Aris Jansons

Two-dimensional (2D) layered materials, particularly transition metal dichalcogenides, exhibit unique electronic and optical properties. Among these, tungsten ditelluride (WTe2) has garnered attention for its semi-metallic behavior and topologically nontrivial band structure, making it a promising candidate for advanced nanoelectronic applications. A significant challenge, however, lies in achieving scalable characterization, determining thickness and coverage of WTe2 structures. Existing methods are often limited by time constraints and lack suitability for high-throughput workflows. This study introduces a refined workflow combining optical imaging, segmentation, and contrast analysis to address these limitations. Calculated values of normalized optical contrast were correlated with thicknesses determined by atomic force microscopy and were found to scale linearly. The proposed workflow provides a scalable, adaptable solution for 2D material characterization.

This study aimed to evaluate the hepatoprotective effects of nettle (Urtica dioica L.) leaf water extracts on oxygen consumption in the fatty acid oxidation (FAO) pathway using an in vitro fatty liver HepG2 cell model and employing an oxygraphy approach. It also examined the impact of these extracts on HepG2 cell lipid accumulation and viability under oxidative stress. The extracts were obtained via maceration with preservatives or by sonication with/without preservatives. Their chemical composition, including polyphenols, vitamins, and minerals, was analyzed. Bioactivity was confirmed through antioxidant and antiglycation in vitro assays. The extracts contained minerals, water-soluble vitamins, and polyphenols, primarily phenolic acids and rutin. Sonication increased the polyphenol yield, advanced glycation end-product (AGE) inhibition, and total antioxidant capacity compared to maceration. The added preservatives enhanced DPPH scavenging, while SOD-mimicking effects were comparable across extraction methods. In the liver steatosis model, the nettle extracts improved HepG2 cell viability under oxidative stress, reduced lipid accumulation, and enhanced mitochondrial oxygen consumption in the FAO pathway at mitochondria complex I. These findings demonstrate the impact of nettle leaf water extracts on oxygen flux in different oxidative phosphorylation states of the FAO pathway and deepen the understanding of nettle’s protective role in hepatic steatosis. The obtained results confirm the hepatoprotective effects of nettles through multiple mechanisms, primarily involving antioxidant activity, modulation of lipid accumulation, and mitochondrial protection.