2,996 research outputs found
Schlafstörungen bei kritisch kranken Patienten
Zusammenfassung: Schlaf ist ein essenzieller Bestandteil des Lebens. FĂŒr eine intakte Immunabwehr, fĂŒr kognitive und muskulĂ€re Funktionen scheint Schlaf wichtig zu sein. Subjektive Schlafstörungen wurden in 20% der arbeitenden Population gefunden und nehmen mit dem Alter zu. Schlafstörungen konnten bei mehr als 50% der Patienten in kritischem Zustand nachgewiesen werden. Bei kritisch kranken Patienten ist der Schlaf bisher nur unzureichend wissenschaftlich untersucht worden. Zur Schlafmessung stehen Fragebogen und als einziges objektivierendes Verfahren die Polysomnographie zur VerfĂŒgung. Schlafstörungen in der Intensivstation haben meist multifaktorielle Ursachen: patientenbedingte Pathologien, wie Status nach gröĂerer Chirurgie, Sepsis, akuter oder chronischer Lungenschaden, Herzinsuffizienz, Schlaganfall oder Epilepsie; therapeutische Interventionen, wie z.B. die mechanische Ventilation, LĂ€rm verursachende technische GerĂ€te, Schmerzen und Medikamente. Neben pharmakologischen Behandlungskonzepten mit Analgetika und zeitlich limitierten Sedativa sollten umwelthygienische MaĂnahmen mit Musik zur Entspannung, nĂ€chtliche LĂ€rmreduktion und TageszeitprĂ€sentation ergriffen werden. Bevor evidenzbasierte "guidelines" erstellt werden können, muss eine intensivierte Forschung im Bereich Schlaf und kritische Krankheit durchgefĂŒhrt werden. Mit groĂen Kohortenstudien sollte untersucht werden: 1. Welche Anteile der Schlafstörungen kritisch kranker Patienten Folge von Krankheiten oder Trauma und damit nichtbeeinflussbar sind, 2. ob der Schweregrad der Schlafstörungen Ausdruck von der Schwere der Krankheit oder des Traumas ist, 3. welcher Anteil Folge medizinischer Interventionen und damit beeinflussbar ist. Mithilfe der nach Pathologie stratifizierten und randomisierten Studien sollten nichtpharmakologische und pharmakologische Konzepte zur Schlafverbesserung getestet werden. Dabei sollten sowohl nosokomiale Infektionen als auch kognitive Funktionen und respiratorische Muskelkraft berĂŒcksichtigt werden. Dann kann beurteilt werden, ob es sinnvoll ist, Schlafstörungen engmaschig zu ĂŒberwachen, um sie als VerlaufsmaĂ des Therapieerfolgs und der kurzfristigen LebensqualitĂ€t zu nutzen. Wichtig ist, dass solche Studien einen genĂŒgend langen Follow-up-Zeitraum haben, um allfĂ€llige Entzugserscheinungen pharmakologischer Interventionen zu erfasse
Observation of mesospheric air inside the arctic stratospheric polar vortex in early 2003
During several balloon flights inside the Arctic polar vortex in early 2003, unusual trace gas distributions were observed, which indicate a strong influence of mesospheric air in the stratosphere. The tuneable diode laser (TDL) instrument SPIRALE (Spectroscopie InFrarouge par Absorption de Lasers Embarqués) measured unusually high CO values (up to 600 ppb) on 27 January at about 30 km altitude. The cryosampler BONBON sampled air masses with very high molecular Hydrogen, extremely low SF6 and enhanced CO values on 6 March at about 25 km altitude. Finally, the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) Fourier Transform Infra-Red (FTIR) spectrometer showed NOy values which are significantly higher than NOy* (the NOy derived from a correlation between N2O and NOy under undisturbed conditions), on 21 and 22 March in a layer centred at 22 km altitude. Thus, the mesospheric air seems to have been present in a layer descending from about 30 km in late January to 25 km altitude in early March and about 22 km altitude on 20 March. We present corroborating evidence from a model study using the KASIMA (KArlsruhe Simulation model of the Middle Atmosphere) model that also shows a layer of mesospheric air, which descended into the stratosphere in November and early December 2002, before the minor warming which occurred in late December 2002 lead to a descent of upper stratospheric air, cutting of a layer in which mesospheric air is present. This layer then descended inside the vortex over the course of the winter. The same feature is found in trajectory calculations, based on a large number of trajectories started in the vicinity of the observations on 6 March. Based on the difference between the mean age derived from SF6 (which has an irreversible mesospheric loss) and from CO2 (whose mesospheric loss is much smaller and reversible) we estimate that the fraction of mesospheric air in the layer observed on 6 March, must have been somewhere between 35% and 100%
European Vegetation Archive (EVA): an integrated database of European vegetation plots
The European Vegetation Archive (EVA) has been developed since 2012 by the IAVS Working Group European Vegetation Survey as a centralized database of European vegetation plots. It stores copies of national and regional vegetation-plot databases on a single software platform. Data storage in EVA does not affect the ongoing independent development of the contributing databases, which remain the property of the data contributors. A prototype of the database management software TURBOVEG 3 has been developed for joint management of multiple databases that use different species lists. This is facilitated by the SynBioSys Taxon Database, a system of taxon names and concepts used in the individual European databases and their matches to a unified list of European flora. TURBOVEG 3 also includes procedures for handling data requests, selections and provisions according to the approved EVA Data Property and Governance Rules. By 30 June 2015, 61 databases from all European regions have joined EVA, contributing in total 1 024 236 vegetation plots from 57 countries, 82% of them with geographical coordinates. EVA provides a unique data source for large-scale analyses of European vegetation diversity both in fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database
Fen and bog plant communities in the Aran valley, in the central Pyrenees
La Vall dâAran estĂ situada al vessant nord dels Pirineus, on el clima de tipus medioeuropeu i de muntanya amb una marcada influĂšncia atlĂ ntica propicia una gran diversitat de molleres. En aquest treball presentem els resultats de lâestudi fitosociolĂČgic dâaquestes molleres, especialment dâaquelles que formen part de sistemes complexos (que nâinclouen dâombrĂČgenes, topĂČgenes, solĂgenes i limnĂČgenes). Hem seguit la metodologia de Braun-Blanquet per a lâaixecament dels inventaris i hem mesurat tambĂ© alguns factors ambientals (pH i conductivitat de lâaigua lliure del sĂČl, profunditat de lâaigua freĂ tica i gruix de la capa de torba) a part de les variables topogrĂ fiques bĂ siques. Presentem 144 inventaris de 22 associacions (una dâelles diversificada en 4 subassociacions), 2 de les quals sĂłn noves descripcions, i 8 es documenten per primer cop dels Pirineus. La majoria dâassociacions corresponen a la classe Scheuchzerio-Caricetea fuscae (molleres i torberes minerogĂšniques) i força menys es refereixen a torberes ombrogĂšniques de la classe Oxycocco-Sphagnetea o a la vegetaciĂł lacustre associada de les aliances Magnocaricion, Phragmition i Scorpidio-Utricularion minoris. Valorem la diversitat de torberes en forma de bony de la classe Oxycocco-Sphagnetea i la presĂšncia de molleres tremoloses del Caricion lasiocarpae, que constitueixen lâĂșnica representaciĂł dels Scheuchzerietalia a Catalunya. Reinterpretem les formacions dominades per Scirpus cespitosus, i proposem el nom Vaccinio microphylli-Sphagnetum capillifolii per al que fins ara sâha anomenat Calluno-Sphagnetum subnitentis Casanovas 1992 (nom. inval.) Com a conclusiĂł general, destaquem la singularitat de la Vall dâAran per la diversitat i excepcionalitat de les comunitats de molleres que sâhi donen. A mĂ©s, aquestes formen sistemes molt particulars pel que fa a la hidrologia i al mosaic de comunitats que acullen; en sĂłn exemples destacats els de bassa Nera, PlanhĂČla dâAiguamĂČg i pla de Tor.Given the topographic situation of the Aran valley, on the north side of the Pyrenees, the climate regimes (from medio-European to high mountain types) have a strong Atlantic influence. This, and the complex relief and bedrock assemblage of the area, enable the formation of great diversity of fens and bogs, covering from mediumsized to small areas. Here we present a phytosociological study of these vegetation units, and especially of those found in the complex systems, where ombrogenous, topogenous, soligenous and limnogenous mires may occur. We obtained field relevĂ©s according to the Braun-Blanquet approach, and recorded various associated environmental parameters (pH and conductivity of the soil water, depth of the phreatic water table, peat thickness), as well as topographic descriptors. By means of 144 relevĂ©s we discuss 22 associations (one of these split in 4 subassociations), from which 2 are new descriptions and 8 are firstly documented from the Pyrenees. Most of the associations treated are included in the vegetation class Scheuchzerio-Caricetea fuscae (fens), whereas few are referred to the Oxycocco-Sphagnetea ombrogenic bogs or to the neighbouring lacustrine alliances Magnocaricion, Phragmition and Scorpidio-Utricularion minoris. We discuss the diversity of the Oxycocco-Sphagnetea bog hummocks, and the occurrence of the Caricion lasiocarpae floating carpets,
which are the sole Scheuchzerietalia representation in Catalonia. Other novelties are the reinterpretation of the Scirpus cespitosus communities, and the new name Vaccinio microphylli-Sphagnetum capillifolii, which properly refers to the Calluno- Sphagnetum subnitentis Casanovas 1992 (nom. inval.). As a general conclusion, we point out the singularity of the Aran valley, referred to the diversity and particularity of the fen and bog communities found. Moreover, these communities are combined into particular systems according to hydrologic aspects, which are especially diverse and outstanding at Bassa Nera, PlanhĂČla dâAiguamĂČg and Plan de Tor
Co-registration of Laser Altimeter Tracks with Digital Terrain Models and Applications in Planetary Science
We have derived algorithms and techniques to precisely co-register laser altimeter profiles with gridded Digital Terrain Models (DTMs), typically derived from stereo images. The algorithm consists of an initial grid search followed by a least-squares matching and yields the translation parameters at sub-pixel level needed to align the DTM and the laser profiles in 3D space. This software tool was primarily developed and tested for co-registration of laser profiles from the Lunar Orbiter Laser Altimeter (LOLA) with DTMs derived from the Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) stereo images. Data sets can be co-registered with positional accuracy between 0.13 m and several meters depending on the pixel resolution and amount of laser shots, where rough surfaces typically result in more accurate co-registrations. Residual heights of the data sets are as small as 0.18 m. The software can be used to identify instrument misalignment, orbit errors, pointing jitter, or problems associated with reference frames being used. Also, assessments of DTM effective resolutions can be obtained. From the correct position between the two data sets, comparisons of surface morphology and roughness can be made at laser footprint- or DTM pixel-level. The precise co-registration allows us to carry out joint analysis of the data sets and ultimately to derive merged high-quality data products. Examples of matching other planetary data sets, like LOLA with LRO Wide Angle Camera (WAC) DTMs or Mars Orbiter Laser Altimeter (MOLA) with stereo models from the High Resolution Stereo Camera (HRSC) as well as Mercury Laser Altimeter (MLA) with Mercury Dual Imaging System (MDIS) are shown to demonstrate the broad science applications of the software tool
Impaired modulation of the cardiac L-type Ca2+ channel activity by ahnak-1 after myocardial infarction
Introduction: The L-type cardiac Ca2+ channel (Cav 1.2) is an important determinant of cardiac repolarization and the main source of activator Ca2+ during excitation-contraction coupling in cardiac cells. Its defective regulation is a major cause of arrhythmias and contractile dysfunction. We have recently shown that the cytoskeletal protein ahnak-1 modulates Ca2+ current through Cav 1.2 channels (ICaL) by interacting with the regulatory beta-subunit of the Cav 1.2 channel and that the genetic variant of ahnak-1 I5483T (previously Ile5236Thr), interferes with the beta-adrenergic stimulation of ICaL. Objective: To extend our study of the I5483T variant to ventricular cardiomyocytes dissociated from remodelled infarcted rat hearts (PMI). Methods: The patch-clamp technique was used to record ICaL from enzymatically dissociated ventricular cardiomyocytes from young (2-month-old) and six-month-old sham-operated and PMI rats. Results: Basal ICaL was increased from 11 ± 0.5 A/F in young cardiomyocytes to 14.6 ± 1.1 A/F and 15.7 ± 1 A/F in sham and PMI cardiomyocytes respectively, while isoprenaline (ISO, 1 ”mol/L) further increased ICaL by 101 ± 6%, 109 ± 10% and 104 ± 12% respectively. When cells were intracellularly perfused with a peptide containing the mutated ahnak-1 sequence (10 ”mol/L) basal ICaL was increased to 20 ± 1 A/F, 22 ± 2 A/F and 21 ± 2 A/F in young, sham and PMI cardiomyocytes respectively. In these cells ISO increased ICaL by 11 ± 4%, 33 ± 6% and 79 ± 12% respectively. Conclusion: Modulation of ICaL by ahnak-1is impaired by myocardial ischemia and remodelling. Since ahnak-1 and Cav 1.2 channels co-localize in the transverse T-tubule system, remodelling of T-tubules could affect the interaction of ahnak-1 with the regulatory beta subunit of these channels
Macroclimate and local hydrological regime as drivers of fen vegetation patterns in Tierra del Fuego (Argentina)
In southern South America, a sharp macroclimatic gradient is found, triggered by the Pacific oceanic influence through the Andes. Mires are substantial landscape units along the gradient, where they play varying roles through the area and include varying plant communities. In this study, we analysed the relationship between vegetation and main abiotic factors in the minerotrophic mires (fens) at two different scales. We chose three fens in Isla Grande from Cordillera and Magellanic Steppe zones and their ecotone. There we characterized the distinct habitats by means of monitoring the water table fluctuations, the peat and the groundwater chemistry, and the vascular plant species composition. The main floristic patterns were revealed by means of classification and ordination of 75 vegetation plots. Thus, we classified the relevés through multivariate analyses into six plant community types, two of which found in each fen. Behind the floristic distinctiveness of each site and each community type, structural vegetation descriptors such as species richness were similar. Overall, water table variables and groundwater chemistry showed the most important environmental differences between fens. Our data point that the main environmental force driving vegetation patterns was the macroclimatic gradient, which shapes the regional floristic pools. This gradient would be also responsible for modifying the local conditions of the fen habitats, mostly in the form of broadening the hydrological conditions within the fens of the Steppe. At each fen, the hydrological regime is the main factor in the distribution of vascular plants, particularly through the varying water table depths
Rational Strain Engineering in Delafossite Oxides for Highly Efficient Hydrogen Evolution Catalysis in Acidic Media
The rational design of hydrogen evolution reaction (HER) electrocatalysts
which are competitive with platinum is an outstanding challenge to make
power-to-gas technologies economically viable. Here, we introduce the
delafossites PdCrO, PdCoO and PtCoO as a new family of
electrocatalysts for the HER in acidic media. We show that in PdCoO the
inherently strained Pd metal sublattice acts as a pseudomorphic template for
the growth of a strained (by +2.3%) Pd rich capping layer under reductive
conditions. The surface modification continuously improves the electrocatalytic
activity by simultaneously increasing the exchange current density j from 2
to 5 mA/cm and by reducing the Tafel slope down to 38 mV/decade,
leading to overpotentials < 15 mV for 10 mA/cm, superior
to bulk platinum. The greatly improved activity is attributed to the in-situ
stabilization of a -palladium hydride phase with drastically enhanced
surface catalytic properties with respect to pure or nanostructured palladium.
These findings illustrate how operando induced electrodissolution can be used
as a top-down design concept for rational surface and property engineering
through the strain-stabilized formation of catalytically active phases
Trapping and manipulating neutral atoms with electrostatic fields
We report on experiments with cold thermal Li atoms confined in combined
magnetic and electric potentials. A novel type of three-dimensional trap was
formed by modulating a magnetic guide using electrostatic fields. We observed
atoms trapped in a string of up to six individual such traps, a controlled
transport of an atomic cloud over a distance of 400m, and a dynamic
splitting of a single trap into a double well potential. Applications for
quantum information processing are discussed.Comment: 4 pages, 4 figure
Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays
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