bluuebunny/crossref_metadata_2025 huggingface dataset:
Charge Reconfiguration in Isolated Quantum Dot Arrays
Authors: Bayer Johannes C. , Wagner Timo , Rugeramigabo Eddy P. , Haug Rolf J.
Published: March 2019

A high level of tunability and control over arrays of quantum dots are key ingredients toward the goal of scalable‐based qubit architectures. Increasing array size simultaneously increases the parameter space and therefore the tuning complexity. The electron reconfiguration behavior of quantum dot arrays isolated from the electron reservoirs is studied experimentally. Isolating a quantum dot array from the reservoirs does not only enable a high degree of control over the tunnel couplings but at the same time drastically simplifies the stability diagrams for small numbers of electrons trapped in the array. Experimental results on double, triple, and quadruple quantum dot arrays are presented and complementary model calculations allow the identification of all transitions observed in the experiment. Highly tunable long‐range transitions are observed in isolated triple quantum dots and evidence of higher‐order cotunneling is found for the quadruple quantum dot array.
Fluorescence Probing of Active Lithium Distribution in Lithium Metal Anodes
Authors: Cheng Xiangyang , Xian Fang , Hu Zhenglin , Wang Chen , Du Xiaofan , Zhang Huanrui , Chen Shougang , Dong Shanmu , Cui Guanglei
Published: March 2019

The uncontrollable growth of Li dendrites and the accumulation of byproducts are two severe concerns for lithium metal batteries, which leads to safety hazards and a low Coulombic efficiency. To investigate the deterioration of the cell, it is important to figure out the distribution of active Li species on the anode surface and distinguish Li dendrites from byproducts. However, it is still challenging to identify these issues by conventional visual observation methods. In this work, we introduce a novel fluorescent probing strategy using 9,10‐dimethylanthracene (DMA). By marking the cycled Li‐anode surface, the active Li distribution can be visualized by the fluorescence quenching of DMA reacting with active Li. The method demonstrates validity for electrolyte selection and predictive detection of uneven Li deposition on Li metal anodes. Furthermore, the location of dendrites can be clearly identified after destructive utilization of the anode, which will contribute to the development of failure‐analysis technology for Li metal batteries.
Transforming Ionene Polymers into Efficient Cathode Interlayers with Pendent Fullerenes
Authors: Liu Yao , Sheri Madhu , Cole Marcus D. , Yu Duk Man , Emrick Todd , Russell Thomas P.
Published: March 2019

A new and highly efficient cathode interlayer material for organic photovoltaics (OPVs) was produced by integrating C60 fullerene monomers into ionene polymers. The power of these novel “C60‐ionenes” for interface modification enables the use of numerous high work‐function metals (e.g., silver, copper, and gold) as the cathode in efficient OPV devices. C60‐ionene boosted power conversion efficiencies (PCEs) of solar cells, fabricated with silver cathodes, from 2.79 % to 10.51 % for devices with a fullerene acceptor in the active layer, and from 3.89 % to 11.04 % for devices with a non‐fullerene acceptor in the active layer, demonstrating the versatility of this interfacial layer. The introduction of fullerene moieties dramatically improved the conductivity of ionene polymers, affording devices with high efficiency by reducing charge accumulation at the cathode/active layer interface. The power of C60‐ionene to improve electron injection and extraction between metal electrodes and organic semiconductors highlights its promise to overcome energy barriers at the hard‐soft materials interface to the benefit of organic electronics.
A meso‐Tetraaryl‐21‐carbaporphyrin: Incorporation of a Cyclopentadiene Unit into a Porphyrin Architecture
Authors: Garbicz Mateusz , Latos‐Grażyński Lechosław
Published: March 2019

Incorporation of a cyclopentadiene moiety into the meso‐tetraarylporphyrin framework, using 1,3‐bis(arylhydroxymethyl)ferrocene as a synthon, resulted in the rational synthesis of a meso‐tetraaryl‐21‐carbaporphyrin. The molecular design preserves all essential virtues of the original tetrapyrrolic architecture of meso‐tetraarylporphyrin, including the perfect match between the ionic radii of an inserted metal and the size of the macrocyclic (CNNN) core, and steric protection provided by thoughtfully chosen meso‐aryl substituents. Its protonation of the inner core reveal an adjustable (trigonal versus tetrahedral) geometry.
Mizellare Katalyse für Ruthenium(II)‐katalysierte C‐H‐Arylierung: Schwache Koordination ermöglicht C‐H‐Aktivierung in H2O
Authors: Yetra Santhivardhana Reddy , Rogge Torben , Warratz Svenja , Struwe Julia , Peng Wentao , Vana Philipp , Ackermann Lutz
Published: March 2019

In mizellarer Katalyse wurden chemoselektive C‐H‐Arylierungen durch einen vielseitigen, wohl definierten Rutheniumkatalysator ermöglicht. Diese Strategie eröffnete einen praktischen Zugang zu C‐H‐arylierten Ferrocenen, toleriert eine Vielzahl an funktionellen Gruppen und ermöglicht eine breite Anwendung durch schwache Koordination. Die Nachhaltigkeit der C‐H‐Arylierung zeigt sich besonders in der herausragenden Atomökonomie und den Recyclingstudien. Detaillierte computerchemische Studien untermauern einen durch Thioketon assistierten leichtgängigen C‐H Aktivierungsschritt.
Shifting Oxygen Charge Towards Octahedral Metal: A Way to Promote Water Oxidation on Cobalt Spinel Oxides
Authors: Sun Shengnan , Sun Yuanmiao , Zhou Ye , Xi Shibo , Ren Xiao , Huang Bicheng , Liao Hanbin , Wang Luyuan Paul , Du Yonghua , Xu Zhichuan J.
Published: March 2019

Cobalt spinel oxides are a class of promising transition metal (TM) oxides for catalyzing oxygen evolution reaction (OER). Their catalytic activity depends on the electronic structure. In a spinel oxide lattice, each oxygen anion is shared amongst its four nearest transition metal cations, of which one is located within the tetrahedral interstices and the remaining three cations are in the octahedral interstices. This work uncovered the influence of oxygen anion charge distribution on the electronic structure of the redox‐active building block Co−O. The charge of oxygen anion tends to shift toward the octahedral‐occupied Co instead of tetrahedral‐occupied Co, which hence produces strong orbital interaction between octahedral Co and O. Thus, the OER activity can be promoted by pushing more Co into the octahedral site or shifting the oxygen charge towards the redox‐active metal center in CoO6 octahedra.
Editorial: Securing Academic Freedom through Networks
Authors: Boele‐Woelki Katharina , Fisher Cathleen , Pape Hans‐Christian , Francisco Joseph S.
Published: March 2019

“Academic freedom does not exist for its own sake. Its foundational purpose is to create an environment of openness to advance inquiry in the interest of seeking truth, to support, facilitate, and enable the best minds of our time, and to train the next generation of young researchers to fulfill their roles in society …” Read more in the Guest Editorial by Joseph S. Francisco et al.
Investigation of epoxy‐based wood adhesives
Authors: Mousavi Seyyed Yahya , Huang Jian , Li Kaichang
Published: March 2019

Cold‐set epoxy‐based wood adhesives were investigated for production of exterior plywood. Effective adhesives were composed of bisphenol A diglycidyl ether (BPADGE), polyamidoamine (PAA), and polyethylenimine (PEI). Three‐ply plywood panels were prepared with BPADGE–PAA–PEI adhesives and evaluated for their strengths and water resistance in accordance with a standard for exterior plywood. The effect of BPADGE/(PAA + PEI) weight ratio, PAA/PEI weight ratio, the mixing time for preparing the adhesive, and the pressing time for making plywood panels on the water resistance and the shear strengths of the plywood panels was investigated. The pot life of the adhesive was also measured. Plywood panels made with the BPADGE–PAA–PEI adhesives met the industrial requirements for exterior applications. Adhesion mechanisms are discussed in detail. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47741.
PhenoForecaster: A software package for the prediction of flowering phenology
Authors: Park Isaac , Jones Alex , Mazer Susan J.
Published: March 2019

Premise of the Study

Predicting the flowering times of angiosperm taxa is a goal of mounting importance in the face of future climate change, with applications not only in plant biology and ecology, but also horticulture, agriculture, and invasive species management. To date, no tool is available to facilitate predictions of flowering phenology using multivariate phenoclimatic models. Such a tool is needed by researchers and other stakeholders who need to predict phenological activity, but are unfamiliar with phenoclimate modeling techniques. PhenoForecaster allows users of any background to conduct species‐specific phenological predictions using an intuitive graphical interface and provides an estimate of each prediction's accuracy.

Methods and Results

Elastic net regression techniques were used to develop species‐specific models capable of predicting the flowering dates of 2320 angiosperm species.

Conclusions

PhenoForecaster is the first stand‐alone package to make phenological modeling directly accessible to users without the need for in‐depth phenological observations.
Historical reasoning in authentic research tasks: Mapping cognitive and document spaces
Authors: Kumpulainen Sanna , Keskustalo Heikki , Zhang Boyang , Stefanidis Kostas
Published: March 2019

To support historians in their work, we need to understand their work‐related needs and propose what is required to support those needs. Although the quantity of digitized historical documents available is increasing, historians' ways of working with the digital documents have not been widely studied, particularly in authentic work settings. To better support the historians' reasoning processes, we investigate history researchers' work tasks as the context of information interaction and examine their cognitive access points into information. The analysis is based on a longitudinal observational research and interviews in a task‐based research setting. Based on these findings in the historians' cognitive space, we build bridges into the document space. By studying the information interactions in real task contexts, we facilitate the provision of task‐specific handles into documents that can be used in designing digital research tools for historians.
The impact of the Wolf reforms on education outcomes for lower‐attaining pupils
Authors: Burgess Simon , Thomson Dave
Published: March 2019

Between 2004 and 2012, there had been a significant rise in so‐called ‘equivalent’ qualifications taken by young people in England in the final years of their compulsory schooling. These were qualifications other than GCSEs that were approved for young people under the age of 16 under Section 96 of the Learning and Skills Act 2000. This rise was checked by the Wolf review of vocational education, which led to wholesale changes in the set of qualifications that schools offered to pupils, and which primarily affected lower‐attaining students. We quantify the impact of this reform on these pupils with respect to the qualifications they entered and what they achieved. We do so by comparison to previous national cohorts of pupils unaffected by the reform, including the estimation of counterfactual outcomes for the group of pupils most likely to be affected. These pupils tended to enter fewer qualifications overall after the reform than their predecessors, but with a higher fraction of GCSEs. Age‐16 attainment fell, with a lower percentage achieving level 2 of the National Qualifications Framework (NQF). This finding is repeated in the post‐16 outcome measures, which were stable throughout this period. There is no evidence from the attainment data that these reforms helped low‐attaining pupils.
Introducing Programming Skills for Life Science Students
Authors: Mariano Diego , Martins Pedro , Helene Santos Lucianna , de Melo‐ Minardi Raquel Cardoso
Published: March 2019

The advent of the high‐throughput next‐generation sequencing produced a large number of biological data. Knowledge discovery from the huge amount of available biological data requires researchers to develop solid skills in biology and computer science. As the majority of the Bioinformatics professionals are either computer science or life sciences graduates, to teach biology skills to computer science students and computational skills to life science students has become usual. In this article, we reported the experience of teaching programming for life science students. Our strategy is composed by explaining basic concepts of algorithms, abstraction of biological problems, and script programming using Python language. Based on the student's answers to an assessment questionnaire, we conclude that the course achieved positive results. They reported an improvement in their skills in programming and bioinformatics. Furthermore, the students approved the didactic adopted in the classes and evaluation methods (programming exercises and final presentation). This article is useful for other professors who want to implement an initial bioinformatics training for undergraduate or graduate students in life sciences. We believe that the strategies here demonstrated could be reproduced, which could help in the formation of a new generation of bioinformaticians with hybrid abilities in computation and biology. © 2019 International Union of Biochemistry and Molecular Biology, 47(3):288–295, 2019.
Catalysis of Thermostable Alcohol Dehydrogenase Improved by Engineering the Microenvironment through Fusion with Supercharged Proteins
Authors: Abdallah Walaa , Chirino Vanessa , Wheeldon Ian , Banta Scott
Published: March 2019

The enzymatic microenvironment can impact biocatalytic activity; however, these effects can be difficult to investigate as mutations and fusions can introduce multiple variables and overlapping effects. The fusion of a supercharged protein is a potentially facile means to alter the enzymatic microenvironment. We have investigated complexes made between a thermostable alcohol dehydrogenase (AdhD) and superfolding green fluorescent protein (sfGFP) mutants with extreme surface charges. Three charged sfGFP variants, −30, 0, and +36 were covalently attached to AdhD through the SpyCatcher/SpyTag system. Specific rates for the NAD+‐dependent oxidation of butane‐2,3‐diol were significantly increased in the −30 sfGFP complex, a mixed effect was seen for the 0 sfGFP complexes, and the rates were unaffected by +36 sfGFP complexation. Reactions performed at various pH values (7.8–9.8) and salt concentrations (7.75–500 mm) showed that there was a complex interplay between these effects that was consistent with fusion proteins affecting the local ionic strength, as opposed to the local pH. Steady‐state kinetic analyses were performed with the −30 and 0 AdhD–sfGFP complexes. The overall catalytic efficiency was dependent on the charge of the fused sfGFP variant; the −30 sfGFP fusions exhibited the largest beneficial effects at pH 8.8. The impact of the fusions on the apparent ionic strength provides further insight into the effects of charged patches observed on metabolon‐forming enzyme complexes.
Closing the gender gap (but not the generation gap) in acute coronary syndromes
Authors: Parikh Puja B. , Reilly John P.
Published: March 2019

Key Points

In patients with acute coronary syndromes (ACS) undergoing coronary angiography, elderly women have nearly 50% lower rates of adverse events compared to elderly men, primarily driven by lower cardiovascular mortality.

Nonelderly men and women patients with ACS have similar risk‐adjusted rates of adverse events.

Elderly ACS patients have lower rates of and delays in coronary revascularization than younger patients.
TAVI: How to best predict postprocedural outcomes?
Authors: Shatila Wassim , Krajcer Zvonimir
Published: March 2019

Key Points

Baseline risk scores for TAVI patients, including STS and EuroSCORE, might not predict long‐term outcomes.

Including postprocedural data might improve risk stratification.

The ACEF‐7 risk score includes the lowest creatinine clearance in the first 7 postprocedural days and appears to be a good predictor of worse long‐term outcomes.
Transcatheter aortic valve replacement hemodynamic durability: Still in question?
Authors: Belardi Jorge A. , Lamelas Pablo M.
Published: March 2019

Key Points

This study shows excellent transcatheter aortic valve replacement hemodynamic mid‐term durability, aligned with prior research up to 5‐years.

Long‐term (10+ years) data are needed before treating young low‐risk people with aortic stenosis.

Data so far are excellent, indicating a prosperous future for this procedure in young patients.
Pembrolizumab‐induced sarcoid granulomatous panniculitis and bullous pemphigoid in a single patient
Authors: Honigman Anthony D. , Lai Francis , Elakis Joshua , Prall Owen , Goh Michelle , McCormack Christopher
Published: March 2019

Key Clinical Message

Pembrolizumab is an immune checkpoint inhibitor with antitumor activity in other organ malignancies. We present this case —demonstrating multiple inflammatory adverse events associated with Pembrolizumab (in a single patient), in order to increase awareness and facilitate earlier identification of the wide‐ranging cutaneous side effects associated with immunotherapy.
Nickel‐Catalyzed Dehydrogenative Couplings
Authors: Arun V. , Mahanty Kingshuk , De Sarkar Suman
Published: March 2019

In last decade, nickel‐catalyzed organic reactions made tremendous progress due to their distinctive redox character. It has unfolded many contemporary synthetic transformations namely cross‐coupling, carbon‐carbon bond cleavage and directed C−H functionalization to achieve the targeted medicinal organic molecules in a straightforward manner. Beyond these well documented approaches, dehydrogenative coupling a challenging bond forming strategy by expelling hydrogen from unfunctionalized coupling partners is less explored. In accord with this, nickel‐catalyst has been studied to perform different class of dehydrogenative coupling between easily accessible substrates. Nickel catalyzed processes for the construction of carbon‐carbon, carbon‐heteroatom and heteroatom‐heteroatom bonds by dehydrogenation are discussed herein in a sustainable manner.
Electrolytes for Dual‐Carbon Batteries
Authors: Jiang Xiaoyu , Luo Laibing , Zhong Faping , Feng Xiangming , Chen Weihua , Ai Xinping , Yang Hanxi , Cao Yuliang
Published: March 2019

Dual‐carbon batteries (DCBs) are a promising candidate for smart grid applications, owing to their low cost, high power capability, and environmentally friendly benefits. As an essential component of DCBs, electrolytes not only act as a medium for ion migration during the running of the battery, but also provide active ions to be intercalated into carbon electrodes, exerting significant impacts on the electrochemical performance and safety of the DCB. In this Review, we discuss recent progress in electrolyte research for DCBs, including conventional liquid electrolytes, highly concentrated electrolytes, and gel polymer electrolytes, with a focus on their stability and compatibility with carbon electrodes. Finally, we present perspectives on the current limitations and future research directions of electrolytes for DCBs. Some recommendations for battery evaluation are also offered.
Electrocatalytic Oxidation of Glycerol on Platinum Single Crystals in Alkaline Media
Authors: Sandrini Regiani M. L. M. , Sempionatto Juliane R. , Tremiliosi‐Filho Germano , Herrero Enrique , Feliu Juan M. , Souza‐Garcia Janaina , Angelucci Camilo A.
Published: March 2019

Glycerol adsorption and oxidation reactivity at platinum single crystal electrodes in alkaline media using electrochemical and Fourier transform infrared (FTIR) techniques are reported. The behavior of Pt(100) and Pt(110) for the glycerol electrooxidation reaction (GEOR) were compared and analyzed altogether with those previously reported for Pt(111) ( R. M. L. M. Sandrini, J. R. Sempionatto, E. Herrero, J. M. Feliu, J. Souza‐Garcia, C. A. Angelucci, Electrochem. commun. 2018, 86, 149–152). The voltammetric profiles confirm the structure sensitivity of GEOR as well as the role of the surface atoms orientation on the electrocatalytic activity. The Pt(100) surface has shown to be less prone to poisoning during multiple potential cycles in contrast to Pt(110), which suffers an accentuate deactivation at the first positive‐going scan. Spectroscopic results show that the GEOR on all three surfaces is characterized by the presence of two broad bands, centered at circa 1400 cm−1 and 1600 cm−1. This provides evidence that the GEOR mechanism undergoes glycerol dehydrogenation to alkoxydes followed by the formation of aldehyde intermediates adsorbed as η1(O)‐aldehyde and η1(C)‐acyl geometry, respectively. The surface atomic arrangement induces different selectivity in the oxidation process.
How Outer Coordination Sphere Modifications Can Impact Metal Structures in Proteins: A Crystallographic Evaluation
Authors: Ruckthong Leela , Stuckey Jeanne A. , Pecoraro Vincent L.
Published: March 2019

A challenging objective of de novo metalloprotein design is to control of the outer coordination spheres of an active site to fine tune metal properties. The well‐defined three stranded coiled coils, TRI and CoilSer peptides, are used to address this question. Substitution of Cys for Leu yields a thiophilic site within the core. Metals such as HgII, PbII, and AsIII result in trigonal planar or trigonal pyramidal geometries; however, spectroscopic studies have shown that CdII forms three‐, four‐ or five‐coordinate CdIIS3(OH2)x (in which x=0–2) when the outer coordination spheres are perturbed. Unfortunately, there has been little crystallographic examination of these proteins to explain the observations. Here, the high‐resolution X‐ray structures of apo‐ and mercurated proteins are compared to explain the modifications that lead to metal coordination number and geometry variation. It reveals that Ala substitution for Leu opens a cavity above the Cys site allowing for water excess, facilitating CdIIS3(OH2). Replacement of Cys by Pen restricts thiol rotation, causing a shift in the metal‐binding plane, which displaces water, forming CdIIS3. Residue d‐Leu, above the Cys site, reorients the side chain towards the Cys layer, diminishing the space for water accommodation yielding CdIIS3, whereas d‐Leu below opens more space, allowing for equal CdIIS3(OH2) and CdIIS3(OH2)2. These studies provide insights into how to control desired metal geometries in metalloproteins by using coded and non‐coded amino acids.
Late‐Stage Direct o‐Alkenylation of Phenols by PdII‐Catalyzed C−H Functionalization
Authors: Dou Yandong , Kenry  , Liu Jiang , Jiang Jianze , Zhu Qing
Published: March 2019

o‐Alkenylation of unprotected phenols has been developed by direct C−H functionalization catalyzed by PdII. This work features phenol group as a directing group and realizes highly site‐selective C−H bond functionalization of phenols to achieve the corresponding products in moderate to excellent yields at 60 °C. The advantages of this reaction include unprecedented C−H functionalization using phenol as a directing group, high regioselectivity, good substrate scope, mild reaction conditions, and high efficiency. To the best of our knowledge, this is the first example of a regioselective C−H alkenylation of unprotected phenols utilizing phenolic hydroxyl group as a directing group. The alkenylation of unprotected tyrosine and intramolecular cyclization are also successfully carried out under this catalytic system in good yields. Furthermore, this novel method enables a late‐stage modification of complex phenol‐containing bioactive molecules toward a diversity‐oriented drug discovery.
Sulfide Analogues of Flupirtine and Retigabine with Nanomolar KV7.2/KV7.3 Channel Opening Activity
Authors: Bock Christian , Surur Abdrrahman S. , Beirow Kristin , Kindermann Markus K. , Schulig Lukas , Bodtke Anja , Bednarski Patrick J. , Link Andreas
Published: March 2019

The potassium channel openers flupirtine and retigabine have proven to be valuable analgesics or antiepileptics. Their recent withdrawal due to occasional hepatotoxicity and tissue discoloration, respectively, leaves a therapeutic niche unfilled. Metabolic oxidation of both drugs gives rise to the formation of electrophilic quinones. These elusive, highly reactive metabolites may induce liver injury in the case of flupirtine and blue tissue discoloration after prolonged intake of retigabine. We examined which structural features can be altered to avoid the detrimental oxidation of the aromatic ring and shift oxidation toward the formation of more benign metabolites. Structure–activity relationship studies were performed to evaluate the KV7.2/3 channel opening activity of 45 derivatives. Sulfide analogues were identified that are devoid of the risk of quinone formation, but possess potent KV7.2/3 opening activity. For example, flupirtine analogue 3‐(3,5‐difluorophenyl)‐N‐(6‐(isobutylthio)‐2‐(pyrrolidin‐1‐yl)pyridin‐3‐yl)propanamide (48) has 100‐fold enhanced activity (EC50=1.4 nm), a vastly improved toxicity/activity ratio, and the same efficacy as retigabine in vitro.
Zn−Co−S Colloidal Nanocrystal Clusters as Efficient and Durable Bifunctional Electrocatalysts For Full Water Splitting
Authors: Li Shengnan , Zhao Shuang , Xing Ruimin , Kumbhar V. S. , Lee Kiyoung , Zhou Yanmei , Kazuya Nakata , Fujishima Akira , Liu Shanhu
Published: March 2019

The synthesis of efficient, cost‐effective, and non‐toxic bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly needed for renewable energy related processes (conversion and storage). In the present work, we report a simple and straightforward one‐step hydrothermal strategy to prepare Zn−Co−S colloidal nanocrystal clusters (CNCs) for total water splitting (OER and HER activity) for the first time. The Zn−Co−S CNCs consist of a large number of interconnected nanoparticles forming spherical structures, which is very helpful for the electrochemical activity. Under alkaline conditions, the Zn−Co−S electrocatalyst demonstrates an excellent electrocatalytic activity by driving 10 mA cm−2 at 157 mV HER and 320 mV OER overpotentials, respectively. The Zn−Co−S catalyst electrode maintained the catalytic activity for 12 h exhibiting a good electrochemical stability. Furthermore, as fabricated two‐electrode alkaline water‐splitting system of Zn−Co−S//Zn−Co−S affords 10 mA cm−2 at a voltage of 1.64 V.
Recent Advancements Towards Closing the Gap between Electrocatalysis and Battery Science Communities: The Computational Lithium Electrode and Activity–Stability Volcano Plots
Authors: Exner Kai S.
Published: March 2019

Despite of the fact that the underlying processes are of electrochemical nature, electrocatalysis and battery research are commonly perceived as two disjointed research fields. Herein, recent advancements towards closing this apparent community gap by discussing the concepts of the constrained ab initio thermodynamics approach and the volcano relationship, which were originally introduced for studying heterogeneously catalyzed reactions by first‐principles methods at the beginning of the 21st century, are summarized. The translation of the computational hydrogen electrode (CHE) approach or activity‐based volcano plots to a computational lithium electrode (CLiE) or activity–stability volcano plots, respectively, for the investigation of electrode surfaces in batteries may refine theoretical modeling with the aim that enhancements of the underlying concepts are transferred between the research communities. The presented strategy of developing novel approaches by interdisciplinary research activities may trigger further progress of improved theoretical concepts in the near future.
Combined CO2 Capture and Hydrogenation to Methanol: Amine Immobilization Enables Easy Recycling of Active Elements
Authors: Kar Sayan , Goeppert Alain , Prakash G. K. Surya
Published: March 2019

Amines were immobilized onto solid supports and employed for tandem CO2 capture and conversion to CH3OH using homogeneous hydrogenation catalysts. The hydrogenation proceeded through the formation of formamide intermediates. After hydrogenation, the immobilized amines were easily filtered and collected to be reused. The catalyst and methanol were recovered from the filtrate. Covalently‐attached (to polymer support or silica) amine functionalities displayed the highest recycling potential with almost no leaching under the hydrogenation reaction conditions. Using polyethylenimine grafted onto a solid‐silica support, the catalyst and amine were successfully recycled, and CO2 (either pure or from the air) was efficiently captured and converted to CH3OH over multiple cycles.
FoxN3 is necessary for the development of the interatrial septum, the ventricular trabeculae and the muscles at the head/trunk interface in the African clawed frog, Xenopus laevis (Lissamphibia: Anura: Pipidae)
Authors: Naumann Benjamin , Schmidt Jennifer , Olsson Lennart
Published: March 2019

Background

Fox genes are a large family of transcription factors that play diverse roles in the immune system, metabolism, cancer, cell cycle, and animal development. It has been shown that FoxN3 is indispensable for normal craniofacial development in the mouse and the African clawed frog, Xenopus laevis. Morpholino‐mediated knockdown of FoxN3 in X. laevis delays overall development of early tadpole stages and causes eye defects, the absence of some cranial nerve branches, and malformations of the cranial skeleton and some cranial muscles, while the skeleton, nerves and muscles of the trunk are unaffected.

Results

We report a delay in heart morphogenesis, the absence of the interatrial septum, and a reduction and compaction of the ventricular trabeculation after knockdown of FoxN3 in X. laevis. Furthermore, we found malformations of the cucullaris and diaphragmatico‐branchialis muscles, two head muscles that develop in the head/trunk interface of X. laevis.

Conclusions

FoxN3 is necessary for the development of the interatrial septum and trabeculae in the frog heart, as well as the cranial muscles developing in the head/trunk interface. This gives the first evidence for a dependence on the head myogenic program of the cucullaris muscle in an anuran species.
Estimating the impact of divergent mating phenology between residents and migrants on the potential for gene flow
Authors: Bonner Colin , Sokolov Nina A. , Westover Sally Erin , Ho Michelle , Weis Arthur E.
Published: March 2019

Gene flow between populations can allow the spread of beneficial alleles and genetic diversity between populations, with importance to conservation, invasion biology, and agriculture. Levels of gene flow between populations vary not only with distance, but also with divergence in reproductive phenology. Since phenology is often locally adapted, arriving migrants may be reproductively out of synch with residents, which can depress realized gene flow. In flowering plants, the potential impact of phenological divergence on hybridization between populations can be predicted from overlap in flowering schedules—the daily count of flowers capable of pollen exchange—between a resident and migrant population. The accuracy of this prospective hybridization estimate, based on parental phenotypes, rests upon the assumptions of unbiased pollen transfer between resident and migrant active flowers. We tested the impact of phenological divergence on resident–migrant mating frequencies in experiments that mimicked a single large gene flow event. We first prospectively estimated mating frequencies two lines of Brassica rapaselected or early and late flowering. We then estimated realized mating frequencies retrospectively through progeny testing. The two estimates strongly agreed in a greenhouse experiment, where procedures ensured saturating, unbiased pollination. Under natural pollination in the field, the rate of resident–migrant mating, was lower than estimated by phenological divergence alone, although prospective and retrospective estimates were correlated. In both experiments, differences between residents and migrants in flowering schedule shape led to asymmetric hybridization. Results suggest that a prospective estimate of hybridization based on mating schedules can be a useful, although imperfect, tool for evaluating potential gene flow. They also illustrate the impact of mating phenology on the magnitude and symmetry of reproductive isolation.
Upward elevation and northwest range shifts for alpine Meconopsis species in the Himalaya–Hengduan Mountains region
Authors: He Xie , Burgess Kevin S. , Yang Xue‐Fei , Ahrends Antje , Gao Lian‐Ming , Li De‐Zhu
Published: March 2019

Climate change may impact the distribution of species by shifting their ranges to higher elevations or higher latitudes. The impacts on alpine plant species may be particularly profound due to a potential lack of availability of future suitable habitat. To identify how alpine species have responded to climate change during the past century as well as to predict how they may react to possible global climate change scenarios in the future, we investigate the climatic responses of seven species of Meconopsis, a representative genus endemic in the alpine meadow and subnival region of the Himalaya–Hengduan Mountains. We analyzed past elevational shifts, as well as projected shifts in longitude, latitude, elevation, and range size using historical specimen records and species distribution modeling under optimistic (RCP 4.5) and pessimistic (RCP 8.5) scenarios across three general circulation models for 2070. Our results indicate that across all seven species, there has been an upward shift in mean elevation of 302.3 m between the pre‐1970s (1922–1969) and the post‐1970s (1970–2016). The model predictions suggest that the future suitable climate space will continue to shift upwards in elevation (as well as northwards and westwards) by 2070. While for most of the analyzed species, the area of suitable climate space is predicted to expand under the optimistic emission scenario, the area contracts, or, at best, shows little change under the pessimistic scenario. Species such as M. punicea, which already occupy high latitudes, are consistently predicted to experience a contraction of suitable climate space across all the models by 2070 and may consequently deserve particular attention by conservation strategies. Collectively, our results suggest that the alpine high‐latitude species analyzed here have already been significantly impacted by climate change and that these trends may continue over the coming decades.
Overall grazing tolerance index (overall GTI) is not an ideal predictor for describing a single‐species tolerance to grazing
Authors: Zhang Lulu , Zhu Zhihong , Li Yingnian , Qian Zengqiang , Liu Gang , Wang Xiaoan
Published: March 2019

Plants' pattern of compensatory growth is often used to intuitively estimate their grazing tolerance. However, this tolerance is sometimes measured by the overall grazing tolerance index (overall GTI), which assumes that tolerance is a multivariate linear function of various underlying mechanisms. Because the interaction among mechanisms is not independent, the grazing tolerance expression based on overall GTI may be inconsistent with that based on compensatory growth. Through a manipulative field experiment from 2007 to 2012, we measured the responses of 12 traits of Elymus nutans to clipping under different resource availabilities in an alpine meadow and explored the compensatory aboveground biomass and the overall GTI to assess the possible differences between the two expressions of tolerance. Our results showed that these two expressions of tolerance were completely opposite. The expression based on overall GTI was over‐compensatory and did not vary with clipping and resource availability, while the expression based on compensatory aboveground biomass was under‐compensatory and altered to over‐compensation after fertilization. The over‐expression of highly variable traits with extremely high negative mean GTI to defoliation damage, the influence of random errors contained in traits considered, and the doubling weight of functional redundant traits greatly inflated the overall GTI, which leads to the inconsistency of the two tolerance expressions. This inconsistency is also associated with the different determining mechanisms of the two tolerance expressions. Our data suggest that plants' grazing tolerance is not a multivariate linear function of traits or mechanisms that determine grazing tolerance; the overall GTI is only a measure of traits' variability to defoliation damage. Our findings highlight that the tolerance of E. nutans mainly depends on the response of traits with lower variability to defoliation, and the overall GTI is not an ideal predictor for describing a single‐species tolerance to grazing.
Response of wild bee diversity, abundance, and functional traits to vineyard inter‐row management intensity and landscape diversity across Europe
Authors: Kratschmer Sophie , Pachinger Bärbel , Schwantzer Martina , Paredes Daniel , Guzmán Gema , Goméz José A. , Entrenas José A. , Guernion Muriel , Burel Françoise , Nicolai Annegret , Fertil Albin , Popescu Daniela , Macavei Laura , Hoble Adela , Bunea Claudiu , Kriechbaum Monika , Zaller Johann G. , Winter Silvia
Published: March 2019

Agricultural intensification is a major driver of wild bee decline. Vineyards may be inhabited by plant and animal species, especially when the inter‐row space is vegetated with spontaneous vegetation or cover crops. Wild bees depend on floral resources and suitable nesting sites which may be found in vineyard inter‐rows or in viticultural landscapes. Inter‐row vegetation is managed by mulching, tillage, and/or herbicide application and results in habitat degradation when applied intensively. Here, we hypothesize that lower vegetation management intensities, higher floral resources, and landscape diversity affect wild bee diversity and abundance dependent on their functional traits. We sampled wild bees semi‐quantitatively in 63 vineyards representing different vegetation management intensities across Europe in 2016. A proxy for floral resource availability was based on visual flower cover estimations. Management intensity was assessed by vegetation cover (%) twice a year per vineyard. The Shannon Landscape Diversity Index was used as a proxy for landscape diversity within a 750 m radius around each vineyard center point. Wild bee communities were clustered by country. At the country level, between 20 and 64 wild bee species were identified. Increased floral resource availability and extensive vegetation management both affected wild bee diversity and abundance in vineyards strongly positively. Increased landscape diversity had a small positive effect on wild bee diversity but compensated for the negative effect of low floral resource availability by increasing eusocial bee abundance. We conclude that wild bee diversity and abundance in vineyards is efficiently promoted by increasing floral resources and reducing vegetation management frequency. High landscape diversity further compensates for low floral resources in vineyards and increases pollinating insect abundance in viticulture landscapes.
Can retention harvests help conserve wildlife? Evidence for vertebrates in the boreal forest
Authors: Franklin Caroline M. A. , Macdonald S. Ellen , Nielsen Scott E.
Published: March 2019

Retention harvesting, or the approach of leaving live mature trees behind during forest harvest, is used in natural disturbance‐based management to mitigate the effects of logging on biodiversity. However, responses of many boreal vertebrates to variable retention harvesting are unknown. We investigated the influence of different retention levels in forest harvests on stand use by wildlife 15–18 yr post‐harvest using a combination of surveys of wildlife signs (scats, middens) and camera trapping. Site‐level measures of forest structure, including canopy cover, horizontal cover, tree height, tree diameter, basal area, cover of downed coarse woody material, and understory plant cover, were used to describe post‐harvest differences in habitats used by common wildlife species in northwest Alberta's boreal forest. Stand use of six species (black bear, coyote, fisher, red squirrel, wolverine, woodland caribou) increased with level of retention, while stand use of two species (grouse, snowshoe hare) declined with retention level. Retention level did not significantly affect stand use of five species (American marten, Canada lynx, deer, gray wolf, moose). Higher levels of retention characterized by greater canopy cover, basal area, and abundance of deadwood were associated with use of forest habitats by late‐seral species. Woodland caribou, a species of conservation concern, was detected only in harvested stands with at least 20% retention. Greater understory and horizontal cover characterized lower levels of retention being attractive for early‐seral species. These findings demonstrate the value of retention harvesting for conservation of wildlife species in boreal forest, while highlighting the challenge of managing forests for multiple species with different habitat preferences.
Imidazolium Cyclopentadienide Salts and their Use as Cp‐Transfer Reagents
Authors: Bischoff Inga‐Alexandra , Müller Carsten , Huch Volker , Zimmer Michael , Schäfer André
Published: March 2019

The reaction of N‐heterocyclic carbenes,1a–c, towards cyclopentadienes,2a–c, was studied.N,N′‐diisopropyl‐substituted carbene1aacts as a Brønsted base and deprotonates cyclopentadiene,2a, and isopropylcyclopentadiene,2b, to yield the corresponding imidazolium cyclopentadienide salts,3a,b, whereas there is no reaction towards 1,2,3,4,5‐pentamethylcyclopentadiene. Imidazolium cyclopentadienide salts,3a,b, were characterized in solution by1H and13C NMR spectroscopy, as well as in the solid state by single‐crystal X‐ray diffraction. In addition, it was demonstrated that imidazolium cyclopentadienide salt3acan be used as a Cp‐transfer reagent in the synthesis of different cyclopentadienyl transition metal complexes.
Chemodiscrimination of Olefin Bonds Through Cross‐Metathesis Reactions – Synthesis of Functionalized β‐Lactam and β‐Amino Acid Derivatives
Authors: Nonn Melinda , Benke Zsanett , Fustero Santos , Fülöp Ferenc , Kiss Loránd
Published: March 2019

Chemodifferentiation of C=C bonds of various diolefinated β‐lactams or β‐amino esters has been investigated through cross‐metathesis reactions. The transformations involved substrate‐dependent cross‐metathesis of dialkenylated azetidinones, derived from the ring opening of constrained unsaturated bicyclic β‐lactam isomers. Cross‐metathesis reactions have been carried out under various conditions and catalysts in view of chemodiscrimination affording functionalized β‐lactams or β‐amino acid derivatives.
Structure‐soil‐structure interaction of adjacent buildings subjected to seismic loading
Authors: Bybordiani Milad , Arici Yalin
Published: March 2019

The problem of the through‐soil coupling of structures has puzzled the researchers in the field for a long while, especially regarding the varied performance of identical, adjacent buildings in earthquakes. The phenomenon of structure‐soil‐structure interaction (SSSI) that has often been overlooked is recently being recognized: The possible effects in urban regions are yet to be thoroughly quantified. In this respect, the goal of this work was to rigorously investigate the interacting effects of adjacent buildings in a two‐dimensional setting. Detailed finite element models of 5‐, 15‐, and 30‐story structures, realistically designed, were used in forming building clusters on the viscoelastic half‐space. Perfectly matched layers were used to properly define the half‐space boundaries. The interaction of the structure and the soil medium because of the presence of spatially varying ground motion on the boundary of excavated region was considered. The effects of the foundation material and the distance between adjacent buildings on the structural behavior of the neighboring buildings were investigated using drift ratios and base shear quantities as the engineering demand parameters of interest. The effects of SSSI, first investigated in the frequency domain, was then quantified in the time domain using suites of appropriate ground motions in accordance with the soil conditions, and the results were compared with the counterpart SSI solution of a single building. The results showed that, for identical low‐rise structures, the effects of SSSI were negligible. Yet, neglecting SSSI for neighboring closely spaced high‐rise structures or building clusters with a large stiffness contrast was shown to lead to a considerable underestimation of the true seismic demands even compared with solutions obtained using the rigid base assumption.
Mathematical modeling and numerical simulation of a new thermal energy storage system using thermo‐sensitive magnetic fluid in porous medium
Authors: Jin Licong , Li Decai , Zhang Xinrong
Published: March 2019

Thermal energy storage (TES) system is a preferred thermal management technology used to address a temporal mismatch of thermal energy between supply and demand. In this study, a novel sensible TES system, where magnetic fluid is used as heat transfer fluid and porous medium is used as solid storage material, is proposed to store thermal energy from solar, waste heat and so on. A technical and practical discussion of the novel TES system is carried out then. For a fundamental investigation, a numerical simulation using Lattice Boltzmann method is present by the assumption of the TES physical model. Furthermore, the characteristics of the TES system involve in the temperature, Nusselt number, and thermal storage capacity are analyzed depending on magnetic Rayleigh number, heating temperature, and porosity of the porous material.
Prospects for investigating brain oxygenation in acute stroke: Experience with a non‐contrast quantitative BOLD based approach
Authors: Stone Alan J. , Harston George W. J. , Carone Davide , Okell Thomas W. , Kennedy James , Blockley Nicholas P.
Published: March 2019

Metabolic markers of baseline brain oxygenation and tissue perfusion have an important role to play in the early identification of ischaemic tissue in acute stroke. Although well established MRI techniques exist for mapping brain perfusion, quantitative imaging of brain oxygenation is poorly served. Streamlined‐qBOLD (sqBOLD) is a recently developed technique for mapping oxygenation that is well suited to the challenge of investigating acute stroke. In this study a noninvasive serial imaging protocol was implemented, incorporating sqBOLD and arterial spin labelling to map blood oxygenation and perfusion, respectively. The utility of these parameters was investigated using imaging based definitions of tissue outcome (ischaemic core, infarct growth and contralateral tissue). Voxel wise analysis revealed significant differences between all tissue outcomes using pairwise comparisons for the transverse reversible relaxation rate (R
2′), deoxygenated blood volume (DBV) and deoxyghaemoglobin concentration ([dHb]; p < 0.01 in all cases). At the patient level (n = 9), a significant difference was observed for [dHb] between ischaemic core and contralateral tissue. Furthermore, serial analysis at the patient level (n = 6) revealed significant changes in R
2′ between the presentation and 1 week scans for both ischaemic core (p < 0.01) and infarct growth (p < 0.05). In conclusion, this study presents evidence supporting the potential of sqBOLD for imaging oxygenation in stroke.