637 research outputs found
Novel Polypyridyl Ruthenium(II) Complexes Containing Oxalamidines as Ligands.
The complexes [Ru(bpy)2(H2TPOA)](PF6)2 â
4H2O, (1); [Ru(Me-bpy)2(H2TPOA)](PF6)2
â
2H2O, (2); [Ru(bpy)2(H2TTOA)](PF6)2 â
2H2O, (3); [Ru(Me-bpy)2(H2TTOA)](PF6)2 â
2H2O,
(4) and {[Ru(bpy)2]2(TPOA)}(PF6)2 â
2H2O, (5) (where bpy is 2,2´bipyridine; Me-bpy is 4,4´-
dimethyl-2,2´-bipyridine; H2TPOA is N, N´, N´´, N´´´- tetraphenyloxalamidine; H2TTOA is
N, N´, N´´, N´´´- tetratolyloxalamidine) have been synthesized and characterized by 1H-NMR,
FAB-MS, infrared spectroscopy and elemental analysis. The X-ray investigation shows the
coordination of the still protonated oxalamidine moiety via the 1,2âdiimine unit. The dimeric
compound (5) could be separated in its diastereoisomers (5´) and (5´´) by repeated
recrystallisation. The diastereomeric forms exhibit different 1H-NMR spectra and slightly
shifted electronic spectra. Compared with the model compound [Ru(bpy)3]2+, the absorption
maxima of (1)â(5) are shifted to lower energies. The mononuclear complexes show Ru(III/II)-
couples at about 0.9 V vs SCE, while for the dinuclear complex two well defined metal based
redox couples are observed at 0.45 and 0.65 V indicating substantial interaction between the
two metal centres
THE UTILIZATION OF HIGH FREQUENCY PERCUSSIVE VENTILATION TO REDUCE EXTRACORPOREAL OXYGENATION MEMBRANE SUPPORT.
To minimize the chance of ventilator induced lung injury (VILI), in patients who develop adult respiratory distress syndrome ARDS), Extracorporeal Oxygenation Membrane (ECMO) is a common clinical intervention. The goal of venous-venous ECMO is to provide stable gas exchange, while the goal of the ventilator is to preserve the patient\u27s pulmonary mechanics and minimize VILI. When ECMO parameters are maximized and gas exchange is marginal, often then the ventilator is called upon to help improve or maintain gas exchange often requiring high pressures and oxygen delivery (FI02). An alternative strategy to meet this objective is to utilized high frequency percussive ventilation (HFPV) via the VDR-4 (Sandpoint, Idaho). HFPV provides both an endobronchial wedge via the percussive rate and an oscillatory plateau via the connective rate. With this strategy lower pressures and oxygen delivery can be employed and ECMO parameters can be often reduced. From Jan 2015 to Feb 2016 we utilized the VDR on fifteen V-V ECMO patients. Thirteen (86.7%) of fifteen patients both ECMO FIO2 and sweep were reduced with in twenty-four hours. (Table 1) HFPV pressures and FIO2 were maintain lower than 60% and airway pressure ⤠40cmH20. (Table 1) Prior to placing on HFPV a pressure/tool measurement was performed to determine starting airway pressure and PEEP parameters to set on the VDR. Based on the above results, HFPV can help ECMO maintain gas exchange for patients at a lower FIO2 and sweep settings
The Ulakhan fault surface rupture and the seismicity of the OkhotskâNorth America plate boundary
New field work, combined with analysis of high-resolution aerial photographs, digital elevation models, and satellite imagery, has identified an
active fault that is traceable for âź90 km across the Seymchan Basin
and is part of the Ulakhan fault system, which is believed to form the
OkhotskâNorth America plate boundary. Age dating of alluvial fan sediments
in a channel system that is disturbed by fault activity suggests the current
scarp is a result of a series of large earthquakes (âĽMwâ
7.5)
that have occurred since 11.6Âą2.7 ka. A possible channel feature offset
by 62Âą4 m associated with these sediments yields a slip rate of 5.3Âą1.3 mm yrâ1, in broad agreement with rates suggested from global
plate tectonics. Our results clearly identify the Ulakhan fault as the
OkhotskâNorth America plate boundary and show that tectonic strain release
is strongly concentrated on the boundaries of Okhotsk. In light of our
results, the likelihood of recurrence of Mwâ
7.5 earthquakes is
high, suggesting a previously underestimated seismic hazard across the
region.</p
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The Utilization of High Frequency Percussive Ventilation to Reduce V-V Extracorporeal Oxygenation Membrane Support (Poster).
Honey bee foraging distance depends on month and forage type
To investigate the distances at which honey bee foragers collect nectar and pollen, we analysed 5,484 decoded waggle dances made to natural forage sites to determine monthly foraging distance for each forage type. Firstly, we found significantly fewer overall dances made for pollen (16.8 %) than for non-pollen, presumably nectar (83.2 %; Pâ<â2.2âĂâ10â23). When we analysed distance against month and forage type, there was a significant interaction between the two factors, which demonstrates that in some months, one forage type is collected at farther distances, but this would reverse in other months. Overall, these data suggest that distance, as a proxy for forage availability, is not significantly and consistently driven by need for one type of forage over the other
Loans, logins and lasting the course: Academic library use and student retention
Activities and services that improve student engagement and retention in the higher education sector are important not only to individual studentâs success but also to university planning and funding. This paper reports on a quantitative study that was carried out to explore whether use of the library by new university students is associated with continued enrolment. Studentsâ socioeconomic background and age were also examined in relation to library use. Limited to commencing students in March 2010 at Curtin University, the study drew on demographic data from the Universityâs enrolment system and instances of library use from the Libraryâs management system. Results of the statistical analyses indicate that library use is associated with retention, and importantly, library use in the early weeks of a studentâs first semester is associated with retention. âMature agedâ (21 years and over) students displayed different library use patterns than their younger colleagues and there was some variation in library use between students from different socioeconomic backgrounds. Findings from this study suggest that academic libraries can contribute to the retention of students and that carefully targeted programs and services may improve library use by some groups of students
Adaptation or constraint? Reference-dependent scatter in honey bee dances
The waggle dance of the honey bee is used to recruit nest mates to a resource. Dancer bees, however, may indicate many directions within a single dance bout; we show that this scatter in honey bee dances is strongly dependent on the sensory modality used to determine a reference angle in the dance. Dances with a visual reference are more precise than those with a gravity reference. This finding undermines the idea that scatter is introduced into dances, which the bees could perform more precisely, in order to spread recruits out over resource patches. It also calls into question reported interspecific differences that had been interpreted as adaptations of the dance to different habitats. Our results support a non-adaptive hypothesis: that dance scatter results from sensory and performance constraints, rather than modulation of the scatter by the dancing bee. However, an alternative adaptive hypothesis cannot be ruled out
Narrative exposure therapy for PTSD increases top-down processing of aversive stimuli - evidence from a randomized controlled treatment trial
Adenauer H, Catani C, Gola H, et al. Narrative exposure therapy for PTSD increases top-down processing of aversive stimuli - evidence from a randomized controlled treatment trial. BMC Neuroscience. 2011;12(1): 127.BACKGROUND: Little is known about the neurobiological foundations of psychotherapy for Posttraumatic Stress Disorder (PTSD). Prior studies have shown that PTSD is associated with altered processing of threatening and aversive stimuli. It remains unclear whether this functional abnormality can be changed by psychotherapy. This is the first randomized controlled treatment trial that examines whether narrative exposure therapy (NET) causes changes in affective stimulus processing in patients with chronic PTSD. METHODS: 34 refugees with PTSD were randomly assigned to a NET group or to a waitlist control (WLC) group. At pre-test and at four-months follow-up, the diagnostics included the assessment of clinical variables and measurements of neuromagnetic oscillatory brain activity (steady-state visual evoked fields, ssVEF) resulting from exposure to aversive pictures compared to neutral pictures. RESULTS: PTSD as well as depressive symptom severity scores declined in the NET group, whereas symptoms persisted in the WLC group. Only in the NET group, parietal and occipital activity towards threatening pictures increased significantly after therapy. CONCLUSIONS: Our results indicate that NET causes an increase of activity associated with cortical top-down regulation of attention towards aversive pictures. The increase of attention allocation to potential threat cues might allow treated patients to re-appraise the actual danger of the current situation and, thereby, reducing PTSD symptoms. REGISTRATION OF THE CLINICAL TRIAL: Number: NCT00563888Name: "Change of Neural Network Indicators Through Narrative Treatment of PTSD in Torture Victims" ULR: http://www.clinicaltrials.gov/ct2/show/NCT00563888
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