bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards quantitative demineralization imaging for the assessment of carious lesions based on PS-OCT
Authors: Golde Jonas , Tetschke Florian , Vosahlo Robin , Kirsten Lars , Walther Julia , Hannig Christian , Koch Edmund
Published: August 2020

Assessing the stage and progression of enamel demineralization non-invasively is of high interest in conservative dentistry. By examining tooth samples with suspected occlusal lesions, we show the potential of depolarization imaging based on polarization-sensitive optical coherence tomography for the assessment of carious lesions and validate the results by co-registered X-ray micro-computed tomography volumes.
Second harmonic generation enhancement by polarization-matched nanostructures -INVITED
Authors: Dreser Christoph , Gürdal Emre , Bautista Godofredo , Horneber Anke , Zang Xiaorun , Gollmer Dominik A. , Meixner Alfred J. , Kern Dieter P. , Zhang Dai , Kauranen Martti , Fleischer Monika
Published: August 2020

Frequency conversion plays an important role in both fundamental and applied nano-optics. Doubling the frequency of light by second harmonic generation (SHG) is a vital process e.g. in laser optics or high-resolution microscopy. SHG can be created through symmetry breaking at plasmonic nanostructures, or the local high electric near-fields of plasmonic nanoantennas can be utilized to further enhance the SHG e.g. from nonlinear crystals. Examples of SHG microscopy using cylindrical vector beams in combination with tilted nanocones and radially symmetric oligomers are shown as well as enhancement studies of the SHG from nonlinear crystals decorated with polarization-matched nanostructures.
Towards active electro-optic lithium niobate metasurfaces
Authors: Timpu Flavia , Weigand Helena , Kaufmann Fabian , Richter Felix U. , Vogler-Neuling Viola-Valentina , Karvounis Artemios , Grange Rachel
Published: August 2020

We present the design and fabrication advances on active lithium niobate metasurfaces. We determine by numerical calculations a metasurface design with electro-magnetic resonances in the visible and near-infrared, by taking into account the constraints for fabrication on thin films of lithium niobate. We suggest that the optical properties of the metasurface can be switched using the electro-optical properties of lithium niobate.
Modal expansion of optical far-field quantities using quasinormal modes
Authors: Binkowski Felix , Betz Fridtjof , Colom Rémi , Hammerschmidt Martin , Zschiedrich Lin , Burger Sven
Published: August 2020

We discuss an approach for modal expansion of optical far-field quantities based on quasinormal modes (QNMs). The issue of the exponential divergence of QNMs is circumvented by contour integration of the far-field quantities involving resonance poles with negative and positive imaginary parts. A numerical realization of the approach is demonstrated by convergence studies for a nanophotonic system.
Fast 3D Shape Measurement of Transparent Glasses by Sequential Thermal Fringe Projection
Authors: Landmann Martin , Speck Henri , Dietrich Patrick , Heist Stefan , Kühmstedt Peter , Notni Gunther
Published: August 2020

We present an approach for measuring the shape of transparent glasses, which enables us to significantly reduce the comparatively long measurement time while increasing the measurement accuracy. Instead of using area-like patterns, we irradiate the object to be measured successively in a locally strongly restricted area with considerably higher irradiance.
Fringe Pattern Denoising using U-Net based neural network
Authors: Crespo J. M. , Moreno V. , Rabuñal Juan Ramón , Pazos Alejandro , Canabal Carbia Monica
Published: August 2020

Fringe visibility and noise removal, are key success factors in interferometric techniques, where novel deep learning techniques can be applied. We test the use U-Net deep convolutional network applied to the obtained interference images, trained with an ad-hoc generated image dataset with complex fringe patterns, computed using high order Zernike polynomials.
An optical metrology system for the measurement of the refractive index of glass
Authors: Leite Inês , Cabral Alexandre
Published: August 2020

The measurement of the refractive index of parallel plated, optically simple, glass samples is a common and fundamental activity in numerous fields of expertise. This work aimed to optimize a known technique to a simple, cost-effective and reliable system to be implemented in a lab environment, with an accuracy in the results better than 10-2. A setup with a 632.8nm HeNe laser, automatic stage and CMOS camera was used and data was acquired with the help of LabVIEW controlling software. All system components were carefully controlled and optimized with the help of an uncertainty budget. Measurements had an associated uncertainty in the range from 10-3 to 10-4.
Control of the emission properties of organic light emitting diodes using plasmonic gratings of Ag nanoparticles
Authors: Hamdad Sarah. , Diallo Amadou. Thierno. , Chakaroun Mahmoud. , Boudrioua Azzedine.
Published: August 2020

We report the influence of Ag nanoparticle arrays on the emission properties of organic light emitting diodes (OLED). First, we studied the features of Ag arrays related to the periodicity. The obtained results emphasize the existence of two coupling regimes dominated by near or far field effects, respectively. Thereafter, we studied the influence of these gratings on the performances of OLED devices. Our results reveal the benefit of the plasmonic structures which allow a precise tuning of the OLED properties.
Room-temperature continuous-wave upconverting micro- and nanolasing for bio-optofluidics
Authors: Fernandez-Bravo Angel , Moscardi Liliana , Ross Aaron M. , Lanzani Guglielmo , Chan Emory M. , Odom Teri W. , James Schuck P. , Scotognella Francesco
Published: August 2020

Nanolasers that operate under the continuous-wave pump and are robust in diverse environments will make possible compact optoelectronic devices, biomedical imaging, and large-scale quantum photonics. However, current nanolasers require low temperatures or pulsed excitation because their small mode volumes severely limit gain relative to cavity loss. Here, I will present continuous-wave upconverting micro- and nanolasing at room temperature with record-low thresholds and high photostability. I will explore the future implications of such a low-threshold laser for optofluidics.
Crossing the exceptional point in a fiber-plasmonic waveguide -INVITED
Authors: Tuniz Alessandro , Wieduwilt Torsten , Schmidt Markus A.
Published: August 2020

We experimentally demonstrate a hybrid plasmonic fiber with tuneable Eigenmode interactions near the exceptional point. We experimentally observe a transition through the exceptional point in a fiber-plasmonic system: transmission experiments reveal fundamental changes in the underlying Eigenmode interactions as the environmental refractive index is tuned due to a crossing through the plasmonic exceptional point. These results extend the design opportunities for tunable non-Hermitian physics to plasmonic waveguide systems.
Micro/Nanofiber-coupled low-dimensional structures for nanophotonic applications -INVITED
Authors: Guo Xin
Published: August 2020

Optical micro/nanofiber, with diameter close to the wavelength of the waveguided light, leaves a considerably large fractional evanescent fields for coupling with low-dimensional functional nanostructures. Here I introduce our works on 4micro/nanofiber-coupled low-dimensional structures for nanophotonic applications including gas sensing and ultrashort pulse measurement.
Tapered optical fiber for Micro-Newton force sensor
Authors: Godet Adrien , Chrétien Jacques , Phan Huy Kien , Beugnot Jean-Charles
Published: August 2020

We used Brillouin scattering in silica nanofiber to demonstrate a microNewton force sensor having weak optical losses and using only one access of the nanofiber. The measurements are in good agreement with the theoretical model.
Optical Resonators based on Casimir Forces -INVITED
Authors: Carretero-Palacios Sol , Esteso Victoria , Míguez Hernán
Published: August 2020

The work here presented demonstrates theoretically that it is possible to create optical resonators based on levitation properties of thin films subjected to repulsive Casimir-Lifshitz forces. Our optical cavity design is made up of commonly found materials, such as silicon oxide, polystyrene or gold, with glycerol as a mediating medium, which supports high Q-factor optical modes at visible frequencies. The balance between flotation and repulsive Casimir-Lifshitz forces in the system allows the fine-tuning of the optical cavity thickness and hence its modes. Finally, we show that well-defined spectral features in the reflectivity allows by indirect means, an accurate prediction of the estimated equilibrium distance at which some part of the optical cavity arrangement levitates.
Engineering Local Fields in Nonlinear Plasmonic Metasurfaces -INVITED
Authors: Huttunen Mikko J. , Bin-Alam Saad , Reshef Orad , Mamchur Yaryna , Stolt Timo , Ménard Jean-Michel , Dolgaleva Ksenia , Boyd Robert W. , Kauranen Martti
Published: August 2020

Nonlinear optical phenomena are paramount in many photonic applications ranging from frequency broadening and generation of ultrashort pulses to frequency comb-based metrology. A recent trend has been to miniaturize photonic components, resulting also in a demand for small scale nonlinear components. This demand is difficult to address by using conventional materials motivating the search for alternative approaches. Nonlinear plasmonic metasurface cavities have recently emerged as a promising platform to enable nanoscale nonlinear optics. Despite steady progress, the so far achieved conversion efficiencies have not yet rivalled conventional materials. Here, we discuss our recent work to develop more efficient nonlinear metamaterials, focusing on plasmonic metasurfaces supporting collective responses known as surface lattice resonances. These resonances can exhibit very narrow spectral features, showing potential to considerably enhance nonlinear processes via resonant interactions. We demonstrate a plasmonic metasurface operating at the telecommunications C band that exhibits a record-high quality factor close to 2400, demonstrating an order-of-magnitude improvement compared to existing metasurface cavities. Motivated by this experimental demonstration, we also present numerical predictions suggesting that such metasurfaces could soon answer the existing demand for miniaturized and/or flat nonlinear components.
Pulse nonlinear optical switching in plasmonic structures
Authors: Salgueiro José R. , Ferrando Albert
Published: August 2020

We study switching operation in a plasmonic coupler using fs-pulses. Simulations using the finite difference time-domain method (FDTD) are carried out showing how the output changes as the pulse energy increases raising from zero to a maximum. Both cases of neglecting and realistic losses are considered in order to compare. The work is intended to explore the use of pulses for all-optical signal processing in a potentially interesting system for integrated photonics at the nanometric scale.
3 Dimensional Motion of Photon and Its Energy
Authors: Saleh Gh. , Alizadeh Reza , Dalili Ehsan , Noorbakhsh Amir
Published: August 2020

Since the electron is the photon-generator and the electron is rotating around itself and around the nucleus, the emitted photon from the electron should have the effect of these rotating motions. So, the photon has a three-dimensional motion, including a transition movement and a rotary motion. And it traverses in a helical trajectory. By using this definition, we have proved wave-particle duality at the same time and introduce a new equation for the photon motion and its energy.
Crystallization of HfO2 thin films and their influence on laser induced damage
Authors: Balogh-Michels Zoltán , Stevanovic Igor , Frison Ruggero , Bächli Andreas , Schachtler Daniel , Gischkat Thomas , Neels Antonia , Stuck Alexander , Botha Roelene
Published: August 2020

We present our investigation on the crystallization of IBS HfO2 on (0001) SiO2. The crystallization was studied by in-situ XRD. The activation energy was 2.6±0.5 eV. The growth follows a two-dimensional mode. LIDT measurements (5000-on-1) with 10 ns pulses at 355 nm on 3QWT HfO2 layers shows that the crystallization leads to increase of the laser irradiation resistance. The 0%-LIDT of the as coated sample was 3.1 J/cm2 and increased to 3.7 J/cm2 after 5h @ 500°C.
MEMS-based CAOS Smart Camera 177 dB Linear Extreme Dynamic Range Imaging Tests with Calibrated and Controlled Incoherent White Light and Laser Light Targets
Authors: Riza Nabeel A. , Mazhar Mohsin
Published: August 2020

Highlighted are the linear extreme dynamic range calibrated target imaging tests of the CAOS smart camera showing a 177 dB linear dynamic range operation with an optical attenuation controlled bright laser target
Surface Plasmon Resonance sensor based on a D-shaped photonic crystal fiber with a bimetallic layer
Authors: Cardoso Markos P. , Silva Anderson O. , Romeiro Amanda F. , Giraldi M. Thereza R. , Costa João C.W.A. , Santos José. L. , Baptista José. M. , Guerreiro Ariel
Published: August 2020

The investigation of a D-shaped photonic crystal fiber sensor with a bimetallic layer for operation at the visible and infrared spectra is presented. The bimetallic layer is composed by silver and gold slabs deposited adjacently on the flat face of the fiber. It is shown that this architecture allows the excitation of two sharply distinguished plasmon resonance, which suggest potential applications for multiparameter sensing.
Superhydrophobic Asphalt Pavements: Surface Improvement
Authors: Rocha Segundo Iran , Landi Salmon , Freitas Elisabete , Castelo Branco Verônica , Costa Manuel F. M. , Carneiro Joaquim
Published: August 2020

The most adverse weather condition for road safety happens when there is water, snow, or ice on the road surface because their presence highly decreases friction. Therefore, it is essential to drain or repel them quickly. If the water drops are repelled from the surface or the ice/snow formation is avoided with the application of superhydrophobic coatings, roads become safer. In order to functionalize the asphalt mixtures used in road pavements, nano/micromaterials, such as Polytetrafluoroethylene (PTFE), TiO2, and SiO2, among others have been applied by spraying coating. The mixes are usually characterized by the water contact angle, and the surface roughness is typically assessed by optical and electron analysis. This research work aims to present a brief overview of superhydrophobic asphalt mixtures.
Crystalline lens imaging during accommodation with a slit-scanning tomography system: preliminary results
Authors: Gomes Jessica , Franco Sandra
Published: August 2020

A slit-scanning tomography system previously developed in the Centre of Physics of University of Minho allows to capture images of the eye and posteriorly calculus of the biometric (thickness and curvature) and optical (wavefront aberrations) properties of the corneal and crystalline lens surfaces. It is intended to optimise the system for an accurate computing of these properties of the crystalline lens in the relaxed state and during ocular accommodation. In this study, preliminary experimental results of the crystalline lens imaging of a subject during accommodation are presented.
arthritis + rheuma
Authors: Rüther Wolfgang , Kiltz Uta , Sewerin Philipp
Published: August 2020

Zeitschrift für Orthopädie und Rheumatologie
Schuhversorgung bei Diabetes mellitus
Authors: Zink Karl
Published: August 2020

Bei vorhandener peripherer arterieller Verschlusskrankheit (pAVK) und/ oder Polyneuropathie mit Sensibilitätsverlust droht ein diabetisches Fußsyndrom. Durch die Polyneuropathie entstehen unbemerkte Druckschäden, die häufigste Ursache dieser Druckschäden ist in ca. 50–80 % der Fälle nicht passendes Schuhwerk 1.
Editorial
Authors: Deimel Hubertus
Published: August 2020

Liebe Leserinnen und Leser,

zum Abschluss meiner langjährigen Tätigkeit im wissenschaftlichen Beirat dieser Zeitschrift habe ich noch einmal gern die Planung und Betreuung dieses Schwerpunktheftes zur Bewegungstherapie in der Psychiatrie, Psychosomatik und Suchtbehandlung übernommen. Was Sie allerdings in dieser Ausgabe nicht erwarten dürfen: eine hochaktuelle RCT-Studie, eine weitere Metaanalyse, ein systematisches Review oder gar eine raffiniert angelegte Doppelblindstudie. Als Vertreter einer strengen methodologisch orientierten Sichtweise einer evidenzbasierten Medizin (EbM) mit der Bevorzugung externer Evidenz können Sie also dieses Heft rasch beiseitelegen; da erfahren Sie nichts Neues! Allerdings bestehen deren Hauptaussagen – bezogen auf die Wirkung von bewegungstherapeutischen Interventionen bei psychischen Erkrankungen – grob vereinfachend darin, dass Ausdauer- und Krafttraining im stationären Setting nicht schaden und zudem wirksam sind für körperliche Verbesserungen, was nicht wirklich überraschen kann. Im Hinblick auf das Wesentliche psychischer Erkrankungen, nämlich weitergehende Wirkungen des Trainings auf die Psyche bzw. auf die psychosozialen Bedingungen, besteht allerdings mehr Unklarheit als Klarheit oder wurden erst gar nicht mit einbezogen. Training und Trainingswirkungen werden deshalb z. T. mit einer ähnlichen Vorstellung wie ein pharmakologisches Medikament labormäßig untersucht und bewertet. Diese funktionelle Vorgehensweise hat zweifellos ihre Berechtigung. Inwieweit derartige Trainingsprogramme jedoch zur Entwicklung eines gesundheitsbezogenen aktiven Lebensstils über den Klinikaufenthalt hinaus beitragen bei einer Klientel, die überwiegend nicht über eine diesbezügliche Einstellung verfügt, darf mit einem dicken Fragezeichen versehen werden. Und in der Praxis tätige Bewegungstherapeuten wissen, dass viele Patientinnen und Patienten mehr brauchen als ein alleiniges evidenzgestütztes Ausdauer- und Krafttraining. Zudem werden mit einer derartigen Reduzierung der Bewegungs- und Sporttherapie auf funktionelles körperliches Training weitergehende Aufgaben und Zielsetzungen ausgeklammert; beispielsweise sind hier exemplarisch die Vermittlung bewegungs- und gesundheitsbezogener Kompetenzen oder die Verbesserung sozialer Kompetenzen zur gesellschaftlichen Integration zu nennen. Nun werden bei der Evidenzbeurteilung der bewegungstherapeutischen Interventionen bei psychischen Erkrankungen allerdings ausschließlich Studien mit dem oben genannten Designkriterien herangezogen. Zur Bestätigung dieser Aussage braucht man sich nur die verwendeten Literaturangaben bei den verschiedenen Leitlinien oder den Reha-Therapiestandards anzuschauen, die fast ausschließlich den englischsprachigen Recherchesystemen (Cochrane; PubMed. u. a. ) entnommen sind. Insofern wundert es nicht, dass die Evidenz der Bewegungstherapie aus der Sicht externer Evidenzbasierung eher bescheiden ausfällt, also zweitklassig („kann oder sollte“ als Empfehlungsgrad), da andere Facetten oder Perspektiven ausgeklammert werden, die durchaus zum Beleg ihrer Wirksamkeit beitragen können.
Kann körperliche Aktivität durch eine Verbesserung des Selbstwertes aggressive Gefühle reduzieren?
Authors: Chermette Chloé , Pels Fabian
Published: August 2020

Studien zeigen, dass körperliche Aktivität eine Methode sein kann, um Stimmungslagen zu beeinflussen. Unklar ist jedoch, welche Form von körperlicher Aktivität tatsächlich effektiv ist und über welchen Mechanismus dieser Effekt erklärt werden kann. Das Ziel der vorliegenden Untersuchung war zu untersuchen, inwiefern verschiedene soziale Aufgabenbedingungen bei körperlicher Aktivität (kooperative Aufgabe, kompetitive Aufgabe, individuelle Aufgabe) unterschiedlich auf den Selbstwert eines Individuums wirken und infolgedessen aggressive Gefühle verändern. Vermutet wurde, dass kooperative Aktivitäten durch eine Steigerung des Selbstwertes aggressive Gefühle verringern und kompetitive Aktivitäten durch eine Verringerung des Selbstwertes aggressive Gefühle erhöhen. Die Hypothese wurde in einem quasi-experimentellen Design im Feldsetting an 133 Teilnehmenden geprüft. Die Ergebnisse zeigen, dass kooperative Aufgaben im Gegensatz zu kompetitiven und individuellen Aufgaben die selbst eingeschätzte Beliebtheit (als einen Aspekt des Selbstwertes) stärken und aggressive Gefühle reduzieren. Zukünftige Studien sollten dieses Ergebnis experimentell und an spezifischen Personengruppen replizieren. Für die Praxis wird empfohlen, (ggf. nach einer zuvor erfolgten Diagnostik der Stimmungslage) kooperative Aufgaben durchzuführen, wenn die sportliche Aktivität auf eine Reduktion von aggressiven Gefühlen abzielen soll.
Mehr Beziehungs- und Motivationsarbeit wagen!
Authors: Giesen Esther Sophia
Published: August 2020

Sport- und Bewegungstherapie wird in der Behandlung von Menschen mit schizophrenen Störungen empfohlen. Zahlreiche Gesundheitseffekte werden diesbezüglich angenommen und sind, insbesondere im Hinblick auf die Beeinflussung der Negativsymptomatik sowie in Bezug auf häufig auftretende körperliche Komorbiditäten, hochrelevant. Eine unerlässliche Voraussetzung für die effektive Ausschöpfung dieser Effekte ist jedoch, dass die Betroffenen frühzeitig Zugang zu klinischen Bewegungsinterventionen finden. In der sporttherapeutischen Praxis mit schizophren erkrankten Menschen erweist sich die regelmäßige Einbindung dieser Zielgruppe jedoch oftmals als Herausforderung. In der Rhein-Mosel-Fachklinik Andernach (RMF) wurde sich diesem Problem der mangelnden Inanspruchnahme von sporttherapeutischen Angeboten gezielt gewidmet und ein Rahmenprogramm entwickelt, das mehr Raum für Beziehungs- und Motivationsarbeit zulässt. Im folgenden Artikel werden erstens, personenbezogene und äußere Zugangsbarrieren diskutiert, die bei Menschen mit schizophrenen Störungen auftreten können und zweitens, Lösungswege zur Erleichterung der Zugangsbedingungen vorgestellt, die an der RMF entwickelt wurden.
Therapie der Gicht und des akuten Gichtanfalls
Authors: Alten Rieke , Mischkewitz Max
Published: August 2020

Für die bestmögliche Behandlung der Gicht ist eine umfangreiche Aufklärung des Patienten über die Erkrankung und Therapieoptionen sowie systematisches Screening auf Komorbiditäten und eine Lebensstilmodifikation elementar. Beim Management des akuten Gichtanfalls sollte möglichst frühzeitig mit der medikamentösen Therapie begonnen werden. Hier stehen Colchicin, nichtsteroidale Antirheumatika (NSAR) und Glukokortikoide oral oder intraartikulär oder eine Kombinationstherapie zur Verfügung. Canakinumab ist Mittel der Wahl bei unzureichendem Ansprechen auf die Behandlung. Für bis zu 6 Monate nach einem Anfall ist eine medikamentöse Prophylaxe indiziert. Die harnsäuresenkende Therapie (ULT) sollte zeitnah nach Indikationsstellung begonnen werden. Allopurinol ist Mittel der 1. Wahl. Liegen schwere Nierenfunktionseinschränkungen, Unverträglichkeit oder unzureichendes Therapieansprechen vor, kommen alternativ Urikosurika, Febuxostat oder die Kombination aus einem Urikosurikum mit Febuxostat in Frage. Bei unzureichendem Therapieansprechen ist auch die Kombination von Allopurinol und einem Urikosurikum möglich. Zuletzt kann auch Pegloticase off-label eingesetzt werden. Die Therapieadhärenz der ULT ist unzureichend.
Histopathologische Differenzialdiagnostik von Kristall-Arthritiden
Authors: Krenn V. , Liebisch M. , Badiian N. , Krenn V. T. , Waldstein W.
Published: August 2020

Wenngleich Kristall-induzierte Gelenkerkrankungen mehrheitlich auf klinischen, serologischen und bildgebenden Diagnosekriterien beruhen, kann die histopathologische Diagnostik einen wesentlichen Beitrag leisten. Ein umfassendes Spektrum dieser histopathologischen Differenzialdiagnostik ist im Gelenk-Pathologie- und im Gelenk-Partikel-Algorithmus dargelegt. Dies ist dahingehend von Bedeutung, da oft erst durch diese histopathologische Diagnostik Erkrankungen erkannt werden können, welche in der initialen klinischen Diagnostik nicht berücksichtigt worden sind. Die wichtigsten Kristall-induzierten Gelenkerkrankungen und deren Differenzialdiagnosen umfassen folgende Depositionen: Urat-Kristalle, Kalziumpyrophosphat-Kristalle, kalkartige Depositionen (basisches Kalziumphosphat, Kalziumkarbonat), Knochen-Trabekelfragmente, Blutungsresiduen (Hämosiderin-Granula, Hämatoidin-Konkremente, Gandy-Gamna-Körper, Formalin-Pigment), Lipideinschlüsse und Amyloid-Depositionen. Wesentlich für die Qualität der Diagnostik ist die Übersendung des Gewebes in unterschiedlichen und somit getrennten Fraktionen, da diese krankhaften Veränderungen multifokal im Gelenk vorliegen können. Die Gewebeübersendung erfolgt üblicherweise in 5 % gepuffertem Formalin. Bei der Fragestellung nach Urat-Kristall-Arthritis bzw. Urat-Arthropathien empfiehlt sich die Übersendung eines Teil der Gewebeproben in Alkohol und einer anschließenden wasserfreien bzw. wasserreduzierten Entwässerung, da Urat-Kristalle wasserlöslich sind und bei Wasserkontakt insbesondere aus kleinen Geweben herausgelöst werden können. Diese Modalität stellt aber keine Notwendigkeit dar, da Kristallablagerungen im Allgemeinen auch indirekt, über das Gewebe-Reaktionsmuster (z. B. Urat-Tophus) und über die oft erhaltenen Kristallmatrix mittels der Histopathologie nachweisbar sind.
Medienprävention im frühen Kindesalter aus entwicklungsneurologischer Sicht
Authors: Gaiser Ulrike
Published: August 2020

Die Prävention ist im Bereich Medien extrem wichtig, auch und gerade bei Kindern mit Entwicklungsstörungen. Die Eltern spielen eine zentrale Rolle, da im frühen Kindesalter die eigenen Regulationsmöglichkeiten der Kinder nicht oder noch nicht genügend ausgeprägt sind. Kinder mit neuropädiatrischen Erkrankungen und Entwicklungsstörungen sind ein „Risikokollektiv“, aber Medien bieten auch besonders gute Möglichkeiten der Teilhabe und Erweiterung der Fähigkeiten. Bewusstes Abwägen, Aussuchen pädagogischer Inhalte und Abstimmen mit den laufenden Therapien sind wichtig. Hierzu ist es notwendig, den Mediengebrauch standartmäßig zu erfassen und frühzeitig zu intervenieren, wenn zu viel, das falsche oder sinnlos konsumiert wird. Eltern muss frühzeitig Hilfe, sowohl im Rahmen der Therapien (z. B. durch gemeinsames Erarbeiten eines festen Rituals „Beginn und Beenden“) als auch im psychosozialen Umfeld gegeben werden, ggf. auch im Rahmen einer intensiveren, auch stationären Maßnahme, wenn die Umfeldveränderung dazu notwendig ist.
Die Nutzung von sozialen Medien durch Kinder und Jugendliche
Authors: Müller Kai W.
Published: August 2020

Im Jahr 2020 stellt die gewohnheitsmäßige Nutzung des Internets gerade unter Kindern und Jugendlichen ein selbstverständliches Freizeitverhalten dar. In dieser Altersgruppe sind es überwiegend Online-Computerspiele, zunehmend aber auch soziale Medien, die sich größter Beliebtheit erfreuen. Neben den unbestrittenen Vorteilen, die insbesondere soziale Medien bieten, verdeutlicht ein Blick auf verfügbare Forschungsbefunde, dass gerade bei einem übermäßigen Gebrauch durchaus auch von negativen Effekten auszugehen ist, die im schlimmsten Fall auch entwicklungs- und gesundheitsbeeinträchtigend sein können. In der Hauptsache sind es neu auftretende psychische bzw. sogar psychopathologische Phänomene, wie „Digitaler Stress“, welcher durch wahrgenommenen sozialen Druck und eine zu hohe Kommunikationsflut entstehen kann, sowie ein problematischer, suchtartiger Konsum von sozialen Medien, die mit vergleichsweise eindeutigen abträglichen Folgen für die psychische Gesundheit einhergehen. In dem Überblicksbeitrag wird eine Auswahl der negativen Auswirkungen anhand der Forschungsliteratur vorgestellt, deren Ursachen diskutiert und es werden Handlungsmöglichkeiten für die Praxis skizziert.
Diagnose der diabetischen Neuropathie
Authors: Weisser Gregor , Lobmann Ralf
Published: August 2020

Die diabetische Neuropathie ist eine der häufigsten diabetischen Folgeerkrankungen und betrifft mehr als 30 % aller Diabetespatienten. Sie umfasst unterschiedliche Verlaufsformen, wobei die distal-symmetrische sensomotorische Polyneuropathie (DSPN) die häufigste darstellt. Die DSPN ist der wichtigste Risikofaktor für die Entstehung eines diabetischen Fußsyndroms, außerdem gilt sie als unabhängiger Prädiktor für die kardiovaskuläre Morbidität und Mortalität. Dem Hausarzt und dem betreuenden Diabetologen kommt in der Diagnostik eine Schlüsselrolle zu, denn trotz des großen Stellenwerts zur Prävention von Fußläsionen und etwaigen Amputationen, ist die diabetische Neuropathie weiterhin stark unterdiagnostiziert. Alle Screening-Maßnahmen sind mit einfachen Mitteln in der Praxis umsetzbar, darüber hinaus stehen validierte Scores zur Verfügung.
Micromagnetic modeling of the heat-assisted switching process in high anisotropy FePt granular thin films
Authors: Atkinson Lewis J. , Evans Richard F. L. , Chantrell Roy W.
Published: August 2020

The dynamic process of assisted magnetic switchings has been simulated to investigate the associated physics. The model uses a Voronoi construction to determine the physical structure of the nanogranular thin film recording media, and the Landau–Lifshitz–Bloch equation is solved to evolve the magnetic system in time. The reduction of the magnetization is determined over a range of peak system temperatures and for a number of anisotropy values. The results show that the heat-assisted magnetic recording process is not simply magnetization reversal over a thermally reduced energy barrier. To achieve full magnetization reversal (for all anisotropies investigated), an applied field strength of at least 6 kOe is required and the peak system temperature must reach at least the Curie point (Tc). When heated to Tc, the magnetization associated with each grain is destroyed, which invokes the non-precessional linear reversal mode. Reversing the magnetization through this linear reversal mode is favorable, as the reversal time is two orders of magnitude smaller than that associated with precession. Under these conditions, as the temperature decreases to ambient, the magnetization recovers in the direction of the applied field, completing the reversal process. Also, the model produces results that are consistent with the concept of thermal writability; when heating the media to Tc, the smaller grains require a larger field strength to reverse the magnetization.
Portable ozone sterilization device with mechanical and ultrasonic cleaning units for dentistry
Authors: Taran Valerij , Garkusha Igor , Gnidenko Yuriy , Krasnyj Viktor , Lozina Alina , Taran Anton , Chechelnitskyi Oleg , Starikov Vadym , Starikova Svetlana
Published: August 2020

A portable device for cleaning and ozone sterilization of small-sized delicate dental instruments that cannot withstand the high heat and humidity of standard autoclaving has been developed. The device contains a remote unit for magnetic mechanical washing, an ultrasonic bath for pre-cleaning treatment, and a container for ozone sterilization with a reactor based on dielectric barrier discharge. The maximum ozone concentration in water reached 8.5 mg/l for 10 min of operation at a water temperature of 19 °C. The results of inactivation of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus are presented. Distilled water with such seeded micro-organisms was bubbled with an ozone–air mixture at an ozone concentration of 5.8 mg/l at 17 °C for 5 min, 10 min, 20 min, and 30 min. The maximum bactericidal effect was manifested for Pseudomonas aeruginosa cells with their total elimination within 10 min. Inactivation of Escherichia coli bacteria was monitored after 20 min of treatment, and Staphylococcus aureus—after 30 min of treatment.
A brief history of electronic virus sensors
Authors: Kim Meeri
Published: August 2020

In the past fifty years, electronic virus sensors have become more sensitive and scalable than ever, with a low-cost, at-home diagnostic test on the horizon.
Extracting electron densities in n-type GaAs from Raman spectra: Comparisons with Hall measurements
Authors: Ochoa Maicol A. , Maslar James E. , Bennett Herbert S.
Published: August 2020

We demonstrate quantitatively how values of electron densities in GaAs extracted from Raman spectra of two samples depend on models used to describe electric susceptibility and band structure. We, therefore, developed a theory that is valid for any temperature, doping level, and energy ratio proportional to q2/(ω+iγ) (where q is the magnitude of wave vector, ω is Raman frequency, and γ is plasmon damping). We use a full Mermin–Lindhard description of Raman line shape and compare n-type GaAs spectra obtained from epilayers with our simulated spectra. Our method is unique in two ways: (1) we do a sensitivity analysis by employing four different descriptions of the GaAs band structure to give electron densities as functions of Fermi energies and (2) one of the four band structure descriptions includes bandgap narrowing that treats self-consistently the many-body effects of exchange and correlation in distorted-electron densities of states and solves the charge neutrality equation for a two-band model of GaAs at 300 K. We apply these results to obtain electron densities from line shapes of Raman spectra and thereby demonstrate quantitatively how the values of electron densities extracted from Raman spectra of n-type GaAs depend of various models for susceptibility and band structure.
Effects of synthetic antiferromagnetic coupling on back-hopping of spin-transfer torque devices
Authors: Chen Kuan-Ming , Cheng Chih-Wei , Wei Jeng-Hua , Hsin Yu-Chen , Tseng Yuan-Chieh
Published: August 2020

A synthetic antiferromagnetic (SAF) layer is a key component in spin-transfer torque magneto-resistive random-access memory devices. This study reveals that slight fluctuations in SAF coupling at the margin of the reference layer and hard layer (i.e., concurrent reversal) can lead to write errors in the form of back-hopping (BH). It appears that variable BH behavior can be attributed to competition between antiparallel (AP) → parallel (P) and P → AP transitions associated with SAF coupling. Our conclusions are supported by careful analysis of switching phase diagrams and measurements of self-heating and voltage-controlled magnetic anisotropy. We also observed that one form of coupling provided higher perpendicular magnetic anisotropic energy and thermal stability, which is likely due to the Dzyaloshinskii–Moriya interaction (DMI) effect. Thus, minimizing variations in DMI by optimizing SAF coupling is crucial for minimizing write error rates.
Experimental fluid dynamics characterization of a novel micropump-mixer
Authors: Akbaridoust F. , de Silva C. M. , Szydzik C. , Mitchell A. , Marusic I. , Nesbitt W. S.
Published: August 2020

The application of lab-on-a-chip systems to biomedical engineering and medical biology is rapidly growing. Reciprocating micropumps show significant promise as automated bio-fluid handling systems and as active reagent-to-sample mixers. Here, we describe a thorough fluid dynamic analysis of an active micro-pump-mixer designed for applications of preclinical blood analysis and clinical diagnostics in hematology. Using high-speed flow visualization and micro-particle image velocimetry measurements, a parametric study is performed to investigate the fluid dynamics of six discrete modes of micropump operation. With this approach, we identify an actuation regime that results in optimal sample flow rates while concomitantly maximizing reagent-to-sample mixing.
VISproLF: Self-calibrating instrument for measuring 3D shape of linear Fresnel facets
Authors: Montecchi Marco , Cara Giuseppe , Benedetti Arcangelo
Published: August 2020

Concentrating solar power plants use mirrors to redirect solar radiation toward receivers. Mirrors (facets) are suitably shaped to optimize the radiation capture ratio. Because deviations from ideal shape/slope degrade optical efficiency, the availability of reliable instruments for 3D shape measurement is essential. This paper deals with an innovative instrument, named VISproLF, specific for the case of facets for the primary reflector of linear Fresnel collectors. The instrument is simply composed of a LCD screen and a digital camera; to avoid artifacts, the camera must be equipped with a high quality lens and its characteristic matrix and distortion coefficients have to be accurately evaluated. The arrangement of the LCD screen and camera around the facet must follow the simple rule to view from the camera the facet surface entirely covered by the image of the screen. Then, the position and attitude of the camera (first) and LCD screen (second) are accurately evaluated by a simple procedure based on the pinhole camera model, which makes the instrument self-calibrating. The shape and slope of the facet surfaces are obtained by processing five binary images by means of a completely digital method of which a detailed description is given. In the experimental arrangement used to prepare the present paper, the slope accuracy is about 0.2 mrad. With respect to the most common instruments based on the Fringe reflection technology, VISproLF offers two great advantages: full-digital image processing and a self-calibration feature.
Experimental demonstration of silicon photonic devices optimized by a flexible and deterministic pixel-by-pixel technique
Authors: Boutami Salim , Hassan Karim , Dupré C. , Baud L. , Fan Shanhui
Published: August 2020

We present the experimental realization of photonic devices optimized by a pixel-by-pixel binary optimization method, which can straightforwardly take into account the technological constraints such as minimum feature sizes in the fabrication process. In this approach, for each iteration, one considers all the candidate structures that differ by a single pixel from the starting structure and update by adopting the structure that has the best figure of merit among all candidate structures. This approach can be implemented with high computational efficiency using a Green's function method. The devices optimized by this approach have been realized on 200 mm and 300 mm Silicon-On-Insulator platforms, using either e-beam lithography or deep-UV immersion lithography. Characterizations experimentally demonstrate the reliability of the method, given the technological constraints of Silicon Photonics.
New insights into the physics of rotating spokes in partially magnetized E×B plasmas
Authors: Boeuf J. P. , Takahashi M.
Published: August 2020

Regions of enhanced light emission rotating in the azimuthal direction (“rotating spokes”) have been observed in different types of partially magnetized E×B plasma devices such as magnetron discharges and Hall thrusters. A two-dimensional Particle-In-Cell Monte Carlo Collision (PIC MCC) model is used to study the formation of these rotating structures. The model shows that these current driven rotating structures are the results of a Simon–Hoh instability evolving into an ionization instability. The spoke is sustained by local electron heating induced by ∇B drift along a double layer separating the cathodic presheath from the plasma at a potential close to the anode potential. The PIC MCC simulations predict that spoke rotation can take place in the +E×B direction and in the −E×B direction depending on the magnetic field intensity.
Complete characterization of the 3p Rydberg complex of a molecular ion: MgAr+. I. Observation of the Mg(3pσ)Ar+ B+ state and determination of its structure and dynamics
Authors: Wehrli Dominik , Génévriez Matthieu , Knecht Stefan , Reiher Markus , Merkt Frédéric
Published: August 2020

We report on the experimental observation of the B+ 2Σ+ state of MgAr+ located below the Mg+(3p 2P3/2) + Ar(1S0) dissociation asymptote. Using the technique of isolated-core multiphoton Rydberg-dissociation spectroscopy, we have recorded rotationally resolved spectra of the B+ 2Σ+(v′) ← X+ 2Σ+(v″ = 7) transitions, which extend from the vibrational ground state (v′ = 0) to the dissociation continuum above the Mg+(3p 2P3/2) + Ar(1S0) dissociation threshold. The analysis of the rotational structure reveals a transition from Hund’s angular-momentum-coupling case (b) at low v′ values to case (c) at high v′ values caused by the spin–orbit interaction. Measurements of the kinetic-energy release and the angular distribution of the Mg+ fragments detected in the experiments enabled the characterization of the dissociation mechanisms. The vibrational levels of the B+ state above v′ = 6 are subject to predissociation into the Mg+(3p 2P1/2) + Ar(1S0) continuum, and the fragment angular distributions exhibit anisotropy β parameters around 0.5, whereas direct dissociation into the continuum above the Mg+(3p 2P3/2) + Ar(1S0) asymptote is characterized by β parameters approaching 2. Molecular ions excited to the B+ state with v′ = 0–6 efficiently absorb a second photon to the repulsive part of the 2Σ+ state associated with the Mg+(3d 2D3/2,5/2) + Ar(1S0) continua. The interpretation of the data is validated by the results of ab initio calculations of the low-lying electronic states of MgAr+, which provided initial evidence for the existence of bound vibrational levels of the B+ state and for the photodissociation mechanisms of its low vibrational levels.
Flow field induced by a dielectric barrier discharge plasma actuator analyzed with bi–orthogonal decomposition
Authors: Mishra Bal Krishan , Panigrahi P. K.
Published: August 2020

A typical dielectric barrier discharge (DBD) plasma actuator generates complex periodic flow structures in burst mode. Efficient use of these actuators depends on clear understanding of the relationship between the operational parameters of the actuator and flow structure. The present study reports the temporal and spatial evolution of these flow structures by utilizing the bi-orthogonal decomposition (BOD) technique. The flow induced by the actuator is captured using a time resolved particle image velocimetry (2D–2C–TR–PIV) system. The BOD of flow field is carried out using instantaneous velocity field data. The DBD plasma actuator is operated at different combinations of duty cycle, α (50% ≤ α ≤ 90%), and burst frequency, fb (10 Hz ≤ fb ≤ 90 Hz). The modal energy content is used to characterize the flow field as a function of operating variables, i.e., α and fb of the actuation signal. The mean mode of the decomposition successfully approximates the time averaged behavior of the induced flow field. The mean mode energy level increases with the increase in both α and fb with a more pronounced effect observed as a function of fb. The coherent structures are located close to the near wall at high burst frequency. The non-dimensional entropy decreases with the increase in both α and fb with a more pronounced effect of fb than that of α. The decrease in entropy value indicates that space–time complexities are reduced at higher burst frequency. The topos of higher order modes reveal the presence of coherent structures that grow in time and convect along the wall like a train of vortices. The chronos of mode 2 and mode 3 is locked in with respect to the burst frequency. However, the chronos of mode 4 and mode 5 shows frequency doubling at lower burst frequency actuation and frequency halving at higher burst frequency actuation. The entropy value or space–time complexity of flow structures generated by DBD plasma actuator is related to the nonlinear vortex interaction mechanism, i.e., period doubling and period halving of chronos.
Multiple magnetization reversal and field induced orbital moment switching in intermetallic SmMnSi compound
Authors: Ray Mayukh K. , Maji Bibekananda , Motla Kapil , K. P. Sajilesh , Singh R. P.
Published: August 2020

We report anomalous magnetic reversal (MR)/negative magnetization (NM) state associated with the field induced switching of orbital moment (μLSm) of the Sm atom. This material shows an antiferromagnetic transition at Néel temperature (TN∼240 K) followed by a NM state in between compensation temperatures (T∗ and T∗∗). The MR/NM state vanishes above 12.5 kOe, while T∗ and T∗∗ follow opposite magnetic field dependency in field cooled cooling (FCC) magnetization. In the high field (H>20 kOe), the thermo-magnetization [M(T)] curve produces a mirror like inversion in magnetization within (T∗−T∗∗) with respect to its low field FCC counterpart. Within the NM region, the exchange bias field (HEB) changes its sign across compensation temperatures for suitable field cooling (FC). We estimated a large FC inverse and conventional HEB of 8 and −4.8 kOe at T=130 K. Furthermore, the magnetic entropy change (ΔSm) and adiabatic temperature change (ΔTad) calculated from the specific heat [Cp(T,H)] measurements also show sign reversal at T∗∗. These unusual behaviors are explained in terms of field induced switching of μLSm, which is oppositely coupled to the spin moment of Sm (μSSm), Mn–Mn/Sm exchange interactions, and polarized conduction electron moment (μSCEP). Additionally, Cp(T,H) exhibit Schottky anomaly around 3 K due to Zeeman splitting of Sm energy levels.
Noise reduction of spin torque oscillator by phase-locked loop with combinational frequency tuning method
Authors: Zeng Lang , Ma Xichuan , Chen Hao-Hsuan , Zhou Yan , Zhang Deming , Wang Yijiao , Zhang Youguang , Zhao Weisheng
Published: August 2020

The noise of a spin torque oscillator (STO) is 4–6 orders higher than that of a traditional CMOS Voltage Controlled Oscillator (VCO). This is the biggest obstacle hindering the STO to replace the VCO in pragmatic usage since a high quality RF signal is essential to the modern telecommunication system. The phase-locked loop (PLL) is widely used in RF chips, which can both stabilize VCO frequency and reduce its noise. There are very few experimental and theoretical works investigating the STO stabilized by the PLL, whereas the numerical investigation is totally missing. In this work, the STO stabilized by the PLL is numerically investigated. Based on the analysis, a combinational frequency tuning method is proposed, which is suitable for the PLL operation and can reduce the STO noise even further.
Dielectric enhancement over a broad temperature by nanofiller at ultra-low volume content in poly(ether methyl ether urea)
Authors: Zhang Tian , Chen Xin , Zhang Qiyan , Zhang Q. M.
Published: August 2020

This Letter studies the dielectric responses of nanocomposites of poly(ether methyl ether urea) (PEMEU) with alumina nanofillers at less than 0.7% volume loading (0.7 vol. %). The results show that the dielectric constant K of PEMEU nanocomposites is enhanced by the nanofillers. The enhancement peaks at 0.33 vol. % nanofiller loading, from K = 3.9 of neat polymer to K = 5.5 of nanocomposites from room temperature to 200 °C, above the glass transition (∼150 °C) of the polymer. Except for an enhanced dielectric constant, the nanocomposite maintains a low dielectric loss and a high breakdown strength of 500 MV/m at room temperature and 300 MV/m at 150 °C, respectively. Thus, the nanocomposite with 0.33 vol. % nanofillers delivers discharged energy densities of 6.5 J/cm3 at room temperature and 2 J/cm3 at 150 °C with better than 90% charge/discharge efficiency, 40% higher than the neat polymer.
Magnons parametric pumping in bulk acoustic waves resonator
Authors: Alekseev S. G. , Dizhur S. E. , Polzikova N. I. , Luzanov V. A. , Raevskiy A. O. , Orlov A. P. , Kotov V. A. , Nikitov S. A.
Published: August 2020

We report on the experimental observation of excitation and detection of parametric spin waves and spin currents in the bulk acoustic wave resonator. The hybrid resonator consists of a ZnO piezoelectric film, yttrium iron garnet (YIG) films on a gallium gadolinium garnet substrate, and a heavy metal Pt layer. Shear bulk acoustic waves are electrically excited in the ZnO layer due to piezoeffect at the resonant frequencies of the resonator. The magnetoelastic interaction in the YIG film emerges magnons (spin waves) excitation by acoustic waves either on resonator's eigenfrequencies or the half-value frequencies at supercritical power. We investigate the acoustic pumping of magnons at the half-value frequencies and acoustic spin pumping from parametric magnons, using the inverse spin Hall effect in the Pt layer. The constant electric voltage in the Pt layer, depending on the frequency, the magnetic field, and the pump power, was systematically studied. We explain the low threshold obtained (∼0.4 mW) by the high efficiency of electric power transmission into the acoustic wave in the resonator.