bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi‐Color, Bleaching‐Resistant Super‐Resolution Optical Fluctuation Imaging with Oligonucleotide‐Based Exchangeable Fluorophores
Authors: Glogger Marius , Spahn Christoph , Enderlein Jörg , Heilemann Mike 
Published: December 2020

AbstractSuper‐resolution optical fluctuation imaging (SOFI) is a super‐resolution microscopy technique that overcomes the diffraction limit by analyzing intensity fluctuations of statistically independent emitters in a time series of images. The final images are background‐free and show confocality and enhanced spatial resolution (super‐resolution). Fluorophore photobleaching, however, is a key limitation for recording long time series of images that will allow for the calculation of higher order SOFI results with correspondingly increased resolution. Here, we demonstrate that photobleaching can be circumvented by using fluorophore labels that reversibly and transiently bind to a target, and which are being replenished from a buffer which serves as a reservoir. Using fluorophore‐labeled short DNA oligonucleotides, we labeled cellular structures with target‐specific antibodies that contain complementary DNA sequences and record the fluctuation events caused by transient emitter binding. We show that this concept bypasses extensive photobleaching and facilitates two‐color imaging of cellular structures with SOFI.
A Reagent for Amine‐Directed Conjugation to IgG1 Antibodies
Authors: Märcher Anders , Palmfeldt Johan , Nisavic Marija , Gothelf Kurt V. 
Published: December 2020

AbstractFunctionalized antibodies are an indispensable resource for diagnosis, therapy and as a research tool for chemical biology. However, simpler and better methodologies are often required to improve the labeling of antibodies in terms of selectivity and scalability. Herein, we report the development of an easily available chemical reagent that allows site‐directed labeling of native human IgG1 antibodies in good yield and mono‐labeling selectivity. The salicylaldehyde moiety of the reagent reacts with surface exposed lysine residues to transiently form an iminium ion, and this positions a semi‐reactive ester in proximity of a second lysine residue that reacts with the ester to form an amide. Interestingly, it appears that the formation of the iminium ion also has a significant activating effect of the ester. We use flow cytometry and bio‐layer interferometry to confirm that the labeled antibodies retain antigen binding.
A Systematic Study of Unsaturation in Lipid Nanoparticles Leads to Improved mRNA Transfection In Vivo
Authors: Lee Sang M. , Cheng Qiang , Yu Xueliang , Liu Shuai , Johnson Lindsay T. , Siegwart Daniel J. 
Published: December 2020

AbstractLipid nanoparticles (LNPs) represent the leading concept for mRNA delivery. Unsaturated lipids play important roles in nature with potential for mRNA therapeutics, but are difficult to access through chemical synthesis. To systematically study the role of unsaturation, modular reactions were utilized to access a library of 91 amino lipids, enabled by the synthesis of unsaturated thiols. An ionizable lipid series (4A3) emerged from in vitro and in vivo screening, where the 4A3 core with a citronellol‐based (Cit) periphery emerged as best. We studied the interaction between LNPs and a model endosomal membrane where 4A3‐Cit demonstrated superior lipid fusion over saturated lipids, suggesting its unsaturated tail promotes endosomal escape. Furthermore, 4A3‐Cit significantly improved mRNA delivery efficacy in vivo through Selective ORgan Targeting (SORT), resulting in 18‐fold increased protein expression over parent LNPs. These findings provide insight into how lipid unsaturation promotes mRNA delivery and demonstrate how lipid mixing can enhance efficacy.
Modifizierte Enzyme ermöglichen die selektive N‐Alkylierung von Pyrazolen unter Verwendung einfacher Halogenalkane
Authors: Bengel Ludwig L. , Aberle Benjamin , Egler‐Kemmerer Alexander‐N. , Kienzle Samuel , Hauer Bernhard , Hammer Stephan C. 
Published: December 2020

AbstractDie selektive Alkylierung von Pyrazolen ist eine Herausforderung in der Chemie und könnte die Synthese wichtiger Moleküle vereinfachen. In dieser Arbeit berichten wir über eine katalysatorgesteuerte Alkylierung von Pyrazolen durch eine cyclische Kaskadenreaktion mit zwei Enzymen. In diesem enzymatischen System nutzt ein promiskuitives Enzym Halogenalkane als Ausgangsstoffe, um nicht‐natürliche Analoga des Cosubstrats S‐Adenosyl‐l‐Methionin zu synthetisieren. Ein zweites engineertes Enzym überträgt die Alkylgruppen in einer hochselektiven C−N‐Bindungsknüpfung auf das Pyrazol‐Substrat. Das Cosubstrat wird regeneriert und nur in katalytischen Mengen eingesetzt. Für das Enzym‐Engineering wurde eine computerbasierte Methode verwendet, um eine Mutantenbibliothek in silico zu entwickeln. In einer Runde von Mutagenese und Screening wurde somit eine promiskuitive Methyltransferase in eine kleine Pyrazol‐alkylierende Enzymfamilie umgewandelt. Mit diesem bienzymatischen System konnte die Alkylierung von Pyrazolen (Methylierung, Ethylierung, Propylierung) mit bislang unerreichter Regioselektivität (>99 %), Regiodivergenz und in einem ersten Beispiel in präparativem Maßstab gezeigt werden.
Vorplanarisierte Triphenylamin‐basierte lineare gemischtvalente Ladungstransfersysteme
Authors: Krug Marcel , Fröhlich Nina , Fehn Dominik , Vogel Alexander , Rominger Frank , Meyer Karsten , Clark Timothy , Kivala Milan , Guldi Dirk M. 
Published: December 2020

AbstractDrei lineare Dimere mit jeweils zwei redoxaktiven planarisierten Triphenylaminen wurden synthetisiert, und ihre Struktur wurde mittels Röntgenstrukturanalyse aufgelöst. Diese Verbindungen sind von großem Interesse, da ihre Radikalkationen einen Selbstaustausch des ungepaarten Elektrons zwischen den beiden Redoxzentren aufweisen. Dieser Prozess wurde eingehend mittels Elektronenspinresonanz‐Spektroskopie, Absorptionsspektroskopie und (zeitabhängigen) Dichtefunktionaltheorie‐Rechnungen untersucht. Ein Vergleich der Schlüsselparameter des Elektronentransfers mit nicht‐planarisierten stickstoffzentrierten Bausteinen unterstreicht den Einfluss von Redoxzentren mit niedrigen inneren Reorganisationsenergien. Hingegen bleibt der entfernungsabhängige Abschwächungsfaktor des Superaustauschmechanismus ähnlich.
Robust Supramolecular Nano‐Tunnels Built from Molecular Bricks**
Authors: Wei Peifa , He Xuan , Zheng Zheng , He Donglin , Li Qiyao , Gong Junyi , Zhang Jun , Sung Herman H. Y. , Williams Ian D. , Lam Jacky W. Y. , Liu Ming , Tang Ben Zhong 
Published: December 2020

AbstractHerein we report a linear ionic molecule that assembles into a supramolecular nano‐tunnel structure through synergy of trident‐type ionic interactions and π–π stacking interactions. The nano‐tunnel crystal exhibits anisotropic guest adsorption behavior. The material shows good thermal stability and undergoes multi‐stage single‐crystal‐to‐single‐crystal phase transformations to a nonporous structure on heating. The material exhibits a remarkable chemical stability under both acidic and basic conditions, which is rarely observed in supramolecular organic frameworks and is often related to structures with designed hydrogen‐bonding interactions. Because of the high polarity of the tunnels, this molecular crystal also shows a large CO2‐adsorption capacity while excluding other gases at ambient temperature, leading to high CO2/CH4 selectivity. Aggregation‐induced emission of the molecules gives the bulk crystals vapochromic properties.
Modifying Woodward–Hoffmann Stereoselectivity Under Vibrational Strong Coupling
Authors: Sau Abhijit , Nagarajan Kalaivanan , Patrahau Bianca , Lethuillier‐Karl Lucas , Vergauwe Robrecht M. A. , Thomas Anoop , Moran Joseph , Genet Cyriaque , Ebbesen Thomas W. 
Published: December 2020

AbstractVibrational strong coupling (VSC) has recently been shown to change the rate and chemoselectivity of ground‐state chemical reactions via the formation of light–matter hybrid polaritonic states. However, the observation that vibrational‐mode symmetry has a large influence on charge‐transfer reactions under VSC suggests that symmetry considerations could be used to control other types of chemical selectivity through VSC. Here, we show that VSC influences the stereoselectivity of the thermal electrocyclic ring opening of a cyclobutene derivative, a reaction which follows the Woodward–Hoffmann rules. The direction of the change in stereoselectivity depends on the vibrational mode that is coupled, as do changes in rate and reaction thermodynamics. These results on pericyclic reactions confirm that symmetry plays a key role in chemistry under VSC.
Synthesis of Polycarboxylate Rhodium(II) Metal–Organic Polyhedra (MOPs) and their use as Building Blocks for Highly Connected Metal–Organic Frameworks (MOFs)
Authors: Grancha Thais , Carné‐Sánchez Arnau , Zarekarizi Farnoosh , Hernández‐López Laura , Albalad Jorge , Khobotov Akim , Guillerm Vincent , Morsali Ali , Juanhuix Judith , Gándara Felipe , Imaz Inhar , Maspoch Daniel 
Published: December 2020

AbstractUse of preformed metal‐organic polyhedra (MOPs) as supermolecular building blocks (SBBs) for the synthesis of metal‐organic frameworks (MOFs) remains underexplored due to lack of robust functionalized MOPs. Herein we report the use of polycarboxylate cuboctahedral RhII‐MOPs for constructing highly‐connected MOFs. Cuboctahedral MOPs were functionalized with carboxylic acid groups on their 12 vertices or 24 edges through coordinative or covalent post‐synthetic routes, respectively. We then used each isolated polycarboxylate RhII‐MOP as 12‐c cuboctahedral or 24‐c rhombicuboctahedral SBBs that, upon linkage with metallic secondary building units (SBUs), afford bimetallic highly‐connected MOFs. The assembly of a pre‐synthesized 12‐c SBB with a 4‐c paddle‐wheel SBU, and a 24‐c SBB with a 3‐c triangular CuII SBU gave rise to bimetallic MOFs having ftw (4,12)‐c or rht (3,24)‐c topologies, respectively.
Gradient Solid Electrolyte Interphase and Lithium‐Ion Solvation Regulated by Bisfluoroacetamide for Stable Lithium Metal Batteries
Authors: Li Fang , He Jian , Liu Jiandong , Wu Mingguang , Hou Yuyang , Wang Huaping , Qi Shihan , Liu Quanhui , Hu Jiawen , Ma Jianmin 
Published: December 2020

AbstractThe structures and components of solid electrolyte interphase (SEI) are extremely important to influence the performance of full cells, which is determined by the formulation of electrolyte used. However, it is still challenging to control the formation of high‐quality SEI from structures to components. Herein, we designed bisfluoroacetamide (BFA) as the electrolyte additive for the construction of a gradient solid electrolyte interphase (SEI) structure that consists of a lithophilic surface with C−F bonds to uniformly capture Li ions and a LiF‐rich bottom layer to guide the rapid transportation of Li ions, endowing the homogeneous deposition of Li ions. Moreover, the BFA molecule changes the Li+ solvation structure by reducing free solvents in electrolyte to improve the antioxidant properties of electrolyte and prevent the extensive degradation of electrolyte on the cathode surface, which can make a superior cathode electrolyte interphase (CEI) with high‐content LiF.
Polypyrrole as the interlayer for thin‐film poly(piperazine‐amide) composite membranes: Separation behavior of salts and pesticides
Authors: Mehta Romil , Brahmbhatt Harshad , Bhojani Gopal , Bhattacharya Amit 
Published: December 2020

AbstractThe preparative membrane process is a dynamic one and intertwined with the separation arena. As for the progression of technology in membranes, our direction is to prepare polypyrrole interlayer‐based thin‐film composite (TFC) membrane. Polypyrrole shows its attachment ability with polysulfone membranes. The coverings of pores with the polypyrrole entity result in better flux in terms of TFC membranes compared to TFC membranes on polysulfone (Memb‐I). The membranes are characterized by FTIR‐ATR, contact angle, zeta potential, SEM, AFM. Polypyrrole interlayer‐based membrane (Memb‐II) show better flux though it sacrifices salt separation ability compared to Memb‐I. Memb‐II shows a better separation of pesticides (diuron and isoproturon) compared to Memb‐I. Memb‐II provides isoproturon's separation ability (89.52% rejection, 54.9 LMH), whereas, for diuron, it is 78.82%, 53.46 LMH. The antimicrobial property is seen for interlayer polypyrrole‐based TFC membranes.
Die Verbreiterung der Hochstraße Elbmarsch in Hamburg
Authors: Dawirs Katharina , Krohn Sebastian , Gebert Gregor , Seifried Jörg 
Published: December 2020

AbstractIn Hamburg erfolgt der achtstreifige Ausbau der Hochstraße Elbmarsch (Brückenbauwerk K20), der derzeit längsten Straßenbrücke Deutschlands, südlich des Elbtunnels. Die ca. 3,8 km lange Hochstraße ist mit jeweils drei Richtungsfahrstreifen auf zwei baulich getrennten Überbauten (Rifa Hannover, Rifa Flensburg) ausgebildet. Im Vorfeld des anspruchsvollen Großprojekts wurden aufgrund der besonderen bautechnischen Herausforderungen und zur Planungsoptimierung vorgezogene Maßnahmen geplant und ausgeführt. Mit den daraus gewonnenen Erkenntnissen konnte ein hohes Maß an Planungssicherheit erzielt werden. Der Praxistest ist mit Beginn der Ausführung der Gesamtmaßnahme im letzten Jahr gestartet.
Temperature and oxygen level determine N2O respiration activities of heterotrophic N2O‐reducing bacteria: Biokinetic study
Authors: Zhou Yiwen , Suenaga Toshikazu , Qi Chuang , Riya Shohei , Hosomi Masaaki , Terada Akihiko 
Published: December 2020

AbstractNitrous oxide (N2O), a potent greenhouse gas, is reduced to N2 gas by N2O‐reducing bacteria (N2ORB), a process which represents an N2O sink in natural and engineered ecosystems. The N2O sink activity by N2ORB depends on temperature and O2 exposure, yet the specifics are not yet understood. This study explores the effects of temperature and oxygen exposure on biokinetics of pure culture N2ORB. Four N2ORB, representing either clade I type nosZ (Pseudomonas stutzeri JCM5965 and Paracoccus denitrificans NBRC102528) or clade II type nosZ (Azospira sp. strains I09 and I13), were individually tested. The higher activation energy for N2O by Azospira sp. strain I13 (114.0 ± 22.6 kJ mol−1) compared with the other tested N2ORB (38.3–60.1 kJ mol−1) indicates that N2ORB can adapt to different temperatures. The O2 inhibition constants (KI) of Azospira sp. strain I09 and Ps. stutzeri JCM5965 increased from 0.06 ± 0.05 and 0.05 ± 0.02 μmol L−1 to 0.92 ± 0.24 and 0.84 ± 0.31 μmol L−1, respectively, as the temperature increased from 15°C to 35°C, while that of Azospira sp. strain I13 was temperature‐independent (p = 0.106). Within the range of temperatures examined, Azospira sp. strain I13 had a faster recovery after O2 exposure compared with Azospira sp. strain I09 and Ps. stutzeri JCM5965 (p < 0.05). These results suggest that temperature and O2 exposure result in the growth of ecophysiologically distinct N2ORB as N2O sinks. This knowledge can help develop a suitable N2O mitigation strategy according to the physiologies of the predominant N2ORB.
Pedagogy of teaching introductory text‐based programming in terms of computational thinking concepts and practices
Authors: Kandemir Celal Murat , Kalelioğlu Filiz , Gülbahar Yasemin 
Published: December 2020

AbstractIntroductionProgramming can be an intellectually satisfying skill and is definitely considered useful. However, problem‐solving with a computer involves much more than just learning programming language syntax. The theory and practice are interrelated in fascinating ways. Whether one thinks that the purpose of college or higher education is to prepare students for an occupation or to develop foundational knowledge with lifetime benefits (or both), computer science (CS) has become a fundamental part of 21st‐century life. Even students studying in areas other than CS are likely to have significant encounters with computational thinking (CT) later on in life.Motivation and ObjectivesColleges and universities offer the opportunity for students to take as many courses as they desire in coding, programming, and CS taught by faculty members from that discipline area. However, this approach alone is deemed insufficient for computer‐based problem‐solving and computer programming. Effective programming teaching pedagogy also requires organizational principles that can guide us in formulating the overall design of a programming science curriculum (CS). In particular, we need strategies that help us structure multiple paradigm‐based teaching curricula into manageable modules. This study aims to develop a framework for programming pedagogy.Research Methodology and MethodsA systematic literature review was conducted for identifying, evaluating, and interpreting relevant research to explore programming paradigms that could be incorporated for novice programmers, possible implementation strategies, and instructional methods for teaching text‐based programming, CT concepts, and practices.Results and FindingsThis paper's focus was on the pedagogical phenomenon of teaching programming considering the evolving paradigms, implementation strategies, and instructional methods and techniques through the lens of CT. Hence, a framework to design a learning path for pedagogical approaches that consist of CT concepts and practices within text‐based programming were proposed. The proposed framework is based on the assumption that “any ongoing research on computing pedagogy requires a review of what CT is, how it impacts on teaching and learning and its role within the pedagogy advocated.” The programming pedagogy framework consists of four fundamental components: programming paradigm, implementation strategy, instructional methods, and instructional techniques.
Multidisciplinary management of a fused maxillary incisor: Case report with 5‐year follow‐up
Authors: El Backly Rania M. , Kotry Gehan Sherif , Moussa Hassan 
Published: December 2020

AbstractDetailed treatment planning and execution are crucial if regenerative approaches are to be attempted to retain fused permanent teeth. Long‐term follow‐up is necessary to monitor the stability of the final outcome, both esthetically and functionally.
A useful and safe method for retrieving a round metallic object from an airway
Authors: Jingu Daisuke , Horii Akira , Matsuzono Yu , Ubukata Satoshi , Sato Kosuke , Shoji Makoto , Kondo Noriko , Takahashi Hiroshi , Watanabe Hiroshi 
Published: December 2020

AbstractThe endoscopic net forceps with the support of a laryngeal mask airway are a dependable choice for retrieving a round metallic object from an airway.
The Limits of the Confinement Effect Associated to Cage Topology on the Control of the MTO Selectivity
Authors: Ferri Pau , Li Chengeng , Paris Cecilia , Rodríguez‐Fernández Aída , Moliner Manuel , Boronat Mercedes , Corma Avelino 
Published: December 2020

AbstractThe light olefin product distribution of the methanol‐to‐olefin (MTO) reaction catalyzed by acid zeolites and zeotypes depends on the nature of the entrapped hydrocarbon pool species that act as co‐catalysts. The preferential stabilization by confinement effects of the cationic intermediates involved in the side‐chain or paring pathways of the aromatics‐based cycle of the MTO mechanism in small‐pore cage‐based zeolites is determined by the topology of the cavity, and can be quantitatively described through the Eint(7/5) parameter obtained from DFT calculations. In this work we extend the study of the Eint(7/5) parameter to a wide range of structures (ERI, LEV, AEI, CHA, DDR, AFX, RTH, ITE, SAV, UFI, RHO, KFI, and LTA) and discuss its applicability in small cages with steric constraints to host bulky intermediates, in zeolites with a tight fitting between the cavity and the hosted cations, and in large cages where confinement effects are lost in part and competitive processes occur.
Multi‐faceted Set‐up of a Diverse Ketoreductase Library Enables the Synthesis of Pharmaceutically‐relevant Secondary Alcohols
Authors: Voss Moritz , Küng Robin , Hayashi Takahiro , Jonczyk Magdalena , Niklaus Michael , Iding Hans , Wetzl Dennis , Buller Rebecca 
Published: December 2020

AbstractEnzymes are valuable tools to introduce chirality into small molecules. Especially, ketoreductase (KRED)‐catalyzed transformations of ketones to yield chiral secondary alcohols have become an established biocatalytic process step in the pharmaceutical and fine chemical industry. Development time, however, remains a critical factor in chemical process development and thus, the competitiveness of a biocatalytic reaction step is often governed by the availability of off‐the‐shelf enzyme libraries. To expand the biocatalytic toolbox with additional ketoreductases, we established a multi‐faceted screening procedure to capture KRED diversity from different sources, such as literature, available genome data, and uncharacterized microbial strains. Overall, we built a library consisting of 51 KRED enzymes, 29 of which have never been described in literature before. Notably, 18 of the newly described enzymes exhibited anti‐Prelog preference complementing the majority of ketoreductases which generally follow Prelog's rule. Analysis of the library's catalytic activity toward a chemically diverse ketone substrate set of pharmaceutical interest further highlighted the broad substrate scope and the complementing enantio‐preference of the individual KREDs. Using the generated sequence‐function data of the included short chain dehydrogenases in a bioinformatic analysis led to the identification of possible sequence determinants of the stereospecificity exhibited by these enzymes.
Recent Advances in Aqueous Zinc‐ion Hybrid Capacitors: A Minireview
Authors: Shao Yanyan , Shen Fei , Shao Yuanlong 
Published: December 2020

AbstractThe tremendous demand for wearable electronic systems drives increasing efforts devoted to research on portable electrochemical energy storage devices. Thanks to the environmental benignity, highly intrinsic safety and low cost, zinc‐ion based charge storage systems have attracted extensive attention recently. Zinc‐ion hybrid capacitors (ZHCs) stand for the electrochemical energy storage system with a capacitive electrode as cathode and a zinc metal as the anode. In this minireview, we summarize the history of aqueous ZHCs and present a comprehensive overview of the recent progress in the structure design, charge storage mechanisms and electrochemical properties of the cathode, anode, as well as the electrolytes and their effects on the electrochemical performance of final ZHCs. In the end, the current challenges and our perspectives on the future trends of this field are also briefly anticipated. The pertinent insights into the challenges on the electrodes and electrolyte systems could also shed some lights on other aqueous electrolyte based electrochemical charge storage systems.