We report the experimental demonstration of a broadband negative refractive index obtained in a labyrinthine acoustic metamaterial structure. Two different approaches were employed to prove the metamaterial negative index nature: one-dimensional extractions of effective parameters from reflection and transmission measurements and two-dimensional prism-based measurements that convincingly show the transmission angle corresponding to negative refraction. The transmission angles observed in the latter case also agree very well with the refractive index obtained in the one-dimensional measurements and numerical simulations. We expect this labyrinthine metamaterial to become the unit cell of choice for practical acoustic metamaterial devices that require broadband and significantly negative indices of refraction.
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http://dx.doi.org/10.1103/PhysRevLett.110.175501 | DOI Listing |
Cell Biochem Biophys
January 2025
Department of Otolaryngology, Head and Neck Surgery, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430000, China.
Sensorineural hearing loss (SNHL) is an increasingly prevalent sensory disorder, but the underlying mechanisms remain poorly understood. Adaptor related protein complex 2 subunit beta 1 (AP2B1) has been indicated to be detectable in mature cochleae. Nonetheless, it is unclear whether AP2B1 is implicated in the progression of SNHL.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
School of Psychology and Public Health, La Trobe University, Melbourne, Australia.
Purpose: Prolonged exposure to broadband light with a short-wavelength (blue) or long-wavelength (orange/red) bias is known to impact eye growth and refraction, but the mechanisms underlying this response are unknown. Thus, the present study investigated the effects of broadband blue and orange lights with well-differentiated spectrums on refractive development and global flash electroretinography (gfERG) measures of retinal function in the chick myopia model.
Methods: Chicks were raised for 4 days with monocular negative lenses, or no lens, under blue, orange, or white light.
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 PDFChildren (Basel)
November 2024
Department of Applied Informatics, University of Macedonia, 54636 Thessaloniki, Greece.
Background/objectives: The way people communicate has significantly changed due to technological advances and penetration of cell phones and broadband connection into everyday activities. Nowadays, individuals are constantly connected through the Internet. This influences social experiences, self and social identity, and can cause digital stress, which often leads to negative emotions, psychosomatic outcomes, and diseases.
View Article and Find Full Text PDFmedRxiv
December 2024
Critical Illness and Sepsis Research Center (CISRC), Penn State College of Medicine, Hershey, PA 17036, USA.
Objective: To determine whether neighborhood-level social determinants of health (SDoH) influence mortality following sepsis in the United States.
Study Setting And Design: Retrospective analysis of data from 4.4 million hospitalized patients diagnosed with sepsis, identified using International Classification of Diseases-10 codes, across the United States.
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