Evidence-based indications for the planning of PET or PET/CT capacities are needed

Purpose To identify evidence-based indications for PET/PET–CT scans in support of facilities planning and to describe a pilot project in which this information was applied for an investment decision in an Austrian region. The study updates a Health Technology Assessment (HTA) report (2015) on oncological indications, extending it to neurological indications and inflammatory disorders. Methods A systematic literature search to identify HTA reports, evidence-based guidelines, and systematic reviews/meta-analyses (SR/MA) was performed, supplemented by a manual search for professional society recommendations and explicit “not-to-do’s”. A needs-assessment was conducted in the context of the pilot study on investing in an additional PET–CT scanner in the Austrian region of Carinthia. Results Overall recommendations for indications as well as non-recommendations for the three areas (oncology, neurology, and inflammatory disorders) were compiled from the 2015 PET–HTA report and expanded for a final total of ten HTA, comprising 234 (positive and negative) recommendations from professional societies and databases, and supplemented by findings from 23 SR/MA. For the investment decision pilot study in Carinthia, 1762 PET scans were analyzed; 77.8% were assigned to the category “recommended evidence-based indications” (54.7%), “not recommended” (1.8%) or “contradictory recommendations” (21.3%). The remaining could not be assigned to any of the three categories. Conclusions The piloting of PET capacity planning using evidence-based information is a first of its kind in the published literature. On one hand, the high number of PET scans that could not be ascribed to any of the categories identified limits to the instructive power of the study to use evidence-based indication lists as the basis for a needs-assessment investment planning. On the other hand, this study reveals how there is a need to improve indication coding for enhanced capacity planning of medical services. Overall recommendations identified can serve as needs-based and evidence-based decision support for PET/PET–CT service provision

The effect of physical activity on sleep quality, well-being, and affect in academic stress periods

The stress-buffering hypothesis postulates that physical activity and exercise can buffer the negative effects of (academic) stress on health. It still remains an open question whether students, who regularly engage in physical activity and exercise within their academic examination period, can successfully diminish these negative effects. Sixty-four subjects participated in this study and completed a total of five surveys, with T1 at the end of the semester break (baseline) and T2–T5 being presented every Friday in the last 4 weeks of the semester (examination period). They were asked to answer questions about their activity level, sleep quality, well-being and affect. Hierarchical linear models showed significant dependencies on time for all dependent measures. The expansion of the model for exercise also showed significant main effects of this predictor on well-being and positive affect (PA) and negative affect. Moreover, significant interactions with time for sleep quality and PA were found. Results suggest that physical activity and exercise in the academic examination period may be able to buffer the negative effects of stress on health-related outcomes. Therefore, activity levels should be maintained in times of high stress to prevent negative effects on sleep, well-being and affect in students

The relativistic self-energy in nuclear dynamics

It is a well known fact that Dirac phenomenology of nuclear forces predicts the existence of large scalar and vector mean fields in matter. To analyse the relativistic self-energy in a model independent way, modern high precision nucleon-nucleon ($NN$) potentials are mapped on a relativistic operator basis using projection techniques. This allows to compare the various potentials at the level of covariant amplitudes were a remarkable agreement is found. It allows further to calculate the relativistic self-energy in nuclear matter in Hartree-Fock approximation. Independent of the choice of the nucleon-nucleon interaction large scalar and vector mean fields of several hundred MeV magnitude are generated at tree level. In the framework of chiral EFT these fields are dominantly generated by contact terms which occur at next-to-leading order in the chiral expansion. Consistent with Dirac phenomenology the corresponding low energy constants which generate the large fields are closely connected to the spin-orbit interaction in $NN$ scattering. The connection to QCD sum rules is discussed as well.Comment: 49 pages, 13 figure

Infektionsrisiken im Medizinstudium an deutschen Hochschulen und Interventionsmaßnahmen im Rahmen des Arbeitsmedizinischen Kurses

Beschäftige im Gesundheitsdienst sind einem erhöhtem Risiko hinsichtlich Infektionskrankheiten ausgesetzt. Eine Ansteckung bedeutet für die betroffenen Personen ein eventuell großes persönliches Unglück, aber auch eine hohe finanzielle Belastung für die Träger der Unfallversicherung. Es war Ziel dieser Arbeit, mittels einer Befragung von Medizinstudentinnen und Studenten zu überprüfen, ob sie während des Studiums einem erhöhten Infektionsrisiko ausgesetzt sind, sowie ihren Kenntnisstand bezüglich Präventionsmaßnahmen und des postexponentiellen Handelns zu eruieren. Es zeigte sich, dass ein großer Anteil der befragten Studierenden vor allem während ihrer Famulaturen einem erheblichen Risiko durch Nadelstichverletzungen ausgesetzt waren. Bereits 35% der Studierenden berichteten über ein zurückliegendes Unfallereignis. Zugleich bestanden deutliche Lücken beim Impfschutz. Immerhin 9% der Befragten war nicht gegen Hepatitis B geimpft, bei 29% wurde nach der Impfung keine Kontrolle des Serumtiters durchgeführt. Weiterhin wurde das Ansteckungsrisiko gegenüber bestimmten Infektionskrankheiten von den Studierenden schlecht eingeschätzt. Es gab Lücken beim Wissen bezüglich sekundärer präventiver Maßnahmen, der Notwendigkeit einer Dokumentation eines Unfalls und der Meldung an den zuständigen Träger der gesetzlichen Unfallversicherung. Diese Erkenntnisse begründeten einen dringenden Handlungsbedarf, weshalb in einem zweiten Schritt zwei themenbezogene, fallbasierte Computerlernfälle unter Verwendung des CASUS®-Systems entwickelt wurden. Die Lernfälle wurden von Experten validiert und anschließend im Rahmen des arbeitsmedizinischen Pflichtkurses eingesetzt und von den Studierenden evaluiert. Wesentliche Ergebnisse waren, dass sowohl die Qualität beider Lernfälle von einem Grossteil der Studierenden als hoch eingeschätzt wurde, als auch die Motivation für das Fach Arbeitsmedizin durch die Bearbeitung gesteigert wurde. Auch das Gesamturteil der Studierenden kann mit einem Median von 11 Punkten auf einer Schulnotenskala als positiv ausgelegt werden. Bei einem Vergleich zweier Kurssysteme konnte gezeigt werden, dass die Lernfälle auch zur Bearbeitung in freier Zeiteinteilung, ohne tutorielle Betreuung, geeignet waren. Computergestützte Lernsysteme stellen somit für die arbeitsmedizinische Lehre eine hervorragende Ergänzung zum konventionellen Unterricht dar. Sie bieten eine praktikable und effektive Möglichkeit, den Studierenden die Prävention von Infektionskrankheiten im Gesundheitsdienst nahe zu bringen

A global assessment of gross and net land change dynamics for current conditions and future scenarios

The consideration of gross land changes, meaning all area gains and losses within a pixel or administrative unit (e.g. country), plays an essential role in the estimation of total land changes. Gross land changes affect the magnitude of total land changes, which feeds back to the attribution of biogeochemical and biophysical processes related to climate change in Earth System Models. Global empirical studies on gross land changes are currently lacking. Whilst the relevance of gross changes for global change has been indicated in the literature, it is not accounted for in future land change scenarios. In this study, we extract gross and net land change dynamics from large-scale and high-resolution (30-100m) remote sensing products to create a new global gross and net change dataset. Subsequently, we developed an approach to integrate our empirically derived gross and net changes with the results of future simulation models, by accounting for the gross and net change addressed by the land use model and the gross and net change that is below the resolution of modelling. Based on our empirical data, we found that gross land change within 0.5-degree grid cells were substantially larger than net changes in all parts of the world. As 0.5- degree grid cells are a standard resolution of Earth System Models, this leads to an underestimation of the amount of change. This finding contradicts earlier studies, which assumed gross land changes to appear in shifting cultivation areas only. Applied in a future scenario, the consideration of gross land changes led to approximately 50% more land changes globally compared to a net land change representation. Gross land changes were most important in heterogeneous land systems with multiple land uses (e.g. shifting cultivation, smallholder farming, and agro-forestry systems). Moreover, the importance of gross changes decreased over time due to further polarization and intensification of land use. Our results serve as empirical database for land change dynamics that can be applied in Earth System Models and Integrated Assessment Model

Health technology assessment of medical devices in europe: processes, practices, and methods

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Objectives: To review and compare current Health Technology Assessment (HTA) activities for medical devices (MDs) across European HTA institutions. Methods: A comprehensive approach was adopted to identify institutions involved in HTA in European countries. We systematically searched institutional Web sites and other online sources by using a structured tool to extract information on the role and link to decision making, structure, scope, process, methodological approach, and available HTA reports for each included institution. Results: Information was obtained from eighty-four institutions, forty-seven of which were analyzed. Fifty-four methodological documents from twenty-three agencies in eighteen countries were identified. Only five agencies had separate documents for the assessment of MDs. A few agencies made separate provisions for the assessment of MDs in their general methods. The amount of publicly available HTA reports on MDs varied by device category and agency remit. Conclusions: Despite growing consensus on their importance and international initiatives, such as the EUnetHTA Core Model®, specific tools for the assessment of MDs are rarely developed and implemented at the national level. Separate additional signposts incorporated in existing general methods guides may be sufficient for the evaluation of MDs.EC/FP7/305983/EU/Advancing and strengthening the methodological tools and practices relating to the application and implementation of Health Technology Assessment (HTA)/ADVANCE_HT

Enhanced light emission from top-emitting organic light-emitting diodes by optimizing surface plasmon polariton losses

We demonstrate enhanced light extraction for monochrome top-emitting organic light-emitting diodes (OLEDs). The enhancement by a factor of 1.2 compared to a reference sample is caused by the use of a hole transport layer (HTL) material possessing a low refractive index (1.52). The low refractive index reduces the in-plane wave vector of the surface plasmon polariton (SPP) excited at the interface between the bottom opaque metallic electrode (anode) and the HTL. The shift of the SPP dispersion relation decreases the power dissipated into lost evanescent excitations and thus increases the outcoupling efficiency, although the SPP remains constant in intensity. The proposed method is suitable for emitter materials owning isotropic orientation of the transition dipole moments as well as anisotropic, preferentially horizontal orientation, resulting in comparable enhancement factors. Furthermore, for sufficiently low refractive indices of the HTL material, the SPP can be modeled as a propagating plane wave within other organic materials in the optical microcavity. Thus, by applying further extraction methods, such as micro lenses or Bragg gratings, it would become feasible to obtain even higher enhancements of the light extraction.Comment: 11 pages, 6 figures, will be submitted to PR

Systematics of collective correlation energies from self-consistent mean-field calculations

The collective ground-state correlations stemming from low-lying quadrupole excitations are computed microscopically. To that end, the self-consistent mean-field model is employed on the basis of the Skyrme-Hartre-Fock (SHF) functional augmented by BCS pairing. The microscopic-macroscopic mapping is achieved by quadrupole-constrained mean-field calculations which are processed further in the generator-coordinate method (GCM) at the level of the Gaussian overlap approximation (GOA). We study the correlation effects on energy, charge radii, and surface thickness for a great variety of semi-magic nuclei. A key issue is to work out the influence of variations of the SHF functional. We find that collective ground-state correlations (GSC) are robust under change of nuclear bulk properties (e.g., effective mass, symmetry energy) or of spin-orbit coupling. Some dependence on the pairing strength is observed. This, however, does not change the general conclusion that collective GSC obey a general pattern and that their magnitudes are rather independent of the actual SHF parameters.Comment: 13 pages, 13 figure