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The world’s first room-temperature continuous-wave UV-B laser diode on a sapphire substrate

Ultraviolet-B (UV-B) semiconductor lasers are highly sought for medical, biotechnology, and precision manufacturing applications; however, previous UV-B laser diodes were limited to pulsed operation or required cryogenic cooling, making continuous room-temperature operation unattainable.

Researchers in Japan report the world’s first continuous-wave UV-B semiconductor laser diode operating at room temperature on a low-cost sapphire substrate.

This breakthrough advances compact, energy-efficient UV light sources, potentially replacing bulky gas-based lasers in health care, industrial, and scientific research applications worldwide.

Building the world’s first open-source quantum computer

Researchers from the University of Waterloo’s Faculty of Science and the Institute for Quantum Computing (IQC) are prioritizing collaboration over competition to advance quantum computer development and the field of quantum information. They are doing this through Open Quantum Design (OQD), a non-profit organization that boasts the world’s first open-source, full stack quantum computer.

OQD was co-founded in 2024 by faculty members in the Department of Physics and Astronomy and IQC, Drs. Crystal Senko, Rajibul Islam and Roger Melko, alongside CEO Greg Dick (BSc ‘93).

The group is helping reshape how quantum research is shared, opening doors for the next generation of quantum scientists, and even seeding new quantum startups.

Ultrafast spectroscopy reveals step-by-step energy flow in germanium semiconductors

Whether in a smartphone or laptop, semiconductors form the basis of modern electronics and accompany us constantly in everyday life. The processes taking place inside these materials are the subject of ongoing research. When the electrons in a semiconductor material are activated using light or an electrical voltage, the excited electrons also set the atomic lattice in motion. This results in collective vibrations of the atoms, known as phonons or lattice vibrations, which interact with each other and with the electrons themselves.

These tiny lattice vibrations play a vital role in how energy flows and dissipates through the material—in other words, in how efficiently the energy is redistributed and how strongly the material heats up. Different approaches can be used to control and monitor the propagation of lattice vibrations—and therefore to make the semiconductor more effective and more efficient.

Detailed knowledge of the mechanisms of energy loss and potential overheating is essential in order to design new materials and devices that heat up less, recover faster or respond to external excitation more precisely. A team led by Professor Ilaria Zardo from the University of Basel reports on the unprecedented accuracy they achieved in measurements of energy flow processes within the semiconductor germanium, which is frequently used in computer technology. Their paper is published in Advanced Science.

Stealth quantum sensors unlock possibilities anywhere GPS doesn’t work

As commercial interest in quantum technologies accelerates, entrepreneurial minds at the University of Waterloo are not waiting for opportunities—they are creating them.

Among them is Alex Maierean (MMath ‘24), CEO of Phantom Photonics and part-time Ph.D. student at the Institute for Quantum Computing (IQC). Her startup is developing ultra-sensitive quantum sensors that can filter out background noise and detect the faintest signals, even down to a single photon—the smallest unit of light. This offers new levels of precision and stealth for industries operating in extreme environments, from the depths of the ocean to outer space.

Launched in 2023, the Velocity startup emerged from fundamental research at an IQC lab led by Dr. Thomas Jennewein, IQC affiliate and adjunct faculty in the Department of Physics and Astronomy. Today, the startup is based at Velocity where it has established a dedicated lab space to continue to develop its quantum sensor technology and build its core team.

Bioinspired phototransistor achieves high-sensitivity detection of low-contrast targets

Drawing inspiration from the remarkable adaptability of the human eye, researchers from the Institute of Metal Research (IMR) of the Chinese Academy of Sciences have developed a novel phototransistor with tunable sensitivity.

This breakthrough provides an efficient solution for detecting low-contrast targets in complex visual environments, which is a critical challenge for advanced machine vision systems in applications such as precision guidance and smart surveillance.

The results are published in Light: Science & Applications.

Scientists Say a Major Quantum Computing Breakthrough Was Not What It Seemed

Replication is a cornerstone of science, yet even in the natural sciences, attempts to reproduce results do not always succeed. Quantum computing promises machines that can solve certain problems far beyond today’s computers, but it faces a stubborn obstacle: quantum information is extremely frag

Systematic identification of single transcription factor perturbations that drive cellular and tissue rejuvenation

Significance.

Cellular rejuvenation through transcriptional reprogramming has emerged as exciting approach to counter aging. However, to date, only a few of rejuvenating transcription factor (TF) perturbations have been identified. In this work, we developed a discovery platform to systematically identify single TF perturbations that drive cellular and tissue rejuvenation. Using a classical model of human fibroblast aging, we identified more than a dozen candidate TF perturbations and validated four of them (E2F3, EZH2, STAT3, ZFX) through cellular/molecular phenotyping. At the tissue level, we demonstrate that overexpression of EZH2 alone is sufficient to rejuvenate the liver in aged mice, significantly reducing fibrosis and steatosis, and improving glucose tolerance. Our work expanded the list of candidate rejuvenating TFs for future translation. Abstract.

Cellular rejuvenation through transcriptional reprogramming is an exciting approach to counter aging. Using a fibroblast-based model of human cell aging and Perturb-seq screening, we developed a systematic approach to identify single transcription factor (TF) perturbations that promote rejuvenation without dedifferentiation. Overexpressing E2F3 or EZH2, and repressing STAT3 or ZFX, reversed cellular hallmarks of aging—increasing proliferation, proteostasis, and mitochondrial activity, while decreasing senescence. EZH2 overexpression in vivo rejuvenated livers in aged mice, reversing aging-associated gene expression profiles, decreasing steatosis and fibrosis, and improving glucose tolerance. Mechanistically, single TF perturbations led to convergent downstream transcriptional programs conserved in different aging and rejuvenation models. These results suggest a shared set of molecular requirements for cellular and tissue rejuvenation across species. Sign up for PNAS alerts.

Get alerts for new articles, or get an alert when an article is cited. Cellular rejuvenation through transcriptional reprogramming is an exciting approach to counter aging and bring cells back to a healthy state. In both cell and animal aging models, there has been significant recent progress in rejuvenation research. Systemic factors identified in young blood through models such as heterochronic parabiosis (in which the circulatory systems of a young and aged animal are joined) rejuvenate various peripheral tissues and cognitive function in the brain (1–4). Partial reprogramming at the cellular level with the Yamanaka factors (four stem cell transcription factors) reverses cellular and tissue-level aging markers and can extend lifespan in old mice (5–8). These discoveries support the notion that transcriptional reprogramming is a powerful approach to improving the health of cells and tissues, and one day could be used as an approach for human therapeutics. However, to date, only a couple of rejuvenating transcription factor (TF) perturbations have been identified (9, 10) and most of them require the overexpression of TFs. We hypothesized that there are multiple other TF perturbations which could reset cells and tissues back to a healthier or younger state—rejuvenating them. Identifying complementary rejuvenating strategies is important as it will increase the chance of successful future translation. We developed a high-throughput platform, the Transcriptional Rejuvenation Discovery Platform (TRDP), which combines computational analysis of TF binding motifs and target predictions (Materials and Methods), global gene expression data of old and young cell states, and experimental genetic perturbations to identify which TF can restore overall gene expression and cell phenotypes to a younger, healthier state. We developed TRDP to be applicable to any cell type, and in both aging and disease settings, with the only requirements being baseline comparison of gene expression data comparing the older/diseased state to the younger/healthier state and the ability to perform genetic perturbations. To model aging in vitro as a validation of our approach, we used the canonical aging model of passaged fibroblasts (11, 12). We tested 400 TF perturbations via our screen and validated reversal of key cellular aging hallmarks in late passage human fibroblasts for four top TFs: E2F3, EZH2, STAT3, and ZFX. Moreover, EZH2 overexpression in vivo rejuvenated livers in aged mice—reversing aging-associated global gene expression profiles, significantly reducing steatosis and fibrosis, and improving glucose tolerance. These findings point to a conserved set of molecular requirements for cellular and tissue rejuvenation.

Soft organic electrochemical neurons operating at biological speed

Organic electrochemical neurons respond to brain signals in real time, firing at biologically relevant speeds. Their flexibility and low power use could enable soft, implantable systems for closed-loop neuromodulation and future brain–computer interfaces.

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