bluuebunny/crossref_metadata_2025 huggingface dataset:
Rhodium‐Catalyzed Asymmetric Cycloisomerization of 1,3‐Diketones with Keto‐Vinylidenecyclopropanes: Synthesis of Enantiomerically Enriched Cyclic β‐Amino Alcohols
Authors: Xu Chen , Ning Chao , Yang Song , Wei Yin , Shi Min
Published: February 2021

We report here an effective and atom‐economical method to synthesize enantiomerically enriched cyclic β‐amino alcohols via a rhodium‐catalyzed asymmetric cycloisomerization of 1,3‐diketones with keto‐vinylidenecyclopropanes. The reactions proceed through a Rh‐catalyzed transformation of keto‐vinylidenecyclopropanes via cleavage of the distal C−C bond of the three‐membered ring as a three‐carbon synthon, allowing the generation of a range of enantiomerically enriched cyclic β‐amino alcohols tethered to an alkene and an 1,3‐dione moiety in good yields with high ee values under mild conditions. Derivatizations including allylation of the functionalized β‐amino alcohols and subsequent RCM reaction as well as the preparation of a pyrazole derivative were carried out as well.

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Base‐Mediated Decarboxylative [3+2] Annulation of Ethynyl Benzoxazinanones and Benzimidamides: Synthesis of Imidazole Derivatives
Authors: Wang Lan , Jiang Feng , Gao Xing , Wang Wei , Wu Yongjun , Guo Hongchao , Zheng Bing
Published: February 2021

A base‐mediated decarboxylative [3+2] annulation of trimethylsilylethynyl benzoxazinanones and benzimidamides hydrochloride was achieved under mild reaction conditions to give various imidazole derivatives in high yields. Notably, it demonstrated a new reaction mode of alkynyl benzoxazinanones.

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Does conventional energy pricing induce innovation in renewable energy? New evidence from a nonlinear approach
Authors: Amin Modhurima Dey , Badruddoza Syed , McCluskey Jill J.
Published: February 2021

This article theoretically and empirically studies the association between research and development investments in renewable energy (RE) and oil prices at the country level. We find a positive and robust association between patent counts for RE and price of crude oil using a panel of 46 countries for 1991–2013 in a fixed‐effects hurdle Negative Binomial control function framework. Results suggest that net conventional energy importing countries are more likely to invest in RE when oil prices increase. Countries with more electricity production, less emissions, and greater energy utilization generate more RE patents per year.

JEL CLASSIFICATION

Q13; Q42; Q55
Electrochemical and Thermal Behavior of Modified Li and Mn‐Rich Cathode Materials in Battery Prototypes: Impact of Pentasodium Aluminate Coating and Comprehensive Understanding of Its Evolution upon Cycling through Solid‐State Nuclear Magnetic Resonance Analysis
Authors: Sclar Hadar , Maiti Sandipan , Leifer Nicole , Vishkin Noam , Fayena‐Greenstein Miryam , Hen Meital , Grinblat Judith , Talianker Michael , Solomatin Nickolay , Tiurin Ortal , Tkachev Maria , Ein‐Eli Yair , Goobes Gil , Markovsky Boris , Aurbach Doron
Published: February 2021

In continuation of the work on the stabilization of the electrochemical performance of Li and Mn‐rich LixNiyCozMnwO2 (HE‐NCM, x > 1, w > 0.5, x + y + z + w = 2) cathode materials via atomic layer deposition (ALD) surface coatings, herein, the active role of aluminum oxides‐based coatings, during prolonged cycling in battery prototypes with graphite anodes, is discussed. Notable progress in electrochemical cycling and rate performance of Na‐aluminate‐coated Li1.142Mn0.513Ni0.230Co0.115O2 cathode material is established. These coated electrodes delivered a stable discharge capacity of 145 mAh g−1 (66% retention), compared to only 118 mAh g−1 (55% retention) for the uncoated sample at a 1.0 C rate after 400 cycles. Steady average discharge potential, lower voltage hysteresis, and stable energy density profiles are the noteworthy achievements for the coated material during cycling. Significant improvement in the coated material's thermal stability compared with the uncoated one has also been confirmed. The present study also enlightens about the Na‐aluminate coating's orientation and distribution on HE‐NCM material's surface. 23Na and 27Al solid‐state nuclear magnetic resonance (NMR) studies reveal the Na‐aluminate coating's crystalline constituent's disappearance upon cycling. The partial dissolution of Na5AlO4 coating, followed by forming a secondary disordered edge‐site phase that remains even after long‐term cycling, is disclosed.
Structural Origin of Reversible Li Insertion in Guest‐Free, Type‐II Silicon Clathrates
Authors: Dopilka Andrew , Weller J. Mark , Ovchinnikov Alexander , Childs Amanda , Bobev Svilen , Peng Xihong , Chan Candace K.
Published: February 2021

The guest‐free, type‐II Si clathrate (Si136) is an open cage polymorph of Si with structural features amenable to electrochemical Li storage. However, the detailed mechanism for reversible Li insertion and migration within the vacant cages of Si136 is not established. Herein, X‐ray characterization and density functional theory (DFT) calculations are used to understand the structural origin of electrochemical Li insertion into the type‐II clathrate structure. At low Li content, instead of alloying with Si, topotactic Li insertion into the empty cages occurs at ≈0.3 V versus Li/Li+ with a capacity of ≈231 mAh g−1 (corresponding to composition Li32Si136). A synchrotron powder X‐ray diffraction analysis of electrodes after lithiation shows evidence of Li occupation within the Si20 and Si28 cages and a volume expansion of 0.22%, which is corroborated by DFT calculations. Nudged elastic band calculations suggest a low barrier (0.2 eV) for Li migration through interconnected Si28 cages, whereas there is a higher barrier for Li migration into Si20 cages (2.0 eV). However, if Li is present in a neighboring cage, a cooperative migration pathway with a barrier of 0.65 eV is possible. The results show that the type‐II Si clathrate displays unique electrochemical properties for potential applications as Li‐ion battery anodes.
Cover crops can produce livestock forage in Chinese subtropical regions
Authors: Xu Liuxing , Tang Guojian , Liu Jiaxing , Tian Jing , Wang Xiaoya , Zhang Jianguo
Published: February 2021

It is common in South China that rice (Oryza sativa L.) fields are seeded with a cover crop following autumn harvest. The objective was to compare the effects of different no‐tillage methods on cover crop yield, nutritive composition, and silage fermentation quality of forage wheat (Triticum aestivum L. cv. Shimai‐1) and Italian ryegrass (Lolium multiflorum L.). Cover crops were planted in winter fallow paddy fields 9 (NT9) and 5 (NT5) d prior to rice harvest and 1 d after rice harvest. Cover crops seeded prior to harvest were no‐tillage planted and cover crops seeded after rice harvest were either no‐tillage (NT1) or seeded using conventional techniques (CT1; plow followed by seeding). The cover crop biomass was determined before rice sowing in spring. Compared to NT9 and NT5, the dry matter (DM) and crude protein (CP) yields of NT1 and CT1 were slightly higher. Compared to Italian ryegrass, forage wheat had high relative feed value and DM yield. The neutral detergent fiber concentration of NT9 and NT5 was higher than NT1 and CT1 (P < .05), whereas the water‐soluble carbohydrates (WSC) concentration was lower than NT1 and CT1 (P < .05). The CP, crude fiber, and WSC concentrations of forage wheat were lower than Italian ryegrass (P < .05). Interaction between years and cover crop type were observed in silage fermentation quality (P < .05). The best sowing method for forage wheat and Italian ryegrass on winter fallow paddy fields was no‐tillage sowing after rice harvest, based upon the present study.
Effects of reduced nitrogen application rate on drip‐irrigated cotton dry matter accumulation and yield under different phosphorus and potassium managements
Authors: Liu Yang , Wen Ming , Li Minghau , Zhao Wenqing , Li Penbing , Cui Jing , Ma Fuyu
Published: February 2021

To elucidate effects of reduced N application rate on dry matter accumulation and yield of drip‐irrigated cotton (Gossypium hirsutum L.) under different phosphorus and potassium managements (PK‐Ms), field studies with four reduced N application rates and four PK‐Ms were conducted in 2018 and 2019. Results show that after early peak boll‐forming (PB) stage, the leaf area (LA) in N3PK‐M3 was the highest among all treatments. The net assimilation rate (NAR), crop growth rate (CGR), boll dry weight (BDW), and boll growth rate (BGR) were highest in N2, followed by N3 with insignificant differences, and those parameters in PK‐M3 were the highest. The reproductive/vegetative biomass ratio (RVR) for N3PK‐M3 was the highest. The CGR, BDW, BGR, and NAR for N3PK‐M3 were insignificantly lower than those for N2PK‐M3, which increased yield in N2PK‐M3 and N3PK‐M3 treatments. Correlation analysis showed that BGR was positively related with CGR and NAR from peak flowering (PF) stage to boll opening (BO) stage, and CGR was significantly correlated with NAR and LA from PF to BO stage, and BO stage, respectively. Moreover, the yield was positively correlated with boll weight (BW) and boll number (BN), and BGR was significantly correlated with BN and BW from peak squaring stage to late PB stage. Therefore, high yield in N3PK‐M3 due to higher value in LA after boll‐forming stage, with higher NAR, CGR, RVR, and BGR, suggesting that early boll formation and successive partitioning of dry matter in boll growth were important factors for yield formation.
Enhancing photovoltaic performance via aggregation dynamics control in fused‐ring electron acceptor
Authors: Wang Jiayu , Zhu Runyu , Wang Shijie , Li Yawen , Jia Boyu , Zhou Jiadong , Xue Peiyao , Seibt Susanne , Lin Yuze , Xie Zengqi , Ma Wei , Zhan Xiaowei
Published: February 2021

A new fused‐ring electron acceptor FNIC3 with dynamics controlled aggregation behavior was synthesized. FNIC3 shows strong absorption in 600–900 nm, HOMO/LUMO energy levels of −5.59/−4.04 eV, and electron mobility of 1.2 × 10−3 cm2 V−1 s−1. The aggregation of FNIC3 shows strong dependency on film formation time. Prolongation of film formation time promotes the crystallization of FNIC3, leading to improved crystallinity and enlarged aggregate sizes. Aggregation of FNIC3 significantly influences the photovoltaic device parameters. Appropriate aggregation red‐shifts the absorption and improves the mobilities of the blend, which contributes to high photocurrent and fill factor thus high power conversion efficiency (PCE). Overaggregation leads to increased nonradiative energy loss and insufficient charge generation, resulting in decreased open‐circuit voltage and short‐circuit current density. The blends based on PM6:FNIC3 fabricated under proper film formation time exhibit a PCE of 12.3%, higher than those fabricated under short and long film formation time (10.0–10.5%).
Taylor‐Couette reactor: Principles, design, and applications
Authors: Schrimpf Marco , Esteban Jesús , Warmeling Helge , Färber Tobias , Behr Arno , Vorholt Andreas J.
Published: February 2021

The Taylor‐Couette reactor (TCR) is an apparatus that capitalizes on the Taylor‐Couette flow, which allows many flow regimes and conditions to perform (bio‐)chemical conversions with precise control of various reactor characteristics. With the possibility to continuously perfuse the reactor with a reaction medium, the TCR becomes interesting for chemical engineering applications. In this review, we introduce this reactor type and provide an overview of its history, principles of the flow regimes, and a description and design aspects of the reactors and their elements. Available information in the literature is summarized and harmonized to present available formulas and correlations in a consistent set of variables. Additionally, a wide number of applications in process technology are covered, including reactions in homogeneous, photo, and enzymatic catalysis, polymer synthesis, and crystallization and aggregation‐flocculation processes. Focusing on this reactor configuration, this article intends to be used as a hub for scientific groups interested in TCRs.
Mathematical modeling and parameter estimation of MFI membranes for para/ortho‐xylene separation
Authors: Liu Jingjun , McCool Benjamin , Johnson J. R. , Rangnekar Neel , Daoutidis Prodromos , Tsapatsis Michael
Published: February 2021

A mathematical model of a membrane with a thin, oriented, and selective MFI layer, which also includes contributions from defects, pore blockages, support layer, and external mass transfer, was formulated based on the Maxwell‐Stefan equations. It was validated using reported (Kim et al., Angew Chemie Int Ed, 2018, 57:480–485; Jeon et al., Nature, 2017, 543:690–694) para/ortho‐xylene separation data from five MFI membranes. The diffusivities of the xylenes were considered to be the same for all membranes, while the thickness and the density of defects and pore blockage were treated as unique properties of each membrane, and their contributions were estimated by fitting the model to the corresponding separation data. The effects of these properties and the role of permeate pressure on the separation performance were subsequently analyzed. The proposed modeling, parameter estimation, and analysis framework allow one to quantitatively interpret the variation of separation performance, to understand separation bottlenecks, and to provide guidance for designing membranes with desired performance.
On the trail of primate scent signals: A field analysis of callitrichid scent‐gland secretions by portable gas chromatography‐mass spectrometry
Authors: Poirier Alice C. , Waterhouse John S. , Watsa Mrinalini , Erkenswick Gideon A. , Moreira Laís A. A. , Tang Jia , Dunn Jacob C. , Melin Amanda D. , Smith Andrew C.
Published: February 2021

Chemosignals are mediators of social interactions in mammals, providing con‐ and hetero‐specifics with information on fixed (e.g., species, sex, group, and individual identity) and variable (e.g., social, reproductive, and health status) features of the signaler. Yet, methodological difficulties of recording and quantifying odor signals, especially in field conditions, have hampered studies of natural systems. We present the first use of the Torion® portable gas chromatography‐mass spectrometry (GC‐MS) instrument for in situ chemical analysis of primate scents. We collected and analyzed swab samples from the scent glands and skin from 13 groups (57 individuals) of two sympatric species of wild emperor tamarins,Saguinus imperator, and Weddell's saddleback tamarins,Leontocebus weddelli(Callitrichidae). In total, 11 compounds of interest (i.e., probably derived from the animals) could be detected in the samples, with 31 of 215 samples containing at least one compound of interest. The composition of these 31 samples varied systematically with species, group, sex, and breeding status. Moreover, we tentatively identified seven of the compounds of interest as methyl hexanoate, benzaldehyde, ethyl hexanoate, acetophenone, a branched C15 alkane, 4‐methoxybenzaldehyde, and hexadecan‐1‐ol. As the field of primate semiochemistry continues to grow, we believe that portable GC‐MS instruments have the potential to help make progress in the study of primate chemosignaling in field conditions, despite limitations that we encountered. We further provide recommendations for future use of the Torion® portable GC‐MS for in situ analyses.
A Mediator's Dilemma: Evaluating Without Compromising Self‐Determination or Impartiality
Authors: Barkett John M.
Published: February 2021

A mediator is required to be impartial and to honor the principle of self‐determination. Yet mediation parties look to mediators to provide their views on settlement offers or demands and may even seek what would be called “advice.”
Endosome Dysregulation in Down Syndrome: A Potential Contributor to Alzheimer Disease Pathology
Authors: Filippone Alessia , Praticò Domenico
Published: February 2021

Intracellular protein trafficking via the endosomes plays a key role in the maintenance of normal neuronal function. Although many diseases of the central nervous system exhibit specific pathological hallmarks, abnormalities of the endosome system are common traits for several of them, including Alzheimer disease (AD). Three main routes originate from the endosomes: the recycling, degradation, and retrograde pathways. Studies have shown that the majority of Down syndrome subjects develop AD pathology and manifest altered morphology and number of endosomes, and abnormalities in lysosome acidification and exosome secretion, suggesting that dysfunction of one of these pathways could play a functional role in the AD‐like phenotype of the syndrome. Two of the major endosomal routes are mediated by the retromer complex, a multimeric system responsible for transport of cargo from the endosome to the trans‐Golgi network or to the cell membrane. Recently, a new endosome system structurally related to the retromer, called “retriever,” has been reported. Whereas we know a great deal about the neuropathophysiology of the retromer complex, no precise pathogenic role for the retriever has yet been identified. Here, we will review the neurobiology of the endosome system and its role as key player in the development of AD‐like pathology in Down syndrome. Additionally, we will discuss current knowledge on these two main endosome systems, retromer and retriever, and their potential as novel therapeutic targets. ANN NEUROL 2021;90:4–14
Beyond Trial and Error: A Systematic Development of Liposomes Targeting Primary Macrophages
Authors: Weber Florian , Ivan Daniela C. , Proulx Steven T. , Locatelli Giuseppe , Aleandri Simone , Luciani Paola
Published: February 2021

Monocytes/macrophages are phagocytic innate immune cells playing a pivotal role in tissue homeostasis, inflammation, and antitumor immunity in a microenvironment‐dependent manner. By expressing pattern recognition and scavenger receptors on their surface, macrophages selectively take up pathogens, cellular debris, and often—undesirably—drug delivery systems. On the other hand, the propensity of phagocytic cells to internalize particulate drug carriers is used to load them with a cargo of choice, turning the monocytes/macrophages into a diagnostic or therapeutic Trojan horse. Identifying the ideal physicochemical properties of particulate carriers such as liposomes to achieve the most efficient macrophage‐mediated drug delivery has been object of extensive research in the past, but the studies reported so far rely solely on trial‐and‐error approaches. Herein, a design of experiment (DoE) strategy to identify the optimal liposomal formulation is proposed, fully characterized in terms of size, surface charge, and membrane fluidity, to maximize macrophage targeting. The findings are validated using mouse bone marrow‐derived macrophages, a primary preparation modeling in vivo monocyte‐derived macrophages, thus confirming the robustness and versatility of the systematic and iterative approach and suggesting the promising potential of the DoE approach for the design of cell‐targeting delivery systems.
A Dual Fluorescence–Spin Label Probe for Visualization and Quantification of Target Molecules in Tissue by Multiplexed FLIM–EPR Spectroscopy
Authors: Dong Pin , Stellmacher Johannes , Bouchet Lydia M. , Nieke Marius , Kumar Amit , Osorio‐Blanco Ernesto R. , Nagel Gregor , Lohan Silke B. , Teutloff Christian , Patzelt Alexa , Schäfer‐Korting Monika , Calderón Marcelo , Meinke Martina C. , Alexiev Ulrike
Published: February 2021

Simultaneous visualization and concentration quantification of molecules in biological tissue is an important though challenging goal. The advantages of fluorescence lifetime imaging microscopy (FLIM) for visualization, and electron paramagnetic resonance (EPR) spectroscopy for quantification are complementary. Their combination in a multiplexed approach promises a successful but ambitious strategy because of spin label‐mediated fluorescence quenching. Here, we solved this problem and present the molecular design of a dual label (DL) compound comprising a highly fluorescent dye together with an EPR spin probe, which also renders the fluorescence lifetime to be concentration sensitive. The DL can easily be coupled to the biomolecule of choice, enabling in vivo and in vitro applications. This novel approach paves the way for elegant studies ranging from fundamental biological investigations to preclinical drug research, as shown in proof‐of‐principle penetration experiments in human skin ex vivo.
Electrochemical Radical Silyl‐Oxygenation of Activated Alkenes
Authors: Ke Jie , Liu Wentan , Zhu Xujiang , Tan Xingfa , He Chuan
Published: February 2021

An efficient electrochemical radical silyl‐oxygenation of electron‐deficient alkenes is demonstrated, which gives access to a variety of new highly functionalized silicon‐containing molecules, including β‐silyl‐cyanohydrin derivatives in good yields with excellent chemo‐ and regio‐selectivity. This electrochemical radical silylation process conducts under mild conditions without the use of transition metal catalyst or chemical oxidant and exhibits a wide scope of substrate silanes with high functional‐group tolerance. The ability to access silyl radicals using electrochemical Si−H activation offers new perspectives for the synthesis of valuable organosilicon compounds in a sustainable and green manner.
Cascaded Excited‐State Intramolecular Proton Transfer Towards Near‐Infrared Organic Lasers Beyond 850 nm
Authors: Wu Jun‐Jie , Zhuo Ming‐Peng , Lai Runchen , Zou Sheng‐Nan , Yan Chang‐Cun , Yuan Yi , Yang Sheng‐Yi , Wei Guo‐Qing , Wang Xue‐Dong , Liao Liang‐Sheng
Published: February 2021

Near‐infrared (NIR) organic solid‐state lasers play an essential role in applications ranging from laser communication to infrared night vision, but progress in this area is restricted by the lack of effective excited‐state gain processes. Herein, we originally proposed and demonstrated the cascaded occurrence of excited‐state intramolecular proton transfer for constructing the completely new energy‐level systems. Cascading by the first ultrafast proton transfer of <430 fs and the subsequent irreversible second proton transfer of ca. 1.6 ps, the stepwise proton transfer process favors the true six‐level photophysical cycle, which supports efficient population inversion and thus NIR single‐mode lasing at 854 nm. This work realizes longest wavelength beyond 850 nm of organic single‐crystal lasing to date and originally exploits the cascaded excited‐state molecular proton transfer energy‐level systems for organic solid‐state lasers.
Diastereoselective and Stereodivergent Synthesis of 2‐Cinnamylpyrrolines Enabled by Photoredox‐Catalyzed Iminoalkenylation of Alkenes
Authors: Shen Xu , Huang Congcong , Yuan Xiang‐Ai , Yu Shouyun
Published: February 2021

A photoredox‐catalyzed iminoalkenylation of γ‐alkenyl O‐acyl oximes has been developed. Readily available alkenylboronic acids serve as alkenylation reagents, leading to densely functionalized pyrrolines. Both (E)‐ and (Z)‐cinnamylpyrrolines are accessible depending on the reaction solvent. In dichloromethane, (E)‐cinnamylpyrrolines are produced through a photoredox‐mediated single‐electron‐transfer process. In tetrahydrofuran, (Z)‐cinnamylpyrrolines are generated by photocatalytic contra‐thermodynamic E‐to‐Z isomerization of (E)‐cinnamylpyrrolines though an energy‐transfer pathway. Two stereocenters are established with complete diastereoselectivity and only one diastereomer is isolated.
A Visible‐Light‐Harvesting Covalent Organic Framework Bearing Single Nickel Sites as a Highly Efficient Sulfur–Carbon Cross‐Coupling Dual Catalyst
Authors: Chen Hui , Liu Wanlu , Laemont Andreas , Krishnaraj Chidharth , Feng Xiao , Rohman Fadli , Meledina Maria , Zhang Qiqi , Van Deun Rik , Leus Karen , Van Der Voort Pascal
Published: February 2021

Covalent Organic Frameworks (COFs) have recently emerged as light‐harvesting devices, as well as elegant heterogeneous catalysts. The combination of these two properties into a dual catalyst has not yet been explored. We report a new photosensitive triazine‐based COF, decorated with single Ni sites to form a dual catalyst. This crystalline and highly porous catalyst shows excellent catalytic performance in the visible‐light‐driven catalytic sulfur–carbon cross‐coupling reaction. Incorporation of single transition metal sites in a photosensitive COF scaffold with two‐component synergistic catalyst in organic transformation is demonstrated for the first time.
Metal‐Coordinated Supramolecular Polymers from the Minimalistic Hybrid Peptide Foldamers
Authors: Dey Sanjit , Misra Rajkumar , Saseendran Abhijith , Pahan Saikat , Gopi Hosahudya N.
Published: February 2021

Availing the peptide folded architectures to design metal‐coordinated frameworks and cages is restricted due to the scarcity of readily accessible short and stable secondary structures. The secondary structures, α‐helix and β‐sheets, play significant roles in stabilizing tertiary folds of proteins. Designing such helical structures from the short sequences of peptides without having any steric restrictions is exceptionally challenging. Here we reveal the short α,γ‐hybrid tripeptide sequences that manifest stable helical structures without having any sterically constrained amino acids. These short hybrid tripeptides fold into helices even in the presence of two typically β‐sheet favoring Val residues. The hybrid helix consisting of terminal pyridine units coordinates with the metal ions and drives the helical polymerization. Depending on the sequence and the position of N in pyridine moieties, these peptides form selective metallogels with Ag+ and Cu2+ ions. The X‐ray diffracted analysis of the peptide single crystals obtained from the gel matrix reveals that the helical structure is maintained during the self‐assembly process. Further, by varying the counter anion, a 3D helical crystalline coordination polymer with permanent porosity is generated. The findings reported here can be used to design new functional metal‐foldamer coordinated polymers.
Dynamically Re‐Organized Collagen Fiber Bundles Transmit Mechanical Signals and Induce Strongly Correlated Cell Migration and Self‐Organization
Authors: Fan Qihui , Zheng Yu , Wang Xiaochen , Xie Ruipei , Ding Yu , Wang Boyi , Yu Xiaoyu , Lu Ying , Liu Liyu , Li Yunliang , Li Ming , Zhao Yuanjin , Jiao Yang , Ye Fangfu
Published: February 2021

Correlated cell migration in fibrous extracellular matrix (ECM) is important in many biological processes. During migration, cells can remodel the ECM, leading to the formation of mesoscale structures such as fiber bundles. However, how such mesoscale structures regulate correlated single‐cells migration remains to be elucidated. Here, using a quasi‐3D in vitro model, we investigate how collagen fiber bundles are dynamically re‐organized and guide cell migration. By combining laser ablation technique with 3D tracking and active‐particle simulations, we definitively show that only the re‐organized fiber bundles that carry significant tensile forces can guide strongly correlated cell migration, providing for the first time a direct experimental evidence supporting that matrix‐transmitted long‐range forces can regulate cell migration and self‐organization. This force regulation mechanism can provide new insights for studies on cellular dynamics, fabrication or selection of biomedical materials in tissue repairing, and many other biomedical applications.
Activation of Pyroptosis by Membrane‐Anchoring AIE Photosensitizer Design: New Prospect for Photodynamic Cancer Cell Ablation
Authors: Wu Min , Liu Xingang , Chen Huan , Duan Yukun , Liu Jingjing , Pan Yutong , Liu Bin
Published: February 2021

Pyroptosis as a lytic and inflammatory form of cell death is a powerful tool to fight against cancer. However, pyroptosis is usually activated by chemotherapeutic drugs, which limits its anti‐tumor applications due to drug resistance and severe side effects. Herein, we demonstrate that membrane targeting photosensitizers can induce pyroptosis for cancer cell ablation with noninvasiveness and low side effects. A series of membrane anchoring photosensitizers (TBD‐R PSs) with aggregation‐induced emission (AIE) characteristics were prepared through conjugation of TBD and phenyl ring with cationic chains. Upon light irradiation, cytotoxic ROS were produced in situ, resulting in direct membrane damage and superior cancer cell ablation. Detailed study revealed that pyroptosis gradually became the dominant cell death pathway along with the increase of TBD‐R PSs membrane anchoring capability. This study offers a photo‐activated pyroptosis‐based intervention strategy for cancer cell ablation.
Significantly enhanced the properties of PE/GO composites with segregated structures via two‐step compound
Authors: Cao Jiandong , Ren Shangyuan , Xin Shixuan , Bai Yongxiao , Wang Wenjie , Gao Wensheng
Published: February 2021

Conductive polymer composites (CPCs) have generated significant academic and industrial interest due to the wide applications in anti‐static materials, electromagnetic interface, sensor, and conductors. Nonetheless, the CPCs fabricated by conventional melt‐mixing applied to the scalable production generally have a very high percolation threshold, which always suffer from the various draw backs such as, high melt viscosities, low economic affordability, inferior mechanical properties, and solution compounding by reducing the viscosity improves the uniformity of nano‐particles. This work aims at building a segregated structure in polyethylene to enhance mechanical properties and electrical conductivity, by taking advantage of the solution compounding and melt‐blending methods. Based on the segregated structure, the composites showed the enhanced mechanical properties, thermal stabilities and antistatic properties with a low percolation threshold. In addition, the composite mechanism between graphene oxide and polyethylene and the structure‐performance relationship of the CPCs were elucidated and explored by SEM, TEM, and FTIR.
Structurally modified electrospun poly(methyl methacrylate) nanofibers as advanced host matrices for PbS quantum dots
Authors: Philip Princy , Jose Tomlal , Vanchippurackal Ison V.
Published: February 2021

The present work deals with the studies of the host matrix nature of pure and structurally modified surface roughened and coaxial hollow electrospun poly(methyl methacrylate) (PMMA) nanofibers to lead sulphide (PbS) quantum dots. The various structural and molecular analyses conducted on these samples proved the advancements and structural modifications made in the properties of pure PMMA nanofibers by electrospinning and selective dissolution. The successful incorporation of the quantum dots to pure and structurally modified PMMA nanofibers and hence the host matrix nature of these nanofibers is proved by different spectral analyses of the samples. The coaxial hollow PMMA nanofibers are found to be the best host matrix among these PMMA nanofibers as proved by the optical studies of the samples. Photoluminescence analyses of the samples showed the influence of these quantum dots on the optical properties of PMMA nanofibers. It is observed here that, the quantum dots enhance the intensity of coaxial hollow PMMA nanofibers to about four times than its virgin form. The pure and structurally modified PMMA nanofibers incorporated with PbS quantum dots are proved to be efficient for the degradation of methylene blue dye where coaxial hollow PMMA nanofibers incorporated with PbS quantum dots is the best.
Developing antibacterial surgical adhesives: An enhancement of cyanoacrylate polymers
Authors: Stevens Rhianna , Esteban Gabrielle , Jenkins Emma , Saitow Cassandra , Gurney Rich
Published: February 2021

Surgical site infections (SSIs) and traumatic wounds have a significant risk of becoming contaminated by microbial pathogens of both endogenous and nosocomial origins, including Staphylococcus aureus and Enterococci sp.. One preventative approach is to protect wounds from infection by using a rapidly curing adhesive to seal the wound and prevent further contamination. Here, we demonstrate the covalent incorporation of an antimicrobial, quaternary ammonium chloride monomer (quat) into a 2‐octyl cyanoacrylate (2oc) polymer adhesive. Copolymerization was confirmed via nuclear magnetic resonance spectroscopy. Cytotoxicity of the copolymer was assessed against: S. epidermidis and E. coli, and 3T3 mouse fibroblasts. The CA‐Quat polymer was found to exhibit dose‐dependent bacteriostatic and bactericidal effects against both E. coli and S. epidermidis, importantly without showing any demonstrable toxicity against mammalian 3T3 fibroblast cells. The described experiments provide promising data to suggest successful copolymerization, effective antibacterial properties, and remarkably low cytotoxic effects of the copolymer on mammalian cells.
Hybrid anion exchange membranes with adjustable ion transport channels designed by compounding SEBS and homo‐polystyrene
Authors: Shi Yue , Meng Fanzhi , Zhao Zhongfu , Liu Wei , Zhang Chunqing
Published: February 2021

Hybrid anion exchange membranes (AEMs) were prepared via chemically functionalizing and crosslinking poly(styrene‐b‐[ethylene‐co‐butylene]‐b‐styrene) (SEBS) copolymers and low molecular weight homo‐polystyrene (hPS). Via sequential chloromethylation, crosslinking, quaternization, and alkalization, a series of hPS/SEBS AEMs were obtained with varying content of hPS. Systematic structural, morphological, mechanical, absorption, and transport measurements reveal that these properties depend on the total PS content in the membranes. Particularly, increasing total PS content causes (a) PS domains in the AEMs transition the cylindrical morphology to lamella‐like morphology with comparable correlation length; (b) Young's modulus, water uptake, swelling ratio, ionic exchange capacity and ionic conductivity of the AEMs, and Tg of PS phase increase. In addition, the alkaline stability of the hPS/SEBS AEMs is also improved by addition of hPS. These findings suggest that the proposed method can develop high performance SEBS AEMs that are suitable for fuel cell applications.
Improvement in mechanical, electrical, and shape memory properties of the polystyrene‐based carbon fiber‐reinforced polymer composites containing carbon nanotubes
Authors: Erkmen Berrak , Bayram Goknur
Published: February 2021

Carbon fiber‐reinforced polymers based on polystyrene matrix containing elastomer and carbon nanotubes (CNTs) were produced by compression molding. The effects of carbon fabric (CF) concentration and silane treatment on the morphology, mechanical, electrical, and shape memory properties of the multilayer composites were investigated. The SEM analyses showed that fibers of the silane‐treated CFs were more homogeneously covered with the polymer layers than the untreated CFs. The tensile strength and modulus of the composites increased by 521% and 125%, respectively, with an increasing number of CF plies from one to five. Upon silane treatment, the tensile strength of the multilayer composite improved by 26%, and the tensile modulus decreased by 18.4%. Electrical conductivities of the composites were in the semiconductor region due to the presence of both CNTs and CFs. 100% shape recovery less than a minute recovery time was obtained for all the composites with electrically triggered bending test.
A modified Mask region‐based convolutional neural network approach for the automated detection of archaeological sites on high‐resolution light detection and ranging‐derived digital elevation models in the North German Lowland
Authors: Bonhage Alexander , Eltaher Mahmoud , Raab Thomas , Breuß Michael , Raab Alexandra , Schneider Anna
Published: February 2021

Due to complicated backgrounds and unclear target orientation, automated object detection is difficult in the field of archaeology. Most of the current convolutional neural network (CNN) object‐oriented detection techniques are based on a faster region‐based CNN (R‐CNN) and other one‐stage detectors that often lack adequate processing speeds and detection accuracies. Recently, the two‐stage detector Mask R‐CNN technique achieved impressive results in object detection and instance segmentation problems and was successfully applied in the analysis of archaeological airborne laser scanning (ALS) data. In this study, we outline a modified Mask R‐CNN technique that reliably and efficiently detects relict charcoal hearth (RCH) sites on light detection and ranging (LiDAR) data‐based digital elevation models (DEMs). Using image augmentation and image preprocessing steps combined with the deep learning‐based adaptive gradient method with a dynamic bound on the learning rate (AdaBound) optimization technique, we could improve the model's accuracy and significantly reduce its training time. We use DEMs based on high‐resolution LiDAR data and the visualization for archaeological topography (VAT) technique that give images with a very strong contrast of the terrain and the outline of the sites of interest in the North German Lowland. Therefore, the model can identify RCH sites with an average recall of 83% and an average precision of 87%. Techniques such as the modified Mask R‐CNN method outlined here will help to greatly improve our knowledge about archaeological site densities in the realm of historical charcoal production and past human‐landscape interactions. This method provides an accurate, time‐efficient and bias‐free large‐scale site mapping option not only for the North German Lowland but potentially for other landscapes as well.
Specific Follicular Helper T Cell Signature in Takayasu Arteritis
Authors: Desbois A. C. , Régnier P. , Quiniou V. , Lejoncour A. , Maciejewski‐Duval A. , Comarmond C. , Vallet H. , Rosenzwag M. , Darrasse‐Jèze G. , Derian N. , Pouchot J. , Samson M. , Bienvenu B. , Fouret P. , Koskas F. , Garrido M. , Sène D. , Bruneval P. , Cacoub P. , Klatzmann D. , Saadoun D.
Published: February 2021

Objective

Our aim was to compare transcriptome and phenotype profiles of CD4+ T cells and CD19+ B cells in patients with Takayasu arteritis (TAK), patients with giant cell arteritis (GCA), and healthy donors.

Methods

Gene expression analyses, flow cytometry immunophenotyping, T cell receptor (TCR) gene sequencing, and functional assessments of cells from peripheral blood and arterial lesions from TAK patients, GCA patients, and healthy donors were performed.

Results

Among the most significantly dysregulated genes in CD4+ T cells of TAK patients compared to GCA patients (n = 720 genes) and in CD4+ T cells of TAK patients compared to healthy donors (n = 1,447 genes), we identified a follicular helper T (Tfh) cell signature, which included CXCR5, CCR6, and CCL20 genes, that was transcriptionally up‐regulated in TAK patients. Phenotypically, there was an increase in CD4+CXCR5+CCR6+CXCR3− Tfh17 cells in TAK patients that was associated with a significant enrichment of CD19+ B cell activation. Functionally, Tfh cells helped B cells to proliferate, differentiate into memory cells, and secrete IgG antibodies. Maturation of B cells was inhibited by JAK inhibitors. Locally, in areas of arterial inflammation, we found a higher proportion of tertiary lymphoid structures comprised CD4+, CXCR5+, programmed death 1+, and CD20+ cells in TAK patients compared to GCA patients. CD4+CXCR5+ T cells in the aortas of TAK patients had an oligoclonal α/β TCR repertoire.

Conclusion

We established the presence of a specific Tfh cell signature in both circulating and aorta‐infiltrating CD4+ T cells from TAK patients. The cooperation of Tfh cells and B cells might be critical in the occurrence of vascular inflammation in patients with TAK.
Softcite dataset: A dataset of software mentions in biomedical and economic research publications
Authors: Du Caifan , Cohoon Johanna , Lopez Patrice , Howison James
Published: February 2021

Software contributions to academic research are relatively invisible, especially to the formalized scholarly reputation system based on bibliometrics. In this article, we introduce a gold‐standard dataset of software mentions from the manual annotation of 4,971 academic PDFs in biomedicine and economics. The dataset is intended to be used for automatic extraction of software mentions from PDF format research publications by supervised learning at scale. We provide a description of the dataset and an extended discussion of its creation process, including improved text conversion of academic PDFs. Finally, we reflect on our challenges and lessons learned during the dataset creation, in hope of encouraging more discussion about creating datasets for machine learning use.
Clustering ultrasonic waves propagation time: A hierarchical polynomial semiparametric approach
Authors: Zuanetti Daiane Aparecida , da Paz Rosineide Fernando , Rodrigues Talisson , Mesquita Esequiel
Published: February 2021

In the field of civil engineering, nondestructive evaluation (NDE) can be understood as the process of a material or structural element assessment based on techniques that do not introduces damage to the assessed sample. NDE can be used to inspect the quality of materials or to find some damages, as cracks and voids. This way, ultrasonic data monitoring has become one of the most important tools for detecting local damages in civil engineering elements. Concerning to masonry application, this method consists in the measurement of the time that the ultrasonic wave takes to pass through a material and changes in the ultrasonic wave propagation can be used for identifying damages presence and anomaly. Despite statistical methods be widely used for processing large data sets, in the case of ultrasonic waves some issues need to be overcoming, as the analysis of the path traveled by the ultrasonic wave. Thus, the main aim of this work is to analyze the ultrasonic wave propagation behavior through a new approach of a statistical model. Using a Bayesian semiparametric method with Dirichlet process, a data‐driven hierarchical regression model is applied to simulated and experimental data sets. For simulated data sets, the sensibility of the model in clustering profiles in an unknown number of groups and also detecting outliers is observed. The application in experimental data shows the potential use of the model for real case applications due to its efficiency in identifying different behaviors of the wave propagation in materials. Therefore, considering the advanced of automation and Internet of Things, statistical methods based on clustering are important and useful tools for being explored in the masonry conditions monitoring.
Moment of inertia of magnetized strange stars
Authors: López Pérez Samantha , Manreza‐Paret Daryel , Quintero Angulo Gretel , Pérez Martínez Aurora , Alvear Terrero Diana
Published: February 2021

The macroscopic structure of magnetized Compact Objects is deformed due to the anisotropy of pressures as a consequence of the magnetic field. In this work, we study the impact of the magnetic deformation in the moment of inertia and mass quadrupole moment of strange stars. In order to do that, we first solve the structure equations using the gamma metric: an axially symmetric metric in spherical coordinates. We also discuss the implication of the magnetic deformation in gravitational wave emissions.
Ground‐level muon flux variation in a cosmic ray simulation
Authors: Pereira Elisa G. , Vasconcellos César A. , Hadjimichef Dimiter
Published: February 2021

The oscillatory movements of atmospheric air masses have been claimed to be the origin of the muon flux variation measured at the ground level. Using a cosmic ray toolkit (COsmic Ray SImulations for KAscade [CORSIKA]), we simulate cascade scenarios in a time scale of a year and show the dependence of the muon flux pattern with a proposed oscillatory model atmosphere.
Innendämmung und Oberflächentemperaturen an einbindenden Innenwänden
Authors: Worch Anatol
Published: February 2021

Innendämmungen werden neben dem bekannten Kondensationspotenzial in der sogenannten Tauebene vor allem mit zusätzlichen Wärmebrücken verbunden. Durch die damit einhergehende Temperaturabsenkung werden in aller Regel zusätzliche Dämmmaßnahmen an den Flanken vorgeschrieben. Ziel der hier vorgestellten Parameterstudie ist es, die Grenzen zu bestimmen, ab denen keine zusätzlichen Dämmmaßnahmen an den Flanken der einbindenden Bauteile notwendig sind. Schwerpunkt liegt hierbei auf dem besonders kritischen Fall, dass die Innendämmung nur an einer Seite des einbindenden Bauteils angebracht ist. Die Oberflächentemperatur an der der Innendämmung abgewandten Seite wird durch eine Flankendämmung nochmals erniedrigt. Gerade dieser Punkt sorgt in der Baupraxis immer wieder für große Unsicherheiten und damit zu einer prinzipiellen Vermeidung von Innendämmungen.

Im Rahmen einer umfangreichen Parameterstudie soll der Mindestwärmedurchlasswiderstand der Außenwand ermittelt werden, ab der keine zusätzlichen flankierenden Maßnahmen mehr notwendig sind. Als eine maßgebliche Grenze kann ein Wärmedurchlasswiderstand der Außenwand größer 0,8 (m2K)/W ermittelt werden. Oberhalb dieser Grenze sind in aller Regel wohl keine zusätzlichen Dämmmaßnahmen notwendig. Weitere wichtige Zusammenhänge der maßgeblichen Einflussparameter werden diskutiert und vorgestellt.
Reduzierung des Kunstlichteinsatzes durch Anpassung der Nachlaufzeit an individuelle Anwesenheitsmuster
Authors: Hammes Sascha , Weninger Johannes , Geisler‐Moroder David , Pfluger Rainer , Pohl Wilfried
Published: February 2021

Gegenwärtig sind präsenzgesteuerte Beleuchtungssysteme meist an konstante und relativ lange Ausschaltverzögerungen gekoppelt, um die Systemakzeptanz gegenüber fehlerhafter Abwesenheitsdetektion sicherzustellen. Die dabei zur Anwendung kommenden, generalisierten und für alle Arbeitsplätze und Gebäudenutzenden gleichen Abschaltzeiten werden meist bereits vor der Erstinbetriebnahme entschieden. Eine Berücksichtigung von Nutzerindividualitäten, welche durch Tätigkeitsprofil und Unternehmenskultur maßgeblich beeinflusst werden, bleibt dabei außen vor. Dabei nehmen Nutzerindividualitäten eine entscheidende Rolle bei der Umsetzung von Konzepten ein, die die energetische Systemperformanz steigern. Die im Folgenden vorgestellte Studie untersucht daher auf Basis von Belegungsdaten die Auswirkungen des Verhaltens von Gebäudenutzenden auf den Energiebedarf. Die identifizierten Anwesenheitsmuster dienen dazu, die Beleuchtungssteuerung auf individueller Ebene zuzuschneiden. Die Ergebnisse führen auf, dass eine signifikante Reduktion der Ausschaltverzögerung und des damit verbundenen Energiebedarfs ohne negative Auswirkungen auf Systemakzeptanzraten oder Nutzerkomfort möglich ist. Eine hohe räumliche Sensorauflösung erweist sich dabei jedoch als Ausgleich zu potenziell erhöhten Falsch‐Aus‐Raten als erforderlich. In diesem Zusammenhang wird die Bedeutung der Sensorpositionierung und ‐anzahl herausgestellt.
Non‐Aqueous Electrolytes for Sodium‐Ion Batteries: Challenges and Prospects Towards Commercialization
Authors: Hijazi Hussein , Desai Parth , Mariyappan Sathiya
Published: February 2021

Integration of Na‐ion batteries (NIBs) as a complementary energy storage device to the presently dominating Li‐ion battery (LIB) technology is a must, considering the cost and sustainability issues of lithium. However, despite the important laboratory‐scale achievements concerning Na‐ion electrodes and electrolytes, the improvements needed for realizing battery devices to meet users demands are being relatively slow. More specifically, the development of suitable electrolytes remains as the bottleneck that restrains this technology from meeting the commercial requirements, hence defining a future challenge. This review explains the design strategies in use for NIB electrolytes with a special emphasis on intrinsic differences between Li‐ and Na‐ion chemistries, which are at the origin of difficulties associated with the discovery of optimum electrolytes for NIBs. We highlight the key requirements that an electrolyte must satisfy and related experimental techniques that could be used for quick screening of NIB electrolytes in laboratory‐scale for exploiting in commercial NIB devices.