bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrically transmissive alkyne-anchored monolayers on gold
Authors: Herrer Lucía , González-Orive Alejandro , Marqués-González Santiago , Martín Santiago , Nichols Richard J. , Serrano José Luis , Low Paul J. , Cea Pilar
Published: March 2019

Well-ordered, self-assembled monolayer films of 1,4-bis((4-ethynylphenyl)ethynyl)benzene on gold are shown to be nearly transparent to outer-sphere electron transfer processes.
Synthesis and structure of deuterated ultra-low cross-linked poly(N-isopropylacrylamide) microgels
Authors: Brugnoni Monia , Nickel Anne C. , Kröger Leif C. , Scotti Andrea , Pich Andrij , Leonhard Kai , Richtering Walter
Published: March 2019

Partial deuteration of the N-isopropylacrylamide monomer reveals new insights into the self-cross-linking of polymer chains in ultra-low cross-linked microgels.
Organic light-emitting diodes comprising highly luminescent red-emitting dendrimers with carbazole-based dendrons
Authors: Russell Steven M. , Brewer Anthony M. , Stoltzfus Dani M. , Saghaei Jaber , Burn Paul L.
Published: March 2019

OLEDs containing a red emitting dendrimer with a solution PLQY of 86 ± 9% have an EQE of 12% and CIE co-ordinates of (0.65, 0.34).
Layered Tl2O: a model thermoelectric material
Authors: Huang H. H. , Xing Guangzong , Fan Xiaofeng , Singh David J. , Zheng W. T.
Published: March 2019

Single-layer Tl2O has an ultralow lattice thermal conductivity and is a potential thermoelectric material.
Highly selective chemosensor for repetitive detection of Fe3+in pure water and bioimaging
Authors: Omer Nahla , Zhang Fayin , Zhao Gang , Guang Shanyi , Xu Hongyao
Published: March 2019

Combining octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) with amine-containing polyacrylamide (OV-POSS co-poly(acrylamide)) gives a new fluorescent polymeric chemo-sensor with complete water solubility.
Succinylated casein-coated peptide-mesoporous silica nanoparticles as an antibiotic against intestinal bacterial infection
Authors: Zhao Gaomei , Chen Yin , He Yongwu , Chen Fang , Gong Yali , Chen Shilei , Xu Yang , Su Yongping , Wang Cheng , Wang Junping
Published: March 2019

A biocompatible MSN/SCN delivery system promotes the drug transformation of an enteric defensin derivative into an intestinal antibiotic against resistant bacteria.
One-step synthesis of novel phosphorus nitride dots for two-photon imaging in living cells
Authors: Wu Xiaoxia , Shu Jie , Feng Bo , Yang Lingyan , Lan Jinze , Li Fan , Xi Peng , Wang Fu
Published: March 2019

Novel phosphorus nitride dots with strong fluorescence, excellent dispersibility and outstanding biocompatibility for two-photon imaging in living cells.
Strong positive allosteric cooperativity in ternary complexes based on hydrogen-bonded aromatic amide macrocycles
Authors: Peng Zhiyong , Guo Xuwen , Xu Weitao , Li Jian , Deng Pengchi , Xiao Xin , Feng Wen , Yuan Lihua
Published: March 2019

Strong positive allosteric cooperativity works in hydrogen-bonded cyclo[8]aramide-based ternary complexes.
Polyphenyl polysulfide: a new polymer cathode material for Li–S batteries
Authors: Sang Pengfei , Si Yubing , Fu Yongzhu
Published: March 2019

We report a new class of polyphenyl polysulfides synthesized by condensation reactions between 4,4′-thiobisbenzenethiol (TBBT) and sulfur with four different molar ratios in a toluene/carbon disulfide mixture at room temperature.
A filled organic crystal as a hybrid large-bandwidth optical waveguide
Authors: Catalano Luca , Commins Patrick , Schramm Stefan , Karothu Durga Prasad , Rezgui Rachid , Hadef Kawther , Naumov Panče
Published: March 2019

A 9,10-dicyanoanthracene hollow crystal was filled with a perylene diimide derivative with complementary emissive features and successfully tested as a hybrid optical waveguide.
Cu-Catalyzed atom transfer radical addition reactions of alkenes with α-bromoacetonitrile
Authors: Pu Weiya , Sun Dani , Fan Wanyue , Pan Wenwen , Chai Qinghui , Wang Xiaoxing , Lv Yunhe
Published: March 2019

A novel copper-catalyzed ATRA reaction of alkenes with α-bromoacetonitrile for the synthesis of γ-bromonitriles and β,γ-unsaturated nitriles was developed.
Computational modeling of the catalytic mechanism of hydroxymethylbilane synthase
Authors: Bung Navneet , Roy Arijit , Priyakumar U. Deva , Bulusu Gopalakrishnan
Published: March 2019

Hydroxymethylbilane synthase (HMBS), the third enzyme in the heme biosynthesis pathway, catalyzes the formation of 1-hydroxymethylbilane (HMB) by a stepwise polymerization of four molecules of porphobilinogen (PBG) using the dipyrromethane (DPM) cofactor.
Effects of single and double nickel doping on boron clusters: stabilization of tubular structures in BnNim,n= 2–22,m= 1, 2
Authors: Tam Nguyen Minh , Duong Long Van , Pham Hung Tan , Nguyen Minh Tho , Pham-Ho My Phuong
Published: March 2019

A systematic investigation on structure, relative stabilities, dissociation behavior and bonding of the singly and doubly Ni doped boron clusters BnNimwithn= 2–22 andm= 1–2, was carried out using density functional theory (TPSSh functional) calculations.
Structural manifestation of partial proton ordering and defect mobility in ice Ih
Authors: Fortes A. D.
Published: March 2019

High precision lattice-parameter measurements provide a potential roadmap to producing partially-ordered states of water ice.
Relationship between ferromagnetism and formation of complex carbon bonds in carbon doped ZnO powders
Authors: Beltrán Jailes J. , Barrero Cesar A. , Punnoose Alex
Published: March 2019

Carbon doped ZnO powders showed RTFM. Hybridization of Zn 4s–C 2p mediated by oxygens is the likely source of the FM behavior. C–Zn–C bonds encourage the AFM signal.
Interlinking supertetrahedral chalcogenolate clusters with bipyridines to form two-dimensional coordination polymers for photocatalytic degradation of organic dye
Authors: Xu Chao , Sheng Ming-Ming , Shi Hua-Tian , Strømme Maria , Zhang Qian-Feng
Published: March 2019

Interlinking chalcogenolate clusters with flexible organic linker forms 2D coordination polymers that demonstrate effective photocatalytic degradation of organic dye.
Enhanced nutrient removal in bioretention systems modified with water treatment residuals and internal water storage zone
Authors: Qiu Fuguo , Zhao Shuang , Zhao Dongye , Wang Juanli , Fu Kunming
Published: March 2019

Bioretention systems modified with water treatment residuals and internal water storage zone are effective for removal of N, P, TSS, COD, and heavy metals in rainfall runoff.
H2O2/periodate (IO4−): a novel advanced oxidation technology for the degradation of refractory organic pollutants
Authors: Chadi Nor Elhouda , Merouani Slimane , Hamdaoui Oualid , Bouhelassa Mohammed , Ashokkumar Muthupandian
Published: March 2019

H2O2/periodate: a novel advanced oxidation process.
Changes of urine metabolites in response to n-3 fatty acid supplements and their correlation with metabolic risk factors in patients with type 2 diabetes
Authors: Ruan Yue , Zheng Jusheng , Ren Yiping , Tang Jun , Li Jiaomei , Li Duo
Published: March 2019

The present study aimed to investigate the effects of n-3 fatty acid supplements on urine metabolite profiling and their correlation with metabolic risk factors in Chinese T2D patients.
NHC ligand-enabled Ni-catalyzed reductive coupling of alkynes and imines using isopropanol as a reductant
Authors: Yao Wei-Wei , Li Ran , Li Jiang-Fei , Sun Juan , Ye Mengchun
Published: March 2019

A nickel-catalyzed reductive coupling of alkynes and imines using readily available isopropanol as the reducing agent was developed.
How mithramycin stereochemistry dictates its structure and DNA binding function
Authors: Hou Caixia , Rohr Jürgen , Parkin Sean , Tsodikov Oleg V.
Published: March 2019

The crystal structures of mithramycin and its analogue reveal how the chemistry of mithramycin shapes it for DNA binding.
Ion transport in hydroxide conducting block copolymers
Authors: Elabd Yossef A.
Published: March 2019

An overview of hydroxide ion transport (a property proportional to fuel cell performance) in block copolymers is presented.
Three-dimensional catalyst systems from expanded graphite and metal nanoparticles for electrocatalytic oxidation of liquid fuels
Authors: Chen Xinyue , Li Hui , Zeng Ting , Zhang Yuanyuan , Wan Qijin , Li Yawei , Yang Nianjun
Published: March 2019

Expanded graphite decorated with palladium or platinum/palladium nanoparticles is cost-effective, efficient, and stable for electrocatalytic oxidation of liquid fuels.
Investigations of the generality of quaternary ammonium salts as alkylating agents in direct C–H alkylation reactions: solid alternatives for gaseous olefins
Authors: Schönbauer David , Spettel Manuel , Pollice Robert , Pittenauer Ernst , Schnürch Michael
Published: March 2019

C–H alkylation reactions using short chain olefins as alkylating agents could be operationally simplified on the lab scale by using quaternary ammonium salts as precursors for these gaseous reagents.
α-2′-Deoxyguanosine can switch DNA G-quadruplex topologies from antiparallel to parallel
Authors: Filitcheva Jana , Edwards Patrick J. B. , Norris Gillian E. , Filichev Vyacheslav V.
Published: March 2019

α-2′-Deoxyguanosine (α-dG) converts antiparallel, dimeric G-quadruplex DNA into a parallel, tetramolecular complex.
Clickable coupling of carboxylic acids and amines at room temperature mediated by SO2F2: a significant breakthrough for the construction of amides and peptide linkages
Authors: Wang Shi-Meng , Zhao Chuang , Zhang Xu , Qin Hua-Li
Published: March 2019

A method of SO2F2 mediated direct clickable coupling of carboxylic acids with amines for the synthesis of a broad scope of amides and peptides was developed.
Fluorescent electronic tongue based on soluble conjugated polymeric nanoparticles for the discrimination of heavy metal ions in aqueous solution
Authors: Feng Chuying , Zhao Peng , Wang Lili , Yang Tao , Wu Yusen , Ding Yun , Hu Aiguo
Published: March 2019

A fluorescence sensing array (or fluorescent electronic tongue) based on six sorts of soluble conjugated polymeric nanoparticles (SCPNs) decorated with PEG chains is designed for the rapid identification of heavy metal ions in water.
Synthesis of conjugated polymers via direct C–H/C–Cl coupling reactions using a Pd/Cu binary catalytic system
Authors: Kuwabara Junpei , Tsuchida Wataru , Guo Shuyang , Hu Ziwei , Yasuda Takeshi , Kanbara Takaki
Published: March 2019

Selective C–H/C–Br coupling and polycondensation with C–H/C–Cl coupling afforded conjugated polymers in a short synthetic step.
Thermoresponsive dendronized chitosan-based hydrogels as injectable stem cell carriers
Authors: Zhang Xiacong , Cheng Lin , Feng Letian , Peng Yu , Zhou Zhimin , Yin Guoyong , Li Wen , Zhang Afang
Published: March 2019

A combination of dendronization and Schiff-base chemistry endows injectable chitosan hydrogels with thermoresponsiveness, self-healing abilities and enhanced mechanical properties under physiological conditions.
Oxalamide-based bisdiamidophosphites: synthesis, coordination, and application in asymmetric metallocatalysis
Authors: Gavrilov Konstantin N. , Mikhel Igor S. , Zheglov Sergey V. , Gavrilov Vladislav K. , Chuchelkin Ilya V. , Firsin Ilya D. , Birin Kirill P. , Pytskii Ivan S. , Paseshnichenko Ksenia A. , Tafeenko Victor A. , Chernyshev Vladimir V. , Shiryaev Alexei A.
Published: March 2019

A new group of P*-chiral bisdiamidophosphites has been developed for Pd- and Rh-catalyzed asymmetric reactions with good to excellent enantioselectivities.
Direct access to benzo[b]fluorenes via a gold-catalysed A3-coupling strategy
Authors: Lustosa Danilo M. , Cieslik Patrick , Hartmann Deborah , Bruckhoff Tim , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K.
Published: March 2019

A one-pot combination of gold catalysis and thermal cyclization provides a fast convergent route to benzo[b]fluorenes.
Palladium-catalyzed direct C–H nitration and intramolecular C–H functionalization for the synthesis of 3-nitro-1-(phenylsulfonyl)-1H-indazole derivatives
Authors: Wang Guodong , Sun Jian , Wang Kai , Han Junfen , Li Hongshuang , Duan Guiyun , You Guirong , Li Furong , Xia Chengcai
Published: March 2019

Various 3-nitro-1-(phenylsulfonyl)-1H-indazole derivatives have been obtained in moderate to high yields using palladium catalysis.
Diastereoselective approach to rationally design tetrahydro-β-carboline–isatin conjugates as potential SERMs against breast cancer
Authors: Sharma Bharvi , Singh Amandeep , Gu Liang , Saha Sourav Taru , Singh-Pillay Ashona , Cele Nosipho , Singh Parvesh , Kaur Mandeep , Kumar Vipan
Published: March 2019

A series of tetrahydro-β-carboline–isatin conjugates was prepared and assayed for anti-proliferative activities on Estrogen Responsive ER(+) and non-responsive ER(−ve) cell-lines.
Preparation and electrochemical performance of nitrogen-enriched activated carbon derived from silkworm pupae waste
Authors: Sattayarut Vichuda , Chanthad Chalathorn , Khemthong Pongtanawat , Kuboon Sanchai , Wanchaem Thanthamrong , Phonyiem Mayuree , Obata Michiko , Fujishige Masatsugu , Takeuchi Kenji , Wongwiriyapan Winadda , Khanchaitit Paisan , Endo Morinobu
Published: March 2019

Nitrogen-enriched activated carbon from silkworm pupae prepared by hydrothermal treatment and chemical activation exhibited superior specific capacitance with excellent cycling stability.
A microdroplet-accelerated Biginelli reaction: mechanisms and separation of isomers using IMS-MS
Authors: Sahota Navneet , AbuSalim Deyaa I. , Wang Melinda L. , Brown Christopher J. , Zhang Zhicaho , El-Baba Tarick J. , Cook Silas P. , Clemmer David E.
Published: March 2019

Electrospray ionization (ESI) combined with ion mobility spectrometry (IMS) and mass spectrometry (MS) techniques is used to examine the Biginelli reaction in an ensemble of ions generated from droplets.
Sandwich-type nanoporous CoO/N-doped carbon multi-layers with ultrahigh lithium storage and long-life stability
Authors: Shi Zhaoliang , Fan Yuzun , Zhou Wei , Guo Lin
Published: March 2019

Sandwich-type porous CoO/N-doped carbon multi-layers can provide 2D electron transfer channels and exhibit super long-term capability for lithium-ion batteries.
Effects of microRNA-208a on inflammation and oxidative stress in ketamine-induced cardiotoxicity through Notch/NF-κB signal pathways by CHD9
Authors: Yuan Hongjie , Du Shibin , Deng Youliang , Xu Xiaoqing , Zhang Qian , Wang Miao , Wang Ping , Su Yi , Liang Xiao , Sun Yanyan , An Zhengzhuang
Published: March 2019

Background: MicroRNA can regulate gene expression, and participate in multiple vital activities, such as inflammation, oxidative stress epigenetic modification, cell proliferation, and apoptosis. It plays an important role in the genesis and development of cardiovascular disease.

Objective: To assess the role of microRNA-208a in ketamine-induced cardiotoxicity.

Methods: All rats were randomly selected into two groups: sham and model groups. After fixed, all rats in the model group was intraperitoneally (IP) injected with 100 mg/kg of ketamine. Heart samples were stained with HE assay. Total RNAs from serum were used to hybridize with the SurePrint G3 Rat Whole Genome GE 8×60 K Microarray G4858A platform.

Results: In the rat model with ketamine-induced cardiotoxicity, microRNA-208a expression was increased. Then, over-expression of microRNA-208a increased inflammation and oxidative stress in vitro model. However, down-regulation of microRNA-208a decreased inflammation and oxidative stress in vitro model. Over-expression of microRNA-208a suppressed CHD9 and Notch1, and induced p65 protein expression in vitro model. Overexpression of CHD9 reduced the effects of microRNA-208a on inflammation and oxidative stress in heart cell through Notch/p65 signal pathways. Notch1 activation reduced the effects of microRNA-208a on inflammation and oxidative stress in heart cell through p65 signal pathways.

Conclusion: MicroRNA-208a may be a potential biomarker for ketamine-induced cardiotoxicity through inflammation and oxidative stress by Notch/NF-κB signal pathways by CHD9.
Performance analysis of opportunistic beamforming system under non‐identical imperfect channel environment
Authors: Lee Donghun
Published: March 2019

In this study, the authors study the effect of non‐identical channel estimation error and feedback delay on the performance of an opportunistic beamforming system. This study derives the exact system performance (i.e. outage probability, symbol‐error rate (SER), and ergodic capacity) of the proposed system using moment generating function in an imperfect channel environment. This study also uses an asymptotic analysis to quantify the diversity order of SER and outage probability to analyse which system variables affect system performance. From the results of an asymptotic analysis, it is shown that by channel estimation error and feedback delay, spatial diversity is eliminated, but the benefits of multiuser diversity still exist. Therefore, the diversity order of the SER and the outage probability of the proposed system are proportional to the number of user terminals, but the conventional system is limited to 1 by channel estimation error and feedback delay.
Synthesis of monodisperse ZrO2 microspheres via urea homogeneous precipitation and its effect on the sintering properties
Authors: Tong Fan , Zhao Ye , Wang Mao‐Hua
Published: March 2019

Monodisperse zirconia microspheres were prepared by homogeneous urea precipitation method. The effect of reaction time, reaction temperature and other synthetic parameters on the dispersion of the product was investigated in this experiment. The as‐prepared zirconium oxide (ZrO2) powders were characterised by X‐ray diffraction, Brunauer–Emmett–Teller analysis, field emission‐scanning electron microscopy and Fourier‐transform infrared spectroscopy. The experimental results show that the size and dispersion of ZrO2 microspheres can be controlled by changing the concentration of polyvinylpyrrolidone (PVP). The size of ZrO2 microspheres is changed from 120 nm to 1 μm with the increase of PVP concentration. When the reaction temperature is raised to 90°C and the reaction time is reached to 2 h, the monodisperse ZrO2 microspheres with a diameter of 120 nm are finally prepared. ZrO2 ceramics possessed an ultrafine, uniform microstructure and a narrow pore size distribution, and the grain size increased from 72 to 190 nm with the increase of sintering temperature. Moreover, when ZrO2 ceramics were sintered at 950°C for 2 h, the theoretical density was up to about 98% (a density of 5.65 g/cm3), which is higher than that of conventional ZrO2 ceramics.
ZnO nanorod array/reduced graphene oxide substrate with enhanced performance in photocatalytic degradation
Authors: Ye Xiaoyun , Wang Zhaopeng , Li Zhengdong , Li Wei , Wang Qianting
Published: March 2019

A novel ZnO nanorod array/reduced graphene oxide (ZnO array/rGO) composite coating was synthesised via the combination of seed layers‐growth and aqueous solution reaction for the formation of ZnO nanorod arrays, which was further combined with rGO using a simple water bath method. The results revealed that perpendicular arrays with hexagonal planes were successfully fabricated. The size and density of the arrays could be optimised by adjusting the reactant concentrations. The influence of the rGO fraction in the ZnO array/rGO composites on the photocatalytic degradation of the methylene blue under UV radiation was investigated. It was found that the photocatalytic performance could be significantly improved by adding rGO. The enhanced photocatalytic activities were attributed to the interactions between ZnO nanorod arrays and rGO nanosheets and subsequently effective separation of photo‐generated electron‐hole pairs via rGO as electron sinks. The ZnO array/rGO composites presented advantages including facile and green preparation, long photo‐electron lifetime, easy particle agglomeration and recovery, and therefore is expected to be an ideal photocatalysts for the future utilisation.
CTAB assisted co‐precipitation synthesis of NiO nanoparticles and their efficient potential towards the removal of industrial dyes
Authors: Kaur Navneet , Singh Jagpreet , Kaur Gaganpreet , Kumar Sanjeev , Kukkar Deepak , Rawat Mohit
Published: March 2019

In this work, nickel oxide nanoparticles (NiO NPs) have been synthesised via cost‐effective and highly convenient co‐precipitation method, using cetyl trimethyl ammonium bromide (CTAB) as capping agent and NaOH as a reducing agent. The as‐synthesised NPs have been analysed by a number of spectroscopic and microscopic techniques such as UV–visible spectroscopy, transmission electron microscope, X‐ray diffraction, Fourier transformed infrared and energy dispersive X‐ray. The prepared NiO NPs hold the prodigious potential towards the photocatalytic degradation of reactive blue 81 and Coomassie brilliant blue R‐250 dyes with degradation efficiency of 90.8 and 95.7% and have high dye degradation rate constants of 1.3 × 10− 2 min− 1 and 2.2 × 10− 2 min− 1, respectively. Thus, this work signifies an efficient way to employ the NiO NPs as effective photocatalyst towards the alleviation of noxious industrial dyes.
Single-mode interferometric field of view in partial turbulence correction
Authors: Perrin G. , Woillez J.
Published: March 2019

Context. The GRAVITY instrument on the ESO VLTI is setting a new mark in the landscape of optical interferometers. Long exposures are possible for the first time in this wavelength domain, delivering a dramatic improvement for astrophysics. In particular, faint objects can be observed at the angular resolution of the VLTI, with exposures exceeding by many orders of magnitude the coherence time of atmospheric turbulence.

Aims. Modern interferometers, especially those that combine light collected by large telescopes such as the Unit Telescopes of the VLT, benefit from partial correction of atmospheric turbulence. We investigate in this paper the influence of atmospheric turbulence on the maximum field of view of interferometers such as GRAVITY, where wavefronts are filtered with single-mode fibres. The basic question is whether the maximum field of view is restricted to the diffraction limit of single apertures or if it is wider in practice. We discuss in particular the case of the field around Sgr A* , with an emphasis on the detectability of the massive main-sequence star S2.

Methods. We theoretically investigated the interferometric and photometric lobes of the interferometer and took atmospheric turbulence into account. We computed the lobe functions with and without partial correction for atmospheric turbulence.

Results. The main result of the paper is that the field of view of the interferometer is widened by tip-tilt residues if higher orders of atmospheric turbulence are corrected for. As a particular case, the S2 star can be detected in interferometric frames centred on Sgr A* even when the distance between the two objects is up to about twice the diffraction limit of a single aperture. We also show that the visibilities are not biased in this case if the pointing accuracies of the fibres are of the order of 10 mas.
Two’s a crowd? Characterising the effect of photometric contamination on the extraction of the global asteroseismic parameter νmax in red-giant binaries
Authors: Sekaran S. , Johnston C. , Tkachenko A. , Beck P. G. , Prša A. , Hambleton K. M.
Published: March 2019

Context. Theoretical scaling relations for solar-like oscillators and red giants are widely used to estimate fundamental stellar parameters. The accuracy and precision of these relations have often been questioned in the literature, with studies often utilising binarity for model-independent validation. However, it has not been tested if the photometric effects of binarity introduce a systematic effect on the extraction of the seismic properties of the pulsating component(s).

Aims. In this paper, we present an estimation of the impact of a contaminating photometric signal with a distinct background profile on the global asteroseismic parameter νmax through the analysis of synthetic red-giant binary light curves.

Methods. We generated the pulsational and granulation parameters for single red giants with different masses, radii and effective temperatures from theoretical scaling relations and use them to simulate single red-giant light curves with the characteristics of Kepler long-cadence photometric data. These are subsequently blended together according to their light ratio to generate binary red-giant light curves of various configurations. We then performed a differential analysis to characterise the systematic effects of binarity on the extraction of νmax.

Results. We quantify our methodological uncertainties through the analysis of single red-giant light curves, both in the presence and absence of granulation. This is used as a reference for our subsequent differential binary analysis, where we find that the νmax extraction for red-giant power spectra featuring overlapping power excesses is unreliable if unconstrained priors are used. Outside of this scenario, we obtain results that are nearly identical to single-star case.

Conclusions. We conclude that (i) the photometric effects of binarity on the extraction of νmax are largely negligible as long as the power excesses of the individual components do not overlap, and that (ii) there is minimal advantage to using more than two super-Lorentzian components to model the granulation signal of a binary red-giant.
High energy spatially radiative properties of Vela X pulsar wind nebula
Authors: Lu Fang-Wu , Gao Quan-Gui , Zhu Bo-Tao , Zhang Li
Published: March 2019

Context. Vela X is a middle-aged pulsar wind nebula (PWN) that has been detected in radio, X-ray, and γ-ray bands. The observations indicate that that photon index and flux density of the inner regions of the nebula have obvious changes as the radial distance increases in the X-ray band, and the surface brightness has been discovered to decrease with the increase of radial distance in γ-ray band.

Aims. The multi-band photon emission and high energy spatially radiative properties of Vela X are investigated in the framework of a spatially dependent particle transport model.

Methods. Electron distribution inside the PWN was described by a spatially dependent particle transport equation and the evolution of the non-thermal photon was described as a photon conservation equation under the assumption of a spherically symmetric system with dynamical evolution. In this model, the dynamical and particle evolution equations were simultaneously solved, and the γ-ray attenuation by the supernova remnant (SNR) photon fields in the PWN were taken into account.

Results. The observed spectral energy distributions of Vela X, including X-ray spectra of the inner regions and γ-ray spectra observed at GeV and TeV bands, are well reproduced. The radial variations of the photon index in X-ray band and the surface brightness in the TeV energy range as well as the γ-ray spectra of the inner region and ring extension can also be well reproduced in the framework of our model. The spatial variations of photon indices at GeV and TeV bands are predicted and show that the photon index in GeV band increases with the increase of radial distance while there is only a slight change in the TeV band. Moreover, the modelling results reveal that the γ-ray attenuation by the SNR photon fields is important for modifying very high energy γ-ray spectrum of Vela X.
Starspot activity of HD 199178
Authors: Hackman T. , Ilyin I. , Lehtinen J. J. , Kochukhov O. , Käpylä M. J. , Piskunov N. , Willamo T.
Published: March 2019

Context. Studying the spots of late-type stars is crucial for distinguishing between the various proposed dynamo mechanisms believed to be the main cause of starspot activity. For this research it is important to collect observation time series that are long enough to unravel both long- and short-term spot evolution. Doppler imaging is a very efficient method for studying spots of stars that cannot be angularly resolved.

Aims. High-resolution spectral observations during 1994–2017 are analysed in order to reveal long- and short-term changes in the spot activity of the FK Comae-type subgiant HD 199178.

Methods. Most of the observations were collected with the Nordic Optical Telescope. The Doppler imaging temperature maps were calculated using an inversion technique based on Tikhonov regularisation and utilising multiple spectral lines.

Results. We present a unique series of 41 temperature maps spanning more than 23 years. All reliable images show a large cool spot region centred near the visible rotation pole. Some lower latitude cool features are also recovered, although the reliability of these is questionable. There is an expected anti-correlation between the mean surface temperature and the spot coverage. Using the Doppler images, we construct the equivalent of a solar butterfly diagram for HD 199178.

Conclusions. HD 199178 clearly has a long-term large and cool spot structure at the rotational pole. This spot structure dominated the spot activity during the years 1994–2017. The size and position of the structure has evolved with time, with a gradual increase during the last years. The lack of lower latitude features prevents the determination of a possible differential rotation.
Spectroscopic and dynamical properties of comet C/2018 F4, likely a true average former member of the Oort cloud
Authors: Licandro J. , de la Fuente Marcos C. , de la Fuente Marcos R. , de León J. , Serra-Ricart M. , Cabrera-Lavers A.
Published: March 2019

Context. The population of comets hosted by the Oort cloud is heterogeneous. Most studies in this area have focused on highly active objects, those with small perihelion distances or examples of objects with peculiar physical properties and/or unusual chemical compositions. This may have produced a biased sample of Oort cloud comets in which the most common objects may be rare, particularly those with perihelia well beyond the orbit of the Earth. Within this context, the known Oort cloud comets may not be representative of the full sample meaning that our current knowledge of the appearance of the average Oort cloud comet may not be accurate. Comet C/2018 F4 (PANSTARRS) is an object of interest in this regard.

Aims. Here, we study the spectral properties in the visible region and the cometary activity of C/2018 F4, and we also explore its orbital evolution with the aim of understanding its origin within the context of known minor bodies moving along nearly parabolic or hyperbolic paths.

Methods. We present observations obtained with the 10.4 m Gran Telescopio Canarias (GTC) that we use to derive the spectral class and visible slope of C/2018 F4 as well as to characterise its level of cometary activity. Direct N-body simulations are carried out to explore its orbital evolution.

Results. The absolute magnitude of C/2018 F4 is Hr > 13.62 ± 0.04 which puts a strong limit on its diameter, D < 10.4 km, assuming a pV = 0.04 cometary-like value of the albedo. The object presents a conspicuous coma, with a level of activity comparable to those of other comets observed at similar heliocentric distances. Comet C/2018 F4 has a visible spectrum consistent with that of an X-type asteroid, and has a spectral slope S′ = 4.0 ± 1.0%/1000 Å and no evidence of hydration. The spectrum matches those of well-studied primitive asteroids and comets. The analysis of its dynamical evolution prior to discovery suggests that C/2018 F4 is not of extrasolar origin.

Conclusions. Although the present-day heliocentric orbit of C/2018 F4 is slightly hyperbolic, both its observational properties and past orbital evolution are consistent with those of a typical dynamically old comet with an origin in the Oort cloud.
WATCAT: a tale of wide-angle tailed radio galaxies
Authors: Missaglia V. , Massaro F. , Capetti A. , Paolillo M. , Kraft R. P. , Baldi R. D. , Paggi A.
Published: March 2019

We present a catalog of 47 wide-angle tailed radio galaxies (WATs), the WATCAT, mainly built including a radio morphological classification; WATs were selected by combining observations from the National Radio Astronomy Observatory/Very Large Array Sky Survey (NVSS), the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST), and the Sloan Digital Sky Survey (SDSS). We included in the catalog only radio sources showing two-sided jets with two clear “warmspots” (i.e., jet knots as bright as 20% of the nucleus) lying on the opposite side of the radio core, and having classical extended emission resembling a plume beyond them. The catalog is limited to redshifts z ≤ 0.15, and lists only sources with radio emission extended beyond 30 kpc from the host galaxy. We found that host galaxies of WATCAT sources are all luminous (−20.5 ≳ Mr ≳ −23.7), red early-type galaxies with black hole masses in the range 108 ≲ MBH ≲ 109 M⊙. The spectroscopic classification indicates that they are all low-excitation galaxies (LEGs). Comparing WAT multifrequency properties with those of FR I and FR II radio galaxies at the same redshifts, we conclude that WATs show multifrequency properties remarkably similar to FR I radio galaxies, having radio power of typical FR IIs.
Varied origins of up-bending breaks in galaxy disks
Authors: Watkins Aaron E. , Laine Jarkko , Comerón Sébastien , Janz Joachim , Salo Heikki
Published: March 2019

Aims. Using a sample of 175 low-inclination galaxies from the S4G, we investigate the origins of up-bending (Type III) breaks in the 3.6 μm surface brightness profiles of disk galaxies.

Methods. We reanalyzed a sample of previously identified Type III disk break-hosting galaxies using a new, unbiased break-finding algorithm, which uncovered many new, sometimes subtle disk breaks across the whole sample. We classified each break by its likely origin through close examination of the galaxy images across wavelengths, and compare samples of galaxies separated by their outermost identified break types in terms of their stellar populations and local environments.

Results. We find that more than half of the confirmed Type III breaks in our sample can be attributed to morphological asymmetry in the host galaxies. As these breaks are mostly an artifact of the azimuthal averaging process, their status as physical breaks is questionable. Such galaxies occupy some of the highest density environments in our sample, implying that much of this asymmetry is the result of tidal disturbance. We also find that Type III breaks related to extended spiral arms or star formation often host down-bending (Type II) breaks at larger radius which were previously unidentified. Such galaxies reside in the lowest density environments in our sample, in line with previous studies that found a lack of Type II breaks in clusters. Galaxies occupying the highest density environments most often show Type III breaks associated with outer spheroidal components.

Conclusions. We find that Type III breaks in the outer disks of galaxies arise most often through environmental influence: either tidal disturbance (resulting in disk asymmetry) or heating through, for example, galaxy harrassment (leading to spheroidal components). Galaxies hosting the latter break types also show bimodal distributions in central g − r color and morphological type, with more than half of such galaxies classified as Sa or earlier; this suggests these galaxies may be evolving into early-type galaxies. By contrast, we find that Type III breaks related to apparently secular features (e.g., spiral arms) may not truly define their hosts’ outer disks, as often in such galaxies additional significant breaks can be found at larger radius. Given this variety in Type III break origins, we recommend in future break studies making a more detailed distinction between break subtypes when seeking out, for example, correlations between disk breaks and environment, to avoid mixing unlike physical phenomena.
Pulse-beam heating of deep atmospheric layers, their oscillations and shocks modulating the flare reconnection
Authors: Jelínek P. , Karlický M.
Published: March 2019

Aims.We study the processes occurring after a sudden heating of deep atmospheric layers at the flare arcade footpoints, which is assumed to be caused by particle beams.

Methods.For the numerical simulations we adopt a 2D magnetohydrodynamic (MHD) model, in which we solve a full set of the time-dependent MHD equations by means of the FLASH code, using the adaptive mesh refinement (AMR) method.

Results.In the initial state we consider a model of the solar atmosphere with densities according to the VAL-C model and the magnetic field arcade having the X-point structure above, where the magnetic reconnection is assumed. We found that the sudden pulse-beam heating of deep atmospheric layers at the flare arcade footpoints generates two magnetohydrodynamic shocks, one propagating upwards and the second propagating downwards in the solar atmosphere. The downward-moving shock is reflected at deep and dense atmospheric layers and triggers oscillations of these layers. The period of these oscillations in our case is about 174 s. These oscillations generate the upward-moving magnetohydrodynamic waves that can influence the flare magnetic reconnection in a quasi-periodic way. These processes require a sudden heating in very localized regions in dense atmospheric layers; therefore, they can be also associated with seismic waves.
Stability analysis of a clutch system with uncertain parameters using sparse polynomial chaos expansions
Authors: Kieu Duc Thinh , Bergeot Baptiste , Gobert Marie-Laure , Berger Sébastien
Published: March 2019

In vehicle transmission systems, frictional forces acting during the sliding phase of the clutch engagement may produce unwanted vibrations. The prediction of the stability of a clutch system remains however a laborious task, as the parameters which have the highest impact on the stability, such as the friction law or the damping, lead to significant dispersions and must be considered as uncertain in such studies. Non-intrusive generalized polynomial chaos (gPC) expansions have already been used in this context. However, the number of deterministic model evaluations (i.e. the computational cost) required to compute the PC coefficients becomes prohibitive for large numbers of uncertain parameters. The sparse polynomial chaos, recently developed by Blatman and Sudret, may overcome this issue. In this paper, the method has been applied to the stability analysis of a clutch system owning up to eight uncertain parameters. Comparisons with the reference Monte Carlo method and classic full PC expansions show that sparse PC expansions allow substantial computational cost reductions while ensuring a high accuracy of the results.
Molaires embrassées et agénésie de deuxièmes prémolaires mandibulaires : une anomalie rarissime ! Rapport d’un cas et revue de la littérature
Authors: Desnoës H.
Published: March 2019

La découverte fortuite d’un cas bilatéral de «_molaires embrassées_ » type II associé à une agénésie des deuxièmes prémolaires est à l’origine d’une revue de la littérature en anglais sur le sujet. Aucune traduction du terme en français n’a été trouvée. L’extraction des quatre dents incluses a été préconisée.
Sulfoxide-Directed Iterative Assembly into Oligoarenes
Authors: Yanagi Tomoyuki , Nogi Keisuke , Yorimitsu Hideki
Published: March 2019

A series of oligoarenes have been synthesized via sulfoxide-based iterative dehydrogenative transformations. By utilizing the sulfinyl moieties as on/off-switchable directing groups, overreactions and/or undesired oligomerizations were completely suppressed. Since the dehydrogenative couplings were not hampered by steric hinderance, sterically encumbered oligoarenes were synthesized.
Nucleophilic Trifluoromethylation Reactions Involving Copper(I) Species: From Organometallic Insights to Scope
Authors: Mudarra Ángel L. , Martínez de Salinas Sara , Pérez-Temprano Mónica H.
Published: March 2019

Over the last decades, trifluoromethyl copper(I) complexes have played a key role as reactive species in C–CF3 bond-forming reactions. This Short Review not only covers selected examples of relevant copper-mediated or catalyzed nucleophilic trifluoromethylation reactions, which is one of the most active fields in organic synthesis, but also provides a comprehensive picture of the real behavior of these copper species, including ubiquitous cuprates, in the reaction media.

1 Introduction

2 Historical Perspective of the Identification of Relevant Trifluoro-

methyl Copper(I) Species

3 In Situ Generation of Active Trifluoromethyl Copper(I) Species

4 Well-Defined Active Trifluoromethyl Copper(I) Complexes

5 Recent Advances on the Performance of Trifluoromethylation

Protocols

6 Conclusions
A Rare Case of Monocular Visual Loss after Spinal Surgery in Prone Position with Adequate Eye Protection
Authors: Babu Naresh , Kohli Piyush , Palaniappan Suresh , Krishnamurthi Ilango , Ramasamy Kim
Published: March 2019

The aim of this case report is to present a rare case of monocular visual loss after spinal surgery in prone position with adequate eye protection. A 38-year-old healthy woman underwent an uncomplicated cervical surgery in prone position, while her head was supported on a foam cushion horseshoe headrest. Immediately after recovery, the patient complained of loss of vision in her left eye. Her best-corrected visual acuity was perception of light. Ocular examination was suggestive of central retinal artery occlusion (CRAO). Blood investigations, carotid Doppler, echography, and computed tomography scan were normal. The incidence of CRAO has decreased in the past decade due to the use of appropriate head rest. In addition to following the guidelines laid by the Perioperative Visual Loss (POVL) Task Force of American Society of Anesthesiologists, attention must be paid to avoid any accidental intraoperative movement of the patient. Checking the eyes intermittently is not a foolproof method for preventing compression. New headrests need to be designed, which will allow continuous monitoring of the patient lying in prone position.
Dural Plasmacytoma Involving Calvarium with Soft Tissue Extension Mimicking Meningioma: A Diagnostic Dilemma
Authors: Chhabra Devendra Kumar , Pandey Tarun Kumar , Singh Prashant Raj , Shukla Anju
Published: March 2019

Here, the authors describe a case of 25-year-old man diagnosed with dural plasmacytoma involving calvarium with soft tissue extension. Magnetic resonance imaging (MRI) revealed extra-axial heterogeneously enhancing soft tissue mass lesion in the left parieto-occipital region with a dural tail mimicking meningioma, destroying the left parietal bone, and bulging into the scalp. Mass was excised and histopathologic examination revealed plasmacytoma with amyloid deposition. There is no recurrence after postoperative radiotherapy and 2 years of follow-up, although the future course is still not certain. The clinician should consider alternative diagnosis other than meningioma prior to proceeding to surgery if the dural-based lesion is involving calvarium and soft tissue extension.
Correlation between Ankle Brachial Index with Coronary Artery Disease and Gender
Authors: Yerra Suresh , Kumar Shravan , Garre Indrani , Kumar Achukatla
Published: March 2019

Background Ankle brachial index (ABI) has been shown to be a specific and sensitive for the diagnosis of peripheral artery disease (PAD). Both PAD and coronary artery disease (CAD) are caused by atherosclerosis, which is a narrowing of the arteries due to the build-up of plaque and fatty material inside the lumen. The aim of our study is to find out the relation between ABI and coronary angiographic findings with cardiovascular risk factors and gender in patients admitted in a tertiary care center with a provisional diagnosis of CAD.

Methods It is a cross-sectional observational study, in which patients admitted with suspected CAD are included. In this study, patient characteristics such as demographics, family history, past history of CAD, and other comorbidities were included, and also the risk factors for atherosclerosis such as hypertension, diabetes, dyslipidemia, and smoking history were enquired by using a predetermined proforma. In all study patients, ABI was measured prior to coronary artery angiogram (CAG). ABI ≤ 0.9 was considered as PAD, and ABI between 0.9 and 1.4 was considered as normal. Then, all patients included in the study underwent CAG. The results of the ABI reports were compared with the angiographic findings and atherosclerotic risk factors.

Results In this study, 90 patients were included who were admitted for CAG. Twenty-two patients have ABI ≤ 1.09 among them, 9 patients have no CAD, and 13 patients have CAD on CAG. Sixty-eight patients have ABI ≥ 1.10, with 28 patients having no CAD and 40 patients having CAD. There is difference in the right and left mean ABI with right ABI less than left ABI, and it is statistically significant (p = 0.014). By binary logistic regression, the determinants of CAD are left ventricle ejection fraction (EF) and age, and ABI was not a predictor. In our study, out of 90 patients, only 1 had ABI < 0.9 (1.1%). Therefore, it is not worth doing ABI in all patients undergoing CAG to rule out peripheral vascular disease (PVD). This is true in male and female patients and even in the diabetics. In comparing male and female ABI, there is no significance between ABI in both the sexes.

Conclusion This study findings concluded that ABI is not a useful method in assessing the risk factors and the severity of CAD in suspected patients. Only left ventricle EF and age were the predictors of the presence of CAD, and ABI was not a predictor. This study have shown the difference in the right and left mean ABI with right ABI less than left ABI, which is an important finding. This study has also shown the similar prevalence of ABI in both sexes. However, to make more accurate results on ABI (right vs. left), we should plan studies with larger sample size in future.
Role of Platelets in Rheumatic Mitral Stenosis: An Observational Study
Authors: Chetti Shravan , Kalivela Santhimayee , Yerra Suresh , Garre Indrani , Kumar Achukatla
Published: March 2019

Background As previous studies demonstrated, the mean platelet volume (MPV) is one of the determinant factors for the development of left atrial appendage (LAA) clot. The authors wanted to see other parameters such as platelet distribution width (PDW) along with MPV in patients with chronic rheumatic heart disease (CHRD) in whom transesophageal echocardiogram (TEE) was done.

Methods Total 50 consecutive CRHD patients with predominantly mitral stenosis (MS) came for cardiac outpatient department (OPD) for balloon valvuloplasty and were enrolled. Transthoracic echocardiography (TTE) and TEE were performed for each patient. Laboratory investigations included all biochemical parameters. In addition MPV and PDW were noted.

Results Most of the 50 patients enrolled in this study were middle-aged women (n = 37), with mean age of 40.18 ± 9.50 years. Patients were divided into two groups: with left atrial (LA) clot (n = 24, group 1) and without LA clot (n = 26, group 2). Out of them, male population with severe MS was more prone for LA clot formation (p = 0.031). When comparing severity of MS with electrocardiographic (ECG) rhythm (normal vs. atrial fibrillation), no statistically significant difference was observed with clot formation (p = −0.44). In this study, presence of clot is more when the patient has larger-size platelets, that is, higher MPV, which is statistically significant (9.823 ± 0.759 vs. 10.996 ± 0.534; p = 0.000). Severe MS is associated with high normal PDW whether the clot is present or not but statistically not significant (p = −0.926).

Conclusion Severity of MS in CRHD patients is an independent determinant of LA clot formation irrespective of rhythm abnormalities and higher MPV value. Male patients with severe MS are more prone to LA clot formation.