bluuebunny/crossref_metadata_2025 huggingface dataset:
The scavenging capacity of γ-aminobutyric acid for acrolein and the cytotoxicity of the formed adduct
Authors: Jiang Kaiyu , Yin Zhao , Zhou Ping , Guo Hongyang , Huang Caihuang , Zhang Guangwen , Hu Wenzhong , Ou Shiyi , Ou Juanying
Published: July 2020

Acrolein is a notorious aldehyde with hazardous impacts on humans.
Electrochemical Overhauser dynamic nuclear polarization
Authors: Tamski Mika , Milani Jonas , Roussel Christophe , Ansermet Jean-Philippe
Published: July 2020

The diamagnetic species is converted to a paramagnetic species by electrochemistry. It is then possible to irradiate the EPR line to achieve Overhauser DNP and transfer part of the electron polarization to nuclei.
Tropical foods as functional foods for metabolic syndrome
Authors: John Oliver D. , du Preez Ryan , Panchal Sunil K. , Brown Lindsay
Published: July 2020

Tropical foods are an integral part of the traditional diet and form part of traditional medicine in many countries.
Modification of protein structures by altering the whey protein profile and heat treatment affectsin vitrostatic digestion of model infant milk formulas
Authors: Halabi Amira , Croguennec Thomas , Bouhallab Said , Dupont Didier , Deglaire Amélie
Published: July 2020

The aim was to investigate how protein structures in model infant milk formulas affect proteolysis kinetics duringin vitrodigestion.
Metagenomic insights into the effects of nanobubble water on the composition of gut microbiota in mice
Authors: Guo Zitao , Hu Bo , Han Hanlin , Lei Zhongfang , Shimizu Kazuya , Zhang Liang , Zhang Zhenya
Published: July 2020

Supplementation with nanobubble water (NBW) could alter the composition of gut microbiota in mice under standard diet.
Stability of ionic liquids in Brønsted-basic media
Authors: Raiguel Stijn , Dehaen Wim , Binnemans Koen
Published: July 2020

The stability of ionic liquids towards strong Brønsted bases is reviewed from a fundamental perspective, and approaches for improving the base stability of various classes of ionic liquids are discussed.
Study of interpulse delay effects on orthogonal dual-pulse laser-induced breakdown spectroscopy in bulk seawater
Authors: Song Jiaojian , Li Nan , Tian Ye , Guo Jinjia , Zheng Ronger
Published: July 2020

With the application of an orthogonal DP-LIBS excitation, when compared to SP-LIBS, significant emission intensity enhancements for a wide range of elements were obtained in seawater by using proper shorter interpulse delays.
Synthesizing 1D and 2D metal oxide nanostructures: using metal acetate complexes as building blocks
Authors: Sui Ruohong , Charpentier Paul A. , Marriott Robert A.
Published: July 2020

1D and 2D nanostructures are self-assembled after metal alkoxides react with acetic acid in a non-aqueous solvent.
Correction: Non-reversible heat-induced gelation of a biocompatible Fmoc-hexapeptide in water
Authors: Wojciechowski Jonathan P. , Martin Adam D. , Du Eric Y. , Garvey Christopher J. , Nordon Robert E. , Thordarson Pall
Published: July 2020

Correction for ‘Non-reversible heat-induced gelation of a biocompatible Fmoc-hexapeptide in water’ by Jonathan P. Wojciechowski et al., Nanoscale, 2020, 12, 8262–8267, DOI: 10.1039/D0NR00289E.
Introduction to plastics in a circular economy
Authors: Sardon Haritz , Li Zi-Chen
Published: July 2020

Haritz Sardon and Zi-Chen Li introduce the Polymer Chemistry themed collection on plastics in a circular economy.
Highly crystalline nickel hexacyanoferrate as a long-life cathode material for sodium-ion batteries
Authors: Rehman Ratul , Peng Jian , Yi Haocong , Shen Yi , Yin Jinwen , Li Chang , Fang Chun , Li Qing , Han Jiantao
Published: July 2020

A low-speed synthesis strategy was designed to fabricate Prussian blue analog based electrode materials for high-performance rechargeable batteries.
Exploring stereoselective excretion and metabolism studies of novel 2-(2-hydroxypropanamido)-5-trifluoromethyl benzoic acid enantiomers
Authors: Rong Rong , Zhang Qi-li , Zhang Rui-zhen , Dan Yu-han , Wang Xin , Zhao Yun-li , Yu Zhi-guo
Published: July 2020

R-/S-2-(2-Hydroxypropanamido)-5-trifluoromethyl benzoic acid (R-/S-HFBA), as a novel COX inhibitor, was firstly reported to have remarkable anti-inflammatory and antiplatelet aggregation activities by our group.
Synthesis and characterization of a novel TEMPO@FeNi3/DFNS–laccase magnetic nanocomposite for the reduction of nitro compounds
Authors: Saberi Shima , Zhiani Rahele , Mehrzad Jamshid , Motavalizadehkakhky Alireza
Published: July 2020

Water is an essential substance for life on earth and for all living things.
Elucidating the role of nitrogen plasma composition in the low-temperature self-limiting growth of indium nitride thin films
Authors: Ilhom Saidjafarzoda , Mohammad Adnan , Shukla Deepa , Grasso John , Willis Brian G. , Okyay Ali K. , Biyikli Necmi
Published: July 2020

Hollow-cathode plasma-generated hydrogen radicals induce crystal phase transformation from h-InN to c-In2O3 during plasma-enhanced atomic layer deposition using trimethyl-indium and Ar/N2 plasma.
Facile photocatalytic reduction of carcinogenic Cr(vi) on Fe-doped copper sulfide nanostructures
Authors: Ain Noor ul , Rehman Zia ur , Nayab Ujala , Nasir Jamal Abdul , Aamir Asma
Published: July 2020

This article reports Fe-doped copper sulfide nanostructures and their ability to photocatalytically reduce carcinogenic Cr(vi). The best result is shown by 9% Fe-doped CuS, which reduces Cr(vi) in 6 min in the presence of sunlight.
Giant magnetoelectric coupling observed at high frequency in NiFe2O4–BaTiO3particulate composite
Authors: Shi Zhenhua , Zhang Jing , Gao Daqiang , Zhu Zhonghua , Yang Zhaolong , Zhang Zhipeng
Published: July 2020

A giant magnetoelectric voltage coupling coefficient without direct current magnetic field observed in NiFe2O4–BaTiO3particulate composite is reported.
One-pot preparation of mesoporous KxPMo12O40 (x = 1, 2, 3, 4) materials for oxidative desulfurization: electrochemically-active surface area (ECSA) determines their activity
Authors: He Jun , Guan Lifang , Zhou Yiqian , Shao Peipei , Yao Yue , Lu Shuxiang , Kong Lingbo , Liao Xiaoyuan
Published: July 2020

A series of pure polyoxometalate salts, Kx[PMo12O40]3− (KxPMo, x = 1, 2, 3, 4), have been successfully prepared via a one pot hydrothermal method using F127 as a template.
Salient features of the aza-Wacker cyclization reaction
Authors: Thomas Annu Anna , Nagamalla Someshwar , Sathyamoorthi Shyam
Published: July 2020

The aza-Wacker cyclization reaction is a powerful strategy for alkene amination.
Unusual doping induced phase transitions in NiS via solventless synthesis enabling superior bifunctional electrocatalytic activity
Authors: Shombe Ginena Bildard , Khan Malik Dilshad , Alenad Asma M. , Choi Jonghyun , Ingsel Tenzin , Gupta Ram K. , Revaprasadu Neerish
Published: July 2020

Transition metal sulfides have been investigated as promising bifunctional materials for catalytic energy generation and energy storage applications.
Hearing Aid Use, Auditory Development, and Auditory Functional Performance in Swedish Children With Moderate Hearing Loss During the First 3 Years
Authors: Persson Anna Elisabeth , Al-Khatib Dareen , Flynn Traci
Published: July 2020

Purpose

This study investigated longitudinal hearing aid (HA) use in a cohort of children with moderate hearing loss (CHL), fitted with amplification before the age of 6 months. Additionally, the relationship of HA use and aided audibility on outcomes of parental questionnaires of auditory skills was examined, and these outcomes were compared to a group of children with normal hearing (CNH).

Method

Nine CHL and 29 CNH and their parents participated in the study. Measures were collected at initial fitting, 10, 18, 24, 30, and 36 months of age. Parents reported hours of HA use and situations the HAs were used. Datalogging and speech intelligibility index were also collected. Auditory skills were measured through parental questionnaires.

Results

The mean hours of HA use/day for this cohort increased from 7.55 at the ages of 10 months to 10.15 at 36 months according to datalogging. Parental estimations of hours of HA use and in which situations varied between subjects. Correlations between HA use from datalogging and speech intelligibility index to measures of auditory skills were weak. CHL showed similar results to CNH on auditory development at the ages of 10, 18, and 24 months but presented with significantly lower scores on auditory functional performance in noise at 30 and 36 months of age.

Conclusions

Longitudinal monitoring of HA use from fitting of amplification with the combination of objective and subjective tools may have a positive impact on HA use in CHL. The lower scores on listening in noise compared to CNH call for further attention.
Radiative-transfer modeling of nebular-phase type II supernovae
Authors: Dessart Luc , John Hillier D.
Published: July 2020

Nebular phase spectra of core-collapse supernovae (SNe) provide critical and unique information on the progenitor massive star and its explosion. We present a set of one-dimensional steady-state non-local thermodynamic equilibrium radiative transfer calculations of type II SNe at 300 d after explosion. Guided by the results obtained from a large set of stellar evolution simulations, we craft ejecta models for type II SNe from the explosion of a 12, 15, 20, and 25 M⊙ star. The ejecta density structure and kinetic energy, the 56Ni mass, and the level of chemical mixing are parametrized. Our model spectra are sensitive to the adopted line Doppler width, a phenomenon we associate with the overlap of Fe II and O I lines with Ly α and Ly β. Our spectra show a strong sensitivity to 56Ni mixing since it determines where decay power is absorbed. Even at 300 d after explosion, the H-rich layers reprocess the radiation from the inner metal rich layers. In a given progenitor model, variations in 56Ni mass and distribution impact the ejecta ionization, which can modulate the strength of all lines. Such ionization shifts can quench Ca II line emission. In our set of models, the [O I] λλ 6300, 6364 doublet strength is the most robust signature of progenitor mass. However, we emphasize that convective shell merging in the progenitor massive star interior can pollute the O-rich shell with Ca, which would weaken the O I doublet flux in the resulting nebular SN II spectrum. This process may occur in nature, with a greater occurrence in higher mass progenitors, and this may explain in part the preponderance of progenitor masses below 17 M⊙ that are inferred from nebular spectra.
Regard sur le modèle agricole sénégalais : pratiques foncières et particularités territoriales des moyennes et grandes exploitations agricoles
Authors: Bourgoin Jérémy , Diop Djibril , Dia Djiby , Sall Moussa , Zagré Romaric , Grislain Quentin , Anseeuw Ward
Published: July 2020

L’enjeu alimentaire lié à l’augmentation démographique est au cœur des agendas internationaux de développement durable et nourrit les débats sur les transitions à entreprendre ou soutenir. Souvent défini en opposition à un modèle agro-industriel intensif et capitaliste, le modèle des agricultures familiales, ensemble de types d’exploitations et d’exploitants aux profils variés, reste difficile à considérer dans sa diversité du fait de sa constante évolution. Certains phénomènes restent peu étudiés, notamment la dynamique d’accumulation foncière d’exploitations agricoles identifiée dans certains pays d’Afrique subsaharienne. Notre contribution, basée sur des enquêtes menées au Sénégal, vise à caractériser les profils et les modalités d’accès au foncier de 1399 exploitations agricoles, concentrant le plus de terres. À l’échelle de différentes zones agro-écologiques, nous mettons en évidence que les chefs d’exploitations agricoles possédant plus de 3 hectares sont majoritairement issus de la localité d’origine, cultivent des terres familiales et investissent dans l’agriculture des revenus issus de cette même activité. Globalement, ces exploitations agricoles ne semblent pas inféodées à une dynamique de gentrification, caractérisée par les investissements d’élites urbaines et rurales, souvent non issues du monde agricole, et faisant l’acquisition de terres grâce à des revenus non agricoles. Concernant les dynamiques foncières, les enquêtes montrent que la majorité des terres reste sous occupation coutumière bien que les territoires ruraux soient en constante évolution. Dans un contexte où les pouvoirs publics insistent sur les besoins d’intensification agricole, à travers la promotion de l’entreprenariat privé et du secteur agro-industriel, il est crucial d’avoir une bonne compréhension de la diversité des formes d’exploitations agricoles. Cela est d’autant plus nécessaire qu’une réforme foncière est en cours et qu’elle contribuera à redéfinir les contours du modèle agricole, entre volontés productivistes et exigences de durabilité et d’équité.
Single-peak-regulation and wide-angle dual-band metamaterial absorber based on hollow-cross and solid-cross resonators
Authors: Tang Yibo , He Longhui , Xu Jianming , He Hailang , Li Yuhan , Liu Anfeng
Published: July 2020

A dual-band microwave metamaterial absorber with single-peak regulation and wide-angle absorption has been proposed and illustrated. The designed metamaterial absorber is consisted of hollow-cross resonators, solid-cross resonators, dielectric substrate and metallic background plane. Strong absorption peak coefficients of 99.92% and 99.55% are achieved at 8.42 and 11.31 GHz, respectively, which is basically consistent with the experimental results. Surface current density and changing material properties are employed to illustrate the absorptive mechanism. More importantly, the proposed dual-band metamaterial absorber has the adjustable property of single absorption peak and could operate well at wide incidence angles for both transverse electric (TE) and transverse magnetic (TM) waves. Research results could provide and enrich instructive guidances for realizing a single-peak-regulation and wide-angle dual-band metamaterial absorber.
General polytopal H(div)-conformal finite elements and their discretisation spaces
Authors: Abgrall Rémi , Le Mélédo Élise , Öffner Philipp
Published: July 2020

We present a class of discretisation spaces and H(div)-conformal elements that can be built on any polytope. Bridging the flexibility of the Virtual Element spaces towards the element’s shape with the divergence properties of the Raviart–Thomas elements on the boundaries, the designed frameworks offer a wide range of H(div)-conformal discretisations. As those elements are set up through degrees of freedom, their definitions are easily amenable to the properties the approximated quantities are wished to fulfil. Furthermore, we show that one straightforward restriction of this general setting share its properties with the classical Raviart–Thomas elements at each interface, for any order and any polytopal shape. Then, to close the introduction of those new elements by an example, we investigate the shape of the basis functions corresponding to particular elements in the two dimensional case.
Endo-buccal mucosal punch biopsy and cervico-facial benign subcutaneous emphysema
Authors: Casatuto Thibault , Benat Gauthier , Laurencin-Dalicieux Sara , Cousty Sarah
Published: July 2020

Subcutaneous emphysema is a rare feature caused by traumatism (weapons, accidents: crashes, barotrauma, …), dental care and infections. A 48-year-old woman consults for a right oral mucosa lesion and benefits from a biopsy for anatomopathological diagnosis. Within hours of the biopsy, bilateral jugal then cervical swelling has occured without signs of severity. The examination at 48 hours and the CT scan showed a bilateral cervicofacial emphysema with a spontaneous favorable resolution in a few days making the diagnosis of benign subcutaneous emphysema (BSCE). BSE can occurs after an endobuccal biopsy, a close follow up is necessary to rule out gas gangrene.The resolution is spontaneous with the necessity to reassure the patient.
Milling diagnosis using artificial intelligence approaches
Authors: Knittel Dominique , Makich Hamid , Nouari Mohammed
Published: July 2020

The Industry 4.0 framework needs new intelligent approaches. Thus, the manufacturing industries more and more pay close attention to artificial intelligence (AI). For example, smart monitoring and diagnosis, real time evaluation and optimization of the whole production and raw materials management can be improved by using machine learning and big data tools. An accurate milling process implies a high quality of the obtained material surface (roughness, flatness). With the involvement of AI-based algorithms, milling process is expected to be more accurate during complex operations. In this work, a milling diagnosis using AI approaches has been developed for composite sandwich structures based on honeycomb core. The use of such material has grown considerably in recent years, especially in the aeronautic, aerospace, sporting and automotive industries. But the precise milling of such material presents many difficulties. The objective of this work is to develop a data-driven industrial surface quality diagnosis for the milling of honeycomb material, by using supervised machine learning methods. In this approach cutting forces are online measured in order to predict the resulting surface flatness. The developed diagnosis tool can also be applied to the milling of other materials (metal, polymer, etc.).
Mapping Robust Genetic Variants Associated with Exercise Responses
Authors: Alvarez-Romero Javier , Voisin Sarah , Eynon Nir , Hiam Danielle
Published: July 2020

This review summarised robust and consistent genetic variants associated with aerobic-related and resistance-related phenotypes. In total we highlight 12 SNPs and 7 SNPs that are robustly associated with variance in aerobic-related and resistance-related phenotypes respectively. To date, there is very little literature ascribed to understanding the interplay between genes and environmental factors and the development of physiological traits. We discuss future directions, including large-scale exercise studies to elucidate the functional relevance of the discovered genomic markers. This approach will allow more rigour and reproducible research in the field of exercise genomics.
Carbonyl-Photoredox/Metal Dual Catalysis: Applications in Organic Synthesis
Authors: Li Hong-Xi , Zhu Da-Liang , Young David James
Published: July 2020

Photoredox/metal dual catalysis is a versatile tandem methodology to construct carbon–carbon and carbon–heteroatom bonds. The focus of this short review is the application of this technology to C(sp3)–C(sp3), C(sp3)–C(sp2), C(sp2)–C(sp2), C(sp2)–O, and C(sp3)–O bond formation induced by readily available and inexpensive carbonyl complexes as single electron transfer agents, photosensitizers, or hydrogen atom transfer agents.

1 Introduction

2 Homocoupling of Aryl Halides

3 Functionalization of C(sp3)–H Bonds

3.1 Dehydrogenation of Alkanes

3.2 Arylation/Alkylation

3.3 Carboxylation

3.4 Acylation

3.5 Hydroalkylation of Olefins

3.6 Hydroalkylation of Imines

4 Benzoylation of Aryl Bromides

5 Aryl Esterification

6 Oxidation of β-Keto Esters

7 Conclusions and Future Outlook
Efficient Synthesis of O-tert-Propargylic Oximes via Nicholas Reaction
Authors: Nakamura Itaru , Shiga Keigo , Suzuki Mao , Terada Masahiro
Published: July 2020

A synthetic protocol to access O-tert-propargylic oximes derived from tertiary propargylic alcohols was established via Nicholas reaction. Thus, BF3·OEt2-mediated reaction between the dicobalt hexacarbonyl complex of tert-propargylic alcohols and p-nitrobenzaldoxime followed by decomplexation with cerium(IV) ammonium nitrate afforded the corresponding O-tert-propargylic oximes in good to high yields. The obtained O-tert-propargylic oximes were effectively converted into heterocycles, such as four-membered cyclic nitrones, oxazepines, and isoxazolines, by using π-Lewis acidic catalysts.
Catalyst-Free Synthesis of Diastereomerically Pure 3-Sulfonyl­azetidin-2-ones via Microwave-Assisted Tandem Wolff Rearrangement–Staudinger Cycloaddition
Authors: Krasavin Mikhail , Synofzik Judith , Bakulina Olga , Balabas Olga , Dar’in Dmitry
Published: July 2020

A wide range of α-diazo-β-ketosulfones have been applied to thermally promoted tandem Wolff rearrangement – Staudinger [2+2] cycloaddition with imines to give polysubstituted β-lactam sulfones. Dia­stereomerically pure syn-diastereomers were obtained in good yields and the relative stereochemistry was confirmed by single-crystal X-ray crystallography. These findings significantly expand the scope of this transformation, in contrast to substantial limitations reported previously. Moreover, this methodology enables flexible exploration of new substitution patterns around the privileged β-lactam core for drug design and optimization.
Silver-Catalyzed Decarboxylative Radical Addition/Cyclization of Oxamic Acids with Alkenes towards Quinolin-2-ones
Authors: Feng Gaofeng , Jin Chengan , He Jing-Yao , Bai Qi-Fan
Published: July 2020

An efficient silver-catalyzed tandem decarboxylative radical addition/cyclization of oxamic acids with alkenes has been developed. This method provides a novel and straightforward protocol toward a variety of 4-aryl-3,4-dihydroquinolin-2(1H)-ones, 4-(α-carbonyl)-3,4-dihydroquinolin-2(1H)-ones, and quinolin-2(1H)-ones in aqueous solution.
Synthesis of Allene-Containing Apocarotenoids by Cross-Coupling Strategy
Authors: Sakaguchi Kazuhiko , Nishioka Yuto , Kinashi Naoto , Yukihira Nao , Shinada Tetsuro , Nishimura Takahiro , Hashimoto Hideki , Katsumura Shigeo
Published: July 2020

The stereocontrolled total synthesis of the allene and carbonyl conjugated apocarotenoids, paracentrone and 19-hexanoyloxyparacentrone 3-acetate, was achieved by sequential cross-coupling reactions using boronic acid ester and iodine- or tin-substituted C5 dienes, which were the building blocks for the elongation of the conjugated polyene systems at both terminals.
Quadratic first integrals of autonomous conservative dynamical systems
Authors: Tsamparlis Michael , Mitsopoulos Antonios
Published: July 2020

An autonomous holonomic dynamical system is described by a system of second order differential equations whose solution gives the trajectories of the system. The solution is facilitated by the use of first integrals (FIs) that are used to reduce the order of the system of differential equations and, if there are enough of them, to determine the solution. Therefore, in the study of dynamical systems, it is important that there exists a systematic method to determine the FIs of second order differential equations. On the other hand, a system of second order differential equations defines (as a rule) a kinetic energy (or Lagrangian), which provides a symmetric second order tensor that we call the kinetic metric. This metric via its symmetries (or collineations) brings into the scene the differential geometry that provides numerous results and methods concerning the determination of these symmetries. It is apparent that if one manages to provide a systematic way that will relate the determination of the FIs of a given dynamical system to the symmetries of the kinetic metric defined by this very system, then one will have at his/her disposal the powerful methods of differential geometry in the determination of the FIs and, consequently, the solution of the dynamical equations. This was also a partial aspect of Lie’s work on the symmetries of differential equations. The subject of this work is to provide a theorem that realizes this scenario. The method we follow has been considered previously in the literature and consists of the following steps: Consider the generic quadratic FI of the form I=Kab(t,qc)q̇aq̇b+Ka(t,qc)q̇a+K(t,qc), where Kab(t, qc), Ka(t, qc), and  K(t, qc) are unknown tensor quantities and require dI/dt = 0. This condition leads to a system of differential equations involving the coefficients Kab(t, qc), Ka(t, qc), and  K(t, qc) whose solution provides all possible quadratic FIs of this form. We demonstrate the application of the theorem in the classical cases of the geodesic equations and the generalized Kepler potential in which we obtain all the known results in a systematic way. We also obtain and discuss the time-dependent FIs that are as important as the autonomous FIs determined by other methods.
Microfluidic device reveals cancer cell behavior under oxygen tension gradient conditions
Authors: Mandel Savannah
Published: July 2020

The vitality and motility of cancer cells in normal oxygen conditions and oxygen tension gradient conditions are compared, revealing cancer cells tend towards environments with higher oxygen tension.
Extremely small-diameter, high-density, radio frequency, plasma sources and central gas feeding for next-generation electrodeless plasma thrusters
Authors: Shinohara S. , Kuwahara D. , Ishigami Y. , Horita H. , Nakanishi S.
Published: July 2020

Radio frequency (RF) waves including helicon waves can readily produce high-electron-density (ne up to 1013 cm−3) plasmas with a broad range of external operating parameters. Various featured RF and helicon sources in a wide range of scales are suitable for plasma propulsion schemes. Electrodeless RF plasmas have no direct contact between electrodes and antennas, which enables long-life operation. However, one of the crucial problems is to reduce the plasma size for future applications in nano- and pico-satellites. Diagnostics of the plasma parameters in a small area should also be improved. Furthermore, to increase plasma performance, it is important to consider the radial electron density (ne) profile with an increasing upper limit, observed in high-density helicon sources due to the depletion of neutrals. This problem may be controlled by the location of neutral gas feeding and knowledge of the gas pressure distribution. Here, production of RF plasmas, with extremely small diameters from 3-mm down to 0.5-mm including 1-mm, was demonstrated, and characterization of ne and the electron temperature was performed with a collisional radiative model. Finally, to improve plasma performance such as ne and the thrust force, internal gas feeding was demonstrated using a developed Pirani gauge to measure neutral density.
Functionalization of electrostatic nonlinearities to overcome mode aliasing limitations in the sensitivity of mass microsensors based on energy localization
Authors: Rabenimanana Toky , Walter Vincent , Kacem Najib , Le Moal Patrice , Bourbon Gilles , Lardiès Joseph
Published: July 2020

In order to overcome mode aliasing limitation in linear mode-localized sensors, we demonstrate in this Letter both theoretically and experimentally how to tune the electrostatic nonlinearity and exceed the ultimate sensitivity reachable in the linear regime. A mass sensor composed of two coupled micro-cantilevers with different lengths is considered and the results show that the sensitivity can be significantly enhanced up to 67%. By performing experiments on the fabricated device and depositing the mass perturbation with a focused ion beam, the same phenomenon was observed. These promising results open the way toward ultrasensitive multimodal microsensors with functionalized nonlinearities.
Ultrafast direct charge transfers mediated modification of third order nonlinear optical response in Sb2Se3–Au core shell nanorods
Authors: Yadav Rajesh Kumar , Aneesh J. , Sharma Rituraj , Bera Santu Kumar , Maji Tuhin Kumar , Karmakar Debjani , Loh K. P. , Adarsh K. V.
Published: July 2020

Realization of the direct charge transfer at metal–semiconductor interfaces is a long-standing goal of both fundamental and technological significance. Here we report the synthesis of a colloidal Sb2Se3–Au core–shell nanorod as a model system to demonstrate an efficient direct charge transfer from an Au shell to Sb2Se3 core when the metal is selectively excited at the plasmonic wavelength. In our experiments, direct charge transfer by the Landau damping of the plasmons of metal shell significantly enhances the excited state population that results in an unprecedented ultrafast third-order nonlinear optical response as a function of the plasmon-excitation detuning wavelength. The single step photo-induced charge transfer analogous to the intramolecular electronic transition in molecules is probed by ultrafast transient absorption, which reveals that the electrons are directly transferred from the Fermi level of Au to the unoccupied levels of Sb2Se3 in less than 150 fs. First principles density functional theory calculations indicate that the hybridized eigenstates of the strongly coupled system are delocalized across the metal–semiconductor interfaces. By formulating the theoretical models, we connect our experimental results to the theory.
Conspicuous interatomic bonding in chalcogenide crystals and implications on electronic, optical, and elastic properties
Authors: Hasan Sahib , Adhikari Puja , Baral Khagendra , Ching Wai-Yim
Published: July 2020

Chalcogenide crystals are a unique class of materials very different from semiconductors or metallic alloys. They also have many practical applications, especially in relation to their optical properties. However, the fundamental understanding of their electronic structure and physical properties is rather scattered and incomplete. We present a detailed study using first-principles calculations on the electronic structure, interatomic bonding, and optical and mechanical properties for 32 chalcogenide crystals. They consist of 22 binary (AnBm) and 10 ternary (AnA′Bm) crystals with A = Ag, As, Cu, Ge, Sb, Sn, Cd, Zn; A′ = In, Ge, Sn; and B = S, Se, Te with n = 1, 2, 4 and m = 1, 2, 3, 4, 9. We use the novel concept of total bond order density as a single quantum mechanical metric to characterize the internal cohesion of these crystals and correlate them with the calculated properties, especially the mechanical properties. Based on this large database, we are able to identify some new and conspicuous observations to reach some useful conclusions related to the chemical composition of the chalcogenide compounds and their complex interatomic interactions. Specific examples from crystals and their unique properties in relation to the elements A and A′ and chalcogenide element B (S, Se, and Te) are discussed and highlighted. Finally, generalization of the observed trends and empirical rules can be extended to much larger classes of ternary and quaternary chalcogenide crystals and glasses so far unexplored.
Shifts in timing and duration of breeding for 73 boreal bird species over four decades
Authors: Hällfors Maria H. , Antão Laura H. , Itter Malcolm , Lehikoinen Aleksi , Lindholm Tanja , Roslin Tomas , Saastamoinen Marjo
Published: July 2020

Significance

The changing climate is causing shifts in the timing of species activity. We use data on over 820,000 nesting records to quantify changes in the beginning, end, and duration of breeding among boreal birds. In addition to a general advance of breeding, we find an overall contraction of the breeding period. This pattern was most common among resident and short-distance migrating species. Overall, we detect a shift in the community-level distribution of bird reproduction, involving the start and end of reproduction and how concentrated the breeding period is. From a methodological perspective, our study illustrates that a focus on quantifying phenological advances alone may mask important patterns of phenology change across the season.
Recent anthropogenic curtailing of Yellow River runoff and sediment load is unprecedented over the past 500 y
Authors: Liu Yu , Song Huiming , An Zhisheng , Sun Changfeng , Trouet Valerie , Cai Qiufang , Liu Ruoshi , Leavitt Steven W. , Song Yi , Li Qiang , Fang Congxi , Zhou Weijian , Yang Yinke , Jin Zhao , Wang Yunqiang , Sun Junyan , Mu Xingmin , Lei Ying , Wang Lu , Li Xuxiang , Ren Meng , Cui Linlin , Zeng Xueli
Published: July 2020

Significance

The Yellow River (YR) is the cradle of Chinese civilization. It supports agriculture, social prosperity, and human survival. YR runoff and sediment load have sharply fallen since the late 1980s. We reconstructed natural runoff history for the middle reach of the YR from 1492 to 2013 CE. We found that the recent low observed YR runoff is unprecedented over the past five centuries, mainly due to the combination of decreasing precipitation and increasing water consumption by human activities, particularly agricultural irrigation. Our results provide a valuable historical dataset for YR water management, as well as an important model for how to distinguish and quantify anthropogenic influence from natural variability in global change studies.
Microbial exposure drives polyclonal expansion of innate γδ T cells immediately after birth
Authors: Ravens Sarina , Fichtner Alina S. , Willers Maike , Torkornoo Dennis , Pirr Sabine , Schöning Jennifer , Deseke Malte , Sandrock Inga , Bubke Anja , Wilharm Anneke , Dodoo Daniel , Egyir Beverly , Flanagan Katie L. , Steinbrück Lars , Dickinson Paul , Ghazal Peter , Adu Bright , Viemann Dorothee , Prinz Immo
Published: July 2020

Significance

T cell receptors (TCRs) on the surface of T cells mediate recognition of antigen. Since each new T cell carries an individual clonal TCR, monitoring of TCR repertoires reflects how T cells react and proliferate in response to environmental cues in the developing immune system of neonates and children. γδ T cells appear early during ontogeny and are important for immune surveillance. Here, we longitudinally analyze γδ T cells in neonates and show an immediate polyclonal expansion of phosphoantigen-reactive Vγ9Vδ2+T cells after birth. We also observed differences in γδ TCR repertoires of children from Europe and Africa. Our study highlights the importance of γδ T cells in the neonatal immune system and their prompt expansion directly after birth.
Elevated paleomagnetic dispersion at Saint Helena suggests long-lived anomalous behavior in the South Atlantic
Authors: Engbers Yael A. , Biggin Andrew J. , Bono Richard K.
Published: July 2020

Significance

Earth’s magnetic field is generated in the outer core by convecting liquid iron and protects the atmosphere from solar wind erosion. The most substantial anomaly in the magnetic field is in the South Atlantic (SA). An important conjecture is that this region could be a site of recurring anomalies because of unusual core−mantle conditions, but this has not previously been tested on geological timescales. With paleodirectional data from rocks from Saint Helena, an island in the SA, we show that the directional behavior of the magnetic field in the SA did indeed vary anomalously between ∼8 million and 11 million years ago. This supports the hypothesis of core−mantle interaction being manifest in the long-term geomagnetic field behavior of this region.
An influenza A hemagglutinin small-molecule fusion inhibitor identified by a new high-throughput fluorescence polarization screen
Authors: Yao Yao , Kadam Rameshwar U. , Lee Chang-Chun David , Woehl Jordan L. , Wu Nicholas C. , Zhu Xueyong , Kitamura Seiya , Wilson Ian A. , Wolan Dennis W.
Published: July 2020

Significance

The HA glycoprotein enables viral entry into host cells and is the main target for antibodies in our immune system. While HA has now been established as a validated target for drug discovery, no FDA-approved small molecules are available that specifically prevent HA from binding host receptors or inhibit its membrane fusion activity and, thus, prevent infection. We, therefore, designed a fluorescence polarization probe to enable rapid identification of small molecules that bind to the stem fusion machinery of group 1 HAs. Application of our assay yielded a small molecule to the influenza A group 1 HA stem with antiviral efficacy.
Fc-mediated effector function contributes to the in vivo antiviral effect of an HIV neutralizing antibody
Authors: Asokan Mangaiarkarasi , Dias Joana , Liu Cuiping , Maximova Anna , Ernste Keenan , Pegu Amarendra , McKee Krisha , Shi Wei , Chen Xuejun , Almasri Cassandra , Promsote Wanwisa , Ambrozak David R. , Gama Lucio , Hu Jianfei , Douek Daniel C. , Todd John-Paul , Lifson Jeffrey D. , Fourati Slim , Sekaly Rafick P. , Crowley Andrew R. , Ackerman Margaret E. , Ko Sung Hee , Kilam Divya , Boritz Eli A. , Liao Laura E. , Best Katharine , Perelson Alan S. , Mascola John R. , Koup Richard A.
Published: July 2020

Significance

Neutralizing antibodies (NAbs) against HIV-1 are under clinical development. Despite demonstrated antiviral activity when used as treatment in HIV-infected people, the mechanism of action of NAbs remains controversial. Quantification of the relative contribution of Fab-mediated (neutralization of free virus) and Fc-mediated functions such as antibody-dependent cellular cytotoxicity (ADCC), phagocytosis, and complement fixation is essential to develop better therapies. Here, we treated chronically SHIV-infected rhesus macaques with a single dose of NAb VRC07-523LS with or without Fc modifications. Fc function contributes 21% to the antiviral activity of VRC07-523LS with an unmodified Fc region, when compared to NAb with Fc knockout mutations. However, NAbs with improved ADCC function in vitro did not show enhanced antiviral activity in vivo.
Soft transition between subcritical and supercritical currents through intermittent cascading interfacial instabilities
Authors: Salinas Jorge , Balachandar S. , Shringarpure Mrugesh , Fedele Juan , Hoyal David , Cantero Mariano
Published: July 2020

Significance

Gravity currents are predominantly horizontal flows driven by the density difference between the current’s fluid and the ambient fluid above. The two well-established flow regimes are the supercritical and subcritical regimes. We report on the existence of an intermediate transcritical regime where the flow along the interface undergoes a cyclical transition between quiescent and highly intermittent turbulent states. While the current slowly evolves in the subcritical and supercritical regimes in a near self-similar manner (akin to dynamics near a stable fixed point), the transcritical current with its unique cyclical evolution exhibits a limit-cycle–like behavior. This phenomenon has hitherto been unreported, since it requires highly resolved simulations over very long streamwise length involving about 1 billion grid points.
Protrudin in protrudinG invadopodia: Membrane contact sites and cell invasion
Authors: Arora Amita , Olkkonen Vesa M.
Published: July 2020

Invadopodia are dynamic protrusions that harbor matrix metalloproteinases for pericellular matrix degradation. However, the mechanisms underlying their maturation are poorly understood. Pedersen et al. (2020. J. Cell Biol.https://doi.org/10.1083/jcb.202003063) demonstrate a dual role of Protrudin in invadopodia elongation and matrix degradation, central to cell invasion and cancer metastasis.
Fabrication of high-transmittance and low-reflectance meter-scale moth-eye film via roll-to-roll printing
Authors: Ju Sucheol , Choi Jin-Young , Chae Dongwoo , Lim Hangyu , Kang Hojung , Lee Heon
Published: July 2020

Anti-reflection technology is a core technology in the field of optoelectronic devices that is used to increase efficiency by reducing reflectance. In particular, the bio-mimetic moth-eye pattern has the advantage of being independent of wavelength, polarization, and angle of incidence. In this study, we fabricated a 1.1 m wide meter-scale moth-eye film using roll-to-roll printing. A uniform moth-eye pattern with a height of 170 nm was formed, which reduced the average reflectance value by 3.2% and increased the average transmittance value by 3.1%, in a wide wavelength range of 400–700 nm. Additionally, the moth-eye film coated with a self-assembled monolayer (SAM) exhibited a contact angle of 140.3°, almost equal to the superhydrophobic angle of 150°. Furthermore, the contact angle, transmittance, and reflectance of the SAM-coated moth-eye film were maintained after an environmental test, which was conducted for 168 h at 60 °C and 80% humidity.
Low-dose spectral CT reconstruction based on image-gradient L0-norm and adaptive spectral PICCS
Authors: Wang Shaoyu , Wu Weiwen , Feng Jian , Liu Fenglin , Yu Hengyong
Published: July 2020

The photon-counting detector based spectral computed tomography (CT) is promising for lesion detection, tissue characterization, and material decomposition. However, the lower signal-to-noise ratio within multi-energy projection dataset can result in poorly reconstructed image quality. Recently, as prior information, a high-quality spectral mean image was introduced into the prior image constrained compressed sensing (PICCS) framework to suppress noise, leading to spectral PICCS (SPICCS). In the original SPICCS model, the image gradient L1-norm is employed, and it can cause blurred edge structures in the reconstructed images. Encouraged by the advantages in edge preservation and finer structure recovering, the image gradient L0-norm was incorporated into the PICCS model. Furthermore, due to the difference of energy spectrum in different channels, a weighting factor is introduced and adaptively adjusted for different channel-wise images, leading to an L0-norm based adaptive SPICCS (L0-ASPICCS) algorithm for low-dose spectral CT reconstruction. The split-Bregman method is employed to minimize the objective function. Extensive numerical simulations and physical phantom experiments are performed to evaluate the proposed method. By comparing with the state-of-the-art algorithms, such as the simultaneous algebraic reconstruction technique, total variation minimization, and SPICCS, the advantages of our proposed method are demonstrated in terms of both qualitative and quantitative evaluation results.
Interaction of an atmospheric pressure plasma jet with grounded and floating metallic targets: simulations and experiments
Authors: Viegas Pedro , Hofmans Marlous , van Rooij Olivier , Obrusník Adam , L M Klarenaar Bart , Bonaventura Zdenek , Guaitella Olivier , Sobota Ana , Bourdon Anne
Published: July 2020

The interaction of kHz μs-pulsed atmospheric pressure He jets with metallic targets is studied through simulations and experiments, focusing on the differences between floating and grounded targets. It is shown that the electric potential of the floating target is close to grounded in the instants after the impact of the discharge, but rises to a high voltage, potentially more than half of the applied voltage, at the end of the 1 μs pulse. As a result, a return stroke takes place after the discharge impact with both grounded and floating targets, as a redistribution between the high voltage electrode and the low voltage target. Electric field, electron temperature and electron density in the plasma plume are higher during the pulse with grounded target than with floating target, as gradients of electric potential progressively dissipate in the latter case. Finally, at the fall of the pulse, another electrical redistribution takes place, with higher intensity with the highly-charged floating target than with the grounded target. It is shown that this phenomenon can lead to an increase in electric field, electron temperature and electron density in the plume with floating target.
High quality semiconductor Cd2SnO4 films for solar cell applications
Authors: Diliegros-Godines C J , Castanedo-Pérez R , Torres-Delgado G , Elías-Zúñiga A , Flores-Ruiz F J
Published: July 2020

In this work, we study the effect of Ar/CdS annealing treatment on physical properties of semiconductor Cd2SnO4 (∼260 nm thick) films. The films were produced by sol–gel dip-coating method and annealed at 450 °C ≤ T
a ≤ 650 °C. A full characterization of the optical, electrical, and structural properties, and a discussion of the mechanism that yield enhanced physical properties is presented. All annealing treatments explored led to the improvement of physical properties of the semiconductor films. However, values of electrical resistivity of 6 × 10−4 Ω-cm, carrier concentration of 3 × 1020 cm−3 and mobility of 35 cm2 Vs−1 were reached at T
a = 650 °C, without compromising the optical properties (T ≥ 85% for 450 ≤ λ ≤ 1200 nm). These represent an improvement of almost 6-fold over untreated films. Although the Moss–Burstein effect leads to a band gap of 3.5–3.7 eV, the fundamental band gap was estimated to be 3.3 eV. Moreover, the computed work function, 4.7–4.4 eV, indicates that these films can be used as transparent conductive oxide to design high-efficiency CdS/CdTe thin-film solar cells due to the smooth match of Fermi level with CdS coupled layer.
Modeling the non-linear rheological behavior of magnetorheological gel using a computationally efficient model
Authors: Zhang Guang , Li Yancheng , Yu Yang , Wang Huixing , Wang Jiong
Published: July 2020

Magnetorheological (MR) gel is a novel generation of smart MR material, which has the inherent hysteretic properties and strain stiffening behaviors that are dependent on applied excitation, i.e. magnetic field. The main challenge for the application of the MR gel is the accurate reproduction of the above characteristics by a computationally efficient model that can predict the dynamic stress-strain/rate responses. In this work, parametric modeling on the non-linear rheological behavior of MR gel is conducted. Firstly, a composite MR gel sample was developed by dispersing carbon iron particles into the polyurethane matrix. The dynamic stress-strain/rate responses of the MR gel are obtained using a commercial rheometer with strain-controlled mode under harmonic excitation with frequencies of 0.1 Hz, 5 Hz and 15 Hz and current levels of 1 A and 2 A at a fixed amplitude of 10%. Following a mini-review on the available mathematical models, the experimental data is utilized to fit into the models to find the best candidate utilizing a genetic algorithm. Then, a statistical analysis is conducted to evaluate the model’s performance. The non-symmetrical Bouc–Wen model outperforms all other models in reproducing the non-linear behavior of MR gel. Finally, the parameter sensitivity analysis is employed to simplify the non-symmetrical Bouc–Wen model and then the parameter generalization is conducted and verified for the modified non-symmetrical Bouc–Wen model.
Automatic removal of false image stars in disk-resolved images of the Cassini Imaging Science Subsystem
Authors: Zhang Qing-Feng , Lu Zhi-Cong , Zhou Xiao-Mei , Zheng Yang , Li Zhan , Peng Qing-Yu , Long Shun , Zhu Wei-Heng
Published: July 2020

Taking a large number of images, the Cassini Imaging Science Subsystem(ISS) has been routinely used in astrometry. In ISS images, disk-resolved objects often lead to false detection of stars that disturb the camera pointing correction. The aimof this study was to develop an automated processingmethod to remove the false image stars in disk-resolved objects in ISS images. The method included the following steps: extracting edges, segmenting boundary arcs, fitting circles and excluding false image stars. The proposed method was tested using 200 ISS images. Preliminary experimental results show that it can remove the false image stars in more than 95% of ISS images with disk-resolved objects in a fully automatic manner, i.e., outperforming the traditional circle detection based on Circular Hough Transform (CHT) by 17%. In addition, its speed is more than twice as fast as that of the CHT method. It is also more robust (no manual parameter tuning is needed) when compared with CHT. The proposed method was also applied to a set of ISS images of Rhea to eliminate the mismatch in pointing correction in automatic procedure. Experiment results showed that the precision of final astrometry results can be improve by roughly 2 times that of automatic procedure without the method. It proved that the proposed method is helpful in the astrometry of ISS images in a fully automatic manner.