Intrinsically disordered proteins (IDPs) do not attain a stable secondary or tertiary structure and rapidly change their conformation, making structure prediction particularly challenging. Although these proteins exhibit chaotic and “disordered” structures, they still perform essential functions.
IDPs comprise approximately 30% of the human proteome and play important functional roles in transcription, translation, and signaling. Many mutations linked to neurological diseases, including amyotrophic lateral sclerosis (ALS), are located in intrinsically disordered protein regions (IDRs).
Powerful machine-learning algorithms, including AlphaFold and RoseTTAFold, cannot provide realistic representations of these ‘disordered’ and ‘chaotic’ protein regions as a whole. This is because they have not been trained on such data and because these proteins exhibit inherent dynamic behavior, adopting a range of conformations rather than a single stable one.
Newly achieved precise control over light emitted from incredibly tiny sources, a few nanometers in size, embedded in two-dimensional (2D) materials could lead to remarkably high-resolution monitors and advances in ultra-fast quantum computing, according to an international team led by researchers at Penn State and Université Paris-Saclay.
In a recent study, published in ACS Photonics, scientists worked together to show how the light emitted from 2D materials can be modulated by embedding a second 2D material inside them—like a tiny island of a few nanometers in size—called a nanodot. The team described how they achieved the confinement of nanodots in two dimensions and demonstrated that, by controlling the nanodot size, they could change the color and frequency of the emitted light.
“If you have the opportunity to have localized light emission from these materials that are relevant in quantum technologies and electronics, it’s very exciting,” said Nasim Alem, Penn State associate professor of materials science and engineering and co-corresponding author on the study. “Envision getting light from a zero-dimensional point in your field, like a dot in space, and not only that, but you can also control it. You can control the frequency. You can also control the wavelength where it comes from.”
To study the interactions between electrons in a material, physicists have come up with a number of tricks over the years. These interactions are interesting, among other things, because they lead to technologically important phenomena such as superconductivity.
In most materials, however, electron interactions are very weak and, therefore, hard to detect. One of the tricks that researchers have used for a while now consists in reducing the motional energy of the electrons by artificially creating a crystal lattice with a large lattice constant—that is, with a large distance between the lattice sites in the crystal. In this way, the interaction energy, which is still small, becomes relatively more important, so that interaction effects become visible.
However, the so-called moiré materials used for this suffer from the disadvantage that inside them it is not only the motion of electrons that is modified with respect to ordinary crystal lattices, but also other physical processes that are needed for studying the material.
In a material made of two thin crystal layers that are slightly twisted with respect to each other, researchers at ETH have studied the behavior of strongly interacting electrons. Doing so, they found a number of surprising properties.
Many modern technologies are based on special materials, such as the semiconductors that are important for computers, inside of which electrons can move more or less freely. Exactly how free those electrons are is determined by their quantum properties and the crystal structure of the material. Most of the time they move independently of each other. Under certain conditions, however, strong interactions between the electrons can give rise to particular phenomena. Superconductors, in which electrons pair up to conduct electrical current without resistance, are a well-known example.
At the Institute for Quantum Electronics in Zurich, ETH-professor Ataç Imamoğlu investigates materials with strongly interacting electrons. He wants to understand the behavior of the electrons in those materials better and looks for unexpected properties that might be interesting for future applications. In a “twisted” material, he and his collaborators have now made some surprising discoveries regarding the behavior of electrons, as they report in the scientific journal Nature.
Touch a hot plate and your hand flies back. While the response is almost instant, researchers are still working to better understand the molecular mechanisms behind these sensations of heat and pain.
Now, investigators at the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo have uncovered how heat causes a critical receptor protein within cells to unfold and relay pain. This newfound activation mechanism could open up new therapeutic targets for treating pain and contribute to the development of needed alternatives to opioids.
The study is published in Proceedings of the National Academies of Sciences.
For the first time, scientists have ‘photographed’ a rare plasma instability, where high-energy electron beams form into spaghetti-like filaments.
A new study, published in Physical Review Letters, outlines how a high-intensity infrared laser was used to generate filamentation instability—a phenomenon that affects applications in plasma-based particle accelerators and fusion energy methods.
Plasma is a super-hot mixture of charged particles, such as ions and electrons, which can conduct electricity and are influenced by magnetic fields. Instabilities in plasmas can occur because the flow of particles in one direction or within a specific region can be different from the rest, causing some particles to group up into thin spaghetti-like filaments.
We all encounter gels in daily life—from the soft, sticky substances you put in your hair to the jelly-like components in various foodstuffs. While human skin shares gel-like characteristics, it has unique qualities that are very hard to replicate. It combines high stiffness with flexibility, and it has remarkable self-healing capabilities, often healing completely within 24 hours of an injury.
Until now, artificial gels have either managed to replicate this high stiffness or natural skin’s self-healing properties, but not both. Now, a team of researchers from Aalto University and the University of Bayreuth are the first to develop a hydrogel with a unique structure that overcomes earlier limitations, opening the door to applications such as drug delivery, wound healing, soft robotics sensors and artificial skin.
In the study, the researchers added exceptionally large and ultra-thin specific clay nanosheets to hydrogels, which are typically soft and squishy. The result is a highly ordered structure with densely entangled polymers between nanosheets, not only improving the mechanical properties of the hydrogel but also allowing the material to self-heal.
A team of researchers has developed the first chip-scale titanium-doped sapphire laser—a breakthrough with applications ranging from atomic clocks to quantum computing and spectroscopic sensors.
The work was led by Hong Tang, the Llewellyn West Jones, Jr. Professor of Electrical Engineering, Applied Physics & Physics. The results are published in Nature Photonics.
When the titanium-doped sapphire laser was introduced in the 1980s, it was a major advance in the field of lasers. Critical to its success was the material used as its gain medium—that is, the material that amplifies the laser’s energy. Sapphire doped with titanium ions proved to be particularly powerful, providing a much wider laser emission bandwidth than conventional semiconductor lasers. The innovation led to fundamental discoveries and countless applications in physics, biology, and chemistry.