High harmonic generation in solids presents the possibility for bringing attosecond techniques to semiconductors and a simple source for frequency comb spectroscopy in the vacuum ultraviolet. We generate up to the seventh harmonic of a Tm fiber laser by focusing in silicon or zinc oxide. The harmonics are strong and stable, with no indication of material damage. Calculations show the potential for generating nineteenth harmonic photons at 12 eV photons of energy.
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http://dx.doi.org/10.1364/OL.42.001113 | DOI Listing |
ACS Mater Au
January 2025
Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
Gas bubbles, commonly used in medical ultrasound (US), witness advancements with nanobubbles (NB), providing improved capabilities over microbubbles (MB). NBs offer enhanced penetration into capillaries and the ability to extravasate into tumors following systemic injection, alongside prolonged circulation and persistent acoustic contrast. Low-frequency insonation (<1 MHz) with NBs holds great potential in inducing significant bioeffects, making the monitoring of their acoustic response critical to achieving therapeutic goals.
View Article and Find Full Text PDFSci Rep
January 2025
Preparatory Institute for Engineering Studies of Kairouan, (I.P.E.I.K) University of Kairouan, Kairouan, Tunisia.
We present a comprehensive analysis of the optical attributes of graphene sheets with charge carriers residing on a curved substrate. In particular, we focus on the fascinating case of Beltrami geometry and provide an explicit parametrization for this curved two-dimensional surface. By employing the massless Dirac description that is characteristic of graphene, we investigate the impact of the curved geometry on the optical properties within the sample.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
December 2024
Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, 2, Dublin, Ireland; Discipline of Mechanical, Manufacturing, and Biomedical Engineering, School of Engineering, Trinity College Dublin, 2, Dublin, Ireland; Advanced Materials and Bioengineering Research Centre (AMBER), Trinity College Dublin, Ireland. Electronic address:
Aortic stenosis is a prevalent disease that is treated with either mechanical or bioprosthetic valve replacement devices. However, these implants can experience problems with either functionality in the case of mechanical valves or long-term durability in the case of bioprosthetic valves. To enhance next generation prosthetic valves, such as biomimetic polymeric valves, an improved understanding of the native aortic valve leaflet structure and mechanical response is required to provide much needed benchmarks for future device development.
View Article and Find Full Text PDFUltrasonics
January 2025
College of Aerospace Engineering, Chongqing University, Chongqing 400044, China. Electronic address:
This study delves into the feasibility of leveraging quasi-static component (QSC) generation during primary Lamb wave propagation to discern subtle alterations in the interfacial properties of a two-layered plate. Unlike the second-harmonic generation of Lamb waves, QSC generation doesn't necessitate precise phase-velocity matching but rather requires an approximate matching of group velocities to ensure the emergence of cumulative growth effects. This unique characteristic empowers the QSC-based nonlinear ultrasonic method to effectively surmount the limitations associated with inherent dispersion and multimode traits of Lamb wave propagation.
View Article and Find Full Text PDFEnviron Toxicol Chem
January 2025
School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, PR China.
In silico methods are increasingly important in predicting the ecotoxicity of engineered nanomaterials (ENMs), encompassing both individual and mixture toxicity predictions. It is widely recognized that ENMs trigger oxidative stress effects by generating intracellular reactive oxygen species (ROS), serving as a key mechanism in their cytotoxicity studies. However, existing in silico methods still face significant challenges in predicting the oxidative stress effects induced by ENMs.
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