bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetric Synthesis of α-Alkylated γ-Lactam via Nickel/8-Quinim-Catalyzed Reductive Alkyl-Carbamoylation of Unactivated Alkene
Authors: Wu Xianqing , Shrestha Mohini , Chen Yifeng
Published: January 2021

Chiral-auxiliary-mediated synthesis represents the most frequently used synthetic tool for the induction of chirality on α-position of γ-lactams in organic synthesis. However, the general strategy requires the stoichiometric use of chiral reagents with multiple manipulation steps. Transition-metal-catalyzed asymmetric alkene dicarbofunctionalization using readily available substrates under mild conditions allows the simultaneous construction of two vicinal chemical bonds and a chiral carbon center, hence, gain expedient access to chiral heterocycles. Herein, we disclose a Ni-catalyzed enantioselective reaction of 3-butenyl carbamoyl chloride and primary alkyl iodide enabled by a newly designed chiral 8-quinoline imidazoline ligand (8-Quinim). This protocol features broad functional group tolerance and high enantioselectivities, achieving unprecedented synthesis of chiral nonaromatic heterocycles via catalytic reductive protocol.

1 Introduction

2 Development of 8-Quinim Ligand

3 Nickel/8-Quinim-Catalyzed Enantioselective Synthesis of Chiral α-Alkylated γ-Lactam

4 Conclusion and Outlook
On the 2D dynamics of the magnetoacoustic cyclotron instability driven by fusion-born ions
Authors: Carbajal L. , Calderón F. A.
Published: January 2021

In this work, we present advances in the numerical modeling of the non-linear magnetoacoustic cyclotron instability (MCI) in relation to ion cyclotron emission (ICE) in fusion plasmas. We present the results of first 2D hybrid simulations of the MCI showing that only when excited waves propagate obliquely to the background magnetic field, the characteristic fingerprint of ICE in fusion plasmas is recovered. Different dynamics in 1D and 2D hybrid simulations of the MCI are observed and described. The results in the present work shed some light on the self-consistent dynamics of the non-linear MCI in scenarios where no analytical theory is available.
A numerical fitting routine for frequency-domain thermoreflectance measurements of nanoscale material systems having arbitrary geometries
Authors: Warzoha Ronald J. , Wilson Adam A. , Donovan Brian F. , Smith Andrew N. , Vu Nicholas , Perry Trent , Li Longnan , Miljkovic Nenad , Getto Elizabeth
Published: January 2021

In this work, we develop a numerical fitting routine to extract multiple thermal parameters using frequency-domain thermoreflectance (FDTR) for materials having non-standard, non-semi-infinite geometries. The numerical fitting routine is predicated on either a 2D or 3D finite element analysis that permits the inclusion of non-semi-infinite boundary conditions, which cannot be considered in the analytical solution to the heat diffusion equation in the frequency domain. We validate the fitting routine by comparing it with the analytical solution to the heat diffusion equation used within the wider literature for FDTR and known values of thermal conductivity for semi-infinite substrates (SiO2, Al2O3, and Si). We then demonstrate its capacity to extract the thermal properties of Si when etched into micropillars that have radii on the order of the pump beam. Experimental measurements of Si micropillars with circular and square cross sections are provided and fit using the numerical fitting routine established as part of this work. Likewise, we show that the analytical solution is unsuitable for the extraction of thermal properties when the geometry deviates significantly from the standard semi-infinite case. This work is critical for measuring the thermal properties of materials having arbitrary geometries, including ultra-drawn glass fibers and laser gain media.
On the role of symmetry in XDW-CASPT2
Authors: Battaglia Stefano , Lindh Roland
Published: January 2021

Herewith, we propose two new exponents for the recently introduced XDW-CASPT2 method [S. Battaglia and R. Lindh, J. Chem. Theory Comput. 16, 1555–1567 (2020)], which fix one of the largest issues hindering this approach. By using the first-order effective Hamiltonian coupling elements, the weighting scheme implicitly takes into account the symmetry of the states, thereby averaging Fock operators only if the zeroth-order wave functions interact with each other. The use of Hamiltonian couplings also provides a physically sounder approach to quantitate the relative weights; however, it introduces new difficulties when these rapidly die off to zero. The improved XDW-CASPT2 method is critically tested on several systems of photochemical relevance, and it is shown that it succeeds in its original intent of maintaining MS-CASPT2 accuracy for the evaluation of transition energies and at the same time providing smooth potential energy surfaces around near-degenerate points akin to XMS-CASPT2.
Shear response of magnetorheological fluid with Zn0.2Fe2.8O4 sub-micron hollow spheres
Authors: Saha Priyanka , Rakshit Rupali , Mandal Kalyan
Published: January 2021

Magnetorheological (MR) fluids with Fe3O4 particles are widely studied nowadays due to their soft magnetic nature, controllable morphology, and better chemical stability as compared to their metallic counterpart. However, they can be even more advantageous under Zn doping with elevated magnetization and hollow configuration with low density, making them more active, stable, and dispersible in the carrier fluid. Here, we report the preparation of MR fluids with Zn0.2Fe2.8O4 sub-micrometer hollow spheres and their steady-state MR response under the application of a magnetic field. The MR fluid follows the Bingham plastic nature with a yielding behavior. The variation of yield stress with the applied magnetic field is explained in the context of a newly developed dipolar interaction model.
Flexoelectric effects on the natural frequencies for free vibration of piezoelectric nanoplates
Authors: Wang Bin , Li Xian-Fang
Published: January 2021

Flexoelectricity is an electromechanical coupling phenomenon between polarization and strain gradient. Based on the Kirchhoff thin plate theory, the electromechanical coupling responses of nanoplates with the piezoelectric and flexoelectric effects are studied in this paper. Free vibration of a piezoelectric nanoplate with consideration of flexoelectricity is analyzed with emphasis on the influence of the dynamic flexoelectric effect on the natural frequencies. By means of Hamilton’s variational principle, the governing equation of rectangular plates together with associated boundary conditions is derived. The natural frequencies are evaluated for a nanoplate simply supported at two opposite edges, and exact frequency equations are obtained for the other two opposite edges being simply supported, clamped–clamped, clamped–free, simply supported–free, or clamped–simply supported. The influence of dynamic flexoelectricity on the natural frequencies is elucidated. The results show that the dynamic flexoelectric effect is also size-dependent; the smaller the plate thickness is, the more obvious the dynamic flexoelectric effect is. The results also show that the dynamic flexoelectric effect is more pronounced when the order of vibration modes is higher and nanoplate’s side ratio is larger. The positive and negative choice of static and dynamic flexoelectric coefficients have completely different effects on the natural frequencies. The influence of the dynamic flexoelectric effect on the natural frequencies is closely related to the side constraint and geometry of the plate. The piezoelectric effect does not alter the natural frequencies for free vibration of a homogeneous nanoplate.
Magnetic and ferroelectric properties of oxygen octahedron/tetrahedron mixed ultrathin multiferroic layer by oxygen desorption
Authors: Ichinose T. , Naganuma H.
Published: January 2021

BiFeO3 epitaxial films (tBFO = 1–10 nm) were grown on a LaSrMnO3 (tLSMO = 70 nm) buffer layer and capped with a Ru or Ru/Al layer. The BiFeO3 ultrathin film (tBFO = 3 nm) was confirmed to be continuous and flat over a wide area. Piezoelectric response and switching of spontaneous polarization were observed in the ultrathin films by switching-spectroscopy piezoelectric force microscopy measurements. Using the lock-in method with a modulation frequency of 10 Hz in x-ray absorption spectroscopy (XAS), a difference was observed between the left- and right-circularly polarized XAS signals of Fe L3 and L2 owing to x-ray magnetic circular dichroism (XMCD). The number of Fe L3 and L2 XMCD peaks indicated that a mixture of oxygen octahedron and tetrahedron (divalent and trivalent) structures might be formed. The tBFO dependence of XMCD revealed that approximately 1 nm thick ferro-like magnetic properties emerged on the BiFeO3 side of the BiFeO3/Ru interface. Ru may partially extract oxygen from BiFeO3, forming an oxygen tetrahedron structure. The BiFeO3/Ru bilayer exhibits both a piezoelectric response and ferro-like magnetism, which is promising as the basic structure of multiferroic tunnel junctions.
Estimating entropy rate from censored symbolic time series: A test for time-irreversibility
Authors: Salgado-García R. , Maldonado Cesar
Published: January 2021

In this work, we introduce a method for estimating the entropy rate and the entropy production rate from a finite symbolic time series. From the point of view of statistics, estimating entropy from a finite series can be interpreted as a problem of estimating parameters of a distribution with a censored or truncated sample. We use this point of view to give estimations of the entropy rate and the entropy production rate, assuming that they are parameters of a (limit) distribution. The last statement is actually a consequence of the fact that the distribution of estimations obtained from recurrence-time statistics satisfies the central limit theorem. We test our method using a time series coming from Markov chain models, discrete-time chaotic maps, and a real DNA sequence from the human genome.
In situ millimeter wave spectroscopy of microplasma within a photonic crystal
Authors: Kim Hyunjun , Hopwood Jeffrey
Published: January 2021

Microplasma generated within a millimeter wave (MMW) photonic crystal (PhC) is analyzed by direct measurement of the electron density and the wave transmission spectra (S21) of the crystal. A continuous wave (cw) drive frequency of 43.66 GHz maintains plasma, while a low power frequency sweep (43.5–44.1 GHz) simultaneously probes the wave transmission in the presence of microplasma. Rotational gas temperature and electron density are measured from the CH emission spectrum and the Stark broadening of the Hβ atomic transition. The permittivity of the plasma depends on the electron density. As higher cw power and argon gas pressure increase the electron density in the PhC vacancy, the resonant frequency of the PhC shifts upward in accordance with the measured electron density and plasma permittivity. As the PhC obscures the central core of the microplasma, we present a simple diffusion model that approximates the electron density distribution within the microplasma. The diffuse electron density is then used in a numerical model for S21(ω). The measured and modeled transmission spectra can only be reconciled using the diffusion density gradient of the microplasma, thus resolving previous discrepancies observed when using simplified, abrupt-boundary plasma models.
State and parameter estimation from exact partial state observation in stochastic reaction networks
Authors: Rathinam Muruhan , Yu Mingkai
Published: January 2021

We consider chemical reaction networks modeled by a discrete state and continuous in time Markov process for the vector copy number of the species and provide a novel particle filter method for state and parameter estimation based on exact observation of some of the species in continuous time. The conditional probability distribution of the unobserved states is shown to satisfy a system of differential equations with jumps. We provide a method of simulating a process that is a proxy for the vector copy number of the unobserved species along with a weight. The resulting weighted Monte Carlo simulation is then used to compute the conditional probability distribution of the unobserved species. We also show how our algorithm can be adapted for a Bayesian estimation of parameters and for the estimation of a past state value based on observations up to a future time.
Atomic scale confirmation of ferroelectric polarization inversion in wurtzite-type AlScN
Authors: Wolff Niklas , Fichtner Simon , Haas Benedikt , Islam Md Redwanul , Niekiel Florian , Kessel Maximilian , Ambacher Oliver , Koch Christoph , Wagner Bernhard , Lofink Fabian , Kienle Lorenz
Published: January 2021

This work presents the first atomic scale evidence for ferroelectric polarization inversion on the unit cell level in a wurtzite-type material based on epitaxial Al0.75Sc0.25N thin films. The electric field induced formation of Al-polar inversion domains in the originally N-polar film is unambiguously determined by atomic resolution imaging using aberration-corrected scanning transmission electron microscopy (STEM). Anisotropic etching supports STEM results confirming a complete and homogenous polarization inversion at the film surface for the switched regions and the virtual absence of previous inversion domains in as-deposited regions. Local evidence of residual N-polar domains at the bottom electrode interface is observed and can be explained by both stress gradients and electric field deflection. The epitaxial relationship of the sapphire/AlN/Mo/AlScN multilayer stack is discussed in detail. Selected-area electron diffraction experiments and XRD pole figures reveal a Pitsch–Schrader type orientation relation between the Mo electrode and the AlScN film.
Wavebreaking amplitudes in warm, inhomogeneous plasmas revisited
Authors: Rathee Nidhi , Mukherjee Arghya , Trines R. M. G. M. , Sengupta Sudip
Published: January 2021

The effect of electron temperature on the space–time evolution of nonlinear plasma oscillations in an inhomogeneous plasma is studied using a one-dimensional particle-in-cell code. It is observed that, for an inhomogeneous plasma, there exists a critical value of electron temperature beyond which the wave does not break. These simulation results, which are in conformity with the purely theoretical arguments presented by Trines [Phys. Rev. E 79, 056406 (2009)], represent the first numerical elucidation of the effect of plasma pressure on wave breaking amplitude. The results presented are of relevance to experiments where moderate to large amplitude plasma waves are excited, e.g., laser–plasma interaction experiments.
Time resolved detection of the S(1D) product of the UV induced dissociation of CS2
Authors: Warne Emily M. , Smith Adam D. , Horke Daniel A. , Springate Emma , Jones Alfred J. H. , Cacho Cephise , Chapman Richard T. , Minns Russell S.
Published: January 2021

The products formed following the photodissociation of UV (200 nm) excited CS2 are monitored in a time resolved photoelectron spectroscopy experiment using femtosecond XUV (21.5 eV) photons. By spectrally resolving the electrons, we identify separate photoelectron bands related to the CS2 + hν → S(1D) + CS and CS2 + hν → S(3P) + CS dissociation channels, which show different appearance and rise times. The measurements show that there is no delay in the appearance of the S(1D) product contrary to the results of Horio et al. [J. Chem. Phys. 147, 013932 (2017)]. Analysis of the photoelectron yield associated with the atomic products allows us to obtain a S(3P)/S(1D) branching ratio and the rate constants associated with dissociation and intersystem crossing rather than the effective lifetime observed through the measurement of excited state populations alone.
Parametrization of the Fe–Owater cross-interaction for a more accurate Fe3O4/water interface model and its application to a spherical Fe3O4 nanoparticle of realistic size
Authors: Siani Paulo , Bianchetti Enrico , Liu Hongsheng , Di Valentin Cristiana
Published: January 2021

The accurate description of iron oxides/water interfaces requires reliable force field parameters that can be developed through comparison with sophisticated quantum mechanical calculations. Here, a set of CLASS2 force field parameters is optimized to describe the Fe–Owater cross-interaction through comparison with hybrid density functional theory (HSE06) calculations of the potential energy function for a single water molecule adsorbed on the Fe3O4 (001) surface and with density functional tight binding (DFTB+U) molecular dynamics simulations for a water trilayer on the same surface. The performance of the new parameters is assessed through the analysis of the number density profile of a water bulk (12 nm) sandwiched between two magnetite slabs of large surface area. Their transferability is tested for water adsorption on the curved surface of a spherical Fe3O4 nanoparticle of realistic size (2.5 nm).
Evidence of phonon pumping by magnonic spin currents
Authors: Holanda José , Maior Daniel S. , Santos Obed Alves , Azevedo Antonio , Rezende Sergio M.
Published: January 2021

Spin current phenomena are at the heart of the active research field of spintronics that aims to develop new perspectives for emerging information technologies. In recent years, several groups reported experiments in which spin currents are used to excite coherent magnetization dynamics in magnetic nanostructures. Here, we show experimentally two effects of the large spin current generated by the giant spin Hall effect in a platinum strip with nanoscopic silver particles adjacent to a film of the insulating ferrimagnet yttrium iron garnet (YIG). The first, demonstrated by ferromagnetic resonance (FMR) experiments, is the dramatic reduction of the magnon damping measured by the FMR linewidth due to the spin torque produced by the spin current. The second, observed by Brillouin light scattering (BLS), is the excitation of quasi-particles in the YIG film with frequencies that do not vary with the applied magnetic field. We interpret the BLS signal as due to phonons excited by the magnonic spin current injected into the YIG film, in a process that is the Onsager reciprocal of the spin pumping by coherent elastic waves.
Shadowing of the operating mode by sidebands in gyrotrons with diode-type electron guns
Authors: Chen Xianfei , Nusinovich Gregory S. , Dumbrajs Olgierd , Xiao Houxiu , Xia Donghui , Ding Tonghai , Liu Luwei , Han Xiaotao , Peng Tao
Published: January 2021

In gyrotrons operating in high-order modes, during the startup process, the shadowing of the operating mode by two sidebands may take place. By “shadowing,” we mean the situation when, during the voltage rise, one of the parasitic modes is excited first, and this excitation prevents the excitation of the desired mode. Then, the oscillations of the first parasitic mode, whose frequency is higher than the frequency of the desired operating mode, can be replaced by excitation of the second parasitic mode, whose frequency is lower than the operating one. As a result, the desired mode remains in the “shadow” of these parasitic modes and is never excited. This paper describes such effect in gyrotrons with diode-type electron guns. This paper consists of two parts. First, the problem is studied in a generalized approach, which means that the results are valid to gyrotrons operating at arbitrary voltages and in any modes. By using this approach, it is possible to determine the critical density of the mode spectrum, above which the shadowing occurs. This study is carried out for the cases when the interaction between modes is synchronous and when it is nonsynchronous. Second, this paper contains the analysis of a typical Megawatt-class gyrotron with a diode-type electron gun. It is studied whether the moving of this gyrotron to operating in higher-order modes will lead to the shadowing of the desired mode or other, more complicated, dynamic, and/or stochastic processes will take place.
Relaxation dynamics through a conical intersection: Quantum and quantum–classical studies
Authors: Pieroni Carlotta , Marsili Emanuele , Lauvergnat David , Agostini Federica
Published: January 2021

We study the relaxation process through a conical intersection of a photo-excited retinal chromophore model. The analysis is based on a two-electronic-state two-dimensional Hamiltonian developed by Hahn and Stock [J. Phys. Chem. B 104 1146 (2000)] to reproduce, with a minimal model, the main features of the 11-cis to all-trans isomerization of the retinal of rhodopsin. In particular, we focus on the performance of various trajectory-based schemes to nonadiabatic dynamics, and we compare quantum–classical results to the numerically exact quantum vibronic wavepacket dynamics. The purpose of this work is to investigate, by analyzing electronic and nuclear observables, how the sampling of initial conditions for the trajectories affects the subsequent dynamics.
On how to measure the probabilities of target atom ionization and target ion back-attraction in high-power impulse magnetron sputtering
Authors: Rudolph Martin , Hajihoseini Hamidreza , Raadu Michael A. , Gudmundsson Jon Tomas , Brenning Nils , Minea Tiberiu M. , Anders André , Lundin Daniel
Published: January 2021

High-power impulse magnetron sputtering (HiPIMS) is an ionized physical vapor deposition technique that provides a high flux of ionized target species for thin film growth. Optimization of HiPIMS processes is, however, often difficult, since the influence of external process parameters, such as working gas pressure, magnetic field strength, and pulse configuration, on the deposition process characteristics is not well understood. The reason is that these external parameters are only indirectly connected to the two key flux parameters, the deposition rate and ionized flux fraction, via two internal discharge parameters: the target atom ionization probability αt and the target ion back-attraction probability βt. Until now, it has been difficult to assess αt and βt without resorting to computational modeling, which has hampered knowledge-based optimization. Here, we present a simple method to deduce αt and βt based on measured deposition rates of neutrals and ions. The core of the method is a refined analytical model, which is described in detail. This approach is furthermore validated by independent calculations of αt and βt using the considerably more complex ionization region model, which is a plasma-chemical global discharge model.
On continuous endomorphisms of entire functions
Authors: Shishkin A. B.
Published: January 2021

The paper is concerned with continuous linear operators on the space of entire functions. The properties of such operators that are related to the definition of convolution-type operators in spaces of analytic functions are investigated. Corollaries refining both the approximation theorem for the kernel of a symmetric convolution operator and the dual definition of a differential operator in a complex domain are stated.

Bibliography: 20 titles.
OCT4 induces embryonic pluripotency via STAT3 signaling and metabolic mechanisms
Authors: Stirparo Giuliano G. , Kurowski Agata , Yanagida Ayaka , Bates Lawrence E. , Strawbridge Stanley E. , Hladkou Siarhei , Stuart Hannah T. , Boroviak Thorsten E. , Silva Jose C. R. , Nichols Jennifer
Published: January 2021

Significance

We used single-cell whole-genome transcriptional profiling and protein quantification to investigate the role of OCT4 in establishing pluripotency in the murine embryo. Surprisingly, most pluripotency-associated factors are induced normally in OCT4 null early blastocysts, apart from members of the STAT3 signaling pathway. Coincidentally, certain trophectoderm markers are induced but not
Cdx2
, which was previously implicated to repress
Pou5f1
in vitro. This ectopic gene activation suggests a role for OCT4 in maintaining chromatin in a pluripotency-compatible state, likely via UTF1, a known OCT4 target. At implantation, OCT4 null inner cell masses morphologically resemble trophectoderm but exhibit molecular differences linking metabolic and physical stress responses to loss of OCT4. These effects correlate with reduced STAT3 signaling and consequent reduction of oxidative respiration.
Two-dimensional fluid simulation of pulsed-power inductively coupled Ar/H2 discharge
Authors: Cha Ju-Hong , Seo Kwon-Sang , Jeong Jeehun , Lee Ho-Jun
Published: January 2021

In low-temperature Ar/H2 discharge used for material processing, the main factor influencing the film quality is the active species responsible for surface reactions, such as hydrogen atoms or hydrogen ions. The changes in plasma chemistry with the operating conditions affect the production of active species in the bulk plasma region. In conventional Ar/H2 discharge using continuous-wave plasma, there is not enough information to explain the correlations between the active species generation and process parameters. In particular, it is difficult to investigate the relationship between the generation of H
x
(x = 1, 2) ions using the ratio of Ar to hydrogen as an operating variable, and an additional control parameter is required to research the occurrence of each active species. To improve the efficiency of material processing and enhance process controllability, an inductively coupled plasma Ar/H2 pulsed-power model (source pulsing) was introduced and investigated in this study. This work provides an overview of the generation of each active species in pulsed Ar/H2 discharge and discusses the effects of the Ar/H2 gas mixture ratio, duty cycle, and pulse frequency. In addition, it presents an analysis of the principle of the Ar/H2 pulsed-plasma process for the production of active species, demonstrating that the generation densities of specific ions and neutral particles can be controlled.
Origami-based stretchable bi-functional metamaterials: reflector and broadband absorber
Authors: Pham The-Linh , Bui Xuan Khuyen , Tung Bui Son , Hai Le Dinh , Long Le Van , Vu Dinh Lam  , Tung Nguyen Thanh
Published: January 2021

Multi-functional microwave metamaterials offer a great solution for active components and modules that are potentially applicable in stealth, energy, and wireless communication systems/devices. However, it is challenging to realize a multi-functional behavior in a cost-effective and simple metamaterial system. This paper proposes and demonstrates a metamaterial inspired by origami building blocks that can be controlled by mechanical stimuli. By mechanically changing folding states, the proposed metamaterial can be switched from an ultra-broadband absorber to a reflector. In the compressed mode, the structure exhibits an absorption of more than 90% in a broad frequency range of 6–16 GHz. The absorption characteristic is insensitive to polarization angles and works with a wide range of incident angles. In the stretched mode, the absorption function is turned off and all the incident waves become reflected. Such origami-inspired metamaterials behave in multiple figures of merit involving bandwidth, frequency of operation, angle of polarization, and incidence.
Regulation of the early stages of endoplasmic reticulum inheritance during ER stress
Authors: Chao Jesse T. , Pina Francisco , Niwa Maho
Published: January 2021

The proper inheritance of the endoplasmic reticulum (ER) is paramount to the health and survival of the daughter cell. We used microfluidics and genetic analyses to show that the ER inheritance can be segregated into three distinctive steps and that perturbations to each of these steps affect the cell’s ability to mitigate ER stress.
Quantifying Uncertainty in Mechanistic Models of Infectious Disease
Authors: D’Agostino McGowan Lucy , Grantz Kyra H , Murray Eleanor
Published: January 2021

This primer describes the statistical uncertainty in mechanistic models and provides R code to quantify it. We begin with an overview of mechanistic models for infectious disease, and then describe the sources of statistical uncertainty in the context of a case study on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We describe the statistical uncertainty as belonging to 3 categories: data uncertainty, stochastic uncertainty, and structural uncertainty. We demonstrate how to account for each of these via statistical uncertainty measures and sensitivity analyses broadly, as well as in a specific case study on estimating the basic reproductive number, ${R}_0$, for SARS-CoV-2.
Risk of Incident Hypertension According to Physical Activity and Temporal Changes in Weight
Authors: Kang Jeonggyu , Lee Jong-Young , Lee Mi Yeon , Sung Ki-Chul
Published: January 2021

BACKGROUND

Physical activity (PA) and maintenance of a normal weight contribute to the prevention of hypertension but not always concurrently. Our aim was to investigate whether maintaining PA, regardless of weight change, is associated with a reduced risk of developing hypertension.

METHODS

We conducted a cohort study of 195,045 Koreans (mean age, 37.7 years; standard deviation, 7.1 years) who participated in an occupational health screening program from January 2011 to December 2016. PA levels were measured using the validated Korean version of the International Physical Activity Questionnaire Short Form, and participants were classified into 3 categories as inactive, active, and health-enhancing physically active (HEPA). Weight was tracked, and participants were divided into 2 categories: those whose weight change >0 and those whose weight change ≤0.

RESULTS

During 616,326.5 person-years, 12,206 participants developed hypertension (19.8 per 1,000 person-years). A higher PA level and greater reduction in body mass index were associated with lower risk for incident hypertension. Hazard ratio (HR) for incident hypertension was lower (0.83; 95% confidence interval, 0.79–0.88) in subjects with active/HEPA at baseline and decreased weight than in those in the inactive and increased weight groups after adjustment for confounding factors. Even in the increased weight group, HR for incident hypertension was 0.85 (0.81–0.90) in subjects whose PA was consistently maintained at active or HEPA levels during follow-up.

CONCLUSIONS

In this large cohort of young and middle-aged Koreans, maintaining active or HEPA PA levels was associated with reduced risk of developing hypertension regardless of weight change.
Diospyros kakiextract protects myoblasts from oxidative stress-induced cytotoxicity via secretions derived from intestinal epithelium
Authors: Alfarafisa Nayla Majeda , Kitaguchi Kohji , Yabe Tomio
Published: January 2021

Under oxidative stress, reactive oxygen species (ROS) alter signal transduction and induce macromolecular damage in cells. Such oxidative damage can lead to sarcopenia, an age-related syndrome characterized by a progressive loss of mass and strength of skeletal muscles. Because food components do not directly come in contact with muscle cells, we focused on the effects of secretions produced by stimulated intestinal epithelial cells on oxidative stress in myoblast cells. An extract of Diospyros kaki was fractionated using different concentrations of ethanol. Each fraction showed different levels of antioxidant and phenolic compounds. The biological activity was evaluated using a Caco-2 cell coculture system. Secretions from Caco-2 cells exposed to 0.5 mg/mL D. kaki extract attenuated the oxidative stress-induced reduction of C2C12 cell viability, suggesting that the D. kaki extract could stimulate intestinal epithelial cells to produce secretions that reduce oxidative stress in myoblasts in vitro.
MRCIP: a robust Mendelian randomization method accounting for correlated and idiosyncratic pleiotropy
Authors: Xu Siqi , Fung Wing Kam , Liu Zhonghua
Published: January 2021

Mendelian randomization (MR) is a powerful instrumental variable (IV) method for estimating the causal effect of an exposure on an outcome of interest even in the presence of unmeasured confounding by using genetic variants as IVs. However, the correlated and idiosyncratic pleiotropy phenomena in the human genome will lead to biased estimation of causal effects if they are not properly accounted for. In this article, we develop a novel MR approach named MRCIP to account for correlated and idiosyncratic pleiotropy simultaneously. We first propose a random-effect model to explicitly model the correlated pleiotropy and then propose a novel weighting scheme to handle the presence of idiosyncratic pleiotropy. The model parameters are estimated by maximizing a weighted likelihood function with our proposed PRW-EM algorithm. Moreover, we can also estimate the degree of the correlated pleiotropy and perform a likelihood ratio test for its presence. Extensive simulation studies show that the proposed MRCIP has improved performance over competing methods. We also illustrate the usefulness of MRCIP on two real datasets. The R package for MRCIP is publicly available at https://github.com/siqixu/MRCIP.
A Regulatory Review Approach for Evaluation of Micafungin for Treatment of Neonatal Candidiasis
Authors: Taormina Gillian , Gopinath Ramya , Moore Jason , Yasinskaya Yuliya , Colangelo Philip , Reynolds Kellie , Nambiar Sumati
Published: January 2021

Pathogenesis of neonatal candidiasis (NC) is distinct from systemic candidiasis in adults and older pediatric patients due to the significant incidence of central nervous system involvement in neonates. Thus, although adequate and well-controlled trials in NC are often unfeasible due to difficulty enrolling patients, extrapolation of efficacy from antifungal drug trials in adults is generally not appropriate. However, treatment of NC is an area of great unmet need. We describe a regulatory review approach that combined the assessment of limited clinical efficacy, pharmacokinetics, and safety data from neonates and young infants along with microbiology outcomes and pharmacokinetic data from relevant nonclinical models of candidemia/invasive candidiasis to inform the use of micafungin in pediatric patients younger than 4 months, while communicating areas of remaining uncertainty in labeling.
Population-Based Estimates of Coronavirus Disease 2019 (COVID-19)–like Illness, COVID-19 Illness, and Rates of Case Ascertainment, Hospitalizations, and Deaths—Noninstitutionalized New York City Residents, March–April 2020
Authors: Alroy Karen A , Crossa Aldo , Dominianni Christine , Sell Jessica , Bartley Katherine , Sanderson Michael , Fernandez Steven , Levanon Seligson Amber , Lim Sungwoo , Wang Shu Meir , Dumas Sarah E , Perlman Sharon E , Konty Kevin , Olson Donald R , Gould L Hannah , Greene Sharon K
Published: January 2021

Using a population-based, representative telephone survey, ~930 000 New York City residents had COVID-19 illness beginning 20 March–30 April 2020, a period with limited testing. For every 1000 persons estimated with COVID-19 illness, 141.8 were tested and reported as cases, 36.8 were hospitalized, and 12.8 died, varying by demographic characteristics.
The Affair before the Affair: Zola, Dreyfus and the Lourdes scandal
Authors: White Claire
Published: January 2021

This article examines the legacy of the scandal wrought by Zola’s novel Lourdes (1894) for future controversy over the writer’s pivotal involvement in the Dreyfus Affair. Zola’s fictional account of the Pyrenean shrine—its founding apparitions, and its miracle cures— provoked a deluge of refutations from Catholic clergymen, doctors and writers. The Lourdes scandal has been understood as a flashpoint for Catholic indignation in the ongoing ‘culture wars’ of the Third Republic—one readily reignited with Zola’s intervention in the judicial handling of Dreyfus’ case. This article offers a precise understanding of the Lourdes debates as a dress-rehearsal for the Affair that followed. It reads Catholic attacks on Zola’s naturalist novel for their shared preoccupation with proofs, expertise, authority and the status of truth and evidence, which anticipated the very terms on which his defence of the Jewish captain would be denounced. Both scandals, then, appear bound together by fundamentally literary concerns; and this article shows how quarrels over aesthetics lay at the heart of the ideological differences they described.
Fluid pressure heterogeneity during fluid flow in rocks: new laboratory measurement device and method
Authors: Brantut Nicolas , Aben Franciscus M
Published: January 2021

We present a new type of transducer capable of measuring local pore fluid pressure in jacketed rock samples under elevated confining pressure conditions. The transducers are passive (strain-gauge based), of small size (7 mm in diameter at the contact with the rock and around 10 mm in length), and have minimal dead volume (a few mm3). The transducers measure the differential pressure between the confining fluid and the internal pore pressure. The design is easily adaptable to tune the sensitivity and working pressure range up to several hundred megapascals. An array of four such transducers was tested during hydrostatic pressurization cycles on Darley Dale sandstone and Westerly granite. The prototypes show very good linearity up to 80 MPa with maximum deviations of the order of 0.25 MPa, regardless of the combination of pore and confining pressure. Multiple internal pore pressure measurements allow us to quantify the local decrease in permeability associated with faulting in Darley Dale sandstone, and also prove useful in tracking the development of pore pressure fronts during transient flow in low permeability Westerly granite.
LYRA I: Simulating the multi-phase ISM of a dwarf galaxy with variable energy supernovae from individual stars
Authors: Gutcke Thales A , Pakmor Rüdiger , Naab Thorsten , Springel Volker
Published: January 2021

We introduce the LYRA project, a new high resolution galaxy formation model built within the framework of the cosmological hydro-dynamical moving mesh code arepo. The model resolves the multi-phase interstellar medium down to 10 K. It forms individual stars sampled from the initial mass function (IMF), and tracks their lifetimes and death pathways individually. Single supernova (SN) blast waves with variable energy are followed within the hydrodynamic calculation to interact with the surrounding interstellar medium (ISM). In this paper, we present the methods and apply the model to a 1010 M⊙ isolated halo. We demonstrate that the majority of supernovae are Sedov-resolved at our fiducial gas mass resolution of 4  M⊙. We show that our SN feedback prescription self-consistently produces a hot phase within the ISM that drives significant outflows, reduces the gas density and suppresses star formation. Clustered SN play a major role in enhancing the effectiveness of feedback, because the majority of explosions occur in low density material. Accounting for variable SN energy allows the feedback to respond directly to stellar evolution. We show that the ISM is sensitive to the spatially distributed energy deposition. It strongly affects the outflow behaviour, reducing the mass loading by a factor of 2 − 3, thus allowing the galaxy to retain a higher fraction of mass and metals. LYRA makes it possible to use a comprehensive multi-physics ISM model directly in cosmological (zoom) simulations of dwarf and higher mass galaxies.
Comparing galaxy formation in the L-GALAXIES semi-analytical model and the IllustrisTNG simulations
Authors: Ayromlou Mohammadreza , Nelson Dylan , Yates Robert M , Kauffmann Guinevere , Renneby Malin , White Simon D M
Published: January 2021

We perform a comparison, object by object and statistically, between the Munich semi-analytical model, L-GALAXIES, and the IllustrisTNG hydrodynamical simulations. By running L-GALAXIES on the IllustrisTNG dark matter-only merger trees, we identify the same galaxies in the two models. This allows us to compare the stellar mass, star formation rate, and gas content of galaxies, as well as the baryonic content of subhaloes and haloes in the two models. We find that both the stellar mass functions and the stellar masses of individual galaxies agree to better than ${\sim} 0.2\,$dex. On the other hand, specific star formation rates and gas contents can differ more substantially. At z = 0, the transition between low-mass star-forming galaxies and high-mass quenched galaxies occurs at a stellar mass scale ${\sim} 0.5\,$dex lower in IllustrisTNG than that in L-GALAXIES. IllustrisTNG also produces substantially more quenched galaxies at higher redshifts. Both models predict a halo baryon fraction close to the cosmic value for clusters, but IllustrisTNG predicts lower baryon fractions in group environments. These differences are primarily due to differences in modelling feedback from stars and supermassive black holes. The gas content and star formation rates of galaxies in and around clusters and groups differ substantially, with IllustrisTNG satellites less star forming and less gas rich. We show that environmental processes such as ram-pressure stripping are stronger and operate to larger distances and for a broader host mass range in IllustrisTNG. We suggest that the treatment of galaxy evolution in the semi-analytic model needs to be improved by prescriptions that capture local environmental effects more accurately.
Polydisperse streaming instability – III. Dust evolution encourages fast instability
Authors: McNally Colin P , Lovascio Francesco , Paardekooper Sijme-Jan
Published: January 2021

Planet formation via core accretion requires the production of kilometre-sized planetesimals from cosmic dust. This process must overcome barriers to simple collisional growth, for which the streaming instability (SI) is often invoked. Dust evolution is still required to create particles large enough to undergo vigorous instability. The SI has been studied primarily with single-size dust, and the role of the full evolved dust distribution is largely unexplored. We survey the polydisperse streaming instability (PSI) with physical parameters corresponding to plausible conditions in protoplanetary discs. We consider a full range of particle stopping times, generalized dust size distributions, and the effect of turbulence. We find that while the PSI grows in many cases more slowly with an interstellar power-law dust distribution than with a single size, reasonable collisional dust evolution, producing an enhancement of the largest dust sizes, produces instability behaviour similar to the monodisperse case. Considering turbulent diffusion, the trend is similar. We conclude that if fast linear growth of PSI is required for planet formation, then dust evolution producing a distribution with peak stopping times on the order of 0.1 orbits and an enhancement of the largest dust significantly above the single power-law distribution produced by a fragmentation cascade is sufficient, along with local enhancement of the dust to gas volume mass density ratio to order unity.
Formation of supermassive black holes in galactic nuclei – I. Delivering seed intermediate-mass black holes in massive stellar clusters
Authors: Askar Abbas , Davies Melvyn B , Church Ross P
Published: January 2021

Supermassive black holes (SMBHs) are found in most galactic nuclei. A significant fraction of these nuclei also contains a nuclear stellar cluster (NSC) surrounding the SMBH. In this paper, we consider the idea that the NSC forms first, from the merger of several stellar clusters that may contain intermediate-mass black holes (IMBHs). These IMBHs can subsequently grow in the NSC and form an SMBH. We carry out N-body simulations of the simultaneous merger of three stellar clusters to form an NSC, and investigate the outcome of simulated runs containing zero, one, two, and three IMBHs. We find that IMBHs can efficiently sink to the centre of the merged cluster. If multiple merging clusters contain an IMBH, we find that an IMBH binary is likely to form and subsequently merge by gravitational wave emission. We show that these mergers are catalyzed by dynamical interactions with surrounding stars, which systematically harden the binary and increase its orbital eccentricity. The seed SMBH will be ejected from the NSC by the recoil kick produced when two IMBHs merge, if their mass ratio q ≳ 0.15. If the seed is ejected then no SMBH will form in the NSC. This is a natural pathway to explain those galactic nuclei that contain an NSC but apparently lack an SMBH, such as M33. However, if an IMBH is retained then it can seed the growth of an SMBH through gas accretion and tidal disruption of stars.
3D magnetized jet break-out from neutron-star binary merger ejecta: afterglow emission from the jet and the ejecta
Authors: Nathanail Antonios , Gill Ramandeep , Porth Oliver , Fromm Christian M , Rezzolla Luciano
Published: January 2021

We perform 3D general-relativistic magnetohydrodynamic simulations to model the jet break-out from the ejecta expected to be produced in a binary neutron-star merger. The structure of the relativistic outflow from the 3D simulation confirms our previous results from 2D simulations, namely, that a relativistic magnetized outflow breaking out from the merger ejecta exhibits a hollow core of θcore ≈ 4°, an opening angle of θjet ≳ 10°, and is accompanied by a wind of ejected matter that will contribute to the kilonova emission. We also compute the non-thermal afterglow emission of the relativistic outflow and fit it to the panchromatic afterglow from GRB170817A, together with the superluminal motion reported from VLBI observations. In this way, we deduce an observer angle of $\theta _{\rm obs}= 35.7^{\circ \, \, +1.8}_{\phantom{\circ \, \, }-2.2}$. We further compute the afterglow emission from the ejected matter and constrain the parameter space for a scenario in which the matter responsible for the thermal kilonova emission will also lead to a non-thermal emission yet to be observed.
Chandra and HST studies of six millisecond pulsars in the globular cluster M13
Authors: Zhao Jiaqi , Zhao Yue , Heinke Craig O
Published: January 2021

We analyse 55 ks of Chandra X-ray observations of the Galactic globular cluster (GC) M13. Using the latest radio timing positions of six known millisecond pulsars (MSPs) in M13 from Wang et al. (2020), we detect confident X-ray counterparts to five of the six MSPs at X-ray luminosities of LX(0.3–8 keV)∼3 × 1030–1031 erg s−1, including the newly discovered PSR J1641+3627F. There are limited X-ray counts at the position of PSR J1641+3627A, for which we obtain an upper limit LX < 1.3 × 1030 erg s−1. We analyse X-ray spectra of all six MSPs, which are well described by either a single blackbody (BB) or a single power-law model. We also incorporate optical/UV imaging observations from the Hubble Space Telescope (HST) and find optical counterparts to PSR J1641+3627D and J1641+3627F. Our colour–magnitude diagrams indicate the latter contains a white dwarf, consistent with the properties suggested by radio timing observations. The counterpart to J1641+3627D is only visible in the V band; however, we argue that the companion to J1641+3627D is also a white dwarf, since we see a BB-like X-ray spectrum, while MSPs with non-degenerate companions generally show non-thermal X-rays from shocks between the pulsar and companion winds. Our work increases the sample of known X-ray and optical counterparts of MSPs in GCs.