bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostik erhöhter Leberwerte in der hausärztlichen Versorgung – Eine Befragung zu Voraussetzungen, Vorgehen und erlebten Herausforderungen von Allgemeinmedizinern
Authors: Wangler Julian , Jansky Michael
Published: August 2020

Hintergrund In der hausärztlichen Versorgung treten Leberwerterhöhungen als häufiger Zufallsbefund auf. Neben der Beachtung von Symptomen ist für eine effektive Abklärung entscheidend, welche Leberwerte als Indikatoren einbezogen und wann Patienten zur weiterführenden Diagnostik überwiesen werden. Ebenso kommt es auf eine geregelte Zusammenarbeit zwischen Haus- und Fachärzten an. Bislang fehlt es für den deutschsprachigen Raum an belastbaren Erkenntnissen über das Vorgehen und erlebte Herausforderungen von Hausärzten, wenn es um die Abklärung (unklarer) Leberwerterhöhungen geht.

Methodik Im Zuge einer schriftlichen Befragung, die auf mehreren Vorstudien basiert, wurden zwischen Oktober 2019 und März 2020 insgesamt 2701 Hausärzte in Hessen und Baden-Württemberg zum Vorgehen bei Leberwerterhöhungen befragt. Neben der deskriptiven Analyse erfolgte eine Faktorenanalyse.

Ergebnisse Die Ergebnisse zeigen für die Hausarztmedizin verschiedene Herausforderungen und Problematiken. Hinsichtlich der Beachtung von Warnzeichen sowie mit Blick auf die herangezogenen leberassoziierten Laborparameter sind stark unterschiedliche Cluster hausärztlichen Vorgehens auszumachen. Im Fall erhöhter Leberwerte präferiert eine Mehrheit der Befragten ein kontrolliertes Zuwarten (59 %), allerdings machen Hausärzte im Alltag oft von direkten Überweisungen zu Spezialisten Gebrauch (66 %). In der Zusammenarbeit mit gastroenterologischen Fachärzten bestehen aus hausärztlicher Sicht diverse Schnittstellenprobleme.

Diskussion Es erscheint sinnvoll, Maßnahmen zu ergreifen, die zu einer verstärkten Professionalisierung und Vereinheitlichung der hausärztlichen Diagnostik beitragen und die Zusammenarbeit mit gastroenterologischen Spezialisten besser strukturieren. Dazu zählen etwa ein breiteres Angebot von Schulungs- und Fortbildungsformaten, die Entwicklung eines validierten Diagnose- und Behandlungspfads (v. a. Früherkennung von Patienten mit erhöhtem Risiko für eine Leberfibrose oder Leberzirrhose) oder die feste Verankerung einer leberwertassoziierten Blutuntersuchung im Rahmen des Check-ups. Der Entwicklung einer fundierten hausarztbasierten Leitlinie zur Erkennung und zum Umgang mit erhöhten Leberwerten sollte nachgegangen werden.
The impact of gender on the progression of neuromanifestation in HIV infection
Authors: Akova-Öztürk Esra , Moldokmatova Altynchach , Reichelt Doris , Gregor Nora , Husstedt Ingo W. , Evers Stefan
Published: August 2020

Ds Geschlecht hat einen besonderen Einfluss auf den Verlauf, die Manifestationen und die Behandlung einer HIV-Infektion. Es ist aber nur wenig bekannt über den spezifischen Einfluss des Geschlechts auf die Neuromanifestation. Wir wollten daher Unterschiede in der Prävalenz und in dem Grad der Neuromanifestationen zwischen Frauen und Männern mit HIV-Infektionen evaluieren und haben deshalb eine Fall-Kontroll-Studie mit konsekutiven HIV-infizierten Frauen (n = 167) and Männern (n = 169) durchgeführt, die für die Dauer der Infektion gematcht waren. Die Studie wurde an einer überregionalen HIV-Ambulanz einer neurologischen und an einer medizinischen Klinik durchgeführt. Es wurden die demografischen, klinischen, neurologischen, neurophysiologischen (ereigniskorrelierte Potenziale, Neurografie) und Bildgebungsdaten verglichen. Frauen waren zum Zeitpunkt der Infektion signifikant jünger als Männer. Sie zeigten weniger fortgeschrittene Stadien der HIV-Infektion und eine höhere CD4+-Zellzahl. Frauen erhielten seltener eine antiretrovirale Therapie. Die Nervenleitgeschwindigkeiten und Latenzen der ereigniskorrelierten Potenziale waren signifikant besser bei Frauen. Sie hatten eine signifikant niedrigere Rate einer Polyneuropathie und von generalisierten opportunistischen Infektionen. Außerdem zeigte sich ein Trend zu einer geringeren Rate einer HIV-assoziierten Enzephalopathie bei Frauen. Zusammenfassend zeigten Frauen einen besseren immunologischen Status und eine geringere Rate von Neuromanifestationen im Vergleich zu Männern mit derselben Infektionsdauer.
Sensorische Verarbeitungsstörung bei Säuglingen – wie Hebammen unterstützend begleiten können
Authors: Bauschke Julia , Scholz Silke
Published: August 2020

Regulationsstörungen bei Säuglingen sind für Familien oft sehr belastend. Hebammen, als wichtige Ansprechpartnerinnen und Vertrauenspersonen, leisten hier die entscheidende Unterstützung. Zudem lassen sich durch frühzeitige und vorbeugende Interventionen Entwicklungsrisiken positiv beeinflussen.
Warum Säuglinge anders schlafen
Authors: Renz-Polster Herbert
Published: August 2020

Das Schlafen ist ein menschliches Grundbedürfnis von Anfang an. Doch Säuglinge schlafen anders als Erwachsene. Kein Wunder, dass am Babyschlaf oft Konflikte in jungen Familien aufkeimen: Dürfen Babys ins Elternbett? Müssen sie das Durchschlafen antrainieren? Was ist normal? Diese Fragen beantwortet Dr. med. Herbert Renz Polster beim Forum Hebammenarbeit in Wiesbaden am 14. November 2020. Eine Vorschau auf seinen Vortrag mit Gedanken, die auch für die Beratung junger Eltern hilfreich sein können.
Interdisziplinäre Betreuung von Schwangeren mit Drogenabhängigkeit und ihren Neugeborenen
Authors: Gerhardt Andreas J. , Aschka Carmen
Published: August 2020

Drogen abhängige werdende Mütter zu betreuen, ist eine interdisziplinäre Herausforderung von der Schwangerschaft über die Geburt bis zum Wochenbett. Wie begleiten wir diese Frauen und ihre Familie angemessen, wertschätzend und zugewandt durch diese schwierige Lebensphase? Wie bewältigen wir es, das Leid zu erleben, das der Drogenmissbrauch hervorruft? Welche Chancen können wir bieten? Das Autorenteam beantwortet diese Fragen aus Sicht der klinischen Praxis und auf Basis von Fachliteratur und Leitlinien.
HIV-assoziierte neurokognitive Störungen
Authors: Arendt Gabriele
Published: August 2020

Die HIV-Infektion ist infolge der raschen Entwicklung der antiretroviralen Therapie, als „cART“ = combination antiretroviral treatment bezeichnet, von einer tödlichen Seuche zu einer behandelbaren, chronischen Erkrankung geworden. Dennoch bleiben problematische Aspekte; vor allem die neurologischen Systemmanifestationen (HAND = HIV-associated neurological disorders) stellen weiterhin ein ungelöstes Problem dar. Auch wenn die HIV-assoziierte Demenz in ihrer klassischen Form mit motorischen, kognitiven und emotionalen Defiziten und rascher Progredienz selten geworden ist, bleiben milde Defizite, die gleichwohl die Betroffenen in ihrem Alltag und ihrer Lebensqualität einschränken. Somit ist ein wesentlicher Teil der Betreuung HIV-Positiver, diese Defizite möglichst zu verhindern (früher Therapiebeginn) bzw. früh zu erkennen und zu mildern. Es existiert eine diagnostische Nomenklatur, die Symptomzuordnungen vorgibt, anzuwendende diagnostische Methoden sind festgelegt, die wesentlichen Differenzialdiagnosen beschrieben. An diesen Vorgaben kann sich der in der Behandlung HIV-positiver Patienten unerfahrene Neurologe oder Psychiater orientieren.
Strategy for the Use of Molecular Oxygen in Organic Synthesis
Authors: Taniguchi Tsuyoshi
Published: August 2020

Our recent studies on the development of new synthetic methods using molecular oxygen (O2), which is an environmentally friendly oxidant, are described in this Account. The character of O2 as an electron acceptor can be utilized for activation of simple organic molecules to generate reactive species. Such reactive species are applicable to advanced molecular transformation, such as C–C and C–X (X = heteroatom) bond formation, functionalization of inactivated C(sp3)–H, and catalytic Mitsunobu reaction, by avoiding direct quenching of the reactive species by O2.

1 Introduction

2 Reactions with Iron Catalysts and Oxygen

2.1 Reactions Using Redox Hydration of Alkenes

2.2 Reactions Using Oxidation of Heteroatoms

3 Reactions with tert-Butyl Nitrite and Oxygen

4 Conclusion
Sonic Rhinoplasty: Review and Updated Uses
Authors: Hjelm Nikolaus , Goldfarb Jared , Krein Howard , Heffelfinger Ryan N. , Pribitkin Edmund
Published: August 2020

The ultrasonic bone aspirator (UBA) allows for precision and provides ease of use in multiple steps of cosmetic and functional rhinoplasties. Its use has previously been described; however, since the publication of many studies the UBA has been improved and its applications for rhinoplasty have been modified and expanded. Both bony and cartilaginous modifications to the nose can be aided with the use of the UBA. From our experience, patient results have subjectively been found to be more acceptable, if not better, than with the use of other rhinoplasty instruments.
Gout As a Predictor of Total Knee Arthroplasty Outcomes and Costs
Authors: Rosas Samuel , Zuskov Andrey , Luo Tianyi David , Roche Martin W. , Emory Cynthia L. , Plate Johannes F.
Published: August 2020

Gout is the most common inflammatory arthritis and affects approximately 4% of the U.S. population. As the prevalence of gout and the number of total knee arthroplasties (TKAs) performed continue to increase, the literature on TKA in patients with gout remains scant. The purpose of this study was to evaluate the outcomes of patients with gout following TKA at a population level, that is, how patient with gout fair after TKA. We hypothesized that patients with gout have higher rates of complications and higher costs compared with controls. A case–control study was designed to evaluate two cohorts of Medicare patients who underwent TKA whose only distinguishing feature was the presence or absence of gout. Matching was performed to decrease confounding at a 1:1 ratio based on age, gender, and Charlson comorbidity index (CCI), (10-year survival predictor). The Medicare standard analytical files were queried through International Classification of Disease and current procedural terminology codes. A total of 15,238 patients were evaluated with 7,619 in each cohort. There were no age, gender, or CCI differences and 57.4% were females. Day of surgery and 90-day post-surgery costs were both significantly greater in those with gout (p < 0.001 for both). Multivariate analysis revealed that gout patients had increased odds of infection (odds ratio [OR] 1.229, p = 0.019), cardiac arrest (OR 1.354, p = 0.002), pneumonia (OR 1.161, p < 0.001), hematoma (OR 1.204, p = 0.002), and development of capsulitis (OR 1.208, p = 0.012). Nonetheless these patients had a decreased risk of pulmonary emboli (OR 0.835, p = 0.016). Our results support our hypothesis that patients with gout have higher rates of postoperative complications and increased day of surgery and 90-day costs of care after TKA. Given the high prevalence of gout in the United States, additional study on the utility of preoperative gout optimization for TKA patients is warranted. The level of evidence of this study is III, and it is a retrospective case–control study.
Learning Curve of Robotic-Assisted Total Knee Arthroplasty for a High-Volume Surgeon
Authors: Marchand Kevin B. , Ehiorobo Joseph , Mathew Kevin K. , Marchand Robert C. , Mont Michael A.
Published: August 2020

The learning curve has been established for robotic-assisted total knee arthroplasty (RATKA) during the first month of use; however, there have been no studies evaluating this on a longer term. Therefore, the purpose of this study was to compare operative times for three cohorts during the first year following adoption of RATKA (initial, 6 months, and 1 year) and a prior cohort of manual TKA. We investigated both mean operative times and the variability of operative time in each cohort. This is a learning curve study comparing a single surgeon's experience using RAKTA. The study groups were made up of two cohorts of 60 cementless RATKAs performed at ∼6 months and 1 year of use. A learning curve was created based on the mean operative times and individual operative times were stratified into different cohorts for comparison. Study groups were compared with the surgeon's initial group of 20 cemented RATKAs and 60 cementless manual cases. Descriptive numbers were compiled and mean operative times were compared using Student's t-tests for significant differences with a p-value of < 0.05. The mean surgical times continued to decrease after 6 months of RATKA. In 1 year, the surgeon was performing 88% of the RATKA between 50 and 69 minutes. The initial cohort and 1-year robotic-assisted mean operative times were 81 and 62 minutes, respectively (p < 0.00001). Mean 6-month robotic-assisted operative times were similar to manual times (p = 0.12). A significant lower time was found between the mean operative times for the 1-year robotic-assisted and manual (p = 0.008) TKAs. The data show continued improvement of operative times at 6 months and 1 year when using this new technology. The results of this study are important because they demonstrate how the complexity of a technology which initially increases operative time can be overcome and become more time-effective than conventional techniques.
Formation and crystallographic orientation of NiSi2–Si interfaces
Authors: Fuchs Florian , Bilal Khan Muhammad , Deb Dipjyoti , Pohl Darius , Schuster Jörg , Weber Walter M. , Mühle Uwe , Löffler Markus , Georgiev Yordan M. , Erbe Artur , Gemming Sibylle
Published: August 2020

The transport properties of novel device architectures depend strongly on the morphology and the quality of the interface between contact and channel materials. In silicon nanowires with nickel silicide contacts, NiSi2–Si interfaces are particularly important as NiSi2 is often found as the phase adjacent to the silicide–silicon interface during and after the silicidation. The interface orientation of these NiSi2–Si interfaces as well as the ability to create abrupt and flat interfaces, ultimately with atomic sharpness, is essential for the properties of diverse emerging device concepts. We present a combined experimental and theoretical study on NiSi2–Si interfaces. Interfaces in silicon nanowires were fabricated using silicidation and characterized by high-resolution (scanning) transmission electron microscopy. It is found that {111} interfaces occur in ⟨110⟩ nanowires. A tilted interface and an arrow-shaped interface are observed, which depends on the nanowire diameter. We have further modeled NiSi2–Si interfaces by density functional theory. Different crystallographic orientations and interface variations, e.g., due to interface reconstruction, are compared with respect to interface energy densities. The {111} interface is energetically most favorable, which explains the experimental observations. Possible ways to control the interface type are discussed.
Hybrid vibration control of offshore wind turbines under multiple external excitations
Authors: Xie Shuangyi , He Jiao , Zhang Chenglin , Jin Xin , Gao Jian
Published: August 2020

Structural control methods are a promising way to improve the dynamic response of offshore wind turbines. In this study, the effectiveness of passive tuned mass damper (TMD) and hybrid mass damper (HMD) control is examined for suppressing the vibration in a monopile offshore wind turbine subjected to a combination of wind, wave, and seismic loads. A high-fidelity wind turbine model is established based on the multi-body dynamics simulation code SIMPACK. A reduced-order model of the wind turbine is, then, extracted from input-output time-domain response data, which is used to design an HMD controller using the H∞ loop shaping approach. The controller is, then, applied in the high-fidelity multi-body model of the wind turbine, and an additional control force is applied using feedback from the displacement acceleration at the tower top. The performance of the passive TMD and HMD control systems is examined and compared in terms of the suppression of tower-top displacements under normal operating and parked conditions. The results revealed that the HMD control system can better reduce the tower-top displacement as compared to the passive TMD system before and during earthquakes, albeit at the expense of high input control power and large TMD displacements. However, the two control systems have a negative impact on the dynamic response of tower after the earthquake. Moreover, the investigation of controller gains indicated that the vibration suppression effect of HMD improves with the increase in control power, leading to larger TMD strokes.
Steganography protocols for quantum channels
Authors: Tahmasbi Mehrdad , Bloch Matthieu R.
Published: August 2020

We study several versions of a quantum steganography problem in which two legitimate parties attempt to conceal a cypher in a quantum cover transmitted over a quantum channel without arising suspicion from a warden who intercepts the cover. In all our models, we assume that the warden has an inaccurate knowledge of the quantum channel and we formulate several variations of the steganography problem depending on the tasks used as the cover and the cypher task. In particular, when the cover task is classical communication, we show that the cypher task can be classical communication or entanglement sharing; when the cover task is entanglement sharing and the main channel is noiseless, we show that the cypher task can be randomness sharing; when the cover task is quantum communication and the main channel is noiseless, we show that the cypher task can be classical communication. In the latter case, our results improve earlier ones by relaxing the need for a shared key between the transmitter and the receiver and hold under milder assumptions on the cover quantum communication code.
Influence of the vicinal substrate miscut on the anisotropic two-dimensional electronic transport in Al2O3–SrTiO3 heterostructures
Authors: Wolff K. , Schäfer R. , Arnold D. , Schneider R. , Le Tacon M. , Fuchs D.
Published: August 2020

The electrical resistance of the two-dimensional electron system (2DES) which forms at the interface of SrTiO3 (STO)-based heterostructures displays anisotropic transport with respect to the direction of current flow at low temperature. We have investigated the influence of terraces at the surface of STO substrates from which the 2DES is prepared. Such terraces are always present in commercially available STO substrates due to the tolerance of surface preparation, which result in small miscut angles of the order of γ ≈ 0.1° with respect to the surface normal. By a controlled increase of the substrate miscut, we could systematically reduce the width of the terraces and thereby increase the density of substrate surface steps. The in-plane anisotropy of the electrical resistance was studied as a function of the miscut angle γ and found to be mainly related to interfacial scattering arising from the substrate surface steps. However, the influence of γ was notably reduced by the occurrence of step-bunching and lattice-dislocations in the STO substrate material. Magnetoresistance (MR) depends on the current orientation as well, reflecting the anisotropy of carrier mobility. For γ ≥ 2°, MR is substantially enhanced and shows the trend toward a linear field dependence, which is typical for inhomogeneous conductors. From weak-antilocalization observed at the small magnetic field, we deduce information on inelastic scattering and spin–orbit coupling. While the field scale associated with a Rashba-type spin–orbit coupling in 2D weak-localization does not show a pronounced correlation with γ, distinct changes of the scale are associated with inelastic scattering.
PyFLOSIC: Python-based Fermi–Löwdin orbital self-interaction correction
Authors: Schwalbe Sebastian , Fiedler Lenz , Kraus Jakob , Kortus Jens , Trepte Kai , Lehtola Susi
Published: August 2020

We present pyflosic, an open-source, general-purpose python implementation of the Fermi–Löwdin orbital self-interaction correction (FLO-SIC), which is based on the python simulation of chemistry framework (pyscf) electronic structure and quantum chemistry code. Thanks to pyscf, pyflosic can be used with any kind of Gaussian-type basis set, various kinds of radial and angular quadrature grids, and all exchange-correlation functionals within the local density approximation, generalized-gradient approximation (GGA), and meta-GGA provided in the libxc and xcfun libraries. A central aspect of FLO-SIC is the Fermi-orbital descriptors, which are used to estimate the self-interaction correction. Importantly, they can be initialized automatically within pyflosic; they can also be optimized within pyflosic with an interface to the atomic simulation environment, a python library that provides a variety of powerful gradient-based algorithms for geometry optimization. Although pyflosic has already facilitated applications of FLO-SIC to chemical studies, it offers an excellent starting point for further developments in FLO-SIC approaches, thanks to its use of a high-level programming language and pronounced modularity.
Linearized lattice Boltzmann Method for time periodic electro-osmotic flows in micro- and nanochannels
Authors: Shi Yong , Kang Hang , Ren Yong , Chan Yue
Published: August 2020

Time periodic electro-osmosis (TPEO) is a popular means to pump liquids or manipulate species of interest in today’s micro- and nanofluidic devices. In this article, we propose a double distribution-function lattice Boltzmann (LB) model to describe its oscillatory flows coupled with electrokinetics in micro- and nanochannels. To remove advective effects, we derive the LB model from a linearized Boltzmann Bhatnagar–Gross–Krook-like equation and formulate its equations depending on the alternating current (AC) frequency, instead of time. This treatment facilitates a direct comparison of the LB results to experimental measurements in practical applications. We assessed accuracy of the proposed frequency-based Linearized LB model by simulating time periodic electro-osmotic flows (TPEOFs) with a thin and a thick electric double layer (EDL) at different Stokes parameters. The results are in excellent agreement with analytical solutions. The model was used to simulate TPEOFs with various EDL thicknesses and those driven by an AC electric field combined with an oscillatory pressure gradient. The simulations show distinct distributions of the electric potential and solution velocity subject to different length ratios and frequency ratios in the flows and interesting flow responses to compounding influences of the applied electric and mechanical driving fields. Importantly, diverse vortex patterns and vorticity variations were also revealed for TPEOFs in heterogeneously charged channels. These results demonstrate that the LB model developed in this article can well capture rich TPEO flow characteristics in micro- and nanochannels. It is effective for design and optimization of TPEO-based micro- and nanofluidic devices.
The ozone–water complex: CCSD(T)/CBS structures and anharmonic vibrational spectroscopy of O3(H2O)n, (n = 1 − 2)
Authors: Hui Wallace C. H. , Lemke Kono H.
Published: August 2020

Ozone–water complexes O3(H2O)n (n = 1–2) have been studied using coupled cluster theory with triple excitations CCSD(T) with correlation consistent basis sets aug-cc-pVnZ (n = D, T, Q) and complete basis set (CBS) extrapolation techniques. We identified seven dimer (n = 1) and nine trimer species (n = 2) with open C2v and cyclic D3h ozone. Calculations at the CCSD(T)/CBS level of theory for C2v O3(H2O) on the counterpoise (CP)-corrected potential energy surface yield a dissociation energy of De = 2.31 kcal/mol and an O3 central-oxygen (Oc) H2O oxygen (Ow) distance r[Oc⋯Ow] of 3.097 Å, which is in good agreement with an experimental value of 2.957 Å [J. Z. Gillies et al., J. Mol. Spectrosc. 146, 493 (1991)]. Combining our CCSD(T)/CBS value of De for C2v O3(H2O) with our best estimate anharmonic CCSD(T)/aVTZ ΔZPE yields a Do value of 1.82 kcal/mol; the CCSD(T)/CBS value of De for D3h O3(H2O) is 1.51 kcal/mol and yields an anharmonic CCSD(T)/aVTZ Do = 0.99 kcal/mol. CCSD(T)/aVTZ dissociation energies and structures for C2v O3(H2O)2 are De = 4.15 kcal/mol, (Do = 3.08 kcal/mol) and r[Oc⋯Ow] = 2.973 Å, and De = 2.64 kcal/mol (Do = 1.68 kcal/mol) with r[Oc⋯Ow] = 2.828 Å for D3h O3(H2O)2. The results from ab initio molecular dynamics simulations, which consider dynamic and thermal effects in O3(H2O), show that the O3(H2O) complex remains stable at 50 K and dynamically interconverts between two hydrogen-bonded conformers with short Oc⋯Ow contacts (3.85 Å). Carr–Parrinello molecular dynamic (CPMD) simulations for O3(H2O) and O3(H2O)2 at 100 K demonstrate that O3(H2O)2 remains structurally intact, whereas O3(H2O) dissociates to free ozone and water, a feature consistent with the larger average binding energy in O3(H2O)2 (2.2 kcal/mol) vs that in O3(H2O) (1.8 kcal/mol). Finally, the results from CCSD(T)/CBS and CPMD simulations demonstrate that the large inter-trimer binding energies in O3(H2O)2 would give rise to an elevated trimer/dimer population ratio, making O3(H2O)2 a particularly stable and spectroscopically detectable complex.
Charge density waves beyond the Pauli paramagnetic limit in 2D systems
Authors: Aperis Alex , Varelogiannis Georgios
Published: August 2020

Two-dimensional materials are ideal candidates to host Charge Density Waves (CDWs) that exhibit paramagnetic limiting behavior, similar to the well-known case of superconductors. Here, we study how CDWs in two-dimensional systems can survive beyond the Pauli limit when they are subjected to a strong magnetic field by developing a generalized mean-field theory of CDWs under Zeeman fields that includes incommensurability, imperfect nesting, and temperature effects and the possibility of a competing or coexisting Spin Density Wave (SDW) order. Our numerical calculations yield rich phase diagrams with distinct high-field phases above the Pauli limiting field. For perfectly nested commensurate CDWs, a q-modulated CDW phase that is completely analogous to the superconducting Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) phase appears at high fields. In the more common case of imperfect nesting, the commensurate CDW ground state undergoes a series of magnetic-field-induced phase transitions first into a phase where commensurate CDW and SDW coexist and subsequently into another phase where CDW and SDW acquire a q-modulation that is, however, distinct from the pure FFLO CDW phase. The commensurate CDW + SDW phase occurs for fields comparable to but less than the Pauli limit and survives above it. Thus, this phase provides a plausible mechanism for the CDW to survive at high fields without the need for forming the more fragile FFLO phase. We suggest that the recently discovered 2D materials like the transition metal dichalcogenides offer a promising platform for observing such exotic field-induced CDW phenomena.
Thermochromic behavior of VO2/GO and VO2/rGO nanocomposites prepared by a facile hydrothermal method
Authors: Boochakravarthy Ashwin Agathya , Dhanasekar M. , Bhat S. Venkataprasad
Published: August 2020

Graphene oxide and reduced graphene oxide based nanocomposites of the well-known thermochromic material VO2 were synthesized by an in situ hydrothermal process, and their temperature dependent reflectance was studied. The nanocomposites were characterized using various techniques to observe the changes that occurred in the morphology, structure, and optical absorption of VO2 nanostructures due to the introduction of graphene oxide as well as reduced graphene oxide. The UV-Vis-NIR (200 nm–1100 nm) spectroscopy at two different temperatures, below and above the transition temperature showed that the reflectance of IR radiation was enhanced with the addition of GO as well as rGO, indicating the improved thermochromic behavior of the nanocomposites.
Electric deflection of imidazole dimers and trimers in helium nanodroplets: Dipole moments, structure, and fragmentation
Authors: Kamerin Benjamin S. , Niman John W. , Kresin Vitaly V.
Published: August 2020

Deuterated imidazole (IM) molecules, dimers, and trimers formed in liquid helium nanodroplets are studied by the electrostatic beam deflection method. Monitoring the deflection profile of (IM)D+ provides a direct way to establish that it is the primary product of the ionization-induced fragmentation both of (IM)2 and (IM)3. The magnitude of the deflection determines the electric dipole moments of the parent clusters: nearly 9 D for the dimer and 14.5 D for the trimer. These very large dipole values confirm theoretical predictions and derive from a polar chain bonding arrangement of the heterocyclic imidazole molecules.
Simulation of terahertz-band metamaterial sensor for thin film analyte detection
Authors: Ma Jialu , Wang Shaomeng , Yang Yang , Wang Kaicheng , Guo Lianghao , Gong Yubin
Published: August 2020

A terahertz metamaterial sensor for thin film sensing is proposed and investigated by a numerical study. The designed metamaterial sensor consists of an array of back to back c-shaped double-gap resonators, which can be obtained by simple manufacturing processes. By checking the shift of the resonate frequency of the sensor, the thickness of the analytes deposited on the sensor surface can be identified. We analyzed the sensitivities and corresponding quality factors of the sensor excited by two orthogonal polarized terahertz waves individually for both loss-free and lossy coating analyte layers. The electric field distributions of the metamaterial sensor with different analyte thicknesses are analyzed in detail to illustrate the principle of thin film detection and the principle of improving sensitivity. The transmission line model is built to verify the results of the numerical simulation. This study provides a useful reference for the design of biosensors based on metamaterial sensors in the future.
Strain-dependent electronic and optical properties of boron-phosphide and germanium-carbide hetero-bilayer: A first-principles study
Authors: Hasan Khan Md. Sakib , Islam Md. Rafiqul , Hasan Md. Tanvir
Published: August 2020

Opto-electronic properties of boron phosphide–germanium carbide (BP/GeC), a new van der Walls hetero-bilayer (HBL) with all possible stacking patterns, are studied under the density functional theory originated first-principles. The dynamical and chemical stabilities of the hetero-bilayer are confirmed by phonon spectra and binding energy. Among the dynamically stable HBLs, HBL 1 has the lowest binding energy with the smallest interlayer spacing of about 3.442 Å. Both values and natures (indirect or direct) of the electronic band structure are highly responsive to the stacking patterns. We have found that HBL 1 is indirect, while HBL 2 and HBL 3 become a direct bandgap at the K high symmetry point. All HBLs show type-II band alignment. Both compressive and tensile biaxial strains on the electronic properties of HBLs have been considered. All the HBLs become a direct bandgap for the compressive strain at 4% and 6%. We have also presented the optical property calculations on the HBLs, namely, the complex dielectric function and absorption properties, showing unique optical properties with significant absorption (5 × 105 cm−1 in HBL 2) in the whole solar spectra compared with their comprising monolayers. Moreover, the strain-dependent optical absorption coefficients with varying photon wavelengths are calculated and the maximum value is attained to be about 6.5 × 105 cm−1 in HBL 2 at 4% compressive strain. Consequently, the optoelectronic properties we have explored in our proposed new hetero-bilayer systems can guide the experimental realization of the hetero-bilayers and effective use in the future photovoltaic applications.
Optics of epitaxial strained strontium titanate films
Authors: Tyunina M. , Nepomniashchaia N. , Vetokhina V. , Dejneka A.
Published: August 2020

Diverse effects of lattice strain on the optical properties in the near-infrared to vacuum ultraviolet spectral range are experimentally revealed in cube-on-cube-type epitaxial perovskite SrTiO3 films grown on compressive substrate. Compared to the reference crystal, the tetragonal antiferrodistortive film exhibits spectral blueshifts, which are consistent with the theoretically predicted bandgap widening. In addition to this strain-induced interband effect, the peculiar near-edge absorption and smearing of interband transitions are found. It is shown that Fröhlich-type electron–phonon coupling can be enhanced by strain and lead to this behavior. It is suggested that electron–phonon interactions can play an important role in optical properties of ferroelectric films and deserve further studies.
Perovskite-sensitized upconversion bingo: Stoichiometry, composition, solvent, or temperature?
Authors: Bieber Alexander S. , VanOrman Zachary A. , Wieghold Sarah , Nienhaus Lea
Published: August 2020

Triplet–triplet annihilation-based photon upconversion (UC) using bulk perovskite sensitizers has been previously shown to facilitate efficient UC at low fluences. However, the fabrication of the UC devices has not been fully optimized; thus, there is room for improvement. Here, we apply techniques that have been successful in enhancing the performance of perovskite solar cells in order to also improve perovskite-sensitized UC devices. In particular, we investigate the use of a post-fabrication thermal annealing step, overstoichiometric vs stoichiometric addition of PbI2 to the perovskite precursors, methylammonium vs formamidinium cation-rich lead halide perovskite compositions, and the use of different solvents for the annihilator molecules on the perovskite/annihilator interface. We find that excess PbI2 does not significantly affect the UC process, while the perovskite composition is crucial for the yield of extracted carriers across the interface. Comparing toluene and chlorobenzene, we find that the solvent used to deposit the annihilator is also a key factor in the overall device performance. Moreover, we find that thermal annealing of the whole device architecture significantly improves the UC performance by a factor of three.
New skills, networks and challenges: the changing face of animal production science in Australia
Authors: Mayberry Dianne , Hatcher Sue , Cowley Frances
Published: August 2020

Livestock producers are facing increasing pressure to reduce the environmental and animal-welfare impacts of production, while also managing the challenge of an increasingly variable climate and diminishing resources. This perspective paper highlights the role for animal scientists to contribute to the sustainability of future livestock systems. We argue the need for a broader, more inclusive and more integrated concept of animal science, better connections among scientists, producers, consumers and policy makers, and more support for the next generation of animal scientists. Animal scientists have an important role to play in providing the evidence to support the social licence of livestock production and inform decisions made by policy makers and consumers regarding the production and consumption of livestock products. Animal scientists can also assist producers to adapt to social, environmental and political challenges that affect their livelihoods and the way they farm. Traditionally, animal science has focussed on species- and discipline-specific areas of research such as ruminant nutrition, genetics or reproductive physiology. While this fundamental research remains essential to understand the underlying biology of livestock production and improve production efficiency, it needs to be better integrated into research applied at and beyond the herd or flock level. Systems thinkers who can apply this knowledge across farm, regional and national scales also have an important role in providing information to key decision makers, from farmers to national government. Better engagement with the social and economic sciences can inform how animal scientists and extension services interact with producers to understand constraints to production as well as adoption of new technology and co-develop evidence-based solutions. Underlying this, the demographics of those who study and work in animal science are changing. Australian animal industries require the best and brightest minds to overcome future challenges and engaging these students as the new face of Australian animal science is an essential step towards sustainable future livestock systems.
The 1840 Western Port journey and Aboriginal fire history in the grassy ecosystems of lowland, mesic south-eastern Australia
Authors: Foreman Paul
Published: August 2020

The historic influence of human fire and the role of ‘top-down’ vs ‘bottom-up’ drivers on ecosystems globally is highly contested, and our knowledge of regime diversity is poor. This paper uses an early European account as a case study to describe Aboriginal fire history in south-eastern Australia based on links between fire and: grasslands, native foods and culture. The route and observations detailed in Assistant Protector William Thomas’ 1840 account of a journey led by Aborigines to Western Port, Victoria, were overlayed with grass-tree boundaries compiled from historic plans. The narrative provides direct evidence of up to moderate-scale and intensity burns (with minimal fine-scale patchiness), undertaken in the height of the dry season, opportunistically linked to rainfall. The fires targeted open grassy ‘plains’ to maintain and access preferred hunter-gathering grounds. A synthesis of the earliest records supports high frequency anthropogenic burning maintaining alternative vegetation states with dynamic boundaries on elevated alluvial plains and, in places, adjoining swamps. The narrative represents an important primary source for studying traditional society, including the description of a local historic fire regime (‘koyuga burning’). Establishing such a fire regime ‘benchmark’ has the potential to stimulate new interdisciplinary research around the complex processes controlling grass-tree patterns, and build confidence that fire-stick farming was potentially instrumental in grassland formation, and integral to grassland maintenance throughout this region.
Electronic Wavefunction Tiles
Authors: Liu Yu , Frankcombe Terry J. , Schmidt Timothy W.
Published: August 2020

We review the pre-quantum theories of electronic structure of Lewis and Langmuir, and how this relates to the post-quantum double-quartet theory of Linnett. Linnett’s ideas are put on a firm theoretical footing through the emergence of the wavefunction tile: The 3N-dimensional repeating structure of the N-electron wavefunction. Wavefunction tiles calculated by the dynamic Voronoi Metropolis sampling method are reviewed, and new results are presented for bent bonds of cyclopropane, and electron correlation in Be-O-Be.
Some Products from C=O Condensations of Quinacridones
Authors: Chesman Anthony S. R. , Liepa Andris J.
Published: August 2020

Quinacridone chemistry has been developed which provides a source of new compounds that have potential application in organic photovoltaic (OPV) devices. Phosphoryl chloride is used for the conversion of carbonyl groups in N,N′-dialkylquinacridones, generating reactive intermediates that enable selective condensation with either one or two nucleophilic molecules under mild conditions.
Quantifying surface severity of the 2014 and 2015 fires in the Great Slave Lake area of Canada
Authors: French Nancy H. F. , Graham Jeremy , Whitman Ellen , Bourgeau-Chavez Laura L.
Published: August 2020

The focus of this paper was the development of surface organic layer severity maps for the 2014 and 2015 fires in the Great Slave Lake area of the Northwest Territories and Alberta, Canada, using multiple linear regression models generated from pairing field data with Landsat 8 data. Field severity data were collected at 90 sites across the region, together with other site metrics, in order to develop a mapping approach for surface severity, an important metric for assessing carbon loss from fire. The approach utilised a combination of remote sensing indices to build a predictive model of severity that was applied within burn perimeters. Separate models were created for burns in the Shield and Plain ecoregions using spectral data from Landsat 8. The final Shield and Plain models resulted in estimates of surface severity with 0.74 variance explained (R2) for the Plain ecoregions and 0.67 for the Shield. The 2014 fires in the Plain ecoregion were more severe than the 2015 fires and fires in both years in the Shield ecoregion. In further analysis of the field data, an assessment of relationships between surface severity and other site-level severity metrics found mixed results.
Effect of dispersed form on the bioavailability of β-carotene from daily intake in humans
Authors: Kotake-Nara Eiichi , Hase Megumi
Published: August 2020

In a randomized double-blind crossover study, a canned beverage was prepared using an emulsion dispersion formulation (EM) of β-carotene and a crystal dispersion formulation (CR) of β-carotene; the beverages were ingested by human subjects daily for 2 weeks to compare the β-carotene bioavailability. EM-β-carotene enhanced the β-carotene concentrations in human plasma approximately 4-fold, but CR-β-carotene showed no statistically significant enhancement. Bioaccessibility is the ratio of the solubilized fraction to the whole amount ingested. Bioaccessibility of β-carotene from EM-β-carotene was higher than that from CR-β-carotene in an in vitro digestion test. Contrarily, β-carotene from CR-β-carotene, consists of all-trans-β-carotene, was higher than that from EM-β-carotene, consists of a mixture of cis and all-trans-β-carotene, on the uptake by intestinal Caco-2 cells, suggesting that bioaccessibility was a critical factor in β-carotene bioavailability in this study. EM-β-carotene thus has potential as a food coloring agent with value added because it enhances β-carotene bioavailability.
The septin cytoskeleton regulates natural killer cell lytic granule release
Authors: Phatarpekar Prasad V. , Overlee Brittany L. , Leehan Alexander , Wilton Katelynn M. , Ham Hyoungjun , Billadeau Daniel D.
Published: August 2020

Natural killer (NK) cell–mediated killing involves the membrane fusion of preformed lytic granules. While the roles of actin and microtubules are well accepted during this process, the function of septins, another cytoskeletal component that associates with actin and microtubules, has not been investigated. Here we show that genetic depletion or pharmacologic stabilization of the septin cytoskeleton significantly inhibited NK cell cytotoxicity. Although the stabilization of septin filaments impaired conjugate formation, depletion of septin proteins had no impact on conjugate formation, lytic granule convergence, or MTOC polarization to the cytotoxic synapse (CS). Interestingly, septins copurify and accumulate near the polarized lytic granules at the CS, where they regulate lytic granule release. Mechanistically, we find that septin 7 interacts with the SNARE protein syntaxin 11 and facilitates its interaction with syntaxin binding protein 2 to promote lytic granule fusion. Altogether, our data identify a critical role for septins in regulating the release of lytic granule contents during NK cell–mediated killing.
A flexible and transparent β-Ga2O3 solar-blind ultraviolet photodetector on mica
Authors: Sui Yanxin , Liang Huili , Huo Wenxing , Wang Yan , Mei Zengxia
Published: August 2020

In the present work, we report a flexible transparent β-Ga2O3 solar-blind ultraviolet (UV) photodetector (PD) fabricated on a mica substrate. A laminated a-Ga2O3/Ga/a-Ga2O3 structure is thermally annealed at 1050 °C, forming a β-Ga2O3 film incorporating Ga nanospheres. A PD based on this nanocomposite film has a spectrum response peak at 250 nm, an extremely low dark current of 0.6 pA at a 10 V bias, a very high Ilight/Idark ratio of 3 × 106, and a fast recovery speed of less than 50 ms. Robust flexibility is demonstrated by bending tests and 10 000 cycles of a fatigue test with a radius as small as 8 mm. Compared to a room-temperature-fabricated flexible amorphous Ga2O3 (a-Ga2O3) PD, the flexible β-Ga2O3 PD on mica exhibits improved solar-blind UV photoresponse characteristics. The insertion of a gallium interlayer and treatment by high-temperature post annealing are proposed to contribute to a better stoichiometry and lattice order of the β-Ga2O3 thin film, as evidenced by the pronounced Raman peaks related to the GaI(OI)2 and GaIO4 vibration modes in β-phase Ga2O3. Our research is believed to provide a simple and practical route to achieving flexible transparent β-Ga2O3 solar-blind UV PDs, as well as other devices such as flexible transparent phototransistors and power rectifiers.
stoBEST: an efficient methodology for increased spatial resolution in two-component molecular tagging velocimetry
Authors: Pearce Michael , Sparrow Zachary , Mabote Thabiso R , Sánchez-González Rodrigo
Published: August 2020

A new methodology to analyze two-component molecular tagging velocimetry image pairs is presented. Velocity measurements with high spatial resolution are achieved by determining grid displacements at the intersections as well as along the grid lines using a multivariate adaptive regression splines parameterization along the segments connecting adjacent grid intersections. The methodology can detect the orientation of the grid, contains redundant steps for increased reliability, and handles cases where parts of the grid are missing, indicating potential for automation. Initial demonstration of the algorithm’s performance was illustrated using synthetic data sets derived from Computational Fluid Dynamics simulations and compared to Hough-transform and cross-correlation methodologies. Besides providing comparable results in terms of precision and accuracy to previously reported methodologies, the analysis of images by the proposed methodology results in significantly increased spatial resolution of the flow displacement determinations along the grid lines with comparable precision and accuracy. This methodology’s ability to handle different grid orientations without modifications was assessed using synthetic datasets with grids formed by sets of parallel lines at 90, 45, and 30 degrees from the vertical axis. Comparable results in terms of precision and accuracy were obtained across grid orientations, with all uncertainties below 0.1 pixel for images with signal-to-noise levels exceeding 5, and within 0.5 pixel for the noisiest image sets.
Study on the rheological properties and polishing properties of SiO2@CI composite particle for sapphire wafer
Authors: Pan Jisheng , Chen Zhijun , Yan Qiusheng
Published: August 2020

To study the rheological properties and polishing performance of magnetorheological fluids (MRFs) prepared with SiO2@carbonyl iron (CI) core-shell particles, SiO2@CI core-shell particles with different shell thicknesses were synthesized by an improved Stöber method controlling the amount of tetraethyl orthosilicate (TEOS). Then, four types of MRFs which dispersed with core-shell particles with thin shells, core-shell particles with thick shells, SiO2 particles, or carbonyl iron were prepared for sapphire polishing. The results show that the rheological properties of MRF based on thicker shell SiO2@CI are enhanced compared to those of MRFs prepared by dispersing abrasive and CI. Comparing with other MRFs, sapphire can obtain better surface quality when using thicker shell SiO2@CI. The MRF fabricated by SiO2@CI core-shell particles can increase the contact area between the abrasive and the workpiece and enhance the contact stress, which improves the solid-phase reaction rate and mechanical removal efficiency of silica and sapphire, thereby improve the polishing efficiency.