bluuebunny/crossref_metadata_2025_split huggingface dataset:
Standortspezifisches Ziellastniveau und objektspezifische Lastmodelle für die Nachrechnung auf der Basis von Bauwerksmonitoring
Authors: Steffens Nico , Geißler Karsten 
Published: September 2021

AbstractBei der Bewertung bestehender Brücken wird zunehmend ein unterstützendes Bauwerksmonitoring eingesetzt, um die Beanspruchungen im Tragwerk realistischer als rein rechnerisch zu erfassen und das Rechenmodell zu kalibrieren. Normativ ungeklärt ist derzeit noch die Frage, wie die durch Messungen gewonnenen zusätzlichen Informationen innerhalb des Nachrechnungs‐ einschließlich dessen Sicherheitskonzepts zu berücksichtigen sind. Einwirkungsseitig kann dies durch die modifizierte Definition des Ziellastniveaus oder alternativ durch objektspezifische Lastmodelle für Tragfähigkeit und Ermüdung zur Abbildung des tatsächlichen Verkehrs erfolgen. Weiterhin können auf der Basis der Messdaten die erforderlichen Sicherheitsfaktoren, auch unter Berücksichtigung zukünftiger Verkehrsentwicklungen, bei Einhaltung des normativ erforderlichen Zuverlässigkeitsniveaus begründet werden. In diesem Beitrag werden Möglichkeiten sowie die theoretischen Hintergründe zur Berücksichtigung gemessener Verkehrsbeanspruchungen innerhalb der Nachrechnung von Brückenbauwerken vorgestellt.
Modulare Brückenbauwerke aus carbon‐faserbewehrtem Ultrahochleistungsbeton – Graph‐basierter Entwurf und trajektoriensensitive Fertigung
Authors: Kolbeck Lothar , Auer Daniel , Fischer Oliver , Vilgertshofer Simon , Borrmann André 
Published: September 2021

AbstractFür die Vorfertigung von Brückentragwerken in industrieller Fließfertigung sind weitreichende Veränderungen in Entwurf und Ausführung nötig. Deshalb erläutert dieser Aufsatz einen ganzheitlichen und durchgängig digitalen Planungsprozess für eine modulare Bauweise mit ebenen, additiv gefertigten Grundmodulen. Als Grundlage eines automatisierten Entwurfs wird das System mithilfe eines graph‐basierten Modells abgebildet, darauf aufbauende Graphersetzungsregeln erzeugen modulare Tragwerke gemäß zweier Herangehensweisen: Einerseits werden bestehende Bauteilgeometrien segmentiert, andererseits formalisieren Regeln die Aggregation zu Strukturen. Die zu diesem Prozessschritt vorrangig geometrische Information wird in eine semantisch reichhaltige Darstellung der Zerlegung entwickelt, sodass daraus ein hochdetailliertes Produktionsmodell für jedes Modul parametrisch instanziiert werden kann. Dieses Modell ist durch die flexible Beschreibung mit NURBS in der Lage, eine Vielzahl an Verbindungs‐ und Fügesituationen abzubilden. Schließlich fungiert es auch als Grundlage der Pfadgenerierung für die additive Fertigung. Der Druckpfad wird dabei entlang den Hauptzugspannungsrichtungen ermittelt, durch numerische Interpolation der Ergebnisse einer nichtlinearen FE‐Analyse. Entlang dieses Pfades wird die Ausrichtung von Carbonfaserbewehrung mithilfe angepasster Düsentechnik gesteuert, wodurch herausragende Materialeigenschaften der gefertigten Komponenten erreicht werden können.
Problem solving in the time of coronavirus pandemic
Authors: Bátor Judit , Szeberényi József 
Published: September 2021

AbstractProblem solving, multiple‐choice question‐based educational tools have been used for decades in molecular cell biology courses at the University of Pécs Medical School, Pécs, Hungary. A set of these tests was published in Biochemistry and Molecular Biology Education between 2002 and 2015. Such tests using an experimental approach help students to understand how living cells function. Besides being tools of education, they can be used for examination purposes as well to assess higher levels of intellectual skills (interpretation and problem solving) acquired by the students. The test presented in this paper is based on parts of an original publication in which the authors described seminal observations on the function of a viral protein in the infection process of SARS‐CoV‐2. The test is aimed at helping the students to understand the methods used in the experiments, to analyze the data and to draw conclusions from them regarding certain aspects of the mechanism of coronavirus infection.
Electroacupuncture reactivates estrogen receptors to restore the neuroprotective effect of estrogen against cerebral ischemic stroke in long‐term ovariectomized rats
Authors: Ma Yulong , Niu Erlong , Xie Fei , Liu Min , Sun Miao , Peng Ye , Guo Hang 
Published: September 2021

BackgroundStroke is a sexually dimorphic disease and a leading cause of death and disability. Estrogen replacement therapy (ERT) confers beneficial neuroprotective effects if administered within a widely accepted time window called the “critical period.” However, very few studies have explored the idea of modulating the critical period to enable long‐term post‐menopausal women to regain more benefits from estrogen therapy. Here, motivated by previous findings that electroacupuncture could both alter estrogen metabolism and induce significant tolerance against stroke, it was explored whether EA could restore estrogen's neuroprotection against cerebral ischemia in long‐term ovariectomized (OVX) rats.MethodsWe implemented 1 week(w)‐EA pretreatment on OVX‐10w or OVX‐20w rats, and tested the expression of estrogen receptors, and detected the ERT's neuroprotection against stroke induced by middle cerebral artery occlusion (MCAO).ResultsWe found that the expression levels of phospho‐ERα‐S118 and estrogen receptor β (ERβ) in the striatum of OVX‐10w rats were significantly decreased and ERT's neuroprotection was abolished in the OVX‐10w rats. However, EA‐1w pretreatment could significantly recover the expression levels of phospho‐ERα‐S118 and ERβ, and also restored the neuroprotective effects of ERT in OVX‐10w rats. However, EA‐1w pretreatment could not restore the expression of estrogen receptors and ERT's neuroprotection in OVX‐20w rats.ConclusionTaken together, our study indicates that EA may be an easy intervention that can restore the efficacy of estrogen therapy during the “critical period,” which has the potential to improve the stroke outcomes of an enormous number of long‐term post‐menopausal women. However, the time‐sensitive influences for how EA and estrogen metabolism interact with each other should be considered.
Comprehensive analysis of pan‐cancer reveals potential of ASF1B as a prognostic and immunological biomarker
Authors: Hu Xinyao , Zhu Hua , Zhang Xiaoyu , He Xiaoqin , Xu Ximing 
Published: September 2021

AbstractBackgroundAnti‐silencing function 1 (ASF1) is a conserved histone H3–H4 chaperone protein. ASF1B, a paralog of ASF1, acts by promoting cell proliferation and influencing cell cycle progression. Although there is some evidence demonstrating that ASF1B plays a key role in the development, progression, and prognosis of certain cancers, there are no pan‐cancer analyses of ASF1B.MethodsWe used a range of bioinformatics approaches to investigate the predictive role of ASF1B, including its correlation with prognosis, tumor mutational burden (TMB), microsatellite instability (MSI), tumor microenvironment (TME), and immune cell infiltration, in diverse cancer types.ResultsWe found that ASF1B was highly expressed in 22 cancers and was negatively correlated with the prognosis of multiple major cancer types. Furthermore, ASF1B expression was correlated with TMB in 21 cancers and with MSI in 7 cancers. We found that ASF1B was coexpressed with genes encoding immune activators, immune suppressors, major histocompatibility complexes, chemokines, and chemokine receptors. We further found that the role of ASF1B in the infiltration of different types of immune cells varied across tumor types. ASF1B may potentially affect several key immune‐related pathways, such as those involved in antigen processing and presentation, natural killer cell‐mediated cytotoxicity, and autoimmune thyroid disease.ConclusionsOur findings show that ASF1B may serve as a prognostic marker and potential immunotherapeutic target for several malignancies due to its role in tumorigenesis and immune infiltration.
Unravelling the Selectivity of 6,7‐Dimethyl Quinoxaline Analogs for Kinase Inhibition: An Insight towards the Development of Alzheimer's Therapeutics
Authors: Kumar Jain Arvind , Gupta Arindam , Karthikeyan C. , Trivedi Piyush , Dutt Konar Anita 
Published: September 2021

AbstractUntangling the most selective kinase inhibitors via pharmacological intervention remains one of the challenging affairs to date. In accordance to this drift, herein we describe the design and synthesis of a set of new heterocyclic analogs consisting of 6,7‐dimethyl Quinoxaline, appended to a connector, employing Schiff base strategy (Compounds I–IX). The compounds were characterized by various spectroscopic techniques and the kinase inhibition assay were performed on few prime members of the CMGC family namely the GSK3β, DYRK1A and CLK1 receptors, respectively, that have been known to be directly involved in hyperphosphorylation of Tau. Interestingly the biological evaluation results revealed that Compounds IV and V, with bromo/chloro functionalities in the aromatic core were advantaged of being highly selective towards the target GSK3β over others. To strengthen our analysis, we adopted molecular modelling studies, where compounds IV/V were redocked in the same grid 4AFJ, as that of the reference ligand, 5‐aryl‐4‐carboxamide‐1,3‐oxazole. Surprisingly, our investigation underpinned that for both the compounds IV/V, a primary H‐bonding existed between the designed molecules (IV/V) and Val 135 residue in the receptor GSK3β, in line with the reference ligand. We attribute this interaction to instigate potency in the compounds. Indeed the other non‐covalent interaction, between the derivative's aromatic nucleus and Arg 141/Thr 138 in the receptor GSK3β, might have been responsible for enhancing the selectivity in the targets. Overall, we feel that the present work depicts a logical demonstration towards fine tuning the efficacy of the inhibitors through systematic adjustment of electron density at appropriate positions in the aromatic ring be it the main quinoxaline or the other aromatic nucleus. Thus this pathway offers a convenient strategy for the development of efficient therapeutics for diversified neurodegenerative diseases like that of Alzheimer's.
Boosting the Electrocatalytic Activity of Fe−Co Dual‐Atom Catalysts for Oxygen Reduction Reaction by Ligand‐Modification Engineering
Authors: Li Lei , Li Yameng , Huang Rao , Cao Xinrui , Wen Yuhua 
Published: September 2021

AbstractDevelopment of high‐efficiency and low‐cost electrocatalysts as the platinum substitute for the oxygen reduction reaction (ORR) is of significance for electrochemical energy conversion and storage devices, such as fuel cells and rechargeable batteries. Here we report graphene‐based nitrogen‐coordinated Fe−Co dual‐atom catalysts (referred to as FeCoN6) with markedly enhanced ORR activity by ligand‐modification. By density functional theory calculations, we thoroughly investigated the ORR activity of three preferred FeCoN6 isomers (denoted as FeCoN6‐I, FeCoN6‐II, and FeCoN6‐III) and their complexes with the ligands of ORR intermediates such as *O, *OH, and *O2. Our results reveal that these ligands cause the apparent shift of d‐orbitals of metal atoms toward the Fermi level to modulate the adsorption strength for reaction intermediates, thereby significantly improving the ORR activity of FeCoN6 complexes. Notably, FeCoN6‐I(OH) and FeCoN6‐I(O2) with the lowest overpotential of ∼0.23 V possessed the best ORR activity, which are superior to pristine FeCoN6 and available Pt catalysts. These results not only build on the fundamental understanding of the catalytic mechanism of ligand modified dual‐atom catalysts but also provide a new strategy to develop highly efficient ORR electrocatalysts by ligand‐modification engineering.
Hydrogen Production by Methane Pyrolysis in a Molten‐Metal Bubble Column
Authors: Zaghloul Nada , Kodama Satoshi , Sekiguchi Hidetoshi 
Published: September 2021

AbstractHydrogen was produced by methane pyrolysis in a molten‐metal bubble column reactor. The proposed reactor improves heat transfer to the reactant gas and allows the separation of solid carbon due to the density difference between the molten metal and produced carbon. The effects of the temperature of the molten metal and metal type on the process were studied. The kinetic parameters were estimated by using a semi‐numerical model of two reactors in series developed for the system. Molten tin, as reaction medium, showed improved kinetic parameters compared to those of the conventional tubular reactor. Tin‐copper and tin‐nickel alloys were also used as molten media to study the effect of catalytically active metals. The produced carbon was analyzed to examine its morphology and purity.
How to Look for Compounds: Predictive Screening and in situ Studies in Na−Zn−Bi System
Authors: Gvozdetskyi Volodymyr , Wang Renhai , Xia Weiyi , Zhang Feng , Lin Zijing , Ho Kai‐Ming , Miller Gordon , Zaikina Julia V. 
Published: September 2021

AbstractHere, the combination of theoretical computations followed by rapid experimental screening and in situ diffraction studies is demonstrated as a powerful strategy for novel compounds discovery. When applied for the previously “empty” Na−Zn−Bi system, such an approach led to four novel phases. The compositional space of this system was rapidly screened via the hydride route method and the theoretically predicted NaZnBi (PbClF type, P4/nmm) and Na11Zn2Bi5 (Na11Cd2Sb5 type, P
) phases were successfully synthesized, while other computationally generated compounds on the list were rejected. In addition, single crystal X‐ray diffraction studies of NaZnBi indicate minor deviations from the stoichiometric 1 : 1 : 1 molar ratio. As a result, two isostructural (PbClF type, P4/nmm) Zn‐deficient phases with similar compositions, but distinctly different unit cell parameters were discovered. The vacancies on Zn sites and unit cell expansion were rationalized from bonding analysis using electronic structure calculations on stoichiometric “NaZnBi”. In‐situ synchrotron powder X‐ray diffraction studies shed light on complex equilibria in the Na−Zn−Bi system at elevated temperatures. In particular, the high‐temperature polymorph HT‐Na3Bi (BiF3 type, Fm
m) was obtained as a product of Na11Zn2Bi5 decomposition above 611 K. HT‐Na3Bi cannot be stabilized at room temperature by quenching, and this type of structure was earlier observed in the high‐pressure polymorph HP‐Na3Bi above 0.5 GPa. The aforementioned approach of predictive synthesis can be extended to other multinary systems.
A Water Soluble Pd2L4 Cage for Selective Binding of Neu5Ac
Authors: Schaapkens Xander , van Sluis Roy N. , Bobylev Eduard O. , Reek Joost N. H. , Mooibroek Tiddo J. 
Published: September 2021

AbstractThe sialic acid N‐acetylneuraminic acid (Neu5Ac) and its derivatives are involved in many biological processes including cell‐cell recognition and infection by influenza. Molecules that can recognize Neu5Ac might thus be exploited to intervene in or monitor such events. A key obstacle in this development is the sparse availability of easily prepared molecules that bind to this carbohydrate in its natural solvent; water. Here, we report that the carbohydrate binding pocket of an organic soluble [Pd2L4]4+ cage could be equipped with guanidinium‐terminating dendrons to give the water soluble [Pd2L4][NO3]16 cage 7. It was shown by means of NMR spectroscopy that 7 binds selectively to anionic monosaccharides and strongest to Neu5Ac with Ka=24 M−1. The cage had low to no affinity for the thirteen neutral saccharides studied. Aided by molecular modeling, the selectivity for anionic carbohydrates such as Neu5Ac could be rationalized by the presence of charge assisted hydrogen bonds and/or the presence of a salt bridge with a guanidinium solubilizing arm of 7. Establishing that a simple coordination cage such as 7 can already selectively bind to Neu5Ac in water paves the way to improve the stability, affinity and/or selectivity properties of M2L4 cages for carbohydrates and other small molecules.
Water‐Assisted Chemical Route Towards the Oxygen Evolution Reaction at the Hydrated (110) Ruthenium Oxide Surface: Heterogeneous Catalysis via DFT‐MD and Metadynamics Simulations
Authors: Creazzo Fabrizio , Luber Sandra 
Published: September 2021

AbstractNotwithstanding that RuO2 is a promising catalyst for the oxygen evolution reaction (OER), a plethora of fundamental details on its catalytic properties are still elusive, severely limiting its large‐scale deployment. It is also established experimentally that corrosion and wettability of metal oxides can, in fact, enhance the catalytic activity for OER owing to the formation of a hydrated surface layer. However, the mechanistic interplay between surface wettability, interfacial water dynamics and OER across RuO2, and what degree these processes are correlated are still debated. Herein, spin‐polarized Density Functional Theory Molecular Dynamics (DFT‐MD) simulations, coupled with advanced enhanced sampling methods in the well‐tempered metadynamics framework, are applied to gain a global understanding of RuO2 aqueous interface (explicit water solvent) in catalyzing the OER, and hence possibly help in the design of novel catalysts in the context of photochemical water oxidation. The present study quantitatively assesses the free‐energy barriers behind the OER at the (110)‐RuO2 catalyst surface revealing plausible pathways composing the reaction network of the O2 evolution. In particular, OER is investigated at room temperature when such a surface is exposed to both gas‐phase and liquid‐phase water. Albeit a unique efficient pathway has been identified in the gas‐phase OER, a surprisingly lowest‐free‐energy‐requiring reaction route is possible when (110)‐RuO2 is in contact with explicit liquid water. By estimating the free‐energy surfaces associated to these processes, we reveal a noticeable water‐assisted OER mechanism which involves a crucial proton‐transfer‐step assisted by the local water environment. These findings pave the way toward the systematic usage of DFT‐MD coupled with metadynamics techniques for the fine assessment of the activity of catalysts, considering finite‐temperature and explicit‐solvent effects.
On the Origin of the Non‐Planarity in Biarylsilyloxonium Ions
Authors: Fernandes Anthony J. , Robert Frederic , Landais Yannick , Künzler Sandra , Müller Thomas 
Published: September 2021

AbstractThe structure determination of a series of biphenylsilyloxonium cations through NMR and XRD studies, supported by DFT calculations was carried out, allowing to get insights into the origin of the oxygen pyramidalization in biphenyl and binaphthylsilyl oxoniums. Low barrier of inversion in the oxygenyl series points toward a key role of the biaryl axis in the inversion of configuration at the oxygen center.
Computational Study of Bridge Splitting, Aryl Halide Oxidative Addition to PtII, and Reductive Elimination from PtIV: Route to Pincer‐PtII Reagents with Chemical and Biological Applications
Authors: Canty Allan J. , Ariafard Alireza , van Koten Gerard 
Published: September 2021

AbstractDensity functional theory computation indicates that bridge splitting of [PtIIR2(μ‐SEt2)]2 proceeds by partial dissociation to form R2Pta(μ‐SEt2)PtbR2(SEt2), followed by coordination of N‐donor bromoarenes (L‐Br) at Pta leading to release of PtbR2(SEt2), which reacts with a second molecule of L‐Br, providing two molecules of PtR2(SEt2)(L‐Br‐N). For R=4‐tolyl (Tol), L‐Br=2,6‐(pzCH2)2C6H3Br (pz=pyrazol‐1‐yl) and 2,6‐(Me2NCH2)2C6H3Br, subsequent oxidative addition assisted by intramolecular N‐donor coordination via PtIITol2(L‐N,Br) and reductive elimination from PtIV intermediates gives mer‐PtII(L‐N,C,N)Br and Tol2. The strong σ‐donor influence of Tol groups results in subtle differences in oxidative addition mechanisms when compared with related aryl halide oxidative addition to palladium(II) centres. For R=Me and L‐Br=2,6‐(pzCH2)2C6H3Br, a stable PtIV product, fac‐PtIVMe2{2,6‐(pzCH2)2C6H3‐N,C,N)Br is predicted, as reported experimentally, acting as a model for undetected and unstable PtIVTol2{L‐N,C,N}Br undergoing facile Tol2 reductive elimination. The mechanisms reported herein enable the synthesis of PtII pincer reagents with applications in materials and bio‐organometallic chemistry.
Investigation of CO2 Orientational Dynamics through Simulated NMR Line Shapes**
Authors: Melix Patrick , Heine Thomas 
Published: September 2021

AbstractThe dynamics of carbon dioxide in third generation (i. e., flexible) Metal‐Organic Frameworks (MOFs) can be experimentally observed by 13C NMR spectroscopy. The obtained line shapes directly correlate with the motion of the adsorbed CO2, which in turn are readily available from classical molecular dynamics (MD) simulations. In this article, we present our publicly available implementation of an algorithm to calculate NMR line shapes from MD trajectories in a matter of minutes on any current personal computer. We apply the methodology to study an effect observed experimentally when adsorbing CO2 in different samples of the pillared layer MOF Ni2(ndc)2(dabco) (ndc=2,6‐naphthalene‐dicarboxylate, dabco=1,4‐diazabicyclo‐[2.2.2]‐octane), also known as DUT‐8(Ni). In 13C NMR experiments of adsorbed CO2 in this MOF, small (rigid) crystals result in narrower NMR line shapes than larger (flexible) crystals. The reasons for the higher mobility of CO2 inside the smaller crystals is unknown. Our ligand field molecular mechanics simulations provide atomistic insight into the effects visible in NMR experiments with limited computational effort.
Impact of SARS‐CoV‐2 Infection (COVID‐19) on Cytochromes P450 Activity Assessed by the Geneva Cocktail
Authors: Lenoir Camille , Terrier Jean , Gloor Yvonne , Curtin François , Rollason Victoria , Desmeules Jules Alexandre , Daali Youssef , Reny Jean‐Luc , Samer Caroline Flora 
Published: September 2021

Coronavirus disease 2019 (COVID‐19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, is a severe acute respiratory syndrome with an underlying inflammatory state. We have previously demonstrated that acute inflammation modulates cytochromes P450 (CYPs) activity in an isoform‐specific manner. We therefore hypothesized that COVID‐19 might also impact CYP activity, and thus aimed to evaluate the impact of acute inflammation in the context of SARS‐CoV‐2 infection on the six main human CYPs activity. This prospective observational study was conducted in 28 patients hospitalized at the Geneva University Hospitals (Switzerland) with a diagnosis of moderate to severe COVID‐19. They received the Geneva phenotyping cocktail orally during the first 72 hours of hospitalization and after 3 months. Capillary blood samples were collected 2 hours after cocktail administration to assess the metabolic ratios (MRs) of CYP1A2, 2B6, 2C9, 2C19, 2D6, and 3A. C‐reactive protein (CRP), interleukin 6 (IL‐6), and tumor necrosis factor‐α (TNF‐α) levels were also measured in blood. CYP1A2, CYP2C19, and CYP3A MRs decreased by 52.6% (P = 0.0001), 74.7% (P = 0.0006), and 22.8% (P = 0.045), respectively, in patients with COVID‐19. CYP2B6 and CYP2C9 MRs increased by 101.1% (P = 0.009) and 55.8% (P = 0.0006), respectively. CYP2D6 MR variation did not reach statistical significance (P = 0.072). As expected, COVID‐19 was a good acute inflammation model as mean serum levels of CRP, IL‐6, and TNF‐α were significantly (P < 0.001) higher during SARS‐CoV‐2 infection. CYP activity are modulated in an isoform‐specific manner by SARS‐CoV‐2 infection. The pharmacokinetics of CYP substrates, whether used to treat the disease or as the usual treatment of patients, could be therefore clinically impacted.