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Archive for the ‘chemistry’ category: Page 18

Mar 30, 2024

Invalid SMILES are beneficial rather than detrimental to chemical language models

Posted by in category: chemistry

Generative models for chemical structures are often trained to create output in the common SMILES notation. Michael Skinnider shows that training models with the goal of avoiding the generation of incorrect SMILES strings is detrimental to learning other chemical properties and that allowing models to generate incorrect molecules, which can be easily removed post hoc, leads to better performing models.

Mar 30, 2024

Synaptic Transmission: Not a One-Way Street for Key Brain Synapse in the Hippocampus

Posted by in categories: chemistry, neuroscience

Key synapse acts as a “smart teacher,” sending messages against the usual flow of information in the brain.

Information flows in a well-defined direction in the brain: Chemical and electrical signals are passed from one neuron to the other across the synapse, from the pre-synaptic to the post-synaptic neuron. Now, Peter Jonas and his group at the Institute of Science and Technology Austria (IST Austria) show that information also travels in the opposite direction at a key synapse in the hippocampus, the brain region responsible for learning and memory.

At the so-called mossy fiber synapse, the post-synaptic CA3 neuron influences how the pre-synaptic neuron, the so-called mossy fiber neuron, fires. “We have shown, for the first time, that a retrograde information flow is physiologically relevant for pre-synaptic plasticity,” says Yuji Okamoto, a postdoc in the group of Peter Jonas at IST Austria and co-first author of the paper published in Nature Communications.

Mar 30, 2024

A new path for organic electrochemical transistors

Posted by in categories: chemistry, computing

An article in Nature Electronics presents how to use electron-beam lithography to obtain p-and n-type vertical organic electrochemical transistor matrix arrays and complementary logic circuits.

Mar 29, 2024

Model suggests how ancient RNA may have gained self-cutting ability essential for life

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

Scientists have long pondered the beginnings of life on Earth. One theory is that RNA, which is ubiquitous across all domains of life, played a central role in early life. Similar to DNA, RNA possesses the ability to store genetic information. However, to initiate life’s processes, early RNA must have also possessed the capability to self-replicate and catalyze biochemical reactions independently, without the assistance of specialized enzymes.

Mar 29, 2024

Constructing ‘on-gel’ alveolar organoids as a new screening platform

Posted by in categories: biotech/medical, chemistry

A study led by Professor Shimpei Gotoh (Department of Clinical Application), introduces a new culturing method to generate alveolar organoids suitable for medium-and high-throughput screening and identified several chemicals with synergistic effects on AT1 cell differentiation. The work is published in the journal Stem Cell Reports.

Mar 29, 2024

Researchers challenge the limits of molecular memory, opening the door to the development of molecular chips

Posted by in categories: chemistry, computing

Some molecules respond to external light pulses by changing their structure and holding certain states that can be switched from one to another. These are commonly referred to as photoswitches and usually have two possible states. Recently, however, scientists from the Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague) have developed a molecule that takes the possibilities of photoswitches a step further.

Mar 29, 2024

Inside the 20-year quest to unravel the bizarre realm of ‘quantum superchemistry’

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

More than two decades ago, scientists predicted that at ultra-low temperatures, many atoms could undergo ‘quantum superchemistry’ and chemically react as one. They’ve finally shown it’s real.

Mar 29, 2024

Cheers! NASA’s Webb finds Ethanol, other Icy Ingredients for Worlds

Posted by in categories: chemistry, space

What do margaritas, vinegar, and ant stings have in common? They contain chemical ingredients that NASA’s James Webb Space Telescope has identified surrounding two young protostars known as IRAS 2A and IRAS 23385. Although planets are not yet forming around those stars, these and other molecules detected there by Webb represent key ingredients for making potentially habitable worlds.

An international team of astronomers used Webb’s MIRI (Mid-Infrared Instrument) to identify a variety of icy compounds made up of complex organic molecules like ethanol (alcohol) and likely acetic acid (an ingredient in vinegar). This work builds on previous Webb detections of diverse ices in a cold, dark molecular cloud.

What is the origin of complex organic molecules (COMs)?

Mar 27, 2024

Chemicals Found In Popular Household Products Potentially Linked To Autism, Multiple Sclerosis, Study Suggests

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

“We hope our work will contribute to informed decisions regarding regulatory measures or behavioral interventions to minimize chemical exposure and protect human health,” Tesar said in a statement.

1.8 million. That’s how many people globally have multiple sclerosis, according to the World Health Organization. The agency also found around one in 100 children worldwide have been diagnosed with autism.

“Rigorous safety tests are in place for human health that are evaluated by [the] U.S. Environmental Protection Agency for approval and compliance with all regulatory guidelines,” Brian Sansoni, senior vice president for Communications, Outreach and Membership for the American Cleaning Institute, told Forbes. The ACI represents top cleaning product manufacturers like the Clorox Company and Procter & Gamble. “ACI member company manufacturers make product safety a top priority.” Quats have been known to be effective at killing bacteria, germs, viruses and mold. “The use of cleaning products, disinfectants and their chemistries contribute to public health in homes, schools, healthcare settings and communities every single day,” the ACI said.

Mar 27, 2024

Quantum interference could lead to smaller, faster, and more energy-efficient transistors

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

As transistors get smaller, they become increasingly inefficient and susceptible to errors, as electrons can leak through the device even when it is supposed to be switched off, by a process known as quantum tunneling. Researchers are exploring new types of switching mechanisms that can be used with different materials to remove this effect.

In the nanoscale structures that Professor Jan Mol, Dr. James Thomas, and their group study at Queen Mary’s School of Physical and Chemical Sciences, quantum mechanical effects dominate, and electrons behave as waves rather than particles. Taking advantage of these quantum effects, the researchers built a new transistor.

The transistor’s conductive channel is a single zinc porphyrin, a molecule that can conduct electricity. The porphyrin is sandwiched between two graphene electrodes, and when a voltage is applied to the electrodes, electron flow through the molecule can be controlled using .

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