arXiv subjects

Irina Kabakova

Publications and source records attributed to Irina Kabakova.

4 recordsLinked to original sources

arXiv2024

Consensus Statement on Brillouin Light Scattering Microscopy of Biological Materials

Brillouin Light Scattering (BLS) spectroscopy is a non-invasive, non-contact, label-free optical technique that can provide information on the mechanical properties of a material on the sub-micron scale. Over the last decade it has seen increased applications in the life sciences, driven by the observed significance of mechanical properties in biological processes, the realization of more sensitive BLS spectrometers and its extension to an imaging modality. As with other spectroscopic techniques, BLS measurements not only detect signals characteristic of the investigated sample, but also of the experimental apparatus, and can be significantly affected by measurement conditions. The aim of this consensus statement is to improve the comparability of BLS studies by providing reporting recommendations for the measured parameters and detailing common artifacts. Given that most BLS studies of biological matter are still at proof-of-concept stages and use different--often self-built--spectrometers, a consensus statement is particularly timely to assure unified advancement.

physics.optics↗

arXiv2024

Dynamic Nanodomains Dictate Macroscopic Properties in Lead Halide Perovskites

Empirical A-site cation substitution has advanced the stability and efficiency of hybrid organic-inorganic lead halide perovskites solar cells and the functionality of X-ray detectors. Yet, the fundamental mechanisms underpinning their unique performance remain elusive. This multi-modal study unveils the link between nanoscale structural dynamics and macroscopic optoelectronic properties in these materials by utilising X-ray diffuse scattering, inelastic neutron spectroscopy and optical microscopy complemented by state-of-the-art machine learning-assisted molecular dynamics simulations. Our approach uncovers the presence of dynamic, lower-symmetry local nanodomains embedded within the higher-symmetry average phase in various perovskite compositions. The properties of these nanodomains are tunable via the A-site cation selection: methylammonium induces a high density of anisotropic, planar nanodomains of out-of-phase octahedral tilts, while formamidinium favours sparsely distributed isotropic, spherical nanodomains with in-phase tilting, even when crystallography reveals cubic symmetry on average. The observed variations in the properties of dynamic nanodomains are in agreement with our simulations and are directly linked to the differing macroscopic optoelectronic and ferroelastic behaviours of these compositions. By demonstrating the influence of A-site cation on local nanodomains and consequently, on macroscopic properties, we propose leveraging this relationship to engineer the optoelectronic response of these materials, propelling further advancements in perovskite-based photovoltaics, optoelectronics, and X-ray imaging.

cond-mat.mtrl-sci↗

arXiv2020

Brillouin imaging for studies of micromechanics in biology and biomedicine: from current state-of-the-art to future clinical translation

Brillouin imaging is increasingly recognized to be a powerful technique that enables non-invasive measurement of the mechanical properties of cells and tissues on a microscopic scale. This provides an unprecedented tool for investigating cell mechanobiology, cell-matrix interactions, tissue biomechanics in healthy and disease conditions and other fundamental biological questions. Recent advances in optical hardware have particularly accelerated the development of the technique, with increasingly finer spectral resolution and more powerful system capabilities. We envision that further developments will enable translation of Brillouin imaging to assess clinical specimens and samples for disease screening and monitoring. The purpose of this review is to summarize the state-of-the-art in Brillouin microscopy and imaging with a specific focus on biological tissue and cell measurements. Key system and operational requirements will be discussed to facilitate wider application of Brillouin imaging along with current challenges for translation of the technology for clinical and medical applications.

physics.bio-ph↗

arXiv2018

Brillouin microscopy, what is it really measuring?

Brillouin microscopy measures compressibility, but is being increasingly used to assess stiffness of cells and tissues. Using hydrogels with tunable properties, we demonstrate that Brillouin microscopy is insensitive to stiffness of hydrated materials, but depends strongly on water content, consistent with a theoretical model of biphasic compressibility. Empirical correlations between Brillouin measurements and stiffness arise due to their mutual dependence on water content, but correlations vanish once hydration is controlled.

q-bio.QM↗