259 research outputs found
Enhanced borohydride oxidation kinetics at gold-rare earth alloys
No full textsponsorship: The authors would like to thank the Ministry of Education, Science and Technological Development of the Republic of Serbia (contract no. 451-03-68/2020-14/200146). The authors would also like to thank the Portuguese Foundation for Science and Technology (FCT, Portugal) for a research grant within project UID/CTM/04540/2013 (G. Backovic), for contract IST-ID/156/2018 (B. Sljukic), and for a research contract in the scope of programmatic funding UIDP/04540/2020 (D.M.F. Santos). (Ministry of Education, Science and Technological Development of the Republic of Serbia|451-03-68/2020-14/200146, Portuguese Foundation for Science and Technology (FCT, Portugal)|UID/CTM/04540/2013, Portuguese Foundation for Science and Technology (FCT, Portugal)|IST-ID/156/2018, Portuguese Foundation for Science and Technology (FCT, Portugal)|UIDP/04540/2020)status: Publishe
Solar γ rays as a complementary probe of dark matter
No full textWe show that observations of solar γ rays offer a novel probe of dark matter in scenarios where interactions with the visible sector proceed via a long-lived mediator. As a proof of principle, we demonstrate that there exists a class of models which yield solar γ-ray fluxes observable with the next generation of γ-ray telescopes, while being allowed by a variety of current experimental constraints. The parameter space allowed by big bang nucleosynthesis and beam dump experiments naturally leads to mediator lifetimes sufficient to produce observable solar γ-ray signals. The model allows for solar γ-ray fluxes up to orders of magnitude larger compared to dwarf spheroidal galaxies, without reaching equilibrium between dark matter annihilation and capture rate. Our results suggest that solar γ-ray observations are complementary, and in some cases superior, to existing and future dark matter detection efforts
Probing dark matter long-lived mediators with solar γ rays
No full textWe show that solar γ-ray observations can provide a complementary probe of Dark Matter in scenarios where the interactions with the Standard Model proceed via long-lived mediators. For illustration we consider a simplified model which provides solar γ-ray fluxes observable with the next generation γ-ray telescopes, while complying with the existing experimental constraints. Our results suggest that solar γ-ray fluxes can be orders of magnitude larger than the ones from the Galactic center, while being subject to low backgrounds
Capsid protein expression and adeno-associated virus like particles assembly in <it>Saccharomyces cerevisiae</it>
No full textAbstract Background The budding yeast Saccharomyces cerevisiae supports replication of many different RNA or DNA viruses (e.g. Tombusviruses or Papillomaviruses) and has provided means for up-scalable, cost- and time-effective production of various virus-like particles (e.g. Human Parvovirus B19 or Rotavirus). We have recently demonstrated that S. cerevisiae can form single stranded DNA AAV2 genomes starting from a circular plasmid. In this work, we have investigated the possibility to assemble AAV capsids in yeast. Results To do this, at least two out of three AAV structural proteins, VP1 and VP3, have to be simultaneously expressed in yeast cells and their intracellular stoichiometry has to resemble the one found in the particles derived from mammalian or insect cells. This was achieved by stable co-transformation of yeast cells with two plasmids, one expressing VP3 from its natural p40 promoter and the other one primarily expressing VP1 from a modified AAV2 Cap gene under the control of the inducible yeast promoter Gal1. Among various induction strategies we tested, the best one to yield the appropriate VP1:VP3 ratio was 4.5 hour induction in the medium containing 0.5% glucose and 5% galactose. Following such induction, AAV virus like particles (VLPs) were isolated from yeast by two step ultracentrifugation procedure. The transmission electron microscopy analysis revealed that their morphology is similar to the empty capsids produced in human cells. Conclusions Taken together, the results show for the first time that yeast can be used to assemble AAV capsid and, therefore, as a genetic system to identify novel cellular factors involved in AAV biology.</p
Ruthenium(0) nanoparticles stabilized by metal-organic framework as an efficient electrocatalyst for borohydride oxidation reaction
No full textsponsorship: M. Zahmakiran thanks to the Research Fund of Van Yuzuncu Yil University Office of Scientific Research Project (FOA-20208862). The authors would also like to thank the Portuguese Foundation for Science and Technology (FCT, Portugal) for a research grant within project UID/CTM/04540/2013 (G. Backovic) and contract IST-ID/156/2018 (B.Sljukic) and contract no.IF/01084/2014/CP1214/CT0003 under IF2014 Programme (D.M.F. Santos). (Research Fund of Van Yuzuncu Yil University Office of Scientific Research Project|FOA-20208862, Portuguese Foundation for Science and Technology (FCT, Portugal)|UID/CTM/04540/2013, Portuguese Foundation for Science and Technology (FCT, Portugal)|IST-ID/156/2018, IF2014 Programme|IF/01084/2014/CP1214/CT0003)status: Publishe
Kaposi's sarcoma-associated herpesvirus (KSHV) gB dictates a low-pH endocytotic entry pathway as revealed by a dual-fluorescent virus system and a rhesus monkey rhadinovirus expressing KSHV gB
No full textInteraction with host cell receptors initiates internalization of Kaposi's sarcoma-associated herpesvirus (KSHV) particles. Fusion of viral and host cell membranes, which is followed by release of the viral capsid into the cytoplasm, is executed by the core fusion machinery composed of glycoproteins H (gH), L (gL), and B (gB), that is common to all herpesviruses. KSHV infection has been shown to be sensitive to inhibitors of vacuolar acidification, suggestive of low pH as a fusion trigger. To analyze KSHV entry at the single particle level we developed dual-fluorescent recombinant KSHV strains that incorporate fluorescent protein-tagged glycoproteins and capsid proteins. In addition, we generated a hybrid rhesus monkey rhadinovirus (RRV) that expresses KSHV gB in place of RRV gB to analyze gB-dependent differences in infection pathways. We demonstrated lytic reactivation and infectivity of dual-fluorescent KSHV. Confocal microscopy was used to quantify co-localization of fluorescently-tagged glycoproteins and capsid proteins. Using the ratio of dual-positive KSHV particles to single-positive capsids as an indicator of fusion events we established KSHV fusion kinetics upon infection of different target cells with marked differences in the "time-to-fusion" between cell types. Inhibition of vesicle acidification prevented KSHV particle-cell fusion, implicating low vesicle pH as a requirement. These findings were corroborated by comparison of RRV-YFP wildtype reporter virus and RRV-YFP encoding KSHV gB in place of RRV gB. While RRV wt infection of receptor-overexpressing cells was unaffected by inhibition of vesicle acidification, RRV-YFP expressing KSHV gB was sensitive to Bafilomycin A1, an inhibitor of vacuolar acidification. Single- and dual-fluorescent KSHV strains eliminate the need for virus-specific antibodies and enable the tracking of single viral particles during entry and fusion. Together with a hybrid RRV expressing KSHV gB and classical fusion assays, these novel tools identify low vesicle pH as an endocytotic trigger for KSHV membrane fusion
Between two worlds : approaching Balkan oral music tradition through the use of technology as a compositional and performing medium
No full textThis text explores the problems of interpreting musical identity, meaning, and sociocultural value of a compositional work influenced by two traditions with different values: the modernist tradition based on Western European classical heritage, and the oral tradition of the Balkans. It also follows the process of transformation and recreation of the author's musical language: from classical, notation-oriented to a more intuitive, improvisational and live-performance based. Through detailing some of the
experiences of the author as a composer and a performer, it also discusses some observations on the ways in which this discrepancy between two traditions and practices has affected and still influences those creative practices in Serbia and the former Yugoslavia that relate to traditional music and its derivations. By identifying musical performance within certain socio-cultural contexts this dichotomy can be highlighted. As a result, a substantial part of this text focuses on investigating the
capacity of a technologically assisted composition and performance practice to overcome this issue. Technology is here perceived not only as an instrument for
recording, improvising, composing and performing but also as a medium which communicates musical value. In this study, the oral tradition from the Balkans was approached not only as a purely acoustic phenomenon, but it also included a raised awareness of the nature of the continuous fusion of various cultures in the region, as
well as existing cultural and religious antagonisms. This study investigates the problems of constructing musical identity as well as the meaning of an author’s creative practice in relation to the socio-cultural environment of its origin, whilst observing its reception by audiences outside the Balkan region. Socio-cultural environments are established through exploring the writings of the authors that depict the Balkans historical, cultural and musical spheres in relation to other cultural practices and influences
Measurement of event shape variables in deep-inelastic scattering at HERA
No full textDeep-inelastic ep scattering data taken with the H1 detector at HERA and corresponding to an integrated luminosity of 106 pb(-1) are used to study the differential distributions of event shape variables. These include thrust, jet broadening, jet mass and the C-parameter. The four-momentum transfer Q is taken to be the relevant energy scale and ranges between 14 GeV and 200 GeV. The event shape distributions are compared with perturbative QCD predictions, which include resummed contributions and analytical power law corrections, the latter accounting for non-perturbative hadronisation effects. The data clearly exhibit the running of the strong coupling alpha(s)(Q) and are consistent with a universal power correction parameter alpha(0) for all event shape variables. A combined QCD fit using all event shape variables yields alpha(s)(m(Z)) = 0.1198 +/- 0.0013 (+0.0056)(-0.0043) and alpha(0) = 0.476 +/- 0.008 (+0.018)(-0.059)
Internazionalization of Companies in an Unstable Context - The Development of FIAT in Serbia.
No full textssDNA formation is dependent on ITRs and Rep68.
No full text<p>Southern blot of low M<sub>r</sub> DNA obtained from a clone expressing Rep68 transformed with pAAVpokURA (A) or pRepURA (B) and probed with URA3. (A) Lane 1 shows low M<sub>r</sub> DNA undigested and lane 2, low M<sub>r</sub> DNA subjected to S1 nuclease. (B) Low M<sub>r</sub> DNA of two different clones (lane 1 and 2) expressing Rep68 and transformed with pRepURA.</p
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