In this paper, we present the OPUS (optoacoustic plus ultrasound) system, which is a combination of a wavelength-tunable pulsed optical parametrical oscillator (OPO) laser with a commercial ultrasound (US) scanner. Optoacoustic (OA) or, synonymously, photoacoustic (PA) imaging is a spectroscopic technique to measure optical absorption in semitransparent solids and liquids. The measured signal is an acoustical pressure wave, which represents the absorption of pulsed optical radiation. By temporally and spatially resolved detection of the pressure wave on the sample surface, a 2D or even 3D image of the distribution of the optical absorption in the sample can be generated. In recent years, OA tomography has found increasing application in medical imaging. Most of these applications are based on qualitative OA imaging. The reported system is intended primarily for breast cancer detection, in which the optoacoustic imaging modality offers additional information to the ultrasound image. Consequently, the system is developed in a way that the OA imaging mode can be installed without major changes to the US instrument. The capabilities of the OPUS system for the quantitative analysis of absorber concentrations in tissue models are exploited.
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http://dx.doi.org/10.1007/s00216-010-3685-9 | DOI Listing |
Sci Adv
January 2025
Department of Electrical and Computer Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
Electrical stimulation of existing three-dimensional bioprinted tissues to alter tissue activities is typically associated with wired delivery, invasive electrode placement, and potential cell damage, minimizing its efficacy in cardiac modulation. Here, we report an optoelectronically active scaffold based on printed gelatin methacryloyl embedded with micro-solar cells, seeded with cardiomyocytes to form light-stimulable tissues. This enables untethered, noninvasive, and damage-free optoelectronic stimulation-induced modulation of cardiac beating behaviors without needing wires or genetic modifications to the tissue solely with light.
View Article and Find Full Text PDFTransl Vis Sci Technol
January 2025
College of Optometry, University of Houston, Houston, TX, USA.
Purpose: To characterize frequency-dependent wave speed dispersion in the human cornea using microliter air-pulse optical coherence elastography (OCE), and to evaluate the applicability of Lamb wave theory for determining corneal elastic modulus using high-frequency symmetric (S0) and anti-symmetric (A0) guided waves in cornea.
Methods: Wave speed dispersion analysis for transient (0.5 ms) microliter air-pulse stimulation was performed in four rabbit eyes ex vivo and compared to air-coupled ultrasound excitation.
Nanomaterials (Basel)
January 2025
Key Laboratory of Organic Integrated Circuit, Tianjin Key Laboratory of Molecular Optoelectronic Sciences & Ministry of Education, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China.
The exploitation of high-performance third-order nonlinear optical (NLO) materials that have a favorable optical limit (OL) threshold is essential due to a rise in the application of ultra-intense lasers. In this study, a Cu-based MOF (denoted as Cu-bpy) was synthesized, and its third-order NLO and OL properties were investigated using the Z-scan technique with the nanosecond laser pulse excitation set at 532 nm. The Cu-bpy exhibits a typical rate of reverse saturable absorption (RSA) with a third-order nonlinear absorption coefficient of 100 cm GW and a favorable OL threshold of 0.
View Article and Find Full Text PDFLight Sci Appl
January 2025
Wuhan National Laboratory for Optoelectronics, Next Generation Internet Access National Engineering Laboratory, and Hubei Optics Valley Laboratory, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China.
We propose and validate a novel optical semantic transmission scheme using multimode fiber (MMF). By leveraging the frequency sensitivity of intermodal dispersion in MMFs, we achieve high-dimensional semantic encoding and decoding in the frequency domain. Our system maps symbols to 128 distinct frequencies spaced at 600 kHz intervals, demonstrating a seven-fold increase in capacity compared to conventional communication encoding.
View Article and Find Full Text PDFScience
January 2025
Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
Chirality, a pervasive form of symmetry, is intimately connected to the physical properties of solids, as well as the chemical and biological activity of molecular systems. However, inducing chirality in a nonchiral material is challenging because this requires that all mirrors and all roto-inversions be simultaneously broken. Here, we show that chirality of either handedness can be induced in the nonchiral piezoelectric material boron phosphate (BPO) by irradiation with terahertz pulses.
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