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Surface and Electrochemical Insights into Polyaniline Based Nanocomposites for Advanced Supercapacitors
No full textComposites based on conducting polymers, especially polyaniline (PANI), combined with functionalized nanomaterials, represent highly promising candidates for application in supercapacitors due to their pronounced pseudocapacitive behavior, good electrical conductivity, and chemical stability [1,2]. This study presents the synthesis and characterization of PANI nanocomposites with different functional fillers — TiO₂, CeO₂, and MXene — obtained by chemical oxidative polymerization in an acidic medium. Structural and morphological analyses (FESEM, TEM), as well as spectroscopic characterization (FTIR, Raman), and thermal investigations (TGA/DTA, DSC), revealed strong interactions between PANI chains and the embedded nanoparticles, including hydrogen bonding, electrostatic attraction, and potential orbital hybridization. Particular attention was given to MXene-based materials due to their ability to form three-dimensional conductive networks with PANI chains, providing increased surface area and facilitating electron and ion transport. Electrochemical investigations, including cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS), confirmed that all composites exhibited improved capacitive performance compared to pristine PANI. The obtained results highlight the strong potential of these hybrid nanocomposites for application in next-generation energy storage devices, particularly in environmentally friendly supercapacitors.5th International Meeting on Materials Science for Energy Related Applications, September 25-26, 2025, Belgrade
Photonic integrated circuits based on self-imaging in coupled waveguide arrays
No full textWe propose a novel approach to design of wavelength demultiplexers based on self-imaging of light in optical lattices and validate it experimentally. It applies to all fabrication platforms, enabling scalability, spectral control and low loss.Conference on Lasers & Electro-Optics CLEO 2025; 4–9 May 2025, Long Beach, California, United States
Defect engineering and opening of the ion tracks in the swift heavy ion irradiated thin films of bismuth vanadate: Impact on oxygen evolution reaction for solar water splitting
No full textSwift heavy ion (SHI) irradiation using 150 MeV Xe ions (5×109 to 5×1011 ions cm-2) was applied to engineer defects in hydrothermally synthesized BiVO4 (BVO) thin films and analyze its impact on photoelectrochemical (PEC) performance toward the oxygen evolution reaction (OER). Exposure to SHI induces residual stress and amorphization, accompanied by bismuthrich hillocks forming above oxygen-depleted ion tracks. At high fluence (5 × 1011 ions cm-2), excessive defect accumulation and overlapping tracks lead to irreversible PEC degradation. In contrast, lower fluences (5×109 and 1010 ions cm-2) generate moderate defects that initially trap charge carriers but subsequently enhance performance, resulting in photocurrent density increase of 58.6 and 25.2 %, respectively. Post-PEC analysis reveals that latent ion tracks evolve into nanoscale holes, with diameters up to 30 nm and depths up to 200 nm. Notably, the 1010 ions cm-2 sample exhibits well-defined holes, suggesting an optimal defect–stress balance that facilitates localized restructuring. This study provides new insights into SHI-induced modifications in BVO and demonstrates the potential of ion beam irradiation for nanoscale morphostructural engineering. The controlled formation of nanoscale holes opens opportunities for incorporating cocatalysts or plasmonic structures to further enhance PEC activity.Twenty-sixth annual conference on material science (YUCOMAT 2025), Herceg Novi, Montenegro, 1-5 September 2025
Strain-tuned electron–phonon coupling in FeSe
No full textIron-based superconductors provide a key platform for studying the interplay between lattice, electronic, and spin degrees of freedom that underlies nematicity and unconventional superconductivity. FeSe, in particular, represents a paradigmatic but highly complex case where nematic, orbital, and spin correlations are strongly coupled, and magnetism remains frustrated. To elucidate how external symmetry-breaking fields influence these coupled degrees of freedom, we examined the effect of uniaxial strain on the lattice dynamics of FeSe using high-resolution Raman scattering. In twinned sample, an additional Ag mode appears very close in energy to the symmetry-allowed A1g phonon in the vicinity of nemato-structural transition, giving rise to an asymmetric line shape. In detwinned sample, this feature becomes more pronounced and its evolution is strongly strain direction-dependent: nematic distortion along ⟨110⟩ slightly narrows, whereas strain along ⟨100⟩ broadens the temperature range of the anomaly. The additional Ag mode most likely arises from enhanced scattering with acoustic phonons along the M–A direction of the Brillouin zone, consistent with strain-induced modifications of the electron–phonon interaction. Although similar feature has been detected in isostructural and isoelectronic compound FeS, the present results reveal that the microscopic origin of electron–phonon interactions in these materials differs substantially.Twenty-Third Young Researchers' Conference Materials Science and Engineering, December 3-5, 2025, Belgrade, Serbia
The role of acetylcholinesterase in cancer development and possible therapeutic applications
No full textThe cholinergic system plays a crucial role in essential physiological processes such as memory, learning, autonomic regulation, muscle, and neurological functions. Beyond its well-established functions, the cholinergic system is also directly involved in apoptosis, a process crucial for maintaining balance in development, differentiation, and aging. Dysregulation of apoptosis can lead to diseases, with cancer being of particular concern. Cholinergic signaling significantly influences various aspects of cancer development and progression, including cell proliferation, angiogenesis, migration, invasion, and survival. Acetylcholinesterase (AChE) is a critical enzyme that breaks down the neurotransmitter acetylcholine (ACh) within the synaptic cleft, facilitating nerve signal transmission. Implications of the ACh pathway in cancer development and progression are evident. Dysregulation of the ACh pathway may occur in cancer due to changes in the expression and activity of ACh-synthesizing enzymes (choline acetyltransferase (ChAT)) and ACh-degrading enzyme (AChE), leading to imbalances in ACh levels and disrupted cholinergic signaling. Given AChE's involvement in apoptosis, it has emerged as a potential therapeutic target for cancer treatment. Various strategies have been explored to modulate AChE activity or expression, including AChE inhibitors and agents enhancing AChE expression, revealing promising outcomes in promoting apoptosis and inhibiting tumor growth in preclinical studies. Advancing our understanding of AChE functions will enable the development of novel therapeutic strategies using targeted agents, benefiting cancer and neurodegenerative disease treatments.Chapter 18Section II: Proteases as diagnostics and prognostics biomarker
Role of synthesis temperature in the formation of ZnO nanoparticles via the Sol-Gel process
No full textThis study examines the synthesis of ZnO powder via the sol–gel method at temperatures of 25 °C and 60 °C. Characterization was conducted using standard techniques to investigate how these temperature conditions influence the physicochemical properties of the resulting material. XRD analysis confirmed high crystallinity with a pure hexagonal wurtzite structure, with average crystallite sizes of approximately 20 nm at 25 °C and 38 nm at 60 °C. Both SEM and TEM techniques established needle-like nanorods at 25 °C and nanoflower-like structures at 60 °C. Analyzing the high-resolution XPS spectra of the Zn2p and O1s photoelectron lines revealed a predominant Zn(II) state, with the contribution of ZnO increasing from 14.6 at.% to 41.6 at.% at higher temperatures. This change was accompanied by a decrease in defective oxygen and water content. Furthermore, DSC analysis revealed significant differences in thermal properties of ZnO powders synthesized at 25 °C and 60 °C, with distinct endothermic peaks around 120 °C corresponding to the evaporation of the solvent used in the synthesis process. The energy required for phase transitions was notably higher for the 25 °C synthesis, indicating greater thermal stability and energy demands compared to the 60 °C synthesis. © 2024 Elsevier B.V
Efficient nano-size ZnM/rGO (M = Ni, Cu, and Fe) electrocatalysts for oxygen electrode reactions in alkaline media
No full textHerein, zinc with nickel, copper, and iron was deposited on reduced graphene oxide (rGO) (ZnM/rGO, M = Cu, Ni, Fe) and examined as novel bifunctional electrocatalysts for oxygen evolution (OER) and oxygen reduction (ORR) reaction in alkaline media. Fourier-transform infrared and X-ray photoelectron spectroscopy, X-ray powder diffraction analysis, transmission, and scanning electron microscopy with energy-dispersive X-ray spectroscopy were used for the examination of structural and morphological properties of ZnM/rGO. ZnFe/rGO showed the lowest OER overpotential and Tafel slope, the highest OER current density with the lowest charge-transfer resistance. Furthermore, ORR at ZnFe/rGO proceeds by mixed 2e/4e mechanism, and by 2e mechanism at the other materials. Still, ZnCu/rGO showed the most positive onset potential and low Tafel slope during ORR. Hence, ZnFe/rGO presents the best OER activity with further improvements needed in terms of its ORR performance to reach full potential for rechargeable metal-air batteries and unitized regenerative fuel cells. © 2024 Hydrogen Energy Publications LL
Probability distribution in the Toda system: The singular route to a steady state
No full textThis study reports on the evolution of the probability distribution in the configuration space of the two-dimensional Toda system. The distribution is characterized by singularities, which predominantly take two forms: double-cusped triangular lines and lines parallel to the equipotential line that defines the accessible region. Over time, the number of these singular patterns increases linearly. Consequently, at very large times, the singular patterns fully occupy the accessible area, resulting in a steady state probability distribution with a pronounced singular peak at the center. Changes in the singular patterns arise solely from the system's intrinsic dynamics rather than variations in its parameters, emphasizing the system's self-organizing nature over time. These results provide a deeper understanding of the collective motion of particles in symmetric, bounded, two-dimensional conservative systems. © 202
Bioactivity Assessment of Functionalized TiO2 Powder with Dihydroquercetin
No full textBiological activities, including cell viability, oxidative stress, genotoxicity/antigenotoxicity, and antimicrobial activity, were evaluated for a visible-light-responsive TiO2-based ICT complex with dihydroquercetin (DHQ) and compared with pristine TiO2, its inorganic component. Pristine TiO2 did not induce cytotoxicity in MRC-5 or HeLa cells within the tested concentration range (1–20 mg/mL), while TiO2/DHQ displayed a significant reduction in cell viability in both cell lines at higher concentrations (≥10 mg/mL). The analysis of reactive oxygen species (ROS) production revealed that TiO2/DHQ significantly reduced ROS levels in both cell types (MRC-5 and HeLa), with HeLa cells showing a more substantial reduction at lower concentrations. Genotoxicity assessment using the comet assay demonstrated that TiO2 induced DNA damage in MRC-5 cells, while TiO2/DHQ did not, indicating that DHQ mitigates the genotoxic potential of TiO2. Furthermore, TiO2/DHQ exhibited antigenotoxic effects by reducing H2O2-induced DNA damage in MRC-5 cells, supporting its protective role against oxidative stress. Preliminary antimicrobial tests revealed that TiO2/DHQ exhibits antimicrobial activity against E. coli under visible-light excitation, while TiO2 does not. These findings suggest that the TiO2-based ICT complex with DHQ with enhanced antioxidant properties can potentially serve as a safe, non-toxic biocide agent. © 2025 by the authors
Cell Labeling with Responsive MRI Contrast Agents is Enabled through Solid-Phase Synthesis
No full textBioresponsive or smart contrast agents (SCAs) for magnetic resonance imaging (MRI) can facilitate functional molecular imaging of numerous biological processes. These are MRI probes that alter the MRI signal along with the concentration changes of different biomarkers in their microenvironment, thus enabling the assessment of tissue physiology with high spatiotemporal resolution. One of the common shortcomings of SCA is their structural and functional insufficiency for accumulation in the targeted region, i.e., most frequently internalization into the cells to study the intracellular processes. Here, we report a strategy to prepare a multifunctional SCA that can be successfully incorporated into the cell membrane and internalized. We used the solid-phase synthesis methodology to obtain a trimeric SCA responsive to calcium ions, which bears a hydrophobic tetradecanoyl group to facilitate interaction with primary rat astrocytes. The developed MRI probe maintained high activity, exhibiting high calcium-triggered longitudinal and transverse relaxivity changes. Concurrently, it showed the ability to label the cell membranes and internalize into the astroglial cells while not causing cytotoxicity or affecting the electrophysiology of the cells. © 2025 American Chemical Society