bluuebunny/crossref_metadata_2025_split huggingface dataset:
H∞ filtering of discrete‐time interconnected systems with failed interconnections
Authors: Chen Yuzhi , Wu Chun‐Yu , Xu Ning , Alotaibi Naif D. , Alkhateeb Abdulhameed F. 
Published: September 2020

SummaryThe H∞ filtering problem for interconnected systems is addressed in this paper. In order to facilitate the stability analysis of interconnected systems under the conditions of failed interconnections, a strategy related to switched systems is introduced. Assume that the interconnections among these subsystems disconnect based on the mode‐dependent average dwell time (MDADT), a switching signal is implemented to denote the failed interconnections cases. In the aid of the MDADT method, a filter is designed such that the fault detection (FD) system is asymptotically stable and satisfies the weighted H∞ performance. Finally, a numerical simulation is provided to show the effectiveness of the proposed filter.
Aggregation‐Resistant 3D Ti3C2Tx MXene with Enhanced Kinetics for Potassium Ion Hybrid Capacitors
Authors: Fang Yong‐Zheng , Hu Rong , Zhu Kai , Ye Ke , Yan Jun , Wang Guiling , Cao Dianxue 
Published: September 2020

AbstractPotassium‐ion hybrid capacitors have attracted increasing attention due to good energy density, high power density, and low cost. Ti3C2Tx‐MXene is considered as a promising anode material for K ion storage. However, undesirable stacking issues decrease its exposed area and breeds sluggish K ion transport. Herein, a facile spray‐lyophilization strategy is proposed to construct stacking‐resistant Ti3C2Tx with 3D structures. As‐prepared Ti3C2Tx hollow spheres/tubes present stack resistance, a large specific surface area, and a short ion diffusion pathway. When serving as an anode material, it shows enhanced capacity and thickness‐independent rate performance compared to 2D Ti3C2Tx. After 10 000 cycles, a specific capacity of 122 mAh g−1 is obtained at 1 A g−1. Systematic kinetics analyses demonstrate the significance of concentration polarization on the electrode's rate ability. Furthermore, a 3D Ti3C2Tx‖hierarchical porous activated carbon (HPAC) K‐ion hybrid capacitor is assembled and displays remarkable energy and power densities with energy retention of 100% after 10 000 cycles at 1 A g−1 . Following this strategy, other 3D structures from nanosheets can also be obtained, such as 3D Ti3C2Tx microtubes and graphene oxide nanoscrolls. This study provides a viable approach to solve the stacking issues of 2D nanosheets to promote the application of 2D materials.
Diatomite‐Derived Hierarchical Porous Crystalline‐AmorphousNetwork for High‐Performance and Sustainable Si Anodes
Authors: Zhang Ying , Zhang Rui , Chen Shucheng , Gao Hongpeng , Li Mingqian , Song Xiaolan , Xin Huolin L. , Chen Zheng 
Published: September 2020

AbstractSilicon has attracted considerable interest as a high‐capacity anode material for next‐generation lithium‐ion batteries. However, Si‐based anodes suffer extreme volume change (≈380%) upon lithiation and delithiation, which results in rapid capacity fading due to mechanical and electrochemical failure during cycling. Herein, a sustainable and scalable method to synthesize hierarchically porous micron‐sized Si particles from the low‐cost diatomite precursor is reported, which serves as both the precursor and the template. Through a one‐step magnesiothermic reduction, the SiO2 constituent in diatomite is reduced to form a Si/SiO2 composite network with 10–30 nm crystalline Si domains embedded within an amorphous SiO2 matrix. Controlling the reduction time leads to an optimal ratio between the crystalline Si and the amorphous SiO2 constituent, which endows the composite structure with high capacity and excellent cycling stability. For example, 90% capacity can be retained after 500 cycles at 0.2C for sample reduced by 6 h without any coating or prelithiation. The full cell with such Si/SiO2 as the anode and LiNi0.8Co0.1Mn0.1O2 as the cathode shows ≈80% capacity retention after 200 cycles. This work creates a unique path towards sustainable and scalable production of high‐performance micron‐sized Si anodes, offering new opportunities for potential industrial applications.
Recent Developments in the Polychloroalkylation by Use of Simple Alkyl Chlorides
Authors: Liang Yun‐Yan , Lv Gui‐Fen , Ouyang Xuan‐Hui , Song Ren‐Jie , Li Jin‐Heng 
Published: September 2020

AbstractOwing to their easy availability and cheapness, simple alkyl chlorides are good raw materials for introducing complex polychlorinated groups. Polychlorinated hydrocarbons units, such as di‐ or trichloromethyl groups, not only widely found in pesticide and bioactive molecule, but also can be as a precursor to converted into different functional groups such as −COOH, −CHO and −CO. The direct polychloroalkylation reaction by using simple alkyl chlrides has been considered to be an important tool for synthesizing complex polychlorinated compounds. This review summarizes recent developments, especially free radical strategies, in the polychloroalkylation of different substrates (such as 2‐acylpyridines, benzyl tertiary amines, alkenes, imine and 1,n‐enynes). We hope that this review provides a new perspective on this field and also provides a reference to develop environmentally friendly and sustainable methods.magnified image
Stereospecific Synthesis of Glycoside Mimics Through Migita‐Kosugi‐Stille Cross‐Coupling Reactions of Chemically and Configurationally Stable 1‐C‐Tributylstannyl Iminosugars
Authors: Li Sizhe , Jaszczyk Justyna , Pannecoucke Xavier , Poisson Thomas , Martin Olivier R. , Nicolas Cyril 
Published: September 2020

AbstractA process for the de novo synthesis of imino‐C‐glycosides is described. The methodology is based on the reaction of 1‐C‐stannylated iminosugars with various electrophiles under the conditions of Migita‐Kosugi‐Stille cross‐couplings, which gives 1‐C‐substituted iminosugar derivatives in a stereoretentive process. The required iminoglycosyl stannanes are obtained by way of the highly stereoselective addition of tributylstannyllithium to (SR)‐ or (SS)‐N‐tert‐butanesulfinyl glycosylamines, followed by an activation cyclization sequence. Most interestingly, the methodology is tunable: the configuration of the tin adduct is controlled exclusively by the tert‐butanesulfinyl auxiliary, thus giving access after ring formation to ‘α’‐configured or ‘β’‐configured iminoglycosyl stannanes. With the subsequent stereoretentive C−C bond‐forming process, the methodology allows the synthesis of pseudo anomers of imino‐C‐glycosyl compounds in a controlled fashion.magnified image
Optimization of Catalyst Structure for Asymmetric Propargylation of Aldehydes with Allenyltrichlorosilane
Authors: Vaganov Vladimir Yu. , Fukazawa Yasuaki , Kondratyev Nikolay S. , Shipilovskikh Sergei A. , Wheeler Steven E. , Rubtsov Aleksandr E. , Malkov Andrei V. 
Published: September 2020

AbstractThe design of catalysts for asymmetric propargylations remains a challenging task, with only a handful of methods providing access to enantioenriched homopropargylic alcohols. In this work, guided by previously reported computational predictions, a set of atropisomeric bipyridine N,N’‐dioxides was tested as Lewis base catalysts for the asymmetric propargylation of aldehydes with trichloroallenylsilane. The catalysts are easily prepared in four simple steps starting from readily available methyl ketones. Aryl‐substituted derivatives proved to be highly active and showed a high level of enantiocontrol even at 1 mol% loading. The reaction scope includes a wide range of aromatic, heteroaromatic, and unsaturated aldehydes. New computations confirm that the key stereodetermining transition state structures for the synthesized catalysts are similar to those previously reported for the model structure.magnified image
Dienolate‐Mediated, Regioselective C2‐Polarity Reversal of Chromone‐Based Reactants and Their Application in Nucleophilic Strategies
Authors: Yao Zhen , Liu Xiong‐Wei , Li Zheng , Xu Sheng‐Wen , Xu Lijin , Liu Xiong‐Li 
Published: September 2020

AbstractInspired by the chemistry and biology of chromone, a method for the construction of spirooxindole‐based tetrahydrocyclopenta[b]chromanones is reported with good regio‐ and diastereoselectivity (all cases >20:1 dr) and moderate yields (up to 67%). This method leads to the construction of four contiguous stereogenic tertiary centers and one spiro quaternary center via a one‐step γ‐regioselective cascade [3+2] cycloaddition of an oxindole‐chromone synthon with 3‐methyl‐4‐nitro‐5‐alkenyl‐isoxazole.magnified image
Lignin Doped Carbon Nanotube Yarns for Improved Thermoelectric Efficiency
Authors: Culebras Mario , Ren Guang , O'Connell Steward , Vilatela Juan J. , Collins Maurice N. 
Published: September 2020

AbstractDue to ever increasing public awareness of the deteriorating planetary health condition associated with climate change and increasing carbon emissions, sustainable energy development has come sharply into focus. Here, a thermoelectric material is produced, which consists of macroscopic carbon nanotube yarns (CNTYs) produced continuously from the gas‐phase. The CNTYs are doped with lignin, obtained from lignocellulosic waste, and at 23 wt% lignin, electrical conductivity and the Seebeck coefficient are approximately doubled when compared to pristine CNTY samples. As a consequence, the power factor is remarkably improved to 132.2 µW m−1 K−2, more than six times that of the pristine CNTY. A thermoelectric generator device is manufactured, comprising 20 CNTY/lignin nanocomposite yarns, and they exhibit a maximum power output of 3.8 µW, at a temperature gradient of 30 K.
Nanoarchitectonics for Wide Bandgap Semiconductor Nanowires: Toward the Next Generation of Nanoelectromechanical Systems for Environmental Monitoring
Authors: Pham Tuan‐Anh , Qamar Afzaal , Dinh Toan , Masud Mostafa Kamal , Rais‐Zadeh Mina , Senesky Debbie G. , Yamauchi Yusuke , Nguyen Nam‐Trung , Phan Hoang‐Phuong 
Published: September 2020

AbstractSemiconductor nanowires are widely considered as the building blocks that revolutionized many areas of nanosciences and nanotechnologies. The unique features in nanowires, including high electron transport, excellent mechanical robustness, large surface area, and capability to engineer their intrinsic properties, enable new classes of nanoelectromechanical systems (NEMS). Wide bandgap (WBG) semiconductors in the form of nanowires are a hot spot of research owing to the tremendous possibilities in NEMS, particularly for environmental monitoring and energy harvesting. This article presents a comprehensive overview of the recent progress on the growth, properties and applications of silicon carbide (SiC), group III‐nitrides, and diamond nanowires as the materials of choice for NEMS. It begins with a snapshot on material developments and fabrication technologies, covering both bottom‐up and top‐down approaches. A discussion on the mechanical, electrical, optical, and thermal properties is provided detailing the fundamental physics of WBG nanowires along with their potential for NEMS. A series of sensing and electronic devices particularly for environmental monitoring is reviewed, which further extend the capability in industrial applications. The article concludes with the merits and shortcomings of environmental monitoring applications based on these classes of nanowires, providing a roadmap for future development in this fast‐emerging research field.
Predicting the Outbreak Risks and Inflection Points of COVID‐19 Pandemic with Classic Ecological Theories
Authors: Ma Zhanshan (Sam) 
Published: September 2020

AbstractPredicting the outbreak risks and/or the inflection (turning or tipping) points of COVID‐19 can be rather challenging. Here, it is addressed by modeling and simulation approaches guided by classic ecological theories and by treating the COVID‐19 pandemic as a metapopulation dynamics problem. Three classic ecological theories are harnessed, including TPL (Taylor’s power‐law) and Ma’s population aggregation critical density (PACD) for spatiotemporal aggregation/stability scaling, approximating virus metapopulation dynamics with Hubbell’s neutral theory, and Ma’s diversity‐time relationship adapted for the infection−time relationship. Fisher‐Information for detecting critical transitions and tipping points are also attempted. It is discovered that: (i) TPL aggregation/stability scaling parameter (b > 2), being significantly higher than the b‐values of most macrobial and microbial species including SARS, may interpret the chaotic pandemic of COVID‐19. (ii) The infection aggregation critical threshold (M0) adapted from PACD varies with time (outbreak‐stage), space (region) and public‐health interventions. Exceeding M0, local contagions may become aggregated and connected regionally, leading to epidemic/pandemic. (iii) The ratio of fundamental dispersal to contagion numbers can gauge the relative importance between local contagions vs. regional migrations in spreading infections. (iv) The inflection (turning) points, pair of maximal infection number and corresponding time, are successfully predicted in more than 80% of Chinese provinces and 68 countries worldwide, with a precision >80% generally.
Dual‐Strategy of Cation‐Doping and Nanoengineering Enables Fast and Stable Sodium‐Ion Storage in a Novel Fe/Mn‐Based Layered Oxide Cathode
Authors: Shen Qiuyu , Zhao Xudong , Liu Yongchang , Li Youpeng , Zhang Jian , Zhang Ning , Yang Chenghao , Chen Jun 
Published: September 2020

AbstractIron/manganese‐based layered transition metal oxides have risen to prominence as prospective cathodes for sodium‐ion batteries (SIBs) owing to their abundant resources and high theoretical specific capacities, yet they still suffer from rapid capacity fading. Herein, a dual‐strategy is developed to boost the Na‐storage performance of the Fe/Mn‐based layered oxide cathode by copper (Cu) doping and nanoengineering. The P2‐Na0.76Cu0.22Fe0.30Mn0.48O2 cathode material synthesized by electrospinning exhibits the pearl necklace‐like hierarchical nanostructures assembled by nanograins with sizes of 50–150 nm. The synergistic effects of Cu doping and nanotechnology enable high Na+ coefficients and low ionic migration energy barrier, as well as highly reversible structure evolution and Cu/Fe/Mn valence variation upon repeated sodium insertion/extraction; thus, the P2‐Na0.76Cu0.22Fe0.30Mn0.48O2 nano‐necklaces yield fabulous rate capability (125.4 mA h g−1 at 0.1 C with 56.5 mA h g−1 at 20 C) and excellent cyclic stability (≈79% capacity retention after 300 cycles). Additionally, a promising energy density of 177.4 Wh kg−1 is demonstrated in a prototype soft‐package Na‐ion full battery constructed by the tailored nano‐necklaces cathode and hard carbon anode. This work symbolizes a step forward in the development of Fe/Mn‐based layered oxides as high‐performance cathodes for SIBs.
Assessment of pneumoconiosis in surface coal miners after implementation of a national radiographic surveillance program, United States, 2014–2019
Authors: Hall Noemi B. , Halldin Cara N. , Blackley David J. , Laney A. Scott 
Published: September 2020

AbstractBackgroundPneumoconiosis can occur in surface coal miners. The Coal Workers' Health Surveillance Program (CWHSP) has only included surface coal miners as part of its regular disease surveillance since 2014. This analysis identifies the prevalence of pneumoconiosis among working surface coal miners participating in the CWHSP since their initial inclusion, through 2019.MethodsWorking surface coal miners who had chest radiographs through the CWHSP from January 1, 2014 through December 31, 2019 were included in this analysis. Demographic information, mining tenure and occupation, and radiographic classifications according to the International Labour Office system were included from each miner's most recent encounter with the CWHSP. Prevalence ratios were calculated comparing the prevalence of the disease by region and occupation by log‐binomial regression.ResultsPneumoconiosis was present in 109 (1.6%) surface coal miners, including 12 miners with progressive massive fibrosis, the most severe form of the disease. After taking surface mining tenure into account, surface miners in Central Appalachia (prevalence ratio [PR], 3.2; 95% confidence interval [CI], 2.2–4.7) and surface miners who worked as a driller or blaster (PR, 2.1; 95% CI, 1.3–3.5) were at increased risk of pneumoconiosis.ConclusionThe occurrence of pneumoconiosis in surface coal miners supports including them within a systematic respiratory health surveillance program. The current surveillance findings are consistent with past findings of pneumoconiosis, particularly silicosis, in surface mining occupations such as drilling and blasting.
Intrinsic Apyrase‐Like Activity of Cerium‐Based Metal–Organic Frameworks (MOFs): Dephosphorylation of Adenosine Tri‐ and Diphosphate
Authors: Yang Jian , Li Ke , Li Chunzhong , Gu Jinlou 
Published: September 2020

AbstractApyrase is an important family of extracellular enzymes that catalyse the hydrolysis of high‐energy phosphate bonds (HEPBs) in ATP and ADP, thereby modulating many physiological processes and driving life activities. Herein, we report an unexpected discovery that cerium‐based metal–organic frameworks (Ce‐MOFs) of UiO‐66(Ce) have intrinsic apyrase‐like activity for ATP/ADP‐related physiological processes. The abundant CeIII/CeIV couple sites of Ce‐MOFs endow them with the ability to selectively catalyse the hydrolysis of HEPBs of ATP and ADP under physiological conditions. Compared to natural enzymes, they could resist extreme pH and temperature, and present a broad range of working conditions. Based on this finding, a significant inhibitory effect on ADP‐induced platelet aggregation was observed upon exposing the platelet‐rich plasma (PRP) to the biomimetic UiO‐66(Ce) films, prefiguring their wide application potentials in medicine and biotechnology.
Dual Reactivity of 1,2,3,4‐Tetrazole: Manganese‐Catalyzed Click Reaction and Denitrogenative Annulation
Authors: Khatua Hillol , Das Sandip Kumar , Roy Satyajit , Chattopadhyay Buddhadeb 
Published: September 2020

AbstractA general catalytic method using a Mn‐porphyrin‐based catalytic system is reported that enables two different reactions (click reaction and denitrogenative annulation) and affords two different classes of nitrogen heterocycles, 1,5‐disubstituted 1,2,3‐triazoles (with a pyridyl motif) and 1,2,4‐triazolo‐pyridines. Mechanistic investigations suggest that although the click reaction likely proceeds through an ionic mechanism, which is different from the traditional click reaction, the denitrogenative annulation reaction likely proceeds via an electrophilic metallonitrene intermediate rather than a metalloradical intermediate. Collectively, this method is highly efficient and offers several advantages over other methods. For example, this method excludes a multi‐step synthesis of the N‐heterocyclic molecules described and produces only environmentally benign N2gas a by‐product.
Selektive und skalierbare Synthese von Zuckeralkoholen durch homogene asymmetrische Hydrierung von ungeschützten Ketosen
Authors: Tindall Daniel J. , Mader Steffen , Kindler Alois , Rominger Frank , Hashmi A. Stephen K. , Schaub Thomas 
Published: September 2020

AbstractZuckeralkohole sind für die Lebensmittelindustrie von großer Bedeutung und stellen vielversprechende Bausteine für biobasierte Polymere dar. Industriell werden sie durch heterogene Hydrierung von Zuckern mit H2 hergestellt, in der Regel mit keiner bis geringer Stereoselektivität. Wir präsentieren ein homogenes System auf der Basis kommerziell verfügbarer Komponenten, das nicht nur die Gesamtausbeute erhöht, sondern auch die diastereoselektive Hydrierung einer breiten Palette ungeschützter Ketosen ermöglicht. Darüber hinaus ist das System im Multi‐Gramm‐Maßstab zuverlässig und erlaubt die Isolierung von Zuckeralkoholen in großen Mengen mit hoher Atomökonomie.
Forming All‐Carbon Quaternary Stereocenters by Organocatalytic Aminomethylation: Concise Access to β2,2‐Amino Acids
Authors: Wang Kai , Yu Jianliang , Shao Ying , Tang Shengbiao , Sun Jiangtao 
Published: September 2020

AbstractThe asymmetric synthesis of β2,2‐amino acids remains a formidable challenge in organic synthesis. Here a novel organocatalytic enantioselective aminomethylation of ketenes with stable and readily available N,O‐acetals is reported, providing β2,2‐amino esters bearing an all‐carbon quaternary stereogenic center in high enantiomeric ratios with a catalytic amount of chiral phosphoric acid. Typically, this transformation probably proceeds through an asymmetric counter‐anion‐directed catalysis. As a result, a concise, practical, and atom‐economic protocol toward rapidly access to β2,2‐amino acids has been developed.
Divergent Coupling of Benzocyclobutenones with Indoles via C−H and C−C Activations
Authors: Lu Hong , Zhao Tian‐Tian , Bai Jin‐Hua , Ye Dan , Xu Peng‐Fei , Wei Hao 
Published: September 2020

AbstractHighly selective divergent coupling reactions of benzocyclobutenones and indoles, in which the chemoselectivity is controlled by catalysts, are reported herein. The substrates undergo C2(indole)–C8(benzocyclobutenone) coupling to produce benzylated indoles and benzo[b]carbazoles in the Ni‐ and Ru‐catalyzed reactions. A completely different selectivity pattern C2(indole)–C2(benzocyclobutenone) coupling to form arylated indoles is observed in the Rh‐catalyzed reaction. Preliminary mechanistic studies suggest C−H and C−C activations in the reaction pathway. Synthetic utility of this protocol is demonstrated by the selective synthesis of three different types of carbazoles from the representative products.
Synthesis and Multiplexed Activity Profiling of Synthetic Acylphloroglucinol Scaffolds
Authors: Boyce Jonathan H. , Reisman Benjamin J. , Bachmann Brian O. , Porco John A. 
Published: September 2020

AbstractReported here are novel formic‐acid‐mediated rearrangements of dearomatized acylphloroglucinols to access a structurally diverse group of synthetic acylphloroglucinol scaffolds (SASs). Density‐functional theory (DFT) optimized orbital and stereochemical analyses shed light on the mechanism of these rearrangements. Products were evaluated by multiplexed activity profiling (MAP), an unbiased platform which assays multiple biological readouts simultaneously at single‐cell resolution for markers of cell signaling, and can aid in distinguishing genuine activity from assay interference. MAP identified a number of SASs that suppressed pS6 (Ser235/236), a marker for activation of the mTOR and ERK signaling pathways. These results illustrate how biomimetic synthesis and multiplexed activity profiling can reveal the pharmacological potential of novel chemotypes by diversity‐oriented synthesis.
Structural Evidence for a [4Fe‐5S] Intermediate in the Non‐Redox Desulfuration of Thiouracil
Authors: Zhou Jingjing , Pecqueur Ludovic , Aučynaitė Agota , Fuchs Jonathan , Rutkienė Rasa , Vaitekūnas Justas , Meškys Rolandas , Boll Matthias , Fontecave Marc , Urbonavičius Jaunius , Golinelli‐Pimpaneau Béatrice 
Published: September 2020

AbstractWe recently discovered a [Fe‐S]‐containing protein with in vivo thiouracil desulfidase activity, dubbed TudS. The crystal structure of TudS refined at 1.5 Å resolution is reported; it harbors a [4Fe‐4S] cluster bound by three cysteines only. Incubation of TudS crystals with 4‐thiouracil trapped the cluster with a hydrosulfide ligand bound to the fourth non‐protein‐bonded iron, as established by the sulfur anomalous signal. This indicates that a [4Fe‐5S] state of the cluster is a catalytic intermediate in the desulfuration reaction. Structural data and site‐directed mutagenesis indicate that a water molecule is located next to the hydrosulfide ligand and to two catalytically important residues, Ser101 and Glu45. This information, together with modeling studies allow us to propose a mechanism for the unprecedented non‐redox enzymatic desulfuration of thiouracil, in which a [4Fe‐4S] cluster binds and activates the sulfur atom of the substrate.