bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary and Secondary Hyperparathyroidism in Patients with Primary
Aldosteronism – Findings From the German Conn’s
Registry
Authors: Asbach Evelyn , Bekeran Margareta , König Anna , Lang Katharina , Hanslik Gregor , Treitl Marcus , Ladurner Roland , Bidlingmaier Martin , Beuschlein Felix , Quinkler Marcus , Reincke Martin
Published: November 2019

Context Recent studies support a bidirectional interaction between
aldosterone and parathyroid hormone (PTH), possibly increasing the
individual cardiovascular risk. Primary aldosteronism (PA) and primary
hyperparathyroidism can occur simultaneously.

Objective Our aim was to investigate the prevalence of
hyperparathyroidism in PA.

Patients We performed a case finding of primary hyperparathyroidism
in a retrospective series of 503 patients with PA (cohort 1). We analysed
primary and secondary hyperparathyroidism in 141 prospective PA patients who
underwent PTH, serum calcium and phosphate measurements at time of diagnosis
of PA (cohort 2).

Results The prevalence for primary hyperparathyroidism was
1.2% in cohort 1, and 2.1% in cohort 2. Secondary
hyperparathyroidism was found in 54.6% of the patients. Patients
with secondary hyperparathyroidism had significantly higher aldosterone and
lower potassium levels and took more antihypertensive medications compared
to those with normal PTH levels. In multivariate analysis, aldosterone and
25-hydroxyvitamin D levels were significantly correlated with serum PTH
levels. There was a nonsignificant trend to a higher cardiovascular
morbidity in patients with secondary hyperparathyroidism. Patients with
aldosterone producing adenoma had significantly higher PTH levels compared
to patients with bilateral adrenal hyperplasia. After treatment, there was a
significant decrease of PTH levels in both groups.

Conclusion Patients with PA frequently have primary or secondary
hyperparathyroidism, which is alleviated by correction of PA by surgical or
medical means. Patients affected by secondary hyperparathyroidism seem to
have a more severe phenotype of PA and have a trend towards more
cardiovascular co-morbidities.
Construction of the ACDE Ring System of Calyciphylline A-type Alkaloids via Intramolecular Diels–Alder Reaction of a Tetrasubstituted Olefin
Authors: Nakamura Hugh , Kawakami Manami , Tsukano Chihiro , Takemoto Yoshiji
Published: November 2019

A concise synthesis of the ACDE tetracyclic ring system of calyciphylline A-type alkaloids was investigated. The intramolecular Diels–Alder reaction of a tetrasubstituted olefin with furan enabled the construction of the ACD ring system bearing two contiguous quaternary carbons in one step, and subsequent intramolecular [3+2] cycloaddition successfully gave the E ring.
Cobalt(III)-Catalyzed Diastereoselective Three-Component C–H Bond Addition to Butadiene and Activated Ketones
Authors: Shen Zican , Li Chen , Mercado Brandon Q. , Ellman Jonathan A.
Published: November 2019

A highly diastereoselective three-component C–H bond addition across butadiene and activated ketones is described. This transformation provides homoallylic tertiary alcohols through the formation of two C–C σ-bonds and with complete selectivity for an E-alkene isomer. The reaction exhibits good scope with respect to activated ketone inputs, including highly strained cyclic and electron-deficient cyclic and acyclic ketones. Additionally, high diastereoselectivities were achieved for alcohols prepared from unsymmetrical ketones.
Agreement and Reliability of Lateral Patellar Tilt and Displacement following Total Knee Arthroplasty with Patellar Resurfacing
Authors: Kleimeyer John P. , McQuillan Thomas J. , Arsoy Diren , Aggarwal Vinay K. , Amanatullah Derek F.
Published: November 2019

Patellar position and alignment may be measured on routine axial radiographs by various techniques; however, the agreement and reliability of such measurements with a resurfaced patella remain unknown. This study evaluated the range and reliability of lateral patellar tilt and lateral patellar displacement following total knee arthroplasty (TKA) with a resurfaced patella among three observers on 45° Merchant view in 139 TKAs. Intraclass correlation coefficient (ICCs) were used to evaluate intraobserver agreement (IOA) and inter-rater reliability (IRR). IRR was high between each of the observers for lateral patellar tilt (ICC = 0.8) and lateral patellar displacement (ICC = 0.87). IOA was also high upon repeat measurement for the same observer for lateral patellar tilt (ICC ≥ 0.90) and lateral patellar displacement (ICC ≥ 0.86). Therefore, lateral patellar tilt and lateral patellar displacement are reproducible measurements of patellar position on a Merchant axial radiograph following a well-functioning TKA with a resurfaced patella.
Ion hydration free energies and water surface potential in water nano drops: The cluster pair approximation and the proton hydration Gibbs free energy in solution
Authors: Houriez Céline , Réal Florent , Vallet Valérie , Mautner Michael , Masella Michel
Published: November 2019

We estimate both single ion hydration Gibbs free energies in water droplets, comprising from 50 to 1000 molecules, and water/vacuum surface potentials in pure water droplets comprising up to 10 000 molecules. We consider four ions, namely, Li+, NH4+, F−, and Cl−, and we model their hydration process and water/water interactions using polarizable force fields based on an induced point dipole approach. We show both ion hydration Gibbs free energies and water surface potentials to obey linear functions of the droplet radius as soon as droplets comprising a few hundred water molecules. Moreover, we also show that the differences in anion/cation hydration Gibbs free energies in droplets obey a different regime in large droplets than in small clusters comprising no more than six water molecules, in line with the earlier results computed from standard additive point charge force fields. Hence, both point charge and more sophisticated induced point dipole molecular modeling approaches suggest that methods considering only the thermodynamical properties of small ion/water clusters to estimate the absolute proton hydration Gibbs free energy in solution are questionable. In particular, taking into account the data of large ion/water droplets may yield a proton hydration Gibbs free energy in solution value to be shifted by several kBT units compared to small clusters-based approaches.
Dynamics of a toroidal pure electron plasma using 3D PIC simulations
Authors: Khamaru S. , Sengupta M. , Ganesh R.
Published: November 2019

Nonlinear dynamics of toroidally confined, initially cold, collisionless pure electron plasma has been numerically simulated in a tight aspect ratio, axisymmetric device, confined using a toroidal magnetic field, using a 3D3V particle-in-cell code PEC3PIC. A set of three numerical experiments are conducted by loading the toroidal electron cloud at varying radial distances from the central axis at the vertical midplane, and a comparative analysis of the progression of cloud dynamics and particle transport in the three experiments is carried out. In each experiment, the cloud is seen to initiate toroidal Diocotron oscillations with the following interesting features: (i) initial nonlinear reshaping and density peaking, (ii) elliptical orbital path in the poloidal cross section along with chirp or rotational frequency dynamics and the increase and decrease in the peak density of the filled electron cloud, (iii) cross-field transport and particle loss, and (iv) the measured wall probe signals showing close similarity to experimental signals. It is demonstrated that relatively better confinement of electrons in the toroidal configuration is achieved by loading the initial plasma at the vertical midplane, close to the inner wall of the chamber, supporting the mean-field theoretical predictions. For all cases, the density distribution profiles in the (r−θ) and (r − z) planes of the cylindrical coordinate system (r,θ,z) have consistent peaked density central profiles. The time dependency of the dominant frequencies of the dynamics, obtained from wall probe data using Hilbert–Huang transformation and windowed Fourier transformation, suggests toroidicity induced low poloidal number m (∼1−12) coupling and dynamical chirping.
Development of a novel line structured light measurement instrument for complex manufactured parts
Authors: Mei Junhua , Lai Lei-Jie
Published: November 2019

This paper studies a novel structured light measurement instrument for complex manufactured parts. In this research, a quick and accurate light plane calibration method and a novel light strip center extraction method were used to establish the measurement instrument. First, the intrinsic and external parameters of the camera are calibrated by Zhang’s method. Second, a novel light plane calibration technique is proposed by using the original parameters and images in the process of camera calibration, which can be used to improve the accuracy of the measurement system because both the camera calibration and light plane calibration are based on the same target. Third, a subpixel extraction method is presented to extract the light strip center on the basis of the geometric center method. Finally, the constructed instrument is used to detect the geometric information of the complex manufactured parts. The experimental results show that the maximum measurement error is 0.1 mm under a measurement range of 50 mm and the accuracy is 0.2%, which indicates that the measurement instrument is fast, robust, and accurate enough to be applied to many kinds of measurements, such as railroad track deformation, the inner wall of a pipe, and so on.
Excitation of IAWs by ions shear flow and electron parallel current in positive-negative ion plasma
Authors: Shan Shaukat Ali , Saleem H. , Shahzad K. , Rehman A.
Published: November 2019

It is pointed out that the criterion ωpe≪ωp+, ωp− (where ωpj is the plasma oscillation frequency of jth species and j = e, +, −) presented to define pure pair-ion plasma must also be fulfilled to ignore electron dynamics in positive-negative ion plasma. It is also suggested that the potassium (K+) plasma having negative ions of perfluoromethylcyclohexane (C7F14−) produced in Q-machine seems to have a significant number density of electrons; therefore, ion acoustic waves (IAW) may also exist. If T±<Te and ions have field-aligned shear flow, the fluid theory predicts that the IAWs will be excited. The dimensions of experimentally produced plasma are small; therefore, the local theory is applicable only approximately. Since observations show that Te≃T± in the laboratory performed experiments with positive-negative ions, the kinetic theory is also used to look for electron current-driven IAWs. Kinetic theory predicts that IAWs will be highly damped if electrons flow antiparallel to B0 in opposite direction with respect to positive ions. On the other hand, if electrons flow along B0 as is the case of ionospheric plasma, then IAWs become unstable. Thus, field-aligned shear flow of ions and parallel electron current can produce IAWs both in laboratory and astrophysical electron positive negative ion plasmas.
Strong edge-induced ferromagnetism in sputtered MoS2 film treated by post-annealing
Authors: Shirokura Takanori , Muneta Iriya , Kakushima Kuniyuki , Tsutsui Kazuo , Wakabayashi Hitoshi
Published: November 2019

We report edge-induced ferromagnetism in a sputtered molybdenum disulfide (MoS2) film having a long whole-edge length, with the effects of crystallinity improvement including edge reconstruction by sulfur vapor and argon annealing. Strong edge-induced ferromagnetism was observed by annealing, and its saturation magnetization of 13–26 emu/cc was larger than that of a chemical-vapor deposition sample with edge-induced ferromagnetism, as reported previously. Whereas both the annealing steps improved the crystallinity of the sputtered MoS2 film, argon annealing significantly enhanced the ferromagnetism. We conclude that the difference of the ferromagnetism enhancement between the sulfur and argon annealing steps is attributed to the edge reconstruction shape, which depends on the sulfur chemical potential.
A composite dynamic mode decomposition analysis of turbulent channel flows
Authors: Garicano-Mena J. , Li B. , Ferrer E. , Valero E.
Published: November 2019

In this contribution, we consider the Dynamic Mode Decomposition (DMD) framework as a purely data-driven tool to investigate both standard and actuated turbulent channel databases via Direct Numerical Simulation (DNS). Both databases have comparable Reynolds number Re ≈ 3600. The actuation consists in the imposition of a streamwise-varying sinusoidal spanwise velocity at the wall, known to lead to drag reduction. Specifically, a composite-based DMD analysis is conducted, with hybrid snapshots composed by skin friction and Reynolds stresses. A small number of dynamic modes (∼3–9) are found to recover accurately the DNS Reynolds stresses near walls. Moreover, the DMD modes retrieved propagate at a range of phase speeds consistent with those reported in the literature. We conclude that composite DMD is an attractive, purely data-driven tool to study turbulent flows. On the one hand, DMD is helpful to identify features associated with the drag, and on the other hand, it reveals the changes in flow structure when actuation is imposed.
Effect of glycerol on the mechanical and temperature-sensing properties of pectin films
Authors: Costanza Vincenzo , Bonanomi Luca , Moscato Giovanni , Wang Linghui , Choi Yeong Suk , Daraio Chiara
Published: November 2019

Temperature-sensitive films embedded in electronic skins (e-skins) can provide temperature feedback to robots, high-tech prostheses, and wearable devices for health care monitoring. Pectin-based films have shown a temperature response at least two orders of magnitude higher than previously reported temperature-sensing materials. However, they are not easily stretchable and tearable, which limit their applications as e-skins that require repetitive bending and mechanical stresses. Here, we show how the addition of glycerol as a plasticizer in the fabrication of pectin-based films improves their mechanical properties. We report how the enhancement of the mechanical performance is accompanied by a decrease in the temperature responsivity. Through thermogravimetric analysis, we show that this reduction in responsivity can be associated with water retention due to the addition of the plasticizer. The link between the water content and the temperature response demonstrates that a dehydrated status of pectin is crucial to record its high temperature responsivity. Combining electrical and thermal characterization with the tensile strength test, we estimate the optimal concentration of glycerol for improving the mechanical properties without compromising the temperature response of the pectin films.
Multi-scale dynamics at the glassy silica surface
Authors: Nguyen Huy A. , Liao Can , Wallum Alison , Lyding J. , Gruebele M.
Published: November 2019

Silica-based glass is a household name, providing insulation for windows to microelectronics. The debate over the types of motions thought to occur in or on SiO2 glass well below the glass transition temperature continues. Here, we form glassy silica films by oxidizing the Si(100) surface (from 0.5 to 1.5 nm thick, to allow tunneling). We then employ scanning tunneling microscopy in situ to image and classify these motions at room temperature on a millisecond to hour time scale and 50-pm to 5-nm length scale. We observe two phenomena on different time scales. Within minutes, compact clusters with an average diameter of several SiO2 glass-forming units (GFUs) hop between a few (mostly two) configurations, hop cooperatively (facilitation), and merge into larger clusters (aging) or split into smaller clusters (rejuvenation). Within seconds, Si–O–Si bridges connect two GFUs within a single cluster flip, providing a vibrational fine structure to the energy landscape. We assign the vibrational fine structure using electronic structure calculations. Calculations also show that our measured barrier height for whole cluster hopping at the glass surface (configurational dynamics) is consistent with the configurational entropy predicted by thermodynamic models of the glass transition and that the vibrational entropy for GFU flipping and configurational entropy for cluster hopping are comparable (on a per GFU basis).
Thermal transport in model copper-polyethylene interfaces
Authors: Ren Yuanyang , Wu Kai , Coker David F. , Quirke Nick
Published: November 2019

Thermal transport through model copper-polyethylene interfaces is studied using two-temperature nonequilibrium molecular dynamics. This approach treats electronic and phonon contributions to the thermal transport in the metallic region, but only phonon mediated transport is assumed in the polymer. Results are compared with nonequilibrium molecular dynamics simulations of heat transport in which only phonon contributions are incorporated. The influence of the phase of the polymer component (crystalline, amorphous, and lamella) and, where relevant, its orientation relative to the metallic interface structure is explored. These computational studies suggest that the thermal conductivity of the metal-polymer interface can be more than 40 times greater when the polymer chains of the lamella are oriented perpendicular to the interface than the situation when the interface is formed by an amorphous polymer or a crystalline polymer phase in which the chains orient parallel to the interface. The simulations suggest that the phonon contribution to the thermal conductivity of the copper region can be increased by as much as a factor of three when coupling between the electrons and phonons in the metal region is incorporated. This, combined with the explicit inclusion of the purely electronic component of the thermal transport in the metal region, can lead to a substantial increase in the heat flux promoted by the interface while maintaining a constant temperature drop. These simulation results have important implications for designing materials that have excellent electrical insulation properties but can also be highly effective in heat conduction.
Surface-enhanced spin current to charge current conversion efficiency in CH3NH3PbBr3-based devices
Authors: Sun Dali , Zhang Chuang , Kavand Marzieh , Wang Jingying , Malissa Hans , Liu Haoliang , Popli Henna , Singh Jaspal , Vardeny Shai R. , Zhang Wei , Boehme Christoph , Vardeny Z. Valy
Published: November 2019

Hybrid organic-inorganic perovskites have shown great promise for spintronic applications due to their large spin-orbit coupling induced by the Pb and halogen atoms. Particularly, the large observed surface-induced Rashba splitting in CH3NH3PbBr3 indicates efficient spin-current-to-charge-current (StC) conversion, which, however, has not been demonstrated yet. In this work, the StC conversion efficiency in ferromagnet/CH3NH3PbBr3-based devices is studied using the pulsed spin-pumping technique measured by the inverse spin Hall effect. We found that the StC conversion efficiency is anomalous in that it increases at small perovskite layer thickness. This indicates the existence of a surface-dominated StC mechanism such as the inverse Rashba-Edelstein effect. By inserting a thin LiF layer between the ferromagnet and the perovskite film, the StC conversion efficiency is greatly suppressed, validating the existence of a Rashba surface in the CH3NH3PbBr3 film.
An extended Kozeny-Carman-Klinkenberg model for gas permeability in micro/nano-porous media
Authors: Sabet Safa , Barisik Murat , Mobedi Moghtada , Beskok Ali
Published: November 2019

Gas transport in micropores/nanopores deviates from classical continuum calculations due to nonequilibrium in gas dynamics. In such a case, transport can be classified by the Knudsen number (Kn) as the ratio of gas mean free path and characteristic flow diameter. The well-known Klinkenberg correction and its successors estimate deviation from existing permeability values as a function of Kn through a vast number of modeling attempts. However, the nonequilibrium in a porous system cannot be simply modeled using the classical definition of the Kn number calculated from Darcy’s definition of the pore size or hydraulic diameter. Instead, a proper flow dimension should consider pore connectivity in order to characterize the rarefaction level. This study performs a wide range of pore-level analysis of gas dynamics with different porosities, pore sizes, and pore throat sizes at different Kn values in the slip flow regime. First, intrinsic permeability values were calculated without any rarefaction effect and an extended Kozeny-Carman model was developed by formulating the Kozeny-Carman constant by porosity and pore to throat size ratio. Permeability increased by increasing the porosity and decreasing the pore to throat size ratio. Next, velocity slip was applied on pore surfaces to calculate apparent permeability values. Permeability increased by increasing Kn at different rates depending on the pore parameters. While the characterization by the Kn value calculated with pore height or hydraulic diameter did not display unified behavior, relating permeability values with the Kn number calculated from the equivalent height definition created a general characterization based on the porosity independent from the pore to throat size ratio. Next, we extended the Klinkenberg equation by calculating unknown Klinkenberg coefficients which were found as a simple first order function of porosity regardless of the corresponding pore connectivity. The extended model as a combination of Kozeny-Carman for intrinsic permeability and Klinkenberg for apparent permeability correction yielded successful results.
Configuration dynamics of a flexible polymer chain in a bath of chiral active particles
Authors: Liu Xinshuang , Jiang Huijun , Hou Zhonghuai
Published: November 2019

We investigate the configuration dynamics of a flexible polymer chain in a bath of active particles with dynamic chirality, i.e., particles rotate with a deterministic angular velocity ω besides self-propulsion, by Langevin dynamics simulations in a two dimensional space. Particular attention is paid to how the radius of gyration Rg changes with the propulsion velocity v0, the angular velocity ω, and the chain length N. We find that in a chiral bath with a typical nonzero ω, the chain first collapses into a small compact cluster and then swells again with increasing v0, in quite contrast to the case for a normal achiral bath (ω = 0) wherein a flexible chain swells with increasing v0. More interestingly, the polymer can even form a closed ring if the chain length N is large enough, which may oscillate with the cluster if v0 is large. Consequently, the gyration radius Rg shows nontrivial nonmonotonic dependences on v0, i.e., it undergoes a minimum for relatively short chains and two minima with a maximum in between for longer chains. Our analysis shows that such interesting phenomena are mainly due to the competition between two roles played by the chiral active bath: while the persistence motion due to particle activity tends to stretch the chain, the circular motion of the particle may lead to an effective osmotic pressure that tends to collapse the chain. In addition, the size of the circular motion R0 = v0/ω plays an important role in that the compact clusters and closed-rings are both observed at nearly the same values of R0 for different ω.
Effect of soluble surfactant on the motion of a confined droplet in a square microchannel
Authors: Luo Zheng Yuan , Shang Xing Long , Bai Bo Feng
Published: November 2019

Surfactants are widely used in the manipulation of drop motion in microchannels, which is commonly involved in many applications, e.g., surfactant assisted oil recovery and droplet microfluidics. This study is dedicated to a crucial fundamental problem, i.e., the effects of a soluble surfactant on drop motion and their underlying mechanisms, which is an extension of our previous work of an insoluble-surfactant-covered droplet in a square microchannel [Z. Y. Luo, X. L. Shang, and B. F. Bai, “Marangoni effect on the motion of a droplet covered with insoluble surfactant in a square microchannel,” Phys. Fluids 30, 077101 (2018)]. We make essential improvements to our own three-dimensional front-tracking finite-difference model, i.e., by further integrating the equation governing surfactant transport in the bulk fluid and surfactant mass exchange between the drop surface and bulk fluid. We find that the soluble surfactant generally enlarges the droplet-induced extra pressure loss compared to the clean droplet, and enhancing surfactant adsorption tends to intensify such an effect. We focus specifically on the influences of four soluble-surfactant-relevant dimensionless parameters, including the Biot number, the dimensionless adsorption depth, the Damkohler number, and the bulk Peclet number. Most importantly, we discuss the mechanisms underlying the soluble surfactant effect, which consists of two aspects similar to the insoluble case, i.e., the reduced surface tension to decrease droplet-induced extra pressure loss and the enlarged Marangoni stress playing the opposite role. Surprisingly, we find that the enlarged Marangoni stress always makes the predominant contribution over the reduced surface tension in the effects of above-mentioned four soluble-surfactant-relevant dimensionless parameters on drop motion. This finding explains why the droplet-induced extra pressure loss increases with the film thickness, which is opposite to that observed for clean droplets.
Anisotropy-driven thermal conductivity switching and thermal hysteresis in a ferroelectric
Authors: Seijas-Bellido Juan Antonio , Íñiguez Jorge , Rurali Riccardo
Published: November 2019

We present a theoretical proposal for the design of a thermal switch based on the anisotropy of the thermal conductivity of PbTiO3 and the possibility to rotate the ferroelectric polarization with an external electric field. Our calculations are based on an iterative solution of the phonon Boltzmann Transport Equation and rely on interatomic force constants computed within an efficient second-principles density functional theory scheme. We also characterize the hysteresis cycle of the thermal conductivity in the presence of an applied electric field and show that the response time would be limited by the speed of the ferroelectric switch itself and thus the switch can operate in the high-frequency regime.
Stochasticity of the transfer of reactant molecules between nano-reactors affecting the reversible association A + B ⇆ C
Authors: Szymanski R. , Sosnowski S.
Published: November 2019

Theoretical analysis and computer simulations (Monte Carlo and numerical integration of differential equations) indicate that the statistical effect of a small number of reacting molecules is affected by transfer of reagent molecules between nanoreactors (droplets in this study). As a model reaction, a simple reversible association A + B ⇆ C was chosen, which was studied previously without reagent transfer processes. For sufficiently fast exchange of reactant molecules and a sufficiently high number of nanoreactors, the studied systems virtually do not differ from large volume systems if overall kinetics and thermodynamics of the chemical process are concerned. However, if either reagent molecule exchange is not fast or the number of exchanging nanoreactors is low, then the stochastic effect is clearly visible, influencing the kinetics of reaching reaction equilibrium. In systems with a low number of nanoreactors, the apparent (average) equilibrium constant is affected as well. The distribution of reactant molecules in the nanoreactors is governed by stochastic processes, dependent on stochastic rate constants of all processes, chemical as well as physical (transfer of molecules outside and into droplets). When accumulation of reactant molecules in the continuous phase cannot be neglected, then the partition coefficients of reactants between the continuous and dispersed phases have to be taken into account. Distributions of reactant molecules described in the paper for systems composed of few nanoreactors can be especially important for some biochemical processes in living cells or devised corresponding artificial reactors. If the reactant molecules predominate in a continuous phase, then the kinetics and overall conversion of reversible association may be significantly affected by the presence of the dispersed phase and its catalytic behavior can be observed. It has been shown that Monte Carlo simulations, applying a devised simple algorithm, give reliable results, allowing theoretical studies of nanoscale-droplet systems.
Inverse Henderson problem generalization fills gap for numerical simulations of soft matter
Authors: Johnson-Groh Mara
Published: November 2019

A new generalization of the inverse Henderson problem fills a gap that previously existed in the theoretical foundation for many bottom-up coarse-graining techniques employed in soft matter simulations.
Visible Light-Promoted C–C Bond Formation from Hydroxyaryls in Water
Authors: Saporito Dafne , Rodriguez Sergio A. , Baumgartner Maria T.
Published: November 2019

An eco-friendly and direct arylation of hydroxyaryls in water using photoinduced reactions with different substrates (1-bromo-2-naphthol, 1-iodo-2-naphthol, N-(2-iodophenyl)acetamide, 5-bromouracil, 2-iodo-N-methylbenzamide, and 2-iodobenzamide) was studied. For example, π-expanded coumarins, compounds with potential optical applications, were synthesized in very high yield, without the use of toxic reagents, in a one-pot reaction. In addition, we demonstrate that the irradiation source (halogen lamp) can be efficiently replaced by an LED without altering the reaction yield.
Potential Leptin Receptor Response Modifier Peptides
Authors: Otvos Jr Laszlo
Published: November 2019

Drug targets for the treatment of obesity and comorbidities represent an ever-renewable source of research opportunities worldwide. One of the earliest is the leptin–leptin receptor system that was discovered in the mid-1990s. Leptin, a satiety hormone, is overproduced in overweight patients but the protein is unable to cross the blood–brain barrier and remains inactive. Circulating high levels of leptin induces a series of conditions that would not be manifested without leptin overproduction, including various forms of cancer and inflammatory and cardiovascular diseases. Current pharmaceutical research focuses on improving the blood–brain barrier penetration of leptin receptor agonists and the development of monofunctional antagonists with broad spectrum therapeutic efficacies but without unwanted side effects. Designer peptides with their expanded chemical space as well as well controllable receptor binding and elimination properties slowly replace full-sized leptin products in the drug development pipeline.
Liquid chromatography-electrospray ionization-tandem mass spectrometric assay for d-aspartate N-methyltransferase activity in ark shells
Authors: Shibata Kimihiko , Hagiya Saho , Okawara Rena , Abe Katsumasa , Takahashi Shouji , Kera Yoshio
Published: November 2019

A liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the separation and quantification of the enantiomers of N-methylaspartate and N-methylglutamate, after derivatization with Nα-(5-fluoro-2,4-dinitrophenyl)-l-leucinamide was established. The time required for the LC-ESI-MS/MS analysis was within 20 min and the detection limit was approximately 10 fmol per injection, demonstrating that this method can be used for the rapid determination of d-aspartate N-methyltransferase activity in the ark shell clam Scapharca broughtonii.

Abbreviations: NMDA: N-methyl-d-aspartate; NMLA: N-methyl-l-aspartate; NMDG: N-methyl-d-glutamate; NMLG: N-methyl-l-glutamate; NMA: N-methylaspartate; NMG: N-methylglutamate; HPLC: high-performance liquid chromatography; SAM: S-adenosyl-l-methionine; OPA: o-phthalaldehyde; LC-ESI-MS/MS: liquid chromatography-electrospray ionization-tandem mass spectrometry; FDLA: Nα-(5-fluoro-2,4-dinitrophenyl)-l-leucinamide; FDAA: Nα-(5-fluoro-2,4-dinitrophenyl)-l-alaninamide; ESI: electrospray ionization; LC-ESI-MS: liquid chromatography-electrospray ionization-mass spectrometry; MS/MS: tandem mass spectrometry
Research on risk assessment technology of China’s railway ticket selling and reservation system
Authors: Zhao Yingming , Zhang Dedong , Li Jubao
Published: November 2019

Application of Internet ticketing in railway ticketing is increasingly critical and the corresponding security risk problem is more prominent with development of science and technology. This paper realized analysis of core risk factors of railway ticket selling and reservation system of China and presented a quantifiable risk assessment model with fuzzy mathematics basing on the characteristics of this system with good usability by experimental results.
A Simulation Platform for Vehicle Themal Management System
Authors: Xiaoke Du , Ke Lou
Published: November 2019

New challenges are arising in vehicle thermal managing systems as air-pollution and fuel consumption rules become more rigid. Therefore, automobile manufactures have to face more competitive pressure. The use of software and hardware-in-loop (HIL) simulation is essential to develop and validate new real-time applications of engine, air conditioner and battery thermal management systems. This paper presents a simulation platform developed to work in a joint-simulation approach of thermal system and control system. The joint-simulation platform functions in a closed loop integrating KULI and Matlab/Simulink, which make it possible to validate both the capacity of thermal system and new control policies without a real system controller at the same time. The steady-state performance of the simulator correlates well with the provided manufacturer’s curve. The simulation platform could provide substantial improvements to the thermal management system performance.
Research on Question Answering Technology Based on Bi- LSTM
Authors: Sun Xiaoya , Li Xinmeng
Published: November 2019

Question Answering (QA) is always the key issue in the Natural Language Process (NLP). This paper mainly researches the question answering model based on Bi-directional Long Short Term Memory networks (Bi-LSTM), with the use of the WebQA dataset to train the model. Experiment results show that ACC@1 in Bi-LSTM model is 55.00%, ACC@3 is 73.24%, and ACC@10 reaches to 86.64%. The Bi-LSTM model outperforms Best Match 25 (BM25) algorithm in all of the three metrics, which proves the superiority of Bi-LSTM model.
Design of Phased Array T/R Component Microsystem Based on Heterogeneous Integration Technology
Authors: en-da Liu , Hong-jiang Wu , yong-zhi Zhao
Published: November 2019

An X-band silicon-based 2×2 phased array T/R module was developed based on MEMS technology and three-dimensional heterogeneous integration technology such as through-silicon via (TSV). The module uses a transceiver integrated multifunction chip solution and is packaged in two layers of silicon: upper layer integrated low noise amplifier, power amplifier, switch, power modulation driver, PMOS and other chips; lower layer integrated multi-function chip, serial-to-parallel chip, logic operation chip. Two-layer silicon package are stacked by solder balls. The T/R module sample’s size is 20mm×20mm×3mm. The test results show that at 8-12GHz, the transmit power is higher than 29dBm, the transmit gain is 20dB, the receive gain is 29dB, the noise figure (NF) is 3dB, and the switch isolation is 37dB.
Research and Application of Recurrent Neural Network in Solar Radio Interference Filtering
Authors: Zhang Qiaoman , Li Xin , Du Qingfu , Zhao Yilong , Ji Shixin , Gao Changlin , Du Qingfu
Published: November 2019

The various interfering signals present in the space result in the inability to obtain a clean and clear solar radio dynamic spectrum, which affects the effective observation of solar radio burst events. At the data processing level, we propose a method for predicting and processing radio interference signals in solar radio burst events using recurrent neural network in deep learning. Firstly, the radio signal that satisfies the condition is selected by the amount of solar radio flux of all frequency channels at some moment, and then the position of the initial time of the burst event is located by using the variation curve of the solar radio flux with time under the single frequency channel. After that, the constructed recurrent neural network is used to predict the signal value of the radio in the burst area. Finally, according to the linear additivity of the signal, the value of the clean pure burst event is obtained by subtracting the predicted radio value from the original value of the burst area. The experimental results show that the proposed method can effectively remove the interference in the solar radio dynamic spectrum and preserve the effective information of the burst event to the greatest extent. This provides a new idea and research direction for deep learning in the anti-interference processing of astronomical big data.
The Application of Optimal Frequency Hopping Patterns in Telemetry Communication Systems
Authors: Li Tonghui , Yao Jianguo
Published: November 2019

In telemetry communication, it is crucial to establish correct frame synchronization, a scheme for applying optimal frequency hopping patterns to aerospace telemetry communication systems is proposed, and the architecture of the transceiver system is given. Compared to one-dimensional pseudo-random sequences, optimal frequency hopping patterns have ideal two-dimensional autocorrelation and cross-correlation performance, which can effectively reduce or eliminate the interference caused by delay and Doppler shift and solve the problem of unable to synchronize frames that is caused by low signal-to-noise ratio and strong interference.
Fault Diagnosis Technology of Rolling Bearing in Space Station
Authors: Dequan Yu , Wenbo Wu , Hongyong Fu , Yang Wang , Ke Wang
Published: November 2019

With the development of space station engineering, rolling bearings have been widely used in space station. Whether the bearing is healthy or not is related to the safety of the experimental facilities. Fault diagnosis of rolling bearings includes time domain analysis and frequency domain analysis. By analyzing bearing fault information, time-frequency information entropy is more representative as fault feature. Firstly, the vibration signal of acceleration sensor is decomposed by EEMD method, and the intrinsic mode function is obtained. The time-frequency information is obtained by Fourier transform, and the information entropy of the time-frequency information is calculated. Then, the fault feature is self-adaptive dimensionality reduction. Finally, the fault feature is trained by using support vector machine, and the data is tested. The experimental results show that the method can diagnose bearing fault with high accuracy.
Design and Implementation of Dynamic Expansion of Vehicle Real-Time Data Transmission Architecture Based on Kubernetes
Authors: Chen Chen , Cai Jianjun , Ren Nver , Li Kunhao
Published: November 2019

In order to deal with the overload problem of smart car server, a dynamic capacity expansion technology of vehicle real-time data transmission architecture based on Kubernetes cluster is proposed. The technology uses Docker to split the architecture into multiple micro-services, and uses the HPA feature of Kubernetes to periodically monitor server CPU resource utilization, trigger expansion rules, and automate the increase and decrease of nodes to achieve capacity expansion. It has been proved by experiments that the dynamic expansion technology of the real-time data transmission architecture based on Kubernetes can realize the dynamic expansion of the architecture. It solves a series of problems caused by server service overload caused by the sudden increase of data sent by the car in a short period of time, and ensures the stability of the service.
Derivations of transient thermal Green’s functions in three-dimensional general anisotropic media
Authors: Zhou Jiakuan , Han Xueli
Published: November 2019

In this paper, three-dimensional transient thermal Green’s functions in general anisotropic media are derived in relatively concise forms via the Radon transform. Both situations in full-space and half-space are provided. For the case in full-space, the governing equation of heat conduction problem in three-dimension is reduced to a similar one in one-dimension whose solution is existent. For the case in half-space, both Dirichlet and flux-free boundary conditions are considered, and the solutions are derived by an image method. Applying the inverse Radon transform to solutions in transform domain, Green’s functions in physical domain are subsequently expressed as an integral over a unit sphere. If written in terms of usual spherical coordinate, moreover, these solutions are regular integrals over finite intervals and can be evaluated easily and effectively. Numerical examples are presented to verify the accuracy and applicability of the present derivations, and to demonstrate the effects of distinguishing boundary conditions.
Real-time Training Model for Elderly People Balance Ability
Authors: Xue Jie , Wu Qiong , Mu Wenfei
Published: November 2019

Falling happens when people’s body (excluding feet) unexpectedly touches the ground, which causes serious injuries for old people. Therefore, it is of great significance to assessing old people’s balance characteristics and help them prevent form falling. Based on this, we constructed a feature extraction model and obtained 25 factors that have the greatest influence on body balance by our model. We found that the most influential parts mainly distribute on people’s trunk, left arm, right foot and head, which can be applied in further study of falling prevention and balance supervision.
Dual-band MIMO Antenna with Band-stop Decoupling Network
Authors: Liu Qi , Gao Peng
Published: November 2019

A dual-band MIMO antenna operating at 2.5 GHz and 5.8 GHz which can be used for WLAN application is presented in this paper. Simulation, fabrication and measurement are accomplished to verify the antenna performance. As a simplified design process, firstly a band-stop filtering network is presented to achieve port isolation. And a MIMO antenna is designed through appropriate adjustments. The antenna can provide more than 20 dB isolation at both operating frequencies.
Fast-Flux Detection Method Based on DNS Attribute
Authors: Wang Jiajia , Chen Yu
Published: November 2019

Fast-flux service network provides redirection/proxy services for a large number of malicious and illegal content based on botnet, and provides a high level of protection for botmaster. In this paper, a method is proposed to distinguish fast-flux service network from legal website. Firstly, the differences between the attributes of the above two are analyzed in detail, then the detection features are constructed, and decision tree algorithm is used to detect the existence of fast-flux service network.
A Novel Timing-based Network Covert Channel Detection Method
Authors: Lu Shoupu , Chen Zhifeng , Fu Guangxin , Li Qingbao
Published: November 2019

Network stealth events are endless, and covert timing channel is one of the most difficult means to prevent. In order to further improve the detection rate of covert timing channel, several typical network covert timing channel construction algorithms are analyzed. On the basis of the above analysis, a detection method based on IPDs multidimensional features was proposed in this paper. IPDs of covert timing channels from three dimensions: shape, change rule and data statistics are analyzed. Respectively, polarization feature, autocorrelation feature, clustering feature are proposed, and the three features are unified into a model. The threshold method is used to determine whether the channel to be detected is a normal channel. Experiments show that the method can detect the existing covert timing channel with less time cost and compared with the traditional detection method has a certain rate of improvement.
Variational Bayesian Method for Time-Varying Linear Prediction Modelling
Authors: Wan Hongjie , Zhang Haiyun
Published: November 2019

The speech signal is produced by vocal tract of human beings. The characterics of the vocal tract can be modelled by time varying linear prection analysis. In this paper, a hierarchical Bayesian model is proposed to model the time varying linear prediction model. Then Variational Bayesian method is used to estimate the parameters of the model. Experiments are carried out on real speech to demonstrate the performance of the proposed method.
Identification of Frequency Hopping Radiation Sources Based on the Feature of Ambiguity Function
Authors: Wang Shaobo , Qi Zisen , Yang Xin
Published: November 2019

Aiming at the problem that the traditional feature parameters are difficult to meet the fastness and effectiveness of frequency hopping radiation sources identification, a feature extraction method based on radar ambiguity function theory is proposed. The algorithm applies the radar ambiguity function theory to the identification of frequency hopping radiation sources. Firstly, the single pulse ambiguity function of each hop signal is calculated. Then the particle swarm optimization algorithm is used to extract the main ridge slice of ambiguity function of the signal (MRSAF). Based on the noise reduction processing of MRSAF and the stability of MRSAF envelope, the difference sum, difference maximum value and difference distribution entropy characteristics of MRSAF are extracted. The experimental results of fuzzy cluster mean (FCM) show that the extracted feature parameters can be used to identify signals with high accuracy under dynamic SNR conditions.
Research on the Countermeasures of College Students’ innovation and entrepreneurship development under the perspective of “Internet +”
Authors: Mei Han
Published: November 2019

“Internet +” innovation and entrepreneurship education is a new educational concept, and it is the inherent requirement of university education reform. In this paper, we take the cultivation of College Students’ “Internet +” innovation and entrepreneurship capabilities as the core, in-depth analysis of the major problems encountered by college students in “Internet +” innovation and entrepreneurship, and realize the profound educational reform from four levels of government, universities, enterprises and university students. Based on the evaluation index of graduate innovation and entrepreneurship education, this paper constructs an evaluation model of graduate innovation and entrepreneurship education based on analytic hierarchy process (AHP), which provides basis and reference criteria for the training and evaluation of graduate innovation and entrepreneurship education.
Research on Image Segmentation Method Based on Fuzzy Clustering
Authors: Feng Guilian
Published: November 2019

Image segmentation is to divide an image into several continuous non-overlapping regions with similar characteristics, such as gray level, color and texture information. Through image segmentation, we can extract specific objects from complex background. The image has great uncertainty and fuzziness. Traditional segmentation methods often fail to achieve ideal segmentation effect, which directly affects the subsequent target feature extraction and result analysis. However, the fuzzy theory can well describe the characteristics of the image. Therefore, more and more scholars have studied image segmentation and proposed various related segmentation methods. Firstly, this paper analyses the hierarchical structure of image engineering. Then, this paper analyses the basic concepts of the fuzzy clustering algorithm. Finally, this paper analyses the image segmentation effect of the fuzzy algorithm by experiments.