bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanistic basis of substrate–O2coupling within a chitin-active lytic polysaccharide monooxygenase: An integrated NMR/EPR study
Authors: Courtade Gaston , Ciano Luisa , Paradisi Alessandro , Lindley Peter J. , Forsberg Zarah , Sørlie Morten , Wimmer Reinhard , Davies Gideon J. , Eijsink Vincent G. H. , Walton Paul H. , Aachmann Finn L. 
Published: July 2020

SignificanceLytic polysaccharide monooxygenases (LPMOs) have unique catalytic centers, at which a single copper catalyzes the oxidative cleavage of a glycosidic bond. The mechanism by which LPMOs activate molecular oxygen is key to understanding copper (bio)catalysis but remains poorly understood, largely because the insoluble and heterogeneous nature of LPMO substrates precludes the use of usual laboratory techniques. Using an integrated NMR/EPR approach, we have unraveled structural and electronic details of the interactions of an LPMO fromBacillus licheniformisand β-chitin. EPR spectroscopy on uniformly isotope15N-labeled63Cu(II)-LPMO provided insight into substrate-driven rearrangement of the copper coordination sphere that predisposes the enzyme for O2activation.
Randomized trial shows healthcare payment reform has equal-sized spillover effects on patients not targeted by reform
Authors: Einav Liran , Finkelstein Amy , Ji Yunan , Mahoney Neale 
Published: July 2020

Significance
In the US healthcare system, most medical providers treat patients covered by multiple insurers. As a result, changes in the way one health insurer pays for medical services could, by changing provider behavior, spill over onto patients covered by other insurers. In this article, we present evidence of such spillovers in the context of a large Medicare payment reform that was implemented in some areas of the country but not in others, via random assignment. We show that the payment reform had effects of similar magnitude on both the directly covered patients and on patients covered by other insurers. We discuss implications of these findings for our interpretation of existing estimates as well as for the design of healthcare policy.
Cxcl9l and Cxcr3.2 regulate recruitment of osteoclast progenitors to bone matrix in a medaka osteoporosis model
Authors: Phan Quang Tien , Tan Wen Hui , Liu Ranran , Sundaram Sudha , Buettner Anita , Kneitz Susanne , Cheong Benedict , Vyas Himanshu , Mathavan Sinnakaruppan , Schartl Manfred , Winkler Christoph 
Published: July 2020

Significance
Bone remodeling requires a balanced interplay of osteoblasts and osteoclasts. While the intercellular signaling that triggers bone cell differentiation is well understood, it remains unclear how bone progenitor cells are recruited to remodeling sites. Various chemokines are upregulated under osteoporotic conditions. However, whether they are involved in progenitor recruitment or instead have inflammatory roles is unknown. Here we used a medaka fish osteoporosis model to identify the chemokine ligand Cxcl9l and receptor Cxcr3.2 as essential to control osteoclast progenitor recruitment and differentiation at bone resorption sites. Cxcr3.2 activity can be blocked by small-molecule inhibitors that protect bone from osteoporotic insult. Our study demonstrates the potential of fish for osteoporosis drug discovery and opens avenues for future osteoporosis therapy.
Selective translation by alternative bacterial ribosomes
Authors: Chen Yu-Xiang , Xu Zhi-yu , Ge Xueliang , Hong Jia-Yao , Sanyal Suparna , Lu Zhi John , Javid Babak 
Published: July 2020

SignificanceMany organisms, including bacteria, code for multiple paralogues of some ribosomal protein subunits. The relative contribution of these alternative subunits to ribosome function and protein synthesis is unknown and controversial. Many studies on alternative ribosomes have been confounded by isolation of alternative and canonical ribosomes from different strains or growth conditions, potentially confounding results. Here, we show that one form of alternative ribosome fromMycobacterium smegmatishas a distinct translational profile compared with canonical ribosomes purified from an identical cellular context. We also identify a role for alternative ribosomes in iron homeostasis. Given the prevalence of alternative ribosomal genes in diverse organisms, our study suggests that alternative ribosomes may represent a further layer of regulation of gene translation.
Noninvasive wearable electroactive pharmaceutical monitoring for personalized therapeutics
Authors: Lin Shuyu , Yu Wenzhuo , Wang Bo , Zhao Yichao , En Ke , Zhu Jialun , Cheng Xuanbing , Zhou Crystal , Lin Haisong , Wang Zhaoqing , Hojaiji Hannaneh , Yeung Christopher , Milla Carlos , Davis Ronald W. , Emaminejad Sam 
Published: July 2020

Significance
To achieve the mission of personalized medicine, centering on delivering the right drug to the right patient at the right dose, therapeutic drug monitoring solutions are necessary. By devising a surface engineering strategy, we created a voltammetric sensing interface, featuring an “undistorted potential window,” within which the target electroactive drug’s voltammetric response is dominant and interference is eliminated, rendering reliable target quantification in noninvasively retrievable biofluids (sweat and saliva). Leveraging this sensing interface, a fully integrated, wearable solution was constructed to seamlessly render drug readouts with minute-level temporal resolution. To inform its clinical utility, the solution was utilized to demonstrate noninvasive pharmacokinetic monitoring of a pharmaceutical (here, acetaminophen, a widely used analgesic and antipyretic) in a wearable format.
Fiducial displacements with improved accuracy for the global network of gravitational wave detectors
Authors: Bhattacharjee D , Lecoeuche Y , Karki S , Betzwieser J , Bossilkov V , Kandhasamy S , Payne E , Savage R L 
Published: July 2020

Abstract
As sensitivities improve and more detectors are added to the global network of gravitational wave observatories, calibration accuracy and precision are becoming increasingly important. Photon calibrators, relying on power-modulated auxiliary laser beams reflecting from suspended interferometer optics, enable continuous calibration by generating displacement fiducials proportional to the modulated laser power. Developments in the propagation of laser power calibration via transfer standards to on-line power sensors monitoring the modulated laser power have enabled generation of length fiducials with improved accuracy. Estimated uncertainties are almost a factor of two smaller than the lowest values previously reported. This is partly due to improvements in methodology that have increased confidence in the results reported. Referencing the laser power calibration standards for each observatory to a single transfer standard enables reducing relative calibration errors between elements of the detector network. Efforts within the national metrology institute community to realize improved laser power sensor calibration accuracy are ongoing.
Comments on ‘On Feynman’s handwritten notes on electromagnetism and the idea of introducing potentials before fields’
Authors: Davis Art 
Published: July 2020

Abstract
We address several issues discussed in a recent paper by Heras and Heras (2020 Eur. J. Phys.
41 035202). We offer an interpretation of a somewhat cryptic assertion by Richard P Feynman about reality of the electromagnetic potentials, we discuss the issue of proper definitions in physical science, and we analyze the use of the continuity equation by the authors—relating their paper to the context of a recent paper written by the author of the present comment.
Reply to Comments on ‘Feynman’s handwritten notes on electromagnetism and the idea of introducing potentials before fields’
Authors: Heras José A , Heras Ricardo 
Published: July 2020

Abstract
We reply to some comments made by Davis (2020 Eur. J. Phys.

40

018001) on our paper (2020 Eur. J. Phys.

41

035202), by arguing that Davis’s assertions are unsupported in some cases and are unsatisfactory in other cases.
A modified methodology for dielectric constant measurement of an arbitrary-shaped sheet by using capacitance technique
Authors: Afshar Soudabeh , Nazari Farid , Aliakbarian Hadi 
Published: July 2020

Abstract
The capacitance technique is one of the simplest methods to determine the dielectric constant of dielectric sheets in the low-frequency band. A new methodology and test procedure which eliminates the effect of the capacitors from the calculations and improves the accuracy of measurement is introduced. The main advantage of the method is that it can be applied for arbitrary-shaped dielectric sheets as long as they are smaller than approximately 0.6 of the diameter of the capacitor. The presented measurement results show the effectiveness of the method on measurement. A prototype version of the setup helped us achieve 7% accuracy.
Semi-supervised advancement of underwater visual quality
Authors: Zhu Huabo , Han Xu , Tao Yourui 
Published: July 2020

Abstract
In the underwater environment, the backscattering and attenuation of wavelength-dependent light degrade the quality of underwater vision. Low-quality underwater vision will reduce the accuracy of underwater robot visual navigation and pattern recognition. A novel semi-supervised deep convolutional neural network composed of a supervised learning branch and an unsupervised learning branch is proposed herein to improve underwater visual quality with poor visibility in real time. The network is constrained by a supervised loss function consisting of mean square, underwater index, and adversarial loss. The supervised branch serves as the baseline of the image enhancement algorithm to learn the basic feature information of the images and restore the original colors. The unsupervised learning branch, which makes the generated images more realistic and reduces reliance on the quality of the simulation model of synthetic data, applies underwater dark channel prior loss and total variation loss to learn the feature domain information of real images. Experiments show that the results of the proposed method show less color shift, lower fogging and blurring, and more pleasing high-quality vision. The enhanced images can extract more useful feature information, which is promising in the online visual navigation of underwater robots.
An improved particle filter based indoor tracking system via joint Wi-Fi/PDR localization
Authors: Qian Yongxiang , Chen Xuechen 
Published: July 2020

Abstract
The development of indoor localization has been advanced by the rapid development of intelligent devices. The well-known methods used for indoor localization such as Wi-Fi fingerprint database positioning and pedestrian dead reckoning (PDR) can be implemented in a self-contained smartphone. However, the existing Wi-Fi fingerprint database positioning method can be easily influenced by the dynamic environment while PDR will generate a cumulative error with an increase in walking steps. In this paper, we propose a new hybrid method using PDR and Wi-Fi information. We divide the localization area into several subareas to improve the accuracy of the Wi-Fi fingerprint matching phase and introduce an enhanced particle filter (PF) algorithm which includes subarea information in the state vector and adopts a clonal selection algorithm (CSA) to improve resampling. We conduct a series of experiments in real-world environments, and the experimental results validate that the proposed algorithm is much better than ordinary PF algorithms and standalone methods.
A validated Geant4 model of a whole-body PET scanner with four-layer DOI detectors
Authors: Ahmed Abdella M , Chacon Andrew , Rutherford Harley , Akamatsu Go , Mohammadi Akram , Nishikido Fumihiko , Tashima Hideaki , Yoshida Eiji , Yamaya Taiga , Franklin Daniel R , Rosenfeld Anatoly , Guatelli Susanna , Safavi-Naeini Mitra 
Published: July 2020

Abstract
The purpose of this work is to develop a validated Geant4 simulation model of a whole-body prototype PET scanner constructed from the four-layer depth-of-interaction detectors developed at the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Japan. The simulation model emulates the behaviour of the unique depth of interaction sensing capability of the scanner without needing to directly simulate optical photon transport in the scintillator and photodetector modules. The model was validated by evaluating and comparing performance metrics from the NEMA NU 2-2012 protocol on both the simulated and physical scanner, including spatial resolution, sensitivity, scatter fraction, noise equivalent count rates and image quality. The results show that the average sensitivities of the scanner in the field-of-view were 5.9 cps kBq−1 and 6.0 cps kBq−1 for experiment and simulation, respectively. The average spatial resolutions measured for point sources placed at several radial offsets were 5.2± 0.7 mm and 5.0± 0.8 mm FWHM for experiment and simulation, respectively. The peak NECR was 22.9 kcps at 7.4 kBq ml−1 for the experiment, while the NECR obtained via simulation was 23.3 kcps at the same activity. The scatter fractions were 44% and 41.3% for the experiment and simulation, respectively. Contrast recovery estimates performed in different regions of a simulated image quality phantom matched the experimental results with an average error of -8.7% and +3.4% for hot and cold lesions, respectively. The results demonstrate that the developed Geant4 model reliably reproduces the key NEMA NU 2-2012 performance metrics evaluated on the prototype PET scanner. A simplified version of the model is included as an advanced example in Geant4 version 10.5.
Physics and biology of ultrahigh dose-rate (FLASH) radiotherapy: a topical review
Authors: Esplen Nolan , Mendonca Marc S , Bazalova-Carter Magdalena 
Published: July 2020

Abstract
Ultrahigh dose-rate radiotherapy (RT), or ‘FLASH’ therapy, has gained significant momentum following various in vivo studies published since 2014 which have demonstrated a reduction in normal tissue toxicity and similar tumor control for FLASH-RT when compared with conventional dose-rate RT. Subsequent studies have sought to investigate the potential for FLASH normal tissue protection and the literature has been since been inundated with publications on FLASH therapies. Today, FLASH-RT is considered by some as having the potential to ‘revolutionize radiotherapy’. FLASH-RT is considered by some as having the potential to ‘revolutionize radiotherapy’.
The goal of this review article is to present the current state of this intriguing RT technique and to review existing publications on FLASH-RT in terms of its physical and biological aspects. In the physics section, the current landscape of ultrahigh dose-rate radiation delivery and dosimetry is presented. Specifically, electron, photon and proton radiation sources capable of delivering ultrahigh dose-rates along with their beam delivery parameters are thoroughly discussed. Additionally, the benefits and drawbacks of radiation detectors suitable for dosimetry in FLASH-RT are presented. The biology section comprises a summary of pioneering in vitro ultrahigh dose-rate studies performed in the 1960s and early 1970s and continues with a summary of the recent literature investigating normal and tumor tissue responses in electron, photon and proton beams. The section is concluded with possible mechanistic explanations of the FLASH normal-tissue protection effect (FLASH effect). Finally, challenges associated with clinical translation of FLASH-RT and its future prospects are critically discussed; specifically, proposed treatment machines and publications on treatment planning for FLASH-RT are reviewed.
Automated identification of the predominant site of upper airway collapse in obstructive sleep apnoea patients using snore signal
Authors: Sebastian Arun , Cistulli Peter A. , Cohen Gary , de Chazal Philip 
Published: July 2020

Abstract

Objective: This study provides a novel approach for an automated system using a machine learning algorithm to predict the predominant site of upper airway collapse into four classes (‘lateral wall’, ‘palate’, ‘tongue-base’ related collapse or ‘multi-level’ site-of-collapse) in obstructive sleep apnoea (OSA) patients from the audio signal recorded during normal sleep. Approach: Snore sounds from 58 patients were recorded simultaneously with full-night polysomnography during sleep with a ceiling mounted microphone. The probable site-of-airway collapse was determined by manual analysis of the shape of the airflow signal during hypopnoea. Time and frequency features of the audio signal were extracted from each hypopnoea event to classify the audio signal into ‘lateral wall’, ‘palate’ and ‘tongue-base’ related collapse according to prior research. The data was divided into two sets. The Learning Set contained the data of the first 45 patients and was used for building the model. The Hidden Set contained the data from the remaining 13 patients and was used for testing the performance of the model. Feature selection was employed to boost the classification performance. The classification was carried out with a multi-class linear discriminant analysis classifier to classify the predominant site-of-collapse for a patient into the four classes. Performance was evaluated by comparing the automatic and manually labelled data based on the predominant site-of-collapse and calculating the accuracy. Main results: The model achieved an overall accuracy on the Hidden Set of 77% for discriminating tongue/non-tongue collapse and an accuracy of 62% accuracy for all site-of-collapse classes. Significance: Our results demonstrate that the audio signal recorded during sleep can successfully identify the site-of-collapse in the upper airway. The additional information regarding the obstruction site may assist clinicians in deciding the most appropriate treatment for OSA.
Review: knots and other new topological effects in liquid crystals and colloids
Authors: Smalyukh Ivan I 
Published: July 2020

Abstract
Humankind has been obsessed with knots in religion, culture and daily life for millennia, while physicists like Gauss, Kelvin and Maxwell already involved them in models centuries ago. Nowadays, colloidal particles can be fabricated to have shapes of knots and links with arbitrary complexity. In liquid crystals, closed loops of singular vortex lines can be knotted by using colloidal particles and laser tweezers, as well as by confining nematic fluids into micrometer-sized droplets with complex topology. Knotted and linked colloidal particles induce knots and links of singular defects, which can be interlinked (or not) with colloidal particle knots, revealing the diversity of interactions between topologies of knotted fields and topologically nontrivial surfaces of colloidal objects. Even more diverse knotted structures emerge in nonsingular molecular alignment and magnetization fields in liquid crystals and colloidal ferromagnets. The topological solitons include hopfions, skyrmions, heliknotons, torons and other spatially localized continuous structures, which are classified based on homotopy theory, characterized by integer-valued topological invariants and often contain knotted or linked preimages, nonsingular regions of space corresponding to single points of the order parameter space. A zoo of topological solitons in liquid crystals, colloids and ferromagnets promises new breeds of information displays and a plethora of data storage, electro-optic and photonic applications. Their particle-like collective dynamics echoes coherent motions in active matter, ranging from crowds of people to schools of fish. This review discusses the state of the art in the field, as well as highlights recent developments and open questions in physics of knotted soft matter. We systematically overview knotted field configurations, the allowed transformations between them, their physical stability and how one can use one form of knotted fields to model, create and imprint other forms. The large variety of symmetries accessible to liquid crystals and colloids offer insights into stability, transformation and emergent dynamics of fully nonsingular and singular knotted fields of fundamental and applied importance. The common thread of this review is the ability to experimentally visualize these knots in real space. The review concludes with a discussion of how the studies of knots in liquid crystals and colloids can offer insights into topologically related structures in other branches of physics, with answers to many open questions, as well as how these experimentally observable knots hold a strong potential for providing new inspirations to the mathematical knot theory.
Dissipative dynamics of an open quantum battery
Authors: Carrega M , Crescente A , Ferraro D , Sassetti M 
Published: July 2020

Abstract
Coupling with an external environment inevitably affects the dynamics of a quantum system. Here, we consider how charging performances of a quantum battery, modelled as a two level system, are influenced by the presence of an Ohmic thermal reservoir. The latter is coupled to both longitudinal and transverse spin components of the quantum battery including decoherence and pure dephasing mechanisms. Charging and discharging dynamics of the quantum battery, subjected to a static driving, are obtained exploiting a proper mapping into the so-called spin-boson model. Analytic expressions for the time evolution of the energy stored in the weak coupling regime are presented relying on a systematic weak damping expansion. Here, decoherence and pure dephasing dissipative coupling are discussed in details. We argue that the former results in better charging performances, showing also interesting features reminiscent of the Lamb shift level splitting renormalization induced by the presence of the reservoir. Charging stability is also addressed, by monitoring the energy behaviour after the charging protocol has been switched off. This study presents a general framework to investigate relaxation effects, able to include also non Markovian effects, and it reveals the importance of controlling and, possibly, engineering system-bath coupling in the realization of quantum batteries.
Sulfur and Water Resistance and Activity of Ru-Ce-Zr-O
x
Catalysts for Nitric Oxide Catalytic Oxidation
Authors: Dong Yiwen , Fan,Pubo Chen Xing , Chen Pubo , Li Jian 
Published: July 2020

Abstract
Most mobile pollution sources have narrow space. Due to its small occupation area, fast selective catalytic reduction (SCR) is more suitable for controlling oxynitride (NO
x
) in exhausted gas in mobile pollution sources such as vessels. The fast SCR reaction can be divided into two stages: nitric oxide (NO) catalytic oxidation stage and NO
x
removal stage. This paper focused on the study of NO oxidation catalysts consists of ruthenium-cerium-zirconium (Ru-Ce-Zr) metal-oxides. It was found that the doping of ruthenium (Ru) which is the precious metal, greatly improved the catalytic activity. The NO oxidation rate of catalyst doped with 0.5% Ru at 300 °C was about 15% higher than that without Ru. However, with the increasing content of ruthenium, the sulfur and water resistance of catalysts decreased and the activity of the catalysts was only partially restored after regeneration. The results showed that Ru increased the activity of the catalysts while Ce and Zr improved the resistance of SO2 and H2O. Our work provided a solution to the space problem of mobile pollution sources such as vessels.