A method for freely adjusting the parameters of a loop of optical fiber enables the exploration of exotic topological phases of matter.
Researchers use a laser to excite and precisely measure a long-sought exotic nuclear state, paving the way for precise timekeeping and ultrasensitive quantum sensing.
Any reliably produced, periodic phenomenon—from the swing of a pendulum to the vibrations of a single atom—can form the basis of a clock. Today’s most precise timekeeping is based on extremely narrow electronic transitions in atoms, which resonate at optical frequencies. These stupendously precise optical atomic clocks lose just 1 second (s) in about 30 billion years. However, they could potentially be outperformed by a nuclear clock, which would instead “tick” to the resonant frequency of a transition that occurs in the atomic nucleus instead of in the electronic shell. The most promising candidate for this nuclear standard is an exceptionally low-energy and long-lived excited state, or isomer, of the isotope thorium-229 (229 Th). Researchers have now achieved the long-sought goal of exciting this transition with ultraviolet light.
Plant life first emerged on land about 550 million years ago, and an international research team co-led by University of Nebraska–Lincoln computational biologist Yanbin Yin has cracked the genomic code of its humble beginnings, which made possible all other terrestrial life on Earth, including humans.
A research team at the University of Pittsburgh led by Alexander Star, a chemistry professor in the Kenneth P. Dietrich School of Arts and Sciences, has developed a fentanyl sensor that is six orders of magnitude more sensitive than any electrochemical sensor for the drug reported in the past five years. The portable sensor can also tell the difference between fentanyl and other opioids.
Human activities account for a substantial amount—anywhere from 20% to more than 60%—of toxic thallium that has entered the Baltic Sea over the past 80 years, according to new research by scientists affiliated with the Woods Hole Oceanographic Institution (WHOI) and other institutions.
Precisely measuring the energy states of individual atoms has been a historical challenge for physicists due to atomic recoil. When an atom interacts with a photon, the atom “recoils” in the opposite direction, making it difficult to measure the position and momentum of the atom precisely. This recoil can have big implications for quantum sensing, which detects minute changes in parameters, for example, using changes in gravitational waves to determine the shape of the Earth or even detect dark matter.
A new study co-authored by Yale sociologist Nicholas A. Christakis demonstrates that tapping into the dynamics of friendship significantly improves the possibility that a community will adopt public health and other interventions aimed at improved human well-being.
Hvidovre Hospital has the world’s first prototype of a sensor capable of detecting errors in MRI scans using laser light and gas. The new sensor, developed by a young researcher at the University of Copenhagen and Hvidovre Hospital, can thereby do what is impossible for current electrical sensors—and hopefully pave the way for MRI scans that are better, cheaper and faster.
The work introduces a completely new way to create and study strange metals, whose electrons behave differently than those in a conventional metal like copper. “It is a potential new approach to designing these unusual materials,” says Joseph G. Checkelsky, lead principal investigator of the research and Associate Professor of Physics.
Linda Ye, MIT Ph.D. ‘21, is first author of a paper on the work published earlier this year in Nature Physics. “A new way of making strange metals will help us develop a unifying theory behind their behavior. That has been quite challenging to date, and could lead to a better understanding of other materials, including high-temperature superconductors,” says Ye, now an assistant professor at the California Institute of Technology.
The Nature Physics paper is accompanied by a News & Views article titled, “A strange way to get a strange metal.”
The following is a summary of “Comparative Effectiveness of Partial Gland Cryoablation Versus Robotic Radical Prostatectomy for Cancer Control,” published in the April 2024 issue of Urology by Zhu et al.
In this study, researchers address the notable gap in high-level evidence comparing oncologic endpoints for partial gland ablation, where most existing series rely on prostate-specific antigen (PSA) rather than biopsy endpoints. The objective was to conduct a comprehensive comparison of oncologic outcomes between partial gland cryoablation (PGC) and radical prostatectomy (RP) for the management of prostate cancer.
Through a retrospective, single-center analysis, investigators examined a cohort of subjects treated with either PGC (n = 98) or RP (n = 536) as primary treatment for intermediate-risk (Gleason grade group [GG] 2–3) prostate cancer between January 2017 and December 2022. Key oncologic endpoints included surveillance biopsies per protocol after PGC and serial PSA testing after RP. The primary outcome of interest was treatment failure, which is defined as the necessity for salvage treatment or metastatic disease development. The study group conducted treatment failure and survival analyses using Cox proportional-hazard regression and Kaplan-Meier survival curves. After carefully applying inclusion/exclusion criteria, they compared the PGC (n = 75) and RP (n = 298) groups.