247 research outputs found
Romanian Hotel Groups Listed at Bucharest Stock Exchange a Survey
Get PDFHotel industry is an important component of travel and tourism (T&T) sector. However, less studies are dedicated to hotel industry than to the T&T sector as a hole. Even less studies are available on hotel companies or groups listed on stock exchanges around the world. The present study will focus on Romanian hotel groups listed at Bucharest Stock Exchange, compared with the situation in Europe.hotel industry,travel and tourism,stock exchanges,hotel groups.
Marketing of the banking services in Romania - an analysis regarding the evolution of the influence factors
Get PDFIn this paper we will present the main factors that can influence the banking services’ evolution. In the introduction these factors are briefly present and in the second part they will be discussed more detailed. The final part, that represent the conclusion, present some information regarding Romania and what is happening on this market.banking services, marketing, banks' personnel, external environment
Modulation of Quorum Sensing and Biofilms in Less Investigated Gram-Negative ESKAPE Pathogens
No full text<jats:p>Pathogenic bacteria have the ability to sense their versatile environment and adapt by behavioral changes both to the external reservoirs and the infected host, which, in response to microbial colonization, mobilizes equally sophisticated anti-infectious strategies. One of the most important adaptive processes is the ability of pathogenic bacteria to turn from the free, floating, or planktonic state to the adherent one and to develop biofilms on alive and inert substrata; this social lifestyle, based on very complex communication networks, namely, the quorum sensing (QS) and response system, confers them an increased phenotypic or behavioral resistance to different stress factors, including host defense mechanisms and antibiotics. As a consequence, biofilm infections can be difficult to diagnose and treat, requiring complex multidrug therapeutic regimens, which often fail to resolve the infection. One of the most promising avenues for discovering novel and efficient antibiofilm strategies is targeting individual cells and their QS mechanisms. A huge amount of data related to the inhibition of QS and biofilm formation in pathogenic bacteria have been obtained using the well-established gram-positive <jats:italic>Staphylococcus aureus</jats:italic> and gram-negative <jats:italic>Pseudomonas aeruginosa</jats:italic> models. The purpose of this paper was to revise the progress on the development of antibiofilm and anti-QS strategies in the less investigated gram-negative ES<jats:underline>KA</jats:underline>P<jats:underline>E</jats:underline> pathogens <jats:italic>Klebsiella pneumoniae</jats:italic>, <jats:italic>Acinetobacter baumannii</jats:italic>, and <jats:italic>Enterobacter</jats:italic> sp. and identify promising leads for the therapeutic management of these clinically significant and highly resistant opportunistic pathogens.</jats:p>
Framework for coupled digital twins in digital machining
Get PDFThis paper presents a further elaboration of the use of the digital twin concept in digital machining. The
main goal of the research is an attempt to combine digital representations of different objects involved in
the machining process in a holistic manner. Digital twins of the in-process workpiece, cutting tool,
clamping, and machine tool along with the process twin are connected in a framework in which all these
elements can influence each other. The framework shows different levels of integration of different digital
twins and practical recommendation on the implementation. Besides, the framework supports a simulation
layer that provides data for the intensity of the interaction. Such interactions can result in, for instance,
cascading calculations of cutter workpiece engagement, cutting forces, tool wear, tool deflection, chatter,
and so on. Eventually, a design for a software mockup was elaborated to present the developed
framework. The entire workflow to simulate part machining in such a digital representation can be used
as an ultimate tool for CAM simulation and NC verification within the Zero Defect Manufacturing paradigm
Silver nanoparticles decorated ZnO–CuO core–shell nanowire arrays with low water adhesion and high antibacterial activity
No full textAbstract Nanostructured surfaces based on silver nanoparticles decorated ZnO–CuO core–shell nanowire arrays, which can assure protection against various environmental factors such as water and bacteria were developed by combining dry preparation techniques namely thermal oxidation in air, radio frequency (RF) magnetron sputtering and thermal vacuum evaporation. Thus, high-aspect-ratio ZnO nanowire arrays were grown directly on zinc foils by thermal oxidation in air. Further ZnO nanowires were coated with a CuO layer by RF magnetron sputtering, the obtained ZnO–CuO core–shell nanowires being decorated with Ag nanoparticles by thermal vacuum evaporation. The prepared samples were comprehensively assessed from morphological, compositional, structural, optical, surface chemistry, wetting and antibacterial activity point of view. The wettability studies show that native Zn foil and ZnO nanowire arrays grown on it are featured by a high water droplet adhesion while ZnO–CuO core–shell nanowire arrays (before and after decoration with Ag nanoparticles) reveal a low water droplet adhesion. The antibacterial tests carried on Escherichia coli (a Gram-negative bacterium) and Staphylococcus aureus (a Gram-positive bacterium) emphasize that the nanostructured surfaces based on nanowire arrays present excellent antibacterial activity against both type of bacteria. This study proves that functional surfaces obtained by relatively simple and highly reproducible preparation techniques that can be easily scaled to large area are very attractive in the field of water repellent coatings with enhanced antibacterial function
The Pierre Auger Cosmic Ray Observatory
Get PDFSee paper for full list of authors – Paper submitted to NIM AInternational audienceThe Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above eV and to study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water-Cherenkov particle detector stations spread over 3000 km overlooked by 24 air fluorescence telescopes. In addition, three high elevation fluorescence telescopes overlook a 23.5 km, 61 detector infill array. The Observatory has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Auger Observatory
Impact of Pseudomonas aeruginosa quorum sensing signaling molecules on adhesion and inflammatory markers in endothelial cells
No full textPseudomonas aeruginosa relies on the quorum sensing (QS) signaling system as a central regulator mechanism of virulence expression that contributes to the formation and maintenance of biofilms and tolerance to conventional antimicrobials. QS Signaling molecules (QSSMs) may be recognized and may function also within the host cells, being potentially involved in the progression of the infectious process. In this study we evaluate the expression of adhesion and inflammatory molecules in endothelial cells treated with P. aeruginosa QSSMs, in order to bring new insights on the mechanisms involved in the interaction of P. aeruginosa with host cells during the infectious process. Endothelial cells were stimulated with 20 µM of main P. aeruginosa QSSMs (OdDHL = N-(3-oxododecanoyl)-L-homoserine lactone, C4HSL = N-butyryl-L-homoserine lactone, PQS = 2-heptyl-3-hydroxy-4(1H)-quinolone and HHQ = 2-heptyl-4-quinolone). Adherence to endothelial cells, inert substratum and biofilm formation was evaluated. The expression of adhesion molecules (VE-cadherin, PECAM-1, ICAM-1, and P-selectin) and inflammatory response molecules (IL-1β, IL-6, TNFα, TGFβ, and eNOS) was assessed by qRT-PCR and flow cytometry. Our results showed that bacterial adherence to inert substratum and biofilm were decreased in the presence of all tested QSSMs. The adherence index of PAO1 laboratory strain to host cells was decreased between 10–40% in the presence of QSSMs, as compared to untreated control. Expression of eukaryotic cells adhesion molecules ICAM-1 and P-selectin was stimulated by QSSMs, whereas VE-cadherin and PECAM-1 levels were increased only by C4HSL. The inflammatory response of endothelial cells was also modulated, as observed by the modified expression of IL-1β (for C4HSL, PQS and HHQ), IL-6 (for C4HSL and HHQ), TNFα (for C4HSL and HHQ), TGFβ, and eNOS factors. Our results demonstrate that the main pseudomonadal QSSMs differentially modulate endothelial cells adhesion and proinflammatory cytokine expression. These observations provide new insights in the mechanisms by which different QSSMs activate endothelial cells and modulate the infectious process, and support the importance of recent studies aiming to develop anti-QS therapeutic strategies to fight against P. aeruginosa infections
Active Galactic Nuclei: Sources for ultra high energy cosmic rays?
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76026.pdf (Author’s version preprint ) (Open Access)18 p
Phenotypic and genotypic evaluation of adherence and biofilm development in Candida albicans respiratory tract isolates from hospitalized patients
No full textIn recent years, a significant number of epidemiological variations have been observed for fungal infections. In immunocompromised patients, Candida albicans is crucially involved in invasive infections, mostly originating in respiratory tract colonization. The global rise in candidiasis has led researchers to investigate possible correlations between fungal strains virulence profiles and their pathogenic potential, among the most investigated genes being those involved in adherence and biofilm development. In this study, we established the adherence gene profiles of C. albicans strains isolated from respiratory tract secretions in patients hospitalized for cardiovascular diseases and correlated them with the ability of the respective strains to colonize the epithelial cells and form biofilms on the inert substratum. The strains isolated from the lower respiratory tract exhibited the highest adherence capacity and were intensive biofilm producers. The SAP9, ALS3, ALS5, and ALS6 genes were the most frequently detected. There was a significant association between the presence of ALS 3 gene and the cellular substrate colonizing potential of the harboring strains. We also found that the strains expressing SAP9 were more virulent in the phenotypic assays. Detecting the presence of adherence genes from different clinical isolates is a cost-effective tool that would allow researchers to predict the virulence of a certain strain and estimate its potential to adhere to host cells and develop biofilms
A search for point sources of EeV photons
Get PDFMeasurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from -85° to +20°, in an energy range from 1017.3 eV to 1018.5 eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of -2, is 0.06 eV cm-2 s -1, and no celestial direction exceeds 0.25 eV cm-2 s -1. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galax
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