bluuebunny/crossref_metadata_2025 huggingface dataset:
A human respiratory tract-associated bacterium with an extremely small genome
Authors: Fukuda Kazumasa , Yamasaki Kei , Ogura Yoshitoshi , Kawanami Toshinori , Ikegami Hiroaki , Noguchi Shingo , Akata Kentarou , Katsura Keisuke , Yatera Kazuhiro , Mukae Hiroshi , Hayashi Tetsuya , Taniguchi Hatsumi
Published: May 2021

Recent advances in culture-independent microbiological analyses have greatly expanded our understanding of the diversity of unculturable microbes. However, human pathogenic bacteria differing significantly from known taxa have rarely been discovered. Here, we present the complete genome sequence of an uncultured bacterium detected in human respiratory tract named IOLA, which was determined by developing a protocol to selectively amplify extremely AT-rich genomes. The IOLA genome is 303,838 bp in size with a 20.7% GC content, making it the smallest and most AT-rich genome among known human-associated bacterial genomes to our best knowledge and comparable to those of insect endosymbionts. While IOLA belongs to order Rickettsiales (mostly intracellular parasites), the gene content suggests an epicellular parasitic lifestyle. Surveillance of clinical samples provides evidence that IOLA can be predominantly detected in patients with respiratory bacterial infections and can persist for at least 15 months in the respiratory tract, suggesting that IOLA is a human respiratory tract-associated bacterium.
Unconventional satellite resistance peaks in moiré superlattice of h-BN/ AB-stacked tetralayer-graphene heterostructures
Authors: Mukai Fumiya , Horii Kota , Ebisuoka Ryoya , Watanabe Kenji , Taniguchi Takashi , Yagi Ryuta
Published: May 2021

Most studies on moiré superlattices formed from a stack of h-BN (two-dimensional hexagonal boron nitride) and graphene have focused on single layer graphene; graphene with multiple layers is less understood. Here, we show that a moiré superlattice of multilayer graphene shows features arising from the anisotropic Fermi surface affected by the superlattice structure. The moiré superlattice of a h-BN/AB-stacked tetralayer graphene heterostructures exhibited resistivity peaks showing a complicated dependence on the perpendicular electric field. The peaks were not due to secondary Dirac cones forming, but rather opening of the energy gap due to folding of the anisotropic Fermi surface. In addition, superlattice peaks resulted from mixing of light- and heavy-mass bilayer-like bands via the superlattice potential. The gaps did not open on the boundary of the superlattice Brillouin zone, but rather opened inside it, which reflected the anisotropy of the Fermi surface of multilayer graphene.
Out-of-plane trion emission in monolayer WSe2 revealed by whispering gallery modes of dielectric microresonators
Authors: Andres-Penares Daniel , Habil Mojtaba Karimi , Molina-Sánchez Alejandro , Zapata-Rodríguez Carlos J. , Martínez-Pastor Juan P. , Sánchez-Royo Juan F.
Published: May 2021

The manipulation of light emitted by two-dimensional semiconductors grounds forthcoming technologies in the field of on-chip communications. However, these technologies require from the so elusive out-of-plane photon sources to achieve an efficient coupling of radiated light into planar devices. Here we propose a versatile spectroscopic method that enables the identification of the out-of-plane component of dipoles. The method is based on the selective coupling of light emitted by in-plane and out-of-plane dipoles to the whispering gallery modes of spherical dielectric microresonators, in close contact to them. We have applied this method to demonstrate the existence of dipoles with an out-of-plane orientation in monolayer WSe2 at room temperature. Micro-photoluminescent measurements, numerical simulations based on finite element methods, and ab-initio calculations have identified trions as the source responsible for this out-of-plane emission, opening new routes for realizing on-chip integrated systems with applications in information processing and quantum communications.
Amphiphilic phospholipid–iodinated polymer conjugates for bioimaging
Authors: Djorgbenoo Richmond , Rubio Mac Michael M. , Yin Ziyu , Moore Keyori J. , Jayapalan Anitha , Fiadorwu Joshua , Collins Boyce E. , Velasco Brian , Allado Kokougan , Tsuruta James K. , Gorman Christopher B. , Wei Jianjun , Johnson Kennita A. , He Peng
Published: May 2021

Amphiphilic phospholipid–iodinated polymer conjugates were designed and synthesized as new macromolecular probes for a highly radiopaque and biocompatible imaging technology.
Palladium-catalyzed cascade cyclizations involving C–C and C–X bond formation: strategic applications in natural product synthesis
Authors: Holman K. R. , Stanko A. M. , Reisman S. E.
Published: May 2021

This tutorial review highlights the use of palladium-catalyzed cascade cyclizations in natural product synthesis, focusing on cascades that construct multiple rings and form both C–C and C–X (X = O, N) bonds in a single synthetic operation.
Harnessing the physicochemical properties of DNA as a multifunctional biomaterial for biomedical and other applications
Authors: Chakraborty Aishik , Ravi Shruthi Polla , Shamiya Yasmeen , Cui Caroline , Paul Arghya
Published: May 2021

The review explores the chemical tools and strategies to synthesize bioactive, DNA-based biomaterials. The focus is on the applications of DNA as a generic and not a genetic polymer in biomedical, environmental, and electrochemical fields.
Size-dependent phase stability in transition metal dichalcogenide nanoparticles controlled by metal substrates
Authors: Bruix Albert , Lauritsen Jeppe V. , Hammer Bjørk
Published: May 2021

The interaction with a metal support influences the phase stability of transition metal dichalcogenide nanoparticles. These support effects depend on the particle size, lattice mismatch, and the gas-phase conditions these materials are exposed to.
Feature fusion of Raman chemical imaging and digital histopathology using machine learning for prostate cancer detection
Authors: Doherty Trevor , McKeever Susan , Al-Attar Nebras , Murphy Tiarnán , Aura Claudia , Rahman Arman , O'Neill Amanda , Finn Stephen P. , Kay Elaine , Gallagher William M. , Watson R. William G. , Gowen Aoife , Jackman Patrick
Published: May 2021

A machine learning approach to prostate cancer detection using a multimodal combination of features from Raman chemical imaging and digital histopathology.
Magnetic Fe3O4@SiO2@β-cyclodextrin for solid phase extraction of methyl parathion and fenthion in lettuce samples
Authors: Wu Xinze , Cao Yifei , Sun Bin , Chen Huaixia , Dang Xueping , Liu Xiaolan , Ai Youhong
Published: May 2021

In this study, magnetic Fe3O4@SiO2@β-cyclodextrin copolymerized microparticles were synthesized and applied for the extraction of methyl parathion and fenthion in lettuce samples followed by HPLC-UV detection.
Autophagy inhibitors 3-MA and LY294002 repress osteoclastogenesis and titanium particle-stimulated osteolysis
Authors: Chen Weishen , Xian Guoyan , Gu Minghui , Pan Baiqi , Wu Xiaoyu , Ye Yongyu , Zheng Linli , Zhang Ziji , Sheng Puyi
Published: May 2021

In this study, we found autophagy inhibitors 3-MA and LY294002 reduced osteoclast differentiation and osteoclast-related genes in vitro. In vivo, 3-MA and LY294002 repressed titanium particle-stimulated inflammatory osteolysis and osteoclastogenesis.
Solvation vs. surface charge transfer: an interfacial chemistry game drives cation motion
Authors: Angarita-Gomez Stefany , Balbuena Perla B.
Published: May 2021

Approaching the surface, cation solvation/desolvation compete with surface electron transfer effects, with barriers depending on electrolyte chemistry and structure.
Targeted NIR-II emissive nanoprobes for tumor detection in mice and rabbits
Authors: Li Yaxi , Li Zeshun , Hu Dehong , Wang Shuxian , Zha Menglei , Lu Song-Bo , Sheng Zonghai , Li Kai
Published: May 2021

The functional NIR-II AIEgen (cRGD-TTB NPs) achieved a high quantum yield (10.32%) and a high signal-to-background (S/B) ratio of 7.7, when employed for the visualization of large tumors (∼600 mm3) in rabbit models for the first time.
Chemical reactivity from an activation strain perspective
Authors: Vermeeren Pascal , Hamlin Trevor A. , Bickelhaupt F. Matthias
Published: May 2021

The activation strain model is a universal tool in the chemist's arsenal to unravel the factors controlling reactivity and selectivity of any chemical transformation.
Ab initio dynamics simulation of laser-induced photodissociation of phenol
Authors: Li Xiaojuan , Cheng Xinlu , Zhang Hong
Published: May 2021

Performing RT-TDDFT-MD simulations in Octopus 10.1 on the photodissociation dynamics of phenol molecules induced by ultrafast and strong laser.
Gibbs-ensemble Monte Carlo simulation of H2–H2O mixtures
Authors: Bergermann Armin , French Martin , Redmer Ronald
Published: May 2021

The miscibility gap in H2–H2O mixtures is investigated by conducting Gibbs-ensemble Monte Carlo simulations. Our results indicate that H2–H2O immiscibility regions may have a significant impact on the structure and evolution of ice giant planets.
Bifunctional electrocatalysts for oxygen reduction and oxygen evolution: a theoretical study on 2D metallic WO2-supported single atom (Fe, Co, or Ni) catalysts
Authors: Ma Yuli , Jin Fangming , Hu Yun Hang
Published: May 2021

Single-metal-atom (Fe, Co, or Ni) doped 2D WO2 is theoretically demonstrated to have excellent OER/ORR catalytic activities.
Second harmonic generation theory for a helical macromolecule with high sensitivity to structural disorder
Authors: Abramavicius Darius , Krouglov Serguei , Barzda Virginijus
Published: May 2021

Microscopic theory for the second harmonic generation in a helical molecular system is developed in the minimal coupling representation including non-local interaction effects.
The energy level alignment of the ferrocene–EGaIn interface studied with photoelectron spectroscopy
Authors: Gupta Nipun Kumar , Schultz Thorsten , Karuppannan Senthil Kumar , Vilan Ayelet , Koch Norbert , Nijhuis Christian A.
Published: May 2021

This work describes how the energy level alignment of molecular junctions is affected by the EGaIn top-electrode.
Molecular properties affecting the hydration of acid–base clusters
Authors: Myllys Nanna , Myers Deanna , Chee Sabrina , Smith James N.
Published: May 2021

Monomer properties affect to the formation and properties of clouds, and through it, Earth's radiative balance.
Unravelling the microhydration frameworks of prototype PAH by infrared spectroscopy: naphthalene–(water)1–3
Authors: Chatterjee Kuntal , Roy Tarun Kumar , Khatri Jai , Schwaab Gerhard , Havenith Martina
Published: May 2021

Microhydration structures of the prototypical PAH, naphthalene, are probed by IR spectroscopy in helium droplets. The sequential water addition produces an extended hydrogen-bonded hydration network bound via π hydrogen bond to the aromatic ring.
Phase junction-confined single-atom TiO2–Pt1–CeO2 for multiplying catalytic oxidation efficiency
Authors: Sun Chao , Wei Guangfeng , Liu Huimin , Huang Zhen , Qin Feng , Wang Haitao , Zhao Jing , Liu Zhipan , Zhang Linjuan , Yu Haisheng , Ge Binghui , Shen Wei , Xu Hualong
Published: May 2021

The phase junction confinement within the TiO2–Pt1–CeO2 ensemble leads to 5 times higher CO oxidation efficiency under 300 K.
Quantum dots for photocatalysis: synthesis and environmental applications
Authors: Jouyandeh Maryam , Mousavi Khadem Seyed Soroush , Habibzadeh Sajjad , Esmaeili Amin , Abida Otman , Vatanpour Vahid , Rabiee Navid , Bagherzadeh Mojtaba , Iravani Siavash , Reza Saeb Mohammad , Varma Rajender S.
Published: May 2021

Synthetic methods of QDs from low cost and natural resources.
CO2 turned into a nitrogen doped carbon catalyst for fuel cells and metal–air battery applications
Authors: Ratso Sander , Walke Peter Robert , Mikli Valdek , Ločs Jānis , Šmits Krišjānis , Vītola Virgīnija , Šutka Andris , Kruusenberg Ivar
Published: May 2021

Carbon dioxide is turned into a promising metal-free catalyst for fuel cells via molten salt electrolysis.
Advanced continuous-flow microfluidic device for parallel screening of crystal polymorphs, morphology, and kinetics at controlled supersaturation
Authors: Coliaie Paria , Kelkar Manish S. , Langston Marianne , Liu Chengxiang , Nazemifard Neda , Patience Daniel , Skliar Dimitri , Nere Nandkishor K. , Singh Meenesh R.
Published: May 2021

An advanced continuous-flow microfluidic device for rapid, parallel screening of crystalline materials, which can profoundly impact the discovery and development of active pharmaceutical ingredients and other crystalline materials.
Visualizing defect energetics
Authors: Anand Shashwat , Male James P. , Wolverton Chris , Snyder G. Jeffrey
Published: May 2021

Stability of any point defect type and the corresponding compound can be visualized within the same convex-hull framework. Defect formation enthalpy is determined using intercepts at the compositions of the pure elements involved in defect formation.
Intrinsically stretchable sheath-core ionic sensory fibers with well-regulated conformal and reprogrammable buckling
Authors: He Chenglong , Sun Shengtong , Wu Peiyi
Published: May 2021

Inspired by the human fingertip structure, an intrinsically stretchable sheath-core ionic sensory fiber with conformal and reprogrammable buckling is fabricated which demonstrates significantly enhanced strain sensitivity and versatility.
Bis(NHC)-Pd-catalyzed one-pot competitive C–C*C–C, C–C*C–O, C–C*C–N, and C–O*C–N cross-coupling reactions on an aryl di-halide catalyzed by a homogenous basic ionic liquid (TAIm[OH]) under base-free, ligand-free, and solvent-free conditions
Authors: Zhu Yanfang , Xu Guiyang , Kazemnejadi Milad
Published: May 2021

A new ionic liquid with intrinsic basic, ligand, and solvent properties is developed for efficient and selective Pd-catalyzed asymmetric C–C, C–O, and C–N cross-coupling reactions under mild conditions.
An interlinked computational–experimental investigation into SnS nanoflakes for field emission applications
Authors: Nasane Mamta P. , Rondiya Sachin R. , Jadhav Chandradip D. , Rahane Ganesh R. , Cross Russell W. , Jathar Sagar , Jadhav Yogesh , Barma Sunil , Nilegave Dhanaraj , Jadkar Vijaya , Rokade Avinash , Funde Adinath , Chavan Padmakar G. , Hoye Robert L. Z. , Dzade Nelson Y. , Jadkar Sandesh
Published: May 2021

Layered binary semiconductor materials have attracted significant interest as field emitters due to their low work function, mechanical stability, and high thermal and electrical conductivity.
1,3,4-Oxadiazole-functionalized α-amino-phosphonates as ligands for the ruthenium-catalyzed reduction of ketones
Authors: Hkiri Shaima , Gourlaouen Christophe , Touil Soufiane , Samarat Ali , Sémeril David
Published: May 2021

1,3,4-Oxadiazole-functionalized ruthenium catalysts for the reduction of ketone.
An improved plasmonic Au–Ag/TiO2/rGO photocatalyst through entire visible range absorption, charge separation and high adsorption ability
Authors: Atout Hicham , Bouguettoucha Abdellah , Chebli Derradji , Crespo Julián , Dupin Jean-Charles , López-de-Luzuriaga José M. , Martínez Hervé , Monge Miguel , Olmos M. Elena , Rodríguez-Castillo María
Published: May 2021

Plasmonic nanohybrids for visible light absorption: the combination of small alloyed AuAg NPs, TiO2 NPs and rGO nanosheets provides wide visible light absorption improving the photocatalytic efficiency towards water pollutant remediation.
A novel electrochemical aflatoxin B1 immunosensor based on gold nanoparticle-decorated porous graphene nanoribbon and Ag nanocube-incorporated MoS2 nanosheets
Authors: Karaman Ceren , Karaman Onur , Yola Bahar Bankoğlu , Ülker İzzet , Atar Necip , Yola Mehmet Lütfi
Published: May 2021

The accurate and precisive monitoring of aflatoxin B1 (AFB1), which is one of the most hazardous mycotoxins, especially in agricultural products, is significant for human and environmental health.
Magnetic order-dependent phonon properties in 2D magnet CrI3
Authors: Wang Ke , Zhou WuXing , Cheng Yuan , Zhang Min , Wang Hai , Zhang Gang
Published: May 2021

We carried out a systematic theoretical study on how spin affects the phononic properties of CrI3monolayers.
Graphene-Ta2O5 heterostructure enabled high performance, deep-ultraviolet to mid-infrared photodetection
Authors: Ho Vinh X. , Wang Yifei , Cooney Michael P. , Vinh N. Q.
Published: May 2021

The capability to convert light into electrical signals over a broad spectral range with high sensitivity, ultrafast, and low cost is central to many technological applications.
Plexcitons, electric field gradient and electron–phonon coupling in tip-enhanced Raman spectroscopy (TERS)
Authors: Ma Jialin , Cheng Yuqing , Sun Mengtao
Published: May 2021

Tip-Enhanced Raman Spectroscopy (TERS) provides very high spatial resolution and detection sensitivity, so it has important applications in nano-scale molecular analysis.
Correlations of nanoscale film morphologies and topological confinement of three-armed cage block copolymers
Authors: Ree Brian J. , Satoh Yusuke , Isono Takuya , Satoh Toshifumi
Published: May 2021

Three-armed cage block copolymers composed of immiscible blocks in near equivalent volume fractions formed topologically controlled sub-10 nm cylindrical and lamellar nanostructures in nanoscale films.
Mesoporous polyetherimide thin films via hydrolysis of polylactide-b-polyetherimide-b-polylactide
Authors: Guo Dong , Riet Jocelyn , Khan Assad , Guo Yichen , Xu Zhen , Liu Tianyu , Liu Guoliang
Published: May 2021

Hydrolyzing polylactide-b-polyetherimide-b-polylactide triblock copolymers produces mesoporous polyetherimide thin films with an average pore width of 24 nm.
High-genus multicompartment vesicles evolved from large compound micelles
Authors: Lin Sha , Wang Fangyingkai , Du Jianzhong
Published: May 2021

High-genus multicompartment vesicles (HGMVs) are self-assembled from block copolymers containing fluorescent and photo-responsive azobenzene groups.
Characterization of structural, functional and antioxidant properties and amino acid composition of pepsin-derived glutelin-1 hydrolysate from walnut processing by-products
Authors: Wang Jing , Wang Guoliang , Chen Ning , An Feiran , Zhang Runguang , Zhang Yufeng , Rahman Mati Ur , Zhang Youlin
Published: May 2021

Pepsin-mediated hydrolysis can be used as an effective tool to improve the functional and antioxidant properties of walnut glutelin-1.
Designing highly emissive over-1000 nm near-infrared fluorescent dye-loaded polystyrene-based nanoparticles for in vivo deep imaging
Authors: Ueya Yuichi , Umezawa Masakazu , Takamoto Eiji , Yoshida Moe , Kobayashi Hisanori , Kamimura Masao , Soga Kohei
Published: May 2021

By changing the ratio of acrylic acid to styrene, the loading amount of fluorescent dye can be increased and the optical properties of the resulting bioimaging probe can be improved.
Acidity effects of medium fluids on anhydrous proton conductivity of acid-swollen block polymer electrolyte membranes
Authors: Kajita Takato , Noro Atsushi , Seki Takahiro , Matsushita Yushu , Nakamura Naoki
Published: May 2021

Sulfuric acid-swollen block polymer membranes exhibit anhydrous conductivities of ∼0.1 S cm−1 that is higher than those of phosphoric acid-swollen membranes, whereas temperature dependence of conductivities of the latter is stronger than the former.
Evaluating the potential of a novel hardwood biomass using a superbase ionic liquid
Authors: Muazzam Rabia , Asim Azmat Mehmood , Uroos Maliha , Muhammad Nawshad , Hallett Jason P.
Published: May 2021

Lignocellulosic biomass, being ubiquitous and easily accessible, bears a huge potential for sustainable energy and other products.
An in vitro study of lipase inhibitory peptides obtained from de-oiled rice bran
Authors: Ketprayoon Titima , Noitang Sajee , Sangtanoo Papassara , Srimongkol Piroonporn , Saisavoey Tanatorn , Reamtong Onrapak , Choowongkomon Kiattawee , Karnchanatat Aphichart
Published: May 2021

De-oiled rice bran (DORB) is a potentially useful by-product of the rice bran oil industry.
Mn-based catalysts supported on γ-Al2O3, TiO2 and MCM-41: a comparison for low-temperature NO oxidation with low ratio of O3/NO
Authors: Liu Lijun , Shen Boxiong , Si Meng , Yuan Peng , Lu Fengju , Gao Hongpei , Yao Yan , Liang Cai , Xu Hongjie
Published: May 2021

The Mn/γ-Al2O3 catalyst exhibited excellent performance for NO conversion in the presence of a low ratio of O3/NO, which was due to the coexistence of Mn3+ and Mn4+ and abundant chemically adsorbed oxygen.
CuI nanoparticles supported on a novel polymer-layered double hydroxide nanocomposite: an efficient heterogeneous nanocatalyst for the synthesis of bis-N-arylsulfonamides
Authors: Babamoradi Jamshid , Ghorbani-Vaghei Ramin , Alavinia Sedigheh
Published: May 2021

CuI NPs supported on novel polymer–LDHs nanocomposite was investigated for the synthesis of bis-N-arylsulfonamides.
Plasmonic enhancement of aqueous processed organic photovoltaics
Authors: Chowdhury R. , Tegg L. , Keast V. J. , Holmes N. P. , Cooling N. A. , Vaughan B. , Nicolaidis N. C. , Belcher W. J. , Dastoor P. C. , Zhou X.
Published: May 2021

Plasmonic NaxWO3nanoparticles were introduced to aqueous processed organic photovoltaics with 35% device enhancement.
Conjugation of a smart polymer to doxorubicin through a pH-responsive bond for targeted drug delivery and improving drug loading on graphene oxide
Authors: Bina Ali , Raissi Heidar , Hashemzadeh Hassan , Farzad Farzaneh
Published: May 2021

Polymeric nanoparticles have emerged as efficient carriers for anticancer drug delivery because they can improve the solubility of hydrophobic drugs and also can increase the bio-distribution of drugs throughout the bloodstream.
Molecular mechanism of direct electron transfer in the robust cytochrome-functionalised graphene nanosystem
Authors: Jacquet Margot , Kiliszek Małgorzata , Osella Silvio , Izzo Miriam , Sar Jarosław , Harputlu Ersan , Unlu C. Gokhan , Trzaskowski Bartosz , Ocakoglu Kasim , Kargul Joanna
Published: May 2021

Molecular mechanism of DET between graphene and cytochrome c depends on the metal in the bio-organic interface: Co enhances the cathodic current via electron hopping from graphene to haem, whereas Ni exerts the opposite effect via tunnelling.
Metal-free multicomponent synthesis of novel macrocyclic tetrathiadienes with cyano and amino groups
Authors: Akhmadiev Nail S. , Mescheryakova Ekaterina S. , Akhmetova Vnira R. , Ibragimov Askhat G.
Published: May 2021

Here we developed a selective method for the synthesis of previously unknown macrocyclic cyano and amino substituted 1,4,8,11-tetrathiacyclotetradeca-5,12-dienes.
Silyl-naphthalene endoperoxides as switchable sources of singlet oxygen for bactericidal activity
Authors: Qu Min , Wu Nan , Jiang Wanqing , Wang Lei , Akkaya Mahinur S. , Akkaya Engin U.
Published: May 2021

Fluoride ions remove the bulky stopper, releasing singlet oxygen to kill harmful bacteria.
A stomata-inspired superhydrophobic portable filter system
Authors: Ma Yuanping , Zhao Feng , Wang Lei , Ding Yuchen , Zhao Hongbin , Wang Hao , Liu Jing
Published: May 2021

The bio-fabricated superhydrophobic filter system (a–c). The liquid water is suspended on the top of the papillae surface and hardly contacts the stomata, which filter the incoming air (d).
Enzyme mediated incorporation of zirconium-89 or copper-64 into a fragment antibody for same day imaging of epidermal growth factor receptor
Authors: Rudd Stacey E. , Van Zuylekom Jessica K. , Raicevic Anna , Pearce Lesley A. , Cullinane Carleen , Williams Charlotte C. , Adams Timothy E. , Hicks Rodney J. , Donnelly Paul S.
Published: May 2021

Enzymatic bioconjugation to introduce positron-emitting radionuclides (89Zr, 64Cu) into an anti-EGFR antibody fragment allows same day imaging with positron emission tomography.
Rapid organocatalytic chirality analysis of amines, amino acids, alcohols, amino alcohols and diols with achiral iso(thio)cyanate probes
Authors: Nelson Eryn , Formen Jeffrey S. S. K. , Wolf C.
Published: May 2021

Organocatalysis with a simple arylisocyanate probe enables accelerated optical concentration and enantiomeric ratio determination of a large variety of chiral compounds based on straightforward UV/CD analysis.
Droplet detachment and pinch-off of bidisperse particulate suspensions
Authors: Thiévenaz Virgile , Rajesh Sreeram , Sauret Alban
Published: May 2021

Solid particles dispersed in a liquid phase modifies the pinch-off of droplets. Compared to monodisperse particles, a bimodal distribution reduces the viscosity for a given volume fraction and makes the detachment process faster.
Toward high-performance anodeless batteries based on controlled lithium metal deposition: a review
Authors: Park Se Hwan , Jun Dayoung , Lee Gyu Hyeon , Lee Seong Gyu , Lee Yun Jung
Published: May 2021

This review covers various strategies aimed at controlling Li deposition on a heterogeneous current collector for an anodeless cell configuration in batteries with liquid and solid-state electrolytes.
Thionated benzo[c]thiophen-1(3H)-one as an organic cathode with high capacity for sulfur-rich all organic lithium-ion batteries
Authors: Zhang Bingjie , Yang Xiaodong , He Ben , Wang Qiqi , Liu Zishun , Yu Demei , He Gang
Published: May 2021

Combining two thionation strategies, a novel cathode material benzo[c]thiophen-1(3H)-thione (DPTTO) was prepared, which showed good battery performances in half-cell and sulfur-rich all organic lithium-ion batteries.
Fe–N4 and Co–N4 dual sites for boosting oxygen electroreduction in Zn–air batteries
Authors: Wang Dan , Xu Hao , Yang Peixia , Lu Xiangyu , Ma Jingyuan , Li Ruopeng , Xiao Lihui , Zhang Jinqiu , An Maozhong
Published: May 2021

A facile MOF-mediated approach is proposed to synthesize FeCo–N–C catalyst via one-step impregnation-pyrolysis without any post-treatment. The dual-metal site (Fe–N4 & Co–N4) can synergistically boost the ORR activity in the Zn–air batteries.
Strontium–calcium phosphate hybrid cement with enhanced osteogenic and angiogenic properties for vascularised bone regeneration
Authors: Wu Xiexing , Tang Ziniu , Wu Kang , Bai Yanjie , Lin Xiao , Yang Huilin , Yang Qiang , Wang Zheng , Ni Xinye , Liu Huiling , Yang Lei
Published: May 2021

Sr-CPHC is a starch-reinforced calcium phosphate cement with SrCO3 incorporation, exhibiting synergistic effect of osteogenesis and angiogenesis, which showed a remarkable effect in rat calvarial defect repair.
Efficient organic light-emitting diodes based on iridium(iii) complexes containing indolo[3,2,1-jk]carbazole derivatives with narrow emission bandwidths and low efficiency roll-offs
Authors: Liao Xiang-Ji , Zhu Jin-Jun , Yuan Li , Yan Zhi-Ping , Luo Xu-Feng , Zhang Yi-Pin , Lu Jun-Jian , Zheng You-Xuan
Published: May 2021

OLEDs based on iridium(iii) complexes containing an indolo[3,2,1-jk]carbazole unit exhibit good emission performances with a narrow full width at half maximum of 33 nm, good efficiency and low efficiency roll-off.
Highly efficient phosphorescent organic light-emitting diodes based on novel bipolar iridium complexes with easily-tuned emission colors by adjusting fluorine substitution on phenylpyridine ligands
Authors: Chen Shuonan , Gai Xi , Liang Jie , Ye Kaiqi , Liu Yu , Wang Yue
Published: May 2021

Two novel heteroleptic iridium complexes’ emitting colors can be tuned easily by adjusting F/CF3-substituted cyclometalated ligands, which achieved very high EL efficiency level with peak EQE values of >20% at wide concentration range of 8-25%.
Evaluation of the effects of phosphorylation of synthetic peptide substrates on their cleavage by caspase-3 and -7
Authors: Maluch Izabela , Grzymska Justyna , Snipas Scott J. , Salvesen Guy S. , Drag Marcin
Published: May 2021

Caspases are a family of enzymes that play roles in cell death and inflammation. It has been suggested that in the execution phase of the apoptotic pathway, caspase-3, -6 and -7 are involved. The substrate specificities of two proteases (caspases 3 and 7) are highly similar, which complicates the design of compounds that selectively interact with a single enzyme exclusively. The recognition of residues other than Asp in the P1 position of the substrate by caspase-3/-7 has been reported, promoting interest in the effects of phosphorylation of amino acids in the direct vicinity of the scissile bond. To evaluate conflicting reports on this subject, we synthesized a series of known caspase-3 and -7 substrates and phosphorylated analogs, performed enzyme kinetic assays and mapped the peptide cleavage sites using internally quenched fluorescent peptide substrates. Caspases 3 and 7 will tolerate pSer at the P1 position but only poorly at the P2′ position. Our investigation demonstrates the importance of peptide length and composition in interpreting sequence/activity relationships. Based on the results, we conclude that the relationship between caspase-3/-7 and their substrates containing phosphorylated amino acids might depend on the steric conditions and not be directly connected with ionic interactions. Thus, the precise effect of phospho-amino acid residues located in the vicinity of the cleaved bond on the regulation of the substrate specificity of caspases remains difficult to predict. Our observations allow to predict that natural phosphorylated proteins may be cleaved by caspases, but only when extended substrate binding site interactions are satisfied.
Effects of UHMWPE viscoelasticity on the squeeze‐film lubrication of hip replacements
Authors: Lu Xianjiu , Meng Qingen , Jin Zhongmin
Published: May 2021

Many studies have been performed to analyse the lubrication of artificial joints since the pioneer work by the late Professor Duncan Dowson. However, the viscoelastic deformation of one of the most widely used bearing materials, ultra‐high‐molecular‐weight polyethylene (UHMWPE), has only been considered recently. The described study attempted to investigate the effect of UHMWPE viscoelasticity on the elastohydrodynamic lubrication of such a soft artificial hip replacement under squeeze‐film motion. A transient viscoelastic squeeze‐film lubrication model of a typical hip implant was developed and solved to obtain the film thickness and pressure distributions. A boundary film thickness was adopted to consider the direct and indirect lubricant contact conditions. The results showed that the viscoelasticity had marked effects on the squeeze‐film lubrication performance of UHMWPE artificial hip joints. The minimum film thickness in the viscoelastic model was smaller than that of the elastic model, causing an earlier direct contact. However, the film thickness within the central contact region in the viscoelastic model was greater than that of the elastic model due to the restricted flow of the lubricant, therefore enhancing the lubricating effect and particularly with a short relaxation time and mechanical loss factor.
Robust iterative learning control for uncertain continuous‐time system with input delay and random iteration‐varying uncertainties
Authors: Shokri‐Ghaleh Hamid , Ganjefar Soheil , Shahri Alireza Mohammad
Published: May 2021

This study deals with the problem of robust iterative learning control (ILC) for linear continuous‐time systems with input delay subject to uncertainties in input delay, plant dynamic, reference trajectory, initial conditions and disturbances. Using the internal model control (IMC) structure in the frequency domain, an ILC scheme is proposed in which the IMC structure is responsible for coping with uncertainties in both delay time and plant dynamic. Sufficient conditions are derived to ensure that the tracking error expectation is bounded and converges monotonically to a small neighbourhood of zero (in the ‐norm sense) when uncertainties in reference trajectory, initial conditions and disturbances vary randomly from trial to trial. It is shown that the derived conditions are still valid to guarantee both boundedness and monotonic convergence of the tracking error variance (in the ‐norm sense). Illustrative examples are provided to demonstrate the effectiveness of the proposed method.
A low phase noise microwave source for high‐performance CPT Rb atomic clock
Authors: Li Xiaodong , Yun Peter , Li Qinglin , Ju Bowen , Yu Shaoshao , Hao Qiang , Du Runchang , Xu Feng , Li Wenbing , Gao Yuping , Zhang Shougang
Published: May 2021

Phase noise of the frequency synthesizer is one of the main limitations to the short‐term stability of microwave atomic clocks. Here, a low‐noise, simple‐architecture microwave frequency synthesizer for a coherent population trapping (CPT) clock is demonstrated. The synthesizer is mainly composed of a 100 MHz oven‐controlled crystal oscillator (OCXO), a microwave comb generator, and a direct digital synthesizer (DDS). The absolute phase noises of 3.417 GHz signal are measured to be −55 dBc/Hz, −81 dBc/Hz, −111 dBc/Hz and −134 dBc/Hz, respectively, for 1 Hz, 10 Hz, 100 Hz and 1 kHz offset frequencies, which shows only 1 dB deterioration at the second harmonic of the modulation frequency of the atomic clock. The estimated frequency stability of intermodulation effect is 4.7 × 10−14 at 1 s averaging time, which is about half order of magnitude lower than that of the state‐of‐the‐art CPT Rb clock. Our work offers an alternative microwave synthesizer for high‐performance CPT Rb atomic clock.
The importance of coil conductivity and eddy current effects in the analysis of electromagnetic forming process
Authors: Cao Quanliang , Xia Liangyu , Li Xian , Du Limeng , Lai Zhipeng , Han Xiaotao , Li Liang
Published: May 2021

Coil design and performance analysis are critical for the electromagnetic forming (EMF) process. However, previous studies have paid little attention to the coil conductivity, and the influence of eddy current effects in coil conductors on the forming process has not been well understood. This work aims to address these problems through numerical and experimental investigations. It is found that, due to the eddy current effects, the uneven current distribution appears in the coil conductors that should be considered when analysing the forming process, especially for the cases with large heights of coil conductors. Meanwhile, an important and interesting discovery is that the eddy current effects can greatly reduce the sensitivity of the coil conductivity with respect to the workpiece deformation, the Joule heating and the temperature rise in the coil. For instance, compared to a forming system with a copper coil, the forming height of the workpiece in the forming system with an AA5083‐O coil is reduced by less than 5 % under the same discharge energy, while the copper conductivity is 3.3 times that of the latter. These results are helpful to understand the EMF process and achieve the optimal design of coils.
Viability of providing spinning reserves by RES in Spanish island power systems
Authors: Rajabdorri Mohammad , Sigrist Lukas , Lobato Enrique , Prats Maria del Carmen , Echavarren Francisco M.
Published: May 2021

This paper assesses the viability of providing down and up spinning reserves by renewable energy resources (RES) in island power systems. The process consists of evaluating the impact of providing spinning reserve on the system operation costs of different islands by simulating the unit commitment problem. The assessment is carried out for La Palma (small size) and Tenerife (medium size) island power systems, and by considering different wind source availability scenarios for sample weeks of different seasons in current and future years. This paper differentiates between up and down reserves and studies their impacts separately. Results show that enabling RES to provide just down spinning reserve has economic benefits for all scenarios, by reducing over 40% the amount of thermal generation and over 30% the systems costs for high wind scenarios. It also confirms that employing variable deloading of wind energy as a source of up reserve is advisable, mainly in scenarios with high share of wind sources. In some scenarios, using RES as reserve provider, reduces the amount of thermal generation more than 50%, compared to when RES does not participate as a source of reserve, and can even lead to a full RES coverage of demand.
Transfer learning‐based radar imaging with deep convolutional neural networks for distributed frequency modulated continuous waveform multiple‐input multiple‐output radars
Authors: Seo Jiho , Yang Yunji , Hong Yong‐gi , Park Jaehyun
Published: May 2021

Deep‐learning‐based radar imaging is developed with distributed frequency modulated continuous waveform multiple‐input multiple‐output (FMCW MIMO) radars in which a deep‐learning approach based on the convolutional neural network (CNN) is proposed to achieve radar images robust to adverse circumstances. Differently from the existing deep‐learning methods applied to radar object recognition, the deramped radar signal is exploited as the input of the proposed deep CNN (DCNN) without any processing related to the spectrogram transform and the subspace decomposition. To effectively train the proposed DCNN, the received signal is reformulated in terms of the reflection gain values in the (azimuth, range) patches in the image region of interest such that the output vector of the DCNN is composed of the reflection gain values in the associated patches. Furthermore, to overcome the limitations on the amount of training data and training time, the transfer learning approach is effectively applied to the distributed FMCW MIMO radar imaging. The proposed radar imaging is assessed with synthetic simulation data. Specifically, by transferring the pretrained DCNN model for a given reference radar to other distributed radars, the distributed radars can save about 52.4 % in training time compared with a DCNN having the same architecture but without transfer learning.
Operational Dst index prediction model based on combination of artificial neural network and empirical model
Authors: Park Wooyeon , Lee Jaejin , Kim Kyung-Chan , Lee JongKil , Park Keunchan , Miyashita Yukinaga , Sohn Jongdae , Park Jaeheung , Kwak Young-Sil , Hwang Junga , Frias Alexander , Kim Jiyoung , Yi Yu
Published: May 2021

In this paper, an operational Dst index prediction model is developed by combining empirical and Artificial Neural Network (ANN) models. ANN algorithms are widely used to predict space weather conditions. While they require a large amount of data for machine learning, large-scale geomagnetic storms have not occurred sufficiently for the last 20 years, Advanced Composition Explorer (ACE) and Deep Space Climate Observatory (DSCOVR) mission operation period. Conversely, the empirical models are based on numerical equations derived from human intuition and are therefore applicable to extrapolate for large storms. In this study, we distinguish between Coronal Mass Ejection (CME) driven and Corotating Interaction Region (CIR) driven storms, estimate the minimum Dst values, and derive an equation for describing the recovery phase. The combined Korea Astronomy and Space Science Institute (KASI) Dst Prediction (KDP) model achieved better performance contrasted to ANN model only. This model could be used practically for space weather operation by extending prediction time to 24 h and updating the model output every hour.
Local analysis of electrostatic modes in a two-fluid E×B plasma
Authors: Ramos J. J. , Bello-Benítez E. , Ahedo E.
Published: May 2021

A local study of linear electrostatic modes, applicable to the dynamics perpendicular to the magnetic field in a plasma with crossed electric and magnetic fields, is presented. The analysis is based on a two-fluid model that takes into account the finite-electron-gyroradius effects through a rigorous gyroviscosity tensor and includes a dissipative friction force in the electron momentum equation. A comprehensive dispersion relation, valid for arbitrary electron temperature, is derived, which describes properly all the relevant waves for wavelengths longer than the electron Larmor radius. For a homogeneous and dissipationless plasma, such a fluid dispersion relation agrees with the long-wavelength limit of the kinetic electron–cyclotron-drift instability dispersion relation that extends the results to arbitrary short wavelengths. The general fluid dispersion relation covers different parametric regimes that depend on the relative ion-to-electron drift velocity and on the presence of equilibrium inhomogeneities and/or dissipation. Depending on such conditions, its roots yield as follows: two-stream instabilities, driven solely by the relative drift between species; drift-gradient instabilities, driven by the combination of the relative drift and equilibrium gradients; and drift-dissipative instabilities, driven by the combination of the relative drift and friction. Instability thresholds are determined and some distinctive unstable modes are described analytically.
Conceptual design of heavy ion beam probes on the PLATO tokamak
Authors: Ido T. , Fujisawa A. , Takemura K. , Kobayashi T.-K. , Nishimura D. , Kasuya N. , Fukuyama A. , Moon C. , Yamasaki K. , Inagaki S. , Nagashima Y. , Yamada T.
Published: May 2021

Heavy ion beam probe (HIBP) systems have been designed for the new tokamak, PLATO [A. Fujisawa, AIP Conf. Proc. 1993, 020011 (2018)]. The designs have been completed, and the installations are in progress. Two HIBPs are being installed in toroidal sections 180° apart to investigate long-range correlations in the toroidal direction. Each HIBP consists of an injection beamline and a detection beamline as usual. Yet, one of the HIBPs is equipped with an additional detection beamline; the measurement positions of its two detection beamlines can be placed on almost the same magnetic surface yet at poloidal angles that differ by ∼180°. The use of three detection beamlines allows us to investigate spatial asymmetry and long-range correlations in both the toroidal and poloidal directions, simultaneously. The detected beam intensity is expected to be enough for turbulence measurements in almost the entire plasma region when the electron density is up to 1 × 1019 m−3 by selecting appropriate ion species for the probe beam. Each detector has three channels 10 mm apart, allowing measurement of local structures of micro-scale turbulence. Therefore, using the HIBPs on the PLATO tokamak will enable both local and global properties of plasma turbulence to be investigated, simultaneously.
High-power near-concentric Fabry–Perot cavity for phase contrast electron microscopy
Authors: Turnbaugh Carter , Axelrod Jeremy J. , Campbell Sara L. , Dioquino Jeske Y. , Petrov Petar N. , Remis Jonathan , Schwartz Osip , Yu Zanlin , Cheng Yifan , Glaeser Robert M. , Mueller Holger
Published: May 2021

Transmission electron microscopy (TEM) of vitrified biological macromolecules (cryo-EM) is limited by the weak phase contrast signal that is available from such samples. Using a phase plate would thus substantially improve the signal-to-noise ratio. We have previously demonstrated the use of a high-power Fabry–Perot cavity as a phase plate for TEM. We now report improvements to our laser cavity that allow us to achieve record continuous wave intensities of over 450 GW/cm2, sufficient to produce the optimal 90° phase shift for 300 keV electrons. In addition, we have performed the first cryo-EM reconstruction using a laser phase plate, demonstrating that the stability of this laser phase plate is sufficient for use during standard cryo-EM data collection.
Binding and stability of MgO monomers on anatase TiO2(101)
Authors: Doudin Nassar , Collinge Greg , Persaud Rudradatt R. , Gurunathan Pradeep Kumar , Lee Mal-Soon , Glezakou Vassiliki-Alexandra , Dixon David A. , Rousseau Roger , Dohnálek Zdenek
Published: May 2021

In catalysis, MgO is often used to modify the acid–base properties of support oxides and to stabilize supported metal atoms and particles on oxides. In this study, we show how the sublimation of MgO powder can be used to deposit MgO monomers, hither on anatase TiO2(101). A combination of x-ray electron spectroscopy, high-resolution scanning tunneling microscopy, and density functional theory is employed to gain insight into the MgO monomer binding, electronic and vibrational properties, and thermal stability. In the most stable configuration, the Mg and O of the MgO monomer bind to two surface oxygens and one undercoordinated surface titanium, respectively. The additional binding weakens the Mg–O monomer bond and makes Mg more ionic. The monomers are thermally stable up to 600 K, where the onset of diffusion into the TiO2 bulk is observed. The monomeric MgO species on TiO2(101) represent an ideal atomically precise system with modified acid–base properties and will be employed in our future catalytic studies.
Magneto-optical properties of InSb for infrared spectral filtering
Authors: Peard Nolan , Callahan Dennis , Perkinson Joy C. , Du Qingyang , Patel Neil S. , Fakhrul Takian , LeBlanc John , Ross Caroline A. , Hu Juejun , Wang Christine Y.
Published: May 2021

We present measurements of the Faraday effect in n-type InSb. The Verdet coefficient was determined for a range of carrier concentrations near 1017 cm−3 in the λ=8–12μm long-wave infrared regime. The absorption coefficient was measured and a figure of merit was calculated for each sample. From these measurements, we calculated the carrier effective mass and illustrated the variation of the figure of merit with the wavelength. A method for creating a tunable bandpass filter via the Faraday rotation is discussed along with preliminary results from a prototype device.
Uniaxial and biaxial strain engineering in 2D MoS2 with lithographically patterned thin film stressors
Authors: Azizimanesh Ahmad , Peña Tara , Sewaket Arfan , Hou Wenhui , Wu Stephen M.
Published: May 2021

We introduce a controllable approach to selectively strain (uniaxially or biaxially) MoS2 by depositing e-beam evaporated thin film stressors with a lithographically patterned stripe geometry. This type of strain engineering has been highly successful in commercial silicon-based CMOS processes to enhance carrier mobility by applying uniaxial strain in MOSFET channels. We attempt to outline the basis for using the same techniques with 2D van der Waals materials with weak out-of-plane bonding. The stressor in this work is chosen to be optically transparent to examine the strain distribution within MoS2 using Raman spectroscopic mapping. MoS2 flakes with partial tensile stressor coverage show large tensile strains close to free edges and compressive strain at the center of the stressor strip. Both in-plane and out-of-plane strains are observed. By varying strip width and MoS2 flake thickness, the geometric distribution of both tensile and compressive strained regions can be controlled. The directionality of strain induced by the stressor strip is also explored through polarized Raman spectroscopy where MoS2 shows 0.85% uniaxial strains occurring at strip edges for 25 N/m film force and biaxial strains occurring at strip centers using the same stressor. Using these combined techniques, we show that strain in 2D materials can be uniquely engineered by design to selectively exhibit tension/compression, uniaxiality/biaxiality, and directionality relative to crystal axes through simple lithographic patterning of stressed thin films. This opens the opportunity to create strain patterned devices with a wide variety of strain-tunable 2D materials properties (electronic, optical, superconducting, etc.), now controllable by micro/nanolithographic design.