bluuebunny/crossref_metadata_2025 huggingface dataset:
Schwere Nahrungsmittelallergien – ist eine Toleranzinduktion möglich?
Authors: Meister Jochen , Nemat Katja
Published: October 2020

Die Standardtherapie bei schweren Nahrungsmittelallergien (NMA) umfasst Karenzdiät, Ernährungsberatung sowie Ausstattung mit Notfallmedikamenten und Schulung in den Notfallplan. Aufgrund der starken Einschränkung der Lebensqualität von Patienten mit schwerer Nahrungsmittelallergie sind kausale Therapieansätze wünschenswert, die eine orale Toleranz aktiv induzieren. In den letzten zwei Jahrzehnten wurden verschiedene Applikations-Routen (sublingual, oral, epikutan) einer spezifischen Immuntherapie bei Patienten mit Hühnerei-, Kuhmilch- und Erdnussallergie untersucht. Aktuelle Studien konzentrierten sich vor allem auf die orale Immuntherapie (OIT) mit Erdnuss und zeigten, dass die klinische Reaktionsschwelle durch eine wiederholte Zuführung definierter Allergenmengen tatsächlich angehoben werden konnte. Kürzlich hat die US-amerikanische Arzneimittelbehörde das Erdnuss-Pulver Palforzia als erstes Therapeutikum für Nahrungsmittelallergien bei Kindern und Jugendlichen zugelassen. Jedoch ist die Erdnuss-OIT auch mit systemischen Nebenwirkungen assoziiert. Eine Niedrigdosis-OIT zeigte ein besseres Sicherheitsprofil. Zusätzliche Studien mit direktem Vergleich verschiedener Allergendosen und Dosissteigerungs-Protokolle sind notwendig. Weiterhin müssen Langzeit-Wirksamkeit und Kosteneffektivität verschiedener Ansätze zur Induktion oraler Toleranz bewertet werden.
Compliance von Hunde- und Katzenbesitzern in der Gesundheitsvorsorge
Authors: Eschle Simone , Hartmann Katrin , Bergmann Michèle
Published: October 2020

Die regelmäßige Gesundheitsvorsorge ist ein wesentlicher Bestandteil der Gesundheit und Lebensqualität unserer Haustiere. Durch Vorsorgeuntersuchungen kann der Entstehung von Krankheiten vorgebeugt werden und bestehende gesundheitliche Probleme lassen sich frühzeitig erkennen und behandeln. Ausschlaggebend für das Erreichen einer optimalen Gesundheitsvorsorge ist, neben der tierärztlichen Beratung, vor allem die Compliance der Besitzer. Hunde- und Katzenbesitzer scheinen sich der Notwendigkeit von Vorsorgeuntersuchungen jedoch oftmals nicht bewusst zu sein, und dies leider häufig infolge einer mangelhaften Kommunikation durch den Tierarzt. Aufklärungsgespräche über die Notwendigkeit regelmäßiger Gesundheitsvorsorgeuntersuchungen sind daher essenziell. Die Kommunikation stellt einen der Schlüsselfaktoren für den Aufbau einer Besitzer-Tierarzt-Beziehung dar. Tierärzte sollten sich ausreichend Zeit für die Kommunikation nehmen, sich ihrer verbalen und nonverbalen Aussagen bewusst sein und Besitzer in Behandlungsentscheidungen einbeziehen. Ältere Tiere werden seltener zur Gesundheitsvorsorge vorgestellt als jüngere Tiere, obwohl in zunehmendem Alter die Prävalenz altersbedingter und chronischer Krankheiten steigt. Daher sollte Besitzern vermittelt werden, dass eine frühzeitige Erkennung und Behandlung dieser Krankheiten die Gesundheit und Lebensdauer ihrer Tiere steigert. Katzenbesitzer stellen ihre Tiere seltener zur Gesundheitsvorsorge vor als Hundebesitzer; vielen von ihnen scheint nicht bewusst zu sein, dass Katzen häufig Krankheitssymptome verbergen. Ein weiterer Grund ist, dass viele Katzen das Einfangen, der Transport und der Besuch in der Praxis stresst. Tierärzte könnten Katzenbesitzer über stressreduzierende Transportmaßnahmen aufklären und ihre Praxis katzenfreundlicher gestalten. Durch geeignetes Praxismanagement, z. B. die Möglichkeit monatlicher Ratenzahlungen, das Anbieten jährlicher Vorsorgepläne sowie eine konsequentere Terminvereinbarung, lässt sich die Compliance ebenfalls positiv beeinflussen. Neben einer verbesserten Tiergesundheit kann dies auch zu einer höheren Zufriedenheit der Besitzer führen.
Assessment in der Betrieblichen Gesundheitsförderung
Authors: Huber Gerhard , Weiß Klaus
Published: October 2020

Mit dem Präventionsgesetz wurde dem Betrieb als herausgehobenes Setting der Gesundheitsförderung für erwachsene Menschen Rechnung getragen. Leider erfolgt die Umsetzung der betrieblichen Gesundheitsförderung eher nach den Prinzipien von Glaube und Hoffnung als nach einer validen Erfassung des jeweiligen Bedarfs oder gar der Wirksamkeit der Interventionen. Wenn Daten genutzt werden, so sind dies sehr häufig die von den Krankenkassen gelieferten Daten zum Arbeitsunfähigkeitsgeschehen. Diese haben aber nur eingeschränkte Aussagekraft. Wir plädieren in dem Beitrag deshalb für eine differenzierte Lösung, die die AU-Daten mit Befragung und qualitativen Analysen verbinden. Die mehrperspektivische Verbindung solcher Daten mit AU-Daten und qualitativen Analysen liefert nach unserer Einschätzung ein geeignetes Assessment für die betriebliche Gesundheitsförderung.
Hymenopterengiftallergie – Wer kann wann sein Notfallset ablegen oder lieber nicht?
Authors: Treudler Regina , Simon Jan C.
Published: October 2020

Schwere Soforttypreaktionen aufgrund einer Hymenopterengiftallergie (HGA) sollen mit einer intramuskulären Adrenalingabe behandelt werden. Die Indikation zur Verordnung eines Adrenalin-Autoinjektors (AAI) besteht bei Patienten, die an Mastzellerkrankungen leiden, eine erhöhte Serumtryptase haben und/oder bei Patienten ohne Venomimmuntherapie (VIT), bei denen mindestens zwei Organsysteme betroffen waren. Die Verordnung eines AAI kann ebenfalls in weiteren Risikosituationen vor, während oder nach Ende einer VIT erwogen werden.
Veränderungen der Klauen- und Gliedmaßengesundheit sowie Haarkortisolkonzentration von Milchkühen bei der Umstellung von Anbinde- auf Laufstallhaltung
Authors: Nuss Karl , Nogler Simon , Lüchinger Isabelle , Hässig Michael , Pieper Laura , Knubben-Schweizer Gabriela
Published: October 2020

Gegenstand und Ziel Bei einer Milchkuhherde, die von Anbinde- in Laufstallhaltung umgestallt wurde, sollten die Veränderungen der Klauengesundheit, die der Schädigungen der Karpal- und Tarsalgelenke sowie der mit der Umstallung verbundene Stress untersucht werden.

Material und Methoden Bei 4 Betriebsbesuchen im Abstand von 4–5 Monaten erfolgte bei initial 57 Milchkühen eine Befunderhebung im Klauenstand. Unterschieden wurde zwischen Klauenhorn- und Klauenhauterkrankungen sowie Schädigungen von Karpus und Tarsus. Beim 2. Besuch wurden einige Schwanzhaare abgeschnitten und deren Kortisolgehalt in 3 Segmenten analysiert.

Ergebnisse Die schon in der Anbindehaltung hohe Prävalenz der Hauterkrankungen veränderte sich im Untersuchungszeitraum nicht (49 % beim 1. Besuch, 46 % beim letzten Besuch). Die Ballenhornfäule betraf im Anbindestall nur wenige (14 %) und zuletzt alle Kühe (100 %). Die Prävalenz der sonstigen Schäden des Hornschuhs nahm tendenziell ab. Nach der Umstallung kam es zu einer signifikanten Reduktion der Häufigkeit und Ausprägung der Karpal- und Tarsalschäden. Die Haarkortisolkonzentration war im Zeitraum der Umstallung sowie im Laufstall signifikant höher als im Anbindestall.

Diskussion und Schlussfolgerung Unter der Vielzahl der beeinflussenden Faktoren hatten wahrscheinlich die bequemen Liegeboxen und die Gummilaufflächen den größten positiven Einfluss auf die Gesundheit der Karpal- und Tarsalgelenke. Die wechselnde Häufigkeit der Klauenhornschäden zeigte, dass diesbezüglich eine ständige Kontrolle erforderlich ist. Der Verlauf der Kortisolkonzentration kann auf erhöhtem Stress im Laufstall, jedoch auch auf einem ein „Auswascheffekt“ aus den älteren Haarsegmenten beruhen.

Klinische Relevanz Die Verhältnisse der untersuchten Aufstallungsformen lassen sich nur bedingt auf andere Betriebe übertragen. Anhand der Besserung von Karpal- und Tarsalschäden wird jedoch die entscheidende Bedeutung des Kuhkomforts ersichtlich. Der signifikante Anstieg der Prävalenz der Ballenhornfäule weist auf die Schwächung des Hornschuhs im Laufstallmilieu hin.
Tiotropium in der Asthmatherapie – was sind die Effekte und wirkt es auch antientzündlich?
Authors: Vogelberg Christian
Published: October 2020

Mit der Substanz Tiotropium existiert eine weitere Behandlungsoption bei Asthma bronchiale, die in mehreren pädiatrischen Studien eine deutliche Verbesserung der Lungenfunktion bei zusätzlicher Gabe zur Dauertherapie gezeigt hat und zudem über ein sehr gutes Sicherheitsprofil verfügt. In der aktuellen Auflage der Nationalen Versorgungsleitlinie Asthma bronchiale wird daher nun die zusätzliche Behandlung mit Tiotropium ab der Therapiestufe 4 empfohlen, wenn eine unzureichende Asthmakontrolle unter mitteldosiertem inhalativem Steroid + LABA und/oder LTRA vorliegt. Diese Therapieoption sollte unbedingt beachtet und umgesetzt werden, bevor eine weitere Dosissteigerung des inhalativen Steroids erfolgt.
Wenn die Begriffe nicht stimmen
Authors: Wildner Manfred
Published: October 2020

Vom chinesischen Philosophen Konfuzius – Meister Kong – ist uns ein bemerkenswertes Gespräch überliefert: „Dsï Lu sprach: Der Fürst von We wartet auf den Meister, um die Regierung auszuüben. Was würde der Meister zuerst in Angriff nehmen? Der Meister sprach: Sicherlich die Richtigstellung der Begriffe. […] Wenn die Begriffe nicht richtig sind, so stimmen die Worte nicht; stimmen die Worte nicht, so kommen die Werke nicht zustande; kommen die Werke nicht zustande, so gedeiht Moral und Kunst nicht; gedeiht Moral und Kunst nicht, so treffen die Strafen nicht; treffen die Strafen nicht, so weiß das Volk nicht, wohin Hand und Fuß setzen. […] Der Edle duldet nicht, dass in seinen Worten irgend etwas in Unordnung ist. Das ist es, worauf alles ankommt“ 1.
Appropriate use criteria for dementia amyloid imaging in Switzerland – mini-review and statement on behalf of the Swiss Society of Nuclear Medicine and the Swiss Memory Clinics
Authors: Juengling Freimut Dankwart , Allenbach Gilles , Bruehlmeier Matthias , Klaeser Bernd , Wissmeyer Michael Peter , Garibotto Valentina , Felbecker Ansgar , Georgescu Dan
Published: October 2020

While FDG-PET imaging of the brain for the differential diagnosis of dementia has been covered by the compulsory health insurance in Switzerland for more than a decade, beta-amyloid-PET just recently has been added to the catalogue of procedures that have been cleared for routine use, provided that a set of appropriate use criteria (AUC) be followed. To provide guidance to dementia care practitioners, the Swiss Society of Nuclear Medicine and the Swiss Memory Clinics jointly report a mini-review on beta-amyloid-PET and discuss the AUC set into effect by the Swiss Federal Office of Public Health, as well as their application and limitations.
Modular Synthesis of Streptogramin Antibiotics
Authors: Li Qi , Seiple Ian B.
Published: October 2020

Streptogramins are antibiotics produced by several species of Streptomyces bacteria that are used in both human and veterinary medicine. Group A streptogramins comprise 23-membered macrocyclic polyketide/nonribosomal peptide hybrids for which several innovative fully synthetic routes have been developed. Herein we describe in detail our scalable routes to natural Group A streptogramins and we compare these routes to other reported syntheses.
Oral Contraceptives and Venous Thromboembolism: Focus on Testing that May Enable Prediction and Assessment of the Risk
Authors: Douxfils Jonathan , Morimont Laure , Bouvy Céline
Published: October 2020

Combined oral contraceptives (COCs) induce several changes in the levels of coagulation factors. The levels of procoagulant factors are often increased, while levels of anticoagulant factors are decreased. Fibrinolysis is also affected, even if the effect seems to be more counterbalanced by opposite regulation of profibrinolytic and antifibrinolytic factors. These effects on hemostasis are more pronounced with third- or fourth-generation COC compared with second-generation COC. Venous thromboembolism (VTE) risk increases when multiple risk factors, including genetic and environmental, are present simultaneously. COC use causes changes in coagulation that modify the prothrombotic state induced by preexisting hemostatic alterations in a supra-additive manner. Therefore, testing appears to be of importance not only before implementing COC but also to monitor any potential thrombogenicity induced by COC therapy. Inherited genetic factors, such as factor V Leiden, G20210A prothrombin mutation, antithrombin, protein C or protein S deficiencies, non-O blood group, as well as CYP2C9*2 and the rs4379368 mutations, have all been identified as genetic predictive risk factors of VTE in women. Nevertheless, the screening of these genetic biomarkers is not capable of assessing the phenotypic expression of the risk. This review will focus on the different options for screening the thrombogenic status in this population. Specific attention will be given to the endogenous thrombin potential-based activated protein C resistance, a test aiming at assessing the thrombogenicity induced by hormonal therapies and inherited or acquired thrombophilia.
Thiamine Treatment and Favorable Outcome in an Infant with Biallelic TPK1 Variants
Authors: Eckenweiler Matthias , Mayr Johannes A. , Grünert Sarah , Abicht Angela , Korinthenberg Rudolf
Published: October 2020

Episodic encephalopathy due to mutations in the thiamine pyrophosphokinase 1 (TPK1) gene is a rare autosomal recessive metabolic disorder. Patients reported so far have onset in early childhood of acute encephalopathic episodes, which result in a progressive neurologic dysfunction including ataxia, dystonia, and spasticity. Here, we report the case of an infant with TPK1 deficiency (compound heterozygosity for two previously described pathogenic variants) presenting with two encephalopathic episodes and clinical stabilization under oral thiamine and biotin supplementation. In contrast to other reported cases, our patient showed an almost normal psychomotor development, which might be due to an early diagnosis and subsequent therapy.
The Male Is Significantly Implicated as the Cause of Unexplained Infertility
Authors: Aitken Robert John
Published: October 2020

Male infertility is recognized as a relatively common, complex condition, generated by a broad array of environmental and genetic factors. Historical reliance on the conventional semen profile has tended to underestimate the true contribution of “the male factor” to human infertility. This review highlights the importance of genetic and epigenetic factors in the etiology of male infertility, identifying a range of mutations responsible for primary testicular failure and impaired fertilizing potential. More than three quarters of all de novo mutations arise in the male germline via mechanisms that involve the inefficient or defective repair of DNA damage. Understanding the range of factors capable of creating genetic turmoil in the paternal germline is essential, if we are to gain a deep understanding of the causes of male infertility, rather than just the symptoms that characterize its presence. High levels of DNA fragmentation induced by oxidative stress are part of this equation. Oxidative stress is, in turn, driven by biological (age, ejaculation frequency, varicocele, infection), lifestyle (smoking, obesity), and environmental factors (heat, other forms of electromagnetic radiation, and toxins) that can impair the fertilizing potential of the spermatozoa and influence the incidence of spontaneous mutations that may cause infertility in the offspring.
Interdisciplinary Teams in Endometriosis Care
Authors: Allaire Catherine , Long Alicia Jean , Bedaiwy Mohamed A. , Yong Paul J.
Published: October 2020

Endometriosis-associated chronic pelvic pain can at times be a complex problem that is resistant to standard medical and surgical therapies. Multiple comorbidities and central sensitization may be at play and must be recognized with the help of a thorough history and physical examination. If a complex pain problem is identified, most endometriosis expert reviews and guidelines recommend multidisciplinary care. However, there are no specific recommendations about what should be the components of this approach and how that type of team care should be delivered. There is evidence showing the effectiveness of specific interventions such as pain education, physical therapy, psychological therapies, and pharmacotherapies for the treatment of chronic pain. Interdisciplinary team models have been well studied and validated in other chronic pain conditions such as low back pain. The published evidence in support of interdisciplinary teams for endometriosis-associated chronic pain is more limited but appears promising. Based on the available evidence, a model for an interdisciplinary team approach for endometriosis care is outlined.
Moving Beyond Lewis: Employment and Wage Trends in China’s High- and Low-Skilled Industries and the Emergence of an Era of Polarization
Authors: Rozelle Scott , Xia Yiran , Friesen Dimitris , Vanderjack Bronson , Cohen Nourya
Published: October 2020

One of the defining features of China’s economy over the two decades between 1995 and 2015 was the persistent rise of wages for workers and professionals in nearly every segment of the economy—with wage rates for labor-intensive jobs in manufacturing, construction, and the informal service sector rising the fastest. Recently, however, the economic environment in China has begun to change, including changes in both employment and wages. We identify recent employment/wage trends throughout China’s economy and postulate the sources of these trends as well as possible future consequences if they continue. We use official, nationally aggregated data to examine employment and wages in multiple sectors and industries. Our findings indicate that China may have entered a new phase of economic development in the mid-2010s. According to the data, in recent years, wage growth has begun to polarize: Rising for professionals employed in formal skill-intensive industries; and falling for workers in the informal labor-intensive service sector. We attribute this increase in skill-intensive wages to an increase in demand for skill-intensive employment, due to the emergence of a large middle class in China, for whom the demand for high technology, finance, banking, health, and higher education industries is increasing while, at least in the recent short term, the supply of experienced, high-skilled professionals has not kept up. The employment/wage trend in the informal (low-wage) service sector, however, is following a different pattern. While there is a rising demand for services in China’s economy, the growth, due to a number of factors (e.g., large shares of GDP targeted by policymakers to investment; high rates of savings by consumers), is relatively slow. In contrast, due to a number of economic forces, including globalization and automation, the supply of labor into the service sector of the informal economy is being fueled by the flow of labor out of manufacturing and construction (two industries that that have experienced employment declines since 2013). These supply and demand trends, in turn, are leading to the fall in the growth rate of wages in the informal service sector. We conclude by discussing the possible longer-term consequences of these emerging polarization trends based on an examination of recent experience with wage polarization occurring in both middle- and high-income countries, as well as its consequences. We also present policy recommendations for greater investment in education and human capital, as well as for the development of a more comprehensive set of social safety nets for different segments of China’s population.
Stochastic sequential reduction of commutative Hamiltonians
Authors: Mengütürk Levent Ali , Mengütürk Murat Cahit
Published: October 2020

This paper introduces a class of stochastic processes constructed by conditioning càdlàg processes to take a predetermined set of marginal laws at fixed points in time. We collectively refer to the elements of this class of processes as random n-bridges (RnBs), where n refers to the cardinality of the set of conditioning laws, which can be chosen arbitrarily. We prove that if the underlying càdlàg process is Markov, then its RnB is Markov for n = 1 and has a particular Markov-like property for n > 1. As a canonical subclass, we construct Brownian RnBs (BRnBs) and provide their anticipative representation as well as their non-anticipative semimartingale representation. This motivates the second part of this paper, wherein we apply BRnBs to describe an energy-based state reduction in a composite quantum system involving a set of commuting observables measured successively at different times. The highly tractable so-called energy-based quantum state reduction models are significant in their role as the most important alternative to the popular CLS model. We ask the random variables composing the anticipative form of a BRnB to take the eigenvalues of a set of compatible Hamiltonians and provide a new stochastic Schrödinger evolution on a complex Hilbert space that models sequential reduction dynamics of the eigenstates through a single wave function. By doing so, we also extend the Brody–Hughston finite-time collapse model to a many-body setup with sequential measurements.
Tunable polarization with enhanced multiferroic response of W/Co co-doped Bi4LaFeTi3O15 Aurivillius ceramics
Authors: Patri Tirupathi , Praveen Kumar J. , Ghosh Avijit , Babu P. D.
Published: October 2020

A comprehensive investigation on structural, microstructural, optical, electrical, magnetic, and magnetoelectric (ME) properties of the single phase Bi4LaFeTi3−2x(WyCo2y)xO15 (0.00 ≤ x ≤ 0.15, y = 1.0) Aurivillius ceramics has been presented here. The preliminary x-ray diffraction and Raman spectroscopic studies reveal that a layered-structure perovskite Aurivillius phase of orthorhombic space group A21am. Furthermore, the surface morphology study provides a plate-like to spherical-like granules with increasing the dopant concentrations. The ferroelectric response prevails a slim P–E loop for pristine sample, whereas it provides the highest polarization (Ps) values of 7.21 and 13.25 μC/cm2 for x = 0.10 and 0.15 concentrations, respectively. At low temperature, magnetic measurements provide a weak antiferromagnetic ordering of pristine sample, whereas a strong FM (ferromagnetic) ordering of doped ceramics is attained. The observed strong FM behavior of the Aurivillius phase is attributed to either double exchange interactions between neighboring Fe3+–O–Fe3+, Co3+–O–Co3+, and Fe3+–O–Co3+ ions or antisymmetric Dzyaloshinskii–Moriya interactions for spin canting of adjacent sub-lattices via Co3+/2+–O–Co3+/2+, Fe3+–O–Fe3+, and Co3+/2+–O–Fe3+ ions. The temperature dependent dielectric broad-band spectroscopic study enlightened a dielectric relaxation. This is due to cationic disordering through the generation of oxygen vacancies, which yields a conduction mechanism at high temperature regions. Furthermore, a complex modulus spectroscopic technique is also adopted to investigate the dielectric relaxation at high temperature regimes. The observed magnetic ferroelectric polarization responses and magnitudes of ME coupling coefficients provided that this material could be useful for future magnetoelectric sensors.
Nematic first order phase transition for liquid crystals in the van der Waals–Kac limit
Authors: Erignoux Clément , Giuliani Alessandro
Published: October 2020

In this paper, we revisit and extend some mathematical aspects of Onsager’s theory of liquid crystals that have been investigated in recent years by different communities (statistical mechanics, analysis, and probability). We introduce a model of anisotropic molecules with three-dimensional orientations interacting via a Kac-type interaction. We prove that, in the limit in which the range of the interaction is sent to infinity after the thermodynamic limit, the free energy tends to the infimum of an effective energy functional à la Onsager. We then prove that, if the spherical harmonic transform of the angular interaction has a negative minimum, this effective free energy functional displays a first order phase transition as the total density of the system increases.
The effect of heterogeneity on hypergraph contagion models
Authors: Landry Nicholas W. , Restrepo Juan G.
Published: October 2020

The dynamics of network social contagion processes such as opinion formation and epidemic spreading are often mediated by interactions between multiple nodes. Previous results have shown that these higher-order interactions can profoundly modify the dynamics of contagion processes, resulting in bistability, hysteresis, and explosive transitions. In this paper, we present and analyze a hyperdegree-based mean-field description of the dynamics of the susceptible–infected–susceptible model on hypergraphs, i.e., networks with higher-order interactions, and illustrate its applicability with the example of a hypergraph where contagion is mediated by both links (pairwise interactions) and triangles (three-way interactions). We consider various models for the organization of link and triangle structures and different mechanisms of higher-order contagion and healing. We find that explosive transitions can be suppressed by heterogeneity in the link degree distribution when links and triangles are chosen independently or when link and triangle connections are positively correlated when compared to the uncorrelated case. We verify these results with microscopic simulations of the contagion process and with analytic predictions derived from the mean-field model. Our results show that the structure of higher-order interactions can have important effects on contagion processes on hypergraphs.
Machine learning depinning of dislocation pileups
Authors: Sarvilahti Mika , Skaugen Audun , Laurson Lasse
Published: October 2020

We study a one-dimensional model of a dislocation pileup driven by an external stress and interacting with random quenched disorder, focusing on the predictability of the plastic deformation process. Upon quasistatically ramping up the externally applied stress from zero, the system responds by exhibiting an irregular stress–strain curve consisting of a sequence of strain bursts, i.e., critical-like dislocation avalanches. The strain bursts are power-law distributed up to a cutoff scale that increases with the stress level up to a critical flow stress value. There, the system undergoes a depinning phase transition and the dislocations start moving indefinitely, i.e., the strain burst size diverges. Using sample-specific information about the pinning landscape as well as the initial dislocation configuration as input, we employ predictive models such as linear regression, simple neural networks, and convolutional neural networks to study the predictability of the simulated stress–strain curves of individual samples. Our results show that the response of the system—including the flow stress value—can be predicted quite well, with the correlation coefficient between the predicted and actual stress exhibiting a non-monotonic dependence on strain. We also discuss our attempts to predict the individual strain bursts.
Highly spatially resolved mapping of the piezoelectric potentials in InGaN quantum well structures by off-axis electron holography
Authors: Boureau V. , Cooper D.
Published: October 2020

The internal fields in 2.2 nm thick InGaN quantum wells in a GaN LED structure have been investigated by using aberration-corrected off-axis electron holography with a spatial resolution of better than 1 nm. To improve the spatial resolution, different types of off-axis electron holography acquisitions have been used, including pi phase shifting and phase shifting holography. A series of electron holograms have been summed up to simultaneously improve the sensitivity in the measurements. A value of 20% of indium concentration in the quantum wells has been obtained by comparing the deformation measured by dark-field electron holography and geometrical phase analysis to finite element simulations. The electrostatic potential has then been measured by off-axis electron holography. The mean inner potential difference between the InGaN quantum wells and the GaN quantum barriers is high compared to the piezoelectric potential. Due to the improved spatial resolution, it is possible to compare the experimental results to simulations and remove the mean inner potential component to provide a quantitative measurement of the piezoelectric potential.
Atomic observation of phase transition in layered SnS2 driven by in situ heating and electron beam irradiation
Authors: Xie Ruicong , Hu Min , Liu Dongqi , Yu Yanying , Li Chao , He Jia , Luo Jun
Published: October 2020

The phase transition in transition metal dichalcogenides has a significant effect on the electrical conductivity and thermal conductivity. Herein, the SnS2 phase transition was observed on the atomic scale by in situ scanning transmission electron microscopy. The 1T and 1H mixed phase was formed under in situ heating and electron beam irradiation. First principles calculations demonstrate that the phase transition between 1H and 1T occurs through multiple layers of phase transition rather than layer by layer. The bandgap of the mixed SnS2 phase was found to be much smaller than the reported pure 1T phase. Our results provide microscopic insights into the transformation mechanism and highlight how heating and irradiation can be used to tune the electrical transport property of layered tin chalcogenides.
Parallel high-frequency magnetic sensing with an array of flux transformers and multi-channel optically pumped magnetometer for hand MRI application
Authors: Kim Young Jin , Savukov Igor
Published: October 2020

We investigate an approach for parallel high-frequency magnetic sensing based on a multi-channel radio frequency (RF) optically pumped magnetometer (OPM) coupled to multiple flux transformers (FTs) with a focus on hand magnetic resonance imaging (MRI) application at ultra-low field (ULF). Multiple RF OPM sensing channels are realized by using a single large-area alkali-metal vapor cell and two laser beams for pumping and probing, shared for all the channels. This design leads to significant cost reduction when multi-channel sensing is desirable, as in the case of ULF MRI. The FT, composed of two connected coils, serves as a transmitter of a target magnetic field to the OPM, while decoupling the OPM from untargeted magnetic fields in the sensing area that can limit the OPM performance. For hand MRI application, theoretical and numerical analysis is performed to determine an optimal geometry for the FT array that could improve signal-to-noise ratio (SNR) and sufficiently reduce crosstalk between FTs. We estimate that the optimized multi-channel FT-OPM sensor can achieve a magnetic field sensitivity of the order of 1fT/Hz1/2 above 100 kHz, which would be sufficient for 1 mm resolution MRI. In general, the multi-channel capability enables simultaneous magnetic measurements, thus reducing the sensing time and improving the SNR, and we anticipate many applications of the multi-channel FT-OPM sensor beyond the targeted here hand MRI: anatomical parallel ULF MRI of the human brain and other parts of the body, airport security screening, magnetic material imaging, and many others.
Molecular determinants of Ebola nucleocapsid stability from molecular dynamics simulations
Authors: Xu Chaoyi , Katyal Nidhi , Nesterova Tanya , Perilla Juan R.
Published: October 2020

Ebola virus (EBOV) is a human pathogen with the ability to cause hemorrhagic fever and bleeding diathesis in hosts. The life cycle of EBOV depends on its nucleocapsid. The Ebola nucleocapsid consists of a helical assembly of nucleoproteins (NPs) encapsidating single-stranded viral RNA (ssRNA). Knowledge of the molecular determinants of Ebola nucleocapsid stability is essential for the development of therapeutics against EBOV. However, large degrees of freedom associated with the Ebola nucleocapsid helical assembly pose a computational challenge, thereby limiting the previous simulation studies to the level of monomers. In the present work, we have performed all atom molecular dynamics (MD) simulations of the helical assembly of EBOV nucleoproteins in the absence and presence of ssRNA. We found that ssRNA is essential for maintaining structural integrity of the nucleocapsid. Other molecular determinants observed to stabilize the nucleocapsid include NP–RNA and NP–NP interactions and ion distributions. Additionally, the structural and dynamical behavior of the nucleocapsid monomer depends on its position in the helical assembly. NP monomers present on the longitudinal edges of the helical tube are more exposed, flexible, and have weaker NP–NP interactions than those residing in the center. This work provides key structural features stabilizing the nucleocapsid that may serve as therapeutic targets.
Heat-capacity measurements under uniaxial pressure using a piezo-driven device
Authors: Li Y.-S. , Borth R. , Hicks C. W. , Mackenzie A. P. , Nicklas M.
Published: October 2020

We report the development of a technique to measure heat capacity at large uniaxial pressure using a piezoelectric-driven device generating compressive and tensile strain in the sample. Our setup is optimized for temperatures ranging from 8 K down to millikelvin. Using an AC heat-capacity technique, we are able to achieve an extremely high resolution and to probe a homogeneously strained part of the sample. We demonstrate the capabilities of our setup on the unconventional superconductor Sr2RuO4. By replacing thermometer and adjusting the remaining setup accordingly, the temperature regime of the experiment can be adapted to other temperature ranges of interest.
Rotated angular modulated electronic and optical properties of bilayer phosphorene: A first-principles study
Authors: Yu Weiyang , Li Shaofei , Lin Long , Cai Xiaolin , Zhang Liwei , Yang Xuefeng , Zhang Zhanying , Niu Chun-Yao , Tao Hualong , Sun Jingwen , Zhu Junwu
Published: October 2020

Bilayer phosphorene homojunctions have attracted considerable interest owing to their natural bandgap and high carrier mobility. However, very little is known about the valuableness in arrays of bilayer phosphorene homojunctions with different rotated angles. In this work, we have presented angular modulated electronic and optical properties of rotated bilayer phosphorene employing first-principles calculations based on density functional theory. The angles in the homojunctions of the rotated bilayer phosphorene are set to be 26.02°, 71.61°, 110.54°, 130.39°, and 149.01°, respectively, and the homojunctions demonstrate different bandgaps of 0.66 eV, 0.64 eV, 0.63 eV, 0.68 eV, and 0.67 eV, respectively, implying that these homojunctions are good candidates for application in optoelectronics and nanoelectronics. Interestingly, we found that the rotated bilayer phosphorene can greatly enhance the absorption of visible and infrared light, which would provide encouragement on the modeling of the rotated bilayer phosphorene in nanoelectronic and optoelectronic devices.
High responsivity GaN nanowire UVA photodetector synthesized by hydride vapor phase epitaxy
Authors: Zhang Shuo , Zhang Xinran , Ren Fang , Yin Yue , Feng Tao , Song Wurui , Wang Guodong , Liang Meng , Xu Jianlong , Wang Jianwei , Wang Junxi , Li Jinmin , Yi Xiaoyan , Liu Zhiqiang
Published: October 2020

A gallium nitride (GaN) nanowire (NW) UVA photodetector with high responsivity was reported. The GaN NW was grown by horizontal hydride vapor phase epitaxy. The NW morphology is proved tunable via different growth conditions. The axial and radial growths of GaN NWs were investigated through vapor–liquid–solid and vapor–solid mixed growth models. Besides, NWs with different morphologies exhibit different growth crystal orientations, which depend on the flow rate of HCl. NWs with smaller diameters show better optical properties and crystalline quality. More importantly, the UVA detector fabricated by a single NW exhibits excellent responsivity of 4.35 × 104–1.06 × 105 A/W and external quantum efficiency of 1.48 × 107%–3.6 × 107% under different light power densities. The high responsivity and low production cost make the GaN NW UVA detector extremely attractive for several applications, such as fire sensing and missile and rocket warning.
Analytical model for quasi-linear flow response to resonant magnetic perturbation in resistive-inertial and viscous-resistive regimes
Authors: Huang Wenlong , Zhu Ping , Chen Hui
Published: October 2020

In this work, a quasi-linear model for the plasma flow response to the resonant magnetic perturbation (RMP) in a tokamak has been self-consistently developed in the resistive-inertial and viscous-resistive regimes purely from the two-field reduced MHD model. Models for the plasma response to RMP are commonly composed of equations for the resonant magnetic field response (i.e., the magnetic island) and the torque balance of plasma flow. However, in previous plasma response models, the magnetic island and the torque balance equations are often derived separately from reduced MHD and full MHD equations, respectively. By contrast, in this work, we derive both the magnetic island response and the torque balance equations in a quasi-linear model for the plasma flow response entirely from a set of two-field reduced MHD equations. Such a quasi-linear model can recover previous plasma flow response models within certain limits and approximations. Furthermore, the theoretical origins and physical meanings of quasi-linear forces and moments in the flow response equation are also clarified.
Electrically driven transient and permanent phase transformations in highly strained epitaxial BiFeO3 thin films
Authors: Lee Hyeon Jun , Kim Jeongyong , Hwang Seung Hyun , Choe Hyeokmin , Gorfman Semen , Heo Yeong-Jae , Lee Su Yong , Janolin Pierre-Eymeric , Kornev Igor , Schülli Tobias U. , Richter Carsten , Lee Joo-Hyoung , Pietsch Ullrich , Yang Chan-Ho , Jo Ji Young
Published: October 2020

Electric-field-driven phase transformation phenomena in multiferroic BiFeO3 are directly linked to the functionalities of electronic devices based on multiferroic materials. Understanding how the transformation evolves at the nanoscale under the influence of an electric field will provide fascinating insights into key parameters that utilize the transformation features. Here, we report both the electric-field-driven transient and permanent phase transformations in highly strained BiFeO3 thin films and their transformation dynamics at the nanoscale. We found that two distinct transient and permanent phase transformations were triggered below and above a coercive voltage of the polymorphic phase, indicating that ferroelectric polarization switching could promote permanent phase transformations. We also found that the transient transformations evolve via complex phase boundary motions between the coexisting phases, whereas permanent transformations occurred via nucleation of the other phases.
Application of the sparse-Lagrangian multiple mapping conditioning approach to a model supersonic combustor
Authors: Huang Zhiwei , Cleary Matthew J. , Zhang Huangwei
Published: October 2020

The Multiple Mapping Conditioning/Large Eddy Simulation (MMC-LES) model is extended for the first time to high-speed, compressible flow conditions and validated against non-reacting and reacting experimental data from a model supersonic combustor. The MMC-LES method solves the subgrid joint composition filtered density function through a Monte Carlo approach, and it permits a low-cost numerical implementation using a sparse distribution of stochastic Lagrangian particles. The sensitivity of results to the particle resolution is examined, and similar to past low-speed applications of MMC-LES, that sensitivity is found to be low. In comparison to the model equations for subsonic turbulent combustion conditions, the pressure work and viscous heating effects have been incorporated here to account for the effects of compressibility. As expected, the viscous heating effects are small for this flow case and can be ignored, while the pressure work is not negligible and makes a significant contribution at expansion fans and shock fronts where the magnitude of the pressure derivative term in non-reacting/reacting cases is as much as 23.8%/24.5% and 19.2%/18.6% of the stochastic particle standardized enthalpy, respectively. The MMC-LES predictions show good quantitative agreement with the available experimental data for the mean and root-mean-square of axial velocity, mean temperature, and wall pressure. Good qualitative comparison to the data is also observed for major flow characteristics, including location and size of shocks, expansion fans, and recirculation zone, and combustion characteristics such as flame lift-off distance. Although the effects of the pressure work on the mean flame lift-off distance are negligible, they have a significant influence on the predicted spatial fluctuations of the flame base.
Cryptically galled infructescence: a new sheoak gall type in Allocasuarina luehmannii and Casuarina pauper (Casuarinaceae)
Authors: Riley Ian T.
Published: October 2020

Insect galls formed within the infructescences (cones) of Allocasuarina luehmannii and Casuarina pauper in southern New South Wales, Australia, are described. The galling was internal within the infested cones, which were small and irregularly developed, but could appear superficially normal except that they had a higher than normal proportion of samaras retained on bracteole dehiscence. Cross-sections revealed abnormal morphology and wasp larval chambers. All exit holes found were between bracteole pairs of either fertile or infertile florets. Emergent wasps were tentatively identified as Eurytoma sp. sensu lato (Hymenoptera: Eurytomidae). These cryptically galled infructescences represent a previously undescribed gall type in the Casuarinaceae and, for Eurytoma, potentially a rare instance of phytophagy in Australia. Infested cones were found in a season when normal cones in this drought affected area were not easily found. It was concluded that this phytophagy could negatively impact the regeneration potential of two already compromised sheoak species.
Fire can promote germination, recruitment and seed bank accumulation of the threatened annual grass Arthraxon hispidus
Authors: White Laura , Catterall Claudia , Taffs Kathryn
Published: October 2020

Disturbance plays an important role in plant life history strategies and has been documented as both enhancing and threatening populations of the vulnerable grass Arthraxon hispidus (Thunb.) Makino (hairy jointgrass) on the NSW north coast. Mechanical disturbance (slashing) is often used in A. hispidus conservation management, but many Australian plants are adapted to fire-based disturbance regimes. In this study we undertook a field burning experiment, along with soil seed bank sampling and germination trials, to explore how fire influences A. hispidus population dynamics in terms of plant recruitment and seed bank fluctuations. We found that winter burning strongly promoted A. hispidus spring germination without entirely depleting the residual seedbank. Although drought affected our field study population, burning also led to increased adult cover and substantial seed bank replenishment the following autumn. Exposure to a smoke treatment almost doubled the germination rate of A. hispidus seeds in nursery trials. Our study suggests that appropriate burning regimes can help to maintain this species in the landscape, by both structural and chemical mechanisms, by enhancing plant recruitment and facilitating seed bank accumulation. However, some A. hispidus plants also successfully germinated, established, and reproduced in unburnt plots during our study, suggesting that populations of this species can persist without disturbance in some habitats, such as native wetland communities. We found that A. hispidus has a multi-year seed longevity and a persistent seed bank, providing the species a degree of resilience in the event of unpredictable disturbance regimes and climatic anomalies.
Tuberculosis: yesterday, today and tomorrow
Authors: Lowbridge Chris , Ralph Anna P
Published: October 2020

Tuberculosis (TB) remains an important public health challenge globally and in Australia. For the more than 10 million people who become sick with TB each year, the disease can cause immense personal and economic hardship, including loss of income and education through ill health, prolonged and arduous treatment, and stigmatisation – perpetuating a cycle of disadvantage. Past efforts to control TB have taught us much about modern disease control and public health. As the world grapples with the coronavirus (COVID-19) pandemic, the response to TB provides valuable lessons which can inform our response to COVID-19.
Skin morphology in fossil and living dipnoans
Authors: Kemp Anne
Published: October 2020

The morphology of the skin of living dipnoans can be compared with the arrangements present in the dermis and epidermis of the snout and mandible of fossil dipnoans, but the structures that may have been present in the fossils are significantly reduced in living lungfish. One advantage of assessing the living species is that soft tissues are intact. Fossil dipnoans have cosmine in the epidermis of the snout and mandible, and the dermis is supported by several layers of structured extracellular matrix. Cosmine includes dentine elements as well as pore canals. Among the pore canals are gaps in the cosmine layer that would have housed electroreceptors in the living fish. Below the cosmine is a layer of cancellous bone, separated from the dermal tissues within by a thin, almost continuous, ossified layer. Deep to this layer is a region that lacks any ossified structure, and below this the tubules that pass through the dermis terminate in irregular bulbs. Thin branches with an ossified coat arise from the tubules in the terminal layer and enter the cancellous bone below the cosmine and the pore canals, although they are not numerous. Living dipnoans have no ossified structures in the skin, and lymphatic vessels in the snout are reduced to the plexus below the epidermis, and the lymphatic loops that emerge from the plexus and enter the epidermis. These are numerous and occur in regular layers. In the living species, the lymphatic loops are close to electroreceptors. This may have been the case in fossil lungfish as well. Parallels in fossil and living dipnoans are present.
Increased house mouse (Mus musculus) abundance in wetlands in response to Typha sp. flowering: implications for understanding wetland occupancy patterns of the eastern grass owl (Tyto longimembris)
Authors: Beranek Chad T.
Published: October 2020

Rises in abundance of a population in response to increased resources is often followed by a rise in predator abundance. The non-threatened eastern barn owl (Tyto alba delicatula) and the threatened eastern grass owl (Tyto longimembris) are predators that may have occupancy patterns linked with prey abundance. It is important to identify the resources that cause increases in primary prey items to further understanding of the ecology of these species. Here I test the hypothesis that grass seeds cause increased abundances of wetland-dwelling house mice (Mus musculus) in austral summer, and identify a wetland monocot that provides a food recourse to achieve this effect, as well as report eastern grass owl and barn owl observations. A 2.6 ha wetland area (on Kooragang Island, New South Wales) was surveyed almost weekly to quantify abundance of prey items from September to April for three years (2016–2019). Typha sp. (a monocot) had flowering periods that coincided with increases in house mouse observations (n = 90 in flowering, n = 2 in non-flowering), where 22% were detected feeding on Typha flowers/seeds or fleeing from flower stalks. Eastern grass owls were only observed during a Typha flowering period (n = 3). These observations confirmed the original hypothesis and led to the formulation of another hypothesis: wetland occupancy by eastern grass owls is influenced by Typha flowering. Future studies should aim to test this hypothesis and identify other wetland plants that provide an important food source for wetland-dwelling rodents.