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Archive for the ‘chemistry’ category: Page 148

Mar 7, 2023

Dr. Moupali Das, MD, MPH — Gilead Sciences — Dedicated To Ending The HIV Epidemic

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

Dedicated to ending the HIV epidemic — dr. moupali das, MD, MPH, executive director, HIV clinical research, gilead sciences.


Dr. Moupali Das, MD, MPH, is Executive Director, HIV Clinical Research, in the Virology Therapeutic Area, at Gilead Sciences (https://www.gilead.com/), where she leads the pre-exposure prophylaxis (PrEP) clinical drug development program, including evaluating the safety and efficacy of a long-acting, twice yearly, subcutaneous injection being studied for HIV prevention. Her responsibilities also include expanding the populations who may benefit from PrEP.

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Mar 7, 2023

What makes a neural network remember?

Posted by in categories: biological, chemistry, robotics/AI

Computer models are an important tool for studying how the brain makes and stores memories and other types of complex information. But creating such models is a tricky business. Somehow, a symphony of signals—both biochemical and electrical—and a tangle of connections between neurons and other cell types creates the hardware for memories to take hold. Yet because neuroscientists don’t fully understand the underlying biology of the brain, encoding the process into a computer model in order to study it further has been a challenge.

Now, researchers at the Okinawa Institute of Science and Technology (OIST) have altered a commonly used computer model of called a Hopfield network in a way that improves performance by taking inspiration from biology. They found that not only does the new network better reflect how neurons and other cells wire up in the , it can also hold dramatically more memories.

The complexity added to the network is what makes it more realistic, says Thomas Burns, a Ph.D. student in the group of Professor Tomoki Fukai, who heads OIST’s Neural Coding and Brain Computing Unit. “Why would biology have all this complexity? Memory capacity might be a reason,” Mr. Burns says.

Mar 7, 2023

Researchers fabricate novel flexible supercapacitors on paper

Posted by in categories: chemistry, energy, wearables

Wearable devices such as smartwatches, fitness trackers, and virtual reality headsets are becoming commonplace. They are powered by flexible electronics that consist of electrodes with plastic or metal foil as substrates. However, both of these come with their own drawbacks. Plastics suffer from poor adhesion and low durability, while metal foils make the devices bulky and less flexible.

In light of this, paper is a promising alternative. It is porous, light, thin, foldable, and flexible. Moreover, paper has randomly distributed fibers that provide a large surface area for depositing active electrode material, making for excellent electrochemical properties.

Accordingly, researchers have developed various paper-based supercapacitors, devices that store electric charge and energy, by stacking multiple sheets, acting as positive and negative electrodes and separators. However, such an arrangement increases device size and resistance. In addition, they tend to form creases, peel off, and slip over each other, which further deteriorate device performance.

Mar 3, 2023

‘Forever chemicals’ in your toilet paper might give you cancer: study

Posted by in categories: biotech/medical, chemistry

Your toilet paper might give you cancer, according to scientists. Experts from the University of Florida warn that your toilet paper could contain toxic “forever chemicals,” also known as per-and polyfluoroalkyl substances (PFAs), which have previously been linked to certain cancers and even low sperm count.

Mar 2, 2023

Putting Carbon Dioxide to Good — Scientists Use Electrochemistry To Convert Carbon to Useful Molecules

Posted by in categories: chemistry, innovation

A joint effort in chemistry has resulted in an innovative method for utilizing carbon dioxide in a positive – even beneficial – manner: through electrosynthesis, it is integrated into a series of organic molecules that play a crucial role in the development of pharmaceuticals.

During the process, the team made an innovative discovery. By altering the type of electrochemical reactor used, they were able to generate two distinct products, both of which are useful in medicinal chemistry.

The team’s paper was recently published in the journal Nature. The paper’s co-lead authors are postdoctoral researchers Peng Yu and Wen Zhang, and Guo-Quan Sun of Sichuan University in China.

Mar 2, 2023

Breakthrough in Quantum Chemistry: Tunnel Effect Experimentally Observed in Molecules

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

While tunneling reactions are remarkably hard to predict, a group of researchers were able to experimentally observe such an effect, marking a breakthrough in the field of quantum chemistry.

Tunnel Effect

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Mar 1, 2023

Physics of Superpropulsion: Super-Fast Sharpshooter Insect Urination Using a “Butt Flicker”

Posted by in categories: biological, chemistry, engineering, physics

Tiny insects known as sharpshooters excrete by catapulting urine drops at incredible accelerations. Their excretion is the first example of superpropulsion discovered in a biological system.

Saad Bhamla was in his backyard when he noticed something he had never seen before: an insect urinating. Although nearly impossible to see, the insect formed an almost perfectly round droplet on its tail and then launched it away so quickly that it seemed to disappear. The tiny insect relieved itself repeatedly for hours.

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Mar 1, 2023

Quantum chemistry: Molecules caught tunneling

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

Tunneling reactions in chemistry are difficult to predict. The quantum mechanically exact description of chemical reactions with more than three particles is difficult, with more than four particles it is almost impossible. Theorists simulate these reactions with classical physics and must neglect quantum effects. But where is the limit of this classical description of chemical reactions, which can only provide approximations?

Roland Wester from the Department of Ion Physics and Applied Physics at the University of Innsbruck has long wanted to explore this frontier. “It requires an experiment that allows very and can still be described quantum-mechanically,” says the experimental physicist. “The idea came to me 15 years ago in a conversation with a colleague at a conference in the U.S.,” Wester recalls. He wanted to trace the quantum mechanical tunnel effect in a very simple reaction.

Since the tunnel effect makes the reaction very unlikely and thus slow, its experimental observation was extraordinarily difficult. After several attempts, however, Wester’s team has now succeeded in doing just that for the first time, as they report in the current issue of the journal Nature.

Feb 28, 2023

30 years of NASA’s Magellan mission may finally solve how Venus cools

Posted by in categories: chemistry, space

These peculiar geological structures could explain a long-standing mystery of how Venus loses its heat.

Given Venus and Earth are both rocky planets with roughly the same size and chemistry of their rocks, they should be losing their interior heat to space at a similar rate. How Earth loses its heat is well known, whereas Venus’ flow process remains a mystery.

How does Venus, the hottest planet in the solar system, lose its heat?

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Feb 28, 2023

Super-fast insect urination powered by the physics of superpropulsion

Posted by in categories: chemistry, engineering, physics

Saad Bhamla was in his backyard when he noticed something he had never seen before: an insect urinating. Although nearly impossible to see, the insect formed an almost perfectly round droplet on its tail and then launched it away so quickly that it seemed to disappear. The tiny insect relieved itself repeatedly for hours.

It’s generally taken for granted that what goes in must come out, so when it comes to fluid dynamics in animals, the research is largely focused on feeding rather than excretion. But Bhamla, an assistant professor in the School of Chemical and Biomolecular Engineering at the Georgia Institute of Technology, had a hunch that what he saw wasn’t trivial.

“Little is known about the fluid dynamics of excretion, despite its impact on the morphology, energetics, and behavior of animals,” Bhamla said. “We wanted to see if this tiny insect had come up with any clever engineering or physics innovations in order to pee this way.”