bluuebunny/crossref_metadata_2025 huggingface dataset:
Supercomputer technologies for solving problems of computational physics
Authors: Glinskiy Boris , Zagorulko Yury , Kulikov Igor , Sapetina Anna
Published: December 2019

The issues of using supercomputer technologies developed by the authors to solve compute-intensive problems of mathematical physics are discussed. The technology of developing algorithms and software for supercomputers contains the three related stages: co-design, by which we understand the adaptation of the problem statement, the mathematical method and the computational algorithm to the parallel architecture of the supercomputer at all stages of the problem solution; studying the scalability of computational algorithms for the most promising supercomputers based on simulation modeling; evaluation of the energy efficiency of algorithms for various implementations on a given supercomputer architecture. It is proposed to further develop this approach with the use of the intelligence support for solving compute-intensive problems using the ontology of computational methods and algorithms for solving the problems of computational physics, the ontology of computational heterogeneous architectures and decision rules.
Propagating large open quantum systems towards their asymptotic states: cluster implementation of the time-evolving block decimation scheme
Authors: Volokitin Valentin , Vakulchyk Ihor , Kozinov Evgeny , Liniov Alexey , Meyerov Iosif , Ivanchenko Michail , Laptyeva Tatyana , Denisov Sergey
Published: December 2019

Many-body quantum systems are subjected to the Curse of Dimensionality: The dimension of the Hilbert space H, where these systems live in, grows exponentially with number of their components. However, with some systems, it is possible to escape the curse by using a low-rank tensor approximation known as “matrix-product state/operator (MPS/O) representation” in the quantum community and “tensor-train decomposition” among applied mathematicians. Motivated by recent advances in computational quantum physics, we consider chains of N spins coupled by nearest-neighbor interactions. The spins are subjected to an action coming from the environment. Spatially disordered interaction and environment-induced decoherence drive systems into non-trivial asymptotic states. The dissipative evolution is modeled with a Markovian master equation in the Lindblad form. By implementing the MPO technique and propagating system states with the time-evolving block decimation scheme, which allows keeping the length of the state descriptions fixed, it is in principle possible to reach the asymptotic states. We propose and realize a cluster implementation of this idea. The implementation on four nodes allowed us to resolve the asymptotic states of the model systems with N = 128 spins (total dimension of the Hilbert space dimH = 2128 ≈ 1039).
Numerical homogenization of elastoplastic deformations of composite material with small proportion of inclusions
Authors: Sivtsev Petr V. , Kolesov Aleksandr E. , Zakharov Petr E. , Yang Ying
Published: December 2019

Numerical simulation of the stress-strain state of a composite material may be difficult due to large computational complexity associated with a grid resolution of a large number of inclusions. To overcome the problem one may use the homogenization method. But for material with plastic properties, proper modeling of yield stress and hardening may be overcomplicated. In this work we use some simplification associated with a small proportion of inclusions and restriction of stress values by matrix material strength. As model problem, we use deformation of concrete deep beam reinforced with steel or basalt fiber inclusions. For the numerical solution, the finite element method was applied using the FEniCS computing platform.
Comparison of discrete fiber and asymptotic homogenization methods for modeling deformations of fiber-reinforced materials
Authors: Zakharov Petr E. , Sivtsev Petr V.
Published: December 2019

The main issue in a numerical simulation of fiber-reinforced materials deformation is high computational complexity. Exact resolution of fibers thickness leads to a huge number of degrees of freedom. In this work, we compare discrete fiber and asymptotic homogenization methods for modeling deformations. The discrete fiber method considers fibers as one-dimensional lines and the asymptotic homogenization method averages elasticity coefficients. We investigate the accuracy of these methods for a large range of models and approximation parameters.
Identification of the spacewise dependent right-hand side in one-dimensional parabolic equation
Authors: De Su Ling , Vasil’ev V. I.
Published: December 2019

In this paper we consider numerical solution of the inverse problem of determining a spacewise dependent right-hand side function, which is also called source function, in parabolic equation from measured data of the solution at the final time point. Such inverse problem occurs in mathematical modeling of various physics or engineering areas. Special iterative method is constructed for the approximate solution of the inverse problem, based on the source function at the new iterative step can be identified by the time derivative and space derivative at final time moment. The capabilities of the proposed computational algorithm is confirmed by the results of several numerical experiments.
Microstructure changes responsible for the degradation of the 10CrMo9-10 and 13CrMo4-5 steels during long-term operation
Authors: Gwoździk Monika , Motylenko Mykhaylo , Rafaja David
Published: December 2019

The paper presents results of microstructure and mechanical testing examinations performed using optical and transmission electron microscopy, tensile tests and Charpy tests on 10CrMo9-10 and 13CrMo4-5 steels, before and after they were long-term operated at elevated temperatures in a steam heater. In the 10CrMo9-10 steel, the optical microscopy detected a degradation of original bainite that was accompanied by the formation of ferrite, precipitates and micropores. The transmission electron microscopy revealed that the precipitates are M23C6 and M7C3 type carbides, which are located mainly at the boundaries of former austenite grains, and M3C type carbides, which appear inside the grains. The 13CrMo4-5 steel contained a relatively high amount of ferrite in the ferritic-bainitic/perlitic microstructure already in the originally state. The degradation of the microstructure was less serious than for the 10CrMo9-10 steel. The thermal treatment of the 13CrMo4-5 steel led mainly to the precipitation of carbides. The M23C6 and M7C3 type carbides form in perlitic-bainitic areas, while M3C and M6C type carbides precipitate in ferrite. The higher density of the grain boundary precipitates in the long-term operated 10CrMo9-10 steel facilitated the formation of creep-induced micropores and contributed to the hardness reduction.
Structural and electronic properties of Stanene-BeO heterobilayer
Authors: Chakraborty Bipradip , Borgohain Madhurjya M , Adhikary Nirab C
Published: December 2019

Properties of Sn/BeO heterostructure formed with beryllium oxide (BeO) monolayer and 2D stanene (Sn) is studied in this work. The first-principle study is employed here to systematically investigate the structural stability and electrical properties of the Sn/BeO heterostructure. The results from simulations reveal that the introduction of BeO not only leads to a significant bandgap opening of 98 meV, but it also retains the various intrinsic electrical properties of stanene to a large extent. The effect of spin-orbit coupling (SOC) is studied both in pristine stanene as well as in Sn/BeO heterostructure. The Sn/BeO heterostructure shows the Rashba-type of spin-splitting under SOC, which is very promising for application in spintronic devices. Moreover, it is also observed that the bandgap can be tuned by applying external strain and electric field, while the characteristic Dirac cone is maintained throughout. The application of an external electric field is found to be more effective in bandgap modulation. It leads to a linear change in the bandgap, with a bandgap value of 402 meV for 4 V nm−1. The results obtained from our study indicate that Sn/BeO heterostructure can be a suitable material for the development of spintronic devices.
Microstructure and creep strength evolution in G115 steel during creep at 650 °C
Authors: Liu Zhen , Liu Zhengdong , Chen Zhengzong , Wang Xitao , Bao Hansheng , Dong Chen
Published: December 2019

Microstructure and creep strength evolution in the ruptured 2.6 wt% W G115 specimens after creep tests were investigated under stresses of 120∼200 MPa at 650 °C. The growth of the lath during the creep tests was accompanied with the coarsening of second phase particles and the reduction of dislocation density. The tempered martensitic lath structure (TMLS) transformed into polygonal sub-grain structure when the pinning force due to the precipitates was lower than about 0.68 MPa. The Laves phase particles were irregular during the short-term creep and grew to be equiaxed shape after long-term creep.
Optical properties of Cr doped ZnAl2O4 nanoparticles with Spinel structure synthesized by hydrothermal method
Authors: Shang-Pan Huang , Zhi-Qiang Wei , Xiao-Juan Wu , Ji-Wen Shi
Published: December 2019

Zn1−xCrxAl2O4 (x = 0, 0.01, 0.03, 0.05 and 0.07) nanoparticles were synthesized by hydrothermal method and heat treatment technology, and the effects of Chromium doping ratios on the microstructure, morphology, element distribution, binding energy and optical property of the samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), x-ray energy dispersive spectroscopy (XEDS), x-ray photoemission spectroscopy (XPS), ultraviolet-visible (UV–vis) spectroscopy, photoluminescence spectra (PL) and fourier transform infrared spectroscopy (FT-IR). The experimental results show that Zn1−xCrxAl2O4 nanoparticles possess cubic spinel structure without other impurity phases. The average crystallite size decrease and the lattice parameter increase with the increase of Cr doping concentration. The morphology of the samples exhibits irregular spherical or ellipsoid particles with uniform particle size. XEDS spectra display Cr3+ successfully used as doping agent replaced Zn2+ and entered ZnAl2O4 matrix. XPS spectra demonstrate that the doped Cr ions mainly occupy the tetrahedral sites in Zn0.95Cr0.05Al2O4 sample. UV–vis spectra indicate the band gap of the doped sample decrease and exhibit red shift with the increase of Cr ion concentration. The intensity of FT-IR spectra for Zn1−xCrxAl2O4 samples decreases slowly and occurs red shift. PL spectra show the intensity decrease and occur luminescence quenching phenomenon for Cr doped sample.
Transparent peer review trialled by IOP Publishing
Authors: Banks Michael
Published: December 2019

IOP Publishing has become the first physics publisher to introduce “transparent” peer review – in which the referee reports of an accepted paper are made available to read alongside the published research.
Investigations launched over Hurricane Dorian map
Authors: Gwynne Peter
Published: December 2019

Scientists have criticized the US government for politicizing weather forecasts from the National Weather Service (NWS) following a dispute over the potential path of Hurricane Dorian.
Difficult assessment
Authors: Wakeford Richard
Published: December 2019

In reply to Kate Brown’s letter “Radiation reasoning” (September pp25–26), in which she raised concerns surrounding the research on low-dose exposure to radioactivity, and associated health problems.
Erroneous assertions?
Authors: Padman Rachel
Published: December 2019

In response to David Appell’s feature “The invisibility of length contraction” (August pp41–45), which explained why a 3D object at relativistic speeds would appear rotated, not Lorentz-contracted
Turning science to movie magic
Authors: Lorditch Emilie
Published: December 2019

What better way to accurately depict science in films than to ask the people studying it off screen? Emilie Lorditch talks to physicists who help filmmakers take science from the lab to the red carpet
Black holes have no hair after all
Authors: Johnston Hamish
Published: December 2019

The notion that black holes have only three defining properties – the so-called “no-hair theorem” – has been confirmed by a new analysis of the first-ever gravitational waves to be detected.
Achieving high volumetric EDLC carbons via hydrothermal carbonization and cyclic activation
Authors: Gao Qiang , Titirici Maria-Magdalena
Published: December 2019

A novel activation method involving hydrothermal carbonization (HTC) and a pressure-induced low temperature oxidation has been demonstrated for cellulose derived HTC char by using hydrogen peroxide as an active di-oxygen source. The optimized porosity versus gravimetric capacitance results from cellulose derived HTC char synthesized at 220 °C. Almost homogeneous and small particle size micro-ellipse/sphere, relatively high surface area and narrow pore size distributions lead to a high bulk density, i.e. 0.73 g cm−3, of coating-type electrodes, which is much denser than those manufactured from steam-activated carbons for supercapacitor industry, i.e. 0.52 g cm−3. The resulting carbon prepared herein achieves a relatively high volumetric capacitance in an organic electrolyte-based supercapacitor, reaching a competitive value of an industrial system with the features being environment-friendly, cost-effective as well as high yield, and less energy consumption.
Topology: A Very Short Introduction
Authors: Earl Richard
Published: December 2019

Topology, the mathematical study of the properties that are preserved through the deformations, twistings, and stretchings of objects, is an important area of modern mathematics. Topology: A Very Short Introduction provides a sense of the more visual elements of topology (looking at surfaces) as well as covering the formal definition of continuity. Considering some of the eye-opening examples that led mathematicians to recognize a need for studying topology, it pays homage to the historical people, problems, and surprises that have propelled the growth of this field. As broad and fundamental as algebra and geometry, its study has important implications for science more generally, especially physics.
ngsReports: a Bioconductor package for managing FastQC reports and other NGS related log files
Authors: Ward Christopher M , To Thu-Hien , Pederson Stephen M
Published: December 2019

Motivation

High throughput next generation sequencing (NGS) has become exceedingly cheap, facilitating studies to be undertaken containing large sample numbers. Quality control (QC) is an essential stage during analytic pipelines and the outputs of popular bioinformatics tools such as FastQC and Picard can provide information on individual samples. Although these tools provide considerable power when carrying out QC, large sample numbers can make inspection of all samples and identification of systemic bias a challenge.

Results

We present ngsReports, an R package designed for the management and visualization of NGS reports from within an R environment. The available methods allow direct import into R of FastQC reports along with outputs from other tools. Visualization can be carried out across many samples using default, highly customizable plots with options to perform hierarchical clustering to quickly identify outlier libraries. Moreover, these can be displayed in an interactive shiny app or HTML report for ease of analysis.

Availability and implementation

The ngsReports package is available on Bioconductor and the GUI shiny app is available at https://github.com/UofABioinformaticsHub/shinyNgsreports.

Supplementary information

Supplementary data are available at Bioinformatics online.
Piperacillin-Tazobactam Added to Vancomycin Increases Risk for Acute Kidney Injury: Fact or Fiction?
Authors: Avedissian Sean N , Pais Gwendolyn M , Liu Jiajun , Rhodes Nathaniel J , Scheetz Marc H
Published: December 2019

Vancomycin and piperacillin-tazobactam are 2 of the most commonly prescribed antibiotics in hospitals. Recent data from multiple meta-analyses suggest that the combination increases the risk for vancomycin-induced kidney injury when compared to alternative viable options. However, these studies are unable to prove biologic plausibility and causality as randomized controlled trials have not been performed. Furthermore, these studies define acute kidney injury according to thresholds of serum creatinine rise. Serum creatinine is not a direct indicator of renal injury, rather a surrogate of glomerular function. More reliable, specific, and sensitive biomarkers are needed to truly define if there is a causal relationship with increased toxicity when piperacillin-tazobactam is added to vancomycin. This viewpoint will explore the available evidence for and against increased acute kidney injury in the setting of vancomycin and piperacillin-tazobactam coadministration.
RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes
Authors: Lissoni Alessio , Hulpiau Paco , Martins-Marques Tânia , Wang Nan , Bultynck Geert , Schulz Rainer , Witschas Katja , Girao Henrique , De Smet Maarten , Leybaert Luc
Published: December 2019

Aims

Connexin-based gap junctions are crucial for electrical communication in the heart; they are each composed of two docked hemichannels (HCs), supplied as unpaired channels via the sarcolemma. When open, an unpaired HC forms a large pore, high-conductance and Ca2+-permeable membrane shunt pathway that may disturb cardiomyocyte function. HCs composed of connexin 43 (Cx43), a major cardiac connexin, can be opened by electrical stimulation but only by very positive membrane potentials. Here, we investigated the activation of Cx43 HCs in murine ventricular cardiomyocytes voltage-clamped at −70 mV.

Methods and results

Using whole-cell patch-clamp, co-immunoprecipitation, western blot analysis, immunocytochemistry, proximity ligation assays, and protein docking studies, we found that stimulation of ryanodine receptors (RyRs) triggered unitary currents with a single-channel conductance of ∼220 pS, which were strongly reduced by Cx43 knockdown. Recordings under Ca2+-clamp conditions showed that both RyR activation and intracellular Ca2+ elevation were necessary for HC opening. Proximity ligation studies indicated close Cx43-RyR2 apposition (<40 nm), and both proteins co-immunoprecipitated indicating physical interaction. Molecular modelling suggested a strongly conserved RyR-mimicking peptide sequence (RyRHCIp), which inhibited RyR/Ca2+ HC activation but not voltage-triggered activation. The peptide also slowed down action potential repolarization. Interestingly, alterations in the concerned RyR sequence are known to be associated with primary familial hypertrophic cardiomyopathy.

Conclusion

Our results demonstrate that Cx43 HCs are intimately linked to RyRs, allowing them to open at negative diastolic membrane potential in response to RyR activation.
Characteristics and outcomes of atrial fibrillation in patients without traditional risk factors: an RE-LY AF registry analysis
Authors: Kloosterman Mariëlle , Oldgren Jonas , Conen David , Wong Jorge A , Connolly Stuart J , Avezum Alvaro , Yusuf Salim , Ezekowitz Michael D , Wallentin Lars , Ntep-Gweth Marie , Joseph Philip , Barrett Tyler W , Tanosmsup Supachai , McIntyre William F , Lee Shun Fu , Parkash Ratika , Amit Guy , Grinvalds Alex , Van Gelder Isabelle C , Healey Jeff S
Published: December 2019

Aims 

Data on patient characteristics, prevalence, and outcomes of atrial fibrillation (AF) patients without traditional risk factors, often labelled ‘lone AF’, are sparse.

Methods and results

The RE-LY AF registry included 15 400 individuals who presented to emergency departments with AF in 47 countries. This analysis focused on patients without traditional risk factors, including age ≥60 years, hypertension, coronary artery disease, heart failure, left ventricular hypertrophy, congenital heart disease, pulmonary disease, valve heart disease, hyperthyroidism, and prior cardiac surgery. Patients without traditional risk factors were compared with age- and region-matched controls with traditional risk factors (1:3 fashion). In 796 (5%) patients, no traditional risk factors were present. However, 98% (779/796) had less-established or borderline risk factors, including borderline hypertension (130–140/80–90 mmHg; 47%), chronic kidney disease (eGFR < 60 mL/min; 57%), obesity (body mass index > 30; 19%), diabetes (5%), excessive alcohol intake (>14 units/week; 4%), and smoking (25%). Compared with patients with traditional risk factors (n = 2388), patients without traditional risk factors were more often men (74% vs. 59%, P < 0.001) had paroxysmal AF (55% vs. 37%, P < 0.001) and less AF persistence after 1 year (21% vs. 49%, P < 0.001). Furthermore, 1-year stroke occurrence rate (0.6% vs. 2.0%, P = 0.013) and heart failure hospitalizations (0.9% vs. 12.5%, P < 0.001) were lower. However, risk of AF-related re-hospitalization was similar (18% vs. 21%, P = 0.09).

Conclusion

Almost all patients without traditionally defined AF risk factors have less-established or borderline risk factors. These patients have a favourable 1-year prognosis, but risk of AF-related re-hospitalization remains high. Greater emphasis should be placed on recognition and management of less-established or borderline risk factors.
Azimuthal anisotropy in the wider Vienna basin region: a proxy for the present-day stress field and deformation
Authors: Schippkus Sven , Zigone Dimitri , Bokelmann Götz ,   AlpArray Working Group, Hetényi G , Abreu R , Allegretti I , Apoloner M-T , Aubert C , Besançon S , Bès De Berc M , Bokelmann G , Brunel D , Capello M , Čarman M , Cavaliere A , Chèze J , Chiarabba C , Clinton J , Cougoulat G , Crawford W C , Cristiano L , Czifra T , D'alema E , Danesi S , Daniel R , Dannowski A , Dasović I , Deschamps A , Dessa J-X , Doubre C , Egdorf S ,   ETHZ-Sed Electronics Lab, Fiket T , Fischer K , Friederich W , Fuchs F , Funke S , Giardini D , Govoni A , Gráczer Z , Gröschl G , Heimers S , Heit B , Herak D , Herak M , Huber J , Jarić D , Jedlička P , Jia Y , Jund H , Kissling E , Klingen S , Klotz B , Kolínský P , Kopp H , Korn M , Kotek J , Kühne L , Kuk K , Lange D , Loos J , Lovati S , Malengros D , Margheriti L , Maron C , Martin X , Massa M , Mazzarini F , Meier T , Métral L , Molinari I , Moretti M , Munzarová H , Nardi A , Pahor J , Paul A , Péquegnat C , Petersen D , Pesaresi D , Piccinini D , Piromallo C , Plenefisch T , Plomerová J , Pondrelli S , Prevolnik S , Racine R , Régnier M , Reiss M , Ritter J , Rümpker G , Salimbeni S , Santulin M , Scherer W , Schippkus S , Schulte-Kortnack D , Šipka v , Solarino S , Spallarossa D , Spieker K , Stipčević J , Strollo A , Süle B , Szanyi G , Szücs E , Thomas C , Thorwart M , Tilmann F , Ueding S , Vallocchia M , Vecsey L , Voigt R , Wassermann J , Wéber Z , Weidle C , Wesztergom v , Weyland G , Wiemer S , Wolf F , Wolyniec D , Zieke T , Živčić M
Published: December 2019

We infer seismic azimuthal anisotropy from ambient-noise-derived Rayleigh waves in the wider Vienna Basin region. Cross-correlations of the ambient seismic field are computed for 1953 station pairs and periods from 5 to 25 s to measure the directional dependence of interstation Rayleigh-wave group velocities. We perform the analysis for each period on the whole data set, as well as in overlapping 2°-cells to regionalize the measurements, to study expected effects from isotropic structure, and isotropic–anisotropic trade-offs. To extract azimuthal anisotropy that relates to the anisotropic structure of the Earth, we analyse the group velocity residuals after isotropic inversion. The periods discussed in this study (5–20 s) are sensitive to crustal structure, and they allow us to gain insight into two distinct mechanisms that result in fast orientations. At shallow crustal depths, fast orientations in the Eastern Alps are S/N to SSW/NNE, roughly normal to the Alps. This effect is most likely due to the formation of cracks aligned with the present-day stress-field. At greater depths, fast orientations rotate towards NE, almost parallel to the major fault systems that accommodated the lateral extrusion of blocks in the Miocene. This is coherent with the alignment of crystal grains during crustal deformation occurring along the fault systems and the lateral extrusion of the central part of the Eastern Alps.
Taurine treatment of retinal degeneration and cardiomyopathy in a consanguineous family with SLC6A6 taurine transporter deficiency
Authors: Ansar Muhammad , Ranza Emmanuelle , Shetty Madhur , Paracha Sohail A , Azam Maleeha , Kern Ilse , Iwaszkiewicz Justyna , Farooq Omer , Pournaras Constantin J , Malcles Ariane , Kecik Mateusz , Rivolta Carlo , Muzaffar Waqar , Qurban Aziz , Ali Liaqat , Aggoun Yacine , Santoni Federico A , Makrythanasis Periklis , Ahmed Jawad , Qamar Raheel , Sarwar Muhammad T , Henry L Keith , Antonarakis Stylianos E
Published: December 2019

In a consanguineous Pakistani family with two affected individuals, a homozygous variant Gly399Val in the eighth transmembrane domain of the taurine transporter SLC6A6 was identified resulting in a hypomorph transporting capacity of ~15% compared with normal. Three-dimensional modeling of this variant has indicated that it likely causes displacement of the Tyr138 (TM3) side chain, important for transport of taurine. The affected individuals presented with rapidly progressive childhood retinal degeneration, cardiomyopathy and almost undetectable plasma taurine levels. Oral taurine supplementation of 100 mg/kg/day resulted in maintenance of normal blood taurine levels. Following approval by the ethics committee, a long-term supplementation treatment was introduced. Remarkably, after 24-months, the cardiomyopathy was corrected in both affected siblings, and in the 6-years-old, the retinal degeneration was arrested, and the vision was clinically improved. Similar therapeutic approaches could be employed in Mendelian phenotypes caused by the dysfunction of the hundreds of other molecular transporters.
Extendingp-divisible Groups and Barsotti–Tate Deformation Ring in the Relative Case
Authors: Moon Yong Suk
Published: December 2019

Let $k$ be a perfect field of characteristic $p> 2$, and let $K$ be a finite totally ramified extension of $W(k)\big[\frac{1}{p}\big]$ of ramification degree $e$. We consider an unramified base ring $R_0$ over $W(k)$ satisfying certain conditions, and let $R = R_0\otimes _{W(k)}\mathcal{O}_K$. Examples of such $R$ include $R = \mathcal{O}_K[\![s_1, \ldots , s_d]\!]$ and $R = \mathcal{O}_K\langle t_1^{\pm 1}, \ldots , t_d^{\pm 1}\rangle $. We show that the generalization of Raynaud’s theorem on extending $p$-divisible groups holds over the base ring $R$ when $e < p-1$, whereas it does not hold when $R = \mathcal{O}_K[\![s]\!]$ with $e \geq p$. As an application, we prove that if $R$ has Krull dimension $2$ and $e < p-1$, then the locus of Barsotti–Tate representations of $\textrm{Gal}(\overline{R}\big[\frac{1}{p}\big]/R\big[\frac{1}{p}\big])$ cuts out a closed subscheme of the universal deformation scheme. If $R = \mathcal{O}_K[\![s]\!]$ with $e \geq p$, we prove that such a locus is not $p$-adically closed.
Emergency Department Visits for Opioid Overdoses Among Patients With Cancer
Authors: Jairam Vikram , Yang Daniel X , Yu James B , Park Henry S
Published: December 2019

Background

Patients with cancer may be at risk of high opioid use due to physical and psychosocial factors, although little data exist to inform providers and policymakers. Our aim is to examine overdoses from opioids leading to emergency department (ED) visits among patients with cancer in the United States.

Methods

The Healthcare Cost and Utilization Project Nationwide Emergency Department Sample was queried for all adult cancer-related patient visits with a primary diagnosis of opioid overdose between 2006 and 2015. Temporal trends and baseline differences between patients with and without opioid-related ED visits were evaluated. Multivariable logistic regression analysis was used to identify risk factors associated with opioid overdose. All statistical tests were two-sided.

Results

Between 2006 and 2015, there were a weighted total of 35 339 opioid-related ED visits among patients with cancer. During this time frame, the incidence of opioid-related ED visits for overdose increased twofold (P < .001). On multivariable regression (P < .001), comorbid diagnoses of chronic pain (odds ratio [OR] 4.51, 95% confidence interval [CI] = 4.13 to 4.93), substance use disorder (OR = 3.54, 95% CI = 3.28 to 3.82), and mood disorder (OR = 3.40, 95% CI = 3.16 to 3.65) were strongly associated with an opioid-related visit. Patients with head and neck cancer (OR = 2.04, 95% CI = 1.82 to 2.28) and multiple myeloma (OR = 1.73, 95% CI = 1.32 to 2.26) were also at risk for overdose.

Conclusions

Over the study period, the incidence of opioid-related ED visits in patients with cancer increased approximately twofold. Comorbid diagnoses and primary disease site may predict risk for opioid overdose.
Exploring the radial disc ionization profile of the black hole X-ray binary GRS 1915+105
Authors: Shreeram Soumya , Ingram Adam
Published: December 2019

Accreting black holes show characteristic ‘reflection’ features in their X-ray spectra, including the iron K α fluorescence line, which result from X-rays radiated by a compact central corona being reprocessed in the accretion disc atmosphere. The observed line profile is distorted by relativistic effects, providing a diagnostic for disc geometry. Nearly all previous X-ray reflection spectroscopy studies have made the simplifying assumption that the disc ionization state is independent of radius in order to calculate the rest-frame reflection spectrum. However, this is unlikely to be the case in reality, since the irradiating flux should drop off steeply with radius. Here, we analyse a Nuclear Spectroscopic Telescope Array observation of GRS 1915+105 that exhibits strong reflection features. We find that using a self-consistently calculated radial ionization profile returns a better fit than assuming constant ionization. Our results are consistent with the inner disc being radiation-pressure dominated, as is expected from the high inferred accretion rate for this observation. We also find that the assumed ionization profile impacts on the best-fitting disc inner radius. This implies that the black hole spin values previously inferred for active galactic nuclei and X-ray binaries by equating the disc inner radius with the innermost stable circular orbit may be changed significantly by the inclusion of a self-consistent ionization profile.
Unravelling the unusually curved X-ray spectrum of RGB J0710 + 591 using AstroSat observations
Authors: Goswami Pranjupriya , Sinha Atreyee , Chandra Sunil , Misra Ranjeev , Chitnis Varsha , Gogoi Rupjyoti , Sahayanathan Sunder , Stalin C S , Singh K P , Yadav J S
Published: December 2019

We report the analysis of simultaneous multiwavelength data of the high-energy-peaked blazar RGB J0710 + 591 from the Large Area X-ray Proportional Counters, Soft X-ray focusing Telescope, and Ultraviolet Imaging Telescope (UVIT) instruments onboard AstroSat. The wide band X-ray spectrum (0.35–30 keV) is modelled as synchrotron emission from a non-thermal distribution of high-energy electrons. The spectrum is unusually curved, with a curvature parameter βp ∼ 6.4 for a log parabola particle distribution, or a high-energy spectral index p2 > 4.5 for a broken power-law distribution. The spectrum shows more curvature than an earlier quasi-simultaneous analysis of Swift–XRT/NuSTAR data where the parameters were βp ∼ 2.2 or p2 ∼ 4. It has long been known that a power-law electron distribution can be produced from a region where particles are accelerated under Fermi process and the radiative losses in acceleration site decide the maximum attainable Lorentz factor, γmax. Consequently, this quantity decides the energy at which the spectrum curves steeply. We show that such a distribution provides a more natural explanation for the AstroSat data as well as the earlier XRT/NuSTAR observation, making this as the first well-constrained determination of the photon energy corresponding to γmax. This in turn provides an estimate of the acceleration time-scale as a function of magnetic field and Doppler factor. The UVIT observations are consistent with earlier optical/UV measurements and reconfirm that they plausibly correspond to a different radiative component than the one responsible for the X-ray emission.
Gravitational lensing of gravitational waves: wave nature and prospects for detection
Authors: Meena Ashish Kumar , Bagla Jasjeet Singh
Published: December 2019

We discuss the gravitational lensing of gravitational wave (GW) signals from coalescing binaries. We delineate the regime where wave effects are significant from the regime where geometric limit can be used. Further, we focus on the effect of microlensing and the combined effect of strong lensing and microlensing. We find that microlensing combined with strong lensing can introduce time varying phase shift in the signal and hence can lead to detectable differences in the signal observed for different images produced by strong lensing. This, coupled with the coarse localization of signal source in the sky for GW detections, can make it difficult to identify the common origin of signal corresponding to different images and use observables like time delay. In case we can reliably identify corresponding images, microlensing of individual images can be used as a tool to constrain properties of microlenses. Sources of gravitational waves can undergo microlensing due to lenses in the disc/halo of the Galaxy, or due to lenses in an intervening galaxy even in absence of strong lensing. In general the probability for this is small with one exception: extragalactic sources of GWs that lie in the galactic plane are highly likely to be microlensed. Wave effects are extremely important for such cases. In case of detections of such sources with low signal-to-noise ratio, the uncertainty of occurrence of microlensing or otherwise introduces an additional uncertainty in the parameters of the source.
Kidney function and symptom development over time in elderly patients with advanced chronic kidney disease: results of the EQUAL cohort study
Authors: Janmaat Cynthia J , van Diepen Merel , Meuleman Yvette , Chesnaye Nicholas C , Drechsler Christiane , Torino Claudia , Wanner Christoph , Postorino Maurizio , Szymczak Maciej , Evans Marie , Caskey Fergus J , Jager Kitty J , Dekker Friedo W ,   the EQUAL Study Investigators
Published: December 2019

Background

Initiation of renal replacement therapy often results from a combination of kidney function deterioration and symptoms related to chronic kidney disease (CKD) progression. We investigated the association between kidney function decline and symptom development in patients with advanced CKD.

Methods

In the European Quality study on treatment in advanced CKD (EQUAL study), a European prospective cohort study, patients with advanced CKD aged ≥65 years and a kidney function that dropped <20 mL/min/1.73 m2 were followed for 1 year. Linear mixed-effects models were used to assess the association between kidney function decline and symptom development. The sum score for symptom number ranged from 0 to 33 and for overall symptom severity from 0 to 165, using the Dialysis Symptom Index.

Results

At least one kidney function estimate with symptom number or overall symptom severity was available for 1109 and 1019 patients, respectively. The mean (95% confidence interval) annual kidney function decline was 1.70 (1.32; 2.08) mL/min/1.73 m2. The mean overall increase in symptom number and severity was 0.73 (0.28; 1.19) and 2.93 (1.34; 4.52) per year, respectively. A cross-sectional association between the level of kidney function and symptoms was lacking. Furthermore, kidney function at cohort entry was not associated with symptom development. However, each mL/min/1.73 m2 of annual kidney function decline was associated with an extra annual increase of 0.23 (0.07; 0.39) in the number of symptoms and 0.87 (0.35; 1.40) in overall symptom severity.

Conclusions

A faster kidney function decline was associated with a steeper increase in both symptom number and severity. Considering the modest association, our results seem to suggest that repeated thorough assessment of symptom development during outpatient clinic visits, in addition to the monitoring of kidney function decline, is important for clinical decision-making.
The Use of 5-Aminolevulinic Acid in Low-Grade Glioma Resection: A Systematic Review
Authors: Almekkawi Ahmad Kareem , El Ahmadieh Tarek Y , Wu Eva M , Abunimer Abdullah M , Abi-Aad Karl R , Aoun Salah G , Plitt Aaron R , El Tecle Najib E , Patel Toral , Stummer Walter , Bendok Bernard R
Published: December 2019

BACKGROUND

For optimizing high-grade glioma resection, 5-aminolevulinic acid is a reliable tool. However, its efficacy in low-grade glioma resection remains unclear.

OBJECTIVE

To study the role of 5-aminolevulinic acid in low-grade glioma resection and assess positive fluorescence rates and the effect on the extent of resection.

METHODS

A systematic review of PubMed, Google Scholar, and Cochrane was performed from the date of inception to February 1, 2019. Studies that correlated 5-aminolevulinic acid fluorescence with low-grade glioma in the setting of operative resection were selected. Studies with biopsy only were excluded. Positive fluorescence rates were calculated. The quality index of the selected papers was provided. No patient information was used, so Institutional Review Board approval and patient consent were not required.

RESULTS

A total of 12 articles met the selection criteria with 244 histologically confirmed low-grade glioma patients who underwent microsurgical resection. All patients received 20 mg/kg body weight of 5-aminolevulinic acid. Only 60 patients (n = 60/244; 24.5%) demonstrated visual intraoperative 5-aminolevulinic acid fluorescence. The extent of resection was reported in 4 studies; however, the data combined low- and high-grade tumors. Only 2 studies reported on tumor location. Only 3 studies reported on clinical outcomes. The Zeiss OPMI Pentero microscope was most commonly used across all studies. The average quality index was 14.58 (range: 10-17), which correlated with an overall good quality.

CONCLUSION

There is an overall low correlation between 5-aminolevulinic acid fluorescence and low-grade glioma. Advances in visualization technology and using standardized fluorescence quantification methods may further improve the visualization and reliability of 5-aminolevulinic acid fluorescence in low-grade glioma resection.
One-Stage Anteroposterior Extensive Atlantoaxial Osteotomy Correction With 16 Months Follow-up: Technical Case Report
Authors: Ma Xiangyang , Wang Binbin , Yang Jincheng , Xia Hong , Wang Guoliang , Wang Weijian , Wang Jian
Published: December 2019

BACKGROUND AND IMPORTANCE

Patients with severe thoracic or lumbar deformities can achieve satisfactory correction through appropriate osteotomies. However, patients with multiple craniocervical malformations commonly undergo conservative or finite surgical therapy mainly because of the involvement of the vertebral artery. Anterior oral meningocele is an extremely rare pathology that has not been previously reported. Here, we provide the first report of complex craniocervical anomalies combined with oral meningocele treated with a 1-stage anteroposterior atlantoaxial osteotomy correction surgery, with outcomes after 16 mo follow-up.

CLINICAL PRESENTATION

A 10-yr-old boy presented with recurrent dyspnea, cyanosis, and progressive torticollis. Imaging studies revealed complicated bony abnormalities accompanied by an anterior oral meningocele. A 1-stage extensive atlantoaxial osteotomy through anterior and posterior approaches was performed with an innovatively designed vertebral artery exclusion technique. Lumbar cistern drainage and ceftazidime were used to address the leakage of cerebrospinal fluid and intracranial infection.

CONCLUSION

The satisfactory outcome demonstrates the feasibility of extensive atlantoaxial osteotomy via a vertebral artery exclusion technique that might also be applicable to osteotomy in segments of C3-C6.
Minimally Invasive Laminotomy for Contralateral “Over-the-Top” Foraminal Decompression Using 3-Dimensional Total Navigation: 2-Dimensional Operative Video
Authors: Kirnaz Sertac , Wipplinger Christoph , Schmidt Franziska Anna , Hernandez R Nick , Hussain Ibrahim , Härtl Roger
Published: December 2019

This video demonstrates the step-by-step surgical technique for the minimally invasive laminotomy for contralateral “over-the-top” foraminal decompression. This technique allows for excellent decompression with clearance of the contralateral recess and foramen. In the video, we present the case of a 51-yr-old female patient with a past medical history of left L5-S1 microdiscectomy who presented in clinic with residual/recurrent foraminal disc herniation at L5-S1 compressing the left L5 nerve root. The patient had left lower extremity pain in the left hip and thigh that radiated down the front and side of the leg, as well as tingling and numbness in the left foot. The patient was treated via a L5-S1 microdiscectomy using a portable intraoperative computed tomography scanner, (Airo®, Brainlab AG, Feldkirchen, Germany), combined with 3-dimensional (3D) computer navigation. Patient consent was obtained prior to performing the procedure. The main advantage of this technique is the direct “over-the-top” trajectory to the foraminal pathology that minimizes the need of facet joint resection. The use of 3D navigation facilitates surgical planning and further minimizes facet joint compromise. Particularly, the inferior facet contralateral to the approach side as well as its outer capsular surroundings can be preserved. Recent biomechanical studies have shown that “over-the-top” decompression produces significantly less instability than a traditional open midline laminectomy.
Hanbang Healing for the World: The Eastern Medicine Renaissance in 1930s Japan-ruled Korea
Authors: Flowers James
Published: December 2019

The story of the 1930s Eastern Medicine Renaissance in Korea is an unusual case in the history of colonial medicine. Responding to Japanese colonial rule that began in the first decade of the twentieth century, a few thousand Korean physicians of Eastern medicine complied with the new registration requirements, but they turned that compliance into effective resistance. By organising conferences, publishing journals and books, and through the new medium of advertising, the physicians refuted Japanese official arguments of the superiority of Western medicine. The Koreans flipped on its head the Japanese rhetorical argument of Koreans and Japanese as one body (with the Japanese as ‘the head’) and persuaded the Japanese that they could learn from Korean medical practices. Flipping the Japanese trope of Korean weakness upside down, Koreans thereby used their version of Eastern medicine to demonstrate Korean strength.
Strain-Level Identification of Bacterial Tomato Pathogens Directly from Metagenomic Sequences
Authors: Mechan Llontop Marco E. , Sharma Parul , Aguilera Flores Marcela , Yang Shu , Pollok Jill , Tian Long , Huang Chenjie , Rideout Steve , Heath Lenwood S. , Li Song , Vinatzer Boris A.
Published: December 2019

Routine strain-level identification of plant pathogens directly from symptomatic tissue could significantly improve plant disease control and prevention. Here we tested the Oxford Nanopore Technologies (ONT) MinION sequencer for metagenomic sequencing of tomato plants either artificially inoculated with a known strain of the bacterial speck pathogen Pseudomonas syringae pv. tomato or collected in the field and showing bacterial spot symptoms caused by one of four Xanthomonas species. After species-level identification via ONT’s WIMP software and the third-party tools Sourmash and MetaMaps, we used Sourmash and MetaMaps with a custom database of representative genomes of bacterial tomato pathogens to attempt strain-level identification. In parallel, each metagenome was assembled and the longest contigs were used as query with the genome-based microbial identification Web service LINbase. Both the read-based and assembly-based approaches correctly identified P. syringae pv. tomato strain T1 in the artificially inoculated samples. The pathogen strain in most field samples was identified as a member of Xanthomonas perforans group 2. This result was confirmed by whole genome sequencing of colonies isolated from one of the samples. Although in our case metagenome-based pathogen identification at the strain level was achieved, caution still must be exercised in interpreting strain-level results because of the challenges inherent to assigning reads to specific strains and the error rate of nanopore sequencing.
Managing acute and recurrent idiopathic pericarditis
Authors: Schwier Nicholas C. , Cornelio Cyrille K. , Epperson Taylor M.
Published: December 2019

Pericarditis is the most common form of pericardial disease and may be associated with significant morbidity and mortality. Management of idiopathic pericarditis includes pharmacologic therapies, non-pharmacologic therapies, and surgery. This article describes the diagnosis and management of idiopathic causes of pericarditis, incorporating recommendations included in the European Society of Cardiology guidelines.
Overactivity in Chronic Pain, the Role of Pain-related Endurance and Neuromuscular Activity
Authors: Hasenbring Monika I. , Andrews Nicole E. , Ebenbichler Gerold
Published: December 2019

Objectives:

Decades of research have convincingly shown that fear of pain and pain-related avoidance behavior are important precursors of disability in daily life. Reduced activity as a consequence of avoidance, however, cannot be blamed for chronic disability in all patients. A contrasting behavior, pain-related dysfunctional endurance in a task and overactivity has to be considered. Currently, there is a need to better understand the psychological determinants of overactivity, dysfunctional endurance, and neurobiomechanical consequences.

Methods:

This is a narrative review.

Results:

The first part of this review elucidates research on self-reported overactivity, showing associations with higher levels of pain and disability, especially in spinal load positions, for example, lifting, bending, or spending too long a time in specific positions. In addition, measures of habitual endurance-related pain responses, based on the avoidance-endurance model, are related to objective assessments of physical activity and, again, especially in positions known to cause high spinal load (part 2). The final part reveals findings from neuromuscular research on motor control indicating the possibility that, in particular, overactivity and dysfunctional endurance may result in a number of dysfunctional adaptations with repetitive strain injuries of muscles, ligaments, and vertebral segments as precursors of pain.

Discussion:

This narrative review brings together different research lines on overactivity, pain-related endurance, and supposed neuromuscular consequences. Clinicians should distinguish between patients who rest and escape from pain at low levels of pain, but who have high levels of fear of pain and those who predominantly persist in activities despite severely increasing pain until a break will be enforced by intolerable pain levels.