bluuebunny/crossref_metadata_2025 huggingface dataset:
Urban fragmentation leads to lower floral diversity, with knock-on impacts on bee biodiversity
Authors: Theodorou Panagiotis , Herbst Sarah-Christine , Kahnt Belinda , Landaverde-González Patricia , Baltz Lucie M. , Osterman Julia , Paxton Robert J.
Published: December 2020

Bees and flowering plants are two closely interacting groups of organisms. Habitat loss and fragmentation associated with urbanisation are major threats to both partners. Yet how and why bee and floral richness and diversity co-vary within the urban landscape remain unclear. Here, we sampled bees and flowering plants in urban green spaces to investigate how bee and flowering plant species richness, their phylogenetic diversity and pollination-relevant functional trait diversity influence each other in response to urban fragmentation. As expected, bee abundance and richness were positively related to flowering plant richness, with bee body size (but not bee richness and diversity) increasing with nectar-holder depth of flowering plants. Causal modelling indicated that bottom-up effects dictated patterns of bee-flower relationships, with urban fragmentation diminishing flowering plants richness and thereby indirectly reducing bee species richness and abundance. The close relationship between bees and flowering plants highlights the risks of their parallel declines in response to land-use change within the urban landscape.
N2O decomposition properties of Ru catalysts supported on various oxide materials and SnO2
Authors: Hinokuma Satoshi , Iwasa Takeshi , Kon Yoshihiro , Taketsugu Tetsuya , Sato Kazuhiko
Published: December 2020

Nitrous oxide (N2O) is a stratospheric ozone depleting greenhouse gas that has global warming potential. As the catalytic decomposition of N2O is one of the most promising techniques for N2O emissions abatement, in this study, for this purpose the properties of Ru supported on various oxide materials were investigated under excess O2conditions, and the identities of the N2O adsorption species on the catalysts were confirmed. To clarify the correlation between the catalytic properties and N2O decomposition activity, the supported Ru catalysts were characterised by means of powder X-ray diffraction, X-ray fluorescence measurements, energy-dispersive X-ray mapping and several gas sorption techniques. The results showed that the redox properties for Ru (RuO2) at low temperature are closely associated with N2O decomposition activity. The local structures, optimal Ru loading and N2O adsorption species of the novel Ru/SnO2catalysts were studied and they showed high activity for N2O decomposition.
Reliable and accurate diagnostics from highly multiplexed sequencing assays
Authors: Booeshaghi A. Sina , Lubock Nathan B. , Cooper Aaron R. , Simpkins Scott W. , Bloom Joshua S. , Gehring Jase , Luebbert Laura , Kosuri Sri , Pachter Lior
Published: December 2020

Scalable, inexpensive, and secure testing for SARS-CoV-2 infection is crucial for control of the novel coronavirus pandemic. Recently developed highly multiplexed sequencing assays (HMSAs) that rely on high-throughput sequencing can, in principle, meet these demands, and present promising alternatives to currently used RT-qPCR-based tests. However, reliable analysis, interpretation, and clinical use of HMSAs requires overcoming several computational, statistical and engineering challenges. Using recently acquired experimental data, we present and validate a computational workflow based on kallisto and bustools, that utilizes robust statistical methods and fast, memory efficient algorithms, to quickly, accurately and reliably process high-throughput sequencing data. We show that our workflow is effective at processing data from all recently proposed SARS-CoV-2 sequencing based diagnostic tests, and is generally applicable to any diagnostic HMSA.
Phenotypic Drug Discovery: History, Evolution, Future
Authors: Swinney David C.
Published: December 2020

Historically, empirical observations of phenotypic changes have played a pivotal role in the discovery of new medicines. Scientists and organizations that endeavor to discover new medicines employ all available knowledge and expertise to identify the best starting points and strategies. Unfortunately, knowledge gaps exist between the understanding of disease and the identification of useful therapeutics. History shows a progression in utilizing new knowledge to reduce the uncertainty and reliance on serendipity: from Ehrlich's ideas of ‘chemotherapy’ and ‘magic bullets’, to Black and Janssen's desire to start with ‘pharmacologically active compounds’, to Hitchings and Elion's strategy to utilize ‘new biochemical understandings’, and most recently, the use of genetics and genomics to identify drug targets. Throughout this evolution of knowledge and strategies, trial-and-error empiricism was required to bridge the translational knowledge gap in order to identify first-in-class compounds. Recently, the reliance upon empiricism was formalized as phenotypic drug discovery (PDD). At the core of PDD is an unbiased selection of drug candidates without prior assumptions as to how the candidate will work. PDD is evolving to a more formalized strategy to help address the uncertainty and risk associated with using empiricism to bridge mechanistic knowledge gaps.
A live-cell assay for the detection of pre-microRNA–protein interactions
Authors: Rosenblum Sydney L. , Lorenz Daniel A. , Garner Amanda L.
Published: December 2020

Leveraging bioorthogonal chemistry- and split-luciferase assay technologies, we have devised a new assay for the live-cell detection of RNA–protein interactions, RNA interaction with Protein-mediated Complementation Assay or RiPCA.
Short oligoalanine helical peptides for supramolecular nanopore assembly and protein cytosolic delivery
Authors: Pazo Marta , Salluce Giulia , Lostalé-Seijo Irene , Juanes Marisa , Gonzalez Francisco , Garcia-Fandiño Rebeca , Montenegro Javier
Published: December 2020

The helical enhancement of a short oligoalanine peptide scaffold in anionic membranes triggered the supramolecular assembly of a nanopore, which allowed the transport and release of proteins in the cytosol of cells and tissues.
Blue luminescent N,S-doped carbon dots encapsulated in red emissive Eu-MOF to form dually emissive composite for reversible anti-counterfeit ink
Authors: Gao Jin-Ping , Yao Ru-Xin , Chen Xiao-Hui , Li Hui-Hui , Zhang Chao , Zhang Fu-Qiang , Zhang Xian-Ming
Published: December 2020

By suitable combination a Eu-MOF and its dual-emission fluorescence composite N,S-CDs@Eu-MOF, a visible fluorescent probe for detecting water content in organic solvents and a reversible anti-counterfeit ink were established.
Mesoporous WO3 modified by Au nanoparticles for enhanced trimethylamine gas sensing properties
Authors: Wang Yunan , Zhang Shendan , Huang Chaozhu , Qu Fengdong , Yao Dong , Guo Haichuan , Xu Haohao , Jiang Chunjie , Yang Minghui
Published: December 2020

Au-Doped mesoporous WO3 is prepared and it exhibited higher response to TMA gas.
An in vitro selective inhibitory effect of silver(i) aminoacidates against bacteria and intestinal cell lines and elucidation of the mechanism of action by means of DNA binding properties, DNA cleavage and cell cycle arrest
Authors: Rendošová Michaela , Gyepes Róbert , Maruščáková Ivana Cingeľová , Mudroňová Dagmar , Sabolová Danica , Kello Martin , Vilková Mária , Almáši Miroslav , Huntošová Veronika , Zemek Ondřej , Vargová Zuzana
Published: December 2020

Novel silver(i) aminoacidate complexes {[Ag(HVal)(H2O)(NO3)]}n (AgVal) and {[Ag3(HAsp)2(NO3)]}n·nH2O (AgAsp) were prepared, investigated, fully characterized and their antibacterial, anticancer and DNA cleavage activities were evaluated.
On the non-innocence and reactiveversusnon-reactive nature of α-diketones in a set of diruthenium frameworks
Authors: Khan Farheen Fatima , Mondal Saikat , Chandra Shubhadeep , Neuman Nicolas I. , Sarkar Biprajit , Lahiri Goutam Kumar
Published: December 2020

Slightly modified ligand designs in diruthenium setups have major impacts on the reactivity/stability of coordination complexes. The 1,2-bis(2-hydroxyphenyl)ethane-1,2-dione bridge is also potentially redox non-innocent.
Manganese–gold–manganese complex with vinylidene and acetylide units
Authors: Verpekin Victor V. , Shor Aleksey M. , Vasiliev Alexander D. , Kondrasenko Alexander A. , Chudin Oleg S. , Ivanova-Shor Elena A.
Published: December 2020

Several reactions of Cp(CO)2MnCCHPh with gold(i) complexes resulted in the formation of one trinuclear MnAuMn cluster, which basically can be represented as the complex of Au with two Mn-containing metalloligands.
X-Ray and ultraviolet photoelectron spectroscopy studies of Uranium(iv),(v) and(vi) exposed to H2O-plasma under UHV conditions
Authors: El Jamal Ghada , Gouder Thomas , Eloirdi Rachel , Jonsson Mats
Published: December 2020

We report surface characteristics of UO2, U2O5 and UO3 thin films after exposure to gas plasmas: a new approach of the oxidative dissolution problem.
MOFs assembled from C3 symmetric ligands: structure, iodine capture and role as bifunctional catalysts towards the oxidation–Knoevenagel cascade reaction
Authors: Zhang Ying-Ying , Liu Qing , Zhang Lin-Yan , Bao Yu-Mei , Tan Jing-Yi , Zhang Na , Zhang Jian-Yong , Liu Zhen-Jiang
Published: December 2020

Three new NiII/CoII-based MOFs constructed from C3 symmetric H3BTC and 4-TPT ligands have been characterized. MOF3 as a bifunctional acid−base catalyst showed good activities for the oxidation–Knoevenagel cascade reaction.
A magnetically retrievable copper ionic liquid nanocatalyst for cyclooxidative synthesis of 2-phenylquinazolin-4(3H)-ones
Authors: Gupta Radhika , Arora Gunjan , Yadav Priya , Dixit Ranjana , Srivastava Anju , Sharma Rakesh Kumar
Published: December 2020

The present work reports the design and fabrication of a copper-containing ionic liquid supported magnetic nanocatalyst for the formation of 2-phenylquinazolin-4(3H)-ones using o-aminobenzamide and benzaldehydes as the reaction partners.
Redox-controlled syndio-specific polymerization of styrene catalyzed by ferrocenyl functionalized half-sandwich scandium complexes
Authors: Zhong Yi , Li Min , Deng Meng , Gong Mingliang , Xie Hongzhen , Luo Yunjie
Published: December 2020

Upon activation with [Ph3C][B(C6F5)4], [Fc(1-C9H6)]Sc(CH2C6H4NMe2-o)2 is able to promote the redox-controlled syndio-specific polymerization of styrene by switching the oxidation states of Fe(ii/iii) using AgBF4 and CoCp2.
Highlights of the development and application of luminescent lanthanide based coordination polymers, MOFs and functional nanomaterials
Authors: Gorai Tumpa , Schmitt Wolfgang , Gunnlaugsson Thorfinnur
Published: December 2020

This perspective provides a selected overview of some of the recent developments in the area of Ln CP/MOF based nanomaterials for sensing, optical materials and bio-medicine research.
Forays into rhodium macrocyclic chemistry stabilized by a P2N2 donor set. Activation of dihydrogen and benzene
Authors: Yeo Alyssa , Sanz Corey A. , Fryzuk Michael D.
Published: December 2020

A lithium–rhodium(i) cyclooctene complex oxidatively adds dihydrogen and benzene to generate lithium–rhodium(iii) dihydride and phenyl-hydride derivatives, respectively.
A flexible and portable all-fiber temperature sensor based on the upconversion luminescence of octahedral NaBi(WO4)2:Er3+/Yb3+ phosphors
Authors: Ren Xiaotong , Gao Jia , Shi Haonan , Zhao Shilong , Huang Lihui , Xu Shiqing
Published: December 2020

Octahedral NaBi(WO4)2:Er3+/Yb3+ phosphors were synthesized by a hydrothermal method.
Snapshots of “crystalline” salt-water solutions of inositol hexaphosphate conformers
Authors: Kaur Sandeep , Pramanik Subhamay , Day Victor W. , Bowman-James Kristin
Published: December 2020

The first crystal structures of highly phosphorylated biomolecules, scyllo-inositol hexaphosphates, reveal important internal and interactive external roles with salt-water surroundings.
Supersilyl as an effective monodentate ligand to stabilize four-coordinate manganese(ii) complexes
Authors: Arata Shogo , Suzuki Kosuke , Yamaguchi Kazuya , Sunada Yusuke
Published: December 2020

Supersilyl, –Si(SiMe3)3, serves as an effective ligand to afford a series of four-coordinate manganese(ii) complexes.
On the importance of π-hole spodium bonding in tricoordinated HgIIcomplexes
Authors: Mahmoudi Ghodrat , Masoudiasl Ardavan , Babashkina Maria G. , Frontera Antonio , Doert Thomas , White Jonathan M. , Zangrando Ennio , Zubkov Fedor I. , Safin Damir A.
Published: December 2020

The synthesis and X-ray characterization of two new tri-coordinated Hg complexes where the planar Hg atom participates in π-hole spodium bonding.
Structural and electronic studies of substituted m-terphenyl lithium complexes
Authors: Valentine Andrew J. , Geer Ana M. , Taylor Laurence J. , Teale Andrew M. , Wood Katherine E. , Williams Huw E. L. , Lewis William , Argent Stephen P. , McMaster Jonathan , Kays Deborah L.
Published: December 2020

Spectroscopic and computational investigation of the effects of para-substituted m-terphenyl lithium complexes reveals significant electronic differences at the metal centre.
Cs2AlB5O10: a short-wavelength nonlinear optical crystal with moderate second harmonic generation response
Authors: Baiheti Tuohetijiang , Han Shujuan , Jin Wenqi , Yang Zhihua , Pan Shilie
Published: December 2020

A new compound Cs2AlB5O10 was synthesized by a high temperature solution method in open air.
Building a stable cationic molecule/electrode interface for highly efficient and durable CO2 reduction at an industrially relevant current
Authors: Su Jianjun , Zhang Jun-Jie , Chen Jiacheng , Song Yun , Huang Libei , Zhu Minghui , Yakobson Boris I. , Tang Ben Zhong , Ye Ruquan
Published: December 2020

Effective electronic induction and a stable interface collectively contribute to industrially relevant CO2 reduction performance in a flow cell.
Lead minerals found in drinking water distribution systems increase chlorine dioxide decay to a single inorganic product
Authors: Reuter Margaret M. , Lastoskie Christian M.
Published: December 2020

Mechanistic differences are found when chlorine dioxide, an alternative disinfectant, decays in the presence of both lead and copper minerals found in pipe corrosion scale.
Chocolate as a food matrix reduces the bioavailability of galloylated catechins from green tea in healthy women
Authors: Mukai Rie , Fukuda Takashi , Ohnishi Asami , Nikawa Takeshi , Furusawa Mutsuki , Terao Junji
Published: December 2020

Chocolate reduces the bioavailability of galloylated catechins, and ECG is more bioavailable than EGCg.
Investigating the formation of diverse ZnO nanostructures based on solvent, temperature, and pH as adjustable parameters
Authors: Thakur Smriti , Mandal Sanjay K.
Published: December 2020

The effect of solvent, temperature and pH on the formation of diverse ZnO nanostructures.
Two-dimensional C5678: a promising carbon-based high-performance lithium-ion battery anode
Authors: Li Da
Published: December 2020

A two-dimensional structurally stable carbon allotrope C5678 as a promising electrode for lithium-ion batteries was predicted.
Semimetal to semiconductor transition in Bi/TiO2 core/shell nanowires
Authors: Kockert M. , Mitdank R. , Moon H. , Kim J. , Mogilatenko A. , Moosavi S. H. , Kroener M. , Woias P. , Lee W. , Fischer S. F.
Published: December 2020

Full temperature-dependent thermoelectric and structural characterization of individual bismuth-based core/shell nanowires under the influence of strain induced by the shell.
In situ laser annealing as pathway for the metal free synthesis of tailored nanographenes
Authors: Milotti Valeria , Melle-Franco Manuel , Steiner Ann-Kristin , Verbitskii Ivan , Amsharov Konstantin , Pichler Thomas
Published: December 2020

Tailored synthesis of nanographenes, and especially graphene nanoribbons (GNR), has been achieved on metal substrates via a bottom-up approach from organic precursors, which paves the way to their application in nanoelectronics and optoelectronics.
Defect-assisted electronic metal–support interactions: tuning the interplay between Ru nanoparticles and CuO supports for pH-neutral oxygen evolution
Authors: Porkovich Alexander J. , Kumar Pawan , Ziadi Zakaria , Lloyd David C. , Weng Lin , Jian Nan , Sasaki Toshio , Sowwan Mukhles , Datta Abheek
Published: December 2020

Controlling the crystallinity of Ru NPs is essential for EMSI tuning in CuO supported Ru NPs for enhanced OER.
Full color-tunable vertically stacked quantum dot light emitting diodes for next-generation displays and lighting
Authors: Acharya Krishna P. , Titov Alexandre , Hyvonen Jake , Kim Baek Hyun , Ying Chen , Holloway Paul , Lamkin Mark A. , Guest Stephen , Ringgenberg Kyle
Published: December 2020

A full-color tunable vertically stacked EL-QLED is fabricated by separating subpixels with insulating layers and using transparent electrodes.
A visible light-triggered artificial photonic nociceptor with adaptive tunability of threshold
Authors: Gong Guodong , Gao Shuang , Xie Zhuolin , Ye Xiaoyu , Lu Ying , Yang Huali , Zhu Xiaojian , Li Run-Wei
Published: December 2020

An energy-efficient visible light-triggered artificial photonic nociceptor is demonstrated, which opens up a new avenue towards the development of future intelligent and low-power perceptual systems, such as visual prostheses and humanoid robots.
Copper decorated with nanoporous gold by galvanic displacement acts as an efficient electrocatalyst for the electrochemical reduction of CO2
Authors: Liu Zhonggang , Hossain M. Nur , Wen Jiali , Chen Aicheng
Published: December 2020

The efficient electrochemical reduction of carbon dioxide was achieved at the copper modified nanoporous gold.
Introduction to ‘Chemistry of 2D materials: graphene and beyond’
Authors: Samorì Paolo , Feng Xinliang , Palermo Vincenzo
Published: December 2020

Paolo Samorì, Xinliang Feng and Vincenzo Palermo introduce the Nanoscale themed collection on ‘Chemistry of 2D materials: graphene and beyond’.
Pd/C-Catalyzed transfer hydrogenation of N–H indoles with trifluoroethanol and tetrahydroxydiboron as the hydrogen source
Authors: Zhou Xiao-Yu , Chen Xia
Published: December 2020

Under the guidance of hydrogenation of indoles and transfer hydrogenation with tetrahydroxydiboron, Pd/C catalyzed transfer hydrogenation of N–H indoles with trifluoroethanol and tetrahydroxydiborane as the hydrogen source has been developed.
Removal and modification of directing groups used in metal-catalyzed C–H functionalization: the magical step of conversion into ‘conventional’ functional groups
Authors: Carvalho Renato L. , Almeida Renata G. , Murali Karunanidhi , Machado Luana A. , Pedrosa Leandro F. , Dolui Pravas , Maiti Debabrata , da Silva Júnior Eufrânio N.
Published: December 2020

This feature review is focused on recent approaches for removing versatile directing groups.
First-principles investigation on the bonding mechanisms of two-dimensional carbon materials on the transition metals surfaces
Authors: Zhang Xin , Sun Shenghui , Wang Shaoqing
Published: December 2020

Except for the existing sp and sp2 hybridizations, the carbon shows the sp3 hybridization after graphyne adsorbs on Ti surface.
First total synthesis of versicotide A, B and C
Authors: Posada Laura , Davyt Danilo , Serra Gloria
Published: December 2020

Versicotides A–C, natural products containig anthranilic acid and NMe-Ala, were prepared by Fmoc/SPPS and solution phase macrocyclization.
A chemical circular communication network at the nanoscale
Authors: de Luis Beatriz , Morellá-Aucejo Ángela , Llopis-Lorente Antoni , Godoy-Reyes Tania M. , Villalonga Reynaldo , Aznar Elena , Sancenón Félix , Martínez-Máñez Ramón
Published: December 2020

A community of three nanodevices communicates through a hierarchically programmed circular flow of chemical information between members.
A DNA-mediated crosslinking strategy to enhance cellular delivery and sensor performance of protein spherical nucleic acids
Authors: Yan Jing , Tan Ya-Ling , Lin Min-jie , Xing Hang , Jiang Jian-Hui
Published: December 2020

By crosslinking protein spherical nucleic acid (SNA) into a supramolecular architecture X-SNA, the intracellular enzyme delivery efficiency was significantly enhanced, showing 3–4 times higher signal-to-noise ratio in detecting intracellular lactate.
The synthesis of a chemically reactive and polymeric luminescent gel
Authors: Baruah Upama , Manna Uttam
Published: December 2020

An unprecedented chemically reactive and polymeric luminescent gel is developed, and this material is further employed to develop a portable and rapid sensor for a practically relevant analyte (nitrite ions) with a sensitivity of 3 μM.
The atomic-level structure of bandgap engineered double perovskite alloys Cs2AgIn1−xFexCl6
Authors: Ji Fuxiang , Wang Feng , Kobera Libor , Abbrent Sabina , Brus Jiri , Ning Weihua , Gao Feng
Published: December 2020

Through Fe3+-alloying, the bandgap of benchmark double perovskite Cs2AgInCl6 can be tuned from 2.8 eV to 1.6 eV. The atomic-level structure of Cs2AgIn1−xFexCl6 was revealed by solid-state nuclear magnetic resonance (ssNMR).
Kinetic resolution of racemic allylic alcohols via iridium-catalyzed asymmetric hydrogenation: scope, synthetic applications and insight into the origin of selectivity
Authors: Wu Haibo , Margarita Cristiana , Jongcharoenkamol Jira , Nolan Mark D. , Singh Thishana , Andersson Pher G.
Published: December 2020

Asymmetric hydrogenation is one of the most commonly used tools in organic synthesis, whereas, kinetic resolution via asymmetric hydrogenation was less developed.
Empowering self-reporting polymer blends with orthogonal optical properties responsive in a broader force range
Authors: Wu Mengjiao , Guo Zhen , He Weiye , Yuan Wei , Chen Yulan
Published: December 2020

Probing bond scission process in a broader force range was realized by embedding mechanochromic rhodamine and mechanochemiluminescent 1,2-dioxetane in polymer blends.
A vertical graphene enhanced Zn–MnO2 flexible battery towards wearable electronic devices
Authors: Chen Junyan , Liang Jiaxing , Zhou Yang , Sha Zhao , Lim Sean , Huang Feng , Han Zhaojun , Brown Sonya A. , Cao Liuyue , Wang Da-Wei , Wang Chun H.
Published: December 2020

A multilayer structured cathode for zinc ion batteries is created by using vertical graphene nano-maze to hold MnO2 and encapsulating with an ionic conductive PEDOT:PSS layer. The new electrode exhibits exceptional capacity and cycle performance.
A shape-memory V3O7·H2O electrocatalyst for foldable N2 fixation
Authors: Sun Yuntong , Ding Shan , Zhang Chen , Duan Jingjing , Chen Sheng
Published: December 2020

A shape-memory monolith has been used as a new emerging class of foldable nitrogen-fixing electrocatalysts, which shows remarkable activities both with and without electrode deformations.
Biotechnology, nanotechnology and medicine
Authors: Contera Sonia , Bernardino de la Serna Jorge , Tetley Teresa D.
Published: December 2020

The 1980s mark the starting point of nanotechnology: the capacity to synthesise, manipulate and visualise matter at the nanometre scale. New powers to reach the nanoscale brought us the unprecedented possibility to directly target at the scale of biomolecular interactions, and the motivation to create smart nanostructures that could circumvent the hurdles hindering the success of traditional pharmacological approaches. Forty years on, the progressive integration of bio- and nanotechnologies is starting to produce a transformation of the way we detect, treat and monitor diseases and unresolved medical problems [ 1]. While much of the work remains in research laboratories, the first nano-based treatments, vaccines, drugs, and diagnostic devices, are now receiving approval for commercialisation and clinical use. In this special issue we review recent advances of nanomedical approaches to combat antibiotic resistance, treatment and detection of cancers, targeting neurodegerative diseases, and applications as diverse as dentistry and the treatment of tuberculosis. We also examine the use of advanced smart nanostructured materials in areas such as regenerative medicine, and the controlled release of drugs and treatments. The latter is currently poised to bring ground-breaking changes in immunotherapy: the advent of ‘vaccine implants’ that continuously control and improve immune responses over time. With the increasingly likely prospect of ending the COVID 19 pandemic with the aid of a nanomedicine-based vaccine (both Moderna and BioNTech/Pfizer vaccines are based on lipid nanoparticle formulations), we are witnessing the coming of age of nanomedicine. This makes it more important than ever to concentrate on safety: in parallel to pursuing the benefits of nanomedine, we must strengthen the continuous focus on nanotoxicology and safety regulation of nanomedicines that can deliver the medical revolution that is within our grasp.
Observer‐based adaptive fault estimation and fault‐tolerant tracking control for a class of uncertain nonlinear systems
Authors: Wu Yang , Zhang Guoshan , Wu Libing
Published: December 2020

This paper considers the problem of adaptive fault estimation and fault‐tolerant tracking control for a class of uncertain nonlinear systems with model uncertainty and process fault. By utilising the approximation abilities of fuzzy logic systems, a novel fault estimation fuzzy observer is designed to estimate the unmeasured states, nonlinear functions and process fault. Based on backstepping technologies, a adaptive fuzzy fault‐tolerant controller with the adaptive updated laws is established, which can not only ensure the prescribed tracking performances, but also effectively compensate the process fault. It is proved that all the closed‐loop signals of systems are uniformly ultimately bounded and the tracking errors can constrain to the prescribed bounds. Finally, simulation results can verify the efficiency of the proposed approach.
Prediction of limit cycle oscillations in piecewise linear systems with multiple piecewise nonlinearities
Authors: Yoon Yongeun , Johnson Eric N
Published: December 2020

Mathematical modelings of many electric and mechanical systems involve piecewise linear system. Piecewise linear system can possess a periodic solution called a limit‐cycle oscillation (LCO), which can seriously undermine the system performance. Therefore, how to analyze LCO and its parameters in piecewise linear systems is one of the primary concerns for the control and system engineers. This work presents a novel framework to predict and analyze LCO of piecewise linear systems, focused on systems with multiple piecewise nonlinearities. On top of the well‐known piecewise linear analysis, the Floquet theory is applied to identify LCO parameters and determine the stability of the LCO. The introduction of Floquet theory to piecewise linear systems is allowed through transforming piecewise nonlinearities to corresponding equivalent analytic functions. In addition, the establishment of switching equation provides another necessary condition to predict LCO parameters. An example of a realistic flight control system is taken to demonstrate the effectiveness and efficiency of authors' framework.
Disturbance observer aided optimised fractional‐order three‐degree‐of‐freedom tilt‐integral‐derivative controller for load frequency control of power systems
Authors: Guha Dipayan , Roy Provas Kumar , Banerjee Subrata
Published: December 2020

This work demonstrates a maiden application of a fractional‐order based three‐degree‐of‐freedom tilt‐integral‐derivative controller for escalating the load frequency control performance of power system having wind power generator integrated. The disturbance observer is housed with the proposed fractional‐order‐three‐degree‐of‐freedom‐tilt‐integral‐derivative controller to efficiently estimate the wind velocity's uncertain profile and subsequently enrich the control law. The mastery of the proposed control algorithm has been tested on multi‐area interconnected power systems by performing an extensive comparative study with other prevalent techniques reported in the state‐of‐art. Harris' Hawks optimisation is applied to explore the proposed controllers' optimum gains, exercising an integral error‐based criterion. Time response measurements of the studied test systems in the wake of load fluctuation and intermittent output of wind power generator explicitly establish the efficacy of the proposed Harris' Hawks optimisation tuned disturbance observer‐based fractional‐order‐three‐degree‐of‐freedom‐tilt‐integral‐derivative controller over its other counterparts concerning damping of system oscillations. Furthermore, the developed control system's robust stability is affirmed using Kharitonov's stability theorem, considering ±25% variation in system parameters.
Research on the dynamic characteristics of electric field distribution of the ± 1100 kV Ultra high voltage converter transformer valve‐side bushing using weakly ionised gas conductance model
Authors: Wang Qingyu , Liu Peng , Tian Huidong , Xie Gengsheng , Peng Zongren , Yang Xi
Published: December 2020

Ultra high voltage (UHV) converter transformer valve‐side bushings are the key equipment indirect current (DC) transmission projects, and are subjected to high voltage and large current with large number of harmonics simultaneously. The electric field distribution of converter transformer valve‐side bushings is time‐dependent under DC voltage, polarity reversal voltage and actual voltage waveforms, and the electric and temperature field are coupling with each other in actual operation. The dynamic characteristics of the surface charges and the electric field distribution of China's first ± 1100 kV epoxy/paper – SF6 composite insulation converter trans former valve‐side bushing under 2 h DC withstand test voltage and polarity reversal voltage were analysed considering the natural ionisation, drifting, diffusion and recombination processes of positive and negative ions in SF6 gas and air. The time‐dependent electro‐thermal coupling field of the bushing under the actual voltage waveform in one cycle was obtained. The rationality of the simulation method adopted was verified through type tests of the UHV converter transformer valve‐side bushing. The simulation results of the paper can provide a theoretical foundation for the design of converter transformer valve‐side bushings and it is of great significance to ensure the safe operation of converter stations.
A new approach to spectroscopic phase curves
Authors: Arcangeli J. , Désert J.-M. , Parmentier V. , Tsai S.-M. , Stevenson K. B.
Published: December 2020

We analyse emission spectra of WASP-12b from a partial phase curve observed over three epochs with the Hubble Space Telescope, covering eclipse, quadrature, and transit, respectively. As the 1.1-day period phase curve was only partially covered over three epochs, traditional methods to extract the planet flux and instrument systematic errors cannot recover the thermal emission away from the secondary eclipse. To analyse this partial phase curve, we introduce a new method, which corrects for the wavelength-independent component of the systematic errors. Our new method removes the achromatic instrument and stellar variability, and uses the measured stellar spectrum in eclipse to then retrieve a relative planetary spectrum in wavelength at each phase. We are able to extract the emission spectrum of an exoplanet at quadrature outside of a phase curve for the first time; we recover the quadrature spectrum of WASP-12b up to an additive constant. The dayside emission spectrum is extracted in a similar manner, and in both cases we are able to estimate the brightness temperature, albeit at a greatly reduced precision, because our method removes the absolute level of the spectra, and therefore relies on fitting the slope of the emission spectrum instead of its amplitude. We estimate the brightness temperature from the dayside (Tday = 3186 ± 677 K) and from the quadrature spectrum (Tquad = 2124 ± 417 K) and combine them to constrain the energy budget of the planet. We compare our extracted relative spectra to global circulation models of this planet, which are generally found to be a good match. However, we do see tentative evidence of a steeper spectral slope in the measured dayside spectrum compared to our models. We find that we cannot match this increased slope by increasing optical opacities in our models. We also find that this spectral slope is unlikely to be explained by a non-equilibrium water abundance, as water advected from the nightside is quickly dissociated on the dayside. We present our technique for analysing partial or full phase curves from HST/WFC3 using common mode methods. Importantly, and unlike previous phase curve analyses, this technique does not assume a functional form for the planet’s emission with phase and does not require a full-orbit phase curve. The success of this technique relies upon stable pointing of the telescope between visits, with less than 0.1 pixels drift for example. This technique becomes powerful in the study of new regimes in exoplanetary systems such as for longer period planets, and is ideally suited for future observations with JWST and ARIEL.
Improving the RSM map exoplanet detection algorithm
Authors: Dahlqvist C.-H. , Louppe G. , Absil O.
Published: December 2020

Context. High-contrast imaging is one of the most challenging techniques for exoplanet detection. It relies on sophisticated data processing to reach high contrasts at small angular separations. Most data processing techniques of this type are based on the angular differential imaging observing strategy to perform the subtraction of a reference point spread function (PSF). In addition, such techniques generally make use of signal-to-noise (S/N) maps to infer the existence of planetary signals via thresholding.

Aims. An alternative method for generating the final detection map was recently proposed with the regime-switching model (RSM) map, which uses a regime-switching framework to generate a probability map based on cubes of residuals generated by different PSF subtraction techniques. In this paper, we present several improvements to the original RSM map, focusing on novel PSF subtraction techniques and their optimal combinations, as well as a new procedure for estimating the probabilities involved.

Methods. We started by implementing two forward-model versions of the RSM map algorithm based on the LOCI and KLIP PSF subtraction techniques. We then addressed the question of optimally selecting the PSF subtraction techniques to optimise the overall performance of the RSM map. A new forward-backward approach was also implemented to take into account both past and future observations to compute the RSM map probabilities, leading to improved precision in terms of astrometry and lowering the background speckle noise.

Results. We tested the ability of these various improvements to increase the performance of the RSM map based on data sets obtained with three different instruments: VLT/NACO, VLT/SPHERE, and LBT/LMIRCam via a computation of receiver operating characteristic curves. These results demonstrate the benefits of these proposed improvements. Finally, we present a new framework to generate contrast curves based on probability maps. The contrast curves highlight the higher performance of the RSM map compared to a standard S/N map at small angular separations.
Frakturen der Wirbelsäule bei Morbus Bechterew
Authors: Heyde Christoph-Eckhard , Völker Anna , von der Höh Nicolas Heinz
Published: December 2020

Frakturen der Wirbelsäule bei M. Bechterew bedürfen einer aufmerksamen Diagnostik und der Berücksichtigung spezieller perioperativer und operativer Besonderheiten. Die Grundkrankheit führt zu ausgeprägten biologischen und biomechanischen Veränderungen der Wirbelsäule. Daraus resultiert eine erhöhte Vulnerabilität gegenüber Traumata, insbesondere auch sogenannter Bagatelltraumata. Dies führt sowohl zu einer erhöhten Rate an Wirbelsäulenverletzungen als auch zu einer erhöhten Rate primärer und sekundärer neurologischer Komplikationen. Die Diagnostik umfasst grundsätzlich eine dezidierte Abklärung der gesamten spinalen Achse. Die perioperative Therapie muss den Besonderheiten der Grundkrankheit angepasst werden. Die in aller Regel operative Frakturversorgung kann anspruchsvoll sein. Somit erfordert die Diagnostik und Therapie von Verletzungen der Wirbelsäule bei M. Bechterew chirurgische Erfahrung und gute Kenntnisse der aus der Grundkrankheit resultierenden Besonderheiten dieser Patienten.
Fast Motion Speed Alters the Sit-to-Walk Spatial and Temporal Pattern in Healthy Young Men
Authors: Rousanoglou Elissavet N. , Kondilopoulos Nikolaos , Boudolos Konstantinos D.
Published: December 2020

Sit-to-Walk (STW) is a critical task for daily independence, yet its two inherent destabilizing events (seat-off, walking initiation) may diminish postural stability under fast motion speed (FS). This study aimed at the FS effect on the STW spatial and temporal patterns, with a specific interest in the relative STW temporal pattern. The STW kinetics and kinematics were recorded (n=18 men, 20.7±2.0 years) at preferred and FS. Statistics included One-Way repeated measures ANOVA (SPSS 25.0, p≤0.05). The FS spatial pattern reveals a discontinuous mode of the forward ground reaction force, indicating a balance rather than a propulsive strategy during the Rising phase. The FS relative temporal pattern reveals the prolongation of the Leaning phase (most possibly due to the feet repositioning), the shortening of the Rising and the Walking phases, and a relative delay in the spatial variables (p≤0.05). Overall, the results do not allow the STW consideration at FS as a “magnified” with respect to force, or a “shrinked-in” with respect to time, copy of the preferred motion speed. As more generic and versatile than the absolute one, the relative temporal pattern may be used as a reference for a variety of populations.
Plant-Produced Basic Fibroblast Growth Factor (bFGF) Promotes Cell Proliferation and Collagen Production
Authors: Rattanapisit Kaewta , Jantimaporn Angkana , Kaewpungsup Pornjira , Shanmugaraj Balamurugan , Pavasant Prasit , Namdee Katawut , Phoolcharoen Waranyoo
Published: December 2020

Human fibroblast growth factor regulates a broad spectrum of biological functions, including cell proliferation and tissue differentiation, and has a wider application in tissue engineering. Here, we described the production of human basic fibroblast growth factor in plants by using a geminiviral vector system. In this study, we transiently expressed basic fibroblast growth factor containing a C-terminus 8X-Histidine with and without a barley alpha amylase signal peptide in Nicotiana benthamiana. The expression level of basic fibroblast growth factor without the signal peptide was found to be higher than the basic fibroblast growth factor with the signal peptide. Further, the recombinant basic fibroblast growth factor was purified from the plant crude extract by two-step purification viz., ammonium sulfate precipitation and Ni-affinity chromatography. Our results demonstrated that the purified plant-produced basic fibroblast growth factor was biologically active and promotes the proliferation of human periodontal ligament stem cells and human follicle dermal papilla cells in vitro. Moreover, the plant-produced basic fibroblast growth factor also induced collagen production in human dermal fibroblast cells. Our results suggest the potential use of plant-produced basic fibroblast growth factor as an antiaging and hair growth-promoting agent in the cosmetic industry.
HSF1 Alleviates Microthrombosis and Multiple Organ Dysfunction in Mice with Sepsis by Upregulating the Transcription of Tissue-Type Plasminogen Activator
Authors: Li Tao , Chen Huan , Zhang Huali , Xiao Xianzhong , Shi Xueyan , Yin Leijing , Tan Chuyi , Gu Jia , Liu Yanjuan , Li Caiyan , Xiao Gui , Liu Ke , Liu Meidong , Tan Sipin , Xiao Zihui
Published: December 2020

Sepsis is a life-threatening complication of infection closely associated with coagulation abnormalities. Heat shock factor 1 (HSF1) is an important transcription factor involved in many biological processes, but its regulatory role in blood coagulation remained unclear. We generated a sepsis model in HSF1-knockout mice to evaluate the role of HSF1 in microthrombosis and multiple organ dysfunction. Compared with septic wild-type mice, septic HSF1-knockout mice exhibited a greater degree of lung, liver, and kidney tissue damage, increased fibrin/fibrinogen deposition in the lungs and kidneys, and increased coagulation activity. RNA-seq analysis revealed that tissue-type plasminogen activator (t-PA) was upregulated in the lung tissues of septic mice, and the level of t-PA was significantly lower in HSF1-knockout mice than in wild-type mice in sepsis. The effects of HSF1 on t-PA expression were further validated in HSF1-knockout mice with sepsis and in vitro in mouse brain microvascular endothelial cells using HSF1 RNA interference or overexpression under lipopolysaccharide stimulation. Bioinformatics analysis, combined with electromobility shift and luciferase reporter assays, indicated that HSF1 directly upregulated t-PA at the transcriptional level. Our results reveal, for the first time, that HSF1 suppresses coagulation activity and microthrombosis by directly upregulating t-PA, thereby exerting protective effects against multiple organ dysfunction in sepsis.
Transition-Metal-Catalyzed Cross-Coupling Reactions of Grignard Reagents
Authors: Hell Zoltán , Juhász Kinga , Magyar Ágnes
Published: December 2020

Transition-metal-catalyzed cross-coupling of organo­halides, ethers, sulfides, amines, and alcohols (and derivatives thereof) with Grignard reagents, known as the Kumada–Tamao–Corriu reaction, can be used to prepare important intermediates in the synthesis of numerous­ biologically active compounds. The most frequently used transition metals are nickel, palladium, and iron, but there are several examples for cross-coupling reactions catalyzed by copper, cobalt, manganese, chromium, etc. salts and complexes. The aim of this review is to summarize the most important transition-metal-catalyzed cross-coupling reactions realized in the period 2000 to 2020.

1 Introduction

2 Nickel Catalysis

3 Palladium Catalysis

4 Iron Catalysis

5 Catalysis by Other Transition Metals

5.1 Cobalt Catalysis

5.2 Copper Catalysis

5.3 Manganese Catalysis

5.4 Chromium Catalysis

6 Conclusion
Two short pollen records from the late Holocene and pre last Glacial of Flinders Island, south eastern Australia
Authors: Ladd P. G. , Clarke I. C.
Published: December 2020

The Bass Strait islands are some of the few areas in Australia that were not occupied by humans at the time of European contact. There is archaeological evidence that Flinders Island at the eastern end of Bass Strait supported people until c. 4500 years ago but after that there is no evidence of human presence. Two previous pollen studies, covering the Holocene, from a swamp on the eastern side of the island were interpreted rather differently in terms of how influential humans were in their effects on the island’s vegetation. In this paper, two short pollen diagrams from very different places than the earlier studies are described. These add to the evidence of the type of vegetation on the island over the late Quaternary. One diagram covers only the last 1500 years and is from a 1-m deposit from near the highest peak on the island in the south. This shows that there has been little change over that time in the vegetation around the site and there has been no influence of fire in the area. By contrast, a thin peat deposit, overlying lake sediments containing freshwater mollusc shells and Characeae oogonia, from Killiecrankie Bay in the north of the island dated at c. 34000 14C calibrated (cal) before present (BP) shows evidence of fire. The vegetation at the time was not similar to the vegetation during the Holocene with little representation of eucalypts but prominence of shrubby species (Leptospermum, Melaleuca) and herbaceous taxa such as Restionaceae and Asteraceae, particularly the Pleistocene Asteraceae pollen type. The vegetation on the eastern Bassian isthmus at that time was likely to have had less tree cover than in the Holocene and was more heath-dominated.
A quality control procedure for Fengyun-3A microwave temperature sounder with emphasis on a new cloud detection algorithm
Authors: Wang Xiang , Ren Yifang , Li Gang
Published: December 2020

A cloud detection algorithm for satellite radiance from the microwave temperature sounder (MWTS) on board the first satellite of the Chinese polar-orbiting Fengyun-three series (FY-3A) is proposed based on the measurements at the frequencies of 50.3 and 53.6 GHz. The cloud liquid water path index (LWP index) is calculated using the brightness temperature at these two channels. Analysis of one case carried out in January2010shows the great consistency be-tween this new algorithm result and the available liquid water path product from the Meteorological Operational satellite A (MetOp-A).In general, about 60% of the global MWTS data are considered to be contaminated by cloud by virtue of the new cloud detection algorithm. A quality control (QC) procedure is applied to MWTS measurements with emphasis on the cloud detection. The QC steps are composed of (i) channel 2 over sea ice, land and coastal field of views (FOVs); (ii) channels 2 and 3 over cloudy FOVs; and (iii) outliers with large differences between observations and model simulations. After QC, MWTS measurements of channels 2–4 agree very well with the model simulations using the National Centres for Environmental Prediction (NCEP) forecast data as radiative transfer model input; the scan biases are reduced significantly, especially at the edges of the swath; and the frequency distributions of the differences between observations and model simulations become more Gaussian-like.
Evaluation of the performance of CORDEX regional climate models in simulating present climate conditions of Tanzania
Authors: Luhunga Philbert , Botai Joel , Kahimba Frederick
Published: December 2020

Regional climate models (RCMs) are widely used in regional assessment of climate change impacts. However, the reliability of individual models needs to be assessed before using their output for impact assessment. In this study, we evaluate the performance of RCMs from the Coordinated Regional Climate Downscaling Experiment program (CORDEX) to simulate minimum air temperature (TN), maximum air temperature (TX) and rainfall over Tanzania. Output from four RCMs driven by boundary conditions from three General Circulation Models (GCMs) and ERA-Interim data are evaluated against observed data from 22 weather stations. The evaluation is based on determining how well the RCMs reproduce climatological trends, interannual, and annual cycles of TN, TX and rainfall. Statistical measures of model performance that include the bias, root mean square error, correlation and trend analysis are used. It is found that RCMs capture the annual cycle of TN, TX and rainfall well, however underestimate and overestimate the amount of rainfall in March–April–May (MAM) and October–November–December (OND) seasons respectively. Most RCMs reproduce interannual variations of TN, TX and rainfall. The source of uncertainties can be analysed when the same RCM is driven by different GCMs and different RCMs driven by same GCM simulate TN, TX and rainfall differently. It is found that the biases and errors from the RCMs and driving GCMs contribute roughly equally. Overall, the evaluation finds reasonable (although variable) model skill in representing mean climate, interannual variability and temperature trends, suggesting the potential use of CORDEX RCMs in simulating TN, TX and rainfall over Tanzania.