Publications by authors named "W Thielemans"
Microplastic pollution in aquatic environments is a growing global concern. Microplastics, defined as plastic fragments smaller than five millimetres, accumulate in freshwater reservoirs, especially in urban areas, impacting resident biota. This study examined the effects of microplastics on the performance and microbiome of Daphnia, a keystone organism in freshwater ecosystems, through both in situ sampling of freshwater ponds and a controlled 23-day in vitro exposure experiment.
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- - Cellulose nanocrystals (CNCs) have notable optical properties, but their nonlinear optical behavior, specifically the second-order response, was mostly unexplored until this study.
- - Through Hyper-Rayleigh scattering experiments, researchers found CNCs exhibit a strong second-order nonlinear optical response, comparable to known biomaterials and inorganic materials, due to the orderly arrangement of cellulose chains.
- - The study utilized quantum chemical modeling to predict CNCs' molecular hyperpolarizability and created an electrostatic model to align theoretical predictions with experimental results, highlighting CNCs' potential for optoelectronic applications and two-photon microscopy.
Article Synopsis
- * The study reveals that the antimicrobial activity of GA is enhanced as the pH decreases, with fully protonated GA (at pH = 3) being effective against certain bacteria, while other strains are inhibited at higher pH levels.
- * Results show that the increased antimicrobial activity of GA hydrogels is due to GA's release into the suspension, interacting directly with bacteria, and the variations in activity are linked to the protonation state of GA rather than just
Cellulose nanocrystals (CNCs) are bio-based nanoparticles that, under the right conditions, self-align into chiral nematic liquid crystals with a helical pitch. In this work, we exploit the inherent confocal effect of second-harmonic generation (SHG) microscopy to acquire highly resolved three-dimensional (3D) images of the chiral nematic phase of CNCs in a label-free manner. An in-depth analysis revealed a direct link between the observed variations in SHG intensity and the pitch.
View Article and Find Full Text PDFOptically Active, Paper-Based Scaffolds for 3D Cardiac Pacing.
ACS Appl Mater Interfaces
October 2024
In this work, we report the design and fabrication of a light-addressable, paper-based nanocomposite scaffold for optical pacing and read-out of in vitro grown cardiac tissue. The scaffold consists of paper cellulose microfibers functionalized with gold nanorods (GNRs) and semiconductor quantum dots (QDs), embedded in a cell-permissive collagen matrix. The GNRs enable cardiomyocyte activity modulation through local temperature gradients induced by modulated near-infrared (NIR) laser illumination, with the local temperature changes reported by temperature-dependent QD photoluminescence (PL).
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