99 research outputs found

    WĂ€rmezeitliche Klima- und Gletscherschwankungen im Pollenprofil eines hochgelegenen Moores (2270 m) der Venedigergruppe

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    Das 225 cm mĂ€chtige Torflager eines Moores nahe der Rostocker HĂŒtte im Maurertal (sĂŒdliche Venedigergruppe), in unmittelbarer NĂ€he des Gletschervorfeldes von Simony- und Maurerkees wurde pollenanalytisch untersucht. Das Torfwachstum begann in 2300 m Höhe um 6800 v. Chr. Somit konnte pollenanalytisch die Vegetationsentwicklung der ganzen postglazialen WĂ€rmezeit erfaßt werden. Die sich im Profil abzeichnenden Klimaverschlechterungen wurden mittels 14C datiert und mit unabhĂ€ngig davon datierten oder zeitlich eingegrenzten MorĂ€nen des Simony- und Maurerkees und anderer Gletscher der Venedigergruppe verglichen. Drei wĂ€rmezeitliche Gletscherhochstandsperioden erscheinen damit gut belegt. Es wurden dafĂŒr die lokalen Bezeichnungen „Venedigerschwankung" (ca. 6700— 6000 V. Chr.), „Frosnitzschwankung" (ca. 4400—4200 v. Chr.) und „Löbbenschwankung" (ca. 1500—1300 V. Chr.) eingefĂŒhrt. Weitere Untersuchungen zur Sicherung dieser Ergebnisse sind in Arbeit.researc

    Impact of early enteral versus parenteral nutrition on mortality in patients requiring mechanical ventilation and catecholamines: study protocol for a randomized controlled trial (NUTRIREA-2)

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    BACKGROUND: Nutritional support is crucial to the management of patients receiving invasive mechanical ventilation (IMV) and the most commonly prescribed treatment in intensive care units (ICUs). International guidelines consistently indicate that enteral nutrition (EN) should be preferred over parenteral nutrition (PN) whenever possible and started as early as possible. However, no adequately designed study has evaluated whether a specific nutritional modality is associated with decreased mortality. The primary goal of this trial is to assess the hypothesis that early first-line EN, as compared to early first-line PN, decreases day 28 all-cause mortality in patients receiving IMV and vasoactive drugs for shock. METHODS/DESIGN: The NUTRIREA-2 study is a multicenter, open-label, parallel-group, randomized controlled trial comparing early PN versus early EN in critically ill patients requiring IMV for an expected duration of at least 48 hours, combined with vasoactive drugs, for shock. Patients will be allocated at random to first-line PN for at least 72 hours or to first-line EN. In both groups, nutritional support will be started within 24 hours after IMV initiation. Calorie targets will be 20 to 25 kcal/kg/day during the first week, then 25 to 30 kcal/kg/day thereafter. Patients receiving PN may be switched to EN after at least 72 hours in the event of shock resolution (no vasoactive drugs for 24 consecutive hours and arterial lactic acid level below 2 mmol/L). On day 7, all patients receiving PN and having no contraindications to EN will be switched to EN. In both groups, supplemental PN may be added to EN after day 7 in patients with persistent intolerance to EN and inadequate calorie intake. We plan to recruit 2,854 patients at 44 participating ICUs. DISCUSSION: The NUTRIREA-2 study is the first large randomized controlled trial designed to assess the hypothesis that early EN improves survival compared to early PN in ICU patients. Enrollment started on 22 March 2013 and is expected to end in November 2015. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01802099 (registered 27 February 2013)

    Use of ring-expanded diamino- and diamidocarbene ligands in copper catalyzed azide-alkyne "click" reactions

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    The two-coordinate ring-expanded N-heterocyclic carbene copper­(I) complexes [Cu­(RE-NHC)<sub>2</sub>]<sup>+</sup> (RE-NHC = 6-Mes, 7-<i>o</i>-Tol, 7-Mes) have been prepared and shown to be effective catalysts under neat conditions for the 1,3-dipolar cycloaddition of alkynes and azides. In contrast, the cationic diamidocarbene analogue [Cu­(6-MesDAC)<sub>2</sub>]<sup>+</sup> and the neutral species [(6-MesDAC)­CuCl]<sub>2</sub> and [(6-MesDAC)<sub>2</sub>(CuCl)<sub>3</sub>] show good activity when the catalysis is performed on water

    Neue pollenanalytische Untersuchungen von Gletschereis und gletschernahen Mooren in den Ostalpen

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    Pollen analytical investigations of glacier ice from the Kesselwandferner in the Ötztal Alps, Tyrol, generally confirmed the palynologycal findings of Vareschi (1942) and brought new results. Annual layers were found which distinguish themselves by an increased content of Picea pollen according to extreme Picea-blooming years. These can be used as "guiding horizons" in the firn-area of the glaciers. Long distance transport of African pollen (Ephedra) was proved. The absolute average pollen rain in 3300 m was determined by 28.000 pollen grains per year and dm**2. The investigation of fens near glaciers made it possible to determine the oscillations of the tree-line and the forest-line and to date them by C-14. These oscillations could be connected with moraines also dated by C-14. Oscillations of the forest-line and thus probably glacier oscillations, too, could be determined for the period from 6700 to 6000 B.C. and the periods about 4500, 2600 and 1600 B.C
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