bluuebunny/crossref_metadata_2025 huggingface dataset:
A new approach to the dynamic modeling of an infectious disease
Authors: Shayak B. , Sharma Mohit M.
Published: May 2021

In this work we propose a delay differential equation as a lumped parameter or compartmental infectious disease model featuring high descriptive and predictive capability, extremely high adaptability and low computational requirement. Whereas the model has been developed in the context of COVID-19, it is general enough to be applicable with such changes as necessary to other diseases as well. Our fundamental modeling philosophy consists of a decoupling of public health intervention effects, immune response effects and intrinsic infection properties into separate terms. All parameters in the model are directly related to the disease and its management; we can measure or calculate their values a priori basis our knowledge of the phenomena involved, instead of having to extrapolate them from solution curves. Our model can accurately predict the effects of applying or withdrawing interventions, individually or in combination, and can quickly accommodate any newly released information regarding, for example, the infection properties and the immune response to an emerging infectious disease. After demonstrating that the baseline model can successfully explain the COVID-19 case trajectories observed all over the world, we systematically show how the model can be expanded to account for heterogeneous transmissibility, detailed contact tracing drives, mass testing endeavours and immune responses featuring different combinations of temporary sterilizing immunity, severity-reducing immunity and antibody dependent enhancement.
Novel Pentafluorophenyl- and Alkoxyphenyl-Appended 2,2′-Bipyridine Push–Pull Fluorophores: A Convenient Synthesis and Photophysical Studies
Authors: Varaksin Mikhail V. , Chupakhin Oleg N. , Moseev Timofey D. , Nikiforov Egor A. , Starnovskaya Ekaterina S. , Savchuk Maria I. , Nikonov Igor L. , Kopchuk Dmitry S. , Zyryanov Grigory V. , Charushin Valery N.
Published: May 2021

A convenient method for the synthesis of new highly in non-polar solvents soluble photoactive pentafluorophenyl-substituted and extended alkoxyphenyl-substituted 2,2′-bipyridines is reported. The synthetic strategy for the preparation of such ligands involves a sequence of several structural transformations, such as O-alkylation, nucleophilic substitution of hydrogen (SN
H) in 1,2,4-triazine precursors via the ‘addition–elimination’ scheme, and the subsequent conversion of the obtained 1,2,4-triazines into 2,2′-bipyridines by means of the aza-Diels–Alder reaction. The photophysical properties of the synthesized novel pentafluoroaryl-substituted 2,2′-bipyridines were comprehensively studied. The obtained photophysical data indicate the competitive advantages of the herein reported pentafluoroarylated push–pull fluorophores, bearing extended aliphatic moieties, over their analogues containing benzoxy or phenolic fragments in terms of improvement in quantum yield and well-pronounced positive solvatochromism confirmed by the mathematical analysis according to the Lippert–Mataga equation.
Unified Approach for the Total Synthesis of Bis-THF C15 Acetogenins: A Chloroenyne from Laurencia majuscula, Laurendecumenyne B and Laurefurenynes A/B
Authors: Ramana Chepuri V. , Senapati Sibadatta , Unmesh Nivedya A. , Shet Manoj N. , Ahmad Iram , Ajikumar Nandu
Published: May 2021

A highly diastereoselective total synthesis of several bis-THF C15 acetogenin natural products, chloroenyne from Laurencia majuscula, laurendecumenyne B, and laurefurenynes A/B, is reported. Additionally the synthesis of an advanced intermediate reported in the earlier total synthesis of (E/Z)-elatenynes (formal synthesis) is described. The salient features in the synthesis include epoxide opening, Birch reduction, Sharpless asymmetric dihydroxylation-cycloetherification, SN2 halo­genation, and a relay cross metathesis.
Imaging of Ampullary and Periampullary Conditions
Authors: Sunnapwar Abhijit , Nagar Arpit , Katre Rashmi , Khanna Lokesh , Sayana Hari Prasad
Published: May 2021

The ampulla of Vater is formed by the union of the pancreatic duct and the common bile duct and is also known as hepatopancreatic ampulla or hepatopancreatic duct. The ampulla is surrounded by a muscular valve known as the sphincter of Oddi, which controls the flow of bile and pancreatic juices into the duodenum in response to food. The ampulla is also an important embryological landmark as it marks the anatomical transition from foregut to the midgut. Because of this, it is a watershed zone where the blood supply changes from the celiac axis to the superior mesenteric artery. Radiologic evaluation of the ampulla and the periampullary region is challenging because it requires an understanding of the embryology, the normal appearance, and different anatomic variants. Also, a wide variety of pathologies can occur in this region. The purpose of this review is to present the normal anatomy of the ampulla and the periampullary region on different imaging modalities and to summarize the imaging features of the common variants, and benign and malignant ampullary and periampullary conditions. Understanding of the normal anatomical appearance and variants along with the knowledge of common pathologic conditions affecting the ampulla and periampullary conditions can help radiologists in making accurate diagnosis resulting in optimum patient care.
Beam quality measurement of high power laser by using an involute pinhole array
Authors: Chen Shaowu , Yang Pengling , Luan Kunpeng , Wu Junjie , Feng Gang , Zhao Haichuan
Published: May 2021

A novel method for power-in-the-bucket (PIB) measurement of high power laser beams is proposed. The laser beam spot was first sampled by a rotating involute pinhole array and then collected by using a photodetector placed behind the pinholes. The spatial–temporal distribution and calibrated PIB curve of the laser beam can be obtained. The spatial and temporal resolution is 20 µm and 5 ms, respectively. Compared with conventional methods, the proposed measurement method is simple, convenient, and accurate, which is suitable for high power laser beams with jitter.
Magnetic characterization of paramagnetic reagents by particle tracking velocimetry
Authors: Sannidhi Abhinav , Todd Paul W. , Hanley Thomas R.
Published: May 2021

Magnetic particle characterization determines the quality of magnetic particles and is of great importance in particle technology, drug delivery, cell separation, in vivo diagnostics, and other biomedical applications. The quality of the sample depends on the particle size, intrinsic magnetic properties of the particles, and the uniformity of these properties. A commercial particle tracking velocimeter was used to record and capture dark field images of particle trajectories in an applied isodynamic magnetic field. The calibrated particle size, magnetophoretic mobility, and additional image data were collected for each magnetic bead imaged. Using twenty-one different de-identified calibration beads and transmission electron microscopy to validate the vendor-reported particle size enabled the estimation of intrinsic magnetic properties, namely, apparent magnetic susceptibility and saturation magnetization, of individual paramagnetic particles. The distributions of volume magnetic susceptibility based on the magnetophoretic mobility and size of the particle for different magnetic beads were determined and displayed as two-parameter distributions. The measured apparent susceptibility and saturation magnetization were found to be directly proportional to the percentage of iron oxide in the reagent particles.
A self-powered vibration sensor for downhole drilling tools based on hybrid electromagnetic–triboelectric nanogenerator
Authors: Wu Chuan , Yang Shuo , Wen Guojun , Fan Chenxing
Published: May 2021

The vibration of downhole drilling tools is important to the drilling process, which needs to be measured in real time. Here, a self-powered vibration sensor for downhole drilling tools based on a hybrid electromagnetic–triboelectric nanogenerator is proposed in this research. The sensor has high reliability because the triboelectric nanogenerator (TENG) and the electromagnetic generator (EMG) parts of the sensor can be used as vibration sensors alone, and it may also supply power to other micro-power measurements while drilling instruments when the TENG and the EMG are used in parallel to increase the output power. Test results show that for the TENG part, the maximum output voltage, current, and power are 14 V, 5.2 µA, and 3.2 µW, respectively, with a 1 MΩ resistance in series, and for the EMG part, they are 1.22 V, 33 µA, and 21.8 mW, respectively, with a 10 Ω resistance in series. Further tests show that the measurement range of both the TENG and EMG is 0–11 Hz, the measurement error of both is less than ±5%, and both can work normally in the temperature range of less than 250 °C. In addition, this research also builds a wireless vibration data transmission system based on the sensor, which shows the potential for use in the wireless sensing field.
Atomistic investigation of mechanical response and deformation mechanism of BCC Ta under double shock loading
Authors: Wu Dun , Zhu Yaxin , Zhao Lv , Huang Minsheng , Li Zhenhuan
Published: May 2021

Engineering structures or materials are often subjected to multiple shock loadings. Mechanical response and its physical mechanism under such loadings are extremely complex and need to be studied in depth. To reveal double shock-induced deformation and microstructural evolution in the key structural material Ta, large-scale non-equilibrium molecular dynamics simulations of monocrystalline and polycrystalline Ta under double shock loading were performed. The results show that the activation and re-evolution of twins and dislocations introduced by the first shock dominate the plastic deformation during the second one. Some crystallographic orientation dependent mechanisms of plastic deformation under the second shock are revealed. Twin-dislocation conversion is dominant in the ⟨100⟩-orientated monocrystalline and polycrystalline Ta, while dislocation slipping is dominant in the ⟨110⟩- and ⟨111⟩-orientated Ta. The dependence of flow strength on the loading-paths of single and double shocks was also investigated. Shock-induced amorphization and recrystallization are observed in the single shock-loaded Ta models, leading to lower flow strengths than those of the double shock-loaded ones. These results help understand the complex relationship between the dynamic strength and intrinsic deformation mechanism of Ta under multiple shock loadings.
Filamentation and focusing of electron beams due to interactions with plasma waves
Authors: Bowman A. L. , Williams R. L.
Published: May 2021

Results of numerical modeling of the interaction of an electron beam propagating across relativistic plasma waves indicate that electron beam filamentation and focusing may occur under certain conditions. The model is based on solving the relativistic equation of motion in three dimensions for the individual electrons in a tenuous Gaussian beam, as they pass through a relativistic plasma wave. Several electron beam and plasma wave parameters were varied, and the results are summarized. One of the results is that the spacing of the electron beam filaments correlates with the wavelength of the plasma wave. The electron beam filaments appear as vertical slabs after the beam exits the plasma waves. The electron beam also compresses to a focus after it exits the plasma, and the focal distance depends on several parameters including the electron beam energy and phase velocity of the relativistic plasma wave. It is suggested that these focusing and filamentation phenomena may be the basis for diagnostics schemes for laser plasma interactions. The parameters used in the model were electron beam energies in the 5–50 keV range and plasma wave properties typical for the beat-wave produced by CO2 lasers, which correspond to the facilities available in our laboratory. The limitations of these results to lower energy density beam and plasma regimes and to higher energy density regimes will be discussed.
Measurements of impurity ion temperature and velocity distributions via active charge-exchange recombination spectroscopy in C-2W
Authors: Nations M. , Gupta D. , Sweeney J. , Frausto L. , Tobin M. ,   TAE Team
Published: May 2021

In TAE Technologies’ C-2W experiment, electrode biasing is utilized for boundary control of a field-reversed configuration (FRC) plasma embedded in a magnetic mirror. Understanding the underlying physics associated with FRC rotation, stabilization, and heating is crucial for improving machine performance. Impurity ion rotation and temperature are sensitive to biasing effects, and measurements of these quantities can provide insight into important plasma dynamics and overall effectiveness of the biasing system. To this end, a charge-exchange recombination spectroscopy (ChERS) diagnostic was developed and deployed to measure local impurity ion temperature and velocity in the confinement vessel of C-2W. The system utilizes a new diagnostic neutral beam (40 keV, 8.5 A) and a fiber-coupled spectrometer with an image-intensified high-speed camera to measure beam-induced spectral line emission at multiple lines-of-sight. Design details and the first experimental results obtained with this new diagnostic are presented and discussed.
Pulse width dependence of magnetic field generation using laser-powered capacitor coils
Authors: Chien Abraham , Gao Lan , Zhang Shu , Ji Hantao , Blackman Eric , Chen Hui , Fiksel Gennady , Hill Kenneth , Nilson Philip
Published: May 2021

Megagauss magnetic fields were generated by a current flowing through a U-shaped coil connecting two parallel copper foils. Two kJ-class lasers at various pulse widths from 2 ns to 9.9 ns passed through holes in the front foil and were focused on the back foil with an intensity of ∼1.7×1016 W/cm2. The coil current and resulting magnetic fields were characterized using ultrafast proton radiography, timed at the end of the laser pulses. The measurements show that magnetic field strength decays with increasing laser pulse width. A lumped-circuit model was developed and showed consistency with the experimental measurements, demonstrating an ion shorting effect: as the ion current neutralizes the electron current contribution to interplate voltage, the coil current peaks on a timescale close to the ion transit time ti=d/vion. FLASH simulations of the coil current are performed, and the calculated resistance values are used to constrain ion speed as a function of hot electron temperature.
High-speed giant magnetostrictive actuator using laminated silicon steel core
Authors: Liu Pengfei , Kong Mengmeng , Diao Weidong , Feng Zhihua
Published: May 2021

The high-frequency eddy current loss limits the output speed of the giant magnetostrictive actuator (GMA). This paper investigates a GMA using a laminated silicon steel core. Compared with the integral silicon steel core, the laminated silicon steel core can reduce the equivalent conductivity and eddy currents. The laminated structure reduces the magnetic reluctance of the core and increases the magnetic field intensity in the giant magnetostrictive material rod. Therefore, the actuator can output large vibration amplitude under high-frequency magnetic field. At the sinusoidal excitation current of 35 A (rms) @ 2 kHz, the output vibration amplitude of the actuator using the laminated silicon steel core is 11.1 µm @ 4 kHz, which is 44.2% higher than that of the actuator with the integral silicon steel core. This indicates that the laminated structure of the magnetic core is beneficial to improve the output speed of GMA.
Polarizability of atomic Pt, Pt+, and Pt−
Authors: Irikura Karl K.
Published: May 2021

Electrostatic properties are important for understanding and modeling many phenomena, such as the adsorption of a catalytic metal upon an oxide support. The charge transfer between the metal and the support can lead to positive or negative charges on the metal. Here, the static dipole polarizability is computed for atomic platinum in charge states 0, +1, and −1 in several low-lying electronic terms and levels. Core pseudopotentials are used along with coupled-cluster theory. The best results are estimates for the coupled-cluster CCSDTQ/q-aug-cc-pwCV∞Z-PP values for atomic terms, combined with compositional data from spin–orbit configuration interaction. The polarizability of the anion Pt− is especially challenging for the theory with wildly varying results from different coupled-cluster perturbative approximations such as CCSD(T). For atomic mercury (Hg), selected as a nearby experimental value, our polarizability volume is larger than experiment by 0.8 bohrs3 (or 0.12 × 10−30 m3). For the ground level of neutral platinum, Pt(3D3), we find α0 = (41.2 ± 1.1) bohrs3 or (6.10 ± 0.16) × 10−30 m3. A handful of density functional theory methods are tested and found generally within 10% of our best values.
A fifth-order high-resolution shock-capturing scheme based on modified weighted essentially non-oscillatory method and boundary variation diminishing framework for compressible flows and compressible two-phase flows
Authors: Li Qijie , Yokoi Kensuke , Xie Zhihua , Omar Syazana , Xue Jingjing
Published: May 2021

First, a new reconstruction strategy is proposed to improve the accuracy of the fifth-order weighted essentially non-oscillatory (WENO) scheme. It has been noted that conventional WENO schemes still suffer from excessive numerical dissipation near-critical regions. One of the reasons is that they tend to under-use all adjacent smooth substencils thus fail to realize optimal interpolation. Hence in this work, a modified WENO (MWENO) strategy is designed to restore the highest possible order interpolation when three target substencils or two target adjacent substencils are smooth. Since the new detector is formulated under the original smoothness indicators, no obvious complexity and cost are added to the simulation. This idea has been successfully implemented into two classical fifth-order WENO schemes, which improve the accuracy near the critical region but without destroying essentially non-oscillatory properties. Second, the tangent of hyperbola for interface capturing (THINC) scheme is introduced as another reconstruction candidate to better represent the discontinuity. Finally, the MWENO and THINC schemes are implemented with the boundary variation diminishing algorithm to further minimize the numerical dissipation across discontinuities. Numerical verifications show that the proposed scheme accurately captures both smooth and discontinuous flow structures simultaneously with high-resolution quality. Meanwhile, the presented scheme effectively reduces numerical dissipation error and suppresses spurious numerical oscillation in the presence of strong shock or discontinuity for compressible flows and compressible two-phase flows.
Surface composition of AgPd single-atom alloy catalyst in an oxidative environment
Authors: Hartwig Caroline , Schweinar Kevin , Nicholls Rachel , Beeg Sebastian , Schlögl Robert , Greiner Mark
Published: May 2021

Single-atom alloys (SAAs) have recently gained considerable attention in the field of heterogeneous catalysis research due to their potential for novel catalytic properties. While SAAs are often examined in reactions of reductive atmospheres, such as hydrogenation reactions, in the present work, we change the focus to AgPd SAAs in oxidative environments since Pd has the highest catalytic activity of all metals for oxidative reactions. Here, we examine how the chemical reactivity of AgPd SAAs differs from its constituent Pd in an oxidative atmosphere. For this purpose, electronic structure changes in an Ag0.98Pd0.02 SAA foil in 1 mbar of O2 were studied by in situ x-ray photoemission spectroscopy and compared with the electronic structure of a Pd foil under the same conditions. When heated in an oxidative atmosphere, Pd in Ag0.98Pd0.02 partly oxidizes and forms a metastable PdOx surface oxide. By using a peak area modeling procedure, we conclude that PdOx on Ag0.98Pd0.02 is present as thin, possibly monolayer thick, PdOx islands on the surface. In comparison to the PdO formed on the Pd foil, the PdOx formed on AgPd is substantially less thermodynamically stable, decomposing at temperatures about 270 °C lower than the native oxide on Pd. Such behavior is an interesting property of oxides formed on dilute alloys, which could be potentially utilized in catalytic oxidative reactions such as methane oxidation.
Electronic processes in organic–inorganic composite P3HT with silicon nanocrystals
Authors: Savin Konstantin , Forsh Pavel , Forsh Ekaterina , Kazanskii Andrey
Published: May 2021

The generation mechanisms and charge carrier transfer in a composite of polymer poly-3(hexylthiophene) (P3HT) and silicon nanoparticles (nc-Si) films are investigated using conductivity measurements at different temperatures and electric fields and photocurrent spectroscopy. It is shown that the widely used Gaussian disorder model for describing the electrical and optical properties of polymers is also valid for hybrid organic–inorganic materials consisting of polymer matrix with silicon nanoparticles addition. This indicates that the charge carrier transfer in such materials occurs over the localized states in the polymer part of composite material. It is shown that the nonmonotonic change in the conductivity arising upon the addition of silicon nanoparticles leads only to a change in the distribution of the density of localized states in the polymer, which determines the conductivity and photoconductivity of the hybrid material. It is demonstrated that the addition of nc-Si at lower concentrations to P3HT makes it possible to vary the conductivity and photoconductivity of the composite material over a wide range.
Ab initio simulation of hypersonic flows past a cylinder based on accurate potential energy surfaces
Authors: Grover Maninder S. , Valentini Paolo
Published: May 2021

For the first time in the literature, we present 2D simulations of hypersonic flows around a cylinder obtained from accurate ab initio potential energy surfaces (PESs). We compare results obtained from a low fidelity (empirical) and a high fidelity (ab initio) PES, thus demonstrating the impact of PES accuracy on the entire aerothermodynamic field around the body. We observe that the empirical PES is not adequate to accurately reproduce rotational and vibrational relaxation in the hypersonic flow, both in the compression and expansion regions of the flow field. This approach, enabled by advancements in large-scale computing, paves the way to the direct simulation of hypersonic flows where the only modeling input is the PES that describes molecular interactions between the various air constituents. Such flow field simulations provide benchmark solutions for the validation of reduced-order models.
Dynamics of inner gas during the bursting of a bubble at the free surface
Authors: Singh Digvijay , Das Arup Kumar
Published: May 2021

In the present study, simulations are directed to capture the dynamics of evacuating inner gas of a bubble bursting at the free surface, using Eulerian based volume of fluid (VOF) method. The rate by which surrounding air rushing inside the bubble cavity through the inner gas evacuation is estimated and compared by the collapsing bubble cavity during the sequential stages of the bubble bursting at the free surface. Further, the reachability of inner gas at different horizontal planes over the unperturbed free surface is estimated. The evacuating inner gas accompanies vortex rings, which entrains the surrounding gas-phase. During the successive stages of air entrainment, spatiotemporal characteristics of the vortex ring are obtained. At low Bond numbers (Bo < 1), the axial growth pattern of gas jet and the radial expansion of jet tip are studied with the phase contour of evacuating inner gas. Furthermore, the axial growth of rising inner gas over the free surface and the radial expansion of vortex rings of a bubble bursting at the free surface is compared with the quiescent surrounding air under the respiration process. At last, the effects of various possible asymmetric perforation of the bubble cap keeping the same Bo are studied. The cause of the bent gas jet, as a consequence of the perforation of the bubble cap, asymmetrically, is explained by plotting the velocity vectors. The effect of miscibility on the spreading dynamics of inner gas has been found to be minimal at the early stage of the bursting process.
Potential error from using ZT to optimize thermoelectric performance
Authors: Beekman Matt , Ghantous Jean F. , Thomson Kyle
Published: May 2021

Despite known shortcomings, the dimensionless figure of merit, ZT, continues to be the most widely used material performance metric in thermoelectrics research. Here, we expose yet another potential drawback of using the ZT to evaluate new thermoelectric materials. Specifically, by comparison with more accurate methods of estimating thermoelectric material energy conversion efficiency, we find that using the ZT as the optimization criterion could possibly lead to erroneous conclusions about the optimal doping density when optimizing performance. Using a simple semiconductor model, we find that optimal doping densities as determined using the ZT could be in error by a factor of two or more, potentially contributing a relatively small but non-negligible loss in device efficiency that could be easily avoided by using modern methods for estimation of material conversion efficiency.
Unsteady analysis of turbulent flow and heat transfer behind a wall-proximity square rib using dynamic delayed detached-eddy simulation
Authors: Li Fuqi , He Chuangxin , Wang Peng , Liu Yingzheng
Published: May 2021

In the present study, turbulent wall heat transfer behind a wall-proximity square rib is numerically modeled using dynamic delayed detached-eddy simulations, with the objective of clarifying unsteady flow behaviors and their influence on wall heat transfer. Three configurations with gap-to-height ratios (G/d) of 0, 0.25, and 0.5 are comparatively evaluated at a Reynolds number (Red) of 7600. The wall heat transfer is overwhelmingly affected by the interaction between the upper separated shear layer and the lower wall jet flow, exhibiting distinctly different global characteristics with increases in the wall gap. A proper orthogonal decomposition analysis of the turbulent flow fields is conducted to effectively identify the energetic flow structures superimposed on the shear layers and demonstrates that transformative features are present, from energetic bubble-flapping modes (G/d= 0, 0.25) to Karman-like vortex street modes (G/d= 0.25, 0.5). Finally, the phase-dependent variation of the spatiotemporally varying flow structures is examined. In the G/d=0.25 configuration, the suppressed lower vortical structure oscillated irregularly, leading to a locally thin thermal boundary layer and strong wall heat-transfer augmentation in the 0<x/d<4 region. In the G/d=0.5 configuration, the wall jet flow constantly disrupted the thermal boundary layer, causing Nû to plateau in the 0<x/d<3 region. The periodic shedding of the vortical structures in the upper shear layer intermittently spread onto the wall surface in the 3<x/d<6 region, resulting in the gradual decline of Nû. Accordingly, the cause-and-effect mechanism linking the unsteady flow behaviors with wall heat removal is determined, and the coupling between the large-scale vortical structures and the corresponding thermal boundary distribution is established.
Negative differential resistance and threshold-switching in conical nanopores with KF solutions
Authors: Ramirez Patricio , Perez-Grau Jose J. , Cervera Javier , Nasir Saima , Ali Mubarak , Ensinger Wolfgang , Mafe Salvador
Published: May 2021

Negative differential resistance (NDR) phenomena are under-explored in nanostructures operating in the liquid state. We characterize experimentally the NDR and threshold switching phenomena observed when conical nanopores are immersed in two identical KF solutions at low concentration. Sharp current drops in the nA range are obtained for applied voltages exceeding thresholds close to 1 V and a wide frequency window, which suggests that the threshold switching can be used to amplify small electrical perturbations because a small change in voltage typically results in a large change in current. While we have not given a detailed physical mechanism here, a phenomenological model is also included.
Hypoxia-inducible factor-dependent ADAM12 expression mediates breast cancer invasion and metastasis
Authors: Wang Ru , Godet Ines , Yang Yongkang , Salman Shaima , Lu Haiquan , Lyu Yajing , Zuo Qiaozhu , Wang Yufeng , Zhu Yayun , Chen Chelsey , He Jianjun , Gilkes Daniele M. , Semenza Gregg L.
Published: May 2021

Significance

Hypoxia (reduced oxygen availability) is a common finding in the tumor microenvironment and plays a critical role in stimulating the metastasis of breast cancer cells from the primary tumor to distant organs, which is closely related to patient mortality. Critical transcriptional responses to reduced O2availability are mediated by hypoxia-inducible factors (HIFs). In this study, we demonstrate that hypoxia induces HIF-dependent expression of a disintegrin and metalloproteinase 12 (ADAM12), which clips off the extracellular domain of the membrane-bound heparin-binding epidermal growth factor-like growth factor (HB-EGF). The liberated extracellular domain of HB-EGF binds to the epidermal growth factor receptor, triggering a signal transduction pathway that endows breast cancer cells with increased capability for cell migration and invasion, leading to distant metastasis.
Rapid Buprenorphine Microdosing for Opioid use Disorder in a Hospitalized Patient Receiving Very High Doses of Full Agonist Opioids for Acute Pain Management: Titration, Implementation Barriers, and Strategies to Overcomes
Authors: DeWeese Jonathan P. , Krenz James R. , Wakeman Sarah E. , Peckham Alyssa M.
Published: May 2021

Background

Conventional buprenorphine inductions for OUD are clinically useful but require patients to experience mild to moderate opioid withdrawal symptoms to avoid precipitated withdrawal. This may be intolerable/unreasonable for some, which may have precluded successful buprenorphine treatment in the past. Microdosing buprenorphine, allowing for full agonist opioid overlap, has emerged as a clinically useful strategy for those unable to complete conventional buprenorphine induction. However, many questions remain such as preclusions regarding the amount of full agonist opioid overlap, speed of buprenorphine microdose titration, and overcoming implementation barriers in U.S. hospitals.

Case presentation

A female between the ages of 30 and 40 with severe OUD admitted to the hospital for IDU-related osteomyelitis wished to begin buprenorphine for OUD. Her hospitalization was subject to premature discharge at any time due to competing interests of potential foreclosure on her home, so buprenorphine needed to be started rapidly for safety and improved outcomes. Due to her significant acute pain requirements managed with full agonist opioids, it was unreasonable to consider conventional buprenorphine induction. Buprenorphine microdose strategy was employed at more rapid titration and previously described in the literature, starting at 1 mg TDD on day 1, 3 mg TDD on day 2, and 8 mg TDD on day 3 with full agonist opioid overlap starting at 1,944 MME tapered down to 473 MME. The patient prematurely left the hospital, at which time buprenorphine 8 mg TDD was held at this dose for days 3–8 while full agonist opioid was tapered from 473 MME to 117 MME. BUP was then further titrated to 8 mg TID. This patient tolerated buprenorphine microdosing well, without any treatment-emergent opioid symptoms or worsening of baseline symptoms.

Discussion

This case demonstrates the success of buprenorphine microdose induction despite very high doses of full agonist opioid overlap and demonstrates the ability to titrate buprenorphine microdoses faster than originally described. Strategies to overcoming implementation barriers are also discussed.
Estimating somatotype from a single‐camera 3D body scanning system
Authors: Chiu Chuang‐Yuan , Ciems Raimonds , Thelwell Michael , Bullas Alice , Choppin Simon
Published: May 2021

Somatotype is an approach to quantify body physique (shape and body composition). Somatotyping by manual measurement (the anthropometric method) or visual rating (the photoscopic method) needs technical expertize to minimize intra‐ and inter‐observer errors. This study aims to develop machine learning models which enable automatic estimation of Heath‐Carter somatotypes using a single‐camera 3D scanning system. Single‐camera 3D scanning was used to obtain 3D imaging data and computer vision techniques to extract features of body shape. Machine learning models were developed to predict participants' somatotypes from the extracted shape features. These predicted somatotypes were compared against manual measurement procedures. Data were collected from 46 participants and used as the training/validation set for model developing, whilst data collected from 17 participants were used as the test set for model evaluation. Evaluation tests showed that the 3D scanning methods enable accurate (mean error < 0.5; intraclass correlation coefficients >0.8) and precise (test‐retest root mean square error < 0.5; intraclass correlation coefficients >0.8) somatotype predictions. This study shows that the 3D scanning methods could be used as an alternative to traditional somatotyping approaches after the current models improve with the large datasets.
The need for a paradigm shift in the development of military exoskeletons
Authors: Mudie Kurt , Billing Daniel , Garofolini Alessandro , Karakolis Thomas , LaFiandra Michael
Published: May 2021

An exoskeleton is a body‐worn mechanical device designed to work in concert with the user to enhance human capabilities. For the dismounted close combatant, an exoskeleton could be worn whilst performing a variety of complex tasks and duties. As such, there is a requirement for the human and the exoskeleton to readily adapt to different movements in different contexts. There have been many attempts to design an exoskeleton to improve the performance of the complex adaptive human system with limited success. Despite a vast investment in time and resources, exoskeletons have not yet been adopted for operational use by military leadership for use by the dismounted close combatant as they are yet to demonstrate substantive augmentation to individual warfighter and collective team capability. We argue that a major limitation of current exoskeleton systems is their inability to concurrently adapt to the user, task and environment. Unless a device can meet this requirement, it is unlikely to offer a comparative benefit to the dismounted close combatant. This paper will present the state of the art of current exoskeleton technology, and recommend future research necessary to reach an acceptable standard of augmentation and thereby lead to widespread adoption.
Operando XAFS investigation on the effect of ash deposition on three-way catalyst used in gasoline particulate filters and the effect of the manufacturing process on the catalytic activity
Authors: Panchal Monik , Callison June , Skukauskas Vainius , Gianolio Diego , Cibin Giannantonio , York Andrew P E , Schuster Manfred E , Hyde Timothy I , Collier Paul , Catlow C Richard A , Gibson Emma K
Published: May 2021

Platinum group metals such as palladium and rhodium based catalysts are currently being implemented in gasoline particulate filter (GPF) autoexhaust after treatment systems. However, little is known about how the trapped particulate matter, such as the incombustible ash, interacts with the catalyst and so may affect its performance. This operando study follows the evolution of the Pd found in two different model GPF systems: one containing ash components extracted from a GPF and another from a catalyst washcoat prior to adhesion onto the GPF. We show that the catalytic activity of the two systems vary when compared with a 0 g ash containing GPF. Compared to the 0 g ash sample the 20 g ash containing sample had a higher CO light off temperature, in addition, an oscillation profile for CO, CO2 and O2 was observed, which is speculated to be a combination of CO oxidation, C deposition via a Boudouard reaction and further partial oxidation of the deposited species to CO. During the ageing procedure the washcoat sample reduces NO at a lower temperature than the 0 g ash sample. However, post ageing the 0 g ash sample recovers and both samples reduce NO at 310 °C. In comparison, the 20 g ash GPF sample maintains a higher NO reduction temperature of 410 °C post ageing, implying that the combination of high temperature ageing and presence of ash has an irreversible negative effect on catalyst performance.
The 2021 ultrafast spectroscopic probes of condensed matter roadmap
Authors: Lloyd-Hughes J , Oppeneer P M , Pereira dos Santos T , Schleife A , Meng S , Sentef M A , Ruggenthaler M , Rubio A , Radu I , Murnane M , Shi X , Kapteyn H , Stadtmüller B , Dani K M , da Jornada F H , Prinz E , Aeschlimann M , Milot R L , Burdanova M , Boland J , Cocker T , Hegmann F
Published: May 2021

In the 60 years since the invention of the laser, the scientific community has developed numerous fields of research based on these bright, coherent light sources, including the areas of imaging, spectroscopy, materials processing and communications. Ultrafast spectroscopy and imaging techniques are at the forefront of research into the light–matter interaction at the shortest times accessible to experiments, ranging from a few attoseconds to nanoseconds. Light pulses provide a crucial probe of the dynamical motion of charges, spins, and atoms on picosecond, femtosecond, and down to attosecond timescales, none of which are accessible even with the fastest electronic devices. Furthermore, strong light pulses can drive materials into unusual phases, with exotic properties. In this roadmap we describe the current state-of-the-art in experimental and theoretical studies of condensed matter using ultrafast probes. In each contribution, the authors also use their extensive knowledge to highlight challenges and predict future trends.
Multipole decomposition
of the general luminosity distance Hubble law — a new framework
for observational cosmology
Authors: Heinesen Asta
Published: May 2021

We present the luminosity distance series expansion to third order in redshift for a general space-time with no assumption on the metric tensor or the field equations prescribing it.
It turns out that the coefficients of this general Hubble law can be expressed in terms of a finite number of physically interpretable multipole coefficients. The multipole terms can be combined into effective direction dependent parameters replacing the Hubble constant, deceleration parameter, curvature parameter, and jerk parameter of the Friedmann-Lemaître-Robertson-Walker (FLRW) class of metrics.
Due to the finite number of multipole coefficients, the exact anisotropic Hubble law is given by 9, 25, 61 degrees of freedom in the 𝒪(z), 𝒪(z2), 𝒪(z3) vicinity of the observer respectively, where z:=redshift.
This makes possible model independent determination of dynamical degrees of freedom of the cosmic neighbourhood of the observer and direct testing of the FLRW ansatz.
We argue that the derived multipole representation of the general Hubble law provides a new framework with broad applications in observational cosmology.
New horizons of Space Qualification of Single-Walled Carbon Nano Tubes-Carbon Fibre Reinforced Polymer Composite
Authors: Vartak Dhaval , Ghotekar Yogesh , Deshpande Nandini , Munjal B.S. , Bhatt Pina , Satyanarayana B. , Vyas K.B. , Lal A.K.
Published: May 2021

The requirement of lightweight components for interplanetary missions explore the possibilities of the application of composite materials. Carbon Fibre Reinforced polymers (CFRP) are most practical and widely used in space industries. Enhancement of mechanical, thermal, and electrical properties by reinforcing CFRP with Carbon Nanotubes (CNTs) is advantageous, considering the potential applications of such a modified CFRP material in space payload. CNT composites for space use opens new horizons to improve specific stiffness and electrical conductivity of the CFRP components without degrading the performance index. Composite characterization and space qualification are critical and essential, which demonstrate the capability of fulfilling functional as well as specific requirements for space. CNT Composites have to undergo severe environmental tests without degradation. This paper addresses the synthesis of CNT-CFRP composites, its Characterisation and Space Qualification aspects. Synthesis of CNT-CFRP sample with single-walled CNT (Ø1.6µm & L>5µm) 0.5%wt by solution mixing method is attempted. The characterization in terms of measurement of tensile strength, electrical resistivity, shielding effectiveness, thermal conductivity, Co-efficient of thermal expansion (CTE) is carried out. Limited Space qualification on samples and electroplated coupons has been carried out by conducting various environmental tests. The results indicate that CNT reinforced CFRP composites are a promising potential candidate for use in the space domain.
Comparative study on the aerodynamic performance of airfoil with boundary layer trip of various geometrical shapes
Authors: Sreejith B. K. , Sathyabhama A. , Sandeep Kumar S.
Published: May 2021

Performance of small scale wind turbine (SSWT) and miniature aerial vehicles (MAV) is always effected with Laminar separation bubble. The problem of a laminar separation bubble on the upper surface of an E216 airfoil operated at low Reynolds number (Re=100000) is investigated numerically. Incompressible steady two-dimensional simulation is carried out with Transition γ − Reθ
turbulence model on the airfoil with a boundary layer trip (BLT). The performance of two different types of trips, namely, isosceles triangular (IT) and right-angled triangular (RA) is compared with that of the airfoil with a rectangular (RT) trip. The trip locations used are, 17% of the chord for location-1 and 10% of the chord for location-2 from the leading edge of the airfoil, while the trip heights selected are 0.3 mm, 0.5 mm, 0.7 mm, and 1 mm. Results showed that the boundary layer trip significantly affected the laminar separation and improved the aerodynamic performance of the airfoil. Maximum improvement in drag by 17.41% and corresponding lift to drag ratio by 10.86% are obtained for the isosceles trip at location-2 for the angle of attack of 6°. There is no observable advantage for isosceles and right-angled triangular trips over rectangular trips. Considering the geometrical complexity in fabrication, the rectangular trip is recommended.
Conductivity tensor in semiconductor with the presence of a laser field and an electromagnetic wave field for the case of scattering on ionized impurities
Authors: Ngoc Hoang Van
Published: May 2021

There are a lot of studies on semiconductors and in semiconductors also appear many dynamic effects, from the research results that have many applications in science and technology. Conductivity tensor is a familiar concept in physics in general and semiconductors in particular, but research on scattering on ionized impurities is still limited. This paper presents the influence of laser field and electromagnetic waves on conductivity tensor for the case of scattering on ionized impurities in semiconductor. The particle system is placed in an electromagnetic wave field and a laser field. Using quantum kinetic equations for electrons in semiconductor under the action of an electromagnetic wave field, a laser field, the conductivity tensor is calculated with case of scattering on ionized impurities. Conductivity tensor depends on the frequency of the laser field, the laser field amplitude, the electromagnetic wave frequency and typical parameters for semiconductor system. With different frequency bands, the dependence of tensor conductivity on the frequency is different, and the special conductivity tensor is strongly dependent on the amplitude of the laser field but depends very little on its frequency. The results will be plotted and discussed with GaAs semiconductor case and compared with studies for different scattering cases.
Analysis of Forced Convection heat transfer in laminar flow through a compact pipe filled with Nanofluids using CFD
Authors: Yaksha S J , Akash E , Sanjay U , Babali Balesh
Published: May 2021

In this paper, a Numerical investigation of developing laminar flows with forced convection through a compact circular pipe has been done using water-Al2O3 nano-fluid. Uniform heat flux (UHF) and the steady-state has been maintained at the wall in each model. Throughout the numerical experiments, Nano-fluid models were made by Alumina volume fraction and were processed under the Re=1050. A single-phase fluid model was determined by nano-fluid thermal and physical properties calculation, whereas the Two-phase model, i.e., granular mixture model was defined in 100nm diameter. The results show that the Al2O3 volume fraction increases, the heat transfer rate and Nusselt number increases. All the numerical simulations were developed in ANSYS FLUENT. The result displays the rise of thermal transfer from the volume fraction concentration.
Effective use of online Teaching-Learning Platform and MOOC for Virtual Learning
Authors: Yalagi Pratibha S. , Dixit Rashmi K. , Nirgude Manisha A.
Published: May 2021

The process of Teaching-Learning has evolved tremendously within the last 5-10 years. The mode of teaching is changed from normal blackboard classroom teaching to technological teaching. Due to the COVID-19 outbreak, the education system has been disrupted especially; it affects more for Higher Educational Institutes where students have come from various regions. The immediate lockdown in the country made the outside students reach their homes without any prior knowledge of its effects. Most of the education sector has switched to distance learning. Our institute has also adopted Virtual Learning. Various virtual platforms are available as the Learning Management System. We have adopted the use of ICT in education for the last 3-4 years. This helped us to handle the Teaching-Learning during a pandemic outbreak. We have used Moodle Learning Management System for Virtual Learning. Learners Centric MOOCs (LCM) model is implemented through LMS and the effectiveness is improved by adding Feedback and Assessment to it. The LCM model consists of structural elements: Learning Dialogs (LeD) in the form of short 10 to 12 minutes Videos, Learning by Doing (LbD) in the form of an assignment question or activity to do, Learning Experience Interactions (LxI) in the form reflection spot and discussion on the video provided and Learning Extension Trajectories (LxT) in the form of a small quiz on the video and resources. The major challenge for Virtual Learning is learner’s engagement. We have added feedback to improve the teaching-learning process. The model is effectively applied for Third Year Computer Science and Engineering class. The course of Compiler Construction is taken in to account for the implementation. A total of 73 students were involved in this activity. The results of feedback from students are satisfactory. More than 83% of the learners have given positive feedback towards this technological change of teaching. Learner’s engagement has improved to 30%.