A compact multicore ytterbium doped fiber amplifier has been implemented according to the spectral division scheme. It was shown that it allows amplification of pulses with about 40 nm wide spectrum. Compensation of the different spectral bands delay through bending and twist of the multicore ribbon fiber followed by appropriate setting of their phase permitted the synthesis of pulses close to 100 fs duration.
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http://dx.doi.org/10.1364/OE.23.027448 | DOI Listing |
Science
January 2025
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
Axions, hypothetical elementary particles that remain undetectable in nature, can arise as quasiparticles in three-dimensional crystals known as axion insulators. Previous implementations of axion insulators have largely been limited to two-dimensional systems, leaving their topological properties in three dimensions unexplored in experiment. Here, we realize an axion insulator in a three-dimensional photonic crystal and probe its topological properties.
View Article and Find Full Text PDFAnesthesiology
January 2025
Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston MA, USA.
Introduction: Accurate prognostication in comatose survivors of cardiac arrest is a challenging and high-stakes endeavor. We sought to determine whether internal EEG subparameters extracted by the Bispectral Index (BIS) monitor, a device commonly used to estimate depth-of-anesthesia intraoperatively, could be repurposed to predict recovery of consciousness after cardiac arrest.
Methods: In this retrospective cohort study, we trained a 3-layer neural network to predict recovery of consciousness to the point of command following versus not based on 48 hours of continuous EEG recordings in 315 comatose patients admitted to a single US academic medical center after cardiac arrest (Derivation cohort: N=181; Validation cohort: N=134).
Alzheimers Dement
December 2024
Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
Background: Alzheimer's disease (AD) is associated with cerebral slowing on electroencephalography (EEG), or a shift in oscillatory power from higher to lower frequencies. This change can be captured as the spectral power ratio (SPR) of alpha and beta over delta and theta: (α+β)/(δ+θ). Prior studies have shown that compared to cognitively unimpaired older adults, the SPR was lower in persons with a clinical diagnosis of dementia due to probable AD and those with a biomarker-confirmed diagnosis of amnestic mild cognitive impairment (aMCI) due to AD, and a lower SPR was associated with worse executive functions scores.
View Article and Find Full Text PDFLight Sci Appl
January 2025
Division of Computer, Electrical and Mathematical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
We propose and demonstrate a data-driven plasmonic metascreen that efficiently absorbs incident light over a wide spectral range in an ultra-thin silicon film. By embedding a double-nanoring silver array within a 20 nm ultrathin amorphous silicon (a-Si) layer, we achieve a significant enhancement of light absorption. This enhancement arises from the interaction between the resonant cavity modes and localized plasmonic modes, requiring precise tuning of plasmon resonances to match the absorption region of the silicon active layer.
View Article and Find Full Text PDFCurr Med Chem
January 2025
Department of Biochemistry, School of Medicine, Case Western Reserve University, Woods building, W437, 2109 Adelbert Road, Cleaveland, Ohio, 44106, USA.
Aims: The aim of this study is the evaluation of an Azomethine derivative, BCS2, for its antioxidant and anti-tumor activities against mammary carcinoma through the Nrf2- Keap1-HO-1 pathway.
Background: The global prevalence of breast cancer is rising at an alarming rate. The facilitation of abnormal cell proliferation in mammary carcinoma occurs due to the disruption of signaling pathways that balance pro- and antioxidant status, thereby producing oxidative stress that disrupts genomic stability.
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