Vinča Institute of Nuclear Sciences
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Calibration services for X-ray multimeters in Europe: current situation and future needs
No full textIntroduction: Optimization and quality control of the diagnostic and interventional radiology procedures is usually performed with an X-ray multimeter (XMM) based on the non-invasive measurements of different X-ray tube and output parameters obtained from the X-ray beam, such as air kerma, tube voltage and half-value layer. Standardization and metrological support need to be improved, and harmonized calibration procedures are not available for all quantities. There is also a lack of data on performance of XMMs in different measurement conditions relevant for clinical practice. Methods: The needs for calibration of XMMs and current state of the art of calibration services were investigated by performing an overview of the standards, conducting surveys addressed to the clinical medical physicists and calibration laboratories and investigating the key comparison database. Results: There are widely available calibration services for air kerma measurements for a large range of radiation qualities. However, there is a lack of calibration services for all other measured quantities, and very few laboratories besides the manufacturers are able to perform these calibrations. In addition, standardization gaps with non-harmonized calibration and measurement procedures for these quantities were found. Conclusion: New calibration services with harmonized procedures are needed for XMMs, especially for quantities beyond air kerma. There is a need to better understand and reduce measurement uncertainty for some quantities. New procedures will be developed within the TraMeXI project and disseminated to the standardization bodies, metrology and medical physics community
Small-angle X-ray scattering studies of morphology controlled nano ceria
No full textIn this study, we investigated the structural characteristics of CeO2-xNaOH powders, via hydrothermal method, using Small-Angle X-ray Scattering (SAXS) to analyze the scattering behavior and gain insight into the ceria morphology. The results from both models revealed the presence of a twophase porous structure with a fractal interface in all CeO2-xNaOH samples. As the NaOH concentration increased, variations in the radius of gyration, fractal dimension, and other structural parameters were observed. These findings provide a deeper understanding of the structural properties of CeO2-xNaOH powders and the impact of NaOH content on their morphology, which could be relevant for potential applications in catalysis, sensing, and other fields
Examination of hydroxyapatite application as a potential quercetin - carrying material
No full textThe objective of this work was to investigate a naturally occurring mineral form of calcium apatite, known as hydroxyapatite (Hap), as a potential drug delivery material. Drug delivery materials are utilized to effectively administer drugs to the body, ensuring controlled release, targeted delivery, and enhanced bioavailability. Hydroxyapatite was selected for its widespread use in biomedical applications, attributed to its exceptional biocompatibility, bioactivity, and osteoconductivity. As the main mineral component of human bone and teeth, it is highly appropriate for medical and dental implants, coatings, and bone grafts. Moreover, hydroxyapatite exhibits low biodegradability under physiological conditions, and its surface can be modified to improve protein adsorption and cell attachment, ensuring stability for long-term use. Hydroxyapatite was prepared for drug delivery purposes using the wet precipitation method of NaH2PO4 + H2O into Ca(OH)2. This solution was magnetically stirred, and the pH of the mixture was adjusted with NH4OH to create an alkaline environment at a temperature of around 80 °C. The adsorption experiment was conducted with the well-known flavonoid quercetin, chosen due to its challenging bioavailability, attributed to factors such as low aqueous solubility, a short metabolic period, and toxicity. A quercetin solution was prepared in ethanol with a concentration of 5 ppm. The adsorption experiment was carried out over 24 hours with constant stirring at room temperature. The results were analyzed using a UV-VIS spectrophotometer. Quercetin exhibits two peaks in the UV-VIS spectrum that are between 240–280 nm and 340–440 nm. Results showed that 3,3 mg/g of quercetin was attached tothe hydroxyapatite surface.It was also shown that quercetin was attached to the surface of the hydroxyapatite by intermolecular interactions. The most dominant one is the hydrogen bond, which belongs to the group of dipole- dipole interactions, that occur between the hydroxyl groups of quercetin and the oxygen atoms of the phosphate group in hydroxyapatite.EEM2025 - 9th International Congress Engineering, Environment and Materials in Process Industry; 2-4 april 2025; Bijeljina, Republic of Srpska, Bosnia and Herzegovina
Mitochondrial dysfunction, reactive oxygen species, and diabetes mellitus — A triangular relationship: A review
No full textDiabetes mellitus (DM) disrupts cellular homeostasis and is characterized by mitochondrial structural and functional impairments similar to those found in other metabolic disorders. Mitochondrial dysfunction (MD) leads to the excessive production of reactive oxygen species (ROS), which are central to the progression of cardiovascular (CV) disease—the leading cause of mortality associated with DM. ROS-driven oxidative stress (OS) is implicated in cardiac injury in both clinical and experimental contexts. This review synthesizes recent literature on the role of MD in the development and progression of DM and its associated CV complications, highlighting disrupted pathways that regulate the balance between ROS production and antioxidant defenses. We summarize alterations in mitochondrial dynamics—including fusion, fission, and mitophagy—mtDNA damage, and impaired oxidative phosphorylation characterized by dysregulated mitochondrial membrane potential (ΔΨm), electron transport chain (ETC) defects, uncoupling, and substrate overload. Additionally, we discuss hyperglycemia-activated pathways such as polyol flux, AGE–RAGE interactions, protein kinase C/nicotinamide adenine dinucleotide phosphate (PKC/NADPH) oxidase activation, and poly (ADP-ribose) polymerase 1 (PARP-1)-mediated glyceraldehyde-3-phosphate dehydrogenase (GAPDH) inhibition, which contribute to inflammation, endothelial dysfunction, β-cell failure, insulin resistance, and micro/macrovascular injury. Diagnostic and biomarker strategies encompass mtDNA analysis, bioenergetic assays, metabolomics, proteomics, and imaging techniques including PET, MRI, and NIRS. Therapeutic approaches aimed at restoring mitochondrial function and mitigating OS include mitochondria-targeted antioxidants (such as MitoQ, CoQ10, SkQ1, SS-31, and Mito-TEMPO), metabolic drugs (including metformin and SGLT2 inhibitors), lifestyle modifications, and emerging gene-editing technologies. The interplay between mitochondria, ROS, and DM reflects a tightly regulated aspect of cellular physiology; while targeted and personalized strategies hold promise, they necessitate rigorous evaluation
Improved electrochemical properties of niobium MXenes via addition of lanthanum for application in supercapacitors
No full textMXenes are the newest class of nanostructured two-dimensional materials, with tunable properties. In particular, niobium MXenes are characterized by high chemical stability during prolonged galvanostatic charge/discharge (GCD) cycles, high electrical conductivity and wettability with layered structure for ion transport, in addition to high surface area, and hydro- philicity [1]. The incorporation of other elements into their structure is an effective approach to increase the interlayer spacing, develops surface area and wettability by the electrolyte. This further improves the charge exchange [2] making MXenes advantageous for application energy storage devices, such as supercapacitors. In this work, the etching of Nb4 AlC3 MAX phase with HF 40 % was performed, followed by delamination to a single-layer Nb4 C 3 Tx. MXenes was subsequently doped with lanthanum (La) by mixing the MXene in 1 mol L-1 La(NO3 )3 aqueous solution. The La-doped MXene (Nb4C 3 T xLa) was electrochemically evaluated in a 2-electrode cell in 3 mol L -1 KOH. The addition of La to MXene increased the capacitance from 256 to 316 F g -1 at 5 mV s -1 . The GCD tests demonstrated that Nb 4C 3 T xLa has higher capacitance (~66 F g -1 ) and energy (9.17 Wh kg -1 ) values compared to Nb4 C3 T x after 5,000 cycles. The incorporation of La has been demonstrated to enhance the electrochemical performance of MXene, thereby suggesting its potential application in supercapacitor devices.Twenty-sixth annual conference on material science (YUCOMAT 2025), Herceg Novi, Montenegro, 1-5 September 2025
Determination of fundamental channeling parameters in single- crystal diamond wafers using deuterons and α-particles in the backscattering geometry
No full textDiamond is an allotropic form of carbon, renowned for its exceptional hardness, highest atomic density among solids, and outstanding heat conductivity, despite being an insulator. Artificial diamonds are extensively utilized in the development of advanced radiation detectors and the RBS/C approach has already been extensively utilized to investigate the diamond amorphization caused by ion implantation. Thus, a thorough investigation of the fundamental channeling parameters as studied in the backscattering geometry, namely, the average stopping power ratio of axially channeled ions with respect to the randomly oriented ones, along with the characteristics of the dechanneling function relative to the penetration depth, is deemed necessary. Nonetheless, apart from a study with protons [1], there is a notable deficiency in the literature regarding backscattering investigations of MeV deuterons and α-particles impinging on diamond crystals and the present work aims at contributing in this field, combining EBS/C and NRA/C data for the first time. The studies were conducted at two locations: (a) NCSR ‘Demokritos’ utilizing deuterons within the energy range of 1.2 to 1.5 MeV, and (b) RBI, Zagreb, Croatia employing α-particles between 2 and 3 MeV. In both instances, the beam energy was varied in ~100 keV increments, with a maximum beam spot dimension of approximately 1x1 mm². The current on target did not exceed ~20 nA to prevent potential overheating of the samples. The targets were two single- crystal diamond wafers with [100] axial orientation, suitable for detector fabrication, obtained from Ningbo Cornerstone Semiconductor Co., Ltd (Ningbo, China), which were mounted in the sophisticated, high-precision channeling goniometers at both locations. The analysis of the obtained EBS/C and NRA/C spectra has been conducted using innovative, specific software designed for the backscattering geometry [1], and an effort is made to elucidate the observed similarities and differences in comparison to the proton case.15th European Conference on Accelerators in Applied Research and Technology (ECAART 15); September 8-12, 2025; Zurich, Switzerland
Security of radioactive sources: lessons learned from the Goiania accident
No full textRadioactive sources, widely applicable to both medical and industrial settings, have many risks to security as they are often available to the general public and employees, who might or might not have been subjected to correct security assessments and training. Healthcare establishments, which source radioactive material, need to place as much emphasis on their staff and patients’ security and the security of radioactive sources themselves. Insufficient regulation, unaccountable oversight, and inadequate professional training can do serious damage, from inadvertent exposure and contamination to the potential malicious use of radioactive material. Nowhere was this more painfully demonstrated than in the 1987 Goiania accident, when an abandoned cesium-137 teletherapy unit left without supervision and without notifying the competent regulatory authority, fell into the hands of people who were completely unaware of its dangerous condition. Using relevant scientific literature, this review paper intends to emphasize the need to provide proper management of radioactive sources (including proper licensing, regulation, oversight, and control) as well as identify potential risks, which should be coupled with enhanced safety measures in both medical and industrial settings.5th International Student Conference – DISC2025, 11-12th December 2025, Novi Sad
Quantum materials in extreme environments: Unlocking new frontiers for next-generation technologies
No full textQuantum materials are defined by strong interactions and emergent electronic and magnetic states that are highly sensitive to their environment. Under extreme conditions – for example, very low temperature, high pressure, intense magnetic fields, or ionizing radiation – their electronic structure and collective behavior can change qualitatively, revealing new phases and enabling control over functionality. These responses both expose fundamental mechanisms of correlation and topology and create practical opportunities for sensing, information processing, and harsh-environment electronics. At the same time, the same sensitivity raises challenges for stability, coherence, and scalable integration. Progress will depend on materials-by-design approaches and on experimental methods that probe behavior in operando across length and time scales, together with theory that links microscopic mechanisms to device-relevant performance. This paper discusses recent advances that illustrate these points and outlines strategic directions to translate distinctive quantum phenomena under extreme conditions into robust technologies
Rhythms of heart: signatures of complexity and disorder in electrocardiographic signals
No full textU ovom radu istražujemo različite srčane ritmove primenom formalizma i teorije kompleksnih sistema na EKG signale. Rezultati pokazuju da se metrike zasnovane na RR intervalima, varijabilnost srčanog ritma i Šenonova entropija, mogu koristiti za razlikovanje periodičnih od neperiodičnih ritmova, dok se periodični ritmovi dodatno klasifikuju po frekvenciji srčanih otkucaja. Veličine koje u obzir uzimaju i amplitude signala, kao što su parametri Poenkareovih dijagrama Danka Stojanović Laboratorija za Atomsku fiziku Institut za nuklearne nauke ‘’Vinča’’ Institut od nacionalnog značaja za Republiku Srbiju, Univerzitet u Beogradu Beograd, Srbija [email protected] 0000-0002-7178-1970 Jovana Petrović Laboratorija za Atomsku fiziku Institut za nuklearne nauke ‘’Vinča’’ Institut od nacionalnog značaja za Republiku Srbiju, Univerzitet u Beogradu Beograd, Srbija [email protected] 0000-0002-1002 241X koordinisanu kontrakciju srca [1]. Električna aktivnost srca manifestuje se kroz ciklus koji obuhvata depolarizaciju i repolarizaciju pretkomora i komora, a širi se do površine tela omogućavajući snimanje EKG-a signala. Zbog složenosti mehanizama koji upravljaju srčanom aktivnošću, EKG zapis karakterišu nelinearne, neregularne i često haotične karakteristike. Poremećaji ritma mogu nastati i multifraktalnih spektara, daju nove informacije i indikatore kompleksnosti EKG signala, te predstavljalju potencijalne nove biomarkere aritmija. Prikazani rezultati predstavljaju korak ka sistematičnom povezivanju dinamičkih parametara EKG signala sa biomarkerima korisnim u kliničkoj praksi.In this paper, we investigate various heart rhythms by applying the formalism and theory of complex systems to ECG signals. The results show that metrics based on RR intervals, heart rate variability, and Shannon entropy can be used to distinguish periodic from non-periodic rhythms, while periodic rhythms are further classified according to the heart rate. Quantities that take into account also signal amplitudes, such as parameters of Poincaré plots and multifractal spectra, provide new information and indicators of ECG signal complexity, and thus represent potential new biomarkers of arrhythmias. The presented results are a step towards systematical linking of the dynamic parameters of ECG signals with biomarkers useful in clinical practice
Red mud-fly ash-based geopolymers as an eco-friendly material for immobilization of toxic pollutants (Pb and Cu) from wastewater
No full textThe use of waste materials as a precursor for synthesizing geopolymer materials is increasingly being utilized. This research aimed to examine the potential use of red mud-fly ash geopolymers to remove toxic pollutants such as copper and lead ions from wastewater. Samples of different ratios of red mud (RM) and fly ash (FA) were synthesized through alkaline activation. Based on compressive strength a geopolymer (RMFAGP1) with the highest value of 29.54 MPa, was chosen for further research. The physical-chemical characterization of RMFAGP1 in terms of mineral composition and structure was performed using XRD, DRIFT and SEM analysis. BET analysis was used to define porosity, as well as the specific surfaces necessary for efficient adsorption. The batch equilibration method was used to determine the PZC value, which serves as a guide for predicting the adsorption process. The best adsorption efficiency was achieved at pH =4 (88,5%) i.e. at pH=5 (99,4%) for Cu and Pb, respectively. The performed analyses indicate that waste materials, such as red mud and fly ash, can be used as raw materials for obtaining a geopolymer that can effectively immobilize Pb and Cu from wastewater, offering a low-cost and eco-friendly solution.Употреба отпадних материјала као прекурсора за синтезу геополимерних материјала се све више користи. Ово истраживање је имало за циљ да испита потенцијалну употребу геополимера на бази црвеног муља и летећег пепела за уклањање токсичних загађивача као што су јони бакра и олова из отпадних вода. Алкалном активацијом синтетисани су. узорци различитих односа црвеног муља и летећег пепела. За даља истраживања изабран је геополимер (RMFAGP1) који има највећу вредност притисне чврстоће од 29,54 МPа. Физичкохемијска карактеризација RMFAGP1 извршена је коришћењем XRD, DRIFT i FESEM metoda. BET анализа је коришћена за дефинисање порозности, као и специфичне површине неопходне за ефикасну адсорпцију. За одређивање вредности pHtnn коришћен је метод уравнотежавања посебних проба, који је водич за предвиђање процеса адсорпције. Најбоља ефикасност адсорпције постигнута је при pH =4 (88,5%), односно при pH=5 (99,4%) за Cu и Pb, респективно. Урађене анализе указују да се отпад, попут црвеног муља и летећег пепела, може користити као сировина за добијање геополимера који се може ефикасно користити као економски и еколошки прихватљив материјал за имобилизацију Cu и Pb из отпадних вод