bluuebunny/crossref_metadata_2025 huggingface dataset:
On the pair correlations of neutral K, D, B and Bs mesons with close momenta produced in inclusive multiparticle processes
Authors: Lyuboshitz Valery V. , Lyuboshitz Vladimir L.
Published: April 2019

The phenomenological structure of inclusive cross-sections of the production of two neutral K mesons in hadron–hadron, hadron–nucleus and nucleus–nucleus collisions is theoretically investigated taking into account the strangeness conservation in strong and electromagnetic interactions. Relations describing the dependence of the correlations of two short-lived and two long-lived neutral kaons $K_S^0K_S^0,K_L^0K_L^0$ and the correlations of “mixed” pairs $K_S^0K_L^0$ at small relative momenta upon the space-time parameters of the generation region of K0 and K̅0 mesons have been obtained. These relations involve the contributions of Bose-statistics and S -wave strong final-state interaction of two K0 (K̅0) mesons as well as of the K0 and K̅0 mesons, and also the additional contribution of transitions K+K– → K0 K̅0, and they depend upon the relative fractions of generated pairs K0K0, K̅0 K̅0 and K0 K̅0. It is shown that under the strangeness conservation the correlation functions of the pairs $K_S^0K_S^0$ and $K_L^0K_L^0$, produced in the same inclusive process, coincide, and the difference between the correlation functions of the pairs $K_S^0K_S^0$ and $K_S^0K_L^0$ is conditioned exclusively by the production of the pairs of non-identical neutral kaons K0 K̅0.

For comparison, analogous correlations for the pairs of neutral heavy mesons D0, B0 and $B_s^0$, generated in multiple inclusive processes with charm (beauty) conservation, are also theoretically analyzed. These correlations are described by quite similar expressions: in particular, just as for K0 mesons, the correlation functions for the pairs of states with the same CP parity (RS S = RLL) and with different CP parity (RS L) do not coincide, and the difference between them is conditioned exclusively by the production of pairs D0 D̅0, B0B̅0 and $B_s^0\bar B_s^0$. However, contrary to the case of K0 mesons, here the distinction of CP-even and CP-odd states encounters difficulties – due to the insignificant differences of their lifetimes and the relatively small probability of purely CP-even and CP-odd decay channels. Nevertheless, one may hope that it will become possible at future colliders.
A look at hadronization via high multiplicity
Authors: Kokoulina Elena , Kutov Andrey , Nikitin Vladimir , Riadovikov Vasilii , Vorobiev Alexander
Published: April 2019

Multiparticle production is studied experimentally and theoretically in QCD that describes interactions in the language of quarks and gluons. In the experiment the real hadrons are registered. Various phenomenological models are used for transfer from quarks and gluons to observed hadrons. In order to describe the high multiplicity region, we have developed a gluon dominance model (GDM). It represents a convolution of two stages. The first stage is described as a part of QCD. For the second one (hadronization), the phenomenological model is used. To describe hadronization, a scheme has been proposed, consistent with the experimental data in the region of its dominance. Comparison of this model with data on e+e- annihilation over a wide energy interval (up to 200 GeV) has confirmed the fragmentation mechanism of hadronization, the development of the quark-gluon cascade with energy increase and domination of bremsstrahlung gluons. The description of topological cross sections in pp collisions within GDM testifies that in hadron collisions the mechanism of hadronization is being replaced by the recombination one. At that point, gluons play an active role in the multiparticle production process, and valence quarks are passive. They stay in the leading particles, and only the gluon splitting is responsible for the region of high multiplicity. GDM with inclusion of intermediate quark charged topologies describes topological cross sections in pp̅ annihilation and explains initial linear growth in the region of negative values of a secondary correlative momentum vs average pion multiplicity with increasing of energy. The proposed hadronization scheme can describe the basic processes of multiparticle production.
Monte Carlo model for neutrino-nucleus interactions: past, present and future
Authors: Eliseev Sergey M. , Yuldashev Bekhzad S.
Published: April 2019

Quantum Chromodynamics (QCD) is the correct theory of strong interactions. The main direction of investigations in physics of elementary particles and nuclear physics is testing of QCD. QCD predicts that at high energy density there will be a transformation from ordinary nuclear matter to a plasma of free quarks and gluons, the Quark-Gluon Plasma (QGP). In order to reach new knowledge of QCD from the interaction of relativistic heavy ions, one needs directly comparable data sets from systems of various sizes, different energies and different experimental probes. Lepton-nucleus scattering provides a nontrivial possibility to study space-time evolution of jets inside the nuclear matter. Using QCD-inspired time dependent cross sections for pre-hadrons we have introduced a space-time model for propagation and hadronization of quark and gluon jets in the nuclear matter in DIS. The aim of this work is to examine a multiproduction process of charged-current deep inelasticvμ-nucleus and nuclear emulsion scattering and estimate quantitatively the value of the formation time. These studies may help to explain the jet quenching in heavy ion collisions. In conclusion, the role of neutrino generators in modern neutrino experiments with nuclear targets will be discussed.
Evaluation study of hypernuclei production at NICA/MPD
Authors: Ilieva Mariya , Zinchenko Alexander , Kolesnikov Vadim
Published: April 2019

The main goal of the NICA/MPD facility is a study of the properties of hot and dense baryonic matter. One of the possible ways of doing this is to study strangeness production in nuclear collisions. The enhanced production of strange particles in heavy-ion collisions is considered to be a signal for the quark-gluon plasma formation. In this paper the MPD detector abilities to measure different hypernuclei species in Au+Au collisions at NICA energy region are presented.
MC simulation results for projective geometry version of MPD ECAL at NICA collider
Authors: Dabrowska B. , Kulikov V.V. , Martemianov M.A. , Matsyuk M.A. , Tyapkin I.A.
Published: April 2019

The report describes the Monte-Carlo simulation software developed for the projective geometry version of the electromagnetic calorimeter of the MPD detector. The results of software tests and some characteristics of the calorimeter are presented.
Charmonium radiative transitions, meson and glueball particle properties with the effective strong coupling
Authors: Ganbold Gurjav
Published: April 2019

The particle properties of conventional mesons and scalar glueball, radiative transitions of charmonium excited states χcJ (J = 0, 1, 2) are studied in the framework of relativistic quark models with infrared confinement by taking into account the mass dependence of the effective strong coupling. A specific behaviour of the mass-dependent strong coupling with a freezing point αs (0) = 1.032 has been revealed. The spectrum and leptonic (weak) decay constants of conventional mesons have been calculated in good agreement with the latest experimental data. New estimates on the scalar glueball mass, ’radius’ and gluon condensate value have been obtained. Dominant radiative transitions of the charmonium orbital excitations χcJ → J/ψ + γ have been studied and the partial decay widths have been estimated with reasonable accuracy.
Neutrino propagator in media: spin properties and spectral representation
Authors: Kaloshin Alexander , Voronin Dmitry
Published: April 2019

We have found that in case of propagation of neutrino in the moving matter or external magnetic field there is a fixed 4-axis of polarization, which corresponds to spin projectors commute with a propagator. It means that, states with the definite spin projection on this axis in media have a definite dispersion law. The presence of this axis essentially simplifies the eigenvalue problem and allows one to build spectral representation of the propagator in media.
Study of exclusive processes within the GPD approach
Authors: Goloskokov Sergey
Published: April 2019

In this report, we analyze the exclusive meson production in leptonhadron and hadron processes to study Generalized Parton Distributions (GPDs). It is shown that in both reactions, the photoproduction mechanism of vector meson (VM) production predominates. We estimate the VM production cross section and spin observables.

The possibility to study the exclusive VM production at NICA was analyzed. One can investigate different observables in ρ, ω and J/ψ productions to study quark and gluon GPDs. The other important process is the exclusive Drell-Yan (D-Y) production in the proton-proton reaction determined by two GPDs contributions. This reaction gives an important test of the GPD model and hopefully can be studied at NICA energies.
Dynamics of an orbital polarization of twisted electron beams in electric and magnetic fields
Authors: Silenko Alexander J. , Zhang Pengming , Zou Liping
Published: April 2019

Relativistic classical and quantum dynamics of twisted (vortex) Dirac particles in arbitrary electric and magnetic fields is constructed. The relativistic Hamiltonian and equations of motion in the Foldy-Wouthuysen representation are derived. Methods for the extraction of an electron vortex beam with a given orbital polarization and for the manipulation of such a beam are developed. The new effect of a radiative orbital polarization of a twisted electron beam in a magnetic field resulting in a nonzero average projection of the intrinsic orbital angular momentum on the field direction is predicted.
Spin transparency mode in the NICA collider
Authors: Filatov Yury , Kovalenko Alexander , Butenko Andrey , Syresin Evgeniy , Mikhailov Vladimir , Shimanskiy Stepan , Kondratenko Anatoliy , Kondratenko Mikhail
Published: April 2019

The NICA collider can operate with polarized light ions in two modes. At the Preferred Spin mode (PS mode) the periodic spin motion along the closed orbit is unique, i.e. the static magnetic lattice determines a single stable orientation of the beam polarization at any collider's place. At the Spin Transparency mode (ST mode) any spin direction repeats every particle turn along the closed orbit, i.e. the colliders magnetic lattice is transparent to the spin. ST mode allows one to use a completely new approach to carry out experiments with polarized ions at high precision level. The features of ion polarization control in the ST mode are discussed. The schemes of polarization control in the NICA collider in the ST mode are presented.
Fast Interaction Trigger for the upgrade of the ALICE experiment at CERN: design and performance
Authors: Maevskaya Alla
Published: April 2019

ALICE (A Large Ion Collider Experiment) at the CERN LHC is designed to study the properties of the Quark–Gluon Plasma (QGP) in heavy-ion collisions. In 2019–2020 the upgrade of the LHC will increase the luminosity and the collision rate beyond the design parameters of the current ALICE setup. To be able to benefit from the improved performance of the LHC, ALICE will upgrade several of its key detector systems including the Fast Interaction Trigger (FIT). FIT is designed to provide the functionality of the existing forward detectors while retaining or even improving their performance. It will provide minimum bias (MB) trigger with an efficiency higher than 90% for pp collisions, measure the luminosity for pp and Pb–Pb collisions, and sustain interaction rates up to 1 MHz and 50 kHz, respectively. FIT will determine the collision time with a resolution better than 50 ps and will be used to measure the event multiplicity, the centrality, and the reaction plane. The detector consists of two arrays of Cherenkov radiators with micro-channel plate photo-multiplier (MCP-PMT) sensors, placed on both sides of the interaction point and of a single large-diameter scintillator ring. This article discusses the main design concepts, detector construction, beam test results, Monte Carlo simulations, and the results of detector performance studies.
Taxiing Characteristic Analysis and Control for Full-Wing Solar-Powered Unmanned Aerial Vehicle
Authors: Ma Zhenyu , Zhu Xiaoping , Zhou Zhou
Published: April 2019

To solve the taxiing control problem of the full-wing solar-powered unmanned aerial vehicle (UAV) without front wheel steering servo and rudder, a control approach using differential propeller thrust to control the taxiing is proposed in this paper. Firstly, the taxiing mathematical models of two kinds of full-wing solar-powered UAVs with the front wheels turning freely or fixed are established. Meanwhile, the taxiing characteristics of full-wing solar-powered UAV in different taxiing speeds are analyzed. Secondly, based on the linear active disturbance rejection control (LADRC) theory, a yaw angle controller is designed by using differential propeller thrust as the control output. Finally, a straight line trajectory tracking scheme which is suitable for take-off and landing taxiing is designed on the base of improved vector field theory. Simulation results show that the designed controller has a good control effect on full-wing solar-powered UAV's take-off and landing taxiing periods, and better robustness.
A Numerical Method for Estimating the Nonlinear Eigenvalue Numbers of Boundary Element
Authors: Wang Junpeng , Xiao Jinyou , Wen Lihua
Published: April 2019

Recently, some new proposed methods for solving nonlinear eigenvalue problems (NEPs) have promoted the development of large-scale modal analysis using BEM. However, the efficiency and robustness of such methods are generally still dependent on input parameters, especially on the parameters related to the number of eigenvalues to be solved. This limitation obviously restricts the popularization of the practical engineering application of modal analysis using BEM. Therefore, this paper develops a numerical method for estimating the number of nonlinear eigenvalues of the boundary element method. Firstly, the interpolation method based on the discretized Cauchy integral formula of analytic function is used for obtaining the BEM matrix's derivative with regard to frequency, and this method is easily combined with the mainstream fast algorithm libraries of BEM. Secondly, the method for evaluating the eigenvalue number of BEM under various boundary conditions is obtained by combining the interpolation method with the analytic formula to obtain the eigenvalue number, while the unbiased estimation is used to determine the trace of matrix. Finally, a series of typical examples are used to explore the principle for selecting optimal input parameters in this method, and then a set of optimal input parameters are determined. The overall excellent performance of this method is verified by a complex large-scale example.
Building Sound Absorption Performance Model of Porous Glass Based on GRNN
Authors: Zhang Xubo , Xu Ying , Zhang Tingying , Li Guodong
Published: April 2019

The generalized regression neural network (GRNN) model of sound absorption coefficient of porous glass was built on data from 16 groups gained by experiments, where 12 groups were randomly selected as trained samples and the other 4 groups were as tested ones. This GRNN model which has two parameters, porosity and thickness as the inputs, was set the maximum iteration number 20, getting the optimal trained spread parameter σ=0.1. The results showed that the average error of this model was 0.003, and this model has high precision and the prediction curve of the sound absorption coefficient was very similar to the experiments. The advantages of this method are simple, needing less trained samples, rapid and accurate.
Underwater Acoustic Target Feature Fusion Method Based on Multi-Kernel Sparsity Preserve Multi-Set Canonical Correlation Analysis
Authors: Yang Honghui , Yi Shuzhen
Published: April 2019

To solve high-dimensional and small-sample-size classification problem for underwater target recognition, a new feature fusion method is proposed based on multi-kernel sparsity preserve multi-set canonical correlation analysis. The multi-set canonical correlation analysis algorithm is used to quantitatively analyze the correlation of multi-domain features, remove redundant and noise features, in order to achieve multi-domain feature fusion. The multi-kernel sparsely preserved projection algorithm is used to constrain the sparse reconstruction of the extracted multi-domain feature samples, which enhances the feature's classification ability. Results of applying real radiated noise datasets to underwater target recognition experiments show that our new method can effectively remove the redundancy and noise features, achieve the fusion of multi-domain underwater target features, and improve the recognition accuracy of underwater targets.
The Chip Cooling Model and Route Optimization with Digital Microfluidics
Authors: Wang Shaoxi , Yin Yue , Fan Xiaoya
Published: April 2019

Using microfluidic technology to achieve integrated chip cooling is becoming a promising method to extend Moore law effective period. The thermal management is always critical for 3D integrated circuit design. Hot spots due to spatially non-uniform heat flux in integrated circuits can cause physical stress that further reduces reliability. The critical point for chip cooling is to use microfluidic cooling accurately on the hot spots. First, based on electro-wetting on dielectric, the paper presents an adaptive chip cooling technique using the digital microfluidics. Then, a two-plans 3D chip cooling model has been given with its working principle and characteristics. And single plan chip cooling model is presented, including its capacitance performance and models. Moreover, the dentate electrode is designed to achieve droplet continuing movement. Next, the ant colony optimization is adopted to get optimal route during electrode moving. Last, the experiments demonstrate the adaptive chip cooling technique proposed in this paper is effective and efficiency.
Image Fusion Algorithm of Focal Region Detection and TAM-SCM Based on SHT Domain
Authors: Wang Feng , Cheng Yongmei , Li Hui
Published: April 2019

The selection of texture information and block ringing effect in multi-focus fusion process, a new multi-focus image fusion algorithm based on Three Activity Measures (TAM) excitation Spiking Cortical Model, (SCM) in shearlet (SHT) domain is proposed. Firstly, in SHT domain, using local spatial frequency (SF), local energy of gradient (EOG) and different measurements (SF, EOG, and local laplace energy sum (SML)) motivated SCM selected the texture information and construct the initial fusion image (P). Then, the focal region was extracted from the significant feature of the difference between the image P and the original image. Finally, the joint focus area produces fusion images. To verify the superiority of the proposed algorithm, compare the results of this paper with seven competing methods. Experimental results show that the algorithm can produce clear edges, good visual perception and less distortion.
Exploring Mode Hopping Performance of a Prism Laser Gyro
Authors: Tao Yuanbo , Li Sihai , Lu Zheng
Published: April 2019

In view of the poor mode hopping performance of prism laser gyros, the mode hopping performance of a prism laser gyro is systematically studied. A mathematical model of frequency stabilization actuating mechanism is established, and the mode hopping is analyzed theoretically. The functional relation between the incremental voltage of the mode hopping and its temperature and starting voltage is given, and the phenomenon that the gyro's pulses fluctuate greatly in the process of mode hopping is eliminated. The open closed-loop scanning mode of the prism laser gyro is further studied. The experimental results show that the shallow light limiting mode causes the competition between two longitudinal modes, resulting in the gyro's pulse hopping. Without changing the optical limiting parameters of the resonator, adjusting the light intensity reference voltage or feedback loop pre-amplification gain can make the open closed-loop scanning mode performance appropriate and avoid the gyro's pulse hopping. The analysis result improves the precision of the gyro, reduces the rework rate of the resonator and improves the production efficiency of the gyro.
Numerical Investigation of Unsteady Interaction between Rim Seal Flow and Upstream Vane
Authors: Yang Fan , Zhou Li , Wang Zhanxue
Published: April 2019

To investigate unsteady interaction mechanism between the rim seal flow in turbine stator-rotor cavity and main flow, detailed unsteady numerical simulations of the flow field and unsteady characteristic of the vane were conducted under different rim seal mass flow rate. The results show the blockage effect resulting from the egress flow leads to the pressure to increase and static entropy to reduce on the latter half of suction side near the hub. From the case without a cavity to RI=1.7%, at 5% span, the maximum pressure coefficient increase on the suction side reaches 6%. Moreover, the blockage effect causes the velocity to decrease at vane exit. Furthermore, the rim seal flow results in the decrease in lateral pressure gradient, causing the strength of hub passage vortex and hub trailing shedding vortex to reduce. Without rim seal flow, the ingress flow contributes to decreasing unsteady fluctuation from the hub to 10% span. When there is rim seal flow, unsteady fluctuation continues to reduce due to coupling effects of the egress flow from the ingress and the egress flow form the cavity inlet.
Investigation of Rotor Tip Vortex in Hover Based on IDDES Methods
Authors: Fu Weijia , Ma Jingzhong , Li Jie
Published: April 2019

A calculation and analysis program of high-precision numerical simulation for rotor blade tip vortex in hovering state was developed. The fifth order Roe-WENO scheme was carried out in order to reduce the numerical dissipation of the rotor wake region. The rotary motion of the rotor was realized by using the dynamic patched technology of structured grids. And at the same time, the technology also helped to avoid the tremendous increase of grid number of the far-field due to the refined grids of the flow region where emphasis was placed on. Hybrid RANS/LES approach was investigated based on the issues about inadequate capabilities of simulations of complex turbulent flows, and IDDES approach was developed. The numerical simulation of the tandem cylinder was carried out firstly to verify the reliability of the IDDES method and the patched grid technology. Then the RANS and IDDES approaches were used to simulate the flow field of the rotor in hover performance, respectively. The analysis of the vortex magnitude, vortex core position and diameter as well as the velocity profiles of the rotor tip vortex were made comparatively in detail. The numerical results showed that the resolutions obtained through IDDEES approach agreed with the experimental results much better than that of the RANS approach with the same gird scales. Meanwhile, the IDDES results can capture the tiny worm vortex structures and vortex paring phenomena in accordance with the practical status, which contributes to study the flow mechanism of rotor and related problems.
Detection of tick-borne pathogens in questing Ixodes ricinus in the French Pyrenees and first identification of Rickettsia monacensis in France
Authors: Akl Toufic , Bourgoin Gilles , Souq Marie-Line , Appolinaire Joël , Poirel Marie-Thérèse , Gibert Philippe , Abi Rizk Georges , Garel Mathieu , Zenner Lionel
Published: April 2019

Ticks are important vectors of several human and animal pathogens. In this study, we estimated the prevalence of important tick-borne infections in questing ticks from an area in Southwestern France (Hautes-Pyrénées) inhabited by Pyrenean chamois (Rupicapra pyrenaica pyrenaica) experiencing high tick burden. We examined adult and nymph ticks collected by the flag dragging method from 8 to 15 sites in the Pic de Bazès during the years 2009, 2011, 2013 and 2015. PCR assays were conducted on selected ticks for the detection of Borrelia burgdorferi s.l., Babesia spp., Rickettsia spp., spotted fever group (SFG) Rickettsia and Anaplasma phagocytophilum. Randomly selected positive samples were submitted for sequence analysis. A total of 1971 questing ticks were collected including 95 males, 101 females and 1775 nymphs. All collected ticks were identified as Ixodes ricinus. Among them, 696 ticks were selected for pathogen detection and overall prevalence was 8.4% for B. burgdorferi s.l.; 0.4% for Babesia spp.; 6.1% for A. phagocytophilum; 17.6% for Rickettsia spp.; and 8.1% for SFG Rickettsia. Among the sequenced pathogens, we detected in this population of ticks the presence of Babesia sp. EU1 and Rickettsia helvetica, as well as Rickettsia monacensis for the first time in France. The detection of these pathogens in the Pic de Bazès highlights the potential infection risks for visitors to this area and the Pyrenean chamois population.
Der intelligente HNO-Operationssaal der Zukunft
Authors: Pirlich Markus , Stöhr Matthäus , Neumuth Thomas , Dietz Andreas
Published: April 2019

Die zunehmende Pluralität und Komplexität technischer Assistenzsysteme stellen eine Herausforderung für den klinisch tätigen Mediziner dar. Insbesondere im OP Saal steigt der Bedarf medizintechnische Systeme und Softwarelösungen in eine gesamtheitliche Infrastruktur zu integrieren. Primäres Ziel des Aufbaus eines „digitalen (HNO-) OP Saals der Zukunft“ ist nicht nur die reine technische Verbesserung der einzelnen computergestützten Geräte und Instrumente, sondern vielmehr deren dynamische Vernetzung und Systemintegration in einem offenen modularen System. Vielversprechende wissenschaftliche Projekte gehen dabei den Fragen nach, wie die Qualität, die Sicherheit und die Anwenderfreundlichkeit technischer Systeme im Gesundheitswesen des 21. Jahrhunderts verbessert werden können. Am Beispiel der Arbeiten zu SCOT, MD PnP und OR.NET werden die verschiedenen Komponenten sichtbar, die im Gesamtkontext die Vision des HNO-Operationssaals der Zukunft erfahrbar und realistisch erscheinen lassen.
Telemedizinische Methoden in der Hals-Nasen-Ohrenheilkunde
Authors: Beule Achim
Published: April 2019

Telemedizin ist ein Oberbegriff, der alle kommunikationstechnologisch unterstützte Verfahren zusammenfasst, die medizinische Leistungen über räumliche Entfernungen erbringen. Dieser rasch sich entwickelnde Bereich der Medizin besitzt gerade für das stark endoskopisch/mikroskopisch ausgerichtete Fach der Hals-Nasen-Ohrenheilkunde interessante Optionen. Für die klinische Untersuchung von Ohr, Nase, Rachen und Larynx, aber auch für die postoperative Nachsorge und die Betreuung nach Kopf-Hals-Tumor-Erkrankungen liegen Daten zum telemedizinischen Vorgehen vor, ebenso für die audiologischen Messungen nach Cochlea-Implantation. Diese Daten bieten z. T. ein interessantes Potential, z. T. weisen sie aber gerade auch auf Probleme bei unkritischer Anwendung der Telemedizin hin, deren Erfolg entscheidend von der Ausbildung des Untersuchers vor Ort abhängt. Der vorgestellte Artikel fasst die wesentlichen Erkenntnisse dieses sich sehr rasch entwickelnden Forschungsgebietes überblickartig zusammen.
Digitale Strategien in der Lehre
Authors: Dombrowski Tobias , Dazert Stefan , Volkenstein Stefan
Published: April 2019

Die Entwicklung digitaler Strategien in der Lehre beruht auf den technologischen Fortschritten der letzten Jahrzehnte, aber auch auf der Motivation, ein didaktisches Konzept verstärkt auf den Lernenden zu zentrieren. Aus verfügbaren Daten der deutschen Hochschulmedizin ergibt sich das Bild, dass in der Medizin ganz allgemein und speziell in der HNO-Heilkunde digitale Lehrkonzepte aktuell noch eine untergeordnete Rolle spielen. Durch Erhebung eigener Daten konnten wir zeigen, dass die Studierenden in der HNO-Heilkunde in der Mehrheit auf durch den Dozenten ausgegebene Materialien als einzige Lernquelle zurückgreifen. Die Anwendung fundierter digitaler Lehrstrategien bietet daher, insbesondere fachbezogen für die HNO-Heilkunde, besondere Chancen, u. a. um dem Überangebot von Informationen aus teils unklaren Quellen im Internet entgegenzutreten.

Der mögliche Digitalisierungsgrad der Lehre reicht heute von digitalen Serviceangeboten über punktuelle Angebote klassischer Lehrkonzepte und Blended Learning bis hin zum volldigitalen Studium. Die Attraktivität der curricularen Integration digitaler Lehrstrategien beruht dabei weniger auf der Nutzung rein technischer Fortschritte, sondern vielmehr auf den Möglichkeiten der Anwendung innovativer Curricula und neuer didaktischer Konzepte. In Abhängigkeit vom beabsichtigten Lehrzweck werden insbesondere dem Flipped Classroom und der digitalisierten Realität großes Potenzial zugeschrieben, während mobiles Lernen sich in der Praxis bereits individuell etabliert hat. Die Erprobung und Evaluierung digitaler Lehrinnovationen für konkrete Szenarien gehört aktuell zu den wichtigen wissenschaftlichen Herausforderungen digitaler Lehrkonzepte.

Der flächendeckenden Etablierung digitaler Lehre stehen heute weniger technische Voraussetzungen, sondern vielmehr fehlende Finanzierungsmöglichkeiten im Wege, da Förderungen derzeit überwiegend projektgebunden stattfinden, bei dauerhafter Umsetzung jedoch regelmäßige Kosten vorhanden sind. Zur Unterstützung dieser vielversprechenden Lehrformen könnte die Förderung der Einrichtung von Abteilungen für digitale Lehre mit Bereitstellung von entsprechenden Hard- und Softwarelösungen an den Universitäten wesentlich beitragen. Durch die Bildung von Kooperationen zur Nutzung solcher digitalen Plattformen ergäbe sich eine hohe Effizienz in der Verbreitung unter gleichzeitiger Ausnutzung von Sparpotenzialen.
Register – Auswertung von multizentrischen Daten
Authors: Schraven Sebastian , Mlynski Robert
Published: April 2019

Ein Register dokumentiert aktiv und standardisiert Patientendaten zu vorab definierten Fragestellungen. Der Begriff „Register“ (lat. regerere – „eintragen“) hebt den datenhaltenden Aspekt hervor mit dem Ziel epidemiologische Zusammenhänge und Unterschiede zu beschreiben, die Qualitätssicherung und -verbesserung sowie die klinische Forschung zu unterstützen. Die Evaluation der Wirksamkeit in der Versorgungsroutine, das Monitoren der Patientensicherheit sowie die ökonomische Evaluation und die Mindestmengenforschung sind weitere Aufgaben von Registern. Patienten und meldende Einrichtungen bestimmen maßgeblich die Registerqualität durch Vollständigkeit, Vollzähligkeit und hohe Datenvalidität. Dies ist bei der Konzeption, der Finanzierung und dem Betrieb eines Registers zu berücksichtigen. Bei der Auswertung der multizentrischen Daten des Registers kommt der Analyse von potenziell konfundierender oder Effekt modifizierender Variablen eine hohe Bedeutung zu. Regelmäßiges Feedback an die Meldeeinrichtungen, Patienteninformationen, öffentliche Mitteilungen sowie wissenschaftliche Publikationen erhöhen ebenso wie die Einhaltung des Datenschutzes die Transparenz des Registers. Die Hals-, Nasen- und Ohrenheilkunde hat bis auf die Integration in das Krebsregister und dem sich im Aufbau befindenden Neugeborenen Hörscreening-Register wenig Berührungspunkte mit Registern. Die Vielzahl messbarer Parameter in den einzelnen Schwerpunkten des Fachgebiets, wie z. B. der Otologie, Phoniatrie, Rhinologie, Allergologie, usw., stellt die Grundlage für verschiedene potenzielle Register dar. Klinische Fragestellungen, Präventionsmaßnahmen, Qualitätssicherung, Versorgungsforschung und Empfehlungen für die Gesundheitspolitik wären wissenschaftlich fundiert und evidenzbasiert.
Topographic mapping of a specimen after endoscopic submucosal dissection
Authors: Ebigbo Alanna , Probst Andreas , Messmann Helmut , Märkl Bruno , Nam-Apostolopoulos Yun-Chung
Published: April 2019

Background and study aims Mapping of pathologic specimens after endoscopic submucosal dissection (ESD) is common practice in Asian countries, especially in Japan. However, there is a lack of awareness for this technique in Europe. In this report, we demonstrate the feasibility and benefits of topographic mapping in a Western setting.
Contrast-enhanced endoscopic ultrasound for the differential diagnosis between benign and malignant lymph nodes: a meta-analysis
Authors: Lisotti Andrea , Ricci Claudio , Serrani Marta , Calvanese Claudio , Sferrazza Sandro , Brighi Nicole , Casadei Riccardo , Fusaroli Pietro
Published: April 2019

Background The differential diagnosis between benign and malignant lymph nodes (LNs) is crucial for patient management and clinical outcome. The use of contrast-enhanced endoscopic ultrasound (EUS) has been evaluated in several studies with diverse results. The aim of this meta-analysis was to evaluate the pooled diagnostic accuracy of contrast-enhanced EUS (CE-EUS) and contrast-enhanced harmonic EUS (CH-EUS) in this setting.

Methods A systematic electronic search was performed, including all original papers dealing with assessment of the nature of the LNs using CE-EUS or CH-EUS. A meta-analysis was performed to obtain pooled sensitivity, specificity, positive and negative likelihood ratio, and diagnostic odds ratio. The Summary Receiver Operating Characteristic (ROC) Curve method was used to calculate the area under the curve. Statistical analysis was carried out using Meta-Disc V.1.4, Stata V.12.0 and Review Manager V.5.2.

Results Among 210 pertinent studies, four (336 patients) were included in the analysis. The pooled sensitivity was 82.1 % (75.1 – 87.7 %) and pooled specificity was 90.7 % (85.9 – 94.3 %) with significant heterogeneity found in sensitivity; the positive-likelihood ratio (LR) was 7.77 (5.09 – 11.85) and the negative-LR was 0.15 (0.05 – 0.46); the pooled diagnostic odds ratio (DOR) was 54 (15 – 190). Subgroup analysis including studies performed using CH-EUS (two studies, 177 LNs) showed a pooled sensitivity of 87.7 % (77.0 – 93.9 %) and a pooled specificity of 91.8 % (84.5 % – 96.4 %) with no significant heterogeneity; the pooled positive-LR was 9.51 (4.95 – 18.28) and the pooled negative-LR was 0.14 (0.06 – 0.35); pooled DOR was 68.42 (15.5 – 301.4).

Conclusions From these data, CE-EUS is not recommended due to inadequate sensitivity. On the other hand, CH-EUS studies showed optimal accuracy (pooled sensitivity 87.7 % and specificity 91.8 %), comparable to elastography and even EUS-guided fine needle aspiration (EUS-FNA), suggesting a role in the diagnostic algorithm.
Direct Synthesis of Vicinal Tricarbonyl Amides by Coupling of α-Oxo Acid Chlorides with Carbamoylsilanes
Authors: Han Yuling , Li Yuping , Han Shenghua , Zhang Pengpeng , Chen Jianxin
Published: April 2019

A convenient synthetic method for vicinal tricarbonyl amides by the cross-coupling reaction of α-oxo acid chlorides with carbamoylsilanes is developed. The reaction tolerates a broad range of substituents on the amido nitrogen of carbamoylsilanes, and directly affords good yields of vicinal tricarbonyl amides under mild conditions without use of oxidants. The reaction of carbamoylsilanes with oxalyl chloride has also been explored, and is accompanied by decarbonylation to give vicinal tricarbonyl amides.
In Vitro Fertilization and Vasa Previa: A Report of Two Cases
Authors: Isotton Ana Lúcia , Salazar Cristiano Caetano , Peralta Cleisson Fábio Andrioli , Abdalla Juliana Moysés Leite , Vettorazzi Janete
Published: April 2019

Vasa previa (VP) is a dangerous obstetric condition associated with perinatal mortality and morbidity. In vitro fertilization (IVF) is a risk factor for VP due to the high incidence of abnormal placentation. The diagnosis should be made prenatally, because fetal mortality can be extremely high. We report two cases to demonstrate the accuracy of transvaginal ultrasound in the prenatal diagnosis of VP. A 40-year-old primiparous Caucasian woman with IVF pregnancy was diagnosed with VP at 29 weeks of gestation and was hospitalized for observation at 31 weeks of gestation. She delivered a male newborn weighing 2,380 g, with an Apgar score of 10 at 5 minutes, by elective cesarean section at 34 weeks + 4 days of gestation, without complications. A 36-year-old primiparous Caucasian woman with IVF pregnancy was diagnosed with placenta previa, bilobed placenta increta and VP. The cord insertion was velamentous. She was hospitalized for observation at 26 weeks of gestation. She delivered a female newborn weighing 2,140 g, with an Apgar score of 9 at 5 minutes, by emergency cesarean section at 33 weeks + 4 days of gestation due to vaginal bleeding. The prenatal diagnosis of VP was associated with a favorable outcome in the two cases, supporting previous observations that IVF is a risk factor for VP and that all IVF pregnancies should be screened by transvaginal ultrasound.
The Rejuvenation of the Aged Central Lower Face: A Contemporary Perspective
Authors: Fedok Fred
Published: April 2019

Aging of the central face is typified by several common characteristics such as generalized volume loss, the appearance of a mental crease and marionette lines, thinning of the lips, and fixed and dynamic rhytids. These result from several processes such as atrophy of adipose and bone, changes in the support of the mandibular septum, and a loss of skin elasticity. There are many methods available for the improvement and rejuvenation of this facial anatomical area. Options include traditional surgical techniques, the application of volume and the use of laser, light, and energy-based devices. The recent application of biological interventions offers the possibility of cellular-based therapies to usher in a new era of true tissue regeneration. Optimal correction of the abnormalities may be accomplished through an understanding and identification of the causes of the observed abnormalities and targeting with the best available intervention. There are a growing number of techniques and technologies to accomplish this.
Lip Lifting: Not Just Fullness—Everything You Need to Know about Lifting and Creating Youthful, Beautiful Lips
Authors: Spiegel Jeffrey , Spiegel Onir
Published: April 2019

This article will explain the theories and practice of creating the most beautiful lips. This article also discusses lip lifting, lip augmentation, and lip injectables.
Mandibular Angle Implants
Authors: Eppley Barry
Published: April 2019

After studying this article, the reader should be able to understand the two basic types of implants for aesthetic augmentation of the jaw angles and the aesthetic goals in using them. The operative steps for surgical placement are described with emphasis on avoiding the common complications of jaw angle implants. The indications for the use of standard versus custom jaw angle implants are also described.
Nivolumab in the Treatment of Recurrent/Metastatic Squamous Cell Carcinoma of the Head and Neck (RM-SCCHN): A Report of 16 Cases at a Single Institution
Authors: Yamazaki Tomoko , Aoi Jiro , Kishimoto Kazutaka , Saijo Satoshi , Fujii Keitaro , Imai Takayuki , Asada Yukinori , Matsuura Kazuto
Published: April 2019

Background Nivolumab, approved in Japan for platinum-refractory recurrent/metastatic squamous cell carcinoma of the head and neck (RM-SCCHN) in 2017, is of uncertain cost-effectiveness.

Patients and Methods We reviewed the data of 16 patients with platinum-refractory RM-SCCHN treated with nivolumab monotherapy, 3 mg/kg every 2 weeks, between April 2017 and February 2018.

Results All 16 patients were male. The number of previous treatments was 1, 2, and 3 in 1, 5, and 10 patients, respectively. All patients had been previously treated with regimens that included platinum, and 15 patients had previously received cetuximab. The best response rate was a partial response in two patients. Stable disease occurred in 11 patients and disease progression occurred in 2 patients. The disease control rate was 81.2%. Median follow-up time was approximately 8.7 months, and median progression-free survival (PFS) was 2.1 months. Adverse events (AEs) ≤ Grade 3 included pneumonitis and rash in 38%, pruritus in 31%, fatigue in 25%, and kidney dysfunction and endocrine disorder in 12% each. AEs > Grade 3 included pruritus in 12%, and pneumonitis in 6%. Drug discontinuation was requested by patients' clinicians for disease progression in seven patients and Grade 3 AEs in three. Following nivolumab treatment, seven patients received salvage treatment.

Conclusion Nivolumab showed some efficacy in disease control, but PFS was low. The AE rate was acceptable, with no Grade 4 or 5. If patient selection can be fine-tuned, treatment with this agent may become cost-effective.
Calculation and optimization of acoustic radiation force produced by a two-dimensional transducer array
Authors: Xu Jiaxin , Gui Yifei , Ma Jianmin
Published: April 2019

The beam-shape coefficients of a focused sound field from a two-dimensional transducer array are obtained by using the translational addition theorem for spherical functions, and the acoustic radiation force function of a sphere is given in terms of the beam-shape coefficients and the scattering coefficients. The numerical results of acoustic radiation force function show that when the radius of the sphere is much smaller than the acoustic wavelength, the acoustic radiation force function increases sharply with the increase in the radius, while it begins to decrease as the radius continues to increase. Increasing the vibration frequency of the transducer, the array element spacing and the number of elements will enhance the directivity of the acoustic beam and make the acoustic radiation force distribution much more concentrated at the bottom of the sphere. Through optimization of acoustic radiation force distribution by adjusting the phase distribution of the transducer array, the acoustic radiation force distribution range at the bottom of the sphere becomes wider.
Catalytic and noncatalytic conversion of spent fat oil into combustible gases and liquids
Authors: Hussain Zahid , Naz Humaira , Naz Muhammad Y. , Gulab Hussain , Sulaiman Shaharin A. , Khan Khalid M. , Shukrullah Shazia
Published: April 2019

A huge amount of spent oils is produced in the world every day. These oils contain some toxic aldehydes, which affect human health. The disposal of used oils in sewers and drains not only raises the blockage and aesthetic problems but also pollutes the water resources. In the present work, spent fat oil (SFO) was converted into a combustible liquid and gaseous fuels by using a batch type reactor. For catalytic pyrolysis, the Portland cement raw mix, white cement raw mix, and powdered nonbrick or clay catalysts were used to convert SFO into useful fuels. The uncatalyzed pyrolysis took 60 min to convert SFO into liquid and gaseous fuels. The pyrolysis time was reduced to 30 min after catalyzing the reaction with a suitable catalyst. The white cement raw mix and clay catalysts promoted the formation of gaseous products, whereas the Portland cement raw mix promoted the formation of liquid fuel. The uncatalyzed pyrolysis of SFO produced only 3.527% hydrocarbons. Among the catalyzed reactions, the highest percentage of hydrocarbons (67.884%) was obtained with clay catalyst followed by the white cement (55.24%) and Portland cement (35.893%) formulations. The uncatalyzed reaction mainly produced fatty acids, the Portland cement and clay/burnt brick catalyzed reactions produced only esters, and the white cement catalyzed reaction produced a single fatty acid.
The self-collimation effect induced by non-Hermitian acoustic systems
Authors: Yang Hang , Zhang Xin , Zhao Degang , Liu Yuechang , Guo Jianhua , Yao Yuanwei , Wu Fugen
Published: April 2019

With the proposal of the concept of parity-time-symmetry, more and more exotic properties are being unearthed in non-Hermitian systems. In this work, we investigate the related acoustic feature and phenomenon in two-dimensional phononic crystals with a complex modulus by introducing the balanced loss and gain. Different from Hermitian properties, partial band degeneracy has occurred in the dispersion diagram, leading to higher density of states, and self-collimated wave propagation has been predicted at the merged frequency. More importantly, the input locations of the point source have a significant impact not only on the direction of self-collimation waves but also on the intensity profiles of the pressure field, which is not achieved in self-collimation of Hermitian systems. We also propose a digital single-pole double-throw switch, which corresponds to two special self-collimating situations. Our finding provides an effective approach for controlling the wave direction and designing more digital acoustic functional devices in non-Hermitian systems.
A strong dependence of the CH3 internal rotation barrier on conformation in thioacetic acid: Microwave measurements and an energy decomposition analysis
Authors: Smith C. J. , Huff Anna K. , Zhang Huaiyu , Mo Yirong , Leopold Kenneth R.
Published: April 2019

Rotational spectra of thioacetic acid (CH3COSH) have been observed by pulsed-nozzle Fourier transform microwave spectroscopy. Spectroscopic constants are reported for both the syn and anti conformers of the parent species, as well as the 34S and 13C carbonyl isotopologues. Transitions arising from the lowest A and E internal rotor states of the methyl group have been observed and analyzed. Experimental values of the three-fold internal rotation barrier, V3, for the syn and anti conformers of the parent isotopologue are 76.300(12) and 358.056(51) cm−1, respectively, indicating a large effect of the S−H orientation on the CH3 internal rotation potential. M06-2X/6-311+G(d,p) calculations are in good agreement with these results. The block localized energy decomposition method has been applied to understand the origins of this strong dependence of V3 on conformation. The results indicate that π conjugation from the SH to the carbonyl group and steric repulsion between the SH and the methyl group in the anti form are main contributors to the difference.
Measuring strong one-bond dipolar couplings using REDOR in magic-angle spinning solid-state NMR
Authors: Jain Mukul G. , Mote Kaustubh R. , Hellwagner Johannes , Rajalakshmi G. , Ernst Matthias , Madhu P. K. , Agarwal Vipin
Published: April 2019

Rotational-Echo DOuble Resonance, REDOR, is an experimentally robust and a well-established dipolar-recoupling technique to measure dipolar couplings between isolated pairs of spin-1/2 heteronuclei in solid-state nuclear magnetic resonance. REDOR can also be used to estimate motional order parameters when the bond distance is known, for example, in the case of directly bound nuclei. However, the relatively fast dipolar dephasing for strongly coupled spin-1/2 pairs, such as 13C–1H, makes the stroboscopic measurement required in this experiment challenging, even at fast Magic-Angle-Spinning (MAS) frequencies. In such cases, modified REDOR-based methods like Shifted-REDOR (S-REDOR) are used to scale the dipolar coupling compared to REDOR. This is achieved by changing the position of one of the two recoupling π-pulses in a rotor period. This feature, however, comes at the cost of mixing multiple Fourier components of the dipolar coupling and can, additionally, require high radio-frequency amplitudes to realise small scaling factors. We introduce here a general pulse scheme which involves shifting both the π pulses in the REDOR scheme to achieve arbitrary scaling factors whilst retaining the robustness and simplicity of REDOR recoupling and avoiding the disadvantages of S-REDOR. The classical REDOR is a specific case of this scheme with a scaling factor of one. We demonstrate the results on isolated 13C–15N and 1H–13C spin pairs at 20 and 62.5 kHz MAS, respectively.