bluuebunny/crossref_metadata_2025 huggingface dataset:
Thiourea participation in [3+2] cycloaddition with donor–acceptor cyclopropanes: a domino process to 2-amino-dihydrothiophenes
Authors: Xie Ming-Sheng , Zhao Guo-Feng , Qin Tao , Suo Yong-Bo , Qu Gui-Rong , Guo Hai-Ming
Published: January 2019

The Yb(OTf)3 catalyzed [3+2] cycloaddition of donor–acceptor cyclopropanes with thiourea offers an efficient route to diverse 2-amino-4,5-dihydrothiophenes.
High index facet bounded α-Fe2O3 pseudocubic nanocrystals with enhanced electrochemical properties: Zn2+ ion assisted solvo-hydrothermal synthesis
Authors: Divya Neravathu G. , Junaid Bushiri M.
Published: January 2019

Pseudocubic α-Fe2O3 nanocrystals were grown by a surfactant-free, low temperature, solvo-hydrothermal process and characterised by XRD, FESEM, TEM, FTIR, Raman, XPS and UV-vis analysis.
Effects of the long octyl chain on complex formation of nickel(ii) with dimethyl sulfoxide, methanol, and acetonitrile in ionic liquid of [C8mim][TFSA]
Authors: Takamuku Toshiyuki , Sakurai Hiroyuki , Ogawa Akira , Tashiro Atsuya , Kawano Masahiro , Kawazu Yutaro , Sadakane Koichiro , Iwase Hiroki , Ozutsumi Kazuhiko
Published: January 2019

The mono-DMSO complex is formed in [C8mim][TFSA]-DMSO solutions, but not in [C2mim][TFSA]-DMSO solutions.
Experimental and computational studies of Criegee intermediate reactions with NH3and CH3NH2
Authors: Chhantyal-Pun Rabi , Shannon Robin J. , Tew David P. , Caravan Rebecca L. , Duchi Marta , Wong Callum , Ingham Aidan , Feldman Charlotte , McGillen Max R. , Khan M. Anwar H. , Antonov Ivan O. , Rotavera Brandon , Ramasesha Krupa , Osborn David L. , Taatjes Craig A. , Percival Carl J. , Shallcross Dudley E. , Orr-Ewing Andrew J.
Published: January 2019

The significance of removal of atmospheric ammonia and amines by reaction with Criegee intermediates is assessed by kinetic studies.
Dealing with supramolecular structure for ionic liquids: a DOSY NMR approach
Authors: Zanatta Marcileia , Antunes Víctor U. , Tormena Cláudio F. , Dupont Jairton , dos Santos Francisco P.
Published: January 2019

Diffusion-ordered spectroscopy (DOSY) is a powerful method for the NMR analysis of ionic liquids. Thus the dynamic-structural behaviour of imidazolium ionic liquids has been investigated by measurements of direct 1H diffusion coefficients in different solvents.
Thermodynamic limits of countercurrent reactor systems, with examples in membrane reactors and the ceria redox cycle
Authors: Bulfin Brendan
Published: January 2019

Countercurrent reactors can be utilized in chemical reaction systems which involve either a reaction between flows of different phases, or reactions between flows separated by a selective permeable membrane.
Hydrogen- and noble metal-free conversion of nitro aromatics to amino aromatics having reducible groups over an organically modified TiO2 photocatalyst under visible light irradiation
Authors: Yamamoto Yuhei , Fukui Makoto , Tanaka Atsuhiro , Hashimoto Keiji , Kominami Hiroshi
Published: January 2019

A TiO2 modified with 2,3-dihydroxynaphthalene responds to visible light, and electrons are photogenerated to the CB of TiO2 under light irradiation in the presence of a suitable hole scavenger.
Dinuclear manganese(iii) complexes with bioinspired coordination and variable linkers showing weak exchange effects: a synthetic, structural, spectroscopic and computation study
Authors: Shova Sergiu , Vlad Angelica , Cazacu Maria , Krzystek J. , Ozarowski Andrew , Malček Michal , Bucinsky Lukas , Rapta Peter , Cano Joan , Telser Joshua , Arion Vladimir B.
Published: January 2019

High-resolution HFEPR indicates weak exchange interactions between MnIII ions in agreement with DFT calculations.
Principles of photothermal gas-phase heterogeneous CO2 catalysis
Authors: Ghoussoub Mireille , Xia Meikun , Duchesne Paul N. , Segal Dvira , Ozin Geoffrey
Published: January 2019

Photothermal catalysis is an emerging sub-discipline of heterogeneous catalysis that exploits broad absorption of the solar spectrum to stimulate a combination of thermochemical and photochemical processes, which contribute synergistically to driving catalytic reactions. In particular, it is proving an effective and promising strategy for converting CO2 to synthetic fuels.
Extremely stable antimony–carbon composite anodes for potassium-ion batteries
Authors: Zheng Jing , Yang Yong , Fan Xiulin , Ji Guangbin , Ji Xiao , Wang Haiyang , Hou Singyuk , Zachariah Michael R. , Wang Chunsheng
Published: January 2019

A novel Sb nanoparticle embedded 3D carbon sphere network (Sb@CSN), fabricated via a scalable electrospray-assisted strategy, delivers one of the highest K storage capacity and longest cycle life in the first-ever reported 4 M KTFSI/EC + DEC electrolyte when compared with all K-ion battery anodes reported to date.
A prospective on energy and environmental science
Authors: Lewis Nathan S.
Published: January 2019

Nate Lewis outlines his thoughts on opportunities for growth in the future in energy and environmental science.
Recovery of gold from wastewater using nanoscale zero-valent iron
Authors: Li Shaolin , Li Jianhua , Wang Wei , Zhang Wei-xian
Published: January 2019

Kilograms of gold were recovered from wastewater using nanoscale zero-valent iron in a smelting plant since 2012.
Ordered mesoporous carbons from lignin: a new class of biobased electrodes for supercapacitors
Authors: Herou Servann , Ribadeneyra Maria Crespo , Madhu Rajesh , Araullo-Peters Vicente , Jensen Anders , Schlee Philipp , Titirici Magdalena
Published: January 2019

We report the synthesis of sustainable ordered mesoporous carbons (OMCs) produced from lignin, using the evaporation induced self-assembly (EISA) method.
Targeting of the mitochondrion by dinuclear thiolato-bridged arene ruthenium complexes in cancer cells and in the apicomplexan parasite Neospora caninum
Authors: Basto Afonso P. , Anghel Nicoleta , Rubbiani Riccardo , Müller Joachim , Stibal David , Giannini Federico , Süss-Fink Georg , Balmer Vreni , Gasser Gilles , Furrer Julien , Hemphill Andrew
Published: January 2019

Dinuclear ruthenium complexes inhibit N. caninum and specifically target the parasite mitochondria.
Regulation of gasdermin D by miR-379-5p is involved in arsenite-induced activation of hepatic stellate cells and in fibrosis via secretion of IL-1β from human hepatic cells
Authors: Li Junjie , Xue Junchao , Wang Dapeng , Dai Xiangyu , Sun Qian , Xiao Tian , Wu Lu , Xia Haibo , Mostofa Golam , Chen Xiong , Wei Yongyue , Chen Feng , Quamruzzaman Quazi , Zhang Aihua , Liu Qizhan
Published: January 2019

Arsenic is an environmental toxicant and human carcinogen.
An atomically thin molecular aperture: two-dimensional gallium phosphate
Authors: Hutchings Gregory S. , Altman Eric I.
Published: January 2019

Stretching two-dimensional GaPO4 causes its GaO4 and PO4 building blocks to counter-rotate allowing its pore size to be dynamically tuned to allow specific molecules to pass through.
Designing biocompatible sterile organogel–bigel formulations for drug delivery applications using green protocol
Authors: Singh Baljit , Kumar Rajender
Published: January 2019

Present article discusses the formation of a bigel formulation for drug delivery applications via a newly developed green approach using gamma radiation induced crosslinking.
Diastereoselective synthesis of 3,3-disubstituted 3-nitro-4-chromanone derivatives as potential antitumor agents
Authors: Chen Huiqing , Xie Jia , Xing Dong , Wang Jinping , Tang Jie , Yi Zhengfang , Xia Fei , Qiu Wen-Wei , Yang Fan
Published: January 2019

We report an efficient and highly diastereoselective protocol for the rapid construction of 3-nitro substituted 4-chromanones by an intramolecular Michael-type cyclization of α-nitro aryl ketones bearing unsaturated ester units.
Stereoselective synthesis of a phosphonate pThr mimetic via palladium-catalyzed γ-C(sp3)–H activation for peptide preparation
Authors: Duan Hua-Zhen , Chen Hong-Xue , Yu Qing , Hu Jun , Li Yan-Mei , Chen Yong-Xiang
Published: January 2019

We report a facile and efficient synthetic strategy toward a CH2-substituted phosphonate pThr mimetic and its application in phosphopeptide inhibitor synthesis.
Supramolecular vesicles based on pillar[n]arenes: design, construction, and applications
Authors: Xiao Tangxin , Zhong Weiwei , Xu Lixiang , Sun Xiao-Qiang , Hu Xiao-Yu , Wang Leyong
Published: January 2019

Recent progress in supramolecular vesicles based on pillar[n]arenes is reviewed.
Quadruply N-methylated octaphyrin: a helical macrocycle exhibiting chiroptical properties and dynamic conformation changes correlated with helical and inner N-methyl orientations
Authors: Naito Wakana , Urakawa Kazuki , Sato Ryuma , Shigeta Yasuteru , Yasuda Nobuhiro , Maeda Hiromitsu
Published: January 2019

[38]Octaphyrin(1.1.1.1.1.1.1.1) bearing four methyl moieties at the inner nitrogen sites has been synthesized and exhibited chiroptical properties and dynamic conversions.
The Raman scattering of trirutile structure MgTa2O6 single crystals grown by the optical floating zone method
Authors: Xu Dapeng , Gao Shuohui , Liu Wenqiang , Liu Ying , Zhou Qiang , Li Liang , Cui Tian , Yuan Hongming
Published: January 2019

Single crystals of the trirutile structure MgTa2O6 were grown via an optical floating zone method in an air atmosphere.
Luminescence properties in relation to controllable morphologies of Ba3[Ge2B7O16(OH)2](OH)(H2O):Eu3+ and its thermal conversion product Ba3Ge2B6O16:Eu3+
Authors: Liang Pan
Published: January 2019

The photoluminescence properties (PL) related to three morphologies of Ba3[Ge2B7O16(OH)2](OH)(H2O):Eu3+ have been discussed in this paper.
Ordering of colloidal hard spheres under gravity: from monolayer to multilayer
Authors: Guo Ziwei , Wu Peiyao , Kindt James T.
Published: January 2019

Simulated quasi-2D ordering transitions of colloidal hard spheres under gravity show great variation over a narrow range of particle size.
Effect of gelatin source and photoinitiator type on chondrocyte redifferentiation in gelatin methacryloyl-based tissue-engineered cartilage constructs
Authors: Pahoff Stephen , Meinert Christoph , Bas Onur , Nguyen Long , Klein Travis J. , Hutmacher Dietmar W.
Published: January 2019

This work investigates neocartilage formation in bovine and porcine gelatin methacryloyl-based hydrogels photocrosslinked using ultraviolet or visible light photoinitiator systems.
Novel prominent nylon-1 with excellent dielectric properties and a high Curie point
Authors: Yuan Dandan , Xu Yuanting , Huang Lei , Ma Jun , Peng Qinghai , Ren Ying , Li Wenmin , Cai Xufu
Published: January 2019

Novel prominent nylon-1 has been investigated for the first time and exhibits excellent dielectric properties and high phase transition temperature.
Organic semiconductors for biological sensing
Authors: Borges-González Jorge , Kousseff Christina J. , Nielsen Christian B.
Published: January 2019

In this review, we provide an overview of conjugated organic semiconductors and their applications in biological sensing with a primary focus on the role of the organic semiconductor.
Identification of substrate-specific inhibitors of cathepsin K through high-throughput screening
Authors: Law Simon , Du Xin , Panwar Preety , Honson Nicolette S. , Pfeifer Tom , Roberge Michel , Brömme Dieter
Published: January 2019

Cathepsin K (CatK) is a cysteine protease and drug target for skeletal disorders that is known for its potent collagenase and elastase activity. The formation of oligomeric complexes of CatK in the presence of glycosaminoglycans has been associated with its collagenase activity. Inhibitors that disrupt these complexes can selectively block the collagenase activity without interfering with the other regulatory proteolytic activities of the enzyme. Here, we have developed a fluorescence polarization (FP) assay to screen 4761 compounds for substrate-specific ectosteric collagenase inhibitors of CatK. A total of 38 compounds were identified that block the collagenase activity without interfering with the hydrolysis of active site substrates such as the synthetic peptide substrate, benzyloxycarbonyl-Phe-Arg-7-amido-4-methylcoumarin, and gelatin. The identified inhibitors can be divided into two main classes, negatively charged and polyaromatic compounds which suggest the binding to different ectosteric sites. Two of the inhibitors were highly effective in preventing the bone-resorption activity of CatK in osteoclasts. Interestingly, some of the ectosteric inhibitors were capable of differentiating between the collagenase and elastase activity of CatK depending on the ectosteric site utilized by the compound. Owing to their substrate-specific selectivity, ectosteric inhibitors represent a viable alternative to side effect-prone active site-directed inhibitors.
Fetal programming and the angiotensin-(1-7) axis: a review of the experimental and clinical data
Authors: South Andrew M. , Shaltout Hossam A. , Washburn Lisa K. , Hendricks Alexa S. , Diz Debra I. , Chappell Mark C.
Published: January 2019

Hypertension is the primary risk factor for cardiovascular disease that constitutes a serious worldwide health concern and a significant healthcare burden. As the majority of hypertension has an unknown etiology, considerable research efforts in both experimental models and human cohorts has focused on the premise that alterations in the fetal and perinatal environment are key factors in the development of hypertension in children and adults. The exact mechanisms of how fetal programming events increase the risk of hypertension and cardiovascular disease are not fully elaborated; however, the focus on alterations in the biochemical components and functional aspects of the renin–angiotensin (Ang) system (RAS) has predominated, particularly activation of the Ang-converting enzyme (ACE)-Ang II-Ang type 1 receptor (AT1R) axis. The emerging view of alternative pathways within the RAS that may functionally antagonize the Ang II axis raise the possibility that programming events also target the non-classical components of the RAS as an additional mechanism contributing to the development and progression of hypertension. In the current review, we evaluate the potential role of the ACE2-Ang-(1-7)-Mas receptor (MasR) axis of the RAS in fetal programming events and cardiovascular and renal dysfunction. Specifically, the review examines the impact of fetal programming on the Ang-(1-7) axis within the circulation, kidney, and brain such that the loss of Ang-(1-7) expression or tone, contributes to the chronic dysregulation of blood pressure (BP) and cardiometabolic disease in the offspring, as well as the influence of sex on potential programming of this pathway.
USP4 deficiency exacerbates hepatic ischaemia/reperfusion injury via TAK1 signalling
Authors: Zhou Jiangqiao , Qiu Tao , Wang Tianyu , Chen Zhongbao , Ma Xiaoxiong , Zhang Long , Zou Jilin
Published: January 2019

Ubiquitin-specific peptidase 4 (USP4) protein is a type of deubiquitination enzyme that is correlated with many important biological processes. However, the function of USP4 in hepatic ischaemia/reperfusion (I/R) injury remains unknown. The aim of the present study was to explore the role of USP4 in hepatic I/R injury. USP4 gene knockout mice and primary hepatocytes were used to construct hepatic I/R models. The effect of USP4 on hepatic I/R injury was examined via pathological and molecular analyses. Our results indicated that USP4 was significantly up-regulated in liver of mice subjected to hepatic I/R injury. USP4 knockout mice exhibited exacerbated hepatic I/R injury, as evidenced by enhanced liver inflammation via the nuclear factor κB (NF-κB) signalling pathway and increased hepatocyte apoptosis. Additionally, USP4 overexpression inhibited hepatocyte inflammation and apoptosis on hepatic I/R stimulation. Mechanistically, our study demonstrates that USP4 deficiency exerts its detrimental effects on hepatic I/R injury by inducing activation of the transforming growth factor β-activated kinase 1 (TAK1)/JNK signalling pathways. TAK1 was required for USP4 function in hepatic I/R injury as TAK1 inhibition abolished USP4 function in vitro. In conclusion, our study demonstrates that USP4 deficiency plays a detrimental role in hepatic I/R injury by promoting activation of the TAK1/JNK signalling pathways. Modulation of this axis may be a novel strategy to alleviate the pathological process of hepatic I/R injury.
Design and control of a SiC‐based three‐stage AC to DC power electronic transformer for electric traction applications
Authors: Yao Ruidi , Zheng Zedong
Published: January 2019

By operating at much higher frequencies, power electronic transformers (PETs) offer many advantageous features consisting of high power density, high efficiency and diverse functionalities. But the trade‐off between the operating frequency and the conversion efficiency limits the further development of PETs. Nevertheless, with the advancements on SiC‐MOSFET devices, this limitation can be overcome due to the higher blocking voltage utilisation factor and lower on‐state losses of SiC devices. The potential applications of the proposed SiC‐based PET are railway traction for electric multiple units (EMUs), interfacing electric vehicles, marine propulsion, etc. This paper focuses on a SiC‐based three‐stage AC to DC PET, which employs an input series and output parallel (ISOP) configuration. By synthetically comparing some typical topologies of PETs, their merits and demerits are summarised. By minutely analysing requirements and rigorously calculating, the design of the high power medium‐frequency transformer (MFT) is presented. By operating simulations of topological structures of the proposed PET on the basis of MATLAB/Simulink, control strategies including phase‐shift control and voltage balancing control are described. Simulations with prototype model are provided to demonstrate the operation of the PET.
Observation of aerodynamic instability in the flow of a particle stream in a dilute gas
Authors: Capelo Holly L. , Moláček Jan , Lambrechts Michiel , Lawson John , Johansen Anders , Blum Jürgen , Bodenschatz Eberhard , Xu Haitao
Published: January 2019

Forming macroscopic solid bodies in circumstellar discs requires local dust concentration levels significantly higher than the mean. Interactions of the dust particles with the gas must serve to augment local particle densities, and facilitate growth past barriers in the metre size range. Amongst a number of mechanisms that can amplify the local density of solids, aerodynamic streaming instability (SI) is one of the most promising. This work tests the physical assumptions of models that lead to SI in protoplanetary discs (PPDs). We conduct laboratory experiments in which we track the three-dimensional motion of spherical solid particles fluidised in a low-pressure, laminar, incompressible, gas stream. The particle sizes span the Stokes–Epstein drag regime transition and the overall dust-to-gas mass density ratio,ϵ, is close to unity. A recently published study establishes the similarity of the laboratory flow to a simplified PPD model flow. We study velocity statistics and perform time-series analysis of the advected flow to obtain experimental results suggesting an instability due to particle-gas interaction: (i) there exist variations in particle concentration in the direction of the mean relative motion between the gas and the particles, that is the direction of the mean drag forces; (ii) the particles have a tendency to “catch up” to one another when they are in proximity; (iii) particle clumping occurs on very small scales, which implies local enhancements above the backgroundϵby factors of several tens; (iv) the presence of these density enhancements occurs for a meanϵapproaching or greater than 1; (v) we find evidence for collective particle drag reduction when the local particle number density becomes high and when the background gas pressure is high so that the drag is in the continuum regime. The experiments presented here are precedent-setting for observing SI under controlled conditions and may lead to a deeper understanding of how it operates in nature.
Optical spectroscopic and polarization properties of 2011 outburst of the recurrent nova T Pyxidis
Authors: Pavana M. , Anche Ramya M. , Anupama G. C. , Ramaprakash A. N. , Selvakumar G.
Published: January 2019

Aims. We aim to study the spectroscopic and ionized structural evolution of T Pyx during its 2011 outburst, and also study the variation in degree of polarization during its early phase.

Methods. Optical spectroscopic data of this system obtained from day 1.28–2415.62 since discovery, and optical, broadband imaging polarimetric observations obtained from day 1.36–29.33 during the early phases of the outburst were used in the study. The physical conditions and the geometry of the ionized structure of the nova ejecta was modelled for a few epochs using the photo-ionization code, CLOUDY in 1D and pyCloudy in 3D.

Results. The spectral evolution of the nova ejecta during its 2011 outburst is similar to that of the previous outbursts. The variation in the line profiles is seen very clearly in the early stages due to good coverage during this period. The line profiles vary from P Cygni (narrower, deeper, and sharper) to emission profiles that are broader and structured, which later become narrower and sharper in the late post-outburst phase. The average ejected mass is estimated to be 7.03 × 10−6 M⊙. The ionized structure of the ejecta is found to be a bipolar conical structure with equatorial rings, with a low inclination angle of 14.75 ° ±0.65°.
Histogram of oriented gradients: a technique for the study of molecular cloud formation
Authors: Soler J. D. , Beuther H. , Rugel M. , Wang Y. , Clark P. C. , Glover S. C. O. , Goldsmith P. F. , Heyer M. , Anderson L. D. , Goodman A. , Henning Th. , Kainulainen J. , Klessen R. S. , Longmore S. N. , McClure-Griffiths N. M. , Menten K. M. , Mottram J. C. , Ott J. , Ragan S. E. , Smith R. J. , Urquhart J. S. , Bigiel F. , Hennebelle P. , Roy N. , Schilke P.
Published: January 2019

We introduce the histogram of oriented gradients (HOG), a tool developed for machine vision that we propose as a new metric for the systematic characterization of spectral line observations of atomic and molecular gas and the study of molecular cloud formation models. In essence, the HOG technique takes as input extended spectral-line observations from two tracers and provides an estimate of their spatial correlation across velocity channels. We characterized HOG using synthetic observations of HIand13CO (J= 1 → 0) emission from numerical simulations of magnetohydrodynamic (MHD) turbulence leading to the formation of molecular gas after the collision of two atomic clouds. We found a significant spatial correlation between the two tracers in velocity channels wherevHI≈v13CO, almost independent of the orientation of the collision with respect to the line of sight. Subsequently, we used HOG to investigate the spatial correlation of the HI, from The HI/OH/recombination line survey of the inner Milky Way (THOR), and the13CO (J= 1 → 0) emission from the Galactic Ring Survey (GRS), toward the portion of the Galactic plane 33°.75 ≤l≤ 35°.25 and |b| ≤ 1°.25. We found a significant spatial correlation between the two tracers in extended portions of the studied region. Although some of the regions with high spatial correlation are associated with HIself-absorption (HISA) features, suggesting that it is produced by the cold atomic gas, the correlation is not exclusive to this kind of region. The HOG results derived for the observational data indicate significant differences between individual regions: some show spatial correlation in channels aroundvHI≈v13COwhile others present spatial correlations in velocity channels separated by a few kilometers per second. We associate these velocity offsets to the effect of feedback and to the presence of physical conditions that are not included in the atomic-cloud-collision simulations, such as more general magnetic field configurations, shear, and global gas infall.
Shape evolution of cometary nuclei via anisotropic mass loss
Authors: Vavilov D. E. , Eggl S. , Medvedev Yu. D. , Zatitskiy P. B.
Published: January 2019

Context.Breathtaking imagery recorded during the European Space Agency Rosetta mission confirmed the bilobate nature of the nucleus of comet 67P/Churyumov-Gerasimenko. The peculiar appearance of the nucleus is not unique among comets. The majority of cometary cores imaged at high resolution exhibit a similar build. Various theories have been brought forward as to how cometary nuclei attain such peculiar shapes.

Aims.We illustrate that anisotropic mass loss and local collapse of subsurface structures caused by non-uniform exposure of the nucleus to solar irradiation can transform initially spherical comet cores into bilobed cores.

Methods.We derived a mathematical framework to describe the changes in morphology resulting from non-uniform insolation during the spin-orbit evolution of a nucleus. We solved the resulting partial differential equations that govern the change in the shape of a nucleus subject to mass loss and consequent collapse of depleted subsurface structures analytically for simple insolation configurations and numerically for more realistic scenarios.

Results.The proposed mechanism is capable of explaining why a large percentage of periodic comets appear to have peanut-shaped cores and why light-curve amplitudes of comet nuclei are on average larger than those of typical main belt asteroids of the same size.
Data comparisons and uncertainty: a roadmap for gaining in competence and improving the reliability of results
Authors: Charki Abdérafi , Pavese Franco
Published: January 2019

This paper traces a roadmap for gaining in competence and for improving the reliability of results in a laboratory. The roadmap was built from the requirements concerning the results quality and measurement uncertainty, which accreditation bodies use for the accreditation of testing and calibration laboratories. In industry, accreditation is the accepted proof of a laboratory's assigned level of competence. The level of performance of a laboratory is demonstrated through the quality of its management of test and calibration results. Inter-laboratory comparisons and the evaluation of measurement uncertainties are recommended as the most appropriate methods for demonstrating continuous improvement in laboratories. The common methods used for data comparisons and for the evaluation of measurement uncertainties are highlighted. An overview of the main indicators used in data comparisons is presented. Some recommendations are made that are useful to the design of a roadmap for gaining in competence and for improving the quality of results obtained by a laboratory.
Patterns of plasma jet arrays in the gas flow field of non-thermal atmospheric pressure plasma jets
Authors: Hasnain Qaisrani M. , Li Congyun , Xuekai Pei , Khalid M. , Yubin Xian , Xinpei Lu
Published: January 2019

Schlieren photography, the state-of-art to visualize the invisible flows, has appealed gigantic attention of various researchers in the plasma community. Here, this technique is utilized to address the behavior of the plasma jet arrays in the gas flow field. The goal of this study is to probe the signatures of different parameters and their response in the gas flow field. It is concluded that every parameter exhibits its sensitivity to the plasma in the gas flow field. However, frequency has a significant impact on the reduction of the laminar flow. Furthermore, it is suggested that the flow of the higher momentum region to the lower region is the cause in establishing the instabilities. The compression and rarefaction at the rising and falling edges of the discharge pulses play the dominant role. Plasma jet arrays can be a handy tool for industrial applications unless proper parameters are selected.
Numerically studying the effects of discharge conditions on plasma-wall transition region of magnetized methane plasma
Authors: Bahador Hamid , Pourali Nima
Published: January 2019

By combining the global model for rf plasma discharge and the multi-component fluid model for the plasma-wall transition region, the effects of discharge conditions and reactor characteristics on the sheath and pre-sheaths of magnetized methane plasma are studied numerically. The global model determines the density of all species considered in the model as well as electron temperature for the given discharge conditions and reactor size, while the multi-component fluid model uses the parameters calculated by the global model to specify the distribution of potential and species densities in the transition region for a given magnetic field intensity and orientation. The results show that the transition region characteristics are affected by changing the discharge conditions and reactor size. As the sheath and the magnetized pre-sheath become narrower by increasing the input power and background gas pressure, their thicknesses increase with the increase in the electrode radius. Also, they become narrower by increasing the magnetic field intensity and the angle between the electric and magnetic fields.
An autonomous robot for continuous tracking of millimetric-sized walkers
Authors: Serrano-Muñoz A. , Frayle-Pérez S. , Reyes A. , Almeida Y. , Altshuler E. , Viera-López G.
Published: January 2019

The precise and continuous tracking of millimetric-sized walkers—such as ants—is quite important in behavioral studies. However, due to technical limitations, most studies concentrate on trajectories within areas no more than 100 times bigger than the size of the walker or longer trajectories at the expense of either accuracy or continuity. Our work describes a scientific instrument designed to push the boundaries of precise and continuous motion analysis up to 1000 body lengths or more. It consists of a mobile robotic platform that uses digital image processing techniques to track the targets in real time by calculating their spatial position. During the experiments, all the images are stored and afterwards processed to estimate with higher precision the path traced by the walkers. Some preliminary results achieved using the proposed tracking system are presented.
Strong interfacial perpendicular anisotropy and interfacial damping in Ni0.8Fe0.2 films adjacent to Ru and SiO2
Authors: Beik Mohammadi Jamileh , Mankey Gary , Mewes Claudia K. A. , Mewes Tim
Published: January 2019

We report detailed investigations of a strong perpendicular magnetic anisotropy in Ni0.8Fe0.2 thin films originating from interfaces with adjacent Ru and SiO2 layers. The anisotropy is quantified using broadband ferromagnetic resonance measurements for three types of layered heterostructures, namely an asymmetric structure of SiO2/Ni0.8Fe0.2/Ru and symmetric structures of Ru/Ni0.8Fe0.2/Ru and SiO2/Ni0.8Fe0.2/SiO2. The results show a stronger perpendicular anisotropy at the Ni0.8Fe0.2/SiO2 interface than at the Ni0.8Fe0.2/Ru interface and a lower interfacial damping contribution for the Ni0.8Fe0.2/SiO2 interface compared to the Ni0.8Fe0.2/Ru interface.
Thermally activated, light-induced electron-spin-resonance spin density reflected by photocurrents in a perovskite solar cell
Authors: Jeon N. J. , Yang T.-Y. , Park H. H. , Seo J. , Nam D. Y. , Jeong D. , Hong S. , Kim S. H. , Cho J. M. , Jang J. J. , Lee J.-K.
Published: January 2019

Light-induced electron-spin-resonance (LESR) spin density in a perovskite solar cell (PSC) is ascribed to photo-induced charges accumulated at the interface of the perovskite and the hole transport layer (HTL). The LESR spin density was observed to be decreased as the temperature was lowered from room temperature to 170 K in a PSC; below ∼170 K, no LESR was found. Meanwhile, the photocurrent showed only an ∼25% decrease between room temperature and 170 K. The comparison of LESR in temperature-dependence with transient or steady photocurrents suggested that the decrease in photocurrent at the low temperatures stems mainly from trapping of delocalized holes at the interface of perovskite and HTL.
A comparative study of topology and local disorder in Y2O3, Y2TiO5, and Y2Ti2O7 crystals
Authors: Dholakia Manan , Chandra Sharat , Mathi Jaya S.
Published: January 2019

Y 2 O 3 , Y2TiO5, and Y2Ti2O7 precipitates are the key ingredients of the oxide dispersion strengthened (ODS) steels, and a study of their irradiation behavior and amorphization resistance is very important for the nuclear industry. We perform molecular dynamics simulations of disorder induced by displacement cascades and by equilibrating the systems at high temperatures and study the topology and defect morphology using various analyses. The studies show that a radiation damaged and a melted system can have very different topologies, and this difference can be effectively discerned by a topology based analysis. It is shown that all the three systems are constrained and quite resistant to amorphization; however, Y2O3 and Y2Ti2O7 have a better resistance to amorphization as compared to Y2TiO5.
Deep acceptors and their diffusion in Ga2O3
Authors: Peelaers Hartwin , Lyons John L. , Varley Joel B. , Van de Walle Chris G.
Published: January 2019

β–Ga2O3 is a wide-bandgap material with promising applications in high-power electronics. While n-type doping is straightforward, p-type doping is elusive, with only deep acceptors available. We explore the properties of these acceptors, from the point of view of achieving stable semi-insulating layers, which are essential in many device structures. Using hybrid density functional theory, we obtain the comprehensive first-principles results for a variety of deep-acceptor impurities in Ga2O3. Among the impurities examined, nitrogen on an oxygen site and magnesium on a gallium site have particularly low formation energies, making them prime candidates for acceptor doping. Closer inspection of various configurations shows that Mg can incorporate not only on Ga sites (where it acts as a deep acceptor under n-type conditions) but also on O sites, where it acts as a deep donor. Mg interstitials adopt a split-interstitial configuration, sharing a site with a host Ga atom. Similarly, N substituting on an O site acts as a compensating center, but N can also incorporate on the Ga site. We evaluate the diffusivities of these species in the crystal by calculating migration barriers and considering which native defects assist in diffusion. We find that diffusion of N is dominantly assisted by O vacancies, while Mg diffusion is assisted by gallium interstitials. Diffusion of Mg proceeds with significantly lower activation energies than diffusion of N. Our results can be used to assess activation energies and diffusion mechanisms for other impurities in Ga2O3.
Impact of geometry and non-idealities on electron “optics” based graphene p-n junction devices
Authors: Elahi Mirza M. , Masum Habib K. M. , Wang Ke , Lee Gil-Ho , Kim Philip , Ghosh Avik W.
Published: January 2019

We articulate the challenges and opportunities of unconventional devices using the photon like flow of electrons in graphene, such as Graphene Klein Tunnel (GKT) transistors. The underlying physics is the employment of momentum rather than energy filtering to engineer a gate tunable transport gap in a 2D Dirac cone bandstructure. In the ballistic limit, we get a clean tunable gap that implies subthermal switching voltages below the Boltzmann limit, while maintaining a high saturating current in the output characteristic. In realistic structures, detailed numerical simulations and experiments show that momentum scattering, especially from the edges, bleeds leakage paths into the transport gap and turns it into a pseudogap. We quantify the importance of reducing edge roughness and overall geometry on the low-bias transfer characteristics of GKT transistors and benchmark against experimental data. We find that geometry plays a critical role in determining the performance of electron optics based devices that utilize angular resolution of electrons.
Multimode quantum dynamics with multiple Davydov D2 trial states: Application to a 24-dimensional conical intersection model
Authors: Chen Lipeng , Gelin Maxim F. , Domcke Wolfgang
Published: January 2019

The ultrafast nonadiabatic dynamics of a two-electronic-state four-vibrational-mode conical intersection coupled to a finite bath with up to 20 harmonic oscillators has been investigated by employing the multiple Davydov D2 ansatz. It is demonstrated, using the multi-configuration time-dependent Hartree method as a benchmark, that this approach provides an efficient and robust description of the internal conversion process at multimode conical intersections. Thanks to the Gaussian nature of the Davydov ansatz, it allows for numerically accurate simulations of time-dependent diabatic and (for the first time for a 24-mode system) adiabatic populations of the electronic states and reduced probability densities of the tuning and coupling modes. The obtained adiabatic populations and wave packets can be used as benchmarks for the testing of various simulation methods, in particular, surface-hopping methods.
Design and construction of a multistage Zeeman decelerator for crossed molecular beams scattering experiments
Authors: Cremers Theo , Janssen Niek , Sweers Edwin , van de Meerakker Sebastiaan Y. T.
Published: January 2019

Zeeman deceleration is a relatively new technique used to obtain full control over the velocity of paramagnetic atoms or molecules in a molecular beam. We present a detailed description of a multistage Zeeman decelerator that has recently become operational in our laboratory [Cremers et al., Phys. Rev. A 98, 033406 (2018)] and that is specifically optimized for crossed molecular beams scattering experiments. The decelerator consists of an alternating array of 100 solenoids and 100 permanent hexapoles to guide or decelerate beams of paramagnetic atoms or molecules. The Zeeman decelerator features a modular design that is mechanically easy to extend to arbitrary length and allows for solenoid and hexapole elements that are convenient to replace. The solenoids and associated electronics are efficiently water cooled and allow the Zeeman decelerator to operate at repetition rates exceeding 10 Hz. We characterize the performance of the decelerator using various beams of metastable rare gas atoms. Imaging of the atoms that exit the Zeeman decelerator reveals the transverse focusing properties of the hexapole array in the Zeeman decelerator.
An electrodynamic energy harvester with a 3D printed magnet and optimized topology
Authors: Wang Zhongxu , Huber Christian , Hu Jun , He Jinliang , Suess Dieter , Wang Shan X.
Published: January 2019

An electrodynamic energy harvester is proposed for scavenging the electromagnetic energy in the vicinity of a power transmission line. To improve the efficiency and to maximize the distortion power factor of the energy harvester, the permanent magnet in the energy harvester is especially designed by the finite element method to optimize the topology and subsequently fabricated by additive manufacturing. An isotropic polymer-bonded NdFeB material is used for the fused-deposition modeling 3D printing process. Tensile tests of the printed magnetic parts show proper mechanical properties for harsh environments. Compared to a non-optimized magnet, the distortion power factor can be increased by 55%. The power and power density under the resonance condition of the fabricated harvester can reach 93 mW and 2.6 mW/cm3, respectively. The advantages of such an optimized energy harvester include being a fast and affordable manufacturing technique, an enhanced distortion power factor, and high output power. The properties of the energy harvester show that it has great potential for many self-powered applications such as wireless sensor networks and Internet of things.
Nanoscale detection of spin wave deflection angles in permalloy
Authors: Groß Felix , Träger Nick , Förster Johannes , Weigand Markus , Schütz Gisela , Gräfe Joachim
Published: January 2019

Magnonics is a potential candidate for beyond CMOS and neuromorphic computing technologies with advanced phase encoded logic. However, nanoscale imaging of spin waves with full phase and magnetization amplitude information is a challenge. We show a generalized scanning transmission x-ray microscopy platform to get a complete understanding of spin waves, including the k-vector, phase, and absolute magnetization deflection angle. As an example, this is demonstrated using a 50 nm thin permalloy film where we find a maximum deflection angle of 1.5° and good agreement with the k-vector dispersion previously reported in the literature. With a spatial resolution approximately ten times better than any other methods for spin wave imaging, x-ray microscopy opens a vast range of possibilities for the observation of spin waves and various magnetic structures.
External stokes shift of perovskite nanocrystals enlarged by photon recycling
Authors: Gan Zhixing , Chen Weijian , Yuan Lin , Cao Guiyuan , Zhou Chunhua , Huang Shujuan , Wen Xiaoming , Jia Baohua
Published: January 2019

Lead halide perovskite nanocrystals (NCs) have rapidly emerged as promising materials for low-cost and high-efficiency photovoltaic, optoelectronic, and photonic devices. The Stokes shift is a crucial parameter affecting their performance. In this work, we find that the external Stokes shift is strongly dependent on photon recycling. Due to the nonlinear nature of the quantum confinement effect (QCE), the bandgap distribution becomes extremely broad when the sizes are ultra-small, resulting in many repetitions of photon recycling and substantial emission redshift. Thereby, the smaller NCs exhibit larger external Stokes shifts. In detail, for the small NCs with the most probable size of 6.4 nm, the intrinsic Stokes shift is about 71 meV, but the observed external Stokes shift becomes 143.4 meV in the concentrated solution, whereas the intrinsic and apparent Stokes shifts are 69 and 97.6 meV for large NCs of 9.7 nm. Therefore, photon recycling significantly contributes to the external Stokes shift of perovskite NCs, in particular for the ultra-small sizes with strong QCE. This finding will add to the growing fundamental physical understanding of perovskites, which is of great interest due to their applications in photovoltaics and other fields.
New deposition process and design for CoPtP micromagnets
Authors: Johnson-Groh Mara
Published: January 2019

New way to fabricate smooth, crack-free cobalt-rich CoPtP films may yield new possibilities for MEMS applications.
The bright side of PV production in snow-covered mountains
Authors: Kahl Annelen , Dujardin Jérôme , Lehning Michael
Published: January 2019

Significance

Our work shows that it is possible to turn solar photovoltaics (PV) into a more reliable and better-suited contributor to a future renewable energy mix. The correct placement and orientation of solar panels in mountain areas shift a significant amount of electricity generation from the summer to the winter months. PV technology is economically and technologically very promising. Bringing the production pattern closer to typical consumption patterns in the midlatitudes represents an important step toward higher penetration of PV technology on future energy markets. Moreover, a reduction of the winter energy gap by placing PV on (existing) mountain infrastructure lowers the need for (unrealistic) additional storage.
Clonal-level lineage commitment pathways of hematopoietic stem cells in vivo
Authors: Lu Rong , Czechowicz Agnieszka , Seita Jun , Jiang Du , Weissman Irving L.
Published: January 2019

Significance

Hematopoietic stem cells (HSCs) are the key therapeutic component of bone marrow transplantation, the first and most prevalent clinical stem cell therapy. HSCs sustain daily and life-long blood and immune production through a complex stepwise lineage commitment process. In this work, we analyzed HSC lineage commitment at the clonal level and identified HSC regulatory mechanisms that are undetectable by conventional population-level studies. We uncovered distinct HSC clonal pathways that lead to differential blood production and imbalances. Furthermore, we showed that regulation of HSCs transplanted into unconditioned hosts is strikingly different from that after irradiation and after an antagonistic antibody treatment, which has important implications for understanding, interpreting, and optimizing HSC transplantation.
The methyltransferase SETD6 regulates Mitotic progression through PLK1 methylation
Authors: Feldman Michal , Vershinin Zlata , Goliand Inna , Elia Natalie , Levy Dan
Published: January 2019

Significance

The involvement of nonhistone protein methylation in cellular essential pathways is a rising field. Here we show evidence for the involvement of direct lysine methylation of the mitosis regulator PLK1 by SETD6 methyltransferase in cell cycle promotion. Our results reveal that this methylation occurs on two lysine residues and that lack of methylation leads to enhanced PLK1 catalytic activity, causing accelerated mitosis pace and thus faster proliferation rates. These findings suggest that PLK1 methylation by SETD6 controls the pace of mitotic progression, greatly enhancing our understanding of cell cycle complexity. The role of methylation in mitotic progression raises the possibility of its involvement in tumorigenic pathways by orchestrating cell division rates and might have insightful implications for the development of cancer-specific markers.
Body camera footage leads to lower judgments of intent than dash camera footage
Authors: Turner Broderick L. , Caruso Eugene M. , Dilich Mike A. , Roese Neal J.
Published: January 2019

Police departments use body-worn cameras (body cams) and dashboard cameras (dash cams) to monitor the activity of police officers in the field. Video from these cameras informs review of police conduct in disputed circumstances, often with the goal of determining an officer’s intent. Eight experiments (
N
= 2,119) reveal that body cam video of an incident results in lower observer judgments of intentionality than dash cam video of the same incident, an effect documented with both scripted videos and real police videos. This effect was due, in part, to variation in the visual salience of the focal actor: the body cam wearer is typically less visually salient when depicted in body versus dash cam video, which corresponds with lower observer intentionality judgments. In showing how visual salience of the focal actor may introduce unique effects on observer judgment, this research establishes an empirical platform that may inform public policy regarding surveillance of police conduct.
IQGAP-related protein IqgC suppresses Ras signaling during large-scale endocytosis
Authors: Marinović Maja , Mijanović Lucija , Šoštar Marko , Vizovišek Matej , Junemann Alexander , Fonović Marko , Turk Boris , Weber Igor , Faix Jan , Filić Vedrana
Published: January 2019

Macropinocytosis and phagocytosis are evolutionarily conserved forms of bulk endocytosis used by cells to ingest large volumes of fluid and solid particles, respectively. Both processes are regulated by Ras signaling, which is precisely controlled by mechanisms involving Ras GTPase activating proteins (RasGAPs) responsible for terminating Ras activity on early endosomes. While regulation of Ras signaling during large-scale endocytosis in WTDictyosteliumhas been, for the most part, attributed to theDictyosteliumortholog of human RasGAP NF1, in commonly used axenic laboratory strains, this gene is mutated and inactive. Moreover, none of the RasGAPs characterized so far have been implicated in the regulation of Ras signaling in large-scale endocytosis in axenic strains. In this study, we establish, using biochemical approaches and complementation assays in live cells, thatDictyosteliumIQGAP-related protein IqgC interacts with active RasG and exhibits RasGAP activity toward this GTPase. Analyses ofiqgC−and IqgC-overexpressing cells further revealed participation of this GAP in the regulation of both types of large-scale endocytosis and in cytokinesis. Moreover, given the localization of IqgC to phagosomes and, most prominently, to macropinosomes, we propose IqgC acting as a RasG-specific GAP in large-scale endocytosis. The data presented here functionally distinguish IqgC from other members of theDictyosteliumIQGAP family and call for repositioning of this genuine RasGAP outside of the IQGAP group.