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Electrical impedance spectroscopy is promising for intraoperative cancer diagnosis by differentiating tissue based on its electrical properties, yet faces challenges from material nonlinearities and sensor effects. In this study, 3D finite element simulations were performed to analyze geometric dependencies. Two different tetrapolar ring electrode layouts are placed on virtual piece of normal and tumor tissue with each radius varied using Monte Carlo simulations and the resulting impedances and cell constants were evaluated statistically. Additionally, a novel sensitivity quality metric is introduced, enabling the identification of the geometry more suitable for impedance measurements. The results highlight the superior sensitivity quality of the improved geometry. Future research should integrate the geometric Monte Carlo approach with variations of dielectric properties of tissue and optimizing the quality metric taking electrode polarization effects into considerations.

Lake Balaton is the largest European shallow lake, which underwent cultural eutrophication in the '70-80s. Therefore, strict pollution control measures were introduced and the water quality has become meso-eutrophic since the millennium. Due to the touristic significance and change in trophic levels of the lake, numerous ecological studies were carried out, but none of them was focused on both benthic and planktonic microbial communities at the same time. In our study, an attempt was made to reveal the spatial bacterial heterogeneity of the Lake Balaton and Zala River by 16S rDNA terminal restriction fragment length polymorphism fingerprinting and Illumina amplicon sequencing methods in the summer of 2017. According to the molecular biology results, mostly well-known freshwater microorganisms, adapted to nutrient-poor conditions were found in the pelagic water column. The LD12 subclade member Fonsibacter ubiquis, the cyanobacterial Synechococcus sp. and unknown Verrucomicrobia species were abundant in the less nutrient-dense basins, while the hgcI clade members showed various distribution. In the estuary and in the nutrient-dense western part of the lake, some eutrophic conditions preferring cyanobacteria (filamentous Anabaena and Aphanizomenon species) were also detectable. The benthic microbial community showed higher diversity, according to the observed appearance of microorganisms adapted to the deeper, less aerated layers (e.g. members of Desulfobacteraceae, Nitrosomonadaceae).