bluuebunny/crossref_metadata_2025 huggingface dataset:
A ‘mixed’ dielectric response in langasite Ba3NbFe3Si2O14
Authors: Rathore Satyapal S. , Nathawat Rashi , Vitta Satish
Published: November 2020

The combined structural and dielectric response of langasite, Ba3NbFe3Si2O14 shows unique temperature and frequency dependence, attributed to presence of distributed potential wells.
Computational investigation of a switchable emulsion stabilized by the mixture of a surfactant and tertiary amine
Authors: Wang Yue , Yan Hui , Zhong Xiujuan , Yuan Shiling
Published: November 2020

Molecular dynamics simulations were performed to investigate the CO2-responsiveness of an oil-in-water (O/W) emulsion stabilized by sodium oleate (NaOA) with a tertiary amine additive, named pentamethyl diethylenetriamine (PMA).
Insertion reactions of the C–B–N-substituted borinium cation [MesBNiPr2]+
Authors: Bamford Karlee L. , Stephan Douglas W.
Published: November 2020

The borinium cation [MesBNiPr2]+ reacts with isothiocyanate and carbodiimides affording a nitrilium and borenium amidinate salts, respectively. The related triflate derivative undergoes double insertion of carbodiimide to give a bis(amidinate) boronium salt.
Continuous-flow Si–H functionalizations of hydrosilanes via sequential organolithium reactions catalyzed by potassium tert-butoxide
Authors: Lee Hyune-Jea , Kwak Changmo , Kim Dong-Pyo , Kim Heejin
Published: November 2020

We herein report an atom-economic flow approach to the selective and sequential mono-, di-, and tri-functionalizations of unactivated hydrosilanes via serial organolithium reactions catalyzed by earth-abundant metal compounds.
Discovering positively charged Pt for enhanced hydrogenolysis of glycerol to 1,3-propanediol
Authors: Zhao Binbin , Liang Yu , Liu Lei , He Qian , Dong Jinxiang
Published: November 2020

WOx-stabilized Ptδ+ species in atomic-level dispersion on tantalum oxide exhibiting a remarkable catalytic performance for glycerol hydrogenolysis to 1,3-PDO.
Oxidative cleavage of cycloalkenes using hydrogen peroxide and a tungsten-based catalyst: towards a complete mechanistic investigation
Authors: Cousin Tony , Chatel Gregory , Andrioletti Bruno , Draye Micheline
Published: November 2020

The identification of intermediates and by-products issuing from the oxidative cleavage of cycloolefins allows proposing of a reaction mechanism.
Polyacrylamide hydrogel-derived three-dimensional hierarchical porous N,S co-doped carbon frameworks for electrochemical capacitors
Authors: Meng Xiaotang , Zhang Jinyang , Chen Qiuli , Hou Linrui , Yuan Changzhou
Published: November 2020

Polyacrylamide hydrogel-derived 3D porous hierarchical N,S co-doped carbon frameworks are purposefully fabricated, and exhibit superior electrochemical capacitance in both alkaline and acidic electrolytes.
rGO–diaminobutane surfaces with optimized N doping and hydrodynamics as dual proton–electron conductors and carbon photocatalysts
Authors: Karim Mohammad Razaul , Rahman Mohammed M. , Asiri Abdullah M.
Published: November 2020

A reduced graphene oxide–diaminobutane (rGO–DAB) organic hybrid revealed excellent N doping, flexible interlayer distance, and light-harvesting property to support optimized photocatalytic activity for water splitting and dye degradation.
NHC ligand-powered palladium-catalyzed carbonylative C–S bond cleavage of vinyl sulfides: efficient access totert-butyl arylacrylates
Authors: Xu Jian-Xing , Zhao Fengqian , Wu Xiao-Feng
Published: November 2020

A palladium-catalyzed carbonylative C–S bond activation of divinyl sulfides to synthesize varioustert-(E)-butyl arylacrylates under 1 bar of CO has been developed. A series oftert-(E)-butyl acrylates were obtained in moderate to good yields.
Novel aryltriazole acyclic C-azanucleosides as anticancer candidates
Authors: Zhang Yanhua , Lin Yun , Hou Qianqian , Liu Xi , Pricl Sabrina , Peng Ling , Xia Yi
Published: November 2020

Novel aryltriazole acyclic C-azanucleosides synthesized by the simple and efficient “Click reaction” exhibited anticancer activity via inhibition of HSR pathway.
Advanced design and development of nanoparticle/microparticle dual-drug combination lactose carrier-free dry powder inhalation aerosols
Authors: Muralidharan Priya , Mallory Evan K. , Malapit Monica , Phan Hanna , Ledford Julie G. , Hayes Don , Mansour Heidi M.
Published: November 2020

Advanced co-spray drying of fluticasone propionate, salmeterol xinafoate, andd-mannitol leads to high-performing inhalable dry powders as molecular mixtures.
Advanced bioH2 and bioCH4 production with cobalt-doped magnetic carbon
Authors: Zhang Jishi , Zhao Wenqian , Fan Chuanfang , Li Wenqing , Zang Lihua
Published: November 2020

In this work, a novel cobalt-doped magnetic carbon (CDMC) was prepared to boost hydrogen (H2) and methane (CH4) generation.
Anomalous boron isotope effects on electronic structure and lattice dynamics of CuB2O4
Authors: Mero Rea Divina , Lai Chun-Hao , Du Chao-Hung , Liu Hsiang-Lin
Published: November 2020

Copper metaborate had a unique crystal structure and exhibited noteworthy magnetic phase transitions at 21 and 10 K.
In situ and non-cytotoxic cross-linking strategy for 3D printable biomaterials
Authors: Sümbelli Yiğitcan , Emir Diltemiz Sibel , Say Mehmet Girayhan , Ünlüer Özlem Biçen , Ersöz Arzu , Say Rıdvan
Published: November 2020

A new cross-linking method maintaining structural stability and elastic properties.
Envisioned strategy for an early intervention in virus-suspected patients through non-invasive piezo- and pyro-electric-based wearable sensors
Authors: Ghosh Sujoy Kumar , Mandal Dipankar
Published: November 2020

This perspective explores the scope of piezo- and pyro-electric wearable sensors towards the early intervention of virus-affected patients, particularly in the context of the ongoing COVID-19 pandemic.
Recent advances in and comprehensive consideration of the oxidation half reaction in photocatalytic CO2 conversion
Authors: Wang Yanjie , He Tao
Published: November 2020

This review highlights oxidation reactions that accompany the CO2RR, which can provide a complete picture of photocatalysis to improve the conversion efficiency.
Mussel byssus cuticle-inspired ultrastiff and stretchable triple-crosslinked hydrogels
Authors: Dong Chenglong , Fan Hailong , Tang Feng , Gao Xiaobin , Feng Kai , Wang Jiahui , Jin Zhaoxia
Published: November 2020

The triple-crosslinked hydrogel constructed through a crosslinking hierarchy exhibits significant increase in stiffness but without sacrificing the maximum elongation.
Resistive switching in formamidinium lead iodide perovskite nanocrystals: a contradiction to the bulk form
Authors: Muthu Chinnadurai , Resmi A. N. , Pious Johnpaul K. , Dayal G. , Krishna Nayana , Jinesh K. B. , Vijayakumar C.
Published: November 2020

The capping ligands reduce the interaction energy between iodide vacancies leading to reversible resistive switching in α-FAPbI3 perovskite nanocrystals.
Decoding the relationship between the electrocaloric strength and phase structure in perovskite ferroelectrics towards high performance
Authors: Wei Xiaowei , Zhao Chunlin , Zheng Ting , Wu Jiagang
Published: November 2020

The adverse variation of electrocaloric coefficient ΔT/ΔE versusthe electric field at different phase structures was first noticed and reported, and it was employed to explore the optimization of both electrocaloric temperature change ΔTand ΔT/ΔE.
Pentacene/non-fullerene acceptor heterojunction type phototransistors for broadened spectral photoresponsivity and ultralow level light detection
Authors: Shi Keli , Jin Risheng , Huang Shihua , Lei Hongwei , Dai Pei , Chi Dan , Zhang Weifeng , Yu Gui
Published: November 2020

Pentacene/non-fullerene acceptor heterojunction type phototransistors were fabricated for broadened spectral photoresponsivity and ultralow level light detection.
Marfan syndrome: whole-exome sequencing revealsde novomutations, second gene and genotype–phenotype correlations in the Chinese population
Authors: Wu Yuduo , Sun Hairui , Wang Jianbin , Wang Xin , Gong Ming , Han Lu , He Yihua , Zhang Hongjia
Published: November 2020

Marfan syndrome (MFS) is a dominant monogenic disease caused by mutations in fibrillin 1 (FBN1). Cardiovascular complications are the leading causes of mortality among MFS. In the present study, a whole-exome sequencing of MFS in the Chinese population was conducted to investigate the correlation between FBNI gene mutation and MFS. Forty-four low-frequency harmful loci were identified for the FBN1 gene in HGMD database. In addition, 38 loci were identified in the same database that have not been related to MFS before. A strict filtering and screening protocol revealed two patients of the studied group have double mutations in the FBN1 gene. The two patients harboring the double mutations expressed a prominent, highly pathological phenotype in the affected family. In addition to the FBN1 gene, we also found that 27 patients had mutations in the PKD1 gene, however these patients did not have kidney disease, and 16 of the 27 patients expressed aortic related complications. Genotype-phenotype analysis showed that patients with aortic complications are older in the family, aged between 20 and 40 years.
Prognostic factors and predictors of outcome in patients with COVID-19 and related pneumonia: a retrospective cohort study
Authors: Boari Gianluca E.M. , Chiarini Giulia , Bonetti Silvia , Malerba Paolo , Bianco Gianluca , Faustini Cristina , Braglia-Orlandini Federico , Turini Daniele , Guarinoni Vittoria , Saottini Michele , Viola Sara , Ferrari-Toninelli Giulia , Pasini Giancarlo , Mascadri Cristina , Bonzi Bianca , Desenzani Paolo , Tusi Claudia , Zanotti Eros , Nardin Matteo , Rizzoni Damiano
Published: November 2020

The aim of the present study was to simultaneously assess several potential predictors of outcome (co-morbidity, previous and in-hospital treatment, radiologic Brixia score) in patients with COVID-19.

This retrospective cohort study included 258 consecutive patients with confirmed COVID-19 admitted to a medical ward at Montichiari Hospital, Brescia, Italy from February 28th to April 30rd, 2020. Patients had SARS-CoV-2 related pneumonia with respiratory failure, and were treated with hydroxychloroquine and lopinavir plus ritonavir. In some patients, additional treatment with tocilizumab, dexamethasone and enoxaparin was adopted. Outcomes (death or recovery) were assessed at the end of the discharge period or at the end of the follow-up (August 2020).

During hospitalization, 59 patients died, while 6 died after discharge. The following variables were demonstrated to be associated with a worse prognosis: Radiologic Brixia score higher than 8, presence at baseline of hypertension, diabetes, chronic obstructive pulmonary disease, heart disease, cancer, previous treatment with ACE-inhibitors or anti-platelet drugs. Anticoagulant treatment during hospital admission with enoxaparin at a dose higher than 4000 U once daily was associated with a better prognosis.

In conclusion, our study demonstrates that some co-morbidities and cardiovascular risk factors may affect prognosis. The radiologic Brixia score may be a useful tool to stratify the risk of death at baseline. Anticoagulant treatment with enoxaparin might be associated to a clinical benefit in terms of survival in patients with COVID-19.
Extreme ultra-soft X-ray variability in an eROSITA observation of the narrow-line Seyfert 1 galaxy 1H 0707−495
Authors: Boller Th. , Liu T. , Weber P. , Arcodia R. , Dauser T. , Wilms J. , Nandra K. , Buchner J. , Merloni A. , Freyberg M. J. , Krumpe M. , Waddell S. G. H.
Published: November 2020

The ultra-soft narrow-line Seyfert 1 galaxy 1H 0707−495 is a well-known and highly variable active galactic nucleus (AGN), with a complex, steep X-ray spectrum, and has been studied extensively with XMM-Newton. 1H 0707−495 was observed with the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) aboard the Spectrum-Roentgen-Gamma (SRG) mission on October 11, 2019, for about 60 000 s as one of the first calibration and pointed verification phase (CalPV) observations. The eROSITA light curves show significant variability in the form of a flux decrease by a factor of 58 with a 1 σ error confidence interval between 31 and 235. This variability is primarily in the soft band, and is much less extreme in the hard band. No strong ultraviolet variability has been detected in simultaneous XMM-Newton Optical Monitor observations. The UV emission is LUV ≈ 1044 erg s−1, close to the Eddington limit. 1H 0707−495 entered the lowest hard flux state seen in 20 yr of XMM-Newton observations. In the eROSITA All-Sky Survey (eRASS) observations taken in April 2020, the X-ray light curve is still more variable in the ultra-soft band, but with increased soft and hard band count rates more similar to previously observed flux states. A model including relativistic reflection and a variable partial covering absorber is able to fit the spectra and provides a possible explanation for the extreme light-curve behaviour. The absorber is probably ionised and therefore more transparent to soft X-rays. This leaks soft X-rays in varying amounts, leading to large-amplitude soft-X-ray variability.
Remarks on generating realistic synthetic meteoroid orbits
Authors: Jopek T. J.
Published: November 2020

Context. To identify the real associations of small bodies, we can use synthetic sets of orbits generated by various methods. These are not perfect methods, therefore the assessment of their quality is an essential task.

Aims. In this study, we compared five methods for generating synthetic meteoroid orbits. Three of them (ME0, KD10, and KDns) had already been proposed in the literature, while two additional ones (ME1 and ME4) are new methods.

Methods. As far as possible, the synthetic orbits were compared with the orbits of the observed meteoroids. For quantitative comparison, we applied a few tests: the χ2-distance and the nearest neighbor NNN tests used in previous works, and one-dimensional χ2 and Kolmogorov-Smirnov (K-S) tests, as well as a two-dimensional K-S test implemented in this study. To estimate a general property of the orbital sample, we proposed the use of the entropy HN of the data set based on the nearest neighbor distances. Finally, we did a cluster analysis of the synthetic orbits. We calculated and compared the values of the orbital similarity thresholds.

Results. We showed that generating “realistic” meteoroid orbits and testing their quality is a complex issue. An assessment of the quality of the generated orbits depends on the type of test applied, and it refers to the sample of the observed orbits used. Different tests give different assessments. However, in practice, the investigated methods produced similar results if they were applied correspondingly.
A new high-precision strong lensing model of the galaxy cluster MACS J0416.1−2403
Authors: Bergamini P. , Rosati P. , Vanzella E. , Caminha G. B. , Grillo C. , Mercurio A. , Meneghetti M. , Angora G. , Calura F. , Nonino M. , Tozzi P.
Published: November 2020

We present a new high-precision parametric strong lensing model of the galaxy cluster MACS J0416.1−2403, at z = 0.396, which takes advantage of the MUSE Deep Lensed Field (MDLF), with 17.1 h integration in the northeast region of the cluster, and Hubble Frontier Fields data. We spectroscopically identify 182 multiple images from 48 background sources at 0.9 < z < 6.2, and 171 cluster member galaxies. Several multiple images are associated to individual clumps in multiply lensed resolved sources. By defining a new metric, which is sensitive to the gradients of the deflection field, we show that we can accurately reproduce the positions of these star-forming knots despite their vicinity to the model critical lines. The high signal-to-noise ratio of the MDLF spectra enables the measurement of the internal velocity dispersion of 64 cluster galaxies, down to mF160W = 22. This allowed us to independently estimate the contribution of the subhalo mass component of the lens model from the measured Faber-Jackson scaling relation. Our best reference model, which represents a significant step forward compared to our previous analyses, was selected from a comparative study of different mass parametrizations. The root-mean-square displacement between the observed and model-predicted image positions is only 0.40″, which is 33% smaller than in all previous models. The mass model appears to be particularly well constrained in the MDLF region. We characterize the robustness of the magnification map at varying distances from the model critical lines and the total projected mass profile of the cluster.
Effect of heating temperature on oxidation behavior of low density steels with medium manganese content
Authors: Shujia Li , Naibing Lyu , Suhuai Deng , Zhijun Luo , Shixin Xu
Published: November 2020

The high temperature oxidation behavior of Fe–C (0.22%)–Mn (5.3%)–Al (2.5–3.2%)–Si (2.2%) low density steel was studied in the atmosphere of (2%O2 + Ar) by high temperature oxidation simulation tests. The samples were kept at 900 °C–1300 °C for 30 minutes and the morphology and the content distribution of oxide layer in the scale were characterized by scanning electron microscope combined with energy dispersive spectrometer. The results show that: when the holding temperature is below 1150 °C, the oxidized weight gain increases parabolically with time; when the temperature is maintained above 1200 °C, the oxidized weight gain increases linearly. Oxidation activation energy decreases with experimental temperature from 225.31 to 43.4 kJ/mol and due to formation of liquid oxidation products the value of Ea decreases sharply from 1100 °C.For all range of temperature the outer layer of the scale is FeOn–MnO oxide while the scale is mainly SiO2–Al2O3–FeOn–MnO near the matrix. Few variations could be observed for the morphology of scales when the heating temperature ranged from 900 °C to 1100 °C. When the heating temperature is over 1150 °C the liquid Fe2SiO4 and FeO–SiO2–MnO phases in the scale were newly formed, leading to the penetration of liquid oxide scale into the steel, which makes descaling difficult. Therefore, to facilitate the descaling operation before hot rolling, temperature should be controlled below 1150 °C in the reheating furnace.
Fetal Tachycardia in the Delivery Room: Fetal Distress, Supraventricular Tachycardia, or Both?
Authors: Bhatia Satvinder Singh , Burgess Wendy H. , Skinner Jonathan R.
Published: November 2020

Background Supraventricular tachycardia (SVT) is seldom considered a cause for fetal tachycardia; commoner etiologies including maternal fever and fetal distress are usually envisaged. Fetal arrhythmia can be missed as a diagnosis, potentially leading to suboptimal management.

Cases Three cases are described where detection of fetal tachycardia >200 beats per minute (bpm) at 36, 40, and 38 weeks gestation resulted in emergency cesarean section for presumed fetal distress. Retrospective review of the cardiotocograph in two cases revealed baseline heart rates 120 to 160 bpm, with loss of trace associated with auscultated rates over 200 bpm. The diagnosis of SVT was not initially considered and made later when the infants required cardioversion at the age of 3 weeks, 2 days, and 8 days, respectively. The 36-week infant required noninvasive ventilation for prematurity.

Conclusion SVT should be actively considered in the differential diagnosis of fetal tachycardia. Unrecognized fetal SVT may result in avoidable caesarean for suspected fetal distress, with potential prematurity-related problems. The cardiotocograph can be helpful if showing contact loss associated with rapid heart rate auscultation. The antenatal detection of fetal SVT is important as it can allow anticipation and prevention of neonatal SVT, which is potentially life-threatening if not detected and treated promptly.
Spacetime diffeomorphisms as matter fields
Authors: Capoferri Matteo , Vassiliev Dmitri
Published: November 2020

We work on a 4-manifold equipped with Lorentzian metric g and consider a volume-preserving diffeomorphism that is the unknown quantity of our mathematical model. The diffeomorphism defines a second Lorentzian metric h, the pullback of g. Motivated by elasticity theory, we introduce a Lagrangian expressed algebraically (without differentiations) via our pair of metrics. Analysis of the resulting nonlinear field equations produces three main results. First, we show that for Ricci-flat manifolds, our linearized field equations are Maxwell’s equations in the Lorenz gauge with exact current. Second, for Minkowski space, we construct explicit massless solutions of our nonlinear field equations; these come in two distinct types, right-handed and left-handed. Third, for Minkowski space, we construct explicit massive solutions of our nonlinear field equations; these contain a positive parameter that has the geometric meaning of quantum mechanical mass and a real parameter that may be interpreted as electric charge. In constructing explicit solutions of nonlinear field equations, we resort to group-theoretic ideas: we identify special four-dimensional subgroups of the Poincaré group and seek diffeomorphisms compatible with their action in a suitable sense.
Optimal sizing and operation for microgrid with renewable energy considering two types demand response
Authors: Sugimura Makoto , Gamil Mahmoud M. , Akter Homeyra , Krishna Narayanan , Abdel-Akher Mamdouh , Mandal Paras , Senjyu Tomonobu
Published: November 2020

The integration of renewable energy sources into the power grid poses several challenges due to their variability in output power as they primarily depend on weather conditions. As a countermeasure, battery energy storage systems are introduced in order to mitigate output power fluctuations of the renewable energy sources. Moreover, demand response programs have been attracting huge attention as an effective mechanism for efficient energy management. It enables power suppliers to cope with the output uncertainty of renewable energy systems. First step, we propose an HRES design methodology that takes into account one year. In order to find the optimal power supply configuration, it is necessary to take into account the changes in load demand due to weather conditions and seasons for one year. However, the computational cost of simulating one year is huge and requires a rather long simulation time. Therefore, we propose a simplified simulation method that uses clustering to account for changes in load demand due to weather and seasonality in one year. Second, the first proposed method is used to propose a method for optimizing the HRES equipment capacity and operation schedule considering demand response. In this paper, mixed-integer linear programing is used as the optimization method. The proposed method considers two types of demand response and achieves cost reduction by controlling load demand in response to generated power fluctuations.
Effect of cross-beam energy transfer on target-offset asymmetry in direct-drive inertial confinement fusion implosions
Authors: Anderson K. S. , Forrest C. J. , Mannion O. M. , Marshall F. J. , Shah R. C. , Michel D. T. , Marozas J. A. , Radha P. B. , Edgell D. H. , Epstein R. , Goncharov V. N. , Knauer J. P. , Gatu Johnson M. , Laffite S.
Published: November 2020

The unintentional mispositioning of inertial confinement fusion (ICF) capsules from the center of laser beam convergence has long been shown in simulations to generate large ℓ=1 asymmetry and significantly degrade implosion symmetry and fusion yields. Experimental yields on the OMEGA laser system, however, have shown much less sensitivity to this initial target offset. This paper presents simulations of offset ICF implosions improved by including a physics model of cross-beam energy transfer (CBET), a mechanism of laser energy scattering from one beam to another. Room-temperature OMEGA implosion experiments with prescribed target offsets are simulated with and without CBET, illustrating that CBET mitigates the ℓ=1 implosion asymmetry from the target offset. Comparison of simulations to multiple complementary experimental observables indicates that the addition of CBET physics in offset simulations is necessary to match experimental results.
Cavity-enhanced Ramsey spectroscopy at a Rydberg-atom–superconducting-circuit interface
Authors: Walker D. M. , Morgan A. A. , Hogan S. D.
Published: November 2020

The coherent interaction of Rydberg helium atoms with microwave fields in a λ/4 superconducting coplanar waveguide resonator has been exploited to probe the spectral characteristics of an individual resonator mode. This was achieved by preparing the atoms in the 1s55s 3S1 Rydberg level by resonance enhanced two-color two-photon excitation from the metastable 1s2s 3S1 level. The atoms then traveled over the resonator in which the third harmonic microwave field, at a frequency of ωres=2π×19.556 GHz, drove the two-photon 1s55s 3S1 → 1s56s 3S1 transition. By injecting a sequence of Ramsey pulses into the resonator and monitoring the coherent evolution of the Rydberg state population by state-selective pulsed electric field ionization as the frequency of the microwave field was tuned, spectra were recorded that allowed the resonator resonance frequency and quality factor to be determined with the atoms acting as microscopic quantum sensors.
Multilevel nonvolatile regulation of magnetism by electric field in amorphous hard magnetic SmCo/PMN-PT(011) heterostructure
Authors: Liang Wenhui , Zhou Houbo , Qiao Kaiming , Hu Fengxia , Zhang Jian , Hao Jiazheng , Li Jia , Shen Feiran , Zhang Cheng , Yu Zibing , Gao Yihong , Wang Jing , Sun Jirong , Shen Baogen
Published: November 2020

Multilevel nonvolatile regulation (MNR) is demonstrated in a heterostructure composed of an amorphous hard magnetic SmCo thin film and a (011)-oriented ferroelectric 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) substrate. Two alternative ways of obtaining MNR are employed: the quasi-unipolar method and the quasi-minor-loop method, both of which utilize the transition from the rhombohedral (R) to monoclinic (MB) and then to orthorhombic (O) phase in a PMN-PT substrate. The mechanism is distinct from the conventional unipolar method inducing MNR, which mainly makes use of switching the ferroelectric domain in the R phase. The introduction of these two methods provides different ideas for achieving MNR in ferromagnetic/PMN-PT heterostructures. The observed MNR in an amorphous SmCo/(011) PMN-PT heterostructure demonstrates the potential applicability of hard magnetic materials for multifunctional information storage and spintronic devices.
Tuning the dynamics of imidazolium-based ionic liquids via hydrogen bonding. I. The viscous regime
Authors: Thomann C. A. , Münzner P. , Moch K. , Jacquemin J. , Goodrich P. , Sokolov A. P. , Böhmer R. , Gainaru C.
Published: November 2020

Combining results from impedance spectroscopy and oscillatory shear rheology, the present work focuses on the relation between the mass and charge flows and on how these are affected by the H-bonding in viscous ionic liquids (ILs). In particular, we compare the relaxational behaviors of the paradigmatic IL 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI) and its OH-functionalized counterpart 1-(2-hydroxyethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (OHEMIM-TFSI). Our results and their analysis demonstrate that the presence of cationic OH-groups bears a strong impact on the overall dynamics of OHEMIM-TFSI, although no signatures of suprastructural relaxation modes could be identified in their dielectric and mechanical responses. To check whether at the origin of this strong variation is the H-bonding or merely the difference between the corresponding cation sizes (controlling both the hydrodynamic volume and the inter-charge distance), the present study includes 1-propyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (PMIM-TFSI), mixtures of EMIM-TFSI and PMIM-TFSI with lithium bis(trifluoromethylsulfonyl)imide (Li-TFSI), and mixtures of OHEMIM-TFSI with PMIM-TFSI. Their investigation clearly reveals that the dynamical changes induced by H-bonding are significantly larger than those that can be attributed to the change in the ion size. Moreover, in the mixtures of OHEMIM-TFSI with PMIM-TFSI, a dilution of the OH-groups leads to strong deviations from ideal mixing behavior, thus highlighting the common phenomenological ground of hydroxy-functionalized ILs and other H-bonded liquids.
Modeling of sub-grid conditional mixing statistics in turbulent sprays using machine learning methods
Authors: Yao S. , Wang B. , Kronenburg A. , Stein O. T.
Published: November 2020

Deep artificial neural networks (ANNs) are used for modeling sub-grid scale mixing quantities such as the filtered density function (FDF) of the mixture fraction and the conditional scalar dissipation rate. A deep ANN with four hidden layers is trained with carrier-phase direct numerical simulations (CP-DNS) of turbulent spray combustion. A priori validation corroborates that ANN predictions of the mixture fraction FDF and the conditional scalar dissipation rate are in very good agreement with CP-DNS data. ANN modeled solutions show much better performance with a mean error of around 1%, which is one order of magnitude smaller than that of standard modeling approaches such as the β-FDF and its modified version. The predicted conditional scalar dissipation rate agrees very well with CP-DNS data over the entire mixture fraction space, whereas conventional models derived for pure gas phase combustion fail to describe ⟨N|ξ = η⟩ in regions with higher mixture fraction and low probability. In the second part of this paper, uncertainties associated with ANN predictions are analyzed. It is shown that a suitable selection of training sets can reduce the size of the necessary test database by ∼50% without compromising the accuracy. Feature importance analysis is used to analyze the importance of different combustion model parameters. While the droplet evaporating rate, the droplet number density, and the mixture fraction remain the dominant features, the influence of turbulence related parameters only becomes important if turbulence levels are sufficiently high.
Identification of surface and volume hot-carrier thermalization mechanisms in ultrathin GaAs layers
Authors: Giteau Maxime , de Moustier Edouard , Suchet Daniel , Esmaielpour Hamidreza , Sodabanlu Hassanet , Watanabe Kentaroh , Collin Stéphane , Guillemoles Jean-François , Okada Yoshitaka
Published: November 2020

Hot-carrier solar cells offer the opportunity to harvest more energy than the limit set by the Shockley–Queisser model by reducing the losses due to the thermalization of photo-generated carriers. Previous reports have shown lower thermalization rates in thinner absorbers, but the origin of this phenomenon is not precisely understood. In this work, we investigate a series of ultrathin GaAs absorber layers sandwiched between AlGaAs barriers and transferred on host substrates with a gold back mirror. We perform power-dependent photoluminescence characterizations at different laser wavelengths from which we determine the carrier temperature in four absorber thicknesses between 20 and 200 nm. We observe a linear relationship between the absorbed power and the carrier temperature increase. By relating the absorbed and thermalized power, we extract a thermalization coefficient for all samples. It shows an affine dependence with the thickness, leading to the identification of distinct volume and surface contributions to thermalization. We confirm that volume thermalization is linked to LO phonon decay. We discuss the origin of the interface-related thermalization, showing that the effect of LO phonon transport is negligible. Overall, this work sheds new light on thermalization processes in ultrathin semiconductor layers and introduces a method to compare the performance of hot-carrier absorbers.
Travel restrictions during pandemics: A useful strategy?
Authors: Zanin Massimiliano , Papo David
Published: November 2020

Though carrying considerable economic and societal costs, restricting individuals’ traveling freedom appears as a logical way to curb the spreading of an epidemic. However, whether, under what conditions, and to what extent travel restrictions actually exert a mitigating effect on epidemic spreading are poorly understood issues. Recent studies have actually suggested the opposite, i.e., that allowing some movements can hinder the propagation of a disease. Here, we explore this topic by modeling the spreading of a generic contagious disease where susceptible, infected, or recovered point-wise individuals are uncorrelated random-walkers evolving within a space comprising two equally sized separated compartments. We evaluate the spreading process under different separation conditions between the two spatial compartments and a forced relocation schedule. Our results confirm that, under certain conditions, allowing individuals to move from regions of high to low infection rates may turn out to have a positive effect on aggregate; such positive effect is nevertheless reduced if a directional flow is allowed. This highlights the importance of considering travel restriction policies alternative to classical ones.
Turbulence anisotropy and intermittency in open-channel flows on rough beds
Authors: Coscarella F. , Penna N. , Servidio S. , Gaudio R.
Published: November 2020

An experimental campaign, based on Particle Image Velocimetry measurements in a laboratory flume with different median sediment sizes in the no-motion condition, has been carried out aiming at investigating the effects of bed roughness on turbulence anisotropy in two different vertical zones of the turbulent open-channel flow. An analysis of turbulence anisotropy, which relies on second-order structure functions and anisotropy angle, has been performed. The scale-dependent anisotropy level has been quantified, verifying the tendency of the system to span from large-scale anisotropy, due to the main shear of the boundary layer, to small-scale isotropy. Isotropy is well-established for the largest sediment sizes. High-order structure function analysis reveals that intermittency is more pronounced in the near-bed layers, where the flow is more populated by coherent vortices. Spectral anisotropy and intermittency strongly characterize the transport properties of turbulence and are, therefore, important phenomena for natural bed rivers.
Unsteady magnetohydrodynamic flow of generalized second grade fluid through porous medium with Hall effects on heat and mass transfer
Authors: Jiang Xiaoyun , Zhang Hui , Wang Shaowei
Published: November 2020

This work investigates the unsteady magnetohydrodynamic flow of generalized second grade fluid through a porous medium with Hall effects on heat and mass transfer. The second grade fluid with a fractional derivative is used for the constitutive equation. A second-order fractional backward difference formula in the temporal direction and a spectral collocation method in the spatial direction are proposed to solve the model numerically. In the numerical implementation, a fast method is applied to decrease the memory requirement and computational cost. The velocity, temperature, and concentration profiles are discussed through graphs. The effects of various parameters on the velocity profiles, temperature field, and concentration field are shown. Results indicate that as the fractional derivative γ increases and the Hall parameter m decreases, the amplitudes of the velocity components decrease.
COVID-19 transmission in the first presidential debate in 2020
Authors: Shao Xiaoliang , Li Xianting
Published: November 2020

The infection risks of Biden, Wallace, and the audience by Trump and the first lady were assessed during the first presidential debate. The debate scene was established numerically, and two cases, i.e., only Trump being infected and both Trump and the first lady being infected, were set up for risk analysis. The infection probabilities at different positions were assessed by using the Wells–Riley equation with consideration of the effects of air distribution and face mask. It was concluded that (1) the infection risks of Biden and Wallace were lower due to the reasonable distance from Trump, with the maximum probability of 0.34% at 40 quanta/h for both Trump and the first lady being infected; (2) the infection probabilities in the audience area were lower for the long distance from the debate stage, with the maximum probability of 0.35%. Wearing masks resulted in a notable decrease in the infection probability to 0.09%; and (3) there was a certain local area surrounding Trump and the first lady with a relatively greater infection probability. The preliminary analysis provides some reference for protection of the next presidential debate and other public events.
Unbiased in vivo preclinical evaluation of anticancer drugs identifies effective therapy for the treatment of pancreatic adenocarcinoma
Authors: Grbovic-Huezo Olivera , Pitter Kenneth L. , Lecomte Nicolas , Saglimbeni Joseph , Askan Gokce , Holm Matilda , Melchor Jerry P. , Chandwani Rohit , Joshi Suhasini , Haglund Caj , Iacobuzio-Donahue Christine A. , Chiosis Gabriela , Tammela Tuomas , Leach Steven D.
Published: November 2020

Significance

The clinical management of pancreatic cancer has not seen significant improvement in decades, in part because prediction of tumor drug sensitivity using in vitro assays has proven notoriously inaccurate in this disease. We performed a large-scale, unbiased in vivo screen of 57 different single agent and combination targeted therapies in an in vivo orthotopic mouse model. In this ambitious effort, we identified previously unsuspected synergy between HSP90 inhibition and MEK inhibition as effective combination therapy in this disease. The results underscore the utility of unbiased, in vivo drug screens in the identification of effective cancer therapies for evaluation in subsequent clinical trials.
A source for awareness-dependent figure–ground segregation in human prefrontal cortex
Authors: Huang Ling , Wang Lijuan , Shen Wangming , Li Mengsha , Wang Shiyu , Wang Xiaotong , Ungerleider Leslie G. , Zhang Xilin
Published: November 2020

Significance

Figure–ground segregation, segmenting images by the visual system into figures and background, is the first processing step on the way to visual perception and relies on three complementary processes: boundary detection, region filling, and background suppression. By combining psychophysics, functional magnetic resonance imaging, and effective connectivity analysis, we showed that awareness was important for both region filling and background suppression, but less so for boundary detection. More importantly, we revealed that the awareness-dependent region-filling and background-suppression processes in V1 were derived by feedback from FEF and DLPFC, respectively. Our study indicates an awareness-dependent figure–ground segregation and identifies the human prefrontal cortex as a source of this fundamental process.
Aberrant expression of USF2 in refractory rheumatoid arthritis and its regulation of proinflammatory cytokines in Th17 cells
Authors: Hu Dan , Tjon Emily C. , Andersson Karin M. , Molica Gabriela M. , Pham Minh C. , Healy Brian , Murugaiyan Gopal , Pochet Nathalie , Kuchroo Vijay K. , Bokarewa Maria I. , Weiner Howard L.
Published: November 2020

Significance

Identifying signaling pathways contributing to resistance to anti-TNF therapy in rheumatoid arthritis is crucial for the development of new therapeutic strategies for refractory rheumatoid arthritis. Th17 cells, a subset of proinflammatory CD4+T cells, are implicated in the pathogenesis of the disease. We analyzed the gene expression profiles of Th17-enriched CD4+T cells in anti-TNF–treated patients with rheumatoid arthritis and found that the elevated expression levels of transcription factor USF2 in anti-TNF refractory patients were associated with increased proinflammatory signaling of Th17 cells. USF2-knockdown experiments in Th17 cells revealed that USF2 promotes the pathogenicity of Th17 cells. These findings have implications for the development of new therapeutic strategies for refractory rheumatoid arthritis.
The confidence gap predicts the gender pay gap among STEM graduates
Authors: Sterling Adina D. , Thompson Marissa E. , Wang Shiya , Kusimo Abisola , Gilmartin Shannon , Sheppard Sheri
Published: November 2020

Significance

Is there a gender pay gap among graduates in some science, technology, engineering, and math (STEM) fields? Women and men have near-identical human capital at college exit, but cultural beliefs about men as more fit for STEM professions than women may lead to self-beliefs that affect pay. We hypothesized that women and men would be paid differently upon college exit, and that gender gaps in self-beliefs about one's abilities, or self-efficacy, would correspond to this difference. Using data from a three-wave longitudinal study of graduates of engineering programs from 2015–2017, we find a confidence gap that aligns with a gender pay gap. Overall, these findings point to the role that cultural beliefs play in creating gender disparities among STEM degree-holders.
The antibiotic sorangicin A inhibits promoter DNA unwinding in a
Mycobacterium tuberculosis
rifampicin-resistant RNA polymerase
Authors: Lilic Mirjana , Chen James , Boyaci Hande , Braffman Nathaniel , Hubin Elizabeth A. , Herrmann Jennifer , Müller Rolf , Mooney Rachel , Landick Robert , Darst Seth A. , Campbell Elizabeth A.
Published: November 2020

Significance

Rifampicin (Rif) is an antibiotic that targets bacterial RNA polymerase (RNAP). The search for new antibiotics against proven targets is one approach to combat multidrug-resistant tuberculosis (TB), a global threat. Here, we characterized the effects of the antibiotic sorangicin A (Sor) on a Rif-resistant (Rif
R
) RNAP found in clinically isolated Rif
R
strains. Sor binds in the same pocket and inhibits wild-type RNAP by the same mechanism as Rif. However, Sor inhibits Rif
R
RNAPs by a distinct mechanism, providing a new target for drug design. Intriguingly, Sor displays a better pharmacokinetic profile compared to rifamycins, which is important for development of inhibitors to treat TB patients suffering from comorbidities. These results inform approaches toward drug development against antibiotic-resistant targets.
Mutation bias within oncogene families is related to proliferation-specific codon usage
Authors: Benisty Hannah , Weber Marc , Hernandez-Alias Xavier , Schaefer Martin H. , Serrano Luis
Published: November 2020

Significance

In light of the genetic code, combinations of three nucleotides which are known as synonymous codons, can give rise to the same amino acid. Despite the homology at the protein level, these different codons are recognized distinctly by the translational machinery. The unequal use of synonymous codons influences protein expression. Surprisingly, we find that the coding sequences of KRAS and other frequently mutated cancer genes are adapted to be efficiently translated in proliferating cells in comparison to their family counterparts. Our work contributes to the unsolved question of why in tumors some members of cancer gene families show a higher mutation rate than their family counterparts. Thus, our results elucidate the relationship between tRNA expression, codon usage, and oncogenicity.
Fast recovery of disrupted tip links induced by mechanical displacement of hair bundles
Authors: Alonso R. G. , Tobin M. , Martin P. , Hudspeth A. J.
Published: November 2020

Significance

Each of the sensory receptors responsible for hearing or balance—a hair cell—has a mechanosensitive hair bundle. Mechanical stimuli pull upon molecular filaments—the tip links—that open ionic channels in the hair bundle. Loud sounds can damage hearing by breaking the tip links; recovery by replacement of the constituent proteins then requires several hours. We disrupted the tip links in vitro by removing the calcium ions that stabilize them, and then monitored the electrical response or stiffness of hair bundles to determine whether the links could recover. We found that tip links recovered within seconds if their ends were brought back into contact. This form of repair might occur in normal ears to restore sensitivity after damage.
Constitutive relationship and governing physical properties for magnetophoresis
Authors: Ayansiji Ayankola O. , Dighe Anish V. , Linninger Andreas A. , Singh Meenesh R.
Published: November 2020

Significance

The motion of magnetic particles under magnetic field, referred to as magnetophoresis, is fundamental to nature. While several empirical observations have been gathered, the multitude and complexity of magnetic-field-induced interactions on magnetic particles have prevented the full understanding of this phenomenon. The magnetophoresis is central to several advanced technologies such as magnetic drug targeting, bioseparation, and imaging, yet the efficient targeting of magnetic particles is hampered for the lack of a theoretical framework. We present a fundamental approach utilizing a detailed force balance on magnetic particles to develop a constitutive relationship for magnetophoresis that includes contributions from magnetic diffusion, magnetic convection, and residual magnetization. The application of this theory will enable the predictive design of magnetic targeting applications.
STING induces LC3B lipidation onto single-membrane vesicles via the V-ATPase and ATG16L1-WD40 domain
Authors: Fischer Tara D. , Wang Chunxin , Padman Benjamin S. , Lazarou Michael , Youle Richard J.
Published: November 2020

Following the detection of cytosolic double-stranded DNA from viral or bacterial infection in mammalian cells, cyclic dinucleotide activation of STING induces interferon β expression to initiate innate immune defenses. STING activation also induces LC3B lipidation, a classical but equivocal marker of autophagy, that promotes a cell-autonomous antiviral response that arose before evolution of the interferon pathway. We report that STING activation induces LC3B lipidation onto single-membrane perinuclear vesicles mediated by ATG16L1 via its WD40 domain, bypassing the requirement of canonical upstream autophagy machinery. This process is blocked by bafilomycin A1 that binds and inhibits the vacuolar ATPase (V-ATPase) and by SopF, a bacterial effector that catalytically modifies the V-ATPase to inhibit LC3B lipidation via ATG16L1. These results indicate that activation of the cGAS-STING pathway induces V-ATPase–dependent LC3B lipidation that may mediate cell-autonomous host defense, an unanticipated mechanism that is distinct from LC3B lipidation onto double-membrane autophagosomes.
Isotropic compact stars in 4D Einstein–Gauss–Bonnet gravity
Authors: Hansraj Sudan , Banerjee Ayan , Moodly Lushen , Jasim M K
Published: November 2020

Recently it has been proposed that the Gauss–Bonnet coupling parameter of Lovelock gravity may suitably be rescaled in order to admit physically viable models of celestial phenomena such that higher curvature effects are active in standard four dimensions as opposed to the usual higher dimensions. We investigate the consequences of this modification in the context of stellar modelling. The evolution of perfect fluid distributions is governed by the pressure isotropy condition and through stipulation of one of the metric potentials complete models emerge from solutions of the master differential equation. New classes of exact solution with this approach have been reported. One particular model is analysed in detail and shown to comport with elementary physical requirements demanded of realistic compact stars suggesting that the modified theory is not inconsistent with observations.