bluuebunny/crossref_metadata_2025 huggingface dataset:
Intersection of regulatory pathways controlling hemostasis and hemochorial placentation
Authors: Muto Masanaga , Chakraborty Damayanti , Varberg Kaela M. , Moreno-Irusta Ayelen , Iqbal Khursheed , Scott Regan L. , McNally Ross P. , Choudhury Ruhul H. , Aplin John D. , Okae Hiroaki , Arima Takahiro , Matsumoto Shoma , Ema Masatsugu , Mast Alan E. , Grundberg Elin , Soares Michael J.
Published: December 2021

Significance

Trophoblast cell–guided uterine spiral artery remodeling is a key event in successful hemochorial placentation. Connections between coagulopathies and diseases of placentation are compelling. Tissue factor pathway inhibitor (TFPI) is a prominent regulator of blood coagulation and an intriguing constituent of trophoblast cells situated at the uterine–placental interface. The actions of TFPI extend beyond controlling hemostasis and directly affect trophoblast cell development. TFPI facilitates the differentiation of rat and human trophoblast stem cells into the invasive/extravillous trophoblast cell lineage and promotes intrauterine trophoblast invasion and trophoblast-guided uterine spiral artery remodeling at the maternal–fetal interface. Thus, TFPI is a conserved regulator of a fundamental event determining the efficacy of the hemochorial placenta.
Conflict and cooperation in tick-host-pathogen interactions contribute to increased tick fitness and survival.
Authors: de la Fuente José , Villar Margarita
Published: December 2021

This expert opinion discusses the mechanisms of tick-host-pathogen interactions and how these mediate the adaptation of tick species to climate change and hosts while guaranteeing completion of tick and pathogen life cycles as well as their impact on the prevalence of ticks and tick-borne diseases under climatic change events. A spotlight is given on the impact of Anaplasma phagocytophilum infection on tick and human cells as well as the relationship between conflict and cooperation of tick-host-pathogen interactions and climate change.
Melting, melting pot - climate change and its impact on ticks and tick-borne pathogens in the Arctic.
Authors: Černý Jiří , Elsterová Jana , Culler Lauren
Published: December 2021

This expert opinion defines the Arctic and its ecological conditions for ticks and discusses the potential impact of climatic change on the abundance and distribution of ticks and associated tick-borne diseases.
Ticks and tick-borne pathogens in China.
Authors: Li Hao , Fang Li-Qun , Liu Wei
Published: December 2021

This expert opinion provides an overview of the type and distribution of tick species and emerging tick-borne pathogens in tick vectors and human beings (such as Anaplasma, Babesia, spotted fever group rickettsiae, Borrelia and viruses) in China and considers the potential influence of global warming and climate change.
Climate and the emergence of tick-borne disease in Canada.
Authors: Leighton Patrick , Lindsay L. Robbin , Ogden Nicholas
Published: December 2021

This expert opinion focuses on the impact of climatic change on the local densities of tick populations, transmission potential for tick-borne pathogens, the abundance of infected ticks in the environment and, ultimately, the human and animal health burden of tick-borne diseases in Canada.
Climate change, ticks and tick-borne pathogens in Northern Europe.
Authors: Pettersson John H. O.
Published: December 2021

This chapter focuses on the potential impacts of climate change on tick survival, reproduction and distribution as well as the prevalence of tick-borne pathogens in Northern Europe.
Domain wall between the Dirac sea and the ‘anti-Dirac sea’
Authors: Vergeles S N
Published: December 2021

It was shown in work (Vergeles 2021 Class. Quantum Grav.
38 085022) that in the theory of gravity coupled with the Dirac field, each state |λ⟩ has its own twin |λ; PT⟩, which is obtained by a discrete PT transformation. If in the state |λ⟩ the Dirac sea is filled, then in the state |λ; PT⟩ there is an ‘anti-Dirac’ filling (in terms of the state |λ⟩). It is important that the energies of these states are the same. Therefore, there may be domains with different filling of the Dirac sea. Here we study a domain wall connecting two such adjacent domains.
Pythagorean means: thermodynamic examples
Authors: Anacleto Joaquim
Published: December 2021

We present the definitions of the Pythagorean means—arithmetic, geometric, and harmonic—and discuss some examples from thermodynamics where these means are found. This paper has a pedagogical character and highlights the close connection between mathematics and physics.
The superconducting transition and mixed state of YBa2Cu3O6.95: an undergraduate experiment
Authors: Huang Zhongda , Tong Yihang , Bobowski Jake S
Published: December 2021

We describe a simple AC susceptometer built in-house that can be used to make high-resolution measurements of the magnetic susceptibility of high-temperature superconductors in an undergraduate physics lab. Our system, cooled using liquid nitrogen, can reach a base temperature of 77 K. Our apparatus does not require gas handling systems or PID temperature controllers. Instead, it makes use of a thermal circuit that is designed to allow the sample to cool on a time scale that is suitable for an undergraduate lab. Furthermore, the temperature drift rate at the superconducting transition temperature T
c is low enough to allow for precise measurements of the complex magnetic susceptibility through T
c, even for single-crystal samples with exceedingly sharp superconducting transitions. Using an electromagnet, we were able to apply static magnetic fields up to 63 mT at the sample site. By measuring the change in susceptibility as a function of the strength of an applied of static magnetic field, we were able to estimate the lower critical field H
c1 of a single-crystal sample of optimally-doped YBa2Cu3O6.95 at 77 K. We also investigated the mixed state of a sintered polycrystalline sample of YBa2Cu3O6+y
.
Development of droplet microfluidics capable of quantitative estimation of single-cell multiplex proteins
Authors: Yang Hongyu , Yang Guang , Zhang Ting , Chen Deyong , Wang Junbo , Chen Jian
Published: December 2021

This study presented constriction microchannel based droplet microfluidics realizing quantitative measurements of multiplex types of single-cell proteins with high throughput. Cell encapsulation with evenly distributed fluorescence labelled antibodies stripped from targeted proteins by proteinase K was injected into the constriction microchannel with the generated fluorescence signals captured and translated into protein numbers leveraging the equivalent detection volume formed by constriction microchannels in both droplet measurements and fluorescence calibration. In order to form the even distribution of fluorescence molecules within each droplet, the stripping effect of proteinase K to decouple binding forces between targeted proteins and fluorescence labelled antibodies was investigated and optimized. Using this microfluidic system, binding sites for beta-actin, alpha-tubulin, and beta-tubulin were measured as 1.15 ± 0.59 × 106, 2.49 ± 1.44 × 105, and 2.16 ± 1.01 × 105 per cell of CAL 27 (N
cell = 15 486), 0.98 ± 0.58 × 106, 1.76 ± 1.34 × 105 and 0.74 ± 0.74 × 105 per cell of Hep G2 (N
cell = 18 266). Neural net pattern recognition was used to differentiate CAL 27 and Hep G2 cells, producing successful rates of 59.4% (beta-actin), 64.9% (alpha-tubulin), 88.8% (beta-tubulin), and 93.0% in combination, validating the importance of quantifying multiple types of proteins. As a quantitative tool, this approach could provide a new perspective for single-cell proteomic analysis.
Polarization control of attosecond pulses using bi-chromatic elliptically polarized laser
Authors: Rajpoot Rambabu , Holkundkar Amol R , Bandyopadhyay Jayendra N
Published: December 2021

We study the high harmonic generation (HHG) using elliptically polarized two-color driving fields. The HHG via bi-chromatic counter-rotating laser fields is a promising source of circularly polarized ultrashort XUV radiation at the attosecond time scale. The ellipticity or the polarization of the attosecond pulses (APs) can be tweaked by modifying the emitted harmonics’ ellipticity, which can be controlled by varying the driver fields. A simple setup is used to control the polarization of the driving fields, which eventually changes the ellipticity of the APs. A well-defined scaling for the ellipticity of the AP as a function of the rotation angle of the quarter-wave plate is also deduced by solving the time-dependent Schrödinger equation in two dimensions. The scaling can further be explored to obtain the APs of the desired degree of polarization, ranging from linear to elliptical to circular polarization.
Low energy electron scattering from pyridine using a Surko trap and beam
Authors: Stevens D , Babij T J , Machacek J R , Sullivan J P
Published: December 2021

This paper presents measurements of low energy electron scattering from pyridine. The low energy positron beamline at the Australian National University was used for these measurements, with a change in operational parameters allowing for the measurement of electron scattering processes. We have collected data for the low energy total cross section for electron scattering, as well as measurements of the differential cross sections for electrons up to 3 eV impact energy. The operation of the beamline will be briefly outlined and data are compared to R-matrix and Schwinger multichannel theoretical calculations, as well as previous experimental data.
Modulation and optimization of terahertz absorption in micro-cavity quantum well structures by graphene grating
Authors: Li Zhiguo , Zhao Qiang , Chen Pingping , Wang Jiqing
Published: December 2021

Metal–insulator–metal-based plasmonic microcavities have attracted widespread interest due to their ability to manipulate and concentrate photons on the sub-wavelength scale. However, noble metals suffer from large intrinsic loss and lack active tunability. Here, a micro-cavity structure of a quantum well sandwiched between a periodic top contact of graphene grating and a bottom contact of graphene is proposed. Graphene plasmons provide a suitable alternative for metal plasmons and have the advantage of being highly tunable by electrostatic gating. The effect of changes in both the physical graphene and the device’s structural parameters on optimized absorption performance is systematically analyzed through the calculation of reflectivity curves of incident light. Our results indicate that the intersubband absorption of the device can be improved by adjusting the parameters of both the graphene material and the device structure. Furthermore, the cavity resonant mode excited by surface plasmon polaritons can be tuned to the response frequency of the quantum well under optimized parameters. Intersubband absorption is almost 1.5 times higher than that of a micro-cavity structure that uses metal grating.
Spatiotemporally resolved measurements of electric field around a piezoelectric transformer using electric-field induced second harmonic (E-FISH) generation
Authors: Yang Jinyu , Barnat Edward V , Im Seong-kyun , Go David B
Published: December 2021

When a piezoelectric transformer (PT) is actuated at its second harmonic frequency by a low input voltage, the generated electric field at the distal end can be sufficient to breakdown the surrounding gas, making them attractive power sources for non-equilibrium plasma generation. Understanding the potential and electric field produced in the surrounding medium by the PT is important for effectively designing and using PT plasma devices. In this work, the spatiotemporally resolved characteristics of the electric field generated by a PT operating in open air have been investigated using the femtosecond electric field-induced second harmonic generation (E-FISH) method. Electric field components were determined by simultaneously conducting E-FISH measurements with the incident laser polarized in two orthogonal directions relative to the PT crystal. Results of this work demonstrate the spatial distribution of electric field around the PT’s output distal end and how it evolves as a function of time. Notably, the strongest electric field appears on the face of the PT’s distal surface, near the top and bottom edges and decreases by approximately 70% over 3 mm. The time delay between the PT’s input voltage and measured electric field indicates that there is an about 0.45π phase difference between the PT’s input voltage and output signal.
Defect characterization of heavy-ion irradiated AlInN/GaN on Si high-electron-mobility transistors
Authors: Challa S R , Witte H , Schmidt G , Bläsing J , Vega N , Kristukat C , Müller N A , Debray M E , Christen J , Dadgar A , Strittmatter A
Published: December 2021

The characteristic energies of traps in InAlN/AlN/GaN high-electron mobility transistor structures on Si(111) substrates formed after irradiation with 75 MeV S-ions are studied by means of c-lattice parameter analysis, vertical IV-characteristics, micro-photoluminescence (µ-PL), photocurrent (PC) and thermally stimulated current (TSC) spectroscopy. From the lattice parameter analysis, point defect formation is concluded to be the dominant source of defects upon irradiation. A strong compensation effect manifests itself through enhanced resistivity of the devices as found in vertical IV-measurements. Defect formation is detected optically by an additional PL-band within the green spectral region, while defect states with threshold energies at 2.9 eV and 2.65 eV were observed by PC spectroscopy. The TSC spectra exhibit two defect-related emissions between 300 K and 400 K with thermal activation energies of 0.78–0.82 eV and 0.91–0.98 eV, respectively. The data further supports the formation of Ga vacancies (V
Ga) and related complexes acting mainly as acceptors compensating the originally undoped n-type GaN buffer layers after irradiation.
Plasma degradation of trichloroethylene: process optimization and reaction mechanism analysis
Authors: Chang Tian , Ma Chuanlong , Nikiforov Anton , Veerapandian Savita K P , De Geyter Nathalie , Morent Rino
Published: December 2021

In this study, a multi-pin-to-plate negative corona discharge reactor was employed to degrade the hazardous compound trichloroethylene (TCE). The response surface methodology was applied to examine the influence of various process factors (relative humidity (RH), gas flow rate, and discharge power) on the TCE decomposition process, with regard to the TCE removal efficiency, CO2 and CO selectivities. The variance analysis was used to estimate the significance of the single process factors and their interactions. It has been proved that the discharge power had the most influential impact on the TCE removal efficiency, CO2 and CO selectivities and subsequently the gas flow rate, and finally RH. Under the optimal conditions with 20.83% RH, 2 W discharge power and 0.5 l min–1 gas flow rate, the optimal TCE removal efficiency (86.05%), CO2 selectivity (8.62%), and CO selectivity (15.14%) were achieved. In addition, a possible TCE decomposition pathway was proposed based on the investigation of byproducts identified in the exhaust gas of the non-thermal plasma reactor. This work paves the way for control of chlorinated volatile organic compounds.
Fast magnetization reversal of a magnetic nanoparticle induced by cosine chirp microwave field pulse
Authors: Islam Md. Torikul , Akanda Md. Abdus Sami , Pikul Md. Abu Jafar , Wang Xiansi
Published: December 2021

We investigate the magnetization reversal of single-domain magnetic nanoparticle driven by the circularly polarized cosine chirp microwave pulse (CCMP). The numerical findings, based on the Landau–Lifshitz–Gilbert equation, reveal that the CCMP is by itself capable of driving fast and energy-efficient magnetization reversal. The microwave field amplitude and initial frequency required by a CCMP are much smaller than that of the linear down-chirp microwave pulse. This is achieved as the frequency change of the CCMP closely matches the frequency change of the magnetization precession which leads to an efficient stimulated microwave energy absorption (emission) by (from) the magnetic particle before (after) it crosses over the energy barrier. We further find that the enhancement of easy-plane shape anisotropy significantly reduces the required microwave amplitude and the initial frequency of CCMP. We also find that there is an optimal Gilbert damping for fast magnetization reversal. These findings may provide a pathway to realize the fast and low-cost memory device.
Observation of possible nonlinear anomalous Hall effect in organic two-dimensional Dirac fermion system
Authors: Kiswandhi Andhika , Osada Toshihito
Published: December 2021

We report the observation of nonlinear anomalous Hall effect (NLAHE) in the multilayered organic conductor α-(BEDT-TTF)2I3 in the charge order (CO) insulating phase just under the critical pressure for transition into two-dimensional (2D) massless Dirac fermion (DF) phase. We successfully extracted the finite nonlinear Hall voltage proportional to square current at zero magnetic field. The observed NLAHE features, current direction dependence and correlation with CO, are consistent with the previous estimation assuming 2D massive DF with a pair of tilted Dirac cones. This is the first observation of topological transport in organic conductors, and also the first example of NLAHE in the electronic phase with spontaneous symmetry breaking.
Study on the relationship between uniaxial strain and critical transition temperature of MgB2 based on first-principles
Authors: Yang Yong , Yue Tianbao , Wang Shenglong
Published: December 2021

It has been indicated the critical transition temperature (T
c) of MgB2 decreases with the increase of hydrostatic pressure, but this is a comprehensive T
c change after the multiaxial strain, and the influence of strain on T
c is not fully understood. In this paper, based on the McMillan superconducting calculation formula and the first-principles density functional theory, the T
c change and the properties of MgB2 such as energy band, Fermi surface, differential charge density, and phonon dispersion under uniaxial strain were studied, and the relationship between uniaxial strain and these properties was analyzed. The calculated T
c of MgB2 at zero strain was 38.35 K, which is in good agreement with the experimental value of 39 K. When the a-axis strain was 1%, the T
c value could increase to 49.7 K, and there was a further improvement trend. When the a-axis compression strain was −1%, T
c decreases to 31.52 K. When the c-axis tension–compression strain was applied, the change of T
c value was small. Further analysis showed that the impact of a-axis strain on the differential charge density, electronic band structure, phonon dispersion, and other properties of MgB2 was significantly greater than that of c-axis strain, and the influence of these properties on T
c was discussed. The work in this paper has certain theoretical and guiding significance for preparing MgB2 with higher T
c and the study of the effect of uniaxial strain on T
c of superconducting materials.
Calibration model and numerical simulation of a 7-hole probe based on pressure–velocity parameterization equation
Authors: Yao Tao , Zhou Shu-dao , Wang Min , Zhang Yang-chun , Ye Song
Published: December 2021

As a sensor of a flow field detection system, a 7-hole probe can detect the flow field velocity and retrieve three-dimensional (3D) information of the flow field. Owing to its simple structure and strong environmental adaptability, it is particularly important to calibrate it when it is widely used in turbine machinery, aerospace, and other fields. To detect the 3D flow field in the middle atmosphere, a novel calibration method based on the potential flow theory is designed using a hemispherical 7-hole probe. The hemispherical 7-hole probe was numerically calibrated through numerical simulation, and the coefficients of the calibration equation are provided. In comparison with the traditional 7-hole probe calibration method, the calibration process is significantly shortened while maintaining good measurement accuracy. The velocity error was less than 5% and the angle error was approximately 0.5°.
A surface roughness grade recognition model for milled workpieces based on deep transfer learning
Authors: Su Jinzhao , Yi Huaian , Ling Lin , Wang Shuai , Jiao Yanming , Niu Yilun
Published: December 2021

Many roughness measurement methods rely on designed feature indexes that cannot accurately characterize the roughness and are demanding on the workpiece imaging environment. Roughness measurement methods based on deep neural networks require huge numbers of training samples and the same data distribution for training samples and testing samples, which makes it difficult to achieve wide application in the machining industry. Deep AlexCORAL, a surface roughness grade recognition model for milled workpieces based on deep transfer learning, is proposed in this paper to automatically extract more general roughness-related features. It not only reduces the amount of data required by the model but also the difference in data distribution between the source domain (training set) and the target domain (testing set). The experimental results show that Deep AlexCORAL has 99.33% cross-domain recognition accuracy in a variety of cases with inconsistent data distribution due to various lighting environments. This is unmatched by other roughness grade recognition models.
Compressive nano-FTIR chemical mapping
Authors: Wübbeler Gerd , Marschall Manuel , Rühl Eckart , Kästner Bernd , Elster Clemens
Published: December 2021

Nano-Fourier-transform infrared spectroscopy (nano-FTIR) combines infrared spectroscopy with scanning probe microscopy (SPM) techniques and enables spectroscopic imaging of molecular and electronic properties of matter at nanometer spatial resolution. The spectroscopic imaging can be used to derive chemical mappings, i.e. the spatial distribution of concentrations of the species contained in a given sample. However, due to the sequential scanning principle underlying SPM, recording the complete spectrum over a large spatial area leads to long measurement times. Furthermore, the acquired spectrum often contains additional signals from species and lineshape effects that are not explicitly accounted for. A compressive chemical mapping approach is proposed for undersampled nano-FTIR data that utilizes sparsity of these additional signals in the spectral domain. The approach combines a projection technique with standard compressed sensing, followed by a spatially regularized regression. Using real nano-FTIR measurements superimposed by simulated interferograms representing the chemical mapping of the contained species, it is demonstrated that the proposed procedure performs well even in cases in which the simulated interferograms and the sparse additional signals exhibit a strong spectral overlap.
Recent developments on an interferometric multilateration measurement system for large volume coordinate metrology
Authors: Rafeld Eva Katharina , Koppert Nils , Franke Matthias , Keller Frank , Heißelmann Daniel , Stein Martin , Kniel Karin
Published: December 2021

A mobile multilateration measurement system developed at the Physikalisch-Technische Bundesanstalt (PTB) around 2010 has been thoroughly investigated and refined to gain better performance with smaller uncertainties even when applied to the calibration of large complex workpieces. The mathematical background of multilateration and the propagation of uncertainties for the algorithms involved is explained in detail. Using the example of simple 1D and 2D measuring tasks, the influence of certain parameters characterizing the setup of the measurement system on the overall uncertainty is quantified. A strategy is developed to incorporate multi-stylus measurements which are often inevitable when workpieces feature complex shapes. The findings are verified on a large involute gear which is 2 m in diameter. All measurements are performed on PTB’s large coordinate measuring machine with a working range of

5
 

m

×
4
 

m

×
2
 

m

.
V2O5/NaV6O15 nanocomposites synthesized by molten salt method as a high-performances cathode material for aqueous zinc-ion batteries
Authors: Ran Yan , Hong Ping , Ren Jie , Wang Bingsen , Xiao Mingjing , Chen Yunhua , Xiao Xuechun , Wang Yude
Published: December 2021

Aqueous zinc-ion batteries (ZIBs) is a potential energy storage system due to its advantages of low cost, good safety, and high theoretical capacity (820 mAh g−1). However, the lack of cathode materials with long cycle stability severely restricts the development of ZIBs. In this paper, V2O5/ NaV6O15 nanocomposites are synthesized by molten salt method in one step and used as cathode material for ZIBs, which have good electrochemical performances. The specific capacity of the materials remain 160 mAh g−1 when the current density is 0.5 A g−1 after 1000 cycles, and the capacity retention rate is 102.03% when the current density is 5 A g−1 for 1000 cycles. This is mainly due to the large number of active sites generated by crystal defects and the synergistic interaction between the dual-phase materials, which reduces the stress of ions inserted/extracted during the Zn2+ storage process and improves the electrochemical performance.
Designing polymer coatings for lithium metal protection
Authors: Zhou Hongyao , Liu Ping
Published: December 2021

Protection of lithium metal has been one of the great challenges to realize a long-life, high-energy-density battery. Polymer coatings on lithium metal surface have been proven to be an effective protection method in terms of improved morphology, higher coulombic efficiency, and a longer cycle life. However, there is a variety of design principles of polymer coatings proposed by the research community, and the influence of polymer swelling in liquid electrolytes remains poorly understood. Herein we use crosslinking density and solvent–polymer interaction to quantitatively explain the mechanical property and the ion-transport property of polymer coatings when swollen in liquid electrolytes. Low crosslinking density is beneficial for reducing the rigidity and enhancing the viscosity of the polymer. Ion conductivity increases with the swelling ratio, and activation energy of lithium-ion transport increases in a polar polymer with strong ion–polymer coupling. We propose that polymer coatings must be combined with the emerging electrolytes with unconventional solvent compositions to realize a practical high-performance lithium metal battery. This study can provide design guidelines for polymer coatings through the optimized interactions with upcoming high-performance electrolytes.
Precise strain mapping of nano-twinned axial ZnTe/CdTe hetero-nanowires by scanning nanobeam electron diffraction
Authors: Kryvyi Serhii , Kret Slawomir , Wojnar Piotr
Published: December 2021

The occurrence of strain is inevitable for the growth of lattice mismatched heterostructures. It affects greatly the mechanical, electrical and optical properties of nano-objects. It is also the case for nanowires which are characterized by a high surface to volume ratio. Thus, the knowledge of the strain distribution in nano-objects is critically important for their implementation into devices. This paper presents an experimental data for II-VI semiconductor system. Scanning nanobeam electron diffraction strain mapping technique for hetero-nanowires characterized by a large lattice mismatch (>6% in the case of CdTe/ZnTe) and containing segments with nano-twins has been described. The spatial resolution of about 2 nm is 10 times better than obtained in synchrotron nanobeam systems. The proposed approach allows us to overcome the difficulties related to nanowire thickness variations during the acquisition of the nano-beam electron diffraction data. In addition, the choice of optimal parameters used for the acquisition of nano-beam diffraction data for strain mapping has been discussed. The knowledge of the strain distribution enables, in our particular case, the improvement of the growth model of extremely strained axial nanowires synthetized by vapor-liquid solid growth mechanism. However, our method can be applied for the strain mapping in nanowire heterostructures grown by any other method.
Interference-free SERS nanoprobes for labeling and imaging of MT1-MMP in breast cancer cells
Authors: Zhu Dan , Li Anran , Di Yunsong , Wang Zhuyuan , Shi Jingzhan , Ni Xiaoqi , Wang Yiping
Published: December 2021

The expression of membrane type-1 matrix metalloproteinase (MT1-MMP) in cancer cells is critical for understanding the development, invasion and metastasis of cancers. In this study, we devised an interference-free surface-enhanced Raman scattering (SERS) nanoprobe with high selectivity and specificity for MT1-MMP. The nanoprobe was comprised of silver core-silica shell nanoparticle with a Raman reporter tag (4-mercaptobenzonitrile) embedded in the interface. Moreover, the nitrile group in 4-mercaptobenzonitrile shows a unique characteristic peak in the Raman-silent region (1800–2800 cm−1), which eliminates spectral overlapping or background interference in the Raman fingerprint region (500–1800 cm−1). After surface modification with a targeting peptide, the nanoprobe allowed visualization and evaluation of MT1-MMP in breast cancer cells via SERS spectrometry. This interference-free, peptide-functionalized SERS nanoprobe is supposed to be conducive to early diagnosis and invasive assessment of cancer in clinical settings.
One-pot synthesis of double silane-functionalized carbon dots with tunable emission and excellent coating properties for WLEDs application
Authors: Cao Wenbing , Wu Yuhan , Li Xin , Jiang Xuanfeng , Zhang Yuhong , Zhan Yuan , Sun Zhengguang
Published: December 2021

Silane-functionalized carbon dots (SiCDs) can be exploited as effective color converting materials for the solid-state light-emitting devices. However, most of SiCDs reported thus far have shown photoluminescence emissions in the blue and green spectral range, which limit them to construct an efficient white light-emitting diodes (WLEDs) due to the lack of long-wavelength emission. Herein, a series of double silane-functionalized carbon dots (DSiCDs) were prepared via a one-step solvothermal method. The results show that the organic functional group of the silane has great influence on the optical properties of DSiCDs and the number of alkoxy group in the silane has great influence on coating properties of DSiCDs. In addition, the DSiCDs prepared by (3-aminopropyl)triethoxysilane and N-[3-(trimethoxysilyl)propyl]ethylenediamine with molar ratio of 7:3 show excellent optical properties with the maximum emission at 608 nm under 570 nm excitation. Furthermore, they can be completely cured within 1 h at room temperature to form fluorescent coating with high stability and strong adhesion to the substrate. Together with their excellent optical and coating properties, they can be directly coated on LED chips to prepare WLEDs, with a CIE coordinate of (0.33,0.31), color rendering index of 81.6, and color temperature of 5774 K.
How high is a MoSe2 monolayer?
Authors: Cowie Megan , Plougmann Rikke , Benkirane Yacine , Schué Léonard , Schumacher Zeno , Grütter Peter
Published: December 2021

Transition metal dichalcogenides (TMDCs) have attracted significant attention for optoelectronic, photovoltaic and photoelectrochemical applications. The properties of TMDCs are highly dependent on the number of stacked atomic layers, which is usually counted post-fabrication, using a combination of optical methods and atomic force microscopy height measurements. Here, we use photoluminescence spectroscopy, Raman spectroscopy, and three different AFM methods to demonstrate significant discrepancies in height measurements of exfoliated MoSe2 flakes on SiO2 depending on the method used. We also highlight the often overlooked effect that electrostatic forces can be misleading when measuring the height of a MoSe2 flake using AFM.
Retracted: Zeptomolar detection of 4-aminothiophenol by SERS using silver nanodendrites decorated with gold nanoparticles
Authors: Ceballos Manuel , López Israel , Arizmendi-Morquecho Ana , Sánchez-Domínguez Margarita
Published: December 2021

In the present work, we report a simple, fast, reproducible and cheap methodology for SERS substrate fabrication of silver dendritic nanostructures (prepared by electrodeposition) decorated with gold nanospheres by electrophoretic deposition. This is the first report where a metal dendritic nanostructure has been decorated with another type of metal nanoparticles by this technique. The decorated nanostructures were used directly as SERS substrate using 4-aminothiophenol (4-ATP) as analyte. The objective of the decoration is to create more hot-spots in order to detect the analyte in a lower concentration. Decorated nanodendrites had a detection limit one million times lower than bare silver nanodendrites and all the substrates showed an increase in the Raman intensity at concentrations below 1 nM; because this concentration corresponds to the threshold for the formation of a monolayer resulting in a triple mechanism of intensity increase, namely electric field, chemical factor and hot-spots. 4-ATP was detected in zeptomolar concentration, which is below 1 ppq, corresponding to an analytical enhancement factor in the order of 1015.
Numerical study of silicon vacancy color centers in silicon carbide by helium ion implantation and subsequent annealing
Authors: Fan Yexin , Song Ying , Xu Zongwei , Wu Jintong , Zhu Rui , Li Qiang , Fang Fengzhou
Published: December 2021

Molecular dynamics simulation is adopted to discover the formation mechanism of silicon vacancy color center and to study the damage evolution in 4H-SiC during helium ion implantation with different annealing temperatures. The number and distribution of silicon vacancy color centers during He ion implantation can be more accurately simulated by introducing the ionization energy loss during implantation. A new method for numerical statistic of silicon vacancy color centers is proposed, which takes into account the structure around the color centers and makes statistical results more accurate than the Wigner–Seitz defect analysis method. Meanwhile, the photoluminescence spectra of silicon vacancy color centers at different helium ion doses are characterized to verify the correctness of the numerical analysis. The new silicon vacancy color center identification method can help predicting the optimal annealing temperature for silicon vacancy color centers, and provide guidance for subsequent color center annealing experiments.
Atomic layer deposition for rutile structure TiO2 thin films using a SnO2 seed layer and low temperature heat treatment
Authors: Kim Byunguk , Choi Yeonsik , Lee Dahyun , Cheon Seonghak , Byun Younghun , Jeon Hyeongtag
Published: December 2021

We study the rutile-TiO2 film deposition with a high-k value using a SnO2 seed layer and a low temperature heat treatment. Generally, heat treatment over 600 °C is required to obtain the rutile-TiO2 film. However, By using a SnO2 seed layer, we obtained rutile-TiO2 films with heat treatments as low as 400 °C. The XPS analysis confirms that the SnO2 and TiO2 film were deposited. The XRD analysis showed that a heat treatment at 400 °C after depositing the SnO2 and TiO2 films was effective in obtaining the rutile-TiO2 film when the SnO2 film was thicker than 10 nm. The TEM/EDX analysis show that no diffusion in the thin film between TiO2 and SnO2. The dielectric constant of the TiO2 film deposited on the SnO2 film (20 nm) was 67, which was more than twice as high as anatase TiO2 dielectric constant (Anatase TiO2 dielectric constant : 15–40). The current density was 10−4 A cm−2 at 0.7 V and this value confirmed that the leakage current was not affected by the SnO2 seed layer.
Physics-constrained intraventricular vector flow mapping by color Doppler
Authors: Vixège Florian , Berod Alain , Sun Yunyun , Mendez Simon , Bernard Olivier , Ducros Nicolas , Courand Pierre-Yves , Nicoud Franck , Garcia Damien
Published: December 2021

Color Doppler by transthoracic echocardiography creates two-dimensional fan-shaped maps of blood velocities in the cardiac cavities. It is a one-component velocimetric technique since it only returns the velocity components parallel to the ultrasound beams. Intraventricular vector flow mapping (iVFM) is a method to recover the blood velocity vectors from the Doppler scalar fields in an echocardiographic three-chamber view. We improved our iVFM numerical scheme by imposing physical constraints. The iVFM consisted in minimizing regularized Doppler residuals subject to the condition that two fluid-dynamics constraints were satisfied, namely planar mass conservation, and free-slip boundary conditions. The optimization problem was solved by using the Lagrange multiplier method. A finite-difference discretization of the optimization problem, written in the polar coordinate system centered on the cardiac ultrasound probe, led to a sparse linear system. The single regularization parameter was determined automatically for non-supervision considerations. The physics-constrained method was validated using realistic intracardiac flow data from a patient-specific computational fluid dynamics (CFD) model. The numerical evaluations showed that the iVFM-derived velocity vectors were in very good agreement with the CFD-based original velocities, with relative errors ranged between 0.3% and 12%. We calculated two macroscopic measures of flow in the cardiac region of interest, the mean vorticity and mean stream function, and observed an excellent concordance between physics-constrained iVFM and CFD. The capability of physics-constrained iVFM was finally tested with in vivo color Doppler data acquired in patients routinely examined in the echocardiographic laboratory. The vortex that forms during the rapid filling was deciphered. The physics-constrained iVFM algorithm is ready for pilot clinical studies and is expected to have a significant clinical impact on the assessment of diastolic function.
Quantifying tidal expiratory flow limitation using a vector-based analysis technique
Authors: Welch Ryan , Francis Alaina , Babbage Thalia , Lardenoye Mandy , Kolbe John , Ellyett Kevin
Published: December 2021

Objective. Tidal expiratory flow limitation (EFLT) is commonly identified by tidal breaths exceeding the forced vital capacity (FVC) loop. This technique, known as the Hyatt method, is limited by the difficulties in defining the FVC and tidal flow-volume (TV) loops. The vector-based analysis (VBA) technique described and piloted in this manuscript identifies and quantifies EFLT as tidal breaths that conform to the contour of the FVC loop. Approach. The FVC and TV loops are interpolated to generate uniformly spaced plots. VBA is performed to determine the smallest vector difference between each point on the FVC and TV curves, termed the flow reserve vector (FRV). From the FVC point yielding the lowest FRV, the tangential angles of the FVC and TV segments are recorded. If the TV and FVC loops become parallel, the difference between the tangential angles tends towards zero. We infer EFLT as parallel TV and FVC segments where the FRV is < 0.1 and the tangential angle is within ±18 degrees for ≥5% of TV. EFLT is quantified by the percent of TV loop fulfilling these criteria. We compared the presence and degree of EFLT at rest and during peak exercise using the Hyatt method and our VBA technique in 25 healthy subjects and 20 subjects with moderate-severe airflow obstruction. Main results. Compared to the Hyatt method, our VBA technique reported a significantly lower degree of EFLT in healthy subjects during peak exercise, and in obstructed subjects at rest and during peak exercise. In contrast to the Hyatt method, our VBA technique re-classified five subjects (one in the healthy group and four in the obstructed group) as demonstrating EFLT. Significance. Our VBA technique provides an alternative approach to determine and quantify EFLT which may reduce the overestimation of the degree EFLT and more accurately identify subjects experiencing EFLT.
Near real-time streaming analysis of big fusion data
Authors: Kube R , Churchill R M , Chang C S , Choi J , Wang R , Klasky S , Stephey L , Dart E , Choi M J
Published: December 2021

Experiments on fusion plasmas produce high-dimensional data time series with ever-increasing magnitude and velocity, but turn-around times for analysis of this data have not kept up. For example, many data analysis tasks are often performed in a manual, ad-hoc manner some time after an experiment. In this article, we introduce the Delta framework that facilitates near real-time streaming analysis of big and fast fusion data. By streaming measurement data from fusion experiments to a high-performance compute center, Delta allows computationally expensive data analysis tasks to be performed in between plasma pulses. This article describes the modular and expandable software architecture of Delta and presents performance benchmarks of individual components as well as of an example workflow. Focusing on a streaming analysis workflow where electron cyclotron emission imaging (ECEi) data is measured at KSTAR on the National Energy Research Scientific Computing Center’s (NERSC’s) supercomputer we routinely observe data transfer rates of about 4 Gigabit per second. In NERSC, a demanding turbulence analysis workflow effectively utilizes multiple nodes and graphical processing units and executes them in under 5 min. We further discuss how Delta uses modern database systems and container orchestration services to provide web-based real-time data visualization. For the case of ECEi data we demonstrate how data visualizations can be augmented with outputs from machine learning models. By providing session leaders and physics operators, results of higher-order data analysis using live visualizations may make more informed decisions on how to configure the machine for the next shot.
Third-order transport coefficients for electrons in N2 and CF4: effects of non-conservative collisions, concurrence with diffusion coefficients and contribution to the spatial profile of the swarm
Authors: Simonović I , Bošnjaković D , Petrović Z Lj , White R D , Dujko S
Published: December 2021

Using a multi-term solution of the Boltzmann equation and Monte Carlo simulation technique we study behaviour of the third-order transport coefficients for electrons in model gases, including the ionisation model of Lucas and Saelee and modified Ness–Robson model of electron attachment, and in real gases, including N2 and CF4. We observe negative values in the E/n
0-profiles of the longitudinal and transverse third-order transport coefficients for electrons in CF4 (where E is the electric field and n
0 is the gas number density). While negative values of the longitudinal third-order transport coefficients are caused by the presence of rapidly increasing cross sections for vibrational excitations of CF4, the transverse third-order transport coefficient becomes negative over the E/n
0-values after the occurrence of negative differential conductivity. The discrepancy between the two-term approximation and the full multi-term solution of the Boltzmann equation is investigated for electrons in N2 and CF4. While the accuracy of the two-term approximation is sufficient to investigate the behaviour of the third-order transport coefficients in N2, it produces large errors and is not even qualitatively correct for electrons in CF4. The influence of implicit and explicit effects of electron attachment and ionisation on the third-order transport tensor is investigated. In particular, we discuss the effects of attachment heating and attachment cooling on the third-order transport coefficients for electrons in the modified Ness–Robson model, while the effects of ionisation are studied for electrons in the ionisation model of Lucas and Saelee, N2 and CF4. The concurrence between the third-order transport coefficients and the components of the diffusion tensor, and the contribution of the longitudinal component of the third-order transport tensor to the spatial profile of the swarm are also investigated. For electrons in CF4 and CH4, we found that the contribution of the component of the third-order transport tensor to the spatial profile of the swarm between approximately 50 Td and 700 Td, is almost identical to the corresponding contribution for electrons in N2. This suggests that the recent measurements of third-order transport coefficients for electrons in N2 may be extended and generalized to other gases, such as CF4 and CH4.
High-performance SiC MOSFET embedded heterojunction diode with electric field protection region
Authors: Yoon Jongwoon , Kim Kwangsoo
Published: December 2021

In this study, we proposed high-performance SiC metal-oxide-semiconductor field effect transistors (MOSFETs) embedded heterojunction diode (HJD) with an electric field protection (EFP) region and analyzed it using a Sentaurus TCAD simulation. The proposed device features an HJD positioned at the trench side wall in the middle of the junction field effect transistor region and a highly doped EFP region under the P+ polysilicon to features excellent static performance and high reliability. The simulation results revealed that the maximum oxide electric field (E
MOX) and the Baliga’s figure-of-merit improved by 54% and 12%, respectively, compared with those of conventional SiC MOSFETs (C-MOSFETs). In addition, the EFP region suppressed the drain induced barrier lowering effect and leakage current in the HJD interface sufficiently. The HJD suppressed the bipolar degradation of the PiN body diode effectively due to its low V
F (1.75 V). In addition, the proposed device demonstrated superior reverse-recovery characteristics, thereby improving t
rr and Q
rr by 35% and 57%, respectively, compared to the corresponding values in C-MOSFET. Moreover, the input capacitance (C
ISS) was reduced by 17.5%, and C
GD was reduced by 96%. Therefore, the high-frequency figure-of-merit improved by a factor of 25.8 in terms of R
ON × C
GD. As a result, the proposed device is a promising structure for high-frequency and high-reliability applications.
Magnetic behavior of magneto-rheological foam under uniaxial compression strain
Authors: Diguet Gildas , Sebald Gaël , Nakano Masami , Lallart Mickaël , Cavaillé Jean-Yves
Published: December 2021

This study reports the development of a magneto-rheological foam, which consists in a porous matrix filled by ferromagnetic particles. The porous matrix of such a composite being easily deformable, large magnetic properties changes are expected. The measurements of the magnetic properties of such a magneto-rheological foam submitted to a compressive strain are reported. Main aspect of the magnetic properties is the low field magnetic permeability as the function of the compression and filling factor. Then, larger field magnetization measurement allowed to investigate the saturation field as a function of the filling factor. Because of the large amount of pores in the material, the magnetic relative permeability, µ
r, is quite small (µ
r ∼ 1). However, these materials can be easily deformed over a large range of strain providing important relative variation of the magnetic properties under mechanical solicitation. The composite magnetic permeability is increasing under compression for all the considered filling factors. A model is then developed to understand the variation of the permeability with the strain. Hence, from a simple concept consisting of taking advantage of high deformation of foams, the present study demonstrates the interest of such a highly compressible while cheap composite for obtaining a large magneto-rheological effect.