bluuebunny/crossref_metadata_2025 huggingface dataset:
A Reagent for Amine‐Directed Conjugation to IgG1 Antibodies
Authors: Märcher Anders , Palmfeldt Johan , Nisavic Marija , Gothelf Kurt V.
Published: December 2020

Functionalized 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

Lipid 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

Die 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

Drei 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

Herein 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

Vibrational 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

Use 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

The 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

The 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

In 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

Nitrous 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

Introduction

Programming 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 Objectives

Colleges 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 Methods

A 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 Findings

This 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

Detailed 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

The 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

The 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

Enzymes 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

The 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.
Nitrogen's influence on stockpiling of ‘Jesup’ tall fescue cultivars with diverse fungal endophyte presence
Authors: Lemus Rocky , Walker Dennis
Published: December 2020

Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] is used in the southern United States to extend the cow–calf grazing season during autumn and winter by stockpiling. However, livestock producers are reluctant to graze tall fescue because of the toxicity associated with the presence of an endophyte within the grass plant. In this study, the effects of the amount of N fertilizer rate (0, 50, and 100 acre–1), the N source (ammonium nitrate and urea), and the date of N application (September and October) were evaluated for the herbage accumulation (HA) and nutritive value on stockpiled tall fescue. The study was conducted in the autumn of 2007–2009 with six experimental ‘Jesup’ tall fescue cultivars with different endophytic fungal strains: endophyte‐infected wild‐type, endophyte‐free, and infected with the novel endophytes (NE) AR502, AR514, AR542, and AR584. Greater HA was observed with the September N application. Ammonium nitrate was more efficient at increasing HA than urea at both N application rates. Herbage accumulation increased by 56 and 98% at 50 and 100 lb N acre–1 compared with the control. The nutritive value of the stockpiled tall fescue declined as the winter season advanced, despite the source, rate, and timing of fertilizer application. Although the study reported a reduction in nutritive value from November to January, the nutritive value concentrations and estimations are considered optimum for livestock production.
Visible‐Light‐Induced Synthesis of 1,2,3,4‐Tetrahydroquinolines through Formal [4+2] Cycloaddition of Acyclic α,β‐Unsaturated Amides and Imides with N,N‐Dialkylanilines
Authors: Itoh Kennosuke , Nagao Shun‐ichi , Tokunaga Ken , Hirayama Shigeto , Karaki Fumika , Mizuguchi Takaaki , Nagai Kenichiro , Sato Noriko , Suzuki Mitsuaki , Hashimoto Masashi , Fujii Hideaki
Published: December 2020

1,2,3,4‐Tetrahydroquinolines should be applicable to the development of new pharmaceutical agents. A facile synthesis of 1,2,3,4‐tetrahydroquinolines that is achieved by a photoinduced formal [4+2] cycloaddition reaction of acyclic α,β‐unsaturated amides and imides with N,N‐dialkylanilines under visible‐light irradiation, in which a new IrIII complex photosensitizer, a thiourea, and an oxidant act cooperatively in promoting the reaction, is reported. The photoreaction enables the synthesis of a wide variety of 1,2,3,4‐tetrahydroquinolines, while controlling the trans/cis diastereoselectivity (>99:1) and constructing contiguous stereogenic centers. A chemoselective cleavage of an acyclic imide auxiliary is demonstrated.
An Antimony(III) Fluoride Oxalate with Large Birefringence
Authors: Chen Yangxin , Chen Zhangxian , Zhou Yang , Li Yanqiang , Liu Youchao , Ding Qingran , Chen Xin , Zhao Sangen , Luo Junhua
Published: December 2020

Birefringent materials play a key role in modulating the polarization of light and thus in optical communication as well as in laser techniques and science. Designing new, excellent birefringent materials remains a challenge. In this work, we designed and synthesized the first antimony(III) fluoride oxalate birefringent material, KSb2C2O4F5, by a combination of delocalized π‐conjugated [C2O4]2− groups, stereochemical active Sb3+ cations, and the most electronegative element, fluorine. The [C2O4]2− groups are not in an optimal arrangement in the crystal structure of KSb2C2O4F5; nonetheless, KSb2C2O4F5 exhibits a large birefringence (Δn=0.170 at 546 nm) that is even better than that of the well‐known commercial birefringent material α‐BaB2O4, even though the latter features an optimal arrangement of π‐conjugated [B3O6]3− groups. Based on first‐principles calculations, this prominent birefringence should be attributed to the alliance of planar π‐conjugated [C2O4]2− anions, highly distorted SbO2F2 and SbOF3 polyhedra with a stereochemically active lone pair. The combination of lone‐pair electrons and π‐conjugated systems boosts the birefringence to a large extent and will help the development of high‐performance birefringent materials.
Mechanical Modulation of the Solid‐State Luminescence of Tricarbonyl Rhenium(I) Complexes through the Interplay between Two Triplet Excited States
Authors: Calupitan Jan Patrick , Poirot Alexandre , Wang Jinhui , Delavaux‐Nicot Béatrice , Wolff Mariusz , Jaworska Maria , Métivier Rémi , Benoist Eric , Allain Clémence , Fery‐Forgues Suzanne
Published: December 2020

Mechanoresponsive luminescence (MRL) materials promise smart devices for sensing, optoelectronics and security. We present here the first report on the MRL activity of two ReI complexes, opening up new opportunities for applications in these fields. Both complexes exhibit marked solid‐state luminescence enhancement (SLE). Furthermore, the pristine microcrystalline powders emit in the yellow‐green region, and grinding led to an amorphous phase with concomitant emission redshift and shrinking of the photoluminescence (PL) quantum yields and lifetimes. Quantum chemical calculations revealed the existence of two low‐lying triplet excited states with very similar energy levels, that is, 3IL and 3MLCT, having, respectively, almost pure intraligand (IL) and metal‐to‐ligand charge‐transfer (MLCT) character. Transition between these states could be promoted by rotation around the pyridyltriazole−phenylbenzoxazole bond. In the microcrystals, in which rotations are hindered, the 3IL state induces the prominent PL emission at short wavelengths. Upon grinding, rotation is facilitated and the transition to the 3MLCT state results in a larger proportion of long‐wavelength PL. FTIR and variable‐temperature PL spectroscopy showed that the opening of the vibrational modes favours non‐radiative deactivation of the triplet states in the amorphous phase. In solution, PL only arises from the 3MLCT state. The same mechanism accounts for the spectroscopic differences observed when passing from crystals to amorphous powders, and then to solutions, thereby clarifying the link between SLE and MRL for these complexes.
Photocatalyzed Transition‐Metal‐Free Oxidative Cross‐Coupling Reactions of Tetraorganoborates**
Authors: Music Arif , Baumann Andreas N. , Boser Florian , Müller Nicolas , Matz Florian , Jagau Thomas C. , Didier Dorian
Published: December 2020

Readily accessible tetraorganoborate salts undergo selective coupling reactions under blue light irradiation in the presence of catalytic amounts of transition‐metal‐free acridinium photocatalysts to furnish unsymmetrical biaryls, heterobiaryls and arylated olefins. This represents an interesting conceptual approach to forge C−C bonds between aryl, heteroaryl and alkenyl groups under smooth photochemical conditions. Computational studies were conducted to investigate the mechanism of the transformation.
Ionic Liquids as Surfactants in Aqueous Multiphase Systems for the Pd‐Catalyzed Hydrocarboxylation
Authors: Weber Ariane , Isbrücker Philipp , Schmidt Marcel , Schomäcker Reinhard
Published: December 2020

The suitability of ionic liquids (alkylmethylimidazolium bromides) as surfactants in an aqueous multiphase system for the Pd‐catalyzed hydrocarboxylation of 1‐dodecene is discussed. Attention is paid to the influence of these ionic liquids on the reaction performance and the phase separation. All tested ionic liquids are suitable as surfactants, but their concentration has a strong impact on the reaction performance. The resulting product concentrations are crucial for the phase behavior and so for the phase separation. In recycling experiments, the Pd‐catalyst is successfully separated and reused.
Conditional survival among patients with oropharyngeal cancer treated with radiation therapy and alive without recurrence 5 years after diagnosis
Authors: Dahlstrom Kristina R. , Song Juhee , Thall Peter F. , Fuller Clifton D. , Hutcheson Katherine A. , Johnson Faye M. , Gunn G. Brandon , Phan Jack , Frank Steven J. , Morrison William H. , Ferrarotto Renata , Rosenthal David I. , Sturgis Erich M. , Garden Adam S.
Published: December 2020

Background

Risk of recurrence among patients with oropharyngeal cancer (OPC) who survive 5 years is low. The goal of this study was to assess long‐term survival of patients with OPC alive without recurrence 5 years after diagnosis.

Methods

This study included newly diagnosed patients with OPC, who had been treated with radiation and were alive without recurrence 5 years after diagnosis. Overall survival (OS) probabilities beyond 5 years were estimated using the Kaplan‐Meier method. Factors associated with OS were determined using Bayesian piecewise exponential survival regression. Standardized mortality ratios for all‐cause death were estimated controlling for study year, age, and sex in the US general population.

Results

Among 1699 patients, the additional 2‐year, 5‐year, and 10‐year OS probabilities were 94%, 83%, and 63%, respectively, and were lower than those in the general population. Patients who were older, were current or former smokers, had other than tonsil or base of tongue tumors, or had T4 tumors had a higher risk of death. Patients who had base of tongue tumors and had received intensity‐modulated radiation therapy (IMRT) or lower‐radiation doses had a lower risk of death. Standardized mortality ratios were higher among current and heavy smokers and lower among recipients of IMRT and lower radiation doses.

Conclusions

In this large cohort, long‐term survival among patients with OPC was good but lower than predicted for the general population. Patients treated with IMRT and those with less tobacco exposure had better outcomes.
Comparison of a standard computer‐assisted cognitive training program to a music enhanced program: A mixed methods study
Authors: Smith Theresa M. , Wang Wanyi
Published: December 2020

Background

Between 17 and 75% of breast cancer survivors (BCS) experience long‐term cognitive deficits such as deficits in memory, attention, processing speed, and executive function.

Aims

This study aimed to (a) compare effects of a standard computer‐assisted cognitive training (CACT) program to a CACT program enhanced with music (CACT+A) to improve focus and concentration on BCS' memory, cognition, quality of life (QOL), and participation in everyday activities; and (b) garner participants' perspectives of effects of the programs to determine best practice.

Methods

An embedded design was employed in this mixed methods study. Participants who reported cognitive problems were recruited through breast cancer support groups. Four pre and post‐tests were used followed by a qualitative interview.

Results

Twenty‐five BCS, ages 31 to 72 years participated. The CACT group demonstrated significantly improved pre to post‐test scores for working memory, QOL, and three subscales of the Model of Human Occupation Screening Tool (MOHOST) measuring participation in everyday activities. The CACT+A group had significant improvement for four FACT‐Cog cognitive function subscales and the total score. Five themes emerged from the interview: Cognitive skill, Strategy learned, No change, QOL factors, and Participation in everyday activities. The CACT+A group expressed experiencing a larger ratio of improvements, most notably for memory and QOL factors.

Conclusion

CACT+A is an auspicious intervention option for BCS who self‐report cognitive issues. It is convenient to participate in at home and allows BCS to safely self‐isolate if need be.

This study is a registered clinical trial protocol: TexasWU record 19 959.
A Small Dye Puzzle: π‐Conjugation of Perylenes with External Aromatic Compounds via Imidazo‐Quinoxaline Bridges
Authors: Dobeneck Michaela , Kaur Ramandeep , Platzer Benedikt , Guldi Dirk M. , Hirsch Andreas
Published: December 2020

The front cover artwork is provided by the Chair of Organic Chemistry II at Friedrich‐Alexander University Erlangen‐Nürnberg (Germany). The image shows three puzzle pieces representing the three building blocks for a facile stepwise synthetic pathway towards a library of unprecedented perylene chromophores with linearly elongated π systems. Read the full text of the Article at 10.1002/cptc.2020000243.
Individual consumer movement mediates food web coupling across a coastal ecosystem
Authors: Rezek Ryan J. , Massie Jordan A. , Nelson James A. , Santos Rolando O. , Viadero Natasha M. , Boucek Ross E. , Rehage Jennifer S.
Published: December 2020

The movement and foraging patterns of consumers are a major driver of nutrient and energy distribution in ecosystems. However, relatively little is known about how intraspecific variation in consumer movement behavior might affect food web coupling and ecosystem processes across landscapes and seascapes. Here we use long‐term acoustic telemetry and stable isotope niche metrics to understand how differences in predatory fish movement patterns control food web coupling and resource subsidies across the Florida Coastal Everglades (USA). We found common snook (Centropomus undecimalis) that spent most of their time in freshwater riverine areas of the Shark River Estuary primarily foraged on prey subsidies originating from adjacent marsh habitats, serving as an important vector of nutrient subsidies to downstream habitats. Snook that spent the majority of their time in downstream estuarine habitats displayed a diversity of resource usage across wide spatial scales, occupied a much larger trophic niche, and serve as a multidirectional vector of trophic coupling among marine, estuarine, and freshwater riverine habitats. These results demonstrate how individual variations in predator movement behavior can mediate the direction and scale of food web subsidies across coastal seascapes.
Longitudinal changes in risk status in pulmonary arterial hypertension
Authors: Bouzina Habib , Rådegran Göran , Butler Oisin , Hesselstrand Roger , Hjalmarsson Clara , Holl Katsiaryna , Jansson Kjell , Klok Rogier , Söderberg Stefan , Kjellström Barbro
Published: December 2020

Aims

Low‐risk status in pulmonary arterial hypertension (PAH) predicts better survival. The present study aimed to describe changes in risk status and treatment approaches over multiple clinical assessments in PAH, taking age and comorbidity burden into consideration.

Methods and results

The study included incident patients from the Swedish PAH registry, diagnosed with PAH in 2008–2019. Group A (n = 340) were ≤75 years old with <3 comorbidities. Group B (n = 163) were >75 years old with ≥3 comorbidities. Assessments occurred at baseline, first‐year (Y1) and third‐year (Y3) follow‐ups. The study used an explorative and descriptive approach. Group A: median age was 65 years, 70% were female, and 46% had no comorbidities at baseline. Baseline risk assessment yielded low (23%), intermediate (66%), and high risk (11%). Among patients at low, intermediate, or high risk at baseline, 51%, 18%, and 13%, respectively, were at low risk at Y3. At baseline, monotherapy was the most common therapy among low (68%) and intermediate groups (60%), while dual therapy was the most common among high risk (69%). In patients assessed as low, intermediate, or high risk at Y1, 66%, 12%, and 0% were at low risk at Y3, respectively. Of patients at intermediate or high risk at Y1, 35% received monotherapy and 13% received triple therapy. In low‐risk patients at Y1, monotherapy (40%) and dual therapy (43%) were evenly distributed. Group B: median age was 77 years, 50% were female, and 44% had ≥3 comorbidities at baseline. At baseline, 8% were at low, 80% at intermediate, and 12% at high risk. Monotherapy was the most common therapy (62%) in Group B at baseline. Few patients maintained or reached low risk at follow‐ups.

Conclusions

Most patients with PAH did not meet low‐risk criteria during the 3 year follow‐up. The first year from diagnosis seems important in defining the longitudinal risk status.
Predicting maximal oxygen uptake from the 6 min walk test in patients with heart failure
Authors: Deka Pallav , Pozehl Bunny J. , Pathak Dola , Williams Mark , Norman Joseph F. , Alonso Windy W. , Jaarsma Tiny
Published: December 2020

Aims

A cardiopulmonary exercise (CPX) test is considered the gold standard in evaluating maximal oxygen uptake. This study aimed to evaluate the predictive validity of equations provided by Burr et al., Ross et al., Adedoyin et al., and Cahalin et al. in predicting peak VO2 from 6 min walk test (6MWT) distance in patients with heart failure (HF).

Methods and Results

New York Heart Association Class I–III HF patients performed a maximal effort CPX test and two 6MWTs. Correlations between CPX VO2 peak and the predicted VO2 peak, coefficient of determination (R2), and mean absolute percentage error (MAPE) scores were calculated. P‐values were set at 0.05. A total of 106 participants aged 62.5 ± 11.5 years completed the tests. The mean VO2 peak from CPX testing was 16.4 ± 3.9 mL/kg/min, and the mean 6MWT distance was 419.2 ± 93.0 m. The predicted mean VO2 peak (mL/kg/min) by Burr et al., Ross et al., Adedoyin et al., and Cahalin et al. was 22.8 ± 8.8, 14.6 ± 2.1, 8.30 ± 1.4, and 16.6 ± 2.8. A significant correlation was observed between the CPX test VO2 peak and predicted values. The mean difference (0.1 mL/kg/min), R2 (0.97), and MAPE (0.14) values suggest that the Cahalin et al. equation provided the best predictive validity.

Conclusions

The equation provided by Cahalin et al. is simple and has a strong predictive validity, and researchers may use the equation to predict mean VO2 peak in patients with HF. Based on our observation, equations to predict individual maximal oxygen uptake should be used cautiously.
Cross talk between human regulatory T cells and antigen‐presenting cells: Lessons for clinical applications
Authors: Wardell Christine M , MacDonald Katherine N , Levings Megan K , Cook Laura
Published: December 2020

Regulatory T cells (Tregs) have a critical role in maintaining self‐tolerance and immune homeostasis. There is much interest in using Tregs as a cell therapy to re‐establish tolerance in conditions such as inflammatory bowel disease and type 1 diabetes, with many ongoing clinical studies testing the safety and efficacy of this approach. Manufacturing of Tregs for therapy typically involves ex vivo expansion to obtain sufficient cell numbers for infusion and comes with the risk of altering the activity of key biological processes. However, this process also offers an opportunity to tailor Treg function to maximize in vivo activity. In this review, we focus on the roles of antigen‐presenting cells (APCs) in the generation and function of Tregs in humans. In addition to stimulating the development of Tregs, APCs activate Tregs and provide signals that induce specialized functional and homing marker expression. Cross talk between Tregs and APCs is a critical, often under‐appreciated, aspect of Treg biology, with APCs mediating the key properties of infectious tolerance and bystander suppression. Understanding the biology of human Treg‐APC interactions will reveal new ways to optimize Treg‐based therapeutic approaches.
Graphene and graphene‐like structure from biomass for Electrochemical Energy Storage application‐ A Review
Authors: Poorna AR. , Saravanathamizhan R. , Balasubramanian N.
Published: December 2020

Graphene, an SP2 hybridized 2‐D atomic crystal, has been one of the most significant materials of the current century. Researchers in the recent years find graphene to be highly appealing for its superlative electrochemical energy storage applications and some of its unique features such as fractional quantum hall effect which is even exhibited in normal temperatures such as room temperature, ballistic conduction of charge carriers along with the exhibition of ambipolar electric field effect and modifiable bandgap. Enhanced electrochemical performances have been achieved by coalescing graphene with other electrochemical materials. This review focuses on various bio‐precursors involved in the synthesis of graphene and its diverse production methods along with their merits and demerits. It also summarizes the ensuing features and macro‐structural complexity of the graphene‐derived structural composites as well as its applications as competent electrode material in energy storage devices. It specifically endeavors in providing a comprehensible idea on the availability of a variety of biomass sources and its synthesis techniques for a better and optimized mass production of graphene with uncompromising purity as well as the perspectives of the graphene‐based composites that pave path for its improved application in advanced storage devices. This review article casts light upon the enormous opportunities of graphene production with easy synthesizing techniques that could aid in the fabrication of high performance of supercapacitors.
Computing viscous flow along a 2D open channel using the immersed interface method
Authors: Patterson Sarah E. , Layton Anita T.
Published: December 2020

We present a numerical method for simulating 2D flow through a channel with deformable walls. The fluid is assumed to be incompressible and viscous. We consider the highly viscous regime, where fluid dynamics are described by the Stokes equations, and the less viscous regime described by the Navier–Stokes equations. The model is formulated as an immersed boundary problem, with the channel defined by compliant walls that are immersed in a larger computational fluid domain. The channel traverses through the computational domain, and the walls do not form a closed region. When the walls deviate from their equilibrium position, they exert singular forces on the underlying fluid. We compute the numerical solution to the model equations using the immersed interface method, which preserves sharp jumps in the solution and its derivatives. The immersed interface method typically requires a closed immersed interface, a condition that is not met by the present configuration. Thus, a contribution of the present work is the extension of the immersed interface method to immersed boundary problems with open interfaces. Numerical results indicate that this new method converges with second‐order accuracy in both space and time, and can sharply capture discontinuities in the fluid solution.
Review of vibration‐based electromagnetic–piezoelectric hybrid energy harvesters
Authors: Ahmad Muhammad Masood , Khan Farid Ullah
Published: December 2020

These days the health monitoring of machines and structures is performed using wireless sensor nodes (WSNs). The disadvantage of short life span of batteries in WSN is overcome by using energy harvesting techniques and the required power is extracted from the environment for operating WSNs. The energy available in environment is in the form of thermal, solar, wind, vibration, RF and acoustic energy. The Piezoelectric (PE), electromagnetic (EM), electrostatic and triboelectric transduction may be utilized to harvest power from vibration energy available on structure which otherwise may be going waste. Moreover, for enhancing power generation hybrid vibration energy harvesters are developed by combining two of such transduction mechanisms. The piezoelectric and electromagnetic based hybrid harvesters are discussed in this work for vibration energy harvesting. The hybrid vibration energy harvesters are classified here as resonant, frequency tuned, nonlinear, non‐resonant, multi‐mode and frequency up conversion harvesters. The architecture, input excitation levels and performance of the reported hybrid harvesters is discussed and compared to know the advantage of harvester's configuration. Moreover, all the reported harvesters are compared on the basis of input vibration to which these harvesters are subjected, their resonant frequencies, size, output voltage, power levels and power density. Most of the developed hybrid energy harvesters are resonant harvesters. The multi‐mode hybrid energy harvesters are generating comparatively higher power levels of up to 250.25 mW and power density 2669.3 µW/cm3 in the reported literature. The overall voltage and power generation range of the hybrid harvesters is from 0.131 mV to 26 V and 0.637 µW to 250.25 mW. Moreover, the power density for the reported energy harvesters is in the range from 1.96 µW/cm3 to 2669 µW/cm3.
Building stock energy modeling: Feasibility study on selection of important input parameters using stepwise regression
Authors: Arababadi Reza , Naganathan Hariharan , Saffari Pour Mohsen , Dadvar Atefeh , Parrish Kristen , Chong Oswald
Published: December 2020

Building energy assessment is essential to accomplish the sustainable energy targets of new and present buildings. Retrofitting of the existing buildings by assessing them through energy models is the most prominent method. Studies revealed that there is still blank information about the building stocks, and these affect the valuation of building energy efficiency policies. Literature also recommends that the existing energy models are too complex and unreliable to predict the energy use. Reliability of such energy models would improve through a better alignment of the input parameters and the model assumptions. The authors hypothesized that the reliability of models would be improved through identification of the most relevant energy use parameters for the building stocks in different regions and models. One of the most commonly accepted methods for detecting the most dominant input parameters is sensitivity analysis, though its shortcomings include the need for a large number of data samples and long computing time. In this research, the Energy, Carbon, and Cost Assessment for Buildings Stocks (ECCABS) model is adopted to identify the most important parameters of the presented model. The research team uses the model that has been validated by studies conducted for the UK building stock. Moreover, by assessing the feasibility study with the stepwise regression to identify the significant input parameters have been discussed. Results show that stepwise regression method could produce the same results compared to sensitivity analysis. This paper also indicates that stepwise regression is considerably faster and less computationally intensive compared to common sensitivity analysis methods.