Iron is essential for neuronal metabolism, neurotransmitter synthesis, and enzymatic function; however, dysregulated accumulation contributes to oxidative stress and neurodegeneration. The basal ganglia, particularly the globus pallidus, represent a hotspot for iron deposition, yet the precise structural forms and their implications remain incompletely understood. Here, a multimodal approach was applied combining Raman microspectroscopy, light microscopy, transmission (TEM) and scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM–EDX) to characterise iron-rich deposits in post-mortem human globus pallidus. Tissue samples from six individuals without neurological disease were examined. Perls’ staining revealed iron-positive, spherical inclusions 10–20 µm in diameter. Raman spectroscopy revealed bands at 268–278, 490, 526, and 603 cm−1, as well as broader signals at 1259–1349 cm−1, consistent with magnetite, maghemite, hematite, and ferritin-like structures. Additional vibrations in the 682–1532 cm−1 range indicated interactions with organic matrices, such as protein or lipid components. SEM–EDX identified both regular and irregular iron-rich particles with multielemental composition, including C, O, Al, Si, P, S, Ca, Cr, and Ni, in addition to Fe. TEM examination showed the micrometre-sized particles of hematite and aggregation of ferrihydrite. These findings suggest that iron deposits in the globus pallidus comprise heterogeneous mixtures of oxides and hydroxides with variable crystallinity. Depending on their crystallinity and surface reactivity, such phases may represent a potential pool of redox-active iron; however, the present study did not assess markers of oxidative stress, and their physiological versus pathological significance remains to be established.

Cryopreservation of cells is a critical challenge in contemporary cryobiology, particularly in the burgeoning field of tissue engineering. The method of cryopreservation significantly affects the quality of cells post-thaw, as cells are sensitive to the stress induced by freezing and thawing, leading to physical damage, loss of functionality, or cell death. It is essential to develop protocols that ensure good physiological and adherent conditions post-thaw. This study investigates the effect of cryopreservation on human keratinocytes using the intracellular cryoprotective agent dimethyl sulfoxide (DMSO), known for mitigating cell damage during freezing and thawing, although its toxicity remains debated. We evaluated the cryopreservation of human keratinocytes with low (1.8% and 2.2% v/v) and standard (5% and 10% v/v) concentrations of DMSO during short-term storage (4 days) at -80°C. Post-thaw, we examined the impact of the cryopreservation process on cell viability, plasma membrane fluidity, and identified signs of cell death depending on the concentration of DMSO used in the freezing medium. This study is the first to systematically examine the impact of various DMSO concentrations on cell viability and plasma membrane fluidity of keratinocytes in the context of 30% FBS concentration in the freezing medium, slow cooling, and − 80°C temperature, highlighting the originality and significance of our research. This research demonstrated that lower DMSO concentrations (1.8% and 2.2%) significantly reduce keratinocyte viability due to increased apoptotic activity and cellular stress. In contrast, higher concentrations (5% and 10%) provide better protection and maintain higher cell viability. The study revealed that membrane fluidity increases with higher DMSO concentrations, which may facilitate the clustering of death receptors and the formation of apoptotic signaling complexes, thereby increasing the sensitivity of keratinocytes to apoptotic stimuli. Morphological analysis showed that lower DMSO concentrations lead to significant morphological changes and apoptosis, while higher concentrations result in cell enlargement and shape alteration. Ultrastructural analysis provided detailed insights into the internal structure of cells, revealing changes in the nucleus, mitochondria, and the presence of vesicles around the plasma membrane at lower DMSO concentrations, whereas higher DMSO concentration led to significant nuclear damage. These findings have implications for cryopreservation to improve cell viability and functionality post-thaw and may enhance the success of cell preservation in biomedical applications.

Metals are essential for the physiological and biochemical processes in the human brain. However, their accumulation can cause neurotoxic effects, including the generation of reactive oxygen species and structural changes in biomolecules. This study aimed to assess the presence and distribution of metals in the human globus pallidus internus using Particle-Induced X-ray Emission (PIXE) and Scanning Electron Microscopy with Energy-Dispersive X-ray (SEM-EDX). Post-mortem brain tissue samples from six individuals without clinical neuropathological findings were analysed. PIXE analysis revealed the presence of Fe, Cr, Al, Zn, Pb, and Ca. SEM-EDX analysis provided the qualitative elemental composition of an observed aggregate, revealing C, N, O, Na, Ca, Al, Si, S, K, Mg, Cl, Fe, Ni, and Cr. Our findings suggest that metal accumulation in the brain can result from environmental pollution and protein aggregation, as well as biomineralisation processes that sequester metal ions to mitigate their harmful effects. A deeper understanding of these accumulation pathways could contribute to improved therapeutic strategies for neurological diseases associated with metal toxicity.

The accumulation of metallic micro- and nanoparticles in the human hippocampus is increasingly linked to neurotoxic processes and neurodegenerative disorders. Precise segmentation and detailed characterization of these particles are crucial to understanding their role. This study presents a novel method that combines discrete segmentation based on graph-cut theory with Dinic’s algorithm for the computation of maximum flow. The images are modeled as directed weighted graphs, with pixel intensities and gradients defining edge capacities, enabling robust segmentation in electron microscopy data. To ensure robustness, the method is validated against ground-truth masks, achieving a Dice coefficient of 0.97898 ± 0.0172 and an Intersection over Union (IoU) of 0.9609 ± 0.0326. Morphometric parameters—area, perimeter, circularity, and Feret diameters—are automatically extracted. Concurrently, elemental analysis using Energy-Dispersive X-ray Spectroscopy (EDS) reveals a heterogeneous composition, including iron-rich particles and compounds containing nickel and chromium. The observed variability highlights the importance of single-particle analysis in better understanding the neurobiological impact of metallic deposits.

This study investigates the 210Pb activity concentrations in tobacco and cigarettes available in Slovakia, utilizing two specific extraction methods including the Sr Resin sorbent used in extraction chromatography, and the AnaLig Sr01 sorbent, which operates based on molecular recognition principles. The findings revealed significant variations in 210Pb activity concentrations, with concentrations ranging from 13.3 to 33.8 mBq/g in tobacco, and from 16.8 to 28.5 mBq/g in cigarettes. The average 210Pb activity per cigarette was 14.4 mBq ± 1.7 mBq. Annual effective doses for smokers were calculated, with values for tobacco ranging from 27.9 to 126.7 µSv and for cigarettes from 25.5 to 115.7 µSv. The study highlights the importance of comparing these two methods to ensure an accurate assessment of 210Pb exposure and evaluation of radiological risks associated with smoking in Slovakia.

This study aims to statistically compare two methods for determining 210Pb in tobacco: the molecular recognition sorbent method (AnaLig Sr01) and the extraction chromatography sorbent method (Sr Resin). The TriCarb 3100 TR liquid scintillation spectrometer was used to measure and determine 210Pb activity in the tobacco solution. Statistical analysis confirmed the accuracy and precision of the 210Pb measurements, with high detection efficiencies of 82

This is an exclusively systematic background study reviewing 85 Mesozoic (latest Jurassic and Cretaceous) cockroaches and praying mantises from northern palaeo-polar (i.e. deposited within polar circles) deposits in Yakutia, Taimyr, Khabarovsk, Magadan and Chukotka (Russia), revealing 15 new species, which are herein characterised using systematic two-way analysis. The taphonomic conditions within these ‘Arctic’ paleo- polar sites were strongly influenced by long periods of pre-depositional transport.

Biomedical data (structured and unstructured) has grown dramatically in strength and volume over the last few years. Innovative, intelligent, and autonomous scientific approaches are needed to examine the large data sets that are gradually becoming widely available. In order to predict unique symmetric and asymmetric patterns, there is also an increasing demand for designing, analyzing, and understanding such complicated data sets. In this paper, we focused on a different way of processing biological and medical data. We provide an overview of known methods as well as a look at optimized mathematical approaches in the field of biological data analysis. We deal with the RGB threshold algorithm, new filtering based on the histogram and on the RGB model, the Image J program, and the structural similarity index method (SSIM) approaches. Finally, we compared the results with the open-source software. We can confirm that our own software based on new mathematical models is an extremely suitable tool for processing biological images and is important in research areas such as the detection of iron in biological samples. We study even symmetric and asymmetric properties of the iron existence as a design analysis of the biological real data. Unique approaches for clinical information gathering, organizing, analysis, information retrieval, and inventive implementation of contemporary computing approaches are all part of this research project, which has much potential in biomedical research. These cutting-edge multidisciplinary techniques will enable the detection and retrieval of important symmetric and asymmetric patterns, as well as the faster finding of pertinent data and the opening of novel learning pathways.

In the field of printed electronics, carbon and its allotropes are today among the most studied materials due to their unique physical and chemical properties. In this work, carbon dispersions were used for the preparation of screen-printed carbon electrodes applied as counter electrodes (CEs) for the dye-sensitized solar cells and as working electrodes for electrochemical sensing. Following the simple and quick homogenization process, carbon dispersions were subjected to thermogravimetric analysis to closely examine drying, eventually sintering processes after printing. The influence of the graphite:carbon black ratio was investigated. The structure of composite carbon layers was analyzed by scanning electron microscopy and optical microscopy. The DSSC CEs printed from the dispersion containing 100 wt% of CB exhibited the highest catalytic activity for the effective reduction of oxidized triiodide I3− back to iodide I− within the solar cell. The highest conversion efficiency achieved for the high-temperature processed CE was 3.05% with the fill factor of 0.65. The same composition of the carbon WE was used for the quantitative analysis of neurotransmitter dopamine. Based on the cyclic voltammetry measurements, the sensor showed a limit of detection of 13.3 nM for dopamine.

Iron, an essential element for most living organism, participates in a wide variety of physiological processes. Disturbance in iron homeostasis has been associated with numerous pathologies, particularly in the heart and brain, which are the most susceptible organs. Under iron-overload conditions, the generation of reactive oxygen species leads to impairment in Ca2+ signaling, fundamentally implicated in cardiac and neuronal physiology. Since iron excess is accompanied by increased expression of iron-storage protein, ferritin, we examined whether ferritin has an effect on the ryanodine receptor - isoform 2 (RYR2), which is one of the major components of Ca2+ signaling. Using the method of planar lipid membranes, we show that ferritin induced an abrupt, permanent blockage of the RYR2 channel. The ferritin effect was strongly voltage dependent and competitively antagonized by cytosolic TEA+, an impermeant RYR2 blocker. Our results collectively indicate that monomeric ferritin highly likely blocks the RYR2 channel by a direct electrostatic interaction within the wider region of the channel permeation pathway.

Interactions between tumor cells and immune cells are sparsely explored in 3D models, although occasional studies with 3D cell culture technologies have confirmed that tumor architecture influences cancer cell-immune system interactions. The development of technologies enabling controlled analysis of tumor-immune system interactions especially in 3D is highly challenging. Two photon polymerization (2PP) as a method for fabrication of various microstructures suitable for preparation of 3D tumor models finds applications in this context. In the present study 2PP technology was used to fabricate polymeric microfibers in 3D microspace that mimic fibers of extracellular matrix. UV-curable polymer OrmoComp (Micro Resist Technology GmbH) was irradiated by Newport Spirit ultrafast amplified laser operating at 520 nm. The fibers were made with one side anchored to the substrate with the supporting structure, whereas the other side was freely movable in space. The shape and curliness of fibers were adjusted by alternating parameters of fabrication, namely energy intensities and speed of fabrication. Before exposing fabricated fibers to live cells, microstructures were processed with KOH based treatment to enhance adhesion of cancer cells. Arrangement of the cancer cells in the network of polymeric fibers was visualized by confocal scanning microscopy. Cancer cells were able to proliferate and form spatial cellular clusters among polymeric fibers after several days of cultivation. At the same time they were available to immune cells that could be supplemented to the culture at any time. The results of the present study document feasibility to use 2PP technology to develop in vitro 3D models suitable for studies of tumor-immune cell interactions.

We studied the influence of etching time in hydrofluoric acid and methanol solution on the structure and morphology of n-type porous silicon (PSi). Dissolution of Si in the solution of hydrofluoric acid with methanol with surface oxidation occurs. All investigated samples reveal pores with increasing average size proportional to the etching time. Areic density and RMS roughness observed by scanning electron and atomic force microscopies have maximum for 10 min etching time. Additional etching time leads to slight increase in the pore size diameter and decreasing the RMS roughness of layers. All amorphous PSi samples are covered with the SiO2 layer containing probably HySiOx and SiFxHy complexes. The presence of SiH complexes leads probably to the growth of PSi layers with pores. The thickness of this layer depends on etching time and probably contains HySiOx and SiFxOy complexes.

Iron is critically important and highly regulated trace metal in the human body. However, in its free ion form, it is known to be cytotoxic; therefore, it is bound to iron storing protein, ferritin. Ferritin is a key regulator of body iron homeostasis able to form various types of minerals depending on the tissue environment. Each mineral, e.g. magnetite, maghemite, goethite, akaganeite or hematite, present in the ferritin core carry different characteristics possibly affecting cells in the tissue. In specific cases, it can lead to disease development. Widely studied connection with neurodegenerative conditions is widely studied, including Alzheimer disease. Although the exact ferritin structure and its distribution throughout a human body are still not fully known, many studies have attempted to elucidate the mechanisms involved in its regulation and pathogenesis. In this review, we try to summarize the iron uptake into the body. Next, we discuss the known occurrence of ferritin in human tissues. Lastly, we also examine the formation of iron oxides and their involvement in brain functions.

Iron is very important element for functioning of the brain. Its concentration changes with aging the brain or during disease. The aim of our work was the histological examination of content of ferritin and free iron (unbound) in brain cortex in association with A beta plaques from their earliest stages of accumulation in amyloid plaque forming APP/PS1 transgenic mice. Light microscopy revealed the onset of plaques formation at 8-monthage. Detectable traces of free iron and no ferritin were found around plaques at this age, while the rate of their accumulation in and around A beta plaques was elevated at 13 months of age. Ferritin accumulated mainly on the edge of A beta plaques, while the smaller amount of free iron was observed in the plaque-free tissue, as well as in and around A beta plaques. We conclude that free iron and ferritin accumulation follows the amyloid plaques formation. Quantification of cortical iron and ferritin content can be an important marker in the diagnosis of Alzheimer's disease.

The pineal gland (glandula pinealis) is neuroendocrine gland located at the epithalamus of the brain secreting melatonin. The aim of this study was to explore effects of prenatal hypoxia in rats at the age of 33 weeks on the occurrence of pineal gland calcification. Distribution and chemical composition of calcerous material by light, scanning and transmission electron microscopy was investigated. Melatonin concentrations in blood plasma by direct radioimmunoassay were measured. Rats were exposed to prenatal hypoxia for 12 h at day 20 of development and second group to prenatal hypoxia for 2x8 h at days 19 and 20 of development. Vacuoles of intracellular edema in the pineal samples after 12 h hypoxia were found. Their size ranges up to 30 µm. Some of them were filled with the flocculent and fibrous material. Samples of pineal glands after 2 x 8 h hypoxia revealed the pericellular edema of pinealocytes. The amount of calcium rich particles in 2 x 8 h hypoxia group was lower than in 12 h hypoxia group. Plasma melatonin levels did not differ between control and both hypoxia groups. We concluded that calcification is a process induced by osteoblasts and osteocytes with melatonin as a promotor and it is favored under hypoxic conditions.

Samples taken from the human brain (Globus Pallidus) have been investigated by physical techniques such as light microscopy, scanning electron microscopy, transmission electron microscopy, Mössbauer spectroscopy and SQUID magnetometry. SEM-EDX/TEM investigation reveals multielemental composition of hematite and magnetite nanocrystals with sizes ranging from 40 nm to 100 nm and hematite microcrystals from 3 μm to 7 μm. Room temperature Mössbauer spectra show quadrupole doublets assigning to hematite and ferrihydrite. SQUID measurements of temperature dependence of the mass magnetic susceptibility between T = 2 – 300 K at DC field B0 = 0.1 T, the field dependence of the mass magnetization taken at the fixed temperature T0 = 2.0 and 4.6 K and the zero-field cooled and field cooled magnetization experiments (ZFCM/FCM) confirm a presence of ferrimagnetic phases such as maghemite and/or magnetite with hysteresis loops surviving until the room temperature. Differences between these measurements from the point of view of iron oxides detected can indicate important processes in human brain and interactions between ferritin as a physiological source of iron and surrounding environment.

The aim of work is to identify the main points for optimizing of biophysical curriculum for medicine study. The solution was based on Memorandum on the content and status of medical physics in the medical study system, the profile of graduate students of medical faculty and Decree of the Ministry of Health of the Slovak Republic about the minimal requirements for personnel security and material and technical equipment of individual healthcare facilities. We found out, that current content of biophysical curriculum at the Medical faculties only partially covers knowledge about medical devices and instruments, which are recommended for minimum equipment at key departments in general hospital by Ministry of Health. Physical principles appliances and tools designed especially for resuscitation of the patient are underrepresented in teaching biophysics at the Medical Faculty. Results of the analysis showed that it is necessary to optimize the (bio) physics curriculum to promote the skills of graduate students of medical faculties in key medical disciplines.

Porous silicon (PSi) is a semiconductor produced by a dissolution p-type silicon wafers in hydrofluoric acid (HF) solution by applying a positive potential to a silicon electrode. We investigate the effect of etching time on morphology, structure and photoluminescence of PSi produced by a solution of hydrofluoric acid (HF) and methanol without UV irradiation. We found that surface structure depends strongly on etching time. From Fourier transform infrared spectroscopy and grazing incidence X-ray diffraction we suggest formation towards less-ordered amorphous phase of PSi. All samples reveal red-band photoluminescence. Although we observe different morphology of samples (channel-like morphology versus nanometer-sized hillocks morphology) slight effect on PL active structures (small red shift) was observed. We suggest that source of luminescence in our experiment is hydrogenated amorphous silicon structures and various HySiOx complexes. We cannot rule out the effect of SixFyO complexes. Surface morphology has small effect on photoluminescence. (C) 2018 Elsevier B.V. All rights reserved.

Knowledge about the three-dimensional fine structure of human heart, as a crucial vital organ of the body, is not only fascinating from the scientific or educational points of view, but has a very important clinical impact. Therefore, we decided to create a three-dimensional atlas of fine structure of the human heart. Tissue samples from ten human hearts were rinsed in phosphate-buffer solution, fixed by glutaraldehyde buffered solution, and post-fixed in osmium tetroxide solution. A gentle dehydration with ethanol in different concentration and drying at the critical point of CO2 were applied as next procedures. Non-conductive specimens were galvanized with thin gold layer and observed in scanning electron microscope. In this study, we present the three-dimensional ultrastructural architecture of the human heart from patients after myocardial infarction, end-stage failing heart as well as without apparent cardiac abnormalities at the time of autopsy. The results are presented as a histological atlas. Its images illustratively describe the fine structure of endocardium including the morphology of Purkyně (Purkinje) fibres, spatial arrangements of cardiac muscle cells inside myocardium or the arrangements of adipose tissue of epicardium. We present also figures of the ultrastructure of papillary muscles, intercalated discs as well as the connective tissue scars after myocardial infarction. The scanning electron microscopy could be a reliable technique to perform a more complete morphological data and to improve our knowledge of some pathological changes of tissues and cells, not always detected by conventional morphological examinations.

The morphology and chemical bods of p-type and n-type porous Si was compared. The surface of n-type sample is smooth, homogenous without any features. The surface of p-type sample reveals micrometer-sized islands. FTIR investigation reveals various distribution of SiOxHy complexes in both p-and n-type samples. From the conditions leading to porous silicon layer formation (the presence of holes) we suggest both SiOxHy and SiFxHy complexes in the layer.