bluuebunny/crossref_metadata_2025 huggingface dataset:
Untargeted effects in organic exciton–polariton transient spectroscopy: A cautionary tale
Authors: Renken Scott , Pandya Raj , Georgiou Kyriacos , Jayaprakash Rahul , Gai Lizhi , Shen Zhen , Lidzey David G. , Rao Akshay , Musser Andrew J.
Published: October 2021

Strong light–matter coupling to form exciton– and vibropolaritons is increasingly touted as a powerful tool to alter the fundamental properties of organic materials. It is proposed that these states and their facile tunability can be used to rewrite molecular potential energy landscapes and redirect photophysical pathways, with applications from catalysis to electronic devices. Crucial to their photophysical properties is the exchange of energy between coherent, bright polaritons and incoherent dark states. One of the most potent tools to explore this interplay is transient absorption/reflectance spectroscopy. Previous studies have revealed unexpectedly long lifetimes of the coherent polariton states, for which there is no theoretical explanation. Applying these transient methods to a series of strong-coupled organic microcavities, we recover similar long-lived spectral effects. Based on transfer-matrix modeling of the transient experiment, we find that virtually the entire photoresponse results from photoexcitation effects other than the generation of polariton states. Our results suggest that the complex optical properties of polaritonic systems make them especially prone to misleading optical signatures and that more challenging high-time-resolution measurements on high-quality microcavities are necessary to uniquely distinguish the coherent polariton dynamics.
Two-dimensional flexible thermoelectric devices: Using modeling to deliver optimal capability
Authors: Xu Shengduo , Hong Min , Li Meng , Sun Qiang , Yin Yu , Liu Weidi , Shi Xiaolei , Dargusch Matthew , Zou Jin , Chen Zhi-Gang
Published: October 2021

Two-dimensional flexible thermoelectric devices (2D FTEDs) are a promising candidate for powering wearable electronics by harvesting low-grade energy from human body and other ubiquitous energy sources. However, immature device designs in the parametric geometries of FTEDs cannot provide an optimized output power density because of either insufficient temperature difference or unnecessarily large internal resistance. Here, we theoretically design optimal parametric geometries of 2D FTEDs by systematically considering applied temperature difference, temperature-dependent thermoelectric properties of materials, leg thickness, and thermodynamic conditions. The obtained analytical solution determines the optimal leg length for 2D FTEDs when these parameters are given and, therefore, minimizes the internal device resistance and simultaneously maintains the high temperature difference across the TE legs to maximize the device output power density. According to this design, we use flexible Ag2Se films as thermoelectric legs to assemble a 2D FTED, which displays a maximum power output of 11.2 mW and a normalized output power density of 1.43 μW cm−2 K−1 at a temperature difference of 150 K, outnumbering other 2D FTEDs by threefolds. Our 2D FTED can power up four light-emitting diodes, which shows great potential for harvesting electricity from low-grade heat. The exotic and reliable device design concept of 2D FTEDs reported here can be extended to other thermoelectric systems to boost the practical applications of FTEDs.
Highly efficient solution-processed white OLEDs via TADF host-sensitized dinuclear platinum (III) complex
Authors: Wang Sai , Liu Denghui , Wu Xiugang , Wang Li , Huang Jingwei , Chen Jun , Wang Yafei , Zhu Weiguo
Published: October 2021

External quantum efficiency (EQE), color rendering index (CRI), color correlated temperature (CCT), and spectral stability are key challenges for constructing high-performance white organic light-emitting diodes (WOLEDs) with a simple device structure. Herein, in order to resolve these issues, we primarily employed a thermally activated delayed fluorescence (TADF) emitter of CzAcSF as a host emitter and a dinuclear platinum (III) complex (Pt-1) as a guest emitter to construct solution-processed single-emitting layer WOLEDs at low guest concentrations of 0.75–1.50 wt. %. Thanks to their broad coverage of visible spectra, efficient energy transfer, and weak charge trap of Pt-1, the optimized WOLEDs showed an increasing EQE of 11.93% and a current efficiency of 30.76 cd/A with a high CRI of 75 and a CCT of 5210 K. Furthermore, the stable electroluminescent spectra with CIE (commission internationale de L'Eclairage) coordinate deviations of Δx = 0.022 and Δy = 0.015 were exhibited. This is an outstanding example for high-performance WOLEDs via employing a TADF host-sensitized low-concentration dinuclear platinum (III) complex simultaneously with high efficiency, CRI, CCT, and color stability.
Vibrational mode-specific dynamics of the F(2P3/2) + C2H6 → HF + C2H5 reaction
Authors: Papp Dóra , Czakó Gábor
Published: October 2021

We investigate the competing effect of vibrational and translational excitation and the validity of the Polanyi rules in the early- and negative-barrier F(2P3/2) + C2H6 → HF + C2H5 reaction by performing quasi-classical dynamics simulations on a recently developed full-dimensional multi-reference analytical potential energy surface. The effect of five normal-mode excitations of ethane on the reactivity, the mechanism, and the post-reaction energy flow is followed through a wide range of collision energies. Promoting effects of vibrational excitations and interaction time, related to the slightly submerged barrier, are found to be suppressed by the early-barrier-induced translational enhancement, in contrast to the slightly late-barrier Cl + C2H6 reaction. The excess vibrational energy mostly converts into ethyl internal excitation while collision energy is transformed into product separation. The substantial reaction energy excites the HF vibration, which tends to show mode-specificity and translational energy dependence as well. With increasing collision energy, direct stripping becomes dominant over the direct rebound and indirect mechanisms, being basically independent of reactant excitation.
Koala tree selection in a mixed-tenure landscape and post-fire implications
Authors: Gallahar Nicole , Leigh Kellie , Phalen David
Published: October 2021

Abstract Context The more frequent and intense bushfires predicted under climate change are likely to heavily impact koalas living inside protected areas and intact forests, which makes koala habitat in asset protection zones more important. Understanding how koalas use different habitats in a mixed-tenure landscape can inform effective conservation management. Aims The aims of this study were to determine (1) the species and size of trees used by koalas, (2) whether choice of daytime trees was affected by available proportions of tree species and sizes in koala home ranges, and (3) whether developed land was used as frequently as native forest. Methods Tree use by koalas was determined by radio-tracking 10 koalas for an average of 12 months and recording the species and diameter of trees they occupied. To compare the proportions of tree species used by koalas with those available, tree availability was measured using random quadrats in the home ranges of five koalas that used forested areas extensively. The habitats used by 10 koalas were classified as native forest or developed land to investigate the importance of human-modified areas. Key results Eucalyptus punctata was a preferred tree species, but each individual used four to nine species. Tree species were not chosen solely on the basis of available proportions; some species were selected preferentially. Half of the koalas used more developed land than native forest. Koalas preferentially used trees with larger diameters than the mean of available trees, and selected larger trees in developed areas than in native forest and when re-using trees. Conclusions Despite the higher availability of trees in protected native forest at the site, 70% of the koalas used developed land in and around asset protection zones. Koalas whose home ranges were geographically close, but had different soil types and vegetation communities, were able to utilise different tree species. Implications Koalas would benefit from protection of remnant native forests containing preferred trees on shale cap soil and conservation of native vegetation corridors along fence lines and in paddocks in developed areas because they are valuable resources and connect patchy landscapes. Protecting koalas on developed land improves their likelihood of surviving bushfires, allowing recolonisation of surrounding protected areas.
Martin on discourse semantics, genre, educational linguistics
Authors: Martin James R. , Gao Yanmei , Li Hanbing , Song Chengfang , Wei Minglong
Published: October 2021

J. R. Martin is a leading scholar who has greatly developed the theoretical framework of systemic functional
linguistics (SFL) over the past four decades. Some of these contributions, such as the systems of discourse semantics, the
appraisal framework and genre relations have been widely applied in various areas of linguistic studies and language education.
The educational linguistic model he and his colleagues have cultivated and developed has attracted the attention of more and more
educators from different disciplines around the globe. In this interview, he firstly elaborates on the significance of the
concepts of discourse semantics, grammatical metaphor and genre. Then he continues with applications of genre theory in secondary
school education, language maintenance, the relation and collaboration between Legitimation Code Theory (LCT) and SFL, and how the
two paradigms complement each other. Finally, he introduces some of his recent collaborations with grammarians of different
languages.
Instantiation and individuation in Buddhist scripture translation
Authors: Wang Pin
Published: October 2021

This paper analyses and compares the systemic functional features of the Sanskrit original text and the Chinese and English translations of the Buddhist scripture Heart Sutra, focusing on the ideational components that are manifest on the strata of discourse semantics and lexicogrammar. Results show that there are both expected equivalence and significant differences among the Sanskrit original text and the two translated texts. The accounts for the equivalence and differences are twofold (on two hierarchies): in terms of instantiation, the translators go along different re-instantiation routes in finding corresponding potentials between the source text and their respective target texts; in terms of individuation, the English and Chinese translators’ personal and social identity has an immediate influence on their respective reproductions of the text.
Characterisation and structural transformation of yttria dispersed austenitic steel through VHP
Authors: Arun Prasad M. , Pavithra E. , Dharmalingam G. , Siva Prakasham D.
Published: October 2021

Two different alloys were developed from the mixtures of pre-alloyed powders consisting of ferroalloys to get the required composition of austenitic stainless steel via the powder metallurgy technique along with the presence and absence of Y2O3. The subsequent mechanical alloyed powders were subject to vacuum hot pressing at 1200°C. The samples were subject to microstructural characterisation post-vacuum hot pressing process. With the addition of yttria, the structure of the grains was fine for the mechanical alloyed vacuum hot pressed samples. The TEM analysis revealed the presence of heterogeneous distribution of yttria particles along the grain boundaries. With the addition of yttria within the metal matrix, the hot pressed density was increased marginally.
Justifying the classical partition function for bosonic and fermionic systems using computer based experiments
Authors: Singh Sushil Kumar , Kaur Savinder
Published: October 2021

The partition function (PF) for a system of non-interacting N-particles can be found by summing over all the accessible states of the system. The PF for an ideal gas differs from bosonic or fermionic PF in the classical regime. Students find it difficult to follow the differences arising out of incorrect counting by the classical PF by missing out on the indistinguishability of particles and Fermi–Bose statistics. We present a pedagogical computer-based experiment to probe and demonstrate the key differences in the PFs (i) Q, for the system of distinguishable and indistinguishable particles (ii) B, for bosons and (iii) F, for fermions without formally using the single-particle PF.
Reconstruction of a source domain from the Cauchy data: II. Three-dimensional case
Authors: Ikehata Masaru
Published: October 2021

This paper is concerned with reconstruction issue of some typical inverse problems and consists of three parts. First a framework of the enclosure method for an inverse source problem governed by the Helmholtz equation at a fixed wave number in three dimensions is introduced. It is based on the nonvanishing of the coefficient of the leading profile of an oscillatory integral over a domain having a conical singularity. Second an explicit formula of the coefficient for a domain having a circular cone singularity and its implication under the framework are given. Third, an application under the framework to an inverse obstacle problem governed by an inhomogeneous Helmholtz equation at a fixed wave number in three dimensions is given.
Analysis of a generalized regularized Gauss–Newton method under heuristic rule in Banach spaces
Authors: Fu Zhenwu , Chen Yong , Li Li , Han Bo
Published: October 2021

In this work, we propose a generalized regularized Gauss–Newton method to solve nonlinear inverse problems in Banach spaces and consider its heuristic stopping rule. The proposed method only requires a generalized operator which could be independent of the Fréchet derivative of the forward operator, thus it can solve smooth as well as non-smooth inverse problems. In addition, the proposed heuristic rule is fully data driven and does not require any information on the noise level. Therefore, it can cope with inverse problems whose noise levels are unknown. An a posteriori error for this method under heuristic rule is obtained and general convergence result is given under some standard assumptions. Numerical experiments are presented to illustrate the efficiency of the proposed method.
SAW-driven self-cleaning drop free glass for automotive sensors
Authors: Song Hyeonseok , Jang Deasung , Lee Jeongmin , Lee Kang Yong , Chung Sang Kug
Published: October 2021

This paper presents surface acoustic wave (SAW)-driven self-cleaning glass aimed at removing contaminants that occur on the surfaces of automotive sensors for autonomous driving. The proposed self-cleaning glass comprises an interdigitated transducer (IDT) patterned on top of the transparent piezoelectric substrate (LiNbO3) and a hydrophobic layer (Cytop) covering the IDT. First, the sliding angle and contact angle of a droplet on a hydrophobic layer are measured in different volumes without the application of any external forces. The experiment shows that the droplets smaller than 4 μl do not slide on the inclined surface. To investigate the effect of SAW on droplet removal, the traveled distances and speeds of droplets are measured in different volumes, viscosities, and applied voltages when the droplets are removed on the surface by the SAW operation of the fabricated self-cleaning glass. Then, it is also investigated that the motion of the droplets by SAW on the inclined substrate in the direction of gravity and the opposite direction. Quantitative tests on the droplet removal performance of the SAW-driven self-cleaning glass are carried out by analyzing captured images recorded during the droplet removal by the SAW operation. As proof of concept, the proposed self-cleaning technology is demonstrated on droplets formed on a lens surface of a camera on which the SAW device is mounted. The demonstration shows that the camera image distorted by droplets that occur on the initial glass cover of the camera module is quickly restored by the SAW operation. The proposed SAW-driven drop free glass can promptly remove various contaminants on the surface of the sensors. Hence, it can be applied not only for automotive sensors but also for outdoor security cameras for daily life safety and future industries such as smart factories and smart cities.
Bismuth-based halide perovskite and perovskite-inspired light absorbing materials for photovoltaics
Authors: Ünlü Feray , Deo Meenal , Mathur Sanjay , Kirchartz Thomas , Kulkarni Ashish
Published: October 2021

The efficiency of organic-inorganic hybrid lead halide perovskite solar cells (PSCs) has increased over 25% within a frame of ten years, which is phenomenal and indicative of the promising potential of perovskite materials in impacting the next generation solar cells. Despite high technology readiness of PSCs, the presence of lead has raised concerns about the adverse effect of lead on human health and the environment that may slow down or inhibit the commercialization of PSCs. Thus, there is a dire need to identify materials with lower toxicity profile and comparable optoelectronic properties in regard to lead-halide perovskites. In comparison to tin-, germanium-, and copper-based PSCs, which suffer from stability issues under ambient operation, bismuth-based perovskite and perovskite-inspired materials have gained attention because of their enhanced stability in ambient atmospheric conditions. In this topical review, we initially discuss the background of lead and various lead-free perovskite materials and further discuss the fundamental aspects of various bismuth-based perovskite and perovskite-inspired materials having a chemical formula of A3Bi2X9, A2B′BiX6, B′aBibXa+3b(A = Cs+, MA+and bulky organic ligands; B′ = Ag+, Cu+; X = I−, Cl−, Br−) and bismuth triiodide (BiI3) semiconducting material particularly focusing on their structure, optoelectronic properties and the influence of compositional variation on the photovoltaic device performance and stability
Quantum shape oscillations in the thermodynamic properties of confined electrons in core–shell nanostructures
Authors: Aydin Alhun , Fransson Jonas , Sisman Altug
Published: October 2021

Quantum shape effect appears under the size-invariant shape transformations of strongly confined structures. Such a transformation distinctively influences the thermodynamic properties of confined particles. Due to their characteristic geometry, core–shell nanostructures are good candidates for quantum shape effects to be observed. Here we investigate the thermodynamic properties of non-interacting degenerate electrons confined in core–shell nanowires consisting of an insulating core and a GaAs semiconducting shell. We derive the expressions of shape-dependent thermodynamic quantities and show the existence of a new type of quantum oscillations due to shape dependence, in chemical potential, internal energy, entropy and specific heat of confined electrons. We provide physical understanding of our results by invoking the quantum boundary layer concept and evaluating the distributions of quantized energy levels on Fermi function and in state space. Besides the density, temperature and size, the shape per se also becomes a control parameter on the Fermi energy of confined electrons, which provides a new mechanism for fine tuning the Fermi level and changing the polarity of semiconductors.
Non-contact, automated adjustment procedure for capacitive displacement sensors
Authors: Daul Lars , Tao Jin , Busch Ingo , Koenders Ludger , Meeß Rudolf , Wolff Helmut
Published: October 2021

Capacitive sensors enable non-contact displacement measurements in the micrometer range with sub-nanometer resolution. To achieve this, a proper alignment of capacitive sensors is necessary. In this work, a non-contact, automated and intrinsic adjustment procedure is presented which is based on determining the extrema of slope error and nonlinearity. After the final adjustment step, the remaining tilt is less than 1.5 mrad. A measurement routine is used to evaluate the adjustment procedure by applying tilt around the final adjustment position and measuring the global slope error and the global nonlinearity. The combination of adjustment procedure and measurement routine enables the investigation of capacitive displacement sensors with higher accuracy in order to establish a comprehensive uncertainty budget and to explore improvements in capacitive sensor technology.
Transition metal nitrides and their mixed crystals for spintronics
Authors: Ito Keita , Honda Syuta , Suemasu Takashi
Published: October 2021

Anti-perovskite transition metal nitrides exhibit a variety of magnetic properties—such as ferromagnetic, ferrimagnetic, and paramagnetic—depending on the 3d transition metal. Fe4N and Co4N are ferromagnetic at room temperature (RT), and the minority spins play a dominant role in the electrical transport properties. However, Mn4N is ferrimagnetic at RT and exhibits a perpendicular magnetic anisotropy caused by tensile strain. Around the magnetic compensation in Mn4N induced by impurity doping, researchers have demonstrated ultrafast current-induced domain wall motion reaching 3000 m s−1 at RT, making switching energies lower and switching speed higher compared with Mn4N. In this review article, we start with individual magnetic nitrides—such as Fe4N, Co4N, Ni4N, and Mn4N; describe the nitrides’ features; and then discuss compounds such as Fe4−x
A
x
N (A = Co, Ni, and Mn) and Mn4−x
B
x
N (B = Ni, Co, and Fe) to evaluate nitride properties from the standpoint of spintronics applications. We pay particular attention to preferential sites of A and B atoms in these compounds, based on x-ray absorption spectroscopy and x-ray magnetic circular dichroism.
Surprisingly good thermoelectric performance of monolayer C3N
Authors: Jiao W Y , Hu R , Han S H , Luo Y F , Yuan H M , Li M K , Liu H J
Published: October 2021

The rapid emergence of graphene has attracted numerous efforts to explore other two-dimensional materials. Here, we combine first-principles calculations and Boltzmann theory to investigate the structural, electronic, and thermoelectric transport properties of monolayer C3N, which exhibits a honeycomb structure very similar to graphene. It is found that the system is both dynamically and thermally stable even at high temperature. Unlike graphene, the monolayer has an indirect band gap of 0.38 eV and much lower lattice thermal conductivity. Moreover, the system exhibits obviously larger electrical conductivity and Seebeck coefficients for the hole carriers. Consequently, the ZT value of p-type C3N can reach 1.4 at 1200 K when a constant relaxation time is predicted by the simple deformation potential theory. However, such a larger ZT is reduced to 0.6 if we fully consider the electron–phonon coupling. Even so, the thermoelectric performance of monolayer C3N is still significantly enhanced compared with that of graphene, and is surprisingly good for low-dimensional thermoelectric materials consisting of very light elements.
Spectral analysis of heart sounds associated with coronary artery disease
Authors: Larsen Bjarke Skogstad , Winther Simon , Nissen Louise , Diederichsen Axel , Bøttcher Morten , Jan Struijk Johannes , Christensen Mads Græsbøll , Schmidt Samuel Emil
Published: October 2021

Objective. The aim of this study was to find spectral differences of diagnostic interest in heart sound recordings of patients with coronary artery disease (CAD) and healthy subjects. Approach. Heart sound recordings from three studies were pooled, and patients with clear diagnostic outcomes (positive: CAD and negative: Non-CAD) were selected for further analysis. Recordings from 1146 patients (191 CAD and 955 Non-CAD) were analyzed for spectral differences between the two groups using Welch’s spectral density estimate. Frequency spectra were estimated for systole and diastole segments, and time-frequency spectra were estimated for first (S1) and second (S2) heart sound segments. An ANCOVA model with terms for diagnosis, age, gender, and body mass index was used to evaluate statistical significance of the diagnosis term for each time-frequency component. Main results. Diastole and systole segments of CAD patients showed increased energy at frequencies 20–120 Hz; furthermore, this difference was statistically significant for the diastole. CAD patients showed decreased energy for the mid-S1 and mid-S2 segments and conversely increased energy before and after the valve sounds. Both S1 and S2 segments showed regions of statistically significant difference in the time-frequency spectra. Significance. Results from analysis of the diastole support findings of increased low-frequency energy from previous studies. Time-frequency components of S1 and S2 sounds showed that these two segments likely contain heretofore untapped information for risk assessment of CAD using phonocardiography; this should be considered in future works. Further development of features that build on these findings could lead to improved acoustic detection of CAD.
Enhancing the directivity of a radiating array element for an optical true-time-delay network
Authors: Zarezadeh Esmail , Ghorbani Ayaz
Published: October 2021

The directivity of a horn antenna as a true-time-delay array element of an optical beam-forming network is enhanced by using a graded index dielectric lens. The proposed refractive index distribution of the lens is designed to mitigate the phase error at the antenna aperture while keeping the antenna reflectionless. Ray-tracing-based optimization is carried out to achieve the best design parameters and modify the horn’s body. Realization of the lens is also demonstrated by discretizing the refractive index of the lens into several layers. The half-power beamwidth value of an example horn antenna is divided by four using the proposed lens. The functionality of the proposed lens is verified by conducting ray-tracing and full-wave simulations using COMSOL.
3D mapping in optical trapping of polystyrene particles applying the Gerchberg–Saxton modified with 2D Legendre polynomials
Authors: Arriaga Hernández J A , Cuevas Otahola B , Oliveros Oliveros J , Morín Castillo M
Published: October 2021

We are focused on the phase retrieval and 3D profiles of microparticles (MP), analyzed in optical trapping. To this aim, we use several image segmentation procedures of MP from an optical trapping video. Moreover, we implement different procedures to remove several errors in the segmented image by means of algorithms based on the Legendre polynomials to enhance the MP image quality, as well as the errors caused by the drift inducing a shift in the MP (considering different MP with drift by shift, static, trapped and untrapped). Once the image corrections are conducted considering these errors, we propose some processes to recover the irradiance distribution of the MP in the image, from which it is possible to retrieve the MP phase to show their 3D profiles as 3D objects. Finally, we analyze the image in gray tones and use different retrieval methods with 2D Legendre polynomials, Gerchberg–Saxton (GS), Goldstein, and Quality Guided. We propose some modifications to such algorithms using Legendre polynomials, resulting in the deformation re-scaling iterative algorithm, ModI-LP, and a modified GS using the 2D-LP code to optimize our results.
Study on the effect of tin and antimony oxide interlayer on the performance of titanium-based manganese dioxide anode
Authors: Du Bo-Yan , Wang San-Fan , Yu Sheng-San
Published: October 2021

Tin-antimony interlayer and manganese dioxide active catalytic coating were prepared on titanium plate by coating and thermal decomposition. The load of interlayer and calcination temperature were selected as the influencing factors for univariate experiment. The seen morphology of the electrode was explored by SEM. The electrocatalytic performance and oxygen evolution mechanism were analyzed by testing the cyclic voltammetry curve, oxygen evolution polarization curve and AC impedance graph, the optimal preparation conditions of the Ti-Mno2anode interlayer were obtained.
Crystal structure, Curie temperature, and electromagnetic absorption properties in FexCo30Ni60−xSi5Al5 (x = 30, 35, 40, 45) high entropy alloys
Authors: Zhang Chen , Yuan Jianhui , Wang Xin , Zheng Guangzhi
Published: October 2021

In order to meet the requirements of future national defense for high temperature electromagnetic (EM) absorbing performance, a series of FexCo30Ni60−xSi5Al5 (x = 30, 35, 40, 45) high-entropy alloys (HEAs) powders was prepared and their Curie temperatures (TC) were measured by a self-made Wheatstone bridge. According to the results, varying the Fe/Ni ratio affected the crystal structure, Curie temperature, oxidation resistance, and electromagnetic absorbing properties of the above compounds. Since Fe has a BCC structure and is thus easier to form the solid solutions with Si and Al, the crystal structure of the alloy has changed from FCC toward BCC with increasing Fe dopant content. In turn, the Curie temperature (TC) decreased from 473.68 °C to 358.07 °C, being lower than their initial oxidation temperature (>800 °C). The reflection losses (RL) of powders at room temperature and high temperatures (≤500 °C) were calculated as well. It was found that the flake powders after ball milling gained a larger aspect ratio, resulting in the better absorption effect, which was due to high toughness and low strength characteristics of the initial FCC structure. Furthermore, the permittivity and permeability of alloys upon heating reached impedance matching at a certain temperature, thus achieving the greater RLmax value. Finally, the high-temperature EM absorption characteristics of HEAs were shown to merit a thorough study.
Deep learning-based thoracic CBCT correction with histogram matching
Authors: Qiu Richard L J , Lei Yang , Shelton Joseph , Higgins Kristin , Bradley Jeffrey D , Curran Walter J , Liu Tian , Kesarwala Aparna H , Yang Xiaofeng
Published: October 2021

Kilovoltage cone-beam computed tomography (CBCT)-based image-guided radiation therapy (IGRT) is used for daily delivery of radiation therapy, especially for stereotactic body radiation therapy (SBRT), which imposes particularly high demands for setup accuracy. The clinical applications of CBCTs are constrained, however, by poor soft tissue contrast, image artifacts, and instability of Hounsfield unit (HU) values. Here, we propose a new deep learning-based method to generate synthetic CTs (sCT) from thoracic CBCTs. A deep-learning model which integrates histogram matching (HM) into a cycle-consistent adversarial network (Cycle-GAN) framework, called HM-Cycle-GAN, was trained to learn mapping between thoracic CBCTs and paired planning CTs. Perceptual supervision was adopted to minimize blurring of tissue interfaces. An informative maximizing loss was calculated by feeding CBCT into the HM-Cycle-GAN to evaluate the image histogram matching between the planning CTs and the sCTs. The proposed algorithm was evaluated using data from 20 SBRT patients who each received 5 fractions and therefore 5 thoracic CBCTs. To reduce the effect of anatomy mismatch, original CBCT images were pre-processed via deformable image registrations with the planning CT before being used in model training and result assessment. We used planning CTs as ground truth for the derived sCTs from the correspondent co-registered CBCTs. The mean absolute error (MAE), peak signal-to-noise ratio (PSNR), and normalized cross-correlation (NCC) indices were adapted as evaluation metrics of the proposed algorithm. Assessments were done using Cycle-GAN as the benchmark. The average MAE, PSNR, and NCC of the sCTs generated by our method were 66.2 HU, 30.3 dB, and 0.95, respectively, over all CBCT fractions. Superior image quality and reduced noise and artifact severity were seen using the proposed method compared to the results from the standard Cycle-GAN method. Our method could therefore improve the accuracy of IGRT and corrected CBCTs could help improve online adaptive RT by offering better contouring accuracy and dose calculation.
What makes a complex a virtual resolution?
Authors: Loper Michael
Published: October 2021

Virtual resolutions are homological representations of finitely generated

Pic
(
X
)

\text {Pic}(X)

-graded modules over the Cox ring of a smooth projective toric variety. In this paper, we identify two algebraic conditions that characterize when a chain complex of graded free modules over the Cox ring is a virtual resolution. We then turn our attention to the saturation of Fitting ideals by the irrelevant ideal of the Cox ring and prove some results that mirror the classical theory of Fitting ideals for Noetherian rings.
Stochastic geometry and dynamics of infinitely many particle systems—random matrices and interacting Brownian motions in infinite dimensions
Authors: Osada Hirofumi
Published: October 2021

We explain the general theories involved in solving an infinite-dimensional stochastic differential equation (ISDE) for interacting Brownian motions in infinite dimensions related to random matrices. Typical examples are the stochastic dynamics of infinite particle systems with logarithmic interaction potentials such as the sine, Airy, Bessel, and also for the Ginibre interacting Brownian motions. The first three are infinite-dimensional stochastic dynamics in one-dimensional space related to random matrices called Gaussian ensembles. They are the stationary distributions of interacting Brownian motions and given by the limit point processes of the distributions of eigenvalues of these random matrices.

The sine, Airy, and Bessel point processes and interacting Brownian motions are thought to be geometrically and dynamically universal as the limits of bulk, soft edge, and hard edge scaling. The Ginibre point process is a rotation- and translation-invariant point process on

R

2

\mathbb {R}^2

, and an equilibrium state of the Ginibre interacting Brownian motions. It is the bulk limit of the distributions of eigenvalues of non-Hermitian Gaussian random matrices.

When the interacting Brownian motions constitute a one-dimensional system interacting with each other through the logarithmic potential with inverse temperature

β
=
2

\beta = 2

, an algebraic construction is known in which the stochastic dynamics are defined by the space-time correlation function. The approach based on the stochastic analysis (called the analytic approach) can be applied to an extremely wide class. If we apply the analytic approach to this system, we see that these two constructions give the same stochastic dynamics. From the algebraic construction, despite being an infinite interacting particle system, it is possible to represent and calculate various quantities such as moments by the correlation functions. We can thus obtain quantitative information. From the analytic construction, it is possible to represent the dynamics as a solution of an ISDE. We can obtain qualitative information such as semi-martingale properties, continuity, and non-collision properties of each particle, and the strong Markov property of the infinite particle system as a whole.

Ginibre interacting Brownian motions constitute a two-dimensional infinite particle system related to non-Hermitian Gaussian random matrices. It has a logarithmic interaction potential with

β
=
2

\beta = 2

, but no algebraic configurations are known.The present result is the only construction.
70 Availability of Personal Protective Equipment in NHS Hospitals During COVID-19: A National Survey
Authors: Mantelakis A , Spiers H , Lee C W , Chambers A , Joshi A
Published: October 2021

Introduction

The continuous supply of personal protective equipment (PPE) in the National Health Service (NHS) is paramount in order to sustain a safe level of staffing and to reduce transmission of COVID-19 to patients, public and staff.

Method

A 16-question survey was created to assess the availability and personal thoughts of healthcare professionals regarding PPE supply in England. The survey was distributed via social media (Facebook © and Twitter ©) to all UK COVID-19 healthcare professional groups, with responses collected over 3 weeks in March 2020 during the beginning of the pandemic.

Results

A total of 121 responses from physicians in 35 different hospitals were collected (105 inpatient wards, 16 from intensive care units). In inpatient wards, eye and face protection were unavailable to 19.1% of respondents. Masks were available to 97.7% of respondents and gloves in all respondents (100%). Body protection was available primarily as a plastic apron (83.8%). All of respondents working in intensive care had access to full-body PPE, except FFP3 respirator masks (available in 87.5%). PPE is ‘Always’ available for 29.8% of all respondents, and ‘Never’ or ‘Almost Never’ in 11.6%. There was a statistically significant difference between London and non-London responders that ‘Always’ had PPE available (43.9% versus 19.0%, p = 0.003).

Conclusions

This is the first survey to evaluate PPE supply in England during the COVID-19 pandemic. Our survey demonstrated an overall lack of PPE volume supply in the UK, with preferential distribution in London. Eye and full body protection are in most lack of supply.
118 Trauma in COVID-19: A comparison analysis of trauma calls at a Major Trauma Centre in the UK during the CoVID pandemic restrictions
Authors: Naseem S , Lee J
Published: October 2021

Aim

Varying restrictions placed on the UK public to manage the COVID-19 Pandemic impacted on the day-to-day lives of most people and changed the presentation and nature of trauma presenting at our UK Major Trauma Centre. Trauma activity during the November and March 2020 lockdown periods were compared and the changes in trauma activity were used to inform workforce planning. During the most restrictive period, March 2020, trauma activity initially decreased compared with 6 weeks preceding lockdown, before returning and then exceeding beyond pre-lockdown levels.

Method

Prospective data was collected for all ED trauma calls and regional referrals to the Major Trauma Service. We compared the initial 27-day lockdown periods in November to March 2020; specifically comparing trends in code red calls, silver trauma, road traffic collisions and injuries resulting from deliberate self-harm.

Results

There were a similar number of RTCs (18 vs 16) in both periods. There was a 28% increase in the number of trauma calls (103 vs 80), and a 4-fold increase in Code RED calls (8 vs 2) and injuries due to deliberate self-harm (8 vs 2). There were almost double the number of silver trauma patients. Interestingly, there was a 30% decrease in alcohol related trauma alerts.

Conclusions

Our results reflected the level of restrictions in place; a higher incidence of trauma calls including code reds and RTCs in November. The higher incidence of self-harm noticed in the second lockdown may reflect the psychological impact of the pandemic and change in restrictions over time.
165 Impact of COVID-19 on management of Foreign Bodies in Otolaryngology
Authors: Mahmood S , Mair M , Hussain M , Conboy P
Published: October 2021

Aim

The primary aim was to assess safety of Ear, nose and throat foreign body extraction during the coronavirus pandemic as this procedure is considered a potential aerosol generating procedure. The secondary aim was to evaluate the potential risks to patients if foreign body removal was delayed.

Method

A prospective study of 50 patients presenting to our unit with foreign bodies between March 2020 and August 2020 during the COVID-19 pandemic was performed. All patients were seen within 1 week of referral. The sites and types of foreign bodies were studied and correlated with complications where present. We assessed the circumstances under which foreign body removal was performed and its effect on health care professionals.

Results

The most common age group was the paediatric age group (52%). The most frequent sites of foreign bodies were the Ears at 78%(39 patients), followed by the nose at 12% (26 patients). Non-organic foreign bodies (52%) were more prevalent than organic foreign bodies (48%). Removal was performed in 31 (62%) patients either in clinic or in theatre. However, 19 patients (38%) were managed conservatively adhering to the British Association for Paediatric Otolaryngology guidance. Only 2 patients developed complications secondary to retained non-organic aural foreign bodies. None of the patients with organic foreign bodies developed complications. No infection rates among medical staff managing these patients were identified.

Conclusions

Contrary to normal practice, it is safe to manage selective ENT foreign bodies in a semi-urgent manner allowing time to implement ample precautions to reduce infection risks.
217 Covid-19 And Femoral Neck Fracture: A Retrospective Review
Authors: Morris R , Elbadri Z , Patel V , Azam A
Published: October 2021

Aim

Covid-19 has dominated healthcare over the past year. It most severely affects the elderly, a population whom also commonly present following falls, sustaining femoral neck fractures. Our aim was to retrospectively evaluate the effects of concomitant covid-19 infection in patients presenting acutely with femoral neck fractures.

Method

We conducted a retrospective review of all patients with femoral neck fractures during the ‘first wave’ of the coronavirus pandemic in Ysbyty Gwynedd (Bangor, UK), between April 2020 to June 2020. We noted each patient’s covid-19 status within 14 days of presentation with their acute femoral neck fracture and compared length of stay, discharge destination and mortality rate between covid and non-covid groups.

Results

There was a total of 75 femoral neck fractures in the 3-month period studied. 4 patients had incomplete data and were excluded from analysis. Of the remaining 71 patients, 15 (21%) were covid-positive within 14 days of admission, 47 patients (66%) were confirmed covid-negative and 9 patients (13%) received no coronavirus testing. The average age of patients was 88 in the covid-positive group and 84 in the covid-negative group. Those who developed covid-19 infection had an increased length of hospital stay (33 days covid-positive versus 14 days covid-negative; p = 0.25) and significantly increased in-hospital mortality rate (47% covid-positive versus 6% covid-negative; p = 0.001).

Conclusions

These results show that concomitant infection with covid-19 shortly after femoral neck fracture is associated with a significant increase in hospital mortality. They highlight the importance of trying to prevent covid-19 infection in this patient group.
Surgical treatment for post-infarction papillary muscle rupture: a multicentre study
Authors: Massimi Giulio , Ronco Daniele , De Bonis Michele , Kowalewski Mariusz , Formica Francesco , Russo Claudio Francesco , Sponga Sandro , Vendramin Igor , Falcetta Giosuè , Fischlein Theodor , Troise Giovanni , Trumello Cinzia , Actis Dato Guglielmo , Carrozzini Massimiliano , Shah Shabir Hussain , Coco Valeria Lo , Villa Emmanuel , Scrofani Roberto , Torchio Federica , Antona Carlo , Kalisnik Jurij Matija , D’Alessandro Stefano , Pettinari Matteo , Sardari Nia Peyman , Lodo Vittoria , Colli Andrea , Ruhparwar Arjang , Thielmann Matthias , Meyns Bart , Khouqeer Fareed A , Fino Carlo , Simon Caterina , Kowalowka Adam , Deja Marek A , Beghi Cesare , Matteucci Matteo , Lorusso Roberto
Published: October 2021

OBJECTIVES

Papillary muscle rupture (PMR) is a rare but potentially fatal complication of acute myocardial infarction. The aim of this study was to analyse the patient characteristics and early outcomes of the surgical management of post-infarction PMR from an international multicentre registry.

METHODS

Patients underwent surgery for post-infarction PMR between 2001 through 2019 were retrieved from database of the CAUTION study. The primary end point was in-hospital mortality.

RESULTS

A total of 214 patients were included with a mean age of 66.9 (standard deviation: 10.5) years. The posteromedial papillary muscle was the most frequent rupture location (71.9%); the rupture was complete in 67.3% of patients. Mitral valve replacement was performed in 82.7% of cases. One hundred twenty-two patients (57%) had concomitant coronary artery bypass grafting. In-hospital mortality was 24.8%. Temporal trends revealed no apparent improvement in in-hospital mortality during the study period. Multivariable analysis showed that preoperative chronic kidney disfunction [odds ratio (OR): 2.62, 95% confidence interval (CI): 1.07–6.45, P = 0.036], cardiac arrest (OR: 3.99, 95% CI: 1.02–15.61, P = 0.046) and cardiopulmonary bypass duration (OR: 1.01, 95% CI: 1.00–1.02, P = 0.04) were independently associated with an increased risk of in-hospital death, whereas concomitant coronary artery bypass grafting was identified as an independent predictor of early survival (OR: 0.38, 95% CI: 0.16–0.92, P = 0.031).

CONCLUSIONS

Surgical treatment for post-infarction PMR carries a high in-hospital mortality rate, which did not improve during the study period. Because concomitant coronary artery bypass grafting confers a survival benefit, this additional procedure should be performed, whenever possible, in an attempt to improve the outcome.

Clinical trial registration

clinicaltrials.gov: NCT03848429.
Inside—and outside—Illibata: composition, context and chronology in a famous Josquin motet
Authors: Rifkin Joshua
Published: October 2021

Opinions remain divided on the date of Illibata Dei virgo nutrix, the motet with the famous acrostic spelling the name Josquin des Prez. Some writers see it as a product of the composer’s years at the papal chapel, 1489–94; others would move its origin considerably earlier, even to 1466–75. The only real foothold we have comes from a Vatican copy made in the mid-1490s. Advocates for an early date see the music as particularly close to the works of Du Fay, Busnoys and Johannes Regis; those supporting a Roman origin point to a trend there during Josquin’s tenure towards similarly ‘archaic’ motets. In both instances, the writers have sought a context in the music of other composers. The present study turns the focus inward to seek a context within the development of Josquin himself. Despite the uncertainty that scholars find in Josquin chronology at every turn, careful analysis of compositional procedure offers a way of breaking the apparent logjam over what everyone recognizes as one of the most significant works of its era.