bluuebunny/crossref_metadata_2025 huggingface dataset:
Radioembolization of Intrahepatic Cholangiocarcinoma: Patient Selection, Outcomes, and Competing Therapies
Authors: Ness Joseph Ray , Molvar Christopher
Published: October 2021

Intrahepatic cholangiocarcinoma is the second most common primary hepatic malignancy and poses a therapeutic challenge owing to its late-stage presentation and treatment-resistant outcomes. Most patients are diagnosed with locally advanced, unresectable disease and are treated with a combination of systemic and local regional therapies. Transarterial radioembolization offers a survival benefit and a favorable side effect profile, with a growing body of evidence to support its use. Herein, we review patient selection and detail outcomes of radioembolization for intrahepatic cholangiocarcinoma, together with mention of competing treatments.
Contemporary Algorithm for the Management of Hepatocellular Carcinoma in 2021: The Northwestern Approach
Authors: Swersky Adam , Kulik Laura , Kalyan Aparna , Grace Karen , Caicedo Juan Carlos , Lewandowski Robert J. , Salem Riad
Published: October 2021

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major cause of cancer-related morbidity and mortality around the world. Frequently, concurrent liver dysfunction and variations in tumor burden make it difficult to design effective and standardized treatment pathways. Contemporary treatment guidelines designed for an era of personalized medicine should consider these features in a more clinically meaningful way to improve outcomes for patients across the HCC spectrum. Given the heterogeneity of HCC, we propose a detailed clinical algorithm for selecting optimal treatment using an evidence-based and practical approach, incorporating liver function, tumor burden, the extent of disease, and ultimate treatment intent, with the goal of individualizing clinical decision making.
Radioembolization for the Treatment of Hepatocellular Carcinoma: The Road to Personalized Dosimetry and Ablative Practice
Authors: De la Garza-Ramos Cynthia , Toskich Beau B.
Published: October 2021

Radioembolization dosimetry for the treatment of hepatocellular carcinoma has evolved alongside our understanding of best practice for this therapy. At the core of advances in dosimetry are personalized and ablative applications of radioembolization, which have generated paradigm shifts in both safety and efficacy. This review provides a summary of fundamental radioembolization dosimetry concepts and narrates how our approach to treating patients has shifted from conventional to tailored and definitive therapy.
Utility of 3D CT Rib Study in Presurgical Planning of Autologous Ear Graft for Pinna Reconstruction in Microtia
Authors: Zanje Sneha S. , Kamat Nikhil V. , Taware Kunal K. , Rokade M L. , Bhumkar Ashesh C.
Published: October 2021

Purpose The aim of this study was to demonstrate the utility of three-dimensional computed tomography (3D) CT rib study in presurgical planning to select the autologous rib cartilage graft for pinna reconstruction.

Materials and Methods Total of 35 patients of microtia for autologous rib graft from April 2017 to February 2020 were evaluated in this study. All patients had a plain low-dose multislice CT chest. The length of costal cartilages of sixth to ninth ribs bilaterally and width and height of sixth and seventh rib costal cartilage synchondrosis were measured in 3D reconstructed true size coronal images with best possible length displayed. All patients had high-resolution computed tomography (HRCT) temporal studies done to evaluate for associated anomalies in external canal, middle ear cavities, and inner ear structures. Eleven patients had simultaneous HRCT temporal bone done after plain CT chest and rest who had done recent prior study were reviewed without repetition of study.

Results There were 19 males and 16 females for 3D CT rib study. Average age of the participants was 16.5 years. The average width of synchondrosis of sixth and seventh rib was 15.4 mm on right side and 14.7 mm on left side, average height of synchondrosis was 28.5 mm on right side and 30.7 mm on left side. Average length of the eighth rib costal cartilage was 88.6 mm on the right side and 90.5 mm on the left side. Average length of the ninth rib was 63.2 mm on the right side and 58.2 mm on the left side. Costal cartilage calcifications were present in 9 patients.

Conclusion Preoperative 3D CT rib study provides accurate measurements of rib stock for sculpting autologous ear graft.
Hypertrophic Cardiomyopathy with a Twist
Authors: Francis W. , Alkuwari M. E. , Mohiaddin R. , Carr C. S.
Published: October 2021

Hypertrophic cardiomyopathy is a relatively common inherited cardiac disorder, with echocardiography still being the initial imaging method for its diagnosis. Cardiac fibroma is a primary neoplasm that most commonly presents in childhood. We present a patient who was investigated for typical cardiac symptoms who went on to have cardiac magnetic resonance imaging and was found to have both of these conditions.
Follicular Cholecystitis Mimicking Xanthogranulomatous Cholecystitis and Malignancy: A Case Report
Authors: Aineseder Martina , Grove Roy López , Mullenl Eduardo G. , Spina Juan C.
Published: October 2021

Chronic follicular cholecystitis (CFC) is a rare pathology characterized by prominent lymphoid follicles in the lamina propria distributed throughout the gallbladder wall. It has also been mentioned in the literature as lymphoid hyperplasia and pseudolymphoma. CFC represents less than 2% of cholecystectomies. Its etiopathology is mostly unknown. Most reports are based on histopathological findings, with little or no imaging analysis. We describe a case involving a 66-year-old man radiologically diagnosed as xanthogranulomatous cholecystitis (XGC) versus malignancy, revealing CFC with surrounding inflammatory changes in the cholecystectomy specimen.
The Friedland–Hayman inequality and Caffarelli’s contraction theorem
Authors: Beck T. , Jerison D.
Published: October 2021

The Friedland–Hayman inequality is a sharp inequality concerning the growth rates of homogeneous, harmonic functions with Dirichlet boundary conditions on complementary cones dividing Euclidean space into two parts. In this paper, we prove an analogous inequality in which one divides a convex cone into two parts, placing Neumann conditions on the boundary of the convex cone and Dirichlet conditions on the interface. This analogous inequality was already proved by us jointly with Sarah Raynor. Here, we present a new proof that permits us to characterize the case of equality. In keeping with the two-phase free boundary theory introduced by Alt, Caffarelli, and Friedman, such an improvement can be expected to yield further regularity in free boundary problems.
Design of a tunable turnstile mode converter for high-power microwave applications
Authors: Wang Xiaoyu , Fan Yuwei , Yang Baoping , Shu Ting , Xu Xu , Li Ankun , Liu Zeyang
Published: October 2021

This study investigates the frequency tunability of a coaxial transverse electromagnetic mode (TEM)–linear-polarized TE11 mode tunable turnstile mode converter (TTMC) for high-power microwave applications using a combination of simulation and experiment. In the proposed structure, the sliding folded waveguide can be moved radially to meet the requirement of linear polarization, and the matching structure is designed to eliminate the undesired reflection. The simulation shows that the conversion efficiency of the TTMC can reach over 99% in the frequency range of 1.45–2.35 GHz, corresponding to a frequency tuning bandwidth of about 47.4%. Moreover, the TTMC can maintain a continuous high conversion efficiency at different frequency points by changing the tuning mechanism. The experimental investigation shows that the TTMC can convert the coaxial TEM mode into a circular waveguide TE11 mode with a conversion efficiency of above 95% in the frequency range of 1.55–2.35 GHz. The experimental measurements agree well with the simulation results, implying feasibility of the TTMC design and its superior performance.
Understanding residual stress in thin films: Analyzing wafer curvature measurements for Ag, Cu, Ni, Fe, Ti, and Cr with a kinetic model
Authors: Rao Zhaoxia , Berman Sarah , Yang Peilin , Depla Diederik , Chason Eric
Published: October 2021

An analytical model for the evolution of residual stress in polycrystalline thin films is used to analyze numerous previously reported wafer curvature measurements obtained for a variety of materials and processing conditions. The model, which has been described in previous publications, considers stress-generating mechanisms that occur at the grain boundary as it forms between adjacent grains and stress due to the subsurface grain growth in layers that have already been deposited. Current work extends the model to include different types of microstructural evolutions. A set of parameters for each dataset is obtained by non-linear least square fitting. Model parameters that are not expected to depend on the processing conditions are constrained to have a common value when fitting the multiple datasets for each material. The dependence of the fitting parameters on the material and process conditions is evaluated and compared with the physical mechanisms implemented in the model.
Coexisting vortices and antivortices generated by dually gauged harmonic maps
Authors: Han Xiaosen , Huang Genggeng , Yang Yisong
Published: October 2021

In this paper, we first formulate a dually gauged harmonic map model, suggested from a product Abelian Higgs field theory arising in impurity-inspired field theories, and obtain a new BPS system of equations governing coexisting vortices and antivortices, which are topologically characterized by the first Chern classes of the underlying Hermitian bundles and the Thom classes of their associated dual bundles. We then establish existence and uniqueness theorems for such vortices. For the equations over a compact surface, we obtain necessary and sufficient conditions for the existence of solutions. For the equations over the full plane, we obtain all finite-energy solutions. In addition, we also present precise expressions giving the values of various physical quantities of the solutions, including magnetic charges and energies, in terms of the total numbers of vortices and antivortices, of two species and the coupling parameters involved.
Simple but accurate estimation of light–matter coupling strength and optical loss for a molecular emitter coupled with photonic modes
Authors: Wang Siwei , Chuang Yi-Ting , Hsu Liang-Yan
Published: October 2021

Light–matter coupling strength and optical loss are two key physical quantities in cavity quantum electrodynamics (CQED), and their interplay determines whether light–matter hybrid states can be formed or not in chemical systems. In this study, by using macroscopic quantum electrodynamics (MQED) combined with a pseudomode approach, we present a simple but accurate method, which allows us to quickly estimate the light–matter coupling strength and optical loss without free parameters. Moreover, for a molecular emitter coupled with photonic modes (including cavity modes and plasmon polariton modes), we analytically and numerically prove that the dynamics derived from the MQED-based wavefunction approach is mathematically equivalent to the dynamics governed by the CQED-based Lindblad master equation when the Purcell factor behaves like Lorentzian functions.
A modified Villain formulation of fractons and other exotic theories
Authors: Gorantla Pranay , Lam Ho Tat , Seiberg Nathan , Shao Shu-Heng
Published: October 2021

We reformulate known exotic theories (including theories of fractons) on a Euclidean spacetime lattice. We write them using the Villain approach, and then we modify them to a convenient range of parameters. The new lattice models are closer to the continuum limit than the original lattice versions. In particular, they exhibit many of the recently found properties of the continuum theories, including emergent global symmetries and surprising dualities. In addition, these new models provide a clear and rigorous formulation to the continuum models and their singularities. In Appendixes A–C, we use this approach to review the well-studied lattice models and their continuum limits. These include the XY-model, the ZN clock-model, and various gauge theories in diverse dimensions. This paper clarifies the relation between the condensed-matter and the high-energy views of these systems. It emphasizes the role of symmetries associated with the topology of field space, duality, and various anomalies.
A simple theory for molecular chemotaxis driven by specific binding interactions
Authors: Krist Kathleen T. , Sen Ayusman , Noid W. G.
Published: October 2021

Recent experiments have suggested that enzymes and other small molecules chemotax toward their substrates. However, the physical forces driving this chemotaxis are currently debated. In this work, we consider a simple thermodynamic theory for molecular chemotaxis that is based on the McMillan–Mayer theory of dilute solutions and Schellman’s theory for macromolecular binding. Even in the absence of direct interactions, the chemical binding equilibrium introduces a coupling term into the relevant free energy, which then reduces the chemical potential of both enzymes and their substrates. Assuming a local thermodynamic equilibrium, this binding contribution to the chemical potential generates an effective thermodynamic force that promotes chemotaxis by driving each solute toward its binding partner. Our numerical simulations demonstrate that, although small, this thermodynamic force is qualitatively consistent with several experimental studies. Thus, our study may provide additional insight into the role of the thermodynamic binding free energy for molecular chemotaxis.
Time-dependent principal component analysis: A unified approach to high-dimensional data reduction using adiabatic dynamics
Authors: Morishita Tetsuya
Published: October 2021

Systematic reduction of the dimensionality is highly demanded in making a comprehensive interpretation of experimental and simulation data. Principal component analysis (PCA) is a widely used technique for reducing the dimensionality of molecular dynamics (MD) trajectories, which assists our understanding of MD simulation data. Here, we propose an approach that incorporates time dependence in the PCA algorithm. In the standard PCA, the eigenvectors obtained by diagonalizing the covariance matrix are time independent. In contrast, they are functions of time in our new approach, and their time evolution is implemented in the framework of Car–Parrinello or Born–Oppenheimer type adiabatic dynamics. Thanks to the time dependence, each of the step-by-step structural changes or intermittent collective fluctuations is clearly identified, which are often keys to provoking a drastic structural transformation but are easily masked in the standard PCA. The time dependence also allows for reoptimization of the principal components (PCs) according to the structural development, which can be exploited for enhanced sampling in MD simulations. The present approach is applied to phase transitions of a water model and conformational changes of a coarse-grained protein model. In the former, collective dynamics associated with the dihedral-motion in the tetrahedral network structure is found to play a key role in crystallization. In the latter, various conformations of the protein model were successfully sampled by enhancing structural fluctuation along the periodically optimized PC. Both applications clearly demonstrate the virtue of the new approach, which we refer to as time-dependent PCA.
Electrical coupling analysis of 2D time-multiplexing memory actuators exhibiting asymmetric butterfly hysteresis
Authors: Schmerbauch A. E. M. , Vakis A. I. , Jayawardhana B.
Published: October 2021

We present the modeling and analysis of electrical coupling in a hysteretic deformable mirror with 2D memory piezoactuators, which are made of a purposely designed piezomaterial sandwiched between electrodes arranged crosswise and actuated by a multiplexing approach. Using a modified Miller model to describe the memory effect which is based on the ferroelectric domain switching processes, the proposed framework is used to simulate the electric-field dependence of the strain in the piezoelectric material that exhibits asymmetric butterfly loops with remnant deformation through the finite element method. The desired butterfly memory effect in the material is obtained by modifying the saturated dipole polarization curve in the Miller model. The proposed method allows us to numerically investigate the electrical coupling between actuators in more detail and correspondingly understand their influence to the mirror facesheet.
Experimental insights on the water entry of hydrophobic sphere
Authors: Guleria Sharey Deep , Dhar Atul , Patil Dhiraj V.
Published: October 2021

This article reports experimental insights into the physics of water entry of hydrophobic spheres. In the set of experiments, parameters such as sphere density, diameter, and impact velocity are varied. The trajectory of the sphere after impact, the dynamics of trapped air-cavity, including the cavity formation, and the retraction analysis are given. Furthermore, analysis of the Worthington-jet, the cavity ripple, and early bubble shedding after the air-cavity detachment is carried out. At the location of cavity closure, radial expansion and contraction behavior are reported for the case of the shallow seal (near the air–water interface), while for the deep seal, only one such behavior is observed. Further, five cavity shapes are recorded based on the cavity retraction behavior (i.e., shallow, deep seal), namely, conical shape, slender-cone shape, telescopic shape, spearhead shape, and the thick spearhead shape. The radial dynamics and radial surface energy analysis are reported at various locations on these cavity shapes to find that the thick spearhead cavities hold the most cross-sectional surface energy. The slender-cone shaped cavity generates the fastest Worthington-jet, followed by the telescopic shaped cavities. The thick spearhead shaped cavities are reported to have the longest intact Worthington-jets, followed by the spearhead shaped cavities. Finally, a new regime map is presented for single ripple and multiple ripple behaviors at the time of retraction in the wake of descending spheres. A bubble shedding behavior has also been characterized as the most frequent bubble shedding for shallow seal and associated longer bubble length compared to the other cases.
Temperature measurement of initiation process of microsecond pulsed discharge in water by quantitative schlieren method
Authors: Zhang He , Liu Yi , Zhao Yong , Lin Fuchang
Published: October 2021

In the initiation process of microsecond pulsed discharge in water, Joule heating is believed to be responsible for the formation of a low-density region. Then, electron avalanche can be easily induced in this low-density region. The aim of this paper is to study the feasibility of the quantitative schlieren method in the temperature measurement of water in the initiation process of microsecond pulsed discharge. A lens-type schlieren system was applied in the measurement of the radial temperature around the tip of the electrode. Finite element analysis was used to simulate the electric field and temperature during the discharge. Measurement results of the schlieren quantitative schlieren method are compared with the simulation results of finite element analysis in terms of temperature and energy conversion. The comparison shows that most electrical energy is consumed in Joule heating of water in the initiation process of microsecond pulsed discharge. In the region with no thermal fluid, the temperature distributions obtained by the quantitative schlieren method and finite element analysis are in good agreement. This work is helpful in the quantitative study of the role of Joule heating in the initiation of the streamer in water.
Acoustic wave focusing by 2.5D graded index lens
Authors: Zhao Yuanyan , Subramanian Sriram , Memoli Gianluca
Published: October 2021

Three dimensional sound convergence in air underpins applications ranging from localized acoustic experiences to levitation. Most current solutions, however, are challenging to scale-up: they either require complex electronics or intricate geometries. In this paper, we propose a solution based on sonic crystals: an extruded 2D hexagonal lattice array of rigid cylinders with gradient diameters, capable of focusing in 3D emission of a standard loudspeaker at audio frequencies, which we call a 2.5D lens. First, we use finite-element simulations to describe the underpinning theory in terms of the band structure and equifrequency contours. We then describe how we manufactured two lenses, one of which has a focal length smaller than the wavelength, and compare pressure with simulations. Our measurements not only show good agreement with simulations but also highlight how the efficiency of such lenses strongly depends on how the sound is delivered to them.
Containerless metal single-crystal growth via electromagnetic levitation
Authors: Witteveen J. P. , Vrielink M. A. B. , van Gastel R. , van Houselt A. , Zandvliet H. J. W.
Published: October 2021

The growth of elemental metal single-crystals is usually achieved through classic growth techniques such as the Czochralski or floating zone methods. Drawbacks of these techniques are the susceptibility to contamination from the crucible and thermal stress-induced defects due to contact with the ambient, which can be mitigated by growing in a containerless environment. We discuss the development of a novel crystal growth apparatus that employs electromagnetic levitation in a vacuum to grow metal single-crystals of superior quality and purity. This apparatus enables two growth modes: containerless undercooled crystallization and levitation-based Czochralski growth. We describe the experimental setup in terms of coil design, sample insertion and collection, seed insertion, and sample position and temperature tracking. As a proof of concept, we show the successful growth of copper single-crystals.
Effects of velocity shear layer on detonation propagation in a supersonic expanding combustor
Authors: Dai Jian , Xu Fei , Cai Xiaodong , Mahmoudi Yasser
Published: October 2021

This study investigates the mechanism of detonation propagation in a stoichiometric hydrogen–oxygen mixture with non-uniform flow velocity entering an expanding combustor. For simulation of the detonation propagation, the Navier–Stokes equations with a one-step two-species chemistry model are solved by employing the hybrid sixth-order weighted essentially non-oscillatory centered difference scheme. The self-sustaining mechanism of detonation propagation in an expanding combustor under the action of non-uniform supersonic flow with a velocity shear layer is revealed. The results show that under the influence of velocity shear layer, two different unburned jets are produced behind the detonation front. These jets are induced by the velocity shear layers and the Prandtl–Meyer expansion fan. The two jets interact and mix gradually. The interaction between the mixed unburned jets and highly unstable shear layers creates large-scale vortices that intensify the turbulent mixing of the unburned jets. Meanwhile, the baroclinic mechanism generates numerous vortices on the boundary of the unburned jet. These vortices promote the mixing of the burned and unburned gases, which eventually leads to the rapid consumption of the unburned pockets. The heat released due to the burning of the unreacted pockets behind the detonation wave supports a self-sustaining propagation of the detonation wave. When the velocity difference among the shear layers increases, the surface fluctuation of the detonation wave increases.
Relativistic study of parity-violating nuclear spin-rotation tensors
Authors: Aucar Ignacio Agustín , Borschevsky Anastasia
Published: October 2021

We present a four-component relativistic approach to describe the effects of the nuclear spin-dependent parity-violating (PV) weak nuclear forces on nuclear spin-rotation (NSR) tensors. The formalism is derived within the four-component polarization propagator theory based on the Dirac–Coulomb Hamiltonian. Such calculations are important for planning and interpretation of possible future experiments aimed at stringent tests of the standard model through the observation of PV effects in NSR spectroscopy. An exploratory application of this theory to the chiral molecules H2X2 (X = 17O, 33S, 77Se, 125Te, and 209Po) illustrates the dramatic effect of relativity on these contributions. In particular, spin-free and spin–orbit effects are even of opposite signs for some dihedral angles, and the latter fully dominate for the heavier nuclei. Relativistic four-component calculations of isotropic nuclear spin-rotation constants, including parity-violating electroweak interactions, give frequency differences of up to 4.2 mHz between the H2Po2 enantiomers; on the nonrelativistic level of theory, this energy difference is 0.1 mHz only.
Magnetic field-induced self-assembly of multiple nonmagnetic bubbles inside ferrofluid
Authors: Li Qiao-Zhong , Lu Zhi-Liang , Zhou Di , Niu Xiao-Dong , Guo Tong-Qing , Du Bing-Chen , Li You
Published: October 2021

In this work, a comprehensive numerical study of the magnetic field-induced dynamic self-assembly process of multiple bubbles inside the ferrofluid is presented. For multiple bubbles inside the ferrofluid, the magnetic attraction force between bubbles is usually greater and lasts longer than the magnetic repulsion force, resulting in self-assembly movement. This process can be influenced by a number of factors, such as surface tension, inertia force, and initial position, and their specific mechanisms have not been fully understood. Particularly, what roles the magnetic field strength, the surface tension coefficient, and the initial position play are our major interest. Results show that higher magnetic field strength is unfavorable for improving self-assembly efficiency as it leads to stronger magnetic interactions, including attraction and repulsion. In contrast, an increase in the surface tension coefficient can enhance the effect of attraction and weaken the effect of repulsion. Further analysis of the influence of the initial position shows that the magnetic repulsive force can be enhanced by increasing the horizontal gap, which causes a reversing motion along the magnetic field direction. However, an increase in the vertical gap has a nonlinear effect on the efficiency of the self-assembly process, and there is a critical distance below which the self-assembly process could be accelerated with the increase in the vertical gap.
Hinfp is a guardian of the somatic genome by repressing transposable elements
Authors: Nirala Niraj K. , Li Qi , Ghule Prachi N. , Chen Hsi-Ju , Li Rui , Zhu Lihua Julie , Wang Ruijia , Rice Nicholas P. , Mao Junhao , Stein Janet L. , Stein Gary S. , van Wijnen Andre J. , Ip Y. Tony
Published: October 2021

Significance

Repression of the large number of transposable elements in eukaryotic genomes is essential for genome stability. The Piwi-interacting RNA and short interfering RNA pathways are critical for repressing transposable elements in germlines, but the repression of transposable elements in somatic tissues involves other components. While the mammalian Hinfp has been shown to regulate Histone4 and cell-cycle progression, our manuscript provides evidence that a function of the
Drosophila
Hinfp is to maintain Histone1 expression to repress most transposable elements in somatic genomes. This Hinfp–Histone1 axis provides a venue to study maintenance of genome stability and progression of pathological outcomes.
Switchover phenomenon induced by epidemic seeding on geometric networks
Authors: Ódor Gergely , Czifra Domonkos , Komjáthy Júlia , Lovász László , Karsai Márton
Published: October 2021

Significance

Initial seeding of an epidemic from the best-connected nodes of a network would intuitively lead to the largest outbreak. We challenge this picture and explore a switchover phenomenon: Epidemics started from the central part of a geometric metapopulation network can reach more individuals only if the basic reproduction number is small, but if the epidemic is more infectious, it reaches a larger population when seeded from uniformly selected nodes. We identify spatial geometry to amplify this effect in both data-driven and synthetic epidemic models, and we give rigorous proofs that this phenomenon appears in various random networks. Our results help us understand why real epidemics started from seemingly similar conditions may have significantly different outcomes.
A mutation-mediated evolutionary adaptation of Zika virus in mosquito and mammalian host
Authors: Yu Xi , Shan Chao , Zhu Yibin , Ma Enhao , Wang Jinglin , Wang Penghua , Shi Pei-Yong , Cheng Gong
Published: October 2021

Significance

Zika virus (ZIKV) circulated undetectably for decades until its recent outbreak from 2015 to 2017. Our study demonstrated that a mutation in the ZIKV capsid protein (C-T106A) significantly increased the epidemic potential of ZIKV over its transmission cycle by promoting the efficient assembly of ZIKV virions. Our results offer additional evidence about the evolutionary enhancement of ZIKV infectivity in mammalian hosts and mosquitoes, potentially improving our understanding of the potential relationships between ZIKV evolution and the occasional widespread reemergence in nature.
Use of liquid lithography to form in vitro intestinal crypts with varying microcurvature surrounding the stem cell niche
Authors: Howard R Logan , Wang Yuli , Allbritton Nancy L
Published: October 2021

Objective. The role of the crypt microarchitecture and surrounding tissue curvature on intestinal stem/proliferative cell physiology is unknown. The utility of liquid lithography in creating polydimethylsiloxane (PDMS) micropillar stamps with controlled tip curvature was assessed. Using these stamps, the impact of microcurvature at the crypt base on intestinal cell and cytoskeletal behavior was studied. Approach. An SU-8 master mold as a support, polyols of varying surface energies as sacrificial liquids, and liquid PDMS as the solidifiable material were combined using liquid lithography to form PDMS micropillar arrays. Vapor phase deposition of organosilane onto the master mold was used to modify the surface energy of the master mold to shape the micropillar tips. Collagen was molded using the micropillar arrays forming a scaffold for culture of human primary colonic epithelial cells. Cell proliferation and cytoskeletal properties were assessed using fluorescent stains. Main results. Liquid lithography using low surface energy polyols (<55 dynes cm−1) generated convex-tipped PDMS micropillars, while polyols with higher surface energies (>55 dynes cm−1) yielded concave-tipped PDMS micropillars. Gradients of octyltrichlorosilane deposition across a master mold with an array of microwells yielded a PDMS micropillar array with a range of tip curvatures. Human primary colonic epithelial cells cultured on micropillar-molded collagen scaffolds demonstrated a stem/proliferative cell compartment at the crypt base. Crypts with a convex base demonstrated significantly lower cell proliferation at the crypt base than that of cells in crypts with either flat or concave bases. Crypts with a convex base also displayed higher levels of G-actin activity compared to that of crypts with flat or concave bases. Significance. Liquid lithography enabled creation of arrays of in vitro colonic crypts with programmable curvature. Primary cells at the crypt base sensed and responded to surface curvature by altering their proliferation and cytoskeletal properties.
Ultrafast dynamics of exciton–polariton in optically tailored potential landscapes at room temperature
Authors: Chen Fei , Li Hui , Zhou Hang , Ye Ziyu , Luo Song , Sun Zheng , Sun Fenghao , Wang Jiawei , Xu Huailiang , Xu Hongxing , Chen Zhanghai , Wu Jian
Published: October 2021

In this work, by using femtosecond angle-resolved spectroscopic imaging technique, the ultrafast dynamics of confined exciton–polaritons in an optical induced potential well based on a ZnO whispering-gallery microcavity is explicitly visualized. The sub-picosecond transition between succeeding quantum harmonic oscillator states can be experimentally distinguished. The landscape of the potential well can be modified by the pump power, the spatial distance and the time delay of the two input laser pulses. Clarifying the underlying mechanism of the polariton harmonic oscillator is interesting for the applications of polariton-based optoelectronic devices and quantum information processing.
Real-time multi-class signal quality assessment of photoplethysmography using machine learning technique
Authors: Prasun Pratyush , Mukhopadhyay Sumitra , Gupta Rajarshi
Published: October 2021

Photoplethysmography (PPG) signal quality assessment (SQA) ensures improved measurements of various surrogate cardiovascular measurements like heart rate, SpO2, blood pressure, cardiac output and many more and as well reduces false alrams in ambulatory measurements. Although PPG SQA (PSQA) is a well researched area, but multiclass prediction of signal quality and its hardware implementation is limited. In this paper, a new non-segmenting approach for multiclass PSQA is presented with an optimal set of seven time-frequency domain features in conjuction with supervised classifiers to identify clean, partly clean and corrupted PPG data. The present work was carried out in three major stages- signal (dataset) acquisition, feature extraction and 3-class classification using random forest classifier. The technique was evaluated with volunteers’ data, MIMIC-III data from PhysioNet, CSL data, and combined data and achieved an overall average accuracy of 96.8% with good (0.98 or above) sensitivity, specificity, F1 score, precision and recall. On-device implementation of the proposed PSQA was accomplished using 7.2 h of PPG dataset on a quad-core Broadcom BCM 2837 controller with 1.2 GHz, supported by 1 GB RAM-based standalone device, with an accuracy of 97.09%. The latency and the peak memory requirement of the implementation was 0.81 s and 19 kB respectively to process 3 s PPG data. The present technique may be integrated as a part of a remote healthcare system using wearable sensors.
Thermodynamic properties for Ar-Al, Ar-Cu and Ar-Fe mixtures from 0.3 kK up to 4 kK for 1 atm
Authors: Coufal O
Published: October 2021

The subject of the article is the thermodynamic properties (tdp) of mixtures of Ar-Al, Ar-Cu and Ar-Fe in thermodynamic equilibrium state. In current published works the metals in the mixture are assumed to be in the gaseous state. In the present work, the metals are at a temperature of 0.3 kK crystalline substances which with increasing temperature change to liquid and gaseous substances. The proportion of metal in the mixture is in the interval from 0 to 100 mass%. The calculation results are presented in the figures and in detailed tables in the TDPtables.txt in the Supplementary material. The physical model of the calculation of tdp is a simplification of reality. The results of tdp calculation are affected not only by this simplification but also by the inaccuracy of input data. Attention is devoted to these simplifications and inaccuracies. The discontinuities of thermodynamic properties caused by phase transitions are analysed.
An approach for numerical simulating and processing of measured electrical signals from board sensors installed on wheeled electro-mechanical platforms
Authors: Mamalis A.G. , Nevliudov I. , Romashov Yu.
Published: October 2021

The generalized approaches of mathematical modelling for
numerical simulating and processing of measured electrical signals
from board sensors installed on wheeled electro-mech­an­ical platforms
are developed in this research. The mathematical backgrounds of the
developed approaches are elaborated on the basis of especially
formulated initial-value problems need to be solved numerically or
the identification procedure need to be applied. It is shown that
using the Lagrange's formalism and the electro-mechanical analogies
for constructing the improved coupled mathematical models both the
mechanics and electrics and electronics of the wheeled platforms and
the installed board sensors and the measuring electronic transducers
allows having the more information if processing of the measured
signals will be on the basis of such improved mathematical
models. It is considered the particular example of using the
proposed approaches dealt with simulating and processing the
measured electric signals from the board accelerometer installed on
the four wheeled electro-mechanic platform. Due to this example it
was shown that using of the improved mathematical models allows the
significantly wider possibilities of accelerometer measuring, so
that the different parameters can be estimated by means processing
the direct accelerometer measures using the corresponded
mathematical models. It was shown that, the most difficulties of
identification problems for processing the measured signals from the
board sensors installed on the wheeled platforms are due to inherent
them the mathematical incorrectness according to Hadamard. The
effectiveness of using the filtering of the results of processing
the measured signals is shown for the considered particular example
of the identification problem also.
Sensitivity analysis towards trace-uranium detection with γ-γ coincidence NAA
Authors: Tsang R.H.M. , Nusair O. , Piepke A.
Published: October 2021

We present an improved approach for detection of trace
amounts of 238U by means of neutron activation analysis (NAA).
The analysis enhancement is obtained by utilizing γ-γ
coincidence counting. An empirical method for evaluating the
sensitivity gain in the presence of a large source-related
background is presented. A comparison of detection limits is made
between two counting schemes; namely, counting single gammas using
one HPGe detector versus counting coincident gammas using two HPGe
detectors placed face-to-face. A data-validated radiation transport
model, created in GEANT4 for a single HPGe detector, is extended to
handle the two-detector setup. In this counting scheme, a
238U-detection sensitivity enhancement of about a factor of 8
is predicted for a sample of Saint-Gobain G3 Sapphire when compared
to the simpler singles counting approach.
The world’s largest heliothermal lake newly formed in the Aral Sea basin
Authors: Izhitskiy Alexander S , Kirillin Georgiy B , Goncharenko Igor V , Kurbaniyazov Abilgazy K , Zavialov Peter O
Published: October 2021

The Aral Sea desiccation is one of the worst aquatic ecological disasters of the last century, important for understanding the worldwide trends to degradation of arid lakes under water use and climate change. Formerly the fourth largest lake worldwide, the Aral Sea has lost ∼90% of its water since the early 1960s due to irrigation in its drainage basin. Our survey on the seasonal thermal and mixing regime in Chernyshev—a semi-isolated hypersaline part of the Aral Sea—revealed a newly formed two-layered structure with strong gradients of salinity and water transparency at mid-depths. As a result, the Chernyshev effectively accumulates solar energy, creating a temperature maximum at the water depth of ∼5 m with temperatures up to 37 °C. Herewith, this part of the Aral Sea has evolved to an unprecedently large (∼80 km2) heliothermal lake akin to artificial solar ponds used for ‘green energy’ production. The newly formed heliothermal lake, with transparent and freshened layer on top of the hypersaline and nutrient-rich deep water, acts as a solar energy trap and facilitates intense biogeochemical processes. The latter reveal themselves in practically 100% opacity of the deep layer to the solar light, permanent deep anoxia, and growing methane concentrations. The recent emergence of the Chernyshev as a heliothermal lake provides an opportunity for tracing the biogeochemical and ecological response of aquatic ecosystems to suddenly changed environmental conditions.
Multi-material digital light processing bioprinting of hydrogel-based microfluidic chips
Authors: Bhusal Anant , Dogan Elvan , Nguyen Hai-Anh , Labutina Olga , Nieto Daniel , Khademhosseini Ali , Miri Amir K
Published: October 2021

Recent advancements in digital-light-processing (DLP)-based bioprinting and hydrogel engineering have enabled novel developments in organs-on-chips. In this work, we designed and developed a multi-material, DLP-based bioprinter for rapid, one-step prototyping of hydrogel-based microfluidic chips. A composite hydrogel bioink based on poly-ethylene-glycol-diacrylate (PEGDA) and gelatin methacryloyl (GelMA) was optimized through varying the bioprinting parameters such as light exposure time, bioink composition, and layer thickness. We showed a wide range of mechanical properties of the microfluidic chips for various ratios of PEGDA:GelMA. Microfluidic features of hydrogel-based chips were then tested using dynamic flow experiments. Human-derived tumor cells were encapsulated in 3D bioprinted structures to demonstrate their bioactivity and cell-friendly environment. Cell seeding experiments then validated the efficacy of the selected bioinks for vascularized micro-tissues. Our biofabrication approach offers a useful tool for the rapid integration of micro-tissue models into organs-on-chips and high-throughput drug screening platforms.
Extensions of primes, flatness, and intersection flatness
Authors: Hochster Melvin , Jeffries Jack
Published: October 2021

We study when

R
→
S

R \to S

has the property that prime ideals of

R
R

extend to prime ideals or the unit ideal of

S
S

, and the situation where this property continues to hold after adjoining the same indeterminates to both rings. We prove that if

R
R

is reduced, every maximal ideal of

R
R

contains only finitely many minimal primes of

R
R

, and prime ideals of

R
[

X

1

,

…
,

X

n

]

R[{X}_1, \, \ldots , \, {X}_{n}]

extend to prime ideals of

S
[

X

1

,

…
,

X

n

]

S[{X}_1, \, \ldots , \, {X}_{n}]

for all

n
n

, then

S
S

is flat over

R
R

. We give a counterexample to flatness over a reduced quasilocal ring

R
R

with infinitely many minimal primes by constructing a non-flat

R
R

-module

M
M

such that

M
=
P
M

M = PM

for every minimal prime

P
P

of

R
R

. We study the notion of intersection flatness and use it to prove that in certain graded cases it suffices to examine just one closed fiber to prove the stable prime extension property.
Cardinalities of prime spectra of precompletions
Authors: Barrett Erica , Graf Emil , Loepp S. , Strong Kimball , Zhang Sharon
Published: October 2021

Given a complete local (Noetherian) ring

T
T

, we find necessary and sufficient conditions on

T
T

such that there exists a local domain

A
A

with

|

A

|

>

|

T

|

|A| > |T|

and

A
^

=
T

\widehat {A} = T

, where

A
^

\widehat {A}

denotes the completion of

A
A

with respect to its maximal ideal. We then find necessary and sufficient conditions on

T
T

such that there exists a domain

A
A

with

A
^

=
T

\widehat {A} = T

and
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartAbsoluteValue normal upper S normal p normal e normal c left-parenthesis upper A right-parenthesis EndAbsoluteValue greater-than StartAbsoluteValue normal upper S normal p normal e normal c left-parenthesis upper T right-parenthesis EndAbsoluteValue">

|

S
p
e
c

(
A
)

|

>

|

S
p
e
c

(
T
)

|

|\mathrm {Spec}(A)| > |\mathrm {Spec}(T)|

. Finally, we use “partial completions” to create local rings

A
A

with

A
^

=
T

\widehat {A} = T

such that

S
p
e
c

(
A
)

\mathrm {Spec}(A)

has varying cardinality in different varieties.
Impact of Reverse Causation on Estimates of Cancer Risk Associated With Radiation Exposure From Computerized Tomography: A Simulation Study Modeled on Brain Cancer
Authors: Little Mark P , Patel Ankur , Lee Choonsik , Hauptmann Michael , Berrington de Gonzalez Amy , Albert Paul
Published: October 2021

Use of computed tomography (CT) scanning has increased substantially since its introduction in the 1990s. Several authors have reported increased risk of leukemia and brain tumors associated with radiation exposure from CT scans. However, reverse causation is a concern, particularly for brain cancer; in other words, the CT scan may have been taken because of preexisting cancer and therefore not have been a cause. We assessed the possibility of reverse causation via a simulation study focused on brain tumors, using a simplified version of the data structure for recent CT studies. Five-year–lagged and unlagged analyses implied an observed excess risk per scan up to 70% lower than the true excess risk per scan, particularly when more than 10% of persons with latent cancer had increased numbers of scans or the extra scanning rate after development of latent cancer was greater than 2 scans/year; less extreme values of these parameters imply little risk attenuation. Without a lag and when more than 20% of persons with latent cancer had increased scans—an arguably implausible scenario—the excess risk per scan was increased over the true excess risk per scan by up to 35%–40%. This study suggests that with a realistic lag, reverse causation results in downwardly biased risk, a result of induced classical measurement error, and is therefore unlikely to produce a spurious positive association between cancer and radiation dose from CT scans.
Trajectories of Prescription Opioid Utilization During Pregnancy Among Prepregnancy Chronic Users and Risk of Neonatal Opioid Withdrawal Syndrome
Authors: Straub Loreen , Huybrechts Krista F , Hernández-Díaz Sonia , Zhu Yanmin , Vine Seanna , Desai Rishi J , Gray Kathryn J , Bateman Brian T
Published: October 2021

Little is known about the impact of dose, duration, and timing of prenatal prescription opioid exposure on the risk of neonatal opioid withdrawal syndrome (NOWS). Using a cohort of 18,869 prepregnancy chronic opioid users nested within the 2000–2014 Medicaid Analytic eXtract, we assessed average opioid dosage within biweekly gestational age intervals, created group-based trajectory models, and evaluated the association between trajectory groups and NOWS risk. Women were grouped into 6 distinct opioid use trajectories which, based on observed patterns, were categorized as 1) continuous very low-dose use, 2) continuous low-dose use, 3) initial moderate-dose use with a gradual decrease to very low-dose/no use, 4) initial high-dose use with a gradual decrease to very low-dose use, 5) continuous moderate-dose use, and 6) continuous high-dose use. Absolute risk of NOWS per 1,000 infants was 7.7 for group 1 (reference group), 28.8 for group 2 (relative risk (RR) = 3.7, 95% confidence interval (CI): 2.8, 5.0), 16.5 for group 3 (RR = 2.1, 95% CI: 1.5, 3.1), 64.9 for group 4 (RR = 8.4, 95% CI: 5.6, 12.6), 77.3 for group 5 (RR = 10.0, 95% CI: 7.5, 13.5), and 172.4 for group 6 (RR = 22.4, 95% CI: 16.1, 31.2). Trajectory models—which capture information on dose, duration, and timing of exposure—are useful for gaining insight into clinically relevant groupings to evaluate the risk of prenatal opioid exposure.