We report on the resonant emission in coherently driven single semiconductor quantum dots. We demonstrate that an ultraweak nonresonant laser acts as an optical gate for the quantum dot resonant response. We show that the gate laser suppresses Coulomb blockade at the origin of a resonant emission quenching, and that the optically gated quantum dots systematically behave as ideal two-level systems in both regimes of coherent and incoherent resonant emission.
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http://dx.doi.org/10.1103/PhysRevLett.108.057401 | DOI Listing |
Alzheimers Dement
January 2025
Penn Memory Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Introduction: The generalizability of neuroimaging and cognitive biomarkers in their sensitivity to detect preclinical Alzheimer's disease (AD) and power to predict progression in large, multisite cohorts remains unclear.
Method: Longitudinal demographics, T1-weighted magnetic resonance imaging (MRI), and cognitive scores of 3036 cognitively unimpaired (CU) older adults (amyloid beta [Aβ]-negative/positive [A-/A+]: 1270/1558) were included. Cross-sectional and longitudinal cognition and medial temporal lobe (MTL) structural measures were extracted.
ACS Phys Chem Au
January 2025
Department of Medical Applied Chemistry, Chung Shan Medical University, Taichung 402, Taiwan.
Novel coumarin-triphenyliminophosphorane (TPIPP) fluorophores, synthesized via a nonhydrolytic Staudinger reaction, exhibit remarkable redox-responsive optical properties. Upon chemical and electrochemical oxidation, these compounds display a hypsochromic shift in absorption from 430 to 350 nm, accompanied by up to 11-fold fluorescence enhancement under 405 nm excitation. The fluorescence switching occurs at an electrochemical oxidation potential of approximately +2.
View Article and Find Full Text PDFJCEM Case Rep
February 2025
First Department of Internal Medicine, Wakayama Medical University, Wakayama City, Wakayama 641-8509, Japan.
Tumor-induced osteomalacia is characterized by hypophosphatemia and fragility fractures caused by fibroblast growth factor 23 (FGF23)-producing tumors. We report a case of tumor-induced osteomalacia in which the tumor location could be determined by gallium 68 (Ga)-DOTATOC positron emission tomography (PET)/computed tomography (CT). A 74-year-old woman had recurrent fractures and bone pain.
View Article and Find Full Text PDFNanoscale
January 2025
Nanomaterials for BioImaging Group (nanoBIG), Departamento de Física de Materiales, Universidad Autónoma de Madrid (UAM), Madrid 28049, Spain.
All-optical theranostic systems are sought after in nanomedicine, since they combine in a single platform therapeutic and diagnostic capabilities. Commonly in these systems the therapeutic and diagnostic/imaging functions are accomplished with plasmonic photothermal agents and luminescent nanoparticles (NPs), respectively. For maximized performance and minimized side effects, these two modalities should be independently activated, , in a decoupled way, using distinct near infrared (NIR) wavelengths: a radiation window wherein photon-tissue interaction is reduced.
View Article and Find Full Text PDFNanoscale
January 2025
State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China.
Hyperbolic metamaterials (HMMs) have recently attracted significant research attention due to their hyperbolic wavevector iso-frequency contour, which leads to substantial local electric field (EF) enhancements that benefit optical processes, such as the nonlinear generation, quantum science, biomedical sensing, and more. However, three main challenges hinder their practical implementation: the difficulty in exciting their resonant modes using free-space incidence, the weak enhancement of surface EF, and the narrow spectral range of EF enhancements. Herein, we proposed cross-etched HMMs (CeHMMs) as a novel type of HMM, addressing these issues.
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