISPR-based therapies are already transforming the lives of patients with previously limited treatment options. She also gave her vision for how her serendipitous discovery will revolutionize healthcare for us all. The session was attended by over 9,200 representatives from science, policy and business across the world.

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Jul 1, 2022

As these bacteria eat, they generate an unusual triangular molecule that can be used to make jet fuel

Posted by in categories: chemistry, energy, food, military

Aircrafts transport people, ship goods, and perform military operations, but the petroleum-based fuels that power them are in short supply. In research publishing on June 30 in the journal Joule, researchers at the Lawrence Berkeley Lab have found a way to generate an alternative jet fuel by harvesting an unusual carbon molecule produced by the metabolic process of bacteria commonly found in soil.

“In chemistry, everything that requires to make will release energy when it’s broken,” says lead author Pablo Cruz-Morales, a microbiologist at DTU Biosustain, part of the Technical University of Denmark. When petroleum jet is ignited, it releases a tremendous amount of energy, and the scientists at the Keasling Lab at the Lawrence Berkeley Laboratory thought there must be a way to replicate this without waiting millions of years for new fossil fuels to form.

Jay Keasling, a at University of California, Berkeley, approached Cruz-Morales, who was a postdoc in his lab at the time, to see if he could synthesize a tricky molecule that has the potential to produce a lot of energy. “Keasling told me: it’s gonna be an explosive idea,” says Cruz-Morales.

Jul 1, 2022

Borrowed gene helps maize adapt to high elevations, cold temperatures

Posted by in categories: chemistry, evolution, food

Researchers at North Carolina State University show that an important gene in maize called HPC1 modulates certain chemical processes that contribute to flowering time, and has its origins in “teosinte mexicana,” a precursor to modern-day corn that grows wild in the highlands of Mexico. The findings provide insight into plant evolution and trait selection, and could have implications for corn and other crops’ adaptation to low temperatures.

“We are broadly interested in understanding how natural variation of lipids are involved in the growth and development of plants, and how these compounds may help plants adapt to their immediate environments,” said Rubén Rellán-Álvarez, assistant professor of structural and molecular biochemistry at NC State and the corresponding author of a paper describing the research. “Specifically, we wanted to learn more about variation in lipids called phospholipids, which consist of phosphorus and fatty acids, and their role in adaptation to cold, low phosphorus, and the regulation of important processes for plant fitness and yield like flowering time.”

Maize grown at higher altitudes, like the highlands of Mexico, needs special accommodations in order to grow successfully. The colder temperatures in these mountainous regions put maize at a slight disadvantage when compared with maize grown at lower elevations and higher temperatures.

Jun 30, 2022

Better, Stronger, Faster: The Future of the Bionic Body

Posted by in categories: biotech/medical, chemistry, cyborgs, engineering, mobile phones, neuroscience, transhumanism

In the future, a woman with a spinal cord injury could make a full recovery; a baby with a weak heart could pump his own blood. How close are we today to the bold promise of bionics—and could this technology be used to improve normal human functions, as well as to repair us? Join Bill Blakemore, John Donoghue, Jennifer French, Joseph J. Fins, and P. Hunter Peckham at “Better, Stronger, Faster,” part of the Big Ideas Series, as they explore the unfolding future of embedded technology.

This program is part of the Big Ideas Series, made possible with support from the John Templeton Foundation.

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