The importance of ergonomic principles in design of the traffic signs for childeren

Children represent a vulnerable population from the standpoint of traffic safety. A modern traffic poses complex and high requirements to all its participants, and among them, particularly to young children. Children have a higher risk of pedestrian injuries. Children are experiencing experience traffic differently from adults. How do children view the world? What helps them to link with their environment? How do children imagine traffic signs? To address these questions, this study examines how fast the children (between 6 and 10 years of age) react to traffic signs mounted at different heights. The analysis of the results indicated that there were differences in mean reaction time for traffic signs of different heights. Children best perceive a traffic sign when it is mounted at 1.9 m. The research highlights the importance of ergonomic principles in choosing the appropriate height of traffic signs for children

Importance of testing proliferative markers of cyclin A and Ki-67 and telomerase in renal cell carcinoma

Karcinom bubrežnih ćelija (RCC) je najrasprostranjeniji oblik karcinoma bubrega i čini oko 2-3% svih karcinoma kod odraslih, češće kod muškaraca. U svetu se beleži porast obolelih usled primene savremene tehnologije u dijagnostici koja omogućava raniju i precizniju dijagnostiku RCC. Najčešći histološki podtipovi RCC su: svetloćelijski, papilarni, hromofobni, karcinom sabirnih kanala i neklasifikovani. Proliferativni markeri ciklin A, Ki-67 i telomeraza su bitni u dijagnostici RCC. Cilj: Imunohistohemijski ispitati intenzitet ekspresije ciklina A, Ki67 i telomeraze kod RCC i analizirati korelaciju ovih ekspresija sa kliničko-morfološkim karakteristikama RCC. Analizirati prisustvo mutacija i polimorfizma, amplifikaciju i metilacioni status u promotorskom regionu hTERT gena kod ispitivanih pacijenata sa RCC. Materijal i metode: Za istraživanje je korišćen operativni materijal 74 pacijenta obolela od RCC dobijen parcijalnom nefrektomijom koji je posle obrade i kalupljenja, najpre obojen hematoksilin-eozinom i postavljena je histopatološka dijagnoza RCC, a kasnije su rađene imunohistohemijske metode i molekularno-genetičko istraživanja. Rezultati: Imunohistohemijska ispitivanja ekspresije ciklina A u tkivu RCC pokazala su da postoji statistički značajna razlika ekspresije ciklina A kod različitih histopatoloških tipova. Najintenzivnija ekspresija uočena je u slučajevima papilarnog RCC. Imunohistohemijska ispitivanja ekspresije Ki67 pokazala je da je kod papilarnog RCC dobijena je izrazita pozitivnost u odnosu na preostala dva analizirana histopatološka tipa. Takođe, imunohistohemijska ekspresija telomeraze drastično je veća kod papilarnog RCC u odnosu na ostala dva histopatološka tipa. Sekvenciranje 343 bp dugog promotorskog regiona nije ukazalo na aktivaciju mutacija ni u jednom od ispitivanih uzorka RCC, ali je otkriveno prisustvo tranzicije T/C na poziciji -245 bp. Genska amplifikacija je uočena kod 19.4% pacijenata. HTERT promotor je bio metilovan u 54,8% uzoraka. Zaključak: Proliferativni markeri ciklin A, Ki67 i telomeraze imaju veliki prognostički značaj kod RCC, naročito kod papilarnog RCC. Sekvenciranjem je otkriveno prisustvo tranzicije T/C na poziciji -245 bp. Mutirani alel bio je prisutan u homozigotnom obliku u 7,4%, u heterozigotnom obliku u 40,7%, a 51.9% bilo je homozigotno za nemutirani tip gena (wt alel). Nije uočena povezanost između hTERT amplifikacije i epidemioloških, kliničkih i patoloških nalaza. Značajna razlika zapažena je između histopatoloških tipova tumora, pošto je kod hromofobnog histopatološkog tipa, kod svih 5 pacijenata hTERT promotor bio metilovan.Renal Cell Carcinoma (RCC) is the most common form of renal cancer and makes approximately 2-3% of all carcinoma in adults, being expresed more often in males. An increase in the number of deseased is detected due to the implementation of most contemporary technology in diagnostics that enables an early and accurate diagnostics of RCC. The most common histological subtypes of RCC are the following: clear cell, papillary, chromophobe, collecting duct carcinoma and unclassified. The proliferative markers cycline A, Ki-67 and telomerase are significant in RCC diagnostics. Aims: The goal was to immunohistochemically investigate into the intensity of the cycline A, Ki-67 and telomerase expression in RCC and analyse the correlation of these expressions with clinical-morphological characteristics of RCC. The goal was also to analyse the presence of mutations and polymorphism, gene amplification and metilation status in the hTERT promotor gene region in the examined RCC patients. Materials and Methods: The operational material used in the research was that taken from 74 patients diagnosed with RCC, obtained through partial nephrectomy, which was, following the processing and moulding, first stained by hematoxylin and eosin and then RCC was diagnosed; immunohistochemical methods and molecular-genetic research ensued. Results: Immunohistochemical investigation into the cycline A expression in the RCC tissue have shown a statistically significant discrepancies in the cycline A expression among different histopathological types. The most intensive expression is observed in the cases of papillary RCC. The immunohistochemical investigations into the Ki-67 expression have demonstrated a distinct positivity in comparison with the two other analyzed histopathological types. Similarly, the immunohistopathological expression of telomerase is dramatically higher in papillary RCC in comparisson with the other two histopathological types. The sequencing of 343 bp long promotor region has failed to demonstrate any activation of mutations in any of the examined RCC samples, however, it has shown the presence of T/C transition at the -245 bp position. The gene amplification has been observed in 19.4% patients. HTERT promotor was methylated in 54.8% samples. Conclusion: Proliferative markers, cyclin A, Ki67, and telomerases have great prognostic significance in RCC, especially in papillary RCC. Sequencing detected the presence of the T/C transition at -245 bp position. The variant allele was present in homozygous form in 7.4%, in heterozygous in 40.7%, and 51.9% were homozygous for the wild type allele. There was no association between hTERT amplification and epidemiological, clinical and pathological findings. A significant difference was observed between histopathological types of tumors, since in chromophobe histopathological type, in all 5 patients, the hTERT promoter was methylated

The possibility of obtaining beta-anhydrite from waste nitrogypsum

The possibility of obtaining β - anhydrite from nitrogypsum, which is waste from a nitrocellulose plant, was investigated. It was shown by means of qualitative IR analysis that the product obtained by heating nitrogypsum for 5 hours at 700 o C was â - anhydrite. When the β- anhydrite was mixed with water at a W/S (water/solid) ratio of 0.54 in presence of different accelerators (CaO, mixture CaO - ash, ash, Na2SO4 and K2SO4), pastes were formed which hardened on standing. The compressive strength of the hardened samples was measured after 7 and 28 days and their composition determined by qualitative IR analysis. On the basis of these results, it was observed that a relationship exists between the composition (depending on the used accelerator) and the compression strength of the samples. Namely, the formation of large cores of double salts: syngenite (K2SO4 ⋅CaSO4 ⋅H2O) and glauberite (Na2SO4 ⋅CaSO4), in the presence of the accelerators K2SO4 and Na2SO4, respectively, was due to the rapid and complete crystallization of the dihydrate (CaSO4 ⋅2H2O). This fast crystal growth of the dihydrate resulted in high compressive strengths of these samples. In the other samples (prepared in presence of the accelerators: CaO, mixture CaO - ash and ash), dihydrate did not form and, consequently, their compressive strength was low

The Impact of One Heat Treated Contact Element on the Coefficient of Static Friction

The subject of the paper includes theoretical considerations, the conducting of experimental tests, and the analysis of exposed test results related to determination of the coefficient of static friction of previously heat-treated contact pairs. One contact element is previously, before the procedure of determining the coefficient of static friction, heated at temperatures in the range of ambient temperature to 280°C and then cooled down to ambient temperature. The results of experimental tests of five different materials show that depending on the heat treatment of one contact element, there is a significant decrease in the coefficient of static friction. The authors of the paper consider that the reasons for the decreasing coefficient of static friction are related to oxide formation and changes in the surface layer of the contact element which is previously heat-treated

Hemijske karakteristike visoko-krečnjačkih zemljišta koje određuju raspodelu fosfora

Phosphorus fractions from three highly calcareous soils (average, 24.9 +/- 4.8 %CO32-) from sampling sites with a Mediterranean climate were isolated by sequential extraction. In order to provide a more reliable basis for the definition of the obtained P-fractions, principal component analysis was applied and from the chemical characteristics of the 14 investigated soils, those characteristics which define at he content and association features of the P-fractions were assessed. The soils are characterized by a relatively high pH (8.0-8.2) and by significantly differing contents of organic mater, acid-soluble Mg and total P. These differences affected the various association features of the P-fraction with the soil constituents. The NH4F-P fraction (isolated with 0.5 M NH4F, pH 8.2) is defined by the contents of the main metals of the oxide-hydroxide-clay associations (Al, Fe, Mn) or by the the redox potential (Eh) of Mn. The accumulation of NaOH-phosphorus (extractable with 0.1 M NaOH) depended on the constituents of the oxide hydroxide-clay association, the humic substances and Eh-related factors. In those soils in which NaOH-P is defined by the oxide-hydroxide-clay association, the participation of Fe as a bridge-forming metal is proposed. The main part of total P, i.e., Delta P = TP - (NH4F-P + NaOH-P) is defined by the status of Mn- and Fe-humic complexes or by the concentration of hydroxyl-ions.Iz tri visoko-krečnjačka zemljišta (prosečni sadržaj CO 3 2- 24.9 ± 4.8%, pH 8.0 - 8.2), sa lokacija sa sredozemnom klimom, izolovane su frakcije fosfora sekvencijalnom ekstrakcijom. U cilju obezbeđivanja pouzdanije osnove za definisanje dobijenih frakcijafosfora (P-frakcija), primenjena je analiza principalne komponente (PC-analiza). Među 14 hemijskih karakteristika zemljišta, izdvojene su one koje definišu sadržaj pojedinih P-frakcija i prirodu njihove asocijacije sa sastojcima zemljišta. Frakcija NH 4-P (izolovana sa 0,5M NH 4F, pH = 8,2) definisana je sadržajem glavnih metala oksidne-hidroksidne-glinene asocijacije (Al, Fe, Mn) ili Eh-statusom izraženim sadržajem Mn. Akumulacija NaOH-P (ekstrahovanog sa 0,1 M NaOH) zavisila je od sastojaka oksidne-hidroksidne-glinene asocijacije, od huminskih supstanci i od faktora koji stoje u vezi sa Eh. U onim zemljištima u kojima je NaOH-P definisana sastojcima oksidne-hidroksidne-glinene asocijacije, pretpostavljeno je vezivanje fosfora preko Fe-mostova. Glavna količina fosfora ∆P = TP - (NH 4F-P + NaOH-P), u pojedinim zemljištima definisana je ili statusom Mn- i Fe-huminskih kompleksa, ili pH-vrednošću

The importance of ergonomic principles in design of the traffic signs for childeren

Children represent a vulnerable population from the standpoint of traffic safety. A modern traffic poses complex and high requirements to all its participants, and among them, particularly to young children. Children have a higher risk of pedestrian injuries. Children are experiencing experience traffic differently from adults. How do children view the world? What helps them to link with their environment? How do children imagine traffic signs? To address these questions, this study examines how fast the children (between 6 and 10 years of age) react to traffic signs mounted at different heights. The analysis of the results indicated that there were differences in mean reaction time for traffic signs of different heights. Children best perceive a traffic sign when it is mounted at 1.9 m. The research highlights the importance of ergonomic principles in choosing the appropriate height of traffic signs for children

Supplementary data for article: Rakić, A. A.; Vukomanović, M.; Trifunović, S.; Travas-Sejdic, J.; Chaudhary, O. J.; Horský, J.; Ćirić-Marjanović, G. Solvent Effects on Dopant-Free PH-Falling Polymerization of Aniline. Synthetic Metals 2015, 209, 279–296. https://doi.org/10.1016/j.synthmet.2015.07.031

Supplementary material for: [https://doi.org/10.1016/j.synthmet.2015.07.031]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1996

Supplementary data for the article: Kojić, I.; Bechtel, A.; Aleksić, N.; Životić, D.; Trifunović, S.; Gajica, G.; Stojanović, K. Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal. Polymers 2021, 13 (5), 759. https://doi.org/10.3390/polym13050759.

Supplementary material for: [https://doi.org/10.3390/polym13050759]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4397

Increased H3K27 trimethylation contributes to cone survival in a mouse model of cone dystrophy

Inherited retinal diseases (IRDs) are a heterogeneous group of blinding disorders, which result in dysfunction or death of the light-sensing cone and rod photoreceptors. Despite individual IRDs (Inherited retinal disease) being rare, collectively, they affect up to 1:2000 people worldwide, causing a significant socioeconomic burden, especially when cone-mediated central vision is affected. This study uses the Pde6c$^{cpfl1}$ mouse model of achromatopsia, a cone-specific vision loss IRD (Inherited retinal disease), to investigate the potential gene-independent therapeutic benefits of a histone demethylase inhibitor GSK-J4 on cone cell survival. We investigated the effects of GSK-J4 treatment on cone cell survival in vivo and ex vivo and changes in cone-specific gene expression via single-cell RNA sequencing. A single intravitreal GSK-J4 injection led to transcriptional changes in pathways involved in mitochondrial dysfunction, endoplasmic reticulum stress, among other key epigenetic pathways, highlighting the complex interplay between methylation and acetylation in healthy and diseased cones. Furthermore, continuous administration of GSK-J4 in retinal explants increased cone survival. Our results suggest that IRD (Inherited retinal disease)-affected cones respond positively to epigenetic modulation of histones, indicating the potential of this approach in developing a broad class of novel therapies to slow cone degeneration