Entries by Katy

Wavelength and pulse energy optimization for detecting hypoxia in photoacoustic imaging of the neonatal brain: a simulation study

Cerebral hypoxia is a severe injury caused by oxygen deprivation to the brain. Hypoxia in the neonatal period increases the risk for the development of neurological disorders, including hypoxic-ischemic encephalopathy, cerebral palsy, periventricular leukomalacia, and hydrocephalus. It is crucial to recognize hypoxia as soon as possible because early intervention improves outcomes. Photoacoustic imaging, using at […]

Mass Spectrometry Imaging of Arabidopsis thaliana Leaves at the Single-Cell Level by Infrared Laser Ablation Atmospheric Pressure Photoionization (LAAPPI)

In this study, we show that infrared laser ablation atmospheric pressure photoionization mass spectrometry (LAAPPI-MS) imaging with 70 μm lateral resolution allows for the analysis of Arabidopsis thaliana (A. thaliana) leaf substructures ranging from single-cell trichomes and the interveinal leaf lamina to primary, secondary, and tertiary veins. The method also showed its potential for depth profiling analysis […]

Re-study of Judd-Ofelt spectroscopic properties of Er3+-doped Gd3(Al, Ga)5O12 single crystal

A previous paper [J. Lumin. 177 (2016) 219] has studied Judd-Ofelt spectroscopic properties of Er3+ (0.5 at%)-doped Gd3(Al, Ga)5O12 garnet single-crystal, and reported the Judd-Ofelt intensity parameters Ω2 = 1.47 × 10−20 cm2, Ω4 = 1.38 × 10−20 cm2 and Ω6 = 1.19 × 10−20 cm2. We have performed a re-study on the Judd-Ofelt spectroscopic properties of a similar garnet single-crystal Er3+(20 at%)-doped Gd3(Al0.4Ga0.6)5O12, and obtained quite different values of Judd-Ofelt intensity parameters Ω2 = (0.34 ± 0.11) × 10−20 cm2, Ω4 = […]

A High Sensitivity Transparent Ultrasound Transducer Based on PMN-PT for Ultrasound and Photoacoustic Imaging

We recently introduced piezoelectric lithium niobate (LN) based transparent ultrasound transducers (TUT) as a new platform for developing multimodal optical, ultrasound, and photoacoustic imaging (PAI) systems. However, LN based TUT is limited in its signal-to-noise ratio due to material’s low piezoelectricity ( d33 ). In this letter, we report, for the first time, a 0.2-mm-thick transparent lead […]

Optically Induced Ferroelectric Polarization Switching in a Molecular Ferroelectric with Reversible Photoisomerization

Ferroelectrics usually exhibit temperature-triggered structural changes, which play crucial roles in controlling their physical properties. However, although light is very striking as a non-contact, non-destructive, and remotely controlled external stimuli, ferroelectric crystals with light-triggered structural changes are very rare, which holds promise for optical control of ferroelectric properties. Here, an organic molecular ferroelectric, N-salicylidene-2,3,4,5,6-pentafluoroaniline (SA-PFA), which […]

Photothermal nanofibres enable safe engineering of therapeutic cells

Nanoparticle-sensitized photoporation is an upcoming approach for the intracellular delivery of biologics, combining high efficiency and throughput with excellent cell viability. However, as it relies on close contact between nanoparticles and cells, its translation towards clinical applications is hampered by safety and regulatory concerns. Here we show that light-sensitive iron oxide nanoparticles embedded in biocompatible […]

Mechanisms of Upconversion Luminescence of Er3+-Doped NaYF4 via 980 and 1530 nm Excitation

To date, the mechanisms of Er3+ upconversion luminescence via 980 and 1530 nm excitation have been extensively investigated; however, based on discussions, they either suffer from the lack of convincing evidence or require elaborated and time-consuming numerical simulations. In this work, the steady-state and time-resolved upconversion luminescence data of Er3+-doped NaYF4 were measured; we therefore investigated the […]

A Versatile Light-Triggered Radical-Releasing Surface Coating Technology

Organic based redox active materials and coatings are increasingly being investigated as solutions for more efficient energy devices, catalysts, sensors, and biomedical technologies. Their advantage is negating the necessity for expensive and unsustainable rare earth metals seen in other redox active materials. Challenges to their wide-spread usage remain, including versatility of coatings on a wide […]

Coordination engineering of Cu-Zn-Sn-S aqueous precursor for efficient kesterite solar cells

Aqueous precursors provide an alluring approach for low-cost and environmentally friendly production of earth-abundant Cu2ZnSn(S, Se)4 (CZTSSe) solar cells. The key is to find an appropriate molecular agent to prepare a stable solution and optimize the coordination structure to facilitate the subsequent crystallization process. Herein, we introduce thioglycolic acid (TGA), which possesses strong coordination (SH) and […]

UV photobleaching of carbon nanodots investigated by in situ optical methods

Carbon dots are a family of optically-active nanoparticles displaying a combination of useful properties that make them attractive for many applications in photonics and photochemistry. Despite the initial claims of high photostability of carbon dots even under prolonged illuminations, several recent studies have evidenced their photobleaching (PB) under UV light, detrimental for some applications. A […]