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Category: chemistry – Page 317

Could make awesome computers.

Materials scientists who work with nano-sized components have developed ways of working with their vanishingly small materials. But what if you could get your components to assemble themselves into different structures without actually handling them at all?

Verner Håkonsen works with cubes so tiny that nearly 5 billion of them could fit on a pinhead.

He cooks up the cubes in the NTNU NanoLab, in a weird-looking glass flask with three necks on the top using a mixture of chemicals and special soap.

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Over the past decade or so, the performance of batteries has skyrocketed and their cost has plummeted. Given that many experts see the electrification of everything as key to decarbonizing our energy systems, this is good news. But for researchers like Chueh, the pace of battery innovation isn’t happening fast enough. The reason is simple: batteries are extremely complex. To build a better battery means ruthlessly optimizing at every step in the production process. It’s all about using less expensive raw materials, better chemistry, more efficient manufacturing techniques. But there are a lot of parameters that can be optimized. And often an improvement in one area—say, energy density—will come at a cost of making gains in another area, like charge rate.

Improving batteries has always been hampered by slow experimentation and discovery processes. Machine learning is speeding it up by orders of magnitude.

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Caltech’s OrbNet deep learning tool outperforms state-of-the-art solutions.

Artificial intelligence (AI) machine learning is being applied to help accelerate the complex science of quantum mechanics—the branch of physics that studies matter and light on the subatomic scale. Recently a team of scientists at the California Institute of Technology (Caltech) published a breakthrough study in The Journal of Chemical Physics that unveils a new machine learning tool called OrbNet that can perform quantum chemistry computations 1,000 times faster than existing state-of-the-art solutions.

“We demonstrate the performance of the new method for the prediction of molecular properties, including the total and relative conformer energies for molecules in range of datasets of organic and drug-like molecules,” wrote the researchers.

Quantum chemistry is the scientific study that combines chemistry and physics. Also known as molecular quantum dynamics, quantum chemistry is a subset of chemistry that studies the properties and behavior of molecules at the subatomic level through the lens of quantum mechanics.

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A team of researchers affiliated with several institutions in the Republic of Korea has found that it is possible to replace chemical functional groups with a gold electrode to control the reactivity of a molecule. In their paper published in the journal Science, the group describes attaching target molecules to a gold electrode to change the properties of immobilized molecules and how their technique performed when used to rate changes in the hydrolysis of certain esters.

In chemistry, are assortments of atoms that together work to attach carbon skeletons in . All organic have their own unique functional groups, which play an important role in the formation of molecules. Functional groups can also donate or take away electrons when one molecule comes into contact with another, which is how many occur.

Chemists have found that they can tinker with functional groups to speed up or slow down reactions to suit their needs, and because of that, functional groups play an important role in chemical synthesis. Unfortunately, developing reactions to produce desired products using functional groups has proven to be slow and difficult work. In this new effort, the researchers have found a way to replace the use of functional groups with a gold electrode to make the work easier. They simply attached molecules to a gold electrode and turned on the electricity. The technique allowed for more control over reactions by varying the amount of electricity supplied to the electrode. In such a capacity, the electrode was able to work as a “universal functional group” to inhibit or propel reactions when the researchers manipulated the amount of electricity applied to the electrode.

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Physicists have created a broadband detector of terahertz radiation based on graphene. The device has potential for applications in communication and next-generation information transmission systems, security, and medical equipment. The study came out in ACS Nano Letters.

The new detector relies on the interference of plasma waves. Interference as such underlies many technological applications and everyday phenomena. It determines the sound of musical instruments and causes the rainbow colors in soap bubbles, along with many other effects. The interference of electromagnetic waves is harnessed by various spectral devices used to determine the chemical composition, physical and other properties of objects — including very remote ones, such as stars and galaxies.

Plasma waves in metals and semiconductors have recently attracted much attention from researchers and engineers. Like the more familiar acoustic waves, the ones that occur in plasmas are essentially density waves, too, but they involve charge carriers: electrons and holes. Their local density variation gives rise to an electric field, which nudges other charge carriers as it propagates through the material. This is similar to how the pressure gradient of a sound wave impels the gas or liquid particles in an ever expanding region. However, plasma waves die down rapidly in conventional conductors.

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Virtual reality software which allows researchers to ‘walk’ inside and analyse individual cells could be used to understand fundamental problems in biology and develop new treatments for disease.

The software, called vLUME, was created by scientists at the University of Cambridge and 3D image analysis software company Lume VR Ltd. It allows super-resolution microscopy data to be visualised and analysed in virtual reality, and can be used to study everything from individual proteins to entire cells. Details are published in the journal Nature Methods.

Super-resolution microscopy, which was awarded the Nobel Prize for Chemistry in 2014, makes it possible to obtain images at the nanoscale by using clever tricks of physics to get around the limits imposed by light diffraction. This has allowed researchers to observe molecular processes as they happen. However, a problem has been the lack of ways to visualise and analyse this data in three dimensions.

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In first-of-their-kind observations in the human brain, an international team of researchers has revealed two well-known neurochemicals–dopamine and serotonin–are at work at sub-second speeds to shape how people perceive the world and take action based on their perception.

Furthermore, the neurochemicals appear to integrate people’s perceptions of the world with their actions, indicating dopamine and serotonin have far more expansive roles in the human nervous system than previously known.

Known as neuromodulators, dopamine and serotonin have traditionally been linked to reward processing–how good or how bad people perceive an outcome to be after taking an action.

The study online today in the journal *Neuron* opens the door to a deeper understanding of an expanded role for these systems and their roles in human health.

“An enormous number of people throughout the world are taking pharmaceutical compounds to perturb the dopamine and serotonin transmitter systems to change their behavior and mental health,” said P. Read Montague, senior author of the study and a professor and director of the Center for Human Neuroscience Research and the Human Neuroimaging Laboratory at the Fralin Biomedical Research Institute at Virginia Tech Carilion. “For the first time, moment-to-moment activity in these systems has been measured and determined to be involved in perception and cognitive capacities. These neurotransmitters are simultaneously acting and integrating activity across vastly different time and space scales than anyone expected.”

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“These neuromodulators play a much broader role in supporting human behavior and thought, and in particular they are involved in how we process the outside world,” Bang said. “For example, if you move through a room and the lights are off, you move differently because you’re uncertain about where objects are. Our work suggests these neuromodulators–serotonin in particular– are playing a role in signaling how uncertain we are about the outside environment.”

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In the search for the chemical origins of life, researchers have found a possible alternative path for the emergence of the characteristic DNA pattern: According to the experiments, the characteristic DNA base pairs can form by dry heating, without water or other solvents. The team led by Ivan Halasz from the Rudjer Boskovic Institute and Ernest Mestrovic from the pharmaceutical company Xellia presents its observations from DESYs X-ray source PETRA III in the journal Chemical Communications.

“One of the most intriguing questions in the search for the origin of life is how the chemical selection occurred and how the first biomolecules formed,” says Tomislav Stolar from the Rudjer Boskovic Institute in Zagreb, the first author on the paper. While living cells control the production of biomolecules with their sophisticated machinery, the first molecular and supramolecular building blocks of life were likely created by pure chemistry and without enzyme catalysis. For their study, the scientists investigated the formation of nucleobase pairs that act as molecular recognition units in the Deoxyribonucleic Acid (DNA).

Our genetic code is stored in the DNA as a specific sequence spelled by the nucleobases adenine (A), cytosine ©, guanine (G) and thymine (T). The code is arranged in two long, complementary strands wound in a double-helix structure. In the strands, each nucleobase pairs with a complementary partner in the other strand: adenine with thymine and cytosine with guanine.

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