250 research outputs found
Antimicrobial Resistance Trends among Community-Acquired Respiratory Tract Pathogens in Greece, 2009–2012
The aim of the present study was to determine the antimicrobial resistance trends of respiratory tract pathogens isolated from patients with community-acquired respiratory tract infections (CARTIs) in Crete, Greece, over a 4-year period (2009–2012). A total of 588 community-acquired respiratory pathogens were isolated during the study period. Streptococcus pneumoniae was the most common organism responsible for 44.4% of CARTIs, followed by Haemophilus influenzae (44.2%) and Moraxella catarrhalis (11.4%). Among S. pneumoniae, the prevalence of isolates with intermediate- and high-level resistance to penicillin was 27.2% and 12.3%, respectively. Macrolide resistance slightly decreased from 29.4% over the period 2009-2010 to 28.8% over the period 2011-2012. Multiresistance was observed among 56 (54.4%) penicillin nonsusceptible isolates. A nonsignificant increase in resistance of H. influenzae isolates was noted for β-lactams, cotrimoxazole, and tetracycline. Among the 67 M. catarrhalis tested, 32 produced beta-lactamase and were resistant to ampicillin. Macrolide resistance decreased over the study period. All isolates were susceptible to amoxicillin + clavulanic acid, chloramphenicol, rifampicin, and the fluoroquinolones. Although a decreasing trend in the prevalence of resistance of the three most common pathogens involved in CARTIs was noted, continuous surveillance of antimicrobial susceptibility at the local and national level remains important, in order to guide appropriate empirical antimicrobial therapy
Identification and quantification of phenolic compounds in fresh and processed table olives of cv. ‘Kalamata’
Mediterranean diet is almost synonymous to the healthy lifestyle and diet nowadays. Some of the major components of the diet are the products of the olive tree, fruits and olive oil, which are classified as medical foods, due to their nutraceutical benefits and their protective properties against cancer, cardiovascular diseases, age-related diseases, neurodegenerative disorders and other diseases. The key contributors to these properties are the phenolic compounds such as hydroxytyrosol, tyrosol and oleuropein. Table olives are being processed with several methods in order to reduce the bitterness of the olive fruit and the impact of the processing on phenolic compounds has not been studied extensively. In the present study, changes in the concentration of the most important phenolic compounds were quantified in fresh, Greek-style and Spanish-style processed olive fruits of cv. ‘Kalamata’, using two different analytical methods for identification and quantification: high-performance liquid chromatography diode array detector (HPLC-DAD) and ultrahigh-performance liquid chromatography tandem mass spectrometry (LC-(ESI)-MS/MS). The phenolic compounds that were identified and quantified were hydroxytyrosol, tyrosol, verbascocide, rutin, oleuropein and luteolin. Both processing methods used altered the phenolic compounds concentration in ‘Kalamata’ olive fruits compared to untreated fruits. In both analytical methods, a statistically significant increase in verbascoside and hydroxytyrosol concentration and a statistically significant decrease in rutin concentration was observed in both, Greek-style and Spanish-style, processed olive fruits
Trends in precipitation measurement and climate model data and their influence on the assessment of urban systems
Rainfall statistics are composed based on data gained by precipitation measurements and from climate models. These statistics are carried out for both periods in the past and the future. When analysing the time series, different trends can be seen in the measured data of the past and the model data for future periods. Influences on the statistically determined precipitation amounts caused by changes can be neglected for past periods. However, significant increases of the statistical precipitation amounts can be observed for the future. Here a pragmatic approach is presented, showing how to consider possible increases in the statistical precipitation amounts – due to the climate change signal – in the dimensioning of water management systems
Προσδιορισμός προϊόντων μετασχηματισμού οργανικών ενώσεων σε αιωρούμενα σωματίδια της ατμόσφαιρας
Η παρούσα εργασία εκπονήθηκε στο Εργαστήριο Χημείας Περιβάλλοντος και στο Εργαστήριο Αναλυτικής Χημείας του τμήματος Χημείας ΕΚΠΑ. Σκοπός αυτής της διπλωματικής εργασίας είναι ο προσδιορισμός προϊόντων μετασχηματισμού οργανικών ενώσεων σε αιωρούμενα σωματίδια της ατμόσφαιρας (PM10, PM2.5) στην περιοχή της Αγίας Μαρίνας Ξυλιάτου, κοινότητα της επαρχίας Λευκωσίας στην Κύπρο. Πιο συγκεκριμένα, εξετάστηκε πλήθος πολικών οργανικών ενώσεων στις οποίες ανήκουν: α) δικαρβοξυλικά οξέα (ηλεκτρικό, γλουταρικό, αδιπικό, μηλικό, πιμελικό, σουβερικό, αζελαϊκό σεβακικό), β) δευτερογενείς βιογενείς ενώσεις (πινικό οξύ, πινονικό οξύ, μεθυλερυθριτόλη), γ) αρωματικές ενώσεις (φθαλικό οξύ, ισοθαλικό οξύ, τριμελλιτικό οξύ), δ) μονοκαρβοξυλικά οξέα (λαουρικό, μυριστικό, παλμιτικό, στεαρικό, ολεϊκό, λινολεϊκό,) και ε) δείκτες καύσης βιομάζας (1,6-ανυδρο-β-γλυκοπυρανόζη), και δείκτες βιογενούς δραστηριότητας (μαννιτόλη). Ακολούθησε διερεύνηση των πιθανών πηγών των παραπάνω ενώσεων με τη χρήση κατάλληλων στατιστικών πακέτων και με τη μελέτη συγκεκριμένων διαγνωστικών λόγων. Προσδιορίστηκε επίσης η συγκέντρωση του στοιχειακού (EC) και οργανικού άνθρακα (EC)
(OC) σε κάθε φίλτρο και εκτιμήθηκε η ποσότητα του δευτερογενούς οργανικού άνθρακα(EC)
(OCsec). Ακόμα συλλέχθηκαν 24ωρα δείγματα από τις 18 Νοεμβρίου 2017 έως τις 31 Δεκεμβρίου 2017 που αφορούν πτητικές οργανικές ενώσεις. Εξαιτίας των πολικών ομάδων των ενώσεων που προσδιορίστηκαν για τις δευτερογενείς οργανικές ενώσεις, χρησιμοποιήθηκε τεχνική τριπλής παραγωγοποίησης. O προσδιορισμός των ουσιών που αναφέρθηκαν πραγματοποιήθηκε με τη χρήση αέριου χρωματογράφου συζευγμένου με φασματοσκοπία μαζών.The present study was carried out in the Environmental Chemistry Lab and in the Analytical Chemistry Lab of the Department of Chemistry of the National Kapodistrian University of Athens. The purpose of this master thesis is the determination of products from the transformation of organic compounds in atmospheric particulate matter (PM10, PM2.5), that were collected at Agia Marina Xyliatou, a remote location near Nicosia, Cyprus. In particular, a large number of polar organic compounds was investigated such as: a) dicarboxylic acids (succinic, glutaric, adipic, mallic, pimelic, souberic, azelaic, sebacic), b) secondary biogenic compounds (pinic acid, pinonic acid, methylerythritol), c) aromatic compounds (phthalic acid, isophthalic acid, trimellitic acid), d) monocarboxylic acids (lauric, myristic, palmitic, stearic, oleic, linoleic), e) biomass burning tracers (levoglucosan) and tracers of biogenic activity (mannitol). Subsequently, the possible sources of these compounds were investigated using the appropriate statistical packages and following the study of specific diagnostic mass ratios. Moreover, the concentration of elemental carbon (EC) and organic carbon (OC) was determinated for every filter and the quantity of secondary organic carbon (OCsec) was estimated. In addition samples concerning volatile organic compounds were collected daily from 18th November 2017 to 31st December 2017. A triple derivatization technique was performed for the determination of the secondary organic compounds, due to the polar functional groups of the analytes. The determination of substances mentioned above was carried out with the use of a gas chromatograph combined with mass spectrometer
In vitro Propagation and Assessment of Genetic Relationships of Citrus Rootstocks Using ISSR Molecular Markers
The behavior of six citrus rootstocks, Volkameriana, Citrumelo ‘Swingle’, Citrange ‘Carrizo’, Poncirus trifoliata ‘Serra’, Poncirus trifoliata ‘Rubidoux’ and Poncirus trifoliata ‘Flying Dragon’, in in vitro propagation was studied and compared for shoot proliferation and rooting. In addition, the genetic relationships among the rootstocks studied and other Citrus species, using the Inter-Simple Sequence Repeats (ISSR) molecular markers, were investigated. Nodal explants of three months old shoots were used in Murashige and Skoog medium supplemented with N6-benzyladenine (BA) for shoot proliferation and with naphthaleneacetic acid (NAA) for rooting. The rootstock Volkameriana showed a statistically significant higher number of shoots (1.81), shoot length (15.14 mm) and number of leaves per explant (5.81), while all three Poncirus trifoliata rootstocks showed the lowest numbers. The number of roots and root length per explant were evaluated at the end of the rooting phase. The rootstock ‘Swingle’ showed a higher number of roots per explant (4.2) followed by ‘Flying Dragon’ (3.93) and ‘Carrizo’ (3.23) rootstocks. The rootstocks ‘Swingle’ (140.8 mm), Volkameriana (148 mm) and ‘Flying Dragon’ (131.12 mm) had significantly higher root length per explant compared to ‘Carrizo’ (31 mm) and ‘Rubidoux’ (34.5 mm). The ISSR molecular marker technique used in the present study grouped successfully the different species, varieties and rootstocks studied, revealing their genetic variability. The genetic variability observed among the rootstocks ranged between 0.29 (Poncirus trifoliata ‘Serra’ and Citrumelo ‘Swingle’) and 0.60 (Volkameriana and Citrumelo ‘Swingle’). The response of the rootstocks studied in in vitro propagation however is not related to their genetic affinity
Rendering an online, subject-based navigation service compatible with linked data
Nowadays, an ever-increasing amount of libraries provide their data as linked open data - LOD. Subject headings and thesauri terms are provided online via Internet with the employment of adequate semantic technologies, such as triplestores of LOD and their corresponding SPARQL endpoints. Following the examples of major libraries worldwide, we decided to convert the existing service of interactive information retrieval that is provided by the University of Piraeus digital library of Thesis and Dissertations into a service compatible with LOD. The service through the Graphical User Interface – GUI gives the opportunity to the end-users to navigate to the subject headings of the digital library through the employment of broader and narrower terms and as well through the employment of any common subdivision that may share. At the same time, the users can find information from other repositories that provide their data as well as LOD (i.e. the articles’ database of New York Times).
This paper is structured as follows: Initially, the basic principles and the components that are necessary to participate in the LOD cloud are analyzed. Then, the example of Library of Congress is presented, which provides subject-based information as LOD since 2008. The next section presents the process that was followed to create the local LOD triplestore and demonstrates its connection with other LOD-compliant data sources. Finally, the GUI of the service is presented, followed by some general conclusions
Physiological and growth responses of sour cherry (Prunus cerasus L.) plants subjected to short-term salinity stress
The gradual response of CAB-6P sour cherry (Prunus cerasus L.) plants to NaCl-induced salinity stress (60 mM NaCl) was investigated in a short-term hydroponic experiment, based on parameters relating to the growth, water relations, chlorophyll and mineral nutrition. The results showed that CAB-6P plants are very sensitive to salinity stress because their growth and leaf chlorophyll concentration were both affected negatively from the 3rd and 5th day, respectively, after incurring salinity stress. Since root growth was suppressed more severely than shoot growth, the shoot to root ratio was significantly increased under saline conditions. The concentrations of Na in leaves and stem of NaCl-treated plants were much lower than those measured in roots, suggesting Na exclusion mechanism from the shoot. The opposite trend was observed for Cl, indicating Cl inclusion mechanism to leaves. As regards the concentrations of Ca, Mg, P, K, Na, Fe, Zn and Mn, they were not changed in higher salinity conditions, apart from K, concentrations of which in leaves and roots were significantly increased and decreased, respectively (K translocation to leaves). Salinity further reduced K/Na ratio in root and stem as well as leaf water and osmotic potentials, whereas leaves of control and NaCl-treated plants presented similar turgor potential and K/Na ratio. These data add very important information to our knowledge about the physiological events occurring in sour cherry plants after even short-term exposure to salinity
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