We report optical double resonant enhancement of Raman scattering in a new double microcavity geometry. The design allows almost backscattering geometries, providing easy access to the excitations' in-plane dispersion. The cavity is used to study the phonon spectra of a finite GaAs/AlAs superlattice. A new type of "standing optical vibration" is demonstrated involving the GaAs confined phonons with a standing wave envelope determined by the superlattice thickness. A strong dispersion of the first order standing wave mode is observed, as well as its anticrossing with higher order confined modes of the same symmetry.
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http://dx.doi.org/10.1103/PhysRevLett.86.3411 | DOI Listing |
In this work, we investigated individual bacteria belonging to strains of the Beijing family with different drug sensitivity (sensitive, multi and extensive drug-resistant) by surface-enhanced Raman spectroscopy (SERS) in the fingerprint region. The latter is focused on the spectral bands, which correspond to a set of glutathione bands and DNA methylation patterns revealed due to 5-methylcytosine spectral biomarkers. It is shown that these spectral features can be correlated with drug sensitivity and DNA methylation.
View Article and Find Full Text PDFLangmuir
January 2025
The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, 100 Guilin RD, Shanghai 200234, China.
Ascorbyl tetraisopalmitate (VC-IP) is a novel form of ascorbic acid characterized by reduced water solubility due to complete acylation with palmitate. This study investigated the potential cosmetic application of VC-IP when encapsulated in lyotropic liquid crystal nanoparticles (VC-IP LCNPs) by using a high-pressure homogenization (HPH) method. The particle size, zeta potential, and polydispersity index (PDI) of the obtained VC-IP LCNPs were determined as 158.
View Article and Find Full Text PDFNanotoxicology
January 2025
Infection, Inflammation and Repair, Faculty of Medicine, University of Southampton, Southampton, UK.
The role of surfactant proteins A and D (SP-A and SP-D) in lung clearance and translocation to secondary organs of inhaled nanoparticles was investigated by exposing SP-A and SP-D knockout (AKO and DKO) and wild type (WT) mice nose-only for 3 hours to an aerosol of 20 nm gold nanoparticles (AuNPs). Animals were euthanised at 0-, 1-, 7- and 28-days post-exposure. Analysis by inductively coupled plasma mass spectrometry (ICP-MS) of the liver and kidneys showed that extrapulmonary translocation was below the limits of detection.
View Article and Find Full Text PDFFlow Turbul Combust
November 2024
Institut de Mécanique des Fluides de Toulouse, IMFT, CNRS, Université de Toulouse, Toulouse, France.
Improving mixing between two coaxial swirled jets is a subject of interest for the development of next generations of fuel injectors. This is particularly crucial for hydrogen injectors, where the separate introduction of fuel and oxidizer is preferred to mitigate the risk of flashback. Raman scattering is used to measure the mean compositions and to examine how mixing between fuel and air streams evolves along the axial direction in the near-field of the injector outlet.
View Article and Find Full Text PDFFood Chem X
January 2025
State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
Here, we report a SERS based VFA using PNC as a sensing substrate for highly sensitive multiplex mycotoxins detection. The PNC was fabricated by filtration-based self-assembled monodisperse SiO NPs on a filter membrane as a template, and the obtained PNC had an ordered complementary inverse opal structure. In parallel, three kinds of Raman dyes encoding Au@Ag, Au@Ag and Au@Ag SERS nanotags were synthesized for the detection of OTA, AFB1 and ZON.
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