26 research outputs found
A search for candidate radio supernova remnants in the nearby irregular starburst galaxies NGC 4214 and NGC 4395
We present the results of a search for new candidate radio supernova remnants (SNRs) in the nearby starburst irregular galaxies NGC 4214 and NGC 4395 using archived radio observations made with the Very Large Array (VLA) at the wavelengths of 3.5 cm, 6 cm and 20 cm for NGC 4214 and 6 cm and 20 cm for NGC 4395. These observations were analyzed as part of our ongoing search for candidate radio SNRs in nearby galaxies: the goal of this search is to prepare a large sample of candidate radio SNRs for the purpose of a robust statistical study of the properties of these sources. Based on our analysis, we have confirmed the nonthermal nature of the discrete radio sources α and β in NGC 4214 and classify these sources as candidate radio SNRs based on their positional coincidences with HII regions in that galaxy. We have measured the flux densities of the two candidate radio SNRs at each wavelength and calculated corresponding spectral indices: we have also measured flux densities of two other discrete radio sources in these galaxies - ρ in NGC 4214 and #3 in NGC 4395 which we suspect to be additional candidate radio SNRs based on their positional coincidences with other HII regions in these galaxies. However, the radio data presently available for these sources cannot confirm such a classification and additional observations are needed. We have also calculated the radio luminosities Lradio at the wavelength of 20 cm for these two candidate radio SNRs as well as the corresponding values for the minimum total energy Emin required to power these radio sources via synchrotron emission and the corresponding magnetic field strength Bmin. We have compared our mean calculated values for these properties with the mean values for populations of candidate radio SNRs in other starburst galaxies: while the values for Lradio and Bmin are roughly comparable to the values seen in other starburst galaxies, the mean value for Emin is higher than the mean value of any other starburst galaxy. Finally, we include these two candidate radio SNRs in a discussion of the Σ − D relation for extragalactic candidate radio SNRs and find that these sources are located on the shallower end of the master Σ − D relation for all extragalactic SNRs as derived by Urošević et al.(2005).published_or_final_versio
Examination of Prooxidative Activity of Red Wine in Melanoma Cells
Melanoma is responsible for 75% of all deaths from skin cancer. Its lethality arises from its rapid progression, easy metastasis and drug-resistance as well. Red wine is a natural product rich in polyphenolic compounds with potent anticancer activities. It seems that in cancer cells these compounds behave as prooxidants initiating reactive oxygen species mediated cellular DNA breakage and consequent cell death. The aim of this study was to investigate prooxidative activity of red wine samples (Merlot variety, commercial as well as VCR1 and VCR101 clonal wines) in melanoma A375 cells, through measuring the relationship of reduced and oxidized form of glutathione (GSH/GSSG) and comparison with the GSH/GSSG ratio in control (untreated melanoma cells). The data obtained showed that tested red wine samples decrease GSH/GSSG ratio in A375 cells compared to control (4.6 ± 0), with the largest decrease noticed in treatment with VCR101 wine (0.66 ± 0.05)
Citotoksično dejstvo crvenog vina na tumorske ćelije u in vitro uslovima
Benefitni efekat crvenog vina na zdravlje ljudi od davnina je poznat. Među alkoholnim pićima crveno vino pokazuje najjači efekat protiv pojave oboljenja povezanih sa oksidativnim stresom, kao što su kardiovaskularna, neurodegenerativna oboljenja, dijabetes i kancer.1 U okviru ove studije ispitan je citotoksični efekat crvenog vina sorte merlo (komercijalno dostupno vino i vina dobijena od klonova VCR1 i VCR101) poreklom iz Crne Gore, berba 2011, u odnosu na ćelijsku liniju kancera pankreasa (PANC-1) i ćelijsku liniju melanoma (A375). Citotoksični efekat vina je određen SRB metodom kroz praćenje ćelijskog preživljavanja kancerskih ćelija 48 sati nakon tretmana sa tri različita zapreminska procenta analiziranih vina (5, 10 i 20%). Dobijeni rezultati su pokazali citotoksični efekat svih analiziranih vina na obe ćelijske linije. Ćelijsko preživljavanje nakon tretmana vinima se kretalo od 36 do 64%. Citotoksični efekat svih vina u odnosu na A375 ćelije je bio veći nego na PANC-1 ćelijsku liniju, što je od posebnog značaja ako se uzme u obzir rezistentnost melanomskih ćelija na postojeće terapeutske tretmane. Takođe, klonska sortna vina su pokazala veći citotoksični efekat na A375 ćelijsku liniju od komercijalno dostupnog vina. Dobijeni rezultati su ukazali da umereno konzumiranje crvenog vina sorte merlo sa specifičnim geografskim poreklom predstavlja dobar izvor bioaktivnih komponenata sa pozitivnim biološkim efektom, što je od posebne važnosti za klonska sortna vina.3. kongres biologa Srbije : osnovna i primenjena istraživanja, metodika nastave, 21-25. septembar 2022., Zlatibor, Srbij
In vitro biological effects of clonal red wines
This study aimed to determine the phenolic compound content, in vitro antioxidative potential, and cytotoxic effects of four red wine samples: a commercial (V) and three clonal wines (V1, V2, and V3). LC/MS-MS, cyclic voltammetry, and MTT assay techniques were employed for this purpose. Results revealed that all wines were rich in phenolic compounds. Clonal wines outperformed the commercial ones in most phenolic compounds (except myricetin). Notably, V2 and V3 showed the highest levels of gallic acid, catechin, and epicatechin. Among them, V3 exhibited superior antioxidative activity. The MTT assay demonstrated stronger cytotoxic effects of the wine samples on pancreas (Bx-PC3) and colon (HT29) carcinoma cells (47% to 16% and 27% to 7% compared to control, respectively) than on the normal lung fibroblasts (MRC-5) cell line (106% to 77%). It can be concluded that HT29 cells were more sensitive than Bx-PC3 cells. Finally, both clonal and commercial wines serve as valuable sources of polyphenolic compounds, which could have a significant role in preventing cancer and diseases related to oxidative stress.ICCBIKG 2023 : 2nd International Conference on Chemo and Bioinformatics, 28-29 September 2023, Kragujevac, Serbi
Astrobiological Complexity with Probabilistic Cellular Automata
Search for extraterrestrial life and intelligence constitutes one of the
major endeavors in science, but has yet been quantitatively modeled only rarely
and in a cursory and superficial fashion. We argue that probabilistic cellular
automata (PCA) represent the best quantitative framework for modeling
astrobiological history of the Milky Way and its Galactic Habitable Zone. The
relevant astrobiological parameters are to be modeled as the elements of the
input probability matrix for the PCA kernel. With the underlying simplicity of
the cellular automata constructs, this approach enables a quick analysis of
large and ambiguous input parameters' space. We perform a simple clustering
analysis of typical astrobiological histories and discuss the relevant boundary
conditions of practical importance for planning and guiding actual empirical
astrobiological and SETI projects. In addition to showing how the present
framework is adaptable to more complex situations and updated observational
databases from current and near-future space missions, we demonstrate how
numerical results could offer a cautious rationale for continuation of
practical SETI searches.Comment: 37 pages, 11 figures, 2 tables; added journal reference belo
Superposition operators between weighted Banach spaces of analytic functions of controlled growth
The final publication is available at Springer via: http://dx.doi.org/10.1007/s00605-012-0441-6[EN] We characterize the entire functions which transform a weighted Banach space of holomorphic functions on the disc of type H∞ into another such space by superposition. We also show that all the superposition operators induced by such entire functions map bounded sets into bounded sets and are continuous. Superposition operators that map bounded sets into relatively compact sets are also considered. © 2012 Springer-Verlag Wien.The research of Bonet was partially supported by MICINN and FEDER Project MTM2010-15200, by GV project Prometeo/2008/101, and by ACOMP/2012/090. The research of Vukotic was partially supported by MICINN grant MTM2009-14694-C02-01, Spain and by the European ESF Network HCAA ("Harmonic and Complex Analysis and Its Applications").Bonet Solves, JA.; Vukotić, D. (2013). Superposition operators between weighted Banach spaces of analytic functions of controlled growth. Monatshefte für Mathematik. 170(3-4):311-323. https://doi.org/10.1007/s00605-012-0441-6S3113231703-4Álvarez, V., Márquez, M.A., Vukotić, D.: Superposition operators between the Bloch space and Bergman spaces. Ark. Mat. 42, 205–216 (2004)Appell, J., Zabrejko, P.P.: Nonlinear Superposition Operators, Cambridge Tracts in Mathematics 95. Cambridge University Press, London (1990)Appell, J., Zabrejko, P.P.: Remarks on the superposition operator problem in various function spaces. Complex Var. Elliptic Equ. 55(8–10), 727–737 (2010)Bierstedt, K.D., Bonet, J., Galbis, A.: Weighted spaces of holomorphic functions on bounded domains. Michigan Math. J. 40, 271–297 (1993)Bierstedt, K.D., Bonet, J., Taskinen, J.: Associated weights and spaces of holomorphic functions. Studia Math. 127, 137–168 (1998)Bonet, J., Domański, P., Lindström, M.: Essential norm and weak compactness of composition operators on weighted Banach spaces of analytic functions. Can. Math. Bull. 42(2), 139–148 (1999)Bonet, J., Domański, P., Lindström, M., Taskinen, J.: Composition operators between weighted Banach spaces of analytic functions. J. Aust. Math. Soc. (Ser. A) 64, 101–118 (1998)Boyd, C., Rueda, P.: Holomorphic superposition operators between Banach function spaces. Preprint (2011)Boyd, C., Rueda, P.: Superposition operators between weighted spaces of analytic functions. Preprint (2011)Buckley, S.M., Fernández, J.L., Vukotić, D.: Superposition operators on Dirichlet type spaces. In: Papers on Analysis: A Volume dedicaed to Olli Martio on the occasion of his 60th birthday. Rep. Univ. Jyväskyla Dept. Math. Stat, vol. 83, pp. 41–61. Univ. Jyväskyla, Jyväskyla (2001)Buckley, S.M., Vukotić, D.: Univalent interpolation in Besov spaces and superposition into Bergman spaces. Potential Anal. 29(1), 1–16 (2008)Cámera, G.A.: Nonlinear superposition on spaces of analytic functions. In: Harmonic Analysis and Operator Theory (Carácas, 1994), Contemp. 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In: Functional Analysis (Trier, 1994), pp. 249–280. de Gruyter, Berlin (1996)Levin, B.Ya.: Lectures on Entire Functions. Translations of Mathematical Monographs, vol. 150, Amer. Math. Soc., Providence (1996).Lusky, W.: On weighted spaces of harmonic and holomorphic functions. J. Lond. Math. Soc. 51, 309–320 (1995)Lusky, W.: On the isomorphism classes of weighted spaces of harmonic and holomorphic functions. Studia Math. 175, 19–45 (2006)Pommerenke, Ch.: Boundary Behaviour of Conformal Maps. Springer, Berlin (1992)Ramos Fernández, J.C.: Bounded superposition operators between weighted Banach spaces of analytic functions. Preprint, Available from http://arxiv.org/abs/1203.5857Shields, A.L., Williams, D.L.: Bounded projections, duality and multipliers in spaces of analytic functions. Trans. Am. Math. Soc. 162, 287–302 (1971)Vukotić, D.: Integrability, growth of conformal maps, and superposition operators, Technical Report 10. 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A search for candidate radio supernova remnants in the nearby irregular starburst galaxies NGC 4214 and NGC 4395
We present the results of a search for new candidate radio supernova remnants (SNRs) in the nearby starburst irregular galaxies NGC 4214 and NGC 4395 using archived radio observations made with the Very Large Array (VLA) at the wavelengths of 3.5 cm, 6 cm and 20 cm for NGC 4214 and 6 cm and 20 cm for NGC 4395. These observations were analyzed as part of our ongoing search for candidate radio SNRs in nearby galaxies: the goal of this search is to prepare a large sample of candidate radio SNRs for the purpose of a robust statistical study of the properties of these sources. Based on our analysis, we have confirmed the nonthermal nature of the discrete radio sources α and β in NGC 4214 and classify these sources as candidate radio SNRs based on their positional coincidences with HII regions in that galaxy. We have measured the flux densities of the two candidate radio SNRs at each wavelength and calculated corresponding spectral indices: we have also measured flux densities of two other discrete radio sources in these galaxies - ρ in NGC 4214 and #3 in NGC 4395 which we suspect to be additional candidate radio SNRs based on their positional coincidences with other HII regions in these galaxies. However, the radio data presently available for these sources cannot confirm such a classification and additional observations are needed. We have also calculated the radio luminosities Lradio at the wavelength of 20 cm for these two candidate radio SNRs as well as the corresponding values for the minimum total energy Emin required to power these radio sources via synchrotron emission and the corresponding magnetic field strength Bmin. We have compared our mean calculated values for these properties with the mean values for populations of candidate radio SNRs in other starburst galaxies: while the values for Lradio and Bmin are roughly comparable to the values seen in other starburst galaxies, the mean value for Emin is higher than the mean value of any other starburst galaxy. Finally, we include these two candidate radio SNRs in a discussion of the Σ − D relation for extragalactic candidate radio SNRs and find that these sources are located on the shallower end of the master Σ − D relation for all extragalactic SNRs as derived by Urošević et al.(2005).
Screening for the presence of biosynthetic genes for antimicrobial lipopeptides in natural isolates of Bacillus sp.
A collection of 205 natural isolates of Bacillus was tested for the presence of genes for biosynthesis of antimicrobial lipopeptides, iturin, surfactin, fengycin and bacillomycin D. For the detection of iturin producers by PCR screening, we used forward ITUP1-F and reverse ITUP2-R primers which are capable of detecting a 2-kb region that includes the intergenic sequence between the ituA and ituB genes. A 675-bp fragment from the gene sfp from B. subtilis encoding 4’-phosphopantetheinyl transferase involved in the biosynthesis of surfactin was targeted for amplification by using primers P17 and P18. Other two pairs of primers were BACC1F and BACC1R for bacillomycin D and FEND1F and FEND1R for potential fengycin producers, respectively. The results of the screening showed that the majority of tested strains had more than one biosynthetic operon, since 81% possessed the genes for bacillomycin D production, 54% for surfactin, 38% for iturin and 25% for fengycin production. [Projekat Ministarstva nauke Republike Srbije, br. 173026
Mechanochemical synthesis of CaTiO3 from CaCO3 - TiO2 mixture
The synthesis of calcium titanate, CaTiO3, was performed by mechanical activation and thermal treatment. Milling for up to 360 minutes in a planetary ball mill mechanically activated an equimolar mixture of CaCO 3 and TiO2 powders. A small amount of mechanically activated mixtures was pressed into briquettes and calcined at 850°C for two hours. The effect of mechanical activation on the solid-state reaction was studied using X-ray powder diffraction and differential thermal analysis. The change of morphology and size of powder particles due to milling, were determined by SEM, while BET analysis was used to determine the specific surface area of the powder. The sintering process was followed by a dilatometer during thermal treatment up to 1300°C. The main conclusion of the analysis of conducted investigations is that CaTiO3 ceramics can be obtained from an activated mixture at a much lower temperature than reported in the literature owing to acceleration of the chemical reaction and sintering
Phenolic Composition and Cytotoxic Activity of Red Wine
Positive effects of moderate wine consumption in individuals with cardiovascular disease, hypertension, diabetes, and cancers have been shown in numerous epidemiological and clinical studies. This research examined the phenolic content of commercial and two clonal Merlot wines as well as their biological potential. The obtained results indicated that all analyzed samples were a good source of phenolic compounds. Cytotoxicity assay on melanoma (A375) and cervical (HeLa) cancer cell lines have shown that all analyzed wines inhibited the growth of human cancer cells in vitro with differing susceptibility among tested cell lines. Clonal wines in the volume ratio of 10 and 20% showed to be more efficient anti-proliferative agents than commercial wine regarding the A375 cells. This could be connected with higher total phenolic content in clonal wines. The effect of all analyzed samples on the A375 cells was greater compared to HeLa cell line.XVI International Conference on Fundamental and Applied Aspects of Physical Chemistry, September 26-30, Belgrad