bluuebunny/crossref_metadata_2025 huggingface dataset:
Specific panallergen peptide of Sorghum Polcalcin showing IgE response identified based on in silico and in vivo peptide mapping
Authors: Bokka Chandra Sekhar , Veeramachaneni Ganesh Kumar , Thunuguntla V.B.S.C. , Manda Naresh Kumar , Bondili Jayakumar Singh
Published: October 2019

In India, Sorghum plant allergenicity was reported to be approximately 54.9%. Sorghum bicolor Polcalcin (Sorb PC) was identified as the panallergen but the specificity of this allergen is yet to be characterized. The present study was aimed to characterize the antigenic determinants of Sorb PC that are responsible for eliciting the IgE response. In silico modeling, simulation studies and docking of Sorb PC peptides (PC1–11) against IgG and IgE followed by in vivo evaluation was adopted. Peptide docking studies revealed PC 6 with highest G-score −12.85 against IgE followed by PC-11, 5, 1 and 7 (−10.91) peptides. The mice sensitized with PC7 peptide showed interleukin (IL) 4 (IL-4), IL-5, IL-12, TNF-α and GMCSF levels increased when compared with other peptides and controls, signifying a strong T helper type 2 (Th2)-based response. In tandem, the T helper type 1 (Th1) pathway was inhibited by low levels of cytokine IL-2, interferon γ (IFN-γ) and increased IL-10 levels justifying the role of PC7 in allergic IgE response. Considering the above data of overlapping peptides of PC6 and PC7, N-terminal part of the PC7 peptide (DEVQRMM) is found to play a crucial role in Sorghum Polcalcin allergenic response.
On the stress state of a pressurised pipe with an initial thickness variation, subjected to non-homogeneous internal corrosion
Authors: Zhao Shixiang , Pronina Yulia
Published: October 2019

The paper concerns 2D problem of an elastic thick-walled pipe with an initial thickness variation, subjected to internal pressure and mechanochemical corrosion. The inner perimeter of the pipe cross-section is elliptical, while the outer is circular. The linear Dolinskii corrosion kinetics model is used. In the general case, structural instability of initial boundary value problems with unknown evolving boundaries can cause the divergence of numerical procedures when modelling the processes under study. It is observed that the attempts to circumvent the divergence of numerical procedure can suppress the manifestation of mechanochemical effect and yield inaccurate results. Thus, it is necessary to find a compromise between competing computational processes. Calculations revealed that the variation of the initial pipe wall thickness within the acceptable pipe wall tolerance can noticeably accelerate the growth of stresses and, consequently, reduce the durability of the pipe. The applicability of analytical solutions for a perfect circular pipe with a reduced thickness, equal to the minimum thickness of the imperfect pipe, to the case under study is also discussed.
Mathematical simulation of the rate of carbon dioxide corrosion at the facilities of Gazprom dobycha Urengoy LLC
Authors: Yusupov Aleksandr
Published: October 2019

In Gazprom dobycha Urengoy LLC, as in other oil-and-gas production enterprises, there are problems of increased equipment wear due to corrosion. A special role there plays CO2corrosion. Despite the homogeneity of the extracted fluid and even chemical composition of the working medium, the nature and intensity of corrosion damage to pipelines and equipment varies over a wide range, due to different thermobaric parameters of well operation. To determine parameters influencing the rate of corrosion most different methods of statistical analysis were used. The paper provides a methodology for compiling a mathematical model and assessing its reliability. As a result, the equation of carbon dioxide corrosion in relation to the conditions of Achimov deposits of Urengoy oil, gas and condensate field was obtained. The type of the obtained equation was chosen according to the model of the classical de Waard-Milliams carbon dioxide corrosion equation. The model proposed by the authors describes the processes of carbon dioxide corrosion more reliably than the de Waard-Milliams equation does. The disadvantage of the developed model is that it does not reliably describe the speed of corrosion in wells with corrosion rates, significantly exceeding the average values for all wells studied.
Investigation of the effect of benzothiazinesulfonamide derivatives as inhibitors of microbiological corrosion of steel with composite zinc/biocide coating
Authors: Gribankova Angela , Agievich Maria , Zhai Xiaofan , Duan Jizhou , Hou Baorong
Published: October 2019

This study evaluated the biocidal and electrochemical inhibitory effectiveness of the organic compound (OC) 1,2,3,4,4a, 10b-hexahydro-1,4-methano-6H-dibenzo [c, e] -5,6-thiazine-5,5-dioxide when introduced into a zinc-plating electrolyte. Structural and metallurgical analysis of the resultant coatings was carried out using XRD and SEM techniques. During zinc electrodeposition, OC molecules were adsorbed on the surface of the zinc coatings. In a corrosive medium, destruction of molecules in the crystal lattice surface stopped the sulphate-reducing bacterial metabolic chain and retarded the corrosion process. The coatings exhibited high corrosion-resistance and good physical characteristics.
Polarized forced inverter drainage with controlled reverse-current release
Authors: Sorokendya V.S. , Sorokendya O.V.
Published: October 2019

To solve the problem of limiting the potential displacement of the protected structures to a very negative side, it was proposed to use a controlled release enabling passing the reverse current by direct connection of electric transport rail running on direct current.
Several erosion test results of means of sand control
Authors: Alkhimenko Alexey , Shaposhnikov Nikita , Shemyakinsky Boris , Tsvetkov Anton
Published: October 2019

When screens are used as the sole means of sand control, they function as a downhole filter. The entry of sand or other particles into horizontal and vertical wells presents the problem of steel erosion and productivity lost. Downhole is the most desirable location to restrict its access into the well. The problem of material reliability testing is relevant today, that’s why several erosion tests were made and studied. Self-made test bench allow varying velocity flow and fractions conditions (composition, quantity, size, hardness). Slurry erosion experiments resulted in wear of downhole sand control screens. The wear criteria were checked by weight loss of screen samples material and its integrity degradation. The idea of slurry erosion tests was to reveal screens wear.
Perspective ways to improve the strength properties and resistance to hydrogen induced cracking of low-alloy pipe steels
Authors: Kholodnyi Alexey , Shabalov Ivan , Matrosov Yury , Velikodnev Valery
Published: October 2019

The perspective ways to improve the strength properties and resistance to hydrogen induced cracking (HIC) of low-alloy pipe steels were established. The possibility to improve the strength properties and resistance to HIC of plates due the additive of 0.15% molybdenum while decreasing finish temperature of accelerated cooling from 560 to 420°C was found. The influence of heating in the α-, (α+γ)and γ-regions followed by air cooling on the mechanical properties and resistance to HIC of various alloying systems pipe steels plates was studied. The possibility of increasing the strength while maintaining the resistance to HIC of plates by tempering at heating in the α-region was shown.
Standard as the basis for a corrosion education and certification international. Establishment of an international guide standard for Corrosion Management in industry
Authors: Swierczynski Agatha
Published: October 2019

Corrosion is still responsible for large economic losses in many and very different industry sectors like e.g. marine, refinery and petrochemistry, oil and gas pipelines or of drinking water and appearing by hot gases and combustion products in steel and concrete constructions. There are only some examples chosen. The corrosion phenomena are still a huge astonishment because of some costly repair processes and because of large production losses. The corrosion control systems existing by now help to avoid or to minimize these losses but the question still is, if the existing control system can be working better or longer. If yes, what a key can optimize the corrosion protection depending on the sector’s requirements.
Interior Point Algorithm Applied to the Optimization of the Power Supplied by a Wind Farm with a BESS
Authors: Durán Pablo , Villanueva Daniel , Feijóo Andrés E. , Bokde Neeraj D.
Published: October 2019

Wind power constitutes a variable energy source that introduces unbalance in electrical network management because it cannot be programmed. Then, the possibility of storing wind energy becomes very important. The lack of control is a drawback that disappears when the combination of a wind farm (WF) and a battery energy storage system (BESS) is considered. In that case, the goal is to adjust the power plant output and the load requirements of electrical network, i.e., to contribute to system adequacy as much as possible. Considering the features of the problem, it can be defined as an optimization problem. Two algorithms are proposed to solve it: the primal dual algorithm and the Mehrotra predictor-corrector one. In both cases, the best solution of the proposed problem is reached in an efficient manner. The primal dual algorithm performs better in terms of time and the Mehrotra predictor-corrector one needs fewer iterations.
Wie gut sind Ältere in Deutschland mit essenziellen Nährstoffen versorgt?
Authors: Eggersdorfer Manfred
Published: October 2019

Die Versorgung mit essenziellen Mikronährstoffen, also Vitaminen und Mineralstoffen, ist für ein gesundes Leben und Altern von großer Bedeutung. Der Nutzen eines optimalen Nährstoffstatus für ein gesundes Leben und Altern zeigt sich bei der Mobilität im Alter aufgrund von guter Muskelstärke und Knochendichte, der Augengesundheit durch eine gute optische Makulapigmentdichte, der Aufrechterhaltung der kognitiven Funktion, gute Herzgesundheit durch Blutdruck- und Triglyceridmanagement und der Stärkung des Immunsystems.
School Bag Packs and Associated Problems among School Going Children
Authors: Hassan Danish , Kashif Muhammad , Bandpei Mohammad A.Mohseni , Ali Summiya Qudrat , Raqib Abdul , Manzoor Nosheen , Zahid Saima , Rafiullah Ahmed
Published: October 2019

Objective The objective of this study was to assess school backpacks and associated problems across school going children aged 8–12 years in Lahore, Pakistan. Self-perceived pain related to bag pack use, correlation between self-reported pain and perceived weight of bag pack, duration of bag pack carriage and the method of bag pack carriage were evaluated.

Methodology A cross-sectional survey was conducted on 3500 students from different private schools across Lahore. Both male and female students from the age of 8–12 years that were present on the day of the study with no apparent physical deformity or any musculoskeletal disorder were included in the study. Questionnaire used in this study was a modified questionnaire from a previous study.

Data collected through questionnaire was coded into SPSS version 18.

Data was represented in the form of graphs, tables, cross tabs and bar charts. Chi square test of association was applied with p value<0.05 considered as significant.

Results The results indicate that 82% of students surveyed carry bag packs, 54.66% of the students perceived the weight of their bag pack heavy, 40.22% medium while only 5.12% reported their bag pack lightly weighed. Pain was higher in individuals who perceived their bag pack weight heavy (i. e., 48%) pain, who carried their bag pack for over 20 min (44%) pain and over 30 min (56%) pain, respectively. Similarly percentage of pain was higher in individuals who carried their bag pack at one shoulder (i. e., 74%) pain.

Conclusion The results of the present study show that there is a relationship between bag pack use, duration and method of bag pack carriage this suggests that heavy, medium and light bag packs may have damaging effects for the school going children. A study to compare children who follow and that do not follow the recommended guidelines should be conducted to find out the guidelines could help reduce back pain, the bag pack guidelines have addressed bag pack weight and duration of carriage should be considered.
Development and Characterization of the Neuroregenerative Xanthohumol C/Hydroxypropyl-β-cyclodextrin Complex Suitable for Parenteral Administration
Authors: Kirchinger Michael , Bieler Lara , Tevini Julia , Vogl Michael , Haschke-Becher Elisabeth , Felder Thomas K. , Couillard-Després Sebastien , Riepl Herbert , Urmann Corinna
Published: October 2019

The chroman-like chalcone Xanthohumol C, originally found in hops, was demonstrated to be a potent neuroregenerative and neuroprotective natural product and therefore constitutes a strong candidate for further pharmaceutical research. The bottleneck for in vivo experiments is the low water solubility of this chalcone. Consequently, we developed and validated a suitable formulation enabling in vivo administration. Cyclodextrins were used as water-soluble and nontoxic complexing agents, and the complex of Xanthohumol C and 2-hydroxypropyl-β-cyclodextrin was characterized using HPLC, HPLC-MS, NMR, and differential scanning calorimetry. The water solubility of Xanthohumol C increases with increasing concentrations of cyclodextrin. Using 50 mM 2-hydroxypropyl-β-cyclodextrin, solubility was increased 650-fold. Furthermore, in vitro bioactivity of Xanthohumol C in free and complexed form did not significantly differ, suggesting the release of Xanthohumol C from 2-hydroxypropyl-β-cyclodextrin. Finally, a small-scaled in vivo experiment in a rat model showed that after i. p. administration of the complex, Xanthohumol C can be detected in serum, the brain, and the cerebrospinal fluid at 1 and 6 h post-administration. Mean (± SD) Xanthohumol C serum concentrations after 1, 6, and 12 h were determined as 463.5 (± 120.9), 61.9 (± 13.4), and 9.3 (± 0.8) ng/mL upon i. v., and 294.3 (± 22.4), 45.5 (± 0.7), and 13 (± 1.0) ng/mL after i. p. application, respectively. Accordingly, the formulation of Xanthohumol C/2-hydroxypropyl-β-cyclodextrin is suitable for further in vivo experiments and further pharmaceutical research aiming for the determination of its neuroregenerative potential in animal disease models.
Methyl-α-d-glucopyranoside as Green Ligand for Selective Copper-Catalyzed N-Arylation
Authors: Chen Yuanguang , Du Fangyu , Chen Fengyang , Zhou Qifan , Chen Guoliang
Published: October 2019

In the selective N-arylation of amines or azoles with aryl halides­, methyl-α-d-glucopyranoside (MG) was found to function as a green ligand of copper powder. In addition, nitrogen heterocyclic amine compounds can also undergo the N-arylation coupling with heterocyclic aryl chlorides. This process allows access to a variety of aromatic amines and aryl azoles under mild reaction conditions, has good tolerance, and proceeds in moderate to high yield.
Chlorination of Arylaldehyde-Derived Arylsulfonylhydrazones with N-Chlorosuccinimide Leading to 1,2,4,5-Tetrazine Derivatives
Authors: Ji Yuan-Zhao , Li Hui-Jing , Liu Ying , Wu Yan-Chao
Published: October 2019

It has been reported previously that treatment of aryl­ketone-derived arylsulfonylhydrazones with NXS/(nBu)4NX affords exclusively vinyl halides. In contrast, we have found that treatment of aryl­aldehyde-derived arylsulfonylhydrazones with N-chlorosuccinimide in the presence of potassium hydroxide affords 1,2,4,5-tetrazine derivatives in good to excellent yields. The present reactions are carried out under metal-free and mild reaction conditions.
Construction of a gigahertz-bandwidth radio-frequency scanning tunneling microscope based on a commercial low-temperature system
Authors: Xu Chaoqiang , Que Yande , Zhuang Yuan , Wang Kedong , Xiao Xudong
Published: October 2019

The highest frequency of the electric signal that a conventional scanning tunneling microscope (STM) can process typically lies in the kilohertz regime, imposing a limitation on its temporal resolution to the submillisecond regime. When extracting (feeding) the high frequency, or radio-frequency (RF), signal out of (into) the tunnel junction, the most challenging part is that the tunnel junction has a very high impedance, causing significant reflections. Here, we present a systematic solution on the construction of RF-STM with high sensitivity. To minimize radiation loss, using coaxial cables as conducting wires, we designed an active impedance matching network (IMN) based on a field-effect transistor, which can provide impedance matching over a wide frequency range and can bridge the enormous impedance difference associated with the tunnel junction. To shorten the signal cable before amplification, the STM probe itself was directly mounted on the IMN as the input pin, which is an unprecedented attempt to minimize the undesired parasitic capacitances. Furthermore, we employed a two-stage cryogenic SiGe low noise amplifier and a high-end spectrum analyzer to amplify and subsequently analyze the RF signal of interest. After this systematic engineering, the bandwidth of our STM has been improved to the gigahertz regime, implying a six orders of magnitude improvement. The sensitivity level of our newly built RF-STM is measured to be better than 1.0 pA/√Hz at 200 MHz at 78 K. The RF-STM also finds its application in nanoscale thermometry. Our efforts in its instrumentation should contribute to the development of high frequency scanning tunneling microscopy.
Anneal mediated deep-level dynamics in GaInNAsSb dilute nitrides lattice-matched to GaAs
Authors: Miyashita Naoya , He Yilun , Ahsan Nazmul , Okada Yoshitaka
Published: October 2019

This study focuses on the relationship among defects, annealing temperatures, and solar cell properties in the molecular beam epitaxy-grown GaInNAsSb solar cells. Samples with an n-i-p double heterostructure were annealed at various temperatures from 650 to 850 °C, and the dynamics of deep-level defects were analyzed. A significant improvement was obtained between 750 and 800 °C due to suppression of both the traps and the nonradiative recombination centers. They were distinguished using the DC bias dependence of admittance spectra and were reconfirmed from the electroluminescence and quantum efficiency spectroscopy studies.
Fast reaction of aluminum nanoparticles promoted by oxide shell
Authors: Wu Bao , Wu FengChao , Zhu YinBo , He AnMin , Wang Pei , Wu HengAn
Published: October 2019

Combustion of aluminum nanoparticles (AlNPs) has long been investigated experimentally because of their use in various energetic formulations for propellants and explosives. But the limited spatiotemporal resolution in experiments, in particular, makes it challenging to explore the microstructural evolution of AlNP oxidation and associated mechanisms. Here, we perform large-scale reactive molecular dynamics simulations to study the structural evolution of AlNPs with a 2–4 nm thick oxide shell in an oxygen environment. We find the temporal hollowing processes of AlNPs for both symmetrical and asymmetrical oxidations, in which the morphological evolution can be understood by a discrepant electric field and temperature distributions for different systems. In the early time, core aluminum atoms experience a fast reaction with an oxide shell. Environmental oxygen does not react with AlNPs until the surface O/Al ratio decreases to ∼1.2. Moreover, based on our simulation results, previous experimental data agree well with the proposed model, which can well describe the relationship between combustion efficiency and oxide shell thickness, confirming that the oxide shell promotes rather than hinders the combustion of AlNPs. The molecular insights obtained here would be significant for understanding the underlying mechanism and further modeling of AlNP combustion.
Separation of particle-laden gravity currents down a slope in linearly stratified environments
Authors: He Zhiguo , Zhao Liang , Zhu Rui , Hu Peng
Published: October 2019

Particle-laden gravity currents down a slope in stratified fluid are important processes in lake, estuary, and ocean environments. By conducting direct numerical simulations, this study investigates the detailed dynamic features of lock-exchange particle-laden gravity currents down a slope in linearly stratified environments. The front velocity, separation depth, water entrainment ratio, and energy budget are quantitatively analyzed. This evolutionary process can be divided into three stages, i.e., the acceleration stage, deceleration stage, and separation stage, if the relative stratification parameter is larger than unity. At the acceleration stage, as the collapse of the dense fluid leads to fast entrainment of ambient water into the current, the entrainment ratios have large values, while the settling velocity and the ambient stratification are shown to have less impact on both the entrainment ratios and the front velocity. At the deceleration stage, a larger slope angle, a weaker ambient stratification, and a smaller settling velocity bring a greater front velocity. At the separation stage, the head of the current leaves the slope and intrudes into the environment; meanwhile, the dense fluid at the body of the current also intrudes into the ambient water because the density contrast has largely been reduced due to water entrainment, particle settling, and the density increase in the ambient fluid. A predictive model is developed to determine the separation depth by considering the presence of particles. The fingerlike horizontal intrusions enhance the entrainment effect between the current and the ambient water. A stronger ambient stratification suppresses the conversion of the potential energy to the kinetic energy, while a larger settling velocity accelerates the conversion of the kinetic energy to the dissipated energy.
Nanoelectrode-emitter spectral overlap amplifies surface enhanced electrogenerated chemiluminescence
Authors: Heiderscheit Thomas S. , Gallagher Miranda J. , Baiyasi Rashad , Collins Sean S. E. , Hosseini Jebeli Seyyed Ali , Scarabelli Leonardo , Al-Zubeidi Alexander , Flatebo Charlotte , Chang Wei-Shun , Landes Christy F. , Link Stephan
Published: October 2019

Electrogenerated chemiluminescence (ECL) is a promising technique for low concentration molecular detection. To improve the detection limit, plasmonic nanoparticles have been proposed as signal boosting antennas to amplify ECL. Previous ensemble studies have hinted that spectral overlap between the nanoparticle antenna and the ECL emitter may play a role in signal enhancement. Ensemble spectroscopy, however, cannot resolve heterogeneities arising from colloidal nanoparticle size and shape distributions, leading to an incomplete picture of the impact of spectral overlap. Here, we isolate the effect of nanoparticle-emitter spectral overlap for a model ECL system, coreaction of tris(2,2′-bipyridyl)dichlororuthenium(ii) hexahydrate and tripropylamine, at the single-particle level while minimizing other factors influencing ECL intensities. We found a 10-fold enhancement of ECL among 952 gold nanoparticles. This signal enhancement is attributed exclusively to spectral overlap between the nanoparticle and the emitter. Our study provides new mechanistic insight into plasmonic enhancement of ECL, creating opportunities for low concentration ECL sensing.
Solutions and positive solutions for superlinear Robin problems
Authors: Papageorgiou N. S. , Vetro C. , Vetro F.
Published: October 2019

We consider nonlinear, nonhomogeneous Robin problems with a (p − 1)-superlinear reaction term, which need not satisfy the Ambrosetti-Rabinowitz condition. We look for positive solutions and prove existence and multiplicity theorems. For the particular case of the p-Laplacian, we prove existence results under a different geometry near the origin.
Effect of reflections on 2D tomographic reconstructions of filtered cameras and on interpreting spectroscopic measurements in the JET ITER-like wall divertor
Authors: Karhunen J. , Carr M. , Harrison J. R. , Lomanowski B. , Balboa I. , Carvalho P. , Groth M. , Huber A. , Matthews G. F. , Meakins A. , Silburn S. ,   JET Contributors
Published: October 2019

Considering reflections from metallic wall surfaces in generation of tomographic reconstructions of the tangentially viewing, visible-range spectroscopic divertor cameras in JET has been observed to yield enhanced spatial accuracy and significant reduction of emission artifacts in experimentally resolved 2D line emission distributions. Neglection of reflections in the tomography process was found to lead to overestimation of the emission near the wall surfaces by up to a factor of 4, as well as to formation of bright emission artifacts between the main emission regions and the wall surfaces, comprising locally up to 50% of the emission. Mimicking divertor spectroscopy measurements by integrating the tomographic reconstructions along vertical lines-of-sight implies that reflections comprise 15%–25% of the observed line-integrated emission peaks. The spatial differences in the reflection contribution between the different lines-of-sight are less pronounced than in the 2D reconstructions due to the dominance of the brightest emission regions through which the spectroscopic lines-of-sight pass. However, postprocessing EDGE2D-EIRENE simulations using the CHERAB code and synthetic spectroscopy suggests a decrease of the spectroscopically inferred divertor electron temperature by up to 75%, when redistribution of the observed light due to reflections is considered.
Coherent phonon dynamics in diamond detected via multiphoton absorption
Authors: Zukerstein M. , Trojánek F. , Rezek B. , Šobáň Z. , Kozák M. , Malý P.
Published: October 2019

Coupling between ultrafast lattice dynamics and electronic polarization becomes increasingly important for generating terahertz frequency combs, monitor atomic potential landscapes, or high-speed information processing. Here, we show that the carrier population excited by multiphoton (5-photon) absorption in diamond crystal can be controlled at terahertz frequencies by coherent lattice vibrations-phonons. We introduce and compare two independent methods for direct monitoring of coherent phonon dynamics in diamond by using photoluminescence or photocurrent measurements on femtosecond time scale. We observe a strong signal enhancement compared to standard techniques due to transmission geometry and high-order nonlinearity of optical carrier generation.
Explicit and exact solutions concerning the Antarctic Circumpolar Current with variable density in spherical coordinates
Authors: Martin Calin Iulian , Quirchmayr Ronald
Published: October 2019

We use spherical coordinates to devise a new exact solution to the governing equations of geophysical fluid dynamics for an inviscid and incompressible fluid with a general density distribution and subjected to forcing terms. The latter are of paramount importance for the modeling of realistic flows, that is, flows that are observed in some averaged sense in the ocean. Owing to the employment of spherical coordinates we do not need to resort to approximations (e.g., of f- and β-plane type) that simplify the geometry in the governing equations. Our explicit solution represents a steady purely azimuthal stratified flow with a free surface that—thanks to the inclusion of forcing terms and the consideration of the Earth’s geometry via spherical coordinates—makes it suitable for describing the Antarctic Circumpolar Current and enables an in-depth analysis of the structure of this flow. In line with the latter aspect, we employ functional analytical techniques to prove that the free surface distortion is defined in a unique and implicit way by means of the pressure applied at the free surface. We conclude our discussion by setting out relations between the monotonicity of the surface pressure and the monotonicity of the surface distortion that concur with the physical expectations.
A low-power and high-sensitivity magnetic field sensor based on converse magnetoelectric effect
Authors: Chu Zhaoqiang , Dong Cunzheng , Tu Cheng , Liang Xianfeng , Chen Huaihao , Sun Changxing , Yu Zhonghui , Dong Shuxiang , Sun Nian-Xiang
Published: October 2019

Tremendous progress has been made in boosting the realization of magnetoelectric (ME) magnetometers based on the direct ME effect (DME) for bulk ME laminates. In this work, we studied the potential of an electrically driven bulk magnetic field sensor based on the converse ME effect (CME). Starting from a discussion about the dependence of the induced voltage from the pickup coil on coil parameters and the CME coupling process, we then experimentally measured the optimized bias field in the off resonance region and observed the double-peak phenomenon that occurred within the resonance window. More importantly, the optimization with respect to the sample's dimension, excitation voltage, and frequency was conducted to improve the sensing capability for low-frequency magnetic fields. It was experimentally found that a limit of detection (LoD) of ∼115 pT for a magnetic field of 10 Hz and ∼300 pT for a magnetic field of 1 Hz was achieved when exciting the ME laminate at 1 V without any bias field. In this case, the power consumption for the ME laminate is only 0.56 mW, which is much lower compared to tens of milliwatts (10–100 mW) for optically pumped or flux gate sensors (excluding the power consumption from the electronics) and also shows advantages over conventional ME magnetic field sensors based on DME with a current pump.
Doping single transition metal atom into PtTe sheet for catalyzing nitrogen reduction and hydrogen evolution reactions
Authors: Yang Ye , Xue Xiong-Xiong , Chen Qin-jun , Feng Yexin
Published: October 2019

We systematically explored the catalytic performance of a novel two dimensional material PtTe sheet for nitrogen reduction reaction (NRR) and hydrogen evolution reaction (HER) by using first-principles calculation. Although pristine PtTe shows poor NRR and HER activity, doping transition metal (TM) atoms into the lattice could effectively enhance the catalytic performance. Calculations show that four TM doped structures, including W-Pt18Te17, Ru-Pt18Te17, Mo-Pt18Te17, and Cr-Pt18Te17, are promising NRR catalysts on the prerequisite of whose HER activities are effectively suppressed. Moreover, the HER performance of the PtTe sheet could also be significantly improved with introduced TM atoms. In particular, Cu, Cr, Co, Ni, Mo, Rh, Ru, and Tc atoms supported by the PtTe sheet with Te-vacancy are promising HER electrocatalysts. The improved HER performance is attributed to the reduced adsorption free energy of the H atom. Both the doped TM atoms and the adjacent Pt atoms are effective active sites. Among all considered structures, Mo-, Cr-, and Ru-Pt18Te17 sheets boost catalytic activity for both NRR and HER. This study provides new design strategies to enhance the catalytic performance of the PtTe sheet for the NRR/HER.
Preparation of attapulgite carriers with different pore structures and their effects on thermophysical properties of composite phase change materials
Authors: Wang Yi , Qin Ziyi , Guo Pengran , Li Yong , Zhang Ting
Published: October 2019

In this research, attapulgite was used as the carrier base materials for adsorbing phase change materials. By introducing isocyanate (-NCO) and different amino (-NH2) functional groups, ATP was chemically grafted. A series of porous ATP carriers with different pore structures were constructed based on the reactions between functional groups. The composite phase change materials of different ATP porous carriers were prepared by using stearic acid as phase change material. The TEM, FTIR, XPS, XRD, BET, TG and DSC were used to characterize the morphology, chemical structure and thermophysical properties of the prepared samples. The TEM results showed that the ATP carriers demonstrated favourable porous structure. The results of FTIR, XPS and XRD revealed that the characteristic functional groups isocyanate and amino formed joint molecules successfully, and a dealcoholization condensation reaction took place between the ethoxy groups and silicon hydroxyl on the surface of the ATP. Particularly, according to the characterization results, the enthalpy value of the CPCM reduced with the decrease of the pore size of the ATP carriers, it can also be found that the phase transition temperature of the CPCM declined as long as the pore size of the ATP carriers decreased.
Diffusion barriers, growth pathways, and scaling relations for small supported metal clusters
Authors: Mammen Nisha , Narasimhan Shobhana
Published: October 2019

Sintering is one of the main causes of degradation of nanocatalysts. With a view to studying the process of sintering, and its relative likelihood across elements, we have used ab initio density functional theory to compute the pathways and energy barriers Ed for the diffusion of small clusters Ptn on MgO(001), n = 1–4. We compare with the corresponding results for Aun, Agn, and Pdn. In general, diffusion barriers, but also sintering energies, are highest for Pt, resulting in opposing trends from kinetics and thermodynamics. We find smooth and positive correlations between Ed and Eb, Eb and Ecoh, Ecoh and Tm, and thus, between Ed and Tm, where Eb is the binding energy of the cluster on MgO, and Ecoh and Tm are the cohesive energy and melting temperature, respectively, of the corresponding bulk metal. These trends are present for diffusion of the monomers, trimers, and tetramers, but not the dimers; this can be explained by the topography of the energy landscape separating the global minimum from the transition state. The temperature T0 at which metal clusters on a given support become mobile is given by α + βTm, where α and β are constants that depend on the support. We also present similar results for self-diffusion of monomers of the four metals on the (111) surfaces. Such scaling relations could be used to rapidly estimate diffusion barriers, and hence the growth and sintering behavior, of potential catalytic metal clusters.
Ferromagnetic, antiferromagnetic, and Peierls distortion states in IVA-VA nanoribbons
Authors: Bai Shouyan , Niu Chun-Yao , Li Chong , Zhao Chunxiang , Jia Yu
Published: October 2019

Based on first-principles density-functional theory calculations, we have systematically investigated the electronic and magnetic properties of zigzag IVA-VA nanoribbons (ZIV-VNRs). We find that the ZIV-VNRs can exhibit ferromagnetic semiconducting ground states for CP and CAs while simultaneously exhibiting antiferromagnetic states for SiP and SiAs in their edges. What is more, their spin-polarized energy and magnetic moment are quite large in such special systems. Further, we find that a Peierls-like distortion semiconducting state could also take place when the bonding of the edge state is weaker enough as the atom number increases. The physical origin is the competition between charge, spin, and lattice degrees of freedom in different localization characteristics of ZIV-VNR edge states' p orbitals. Our work provides a route for potential functionalities of spintronics devices at the nanoscale.
Gold-Catalysed Oxidative Cycloisomerisation of 1,6-Diyne Acetates to 1-Naphthyl Ketones
Authors: Holm Andrew Thomas , Nayak Sanatan , Chan Philip Wai Hong
Published: October 2019

A synthetic method to prepare 1-naphthyl ketones from gold(i)-catalysed oxidative cycloisomerisation of 1,6-diyne acetates is described. The proposed mechanism involves cyclopropenation–cycloreversion of the 1,6-diyne motif initiated by a 1,2-acyloxy migration. This is followed by nucleophilic attack of the ensuing gold carbenoid species by a molecule of water and autoxidation to give the aromatic product.
Molecular composition and spatial distribution of dissolved organic matter (DOM) in the Pearl River Estuary, China
Authors: He Chen , Pan Qiong , Li Penghui , Xie Wei , He Ding , Zhang Chuanlun , Shi Quan
Published: October 2019

Environmental contextEstuaries play an important role in global carbon cycling in terms of transforming dissolved organic matter (DOM). We describe the molecular composition and spatial distribution of DOM in the Pearl River Estuary, an area severely impacted by anthropogenic activities, and show how DOM composition gradually changes with salinity. The results will help our understanding of the sources and transformations of anthropogenic DOM discharged to the coastal seas.
AbstractThe Pearl River is the second-largest river in China in terms of water discharge and brings enormous amounts of nutrients and terrestrial organic matter to the South China Sea, which makes the Pearl River Estuary (PRE) highly eutrophic. However, the molecular composition and distribution of dissolved organic matter (DOM) in the PRE have scarcely been investigated. In this study, solid-phase extraction (SPE) was performed to collect DOM samples from PRE along a salinity gradient. The samples were characterised by negative-ion electrospray ionisation (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to analyse their molecular composition and spatial distribution. The FT-ICR MS results showed that the terrestrial organic matter was gradually diluted and/or degraded during the migration from the river to the coastal ocean. Furthermore, both sulfur containing and unsaturated molecules were highly abundant in the upper stream samples, which indicated that anthropogenic input might be another important source of the assigned DOM in PRE. A group of bio-refractory molecules, characterised as carboxylic-rich alicyclic-like molecules, was found to accumulate with the increase of salinity. The composition of the SPE-DOM showed a gradual variation with the salinity and spatial changes; however, the variation was slightly different from those in pristine estuaries. This study demonstrates that the molecular composition of DOM is crucial for elucidating its source and transformation in an estuary.
Inflammasome signaling and regulation of interleukin-1 family cytokines
Authors: Chan Amy H. , Schroder Kate
Published: October 2019

Specific IL-1 family cytokines are expressed by cells as cytosolic pro-forms that require cleavage for their activity and cellular release. IL-1β, IL-18, and IL-37 maturation and secretion is governed by inflammatory caspases within signaling platforms called inflammasomes. By inducing pyroptosis, inflammasomes can also drive the release of the alarmin IL-1α. Recent advances have transformed our mechanistic understanding of inflammasome signaling, cell death decisions, and cytokine activation and secretion. Here, we provide an updated view of inflammasome signaling; mechanisms underpinning IL-1α, IL-1β, IL-18, and IL-37 maturation and release; and the functions of these cytokines in protective and pathological inflammation.
Biology and therapeutic potential of interleukin-10
Authors: Saraiva Margarida , Vieira Paulo , O’Garra Anne
Published: October 2019

The cytokine IL-10 is a key anti-inflammatory mediator ensuring protection of a host from over-exuberant responses to pathogens and microbiota, while playing important roles in other settings as sterile wound healing, autoimmunity, cancer, and homeostasis. Here we discuss our current understanding of the regulation of IL-10 production and of the molecular pathways associated with IL-10 responses. In addition to IL-10’s classic inhibitory effects on myeloid cells, we also describe the nonclassic roles attributed to this pleiotropic cytokine, including how IL-10 regulates basic processes of neural and adipose cells and how it promotes CD8 T cell activation, as well as epithelial repair. We further discuss its therapeutic potential in the context of different diseases and the outstanding questions that may help develop an effective application of IL-10 in diverse clinical settings.
Effects of interleukin-2 in immunostimulation and immunosuppression
Authors: Pol Jonathan G. , Caudana Pamela , Paillet Juliette , Piaggio Eliane , Kroemer Guido
Published: October 2019

Historically, interleukin-2 (IL-2) was first described as an immunostimulatory factor that supports the expansion of activated effector T cells. A layer of sophistication arose when regulatory CD4+ T lymphocytes (Tregs) were shown to require IL-2 for their development, homeostasis, and immunosuppressive functions. Fundamental distinctions in the nature and spatiotemporal expression patterns of IL-2 receptor subunits on naive/memory/effector T cells versus Tregs are now being exploited to manipulate the immunomodulatory effects of IL-2 for therapeutic purposes. Although high-dose IL-2 administration has yielded discrete clinical responses, low-dose IL-2 as well as innovative strategies based on IL-2 derivatives, including “muteins,” immunocomplexes, and immunocytokines, are being explored to therapeutically enhance or inhibit the immune response.
Activation–relaxation processes and related effects in quantum conductance of molecular junctions
Authors: Gasparyan F , Boichuk N , Vitusevich S
Published: October 2019

We reveal the comparative relationship between small changes in quantum conductivity behavior for molecular junctions. We clarify the mechanisms of acquiring and losing additional thermal activation energy during average current flow in a gold-1,4 benzenediamine (BDA)-gold molecular junction and explain the quantum conductance modulation process. Small changes in working temperature lead to a change in quantum conductivity, which is reflected in random telegraph signal behavior. We demonstrate the high sensitivity of the BDA molecules to small changes in temperature. For BDA molecules, conductance thermo-sensitivity values are relatively high near to

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This advantage can be used to measure weak variations in the ambient temperature. We show that the additional thermal energy arising from the change in temperature can impact on the strength of the electrode-molecule coupling, on the modulation of quantum conductivity. Local changes in quantum conductance of the order of quanta or smaller are conditioned by small random changes in the working regime arising from some of the activation processes. On the basis of the modulation of conductance, we calculate the magnitude of the spring constant of the 1,4 benzenediamine molecule as

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at the stretching length of 0.03 nm for the Au−NH2 molecular junction.
End-to-end test of an online adaptive treatment procedure in MR-guided radiotherapy using a phantom with anthropomorphic structures
Authors: Elter A , Dorsch S , Mann P , Runz A , Johnen W , Spindeldreier C K , Klüter S , Karger C P
Published: October 2019

Online adaptive treatment procedures in magnetic resonance (MR)-guided radiotherapy (MRgRT) allow compensating for inter-fractional anatomical variations in the patient. Clinical implementation of these procedures, however, requires specific end-to-end tests to validate the treatment chain including imaging, treatment planning, positioning, treatment plan adaption and accurate dose delivery. For this purpose, a new phantom with reproducibly adjustable anthropomorphic structures has been developed. These structures can be filled either with contrast materials providing anthropomorphic image contrast in MR and CT or with polymer dosimetry gel (PG) allowing for 3D dose measurements. To test an adaptive workflow at a 0.35 T MR-Linac, the phantom was employed in two settings simulating inter-fractional anatomical variations within the patient. The settings included two PG-filled structures representing a tumour and an adjacent organ at risk (OAR) as well as five additional structures. After generating a treatment plan, three irradiation experiments were performed: (i) delivering the treatment plan to the phantom in reference setting, (ii) delivering the treatment plan after changing the phantom to a displaced setting without adaption, and (iii) adapting the treatment plan online to the new setting and delivering it to the phantom. PG measurements revealed a homogeneous tumour coverage and OAR sparing for experiment (i) and a significant under-dosage in the PTV (down to 45% of the prescribed dose) and over-dosage in the OAR (up to 180% relative to the planned dose) in experiment (ii). In experiment (iii), a uniform dose in the PTV and a significantly reduced dose in the OAR was obtained, well-comparable to that of experiment (i) where no adaption of the treatment plan was necessary. PG measurements were well comparable with the corresponding treatment plan in all irradiation experiments. The developed phantom can be used to perform end-to-end tests of online adaptive treatment procedures at MR-Linac devices before introducing them to patients.
Anomalous caustics and Veselago focusing in 8-Pmmn borophene p–n junctions with arbitrary junction directions
Authors: Zhang Shu-Hui , Yang Wen
Published: October 2019

Negative refraction usually demands complex structure engineering while it is very natural for massless Dirac fermions (MDFs) across the p–n junction (PNJ), this leads to Dirac electron optics. The emergent Dirac materials may exhibit hitherto unidentified phenomenon due to their nontrivial band structures in contrast to the isotropic MDFs in graphene. Here, as a specific example, we explore the negative refraction induced caustics and Veselago focusing of tilted MDFs across 8-Pmmn borophene PNJs. To this aim, we develop a technique to effectively construct the electronic Green’s function (GF) in PNJs with arbitrary junction directions. Based on analytical discussions and numerical calculations, we demonstrate the strong dependence of interference pattern on the junction direction. As the junction direction perpendicular to the tilt direction, Veselago focusing or normal caustics (similar to that in graphene) appears resting on the doping configuration of the PNJs, otherwise anomalous caustics (different from that in graphene) occurs which is manipulated by the junction direction and the doping configuration. Finally, the developed GF technique is generally promising to uncover the unique transport of emergent MDFs, and the discovered anomalous caustics makes tilted MDFs potential applications in Dirac electron optics.
Bell inequalities tailored to the Greenberger–Horne–Zeilinger states of arbitrary local dimension
Authors: Augusiak R , Salavrakos A , Tura J , Acín A
Published: October 2019

In device-independent quantum information processing Bell inequalities are not only used as detectors of nonlocality, but also as certificates of relevant quantum properties. In order for these certificates to work, one very often needs Bell inequalities that are maximally violated by specific quantum states. Recently, in Salavrakos et al (2017 Phys. Rev. Lett.
119 040402) a general class of Bell inequalities, with arbitrary numbers of measurements and outcomes, has been designed, which are maximally violated by the maximally entangled states of two quantum systems of arbitrary dimension. In this work, we generalize these results to the multipartite scenario and obtain a general class of Bell inequalities maximally violated by the Greenberger–Horne–Zeilinger states of any number of parties and any local dimension. We then derive analytically their maximal quantum and nonsignaling values. We also obtain analytically the bound for detecting genuine nonlocality and compute the fully local bound for a few exemplary cases. Moreover, we consider the question of adapting this class of inequalities to partially entangled Greenberger–Horne–Zeilinger-like states for some special cases of low dimension and small number of parties. Through numerical methods, we find classes of inequalities maximally violated by these partially entangled states.