bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphate-modified Co–Ni phosphide heterostructure formed by interfacial and electronic tuning for boosted faradaic properties
Authors: Li Zhan , Mi Hongyu , Ji Chenchen , Guo Fengjiao , Qiu Pengtao , Ma Kongjun , He Shixue , Wu Dandan , Cui Haonan , Yang Nianjun
Published: March 2021

Incorporation of the phosphate species and phosphide heterojunction interfaces within the sample can modify the inherent characteristic of transition metal-based materials to alleviate sluggish electron and ion transport issues to improve their electrochemical properties.
A general MOF-intermediated synthesis of hollow CoFe-based trimetallic phosphides composed of ultrathin nanosheets for boosting water oxidation electrocatalysis
Authors: Wang Cheng , Shang Hongyuan , Wang Yuan , Li Jie , Guo Siyu , Guo Jun , Du Yukou
Published: March 2021

A simple MOF-intermediated synthesis has been proposed for the versatile synthesis of hollow CoFeM (M = Bi, Ni, Mn, Cu, Ce, and Zn) trimetallic phosphides to enable highly efficient OER electrolysis.
Heteroatom coordination induces electric field polarization of single Pt sites to promote hydrogen evolution activity
Authors: Peng Xianyun , Bao Haihong , Sun Jiaqiang , Mao Zhiyong , Qiu Yuan , Mo Zhaojun , Zhuo Longchao , Zhang Shusheng , Luo Jun , Liu Xijun
Published: March 2021

Single Pt atomic sites are stabilized on MXene support via the formation of Pt–O and Pt–Ti bonds. The unique asymmetric coordination environment of single Pt sites induces local electric field polarization, which remarkably enhances HER activity.
Direct C–H aminocarbonylation ofN-heteroarenes with isocyanides under transition metal-free conditions
Authors: Zhou Zhong , Ji Huihui , Li Qing , Zhang Qian , Li Dong
Published: March 2021

A C–C bond forming amide synthesis through direct C–H aminocarbonylation ofN-heteroarenes with isocyanides was developed. The reaction was mediated by an inorganic persulfate salt under transition metal-free conditions.
5-(Diarylimino)- and 5-(sulfoximido)dibenzothiophenium triflates: syntheses and applications as electrophilic aminating reagents
Authors: Li Zhen , Vijaykumar Gonela , Li Xiangdong , Golz Christopher , Alcarazo Manuel
Published: March 2021

A new method has been developed for the synthesis of dibenzothiophenium salts containing diarylimino and sulfoximido substituents. The reactivity of these compounds under photochemical conditions is presented.
Polyaniline nano-needles into electrospun bio active fibres support in vitro astrocyte response
Authors: Saracino Emanuela , Zuppolini Simona , Guarino Vincenzo , Benfenati Valentina , Borriello Anna , Zamboni Roberto , Ambrosio Luigi
Published: March 2021

The presence of PnNs into electrospun fibres contributes to support in vitro functionalities of astrocytes.
Comparison of the photocatalytic activity of novel hybrid photocatalysts based on phthalocyanines, subphthalocyanines and porphyrins immobilized onto nanoporous gold
Authors: Steinebrunner David , Schnurpfeil Günter , Thayssen Jan , Tapia Burgos Jorge Adrian , Wichmann Andre , Wöhrle Dieter , Wittstock Arne
Published: March 2021

A set of heterogeneous photocatalysts based on porphyrinoid photosensitizers immobilized onto nanoporous gold was prepared and investigated in respect of differences in photocatalytic singlet oxygen sensitization.
Impedance matching in an elastic actuator
Authors: Guo Tianyi , Zheng Xiaoyu , Palffy-Muhoray Peter
Published: March 2021

We consider energy transfer from an elastic actuator to an elastic load, and show that the energy transfer can be optimized by tuning Young's modulus of the impedance matching host material.
Charge-transfer induced multifunctional BCP:Ag complexes for semi-transparent perovskite solar cells with a record fill factor of 80.1%
Authors: Ying Zhiqin , Yang Xi , Zheng Jingming , Zhu Yudong , Xiu Jingwei , Chen Wei , Shou Chunhui , Sheng Jiang , Zeng Yuheng , Yan Baojie , Pan Hui , Ye Jichun , He Zhubing
Published: March 2021

A charge-transfer induced BCP:Ag complex is employed as a multifunctional buffer layer for efficient inverted semi-transparent perovskite solar cells.
Polyhedral metal–organic framework monolayer colloidal crystals with sharpened and crystal facet-dependent selectivity for organic vapor sensing
Authors: Yu Shimo , Wang Xiang , Jiao Xiuling , Li Cheng , Chen Dairong
Published: March 2021

Polyhedral metal–organic framework monolayer colloidal crystals demonstrate sharpened and crystal facet-dependent selectivity for organic vapors by eliminating grain boundaries and randomly exposed crystal surfaces.
Deep learning‐based action recognition with 3D skeleton: A survey
Authors: Xing Yuling , Zhu Jia
Published: March 2021

Action recognition based on 3D skeleton data has attracted much attention due to its wide application, and it is one of the most popular research topics in computer vision. The 3D skeleton data is an effective representation of motion dynamics and is not easily affected by light, scene variation, etc. Previous research on action recognition has mainly focused on video or RGB data methods. In recent years, the advantages of combining skeleton data and deep learning have been gradually demonstrated, many impressive methods have been proposed, especially GCN‐based methods. In this survey, we first introduce the development process of 3D skeleton‐data action recognition and the classification of graph convolutional network, then introduce the commonly used NTU RGB + D and NTU RGB + D 120 datasets. Finally, a detailed review of existing variants of three mainstream technologies is provided based on deep learning and their performance was compared from three dimensions. To the best of our knowledge, this is the first research to integrate the research of GCN‐based method and its various evolutionary methods. Comparative investigation of existing variants of research in action‐recognition task from different perspectives is made, a generic framework is described, state‐of‐the‐art practices are summarized, and the emerging trends of this topic are explored.
Real‐valued gridless DOA estimation in massive ULA using a single snapshot
Authors: Yuan Jiawen , Zhang Gong , Liu Wenbo , Wang Xinhai , Qi Changyun
Published: March 2021

Basis mismatch challenges the conventional direction‐of‐arrival estimation constrained by sparse representation, especially in the case of massive antennas limited to a single snapshot. In this letter, we develop a real‐valued gridless direction‐of‐arrival estimation method to improve angular precision in the aforementioned circumstances. A new data model is first established through real‐valued transformation and then estimate the large low‐rank matrix with nuclear norm minimization. A fast iterative algorithm is designed to recover the underlying matrix faithfully and efficiently by the alternating direction method of multipliers. Numerical examples validate the performance improvement of the proposed method in the massive uniform linear array. This work also shows the potential to apply in measured data of the millimeter‐wave multiple‐input multiple‐output system.
Method for registration of 3D shapes without overlap for known 3D priors
Authors: Hu P. , Munteanu A.
Published: March 2021

In 3D registration of point clouds, the goal is to find an optimal transformation that aligns the input shapes, provided that they have some overlap. Existing methods suffer from performance degradation when the overlapping ratio between the neighbouring point clouds is small. So far, there is no existing method that can be adopted for aligning shapes with no overlap. In this letter, to the best of knowledge, the first method for the registration of 3D shapes without overlap, assuming that the shapes correspond to partial views of a known semi‐rigid 3D prior is presented. The method is validated and compared to existing methods on FAUST, which is a known dataset used for human body reconstruction. Experimental results show that this approach can effectively align shapes without overlap. Compared to existing state‐of‐the‐art methods, this approach avoids iterative optimization and is robust to outliers and inherent inaccuracies induced by an initial rough alignment of the shapes.
Selective spectral correlation for efficient map merging in multi‐robot systems
Authors: Lee Heoncheol
Published: March 2021

This letter addresses the problem of grid map merging in multi‐robot systems without knowledge of inter‐robot observations, common landmarks and initial relative poses. Several map merging methods have been proposed to solve the problem while overcoming the lack of features or local minima. This letter proposes a selective spectral correlation method for more efficient map merging which can reduce computation times while maintaining the accuracy. The performance of the proposed method was tested with experimental datasets and compared with other existing methods.
Toward developing tangling noise removal and blind inpainting mechanism based on total variation in image processing
Authors: Khan Muhammad Ashfaq , Dharejo Fayaz Ali , Deeba Farah , Ashraf Shahzad , Kim Juntae , Kim Hoon
Published: March 2021

In the field of image processing, tangling noise and artefacts elimination of objects are two essential tasks. Tangling noise and lack of intensity in certain applications also occur at the same time. In this paper, a new variational model is proposed based on total variation and l0 the norm for simultaneously removing the tangling noise, estimating the location of missing pixels, and filling in them. To be specific, the total variation is used to regularize the estimated image and use the l0 norm to make the missing pixel to be sparse. Moreover, the data fidelity term is given by a new forward description about the degraded process and the gamma noise assumption. Finally, an algorithm based on the alternating direction multiplier method is exploited to solve the model. By conducting simulated and real experiments, the damaged images can be effectively restored by the proposed method. In qualitative and quantitative terms, this approach works better.
Evaluation and analysis of novel flux‐adjustable permanent magnet eddy current couplings with multiple rotors
Authors: Li Zhao , Zhang Liang , Qu Boyang , Yang Hui , Wang Dazhi
Published: March 2021

This article proposes a novel flux‐adjustable permanent magnet eddy current coupling with multiple rotors. According to the different functions, the permanent magnet rotors are divided into fixed‐flux and flux‐adjustable rotors. By adjusting the relative position between two types of permanent magnet rotors, the magnetic field, torque, and output speed are controlled without changing the air‐gap length. To quickly and easily analyse the torque performance, an analytical model for the torque of such devices is developed based on the non‐linear magnetic equivalent circuit approach. In the modelling phase, a number of factors are considered, such as the skin effect, the inductance of eddy current field, the temperature effect, and so on. A three‐dimensional finite element method is employed to validate the model results, and the comparative analysis shows the advantages and potential of the proposed topology. The further sensitivity analysis of the key parameters is also made, which offers helpful information for the preliminary design of such devices.
Novel rotor design of dual‐stator brushless doubly fed generator based on surrogate model
Authors: Wang Hao , Zhang Yue , Jin Shi , Wang Huijun , Zhang Fengge
Published: March 2021

Dual‐stator brushless doubly fed generator (DSBDFG) is a novel generator applied for wind power generation, and the electromechanical energy conversion between the stator and rotor is realised by the magnetic field modulation of the special rotor structure. Therefore, the rotor design is critical to improve the performance of DSBDFG. In this study, the different rotor structures are compared and analysed, and the position of the non‐magnetic ring is determined. In order to reduce the computational cost and improve the optimisation efficiency, the surrogate model coupled with the multi‐island geometric algorithm is applied for the optimisation of the magnetic barrier layer of the cage barrier rotor. In addition, in order to reduce the effect of skin effect on the copper loss of cage bars of the rotor, the different simulation models, whose cage bars have different layer number, are simulated and analysed. Finally, the simulation and experimental results verify the correctness of the theoretical analysis and the effectiveness of surrogate model used for the rotor optimisation design of DSBDFG.
Shade dispersion methodologies for performance improvement of classical total cross‐tied photovoltaic array configuration under partial shading conditions
Authors: Pachauri Rupendra Kumar , Bai Jianbo , Kansal Isha , Mahela Om Prakash , Khan Baseem
Published: March 2021

Large size photovoltaic (PV) systems face a large number of issues based on malfunction and unfavourable climatic conditions such as partial shading conditions (PSCs). These PSCs are the major causes of PV systems’ performance degradation. In this paper, a symmetric matrix (SM) game puzzle is used to reconfigure the electrical connections of the PV array system. Present shade dispersion methodology is based on the ‘physical reallocation of PV module‐fixed electrical connections’ principle. Modification in the electrical connections of conventional total cross‐tied (TCT) PV array configuration introduces a new ‘SM‐TCT’ configuration. An extensive comparative study of conventional TCT and novel‐TCT (NTCT) configurations with proposed SM‐TCT configuration prove the effectiveness to achieve higher performance. The MATLAB/Simulink results are obtained on the basis of the non‐linear nature of current‐voltage and power‐voltage characteristics. SM‐TCT, Shape‐do‐Ku, NTCT and TCT configurations are examined under three realistic PSCs in terms of power and voltage at global maximum power point, improved fill factor, reduced power losses, performance ratio and power enhancement.
Simultaneous wound border segmentation and tissue classification using a conditional generative adversarial network
Authors: Sarp Salih , Kuzlu Murat , Pipattanasomporn Manisa , Guler Ozgur
Published: March 2021

Generative adversarial network (GAN) applications on medical image synthesis have the potential to assist caregivers in deciding a proper chronic wound treatment plan by understanding the border segmentation and the wound tissue classification visually. This study proposes a hybrid wound border segmentation and tissue classification method utilising conditional GAN, which can mimic real data without expert knowledge. We trained the network on chronic wound datasets with different sizes. The performance of the GAN algorithm is evaluated through the mean squared error, Dice coefficient metrics and visual inspection of generated images. This study also analyses the optimum number of training images as well as the number of epochs using GAN for wound border segmentation and tissue classification. The results show that the proposed GAN model performs efficiently for wound border segmentation and tissue classification tasks with a set of 2000 images at 200 epochs.
Research on the electromagnetic scattering from foam sea based on small slope approximation
Authors: Li Xin‐Hong
Published: March 2021

In order to improve the research of electromagnetic scattering characteristics and mechanism of the foam in the marine environment, considering the complexity and sensitivity of the electromagnetic scattering characteristics of the sea surface, the electromagnetic scattering characteristics of the foam sea surface are studied by the improved small slope approximation (SSA) method. The double Debye dielectric constant model is adopted to calculate the dielectric constant of seawater and foam. Based on the Elfouhaily sea spectrum model, the expression of scattering coefficient of the foam sea surface under SSA is derived, and then the theoretical calculation results of the SSA method are compared with the finite‐difference time‐domain method and the measured values in the literature, which verifies the effectiveness of the proposed algorithm. The model of the relationship between the thickness of the foam layer and the wind speed is established, and the composite backscattering characteristics of the ocean below the wind speed of 20 m/s are simulated. It is found that as the wind speed increases, the foam layer becomes thicker and the scattering intensity increases. The foam layer will weaken the ocean specular reflection and increase the diffuse reflection, which is more obvious when viewed at grazing and large incidence angle, and when the incident angle is greater than 83 degrees, the inflexion point caused by the foam will be clearly observed in the backscattering curve. The results of this study can provide a reference for civil and military activities and optimise the detection capability in the marine environment.
Nowhere to hide: Radio-faint AGN in the GOODS-N field
Authors: Radcliffe J. F. , Barthel P. D. , Thomson A. P. , Garrett M. A. , Beswick R. J. , Muxlow T. W. B.
Published: March 2021

Context. Obtaining a census of active galactic nuclei (AGN) activity across cosmic time is critical to our understanding of galaxy evolution and formation. Many AGN classification techniques are compromised by dust obscuration. However, very long baseline interferometry (VLBI) can be used to identify high brightness temperature compact radio emission (> 105 K) in distant galaxies that can only be reliably attributed to AGN activity.

Aims. We present the second in a series of papers dealing with the compact radio population in the GOODS-N field. This paper reviews the various multi-wavelength data and AGN classification techniques in the context of a VLBI-detected sample and use these to investigate the nature of the AGN as well as their host galaxies.

Methods. Multi-wavelength data from radio to X-ray were compiled for the GOODS-N AGN sample, and fourteen widely used multi-wavelength AGN classification schemes were tested. We discuss and compare the various biases that affect multi-wavelength and VLBI selection. We use the physical interpretation to imply the nature of VLBI-selected AGN and their hosts.

Results. Firstly, we find that no single identification technique can identify all VLBI objects as AGN. Infrared colour–colour selection is most notably incomplete. However, the usage of multiple classification schemes can identify all VLBI-selected AGN, independently verifying similar approaches used in other deep field surveys. In the era of large area surveys with instruments such as the SKA and ngVLA, multi-wavelength coverage, which relies heavily upon observations from space, is often unavailable. Therefore, VLBI remains an integral component in detecting AGN of the jetted efficient and inefficient accretion types. Secondly, a substantial fraction (46%) of the VLBI AGN have no X-ray counterpart, which is most likely due to lack of sensitivity in the X-ray band. Thirdly, a high fraction of the VLBI AGN reside in low or intermediate redshift dust-poor early-type galaxies. These most likely exhibit inefficient accretion. Fourthly, A significant fraction of the VLBI AGN reside in symbiotic dusty starburst – AGN systems. Finally, in the appendix, we present an extensive compilation of the multi-wavelength properties of all the VLBI AGN in GOODS-N.
Monitoring precipitable water vapour in near real-time to correct near-infrared observations using satellite remote sensing
Authors: Meier Valdés E. A. , Morris B. M. , Demory B.-O.
Published: March 2021

Context. In the search for small exoplanets orbiting cool stars whose spectral energy distributions peak in the near infrared, the strong absorption of radiation in this region due to water vapour in the atmosphere is a particularly adverse effect for ground-based observations of cool stars.

Aims. To achieve the photometric precision required to detect exoplanets in the near infrared, it is necessary to mitigate the effect of variable precipitable water vapour (PWV) on radial-velocity and photometric measurements. The aim is to enable global PWV correction by monitoring the amount of precipitable water vapour at zenith and along the line of sight of any visible target.

Methods. We developed an open-source Python package that uses imagery data obtained with the Geostationary Operational Environmental Satellites (GOES), which provide temperature and relative humidity at different pressure levels to compute the near real-time PWV above any ground-based observatory that is covered by GOES every 5 min or 10 min, depending on the location.

Results. We computed PWV values on selected days above Cerro Paranal (Chile) and San Pedro Mártir (Mexico) to benchmark the procedure. We also simulated different pointing at test targets as observed from the sites to compute the PWV along the line of sight. To asses the accuracy of our method, we compared our results with the on-site radiometer measurements obtained from Cerro Paranal.

Conclusions. Our results show that our publicly available code proves to be a good supporting tool for measuring the local PWV for any ground-based facility within the GOES coverage, which will help to reduce correlated noise contributions in near-infrared ground-based observations that do not benefit from on-site PWV measurements.
HD 142527: quantitative disk polarimetry with SPHERE
Authors: Hunziker S. , Schmid H. M. , Ma J. , Menard F. , Avenhaus H. , Boccaletti A. , Beuzit J. L. , Chauvin G. , Dohlen K. , Dominik C. , Engler N. , Ginski C. , Gratton R. , Henning T. , Langlois M. , Milli J. , Mouillet D. , Tschudi C. , van Holstein R. G. , Vigan A.
Published: March 2021

Aims. We present high-precision photometry and polarimetry based on visual and near-infrared imaging data for the protoplanetary disk surrounding the Herbig Ae/Be star HD 142527, with a strong focus on determining the light scattering parameters of the dust located at the surface of the large outer disk.

Methods. We re-reduced existing polarimetric differential imaging data of HD 142527 in the VBB (735 nm) and H-band (1625 nm) from the ZIMPOL and IRDIS subinstruments of SPHERE at the VLT. With polarimetry and photometry based on reference star differential imaging (RDI), we were able to measure the linearly polarized intensity and the total intensity of the light scattered by the circumstellar disk with high precision. We used simple Monte Carlo simulations of multiple light scattering by the disk surface to derive constraints for three scattering parameters of the dust: the maximum polarization of the scattered light Pmax, the asymmetry parameter g, and the single-scattering albedo ω.

Results. We measure a reflected total intensity of 51.4 ± 1.5 mJy and 206 ± 12 mJy and a polarized intensity of 11.3 ± 0.3 mJy and 55.1 ± 3.3 mJy in the VBB and H-band, respectively. We also find in the visual range a degree of polarization that varies between 28% on the far side of the disk and 17% on the near side. In the H-band, the degree of polarization is consistently higher by about a factor of 1.2. The disk also shows a red color for the scattered light intensity and the polarized intensity, which are about twice as high in the near-infrared when compared to the visual. We determine with model calculations the scattering properties of the dust particles and find evidence for strong forward scattering (g ≈ 0.5–0.75), relatively low single-scattering albedo (ω ≈ 0.2–0.5), and high maximum polarization (Pmax ≈ 0.5–0.75) at the surface on the far side of the disk for both observed wavelengths. The optical parameters indicate the presence of large aggregate dust particles, which are necessary to explain the high maximum polarization, the strong forward-scattering nature of the dust, and the observed red disk color.
In search of Bennu analogs: Hapke modeling of meteorite mixtures
Authors: Merlin F. , Deshapriya J. D. P. , Fornasier S. , Barucci M. A. , Praet A. , Hasselmann P. H. , Clark B. E. , Hamilton V. E. , Simon A. A. , Reuter D. C. , Zou X.-D. , Li J.-Y. , Schrader D. L. , Lauretta D. S.
Published: March 2021

Context.The OSIRIS-REx Visible and InfraRed Spectrometer onboard the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer spacecraft obtained many spectra from the surface of the near-Earth asteroid (101955) Bennu, enabling the characterization of this primitive small body. Bennu is spectrally similar to the hydrated carbonaceous chondrites (CCs), but questions remain as to which CCs, or combinations thereof, offer the best analogy to its surface.

Aims.We aim to understand in more detail the composition and particle size of Bennu’s surface by refining the relationship between this asteroid and various CC meteorites.

Methods.We used published absorbance and reflectance data to identify new optical constants for various CC meteorites measured in the laboratory at different temperatures. We then used the Hapke model to randomly generate 1000 synthetic spectra in order to find the combinations of these potential meteoritic analogs that best reproduce the spectral features of the asteroid.

Results.Our investigations suggest that the surface of Bennu, though visibly dominated by boulders and coarse rubble, is covered by small particles (tens to a few hundreds of μm) and that possibly dust or powder covers the larger rocks. We further find that the surface is best modeled using a mixture of heated CM, C2-ungrouped, and, to some extent, CI materials.

Conclusions.Bennu is best approximated spectrally by a combination of CC materials and may not fall into an existing CC group.
Spinalanalgesie – clever nutzen zur vaginalen Geburt
Authors: Töpel Lisa , Wenk Manuel
Published: March 2021

Neuroaxiale Verfahren stellen eine Möglichkeit der Analgesie in der Geburtshilfe dar. Insbesondere in der späten Phase der vaginalen Entbindung erfordern überraschende Momente, instrumentelle Methoden oder spezielle Manöver eine schnelle und suffiziente Analgesie. Hier können die Vorteile der Spinalanästhesie gegenüber der Epiduralanästhesie clever genutzt werden.
Perioperatives Management: vom OP auf die Intensivstation
Authors: Iken Sonja
Published: March 2021

Jährlich unterziehen sich weltweit über 300 Mio. Patienten einem chirurgischen Eingriff und ihr postoperativer Weg ist oft nicht klar vorgegeben. „Braucht mein Patient postoperativ ein Intensivbett?“ ist eine Frage, die sich die behandelnden Ärzte täglich stellen und die hier diskutiert wird – ebenso wie die Anforderungen an den Intrahospitaltransport auf die Intensivstation sowie die strukturierte Patientenübergabe nach dem SBAR-Konzept.
CO2-Trockengasbäder verändern den topischen pH-Wert auf Wundflächen und intakter Haut
Authors: Ranker Alexander , Gutenbrunner Christoph , Korallus Christoph , Krezdorn Nicco , Bingöl Alperen , Enechukwu Anieto , Sturm Christian
Published: March 2021

Hintergrund CO2-Therapie ist seit Jahrzehnten ein etabliertes physikalisch-medizinisches Therapieverfahren. CO2 reagiert mit Wasser zu Kohlensäure und könnte den kutanen pH-Wert verändern. Veränderungen des Wund-pH-Wertes spielen eine große Rolle beim modernen Wundmanagement chronischer Wunden. Da Kohlensäure eine schwache Säure ist, könnte CO2-Therapie den Wund-pH-Wert positiv beeinflussen. Bislang wurde noch keine explorative Datenanalyse durchgeführt, die pH-Veränderung an Wunden und Haut durch CO2-Therapie systematisch analysiert. Das Ziel dieser explorativen Pilotstudie ist es, Veränderungen von Haut-und Wund-pH-Werten vor und nach CO2-Trockengasbädern zu erheben. Dies soll Auskünfte über mögliche weitere Wirkmechanismen von CO2-Therapie geben.

Material und Methoden Von April bis Oktober 2020 wurde bei alle Patienten einer physikalisch-medizinischen Universitätsklinik-Ambulanz, die aufgrund Wundheilungsstörungen CO2-Therapie erhalten haben, vor und nach der CO2-Therapie der Haut- bzw. Wund-pH-Wert gemessen. Dies geschah mittels einer pH-Oberflächenmesssonde an 3 Messpunkten: Wundzentrum, intakte Haut im CO2-Expositionsbereich (Kontrolle1) und intake Haut ohne CO2-Exposition (Kontrolle2). Die Daten wurden retrospektiv analysiert. Alle Patienten erhielten CO2-Trockengasbäder im Regelfall mit 12 Therapiesitzungen à 20 min.

Ergebnisse Ausgewertet wurden die Messungen von N=13 Patienten (N=936 Messungen). Die gesamte Therapiezeit betrug 5,38±1,67 Wochen. Alle Patienten wiesen initial an der Wunde einen alkalischen pH-Wert auf (7,22±0,81), der sich signifikant von den pH-Werten der intakten Haut unterschied (Kontrolle 1: pH=5,86±0,26; p<0,001, Kontrolle2: pH=4,98±0,28; p<0,001). Im Mittel konnte CO2-Therapie die alkalischen Werte signifikant in Richtung saures Milieu verschieben (p=0,009). Die kutanen pH-Werte intakter Haut wurden alkalischer.

Schlussfolgerung CO2-Trockengasbäder verändern den topischen pH-Wert auf Wundflächen und intakter Haut. Sie beeinflussen den oberflächlichen Wund-pH günstig mit einem Shift in Richtung physiologischer Haut-pH-Werte.
Real Metal-Free C–H Arylation of (Hetero)arenes: The Radical Way
Authors: Bellina Fabio
Published: March 2021

Synthetic methodologies involving the formation of carbon–carbon bonds from carbon–hydrogen bonds are of significant synthetic interest, both for efficiency in terms of atom economy and for their undeniable usefulness in late-stage functionalization approaches. Combining these aspects with being metal-free, the radical C–H intermolecular arylation procedures covered by this review represent both powerful and green methods for the synthesis of (hetero)biaryl systems.

1 Introduction

2 Arylation with Arenediazonium Salts and Related Derivatives

2.1 Ascorbic Acid as the Reductant

2.2 Hydrazines as Reductants

2.3 Gallic Acid as the Reductant

2.4. Polyanilines as Reductants

2.5 Chlorpromazine Hydrochloride as the Reductant

2.6 Phenalenyl-Based Radicals as Reductants

2.7 Electrolytic Reduction of Diazonium Salts

2.8 Visible-Light-Mediated Arylation

3 Arylation with Arylhydrazines: Generation of Aryl Radicals Using an Oxidant

4 Arylation with Diaryliodonium Salts

5 Arylation with Aryl Halides

6 Conclusions
Factores de riesgo y estrategias de prevención para el desarrollo de estrechez uretral de origen iatrogénico: Papel del urólogo
Authors: Goméz Hoyos Andres , Gaviria Gil Federico
Published: March 2021

La estrechez uretral constituye una patología con morbilidad importante en el sexo masculino. Se evidencia en la actualidad un cambio en la frecuencia de las etiologías, con la disminución de causas inflamatorias y una transición hacia la iatrogenia como la más común. Mediante la búsqueda del estado del arte en cuanto a los procedimientos diagnósticos y terapéuticos conocidos como factores asociados a la estrechez uretral iatrogénica, se realizó una revisión narrativa de la literatura con el fin de describir y generar estrategias para su prevención. De los procedimientos terapéuticos que originan la estrechez uretral como complicación, el sondaje vesical es la mayor causa (hasta 34,3%), seguido de la prostatectomía radical (29,9%). Una buena técnica de sondaje vesical orientada desde el adecuado entrenamiento del personal disminuye de forma considerable su incidencia. Por otra parte, la adecuada selección de tratamientos y aspectos técnicos en pacientes que requieren el manejo de patologías obstructivas del tracto urinario como la hiperplasia prostática y litiasis u oncológicas como el cáncer de próstata, son unas de las recomendaciones para la prevención de ese trastorno. El entendimiento de los factores de riesgo y la adherencia a las estrategias de prevención descritas buscan disminuir la incidencia de la estrechez uretral de origen iatrogénico.
Clinical and Laboratory Markers of Brain Abscess in Tetralogy of Fallot (‘BA-TOF’ Score): Results of a Case–Control Study and Implications for Community Surveillance
Authors: Kanneganti Vidyasagar , Thakar Sumit , Aryan Saritha , Kini Prayaag , Mohan Dilip , Hegde Alangar S.
Published: March 2021

Background Cardiogenic brain abscess (CBA) is the commonest noncardiac cause of morbidity and mortality in cyanotic heart disease (CHD). The clinical diagnosis of a CBA is often delayed due to its nonspecific presentations and the scarce availability of computed tomography (CT) imaging in resource-restricted settings. We attempted to identify parameters that reliably point to the diagnosis of a CBA in patients with Tetralogy of Fallot (TOF).

Methods From among 150 children with TOF treated at a tertiary care institute over a 15-year period from 2001 to 2016, 30 consecutive patients with CBAs and 85 age- and sex-matched controls without CBAs were included in this retrospective case–control study. Demographic and clinical features, laboratory investigations, and baseline echocardiographic findings were analyzed for possible correlations with the presence of a CBA.

Statistical Analysis Variables demonstrating significant bivariate correlations with the presence of a CBA were further analyzed using multivariate logistic regression (LR) analysis. Various LR models were tested for their predictive value, and the best model was then validated on a hold-out dataset of 25 patients.

Results Among the 26 variables tested for bivariate associations with the presence of a CBA, some of the clinical, echocardiographic, and laboratory variables demonstrated significant correlations (p < 0.05). LR analysis revealed elevated neutrophil–lymphocyte ratio and erythrocyte sedimentation rate values and a lower age-adjusted resting heart rate percentile to be the strongest independent biomarkers of a CBA. The LR model was statistically significant, (χ2 = 23.72, p = <0.001), and it fitted the data well. It explained 53% (Nagelkerke R
2) of the variance in occurrence of a CBA, and correctly classified 83.93% of cases. The model demonstrated a good predictive value (area under the curve: 0.80) on validation analysis.

Conclusions This study has identified simple clinical and laboratory parameters that can serve as reliable pointers of a CBA in patients with TOF. A scoring model—the ‘BA-TOF’ score—that predicts the occurrence of a CBA has been proposed. Patients with higher scores on the proposed model should be referred urgently for a CT confirmation of the diagnosis. Usage of such a diagnostic aid in resource-limited settings can optimize the pickup rates of a CBA and potentially improve outcomes.
Analysis of the Long-Term Outcome in Open Carpal Tunnel Release Surgeries with and without External Neurolysis of Median Nerve, Using Boston Carpal Tunnel Questionnaire (BCTQ)–Hindi Version
Authors: Pattankar Sanjeev , Roy Rohan , Warade Anshu , Desai Ketan
Published: March 2021

Background The effectiveness of open carpal tunnel release (OCTR) in treating carpal tunnel syndrome (CTS) is well known. However, the role of ancillary external neurolysis of the median nerve is not well-documented. The Boston carpal tunnel questionnaire (BCTQ) is a commonly used disease-specific outcome instrument for CTS, which is validated across major languages of the world. No such validated Hindi version of BCTQ exists.

Objectives To analyze and compare the long-term outcome in patients who underwent OCTR alone and OCTR with external neurolysis of the median nerve, using BCTQ–Hindi version, while checking its validity.

Materials and Methods A retrospective, cross-sectional study was conducted at a tertiary care institute. The BCTQ was translated into Hindi language by a language expert. Eighty-four consecutive patients who underwent either unilateral/bilateral OCTR, with or without external neurolysis of the median nerve, between 2009 and 2019 were included in the study. Outcome analysis was done using BCTQ–Hindi version and patient satisfaction scoring. BCTQ–Hindi version was examined for statistical validity. Subgroup analysis of the outcome based on surgical technique (OCTR vs. OCTR with external neurolysis) used was carried out.

Results Response rate was 80.9%. Total hands evaluated were 108. BCTQ–Hindi version showed statistical validity. Overall symptom severity score (SSS) and functional severity score (FSS) were 1.14 ± 0.4 and 1.12 ± 0.35, respectively. Subgroup analysis of outcome revealed statistically significant results in favor of OCTR with external neurolysis of the median nerve.

Conclusions BCTQ–Hindi version is statistically validated. OCTR with external neurolysis of the median nerve is a promising avenue in surgical management of CTS. Further prospective studies are warranted.
A Comprehensive Treatment Approach to Address Speech Production and Literacy Skills in School-Age Children with Speech Sound Disorders
Authors: Loudermill Chenell , Greenwell Tamar , Brosseau-Lapré Françoise
Published: March 2021

Children with speech sound disorders (SSDs) represent a large proportion of clients served by school-based speech-language pathologists (SLPs). While considerable evidence is available regarding the identification of SSD in school-age children, there is a paucity of information regarding service delivery aspects of school-based speech therapy, such as frequency of sessions, number of trials, distribution of sessions over time, and format (individual or group intervention) that impacts the ability of SLPs to effectively treat SSD in the schools. School-age children with SSD are at risk for later literacy deficits, and strategically addressing their language and emerging literacy needs in addition to speech production accuracy may lead to increased intelligibility and better educational outcomes. In this article, we discuss the heterogeneity of school-age children with SSD with regard to weaknesses in phonological processing skills and language skills. We summarize the information currently available regarding the aspects of service delivery that contribute to gains in speech production accuracy. We conclude by sharing an example of how school-based SLPs could target speech production, phonological awareness, and morphological awareness in the same session with a child with SSD to maximize gains in speech and literacy skills.
The Communication Benefits of Participation in Camp Dream. Speak. Live.: An Extension and Replication
Authors: Byrd Courtney T. , Winters Katherine L. , Young Megan , Werle Danielle , Croft Robyn L. , Hampton Elizabeth , Coalson Geoffrey , White Andrew , Gkalitsiou Zoi
Published: March 2021

School-based guidelines often require that treatment focuses on minimizing or eliminating stuttered speech. The purpose of this study was to examine the benefits of explicit training in communication competencies to children who stutter without targeting stuttered speech. Thirty-seven children (ages 4–16) completed Camp Dream. Speak. Live., an intensive group treatment program which targets the psychosocial needs and communication of children who stutter. Outcome measures included the Overall Assessment of the Speaker's Experience of Stuttering (OASES), the Communication Attitude Test for Preschool and Kindergarten Children Who Stutter (KiddyCAT), and the Patient Reported Measurement Information System (PROMIS) Pediatric Peer Relationships Short Form (PROMIS Peer Relationships) and Parent Proxy Peer Relationships Short Form (PROMIS Parent Proxy). Pre- and posttreatment public presentations were rated on nine core verbal and nonverbal communication competencies by a neutral observer. Similar to previous studies, participants demonstrated significant improvements in communication attitudes (OASES) and perceived ability to establish peer relationships (PROMIS Peer Relationships), particularly school-aged participants (ages 7–16). Participants also demonstrated significant improvement in eight of the nine communication competencies. Findings suggest that, in addition to the psychosocial gains of programs such as Camp Dream. Speak. Live., children who stutter benefit from explicit training in communication skills, and these gains are not dependent on the presence of stuttered speech.
Artificial spin ice: Progress and future directions of the field
Authors: Kim Meeri
Published: March 2021

The field of artificial spin ice today studies novel, complex geometries that reveal new and unusual phenomena.
Direct measurements of the thermal dissipation rate in turbulent Rayleigh–Bénard convection
Authors: Hertlein Anna , du Puits Ronald
Published: March 2021

We report measurements of the thermal dissipation rate in turbulent Rayleigh-Bénard convection using a four-thermistor temperature gradient probe. The measurements have been undertaken in a Rayleigh-Bénard cell filled with air (Prandtl number Pr=0.7). The focus of this work is on large aspect ratios Γ (ratio between the horizontal and vertical extension of the cell), for which reason four datasets in the range of Rayleigh number Ra=3.9×106 to Ra=1.8×109 were taken at Γ≥8. In order to extend the range toward higher Rayleigh numbers, two smaller aspect ratios were also investigated (Γ=4 with Ra=1.7×1010 and Γ=2 with Ra=1.6×1011). We present highly resolved, vertical profiles of the thermal dissipation rate in the central vertical axis and discuss how these profiles change with the Rayleigh number. With its maximum near the wall and at the highest Rayleigh number, the thermal dissipation rate decreases monotonically with the distance from the plate. Moreover, the normalized, volume-averaged thermal dissipation rate, which effectively results in the Nusselt number Nu, scales with an exponent of about 0.29 with the Rayleigh number. In the Rayleigh number range investigated here, the dissipation is always higher in the boundary layer than in the bulk region. However, by means of an extrapolation of the considered Rayleigh number range to larger Rayleigh numbers, the intersection point between the dissipation in the boundary layer and the bulk region can be estimated as Ra≈3×1012.
Comparison of K0.5Na0.5NbO3 and PbZr0.52Ti0.48O3 compliant-mechanism-design energy harvesters
Authors: Kovacova Veronika , Yang Jung In , Jacques Leonard , Yeo Hong Goo , Lanari Valentin , Rahn Christopher , Trolier-McKinstry Susan
Published: March 2021

Piezoelectric energy harvesting from ambient vibrations offers an environmentally friendly approach to powering distributed sensors for the Internet of Things. This paper gives a direct comparison of Pb(Zr,Ti)O3 (PZT)- and (K,Na)NbO3 (KNN)-based harvesters using a compliant mechanism harvester design for resonant frequencies of 20, 40, and 70 Hz. At 70 Hz, the measured power densities for PZT- and KNN-based devices are 1139 and 31 μW/mm3, respectively, for unimorph structures on nickel foils of 25 and 50 μm in thickness. The power density ratios scale proportionally to the material energy harvesting figures of merit. Energy harvesting with the compliant mechanism design is twice as efficient when compared to harvesting with a simple cantilever beam.
Enhanced thermal stability of Ni/GeSn system using pre-amorphization by implantation
Authors: Quintero A. , Mazen F. , Gergaud P. , Bernier N. , Hartmann J.-M. , Reboud V. , Cassan E. , Rodriguez Ph.
Published: March 2021

Improving the thermal stability of Ni/GeSn intermetallics is of great importance to avoid surface degradation and Sn segregation. For this purpose, we studied the effects of pre-amorphization by ion implantation (PAI) of GeSn layers prior to metallization. The impact of Si, Ge, C, or Ge + C PAI was evaluated in terms of phase sequence, morpohological, and electrical evolution during the solid-state reaction. The overall phase sequence, followed by in situ x-ray diffraction, was comparable with or without PAI and went as follows: the Ni5(GeSn)3 hexagonal phase was obtained first, followed by the mono-stanogermanide phase: Ni(GeSn). Nevertheless, the threshold temperature for phase formation varied. These variations, depending on the nature of the implanted ions, can be related to kinetic and/or thermodynamic factors as supported by the analysis of bibliography for silicides and germanides. Additionally, it was reported that the use of Si or Ge implantation did not significantly impacted the surface morphology of the layers. On the other hand, the implantation of C positively impacts the surface morphology evolution by delaying Sn long-range diffusion and Ni(GeSn) agglomeration. This trend was then highly beneficial for preserving electrical stability in an enhanced process window.
Systematic evaluation of magnetic sensitivities of anisotropic magnetoresistive sensors at liquid helium temperature for superconducting cavities
Authors: Okada T. , Kako E. , Konomi T. , Masuzawa M. , Sakai H. , Tsuchiya K. , Ueki R. , Umemori K. , Pizzol P. , Poudel A. , Tajima T.
Published: March 2021

Trapped magnetic flux in bulk superconductors reduces the quality factor Q in superconducting radio-frequency (SRF) cavities. However, the mechanisms underlying flux trapping and radio-frequency loss are not well understood. Detailed observation of the magnetic distributions is important for understanding such phenomena. Magnetic field mapping is useful for observing the magnetic field distribution around SRF cavities. Measuring the change in the magnetic field around the cavity elucidates the flux trapping behavior. Anisotropic magnetoresistive (AMR) sensors are inexpensive and small devices that can detect magnetic flux density. The magnetic sensitivities of AMR sensors need to be evaluated at liquid helium temperature for the magnetic field mapping of SRF cavities. In this study, a test stand was constructed to calibrate the magnetic sensitivities of AMR sensors in liquid helium, and 110 AMR sensors were tested using this stand. The magnetic sensitivities were evaluated systematically. A solenoid coil was used to control the uniform external magnetic field and to measure the magnetic sensitivity at low temperatures. All AMR sensors exhibited suitable sensitivities to the magnetic field around the SRF cavity. The variation in these sensitivities in all AMR sensors was ∼1%. The AMR sensors were found to have sufficient sensitivity for mapping the magnetic field around the exterior surface of the SRF cavity.
Wave-kinetic approach to zonal-flow dynamics: Recent advances
Authors: Zhu Hongxuan , Dodin I. Y.
Published: March 2021

The basic physics of drift-wave turbulence and zonal flows has long been studied within the framework of the wave-kinetic theory. Recently, this framework has been reexamined from first principles, which has led to more accurate yet still tractable “improved” wave-kinetic equations. In particular, these equations reveal an important effect of the zonal-flow “curvature” (the second radial derivative of the flow velocity) on the dynamics and stability of drift waves and zonal flows. We overview these recent findings and present a consolidated high-level picture of (mostly quasilinear) zonal-flow physics within reduced models of drift-wave turbulence.
Nonperturbative decay dynamics in metamaterial waveguides
Authors: Liberal Iñigo , Ziolkowski Richard W.
Published: March 2021

In this work, we investigate the nonperturbative decay dynamics of a quantum emitter coupled to a composite right-/left-handed transmission line. Our theory captures the contributions from the different spectral features of the waveguide, providing an accurate prediction beyond the weak coupling regime and illustrating the multiple possibilities offered by the nontrivial dispersion of metamaterial waveguides. We show that the waveguide is characterized by a bandgap with two asymmetric edges: (i) a mu-near-zero band edge, where spontaneous emission is inhibited and an unstable pole is smoothly transformed into a bound state, and (ii) an epsilon-near-zero band edge, where the decay rate diverges and unstable and real (bound state) poles coexist. In both cases, branch cut singularities contribute with fractional decay dynamics whose nature depends on the properties of the band edges.