676 research outputs found

    The Preparation and Kinetics of the Sterically Hindered Gold (III) Complex, [Au(1,1,4 - Me3 dien)Cl] (PF6)2

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    The N-alkylated gold (III) complex has been synthesized. The rate constant for the monobromination reaction was determined to be 132 ι mole -1 dec -1. The implications of such a value relative to similar non N0alkylated and other N-alkylated complexes are discussed

    A Most Unusual Zeolite Templating: Cage to Cage Connection of One Guest Molecule

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    An unusual case of a diquaternary ammonium dication, with large bulky end groups built from the tropane moiety and connected by a C4 methylene chain, is found to reside in zeolite SSZ-35 (STF). The structure of the guest/host product is such that the tropane bicylic entities reside in the shallow cavities of the cages of the STF structure and the C4 methylene chain runs through the 10-ring (~5.5 Ã…) window that connects the cages. This is a most unusual (and energy-intensive) templating of a zeolite structure with the guest molecule spanning two unit cells. The unusual result was found by single crystal studies with the addition of the use of the SQUEEZE program to show a consistent fit for the guest molecule following from measured electron densities in the crystal structure work. These analyses were followed with MAS NMR studies to confirm the integrity of the diquaternary guest molecule in the host sieve. A few comparative diquaternary guest molecules in MFI zeolite are also studied

    Determinants of Ongoing Participation in a Masters-level Sport: The Impact of Internal Attributes and Experiences with the Organization

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    This research aims to empirically determine which factors best explain ongoing participation in a masters-level sport. Ongoing participation, a form of customer loyalty, is critical in many non-profit service industries where organizations have limited resources available to attract new customers. The objective of this research leads to the inclusion of a breadth of variables. Several internal factors are hypothesized to play a role in ongoing membership, including the source of motivation, perceived ability in the sport, identification with the organization, level of participation, and personal attributes such as age, gender, and family stage. External factors that are hypothesized to influence membership include attributes of the service organization: the quality of service received, and the impact of coaching. The hypotheses are tested in the context of membership in United States Masters Swimming (USMS). USMS is a national, non-profit, member-based organization that supports fitness and competitive adult swimmers. Members pay an annual fee to join and must renew membership at the beginning of each year. Data was collected using two online survey instruments: (1) targeting recently renewed USMS members and (2) targeting former members. Usable responses include 5,496 continuous members of more than one year and 543 former members with low intent to rejoin. The results provide empirical evidence that several factors help determine whether a member of an athletic membership organization will stay with the organization. The motivational factors of enjoyment and fitness, competition, and social connection all support ongoing membership. In addition, a feeling of connection to the organization, as well as positive perceptions of service attributes are important in developing lasting customer relationships. This research contributes to theory-building regarding member-based organizations in sports and provides practical insights for managers in masters sports and member-based sports organizations

    Twisted equivariant K-theory, groupoids and proper actions

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    In this paper we define twisted equivariant K-theory for actions of Lie groupoids. For a Bredon-compatible Lie groupoid, this defines a periodic cohomology theory on the category of finite CW-complexes with equivariant stable projective bundles. A classification of these bundles is shown. We also obtain a completion theorem and apply these results to proper actions of groups.Comment: 26 page

    Automorphisms of p-compact groups and their root data

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    We construct a model for the space of automorphisms of a connected p-compact group in terms of the space of automorphisms of its maximal torus normalizer and its root datum. As a consequence we show that any homomorphism to the outer automorphism group of a p-compact group can be lifted to a group action, analogous to a classical theorem of de Siebenthal for compact Lie groups. The model of this paper is used in a crucial way in our paper ``The classification of 2-compact groups'', where we prove the conjectured classification of 2-compact groups and determine their automorphism spaces.Comment: 24 pages. Introduction restructured and title changed (from "Automorphisms of root data, maximal torus normalizers, and p-compact groups"). Various other adjustments mad

    Brucellosis in a refugee who migrated from Syria to Germany and lessons learnt, 2016

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    A teenage woman migrating from Syria arrived in May 2015 in Germany. She gave birth to a healthy child in early 2016, but became febrile shortly after delivery. Blood cultures revealed Brucella melitensis. In retrospect, she reported contact with sheep in Syria and recurrent pain in the hip joints over about five months before diagnosis of brucellosis. We discuss consequences for adequate treatment of mother and child as well as for clinical and laboratory management

    Multi-phase postmortem CT angiography: recognizing technique-related artefacts and pitfalls

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    Background and purpose: Multi-phase postmortem CT angiography (MPMCTA) is increasingly being recognized as a valuable adjunct medicolegal tool to explore the vascular system. Adequate interpretation, however, requires knowledge about the most common technique-related artefacts. The purpose of this study was to identify and index the possible artefacts related to MPMCTA. Material and methods: An experienced radiologist blinded to all clinical and forensic data retrospectively reviewed 49 MPMCTAs. Each angiographic phase, i.e. arterial, venous and dynamic, was analysed separately to identify phase-specific artefacts based on location and aspect. Results: Incomplete contrast filling of the cerebral venous system was the most commonly encountered artefact, followed by contrast agent layering in the lumen of the thoracic aorta. Enhancement or so-called oedematization of the digestive system mucosa was also frequently observed. Conclusion: All MPMCTA artefacts observed and described here are reproducible and easily identifiable. Knowledge about these artefacts is important to avoid misinterpreting them as pathological finding

    Virtopsy: Zukunftsträchtige Forschung in der Rechtsmedizin

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    Computed tomography techniques have been developed over the last 10 years and have found various applications in the forensic field. The most recent development is multislice computed tomography combined with photogrammetry-based surface optical scanning and image rendering techniques. This combination of techniques can be used to produce 3-dimensional images of injury patterns for comparison with suspect weapons and also to screen for pathological conditions in the living or deceased. This technology provides a minimally invasive procedure for capturing forensically relevant images which can be produced in the courtroom. The rapid developments in imaging techniques could provide an alternative to conventional autopsy procedures in the futur

    Measures for pathway analysis in brain white matter using diffusion tensor images

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    In this paper we discuss new measures for connectivity analysis of brain white matter, using MR diffusion tensor imaging. Our approach is based on Riemannian geometry, the viability of which has been demonstrated by various researchers in foregoing work. In the Riemannian framework bundles of axons are represented by geodesies on the manifold. Here we do not discuss methods to compute these geodesies, nor do we rely on the availability of geodesies. Instead we propose local measures which are directly computable from the local DTI data, and which enable us to preselect viable or exclude uninteresting seed points for the potentially time consuming extraction of geodesies. If geodesies are available, our measures can be readily applied to these as well. We consider two types of geodesic measures. One pertains to the connectivity saliency of a geodesic, the second to its stability with respect to local spatial perturbations. For the first type of measure we consider both differential as well as integral measures for characterizing a geodesic's saliency either locally or globally. (In the latter case one needs to be in possession of the geodesic curve, in the former case a single tangent vector suffices.) The second type of measure is intrinsically local, and turns out to be related to a well known tensor in Riemannian geometry.</p

    Clinical application of a rapid microbiological test based on capillary zone electrophoresis to assess local skin infection

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    <p>Abstract</p> <p>Background</p> <p>The basic clinical problem associated with infection treatment is the fact that classic, commonly and routinely used isolation and identification methods are based on long-term processes of a phenotypic analysis of microorganisms. Consequently sometimes, especially in small centres, rapid implementation of antibacterial treatment becomes delayed.</p> <p>The work presents the initial results of rapid microbiological identification based on an original method of capillary zone electrophoresis (CZE). The study involved the analysis of 78 biological samples from post-operative wounds and trophic ulcers.</p> <p>Results</p> <p>The attempt was made to identify individual bacterial species based on characteristic features of electropherograms achieved. Finally, G(+) cocci type bacteria and different G(-) rods were identified with sensitivity of 88.1% and specificity of 100%.</p> <p>Conclusions</p> <p>Based on the clinical trials using an electrophoretic technique in the field of microbiological diagnostics of infected exudate from a post-operative wound it can be concluded that it is a rapid and relatively sensitive method for initial identification of infectious pathogens.</p
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