756 research outputs found

    Angular and spatial distributions of protons channeled in a bent and radially deformed single-wall boron-nitride nanotubes

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    This study is devoted to the angular and spatial distribution of protons channeling through a bent and radially deformed single-wall boron-nitride nanotubes (SWBNNTs). These nanotubes are more thermal and chemical stable then carbon nanotubes, and they are good candidates for future channeling experiments. This investigation is continuation of our previous study [1, 2] and now we investigate channeling properties of SWBNNTs as a function of the very realistic effects: bending angle of nanotube and its radial deformation. For the first time we presented here investigation of these effects with boron-nitride nanotubes and combination of both effect. The angular and spatial distributions of channeled protons were generated using the Molière’s expression for the continuum potential of the SWBNNT’s atoms and computer simulation method. We also calculate the total yield of protons channeled in the nanotubes as a function of the bending angle. We demonstrate that varying bending angle and taking into account radial deformation we can get a significant rearrangement of the propagating protons within the boron-nitride nanotube. This investigation may be very useful to give us detailed information on the relevant interaction potentials inside SWBNNTs and for creating nanosized proton beams to be used in different applications in medicine and materials science. © 2019, Editura Academiei Romane. All rights reserved

    Angular and spatial distributions of protons channeled in a bent and radially deformed single-wall boron-nitride nanotubes

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    This study is devoted to the angular and spatial distribution of protons channeling through a bent and radially deformed single-wall boron-nitride nanotubes (SWBNNTs). These nanotubes are more thermal and chemical stable then carbon nanotubes, and they are good candidates for future channeling experiments. This investigation is continuation of our previous study [1, 2] and now we investigate channeling properties of SWBNNTs as a function of the very realistic effects: bending angle of nanotube and its radial deformation. For the first time we presented here investigation of these effects with boron-nitride nanotubes and combination of both effect. The angular and spatial distributions of channeled protons were generated using the Molière’s expression for the continuum potential of the SWBNNT’s atoms and computer simulation method. We also calculate the total yield of protons channeled in the nanotubes as a function of the bending angle. We demonstrate that varying bending angle and taking into account radial deformation we can get a significant rearrangement of the propagating protons within the boron-nitride nanotube. This investigation may be very useful to give us detailed information on the relevant interaction potentials inside SWBNNTs and for creating nanosized proton beams to be used in different applications in medicine and materials science. © 2019, Editura Academiei Romane. All rights reserved

    Bifid and secondary superior nasal turbinates

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    The lateral nasal wall contains the nasal turbinates (conchae) which are used as landmarks during functional endoscopic surgery. Various morphological pos- sibilities of turbinates were reported, such as bifidity of the inferior turbinate and extra middle turbinates, such as the secondary middle turbinate. During a retrospective cone beam computed tomography study of nasal turbinates in a patient we found previously unreported variants of the superior nasal turbina- tes. These had, bilaterally, ethmoidal and sphenoidal insertions. On the right side we found a bifid superior turbinate and on the left side we found a secondary superior turbinate located beneath the normal/principal one, in the superior nasal meatus. These demonstrate that if a variant morphology is possible for a certain turbinate, it could occur in any nasal turbinate but it has not been yet observed or reported.

    A new ornithopod dinosaur, Transylvanosaurus platycephalus gen. et sp. nov. (Dinosauria: Ornithischia), from the Upper Cretaceous of the Haţeg Basin, Romania

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    Rhabdodontid dinosaurs were a group of medium-sized iguanodontian ornithopods from the Late Cretaceous of Europe. The uppermost Cretaceous continental deposits from the Haţeg Basin of western Romania yielded a very rich assemblage of vertebrates including abundant rhabdodontid remains, which have been exclusively referred to the genus Zalmoxes thus far. Here we describe a new rhabdodontid dinosaur, Transylvanosaurus platycephalus gen. et sp. nov., from the uppermost Cretaceous of the Haţeg Basin. The holotype of the new taxon was discovered in early–late Maastrichtian strata near Pui in the eastern part of the basin and comprises the articulated basicranium and both frontals. Transylvanosaurus differs from all previously reported rhabdodontids in having particularly wide and crested frontals, elongated and straight paroccipital processes that make only a gentle lateral curve and project mostly posterolaterally, prominent and massive prootic processes that extend mainly anterolaterally and ventrally, wide and crest-like basal tubera that meet the long axis of the braincase at a very flat angle, widely splayed basipterygoid processes that extend mainly ventrolaterally and slightly anteriorly, as well as a well-developed notch on the lateral side of the basicranium that is continuous, straight, and inclined anteroventrally. Phylogenetic analyses employing two different datasets consistently recovered the new taxon within the Rhabdodontidae, at the base of the iguanodontian radiation. Based on the morphological comparisons presented herein, we propose a particularly close relationship between Transylvanosaurus and Rhabdodon from southern France, which in turn provides evidence for a more complex biogeographic history of the Rhabdodontidae than previously thought

    Phytochemical, Free Radical Scavenging and Antifungal Profile of Cuscuta campestris Yunck. Seeds

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    This work was conceptualized with the goal to investigate the phytochemical, free radical scavenging and antifungal profile of Cuscuta campestrisYunck. seeds. Total phenolics, amino acid and carbohydrate contents were evaluated in ethanolic, acetone and chloroform extract. Effective antioxidant activity was evaluated throughout seven antioxidant methods. The antifungal activity was assessed against eight fungal strains and Candida albicans. The results showed total phenol, flavonoid, flavonols and phenolic acids contents in amount of 1.51-6.35mg GAE/mL, 78-425g RU/mL, 1.04-2.98mg QU/g and 12.01-30.58g CAE/mL, respectively. The total amino acids and carbohydrates content ranged from 8.29 to 185.45g Gly/mL and from 0.05 to 0.12g Glu/mL. The ethanolic extract showed the best antioxidant activity in phosphomolybdenum, DPPH free radical scavenging, ferric reducing power and lipid peroxidation assays. The best activity in ferrous ion chelating and H2O2 assays had the acetone extract, whereas the best hydroxyl radical scavenging activity was observed with the chloroform extract. The ethanolic extract at a concentration of 6mg/mL proved to be the most effective antimycotic, since it inhibited the growth of all tested fungi except Penicillium verrucosum. The obtained results indicate that C.campestris seeds could be attributed to a potential source of natural antioxidants in food and pharmaceutical products.This is the peer-reviewed version of the article: Jakovljević, V. D.; Vrvić, M. M.; Vrbničanin, S.; Sarić-Krsmanović, M. Phytochemical, Free Radical Scavenging and Antifungal Profile of Cuscuta Campestris Yunck. Seeds. Chemistry & Biodiversity 2018, 15 (8). [https://doi.org/10.1002/cbdv.201800174]

    Bioindicative values of microfungi in starch and possible deficiencies of the new Serbian regulation on food hygiene

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    The results of tests on the presence of yeasts and molds in cornstarch [AD ‘IPOK’ Zrenjanin, 2007-2008, made at the time when previous Regulations were valid] were analyzed in terms of bioindicative values of microfungi as indicators of quality and safety of raw material or final food products. Microbiological analysis was used to detect the presence of a number of microorganisms MMI-0001, and a questionnaire was designed at the Department of Public Health in Zrenjanin town (Republic of Serbia), where the anal­yses were done, regarding the microbiological tests on starch. In order to rationalize the analyses and make them more economical, several areas of product quality control (water, food, raw materials, space) were recommended either to be excluded or regarded as optional. Thus, analysis of presence of microfungi as indicators of product quality was categorized as optional. The results obtained from this research suggest a different conclusion because the bacteria in the samples indicated ˮmicrobiologically“, namely bacteriologically, safe samples of food, while, on the contrary, the presence of some microfungi as distinct xerophilous or xerotolerant microorganisms, indicated that the food was mycologically non-safe. The obtained data are crucial for questioning the decision to exclude the earlier required (mycological) analysis of the samples (in the production of starch, or end products, etc.) and categorize such analyses in new Regulations as optional, depending on the manufacturer’s preference. Bioindicative values of microfungi as indicators of the quality of starch, clearly point to the shortsightedness of the new Regulations on food hygiene and safety, where tests on certain microorganisms (in this case, yeasts and molds) are not legally defined as mandatory, but the Law leaves manufacturers a possibility to choose (or not to choose) the testing and frequency of testing on the presence (absence) of microorganisms, which can be risky, both in the production and marketing of the finial products. [Projekat Ministarstva nauke Republike Srbije, br. OI-179079

    Inhibition of endothelial cell functions and of angiogenesis by the metastasis inhibitor NAMI-A

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    NAMI-A is a ruthenium-based compound with selective anti-metastasis activity in experimental models of solid tumours. We studied whether this activity was dependent on anti-angiogenic ability of NAMI-A. We thus investigated its in vitro effects on endothelial cell functions necessary for angiogenesis to develop, as well as its in vivo effects in the chick embryo chorioallantoic membrane model. Endothelial cell proliferation, chemotaxis, and secretion of the matrix-degrading enzyme metalloproteinase-2 were inhibited by NAMI-A in a dose-dependent manner, and without morphologic signs of cell apoptosis or necrosis. Lastly, NAMI-A displayed a dose-dependent in vivo anti-angiogenic activity in the chorioallantoic membrane model. These data suggest that the anti-angiogenic activity of NAMI-A can contribute to its anti-metastatic efficacy in mice bearing malignant solid tumours

    Uticaj meteoroloških parametara na koncentraciju SO2 u Obrenovcu, Srbija

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    In this paper, the impacts of some meteorological parameters on the SO2 concentrations in the City of Obrenovac are presented. The City of Obrenovac is located in the north-west part of Serbia on the banks of the River Sava. The observed source emission, the power plants TENT A and B are situated on the bank of the Sava River in the vicinity of Obrenovac. During the period from January to November 2006, the concentrations of sulfur dioxide in the air at 4 monitoring sites in Obrenovac were measured. It was noticed that the maximal measured daily concentrations of sulfur dioxide ranged from 1 μg m-3 (16th November, 2006) to 98 μg m-3 (29th January 2006) and lie under the maximal allowed concentration value according to the Serbian Law on Environmental Protection. The measured sulfur dioxide concentrations mostly showed characteristics usual for a daily acidification sulfur dioxide cycle, excluding the specificities influenced by the measuring site itself. Sulfur dioxide transport was recorded at increased wind speeds, primarily from the southeast direction. Based on the impact of meteorological parameters on the sulfur dioxide concentration, a validation of the monitoring sites was also performed from the aspect of their representivity.U radu su predstavljeni rezultati monitoringa koncentracije SO2 u vazduhu u Obrenovcu koji se nalazi na severozapadu Srbije na obalama reke Save. Posmatran je uticaj meteoroloških parametara na koncentraciju SO2 emitovanog iz termoelektrana TENT A i B koji se smatraju najvećim izvorima emisije. U periodu od januara do novembra 2006. godine praćene su koncentracije sumpor-dioksida u vazduhu na 4 merna mesta lokalizovana na različitim udaljenostima od izvora emisije. Maksimalne izmerene dnevne koncentracije sumpor-dioksida su se kretale od 1 μg m-3 (16. novembra, 2006) do 24 μg m-3 (29. januara, 2006). Izmerene promene koncentracija sumpor-dioksida uglavnom pokazuju uobičajene karakteristike dnevne acidifikacije ciklusa uz razlike koje potiču od osobenosti mernih mesta. Transport sumpor-dioksida zabeležen je pri pojačanom vetru prvenstveno iz jugoistočnog pravca. Na osnovu korelacionih odnosa između koncentracije sumpor-dioksida i odgovarajućih meteroloških parametara izvršena je karakterizacija mernih mesta u pogledu njihove reprezentativnosti za merenje sumpor-dioksida
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