144 research outputs found
Synthesis and Structural Characterization of Tetraalkylammonium Salts of the Weakly Coordinating Anion [Al(OTeF5)4]â
The weakly coordinating properties of the [Al(OTeF5)4]â anion were studied by the synthesis and characterization of its tetraalkylammonium salts [NAlk4][Al(OTeF5)4] [Alk4 = â(CH3)4, â(C2H5)4, â(C2H5)3CH3, â(C3H7)4, â(C4H9)4]. The oneâpot synthesis includes formation of the BrĂžnsted acid in 1,2âdifluorobenzene, H[Al(OTeF5)4](solv.), and its reaction with [NAlk4]Cl [Alk4 = â(CH3)4, â(C2H5)4, â(C2H5)3CH3, â(C3H7)4, â(C4H9)4] to the corresponding salts. Single crystals were obtained for [N(C4H9)4][Al(OTeF5)4] and characterized by Xâray diffraction analysis
Insights on the Lewis Superacid Al(OTeF5)3: Solvent Adducts, Characterization and Properties
Preparation and characterization of the dimeric Lewis superacid [Al(OTeF5)3]2 and various solvent adducts is presented. The latter range from thermally stable adducts to highly reactive, weakly bound species. DFT calculations on the ligand affinity of these Lewis acids were performed in order to rank their remaining Lewis acidity. An experimental proof of the Lewis acidity is provided by the reaction of solventâadducts of Al(OTeF5)3 with [PPh4][SbF6] and OPEt3, respectively. Furthermore, their reactivity towards chloride and pentafluoroorthotellurate salts as well as (CH3)3SiCl and (CH3)3SiF is shown. This includes the formation of the dianion [Al(OTeF5)5]2â
[P4H]+[Al(OTeF5)4]â: protonation of white phosphorus with the BrĂžnsted superacid H[Al(OTeF5)4](solv)
A sustainable transformation of white phosphorus (P4) into chemicals of higher value is one of the key aspects in modern phosphorus research. Even though the chemistry of P4 has been investigated for many decades, its chemical reactivity towards the simplest electrophile, the proton, is still virtually unknown. Based on quantum-chemical predictions, we report for the first time the successful protonation of P4 by the BrĂžnsted acid H[Al(OTeF5)4](solv). Our spectroscopic results are in agreement with acid-mediated activation of P4 under protonation of an edge of the P4-tetrahedron and formation of a three-center two-electron PâHâP bond. These investigations are of fundamental interest as they permit the activation of P4 with the simplest electrophile as a new prototype reaction for this molecule
High Frequencies of Theropod Bite Marks Provide Evidence for Feeding, Scavenging, and Possible Cannibalism in a Stressed Late Jurassic Ecosystem
Bite marks provide direct evidence for trophic interactions and competition in the fossil record. However, variations in paleoecological dynamics, such as trophic relationships, feeding behavior, and food availability, govern the frequency of these traces. Theropod bite marks are particularly rare, suggesting that members of this clade might not often focus on bone as a resource, instead preferentially targeting softer tissues. Here, we present an unusually large sample of theropod bite marks from the Upper Jurassic Mygatt-Moore Quarry (MMQ). We surveyed 2,368 vertebrate fossils from MMQ in this analysis, with 684 specimens (28.885% of the sample) preserving at least one theropod bite mark. This is substantially higher than in other dinosaur-dominated assemblages, including contemporaneous localities from the Morrison Formation. Observed bite marks include punctures, scores, furrows, pits, and striations. Striated marks are particularly useful, diagnostic traces generated by the denticles of ziphodont teeth, because the spacing of these features can be used to provide minimum estimates of trace maker size. In the MMQ assemblage, most of the striations are consistent with denticles of the two largest predators known from the site: Allosaurus and Ceratosaurus. One of the bite marks suggests that a substantially larger theropod was possibly present at the site and are consistent with large theropods known from other Morrison Formation assemblages (either an unusually large Allosaurus or a separate, large-bodied taxon such as Saurophaganax or Torvosaurus). The distribution of the bite marks on skeletal elements, particularly those found on other theropods, suggest that they potentially preserve evidence of scavenging, rather than active predation. Given the relative abundances of the MMQ carnivores, partnered with the size-estimates based on the striated bite marks, the feeding trace assemblage likely preserves the first evidence of cannibalism in Allosaurus
What Comes after the Trial? An Observational Study of the Real-World Uptake of an E-Mental Health Intervention by General Practitioners to Reduce Depressive Symptoms in Their Patients
Unguided and free e-mental health platforms can offer a viable treatment and self-help
option for depression. This study aims to investigate, from a public health perspective, the real-world
uptake, benefits, barriers, and implementation support needed by general practitioners (GPs). The
study presents data from a spin-off GP survey conducted 2.5 years subsequent to a cluster-randomized
trial. A total of N = 68 GPs (intervention group (IG) GPs = 38, control group (CG) GPs = 30) participated
in the survey (response rate 62.4%). Data were collected via postal questionnaires. Overall,
66.2% of the GPs were female. The average age was 51.6 years (SD = 9.4), and 48.5% of the GPs
indicated that they continued (IG) or started recommending (CG) the e-mental health intervention
under real-world conditions beyond the trial. A number of benefits could be identified, such as ease
of integration and strengthening patient activation in disease management. Future implementation
support should include providing appealing informational materials and including explainer videos.
Workshops, conferences, and professional journals were identified as suitable for dissemination.
Social media approaches were less appealing. Measures should be taken to make it easier for health
care professionals to use an intervention after the trial and to integrate it into everyday practice
Air-stable aryl derivatives of pentafluoroorthotellurate
We report on two different sets of air-stable derivatives of pentafluoroorthotellurate containing fluorinated and non-fluorinated aryl groups. The acid cis-PhTeF4OH was obtained in gram scale and further transformed to Ag[cis-PhTeF4O], which was used as a cis-PhTeF4O transfer reagent to obtain [PPh4][cis-PhTeF4O]. Furthermore, the synthesis of trans-(C6F5)2TeF3OH was achieved by a selective hydrolysis of trans-(C6F5)2TeF4 in the presence of KF and subsequent protonation by aHF. Quantum-chemical calculations show a higher acidity and robustness against fluoride abstraction for trans-(C6F5)2TeF3OH compared to cis-PhTeF4OH
UbiquitÀre Systeme (Seminar) und Mobile Computing (Proseminar) WS 2014/15. Mobile und Verteilte Systeme. Ubiquitous Computing. Teil XII
UbiquitÀre Systeme (Seminar) und Mobile Computing (Proseminar) SS 2014. Mobile und Verteilte Systeme. Ubiquitous Computing. Teil XI
"Miteinander statt ĂŒbereinander": Ergebnisse einer Begleitstudie zum Weddinger Psychoseseminar und Erfahrungen mit der Forschungspartizipation von Psychoseerfahrenen
Es wird informiert ĂŒber Erfahrungen, die mit dem Experimentieren mit Möglichkeiten kommunikativer Forschungspartizipation von Psychoseerfahrenen gesammelt wurden. Ausgangsbasis hierfĂŒr ist eine Begleitstudie zum "Weddinger Psychoseseminar". Dieses Seminar wird beschrieben als ein öffentliches Forum, in dem alle Teilnehmer und Teilnehmerinnen als Experten bzw. Expertinnen ihrer selbst gemeinsam etwas voneinander lernen können. Es wird ein Entwicklungsprozess des Weddinger Psychoseseminars rekonstruiert, in dem sich dessen Teilnehmer und Teilnehmerinnen (Psychoseerfahrene, Angehörige, im psychiatrischen Bereich TĂ€tige und Studierende) an den normativen Forderungen des Seminars nach Gleichberechtigung und Offenheit orientierten und diese zu verwirklichen suchten. Dieser Prozess wird als nicht abgeschlossen beschrieben. AnschlieĂend werden die Möglichkeiten und Grenzen kommunikativer Forschungspartizipation aus der Sicht der Beteiligten drei Jahre nach Abschluss der Studie diskutiert.Experimenting with possibilities of a communicative participant research (sounds really scientific, doesn't it?) is in the focus of this contribution. The research partner were people with psychotic experiences, who were till than examination objects in psychological and psychiatric research, and one student of psychology. Starting point for discussing participant research is an accompanying study of the first Berlin "Psychoseseminar" in the district Wedding. The "Weddinger Psychoseseminar" is described as a public forum, in which all participants as experts can learn something from each other. We reconstruct the developing process of the "Weddinger Psychoseseminar". All participants ("Psychoseerfahrene" â psychosis experienced â, relatives, professionals and students) orientate themselves at the normative demands of the "Psychoseseminar" for equal rights and openess. The participants tried to realize these claims. This process is described as not completed. Prerequisites for realizing these claims are demystification of psychosis and that the participants reassure themselves of taking each other seriously. This process was stimulated particularly by the psychosis experienced. They became more and more self-confident and began to point out for instance if participants lost the normative demands of the seminar or the reference to everyday life respectively to practice. Following we discuss the possibilities and limits to communicative participant research, with which we experimented in the context of a working group for the psychosis seminar. Three years after finishing the study, we discuss the effects on the "Psychoseseminar" and primarily on our own development from the view of the ones involved. We â the authors â realize our intension of plural authorship (Clifford, in Berg and Fuchs 1993) at the first time by writing this article
Validity and responsiveness of the EQ-5D in assessing and valuing health status in patients with anxiety disorders
<p>Abstract</p> <p>Background</p> <p>The EQ-5D is a generic questionnaire which generates a health profile as well as index scores for health-related quality of life that may be used in cost-utility analysis.</p> <p>Aims of the study</p> <p>To examine validity and responsiveness of the EQ-5D in patients with anxiety disorders.</p> <p>Methods</p> <p>389 patients with anxiety disorders completed the EQ-5D at baseline and 6-month follow-up. Subjective measures of quality of life (WHOQOL-BREF) and psychopathology (BAI, BDI-II, BSQ, ACQ, MI) were used for comparison. Validity was analyzed by assessing associations between EQ-5D scores and related other scores. Responsiveness was analyzed by calculating effect sizes of differences in scores between baseline and follow-up for 3 groups indicating more, constant or less anxiety. Meaningful difference scores for shifting to less or more anxiety were derived by means of regression analysis.</p> <p>Results</p> <p>88.4% of respondents reported problems in at least one of the EQ-5D dimension at baseline; the mean EQ VAS score was 63.8. The EQ-5D dimension most consistently associated with the measures used for comparison was 'anxiety/depression'. EQ VAS and EQ-5D index scores were highly correlated (|r|>0.5) with scores of the WHOQOL-BREF dimensions 'physical', 'mental' and 'overall' as well as BAI and BDI-II. The EQ-5D index tended to be the most responsive score. Standardized meaningful difference scores were not significantly different between EQ VAS, EQ-5D index and measures used for comparison.</p> <p>Conclusions</p> <p>The EQ-5D seems to be reasonably valid and moderately responsive in patients with anxiety disorders. The EQ-5D index may be suitable for calculating QALYs in economic evaluation of health care interventions for patients with anxiety disorders.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN15716049</p
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