A new series of trans-alkenes (3a-3e) containing different electron-donating groups were synthesized by the solvent-free Horner-Wadsworth-Emmons reaction, and characterized by infrared, hydrogen nuclear magnetic resonance, mass spectrometry and elemental analysis. Their UV-visible absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence were systematically investigated in different solvents. Experimental results show different trends in linear and nonlinear optical properties with different donor units. 3a with triphenylamine donor exhibits the best optical properties. It emits strong blue up-converted fluorescence, and the two-photon absorption cross-section can be as large as 218 GM in DCM.
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http://dx.doi.org/10.1016/j.saa.2015.10.034 | DOI Listing |
Chem Biomed Imaging
December 2024
College of Chemistry and Materials Science, Jinan University, Guangzhou, Guangdong 510632, China.
The large-scale preparation of fluorescent nanomaterials with laboratory-relevant chemical and optical properties will greatly forward their consumer market applications; however, it still remains challenging. In this work, a universal strategy was developed for the rapid and large-scale synthesis of fluorescent sulfur quantum dots that recently has drawn great attention because of their unique optical characteristics. From the fact that empty 3d orbitals of sulfide species are able to bind with lone-pair π electrons of the heteroatomic groups, many amino-group containing compounds, such as amino acid and polyethylenimine molecules, were exploited to synthesize sulfur quantum dots.
View Article and Find Full Text PDFBackground: The ciliary muscle is known to play a part in presbyopia, but the mechanism has not received a comprehensive review, which this study aims to achieve. We examined relevant articles published from 1975 through 2022 that explored various properties of the muscle and related tissues in humans and rhesus monkeys. These properties include geometry, elasticity, rigidity, and composition, and were studied using a range of imaging technologies, computer models, and surgical methods.
View Article and Find Full Text PDFACS Cent Sci
December 2024
Research Center for Crystal Materials, State Key Laboratory of Functional Materials and Devices for Special Environmental Conditions, Xinjiang Key Laboratory of Functional Crystal Materials, Xinjiang Technical Institute of Physics and Chemistry, CAS, 40-1 South Beijing Road, Urumqi 830011, China.
For non-π-conjugated [SO] units, it is challenging to generate sufficient birefringence, owing to the high symmetry of the regular tetrahedron. Unlike the traditional trial-and-error approach, we propose a new paradigm for birefringence engineering to tune the optical properties based on [SO] units. Through the strategy of ligand substitution, we can predict its effect on the band gap and anisotropy.
View Article and Find Full Text PDFCureus
November 2024
Department of Plastic Surgery, University Hospital of Heraklion, Heraklion, GRC.
The Greco-Roman physician Galen of Pergamon was the first to mention a drug named Paccianon. This drug was unknown in ancient Greece and most probably through the School of Alexandria entered medical literature. Oribasius and Aetius were the only two practitioners who mentioned it after Galen, administrating it in various forms, such as poultice, mixture, and collyrium, for a series of ophthalmic diseases and cutaneous lesions.
View Article and Find Full Text PDFDent Mater
December 2024
Graduate Program in Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Rua Ramiro Barcelos, Porto Alegre 2492, Brazil; Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Rua Ramiro Barcelos, Porto Alegre 2492, Brazil. Electronic address:
Objectives: To evaluate the self-etch bonding potential of universal adhesive systems with varying acidic compositions by analyzing the wettability properties, topographical change, and microshear bond strength (µSBS) to enamel.
Methods: Eight universal adhesives were tested: All-Bond Universal (Bisco), Ambar Universal (FGM), Gluma Bond Universal (Kulzer), OptiBond Universal (Kerr), Peak Universal Bond (Ultradent), Prime&Bond Universal (Dentsply), Singlebond Universal (3 M ESPE), and Tetric N-Bond Universal (Ivoclar). Bovine incisors were prepared and treated with each adhesive according to the manufacturer's instructions.
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