bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Kosten des Schlaganfalls in Deutschland: eine systematische Übersichtsarbeit
Authors: Düvel Juliane A. , Damm Oliver , Greiner Wolfgang
Published: October 2020

Zielsetzung Ziel dieser Studie war es, eine umfassende Übersicht über die Literatur zu Kosten des Schlaganfalls oder der transitorischen ischämischen Attacke (TIA) in Deutschland zu geben.

Methodik Es wurde eine systematische Literaturrecherche in PubMed und Embase durchgeführt, um kostenberichtende Studien zu Schlaganfall und TIA, die vor Juni 2019 veröffentlicht wurden, zu identifizieren. Studien wurden eingeschlossen, sofern die Gesamtkosten, eine spezifische Kostenkategorie oder mindestens eine Behandlungsphase nach einem Schlaganfall oder einer TIA dargestellt wurde. Dagegen wurden Studien ausgeschlossen, die den Schlaganfall lediglich als Folge einer anderen Erkrankung oder eines Risikofaktors berücksichtigt haben, soweit dort keine separate Beschreibung der schlaganfallspezifischen Kosten vorgenommen wurde. Um die Vergleichbarkeit der Studienergebnisse zu gewährleisten, wurden alle Kostenschätzungen mithilfe des Verbraucherpreisindex des Statistischen Bundesamtes auf das einheitliche Preisjahr 2018 angepasst.

Ergebnisse Die Suchen in den Datenbanken ergaben 482 Treffer zuzüglich 3 Handrechercheartikeln, von denen 66 Studien für die Volltextüberprüfung ausgewählt wurden. Davon wurden schlussendlich 16 Studien in die Ergebnissynthese eingeschlossen. Die durchschnittlichen direkten Kosten lagen zwischen 14 240 € und 44 060 € pro Patient. Wenn indirekte Kosten erhoben wurden, lagen diese zwischen 2470 € und 17 860 €. Im ersten Jahr nach einem Schlaganfall stellten die stationären Kosten den größten Kostenblock dar, während die ambulanten Behandlungs- und Pflegekosten insbesondere in den Folgejahren dominierten.

Schlussfolgerung Die Ergebnisse der Studien betonen die monetäre Relevanz des Schlaganfalls für das deutsche Gesundheitssystem. Daneben verdeutlicht die Übersichtsarbeit die Notwendigkeit einheitlicher Ansätze zur Erhebung und Analyse von Krankheitskosten, um eine Vergleichbarkeit zu gewährleisten und Handlungsbedarf anhand kostentreibender Aspekte identifizieren zu können.
Vestibular Schwannoma Tumor Size and Growth Rate Predict Response with Gamma Knife Stereotactic Radiosurgery
Authors: Killeen Daniel E. , Tolisano Anthony M. , Isaacson Brandon , Kutz J Walter , Barnett Samuel , Wardak Zabi , Hunter Jacob B.
Published: October 2020

Objective The aim of this study is to determine if pretreatment growth of sporadic vestibular schwannomas (VS) predicts postradiosurgery response.

Methods This study was a retrospective chart review at a tertiary referral center of patients with VS that had at least two pretreatment magnetic resonance imaging (MRI) studies at least 6 months apart and underwent Gamma Knife radiosurgery with a minimum of 14 months postradiosurgery imaging surveillance. Tumor linear measurements and volumetric segmentation were assessed before and after radiosurgery. The main outcome measure was persistent enlargement following radiosurgery, defined as 2 mm enlargement in greatest axial diameter or 20% enlargement in volume without size regression.

Results Thirty-five patients met the inclusion criteria. Patients were observed for median pre- and posttreatment intervals of 29.5 and 40.6 months, respectively. Median dose to the tumor margin was 13 Gy. Postradiosurgery enlargement occurred in six (17.1%) and nine (25.7%) patients based on linear and volumetric enlargement definitions, respectively. Pseudoprogression—defined as tumor enlargement—followed by linear or volumetric regression that occurred in 34.3% of tumors, reaching a maximum size at a median time of 6.3 months (3.3–8.4) postradiosurgery. When controlling for age, gender, and radiation dose, preradiosurgery tumor volume less than 0.3 cm3 (odds ratio [OR]: 59.7, p = 0.012) and preradiosurgery tumor diameter growth rate greater than or equal to 2.5 mm/year (OR: 19.3, p = 0.045) were associated with persistent postradiosurgery tumor enlargement.

Conclusion Smaller pretreatment tumor volume and greater linear tumor growth rates were associated with postradiosurgery tumor enlargement when controlling for age, gender, and radiation dose.

Level of Evidence This study indicates that the level of evidence is V.
Erythrocyte Complement Receptor 1 Gene Polymorphisms and Neonatal Respiratory Distress Syndrome
Authors: Rabie Walaa , Al-Taweel Ahmed , Abuelhamd Walaa A. , Shahin Walaa , Nazeer Marian , Aly Hany
Published: October 2020

To evaluate the role of erythrocyte complement receptor 1 (ECR1) gene in the predisposition to respiratory distress syndrome (RDS), we studied 50 infants with RDS and 50 controls. Real-time polymerase chain reaction allelic discrimination analysis of A3650G (rs2274567) and genotyping of the alleles (HindIII) were performed. Allele L of HindIII restricted single nucleotide polymorphism (SNP) associated with the severity of RDS. Duration of oxygen and ventilation in genotypes AA and AG of A3650G SNP was longer than genotype GG (17.6 ± 19.4 and 8.6 ± 4.5 days, p = 0.01) and (8.9 ± 11.9 and 3.9 ± 3.53 days, p = 0.03), respectively. A3650G and HINDIII digested gene polymorphisms of ECR1 may be of little importance for RDS.
Unternehmenskommunikation: Lasst uns mehr miteinander reden
Authors: Heeser Alexandra
Published: October 2020

In der Corona-Krise wurde überdeutlich, dass auch die eigenen Mitarbeiter aktuell und transparent mit nützlichen Informationen versorgt werden müssen. Viele Kliniken denken deshalb um und definieren die Rolle der Unternehmenskommunikation neu. Im Zuge dieses Umbruchs erobert gerade bei Klinikverbünden oder großen Klinikträgern der aus Zeitungsredaktionen bekannte Newsroom die Kliniken.
Neubau In Thüringen: Das Eisenberg-Modell
Authors: Kohrs Jens
Published: October 2020

Im thüringischen Eisenberg ist ein Krankenhausneubau entstanden, der Hotelstandard verspricht. David-Ruben Thies ist der Mann dahinter – ein Klinikchef, der verändern will und vor Ideen nur so sprüht. kma hat den Macher mit Mission getroffen.
Integration of 3D-printing for a desorption electrospray ionization source for mass spectrometry
Authors: Zemaitis Kevin J. , Wood Troy D.
Published: October 2020

The field of ambient ionization mass spectrometry has witnessed the development of many novel and capable methods for the analysis and imaging of surfaces, with desorption electrospray ionization being a prominent technique that has been commercialized. The adaptation of this technique to existing mass spectrometry platforms requires a laboratory-built solution manufactured with the capability of fine, stable adjustments of the electrospray emitter for liquid or solid sampling purposes. The development, fabrication, and machining require tens of hours of labor for many custom solutions. Herein described is a highly modifiable alternative approach for the fabrication of a desorption electrospray ionization source, using computer-aided design and fused deposition modeling to three-dimensionally print a source platform that utilizes standard accessories of a commercial Bruker Daltonics mass spectrometer. Three-dimensional printing allows for the inexpensive, rapid development of highly modifiable plastic parts, with the total printing time of the apparatus requiring a singular day and only a few dollars of material using a consumer grade printer. To demonstrate the utility of this printed desorption electrospray ionization source, it was fitted on an unmodified Fourier transform ion cyclotron resonance mass spectrometer for a lipid fingerprint analysis in serial sections of rat brain tissue, with the acquisition of line scans of dye-coated slides for the demonstration of serial acquisition.
What can microfluidics do for human microbiome research?
Authors: Tan Hsih-Yin , Toh Yi-Chin
Published: October 2020

Dysregulation of the human microbiome has been linked to various disease states, which has galvanized the efforts to modulate human health through microbiomes. Currently, human microbiome research is going through several phases to identify the constituent components of the microbiome, associate microbiome changes with physiological and pathological states, understand causative relationships, and finally translate this knowledge into therapeutics and diagnostics. The convergence of microfluidic technologies with molecular and cell profiling, microbiology, and tissue engineering can potentially be applied to these different phases of microbiome research to overcome the existing challenges faced by conventional approaches. The goal of this paper is to discuss and highlight the opportunities of applying different microfluidic technologies to specific areas of microbiome research as well as unique challenges that microfluidics must overcome when working with microbiome-relevant biological materials, e.g., micro-organisms, host tissues, and fluids. We will discuss the applicability of integrated microfluidic systems for processing biological samples for genomic sequencing analyses. For functional analysis of the microbiota, we will cover state-of-the-art microfluidic devices for microbiota cultivation and functional measurements. Finally, we highlight the use of organs-on-chips to model various microbiome–host tissue interactions. We envision that microfluidic technologies may hold great promise in advancing the knowledge on the interplay between microbiome and human health, as well as its eventual translation into microbiome-based diagnostics and therapeutics.
Electrical discharge in gas bubbles in gel
Authors: Gershman S. , Belkind A.
Published: October 2020

The development of electrical discharge in gas bubbles immersed in a liquid or a gel depends on the combination of the conductivity and dielectric properties of the medium as well as on the composition of the gas in the bubbles. The interest in a discharge in hydrogels is strongly stimulated by its use in combination with plasma in biology and medicine. Here, we use the electrical measurements of the current waveform and fast imaging and demonstrate the correlation between the discharge propagation in the bubble and the time evolution of the discharge current. We demonstrate experimentally that, if the dielectric constant is low and the conductivity is high (short time constant), then the discharge continues to propagate and to increase in brightness and the current continues to grow until the applied voltage is removed. The quenching of the discharge typical for dielectric barrier discharge is not observed and the effects are similar in hydrogels and in water. A simple circuit model is used to explore the dependence of the current waveform on the parameters of the medium and plasma. The shape of the current pulse significantly affects the amount of energy produced by the discharge and hence is an important property for the design and monitoring of plasma sources used for water decontamination and for plasma activation of gels.
Investigation of local structures and electronic states of Sb-doped Mg2Si by fluorescence XAFS and HAXPES
Authors: Kadono Tomoyuki , Hirayama Naomi , Nishio Tadashi , Yamazawa Shingo , Oki Naoto , Takahashi Yoshinobu , Takikawa Natsumi , Yasui Akira , Nitta Kiyofumi , Sekizawa Oki , Tokumura Mako , Takemoto Shoji , Iida Tsutomu , Kotsugi Masato
Published: October 2020

To clarify the origin of the figure of merit in the thermoelectric material Mg2Si, we performed extended x-ray absorption fine structure (EXAFS) analysis and hard x-ray photoelectron spectroscopy (HAXPES). We elucidate the local structures and electronic states of Mg2Si, especially focusing on the contribution of doped Sb. EXAFS analysis revealed that Sb substituted Si and that the nearest neighbor distance expanded around Sb. Furthermore, HAXPES confirmed the formation of density of states near the Fermi level by co-doping with 0.5% Zn and 0.5% Sb. The comparison of the experimental and theoretical results suggested that the density of states at the Fermi level was due to the tail of the conduction band, and it was filled by the electrons provided by doped Sb. From a microscopic viewpoint, the results obtained in this study suitably explain why Sb doping increases electrical conductivity and decreases thermal conductivity in Mg2Si, as reported in a previous study.
Dynamics and concentration variations of fine particles of different sizes in the vicinity of DC conductors
Authors: Zhu Jie , He Zichen , Xie Qing , Bian Xingming , Shen Boyang
Published: October 2020

The dynamics of fine particles of different sizes in the vicinity of DC conductors have been studied. It was observed that the particles aggregated with each other and were distributed in parallel chains on the surface of the conductors. Moreover, an interesting “layering phenomenon” was discovered in the spaces where particles concentrated. Variations in the concentration of particles of different sizes were measured in the sump. A higher voltage and a larger particle size were found to be associated with a faster decrease in the particle concentration. Based on a coupled model of the electric field and the force field, the different forces acting on particles of different sizes were analyzed. Particles of different sizes were observed to reunite into a spindle shape in the calculation space, with large particles playing a leading role. According to the calculation results, the particles around the conductor will settle and reunite, and the gathering of particles accelerates the settlement.
Variational fitting of the Fock exchange potential with modified Cholesky decomposition
Authors: Pedroza-Montero Jesús Naín , Delesma Francisco Antonio , Morales José Luis , Calaminici Patrizia , Köster Andreas M.
Published: October 2020

The variational fitting of the Fock potential employing localized molecular orbitals requires either the inversion of the local two-center Coulomb matrices or alternatively the solution of corresponding linear equation systems with these matrices. In both cases, the method of choice is the Cholesky decomposition of the formally positive definite local two-center Coulomb matrices. However, due to finite-precision round-off errors, the local Coulomb matrices may be indefinite, and thus, the Cholesky decomposition is not applicable. To overcome this problem, we propose to make use of a modified Cholesky decomposition based on the indefinite factorization of local two-center Coulomb matrices. To this end, the working equations for the use of the modified Cholesky decomposition within the variational fitting of the Fock potential are presented. Benchmark calculations with global and range-separated hybrid functionals show that the proposed method can improve considerably the workload balance in parallel calculations.
Hybrid magnonics: Physics, circuits, and applications for coherent information processing
Authors: Li Yi , Zhang Wei , Tyberkevych Vasyl , Kwok Wai-Kwong , Hoffmann Axel , Novosad Valentine
Published: October 2020

Hybrid dynamic systems have recently gained interest with respect to both fundamental physics and device applications, particularly with their potential for coherent information processing. In this perspective, we will focus on the recent rapid developments of magnon-based hybrid systems, which seek to combine magnonic excitations with diverse excitations for transformative applications in devices, circuits, and information processing. Key to their promising potentials is that magnons are highly tunable excitations and can be easily engineered to couple with various dynamic media and platforms. The capability of reaching strong coupling with many different excitations has positioned magnons well for studying solid-state coherent dynamics and exploiting unique functionality. In addition, with their gigahertz frequency bandwidth and the ease of fabrication and miniaturization, magnonic devices and systems can be conveniently integrated into microwave circuits for mimicking a broad range of device concepts that have been applied in microwave electronics, photonics, and quantum information. We will discuss a few potential directions for advancing magnon hybrid systems, including on-chip geometry, novel coherent magnonic functionality, and coherent transduction between different platforms. As a future outlook, we will discuss the opportunities and challenges of magnonic hybrid systems for their applications in quantum information and magnonic logic.
Electronic structure of non-centrosymmetric PtBi2 studied by angle-resolved photoemission spectroscopy
Authors: Jiang Wenxiang , Zhu Fengfeng , Li Ping , Li Yunlong , Wang Guohua , Jing Qiang , Gao Wenshuai , Tian Mingliang , Ma Jie , Zhang Wentao , Luo Weidong , Qian Dong
Published: October 2020

Using high-resolution angle-resolved photoemission spectroscopy (ARPES), we have systematically studied the electronic structure of non-centrosymmetric PtBi2 with a layered structure. Through photon energy dependent measurements, the surface state and the bulk state were identified. Consistent with the non-centrosymmetric structure, different surface states were observed on opposite PtBi2(001) surfaces. Experimental bulk bands agree nicely with first-principle calculations. By combining ARPES and calculations, energy bands that contribute to triply degenerate point fermion were all detected. We also suggest that there are “canted” tube-like Fermi surfaces that might cause strong anisotropy in electronic transportation in non-centrosymmetric PtBi2.
Lead-free halide perovskite photovoltaics: Challenges, open questions, and opportunities
Authors: Pecunia Vincenzo , Occhipinti Luigi G. , Chakraborty Abhisek , Pan Yiting , Peng Yueheng
Published: October 2020

In recent years, lead-free metal-halide perovskite photovoltaics has attracted ever-growing attention, in view of its potential to replicate the outstanding properties of lead-halide perovskite photovoltaics, but without the toxicity burden of the latter. Despite a research effort much smaller in scale than that pursued with lead-based perovskites, considerable progress has been achieved in lead-free perovskite photovoltaics, with the highest power conversion efficiencies now being in the region of 13%. In this Perspective, we first discuss the state of the art of lead-free perovskite photovoltaics and additionally highlight promising directions and strategies that could lead to further progress in material exploration and understanding as well as in photovoltaic efficiency. Furthermore, we point out the widespread lack of experimental data on the fundamental optoelectronic properties of lead-free halide perovskite absorbers (e.g., charge carrier mobility, defect parameters, Urbach energy, and the impact of dimensionality). All of this currently hampers a rational approach to further improving their performance and points to the need for a concerted effort that could bridge this knowledge gap. Additionally, this Perspective brings to the fore the manifold photovoltaic opportunities—thus far largely unexplored with lead-free perovskite absorbers—beyond single-junction outdoor photovoltaics, which may potentially enable the realization of their full potential. The exploration of these opportunities (tandem photovoltaics, indoor photovoltaics, and building-integrated and transparent photovoltaics) could energize the investigation of existing and new classes of lead-free perovskite absorbers beyond current paradigms and toward high photovoltaic performance.
Effects of forced frequency oscillations and free stream turbulence on the separation-induced transition in pressure gradient dominated flows
Authors: Sengupta Aditi , Tucker Paul
Published: October 2020

The individual and cumulative effects of forced frequency oscillations and free stream turbulence (FST), on the separation-induced transition caused by an adverse pressure gradient on a flat plate geometry, are numerically investigated by solving the Navier–Stokes equation. The flat plate is subjected to a streamwise pressure gradient via a contoured wall, representative of a low pressure turbine blade. The results are validated against existing numerical data, and insights into flow physics of the pre-transitional and turbulent regimes are gained using instantaneous, time-averaged, and phase-averaged flow fields, turbulent kinetic energy budgets, and a disturbance enstrophy-based nonlinear analysis based on direct numerical simulations. Oscillations are imposed at two values of reduced frequency (kosc). Higher reduced frequency oscillations are more effective in triggering early transition and reducing the separated region. This suppression of the separated region is more pronounced with FST. A reduction in the size of the separation bubble is noted along with enhanced near-wall mixing resulting in a shift in the inflection point of the velocity profile toward the wall, with FST and oscillations. The budget of the turbulent kinetic energy shows the dominance of the production term for the case with FST and forced oscillations. The disturbance enstrophy-based analysis provides insight into budget terms of the enstrophy equation, specifically on the role of vortex stretching. Finally, spatiotemporal linear receptivity of the case with oscillations near the separation bubble is reported. This provides a quantitative description of the instability triggered by the pressure gradient and oscillations.
Direct numerical simulation of particle-laden turbulent boundary layers without and with combustion
Authors: Wang Zhuo , Wang Haiou , Luo Kun , Fan Jianren
Published: October 2020

In the present work, direct numerical simulations of non-reactive and reactive turbulent boundary layers laden with inert particles were performed to investigate the influences of combustion on particle motions in wall-bounded flows. It was found that the coherent vortical structures of turbulent boundary layers are significantly modified by combustion. The streamwise velocity of particles is enhanced, while the velocity fluctuation is reduced in the reactive case due to the relaminarization effects. The preferential concentration of particles in the reactive case was found to be attenuated based on both visualization and the Voronoi analysis. The particle concentration in the outer layer of the reactive case is reduced because of the thermal expansion effects. However, the concentration is increased in the near-wall regions. The quadrant analysis of the Reynolds stress component was applied to explain this behavior. It was revealed that the magnitude of the mean Reynolds stress component is attenuated as a result of relaminarization. The frequency of the sweep event is increased but that of the injection event is reduced in the near-wall regions, which is responsible for the high particle concentration near the wall of the reactive case. The present study improves fundamental understandings of particle behaviors in non-reactive and reactive turbulent boundary layers.
Super quantum Dirac operator on the q-deformed super fuzzy sphere in instanton sector using quantum super Ginsparg–Wilson algebra
Authors: Lotfizadeh M.
Published: October 2020

The quantum super fuzzy Dirac and chirality operators on the q-deformed super fuzzy sphere are constructed. Using the quantum super fuzzy Ginsparg–Wilson algebra, the q-deformed super gauged fuzzy Dirac and chirality operators in the instanton sector are studied. It has been shown that they have a correct commutative limit in the limit case when the noncommutative parameter l tends to infinity and q tends to unity.
Driving mechanism of thermal transpiration pump with porous material
Authors: Sugimoto Shogo , Sugimoto Hiroshi
Published: October 2020

The behavior of the rarefied gas in the thermal transpiration pump with the porous material is investigated numerically by the direct simulation Monte Carlo method. The mass flux achieved by the pump is analyzed for a wide range of Knudsen numbers and ratios of the pore length to the pore diameter. The results show that the thermal edge flows around the ends of the pore play an essential role in determining the maximum performance. The effect of the thermal edge flow leads to a qualitative difference in the driving mechanism from a similar thermal transpiration pump by Knudsen. The mass flow takes a maximum value at a considerably large Knudsen number when the pore length is much larger than the pore diameter. The numerical tests show that a larger mass flux is possible when the edge flow is suppressed. The mass flux is investigated for several values of accommodation coefficient and complex pore geometries. The present results show that only the latter leads to the reduction in the mass flux. The compression ratio, including the performance curve of the pump, is also analyzed for several cases. The results show that the small accommodation coefficient decreases the compression ratio of the pump.
On a model of the vacuum arc at a volatile cathode (Cd and Hg)
Authors: Nemchinsky Valerian
Published: October 2020

For volatile cathodes (e.g., Hg), the ratio of the work function and the latent heat of vaporization is such that vaporization cooling overwhelmingly exceeds ion heating at moderate cathode temperatures. This fact was an obstacle in cathode spot modeling for cathodes of such metals. Analysis of the emission process at higher temperatures revealed the effect of “phase transition” that takes place at some critical temperatures: 1360 K for mercury and 2040 K for cadmium. During a very sharp transition that occurs within a few degrees or less, there is a simultaneous rise of electron emission, the arrival of an intense ion flux at the cathode, and a reduction or even reverse of emission cooling (the Nottingham effect), which leads to a completely new cathode state. Heat flux to the cathode goes from being highly negative to highly positive. This makes it possible for the arc to burn. The characteristics of that new state are similar to that of a regular cathode spot of a vacuum arc. A scenario of cathode spot cycling with this new state is suggested.
Dynamical behavior of droplets transiently impacting on superhydrophobic microstructures
Authors: Liu Chunbao , Liu Qi , Lin Zhaohua
Published: October 2020

Superhydrophobic microstructures (100 μm–1 mm) on a solid surface can change the droplet impact dynamics and reduce the contact time, both of which are potentially relevant for various industrial applications. In the study described here, the effects of two superhydrophobic microstructures are compared: a uniformly distributed convex hull structure and a striated structure. Droplet impact dynamics are simulated for a wide range of impact velocities (0.15 m/s–4.4 m/s) with the aim of quantitatively recording the morphological changes in droplets and the formation of splashed droplets using the curves of the spreading diameter and contact diameter vs time. Different types of bouncing behavior are also investigated. The results indicate that an increase in the impact velocity leads to a transition from rebound with full retraction, to a rebound without full retraction, then to a rebound with splashed droplets, and finally to a splashing phenomenon. The special morphologies during rebounding are also analyzed, in particular, pancake bouncing and bouncing in the flying-eagle configuration. The former had no significant change in contact time, owing to reattachment occurring, but the latter can reduce the contact time by 27.6% for an impact velocity of 1.4m/s. Finally, the dynamic behavior is quantitatively characterized, with a focus on the analysis of the maximum spread diameter, maximum retraction velocity, and contact time. As the impact velocity increases, the first two increase, but the third decreases. A sharp drop in the contact time at a high impact velocity is found to be due to the occurrence of the splashing phenomenon.
Rheological behavior of molecular vs network chalcogenide supercooled liquids
Authors: Sen S. , Zhu W. , Yuan B. , Aitken B. G.
Published: October 2020

The viscoelastic behavior of supercooled glass-forming liquids along the binary join As4S3–GeS2 with As4S3 contents varying from 81.25 to 9 mol. % and correspondingly with structures varying from predominantly molecular to a three-dimensional tetrahedral network is studied by small-amplitude oscillatory shear parallel plate rheometry. The storage shear modulus G′ shows a scaling behavior of G′(ω) ∼ ωn in the terminal (low-frequency) regime, where n varies between 1 and 2 and shows an increasingly anomalous departure from the expected value of 2 (Maxwell scaling) with increasing molecule content. A concomitant departure from the Maxwell scaling is also observed for the loss modulus G″ at frequencies above the G′–G″ crossover. On the other hand, the variation in the phase angle δ with the complex modulus indicates that the molecular liquid does not display a purely viscous response even at the lowest frequencies. These results, combined with an analysis of the relaxation spectra of these liquids, suggest that the anomalous behavior of molecular liquids may be linked to their rather broad relaxation spectrum and the presence of slow relaxation processes associated with molecular clusters. Additionally, these liquids are also characterized by a wide high-frequency plateau in the relaxation spectral density that can be linked to the rotational dynamics of the constituent molecules. Such fundamental differences between the rheological behavior of molecular and network liquids may explain the significantly higher fragility of the former.
Extraordinary sequence of severe weather events in the late-nineteenth century
Authors: Callaghan Jeff
Published: October 2020

Between 1883 and 1898, 24 intense tropical cyclones and extra tropical cyclones directly impacted on the southern Queensland and northern New South Wales coasts, with at least 200 fatalities in what was then a sparsely populated area. These events also caused record floods and rainfall, for example Brisbane City experienced its two largest ever floods over this period and Brisbane City set a 24-h rainfall record that still stands today. Additionally, a 24-h rainfall total of 907 mm occurred in a tributary of the upper Brisbane River resulting in a 15-m wall of water advancing down the river. Recent studies have shown that this part of Australia incurs the largest weather-related insurance losses. A major focus in this study is the seas these storms generated, leading to the loss of many marine craft and changes these waves brought to coastal areas. As a famous example of coastal erosion near Brisbane, the continual impacts from large waves caused a channel to form through Stradbroke Island to the open ocean forming two separate islands. Details of how this channel formed are described in relation to the storms. A climatology study of 239 Australian east coast storms that caused severe ocean damage between Brisbane and the Victorian border over the period between 1876 and February 2020 showed that 153 events occurred with a positive Southern Oscillation Index (SOI) trend and 86 events with a negative trend. The most active years were 1893 and 1967, both during positive SOI periods and both dominated by tropical cyclone activity. The 1893 events caused unparalleled floods and strongly contributed to the Jumpinpin breakthrough on Stradbroke Island, and the 1967 event was associated with historical Gold Coast beach erosion causing 9 billion normalised Australian dollars of insurance losses. The study also showed how direct tropical cyclone impacts in the study area decreased markedly following the June 1976 climate shift.
The tabloidization of the Brexit campaign
Authors: Zappettini Franco
Published: October 2020

Consistent with a populist script, evoking the people has been a nodal point in the discursive unfolding of Brexit and its
legitimation. This paper focuses on the mediatization of the Brexit referendum campaign in a corpus of online British tabloids to address
the critical question of how the people in whose name Brexit was (de)legitimised were discursively constructed and mobilized. The argument
put forward is that the legitimation of Brexit was achieved through exclusionary definitions of the people and through strategies of fear,
resentment and empowerment. This discursive framing points to the wider question of the instrumental role that a large section of the
British tabloid press has had not simply in the contingency of referendum but also in the longer-term legitimation chain of Brexit and in
its institutionalization and more generally in the historical priming of their readership with negative coverage of the UK/EU
relationship.
Romance Interrogative Syntax
Authors: Bonan Caterina
Published: October 2020

This monograph offers an innovative understanding of the mechanisms involved in Romance ‘optional’ wh-in situ. New supporting evidence in favour of Cable’s (2010) Grammar of Q is presented, as well as novel implementations of his original theory. In particular, it is claimed that wh-in situ idioms are characterised not only by language-specific choices between Q-projection and Q-adjunction, and between overt and covert movement of Q, but also in terms of the locus where they check the features relevant to wh-questions: while some languages check both [q] and [focus] in C, others make use of the clause-internal vP-periphery to check [focus]. Thanks to the vast amount of data presented and discussed, along with the predictions and theoretical contributions made, this monograph will be of interest to a wide range of specialists in human language, from typologists to Romance specialists and formal syntacticians, but also to the many experts in languages with overt Q-particles who wonder why Romance specialists have long been so resistant to the implementation of silent Q-particles in their theoretical models.
Visualization of flat and curved spacetimes with simple cartography tools
Authors: Scott R B
Published: October 2020

Well-developed tools from cartography are adapted and used to visualize curved and flat spacetime to further understanding of relativistic effects, while interpretation of these tools is aided through their application to the familiar world map. First spacetime is cut into two-dimensional subspaces that are mapped to the Minkowski or Euclidean plane using map projections. Then, exploiting the cartographic technique of map interruptions, the two-dimensional subspaces are further cut into ‘wedges’ to minimize the distortion. The mental exercise of sewing the wedges back together aids in visualizing and interpreting the geometry of the spacetime slice. Map distortion indicators alert the reader to the inevitable effects of distortion. This wedge diagram provides a simple yet powerful tool to visualize both flat and curved spacetime geometry. It is more general than the familiar embedding diagram and avoids the pitfall of confusing the space in question with the embedding space. The wedge diagram is applied first to Minkowski spacetime with the cartographers’ azimuthal equidistant map projection and, when combined with the wedge technique, provides a simple visualization of the twin paradox. The wedge diagram is then applied to the exterior Schwarzschild spacetime to visualize the physical significance of spacetime curvature. In particular it is shown how gravitational time dilation results from intrinsic curvature of a radial-time slice of spacetime. Then this diagram is applied to the Friedmann–Robertson–Walker (FRW) spacetime revealing how expansion of the Universe results from a qualitatively similar curvature of a radial-time slice, but with the roles of space and time reversed. The analogy between the two spacetimes suggests novel interpretations of the two spacetimes. We interpret the Schwarzschild spacetime as time expanding with increasing distance from the horizon. And we interpret the FRW spacetime as the Universe expanding as the influence of the big bang peters out.
A direct reconstruction algorithm for the anisotropic inverse conductivity problem based on Calderón’s method in the plane
Authors: Murthy Rashmi , Lin Yi-Hsuan , Shin Kwancheol , Mueller Jennifer L
Published: October 2020

A direct reconstruction algorithm based on Calderón’s linearization method for the reconstruction of isotropic conductivities is proposed for anisotropic conductivities in two-dimensions. To overcome the non-uniqueness of the anisotropic inverse conductivity problem, the entries of the unperturbed anisotropic tensors are assumed known a priori, and it remains to reconstruct the multiplicative scalar field. The quasi-conformal map in the plane facilitates the Calderón-based approach for anisotropic conductivities. The method is demonstrated on discontinuous radially symmetric conductivities of high and low contrast.
Bright, polarization-tunable high repetition rate extreme ultraviolet beamline for coincidence electron–ion imaging
Authors: Comby A , Bloch E , Beauvarlet S , Rajak D , Beaulieu S , Descamps D , Gonzalez A , Guichard F , Petit S , Zaouter Y , Blanchet V , Mairesse Y
Published: October 2020

After decades of supremacy of the Titanium:Sapphire technology, Ytterbium-based high-order harmonic sources are emerging as a promising alternative for experiments requiring high flux of ultrashort extreme ultraviolet (XUV) radiation. In this article we describe a versatile experimental setup delivering XUV photons in the 10–50 eV range. The use of cascaded high-order harmonic generation enables us to reach 1.9 mW of average power at 18 eV. Several spectral selection schemes are presented, to isolate a single high-harmonic or a group of them. In the perspective of circular dichroism experiments, we produce highly elliptical XUV radiation using resonant elliptical high-harmonic generation, and circularly polarized XUV by bichromatic bicircular high-harmonic generation. As an illustration of the capacities of the beamline, we focus the XUV beam in a coincidence electron–ion imaging spectrometer, where we measure the photoelectron momentum angular distributions of xenon monomers and dimers.
Analysis of Compton profile through information theory in H-like atoms inside impenetrable sphere
Authors: Mukherjee Neetik , Roy Amlan K
Published: October 2020

Confinement of atoms inside various cavities has been studied for nearly eight decades. However, the Compton profile (CP) for such systems has not yet been investigated. Here we construct the CP for a H atom radially confined inside a hard spherical enclosure, as well as in a free condition. Some exact analytical relations for the CP’s of circular or nodeless states of free atoms is presented. By means of a scaling idea, this has been further extended to the study of a H-like atom trapped inside an impenetrable cavity. The accuracy of these constructed CPs has been confirmed by computing various momentum moments. Apart from that, several information theoretical measures, like Shannon entropy (S) and Onicescu energy (E) have been exploited to characterize these profiles. Exact closed-form expressions are derived for S and E using the ground state CP in free H-like atoms. A detailed study reveals that, increase in confinement inhibits the rate of dissipation of kinetic energy. At a fixed ℓ, this rate diminishes with a rise in n. However, at a certain n, this rate accelerates with progress in ℓ. Similar analysis on the respective free counterpart displays an exactly opposite trend as that in a confined system. However, in both free and confined environments, the CP generally gets broadened with rise in Z. Representative calculations are done numerically for low-lying states of the confined systems, taking two forms of position-space wave functions: (a) exact (b) highly accurate eigenfunctions through a generalized pseudospectral method. In essence, CPs are reported for confined H atoms (and isoelectronic series) and investigated adopting an information-theoretic framework.
Single and multiple excitations in double-core-hole states of free water molecules
Authors: Marchenko T , Carniato S , Goldsztejn G , Travnikova O , Journel L , Guillemin R , Ismail I , Koulentianos D , Martins J , Céolin D , Püttner R , Piancastelli M N , Simon M
Published: October 2020

We present a combined experimental and theoretical study of the double-core-hole photoelectron spectrum obtained in isolated water molecules irradiated with hard x-rays above the oxygen K
−2 threshold. States of the type O K
−2
V and multiply excited states are created by single-photon absorption and subsequent one-electron emission. A detailed analysis enabled by high experimental resolution reveals dissociative nuclear dynamics in the K
−2
V pre-edge states. At the binding energies above the K
−2 double-ionization potential, a complex spectral pattern is observed and attributed to highly excited states involving multiple shake-up excitation processes with the aid of state-of-the-art theoretical calculations. A strong broadening due to the nuclear motion indicates a highly dissociative nature of these multiply excited states, in agreement with the theoretical analysis.
Double differential distributions of e-emission in ionization of N2 by 3, 4 and 5 keV electron impact
Authors: Chowdhury Madhusree Roy , Chauhan Dhaval , Limbachiya Chetan G , Tőkési Karoly , Champion Christophe , Weck Philippe F , Tribedi Lokesh C
Published: October 2020

We report the measurement of the absolute double differential cross sections (DDCS) of secondary electrons emitted due to the ionization of N2 molecule in collisions with fast electrons having energies between 3 and 5 keV. The emitted electrons with energies from 1–500 eV have been measured for different forward and backward emission angles. The measured DDCS have been compared with the state-of-the-art first Born approximation with correct boundary condition (CB1) model calculations as well as with the classical trajectory Monte Carlo (CTMC) method. From the measured DDCS, the single differential cross sections (SDCS) as a function of the emission energies have been computed and eventually the total ionization cross sections (TCS) have been derived. The TCS values are also compared with a semi-empirical calculation, namely, the CSP-ic (complex scattering potential-ionization contribution) model.
Novel repumping on 3P0
→
3D1 for Sr magneto-optical trap and Landé g factor measurement of 3D1
Authors: Zhang Shengnan , Ramchurn Preetam , Menchetti Marco , Ubaid Qasim , Jones Jonathan , Bongs Kai , Singh Yeshpal
Published: October 2020

We realize an experimental facility for cooling and trapping strontium (Sr) atoms and measure the Landé g factor of 3D1 of 88Sr. Thanks to a novel repumping scheme with the 3P2 → 3S1 and 3P0 → 3D1 combination and the permanent magnets based self-assembled Zeeman slower, the peak atom number in the continuously repumped blue magneto-optical trap is enhanced by a factor of 15 with respect to the non-repumping case, and reaches ∼1 billion. Furthermore, using the resolved-sideband Zeeman spectroscopy, the Landé g factor of 3D1 is measured to be 0.4995(88) showing a good agreement with the theoretical value of 0.4988. The results will have an impact on various applications including atom laser, dipolar interactions, quantum information and precision measurements.
Magnetic noise calculation of mu-metal shields at extremely low frequencies for atomic devices
Authors: Ma Danyue , Ding Ming , Lu Jixi , Zhao Junpeng , Yang Ke , Fang Xiujie , Wang Kun , Zhang Ning , Han Bangcheng
Published: October 2020

Mu-metal shields are widely used in atomic devices, but their magnetic noise related to loss is the key performance limit. The magnetic noise can be calculated by using complex permeability and the magnetic field intensity in the shield. In this study, Bertotti loss separation is used for the first time to accurately calculate the changes of complex permeability due to the hysteresis loss in different frequencies and magnetic field intensities, and we further consider the change in magnetic field intensity due to the induced eddy current, which also increases the accuracy of the magnetic noise calculation. For extremely low frequencies below 20 Hz, the improved noise simulation model differs from the measured results by less than 11%. If the loss separation is not considered, the difference between the measured value and the simulated value would be as high as 54%. The high agreement between the calculation and the experimental results proves the accuracy of the proposed method. Our method can be used in the design and optimization of low-noise magnetic shields to improve the sensitivity of atomic devices
Impact of thermal annealing in forming gas on the optical and electrical properties of MoS2 monolayer
Authors: Iacovella Fabrice , Koroleva Aleksandra , Rybkin Artem G , Fouskaki Maria , Chaniotakis Nikolaos , Savvidis Pavlos , Deligeorgis George
Published: October 2020

Technological applications involving 2D MoS2 require transfer of chemical vapor deposition (CVD) grown material from its original substrate and subsequent lithographic processes. Inevitably, those steps contaminate the surface of the 2D material with polymeric residues affecting the electronic and optical properties of the MoS2. Annealing in forming gas is considered an efficient treatment to partially remove such residues. However, hydrogen also interacts with MoS2 creating or saturating sulfur vacancies. Sulfur vacancies are known to be at the origin of n-doping evident in the majority of as-grown MoS2 samples. In this context, investigating the impact of thermal annealing in forming gas on the electronic and optical properties of MoS2 monolayer is technologically important. In order to address this topic, we have systematically studied the evolution of CVD grown MoS2 monolayer using Raman spectroscopy, photoluminescence, x-ray photoelectron spectroscopy and transport measurements through a series of thermal annealing in forming gas at temperatures up to 500 °C. Efficient removal of the polymeric residues is demonstrated at temperatures as low as 200 °C. Above this value, carrier density modulation is identified by photoluminescence, x-ray photoelectron spectroscopy and electrical characterization and is correlated to the creation of sulfur vacancies. Finally, the degradation of the MoS2 single layer is verified with annealing at or above 350 °C through Raman and photocurrent measurements.
A polynomial approach to the spectrum of Dirac–Weyl polygonal Billiards
Authors: Quintela M F C Martins , Lopes dos Santos J M B
Published: October 2020

The Schrödinger equation in a square or rectangle with hard walls is solved in every introductory quantum mechanics course. Solutions for other polygonal enclosures only exist in a very restricted class of polygons, and are all based on a result obtained by Lamé in 1852. Any enclosure can, of course, be addressed by finite element methods for partial differential equations. In this paper, we present a variational method to approximate the low-energy spectrum and wave-functions for arbitrary convex polygonal enclosures, developed initially for the study of vibrational modes of plates. In view of the recent interest in the spectrum of quantum dots of two dimensional materials, described by effective models with massless electrons, we extend the method to the Dirac–Weyl equation for a spin-1/2 fermion confined in a quantum billiard of polygonal shape, with different types of boundary conditions. We illustrate the method’s convergence in cases where the spectrum is known exactly, and apply it to cases where no exact solution exists.