Bottom quarks are increasingly more likely to exist in three-quark states rather than two-quark ones as the density of their environment increases.
The atomic bombing of Hiroshima, Japan, by the United States in August 1945 was not only devastating at the time, resulting in the deaths of hundreds of thousands of people, but it has had long-standing impacts to the present day, particularly the elevated incidence of cancer from radiation.
Continued research of Hiroshima Bay has uncovered a new kind of debris from the fallout, known as Hiroshima glasses. These formed from vaporized materials of the bomb and the surrounding landscape and infrastructure being targeted.
New research published in Earth and Planetary Science Letters has analyzed the chemical and isotopic compositions of these glasses to ascertain their formation process during the nuclear event.
The somatosensory cortex is a brain region known to play a role in the detection of tactile information, changes in temperature, and pain sensations. Some recent studies found that this crucial brain region is also involved in the human ability to learn and retain new motor skills.
Despite initial findings hinting at the involvement of the somatosensory cortex in motor learning, the nature of its involvement remains poorly understood.
Researchers at University of Pittsburgh Brain Institute recently carried out a study aimed at better understanding the contributions of the somatosensory cortex to the learning and retention of new movements. Their findings, published in Proceedings of the National Academy of Sciences, suggest that the somatosensory cortex could be specifically responsible for encoding new sensory targets or, in other words, learning-adapted sensory states.
A chemical compound essential to all living things has been synthesized in a lab in conditions that could have occurred on early Earth, suggesting it played a role at the outset of life, finds a new study led by University College London researchers.
The compound, pantetheine, is the active fragment of Coenzyme A. It is important for metabolism—the chemical processes that maintain life. Earlier studies failed to synthesize pantetheine effectively, leading to suggestions that it was absent at life’s origin.
In the new study, published in the journal Science, the research team created the compound in water at room temperature using molecules formed from hydrogen cyanide, which was likely abundant on early Earth.
Understanding complex biological and biomedical systems is greatly aided by 3D imaging, which provides much more detailed information than traditional two-dimensional methods. However, live cell and tissue imaging remain challenging due to factors like limited imaging speed and significant scattering in turbid environments.
In this context, multimodal microscopy techniques are notable. Specifically, nonlinear techniques like CRS (coherent Raman scattering) use optical vibrational spectroscopy, providing precise chemical imaging in tissues and cells in a label-free way.
Furthermore, stimulated Raman scattering (SRS) microscopy, a CRS method, can accurately capture images of biomolecules due to the linear relationship between stimulated Raman intensity and the concentration of target molecules. It does so with high sensitivity and without interference from unwanted nonresonant backgrounds.
AEgIS is one of several experiments at CERN’s Antimatter Factory producing and studying antihydrogen atoms with the goal of testing with high precision whether antimatter and matter fall to Earth in the same way.
In a paper published today in Physical Review Letters, the AEgIS collaboration reports an experimental feat that will not only help it achieve this goal but also pave the way for a whole new set of antimatter studies, including the prospect to produce a gamma-ray laser that would allow researchers to look inside the atomic nucleus and have applications beyond physics.
A team of researchers from the Max Born Institute in Berlin has, for the first time, demonstrated attosecond-pump attosecond-probe spectroscopy (APAPS) at a repetition rate of 1 kilohertz. This became possible by the development of a compact, intense attosecond source using an out-of-focus generation geometry. The approach opens new avenues for the investigation of extremely fast electron dynamics in the attosecond regime.
The first generation of attosecond pulses (1 attosecond corresponds to 10-18 seconds) at the turn of this century has enabled unprecedented insights into the world of electrons. For their pioneering work, first leading to the demonstration of attosecond pulses in 2001, Anne L’Huillier, Pierre Agostini, and Ferenc Krausz were awarded the Nobel Prize in Physics in 2023.
Current attosecond techniques, however, come with an important drawback: To be able to record a movie in a pump-probe experiment, an attosecond pulse typically has to be combined with a femtosecond pulse (1 femtosecond corresponds to 10-15 seconds) whose optical cycles (a few femtoseconds long) is used as a clock with attosecond resolution. This constitutes a limitation for the investigation of electron dynamics on attosecond timescales.
National University of Singapore researchers and their collaborators have unveiled a novel concept termed “supercritical coupling” that enables a several-fold increase in photon upconversion efficiency. This discovery not only challenges existing paradigms, but also opens a new direction in the control of light emission.
Photon upconversion, the process of converting low-energy photons into higher-energy ones, is a crucial technique with broad applications, ranging from super-resolution imaging to advanced photonic devices. Despite considerable progress, the quest for efficient photon upconversion has faced challenges due to inherent limitations in the irradiance of lanthanide-doped nanoparticles and the critical coupling conditions of optical resonances.
The concept of “supercritical coupling” plays a pivotal role in addressing these challenges. This fundamentally new approach, proposed by a research team led by Professor Liu Xiaogang from the Department of Chemistry, NUS and his collaborator, Dr. Gianluigi Zito from the National Research Council of Italy leverages on the physics of “bound states in the continuum” (BICs).
At approximately 18:17 CET (17:17 UTC) on Wednesday, February 21, 2024, ESA’s ERS-2 satellite completed its atmospheric reentry over the North Pacific Ocean. No damage to property has been reported.
ESA’s second European Remote Sensing satellite, ERS-2, was launched almost 30 years ago, on April 21, 1995. Together with the almost-identical ERS-1, it provided invaluable long-term data on Earth’s land surfaces, ocean temperatures, ozone layer, and polar ice extent that revolutionized our understanding of the Earth system. It was also called upon to monitor and assist the response to natural disasters.
“The ERS satellites have provided a stream of data which has changed our view of the world in which we live,” said ESA’s Director of Earth Observation Programmes, Simonetta Cheli. “They have provided us with new insights on our planet, the chemistry of our atmosphere, the behavior of our oceans, and the effects of mankind’s activity on our environment – creating new opportunities for scientific research and applications.”
The U.S. Naval Research Laboratory (NRL), working together with Kansas State University, has announced the discovery of slab waveguides made from the two-dimensional material hexagonal boron nitride. This milestone has been documented in the journal Advanced Materials.
Two-dimensional (2D) materials are a class of materials that can be reduced to the monolayer limit by mechanically peeling the layers apart. The weak interlayer attractions, or van der Waals attraction, allows the layers to be separated via the so-called “Scotch tape” method. The most famous 2D material, graphene, is a semimetallic material consisting of a single layer of carbon atoms. Recently, other 2D materials including semiconducting transition metal dichalcogenides (TMDs) and insulating hexagonal boron nitride (hBN) have also garnered attention. When reduced near the monolayer limit, 2D materials have unique nanoscale properties that are appealing for creating atomically thin electronic and optical devices.
