bluuebunny/crossref_metadata_2025 huggingface dataset:
Multidimensionality of Patient-Reported Outcome Measures in Rhinoplasty Satisfaction
Authors: Verkest Valérie , Pingnet Laura , Fransen Erik , Declau Frank
Published: February 2022

The FACE-Q rhinoplasty module (nose and nostrils), Utrecht questionnaire, and Nasal Obstruction Symptom Evaluation (NOSE) scale are validated Dutch patient-reported outcome measures (PROMs) to evaluate rhinoplasty satisfaction. The objective of this study was to analyze the dimensionality of the measured variables in these four existing questionnaires. Additionally, we investigated the ability of the PROMS to measure change. A prospective single-center study was performed in a consecutive cohort of 106 Dutch-speaking patients. Patients were invited to fill in four PROMs: FACE-Q rhinoplasty module (nose and nostrils), Utrecht questionnaire, and NOSE scale, preoperatively and 3 months postoperatively. Item quality was calculated in all four questionnaires. The ability of the questionnaires to differentiate between pre- and postoperative patients was determined with a binary logistic regression. Exploratory factor analysis was performed to determine the latent dimensions. Item quality was confirmed in all questionnaires. Backward binary logistic regression revealed that NOSE and FACE-Q nose module were the best discriminant factors pre- and postoperatively. Combination of these two questionnaires gave a specificity of 97.33% and a sensitivity of 94.52% to discriminate between pre- and postoperative cases. Exploratory factor analysis identified the presence of four dimensions: (1) cosmesis of the nose, (2) cosmesis of the nostrils, (3) nasal function, and (4) psychosocial well-being in rhinoplasty patients. Lack of factorial invariance in the preoperative phase, as compared with the postoperative phase, was detected, especially with the FACE-Q nose and to a lesser extent with the Utrecht questionnaire. The FACE-Q rhinoplasty modules (nose and nostrils), the Utrecht questionnaire, and NOSE scale measure different dimensions of rhinoplasty satisfaction and can be used complementary to each other to obtain a more holistic evaluation of rhinoplasty patients. However, the surgeon should keep in mind that lack of factorial invariance preoperative, as opposed to the postoperative phase, may influence the outcome of these questionnaires.
Pulling Outward but Reacting Inward: Mechanically Induced Symmetry-Allowed Reactions of cis- and trans-Diester-Substituted Dichlorocyclopropanes
Authors: Craig Stephen L. , Wang Zi , Kouznetsova Tatiana B.
Published: February 2022

The mechanically induced symmetry-allowed disrotatory ring openings of cis- and trans-gem-dichlorocyclopropane (gDCC) diesters are demonstrated through sonication and single-molecule force spectroscopy (SMFS) studies. In contrast to the previously reported symmetry-forbidden conrotatory ring opening of alkyl-tethered trans-gDCC, we show that the diester-tethered trans-gDCC primarily undergoes a symmetry-allowed disrotatory pathway even at the high forces (>2 nN) and short-time scales (ms or less) of sonication and SMFS experiments. The quantitative force-rate data obtained from SMFS data is consistent with computational models of transition-state geometry for the symmetry-allowed process, and activation lengths of 1.41 ± 0.02 Å and 1.08 ± 0.03 Å are inferred for the cis-gDCC diester and trans-gDCC diester, respectively. The strong mechanochemical coupling in the trans-gDCC is notable, given that the directionality of the applied force may appear initially to oppose the disrotatory motion associated with the reaction. The stereochemical perturbations of mechanical coupling created by the ester attachments reinforce the complexity that is possible in covalent polymer mechanochemistry and illustrate the breadth of reactivity outcomes that are available through judicious mechanophore design.
Asymmetric Formal Synthesis of (–)-Swainsonine from Chiral-Pool Precursors d-Mannose and d-Arabinose
Authors: Lamor Anphisa , Uipanit Suwanan , Chuanopparat Nutthawat , Yakhampom Sujitra , Ngernmeesri Paiboon , Kongkathip Ngampong , Kongkathip Boonsong
Published: February 2022

Carbohydrates have played an important role in organic synthesis. Since they contain many stereocenters, they have been widely used as chiral-pool starting materials. Herein, we report the asymmetric formal synthesis of (–)-swainsonine, which exhibits anticancer and immunosuppressive activities and inhibits lysosomal α-mannosidase activity, from d-mannose and d-arabinose. The synthesis utilized Zn-mediated Bernet–Vasella reaction, Horner–Wadsworth–Emmons olefination, and Grubbs olefin metathesis as key reactions.
Classical Hodgkin Lymphoma Presenting as Cutaneous and Soft Tissue Mass Lesion: An Enigmatic Presentation Posing a Diagnostic Challenge—A Case Report and Review of Literature
Authors: Shrivastava Ayushi , Jain Sandeep , Malhotra Payal , Mishra Shalini , Pasricha Sunil , Kapoor Gauri
Published: February 2022

Hodgkin lymphoma (HL) is primarily a nodal disease. Cutaneous involvement of HL as a presenting feature is extremely rare. Skin involvement is usually seen as a metachronous involvement in the course of disease and is associated with poor prognosis. Primary skin and soft tissue involvement can be construed as nonhematological, inflammatory, or infective etiology. We report a 14-year-old girl with fever, weight loss, lymphadenopathy, and multiple papular lesions over the right chest wall as initial manifestation of HL, posing a diagnostic challenge. In view of stage IVBE, patient was managed with intensive chemotherapy regimen and is currently free of disease at 6 months of follow-up.
Tear Trough and Lid–Cheek Junction Anatomy: Current Understanding and Nonsurgical Treatment
Authors: Liew Steven , De Silva Dinuksha
Published: February 2022

The tear trough and lower eyelid are sentinel sites of facial aging and are increasingly the target of nonsurgical aesthetic procedures. This article will review the advances that have led to our current understanding of tear trough anatomy. We propose a new functional classification of the lid–cheek junction for soft tissue filler treatment, and suggest simpler stratification of patients seeking lower eyelid treatment based on the etiology of their tear trough depression. We aim to describe a stepwise approach to management, with specific technical considerations targeting the underlying causes of lower eyelid pathology. The common complications and pitfalls of nonsurgical tear trough management will be discussed.
Neuropsychiatric Treatment for Mild Traumatic Brain Injury: Nonpharmacological Approaches
Authors: Mollica Adriano , Dey Ayan , Cairncross Molly , Silverberg Noah , Burke Matthew J.
Published: February 2022

Postconcussive symptoms following mild traumatic brain injury (mTBI)/concussion are common, disabling, and challenging to manage. Patients can experience a range of symptoms (e.g., mood disturbance, headaches, insomnia, vestibular symptoms, and cognitive dysfunction), and neuropsychiatric management relies heavily on nonpharmacological and multidisciplinary approaches. This article presents an overview of current nonpharmacological strategies for postconcussive symptoms including psychoeducation; psychotherapy; vestibular, visual, and physical therapies; cognitive rehabilitation; as well as more novel approaches, such as neuromodulation. Ultimately, treatment and management of mTBI should begin early with appropriate psychoeducation/counseling, and be tailored based on core symptoms and individual goals.
Using the Biopsychosocial Model to Guide Patient-Centered Neurological Treatments
Authors: Saxena Aneeta , Paredes-Echeverri Sara , Michaelis Rosa , Popkirov Stoyan , Perez David L.
Published: February 2022

The biopsychosocial model was defined by George L. Engel to propose a holistic approach to patient care. Through this model, physicians can understand patients in their context to aid the development of tailored, individualized treatment plans that consider relevant biological, psychological, and social–cultural–spiritual factors impacting health and longitudinal care. In this article, we advocate for the use of the biopsychosocial model in neurology practice across outpatient and inpatient clinical settings. To do so, we first present the history of the biopsychosocial model, and its relationships to precision medicine and deep phenotyping. Then, we bring the neurologist up-to-date information on the components of the biopsychosocial clinical formulation, including predisposing, precipitating, perpetuating, and protective factors. We conclude by detailing illustrative neurological case examples using the biopsychosocial model, emphasizing the importance of considering relevant psychological and social factors to aid the delivery of patient-centered clinical care in neurology.
Mathematical Modeling of Eyebrow Curvature
Authors: Tran Ann Q. , Yang Cameron , Tooley Andrea A. , Kazim Michael , Glass Lora R. Dagi
Published: February 2022

The aim of the study is to describe a mathematical model for analyzing eyebrow curvature that can be applied broadly to curvilinear facial features. A total of 100 digital images (50 men, 50 women) were obtained from standardized headshots of medical professionals. Images were analyzed in ImageJ by plotting either 8 or 15 points along the inferior-most row of contiguous brow cilia. A best-fit curve was automatically fit to these points in Microsoft Excel. The second derivative of the second-degree polynomial and a fourth-degree polynomial were used to evaluate brow curvature. Both techniques were subsequently compared with each other. A second-degree polynomial and fourth-degree polynomial were fit to all eyebrows. Plotting 15 points yielded greater goodness-of-fit than plotting 8 points along the inferior brow and allowed for more sensitive measurement of curvature across all images. A fourth-degree polynomial function provided a closer fit to the eyebrow than a second-degree polynomial function. This method provides a simple and reliable tool for quantitative analysis of eyebrow curvature from images. Fifteen-point plots and a fourth-degree polynomial curve provide a greater goodness-of-fit. The authors believe the described technique can be applied to other curvilinear facial features and will facilitate the analysis of standardized images.
Meso-scale simulation of energetic materials. II. Establishing structure–property linkages using synthetic microstructures
Authors: Seshadri Pradeep K. , Nguyen Yen T. , Sen Oishik , Udaykumar H. S.
Published: February 2022

Meso-scale simulations of pressed energetic materials are performed using synthetic microstructures generated using deep feature representation, a deep convolutional neural network-based approach. Synthetic microstructures are shown to mimic real microstructures in the statistical representation of global and local features of micro-morphology for three different classes of pressed HMX with distinctive micro-structural characteristics. Direct numerical simulations of shock-loaded synthetic microstructures are performed to calculate the meso-scale reaction rates. For all three classes, the synthetic microstructures capture the effect of morphological uncertainties of real microstructures on the response to shock loading. The calculated reaction rates for different classes also compare well with those of the corresponding real microstructures. Thus, the article demonstrates that machine-generated ensembles of synthetic microstructures can be employed to derive structure–property–performance linkages of a wide class of real pressed energetic materials. The ability to manipulate the synthetic microstructures using deep learning-based approaches then provides an opportunity for material designers to develop and manufacture pressed energetic materials that can yield targeted performance.
Multi-scale modeling of shock initiation of a pressed energetic material I: The effect of void shapes on energy localization
Authors: Nguyen Yen , Seshadri Pradeep , Sen Oishik , Hardin D. Barrett , Molek Christopher D. , Udaykumar H. S.
Published: February 2022

Accurate simulations of the shock response of heterogeneous energetic (HE) materials require closure models, which account for energy localization in the micro-structure. In a multi-scale framework, closure is provided by reaction rate models that account for ignition and growth of hotspots, allowing for prediction of the overall macro-scale sensitivity of a HE material. In the present meso-informed ignition and growth (MES-IG) model, the reaction rate is expressed as a function of shock pressure and morphology of the void field in a pressed energetic material. In MES-IG, the void morphology is quantified in terms of a limited number of parameters: viz., overall porosity, void size, and shape (aspect ratio and orientation). In this paper, we quantify the effects of arbitrary variations in void shapes on meso-scale energy deposition rates. A collection of voids of arbitrary shapes is extracted from scanning electron microscope (SEM) images of real, pressed HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) samples and classified into groups based on their similarity in shapes. Direct numerical simulations (DNS) are performed on the highly contorted “real” void shapes, and the calculated hotspot ignition and growth rates are compared with values predicted by the MES-IG. It is found that while the parameterization of complex void morphologies in terms of orientation and aspect ratio gives fairly good agreement between DNS and MES-IG reaction rates, the intricate details of highly complex void shapes impact hotspot characteristics to a significant extent. This work suggests possible improvements for the prediction of reaction rate in the energetic microstructure by adopting a more detailed description of shapes.
Overview of diagnostics on a small-scale RF source for fusion (ROBIN) and the one planned for the diagnostic beam for ITER
Authors: Bandyopadhyay M. , Singh M. J. , Pandya K. , Bhuyan M. , Tyagi H. , Bharathi P. , Shah Sejal , Chakraborty A. K.
Published: February 2022

India is responsible for the supply of diagnostic neutral beam systems for ITER to diagnose its helium ash during the deuterium–tritium plasma phase using the charge exchange recombination spectroscopy technique. Considering the many first of its kind in terms of technologies and beam development aspects, ITER Indian domestic agency has adopted a strategy of developing the technology and beam experimentation in parallel. On the beam development front three test beds, namely, the ROBIN (Rf Operated Beam source in India for Negative ion research), the TWIN (TWo rf driver-based Indigenously built Negative ion source), and the INTF (INdian Test Facility) are presently in their various phases of operation, optimization, and setting up at IPR, respectively. Experiments related to plasma production, beam production, and acceleration up to 30 keV in volume and surface mode have been performed on ROBIN. The maximum negative hydrogen ion current density to a tune of 27 mA/cm2 is obtained in the surface mode with Cs injection. Optimal source performance requires optimal surface conditions, minimum impurities, careful characterization of the plasma, cesium feed and its redistribution, and optimal wall temperatures of the surfaces of the plasma box and the plasma grid. A combination of probe, optical, vacuum, laser based, electrical, and calorimetric diagnostic measurements enables such a control. At ROBIN, the above diagnostics are being used regularly. The operational and diagnostic experiences on ROBIN shall provide the desired experience and database for operations of TWIN and INTF in the coming years. A large number of conventional and advanced diagnostic techniques are used for plasma and beam characterization. These diagnostics are suitable not only to detect and understand the plasma but also for studies related to impurity evolution. The temporal evolution of impurities significantly impacts the plasma and beam properties. The studies help in establishing correlations between physical parameters and operational parameters to optimize the source performance ensuring adequate safety and investment protection. This paper will present a brief overview of various diagnostics implemented, lessons learned, and the results obtained from ROBIN. In addition, an outline of the diagnostics planned for INTF based on the experience and understandings developed during the present experiments on ROBIN and TWIN and considering the requirements of large systems shall be discussed.
Limit cycle oscillations, response time, and the time-dependent solution to the Lotka–Volterra predator–prey model
Authors: Leconte M. , Masson P. , Qi Lei
Published: February 2022

In this work, the time-dependent solution for the Lotka–Volterra predator–prey model is derived with the help of the Lambert W function. This allows an exact analytical expression for the period of the associated limit cycle oscillations and also for the response time between predator and prey population. These results are applied to the predator–prey interaction of zonal density corrugations and turbulent particle flux in gyrokinetic simulations of the collisionless trapped-electron mode turbulence. In the turbulence simulations, the response time is shown to increase when approaching the linear threshold, and the same trend is observed in the Lotka–Volterra model.
General electron conductance expression of the multi-gap extended interaction cavity
Authors: Zhao Ding , Ding Yaogen , Zhang Zhiqiang
Published: February 2022

To predict the stability of a multi-gap extended interaction cavity used in the klystrons, a general electron conductance expression has been rigorously derived from the small-signal space charge wave theory, where the field shape at the gap edge is described by a uniform distribution or a hyperbolic cosine function. Moreover, it is also pointed out that a simplified expression is acceptable in applications. This formula can be readily applied to the solid and annular beams, and its validity has been demonstrated through the stability analysis of a triple-gap extended interaction cavity, where the effect of adopting different gap field shapes is presented. This general expression is very useful for the parameter choice during the cavity design of extended interaction klystrons.
Critical shear stresses of Pseudomonas aeruginosa biofilms from dental unit waterlines studied using microfluidics and additional magnesium ions
Authors: Greener Jesse , Harvey William Y. , Gagné-Thivierge Cynthia , Fakhari Sepideh , Taghavi Seyed Mohammad , Barbeau Jean , Charette Steve J.
Published: February 2022

A microfluidic approach was used to study the effect of shear stress on biofilms from a dental unit waterline (DUWL)-isolated P. aeruginosa strain, PPF-1. During the application of relevant shear stress levels to DUWLs, the response of the PPF-1 biofilm was observed and compared to that of a well-studied clinical P. aeruginosa strain, PAO1. The response measurements were repeated for biofilms exposed to additional Mg2+ ions. Optical density maps were transformed into pseudo three-dimensional representations of the complex biofilm structures, and computational fluid dynamic simulations were used to determine the critical shear stresses for biofilm sloughing. In the absence of Mg2+, PPF-1 biofilms showed weaker attachment than PAO1 biofilms and highly intertwined slough/regrowth cycles occurring within the shear stress range of 1.42 ± 0.32 and 0.95 ± 0.27 Pa. This suggests that in a low ionic environment, the PPF-1 strain produces ejected biofilm material nearly continuously, which can result in increased downstream colonization of engineered flow systems. Introducing Mg2+ into the PPF-1 biofilm culture increased mechanical stability, which resulted in elevated tolerances to shear stresses up to a critical value of 5.43 ± 1.52 Pa, which was similar to the critical shear stress value of 4.23 ± 1.22 Pa for the PAO1 strain. Moreover, the enhanced Mg2+ concentrations seemed to place the PPF-1 biofilm into a viscoplastic mechanical state, which resulted in signature responses to critical shear stresses, such as catastrophic sloughing involving abrupt tearing that produced clean edges at the fracture boundary, indicating that the biofilm had become brittle.
Near-field thermophotonic system for power generation and electroluminescent refrigeration
Authors: Yang Fan , Chen Kaifeng , Zhao Yiting , Kim Sun-Kyung , Luo Xiaobing , Hu Run
Published: February 2022

Near-field thermophotonic (TPX) systems that replace the high-temperature emitter in the thermophotovoltaic systems with a light-emitting diode (LED) have been reported to achieve low-grade heat harvesting and electroluminescent cooling, respectively. Nevertheless, the requirements for the two functionalities are different, leading to challenges to coordinate them. In our work, we propose a near-field TPX system composed of the CdTe LED and InP photovoltaic (PV) cell to realize two such functionalities with high performance. With wide-bandgap and high-quality semiconductors, the proposed system achieves a bandgap alignment at various temperatures and has low nonradiative recombination rates, thus enabling the functionality integration. Without changing the structures and materials, the system can switch functionality from power generation to electroluminescent refrigeration by tuning the LED temperature from 800 to 260 K while the PV temperature is maintained at 300 K. In addition, we suggest an additional layer of a thin Pt film on the PV cell to suppress phonon-polaritons parasitic heat transfer and further improve the system efficiency of both functionalities. This work theoretically demonstrates the possible integration of multiple functionalities and triggers further explorations of practical TPX systems.
Single and sequential double ionization of NO radical in intense laser fields
Authors: Fukahori Shinichi , Iwasaki Atsushi , Yamanouchi Kaoru , Hasegawa Hirokazu
Published: February 2022

We examine the dependences of the single and double ionization probabilities of NO radical on the angle between the NO axis and the laser polarization direction in an intense laser field (790 nm, 100 fs, 1–10 × 1014 W/cm2) and show that the double ionization is enhanced when the NO axis is parallel to the laser polarization direction. We reveal that the angular dependence of the sequential double ionization probability is determined by the shape of the 5σ orbital of NO+ from which the second photoelectron is emitted in the ionization from NO+ to NO2+. We also reveal that the fast oscillation in the probability of the tunnel ionization of NO originating from a coherent superposition of the two spin–orbit components in the electronic ground X2Π state is described well based on the molecular Ammosov-Delone-Krainov (MO-ADK) theory in which the time evolution of the electron density distribution of the 2π orbital is taken into account.
The influence of a Hamiltonian vibration vs a bath vibration on the 2D electronic spectra of a homodimer
Authors: Humphries Ben S. , Green Dale , Jones Garth A.
Published: February 2022

We elucidate the influence of the system–bath boundary placement within an open quantum system, with emphasis on the two-dimensional electronic spectra, through the application of the hierarchical equations of motion formalism for an exciton system. We apply two different models, the Hamiltonian vibration model (HVM) and bath vibration model (BVM), to a monomer and a homodimer. In the HVM, we specifically include the vibronic states in the Hamiltonian capturing vibronic quenching, whereas in the BVM, all vibrational details are contained within the bath and described by an underdamped spectral density. The resultant spectra are analyzed in terms of energetic peak position and thermodynamic broadening precision in order to evaluate the efficacy of the two models. The HVM produces 2D spectra with accurate peak positional information, while the BVM is well suited to modeling dynamic peak broadening. For the monomer, both models produce equivalent spectra in the limit where additional damping associated with the underdamped vibration in the BVM approaches zero. This is supported by analytical results. However, for the homodimer, the BVM spectra are redshifted with respect to the HVM due to an absence of vibronic quenching in the BVM. The computational efficiency of the two models is also discussed in order to inform us of the most appropriate use of each method.
Nonlinear Schrödinger waves in a disordered potential: Branched flow, spectrum diffusion, and rogue waves
Authors: Sun Zhi-Yuan , Yu Xin
Published: February 2022

The problem of nonlinear Schrödinger (NLS) waves in a disordered potential arises in many physical occasions, such as hydrodynamics, optics, and cold atoms. It provides a paradigm for studying the interaction between nonlinearity and random effect, but the current results are far from perfect. In this paper, we systematically simulate the turbulent waves for the focusing NLS equation with dynamical (time-dependent) random potentials, where the enhanced branching structures evolve into branched soliton flows as the nonlinearity increases. In this process, the occurrence of rogue waves for short times results from the interplay of linear random focusing and modulation instability. While the nonlinear spectral analysis reveals that for longer times, it is due to a self-organization of larger solitons competing with breakup of intermediate solitons. On the other hand, we found that the strong nonlinearity can significantly increase the width of the linear (Fourier) spectrum for several time scales, but its spreading rate becomes suppressed, which has a dependence on the correlation length of the potential. We hope that our findings will facilitate a deeper understanding of the nonlinear waves interacting with disordered media.
Effect of ring-source release on dispersion process in Poiseuille flow with wall absorption
Authors: Debnath Sudip , Jiang Weiquan , Guan Mingyang , Chen Guoqian
Published: February 2022

The analysis of Taylor dispersion in a fluid flowing through a narrow pipe is of considerable interest among the scientific community. Most of the studies on dispersion primarily considered a transversely uniform release of contaminant at the initial moment, while only a few have addressed the influence of the initial condition on the dispersion process in a tube flow. The present work investigates the transient dispersion process with a ring-source release of solute by means of an unsteady two-dimensional transport model. An irreversible absorptive type of a first-order reaction is also considered. The transport model is solved using the series expansion technique of W. N. Gill [“A note on the solution of transient dispersion problems,” Proc. R. Soc. A 298, 335 (1967)], known as the generalized dispersion technique. The whole transport model is explained using the transport coefficients obtained from the first four terms of Gill's series expansion. Meanwhile, the concept of statistical moments is also used for finding the transport coefficients. The study outcomes are well established, satisfying the result of existing literature under limiting conditions. The inclusion of the ring-source release of solute in the study of dispersion has a significant effect at the initial time. In addition, the view of the cross-sectional distribution of solute concentration gives more detailed information on solute scattering under the proposed model.
Influence of surface properties on the dynamics of fluid flow
Authors: Istenič E. , Šajn V. , Brojan M.
Published: February 2022

In this paper, we study how the fluid flow near the surface of a monocrystalline body is affected by the surface properties due to atom-surface scattering. We propose a toy model for this system by parameterizing the surface with a periodic function of the tangential position. This allows us to derive the velocity probability density function in the Knudsen layer and determine statistical averages of fluid velocity and stress tensor components in the region of interest. The results of this analysis provide a potentially more fundamental and accurate explanation for empirically observed phenomena such as the no-slip boundary condition, boundary layer formation, and the onset of hydrodynamic instability.
Vertical ionization potential benchmark for unitary coupled-cluster and algebraic-diagrammatic construction methods
Authors: Dempwolff Adrian L. , Hodecker Manuel , Dreuw Andreas
Published: February 2022

The performance of several methods for the calculation of vertical ionization potentials (IPs) or, more generally, electron-detachment energies based on unitary coupled-cluster (UCC) theory and the algebraic-diagrammatic construction (ADC) scheme is evaluated with respect to benchmark data computed at the level of equation-of-motion coupled-cluster theory, including single, double, and triple excitations (IP-EOM-CCSDT). Based on a statistical evaluation of about 200 electron-detached states of 41 molecules, the second-order methods IP-ADC(2) and IP-UCC2 show modest accuracies with IP-EOM-CCSDT as reference, exposing a mean signed error and a standard deviation of the error of −0.54 ± 0.50 and −0.49 ± 0.54 eV, respectively, accompanied by a mean absolute error (MAE) of 0.61 and 0.58 eV, respectively. The strict third-order IP-ADC method demonstrates an accuracy of 0.26 ± 0.35 eV (MAE = 0.35 eV), while the IP-UCC3 method is slightly more accurate with 0.24 ± 0.26 eV (MAE = 0.29 eV). Employing the static self-energy computed using the Dyson expansion method (DEM) improves the IP-ADC(3) performance to 0.27 ± 0.28 eV, with the mean absolute error of this method being 0.32 eV. However, employing the simpler improved fourth-order scheme Σ(4+) for the static self-energy provides almost identical results as the DEM. Based on the quality of the present benchmark results, it therefore appears not necessary to use the computationally more demanding DEM.
Thixotropy and rheological hysteresis in blood flow
Authors: Javadi Elahe , Jamali Safa
Published: February 2022

Hemorheology is known to be a major diagnostic tool for many blood-altering diseases. While hemorheological measures of blood, such as the general flow curve, shear-thinning behavior, and its yield stress, are much more studied in detail, thixotropic behavior and thermokinematic memory formation in blood are less understood. Here, we study the thermokinematic memory formation in blood, resulting in a clear sensitivity to the flow history, i.e., thixotropic behavior. We also measure the thixotropic timescale for blood flow using a well-defined flow protocol. Employing a series of in silico flow loops in which the blood is subject to a sweep down/up flow, we measure and discuss the dependence of the thixotropic timescale to the concentration of fibrinogen in the plasma as the main driver of structural evolution under flow.
A compact, transportable optical clock with 1×10−17 uncertainty and its absolute frequency measurement
Authors: Cao Jian , Yuan Jinbo , Wang Shaomao , Zhang Ping , Yuan Yi , Liu Daoxin , Cui Kaifeng , Chao Sijia , Shu Hualin , Lin Yige , Cao Shiying , Wang Yuzhuo , Fang Zhanjun , Fang Fang , Li Tianchu , Huang Xueren
Published: February 2022

We report a robust, compact, and transportable optical clock (TOC-729-2) based on a trapped single 40Ca+ ion with a systematic uncertainty of 1.1×10−17, which is limited by the black-body radiation shift uncertainty at room temperature. By comparing it with the previous transportable optical clock (TOC-729-1) similar but completely independent, the instability was measured to be better than 1.2×10−14/τ. Benefiting from the modular and integrated design, this TOC was constructed in a volume of ∼0.33 m3 excluding the controlling electronics in 19-in. racks. After being moved ∼1200 km away by express delivery, the single-ion signal was restored within 24 h. With the TOC uptime of 92% in 35-day period, the absolute frequency of the 729 nm transition of 40Ca+ was measured using a satellite link to International Atomic Time (TAI) to provide traceability to the SI second, and the result is 411 042 129 776 400.15(22) Hz, corresponding to a relative uncertainty of 5.3×10−16.
A lumped parameter model to describe the electromechanics of mesoscale droplets
Authors: Memon Faisal Bilal , Prathyusha Vishwa Sai , Burugupally Sindhu Preetham , Li Bin
Published: February 2022

An understanding of droplet electromechanics will advance the development of droplet-based technologies, such as lab-on-chip platforms, precision additive manufacturing tools, and fluid property sensors. To describe the electromechanics of mesoscale droplets, a simplified mathematical model is derived by treating the droplet as a spring–mass–damper system and validated with finite-element simulation and experiments. Through the model and experiments, the role of fluid properties on droplet electromechanics is investigated using different fluids—with over three orders of magnitude in dynamic viscosity—for a range of actuation voltage amplitudes V¯ and frequencies f. Despite the simplified modeling approach, the lumped model predicts two important droplet characteristic parameters: coalescence time tc and critical electric field Ecr with less than 30% error. Three observations are reported here: (1) applying the scaling laws to the electric field–time E–t relation for E≫Ecr shows that the coalescence time tc is proportional to the droplet length scale characterized in terms of radius r; (2) at lower voltage actuation frequencies f≤ 10 Hz and sub-critical electric fields E≪Ecr, the droplet dynamics is strongly dependent on the surface tension, while at higher voltage actuation frequencies f  > 10 Hz, the droplet dynamics is dictated by all the three fluid properties, namely, surface tension, viscosity, and density; and (3) droplets of different fluids exhibit characteristics of a second-order system—validating our approach of modeling the droplet as the spring–mass–damper system.
Transverse wave dynamics in short tubes with axisymmetric headwall injection
Authors: Haddad Charles T. , Majdalani Joseph
Published: February 2022

This work describes both traveling and standing vorticoacoustic waves in circular tubes that are driven by axisymmetric headwall injection. In this process, perturbation tools, field decomposition, and boundary-layer theory are jointly used. First, perturbation expansions are initiated to linearize the Navier–Stokes equations. Second, a Helmholtz decomposition of the first-order disturbances is pursued to identify a suitable set of acoustic wave equations. The last step consists of solving for the vortical mode using boundary-layer theory and a viscous expansion of the unsteady rotational set. At the outset, an explicit formulation for arbitrary headwall injection is obtained and confirmed both numerically and through limiting process verifications; the latter take into account special cases involving uniform and bell-shaped injection profiles. The resulting formulation is then described using both laminar and turbulent injection patterns. Using four canonical cases, the characteristics of the evolving vorticoacoustic wave, including its penetration depth, spatial wavelength, and overshoot factor, are systematically explored and discussed. Several fundamental flow features are also unraveled including the radial, tangential, and axial velocities of the time-dependent vortical field. Most rotational flow features are found to depend on the penetration number, the Strouhal number, and the distance from the centerline. The corresponding standing modes are expressed in closed form and shown to be appreciable in view of their amplitudes that twice exceed those associated with strictly traveling waves. Finally, by extending the boundary-layer analysis from the headwall to the sidewall, a uniformly valid wave approximation is achieved, which remains observant of the no-slip requirement everywhere.
Molecular modeling of the interface of an egg yolk protein-based emulsion
Authors: Ferrari Marco , Handgraaf Jan-Willem , Boccardo Gianluca , Buffo Antonio , Vanni Marco , Marchisio Daniele L.
Published: February 2022

Many food emulsions are stabilized by functional egg yolk biomolecules, which act as surfactants at the oil/water interface. Detailed experimental studies on egg yolk emulsifying properties have been largely hindered due to the difficulty in isolating individual chemical species. Therefore, this work presents a molecular model of an oil/water interfacial system where the emulsifier is one of the most surface-active proteins from the egg yolk low-density lipoproteins (LDL), the so-called Apovitellenin I. Dissipative particle dynamics (DPD) was here adopted in order to simulate large systems over long time scales, when compared with full-atom molecular dynamics (MD). Instead of a manual assignment of the DPD simulation parameters, a fully automated coarse-graining procedure was employed. The molecular interactions used in the DPD system were determined by means of a parameter calibration based on matching structural data from atomistic MD simulations. Despite the little availability of experimental data, the model was designed to test the most relevant physical properties of the protein investigated. Protein structural and dynamics properties obtained via MD and DPD were compared highlighting advantages and limits of each molecular technique. Promising results were achieved from DPD simulations of the oil/water interface. The proposed model was able to properly describe the protein surfactant behavior in terms of interfacial tension decrease at increasing protein surface concentration. Moreover, the adsorption time of a free protein molecule was estimated and, finally, an LDL-like particle adsorption mechanism was qualitatively reproduced.
Complex absorbing potential method for Stark resonances
Authors: Kameoka Kentaro
Published: February 2022

We characterize the resonances of Stark Hamiltonians by the complex absorbing potential method. Namely, we prove that the Stark resonances are the limit points of complex eigenvalues of the Stark Hamiltonian with a quadratic complex absorbing potential when the absorbing coefficient tends to zero. The proof employs the complex distortion outside a cone introduced in the previous work by the author. Potentials with local singularities, such as the Coulomb potential, are allowed as perturbations.
Hard-disk dipoles and non-reversible Markov chains
Authors: Höllmer Philipp , Maggs A. C. , Krauth Werner
Published: February 2022

We benchmark event-chain Monte Carlo (ECMC) algorithms for tethered hard-disk dipoles in two dimensions in view of application of ECMC to water models in molecular simulation. We characterize the rotation dynamics of dipoles through the integrated autocorrelation times of the polarization. The non-reversible straight, reflective, forward, and Newtonian ECMC algorithms are all event-driven and only move a single hard disk at any time. They differ only in their update rules at event times. We show that they realize considerable speedups with respect to the local reversible Metropolis algorithm with single-disk moves. We also find significant speed differences among the ECMC variants. Newtonian ECMC appears particularly well-suited for overcoming the dynamical arrest that has plagued straight ECMC for three-dimensional dipolar models with Coulomb interactions.
Formation behavior of oxygen precipitates in silicon wafers subjected to ultra-high-temperature rapid thermal process
Authors: Sudo Haruo , Nakamura Kozo , Okamura Hideyuki , Maeda Susumu , Sueoka Koji
Published: February 2022

In this study, we investigated the formation behavior of oxygen precipitates in Si wafers after a rapid thermal process (RTP) at 1350 °C in an oxygen atmosphere through experiments and simulations. The oxygen precipitate density varied based on the temperature (750–950 °C) and duration (0.5–16 h) of the first step of the two-step heat treatment after RTP. The highest oxygen precipitate density was achieved when the first-step temperature was set to 850 °C, and the second-step temperature was fixed at 1000 °C. The simulation consisted of the calculation of the depth profiles of the residual vacancy concentrations after RTP and oxygen precipitation during the two-step heat treatment after RTP. An empirical formula, in which the nucleation rate of the oxygen precipitates was assumed to be proportional to the fourth power of the residual vacancy concentration, was used in the temperature range of 600–1000 °C. In addition, we assumed that interstitial Si atoms, which were generated by the growth of the oxygen precipitates, consumed the residual vacancies through pair annihilation, thus stopping oxygen precipitation owing to the depletion of the residual vacancies. The simulation effectively reproduced the variations in the oxygen precipitate densities under different conditions in the first step of the heat treatment. Considering the results of the simulation, we concluded that the resulting oxygen precipitate density was determined by the nucleation rate, growth size, and timing of the terminal point of the nucleation.
Microscopic structural origin behind slowing down of colloidal phase separation approaching gelation
Authors: Tateno Michio , Yanagishima Taiki , Tanaka Hajime
Published: February 2022

The gelation of colloidal particles interacting through a short-range attraction is widely recognized as a consequence of the dynamic arrest of phase separation into colloid-rich and solvent-rich phases. However, the microscopic origin behind the slowing down and dynamic arrest of phase separation remains elusive. In order to access microscopic structural changes through the entire process of gelation in a continuous fashion, we used core–shell fluorescent colloidal particles, laser scanning confocal microscopy, and a unique experimental protocol that allows us to initiate phase separation instantaneously and gently. Combining these enables us to track the trajectories of individual particles seamlessly during the whole phase-separation process from the early stage to the late arresting stage. We reveal that the enhancement of local packing and the resulting formation of locally stable rigid structures slow down the phase-separation process and arrest it to form a gel with an average coordination number of z = 6–7. This result supports a mechanical perspective on the dynamic arrest of sticky-sphere systems based on the microstructure, replacing conventional explanations based on the macroscopic vitrification of the colloid-rich phase. Our findings illuminate the microscopic mechanisms behind the dynamic arrest of colloidal phase separation, the emergence of mechanical rigidity, and the stability of colloidal gels.
Stabilizing amplifier with a programmable load line for characterization of nanodevices with negative differential resistance
Authors: Hennen T. , Wichmann E. , Waser R. , Wouters D. J. , Bedau D.
Published: February 2022

Resistive switching devices and other components with negative differential resistance (NDR) are emerging as possible electronic constituents of next-generation computing architectures. Due to the exhibited NDR effects, switching operations are strongly affected by the presence of resistance in series with the memory cell. Experimental measurements useful in the development of these devices use a deliberate addition of series resistance, which can be done either by integrating resistors on-chip or by connecting external components to the wafer probing system. The former approach is considered inflexible because the resistance value attached to a given device cannot be changed or removed, while the latter approach tends to create parasitic effects that impact controllability and interfere with measurements. In this work, we introduce a circuit design for flexible characterization of two-terminal nanodevices that provides a programmatically adjustable external series resistance while maintaining low parasitic capacitance. Experimental demonstrations show the impact of the series resistance on NDR and resistive switching measurements.
Numerical study on discharge characteristics and plasma chemistry in atmospheric CO2 discharges driven by pulsed voltages
Authors: Wang Xu-Cheng , Zhang Tai-Heng , Sun Ying , Wu Zhong-Chen , Zhang Yuan-Tao
Published: February 2022

In recent years, plasma technology as a new approach for CO2 splitting has attracted growing interest. The understanding of discharge characteristics and plasma chemistry is particularly important to improve the conversion of CO2 in applications. In this paper, the dissociation of CO2 driven by short pulsed voltages at atmospheric pressure is numerically investigated with 24 species and 137 reactions considered in the fluid model, to explore the discharge characteristics and plasma chemistry. The key reaction pathways of CO2 conversion are unveiled according to the simulation, and the calculated conversion and energy efficiency relying on the specific energy input agrees well with the experimental measurements. The simulation shows that by increasing the pulse rising rate of pulsed voltage, the breakdown voltage is enhanced and the densities of CO and O2 are significantly improved with the increase in current density. From the simulation, a relatively strong electric field of 2.6 kV/cm always persists during the plateau phase to drive the heavy positive (CO2+) and negative ions (CO3−) to the electrodes, and the electric field induced by the surface charge significantly affects the discharge current during the pulse falling phase. As the duration of plateau phase increases from 200 to 1000 ns, the discharge current density during the pulse falling phase is enhanced from −20.9 to −116.0 mA/cm2, indicating a very different discharge behavior from the atmospheric helium plasmas. This study provides deep insight into the atmospheric CO2 discharges driven by pulsed voltages, and according to the computational data the production of CO and O2 can be effectively optimized by tailoring the waveforms of pulsed voltages in many applications.
Variation in boldness behaviour across individuals, sexes and strains of the guppy (
Authors: Kemp Darrell J. , Lynch K. E. , Samantha St. Jean
Published: February 2022

The concept of animal personality is based on consistent individual differences in behaviour, yet little is known about the factors responsible for such variation. Theory based on sex-specific selection predicts sexual dimorphism in personality-related traits and, in some cases, differences in trait variances between the sexes. In this study, we examined the sources of individual variation for boldness behaviour in guppies (Poecilia reticulata). We first demonstrated heightened boldness expression in males relative to females across feral wild types, artificially selected domestic ‘designer’ guppies, and putative hybrids of the two. Boldness and body size covaried at the strain level but were not associated among individuals within strains. We also found high and repeatable behavioural differences among individuals (0.40 > intraclass r > 0.60) in all sex/strain groups except hybrid strain females. However, there was no evidence for the heightened inter-individual male variance anticipated for personality traits subject to certain forms of directional sex-specific selection. Domestic fish were boldest overall, and indicated the largest sex difference, which is consistent with genetic linkage between boldness and male ornamental colouration. Consistently high intrinsic variation in boldness behaviour, which extends to inbred domesticated fish, may in part underpin the invasive potential of this species.