bluuebunny/crossref_metadata_2025 huggingface dataset:
Orwell lässt grüßen! – Korpuslinguistische Untersuchungen zur Aktualität Orwells in Plenardebatten des Bundestags
Authors: Albers Marius
Published: February 2021

Der NameGeorge Orwellfungiert insbesondere als Synonym für die fiktionale dystopische Vision in seinem Roman1984und kann in dieser Hinsicht als Kollektivsymbol aufgefasst werden. Ausgehend davon wird der Name auch in Plenardebatten des Bundestags (und damit im politischen Diskurs) strategisch verwendet. Dabei zeigt sich, dass die Orwell-Referenzen in den letzten Jahren eine deutlich steigende Tendenz aufweisen. Insbesondere lassen sich solche in Debatten um Datenschutz und Überwachung, aber auch um den Sprachgebrauch finden, in Verbindung mit Warnungs‑, Vorwurfs- und Zurückweisungshandlungen.
A stepwise approach to open surgery for the frontal sinus
Authors: Kelly A , Alhelali N , McGarry G W
Published: February 2021

Background

Despite advances in endoscopic techniques, there are still instances when the frontal sinus must be approached externally. Given its variable anatomy, the frontal sinus continues to present a challenge to the surgeon. Our rule of thumb capitalises on the consistent embryological development of the frontal sinus, aiding safe external access.

Methods and results

The presented stepwise approach includes trephination, fenestration, an osteoplastic flap and obliteration. The obliteration procedure has produced good results in managing those patients with disabling symptoms despite multiple endoscopic procedures.
A systematic review of the primary squamous cell carcinoma of the external auditory canal: survival outcome based on T-staging and proposal of a new classification
Authors: George M , Borsotti F , Gereige R , Kolethekkat A A , Das A , Messerer M , Mahasampath G , Simon C
Published: February 2021

Objective

This study aimed to provide a systematic review on survival outcome based on Pittsburgh T-staging for patients with primary external auditory canal squamous cell carcinoma.

Method

This study was a systematic review in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines performed until January 2018; pertinent studies were screened. Quality of evidence was assessed using the grading of recommendation, assessment, development and evaluation working group system.

Results

Eight articles were chosen that reported on 437 patients with external auditory carcinoma. The 5-year overall survival rate was 53.0 per cent. The pooled proportion of survivors at 5 years for T1tumours was 88.4 per cent and for T2tumours was 88.6 per cent. For the combined population of T1and T2cancer patients, it was 84.5 per cent. For T3and T4tumours, it was 53.3 per cent and 26.8 per cent, respectively, whereas for T3and T4tumours combined, it was 40.4 per cent. Individual analysis of 61 patients with presence of cervical nodes showed a poor survival rate.

Conclusion

From this review, there was not any significant difference found in the survival outcome between T1and T2tumours. A practical classification incorporating nodal status that accurately stratifies patients was proposed.
Naturwissenschaftliche Kompetenz in der Grundschule: Effekte von Familienmerkmalen und Klassenkomposition
Authors: Kähler Jana , Hahn Inga , Köller Olaf
Published: February 2021

Zusammenfassung. Im vorliegenden Beitrag wurden anhand der Daten von 6,492 Schülerinnen und Schülern der Startkohorte 2 des Nationalen Bildungspanels (NEPS) die Entwicklung der naturwissenschaftlichen Kompetenz von der 1. bis zur 3. Klasse sowie mögliche Effekte der Klassenkomposition unter Berücksichtigung relevanter Familienmerkmale untersucht. Die Analysen belegen im Mittel einen Zuwachs der naturwissenschaftlichen Kompetenz über zwei Jahre mit einer Effektstärke von d = 1.36. Die Mehrebenenanalysen zeigen darüber hinaus, dass die Ausgangskompetenz in der 1. Klasse (standardisiertes Regressionsgewicht >β = .53) der stärkste Prädiktor für die naturwissenschaftliche Kompetenz in der 3. Klasse ist. Des Weiteren zeigen sich für die Anzahl an Büchern (>β = .05), den sozioökonomischen Status (>β = .06) und die Bildung der Eltern (>β = .09) signifikante Effekte. Auf Klassenebene erweist sich das Ausgangsniveau in der 1. Klasse (>β = .46) als mit Abstand stärkster Prädiktor. Zusätzlich kann ein signifikanter Effekt der sozialen Zusammensetzung der Klasse (>β = –.17) nachgewiesen werden: Schülerinnen und Schüler aus Klassen mit einem höheren Anteil an Kindern mit niedrigem sozioökonomischen Status erreichen einen geringeren Kompetenzzuwachs als Kinder aus Klassen mit einer niedrigeren Anzahl an sozial benachteiligten Kindern. Auch die Anzahl an Stunden von Heimat- und Sachunterricht in den Klassen (>β = .11) hat einen signifikanten Effekt. Demnach trägt mehr naturwissenschaftlicher Unterricht zu einem höheren Wachstum naturwissenschaftlicher Kompetenz bei. Abschließend zeigen Mediationsanalysen signifikant indirekte Effekte über die naturwissenschaftliche Kompetenz in der 1. Klasse. Sozial- und migrationsbedingte Disparitäten ergeben sich demnach bereits in der 1. Klasse und werden über die anfängliche naturwissenschaftliche Kompetenz auf die Kompetenz in der 3. Klasse vermittelt.
Zusammenhänge zwischen selbstberichteter Resilienz, wahrgenommener sozialer Unterstützung und Wohlbefinden bei Mitgliedern der Freiwilligen Feuerwehr
Authors: Kleine Berit , Muschalla Beate
Published: February 2021

Zusammenfassung. Soziale Unterstützung und eine ausgeprägte Resilienz werden in der Forschungsliteratur als protektiv für das psychische Wohlbefinden von Einsatzkräften diskutiert. Die hier dargestellte Untersuchung verfolgt das Ziel, Resilienz und ihren Zusammenhang mit psychischem Wohlbefinden bei der speziellen Gruppe der Freiwilligen Feuerwehr (FF) zu untersuchen. In einer Untersuchung mit mehreren Messzeitpunkten (November 2016-Mai 2018, T1: N = 475, T2: N = 117, T3: N = 58) wurden FF gebeten, Selbstbeurteilungsfragebögen auszufüllen. Es fanden sich geringe bis mittlere Zusammenhänge von Resilienz mit dem psychischen Wohlbefinden ( r = .20-.65). Soziale Unterstützung zeigte kleine Zusammenhänge mit Wohlbefinden ( r = .14, r = .23). Ein indirekter Zusammenhang bestand zwischen wahrgenommener sozialer Unterstützung mit dem psychischen Wohlbefinden, mediiert durch Resilienz. Weiterführende Forschung sollte klären, ob, und ggf. wie Resilienz für diese Berufsgruppe trainierbar ist und ob Verbesserungen im Wohlbefinden damit einhergehen.
Chemo‐Mechanical Coupling in Fractured Shale With Water and Hydrocarbon Flow
Authors: Wenning Quinn C. , Madonna Claudio , Kurotori Takeshi , Petrini Claudio , Hwang Junyoung , Zappone Alba , Wiemer Stefan , Giardini Domenico , Pini Ronny
Published: February 2021

The transport of chemically reactive fluids through fractured clay‐rich rocks is fundamental to many subsurface engineering technologies. Here, we present results of direct‐shear laboratory experiments with simultaneous imaging by X‐ray Computed Tomography in Opalinus claystone with subsequent fluid injection to unravel the interplay between mechanical fracture deformation, fluid sorption, and flow. Under constant radial stress (σc = 1.5 MPa), the average mechanical aperture increases with shear displacement. Upon brine injection, is reduced by 40% relative to initial conditions ( μm) and fluid‐sorption induces a divergent displacement of the two sample halves (Δh = ±50 − 170 μm) quantified by digital image correlation. None of these changes are observed in a control experiment with decane, indicating that creep is subordinate to swelling in sealing the fracture. Swelling‐induced changes in permeability within the fracture are heterogeneous and largely affect the fracture flow field, as computed using numerical simulations.
Rapidly Migrating Secondary Bedforms Can Persist on the Lee of Slowly Migrating Primary River Dunes
Authors: Zomer J. Y. , Naqshband S. , Vermeulen B. , Hoitink A. J. F.
Published: February 2021

Trains of secondary bedforms, superimposed on primary dunes, have been observed in rivers worldwide. To date, it has remained unclear how these secondary bedforms affect the sediment transport dynamics in a fluvial system. In this study, a field campaign was conducted to acquire a data set with a high spatial and temporal resolution, enabling to track secondary bedform migration. Results show that two distinct scales of bedforms are actively migrating. In parts of the study area, superimposed bedforms fully dissipate at the lee slope of the underlying primary dune, suggesting that the secondary bedforms contribute to the migration of the primary dune. In other parts, however, superimposed bedforms persist on the lee slope and in the trough of the primary dune. The steepness of the primary lee slope seems to control this. We calculated the sediment transport rates associated with both primary and secondary bedform migration, based on dune tracking. The sediment transport associated with secondary bedform migration is of the same order of magnitude, and even exceeds the transport associated with primary dune migration. This implies that secondary bedforms play a crucial role in the transport of bedload sediment, and cannot be ignored in the quantification of sediment transport based on dune tracking.
Evaluating Environmental Predictors of Western U.S. Wildfires
Authors: Cook Terri
Published: February 2021

A new analysis highlights the importance of carefully selecting the environmental variables used to drive future changes in wildfire burn area in climate models.
Earthquakes Can Acidify Groundwater
Authors: Sidder Aaron
Published: February 2021

Fracturing during microearthquakes can cause groundwater pH drops. The change is temporary but can be equivalent to the difference between water and vinegar.
Gene delivery to the hypoglossal motor system: preclinical studies and translational potential
Authors: Doyle Brendan M. , Singer Michele L. , Fleury-Curado Thomaz , Rana Sabhya , Benevides Ethan S. , Byrne Barry J. , Polotsky Vsevolod Y. , Fuller David D.
Published: February 2021

Dysfunction and/or reduced activity in the tongue muscles contributes to conditions such as dysphagia, dysarthria, and sleep disordered breathing. Current treatments are often inadequate, and the tongue is a readily accessible target for therapeutic gene delivery. In this regard, gene therapy specifically targeting the tongue motor system offers two general strategies for treating lingual disorders. First, correcting tongue myofiber and/or hypoglossal (XII) motoneuron pathology in genetic neuromuscular disorders may be readily achieved by intralingual delivery of viral vectors. The retrograde movement of viral vectors such as adeno-associated virus (AAV) enables targeted distribution to XII motoneurons via intralingual viral delivery. Second, conditions with impaired or reduced tongue muscle activation can potentially be treated using viral-driven chemo- or optogenetic approaches to activate or inhibit XII motoneurons and/or tongue myofibers. Further considerations that are highly relevant to lingual gene therapy include (1) the diversity of the motoneurons which control the tongue, (2) the patterns of XII nerve branching, and (3) the complexity of tongue muscle anatomy and biomechanics. Preclinical studies show considerable promise for lingual directed gene therapy in neuromuscular disease, but the potential of such approaches is largely untapped.
A review framework of how earthquakes trigger volcanic eruptions
Authors: Seropian Gilles , Kennedy Ben M. , Walter Thomas R. , Ichihara Mie , Jolly Arthur D.
Published: February 2021

It is generally accepted that tectonic earthquakes may trigger volcanic activity, although the underlying mechanisms are poorly constrained. Here, we review current knowledge, and introduce a novel framework to help characterize earthquake-triggering processes. This framework outlines three parameters observable at volcanoes, namely magma viscosity, open- or closed-system degassing and the presence or absence of an active hydrothermal system. Our classification illustrates that most types of volcanoes may be seismically-triggered, though require different combinations of volcanic and seismic conditions, and triggering is unlikely unless the system is primed for eruption. Seismically-triggered unrest is more common, and particularly associated with hydrothermal systems.
EGCG binds intrinsically disordered N-terminal domain of p53 and disrupts p53-MDM2 interaction
Authors: Zhao Jing , Blayney Alan , Liu Xiaorong , Gandy Lauren , Jin Weihua , Yan Lufeng , Ha Jeung-Hoi , Canning Ashley J. , Connelly Michael , Yang Chao , Liu Xinyue , Xiao Yuanyuan , Cosgrove Michael S. , Solmaz Sozanne R. , Zhang Yingkai , Ban David , Chen Jianhan , Loh Stewart N. , Wang Chunyu
Published: February 2021

Epigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 μM). Large scale atomistic simulations (>100 μs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG’s anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.
Probing resonating valence bond states in artificial quantum magnets
Authors: Yang Kai , Phark Soo-Hyon , Bae Yujeong , Esat Taner , Willke Philip , Ardavan Arzhang , Heinrich Andreas J. , Lutz Christopher P.
Published: February 2021

Designing and characterizing the many-body behaviors of quantum materials represents a prominent challenge for understanding strongly correlated physics and quantum information processing. We constructed artificial quantum magnets on a surface by using spin-1/2 atoms in a scanning tunneling microscope (STM). These coupled spins feature strong quantum fluctuations due to antiferromagnetic exchange interactions between neighboring atoms. To characterize the resulting collective magnetic states and their energy levels, we performed electron spin resonance on individual atoms within each quantum magnet. This gives atomic-scale access to properties of the exotic quantum many-body states, such as a finite-size realization of a resonating valence bond state. The tunable atomic-scale magnetic field from the STM tip allows us to further characterize and engineer the quantum states. These results open a new avenue to designing and exploring quantum magnets at the atomic scale for applications in spintronics and quantum simulations.
Three-component radical homo Mannich reaction
Authors: Shi Shuai , Qiu Wenting , Miao Pannan , Li Ruining , Lin Xianfeng , Sun Zhankui
Published: February 2021

Aliphatic amine, especially tertiary aliphatic amine, is one of the most popular functionalities found in pharmaceutical agents. The Mannich reaction is a classical and widely used transformation for the synthesis of β-amino-carbonyl products. Due to an ionic nature of the mechanism, the Mannich reaction can only use non-enolizable aldehydes as substrates, which significantly limits the further applications of this powerful approach. Here we show, by employing a radical process, we are able to utilize enolizable aldehydes as substrates and develop the three-component radical homo Mannich reaction for the streamlined synthesis of γ-amino-carbonyl compounds. The electrophilic radicals are generated from thiols via the desulfurization process facilitated by visible-light, and then add to the electron-rich double bonds of the in-situ formed enamines to provide the products in a single step. The broad scope, mild conditions, high functional group tolerance, and modularity of this metal-free approach for the synthesis of complex tertiary amine scaffolds will likely be of great utility to chemists in both academia and industry.
A new estimator for the multicollinear Poisson regression model: simulation and application
Authors: Lukman Adewale F. , Adewuyi Emmanuel , Månsson Kristofer , Kibria B. M. Golam
Published: February 2021

The maximum likelihood estimator (MLE) suffers from the instability problem in the presence of multicollinearity for a Poisson regression model (PRM). In this study, we propose a new estimator with some biasing parameters to estimate the regression coefficients for the PRM when there is multicollinearity problem. Some simulation experiments are conducted to compare the estimators' performance by using the mean squared error (MSE) criterion. For illustration purposes, aircraft damage data has been analyzed. The simulation results and the real-life application evidenced that the proposed estimator performs better than the rest of the estimators.
Mangrove tree (Avicennia marina): insight into chloroplast genome evolutionary divergence and its comparison with related species from family Acanthaceae
Authors: Asaf Sajjad , Khan Abdul Latif , Numan Muhammad , Al-Harrasi Ahmed
Published: February 2021

Avicennia marina(family Acanthaceae) is a halotolerant woody shrub that grows wildly and cultivated in the coastal regions. Despite its importance, the species suffers from lack of genomic datasets to improve its taxonomy and phylogenetic placement across the related species. Here, we have aimed to sequence the plastid genome ofA. marinaand its comparison with related species in family Acanthaceae. Detailed next-generation sequencing and analysis showed a complete chloroplast genome of 150,279 bp, comprising 38.6% GC. Genome architecture is quadripartite revealing large single copy (82,522 bp), small single copy (17,523 bp), and pair of inverted repeats (25,117 bp). Furthermore, the genome contains 132 different genes, including 87 protein-coding genes, 8 rRNA, 37 tRNA genes, and 126 simple sequence repeats (122 mononucleotide, 2 dinucleotides, and 2 trinucleotides). Interestingly, about 25 forward, 15 reversed and 14 palindromic repeats were also found in theA. marina. High degree synteny was observed in the pairwise alignment with related genomes. The chloroplast genome comparative assessment showed a high degree of sequence similarity in coding regions and varying divergence in the intergenic spacers among ten Acanthaceae species. The pairwise distance showed that A.marinaexhibited the highest divergence (0.084) withJusticia flavaand showed lowest divergence withAphelandra knappiae(0.059). Current genomic datasets are a valuable resource for investigating the population and evolutionary genetics of family Acanthaceae members’ specificallyA. marinaand related species.
Association of the plasma xanthine oxidoreductase activity with the metabolic parameters and vascular complications in patients with type 2 diabetes
Authors: Okuyama Tomoko , Shirakawa Jun , Nakamura Takashi , Murase Takayo , Miyashita Daisuke , Inoue Ryota , Kyohara Mayu , Togashi Yu , Terauchi Yasuo
Published: February 2021

Xanthine oxidoreductase (XOR) catalyzes the oxidation of hypoxanthine to xanthine, and of xanthine to uric acid. XOR also enhances the production of reactive oxygen species and causes endothelial dysfunction. In this study, we evaluated the association of XOR and its substrate with the vascular complications in 94 Japanese inpatients with type 2 diabetes (T2DM). The plasma XOR activity and plasma xanthine levels were positively correlated with the body mass index, aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-GTP, fasting plasma insulin, and the homeostasis model of assessment of insulin resistance (HOMA-IR), and negatively correlated with the high density lipoprotein cholesterol. The plasma XOR activity also showed a positive correlation with the serum triglyceride. Multivariate analyses identified AST, ALT, fasting plasma insulin and HOMA-IR as being independently associated with the plasma XOR activity. The plasma XOR activity negatively correlated with the duration of diabetes, and positively correlated with the coefficient of variation of the R-R interval and sensory nerve conduction velocity. Furthermore, the plasma XOR activity was significantly decreased in patients with coronary artery disease. Thus, the plasma XOR activity might be a surrogate marker for the development of vascular complications, as well as liver dysfunction and insulin resistance, in T2DM.

Trial registration: This study is registered at the UMIN Clinical Trials Registry (UMIN000029970; https://www.umin.ac.jp/ctr/index-j.htm). The study was conducted from Nov 15, 2017.
Excitation and ionisation cross-sections in condensed-phase biomaterials by electrons down to very low energy: application to liquid water and genetic building blocks
Authors: de Vera Pablo , Abril Isabel , Garcia-Molina Rafael
Published: February 2021

A model is presented for computing electron-impact electronic excitation and ionisation cross-sections for arbitrary condensed-phase biomaterials in a wide energy range, showing a general good agreement with the available experimental data.
Addressing a lattice of rotatable molecular dipoles with the electric field of an STM tip
Authors: Frauhammer Timo , Gerhard Lukas , Edelmann Kevin , Lindner Marcin , Valášek Michal , Mayor Marcel , Wulfhekel Wulf
Published: February 2021

Electrostatic interactions within a lattice of freestanding rotatable head groups mounted on tripodal molecular platforms.
Polytypism and superconductivity in the NbS2system
Authors: Witteveen Catherine , Górnicka Karolina , Chang Johan , Månsson Martin , Klimczuk Tomasz , von Rohr Fabian O.
Published: February 2021

This work maps out the structure–property relations in the unique metallic van der Waals system of NbS2.
Visible light promoted tandem dehydrogenation-deaminative cyclocondensation under aerobic conditions for the synthesis of 2-aryl benzimidazoles/quinoxalines from ortho-phenylenediamines and arylmethyl/ethyl amines
Authors: Sofi Firdoos Ahmad , Sharma Rohit , Rawat Ravi , Chakraborti Asit K. , Bharatam Prasad V.
Published: February 2021

Visible light promoted tandem dehydrogenation-deaminative cyclocondensation of arylmethyl/ethyl amines with ortho-phenylenediamines under aerobic conditions is reported for the synthesis of 2-aryl benzimidazoles/quinoxalines.
A transient non-covalent hydrogel by a supramolecular gelator with dynamic covalent bonds
Authors: Mondal Sahabaj , Haldar Debasish
Published: February 2021

In aqueous solution, equilibrium self-assembly and gelation occur at higher concentration but on addition of EDC non-equilibrium self-assembly and transient hydrogels are formed at low concentration, which dissolve upon anhydride hydrolysis.
Covalent cell surface recruitment of chemotherapeutic polymers enhances selectivity and activity
Authors: Tomás Ruben M. F. , Gibson Matthew I.
Published: February 2021

Chemotherapeutic polymers are targeted to cells by introduction of unnatural glycans to their glycocalyx, enhancing their cytotoxic effect.
Highly sensitive detection of DNA damage in living cells by SERS and electrochemical measurements using a flexible gold nanoelectrode
Authors: Zhou Jing , Yang Dan , Liu Guohui , Li Siying , Feng Wennan , Yang Guocheng , He Jin , Shan Yuping
Published: February 2021

Guanine (G) oxidation products, such as 8-hydroxy-2′-deoxyguanosine (8-OHdG) and 8-oxo-guanine (8-OXOG), have been widely studied as promising biomarkers for DNA oxidative damage.
Detection of the SARS-CoV-2 spike protein in saliva with Shrinky-Dink© electrodes
Authors: Zakashansky Julia A. , Imamura Amanda H. , Salgado Darwin F. , Romero Mercieca Heather C. , Aguas Raphael F. L. , Lao Angelou M. , Pariser Joseph , Arroyo-Currás Netzahualcóyotl , Khine Michelle
Published: February 2021

We introduce a simple, scalable, and portable electrochemical aptamer-based system for detection of the SARS-CoV-2 spike protein in saliva with attomolar sensitivity.
Synthesis of redox-active fluorinated 5-hydroxytryptophans as molecular reporters for biological electron transfer
Authors: Ohler Amanda , Long Hanna , Ohgo Kei , Tyson Kristin , Murray David , Davis Amanda , Whittington Chris , Hvastkovs Eli G. , Duffy Liam , Haddy Alice , Sargent Andrew L. , Allen William E. , Offenbacher Adam R.
Published: February 2021

Chemoenzymatic synthesis of fluorinated 5-hydroxytryptophans provides a novel set of non-canonical tryptophan amino acids useful for probes of biological electron transfer reactions.
Interplay of physically different properties leading to challenges in separating lanthanide cations – an ab initio molecular dynamics and experimental study
Authors: Leung Kevin , Ilgen Anastasia G. , Criscenti Louise J.
Published: February 2021

Lanthanide trivalent cations have similar adsorption free energies on silica surfaces, making it difficult to separate them. We elucidate the fundamental scientific reasons for this behavior. Our findings inform future separation technology.
Intrinsic chemistry of [OUCH]+: reactions with H2O, CH3CN and O2
Authors: Metzler Luke J. , Farmen Christopher T. , Corcovilos Theodore A. , Van Stipdonk Michael J.
Published: February 2021

We report the reactions of a gas-phase U-methylidyne species, [OUCH]+, with H2O, O2 and CH3CN.
Presolvated electron reactivity towards CO2 and N2O in water
Authors: Denisov Sergey A. , Mostafavi Mehran
Published: February 2021

The reactivity of presolvated electrons with CO2 and N2O was studied in the gas pressure range of 1 to 52 bar.
Correlation of hepcidin and serum ferritin levels in thalassemia patients at Chiang Mai University Hospital
Authors: Tantiworawit Adisak , Khemakapasiddhi Sujaree , Rattanathammethee Thanawat , Hantrakool Sasinee , Chai-Adisaksopha Chatree , Rattarittamrong Ekarat , Norasetthada Lalita , Charoenkwan Pimlak , Srichairatanakool Somdet , Fanhchaksai Kanda
Published: February 2021

Hepcidin is a key iron-regulatory hormone, the production of which is controlled by iron stores, inflammation, hypoxia and erythropoiesis. The regulation of iron by hepcidin is of clinical importance in thalassemia patients in which anemia occurs along with iron overload. The present study aimed to evaluate the correlation between serum hepcidin and ferritin levels in thalassemia patients. This cross-sectional study investigated 64 patients with thalassemia; 16 β-thalassemia major (BTM), 31 β-thalassemia/hemoglobin (Hb) E (BE), and 17 Hb H + AE Bart’s disease (Hb H + AE Bart’s). The levels of serum hepcidin and ferritin, and Hb of the three groups were measured. The median values of serum ferritin and Hb were significantly different among the three groups, whereas serum hepcidin values were not observed to be significantly different. The correlation of the serum hepcidin and ferritin levels was not statistically significant in any of the three groups of thalassemia patients with BTM, BE, or Hb H + AE Bart’s (r = −0.141, 0.065 and −0.016, respectively). In conclusion, no statistically significant correlations were observed between serum hepcidin with any variables including serum ferritin, Hb, age, labile plasma iron (LPI), and number of blood transfusion units among the three groups of thalassemia patients. Likely, the regulation of hepcidin in thalassemia patients is affected more by erythropoietic activity than iron storage.
Stability of switched singular time delay systems with switching induced state jumps
Authors: Lin Jinxing , Wu Xiang , Ding Jie , Lou Zhi‐E
Published: February 2021

This study addresses the problem of exponential stability for switched singular state‐delayed systems with switching induced state jumps, which has not been studied up to now. The considered state delay varies in a time‐varying interval. On the basis of equivalent dynamics decomposition, a model of state jump at switching instants is firstly established under an assumption that the time length between arbitrary two adjacent switches is larger than the upper bound of the state delay. Then, a sufficient condition on exponential stability of the system under the reranged dwell‐time switching constraint is presented. The key idea is the design of a dwell‐time‐dependent generalised Lyapunov function as well as a dwell‐time‐dependent function with respect to algebraic variables and application of the Razumikhin approach. The obtained stability condition exploits the lower bound and the upper bound of the dwell time. In addition, it is independent of the size of the state delay and allows the delay to be a fast time‐varying function. Finally, two numerical examples are given to show the efficacy of the derived result.
Integrated stabilisation policy over multipath routing‐enabled network
Authors: Tan Cheng , Wong Wing Shing , Zhang Huanshui , Zhang Zhengqiang
Published: February 2021

In this study, a sampled‐data networked control system over a multipath routing‐enabled network is investigated, where each delivered signal in a path suffers a random delay. For such a system, the mean square stabilisation problem is considered under the joint design of the event‐driven strategy on the actuator side and the control policy on the decision‐maker side. The contributions of this study are twofold. First, by pre‐defining an application time as an event‐triggering parameter, the sampled‐data system is transformed into a stochastic form with input delay and packet dropout. When the probability distribution of random delay is known a priori, the close form of packet dropout rate is proposed and a set of necessary and sufficient stabilisation conditions are developed simultaneously. When is unknown, the reduced system is an uncertain dynamic system. Utilising matrix polynomials, a verifiable criterion is derived for stabilising the uncertain system, which is also necessary and sufficient. Second, for the scalar system, the close form of allowable sampling period bound is developed in terms of and system parameters.
Multi‐camera 3D ball tracking framework for sports video
Authors: Wu Wanneng , Xu Min , Liang Qiaokang , Mei Li , Peng Yu
Published: February 2021

Accurate ball tracking in sports is vital for automatic sports analysis yet it is challenging mainly due to the small size and occlusions. This study proposes a novel multi‐camera 3D ball tracking (MBT) framework for sports video. The proposed framework consists of four parts: 2D ball detection, 2D ball tracking, 3D position fusion, and 3D ball tracking. In 2D aspect, the multi‐scale features are introduced to enhance the 2D ball detection, and the 2D ball tracking is also improved by exploring cross‐view information to handle the occlusion and timely updating tracking model with detection results to alleviate the problem of tracking drift. For 3D ball, a novel 3D position fusion method is proposed to optimise the ball position and the 3D ball tracking approach with improved Kalman filter is finally applied to ensure a smooth 3D ball trajectory. Moreover, compared to the existing products in commercial, the proposed framework does not require any special equipment and is thus low cost. Extensive experiments for 2D and 3D ball on a public dataset demonstrate that the proposed framework is robust to ball tracking in sports video, even in the presence of environmental interferences, substantial occlusions, and even calibration errors.
Lane‐changing decision method based Nash Q‐learning with considering the interaction of surrounding vehicles
Authors: Zhou Xiaochuan , Kuang Dengming , Zhao Wanzhong , Xu Can , Feng Jian , Wang Chunyan
Published: February 2021

In order to ensure a safer and more reliable trajectory during the lane change process, the motion decision algorithm needs to predict the possibility of different interaction behaviours with surrounding vehicles and then makes an advantageous decision. For this purpose, a motion decision method of considering the interaction of surrounding vehicles is proposed. Firstly, this study builds the payoff functions to determine the driving revenue of autonomous driving vehicles. Then, an interactive motion prediction method based on game theory is established to predict the interaction behaviours possibility and future local trajectories of surrounding vehicles. Based on this, a motion decision algorithm based on Nash Q‐learning for an autonomous driving vehicle is established. With externalising the main behaviours predicted by the interactive game and the greedy optimisation method, the autonomous vehicle can determine the optimal sequence of actions and take into account the interaction of the surrounding vehicles. Finally, the motion decision in this study is validated by MATLAB in the merging lane scene, and compared with the existing rule‐based lane change decision algorithm. The results show that the decision method in this study not only has superiority in safety and efficiency but also can effectively predict the interaction of surrounding vehicles.
Load frequency control scheme design considering flexible disturbances
Authors: Chen Chunyu , Zhang Kaifeng , Ding Zhetong , Dong Wenjie , Li Xiaoqiang , Liang Rui
Published: February 2021

Good power quality cannot be achievedwithout the frequency stability of power systems. Nevertheless, with the large‐scale integration of highly flexible renewable energy sources (RESs) such as wind and solar energy, frequency stability is threatened by RES‐generated disturbances due to their volatility and intermittency especially in the very short time scale. Therefore, a new frequency control scheme should be designed to attenuate these highly time‐varying disturbances. In this study, load frequency control (LFC) considering flexible RES suppression is investigated. Inspired by the idea of disturbance estimation and compensation, a novel active disturbance rejection (ADR) scheme is proposed. Unlike previous ADR‐based LFC schemes, the proposed one can significantly reduce estimation errors via a novel extended state observer. Then a sliding mode control scheme is used to force the area control error to slide along the equilibrium, thus significantly attenuating the power imbalance. Simulation results show the effectiveness of the proposed schemes.
Mysterious, variable, and extremely hot: White dwarfs showing ultra-high excitation lines
Authors: Reindl Nicole , Schaffenroth Veronika , Filiz Semih , Geier Stephan , Pelisoli Ingrid , Kepler Souza Oliveira
Published: February 2021

Context. About 10% of all stars exhibit absorption lines of ultra-highly excited (UHE) metals (e.g., O VIII) in their optical spectra when entering the white dwarf cooling sequence. This is something that has never been observed in any other astrophysical object, and poses a decades-long mystery in our understanding of the late stages of stellar evolution. The recent discovery of a UHE white dwarf that is both spectroscopically and photometrically variable led to the speculation that the UHE lines might be created in a shock-heated circumstellar magnetosphere.

Aims. We aim to gain a better understanding of these mysterious objects by studying the photometric variability of the whole population of UHE white dwarfs, and white dwarfs showing only the He II line problem, as both phenomena are believed to be connected.

Methods. We investigate (multi-band) light curves from several ground- and space-based surveys of all 16 currently known UHE white dwarfs (including one newly discovered) and eight white dwarfs that show only the He II line problem.

Results. We find that 75−13+8% of the UHE white dwarfs, and 75−19+9% of the He II line problem white dwarfs are significantly photometrically variable, with periods ranging from 0.22 d to 2.93 d and amplitudes from a few tenths to a few hundredths of a magnitude. The high variability rate is in stark contrast to the variability rate amongst normal hot white dwarfs (we find 9−2+4%), marking UHE and He II line problem white dwarfs as a new class of variable stars. The period distribution of our sample agrees with both the orbital period distribution of post-common-envelope binaries and the rotational period distribution of magnetic white dwarfs if we assume that the objects in our sample will spin-up as a consequence of further contraction.

Conclusions. We find further evidence that UHE and He II line problem white dwarfs are indeed related, as concluded from their overlap in the Gaia HRD, similar photometric variability rates, light-curve shapes and amplitudes, and period distributions. The lack of increasing photometric amplitudes towards longer wavelengths, as well as the nondetection of optical emission lines arising from the highly irradiated face of a hypothetical secondary in the optical spectra of our stars, makes it seem unlikely that an irradiated late-type companion is the origin of the photometric variability. Instead, we believe that spots on the surfaces of these stars and/or geometrical effects of circumstellar material might be responsible.
Die Wiederkehr der tropischen Treponematosen
Authors: Stingl Peter
Published: February 2021

Nach erfolgreicher Massenbekämpfung in den 1950er und 1960er Jahren ist eine Wiederkehr endemischer Herde der tropischen Treponematosen zu beobachten. Kenntnisse für in den Tropen tätige Ärzte sind daher erforderlich. Es werden die 3 vorkommenden Krankheitssyndrome Frambösie, endemische Syphilis und Pinta vorgestellt. V. a. die Frambösie ist bei nach Europa einwandernden Kindern aus Endemiezonen in die Differenzialdiagnose von Haut - , Schleimhaut – und Knochenpathologien miteinzubeziehen. Und dies unter Beachtung der oft langen, klinisch teils stummen Latenzzeiten zwischen den Krankheitsstadien. Unbehandelt können ernste, irreversible Körperentstellungen folgen.
Veraltete Ansichten verhindern erfolgreiche Reha nach VKB-Plastik
Authors: Vielitz Arne
Published: February 2021

Noehren B, Synder-Mackler L. Who’s Afraid of the Big Bad Wolf? Open-Chain Exercises After Anterior Cruciate Ligament Reconstruction. J Orthop Sports Phys Ther 2020; 50: 473–475. doi:10.2519/jospt.2020.0609
Synthesis of Annulated Carbazoles via FeCl3/SnCl4‑Mediated Domino Reaction of Vinyl Ketone Tethered Bromomethylindoles with Arenes and Heteroarenes
Authors: Mohanakrishnan Arasambattu K. , Saravanan Velu
Published: February 2021

One-pot synthesis of aryl- as well as heteroaryl-annulated carbazoles was achieved from 2/3-bromomethylindoles involving Lewis acid mediated domino reaction with arenes as well as heteroarenes via successive Friedel–Crafts intermolecular as well as intramolecular alkylations followed by elimination of acetone. Further, the bis-domino reaction of 2,5-bis(bromomethyl)pyrrole was also carried out with selected heteroarenes. Additionally, the synthesized thienocarbazoles and thieno­dibenzofurans were successfully utilized for a second-generation domino reaction.
Large linear magnetoresistance in single HgSe crystals induced by low-concentration Co impurity
Authors: Lonchakov A. T. , Bobin S. B.
Published: February 2021

A large linear magnetoresistance up to 600% at a magnetic field of 9 T was discovered in single HgSe:Co crystals with a low Co content (not exceeding 0.035 at. %). This was accompanied by a noticeable rise in relative magnetoresistance in comparison with undoped HgSe. An analysis of sample inhomogeneity is presented. Possible sources of linear magnetoresistance in HgSe:Co are discussed.
Smooth GaN membranes by polarization-assisted electrochemical etching
Authors: Ciers J. , Bergmann M. A. , Hjort F. , Carlin J.-F. , Grandjean N. , Haglund Å.
Published: February 2021

III-nitride membranes offer promising perspectives and improved device designs in photonics, electronics, and optomechanics. However, the removal of the growth substrate often leads to a rough membrane surface, which increases scattering losses in optical devices. In this work, we demonstrate membranes with etched surface roughness comparable to that of the as-grown epitaxial material, accomplished by the implementation of a properly designed built-in polarization field near the top of the sacrificial layer from an AlInN interlayer, which is polarization-mismatched to GaN. This leads to a steeper reduction in free carrier density during the electrochemical etching of the sacrificial layer, limiting the etching current and thus causing an abrupter etch stop. As a result, the root mean square roughness is reduced to 0.4 nm over 5 × 5 μm2. These smooth membranes open attractive pathways for the fabrication of high-quality optical cavities and waveguides operating in the ultraviolet and visible spectral regions.
Spin–orbit torque and Dzyaloshinskii–Moriya interaction in perpendicularly magnetized heterostructures with iridium
Authors: Yang Huanglin , Hu Shuai , Tang Meng , Chen Shiwei , Chen Huanjian , Wu Di , Qiu Xuepeng
Published: February 2021

Spin–orbit torque and Dzyaloshinskii–Moriya interaction are systematically investigated in perpendicularly magnetized [Ni-Co]2/Ir heterostructures. From the thickness study, the spin Hall angle θSH and spin diffusion length lsd of Ir are determined to be θSH ≈ 0.005 and lsd ≈1.2 nm. Remarkably, it is found that by taking advantage of the low resistivity of Ir, the Ir-based device consumes less power for spin–orbit torque-driven magnetization switching compared to the one based on Pt or Ta. Furthermore, the Dzyaloshinskii–Moriya interaction field and coefficient D at the [Ni-Co]2/Ir interface are determined to be 174 Oe and 0.82 mJ m−2. This study suggests Ir as an advantageous material for ultralow-power and high-density spin–orbit torque memory and logic devices.
Flexoelectric barium strontium titanate (BST) hydrophones
Authors: Hahn Michael , Trolier-McKinstry Susan , Meyer Richard J.
Published: February 2021

Flexoelectric hydrophones offer the possibility of reasonable sensitivity in lead-free systems. In this work, a dense barium strontium titanate ceramic with a Ba:Sr ratio of 70:30 and an effective flexoelectric coefficient, μ~12, of 105.6 ± 0.6 μC/m at room temperature was utilized in a prototype three-point bending hydrophone with dimensions of 77 × 10 × 0.67 mm3. Tap testing of this hydrophone with a calibrated acoustic hammer showed a resonant frequency of 250 Hz and a maximum sensitivity of 80 pC/N. Finite element analysis (FEA) was employed to verify the experimental results and to refine the predictive modeling capability. FEA was used to predict the resonant frequency of devices based on geometry, boundary conditions, and material properties. The error in resonant frequency between the FEA model and the experiment was 7.6%. FEA also enables calculations of the strain gradient produced in a material, allowing the numerical analysis of the element's expected flexoelectric output. Using this technique, single and three bending point hydrophone designs were compared. The results showed a 43% increase in charge output in the three bending point design vs the single bending point design despite an average strain decrease of 48% in each electrode pair. This design would lower the voltage output by 48% in a voltage-based design unless the voltages could be added in series. FEA studies also found the greatest flexoelectric output at low frequencies with improved high frequency output using larger electrode areas.
Resonant electron–plasmon interactions in drifting electron gas
Authors: Akbari-Moghanjoughi M.
Published: February 2021

In this paper, we investigate the resonant electron–plasmon interactions in a drifting electron gas of arbitrary degeneracy. The kinetic-corrected quantum hydrodynamic model is transformed into the effective Schrödinger–Poisson model, and the driven coupled pseudoforce system is obtained via separation of variables from the appropriately linearized system. It is noted that in the low phase–speed kinetic regime, the characteristic particle-like plasmon branch is significantly affected by the correction factor, which is a function of electron number density and temperature. It is shown that the electron current density of drifting electron gas sharply peaks at two distinct drift wavenumbers for a given value of electron density, temperature, plasmon energy, and damping parameter. The Fano-resonance of current density profile confirms the electron–plasmon resonant interaction in the presence of underlying interference effect. The electron drift current density shows fundamentally different resonance effects for plasmon energies with a wavenumber below and above a critical wavenumber. Moreover, an extension to the multistream model is presented, and the total current density of drifting electron gas in the presence of resonant electron–plasmon interactions is obtained. We further investigate the kinetic correction effect on matter-wave energy dispersion of the electron gas. It is also found that the increase in the electron number density leads to an increase in effective mass and consequently a decrease in electron mobility, whereas the increase in electron temperature has the converse effect. The kinetic correction is noted to significantly lower the quasiparticle conduction band minimum. The current model may be further elaborated to investigate the electron beam–plasma interactions.
Pedestal magnetic turbulence measurements in ELMy H-mode DIII-D plasmas by Faraday-effect polarimetry
Authors: Chen J. , Brower D. L. , Ding W. X. , Yan Z. , Curie M. , Kotschenreuther M. , Osborne T. , Strait E. , Hatch D. R. , Halfmoon M. R. , Mahajan S. M. , Jian X.
Published: February 2021

Internal magnetic fluctuation measurements are utilized to identify turbulence associated with micro-tearing modes (MTM) in the DIII-D Edge-Localized-Mode (ELM)-y H-mode pedestal. Using a Faraday-effect polarimeter, magnetic turbulence (150–500 kHz) is directly observed with a typical line-averaged fluctuation amplitude of ∼0.8 G at peak frequency (250 kHz) and ∼15 G integrated over the spectrum from 150 to 500 kHz. Frequency, poloidal wavenumber, and propagation direction of the magnetic turbulence all serve to identify as MTM. Magnetic turbulence amplitude non-monotonically correlates with collision frequency, peaks off mid-plane, and correlates with electron temperature gradient evolution between ELMs, consistent with MTM features identified from theory and gyro-kinetic simulation. The magnetic turbulence growth correlates with confinement degradation in ELMy H-mode plasmas during a slow density ramp. These internal measurements provide unique constraints toward developing physics understanding and validating models of the H-mode pedestal for future devices.
Oblate electron holes are not attributable to anisotropic shielding
Authors: Hutchinson I. H.
Published: February 2021

The influence of shielding mechanisms on the ratio of perpendicular to parallel scale lengths of multidimensional plasma electron hole equilibria is analyzed theoretically and computationally. It is shown that the “gyrokinetic” model, invoking perpendicular polarization, is based on a misunderstanding and cannot explain the observational trend that greater transverse extent accompanies a lower magnetic field. Instead, the potential in the wings of the hole, outside the region of trapped-electron depletion, has isotropic shielding giving ϕ∝e−r/L/r, with the shielding length L equal to the Debye length for holes much slower than the electron thermal speed. Particle in cell simulations confirm the analysis. Trapped electron charge distribution anisotropy must, therefore, instead underlie the oblate shape of electron holes.