20 research outputs found

    The interstellar medium towards the Ara OB1 region

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    We present high resolution (R ~ 4 km/s) absorption measurements of the interstellar NaI and CaII lines measured towards 14 early-type stars of distance 123 pc - 1650 pc, located in the direction of the Ara OB1 stellar cluster. The line profiles can broadly be split into four distinct groupings of absorption component velocity, and we have attempted to identify an origin and distance to each of these interstellar features. For gas with absorption covering the velocity range -10 km/s < V_helio < +10 km/s, we can identify the absorbing medium with local gas belonging to the Lupus-Norma interstellar cavity located between 100 and 485 pc in this galactic direction. Gas with velocities spanning the range -20 km/s < V_helio < +20 km/s is detected towards stars with distances of 570-800 pc. We identify a wide-spread interstellar feature at V_helio ~ -15 km/s with the expanding HI shell called GSH 337+00-05, which is now placed at a distance of ~530 pc.Comment: 12 pages, 5 figures, accepted for publication in Astrophysics & Space Scienc

    High-resolution observations of interstellar Na I and Ca II towards the southern opening of the 'Local Interstellar Chimney': probing the disc—halo connection

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    We present high-resolution (R = 400 000) observations of interstellar Ca II and Na I absorption lines towards seven stars in the direction of the southern opening of the recently identified Local Interstellar Chimney. These lines of sight probe the lower Galactic halo (0.3 ≲∣z∣≲ 2.5 kpc), without the complication of sampling dense foreground interstellar material. In addition to components with velocities expected from Galactic rotation, these stars also exhibit components with negative local standard of rest velocities, which are contrary to the sense of Galactic rotation for the sightlines observed. After a discussion of possible origins for these peculiar velocities, we conclude that at least some of them result from gas falling towards the Galactic plane from distances of ∣z∣≳ 300 pc. The narrow linewidths are generally inconsistent with temperatures as high as the ∼6000 K generally assumed for the so-called Lockman layer. Rather, the picture that emerges is one of a scattered, generally infalling, population of high-∣z∣ diffuse clouds, seemingly not very different from those encountered in the local interstellar medium. Overall, we argue that our results are most consistent with a ‘Galactic fountain’ model

    Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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    Contains fulltext : 172380.pdf (publisher's version ) (Open Access

    Riboflavin Binding Protein Chiral Stationary Phase: Investigation on the Retention Mechanism.

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    The chiral recognition mechanism of Riboflavin Binding Protein (RfBP) stationary phase has been investigated by studying the influence of temperature on the retention process. The effect of temperature on retention and resolution of two analytes was studied between 15°C and 55°C and van't Hoff plots of lnk and ln versus 1/T were acquired. The thermodynamic parameters were calculated and the data were used to derive some information regarding the retention mechanism in this chromatographic system. Quantitative structure-enantioselective retention relationships (QSERR) were derived by multiple regression analysis using various molecular descriptors and the retention data determined on RfBP-stationary phase. The results were interpreted in terms of structural requirements of the specific binding site on the biomacromolecule to provide an insight of the recognition mechanism

    New chemical structures of hypolipidemic and antiplatelet activity*

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    Abstract: Elevated lipid level is supposed to be one of the main risk factors of atherosclerosis and subsequent cardiovascular disease (and is connected to mortality). Therefore, lipid lowering is one of the major targets in cardiovascular disease treatment and prevention. Also, blood platelets play a pivotal role in the development of atherosclerosis and fatal thrombus formation in the course of coronary heart disease. Therefore, there is a great necessity to acquire drugs inhibiting platelet aggregation and clot generation. The present paper reviews new chemical structures in development for the treatment and prevention of hyperlipidemia, atherosclerosis, and subsequent cardiovascular disease. The authors&apos; recent results are also reported regarding synthesis of a new group of α-asarone analogs. These compounds were identified as an original class of agents exhibiting hypolipidemic and antiplatelet (mice, rats) activities. Although the mechanism of the compounds&apos; pharmacological activity has not been identified, quantum-mechanical calculations allowed structural requirements to be described that correspond to the activity (a hypothetical pseudoreceptor structure). Since it is known that asarone and its derivatives may exhibit genotoxicity, calculations were carried out to identify derivatives of possibly low genotoxic activity

    Development of a Computational Tool for Measuring Organizational Competitiveness in the Photovoltaic Power Plants

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    Photovoltaic (PV) power generation is embedded in a globally competitive environment. This characteristic forces PV power plants to perform most processes relevant for their competitiveness with maximum efficiency. From managers’ point of view, the evaluation of solar energy performance from installed plants is justified to indicate their level of organizational competitiveness, which supports the decision-making process. This manuscript purposes a computational tool that graphically presents the level of competitiveness of PV power plants units based on performance indicators. This tool was developed by using the Key Performance Indicators (KPIs) concept, which represents a set of measures focusing on the most critical aspects for the success of the organizations. The KPIs encompass four Fundamental Viewpoints (FV): Strategic Alliances, Solar Energy Monitoring, Management and Strategic Processes, and Power Generation Innovations. These four FVs were deployed on 26 Critical Success Factors (CSFs) and 39 KPIs. Sequentially, the tool was applied in four solar generation plants, where three presented an organizational competitiveness global level “potentially competitive”. The proposed computational tool allows managers to assess the degree of organization competitiveness as well as aid in prospecting of future scenarios and decision-making
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