bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non‐Thermal Plasma in Contact with Water: The Origin of Species
Authors: Gorbanev Yury , O'Connell Deborah , Chechik Victor 
Published: February 2016

AbstractNon‐thermal atmospheric pressure plasma has attracted considerable attention in recent years due to its potential for biomedical applications. Determining the mechanism of the formation of reactive species in liquid treated with plasma is thus of paramount importance for both fundamental and applied research. In this work, the origin of reactive species in plasma‐treated aqueous solutions was investigated by using spin‐trapping, hydrogen and oxygen isotopic labelling and electron paramagnetic resonance (EPR) spectroscopy. The species originating from molecules in the liquid phase and those introduced with the feed gas were differentiated by EPR and 1H NMR analysis of liquid samples. The effects of water vapour and oxygen admixtures in the feed gas were investigated. All the reactive species detected in the liquid samples were shown to be formed largely in the plasma gas phase. It is suggested that hydrogen peroxide (determined by UV/Vis analysis) is formed primarily in the plasma tube, whereas the radical species ⋅OOH, ⋅OH and ⋅H are proposed to originate from the region between the plasma nozzle and the liquid sample.
Regioselective Synthesis of Quinazolinone‐/Phenanthridine‐Fused Heteropolycycles by Pd‐Catalyzed Direct Intramolecular Aerobic Oxidative C−H Amination from Aromatic Strained Amides
Authors: Banerji Biswadip , Bera Suvankar , Chatterjee Satadru , Killi Sunil Kumar , Adhikary Saswati 
Published: February 2016

AbstractA new route for the expedient synthesis of specific regioisomer of quinazolinone‐ and phenanthridine‐fused heterocycles through a palladium‐catalyzed regioselective intramolecular oxidative C−H amination from cyclic strained amides of aromatic amido–amidine systems (quinazolinones) has been developed. The amine functionalization of an aromatic C−H bond from a strained amide nitrogen involved in aromaticity has been a challenging work so far. The fusion of two heterocyclic cores, quinazolinone and phenanthridine, can occur in two different ways (linear and angular), but under the conditions reported here, only linear type isomer is exclusively produced. This approach provides a variety of substituted quinazolinone‐ and phenanthridine‐fused derivatives in moderate to excellent yields. Moreover, such fused molecules show excellent fluorescent properties and have great potential to be a new type of fluorophores for the use in medicinal and material science.
Optimal ATRP‐Made Soluble Polymer Supports for Phosphoramidite Chemistry
Authors: Oswald Laurence , Al Ouahabi Abdelaziz , Charles Laurence , Lutz Jean‐François 
Published: February 2016

AbstractSoluble polystyrene supports with optimal molecular structures for iterative phosphoramidite chemistry were prepared by atom‐transfer radical polymerization (ATRP) and subsequent chain‐end modification steps. The controlled radical polymerization of styrene was first performed in the presence of an 9‐fluorenylmethoxycarbonyl (Fmoc)‐protected amino‐functional ATRP initiator. Soluble supports of different molecular weight were prepared. Size‐exclusion chromatography and NMR analysis indicated formation of well‐defined polymers with controlled chain lengths and narrow dispersity. After synthesis, the bromo ω end group of the ATRP polymer was removed by dehalogenation in the presence of tributyltin hydride, and the Fmoc protecting group of the α moiety was subsequently cleaved with piperidine. The resulting α‐primary amine was afterwards treated with a linker containing a carboxyl group, a cleavable ester site, and a dimethoxytrityl‐protected hydroxyl group to afford ideal soluble supports for phosphoramidite chemistry. NMR analysis indicated that these chain‐end modifications were quantitative. The supports were tested for the synthesis of a non‐natural sequence‐defined oligophosphates. High‐resolution ESI‐MS analysis of the cleaved oligomers indicated formation of uniform species, and thus confirmed the efficiency of the ATRP‐made soluble polymer supports. In addition, the synthesis of a thymidine‐loaded soluble support was achieved.
Fused π‐Extended Truxenes via a Threefold Borylation as the Key Step
Authors: Zhang Gang , Rominger Frank , Mastalerz Michael 
Published: February 2016

AbstractOn the basis of a threefold borylated truxene, which is accessible in high yields by iridium‐catalyzed borylation under CH‐activation, fused π‐extended truxenes have been synthesized by a two‐step method of first Suzuki–Miyaura cross‐coupling reaction and subsequent condensation reaction. The mild condensation method tolerates the presence of a variety of functional groups, such as nitro, fluoro, or carboxyl moieties. Furthermore, by using this approach, N‐ and S‐heteroarene analogues become accessible for the first time, as well as larger structures that represent derivatives of precursors for fullerene C60 or buckybowls. The attached tert‐butyl groups make all derivatives sufficiently soluble to allow full spectroscopic and electrochemical investigations. Postfunctionalization of selected derivatives for further synthetic applications of the compounds is also presented.
Design and Synthesis of Novel Chiral Dirhodium(II) Carboxylate Complexes for Asymmetric Cyclopropanation Reactions
Authors: Adly Frady G. , Gardiner Michael G. , Ghanem Ashraf 
Published: February 2016

AbstractA novel approach to the design of dirhodium(II) tetracarboxylates derived from (S)‐amino acid ligands is reported. The approach is founded on tailoring the steric influences of the overall catalyst structure by reducing the local symmetry of the ligand's N‐heterocyclic tether. The application of the new approach has led to the uncovering of [Rh2(S‐tertPTTL)4] as a new member of the dirhodium(II) family with extraordinary selectivity in cyclopropanation reactions. The stereoselectivity of [Rh2(S‐tertPTTL)4] was found to be comparable to that of [Rh2(S‐PTAD)4] (up to >99 % ee), with the extra benefit of being more synthetically accessible. Correlations based on X‐ray structures to justify the observed enantioinduction are also discussed.
Trichloromethylthiolation of N‐Heterocycles: Practical and Completely Regioselective
Authors: Ernst Johannes B. , Rühling Andreas , Wibbeling Birgit , Glorius Frank 
Published: February 2016

AbstractThe first trichloromethylthiolation of a broad range of indoles and pyrroles is reported employing bench‐stable N‐trichloromethylthiosaccharin as reagent. This methodology is highly regioselective, exhibits high functional group tolerance, and provides access to two previously unknown classes of potentially bioactive compounds.
Rosetta detektiert organische Moleküle
Authors: Feil Sylvia 
Published: February 2016

AbstractKometen geben Einblicke in die Entstehungszeit des Sonnensystems vor rund 4,5 Milliarden Jahren. Ausgewertet wurden nun die ersten Tage des Landers Philae auf dem Kern des Kometen 67P/Churyumov‐Gerasimenko. Die Ergebnisse der Rosetta‐Mission zeigen, dass organische Moleküle, die Zucker und Aminosäuren bilden können, im Kometen enthalten sind.
Charged Inorganic Nanowire‐Directed Mineralization of Amorphous Calcium Carbonate
Authors: Liu Yang‐Yi , Liu Lei , Xue Lei , Mao Li‐Bo , Gao Huai‐Ling , Xu Liang , Yu Shu‐Hong 
Published: February 2016

AbstractCharged inorganic nanowires (e.g., tellurium nanowires, TeNWs), analogous to supramolecular templates, have been used to direct the mineralization of uniform amorphous calcium carbonate (ACC) shells on their surfaces. The role of surface charges of TeNWs, mixed solvent ratio, and the diameter of the TeNWs is discussed, and the formation mechanism of ACC‐coated tellurium nanowires (ACC@TeNWs) is elucidated. This charged‐nanowire‐directed mineralization process represents a new approach that could be extended for the synthesis of other amorphous inorganic nanostructures in the future.
Excited‐State Deactivation of Adenine by Electron‐Driven Proton‐Transfer Reactions in Adenine–Water Clusters: A Computational Study
Authors: Wu Xiuxiu , Karsili Tolga N. V. , Domcke Wolfgang 
Published: February 2016

AbstractThe reactivity of photoexcited 9H‐adenine with hydrogen‐bonded water molecules in the 9H‐adenine–(H2O)5 cluster is investigated by using ab initio electronic structure methods, focusing on the photoreactivity of the three basic sites of 9H‐adenine. The energy profiles of excited‐state reaction paths for electron/proton transfer from water to adenine are computed. For two of the three sites, a barrierless or nearly barrierless reaction path towards a low‐lying S1–S0 conical intersection is found. This reaction mechanism, which is specific for adenine in an aqueous environment, can explain the substantially shortened excited‐state lifetime of 9H‐adenine in water. Depending on the branching ratio of the nonadiabatic dynamics at the S1–S0 conical intersection, the electron/proton transfer process can enhance the photostability of 9H‐adenine in water or can lead to the generation of adenine‐H⋅ and OH⋅ free radicals. Although the branching ratio is yet unknown, these findings indicate that adenine might have served as a catalyst for energy harvesting by water splitting in the early stages of the evolution of life.
Wholly Synthetic Molecular Machines
Authors: Cheng Chuyang , Stoddart J. Fraser 
Published: February 2016

AbstractThe past quarter of a century has witnessed an increasing engagement on the part of physicists and chemists in the design and synthesis of molecular machines de novo. This minireview traces the development of artificial molecular machines from their prototypes in the form of shuttles and switches to their emergence as motors and pumps where supplies of energy in the form of chemical fuel, electrochemical potential and light activation become a minimum requirement for them to function away from equilibrium. The challenge facing this rapidly growing community of scientists and engineers today is one of putting wholly synthetic molecules to work, both individually and as collections. Here, we highlight some of the recent conceptual and practical advances relating to the operation of wholly synthetic rotary and linear motors.
Design of Highly Selective Platinum Nanoparticle Catalysts for the Aerobic Oxidation of KA‐Oil using Continuous‐Flow Chemistry
Authors: Gill Arran M. , Hinde Christopher S. , Leary Rowan K. , Potter Matthew E. , Jouve Andrea , Wells Peter P. , Midgley Paul A. , Thomas John M. , Raja Robert 
Published: February 2016

AbstractHighly active and selective aerobic oxidation of KA‐oil to cyclohexanone (precursor for adipic acid and ɛ‐caprolactam) has been achieved in high yields using continuous‐flow chemistry by utilizing uncapped noble‐metal (Au, Pt & Pd) nanoparticle catalysts. These are prepared using a one‐step in situ methodology, within three‐dimensional porous molecular architectures, to afford robust heterogeneous catalysts. Detailed spectroscopic characterization of the nature of the active sites at the molecular level, coupled with aberration‐corrected scanning transmission electron microscopy, reveals that the synthetic methodology and associated activation procedures play a vital role in regulating the morphology, shape and size of the metal nanoparticles. These active centers have a profound influence on the activation of molecular oxygen for selective catalytic oxidations.
Hydrogen from Water over Openly‐Structured Graphitic Carbon Nitride Polymer through Photocatalysis
Authors: Huang Zhijun , Li Fengbo , Chen Bingfeng , Yuan Guoqing 
Published: February 2016

AbstractOpenly‐structured g‐C3N4 microspheres (CNMS) are developed through a well‐controlled strategy. These materials have unique features of open 3 D structure, ordered hierarchical porosity, and improved optical and electronic properties. Hydrogen evolution from water is performed under a 300 W Xe lamp with a cut‐off filter (λ>420 nm) and Pt nanoparticles are used as the co‐catalyst (3.0 wt %). The catalyst prepared at 600 °C (CNMS‐600) has a hydrogen evolution rate (HER) of 392 μmol h−1 (apparent quantum yield, AQY=6.3 %) at 420 nm. This value is higher than that of g‐C3N4 nanosheets prepared through thermal oxidation, liquid exfoliation, or chemical exfoliation. The HER value is only 27 μmol h−1 (AQY=0.43 %) at 420 nm for bulk g‐C3N4 from melamine. The evolution of openly‐structured CNMS was investigated by TEM, FTIR, and XRD. The improved optical and electronic properties were demonstrated through UV/Vis absorption spectra, valence‐band X‐ray photoelectron spectroscopy, photoluminescence spectroscopy, electron paramagnetic resonance spectroscopy, and electrochemical impedance spectroscopy.
Metal‐free Nanoporous Carbon as a Catalyst for Electrochemical Reduction of CO2 to CO and CH4
Authors: Li Wanlu , Seredych Mykola , Rodríguez‐Castellón Enrique , Bandosz Teresa J. 
Published: February 2016

AbstractS‐doped and dual S,N‐doped polymer‐derived carbons were studied as electrocatalysts for the reduction of CO2. Higher Faradaic efficiencies for conversion to CO and CH4 were obtained for S,N‐doped carbon than its S‐doped counterpart. The former showed a maximum Faradaic efficiency of 11.3 % for CO and 0.18 % for CH4 formation. The S,N‐nanoporous carbon was better at decreasing the overpotential of the reduction process. The pyridinic nitrogen groups were found to be actively participating in binding CO2. The quaternary nitrogen and thiophenic groups were also involved in the reduction process. It is proposed that the positively charged sites on the carbon atoms, adjacent to pyridinic nitrogen, stabilize the CO2.− and COOH* intermediates, promoting the formation of CO. The surface basicity of the catalysts improved the CO2 reduction selectivity when competing with H2 evolution. N2 adsorption measurements suggested that ultra‐micropores enhance the reduction of CO2 to CH4.
Comprehensive Insights into the Reactivity of Electrolytes Based on Sodium Ions
Authors: Eshetu Gebrekidan Gebresilassie , Grugeon Sylvie , Kim Huikyong , Jeong Sangsik , Wu Liming , Gachot Gregory , Laruelle Stephane , Armand Michel , Passerini Stefano 
Published: February 2016

AbstractWe report a systematic investigation of Na‐based electrolytes that comprise various NaX [X=hexafluorophosphate (PF6), perchlorate (ClO4), bis(trifluoromethanesulfonyl)imide (TFSI), fluorosulfonyl‐(trifluoromethanesulfonyl)imide (FTFSI), and bis(fluorosulfonyl)imide (FSI)] salts and solvent mixtures [ethylene carbonate (EC)/dimethyl carbonate (DMC), EC/diethyl carbonate (DEC), and EC/propylene carbonate (PC)] with respect to the Al current collector stability, formation of soluble degradation compounds, reactivity towards sodiated hard carbon (Nax‐HC), and solid–electrolyte interphase (SEI) layer formation. Cyclic voltammetry demonstrates that the stability of Al is highly influenced by the nature of the anions, solvents, and additives. GC–MS analysis reveals that the formation of SEI telltales depends on the nature of the linear alkyl carbonates and the battery chemistry (Li+ vs. Na+). FTIR spectroscopy shows that double alkyl carbonates are the main components of the SEI layer on Nax‐HC. In the presence of Na salts, EC/DMC and EC/DEC presented a higher reactivity towards Nax‐HC than EC/PC. For a fixed solvent mixture, the onset temperature follows the sequence NaClO4<NaFTFSI<NaPF6<NaTFSI<NaFSI, and the total heat generated increases in the order NaFSI<NaTFSI<NaClO4<NaPF6<NaFTFSI.
Metal‐Free Chemoselective Oxidative Dehomologation or Direct Oxidation of Alcohols: Implication for Biomass Conversion
Authors: Kim Sun Min , Shin Hun Yi , Kim Dong Wan , Yang Jung Woon 
Published: February 2016

AbstractInvited for this month′s cover is the group of Jung Woon Yang at the Department of Energy Science, Sungkyunkwan University (SKKU). The image shows how simple base and molecular dioxygen can play a role in the cleavage of lignin model compound for the production of phenol and benzoic acid. The Communication itself is available at 10.1002/cssc.201501359.
Might macronutrient requirements influence grizzly bear–human conflict? Insights from nutritional geometry
Authors: Coogan Sean C. P. , Raubenheimer David 
Published: February 2016

AbstractKnowledge of carnivore nutritional requirements offers a potentially powerful aid for conservation and management strategies, yet has received little attention. We discuss how nutritional ecology, nutritional geometry, and the concept of macronutrient (protein, lipid, and carbohydrate) balance can be used to further our understanding of behavioral regulatory mechanisms that may influence food‐related human–wildlife conflict, focusing on North American grizzly bears (Ursus arctos). We propose that the macronutrient preferences of omnivorous grizzly bears are a strong driver of their conflict with humans due to nutrient‐specific foraging behavior, which we predict will be particularly noticeable during periods in which “key” natural foods high in lipid or carbohydrate are limiting. We demonstrate how nutritional geometry can be used to investigate the concept of nutrient balance by integrating recent research on the macronutrient selection of the grizzly bear with nutritional estimates of potentially consumed anthropogenic foods. Our geometric analysis utilizing right‐angled mixture triangles suggested that anthropogenic foods offer grizzly bears nonprotein energy sources that may allow them to optimize macronutrient intake. This macronutrient‐focused approach gives rise to fundamentally different predictions (and potentially management strategies) than the conventional food and energy‐focused approaches. This article also provides insight into food‐related conflict among other bear and carnivore species, and human–carnivore conflict more generally, by outlining a nutritionally explicit predictive framework for understanding the potentially volatile interface between anthropogenic environments and the behavior of wild animals.
Public lands and private waters: scarce mesic resources structure land tenure and sage‐grouse distributions
Authors: Donnelly J. P. , Naugle D. E. , Hagen C. A. , Maestas J. D. 
Published: February 2016

AbstractWater scarcity in semiarid environments provides a model system to evaluate the role of mesic resources in structuring the distribution and abundance of wildlife. We used remote sensing and point process analyses to evaluate spatio–temporal variability in limited mesic resources in relation to greater sage‐grouse (Centrocercus urophasianus) distributions in Oregon, California, and northwest Nevada, USA, 1984–2011. We then link population distribution to changes in resource availability over time, space, and land tenure. Despite encompassing only 2.4% of landscape area, mesic sites influenced sage‐grouse breeding distributions as evidenced by significantly shorter lek to mesic resource distances in observed (5.3 km) vs. predicted (8.2 km) values. Population abundance increased with proximity to mesic sites. Lag effects evident in abundance and proximity trends of mesic resources suggest a level of drought tolerance that moderated climatic variability. Mesic abundance and proximity remained relatively stable during the study period in comparison to more dynamic climatic patterns. Drought effects were most pronounced during multiyear events as evidenced by the 1987–1992 period that decreased mesic abundance >25% and approximately doubled mean lek to mesic resource distances (4.8–8.3 km). In our study area, 75% of all mesic resources were in private ownership, where the predominant land use is livestock ranching. Results suggest a holistic conservation strategy inclusive of private and public lands is needed to ensure sage‐grouse habitat requisites are met throughout the life cycle of this landscape species.
Analysis of the in‐plane response of earthen masonry infill panels partitioned by sliding joints
Authors: Preti Marco , Bettini Nicola , Migliorati Laura , Bolis Valentino , Stavridis Andreas , Plizzari Giovanni A. 
Published: February 2016

SummaryThe vulnerability of infilled frames represents a critical issue in many regions with high seismicity around the world where infills are typically made of heavy masonry as they are used for thermal control of the buildings because of their thermal inertia. In this context, the use of earthen masonry infills can give a superior performance because of their ability to regulate thermal‐hygrometric performance of the building and sustainability of its life‐cycle.This paper presents a numerical study on the seismic behaviour of infill walls made of earthen masonry and partitioned with horizontal wooden planks that allow the relative sliding of the partitions. The combination of the deformability of earthen masonry and the sliding mechanism occurring along the wooden planks gives a high ductility capacity to the in‐plane response of the infill and, at the same time, significantly reduces its stiffness and strength, as compared with traditional solid infills made of fired clay units. As a result, the detrimental interaction with the frame and the damage in the infill when subjected to in‐plane loading can be minimized.The numerical model is validated with results from an experimental study and is used to perform a parametric analysis to examine the influence of variations in the geometry and mechanical properties of the infill walls, as well as the configuration of the sliding joints. Based on the findings of this study, design guidelines for practical applications are provided, together with simple formulation for evaluating their performance. Copyright © 2016 John Wiley & Sons, Ltd.
Human impact on Holocene sediment dynamics in the Eastern Mediterranean – the example of the Roman harbour of Ephesus
Authors: Stock Friederike , Knipping Maria , Pint Anna , Ladstätter Sabine , Delile Hugo , Heiss Andreas G. , Laermanns Hannes , Mitchell Piers D. , Ployer René , Steskal Martin , Thanheiser Ursula , Urz Ralf , Wennrich Volker , Brückner Helmut 
Published: February 2016

AbstractDuring the past millennia, many erosion and accumulation processes have been modified by anthropogenic impact. This holds especially true for the environs of ancient settlements and their harbours along the Mediterranean coasts. Our multi‐proxy investigations in the Roman harbour and the harbour canal of Ephesus (western Turkey) reveals that humans have significantly triggered soil erosion during the last three millennia. Since the eighth century bc, and especially since the Hellenistic period, a high sedimentation rate indicates fast alluviation and delta progradation of the Küçük Menderes. Deforestation, agriculture (especially ploughing) and grazing (especially goats) were the main reasons for erosion of the river catchment area. One consequence was significant siltation of the Hellenistic/Roman harbour basin. This sediment trap archives the human impact, which was strongly enhanced from Hellenistic/Roman to Byzantine times (second/first centuries bc to the sixth/seventh centuries ad), evidenced by high sedimentation rates, raised values of heavy metal contaminations [lead (Pb), copper (Cu)], the occurrence of fruit tree pollen and of intestinal parasites. From the middle to the end of the first millennium ad, the influence of Ephesus declined, which resulted in a decrease of human impact. Studies of several ancient settlements around the Mediterranean Sea tell a comparable story. They also confirm that during their most flourishing periods the human impact totally overprinted the climatic one. To detect the latter, geo‐bio‐archives of relatively pristine areas have to be investigated in detail. Copyright © 2016 John Wiley & Sons, Ltd.