bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding and utilizing textile-based electrostatic flocking for biomedical applications
Authors: McCarthy Alec , Shah Rajesh , John Johnson V. , Brown Demi , Xie Jingwei
Published: December 2021

Electrostatic flocking immobilizes electrical charges to the surface of microfibers from a high voltage-connected electrode and utilizes Coulombic forces to propel microfibers toward an adhesive-coated substrate, leaving a forest of aligned fibers. This traditional textile engineering technique has been used to modify surfaces or to create standalone anisotropic structures. Notably, a small body of evidence validating the use of electrostatic flocking for biomedical applications has emerged over the past several years. Noting the growing interest in utilizing electrostatic flocking in biomedical research, we aim to provide an overview of electrostatic flocking, including the principle, setups, and general and biomedical considerations, and propose a variety of biomedical applications. We begin with an introduction to the development and general applications of electrostatic flocking. Additionally, we introduce and review some of the flocking physics and mathematical considerations. We then discuss how to select, synthesize, and tune the main components (flocking fibers, adhesives, substrates) of electrostatic flocking for biomedical applications. After reviewing the considerations necessary for applying flocking toward biomedical research, we introduce a variety of proposed use cases including bone and skin tissue engineering, wound healing and wound management, and specimen swabbing. Finally, we presented the industrial comments followed by conclusions and future directions. We hope this review article inspires a broad audience of biomedical, material, and physics researchers to apply electrostatic flocking technology to solve a variety of biomedical and materials science problems.
Origin of layered perovskite device efficiencies revealed by multidimensional time-of-flight spectroscopy
Authors: Ouyang Zhenyu , Zhou Ninghao , McNamee Meredith G. , Yan Liang , Williams Olivia F. , Gan Zijian , Gao Ran , You Wei , Moran Andrew M.
Published: December 2021

Mixtures of layered perovskite quantum wells with different sizes form prototypical light-harvesting antenna structures in solution-processed films. Gradients in the bandgaps and energy levels are established by concentrating the smallest and largest quantum wells near opposing electrodes in photovoltaic devices. Whereas short-range energy and charge carrier funneling behaviors have been observed in layered perovskites, our recent work suggests that such light-harvesting processes do not assist long-range charge transport due to carrier trapping at interfaces between quantum wells and interstitial organic spacer molecules. Here, we apply a two-pulse time-of-flight technique to a family of layered perovskite systems to explore the effects that interstitial organic molecules have on charge carrier dynamics. In these experiments, the first laser pulse initiates carrier drift within the active layer of a photovoltaic device, whereas the second pulse probes the transient concentrations of photoexcited carriers as they approach the electrodes. The instantaneous drift velocities determined with this method suggest that the rates of trap-induced carrier deceleration increase with the concentrations of organic spacer cations. Overall, our experimental results and model calculations suggest that the layered perovskite device efficiencies primarily reflect the dynamics of carrier trapping at interfaces between quantum wells and interstitial organic phases.
Challenges of relaxed n-type GaP on Si and strategies to enable low threading dislocation density
Authors: Hool Ryan D. , Sun Yukun , Li Brian D. , Dhingra Pankul , Tham Rachel W. , Fan Shizhao , Lee Minjoo Larry
Published: December 2021

We directly show that doping type strongly affects the threading dislocation density (TDD) of relaxed GaP on Si, with n-type GaP having a TDD of ∼3.1 × 107 cm−2, nearly 30× higher than both p-type and unintentionally doped GaP at ∼1.1 × 106 cm−2. Such a high TDD is undesirable since n-GaP on Si serves as the starting point for the growth of epitaxial III-V/Si multi-junction solar cells. After highlighting additional challenges for highly n-doped GaP on Si including increased surface roughness, anisotropic strain relaxation, and inhomogeneous TDD distributions from blocking of the dislocation glide, we go on to show that the TDD of n-GaP on Si rises by 10× as the doping concentration increases from ∼5 × 1016 to ∼2 × 1018 cm−3. Next, we investigate the effects of additional dopant choices on the TDD, determining that electronic effects dominate over solute effects on the dislocation velocity at these concentrations. Finally, we demonstrate the respective roles of compressively strained superlattices, low-temperature initiation, and lowered n-type doping concentration on reducing the TDD for n-GaP on Si. By combining all three, we attain relaxed n-GaP on Si with a TDD of 1.54(±0.20) × 106 cm−2, approaching parity with p-GaP on Si. Such high-quality n-GaP on Si will play an important role in boosting the efficiency of epitaxial III-V/Si multi-junction solar cells.
The pervasive impact of critical fluctuations in liquid–liquid extraction organic phases
Authors: Servis Michael J. , Nayak Srikanth , Seifert Soenke
Published: December 2021

Liquid–liquid extraction is an essential chemical separation technique where polar solutes are extracted from an aqueous phase into a nonpolar organic solvent by amphiphilic extractant molecules. A fundamental limitation to the efficiency of this important technology is third phase formation, wherein the organic phase splits upon sufficient loading of polar solutes. The nanoscale drivers of phase splitting are challenging to understand in the complex hierarchically structured organic phases. In this study, we demonstrate that the organic phase structure and phase behavior are fundamentally connected in a way than can be understood with critical phenomena theory. For a series of binary mixtures of trialkyl phosphate extractants with linear alkane diluents, we combine small angle x-ray scattering and molecular dynamics simulations to demonstrate how the organic phase mesostructure over a wide range of compositions is dominated by critical concentration fluctuations associated with the critical point of the third phase formation phase transition. These findings reconcile many longstanding inconsistencies in the literature where small angle scattering features, also consistent with such critical fluctuations, were interpreted as reverse micellar-like particles. Overall, this study shows how the organic phase mesostructure and phase behavior are intrinsically linked, deepening our understanding of both and providing a new framework for using molecular structure and thermodynamic variables to control mesostructure and phase behavior in liquid–liquid extraction.
Full linear Phan-Thien–Tanner fluid model: Exact analytical solutions for steady, startup, and cessation regimes of shear and extensional flows
Authors: Shogin D.
Published: December 2021

Exact, fully explicit, purely real analytical expressions for the material functions describing steady, startup, and cessation regimes of shear flows and of planar, uniaxial, and biaxial extensional flows of full linear Phan-Thien–Tanner fluids are obtained. These expressions, which have no analogs in the literature, are formulated in compact, beautiful forms, partially due to the unique scaling procedure reducing the number of the model parameters from four to one. The properties of the material functions are investigated in detail. For steady extensional flows, the possible shapes of the extensional viscosity curves are described and the conditions for these shapes to occur are determined. For startup flows, it is found when exactly the stress dynamics is oscillatory, and, in this case, a detailed characterization of oscillations is given, which includes expressions for the position and magnitude of stress overshoots and undershoots.
Coarse-grained models for local density gradients
Authors: DeLyser Michael R. , Noid W. G.
Published: December 2021

Coarse-grained (CG) models provide superior computational efficiency for simulating soft materials. Unfortunately, CG models with conventional pair-additive potentials demonstrate limited transferability between bulk and interfacial environments. Recently, a growing number of CG models have supplemented these pair potentials with one-body potentials of the local density (LD) around each site. These LD potentials can significantly improve the accuracy and transferability of CG models. Nevertheless, it remains challenging to accurately describe interfaces where the LD varies rapidly. In this work, we consider a new class of one-body potentials that depend upon the square of the LD gradient around each site. We investigate the impact of this square gradient (SG) potential upon both top-down dissipative particle dynamics (DPD) models and also bottom-up multiscale coarse-graining (MS-CG) models. We demonstrate that SG potentials can be used to tune the interfacial properties of DPD models without significantly altering their bulk properties. Moreover, we demonstrate that SG potentials can improve the bulk pressure–density equation of state as well as the interfacial profile of MS-CG models for acetic acid. Consequently, SG potentials may provide a useful connection between particle-based top-down models and mean-field Landau theories for phase behavior. Furthermore, SG potentials may prove useful for improving the accuracy and transferability of bottom-up CG models for interfaces and other inhomogeneous systems with significant density gradients.
Time-evolving to space-evolving Rayleigh–Bénard instability of a horizontal porous medium flow
Authors: Barletta A.
Published: December 2021

The Rayleigh–Bénard instability of the stationary throughflow in a horizontal porous layer, also known as Prats' problem, is analyzed here in a fresh new perspective. In fact, the classical analysis of linear instability, carried out by employing time-evolving and space-periodic Fourier modes, is reconsidered here by focusing on the effects of time-periodic and space-evolving modes. The basic stationary flow is assumed to be perturbed by a localized source of perturbation that is steady-periodic in time. Then, the spatial development of such perturbations is monitored in order to detect their possible amplification or decay in their direction of propagation. Accordingly, the spatial stability/instability threshold is determined. The study is carried out by employing a Fourier transform formalism, where the transformed variable is time.
Acceptor-oxygen defects in silicon: The electronic properties of centers formed by boron, gallium, indium, and aluminum interactions with the oxygen dimer
Authors: de Guzman Joyce Ann T. , Markevich Vladimir P. , Hawkins Ian D. , Coutinho José , Ayedh Hussein M. , Binns Jeff , Abrosimov Nikolay V. , Lastovskii Stanislau B. , Crowe Iain F. , Halsall Matthew P. , Peaker Anthony R.
Published: December 2021

It is well established that boron reacts with two oxygen atoms in Czochralski-grown silicon (Cz-Si) to form a defect, which is responsible for the dominant light-induced degradation (LID) in solar cells made from Cz-Si:B material. The detrimental effect of LID has stimulated a move by solar cell manufacturers to the use of silicon with other group-III dopants, particularly with gallium. Cz-Si:Ga is immune to the BO-type LID. The information available in the literature on the interactions of oxygen with either Al, Ga, or In impurities in Si is limited. We use ab initio modeling and junction spectroscopy techniques to study a family of defects with unusual electronic properties, which have been detected in Cz-Si samples doped with different shallow acceptor species. We have carried out detailed measurements of the temperature dependencies of hole emission rate, equilibrium occupancy, and hole capture kinetics for the traps observed in differently doped p-type Cz-Si samples. It is found from the analysis of the changes in magnitude of the deep-level-transient signals with temperature that the equilibrium occupancy function of the traps is characteristic for a defect with negative-U properties in all the samples. The positions of the E(−/+) occupancy level of the defects are very close in differently doped samples, E(−/+) = Ev + (0.31 ± 0.01) eV. It is argued that the oxygen dimer interacts with group-III atoms in silicon and these interactions result in the formation of AsO2 complexes (A is either B, Al, Ga, or In atom) with very similar electronic properties.
Revisiting the phase transition sequence in L-methionine: Description of the disordering mechanism in an essential amino acid
Authors: Guinet Yannick , Paccou Laurent , Danède Florence , Hédoux Alain
Published: December 2021

Raman spectroscopy investigations on L-methionine (L-Met) performed in a large temperature range (170–420 K) and in a wide spectral window (5–3600 cm−1) have revealed an extended disordering mechanism triggered by thermally activated motions of the terminal side-chain atoms, from 250 up to 390 K. This very progressive disordering process is characterized by two thermodynamic features, the first corresponding to a broad endotherm (250 → 310 K) marking the beginning of the process, while the second ending the disordering transformation is a sharp endothermic peak at 390 K. These thermodynamic events are correlated with the softening of lattice vibrations and the increase of the quasielastic scattering, considered as the signatures of displacive phase transitions. The amorphous-like band-shape of the low-frequency Raman spectrum collected above 390 K, resulting from the strong anharmonicity of local motions, is contrasting with the detection of additional Bragg peaks above 390 K by x-ray diffraction, consistent with the Cp jump accompanying the endothermic peak. These observations suggest that L-Met is progressively dynamically disordered adopting additional configurations in the crystalline lattice through rotations of CH3 and the side-chain flexibility not clearly detected by x-ray diffraction. These results should be crucial for considering the stability of dried proteins composed of methionine residues.
Planar Hall effect in Cu intercalated PdTe2
Authors: Sonika  , Hooda M. K. , Sharma Shailja , Yadav C. S.
Published: December 2021

The discovery of the planar Hall effect in the topological semimetals has generated extensive research interest recently. We present the planar Hall effect studies on Cu intercalated type-II Dirac semimetal PdTe2 in order to understand the role of chiral anomaly. We observed a positive field dependence of electrical resistivity in both perpendicular and parallel field directions, causing a non-zero anisotropy. The planar Hall signal and anisotropic resistivity oscillate with the in-plane angle with an oscillation period of π. However, the positive longitudinal magnetoresistance, which shows almost linear field dependence at low temperatures, rules out the chiral anomaly as an origin of the planar Hall effect. In addition, Cu0.05PdTe2 is found to exhibit a tilted prolate shaped orbits in parametric plot between transverse and longitudinal resistivities. Our study suggests that for the type-II Dirac semimetal materials with positive longitudinal magnetoresistance, the origin of the planar Hall effect cannot be asserted with certainty to the topological or non-topological origins without considering the anisotropy of the Fermi surface.
Computing free energy barriers for the nucleation of complex network mesophases
Authors: Mukhtyar Ankita J. , Escobedo Fernando A.
Published: December 2021

A previously introduced framework to identify local order parameters (OPs) distinctive of incipient complex mesophases, such as bicontinuous network phases, is used in this work to evaluate nucleation free-energy barriers. The sampling techniques considered are the mean-first-passage-time (MFPT) method and novel variants of umbrella sampling, including Hybrid Monte Carlo (HMC) and a dual-OP-method that uses a blunter global OP for the umbrella bias while keeping record of configurations for analysis with a local OP. These methods were chosen for their ability to minimize or avoid frequent calculation of the expensive local OP, which makes their continuous on-the-fly tracking computationally very inefficient. These techniques were first validated by studying phase-transition barriers of model systems, i.e., the vapor–liquid nucleation of Lennard-Jones argon and a binary nanoparticle model. The disorder-to-order free energy barrier was then traced for the double gyroid and single diamond formed by mesoscopic bead-spring macromolecular models. The dual OP method was found to be the most robust and computationally efficient, since, unlike HMC, it does not require the expensive local OP to be computed on-the-fly, and unlike the MFPT method, it can negotiate large barriers aided by the biased sampling. The dual OP method requires, however, that a cheap global OP be identified and correlated (in a post-processing step) with the local OP that describes the structure of the critical nucleus, a process that can be aided by machine learning.
Multiscale Modeling for the Statics of Nanostructures
Authors: Hoang Kim-Quang , Kadapa Chennakesava
Published: December 2021

Characterization of mechanical properties of materials is essential toward understanding their deformation behavior when subjected to external forces. For a complete understanding of the behavior of materials from the interaction of atoms at the nanoscale to their response at the macroscale using the continuum description, theoretical and computational tools that span a range of length and time scales are vital. To investigate the mechanical properties of novel materials, the recently proposed method of multiscale virtual power (MMVP) is adapted to derive finite element formulations for the micro-discrete to macro-continuum transition based on a discrete representative volume element (RVE) at the nanoscale. The discrete RVE comprises a cloud of atoms interacting among themselves through prescribed linear and nonlinear interatomic potentials and van derWaals forces. In this computational framework, the interactions among the atoms are modeled using nonlinear structural finite elements. The finite element implementation is coupled with the arc-length method to study the effect of damage arising from defects in the interatomic bonds and dislocations in the nanostructure. Determination of the macroscopic properties of the materials such as elastic moduli and strength are carried out by analyzing the homogenized tangent operators and acoustic tensor. The potential of the proposed multiscale framework for the characterization of nanomaterials is demonstrated using numerical examples that are applied to single-layer graphene, without and with defects. The results obtained using the proposed framework are in good agreement with those reported in the literature. With the ability to predict the continuum mechanical properties using micro-discrete to macro-continuum transition models, the proposed methodology proves to be a robust framework for the material characterization of novel nanomaterials.
Theoretical Concepts of Nanostructural Dynamic Problems
Authors: Pradhan Karan Kumar , Chakraverty Snehashish
Published: December 2021

In view of the promising application of nanostructural members, it is essential to study the static and dynamic problems associated with such nanostructural members, namely, nanotubes, nanobeams, nanoplates, nanocomposites, nanoshells, and so on. These problems have attracted considerable attention among research groups throughout the globe. At the nanoscale, not only is it challenging to carry out experimental investigation but also equally important for researchers to provide efficient numerical solution procedures for their molecular dynamics. As a convention, the vibration problems of these nanomembers are governed by a different higher-order continuum theory, which, in turn, assists in obtaining the corresponding governing equations in the form of complicated partial differential equations. This chapter will provide exhaustive theoretical concepts of acquiring the differential equations of various nanostructural members along with analytical as well as numerical solution procedures to handle these dynamic problems.
Vibration Control in Nanostructural Problems
Authors: Kumar Puneet , Srinivas J. , Ryvkin Michael
Published: December 2021

In the nanotechnological era, an astounding demand for energy efficient and light-weight structures has emerged in fields such as nanomanufacturing, nanomachines, nanoelectronics, nanomedicine, aerospace, satellite-launching vehicles, and nuclear and solar energy. In this line, miniature structures (i.e., micro- and nanostructures) have received considerable attention in recent years owing to their small size, low weight, simple fabrication, and high-frequency operations. Nanostructures, such as nanobeams, nanoplates, nanoshells, nanowires, nanorods, nanorings, and nanohelices, have provided the most exciting trend in the current research scenario and have shown wide applications in various nano- and micro-sized devices and systems such as nanoresonators, nanoactuators, nanobots, biosensors, nanoprobes, nanogyroscopes, and micro- and nanoelectromechanical systems (MEMS/NEMS).

Sometimes, these structures may encounter large-amplitude vibrations and dynamic chaos during operational conditions. These undesired phenomena often cause unpleasant motion, disturbing noise, and unacceptable levels of dynamic stresses in nanostructural problems which may lead to potential fatigue failure, degraded performance, energy losses, and decreased reliability. Such detrimental effects need to be mitigated for the safety, reliability, and continuous operation of the nanodevice or system. Hence, a suitable vibration control strategy can only address this problem by integrating the self-controlling and self-monitoring capabilities into the structure. This chapter is devoted to study and summarize the various available vibration control techniques for nanostructural problems. A comprehensive insight into active, hybrid, and semi-active vibration control strategies for nanostructures is presented which will certainly enrich and generate interesting applications in nanodevices and systems.
Building the PEG and the Field of PER Together
Authors: McDermott Lillian C.
Published: December 2021

The formation of the Physics Education Group (PEG) at the University of Washington grew out of, and significantly contributed to, the development of Physics Education Research (PER) as a field. The first part of this chapter details a successful strategy to build internal and external networks of support for the PEG and PER, and describes a number of collaborations with postdocs and visiting faculty. The discussion then turns to the foundational concepts and methods of PER developed by the PEG. The research of the PEG has demonstrated that physics education (from K–12 and through university) can be improved by systematic research to identify and address the specific (and strikingly similar) conceptual difficulties encountered by students at all levels. The approach of the PEG entails using experimental methods in conducting this research, reporting results at conferences and in peer-reviewed journals, and applying those results to the development of curricula and instructional strategies, which are iteratively tested through application and further research.
Research-Based Curriculum Development: Physics by Inquiry
Authors: McDermott Lillian C.
Published: December 2021

The Physics Education Group at the University of Washington (UW) has found that research, curriculum development, and instruction are part of an iterative process that can proceed in either direction. The group was inspired by practical needs arising from experience in instruction and sought to put that experience together with formal research by developing an influential curriculum for science teachers, Physics by Inquiry (PbI). PbI consists of laboratory-based modules that contain carefully structured experiments, exercises, and questions designed to develop competence in teaching by active engagement. This chapter describes the methodology behind the development of PbI and details key examples from formative studies supporting units on mass, volume, density, proportional reasoning, graphical representations, sinking and floating, and electric circuits. The roll-out and implementation of the PbI curriculum are described as part of the evolution of the K–12 teacher preparation program at UW. The chapter closes with a series of generalizations about science teaching and learning derived from experience and validated by associated research.
Growth and Influence of the Physics Education Group at the University of Washington
Authors: McDermott Lillian C.
Published: December 2021

The Physics Education Group (PEG) at the University of Washington has had a major impact on the practice and field of physics education through three key avenues: the research and teaching careers of its students, post-docs, and faculty; the publication of their research; and the widespread use of the research-based curricula developed by the group: Physics by Inquiry (PbI) and Tutorials in introductory Physics. This chapter describes the expansion of the PEG faculty; the growing body of research by PEG graduate students, including in the advanced topics of special relativity, electrodynamics, and quantum mechanics; and the subsequent careers of PEG graduates. It also delineates the implementation and influence of PbI and the Tutorials in many other colleges and universities, as well as in adaptations for high school and faculty training.
Conclusion
Authors: McDermott Lillian C.
Published: December 2021

The concluding chapter summarizes three themes which weave through the book and are embodied in the ongoing commitments of the Physics Education Group at the University of Washington: the value of Physics Education Research as an empirical applied science; the goal of improving student learning from the introductory to the graduate level; and dedication to the preparation of K–12 teachers.
Playing dirty with virus transmission
Authors: Herrmann Christin , Cadwell Ken
Published: December 2021

In this issue of JEM, Fay et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20211220) cohouse dirty pet store mice and rats with clean laboratory mice to gain insights into infection dynamics, discover new viruses, and identify relationships between viruses and the microbiome.
Design and testing of a novel multipath-actuation compliant manipulator
Authors: Yang Xu , Ji Lichao , Zhu Wule , Shang Ying , Li Shizhen
Published: December 2021

In this paper, a novel multipath-actuation compliant manipulator (MCM) driven by piezoelectric actuators is proposed. Specifically, the monolithic MCM employs two vertically arranged compliant limbs with multipath motion transmission to actuate a symmetrically constrained planar mechanism, realizing x- and y-directional motion. For each limb, the multiple branched chains are configured in different paths but all contribute to the output motion, which results in a large displacement amplification ratio as well as a high working bandwidth. The ideal motion transmission of the proposed MCM is revealed by a specially established rigid-body kinematics model. Finite element analysis is carried out to predict the realistic static and dynamic performance of designed MCM. Moreover, a monolithic MCM prototype is fabricated, which is demonstrated to have a large displacement amplification ratio of 11.05, a high resonance frequency of 969 Hz, and a fine motion resolution of 25.48 nm. With promising static and dynamic characteristics, the proposed MCM can be widely used in practical applications.
Evaluating Helium Variations By Modeling Red Giant Branch Bump of Large Magellanic Cluster NGC 1978
Authors: Ji Xin , Li Cheng-Yuan , Deng Li-Cai
Published: December 2021

Many evidences show that the Multiple Population (MP) features exist not only in old clusters but also in intermediate-age clusters in the Megallanic Clouds (MCs), which are characterized by star-to-star abundance scatter of several elements, including helium (He). The red giant branch bump (RGBB)'s photometric properties are proved to be related to the variation in helium abundances of the member stars in star clusters. We use the “Modules for Experiments in Stellar Astrophysics” (MESA) stellar evolution code to calculate the evolution sequences of stars along the red giant branch (RGB) with changing helium content. Following the RGB sequences, we then generate a luminosity function of the RGB stars within the grid of input helium abundances, which are compared with the observational data of an intermediate-age MC cluster NGC 1978.
Pairs and Pairix: a file format and a tool for efficient storage and retrieval for Hi-C read pairs
Authors: Lee Soohyun , Bakker Clara R , Vitzthum Carl , Alver Burak H , Park Peter J
Published: December 2021

As the amount of 3D chromosomal interaction data continues to increase, storing and accessing such data efficiently becomes paramount. We introduce Pairs, a block-compressed text file format for storing paired genomic coordinates from Hi-C data, and Pairix, an open-source C application to index and query Pairs files. Pairix (also available in Python and R) extends the functionalities of Tabix to paired coordinates data. We have also developed PairsQC, a collapsible HTML quality control report generator for Pairs files.

Availability and implementation

The format specification and source code are available at https://github.com/4dn-dcic/pairix, https://github.com/4dn-dcic/Rpairix and https://github.com/4dn-dcic/pairsqc.
Developing a reproducible protocol for culturing functional confluent monolayers of differentiated equine oviduct epithelial cells
Authors: Leemans Bart , Bromfield Elizabeth G , Stout Tom A E , Vos Mabel , Van Der Ham Hanna , Van Beek Ramada , Van Soom Ann , Gadella Bart M , Henning Heiko
Published: December 2021

We describe the development of two methods for obtaining confluent monolayers of polarized, differentiated equine oviduct epithelial cells (EOEC) in Transwell inserts and microfluidic chips. EOECs from the ampulla were isolated post-mortem and seeded either (1) directly onto a microporous membrane as differentiated EOECs (direct seeding protocol) or (2) first cultured to a confluent de-differentiated monolayer in conventional wells, then trypsinized and seeded onto a microporous membrane (re-differentiation protocol). Maintenance or induction of EOEC differentiation in these systems was achieved by air–liquid interface introduction. Monolayers cultured via both protocols were characterized by columnar, cytokeratin 19-positive EOECs in Transwell inserts. However, only the re-differentiation protocol could be transferred successfully to the microfluidic chips. Integrity of the monolayers was confirmed by transepithelial resistance measurements, tracer flux, and the demonstration of an intimate network of tight junctions. Using the direct protocol, 28% of EOECs showed secondary cilia at the apical surface in a diffuse pattern. In contrast, re-differentiated polarized EOECs rarely showed secondary cilia in either culture system (>90% of the monolayers showed <1% ciliated EOECs). Occasionally (5–10%), re-differentiated monolayers with 11–27% EOECs with secondary cilia in a diffuse pattern were obtained. Additionally, nuclear progesterone receptor expression was found to be inhibited by simulated luteal phase hormone concentrations, and sperm binding to cilia was higher for re-differentiated EOEC monolayers exposed to estrogen–progesterone concentrations mimicking the follicular rather than luteal phase. Overall, a functional equine oviduct model was established with close morphological resemblance to in vivo oviduct epithelium.
Establishment of Holistic Quality Control Methods for Nelumbinis Folium Containing Alkaloids and Flavonoids with Simple HPLC Conditions
Authors: Wang Xueyuan , Jiao Qishu , Wang Chaoran , Jin Runa , Zhou Yanyan , Shi Shougang , Huang Zhengjun , Li Mingqian , Qin Xuemei , Chen Shilin , Dai Yuntao
Published: December 2021

In this study, a positive charged C18 column was used to explore its performance in analysis of herbal medicines containing alkaloids and flavonoids with Nelumbinis Folium (NF) as an example. A chromatographic fingerprint analysis method was established by high performance liquid chromatography-diode array detector with commonly used 0.1% formic acid as mobile phase additive and this method could simultaneously detect both alkaloids and flavonoids with good peak shape. It is noted that the HPLC conditions were directly applied in the HPLC-ESI-Orbitrap-MS/MS analysis, and 12 common peaks were identified. In the quantification method of nuciferine, compared with common C18 column, good performance was observed, including sharp and symmetric peak shape of nuciferine, and no obvious retention time shift in chromatogram. The fingerprint method and quantification method of nuciferine and quercetin-3-O-glucuronic acid could be readily utilized as quality control methods for NF and its related preparations.
Clinical applications of cardiac computed tomography: a consensus paper of the European Association of Cardiovascular Imaging—part I
Authors: Pontone Gianluca , Rossi Alexia , Guglielmo Marco , Dweck Marc R , Gaemperli Oliver , Nieman Koen , Pugliese Francesca , Maurovich-Horvat Pal , Gimelli Alessia , Cosyns Bernard , Achenbach Stephan
Published: December 2021

Cardiac computed tomography (CT) was introduced in the late 1990’s. Since then, an increasing body of evidence on its clinical applications has rapidly emerged. From an initial emphasis on its technical efficiency and diagnostic accuracy, research around cardiac CT has now evolved towards outcomes-based studies that provide information on prognosis, safety, and cost. Thanks to the strong and compelling data generated by large, randomized control trials, the scientific societies have endorsed cardiac CT as pivotal diagnostic test for the management of appropriately selected patients with acute and chronic coronary syndrome. This consensus document endorsed by the European Association of Cardiovascular Imaging is divided into two parts and aims to provide a summary of the current evidence and to give updated indications on the appropriate use of cardiac CT in different clinical scenarios. This first part focuses on the most established applications of cardiac CT from primary prevention in asymptomatic patients, to the evaluation of patients with chronic coronary syndrome, acute chest pain, and previous coronary revascularization.
Decolonize Practical Criticism?
Authors: Etherington Ben , Zimbler Jarad
Published: December 2021

This article reflects on what it might mean to decolonize practical criticism in the current moment by considering previous responses to the same imperative. It discusses critical and institutional interventions by Ngũgĩ wa Thiong'o, Mervyn Morris, Chidi Amuta, and, more recently, Harry Garuba and Benge Okot. In this way, the article demonstrates that the antidote to colonial paradigms of literary criticism has not been a pedagogy that prioritizes context over text but a critical practice oriented to a work’s formal and technical context of intelligibility. Such a practice demands that readers inhabit the literary constraints and possibilities encountered by postcolonial or otherwise peripheral writers.
Knowing Outside of English: Decolonizing at York
Authors: Kingston-Reese Alexandra , Jagot Shazia
Published: December 2021

In early 2020, Eugenia Zuroski published a short article in MAI journal's toolkit series critiquing conventional introductory exercises in the university classroom. Called ‘Where Do You Know From?’, the task ‘illustrate[s] the importance of attending conscientiously to the ways we relate to one another in the classroom as part of our pedagogical and political responsibilities’. In this piece, Alexandra Kingston-Reese and Shazia Jagot discuss where they know from and how this knowledge has impacted their teaching, research, and development of the University of York's Decolonising Network.
Environment-specific genomic prediction ability in maize using environmental covariates depends on environmental similarity to training data
Authors: Rogers Anna R , Holland James B
Published: December 2021

Technology advances have made possible the collection of a wealth of genomic, environmental, and phenotypic data for use in plant breeding. Incorporation of environmental data into environment-specific genomic prediction is hindered in part because of inherently high data dimensionality. Computationally efficient approaches to combining genomic and environmental information may facilitate extension of genomic prediction models to new environments and germplasm, and better understanding of genotype-by-environment (G × E) interactions. Using genomic, yield trial, and environmental data on 1,918 unique hybrids evaluated in 59 environments from the maize Genomes to Fields project, we determined that a set of 10,153 SNP dominance coefficients and a 5-day temporal window size for summarizing environmental variables were optimal for genomic prediction using only genetic and environmental main effects. Adding marker-by-environment variable interactions required dimension reduction, and we found that reducing dimensionality of the genetic data while keeping the full set of environmental covariates was best for environment-specific genomic prediction of grain yield, leading to an increase in prediction ability of 2.7% to achieve a prediction ability of 80% across environments when data were masked at random. We then measured how prediction ability within environments was affected under stratified training-testing sets to approximate scenarios commonly encountered by plant breeders, finding that incorporation of marker-by-environment effects improved prediction ability in cases where training and test sets shared environments, but did not improve prediction in new untested environments. The environmental similarity between training and testing sets had a greater impact on the efficacy of prediction than genetic similarity between training and test sets.
Roles of anti-Müllerian hormone and its duplicates in sex determination and germ cell proliferation of Nile tilapia
Authors: Liu Xingyong , Dai Shengfei , Wu Jiahong , Wei Xueyan , Zhou Xin , Chen Mimi , Tan Dejie , Pu Deyong , Li Minghui , Wang Deshou
Published: December 2021

Duplicates of amh are crucial for fish sex determination and differentiation. In Nile tilapia, unlike in other teleosts, amh is located on X chromosome. The Y chromosome amh (amhΔ-y) is mutated with 5 bp insertion and 233 bp deletion in the coding sequence, and tandem duplicate of amh on Y chromosome (amhy) has been identified as the sex determiner. However, the expression of amh, amhΔ-y, and amhy, their roles in germ cell proliferation and the molecular mechanism of how amhy determines sex is still unclear. In this study, expression and functions of each duplicate were analyzed. Sex reversal occurred only when amhy was mutated as revealed by single, double, and triple mutation of the 3 duplicates in XY fish. Homozygous mutation of amhy in YY fish also resulted in sex reversal. Earlier and higher expression of amhy/Amhy was observed in XY gonads compared with amh/Amh during sex determination. Amhy could inhibit the transcription of cyp19a1a through Amhr2/Smads signaling. Loss of cyp19a1a rescued the sex reversal phenotype in XY fish with amhy mutation. Interestingly, mutation of both amh and amhy in XY fish or homozygous mutation of amhy in YY fish resulted in infertile females with significantly increased germ cell proliferation. Taken together, these results indicated that up-regulation of amhy during the critical period of sex determination makes it the sex-determining gene, and it functions through repressing cyp19a1a expression via Amhr2/Smads signaling pathway. Amh retained its function in controlling germ cell proliferation as reported in other teleosts, while amhΔ-y was nonfunctionalized.
Ileal alkaline phosphatase is upregulated following functional amino acid supplementation in Salmonella Typhimurium-challenged pigs
Authors: Rodrigues Lucas A , Wellington Michael O , González-Vega J Caroline , Htoo John K , Van Kessel Andrew G , Columbus Daniel A
Published: December 2021

We recently showed that functional amino acid (FAA) supplementation improves growth performance and immune status of Salmonella Typhimurium (ST)-challenged pigs, which was further improved by a longer adaptation period. It is expected that the effects are associated with increased activity of intestinal alkaline phosphatase (IAP). The objective of this study was to evaluate the effects of FAA supplementation and adaptation period on the ileal, cecal, and colonic activity of IAP in weaned pigs challenged with ST. In experiment 1, a total of 32 mixed-sex weanling pigs were randomly assigned to dietary treatments in a 2 × 2 factorial arrangement with low (LP) or high protein (HP) content and basal (FAA–) or FAA profile (FAA+; Thr, Met, and Trp at 120% of requirements) as factors. In experiment 2, a total of 32 mixed-sex weanling pigs were randomly assigned to one of four dietary treatments, being FAA− fed throughout the experimental period (FAA−) or an FAA profile fed only in the post-inoculation (FAA + 0), for 1 wk pre- and post-inoculation (FAA + 1), or throughout the experimental period (FAA + 2). In experiments 1 and 2, after a 7- and 14-d adaptation period, respectively, pigs were inoculated with saline solution containing ST (3.3 and 2.2 × 109 CFU/mL, respectively). Plasma alkaline phosphatase was measured on days 0 and 7 post-inoculation in experiment 1, and IAP (ileum, cecum, and colon) was measured in experiments 1 and 2. Correlations among ileal IAP and serum albumin and haptoglobin, plasma superoxide dismutase (SOD), malondialdehyde (MDA), and reduced:oxidized glutathione, ileal myeloperoxidase, ST shedding and ileal colonization, and post-inoculation average daily gain, feed intake (ADFI), and gain:feed were also analyzed. In experiment 1, plasma alkaline phosphatase was decreased with ST inoculation and the overall content was increased in LP-FAA+ compared with LP-FAA− (P < 0.05). Moreover, ileal IAP was increased in FAA+ compared with FAA− pigs in both studies (P < 0.05) regardless of adaptation time (P > 0.05). IAP was positively correlated with MDA and ADFI and negatively correlated with SOD and ST shedding in experiment 1 (P < 0.05). These results demonstrate a positive effect of FAA supplementation, but not adaptation period, on ileal alkaline phosphatase activity in Salmonella-challenged pigs, which may be associated with improvements in antioxidant balance.
Impact of geomechanical heterogeneity on multiple hydraulic fracture propagation
Authors: Gao Yunlin , Liu Huiqing , Pu Chao , Tang Huiying , Yang Kun , Dong Xiaohu
Published: December 2021

To extract more gas from shale gas reservoirs, the spacing among hydraulic fractures should be made smaller, resulting in a significant stress shadow effect. Most studies regarding the stress shadow effect are based on the assumption of homogeneity in rock properties. However, strong heterogeneity has been observed in shale reservoirs, and the results obtained with homogeneous models can be different from practical situations. A series of case studies have been conducted in this work to understand the effects of mechanical heterogeneity on multiple fracture propagation. Fracture propagation was simulated using the extended finite element method. A sequential Gaussian simulation was performed to generate a heterogeneous distribution of geomechanical properties. According to the simulation results, the difficulty of fracture propagation is negatively correlated with the Young's modulus and Poisson's ratio, and positively correlated with tensile strength. When each of the multiple fractures propagates in a homogeneous area with different mechanical properties, the final geometry of the fracture is similar to homogeneous conditions. When the rock parameter is a random field or heterogeneity perpendicular to the propagation direction of fracture, the fracture will no longer take the wellbore as the center of symmetry. Based on the analysis of fracture propagation in random fields, a small variance of elastic parameters can result in asymmetrical propagation of multiple fractures. Moreover, the asymmetrical propagation of hydraulic fractures is more sensitive to the heterogeneity of Poisson's ratio than Young's modulus. This study emphasises the importance of considering geomechanical heterogeneity and provides some meaningful suggestions regarding hydraulic fracturing designs.
Surgical management of a local angioinvasive fungal soft tissue infection in the knee: a case report
Authors: Masood Mavra , Jamal Tameem , Nye Anthony , Shah Syed , Shea Sofia
Published: December 2021

A 58-year-old male with an insignificant past medical history presented with chronic myelogenous leukemia in blast crisis. He began induction chemotherapy complicated by neutropenic fever. The patient then developed a nontender 1.5 cm violaceous firm indurated papule above the left patella with satellite lesions on his wrist and chest. A biopsy of the left patella showed obliterated blood vessels in the deep reticular dermis and numerous hyphae with septation and acute angle branching in the vessel wall consistent with angioinvasive aspergillosis. He was started on liposomal amphotericin and empiric voriconazole. Urgent local surgical excision of the primary lesion was recommended for source control. There is no clear recommendation on surgical intervention for angioinvasive aspergillosis, and further direction is needed. We present a case that illustrates surgical debridement for angioinvasive aspergillosis to be an effective method of source control along with systemic antifungal therapy.
The contribution of oncovascular surgery in a young patient with idiopathic retroperitoneal fibrosis
Authors: Kotsis Thomas , Christoforou Panagitsa , Polydorou Andreas
Published: December 2021

Surgical resection remains the cornerstone for the treatment of oncological disease. When a critical arterial or venous structure is involved in a tumor mass, successful relief of symptoms and long-term oncological control are achieved through careful preoperative planning by an interdisciplinary team that necessarily includes a vascular surgeon. We describe the involvement of a vascular surgeon in the oncology of a 22-year-old woman, who is diagnosed with idiopathic retroperitoneal fibrosis.
Incidental finding of mandibular ossifying fibroma with parasymphyseal mandibular fracture
Authors: Wase Saima , Bayne Kilee , Billy Mark
Published: December 2021

We present an interesting case of a young male with incidental finding of a mandibular ossifying fibroma. The patient sustained direct trauma to the mandible which prompted a computer tomography (CT) scan evaluation of the facial bones. The CT scan showed bilateral mandibular fractures with one of the fractures extending through an incidental finding of a 2.3 cm mandibular parasymphyseal lesion. The patient was previously asymptomatic without dental pain, jaw pain or swelling. This case is unique in the fact that the patient has an inherently rare tumor, was asymptomatic prior to his injury, demographically young for the presentation of this size tumor, and highlights the importance of a through trauma workup.
A rare case of gastrointestinal amyloidosis secondary to myeloma with predominant jejunal involvement
Authors: Anandan Manoj , Ying Lei , Macisaac Benjamin , Kilner Alexander , Laurie Robyn , Naidoo Uvarasen K
Published: December 2021

Amyloidosis is a condition identified by the accumulation of abnormal proteins in various tissues and organs that eventually lead to impaired function. Systemic amyloidosis with gastrointestinal (GI) tract involvement is more common than localized GI amyloidosis, whereas predominant jejunal involvement is even more uncommon. We report a rare case of systemic amyloidosis with predominant jejunal involvement in a 76-year-old female who presented with lower abdominal bloating and lethargy.