bluuebunny/crossref_metadata_2025 huggingface dataset:
Holistic approach to assess co-benefits of local climate mitigation in a hot humid region of Australia
Authors: Haddad Shamila , Paolini Riccardo , Ulpiani Giulia , Synnefa Afroditi , Hatvani-Kovacs Gertrud , Garshasbi Samira , Fox Jonathan , Vasilakopoulou Konstantina , Nield Lawrence , Santamouris Mattheos
Published: August 2020

Overheated outdoor environments adversely impact urban sustainability and livability. Urban areas are particularly affected by heat waves and global climate change, which is a serious threat due to increasing heat stress and thermal risk for residents. The tropical city of Darwin, Australia, for example, is especially susceptible to urban overheating that can kill inhabitants. Here, using a modeling platform supported by detailed measurements of meteorological data, we report the first quantified analysis of the urban microclimate and evaluate the impacts of heat mitigation technologies to decrease the ambient temperature in the city of Darwin. We present a holistic study that quantifies the benefits of city-scale heat mitigation to human health, energy consumption, and peak electricity demand. The best-performing mitigation scenario, which combines cool materials, shading, and greenery, reduces the peak ambient temperature by 2.7 °C and consequently decreases the peak electricity demand and the total annual cooling load by 2% and 7.2%, respectively. Further, the proposed heat mitigation approach can save 9.66 excess deaths per year per 100,000 people within the Darwin urban health district. Our results confirm the technological possibilities for urban heat mitigation, which serves as a strategy for mitigating the severity of cumulative threats to urban sustainability.
Direct imaging, three-dimensional interaction spectroscopy, and friction anisotropy of atomic-scale ripples on MoS2
Authors: Dagdeviren Omur E. , Acikgoz Ogulcan , Grütter Peter , Baykara Mehmet Z.
Published: August 2020

Theory predicts that two-dimensional (2D) materials may only exist in the presence of out-of-plane deformations on atomic length scales, frequently referred to as ripples. While such ripples can be detected via electron microscopy, their direct observation via surface-based techniques and characterization in terms of interaction forces and energies remain limited, preventing an unambiguous study of their effect on mechanical characteristics, including but not limited to friction anisotropy. Here, we employ high-resolution atomic force microscopy to demonstrate the presence of atomic-scale ripples on supported samples of few-layer molybdenum disulfide (MoS2). Three-dimensional force/energy spectroscopy is utilized to study the effect of ripples on the interaction landscape. Friction force microscopy reveals multiple symmetries for friction anisotropy, explained by studying rippled sample areas as a function of scan size. Our experiments contribute to the continuing development of a rigorous understanding of the nanoscale mechanics of 2D materials.
Ultrafast and anharmonic Rabi oscillations between non-Bloch bands
Authors: Lee Ching Hua , Longhi Stefano
Published: August 2020

Bloch band theory and bulk-boundary correspondence in non-Hermitian systems are attracting great attention in different areas of science. Interband transitions and Rabi flopping induced by emission or absorption of field quanta are fundamental and well-understood processes in Hermitian systems. However, they are challenged in a non-Hermitian system, where band theory is affected by system boundaries. Here we consider Rabi oscillations in non-Hermitian lattices exhibiting unbalanced non-Hermitian skin effect, and unveil an unprecedented scenario of Rabi flopping. The effective dipole moment of the transition - usually considered a bulk property - is however strongly dependent on boundary conditions. Rabi oscillations become anharmonic and transitions cease to be vertical in the energy-momentum plane in systems with open boundaries. Remaining stable even in the presence of complex energies, Rabi oscillations provide a vivid illustration of how competition between non-Hermitian, non-local and Floquet effects can result in significant enhancements of physically measurable quantities.
Label-free fluorometric detection of microRNA using isothermal rolling circle amplification generating tandem G-quadruplex
Authors: Kim Minhee , Kim Dong-Min , Kim Dong-Eun
Published: August 2020

Fluorometric detection of microRNA using Rolling Circle Amplification generating tandem G-quadruplex (GQ-RCA). Target miRNA triggers the GQ-RCA reaction generating tandem repeats of the G-quadruplex, resulting in enhanced Thioflavin T fluorescence.
Rapid electrotransfer probing for improved detection sensitivity in in-gel immunoassays
Authors: Mourdoukoutas Andoni P. , Grist Samantha M. , Herr Amy E.
Published: August 2020

This study demonstrates electrotransfer probing for improved protein detection sensitivity of hydrogel-based immunoassays in reduced time compared to conventional diffusive probing.
Activatable cell-penetrating peptides: 15 years of research
Authors: de Jong Heleen , Bonger Kimberly M. , Löwik Dennis W. P. M.
Published: August 2020

Since the first report on activatable CPPs (ACPPs) in 2004, various methods of activation have been developed. Here, we provide an overview of the different ACPP strategies known to date and summarize the benefits, drawbacks, and future directions.
Manganese and rhenium-catalyzed selective reduction of esters to aldehydes with hydrosilanes
Authors: Wei Duo , Buhaibeh Ruqaya , Canac Yves , Sortais Jean-Baptiste
Published: August 2020

The selective reduction of carboxylic esters into silyl alkyl acetals promoted by manganese and rhenium catalysts provides facile access to aldehydes upon hydrolysis.
Synthetic access to a phosphorescent non-palindromic pincer complex of palladium by a double oxidative addition – comproportionation sequence
Authors: Feuerstein Wolfram , Breher Frank
Published: August 2020

A highly phosphorescent non-palindromic (C^C^N) palladium complex may be prepared by means of a double oxidative addition – comproportionation sequence, which is a new approach for the synthesis of non-palindromic pincer complexes.
A low symmetry cluster meets a low symmetry ligand to sharply boost MOF thermal stability
Authors: Gao Yajun , Zhang Mingxing , Chen Cong , Zhang Yong , Gu Yuming , Wang Qian , Zhang Wenwei , Pan Yi , Ma Jing , Bai Junfeng
Published: August 2020

An approach in which a low symmetry cluster meets a low symmetry ligand to sharply boost the thermal stability of a MOF is presented.
Selective hydrogenation of primary amides and cyclic di-peptides under Ru-catalysis
Authors: Subaramanian Murugan , Sivakumar Ganesan , Babu Jessin K. , Balaraman Ekambaram
Published: August 2020

A ruthenium(ii)-catalyzed selective hydrogenation of challenging primary amides and cyclic di-peptides to their corresponding primary alcohols and amino alcohols, respectively, is reported.
Access to diverse germylenes and a six-membered dialane with a flexible β-diketiminate
Authors: Pahar Sanjukta , Swamy V. S. V. S. N. , Das Tamal , Gonnade Rajesh G. , Vanka Kumar , Sen Sakya S.
Published: August 2020

The scope of a pendant picolyl group in the β-diketiminate system is explored, which gives rise to diverse germylenes and a six-membered dialane, analogous to cyclohexane.
2D materials towards ultrafast photonic applications
Authors: Zhai Xin-Ping , Ma Bo , Wang Qiang , Zhang Hao-Li
Published: August 2020

Two-dimensional materials are now excelling in yet another arena of ultrafast photonics, including optical modulation through optical limiting/mode-locking, photodetectors, optical communications, integrated miniaturized all-optical devices, etc.
The benefit of poor mixing: kinetics of coacervation
Authors: Blocher McTigue Whitney C. , Voke Elizabeth , Chang Li-Wei , Perry Sarah L.
Published: August 2020

We describe a strategy that tracks the evolution of turbidity for poorly mixed samples to characterize the kinetics of coacervation.
Imaging oxygen molecular adsorption and dissociation on the Ti site of rutile TiO2(110) surface with real configuration at 78 K by atomic force microscopy
Authors: Wen Huan Fei , Sang Hongqian , Sugawara Yasuhiro , Li Yan Jun
Published: August 2020

Transition and dissociation of adsorbed O2 with three different configurations are directly observed at 78 K by atomic force microscopy.
Acetylation of graphite oxide
Authors: Nordenström Andreas , Iakunkov Artem , Baburin Igor , Talyzin Alexandr
Published: August 2020

Unlike many methods of chemical modification of Graphite Oxide (GO) reported during 1930–1960 and re-studied in much detail over the last decade, acetylation somehow escaped attention and remained almost completely unexplored.
Nanolubrication in deep eutectic solvents
Authors: Hallett James E. , Hayler Hannah J. , Perkin Susan
Published: August 2020

We report surface force balance measurements of the normal surface force and friction between two mica surfaces separated by a nanofilm of the deep eutectic solvent ethaline.
Correlation of dynamical disorder and oxy-ion diffusion mechanism in a Dy, W co-doped La2Mo2O9 system: an electrolyte for IT-SOFCs
Authors: Nayyer Ruhi Naz , Anwane Shyamkant , Gaikwad Vishwajit , Sathe Vasant , Acharya Smita
Published: August 2020

Dy, W co-doped La2Mo2O9 (LMX) system is explored to understand the order–disorder phase transition, dynamical disorder state and their influence on the oxy-ion diffusion mechanism.
Using reverse osmosis membranes to control ion transport during water electrolysis
Authors: Shi Le , Rossi Ruggero , Son Moon , Hall Derek M. , Hickner Michael A. , Gorski Christopher A. , Logan Bruce E.
Published: August 2020

A relatively inexpensive commercially available RO membrane was shown to be useful for direct seawater H2 generation as the membrane can selectively transport protons and hydroxide ions over other salt ions, and keep the inert anolyte contained to avoid chlorine gas evolution.
Microplastics removal in wastewater treatment plants: a critical review
Authors: Iyare Paul U. , Ouki Sabeha K. , Bond Tom
Published: August 2020

Wastewater treatment plants (WWTPs) are an important route for microplastics to enter aquatic environments.
Electrochemically enabled synthesis of sulfide imidazopyridines via a radical cyclization cascade
Authors: Zhong Ping-Fu , Lin Hong-Min , Wang Lin-Wei , Mo Zu-Yu , Meng Xiu-Jin , Tang Hai-Tao , Pan Ying-Ming
Published: August 2020

In this paper, we report the synthesis of sulfide imidazo[1,2-a]pyridines from vinyl azides, thiophenols, and pyridines via a radical [3 + 2] cycloaddition.
A 96-well format microvascularized human lung-on-a-chip platform for microphysiological modeling of fibrotic diseases
Authors: Mejías Joscelyn C. , Nelson Michael R. , Liseth Olivia , Roy Krishnendu
Published: August 2020

A 3D microvascularized lung-on-a-chip device for modeling pulmonary diseases.
Hybrid nanoparticle based fluorescence switch for recognition of ketoprofen in aqueous media
Authors: Saini Anu , Kaur Manpreet , Mayank  , Kuwar Anil , Kaur Navneet , Singh Narinder
Published: August 2020

Hybrid nanoassembly, fluorescent chemosensors, selective response to ketoprofen, and nanomolar detection.
Towards the design of a mixture of diether and succinate as an internal donor in a MgCl2-supported Ziegler–Natta catalyst
Authors: Ghasemi Hamedani Nona , Arabi Hassan , Poorsank Fatemeh
Published: August 2020

An investigation into competitions of mixtures of internal donors for interaction with MgCl2was carried out and the subsequent influence on catalyst performance was studied.
Optimization and gas sensing properties of Au nanoparticle modified α-Fe2O3 nanodisk structures for highly sensitive acetone detection
Authors: Yang Haoyue , Zhou Rui , Sun Yongjiao , Li Pengwei , Zhang Wendong , Zhao Zhenting , Shi Jian , Hu Jie , Chen Yong
Published: August 2020

Au nanoparticle (Au NP) modified α-Fe2O3 nanodisk structures are obtained using a facile hydrothermal method and annealing based surface treatment.
Synthesis and characterization of a novel manganese ferrite–metal organic framework MIL-101(Cr) nanocomposite as an efficient and magnetically recyclable sonocatalyst
Authors: Siadatnasab Firouzeh , Farhadi Saeed , Hoseini Akram-Alsadat , Sillanpää Mika
Published: August 2020

A magnetic MnFe2O4/MIL-101(Cr) nanocomposite was synthesized and applied as a novel sonocatalyst for enhanced degradation of organic dye pollutants.
Novel garnished cobalt(ii) phthalocyanine with MWCNTs on modified GCE: sensitive and reliable electrochemical investigation of paracetamol and dopamine
Authors: Mounesh  , Reddy K. R. Venugopal
Published: August 2020

The synthesized CoTBPCAPc was confirmed by physico-electrochemical analysis, is thermally stable, and has good yield. CoTBPCAPc/MWCNTs/GCE detects PA and its toxic degradation product DA at different potentials, simultaneously and with excellent analytical performance.
Correction: Solid-phase extraction followed by deep eutectic solvent based dispersive liquid–liquid microextraction and GC-MS detection of the estrogenic compounds in wastewater samples
Authors: Davoodi Reza , Nodehi Ramin Nabizadeh , Rastkari Noushin , Zinatizadeh Ali Akbar , Mahvi Amir Hossein , Fattahi Nazir
Published: August 2020

Correction for ‘Solid-phase extraction followed by deep eutectic solvent based dispersive liquid–liquid microextraction and GC-MS detection of the estrogenic compounds in wastewater samples’ by Reza Davoodi et al., New J. Chem., 2020, 44, 9844–9851, DOI: 10.1039/D0NJ00911C.
Deep eutectic solvent-based manganese molybdate nanosheets for sensitive and simultaneous detection of human lethal compounds: comparing the electrochemical performances of M-molybdate (M = Mg, Fe, and Mn) electrocatalysts
Authors: Baby Jeena N. , Sriram Balasubramanian , Wang Sea-Fue , George Mary , Govindasamy Mani , Benadict Joseph Xavier
Published: August 2020

Potentially hazardous chemical contaminants endanger the environment and human well-being, challenging scientists and policy makers to develop holistic alternative approaches for remediation.
Recent advances in ultrathin two-dimensional materials and biomedical applications for reactive oxygen species generation and scavenging
Authors: Wang Lifeng , Li Yan , Zhao Lin , Qi Zhaojun , Gou Jingyun , Zhang Sha , Zhang Jin Zhong
Published: August 2020

ROS play an important role physiological processes. Two dimensional materials possess ROS scavenging performance in dark or ROS generation ability under light stimuli. This review providing an overview of 2D materials in ROS related field.
Cu(i)-Catalyzed addition–cycloisomerization difunctionalization reaction of 1,3-enyne-alkylidenecyclopropanes (ACPs)
Authors: Li Peng-Hua , Wei Yin , Shi Min
Published: August 2020

A novel synthesis of 3-trifluoroethylcyclopenta[b]naphthalene-4-carbonitrile derivatives from 1,3-enyne-ACPs via Cu(i)-catalyzed 1,4-addition of 1,3-enynes and aromatic cycloisomerization of allene–ACP-type intermediates has been developed.
Well-defined, linear, wholly aromatic polymers with controlled content and position of pyridine moieties in macromolecules from one-pot, room temperature, metal-free step-polymerizations
Authors: Cetina-Mancilla Enoc , Olvera Lilian I. , Balmaseda Jorge , Forster Michael , Ruiz-Treviño F. Alberto , Cárdenas Jorge , Vivaldo-Lima Eduardo , Zolotukhin Mikhail G.
Published: August 2020

Synthesis of processable, aromatic pyridine-containing polymers has always been a great challenge.
Metal-free anionic polymerization ofn-hexyl isocyanate catalyzed by phosphazene bases
Authors: Heo Chi-Ho , Bak In-Gyu , Chae Chang-Geun , Satoh Toshifumi , Lee Jae-Suk
Published: August 2020

Metal-free anionic polymerization ofn-hexyl isocyanate (HIC) catalyzed by phosphazene bases in THF at −98 °C under 10−6Torr was attempted to obtain poly(n-hexyl isocyanate) (PHIC) peptide mimics with a high purity.
ZIF-8-based vs. ZIF-8-derived Au and Pd nanoparticles as efficient catalysts for the Ullmann homocoupling reaction
Authors: Wang Wenjuan , Chen Shuang , Guisasola Cal Eduardo , Martínez Moro Marta , Moya Sergio , Coy Emerson , Wang Changlong , Hamon Jean-René , Astruc Didier
Published: August 2020

On comparing ZIF-8-based and ZIF-8-derived gold and palladium nanocatalysts, they were found to be very efficient for the optimized Ullmann coupling of iodoarenes in DMF.
Rational design of electrospun nanofibrous materials for oil/water emulsion separation
Authors: Zhang Jichao , Liu Lifang , Si Yang , Yu Jianyong , Ding Bin
Published: August 2020

This review focuses on the preparation of electrospun nanofibers with selective wettability (hydrophobic–oleophilic, hydrophilic–oleophobic, and switchable properties) and porous structure (2D and 3D porous structures) for emulsion separation.
The preparation of (4H)-imidazol-4-ones and their application in the total synthesis of natural products
Authors: Keel Katarina L. , Tepe Jetze J.
Published: August 2020

The first review article summarizing known methodologies for the preparation of (4H)-imidazol-4-ones and their application in the total synthesis of imidazol-4-one containing natural products.
Efficient and controllable ultrasound-assisted depolymerization of organosolv lignin catalyzed to liquid fuels by MCM-41 supported phosphotungstic acid
Authors: Du Boyu , Chen Changzhou , Sun Yang , Yang Ming , Yu Mengtian , Liu Bingyang , Wang Xing , Zhou Jinghui
Published: August 2020

Lignin was subjected to different contents of PTA/MCM-41-catalyzed ultrasound-assisted depolymerization for efficient β-O-4 aryl ether bond cleavage to achieve efficient liquid fuel yields.
Highly stable folic acid functionalized copper-nanocluster/silica nanoparticles for selective targeting of cancer cells
Authors: Fang Xiaoming , Huang Yanhua , Yu Dan , Shi Caiwen , Liu Ming
Published: August 2020

Folic acid functionalized CuNCs@SiO2 nanocomposites with superior fluorescence properties, high stability and good biocompatibility for targeted cell imaging.
Correction: The mechanical, electronic, optical and thermoelectric properties of two-dimensional honeycomb-like of XSb (X = Si, Ge, Sn) monolayers: a first-principles calculations
Authors: Bafekry Asadollah , Shojaei Fazel , Hoat Doh M. , Shahrokhi Masoud , Ghergherehchi Mitra , Nguyen C.
Published: August 2020

Correction for ‘The mechanical, electronic, optical and thermoelectric properties of two-dimensional honeycomb-like of XSb (X = Si, Ge, Sn) monolayers: a first-principles calculations’ by Asadollah Bafekry et al., RSC Adv., 2020, 10, 30398–30405, DOI: 10.1039/D0RA05587E.
Correction: Microwave-assisted synthesis of polypyridyl ruthenium(ii) complexes as potential tumor-targeting inhibitors against the migration and invasion of Hela cells through G2/M phase arrest
Authors: Cao Jieqiong , Wu Qiong , Zheng Wenjie , Li Li , Mei Wenjie
Published: August 2020

Correction for ‘Correction: Microwave-assisted synthesis of polypyridyl ruthenium(ii) complexes as potential tumor-targeting inhibitors against the migration and invasion of Hela cells through G2/M phase arrest’ by Jieqiong Cao et al., RSC Adv., 2017, 7, 29925, DOI: 10.1039/C7RA90067H.
Cu3P/PAN derived N-doped carbon catalyst with non-toxic synthesis for alkaline hydrogen evolution reaction
Authors: Kim HyoWon , Lee Yongju , Song DongHoon , Kwon YongKeun , Kim Eom-Ji , Cho EunAe
Published: August 2020

HER-active Cu3P/N-doped carbon is inspired by the role of PAN in Li-ion batteries, and non-toxic one step synthesis includes phosphorization of Cu and cyclization of PAN. The synergistic effects and mechanical integrity relate to N-doped carbon.
Double membrane formation in heterogeneous vesicles
Authors: Bolmatov Dima , Carrillo Jan-Michael Y. , Sumpter Bobby G. , Katsaras John , Lavrentovich Maxim O.
Published: August 2020

Coarse-grained models show double membrane formation from single-membrane, heterogeneous liposomes in the presence of small, hydrophobic molecules.
Correction: Poly(norbornene) anion conductive membranes: homopolymer, block copolymer and random copolymer properties and performance
Authors: Mandal Mrinmay , Huang Garrett , Hassan Noor Ul , Mustain William E. , Kohl Paul A.
Published: August 2020

Correction for ‘Poly(norbornene) anion conductive membranes: homopolymer, block copolymer and random copolymer properties and performance’ by Mrinmay Mandal et al., J. Mater. Chem. A, 2020, DOI: 10.1039/d0ta04756b.
Phosphatidylinositol(4,5)bisphosphate: diverse functions at the plasma membrane
Authors: Katan Matilda , Cockcroft Shamshad
Published: August 2020

Phosphatidylinositol(4,5) bisphosphate (PI(4,5)P2) has become a major focus in biochemistry, cell biology and physiology owing to its diverse functions at the plasma membrane. As a result, the functions of PI(4,5)P2 can be explored in two separate and distinct roles – as a substrate for phospholipase C (PLC) and phosphoinositide 3-kinase (PI3K) and as a primary messenger, each having unique properties. Thus PI(4,5)P2 makes contributions in both signal transduction and cellular processes including actin cytoskeleton dynamics, membrane dynamics and ion channel regulation. Signalling through plasma membrane G-protein coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and immune receptors all use PI(4,5)P2 as a substrate to make second messengers. Activation of PI3K generates PI(3,4,5)P3 (phosphatidylinositol(3,4,5)trisphosphate), a lipid that recruits a plethora of proteins with pleckstrin homology (PH) domains to the plasma membrane to regulate multiple aspects of cellular function. In contrast, PLC activation results in the hydrolysis of PI(4,5)P2 to generate the second messengers, diacylglycerol (DAG), an activator of protein kinase C and inositol(1,4,5)trisphosphate (IP3/I(1,4,5)P3) which facilitates an increase in intracellular Ca2+. Decreases in PI(4,5)P2 by PLC also impact on functions that are dependent on the intact lipid and therefore endocytosis, actin dynamics and ion channel regulation are subject to control. Spatial organisation of PI(4,5)P2 in nanodomains at the membrane allows for these multiple processes to occur concurrently.
Sustainable transportation system for electronic waste recycling from a social perspective
Authors: Liang Sheng , Pi Huijin , Hsu Ching‐Hsien , Kadry Seifedine Nimer
Published: August 2020

E‐waste is currently identified as the world's fastest‐growing waste stream. The key driver behind this trend is the rapid technological advancement and socio‐economic development. When hazardous chemicals are not properly handled, e‐waste may harm ecosystems and human well‐being. Direct effects include releases of acids, heavy metal toxicity, carcinogens and indirect effects such as heavy metal bio‐enlargement, acids enlargement and toxicity problems. In this study, a specific type of system is utilised to collect and transport the different types of hazardous e‐waste using sustainable transportation with the decision‐making trial and evaluation laboratory (DEMATEL). The proposed method of DEMATEL is utilised to identify the relationship and the degree of impact among determined e‐waste recycling barriers. The experimental results suggest input material, lack of funds and most affecting factors that are required to be addressed for the improvement of e‐waste recycling infrastructure.
Magnetospheric accretion in the intermediate-mass T Tauri star HQ Tauri
Authors: Pouilly K. , Bouvier J. , Alecian E. , Alencar S. H. P. , Cody A.-M. , Donati J.-F. , Grankin K. , Hussain G. A. J. , Rebull L. , Folsom C. P.
Published: August 2020

Context. Classical T Tauri stars are pre-main sequence stars surrounded by an accretion disk. They host a strong magnetic field, and both magnetospheric accretion and ejection processes develop as the young magnetic star interacts with its disk. Studying this interaction is a major goal toward understanding the properties of young stars and their evolution.

Aims. The goal of this study is to investigate the accretion process in the young stellar system HQ Tau, an intermediate-mass T Tauri star (1.9 M⊙).

Methods. The time variability of the system is investigated both photometrically, using Kepler-K2 and complementary light curves, and from a high-resolution spectropolarimetric time series obtained with ESPaDOnS at CFHT.

Results. The quasi-sinusoidal Kepler-K2 light curve exhibits a period of 2.424 d, which we ascribe to the rotational period of the star. The radial velocity of the system shows the same periodicity, as expected from the modulation of the photospheric line profiles by surface spots. A similar period is found in the red wing of several emission lines (e.g., HI, CaII, NaI), due to the appearance of inverse P Cygni components, indicative of accretion funnel flows. Signatures of outflows are also seen in the line profiles, some being periodic, others transient. The polarimetric analysis indicates a complex, moderately strong magnetic field which is possibly sufficient to truncate the inner disk close to the corotation radius, rcor ∼ 3.5 R⋆. Additionally, we report HQ Tau to be a spectroscopic binary candidate whose orbit remains to be determined.

Conclusions. The results of this study expand upon those previously reported for low-mass T Tauri stars, as they indicate that the magnetospheric accretion process may still operate in intermediate-mass pre-main sequence stars, such as HQ Tauri.
Could methylene blue be used to manage burning mouth syndrome? A pilot case series
Authors: Lecor Papa Abdou , Touré Babacar , Moreau Nathan , Braud Adeline , Dieb Wisam , Boucher Yves
Published: August 2020

Objective:Burning mouth syndrome is a disabling condition of complex pathophysiology characterized by spontaneous pain felt in the oral mucosa in the absence of evident mucosal lesions which lacks efficient treatments to this day. The purpose of this study was to demonstrate the efficacy of methylene blue in the management of burning mouth syndrome.Methods:The study was conducted at the dental clinic of the Anta Diop University and Newtown dental clinic of Dakar, Senegal. A solution of methylene blue as a mouth-rinse (0.5%) was applied for 5 minutes in five patients satisfying the ICHD-3 diagnostic criteria for burning mouth syndrome. This procedure was repeated every 6 hours 3 times per 24h, during 7 days. Using numeric rating scale, pain severity was assessed as the mean pain felt during the last day of application.Results:After 7 days, the pain was significantly reduced by two-thirds and almost absent at 3 and 6 months follow-up. No secondary effects of the use of methylene blue were observed. Putative mechanisms of action and potential implications for treatment are discussed.Conclusion:Methylene blue is an old compound but a novel topical therapy that could prove beneficial in the management of burning mouth syndrome.
Symmetries of the Dirac quantum walk and emergence of the de Sitter group
Authors: Apadula Luca , Bisio Alessandro , D’Ariano Giacomo Mauro , Perinotti Paolo
Published: August 2020

A quantum walk describes the discrete unitary evolution of a quantum particle on a discrete graph. Some quantum walks, referred to as the Weyl and Dirac walks, provide a description of the free evolution of relativistic quantum fields in the small wave-vector regime. The clash between the intrinsic discreteness of quantum walks and the continuous symmetries of special relativity is resolved by giving a definition of change of inertial frame in terms of a change of values of the constants of motion, which leaves the walk operator unchanged. Starting from the family of 1 + 1 dimensional Dirac walks with all possible values of the mass parameter, we introduce a unique walk encompassing the latter as an extra degree of freedom, and we derive its group of changes of inertial frames. This symmetry group contains a non-linear realization of SO+(2,1)⋉R3; since one of the two space-like dimensions does not correspond to an actual spatial degree of freedom but rather the mass, we interpret it as a 2 + 1 dimensional de Sitter group. This group also contains a non-linear realization of the proper orthochronous Poincaré group SO+(1,1)⋉R2 in 1 + 1 dimension, as the ones considered within the framework of doubly special relativity, which recovers the usual relativistic symmetry in the limit of small wave-vectors and masses. Surprisingly, for the Dirac walk with a fixed value of the mass parameter, the group of allowed changes of reference frame does not have a consistent interpretation in the limit of small wave-vectors.
Focused acoustic vortex generated by a circular array of planar sector transducers using an acoustic lens, and its application in object manipulation
Authors: Zhou Chenchen , Wang Qingdong , Pu Shifu , Li Yuzhi , Guo Gepu , Chu Hongyan , Ma Qingyu , Tu Juan , Zhang Dong
Published: August 2020

For enhanced energy utilization with improved flexibility and capability for object manipulation, a focused acoustic vortex (FAV) is devised by installing a spherical acoustic lens on a circular array of planar sector transducers. Based on the acoustic refraction of a concave spherical acoustic lens, numerical simulations show that an FAV with considerable pressure gain and strengthened acoustic gradient force (AGF) can be produced by the effective concentration of acoustic waves. The performance of rotational object trapping is shown by the axial and radial distributions of the AGF for FAVs of different orders. Elastic objects of nanometer, micrometer, millimeter, and even larger-than-wavelength size can be captured with the trapping radius determined by the topological charge. With the established 16-channel experimental system, FAVs of different orders are verified by their clear pressure circles and phase spirals. The trapping radius and rotation speed of object capture are demonstrated using polyethylene particles of various sizes and FAVs of different orders. The favorable results provide an experimentally applicable method of FAV generation using the simplified circular transducer array to accomplish more accurate, stable, and flexible object manipulations with strengthened AGFs. Also, FAVs could offer an efficient means of high-intensity focused ultrasound therapy to improve the therapeutic effect of tumor treatments by accumulating drug particles, thereby enabling more potential applications in clinical practice.
Macro-scale sensitivity through meso-scale hotspot dynamics in porous energetic materials: Comparing the shock response of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and 1,3,5,7-tetranitro-1,3,5,7-tetrazoctane (HMX)
Authors: Rai Nirmal Kumar , Sen Oishik , Udaykumar H. S.
Published: August 2020

The sensitivity of an energetic material is strongly influenced by its microstructure. This work distinguishes the roles played by the microstructure (i.e., the meso-scale) in the macro-scale shock sensitivity of two different materials: TATB and HMX. To quantify sensitivity, we develop a meso-informed energy deposition model for a porous TATB material, following procedures from the previous work on HMX. Simulations of reactive void collapse in TATB are employed to calculate the rate of initiation and growth of hotspots. These rates are expressed as surrogate models, expressing meso-scale (hotspot) quantities of interest as functions of shock strength Ps and void size Dvoid. The hotspot ignition and growth rate surrogates for TATB are compared with those for HMX, providing insights into meso-scale physics underlying shock sensitivity of these two energetic materials. The surrogate models are then used in a meso-informed ignition and growth (MES-IG) model to close macro-scale simulations of the shock response of porous TATB. We also obtain the run-to-detonation distances and generate Pop-plots to quantify macro-scale sensitivity. It is shown that Pop-plots for HMX-based energetic materials accord with behavior observed in experimental studies; however, there is a significant discrepancy between MES-IG predictions and experiments for TATB; the causes for this difference between HMX and TATB are discussed, pointing to areas for future work.
Structural and photoluminescence study of TiO2 layer with self-assembled Si1−xGex nanoislands
Authors: Sultan Muhammad Taha , Gudmundsson Jon Tomas , Manolescu Andrei , Svavarsson Halldor Gudfinnur
Published: August 2020

We study the surface morphology and growth process of SiGe nanoislands on TiO2 films, deposited over Si (001) substrates by high power impulse magnetron sputtering, followed by varying annealing parameters (i.e., 500–750 °C for 30 min to 20 h). Structural analysis was performed by atomic force microscopy, scanning electron microscopy, and grazing incidence x-ray diffraction. Two structural schemes were taken into consideration, i.e., SiGe grown over pre-annealed TiO2 (scheme I) and as-grown TiO2 (scheme II). Photoluminescence (PL) study of the structures revealed spectral features comprised of multiple peak features related to localized and surface states within the oxide layer, along with a peak due to the SiGe nano-islands. It was observed that the spectral feature and intensity depend on the surface morphology and the crystallinity of the underlying TiO2 layer. The structures were subjected to low temperature PL measurements, and the spectra were de-convoluted in order to validate the origin of the obtained spectra. Structural analysis revealed that pre-annealing the underlying polycrystalline TiO2 film, prior to deposition of SiGe layers (scheme I), facilitates the formation of SiGe nanoislands, preferably along the grain boundaries (due to their higher interfacial energy). In comparison, for the case of SiGe deposited over as-grown TiO2 (scheme II), annealing of the structure resulted in random distribution of nanoislands across the entire film. The size of the nanoislands grew with increased annealing time up until the point they started to coalesce, forming discontinuous SiGe layers and eventually leading to melting of the layer.
Insights into the hole transport properties of LiTFSI-doped spiro-OMeTAD films through impedance spectroscopy
Authors: Li Bixin , Zhang Shiyang , Xia Fei , Huang Yongliang , Ran Xueqin , Xia Yingdong , Chen Yonghua , Huang Wei
Published: August 2020

Hole transport materials are crucial for efficient charge extraction in perovskite solar cells to achieve high power conversion efficiency and stability. Herein, the hole transport properties of the 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamine)9,9′-spirobifluorene (spiro-OMeTAD) thin films with a dopant lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) are investigated through impedance spectroscopy. Upon doping, we observe a dispersive hole transport with nearly a 100-fold increase in the hole mobility compared with the pristine spiro-OMeTAD films. The hole mobilities slightly decrease with increasing electric fields for both films, exhibiting a negative electric field dependence of mobility due to the positional disorder. Subsequently, the charge carrier density of the LiTFSI-doped spiro-OMeTAD film is three orders of magnitude higher than that of the pristine film. The LiTFSI dopant induces two different electrical regions in the doped thin film, which can be reflected through impedance spectroscopy. The presented investigation through impedance spectroscopy is of high practical interest for the development of hole transport materials and the optimization of the transport layer doping in perovskite solar cells.
Nonlinear analysis of periodic waves in a neural field model
Authors: Budzinskiy S. , Beuter A. , Volpert V.
Published: August 2020

Various types of brain activity, including motor, visual, and language, are accompanied by the propagation of periodic waves of electric potential in the cortex, possibly providing the synchronization of the epicenters involved in these activities. One example is cortical electrical activity propagating during sleep and described as traveling waves [Massimini et al., J. Neurosci. 24, 6862–6870 (2004)]. These waves modulate cortical excitability as they progress. Clinically related examples include cortical spreading depression in which a wave of depolarization propagates not only in migraine but also in stroke, hemorrhage, or traumatic brain injury [Whalen et al., Sci. Rep. 8, 1–9 (2018)]. Here, we consider the possible role of epicenters and explore a neural field model with two nonlinear integrodifferential equations for the distributions of activating and inhibiting signals. It is studied with symmetric connectivity functions characterizing signal exchange between two populations of neurons, excitatory and inhibitory. Bifurcation analysis is used to investigate the emergence of periodic traveling waves and of standing oscillations from the stationary, spatially homogeneous solutions, and the stability of these solutions. Both types of solutions can be started by local oscillations indicating a possible role of epicenters in the initiation of wave propagation.
High performance BiFeO3 ferroelectric nanostructured photocathodes
Authors: Das Shyamashis , Fourmont Paul , Benetti Daniele , Cloutier Sylvain G. , Nechache Riad , Wang Zhiming M. , Rosei Federico
Published: August 2020

Ferroelectric materials may be used as effective photoelectrocatalysts for water splitting due to enhanced charge carrier separation driven by their spontaneous polarization induced internal electric field. Compared to other ferroelectric materials, BiFeO3 exhibits a high catalytic efficiency due to its comparatively smaller bandgap, which enables light absorption from a large part of the solar spectrum and its higher bulk ferroelectric polarization. Here, we compare the photoelectrochemical properties of three different BiFeO3 morphologies, namely, nanofibers, nanowebs, and thin films synthesized via electrospinning, directly on fluorine-doped tin oxide (FTO) coated glass substrates. A significant photocathodic current in the range from −86.2 to −56.5 μA cm−2 at −0.4 V bias (vs Ag/AgCl) has been recorded for all three morphologies in 0.1M Na2SO4 aqueous solution (pH = 6.8). Among these morphologies, BiFeO3 nanofibers exhibit higher efficiency because of their larger surface area and improved charge separation resulting from rapid diffusion of photoinduced charge carriers along the axis of the nanofiber. In the case of BiFeO3 nanofibers, we obtained the highest photocurrent density of −86.2 µA/cm2 at −0.4 V bias (vs Ag/AgCl electrode) and an onset potential of 0.22 V. We also observed that the onset potential of the photocathodic current can be increased by applying a positive polarization voltage, which leads to favorable bending of band edges at the electrode/electrolyte interface resulting in increased charge carrier separation.
Perspective on the pressure-driven evolution of the lattice and electronic structure in perovskite and double perovskite
Authors: Li Nana , Zhang Qian , Wang Yonggang , Yang Wenge
Published: August 2020

Perovskite ABO3 as one of the most common structures has demonstrated great structural flexibility and electronic applications. Evolving from perovskite, the typical double perovskite A2BB′O6 has two element species (B/B′), where the ordered arrangements of BO6 and B′O6 octahedron provide much more tunability. Especially, by applying external pressure, the energetic order between different phases in perovskite and double perovskite materials can be notably modified with more fascinating physical properties. However, it is still a challenge to propose a general model to explain and predict the high-pressure structures and properties of various perovskites and double perovskites due to their flexibility and complexity. In this perspective, we will discuss pressure effects on the crystalline structure and electronic configurations in some perovskites and double perovskites. We then focus on a prediction method for the evolution of the lattice and electronic structure for such materials with pressure. Finally, we will give a perspective on current challenges and opportunities for controlling and optimizing structural and electronic states of a given material for optimized functionalities.
Role of defects in the sensing mechanism of CNTFET gas sensors
Authors: Hankins Andrew , Willard Timothy C. , Liu Amy Y. , Paranjape Makarand
Published: August 2020

In nanotechnology, understanding the effect of interfaces and defects becomes critically important in determining a material's properties and device performance. Many one-dimensional and two-dimensional materials exhibit excellent physical, electrical, thermal, and optical properties, making them highly desirable for a wide array of applications. However, their low dimensionality also means their performance can be susceptible to defects in the material and the interfaces they form with other device components. Carbon nanotubes are often used in sensing applications, typically, in a field-effect transistor configuration (CNTFET). The interface between the contact electrode metal and the nanotube forms a Schottky barrier, which plays an important role in both transistor and sensor characteristics. Modifications to this interface by the environment can modulate the barrier and produce a change in device characteristics. Transistor operation can also be modified by the presence of defects in the carbon nanotube sidewall structure. This paper explores how defects in single-wall carbon nanotubes can affect the sensing mechanism of CNTFET gas sensing devices. Gas exposure measurements were performed on as-grown near pristine (low defect) nanotube devices and compared with plasma irradiated, highly defective nanotube devices. By utilizing selective passivation to isolate structural components that contribute to the sensing mechanism, the study shows that the presence of defects, and their relative densities, has a critical role in gas sensing performance. Recognizing the presence of these defects, even in as-grown nanotubes, can help reconcile seemingly contradictory results in the literature regarding the gas sensing mechanism. This work represents an important step toward understanding the effect of both interfaces and defects for carbon nanotube sensor development.
Tuning plasmonic field enhancement and transients by far-field coupling between nanostructures
Authors: Pápa Z. , Kasza J. , Budai J. , Márton Z. , Molnár Gy. , Dombi P.
Published: August 2020

We study how the collective effects of nanoparticles arranged in rectangular arrays influence their temporal plasmon response and field enhancement property. By systematically changing the lattice constant for arrays containing identical metal nanorods, we experimentally demonstrate how grating-induced effects affect the position and, more importantly, the broadening of extinction spectra. We correlate these effects with the achievable field enhancement and the temporal duration of plasmon transients and formulate criteria for the generation of enhanced few-cycle localized plasmon oscillations.
Influence of external driving on decays in the geometry of the LiCN isomerization
Authors: Feldmaier Matthias , Reiff Johannes , Benito Rosa M. , Borondo Florentino , Main Jörg , Hernandez Rigoberto
Published: August 2020

The framework of transition state theory relies on the determination of a geometric structure identifying reactivity. It replaces the laborious exercise of following many trajectories for a long time to provide chemical reaction rates and pathways. In this paper, recent advances in constructing this geometry even in time-dependent systems are applied to the LiCN ⇌ LiNC isomerization reaction driven by an external field. We obtain decay rates of the reactant population close to the transition state by exploiting local properties of the dynamics of trajectories in and close to it. We find that the external driving has a large influence on these decay rates when compared to the non-driven isomerization reaction. This, in turn, provides renewed evidence for the possibility of controlling chemical reactions, like this one, through external time-dependent fields.
Photochemical motion control of surface active Belousov–Zhabotinsky droplets
Authors: Jamaluddin Syed Jazli Syed , Khaothong Kritsana , Tinsley Mark R. , Showalter Kenneth
Published: August 2020

Photochemical control of the motion of surface active Belousov–Zhabotinsky (BZ) droplets in an oil-surfactant medium is carried out with illumination intensity gradients. Droplet motion is analyzed under conditions of constant uniform illumination and a constant illumination gradient. Control of droplet motion is developed by testing different illumination gradients. Complex hypotrochoid target trajectories are tracked by BZ droplets illuminated with two-dimensional V-shaped gradients.
Interplay of Kelvin–Helmholtz instability with acoustics in a viscous potential flow
Authors: Bilgili Serdar , Ugarte Orlando , Akkerman V’yacheslav
Published: August 2020

Among the hydrodynamic instabilities influencing the evolution, stabilization, and control of flows, the Kelvin–Helmholtz (KH) instability mode is a profound trigger to induce unsteadiness and turbulence—either within a single fluid, by means of a velocity shear, or along the interface of multiple fluids. This mechanism has been analytically studied by Funada and Joseph [“Viscous potential flow analysis of Kelvin–Helmholtz instability in a channel,” J. Fluid Mech. 445, 263 (2001)], for the surface separating two fluids within the approximation of inviscid and viscous potential flows. The present investigation extends the Funada–Joseph formulation to incorporate the effect of imposed acoustic waves on the system under consideration. Specifically, the KH–acoustic interaction is studied by employing a modification of the Bychkov approach [V. Bychkov, “Analytical scalings for flame interaction with sound waves,” Phys. Fluids 11, 3168 (1999)], which has been originally derived for the acoustic coupling to the combustion instability. The analytic formulae for the dispersion relations, growth rates, and neutral curves describing the perturbed interface of the KH instability/acoustic region are derived. Specifically, the limits for stable/unstable regimes as a function of hydrodynamic and acoustic parameters are identified. Two interacting modes are of particular interest: resonant and parametric modes, characterized by acoustic fields having the same frequency (resonant) and twice the frequency (parametric) of the instability oscillations. It is shown that while relatively weak acoustics provide a promising contribution to stabilize the KH instability, those of higher strength can excite the parametric instability. Overall, a comprehensive parametric study of the KH–acoustic coupling and stability limits shows that a global stability region may exist between that of the resonant and parametrically unstable regimes.
Vibrational decoherence induced by ultrafast intramolecular charge separation of an asymmetric bianthryl derivative
Authors: Takeuchi Eisuke , Muramatsu Masayasu , Yoneda Yusuke , Katayama Tetsuro , Iwamoto Akira , Nagasawa Yutaka , Miyasaka Hiroshi
Published: August 2020

Coherent wavepacket oscillation accompanying the ultrafast photoexcited intramolecular charge separation (CS) of 9,9′-bianthryl (BA) and 10-cyano-9,9′-bianthryl (CBA) in a room temperature ionic liquid, N,N-diethyl-N-methyl-N-(methoxyethyl)ammonium tetrafluoroborate (DemeBF4), was investigated by femtosecond time-resolved transient absorption spectroscopy. The frequency of the coherent oscillation observed for CBA in nonpolar n-hexane solution (Hex) was 377 cm−1, while this oscillation was undetectable in DemeBF4. For BA in DemeBF4, coherent oscillation with a frequency of 394 cm−1 was observed, which is similar to that for CBA in Hex. CS of CBA occurs in the ultrashort time range of ≤100 fs, while that of BA occurs in a few picosecond range [E. Takeuchi et al., J. Phys. Chem. C 120, 14502–14512 (2016)]. Hence, the oscillation of CBA in Hex and that of BA in DemeBF4 are assigned to the molecular vibration in the locally excited state, while this oscillation dephases instantaneously for CBA in DemeBF4 due to the ultrafast CS and no oscillation was generated in the CS state. This result suggests that the CS reaction is not mediated by a specific intramolecular vibration in the CS state but occurs incoherently through higher levels of multiple vibrational modes.