bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaktivität von Goldkomplexen in metallorganischen Elementarreaktionen
Authors: Joost Maximilian , Amgoune Abderrahmane , Bourissou Didier 
Published: November 2015

AbstractSeit langem war die Reaktivität von Goldkomplexen überwiegend durch ihre Eigenschaft als Lewis‐Säure bestimmt. Im Unterschied zu anderen Übergangsmetallen wurden metallorganische Elementarschritte – wie oxidative Addition, reduktive Eliminierung, Transmetallierung oder migratorische Insertion – für Gold kaum untersucht, oder sie waren bis kürzlich gar unbekannt. Doch in den letzten Jahren konnten solche Grundreaktionen für Goldkomplexe eindeutig belegt werden, und es wurde gezeigt, dass ihre Reaktionsfähigkeit weit über die π‐Aktivierung hinausgeht. Hier werden die größten Erfolge auf diesem Gebiet im jeweiligen entwicklungszeitlichen Rahmen betrachtet. Ein besonderer Schwerpunkt liegt auf mechanistischen Studien und der Strukturbestimmung entscheidender Zwischenverbindungen. Die elektronischen und strukturellen Parameter werden im Zusammenhang mit der Reaktivität der Goldkomplexe diskutiert, und zukünftige Herausforderungen werden aufgezeigt.
Rational Improvement of Molar Absorptivity Guided by Oscillator Strength: A Case Study with Furoindolizine‐Based Core Skeleton
Authors: Lee Youngjun , Jo Ala , Park Seung Bum 
Published: November 2015

AbstractThe rational improvement of photophysical properties can be highly valuable for the discovery of novel organic fluorophores. Using our new design strategy guided by the oscillator strength, we developed a series of full‐color‐tunable furoindolizine analogs with improved molar absorptivity through the fusion of a furan ring into the indolizine‐based Seoul fluorophore. The excellent correlation between the computable values (oscillator strength and theoretical S0–S1 energy gap) and photophysical properties (molar absorptivity and emission wavelength) confirmed the effectualness of our design strategy.
Development of Genetic Dereplication Strains in Aspergillus nidulans Results in the Discovery of Aspercryptin
Authors: Chiang Yi‐Ming , Ahuja Manmeet , Oakley C. Elizabeth , Entwistle Ruth , Asokan Anabanadam , Zutz Christoph , Wang Clay C. C. , Oakley Berl R. 
Published: November 2015

AbstractTo reduce the secondary metabolite background in Aspergillus nidulans and minimize the rediscovery of compounds and pathway intermediates, we created a “genetic dereplication” strain in which we deleted eight of the most highly expressed secondary metabolite gene clusters (more than 244,000 base pairs deleted in total). This strain allowed us to discover a novel compound that we designate aspercryptin and to propose a biosynthetic pathway for the compound. Interestingly, aspercryptin is formed from compounds produced by two separate gene clusters, one of which makes the well‐known product cichorine. This raises the exciting possibility that fungi use differential regulation of expression of secondary metabolite gene clusters to increase the diversity of metabolites they produce.
Diastereoselektive Synthese von Methylencyclobutanen durch Vereinigung von Bor‐Homologisierungs‐ und ‐Allylierungsstrategie
Authors: Eisold Michael , Didier Dorian 
Published: November 2015

AbstractEs wird eine hoch diastereoselektive Synthese von Methylencyclobutanen mit quartärem Stereozentrum beschrieben. Auf eine Bor‐Homologisierung der leicht zugänglichen Cyclobutenylmetallspezies folgt dabei eine Allylierungsreaktion. Ferner führte eine Kombination der drei Schritte in einer Eintopfreaktion zur Optimierung der Methode, um die erwarteten Produkten ausgehend von kommerziellem 4‐Brombutin in exzellenten Ausbeuten und Stereoselektivitäten zu erhalten.
Structures of Iridoid Synthase from Cantharanthus roseus with Bound NAD+, NADPH, or NAD+/10‐Oxogeranial: Reaction Mechanisms
Authors: Hu Yumei , Liu Weidong , Malwal Satish R. , Zheng Yingying , Feng Xinxin , Ko Tzu‐Ping , Chen Chun‐Chi , Xu Zhongxia , Liu Meixia , Han Xu , Gao Jian , Oldfield Eric , Guo Rey‐Ting 
Published: November 2015

AbstractStructures of the iridoid synthase nepetalactol synthase in the presence of NAD+, NADPH or NAD+/10‐oxogeranial were solved. The 10‐oxogeranial substrate binds in a transoid‐O1‐C3 conformation and can be reduced by hydride addition to form the byproduct S‐10‐oxo‐citronellal. Tyr178 Oζ is positioned 2.5 Å from the substrate O1 and provides the second proton required for reaction. Nepetalactol product formation requires rotation about C1–C2 to form the cisoid isomer, leading to formation of the cis‐enolate, together with rotation about C4–C5, which enables cyclization and lactol production. The structure is similar to that of progesterone‐5β‐reductase, with almost identical positioning of NADP, Lys146(147), Tyr178(179), and F342(343), but only Tyr178 and Phe342 appear to be essential for activity. The transoid 10‐oxogeranial structure also serves as a model for β‐face hydride attack in progesterone 5β‐reductases and is of general interest in the context of asymmetric synthesis.
Ein unkonventionelles Katalysatorsystem auf der Basis von ZrO2 für die Propandehydrierung: Konzept, Synthese und aktive Zentren
Authors: Otroshchenko Tatyana , Sokolov Sergey , Stoyanova Mariana , Kondratenko Vita A. , Rodemerck Uwe , Linke David , Kondratenko Evgenii V. 
Published: November 2015

AbstractDie nichtoxidative Dehydrierung von Propan zu Propen ist ein etablierter großtechnischer Prozess. Allerdings gibt es Verbesserungsbedarf, vor allem bei den verwendeten Katalysatoren: So sind Chromverbindungen toxisch, Pt ist teuer, und die Katalysatorstabilität könnte verbessert werden. In dieser Arbeit beschreiben wir einen wissensbasierten Ansatz für die Entwicklung von unkonventionellen Katalysatoren, die auf Metalloxiden mit einer spezifischen Defektstruktur basieren; ein Beispiel dafür ist mit anderen Metalloxiden dotiertes ZrO2. Unsere Hypothese, dass koordinativ ungesättigte Zr‐Kationen als aktive Zentren für die Propandehydrierung wirken, wurde durch umfassende Charakterisierung gestützt. Ihre Konzentration kann durch die Art des Promotors und/oder durch Aufbringen winziger Mengen an hydrieraktiven Metallen eingestellt werden. Ein nach dieser Herangehensweise entwickelter Cu(0.05 Gew.‐%)/ZrO2‐La2O3‐Katalysator zeigte in einem 240 Stunden dauernden Langzeitexperiment mit 60 Dehydrier‐Regenerier‐Zyklen im Temperaturbereich von 550 bis 625 °C eine mit Industriekatalysatoren vergleichbare Aktivität und Stabilität.
Zinc‐Catalyzed Dehydrogenative Cross‐Coupling of Terminal Alkynes with Aldehydes: Access to Ynones
Authors: Tang Shan , Zeng Li , Liu Yichang , Lei Aiwen 
Published: November 2015

AbstractBecause of the lack of redox ability, zinc has seldom been used as a catalyst in dehydrogenative cross‐coupling reactions. Herein, a novel zinc‐catalyzed dehydrogenative C(sp2)H/C(sp)H cross‐coupling of terminal alkynes with aldehydes was developed, and provides a simple way to access ynones from readily available materials under mild reaction conditions. Good reaction selectivity can be achieved with a 1:1 ratio of terminal alkyne and aldehyde. Various terminal alkynes and aldehydes are suitable in this transformation.
Morphological Analysis for Neuron‐Like Cells in the Vomeronasal Organ of Human Fetuses at the Middle of Gestation
Authors: Takami Shigeru , Yukimatsu Maiko , Matsumura George , Horie Sawa , Nishiyama Fumiaki 
Published: November 2015

ABSTRACTThe vomeronasal organ (VNO) of 5‐month‐old fetuses was examined immunohistochemically by the use of an antiserum to protein gene product 9.5 (PGP). The purpose was to identify if the human fetal VNO is lined by neuroepithelium. The PGP antiserum labeled abundant cells within the vomeronasal epithelium (VE), nerve fiber bundles in its lamina propria, and cells associated with these bundles. PGP‐immunoreactive (ir) vomeronasal epithelial cells were classified into three subtypes. Type I cells, about 44% of the total cells observed, did not have any processes and tended to be located in the basal layer of the VE. Type II cells, about 37% had a single apical process that projected toward the lumen, ending at the epithelial surface. Type III cells sent a prominent process mainly toward the basement membrane, and occupied about 19% of the total cells observed. In the lamina propria, a considerable number of PGP‐ir cells was observed. Some of them were present in nerve fiber bundles and contained processes parallel to the bundles. In addition, PGP‐ir nerve fiber bundles and cells associated with them were even present in the portion of the nasal septal mucosa that was very close to the brain. The present results strongly suggested that the VE in human fetuses at mid‐gestation is a neuroepithelium and that the VE may produce migrating cells toward the brain. Anat Rec, 299:88–97, 2016. © 2015 Wiley Periodicals, Inc.
Obtaining General Relativity's N‐body non‐linear Lagrangian from iterative, linear algebraic scaling equations
Authors: Nordvedt K. 
Published: November 2015

AbstractA local system of bodies in General Relativity whose exterior metric field asymptotically approaches the Minkowski metric effaces any effects of the matter distribution exterior to its Minkowski boundary condition. To enforce to all orders this property of gravity which appears to hold in nature, a method using linear algebraic scaling equations is developed which generates by an iterative process an N‐body Lagrangian expansion for gravity's motion‐independent potentials which fulfills exterior effacement along with needed metric potential expansions. Then additional properties of gravity – interior effacement and Lorentz time dilation and spatial contraction – produce additional iterative, linear algebraic equations for obtaining the full non‐linear and motion‐dependent N‐body gravity Lagrangian potentials as well. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reviewing recent results from the Pierre Auger Observatory
Authors: Dobrigkeit C. , Pierre Auger Collaboration  
Published: November 2015

AbstractThe Pierre Auger Observatory addresses the most fundamental questions about the nature and origin of the highest‐energy cosmic rays. The results obtained by the Auger Observatory have already led to a number of major breakthroughs in the field contributing to the advance of our understanding of these extremely energetic particles. The spectrum and the arrival direction distribution are key observables to search for sources or source regions of ultra‐high energy cosmic rays, and to understand the transition from Galactic to extragalactic cosmic rays. We present the latest results on the energy spectrum, and on the studies of anisotropies performed on the ten‐year dataset of arrival directions of cosmic rays at large and small angular scales. We also address the plans and motivations for the future upgrade of the Pierre Auger Observatory. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Status of the Cherenkov Telescope Array project
Authors: Barres de Almeida U. 
Published: November 2015

AbstractGamma‐ray astronomy holds a great potential for astro‐physics, particle physics, and cosmology. The CTA is an international initiative to build the next generation of ground‐based gamma‐ray observatories which will represent a factor of 5–10× improvement in the sensitivity of observations in the range 100 GeV–10 TeV, as well as an extension of the observational capabilities down to energies below 100 GeV and beyond 100 TeV. The array will consist of two telescope networks (one in the northern hemisphere and another in the south) so to achieve a full‐sky coverage, and will be composed by a hybrid system of 4 different telescope types. It will operate as an observatory, granting open access to the community through calls for submission of proposals competing for observation time. The CTA will give us access to the non‐thermal and high‐energy universe at an unprecedented level, and will be one of the main instruments for high‐energy astro‐physics and astroparticle physics of the next 30 years. CTA has now entered its prototyping phase with the first, stand‐alone instru¬ments being built. Brazil is an active member of the CTA consortium, and the project is represented in Latin America also by Argentina, Mexico, and Chile. In the next few months the consortium will define the site for installation of CTA South, which might come to be hosted in the Chilean Andes, with important impact for the high‐energy community in Latin America. In this talk we will present the basic concepts of the CTA and the detailed project of the observatory. Emphasis will be put on its scientific potential and on the Latin‐American involvement in the preparation and construction of the observatory, whose first seed, the ASTRI mini‐array, is currently being constructed in Sicily, in a cooperation between Italy, Brazil, and South Africa. ASTRI should be installed on the final CTA site in 2016, whereas the full CTA array is expected to be operational by the end of the decade. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An effective field theory for neutron stars with many‐body forces, strong ∑– repulsion, and K– and $\bar K^0$ condensation
Authors: Mesquita A. , Razeira M. , Ruffini R. , Rueda J. A. , Hadjimichef D. , Gomes R. O. , Zen Vasconcellos C. A. 
Published: November 2015

AbstractThe role of many‐body correlations (many‐body forces) and K–‐

condensation in β‐equilibrated hyperonic matter is investigated in order to shed some light in the hyperonization puzzle, ie that neutron star mass of 2M® cannot be obtained in the presence of exotic degree of freedoms. In this investigation, we use an effective relativistic QHD‐model with parameterized couplings which represents an extended compilation of other effective models found in the literature. Our theoretical approach exhausts the whole fundamental baryon octet (n, p, ∑–, ∑0, ∑+, Λ, Ξ–, Ξ0) and simulates n‐order corrections to the minimal Yukawa couplings by considering many‐body nonlinear self‐couplings and meson‐meson interaction terms involving scalar‐isoscalar (σ, σ*), vector‐isoscalar (ω, φ), vector‐isovector (ϱ), and scalar‐isovector (δ) sectors. Following recent experimental results, we consider in our calculations the extreme case where the ∑– experiences such a strong repulsion that its influence in the nuclear structure of a neutron star is excluded at all. We study the effects of this exclusion on the phase transition of conventional exotic hadronic matter to hadronic matter containing a condensate of kaons and anti‐kaons. As a novelty in the treatment of kaon and anti‐kaon condensation in high density nuclear matter, we consider a Lagrangian formulation which describes, in addition to the interaction involving baryons and mesons and the contribution of kaons and anti‐kaons in free propagation, the presence of many‐body forces involving kaon, anti‐kaon and meson fields. To implement the corresponding phase transition we considered the Gibbs conditions combined with the mean‐field approximation, giving rise to a mixed phase of coexistence between baryon matter and the condensed of kaons and anti‐kaons. Our investigation show that even with kaon condensation, the nuclear equation of state satisfies both the maximum mass and the allowed ranges of mass and radius of neutron stars. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Z ' decay and dark matter relic density in a Stueckelberg extension of the Standard Model
Authors: dos Santos A. L. , Vasconcellos C. A. Z. 
Published: November 2015

AbstractAn extension of the Standard Model (SM) is studied, in which two new vector bosons are introduced, a first boson Z ' coupled to the SM by the usual minimal coupling, producing an enlarged gauge sector in the SM. The second boson A ' field, in the dark sector of the model, remains massless and originates a dark photon γ '. A hybrid mixing scenario is considered based on a combined Higgs and Stueckelberg mechanisms. Model parameters are determined in order to fit the experimental relic density. The Z ' decay into fermions is also evaluated. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Smart Polymeric Nanoparticles as Emerging Tools for Imaging—The Parallel Evolution of Materials
Authors: Papadimitriou Sofia A. , Salinas Yolanda , Resmini Marina 
Published: November 2015

AbstractThe field of imaging has developed considerably over the past decade and recent advances in the area of nanotechnology, in particular nanomaterials, have opened new opportunities. Polymeric nanoparticles are particularly interesting and a number of novel materials, characterized by stimuli‐responsive characteristics and fluorescent tagging, have allowed visualization, intracellular labeling and real‐time tracking. In some of the latest applications the nanoparticles have been used for imagining of tumor cells, both in vivo and ex vivo.
Multipurpose Nature of Rapid Covalent Functionalization on Carbon Nanotubes
Authors: González‐Domínguez Jose M. , Santidrián Ana , Criado Alejandro , Hadad Caroline , Kalbáč Martin , Da Ros Tatiana 
Published: November 2015

AbstractIn the vast field of functionalization routes to carbon nanoforms, the fulfillment of such critical requirements as quick and nonharsh methods, good dispersibility, introduction of reactive groups, short reaction time, and low cost can be quite challenging. Traditional thermally induced diazonium chemistry on single‐walled carbon nanotubes (SWCNTs) is revisited by using commercial anilines and providing useful insight into the versatility of this approach. Functionalized SWCNTs with multiple controllable features, such as degree (and ratio) of coverage, orthogonalization, doping, and high water dispersibility, are obtained by introducing benzenesulfonic acid and benzylamine moieties. The scenario opens up an avenue to address relevant applications in which most functionalization methods could not be applied in a straightforward way.
Ag2Mo3O10 Nanorods Decorated with Ag2S Nanoparticles: Visible‐Light Photocatalytic Activity, Photostability, and Charge Transfer
Authors: Chen Xianjie , Liu Fenglin , Yan Xiaodong , Yang Yang , Chen Qian , Wan Juan , Tian Lihong , Xia Qinghua , Chen Xiaobo 
Published: November 2015

AbstractAg2Mo3O10 nanorods decorated with Ag2S nanoparticles have been synthesized by an anion‐exchange route. With thiourea as the sulfur source, sulfur ions replace [Mo3O10]2− units of active sites on the surface of Ag2Mo3O10 nanorods, forming Ag2Mo3O10 nanorods decorated with Ag2S nanoparticles. This induces enhanced absorption in the visible‐light region. Ag2S nanoparticles decorate the surface of Ag2Mo3O10 nanorods uniformly with a suitable amount of thiourea. The Ag2S/Ag2Mo3O10 nanoheterostructure enhances the photocatalytic activity on the degradations of Rhodamine B and glyphosate under visible light. This enhancement is attributed to the improved absorption of visible light and effective separation of charge carriers in the nanoheterostructure. Meanwhile, the Ag2S/Ag2Mo3O10 nanoheterostructure displays good photocatalytic stability based on cyclic photocatalytic experiments.
Developing the Saegusa–Ito Cyclisation for the Synthesis of Difluorinated Cyclohexenones
Authors: Percy Jonathan M. , McCarter Adam W. , Sewell Alan L. , Sloan Nikki , Kennedy Alan R. , Hirst David J. 
Published: November 2015

AbstractPalladium(II)‐catalysed cycloalkenylation (Saegusa–Ito cyclisation) has been used for the first time to transform difluorinated silylenol ethers to difluorinated cycloalkenones under mild conditions. The silylenol ether precursors were prepared in two high‐yielding steps from trifluoroethanol, and cyclised in moderate to good yields. A combination of air and copper(I) chloride in acetonitrile gave the turnover of the initial palladium(II) salt, whereas the provision of an oxygen atmosphere ensured more rapid reaction. Annulations required a minimum level of substitution on the chain, but failed when the alkene was substituted. Annelations allowed a range of n,6‐bicyclic systems to be prepared and afforded three products, in which heterocycles were fused to the new cyclohexenone. The least substituted system explored underwent cyclisation followed by terminal oxidation to a cyclic enal, which corresponded to a Wacker product of unusual regiochemistry.
Cyclodextrin‐Functionalized Monolithic Capillary Columns: Preparation and Chiral Applications
Authors: Adly Frady G. , Antwi Nana Yaa , Ghanem Ashraf 
Published: November 2015

AbstractIn this review, the recently reported approaches for the preparation of cyclodextrin‐functionalized capillary monolithic columns are highlighted, with few applications in chiral separations using capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). Chirality 28:97–109, 2016. © 2015 Wiley Periodicals, Inc.
Handling Climate Change – Establishing Waste CO2 Management A View from Biotechnology
Authors: Ringpfeil Manfred 
Published: November 2015

AbstractThe biggest material flows induced by industry are realized in energy production. Coal, oil and gas as raw material streams are moved from their deposits to their further converting. From there product streams are branched out. However, the biggest material flow of this industry is waste CO2 mobilized by chemical conversion from fossil deposits and released into the atmosphere. A waste management is urgently needed to reduce the amount of this flow, to neutralize its effects on environment and to establish applications yielding a return. Natural backflow of CO2 from the atmosphere to the biosphere waits for completion by industrial methods in order to shift it to a dimension equalizing the finally unavoidable amount of waste CO2 flow into the atmosphere.
Impact of sonication on activated sludge properties and consequences on PAH partitioning
Authors: Mozo Irene , Lesage Nicolas , Sperandio Mathieu , Bessiere Yolaine 
Published: November 2015

AbstractSonication is an efficient sludge disintegration technique that can be used for reducing the excess sludge produced in water treatment. The effects of activated sludge sonication on its physicochemical properties and their consequences on the partitioning of hydrophobic polycyclic aromatic hydrocarbons (PAH) are reported. Ultrasound treatment led to an increase in dissolved and colloidal matter in the aqueous phase, with a predominance of proteins compared to the initial supernatant. This transfer of DCM was found to be directly correlated to the energy applied, and resulted in proportional transfer of PAHs from the particulate phase to the aqueous fraction. The PAH aqueous fraction, initially ranging from 0.012 g/g (pyrene) to 0.19 g/g (naphthalene), reached between 0.25–0.37 g/g when a specific energy of 40 000 kJ/kgTS0 was applied. For the raw sludge, the logarithm of the equilibrium constant varied between 3.0–4.3, depending on the hydrophobicity of the molecule, but when sonication was applied, the affinity for particles decreased significantly, resulting in a narrow distribution (log KG = 2.8–3.0 after 40 000 kJ/kgTS0 was applied). PAH partition is governed by molecule hydrophobicity (log Kow) for raw sludge and by sonication intensity for sonicated sludge.
Iron‐Mediated Chlorotrifluoromethylation of Alkenes with Sodium Trifluoromethanesulfinate
Authors: Yang Bin , Xu Xiu‐Hua , Qing Feng‐Ling 
Published: November 2015

AbstractAn iron‐mediated three‐component chlorotrifluoromethylation of both styrenes and aliphatic alkenes has been presented here. This reaction employs ferric chloride (FeCl3) as the Cl source and the Langlois reagent (CF3SO2Na) as the CF3 source. It provides a convenient pathway towards a wide range of chlorotrifluoromethylated compounds.