This article proposes a new method for detecting slight refractive index changes under conditions of unknown polarization state. It is argued that an insignificant modification of the tilted fiber Bragg grating (TFBG) structure and selecting the appropriate spectral region allows us to accurately track changes in the refractive index. It has also been proven that the method can be easily made insensitive to temperature and that the sensitivity to changes in the polarization plane of the input light can be significantly reduced, which is crucial in later practical applications. Analytes in the form of an aqueous glucose solution were used to calibrate the sensor. The proposed method, based on perpendicular tilted fiber Bragg grating (P-TFBG), has a wide range of universality because its development and slight modification will enable the detection of glucose, pathogens, and viruses.
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http://dx.doi.org/10.3390/s21217318 | DOI Listing |
Sci Rep
January 2025
Department of Ophthalmology, Faculty of Medicine, University of Debrecen, Nagyerdei blvd. 98, Debrecen, 4012, Hungary.
This prospective cohort study is aimed to investigate circadian variations in corneal parameters, focusing on sleep-deprived subjects. Sixty-four healthy individuals (age range: 21-76 years) actively participated in this study, undergoing examinations at least five times within a 24-hour timeframe. The analysis encompassed keratometric parameters of the cornea's front (F) and back (B) surfaces, refractive power in flattest and steepest axes (K1, K2), astigmatism (Astig) and its axis (Axis), aspheric coefficient (Asph), corneal pachymetry values of thinnest corneal thickness (Pachy Min) and corneal thickness in the center of the pupil (Pachy Pupil), volume relative to the 3 and 10 mm corneal diagonal (Vol D3, Vol D10) and surface variance index (ISV).
View Article and Find Full Text PDFCont Lens Anterior Eye
January 2025
Laboratory of Optometry and Vision Sciences, West China School of Medicine, Sichuan University, Chengdu, China; Department of Optometry and Vision Sciences, West China School of Medicine, Sichuan University, Chengdu, China.
Objective: To investigate changes in corneal astigmatism (curvatures and corneal sagittal height difference (C-sagDiff) at 8-mm chord) after temporary discontinuation from long-term spherical and toric orthokeratology (ortho-k) lens wear in a Chinese population.
Methods: Relevant data were retrieved from 110 patients (55 wearing spherical ortho-k lenses, 55 wearing toric ortho-k lenses) who have been undergoing ortho-k treatment for at least one year and stopped lens wear temporarily for scheduled lens replacement. The topographic and refraction data at baseline and post-discontinuation was collected for all the patients.
Eur J Ophthalmol
January 2025
Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples "Federico II", Naples, Italy.
Introduction: Severe visual deprivation during infancy can lead to long-term changes in ocular development, including significant differences in axial length (AL) between eyes. This case report presents three adult patients with monocular infantile visual deprivation who developed substantial AL interocular differences. The aim is to explore the impact of early visual deprivation on AL and its potential implications for myopia progression.
View Article and Find Full Text PDFInt J Pharm
December 2024
Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK. Electronic address:
Pharmaceutical tablets are routinely film-coated to improve appearance, reduce medication errors and enhance storage stability. Terahertz pulsed imaging (TPI) can be utilised to study the liquid penetration into the porous tablet matrix in real time. Using polymer-coated flat-faced tablets with anhydrous lactose or mannitol, we show that when the tablet matrix contains anhydrous material, the anhydrous form transforms to the solid-state hydrate form in the tablet core while the immediate release coating dissolves.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China.
Purpose: To investigate the 10-year changes in visual function and incidence of visual impairment (VI) in highly myopic eyes.
Methods: This longitudinal study enrolled highly myopic individuals who were followed up for 10 years. All participants underwent detailed ophthalmic examinations at baseline and follow-up visits.
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