1. Evaluation of two-dimensional dose distributions for pre-treatment patient-specific IMRT dosimetryĐeni Smilović Radojčić, David Rajlić, Božidar Casar, Manda Švabić Kolacio, Nevena Obajdin, Dario Faj, Slaven Jurković, 2018, izvirni znanstveni članek Povzetek: The accuracy of dose calculation is crucial for success of the radiotherapy treatment. One of the methods that represent the current standard for patient-specific dosimetry is the evaluation of dose distributions measured with an ionization chamber array inside a homogeneous phantom using gamma method. Nevertheless, this method does not replicate the realistic conditions present when a patient is undergoing therapy. Therefore, to more accurately evaluate the treatment planning system (TPS) capabilities, gamma passing rates were examined for beams of different complexity passing through inhomogeneous phantoms. Materials and methods The research was performed using Siemens Oncor Expression linear accelerator, Siemens Somatom Open CT simulator and Elekta Monaco TPS. A 2D detector array was used to evaluate dose distribution accuracy in homogeneous, semi-anthropomorphic and anthropomorphic phantoms. Validation was based on gamma analysis with 3%/3mm and 2%/2mm criteria, respectively. Results Passing rates of the complex dose distributions degrade depending on the thickness of non-water equivalent material. They also depend on dose reporting mode used. It is observed that the passing rate decreases with plan complexity. Comparison of the data for all set-ups of semi-anthropomorphic and anthropomorphic phantoms shows that passing rates are higher in the anthropomorphic phantom. Conclusions Presented results raise a question of possible limits of dose distribution verification in assessment of plan delivery quality. Consequently, good results obtained using standard patient specific dosimetry methodology do not guarantee the accuracy of delivered dose distribution in real clinical cases
Ključne besede: IMRT, 2D dose verification, gamma method, antropomorphic phantom
Objavljeno v DiRROS: 10.06.2024; Ogledov: 39; Prenosov: 27
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2. Gamma-enolase : a well known tumour marker, with a less-known role in cancerTjaša Vižin, Janko Kos, 2015, pregledni znanstveni članek Povzetek: Gamma-enolase, known also as neuron-specific enolase (NSE), is an enzyme of the glycolytic pathway, which is expressed predominantly in neurons and cells of the neuroendocrine system. As a tumour marker it is used in diagnosis and prognosis of cancer; however, the mechanisms enrolling it in malignant progression remain elusive. As a cytoplasmic enzyme gamma-enolase is involved in increased aerobic glycolysis, the main source of energy in cancer cells, supporting cell proliferation. However, different cellular localisation at pathophysiological conditions, proposes other cellular engagements. The C-terminal part of the molecule, which is not related to glycolytic pathway, was shown to promote survival of neuronal cells by regulating neuronal growth factor receptor dependent signalling pathways, resulting also in extensive actin cytoskeleton remodelling. This additional function could be important also in cancer cells either to protect cells from stressful conditions and therapeutic agents or to promote tumour cell migration and invasion. Gamma-enolase might therefore have a multifunctional role in cancer progression: it supports increased tumour cell metabolic demands, protects tumour cells from stressful conditions and promotes their invasion and migration.
Ključne besede: gamma-enolase, cancer, glycolysis, cell survival, tumour marker
Objavljeno v DiRROS: 23.04.2024; Ogledov: 173; Prenosov: 80
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3. Technical and radiological characterisation of fly ash and bottom ash from thermal power plantEmilija Fidanchevski, Biljana Angjusheva, Vojo Jovanov, Pece Murtanovski, Ljubica Vladiceska, Nikolina Stamatovska Aluloska, Jelena Krneta Nikolić, Andrej Ipavec, Katarina Šter, Maruša Mrak, Sabina Dolenec, 2021, izvirni znanstveni članek Povzetek: Huge quantities of fly ash and bottom ash are generated from thermal power plants and it presents great concern for country, mainly due to the environmental effects. In this study, fly ashes and bottom ash were characterized from technical and radiological aspects. Health effect due to the activity of radionuclides 226Ra, 232Th and 40K was estimated via radium equivalent activity (Raeq), external hazards index (Hex), the external absorbed dose rate (D) and annual effective dose rate (EDR). The specific surface area (40.25 m2 g−1), particle density (1.88 g cm−3) and LOI (23.49%) were typical for bottom ash. Siliceous fly ash contained 32% reactive silica. The annual effective dose rate for all ashes is ≤ 0.2 mSv y−1. Both, fly ash and bottom ash present potential secondary raw materials to be used for building purposes as result of their technological and radiological assessment.
Ključne besede: fly ash, bottom ash, gamma spectrometry, building materials
Objavljeno v DiRROS: 22.05.2023; Ogledov: 371; Prenosov: 154
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4. Radiological and physico-chemical characterization of red mud as an Al-containing precursor in inorganic binders for the building industryLjiljana Kljajević, Miljana Mirković, Sabina Dolenec, Katarina Šter, Mustafa Hadžalić, Ivana Vukanac, Miloš Nenadović, 2021, izvirni znanstveni članek Povzetek: The potential re-use of red mud in the building and construction industry has been the subject of research of many scientists. The presented research is a contribution to the potential solution of this environmental issue through the synthesis of potential construction materials based on red mud. A promising way of recycling these secondary raw materials is the synthesis of alkali-activated binders or alkali activated materials. Alkali-activated materials or inorganic binders based on red mud are a new class of materials obtained by activation of inorganic precursors mainly constituted by silica, alumina and low content of calcium oxide. Since red mud contains radioactive elements like 226Ra and 232Th, this may be a problem for its further utilization. The content of naturally occurring radionuclides in manufactured material products with potential application in the building and construction industry is important from the standpoint of radiation protection. Gamma radiation of the primordial radionuclides, 40K and members of the uranium and thorium series, increases the external gamma dose rate. However, more and more precedence is being given to limiting the radiological dose originating from building materials on the population these days. The aim of this research was to investigate the possible influence of alkali activation-polymerization processes on the natural radioactivity of alkali activated materials synthesized by red mud (BOKSIT a. d. Milići, Zvornik, Bosnia and Herzegovina) and their structural properties. This research confirmed that during the polymerization process the natural radioactivity was reduced, and that the process of alkali activation of raw materials has an influence on natural radioactivity of synthesized materials.
Ključne besede: red mud, inorganic binder, DRIFT, natural radioactivity, gamma index, building industry
Objavljeno v DiRROS: 12.05.2023; Ogledov: 425; Prenosov: 137
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5. Freeze-casting of highly porous cellulose-nanofiber-reinforced γ-Al2O3 monolithsHermina Hudelja, Thomas Konegger, Bernd Wicklein, Janko Čretnik, Farid Akhtar, Andraž Kocjan, 2021, izvirni znanstveni članek Povzetek: Freeze-casting is a powerful consolidation technique for the fabrication of highly porous and layered-hybrid materials, including ceramic-metal composites, and porous scaffolds for catalysis, bone substitutes and high- performance membranes. The aqueous suspensions to be freeze-casted usually contain dense particles facilitating macroporous, layered ceramics with dense (nonporous) struts. In the present study, hierarchical macro-mesoporous alumina (HMMA) monoliths were successfully prepared by freeze-casting of aqueous suspensions containing hierarchically-assembled, mesoporous γ‒Al2O3 (MA) powder and cellulose nanofibers (CNF). As- prepared monoliths were ultra-porous (93.1–99.2%), had low densities (0.01–0.25 g/cm3), and displayed relatively high surface areas (91–134 m2/g), but were still remarkably rigid with high compressive strengths (up to 52 kPa). Owing to the columnar porosity and mesoporous nature of the struts the freeze-casted HMMA monoliths exhibited high permeability and high thermal insulation, the latter ranging from 0.039 W/m∙K to 0.071 W/m∙K, depending on pore orientation.
Ključne besede: cellulose nanofiber, freeze-casting, gamma alumina, hierarchical porosity, insulative materials
Objavljeno v DiRROS: 09.05.2023; Ogledov: 347; Prenosov: 235
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6. Carboxypeptidase cathepsin X defines a multifunctional role of gamma-enolase in cancerTjaša Vižin, Anja Pišlar, Ib Jarle Christensen, Hans Jørgen Nielsen, Pika Meško-Brguljan, Janko Kos, 2022, izvirni znanstveni članek Povzetek: Gamma-enolase enzymatic activity is involved in glycolysis, a prevalent process in cancer cell metabolism. Additionally, gamma-enolase has a pro-survival function, exhibited through the active site at the C-terminal end of the molecule. This activity is regulated by cysteine peptidase cathepsin X, which cleaves two amino acids at C-terminal end of gamma-enolase. In clinical practice, the determination of gamma-enolase as a tumour marker does not differ between total, uncleaved and C-terminally cleaved forms. However, levels of uncleaved gamma-enolase alone may provide additional clinical information. In this study we analysed cathepsin X, C- terminally uncleaved and total gamma-enolase in tumour cell lines and sera from 255 patients with colorectal cancer (CRC) by western blot, immunoprecipitation, enzymatic activity, ELISAs and ECLIA. Results show that uncleaved gamma-enolase, rather than total gamma- enolase, exhibits different levels in cells, being the highest in those, derived from metastatic sites or highly invasive tumours. Gamma-enolase is secreted into the extracellular space predominantly as an uncleaved form and levels were congruent to those within the cells. Furthermore, levels of uncleaved gamma-enolase in cells are inversely related to cathepsin X protein level and its enzymatic activity. Uncleaved gamma-enolase is also predominant form in sera of patients with CRC. Both forms exhibit similar stage dependent distribution, with slightly elevated levels in stage IV patients. Higher levels of total gamma-enolase are significantly related to shorter survival in patients with metastatic CRC. Results support evidence of additional pro-survival function of gamma-enolase in cancer. Future studies should focus on analysis of uncleaved gamma-enolase in tumour samples, which may provide additional relations to clinical indicators of disease progression.
Ključne besede: cancer, cathepsin X, cell survival, gamma-enolase, prognosis
Objavljeno v DiRROS: 06.04.2022; Ogledov: 881; Prenosov: 481
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7. Neutralizing anti-interferon-[gamma] autoantibodies: an ameliorating factor in COVID-19 infection?Mark Kačar, Paulina Cortes-Acevedo, Vinesh Patel, Clive Carter, Pamela Hughes, Hugh P. McGann, Effrossyni Gkrania-Klotsas, Helen Baxendale, Gabriela Barcenas-Morales, Rainer Doffinger, Sinisa Savic, 2021, drugi znanstveni članki Ključne besede: SARS-CoV-2, COVID-19, interferon-gamma, respiratory distress syndrome, nontuberculous mycobacteria, macrophage activation syndrome, acute respiratory distress syndrome
Objavljeno v DiRROS: 09.11.2021; Ogledov: 1133; Prenosov: 280
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8. Identification of critical transcriptomic signaling pathways in patients with H syndrome and Rosai-Dorfman diseaseSamuel Lara-Reyna, James A. Poulter, Elton J.R. Vasconcelos, Mark Kačar, Michael F. McDermott, Reuben Tooze, Rainer Doffinger, Sinisa Savic, 2021, izvirni znanstveni članek Povzetek: Biallelic mutations in SLC29A3 cause histiocytosis-lymphadenopathy plus syndrome, also known as H syndrome (HS). HS is a complex disorder, with ~ 25% of patients developing autoinflammatory complications consisting of unexplained fevers, persistently elevated inflammatory markers, and unusual lymphadenopathies, with infiltrating CD68+, S100+, and CD1a[minus] histiocytes, resembling the immunophenotype found in Rosai-Dorfman disease (RDD). We investigated the transcriptomic profiles of monocytes, non-activated (M0), classically activated (M1), and alternatively activated macrophages (M2) in two patients with HS, one without autoinflammatory (HS1) and one with autoinflammatory complications (HS2). RNA sequencing revealed a dysregulated transcriptomic profile in both HS patients compared to healthy controls (HC). HS2, when compared to HS1, had several differentially expressed genes, including genes associated with lymphocytic-histiocytic predominance (e.g. NINL) and chronic immune activation (e.g. B2M). The transcriptomic and cytokine profiles of HS patients were comparable to patients with SAID with high levels of TNF. SERPINA1 gene expression was found to be upregulated in all patients studied. Moreover, higher levels of IFN[gamma] were found in the serum of both HS patients when compared to HC. Gene ontology (GO) enrichment analysis of the DEGs in HS patients revealed the terms "type I IFN," "IFN[gamma] signaling pathway," and "immune responses" as the top 3 most significant terms for monocytes. Gene expression analysis of lymph node biopsies from sporadic and H syndrome-associated RDD suggests common underlying pathological process. In conclusion, monocytes and macrophages from both HS patients showed transcriptomic profiles similar to SAIDs and also uniquely upregulated IFN[gamma] signature. These findings may help find better therapeutic options for this rare disorder.
Ključne besede: interferon-gamma, H syndrome, systemic autoinflammatory disease
Objavljeno v DiRROS: 08.04.2021; Ogledov: 1217; Prenosov: 598
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