bluuebunny/crossref_metadata_2025 huggingface dataset:
Spinale Navigation – Evidenz: Einsatz der Navigation in der Wirbelsäulenchirurgie
Authors: Meyer Hanno , Ryang Yu-Mi
Published: February 2019

Computerassistierte Navigation (CAN) wird in der Wirbelsäulenchirurgie zunehmend eingesetzt. Ziel ist die präzise Anlage spinaler Instrumentierungen, in der Regel von Pedikelschrauben, ohne dabei auf Röntgendurchleuchtung zurückgreifen zu müssen. Die hohe Genauigkeit der Schraubenanlage mit CAN soll dabei helfen, potenzielle Komplikationen von Schraubenfehllagen wie Instabilität, Gefäßverletzungen, neurologische Schäden und Revisionsoperationen zu verhindern. CAN wird darüber hinaus in der spinalen Tumorchirurgie eingesetzt, um das Zugangstrauma zu minimieren und das Resektionsausmaß zu optimieren.

In diesem Artikel werden die Vor- und Nachteile des Einsatzes von CAN in der Wirbelsäulenchirurgie anhand der verschiedenen verfügbaren CAN-Systeme mit Bezug auf die aktuelle Literatur dargestellt.

Intraoperative Computertomografie bietet die bestmögliche Bildqualität, den größten Ringtunnel und das größte Sichtfeld, stellt aber die kostenintensivste Variante dar. Eine günstigere Alternative stellt die intraoperative 3D-Fluoroskopie dar. Deren Bildqualität ist der CT unterlegen, dennoch können damit offene und auch perkutane Verfahren v. a. an der thorakolumbalen Wirbelsäule problemlos navigiert durchgeführt werden. Eine weitere Alternative ist die präoperative (CT-) Bildgebung. Hier ist die Bildqualität herausragend, doch besteht aufgrund der Differenz zwischen Patientenposition im OP und während des präoperativen Scans eine intrinsische Ungenauigkeit.

Die vorliegenden Daten zeigen, dass CAN tatsächlich die Genauigkeit der Schraubenanlage verbessert, die Anzahl von Revisionsoperationen aufgrund von Schraubenfehllagen verringert und damit assoziierte Komplikationen unwahrscheinlicher macht. Auch führt der Einsatz von CAN zu einer reduzierten Strahlenbelastung des Patienten und des OP-Personals. CAN kann an der gesamten Wirbelsäule und sowohl bei offener als auch minimal-invasiver Wirbelsäulenchirurgie eingesetzt werden. Entscheidend für einen erfolgreichen Einsatz von CAN ist eine fundierte Kenntnis der technischen Grundlagen und der Eigenheiten der verwendeten Systeme.

Weiterhin wird ein kleiner Ausblick in die mögliche Zukunft der spinalen Navigation gegeben.
Register: Sind Register nötig, sinnvoll, effektiv? Pro: Aus Sicht des Wirbelsäulenchirurgen
Authors: Ringe Mathis , Meyer Frerk , Siewe Jan , Sobottke Rolf
Published: February 2019

Medizinische Register verschiedenster Fachrichtungen schießen in den letzten Jahren wie die Pilze aus dem Boden. Gründe hierfür sind zum einen die wachsende Akzeptanz und Erkenntnis der vielen Möglichkeiten, die gut geführte Register im Hinblick auf Qualitätskontrolle, Qualitätssicherung sowie Versorgungsforschung leisten können, zum anderen besteht ein mehrseitiges gesundheitspolitisches Interesse, welches ein Register als wichtiges Instrument erforderlich macht.

Neben der Implantatnachverfolgung, die durch die seit dem 25.05.2017 in Kraft getretene Medical Device Regulation (MDR) der EU bindend ist, ist das Gesundheitssystem v. a. im Hinblick auf die Ressourcenplanung auf klinische Daten, Qualitätsabbildung und damit Qualitätssicherung angewiesen.

Die deutsche Wirbelsäulengesellschaft (DWG) betreibt seit Jahren ein eigenständiges Wirbelsäulenregister, welches viele Anforderungen der unterschiedlichen Interessensgruppen und -vertreter bereits jetzt erfüllt. Um sowohl auf die politischen Begebenheiten sowie die fortschreitende Digitalisierung zu reagieren, als auch das Register weiter zu verbessern, werden in den zuständigen Kommissionen der DWG weitreichende Schritte vorwärtsgegangen.
Sagittales Profil der Wirbelsäule: Was ist sinnvoll, was gefährdet den Patienten, was ist Hype? Evidenz für Korrekturoperationen bei sagittaler Dysbalance
Authors: Thomé Claudius
Published: February 2019

In den letzten Jahren hat das sagittale Profil der Wirbelsäule zunehmend Beachtung gefunden und es konnten je nach Beckenkonfiguration unterschiedliche Wirbelsäulentypen identifiziert werden. Kommt es durch die fortschreitende Bandscheibendegeneration zu einer Entlordosierung der Lendenwirbelsäule, resultiert eine sagittale Dysbalance, oft im Sinne einer degenerativen Lumbalskoliose. Nicht selten forcieren Versteifungsoperationen diese Entwicklung iatrogen durch Fixierungen in entlordosierter Position. Fällt das C7-Lot vor die Hüftköpfe, spricht man von dekompensierter sagittaler Dysbalance, die von vielen Wirbelsäulenchirurgen als entscheidend für die Patientendisabilität angesehen wird und aufwändige Korrekturoperationen indiziert werden. Derartige Eingriffe, die häufig Osteotomien erfordern, gehen jedoch mit einem 50 %igen perioperativen Komplikationsrisiko und mit einer Versagens- bzw. Reoperationsrate von ebenfalls 50 % einher, so dass dieser Hype zunehmend kritisch gesehen wird, zumal beispielsweise in Fällen von lumbalen Spinalstenosen ungeachtet des sagittalen Profils reine Dekompressionsoperationen gute Ergebnisse erzielen. Bei insgesamt spärlicher Evidenzlage können daher aktuell umfangreiche Deformitätenkorrekturen nur bei ausgeprägter sagittaler Dysbalance und stärksten, therapierefraktären Beschwerden empfohlen werden. Eine detaillierte präoperative Evaluation und Risikoabschätzung ist in diesem Zusammenhang ebenso unerlässlich wie die Versorgung an spezialisierten Zentren. In diesem selektionierten Patientengut sind Outcome und Patientenzufriedenheit allerdings erstaunlich gut. Es ist davon auszugehen, dass sich die Datenlage in den nächsten Jahren verdichtet und auch altersspezifische Empfehlungen möglich sind. Auch wenn aktuell die routinemäßige Korrektur des sagittalen Profils bei allen Patienten nicht empfohlen werden kann, so macht das Konzept der sagittalen Balance grundsätzlich Sinn. Dementsprechend sollte bei Instrumentationen vor allem der unteren Lendenwirbelsäule eine Wiederherstellung der physiologischen lumbalen Lordose angestrebt werden.
Fettes Potential – Stammzellen des Fettgewebes in der
regenerativen Medizin
Authors: Engel Daniel , Fischer-Posovszky Pamela
Published: February 2019

In der regenerativen Medizin versucht man schon seit längerer Zeit Erkenntnisse
der Stammzellforschung zu optimieren und mit diesen, trotz großer Hürden, eine
praktische Anwendung zu finden. Aus dem Fettgewebe isolierte multipotente
Stammzellen scheinen ein Schritt in die richtige Richtung zu sein, da diese
Zellen den mesenchymalen Stammzellen, die aus dem Knochenmark gewonnen wurden,
in vielen Punkten überlegen sind. Dieser Artikel behandelt die Vor- und die
Nachteile sowie das Anwendungsspektrum dieser Stammzellen.
Diäterfahrungen zur Gewichtsreduzierung von Jugendlichen in
Deutschland – Ergebnisse aus EsKiMo II
Authors: Lehmann Franziska , Lage Barbosa Clarissa , Haftenberger Marjolein , Brettschneider Anna-Kristin , Frank Melanie , Patelakis Eleni , Heide Karoline , Perlitz Hanna , Hölling Heike , Richter Almut , Mensink Gert
Published: February 2019

Das gesellschaftlich vorherrschende Schönheitsideal löst häufig einen starken
Schlankheitsdruck aus. Dies kann vor allem bei Jugendlichen zu Unzufriedenheit
mit dem eigenen Körper führen und den Wunsch nach Gewichtsreduzierung
hervorrufen. Aktuelle und repräsentative Daten zu den Diäterfahrungen, der in
Deutschland lebenden 12- bis 17-Jährigen, liefert die „Ernährungsstudie als
KiGGS-Modul – EsKiMo II“ (2015–2017). Die Auswertungen zeigen, dass rund 17 %
der Jugendlichen in den letzten drei Jahren mindestens eine Diät zur
Gewichtsreduzierung durchgeführt haben, wobei dies für Mädchen signifikant
häufiger gilt als für Jungen. Von den Jugendlichen mit Übergewicht und
Adipositas haben 40 % bereits Diäterfahrung. Der Median der Dauer einer
durchschnittlichen Diät beträgt 30 Tage. Die Ergebnisse aus EsKiMo II zeigen
eine beträchtliche Prävalenz an Diäterfahrung unter Jugendlichen. Damit besteht
ein erheblicher Bedarf an geeigneten Angeboten zur Gewichtsreduzierung bei
Übergewicht und Adipositas.
In Würde zu sich stehen – Ein peer-geleitetes Gruppenprogramm für Jugendliche mit psychischen Erkrankungen
Authors: Rüsch Nicolas , Nehf Luise , Djamali Julia , Mulfinger Nadine , Müller Sabine
Published: February 2019

Angesichts in der Gesellschaft verbreiteter stigmatisierender Einstellungen kämpfen Jugendliche mit psychischen Erkrankungen häufig mit der Entscheidung, ob sie Anderen von ihrer Erkrankung berichten sollen. Die Entscheidung für oder gegen Offenlegung stellt dabei oft eine Schlüsselreaktion im Umgang mit Stigmatisierung dar. Offenlegung und Geheimhaltung können Vor- und Nachteile haben, je nach Kontext und Person. ,In Würde zu sich stehen‘ (IWS) ist ein peer-geleitetes Gruppenprogramm, um Jugendliche bei solchen Offenlegungsentscheidungen zu unterstützen. Hier werden Grundlagen, Ansatz, Aufbau, Inhalt und Daten zu Wirksamkeit sowie Erfahrungen mit IWS für Jugendliche vorgestellt. Eine randomisiert-kontrollierte Studie mit überwiegend in stationärer kinder- und jugendpsychiatrischer Behandlung befindlichen Jugendlichen zeigte signifikante positive Effekte von IWS auf Stigma-Variablen (Selbststigma, Stigma-Stress) sowie auf Lebensqualität, depressive Symptomatik, Recovery und Einstellungen zu Behandlungsteilnahme. Schließlich werden Implikationen für die Implementierung und Stigma-Interventionen diskutiert.
Organisationsformen Praxis, MVZ-Strukturen – ist die Einzelpraxis ein Auslaufmodell?
Authors: Smetak Norbert
Published: February 2019

Das ambulante Gesundheitssystem ist insbesondere in den letzten Jahren einem kontinuierlichen, immer rascheren Wandel ausgesetzt. Waren in den 70er- und 80er-Jahren noch Einzelpraxen die übliche ambulante Versorgungsform, so hat sich in den letzten Jahren zunehmend das Konstrukt der Gemeinschaftspraxen etabliert. Die sich nun in den letzten Jahren zusätzlich verändernde Konstellation des medizinischen Nachwuchses verlangt die Etablierung modernerer Konstruktionen ambulanter Versorgungsformen. Der zunehmende Wunsch junger Ärztinnen und Ärzte, auch im ambulanten Sektor in einer Anstellungssituation arbeiten zu können, erfordert es, Praxisgemeinschaften zu ermöglichen, die neben inhabergeführter Berufsausübung auch eine rein angestellte Arbeit ermöglichen. Solche Strukturen werden zum Beispiel durch medizinische Versorgungszentren oder auch größere Gemeinschaftspraxen, welche rein inhabergeführt sind, ermöglicht. Hierfür sieht unser ambulantes Versorgungssystem verschiedene rechtliche Strukturen vor, welche im Einzelnen erörtert werden.
Balloon enteroscopy-assisted radial incision and cutting method for refractory hepaticojejunostomy anastomotic strictures
Authors: Inoue Tadahisa , Ibusuki Mayu , Kitano Rena , Kobayashi Yuji , Ohashi Tomohiko , Nakade Yukiomi , Sumida Yoshio , Ito Kiyoaki , Nakao Haruhisa , Yoneda Masashi
Published: February 2019

Background Balloon enteroscopy-assisted balloon dilation and temporary biliary stent placement are effective for hepaticojejunostomy anastomotic strictures (HJAS), but the re-stenosis rates are relatively high. We examined the feasibility and efficacy of a novel treatment technique for refractory HJAS, called balloon enteroscopy-assisted radial incision and cutting (BE-RIC).

Methods Between January 2016 and June 2018, 11 patients with refractory HJAS that recurred after balloon dilation and/or stent placement, underwent BE-RIC. We evaluated the technical success, clinical success, adverse events, and re-stenosis rates associated with BE-RIC.

Results The technical success rate of BE-RIC was 91 % (10/11). Clinical success was achieved in all patients who underwent technically successful procedures. The procedure-related adverse event rate was 9 % (1/11). No re-stenosis was observed during the follow-up period; 9 patients were followed up for more than 6 months, and of these, 5, 4, and 2 patients were followed up for more than 12, 18, and 24 months, respectively, without re-stenosis.

Conclusions BE-RIC for refractory HJAS showed favorable results. BE-RIC might be a useful option for treating refractory HJAS.
Malignes Melanom
Authors: Braitmaier Dr. Helmine
Published: February 2019

Krebs in der Schwangerschaft ist selten und betrifft etwa jede 1000. Schwangere. Beim malignen Melanom sind über ein Drittel der betroffenen Frauen im gebärfähigen Alter, die in diese Situation kommen können. Doch die Krebsdiagnose ist kein Grund für einen Schwangerschaftsabbruch, noch sollte die Therapie hinausgezögert werden. Auch Krebsüberlebende können noch schwanger werden, betonte Priv.-Doz. Dr. Angela Köninger, Essen, auf dem Deutschen Hautkrebskongress (ADO).
Speech Sound Disorder and Visual Biofeedback Intervention: A Preliminary Investigation of Treatment Intensity
Authors: Swartz Michelle , Lopez Melissa , Hitchcock Elaine
Published: February 2019

A growing body of research suggests that cases of speech sound errors that have not responded to previous intervention can sometimes be eliminated through speech therapy incorporating visual biofeedback. Aside from considerations related to the specific biofeedback type, acquisition and generalization of a motor plan may be linked to treatment intensity. Several researchers have raised the possibility that inadequate dosage levels may present a significant barrier to success. Thus, the current study aimed to assess the relationship between treatment intensity and treatment outcomes. Twenty-nine articles reporting the use of visual biofeedback intervention for speech sound disorder were identified and coded for treatment intensity using the cumulative intervention index and outcomes using mean level difference scores. Findings reveal small but significant relationships between measures of treatment intensity and efficacy, which should be interpreted with caution given the preliminary nature of this review. Further research in this area is necessary, as inconsistencies in reporting intensity and outcomes across studies underscore the need for more systematic terminology and reporting methods.
Immun-Checkpoint-Inhibitoren
Authors: Krome Dr. Susanne
Published: February 2019

Immun-Checkpoint-Inhibitoren mit den Zielstrukturen CTLA-4 und PD-1 sind insbesondere beim malignen Melanom wirksam und übertreffen die Effektivität konventioneller Therapien. Die Vermeidung der Immunevasion charakterisiert aber auch das Nebenwirkungsprofil mit Autoimmunphänomenen u. a. der Haut. Endpunkt der retrospektiven Beobachtungsstudie war das zeitliche Intervall vom Therapiebeginn bis zum Auftreten schwerer Hautprobleme.
Aggressive primäre Hirntumoren
Authors: Klein Friederike
Published: February 2019

Bislang gibt es noch wenig Fortschritt in der Therapie von aggressiven primären Hirntumoren. Gezielte Therapiestrategien und die Immuntherapie sollen auch hier endlich einen Durchbruch bringen. Aber auf dem ESMO 2018 wurden mehr Rückschläge als Erfolge berichtet.
Früherkennungs-Koloskopie
Authors: Grübler Dr. Beate
Published: February 2019

Durch die qualitätsgesicherte Koloskopie zur Früherkennung von Darmkrebs ist zwar die Karzinommorbidität und -mortalität gesunken, jedoch können sich zwischen den Screening- Untersuchungen Intervallkarzinome entwickeln. In der Gastroenterologischen Gemeinschaftspraxis Herne wurde den möglichen Gründen für die Entstehung eines Intervallkarzinomes nachgegangen.
MEK-Inhibition bei plexiformen Neurofibromen
Authors: Arnheim Dr. Katharina
Published: February 2019

Für Patienten mit plexiformen Neurofibromen stand bislang keine effektive medikamentöse Therapie zur Verfügung. In der SPRINT-Studie hat sich jetzt der MEK1/2- Inhibitor Selumetinib mit hohen Ansprechraten und einer Besserung funktioneller Parameter als erfolgreich erwiesen. Untermauert werden die Daten durch eine Studie zu Trametinib. Die Substanz hat in den USA einen Orphan Drug-Status.
Hirnmetastasen
Authors: Klein Friederike
Published: February 2019

Hirnmetastasen stellen die häufigste Form einer malignen Veränderung im Gehirn dar und betreffen bis zu einem Viertel aller Krebspatienten. Erst langsam wächst das Verständnis, wie sich die Hirnmetastasen genetisch aus dem Primärtumor entwickeln. Gleichzeitig wächst auch das Wissen über Zielstrukturen, die sich für eine Therapie eignen können. Erste Erfolge wurden auf dem ESMO-Kongress in München berichtet.
Rare Case of Surgical Treatment of a Giant Aortic Arch False Aneurysm
Authors: Shlomin Vladimir , Didenko Yury , Drozhzhin Igor , Puzdriak Petr , Bondarenko Pavel , Grebenkina Nadezhda
Published: February 2019

The authors present a clinical case of a 44-year-old male patient with a chronic giant aortic arch pseudoaneurysm with a diameter of 136 × 72 mm. The open resection of false aneurysm was accomplished without artificial circulation. Repair was performed with temporary ascending-to-descending and brachiocephalic bypass without cardiopulmonary bypass.
Radiologic and Intraoperative Finding of Intimal Tear in Type A Intramural Hematoma of the Aorta
Authors: Filippone Gianfranco , Caruana Giovanni , Moscaritolo Violetta , Vacirca Sara , Argano Vincenzo
Published: February 2019

Aortic intramural hematoma (IMH) is described as “dissection without intimal tear” due to rhexis of vasa vasorum, which results in bleeding within the tunica media in the absence of intimal disruption or blood flow communication. The aim of our study is to validate perioperative evidence of intimal entry tear in IMH patients and to suggest that this entity may represent a part of a disease and not a separate disease.
Blood Flow after Endovascular Repair in the Aortic Arch: A Computational Analysis
Authors: van Bakel Theodorus , Romarowski Rodrigo , Morganti Simone , van Herwaarden Joost , Moll Frans , de Beaufort Hector , Marrocco-Trischitta Massimiliano , Secchi Francesco , Conti Michele , Auricchio Ferdinando , Trimarchi Santi
Published: February 2019

Background The benefits of thoracic endovascular aortic repair (TEVAR) have encouraged stent graft deployment more proximally in the aortic arch. This study quantifies the hemodynamic impact of TEVAR in proximal landing zone 2 on the thoracic aorta and the proximal supra-aortic branches.

Methods Patients treated with TEVAR in proximal landing zone 2 having available preoperative and 30-day postoperative computer tomography angiography and phase-contrast magnetic resonance imaging data were retrospectively selected. Blood flow was studied using patient-specific computational fluid dynamics simulations.

Results Four patients were included. Following TEVAR in proximal landing zone 2, the mean flow in the left common carotid artery (LCCA) increased almost threefold, from 0.21 (0.12–0.41) L/min to 0.61 (0.24–1.08) L/min (+294%). The surface area of the LCCA had not yet increased commensurately and therefore maximum flow velocity in the LCCA increased from 44.9 (27.0–89.3) cm/s to 72.6 (40.8–135.0) cm/s (+62%). One of the patients presented with Type Ib endoleak at 1-year follow-up. The displacement force in this patient measured 32.1 N and was directed dorsocranial, perpendicular to the distal sealing zone. There was a linear correlation between the surface area of the stent graft and the resulting displacement force (p = 0.04).

Conclusion TEVAR in proximal landing zone 2 alters blood flow in the supra-aortic branches, resulting in increased flow with high flow velocities in the LCCA. High displacement forces were calculated and related to stent graft migration and Type I endoleak during 1-year follow-up.
Stability and band offsets between GaAs semiconductor and CeO2 gate dielectric
Authors: Wang Jianli , Xue Mengmeng , Liu Hao , Yuan Mengqi , Bai Dongmei , Tang Gang , Zhang Junting , Stampfl C.
Published: February 2019

Cerium oxide (CeO2) appears to be a promising candidate high-k dielectric material in GaAs-based metal-oxide-semiconductor field-effect transistors. The electronic properties of GaAs/CeO2 (001) heterojunctions are investigated by density functional theory. We determine the GaAs/CeO2 heterostructure from the initial adsorption of the Ga and As atoms on the CeO2 (001) surfaces. The surface formation energy indicates that oxygen or Ga atoms may replace Ce atoms at the Ce-terminated CeO2 surface, and Ce atoms may replace oxygen atoms at the O-terminated CeO2 surface. The band offsets, electronic density of states, and atomic charges are analyzed for the GaAs/CeO2 heterojunctions. The band offsets of the As-terminated GaAs/Ce-terminated CeO2 interface are suitable for the design of metal-oxide-semiconductor devices. The OCe defects induce a two-dimensional electron gas at the As-terminated GaAs/Ce-terminated CeO2 interface.
Fowler-Nordheim tunneling characteristics of graphene/hBN/metal heterojunctions
Authors: Iqbal Muhammad Zahir , Faisal Mian Muhammad
Published: February 2019

The heterostructures of low-dimensional materials are considered promising candidates for future electronic devices. In this work, we manifest the interlayer hexagonal boron nitride (hBN) thickness dependent tunneling characteristics of graphene/hBN/metal heterojunction back-gated field effect transistors (FETs). Direct tunneling of charge carriers through the ultrathin hBN layer is noticed at low bias voltages. Besides, Fowler-Nordheim tunneling takes place at high bias voltages revealing an increase in the barrier height with an interlayer film thickness. In addition, the back-gate dependent tunneling properties of graphene/hBN/metal heterojunction back-gated FETs are investigated. Furthermore, the Fermi level of graphene is tuned via back-gate voltages that results in the modification of the tunneling current, threshold voltage, and barrier height of the device. This could be an effective approach to modify the tunneling features of vertical heterostructures for their prospective role in next generation high performance electronic devices.
Three dimensional phase-field simulations on the frequency dependence of polarization vectors and hysteresis loops in ferroelectric crystals
Authors: Zhang Juanjuan , Fang Chao , Weng George J.
Published: February 2019

The phase field approach has been widely used to study the domain structure of ferroelectric crystals in both two and three dimensions (2D and 3D), but in the 3D case, little has been done to address the frequency dependence of ferroelectric characteristics. In this work, we adopt the 3D time-dependent Ginzburg–Landau kinetic equation to calculate the evolution of local polarization vectors and the overall hysteresis loops of ferroelectric crystals under the frequencies from 0.4 kHz to 120 kHz, and then use the fast Fourier transform to analyze the frequency characteristics of the polarizations. It shows the phenomenon of multiple frequencies at low field frequency but not at high one. The distribution and evolution of polarization vectors in x, y, and z directions are obtained, and various forms of electrical hysteresis loops are found from the average of local polarization vectors. The results indicate that, as the frequency increases, the hysteresis loops of Pz versus Ez change from the standard shape to the oval shape, but the loops for Px and Py change from the dumbbell shape to an oblique ellipse, and then to figure-eight curve and eventually to the superparaelectric one. The detailed distribution and evolution of the polarization vectors in the crystal are also vividly displayed. Finally, the effects of lattice size, amplitude of the applied field, depolarization energy, and the initial state of polarizations in the crystal are investigated. It shows that the nature of polarization evolution in a 3D crystal is highly complex and that each of these factors can have a significant effect.
Reynolds number effects on the flow over a twisted cylinder
Authors: Yoon Hyun Sik , Kim Min Il , Kim Hyo Ju
Published: February 2019

We investigated the Reynolds number (Re) effects on the flow statics over a helically twisted elliptical (HTE) cylinder in the range of 3 × 103 ≤ Re ≤ 1 × 104 using large eddy simulation. For comparison, a smooth cylinder was also considered. The present flow statistics for the smooth cylinder are quite consistent with previous findings at Reynolds numbers of Re = 3900/4000 and 10 000 that were obtained by combining particle image velocimetry measurements and direct numerical simulations [Dong et al., “A combined direct numerical simulation-particle image velocity study of the turbulent near wake,” J. Fluid Mech. 569, 185–207 (2006)]. The mean drag and root mean square (RMS) lift coefficients had almost linear relations with Re. The HTE geometry showed more effective performance for the reduction of the drag and the RMS lift coefficients with increasing Re. The RMS streamwise velocity for the HTE cylinder appeared different from that of the smooth cylinder. The HTE cylinder lacked RMS streamwise velocity behind the cylinder base, indicating small magnitudes of the fluctuations. In general, the tip of the mean vorticity layer for the HTE cylinder is thinner than that for the smooth cylinder. The thickness of mean vorticity layer depends on the spanwise direction rather than Re. Also, the tips of contours of the Reynolds stress are much sharper with increasing Re and approach the separation position of the cylinder surface. The elongated vortex formation length decreases almost linearly with Re.
Molecular orientational distribution function of a chiral de Vries smectic liquid crystal from birefringence measurements
Authors: Swaminathan V. , Panov V. P. , Kocot A. , Vij J. K.
Published: February 2019

An alternative method for determining the orientational distribution function and the order parameter from the electric field-induced birefringence measurements of a chiral liquid crystal compound in its Smectic A* is being introduced. A chiral mesogen based on a 5-phenyl-pyrimidine benzoate core terminated by a trisiloxane group on one side and the chiral alkyloxy chain on its opposite side is designed and synthesized to exhibit the “de Vries” smectic characteristics. The compound exhibits first order Smectic A*–Smectic C* phase transition, evidenced by the results of differential scanning calorimetry. The material is being investigated by electro-optical experiment in its smectic phases. We present a model that incorporates the generalised Langevin-Debye model which includes the Maier-Saupe effective mean-field potential term in order to explain the change in birefringence with the electric field. A good agreement between the experimental results and the predictions from the model leads to the determination of the molecular orientational distribution function in Smectic A phase. Furthermore, the temperature dependency of the Saupe orientational order parameter ⟨P2⟩ is obtained using the parameters of the model. Based on the experimental and theoretical results, we show that de Vries Smectic A* phase exhibits a broad volcano-like tilt angle distribution with the two maxima occurring at finite tilt angles closer to the Smectic A*–Smectic C* transition temperature, and a sugarloaf-like distribution occurs in the tilt for temperatures close to the Isotropic—Smectic A* phase transition.
Understanding the validity of impedance and modulus spectroscopy on exploring electrical heterogeneity in dielectric ceramics
Authors: Huang Yuwei , Wu Kangning , Xing Zhaoliang , Zhang Chong , Hu Xiangnan , Guo Panhui , Zhang Jingyuan , Li Jianying
Published: February 2019

Combined modulus and impedance spectra are widely employed to explore electrical inhomogeneity and carriers' behaviors in dielectric ceramics based on equivalent circuit. However, discrepancies are found between practical dielectric responses and widely proposed equivalent circuits. Taking ZnO varistor ceramics as an example, a low-frequency dielectric relaxation, which can be detected in practical dielectric spectroscopy, is overlooked in simulated dielectric spectroscopy based on the proposed equivalent circuit according to modulus and impedance spectra. Therefore, equivalent circuits are frequently incomplete because the real low-frequency dielectric response is unable to be characterized from them. The problem originates from debatable understanding of frequency responses in modulus and impedance spectra. The low-frequency peak in modulus spectroscopy is proved originating from DC conductance instead of a real dielectric relaxation and the involvement of DC conductance component makes a low-frequency dielectric relaxation unable to be characterized in modulus spectroscopy. Therefore, improved dielectric spectroscopy eliminating the component of DC conductance is proposed and a clear peak corresponding to the low-frequency dielectric relaxation appears. In addition, a modified equivalent circuit which is in accordance with practical dielectric responses in not only modulus and impedance spectra but also dielectric spectroscopy is presented.
Hybrid magnetic and deformability based isolation of circulating tumor cells using microfluidics
Authors: Chen Hongmei , Zhang Zhichao , Liu Hailian , Zhang Zhifeng , Lin Changming , Wang Bin
Published: February 2019

Circulating tumor cell (CTC) and their isolation is one potential clinically useful target within a “liquid biopsy”. Detection and characterization of CTCs provide a non-invasive approach for monitoring cancer therapy. In the present research, a magnet- deformability hybrid integrated microfluidic chip was designed to enumerate CTCs. Arrays of narrow gaps (patterned by micro-ellipse microposts) were designed to capture CTCs bonded with magnetic immune beads. Eleven samples, including Gastric of Colorectal, non-small-cell lung cancer (NSCLC), Ureter cancer, and Breast cancer, were used to validate the microfluidic device clinically. Clinical test results show a high capture efficiency (over 90% at 3ml/h) and high viability (96%) at high flow rate. Furthermore, comparisons of device performance with and without magnet beads were also conducted. This hybrid chip design demonstrated excellent performance in the clinical enumeration of CTCs, which is promising in the future cancer therapy evaluation.
State-to-state quasi-classical trajectory study of the D + H2 collision for high temperature astrophysical applications
Authors: Bossion Duncan , Scribano Yohann , Parlant Gérard
Published: February 2019

We report state-to-state quasi-classical trajectory rate constants for the D + H2 reactive collision, using the accurate H3 global potential energy surface of Mielke et al. [J. Chem. Phys. 116, 4142 (2002)]. High relative collision energies (up to ≈56 000 K) and high rovibrational levels of H2 (up to ≈50 000 K), relevant to various astrophysical media, are considered. The HD product molecule is formed in highly excited rovibrational states, over a wide collision energy range. The collision-induced dissociation channel (often overlooked in fully quantum reaction dynamics calculations) is found to be significantly populated, even at collision energies as low as 1500 K.
Scales of natural convection on a convectively heated vertical wall
Authors: Nie Bingchuan , Xu Feng
Published: February 2019

Natural convection on a convectively heated vertical wall, one of the fundamental issues of heat and mass transfer in many engineering applications, is investigated in this work. The configuration is governed by the Rayleigh number (RaL or Ra), the Prandtl number (Pr), and the non-dimensional convective heat transfer coefficient (CiL or Ci). A scaling analysis for the dynamics of the boundary layer flow and heat transfer is carried out. The scales of the velocity/thickness of the boundary layer flow and the temperature/thickness of the thermal boundary layer related to the non-dimensional governing parameters are obtained. The scales are validated using the numerical results by large eddy simulation. The results show that the non-dimensional velocity of the boundary layer flow is proportional to CiL2/5RaL2/5; the thickness from the wall to the layer of the maximal velocity is inversely proportional CiL1/5RaL1/5; the non-dimensional thickness of the thermal boundary layer is inversely proportional CiL1/5RaL1/5; the non-dimensional temperature in the thermal boundary layer is proportional to CiL4/5RaL−1/5. The reduction factor describing the thermal resistance of the thermal boundary layer is further discussed, which is proportional to Ci4/5Ra−1/5.
An improved analytical model for the statistics of SET emergence point in HfO2 memristive device
Authors: Xiang Dong , Zhang Rulin , Li Yu , Ye Cong , Miranda Enrique , Suñé Jordi , Long Shibing
Published: February 2019

In this work, an improved analytical model for the SET switching statistics of HfO2 memristive device is developed from the cell-based percolation model. The statistical results of the SET emergence point related to the beginning stage during SET process are systematically discussed. Moreover, the deviation from Weibull model in high percentiles region is found to originate from the uneven distribution of defect density. Our improved model exhibits excellent consistency with experimental results in Cu/HfO2/Pt device. Besides, we explain the relationship between the parameters of the model and SET resistance. The underlying mechanism of SET process for HfO2 memristive device is fully illuminated.
Heritabilities of IgA and IgE activities against Teladorsagia and Trichostrongylus L3 larval antigens correlated with traits for faecal worm egg count, health and productivity in Merino sheep
Authors: Zhao Zhongquan , Wang Mengzhi , Liu Shimin , Palmer Dieter , Shaw Richard , Karlsson John , Vercoe Philip E. , Martin Graeme B. , Greeff Johan
Published: February 2019

Low faecal worm-egg count (FEC) has been used as a phenotypic trait for breeding sheep for resistance to nematode infection. Application of this trait has resulted in a major reduction in worm-egg output in faeces, but in certain environments some of the resistant sheep develop what is believed to be a hypersensitivity-associated diarrhoea, resulting in soiling of the breech area (dags). To avoid breeding sheep with a propensity to scour, it, therefore, seems logical to combine selection for low FEC with selection for a trait based on the immune response to worm infection. We, therefore, investigated the relationships between immunoglobulin A (IgA) and immunoglobulin E (IgE) activities against L3 larval antigens of Teladorsagia circumcincta and Trichostrongylus colubriformis and measured their inheritance and their genetic relationships with FEC, dag traits and measures of production. Total plasma IgE concentrations were also determined and included in the study. We used 762 progeny from 23 Merino sires selected for resistance to helminths (the ‘Rylington Flock’) and to breech flystrike. Total plasma IgE and IgE activities against T. circumcincta were negatively correlated with liveweight, longissimus dorsi muscle depth, and fleece weight, but positively correlated with severity of dags, softer faeces and back-fat depth. The IgA activity against T. circumcincta was negatively correlated with liveweight and clean fleece weight, but positively correlated with back-fat depth and faecal consistency score. The IgA activity against T. colubriformis was not correlated with any measure, except the breeding value for dags around yearling age. The heritability for the IgA activity against T. circumcincta and T. colubriformis was 0.13 and 0.08 respectively. The heritability for both IgE activity against T. circumcincta and total plasma IgE concentration was 0.39. We conclude that it is feasible to combine FEC and dag traits with an immune trait (in this case, helminth-specific IgE activity and total plasma IgE concentration) and, thus, genetically select sheep for resistance to both helminths and diarrhoea. However, under natural worm-challenge conditions, blood sampling protocols need to developed, on the basis of animal age, season and environment, for optimum estimation of the immune trait and its relationships with other traits.
Unleashing floret fertility in wheat through the mutation of a homeobox gene
Authors: Sakuma Shun , Golan Guy , Guo Zifeng , Ogawa Taiichi , Tagiri Akemi , Sugimoto Kazuhiko , Bernhardt Nadine , Brassac Jonathan , Mascher Martin , Hensel Goetz , Ohnishi Shizen , Jinno Hironobu , Yamashita Yoko , Ayalon Idan , Peleg Zvi , Schnurbusch Thorsten , Komatsuda Takao
Published: February 2019

Floret fertility is a key determinant of the number of grains per inflorescence in cereals. During the evolution of wheat (
Triticum
sp.), floret fertility has increased, such that current bread wheat (
Triticum aestivum
) cultivars set three to five grains per spikelet. However, little is known regarding the genetic basis of floret fertility. The locus
Grain Number Increase 1
(
GNI1
) is shown here to be an important contributor to floret fertility.
GNI1
evolved in the Triticeae through gene duplication. The gene, which encodes a homeodomain leucine zipper class I (HD-Zip I) transcription factor, was expressed most abundantly in the most apical floret primordia and in parts of the rachilla, suggesting that it acts to inhibit rachilla growth and development. The level of
GNI1
expression has decreased over the course of wheat evolution under domestication, leading to the production of spikes bearing more fertile florets and setting more grains per spikelet. Genetic analysis has revealed that the reduced-function allele
GNI-A1
contributes to the increased number of fertile florets per spikelet. The RNAi-based knockdown of
GNI1
led to an increase in the number of both fertile florets and grains in hexaploid wheat. Mutants carrying an impaired
GNI-A1
allele out-yielded WT allele carriers under field conditions. The data show that gene duplication generated evolutionary novelty affecting floret fertility while mutations favoring increased grain production have been under selection during wheat evolution under domestication.
The nature of recollection across months and years and after medial temporal lobe damage
Authors: Heyworth Nadine C. , Squire Larry R.
Published: February 2019

Significance

When memory-impaired patients with medial temporal lobe (MTL) damage recollected the events of a guided walk, their memory was not only impoverished and lacking in detail but was also characterized by peculiarities in language use. However, as time passed after learning (up to 2.6 years), the recollections of healthy volunteers came to exhibit many of the same features with respect to both the richness of memory and language use. Thus, the characteristics of patient recollections appeared as a consequence of weak memory. The patients differed markedly from controls tested after long delays in that they reported events of the walk in a haphazard order. The results illuminate the nature of memory impairment and the function of the MTL.
Propositional information loss in English-to-Chinese simultaneous conference interpreting
Authors: Lu Xinchao
Published: February 2019

Simultaneous Interpreting (SI) as a profession has been gaining momentum in China, but little has been researched on Chinese professional conference interpreting on a basis of large quantity of empirical data. This study adopts an information-based SI fidelity assessment approach to probe into the propositional information loss in an SI corpus of seventeen English(B)-Chinese(A) simultaneous interpreters’ interpretations, and through stimulated retrospective interviews of three conference interpreters. Results show that operational constraints (concurrent listening and speaking, time constraint and incremental processing), source language factors (speed, information density, accent, linguistic complexity, technicality, etc) and interpreting direction (B to A), etc, account for typical propositional omission, incompletion or error.
From a “pornographic” book to a classic
Authors: Bai Ge
Published: February 2019

This article aims to investigate the relationship between paratexts and the translation product with a case study of Lolita translations in China. Since Lolita has been one of the most frequently retranslated literary works in China over the past three decades, it can serve as a bellwether of the changes that have taken place in the translation field as well as those in the social, cultural and historical context. Therefore, a comparative study of the paratextual elements of Lolita translations acts as a reflection of the negotiations between the translation activity and the changing socio-political context. The analysis of paratexts locates translation as a social activity in which many agents are involved other than simply the translator and the source text. Through their organic integration with the translation products, the paratextual elements, functioning as genre indicators, work to promote the translation while potentially predicting its target readership. In the translation and retranslation of the same source text, a discussion of the paratexts may provide new insights into understanding the relationship between translations and retranslations as well as the evolution of the translation field in relation to Chinese society.
Emerging viruses in marine mammals.
Authors: Bossart G. D. , Duignan P. J.
Published: February 2019

Emerging infectious disease has become a serious concern that has consequences for human, animal and environmental health on a global scale. During the past two decades, it has become clear that viruses are emerging in terrestrial environments from the human-animal interface at an unprecedented rate. Thus, the understanding of complex diseases associated with emerging zoonotic pathogens and the creation and execution of strategies to deal with this issue has assumed new public health importance, requiring a One Health approach involving multiple health disciplines. Similar infectious disease trends involving emerging viruses are now being documented in aquatic ecosystems and are impacting marine mammals. As in terrestrial species, emerging viruses in marine mammals may be associated with neoplasia, epizootics and zoonotic disease and involve a complex pathogenesis involving noninfectious cofactors such as anthropogenic toxins, biotoxins, immunologic suppression and other environmental stressors. Among the viruses recently isolated from marine mammals are influenza viruses, morbilliviruses, papillomaviruses, herpesviruses, arboviruses, caliciviruses and others. Many of these emerging marine mammal viruses are associated with disease and specific pathologic findings. In other cases, the disease significance of these novel viruses is unknown and requires further research. In this report, we briefly review emerging viruses that have disease significance for marine mammals and/or public health. Novel concurrent clinicopathologic data will be presented when available broadening the understanding of disease pathogenesis. References will help provide more in-depth information. Additionally, this review has demonstrated that marine mammals may be important sentinel animals that indicate environmental health concerns and parallel emerging public health issues.
Investigation of liquid metal embrittlement of dual phase steel joints by electro-thermomechanical spot-welding simulation
Authors: Frei Julian , Biegler Max , Rethmeier Michael , Böhne Christoph , Meschut Gerson
Published: February 2019

A 3D electro-thermomechanical model is established in order to investigate liquid metal embrittlement. After calibration to a dual phase steel of the 1000 MPa tensile strength class, it is used to analyse the thermo-mechanical system of an experimental procedure to enforce liquid metal embrittlement during resistance spot welding. In this procedure, a tensile stress level is applied to zinc coated advanced high strength steel samples during welding. Thereby, liquid metal embrittlement formation is enforced, depending on the applied stress level and the selected material. The model is suitable to determine and visualise the corresponding underlying stresses and strains responsible for the occurrence of liquid metal embrittlement. Simulated local stresses and strains show good conformity with experimentally observed surface crack locations.
Lattice point problems involving index and joint visibility
Authors: Chaubey Sneha , Tamazyan Albert , Zaharescu Alexandru
Published: February 2019

We study questions concerning the distribution of lattice points in dimensions two and higher. We give asymptotic formulas for the number of integer lattice points of fixed index visible from certain admissible sets. We also study the shape of the body

P

A
1

,
…
,
P

A
k

PA_1, \dots , PA_k

when the lattice points

A
1

,
…
,

A
k

A_1, \dots , A_k

move inside a given large ball, and

P
P

is a lattice point visible from all

A
i

A_i

’s.
On the eventual local positivity for polyharmonic heat equations
Authors: Ferreira Lucas , Ferreira Jr. Vanderley
Published: February 2019

In this paper we show the eventual local positivity property for higher-order heat equations (including noninteger order). As a consequence, we give a positive answer for an open problem stated by Barbatis and Gazzola [Contemp. Math. 594 (2013)] for polyharmonic heat equations. Moreover, we obtain some polynomial decay properties of solutions.
A note on discrete spherical averages over sparse sequences
Authors: Cook Brian
Published: February 2019

This note presents an example of an increasing sequence

(

λ
l

)

l
=
1

∞

(\lambda _l)_{l=1}^\infty

such that the maximal operators associated to the normalized discrete spherical convolution averages
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="sup Underscript l greater-than-or-equal-to 1 Endscripts StartFraction 1 Over r left-parenthesis lamda Subscript l Baseline right-parenthesis EndFraction StartAbsoluteValue sigma-summation Underscript StartAbsoluteValue x EndAbsoluteValue squared equals lamda Subscript l Baseline Endscripts f left-parenthesis y minus x right-parenthesis EndAbsoluteValue comma">

sup

l
≥
1

1

r
(

λ
l

)

|

∑

|

x

|

2

=

λ
l

f
(
y
−
x
)
|

,

\sup _{l\geq 1}\frac {1}{r(\lambda _l)}\left |\sum _{|x|^2=\lambda _l}f(y-x)\right |,

\]
defined for functions

f
:

Z

n

→

C

f:\mathbb {Z}^n\to \mathbb {C}

, are bounded on

ℓ
p

\ell ^p

for all

p
>
1

p>1

when the ambient dimension

n
n

is at least five.
Area estimates and rigidity of non-compact 𝐻-surfaces in 3-manifolds
Authors: Lima Vanderson
Published: February 2019

For appropriate values of

H
H

, we obtain an area estimate for a complete non-compact

H
H

-surface of finite topology and finite area, embedded in a 3-manifold of negative curvature. Moreover, in the case of equality and under additional assumptions, we prove that a neighborhood of the mean convex side of the surface must be isometric to a hyperbolic Fuchsian manifold. Also, we provide a counterexample showing that, in the case of minimal surfaces, equality in the area estimate does not necessarily imply a local rigidity result for the ambient manifold.
Closed-form solutions to irreducible Newton-Puiseux equations by Lagrange inversion formula and diagonalization on polynomial sequences of binomial-type
Authors: Yoon Soowhan
Published: February 2019

In a recent article published in 2017, Barroso, Pérez, and Popescu-Pampu employ the Lagrange inversion formula to solve certain Newton-Puiseux equations when the solutions to the inverse problems are given. More precisely, for an irreducible

f
(
x
,
y
)
∈
K
[
[
x
,
y
]
]

f(x,y)\in K[[x,y]]

over an algebraically closed field

K
K

of characteristic zero, they calculate the coefficients of

η
(

x

1

/

n

)

\eta (x^{1/n})

which would meet

f
(
x
,
η
(

x

1

/

n

)
)
=
0

f(x,\eta (x^{1/n}))=0

in terms of the coefficients of

ξ
(

y

1

/

m

)

\xi (y^{1/m})

that satisfy

f
(
ξ
(

y

1

/

m

)
,
y
)
=
0

f(\xi (y^{1/m}),y)=0

. This article will present an alternative approach to solving the problem using diagonalizations on polynomial sequences of binomial-type. Along the way, a close relationship between binomial-type sequences and the Lagrange inversion formula will be observed. In addition, it will extend the result to give the coefficients of

η
(

x

1

/

n

)

\eta (x^{1/n})

directly in terms of the coefficients of

f
(
x
,
y
)

f(x,y)

. As an application, an infinite series formula for the roots of complex polynomials will be obtained together with a sufficient condition for its convergence.