bluuebunny/crossref_metadata_2025 huggingface dataset:
One‐Step Cathodic and Anodic Synthesis of Hydrophilic Carbon Nanomaterials
Authors: Veloso Andreia D. , Botelho do Rego Ana M. , Ferraria Ana M. , Ferreira Luís F. V. , Ferreira Diana P. , Tavares Pedro B. , Videira Romeu , Viana Ana S. , Oliveira M. Cristina
Published: June 2017

It was demonstrated that the galvanostatic polarization of graphite electrodes in a cell with two separated compartments generates simultaneously and straightforwardly, without further separation and functionalization, two distinct sets of hydrophilic carbon nanomaterials [electrogenerated hydrophilic carbon (EHC)], in the anodic and cathodic compartments, respectively. The synthesized products comprise an amorphous carbonaceous material with aromatic sp2 carbon clusters, differing mainly in their oxidation degree. Surprisingly, it was found that nitrogen is incorporated in the carbon‐based material during the electrolysis, which is provided by the N2 gas present in the air and/or aqueous medium. This phenomenon is explained on the basis that very reactive carbonaceous species are formed during the electrodes polarization, owing to an anomalous high electric field generated along the galvanostatic polarization. In addition, it was also evidenced that ECH materials display a negative charge, counterbalanced by sodium ions and unique optical properties, exhibiting deep ultraviolet emission (ca. 4.1 eV), as well as blue luminescence. It is foreseen that these carbon materials will have important repercussions in optoelectronics devices, energy technology (supercapacitors, batteries, and fuel cells), and biomedicine.
Exploring High‐Energy Li‐I(r)on Batteries and Capacitors with Conversion‐Type Fe3O4‐rGO as the Negative Electrode
Authors: Kim Hyun‐Kyung , Aravindan Vanchiappan , Roh Ms. Ha‐Kyung , Lee Kyujoon , Jung Myung‐Hwa , Madhavi Srinivasan , Roh Kwang Chul , Kim Kwang‐Bum
Published: June 2017

We report a microwave‐assisted solvothermal process for the preparation of magnetite (Fe3O4, ca. 5 nm)‐anchored reduced graphene oxide (rGO). It has been examined as a prospective conversion‐type negative electrode for multiple energy storage applications, such as Li‐ion batteries (LIBs) and Li‐ion capacitors (LICs). A LiFePO4/Fe3O4‐rGO cell is constructed and capable of delivering an energy density of approximately 139 Wh kg−1 with a notable cyclability (ca. 76 %) after 500 cycles. Prior to the fabrication of a LIB, the Fe3O4‐rGO is electrochemically pretreated to eliminate the irreversible capacity loss. In addition to the LIB, a high‐energy LIC is also fabricated by using the pre‐lithiated Fe3O4‐rGO composite as the anode and commercial activated carbon as the cathode. This LIC registered a maximum energy density of approximately 114 Wh kg−1 with good cyclability. For both the LIB and LIC, the mass loading between the electrodes was adjusted based on the performance with metallic Li. The improved electrochemical performance of Fe3O4‐rGO over existing materials is a promising development in the quest for novel, fast, low cost, and efficient energy storage systems without compromising the eco‐friendliness
Structural Phase Transitions and Dielectric Switching in a Series of Organic‐Inorganic Hybrid Perovskites ABX3 (X=ClO4− or BF4−)
Authors: Sun Yu‐Ling , Han Xiang‐Bin , Zhang Wen
Published: June 2017

A series of organic‐inorganic hybrid perovskites ABX3 (A=diprotonated 1,4‐diazabicyclo[2.2.2]octane or piperazine; B=Na+ or K+; X=ClO4− or BF4−) has been synthesized. They feature a cubic cage‐like host‐guest structures of which A is the cationic guest residing in the anionic cage B8X12, B is the vertex of the cage with variable coordination numbers between six and twelve, and X is the bridging ligand with mono‐ and/or bidentate coordination modes. The extended Goldschmidt tolerance factor t is used to describe the phase stability of the compounds. Differential scanning calorimetry, variable‐temperature structural analyses, and dielectric measurements reveal that order‐disorder transitions of the A guest and/or X bridging ligand are supposed to be responsible for structural phase transitions and dielectric switching in the compounds.
E3M3+ (E=C–Pb, M=Li–Cs) Clusters: The Smallest Molecular Stars
Authors: Contreras Maryel , Pan Sudip , Orozco‐Ic Mesías , Cabellos José Luis , Merino Gabriel
Published: June 2017

Extensive potential energy surface explorations of twenty‐five clusters with the formula E3M3+ (E=Group 14 element and M=Group 1 element) through density functional theory and high‐level ab initio computations reveal that the lowest‐energy isomer for all these systems corresponds to a non‐classical D3h star‐like structure in the singlet state, where three M atoms interact electrostatically with the triangular E3 core, occupying three bridging positions around it. More than 18 200 calculations were done in the search for the minima structures, starting with a first phase at the PBE0/LANL2DZ level and ending with an analysis of the most representative clusters at the CCSD(T)/def2‐TZVP//PBE0/def2‐TZVP level. The title clusters represent the smallest molecular stars with three planar tetracoordinate E atoms (E=Group 14 element). All these E3M3+ clusters behave like superalkali cations with small vertical electron affinities (smaller than Cs), large vertical electron detachment energies, and HOMO–LUMO energy gaps. Their energetics, bonding, and electron delocalization are discussed in detail. The high stability of these clusters is reflected from the large dissociation energy needed for different dissociation channels. The electron delocalization is confirmed by the presence of two delocalized π electrons over the E3 core and strong diatropic responses.
Integrative Pericyclic Cascade: An Atom Economic, Multi C−C Bond‐Forming Strategy for the Construction of Molecular Complexity
Authors: Tejedor David , Delgado‐Hernández Samuel , Peyrac Jesús , González‐Platas Javier , García‐Tellado Fernando
Published: June 2017

An all‐pericyclic manifold is developed for the construction of topologically diverse, structurally complex and natural product‐like polycyclic chemotypes. The manifold uses readily accessible tertiary propargyl vinyl ethers as substrates and imidazole as a catalyst to form up to two new rings, three new C−C bonds, six stereogenic centers and one transannular oxo‐bridge. The manifold is efficient, scalable and instrumentally simple to perform and entails a propargyl Claisen rearrangement–[1,3]H shift, an oxa‐6π‐electrocyclization, and an intramolecular Diels–Alder reaction.
Gingival morphology‐controlled design of the complete denture baseplate
Authors: Dai Ning , Yu Xiaoling , Sun Yuchun
Published: June 2017

A removable complete denture is still the main selection for edentulous patients. Over the last 5 years, digital technologies for producing complete dentures have rapidly developed. Nevertheless, the design method for the baseplate has become the bottleneck of digital complete denture technology development. In this study, we report a novel method for the generation of esthetic gingiva and polished surfaces of complete dentures that are driven by the feature curve, which can be conveniently modified using the gingival shape factor. A solid modeling method based on Poisson surface reconstruction is used to generate a high‐quality baseplate solid. This method can aid dentists to realize the rapid design process of personalized esthetic baseplate. Finally, the experimental results verify that the method of digital design for the baseplate proposed is efficient and accurate (standard deviation <0.01 mm).
Functional roles of an engineer species for coastal benthic invertebrates and demersal fish
Authors: Chaalali Aurélie , Brind'Amour Anik , Dubois Stanislas F. , Le Bris Hervé
Published: June 2017

Through their tissues or activities, engineer species create, modify, or maintain habitats and alter the distribution and abundance of many plants and animals. This study investigates key ecological functions performed by an engineer species that colonizes coastal ecosystems. The gregarious tubiculous amphipod Haploops nirae is used as a biological model. According to previous studies, the habitat engineered by H. nirae (i.e., Haploops habitat) could provide food and natural shelter for several benthic species such as benthic diatoms belonging to the gender Navicula, the micrograzer Geitodoris planata, or the bivalve Polititapes virgineus. Using data from scientific surveys conducted in two bays, this study explored whether (1) the Haploops sandy‐mud community modifies invertebrate and ichthyologic community structure (diversity and biomass); (2) H. nirae creates a preferential feeding ground; and (3) this habitat serves as a refuge for juvenile fish. Available Benthic Energy Coefficients, coupled with more traditional diversity indices, indicated higher energy available in Haploops habitat than in two nearby habitats (i.e., Sternaspis scutata and Amphiura filiformis/Owenia fusiformis habitats). The use of isotopic functional indices (IFIs) indicated (1) a higher functional richness in the Haploops habitat, related to greater diversity in food sources and longer food chains; and (2) a higher functional divergence, associated with greater consumption of a secondary food source. At the invertebrate‐prey level, IFIs indicated little specialization and little trophic redundancy in the engineered habitat, as expected for homogenous habitats. Our results partly support empirical knowledge about engineered versus nonengineered habitats and also add new perspectives on habitat use by fish and invertebrate species. Our analyses validated the refuge‐area hypothesis for a few fish species. Although unique benthic prey assemblages are associated with Haploops habitat, the hypothesis that it is a preferential feeding area was not verified. However, specialist feeding behavior was observed for predators, which calls for further investigation.
Soil conditioning effects ofPhragmites australison native wetland plant seedling survival
Authors: Crocker Ellen V. , Nelson Eric B. , Blossey Bernd
Published: June 2017

Interactions between introduced plants and soils they colonize are central to invasive species success in many systems. Belowground biotic and abiotic changes can influence the success of introduced species as well as their native competitors. All plants alter soil properties after colonization but, in the case of many invasive plant species, it is unclear whether the strength and direction of these soil conditioning effects are due to plant traits, plant origin, or local population characteristics and site conditions in the invaded range.Phragmites australisin North America exists as a mix of populations of different evolutionary origin. Populations of endemic nativePhragmites australis americanusare declining, while introduced European populations are important wetland invaders. We assessed soil conditioning effects of native and non‐nativeP. australispopulations on early and late seedling survival of native and introduced wetland plants. We further used a soil biocide treatment to assess the role of soil fungi on seedling survival. Survival of seedlings in soils colonized byP. australiswas either unaffected or negatively affected; no species showed improved survival inP. australis‐conditioned soils. Population ofP. australiswas a significant factor explaining the response of seedlings, but origin (native or non‐native) was not a significant factor.Synthesis: Our results highlight the importance of phylogenetic control when assessing impacts of invasive species to avoid conflating general plant traits with mechanisms of invasive success. Both native (noninvasive) and non‐native (invasive)P. australispopulations reduced seedling survival of competing plant species. Because soil legacy effects of native and non‐nativeP. australisare similar, this study suggests that the close phylogenetic relationship between the two populations, and not the invasive status of introducedP. australis, is more relevant to their soil‐mediated impact on other plant species.
The relationship between male sexual signals, cognitive performance, and mating success in stickleback fish
Authors: Minter Ross , Keagy Jason , Tinghitella Robin M.
Published: June 2017

Cognitive ability varies dramatically among individuals, yet the manner in which this variation correlates with reproduction has rarely been investigated. Here, we ask (1) do male sexual signals reflect their cognitive ability, and (2) is cognitive ability associated with male mating success? Specifically, we presented threespine sticklebacks (Gasterosteus aculeatus) with a detour‐reaching task to assess initial inhibitory control. Fish that performed better were those who solved the detour‐reaching task, solved it faster, and required fewer attempts to solve. We then reexamined males’ performance on this task over several days to assess learning ability in this context. We next measured sexual signals (coloration, nest area, and courtship vigor) and asked whether they reveal information about these male cognitive abilities. Finally, we examined whether success at attracting a female is associated with male cognition. After controlling for the strong effect of neophobia, we found that no measured sexual signals were associated with initial inhibitory control. Sexual signals were also not associated with change in performance on the detour‐reaching task over time (learning). However, females preferred mating with males who had better initial inhibitory control. We speculate that inhibitory control is a critical trait for male sticklebacks. In this system, males perform all parental care, but must avoid eating their own fry which closely resemble their prey items. Therefore, males with better inhibitory control may be more likely to successfully raise their offspring to independence. Our research adds to a growing list of mating systems and taxa in which cognition is important for measures related to fitness.
Exploiting opportunistic observations to estimate changes in seasonal site use: An example with wetland birds
Authors: Ruete Alejandro , Pärt Tomas , Berg Åke , Knape Jonas
Published: June 2017

Nonsystematically collected, a.k.a. opportunistic, species observations are accumulating at a high rate in biodiversity databases. Occupancy models have arisen as the main tool to reduce effects of limited knowledge about effort in analyses of opportunistic data. These models are generally using long closure periods (e.g., breeding season) for the estimation of probability of detection and occurrence. Here, we use the fact that multiple opportunistic observations in biodiversity databases may be available even within days (e.g., at popular birding localities) to reduce the closure period to 1 day in order to estimate daily occupancies within the breeding season. We use a hierarchical dynamic occupancy model for daily visits to analyze opportunistic observations of 71 species from nine wetlands during 10 years. Our model derives measures of seasonal site use within seasons from estimates of daily occupancy. Comparing results from our “seasonal site use model” to results from a traditional annual occupancy model (using a closure criterion of 2 months or more) showed that our model provides more detailed biologically relevant information. For example, when the aim is to analyze occurrences of breeding species, an annual occupancy model will over‐estimate site use of species with temporary occurrences (e.g., migrants passing by, single itinerary prospecting individuals) as even a single observation during the closure period will be viewed as an occupancy. Alternatively, our model produces estimates of the extent to which sites are actually used. Model validation based on simulated data confirmed that our model is robust to changes and variability in sampling effort and species detectability. We conclude that more information can be gained from opportunistic data with multiple replicates (e.g., several reports per day almost every day) by reducing the time window of the closure criterion to acquire estimates of occupancies within seasons.
Flower power: Floral and resource manipulations reveal how and why reproductive trade‐offs occur for lowbush blueberry (Vaccinium angustifolium)
Authors: Bajcz Alex W. , Drummond Francis A.
Published: June 2017

Plant reproductive trade‐offs are thought to be caused by resource limitations or other constraints, but more empirical support for these hypotheses would be welcome. Additionally, quantitative characterization of these trade‐offs, as well as consideration of whether they are linear, could yield additional insights. We expanded our flower removal research on lowbush blueberry (Vaccinium angustifolium) to explore the nature of and causes of its reproductive trade‐offs. We used fertilization, defoliation, positionally biased flower removal, and multiple flower removal levels to discern why reproductive trade‐offs occur in this taxon and to plot these trade‐offs along two continuous axes. We found evidence through defoliation that vegetative mass per stem may trade off with reproductive effort in lowbush blueberry because the two traits compete for limited carbon. Also, several traits including ripe fruit production per reproductive node and fruit titratable acidity may be “sink‐limited”—they decline with increasing reproductive effort because average reproductive structure quality declines. We found no evidence that reproductive trade‐offs were caused by nitrogen limitation. Use of reproductive nodes remaining per stem as a measure of reproductive effort indicated steeper trade‐offs than use of the proportion of nodes remaining. For five of six traits, we found evidence that the trade‐off could be concave down or up instead of strictly linear. Synthesis. To date, studies have aimed primarily at identifying plant reproductive trade‐offs. However, understanding how and why these trade‐offs occur represent the exciting and necessary next steps for this line of inquiry.
Population genetic structure in six sympatric and widespread aquatic plants inhabiting diverse lake environments in China
Authors: Cao Qian‐Jin , Mei Fang‐Fang , Wang Ling
Published: June 2017

Many aquatic plant species are distributed over large areas and diverse environments with populations interconnected by abiotic and biotic mediators. Here, we examined differences and similarities in the population genetic structure of six sympatric and widespread aquatic plant species. We sampled the aquatic species from six Chinese lakes found on plateaus, plains, and different river systems and analyzed them using inter‐simple sequence repeat (ISSR) markers. Samples originating from each lake tended to cluster together. Of the six species, only Nymphoides peltata and Myriophyllum spicatum could be divided into plateau and plain groups, once Taihu Lake individuals were excluded. Genetic similarities between populations connected by the Yangtze River were not consistently higher than unconnected populations. Populations from Taihu Lake and/or Weishanhu Lake were distant from other lake populations for all species except Potamogeton lucens. The Taihu and Weishanhu populations clustered for Ceratophyllum demersum and Typha latifolia. Hydrophilous C. demersum had the lowest gene flow (Nm = 0.913), whereas the entomophilous Hydrocharis dubia (Nm = 2.084) and N. peltata (Nm = 2.204) had the highest gene flow. The genetic relationships among distant populations of aquatic plants reflect the comprehensive effects of environmental selection pressure and biotic and abiotic connectivity. Differences in environmental factors between plateau and plain lakes and long distance hydrochory have limited importance on aquatic plant genetic structures. Among multiple evolutionary forces, gene flow mediated by birds may play the most important role in the formation of genetic patterns in the six species examined. For example, the close genetic relationship between Taihu Lake and Weishanhu Lake populations, each in different river systems and with different climates, may be related to the migration routes of birds. Differences in gene flow among the six aquatic plants may be attributable to different bird‐transport and the fruit traits of each species.
Upstream trophic structure modulates downstream community dynamics via resource subsidies
Authors: Harvey Eric , Gounand Isabelle , Little Chelsea J. , Fronhofer Emanuel A. , Altermatt Florian
Published: June 2017

In many natural systems, the physical structure of the landscape dictates the flow of resources. Despite mounting evidence that communities’ dynamics can be indirectly coupled by reciprocal among ecosystem resource flows, our understanding of how directional resource flows might indirectly link biological communities is limited. We here propose that differences in community structure upstream should lead to different downstream dynamics, even in the absence of dispersal of organisms. We report an experimental test of the effect of upstream community structure on downstream community dynamics in a simplified but highly controlled setting, using protist microcosms. We implemented directional flows of resources, without dispersal, from a standard resource pool into upstream communities of contrasting interaction structure and then to further downstream communities of either one or two trophic levels. Our results demonstrate that different types of species interactions in upstream habitats may lead to different population sizes and levels of biomass in these upstream habitats. This, in turn, leads to varying levels of detritus transfer (dead biomass) to the downstream communities, thus influencing their population densities and trophic interactions in predictable ways. Our results suggest that the structure of species interactions in directionally structured ecosystems can be a key mediator of alterations to downstream habitats. Alterations to upstream habitats can thus cascade down to downstream communities, even without dispersal.
Patterns of seasonality and group membership characterize the gut microbiota in a longitudinal study of wild Verreaux's sifakas (Propithecus verreauxi)
Authors: Springer Andrea , Fichtel Claudia , Al‐Ghalith Gabriel A. , Koch Flávia , Amato Katherine R. , Clayton Jonathan B. , Knights Dan , Kappeler Peter M.
Published: June 2017

The intestinal microbiota plays a major role in host development, metabolism, and health. To date, few longitudinal studies have investigated the causes and consequences of microbiota variation in wildlife, although such studies provide a comparative context for interpreting the adaptive significance of findings from studies on humans or captive animals. Here, we investigate the impact of seasonality, diet, group membership, sex, age, and reproductive state on gut microbiota composition in a wild population of group‐living, frugi‐folivorous primates, Verreaux's sifakas (Propithecus verreauxi). We repeatedly sampled 32 individually recognizable animals from eight adjacent groups over the course of two different climatic seasons. We used high‐throughput sequencing of the 16S rRNA gene to determine the microbiota composition of 187 fecal samples. We demonstrate a clear pattern of seasonal variation in the intestinal microbiota, especially affecting the Firmicutes‐Bacteroidetes ratio, which may be driven by seasonal differences in diet. The relative abundances of certain polysaccharide‐fermenting taxa, for example, Lachnospiraceae, were correlated with fruit and fiber consumption. Additionally, group membership influenced microbiota composition independent of season, but further studies are needed to determine whether this pattern is driven by group divergences in diet, social contacts, or genetic factors. In accordance with findings in other wild mammals and primates with seasonally fluctuating food availability, we demonstrate seasonal variation in the microbiota of wild Verreaux's sifakas, which may be driven by food availability. This study adds to mounting evidence that variation in the intestinal microbiota may play an important role in the ability of primates to cope with seasonal variation in food availability.
Self‐ and intra‐morph incompatibility and selection analysis of an inconspicuous distylous herb growing on the Tibetan plateau (Primula tibetica)
Authors: Jiang Xian‐Feng , Li Qing‐Jun
Published: June 2017

There is discussion over whether pollen limitation exerts selection on floral traits to increase floral display or selects for traits that promote autonomous self‐fertilization. Some studies have indicated that pollen limitation does not mediate selection on traits associated with either pollinator attraction or self‐fertilization.Primula tibeticais an inconspicuous cross‐fertilized plant that may suffer from pollen limitation. We conducted a selection analysis onP. tibeticato investigate whether pollen limitation results in selection for an increased floral display in case the evolution of autonomous self‐fertilization has been difficult for this plant. The self‐ and intra‐morph incompatibility features, the capacity for autonomous self‐fertilization, and the magnitude of pollen limitation were examined through hand‐pollination experiments. In 2016, we applied selection analysis on the flowering time, corolla width, stalk height, flower tube length, and flower number inP. tibeticaby tagging 76 open‐pollinated plants and 37 hand‐pollinated plants in the field. Our results demonstrated thatP. tibeticawas strictly self‐ and intra‐morph incompatible. Moreover, the study population underwent severe pollen limitation during the 2016 flowering season. The selection gradients were found to be significantly positive for flowering time, flower number, and corolla width, and marginally significant for the stalk height. Pollinator‐mediated selection was found to be significant on the flower number and corolla width, and marginally significant on stalk height. Our results indicate that the increased floral display may be a vital strategy for small distylous species that have faced difficulty in evolving autonomous self‐fertilization.
Switchable Dielectric Constant in the Cyanometalate‐Based Hydrogen‐Bonded [(CH3)2NH2]2(H3O)[Co(CN)6] Framework
Authors: Shi Chao , Wang Ya , Han Xiang‐Bin , Zhang Wen
Published: June 2017

An organic–inorganic hybrid compound, [(CH3)2NH2]2(H3O)[Co(CN)6] (1), was synthesized and characterized by differential scanning calorimetry, variable‐temperature structural analyses, and dielectric measurements. The compound was found to undergo two reversible structural phase transitions at 161 and 259 K as a result of order/disorder transitions of half of the dimethylammonium cation and the anions, respectively, in the crystal lattice. The phase transition at 161 K triggered a typical dielectric transition with dielectric switching between the high and low dielectric states, which makes this compound a typical hybrid responsive dielectric material with thermally switchable dielectric constant.
Conventional and Microwave Synthesis of 2‐Fluoro‐diazaborolidines and Their Reaction with Lithium Phosphanides
Authors: Kaaz Manuel , Bäucker Christian , Deimling Max , König Simon , Schlindwein Simon H. , Bender Johannes , Nieger Martin , Gudat Dietrich
Published: June 2017

Condensation of N,N′‐disubstituted ethylenediamines with BF3·OEt2, in the presence or absence of an auxiliary base, gives mixtures of 2‐fluoro‐1,3,2‐diazaborolidines and ammonium tetrafluoroborates, respectively. Using BF3·NEt3 as the reactant allows the introduction of the boron source and the auxiliary in a single component, but suffers from the inhibition of the cyclisation by an excess of free amine formed as a by‐product. In contrast, rapid and quantitative consumption of the starting materials is observed when the reaction is carried out with a 2:1 mixture of BF3·NEt3 and BF3·OEt2 per mol of ethylenediamine at elevated temperature. Extremely short reaction times are achieved by conducting the reaction in a superheated solution in a microwave reactor. The 2‐fluoro‐1,3,2‐diazaborolidines formed under these conditions are readily isolated in high yields, and their synthetic usability is demonstrated by reactions with lithium phosphanides to give 2‐phosphanyl‐1,3,2‐diazaborolidines. Both the F‐ and R2P‐substituted N‐heterocyclic boranes are fully characterised. In addition, the structural characterisation of an unprecedented BF3 complex of Hünig's base (iPr2EtN) and of a 1,3,2‐diazaborolidine–BF3 complex is reported.
Magnesium Reagents Featuring a 1,1′‐Bis(o‐carborane) Ligand Platform
Authors: Axtell Jonathan C. , Kirlikovali Kent O. , Dziedzic Rafal M. , Gembicky Milan , Rheingold Arnold L. , Spokoyny Alexander M.
Published: June 2017

The synthesis of two bis(carboranyl) (bc) magnesium reagents is described. Treatment of 1,1′‐bis(o‐carborane) (H2‐bc) or 8,8′,9,9′,10,10′,12,12′‐octamethyl‐1,1′‐bis(o‐carborane) (H2‐Mebc) with Mg(nBu)2 in 1,2‐dimethoxyethane (DME) affords (bc)Mg(DME)2 (1a,b) as crystalline solids. The magnesium compounds, which have been characterized by NMR spectroscopy and single‐crystal X‐ray crystallography in the case of 1a, serve as competent Grignard‐type reagents to generate bc‐containing species of tin from Me2SnCl2 (2a,b). The type of substitution of the bis(o‐carboranyl) ligand framework is found to strongly affect the electronic character of the tin center, as judged by 119Sn NMR spectroscopy. The disclosed compounds, which are stable solids under an atmosphere of dry nitrogen gas at room temperature, provide a new class of bc‐transfer reagents.
Stannylated Vinylic Addition Polynorbornene: Probing a Reagent for Friendly Tin‐Mediated Radical Processes
Authors: García‐Loma Rodrigo , Albéniz Ana C.
Published: June 2017

Vinylic addition polynorbornenes (VA‐PNB) with stannyl functional groups have been prepared and used in tin‐mediated radical dehalogenation reactions. The aliphatic and robust scaffold of VA‐PNB is well suited for a support in radical processes. VA‐PNB‐(CH2)nSnHBu2 can be used as a stoichiometric reagent and VA‐PNB‐(CH2)nSnBu2Cl as a catalyst in the presence of a hydride donor for the reduction of RBr. The mixture KF (aq.)/polymethylhydrosiloxane (PMHS) is the most convenient hydride source to generate VA‐PNB‐(CH2)nSnHBu2 in situ. Although quite popular in this context, boron hydrides, being a source of radicals themselves, are not adequate to correctly evaluate the performance of the anchored organotin group. VA‐PNB‐(CH2)4SnBu2Cl can be recycled and, even if it loses activity upon reuse, it is still useful after ten cycles. The stannylated VA‐PNB can be separated from the products by simple filtration, and it leads to very low tin contamination (at least 250 times lower than that with use of conventional separation methods).
Biomass and elemental concentrations of 22 rice cultivars grown under alternate wetting and drying conditions at three field sites in Bangladesh
Authors: Norton Gareth J. , Travis Anthony J. , Danku John M. C. , Salt David E. , Hossain Mahmud , Islam Md. Rafiqul , Price Adam H.
Published: June 2017

As the global population grows, demand on food production will also rise. For rice, one limiting factor effecting production could be availability of fresh water, hence adoption of techniques that decrease water usage while maintaining or increasing crop yield are needed. Alternative wetting and drying (AWD) is one of these techniques. AWD is a method by which the level of water within a rice field cycles between being flooded and nonflooded during the growth period of the rice crop. The degree to which AWD affects cultivars differently has not been adequately addressed to date. In this study, 22 rice cultivars, mostly landraces of the aus subpopulation, plus some popular improved indica cultivars from Bangladesh, were tested for their response to AWD across three different field sites in Bangladesh. Grain and shoot elemental concentrations were determined at harvest. Overall, AWD slightly increased grain mass and harvest index compared to plants grown under continually flooded (CF) conditions. Plants grown under AWD had decreased concentrations of nitrogen in their straw compared to plants grown under CF. The concentration of elements in the grain were also affected when plants were grown under AWD compared to CF: Nickel, copper, cadmium and iron increased, but sodium, potassium, calcium, cobalt, phosphorus, molybdenum and arsenic decreased in the grains of plants grown under AWD. However, there was some variation in these patterns across different sites. Analysis of variance revealed no significant cultivar × treatment interaction, or site × cultivar × treatment interaction, for any of the plant mass traits. Of the elements analyzed, only grain cadmium concentrations were significantly affected by treatment × cultivar interactions. These data suggest that there is no genetic adaptation amongst the cultivars screened for response to AWD, except for grain cadmium concentration and imply that breeding specifically for AWD is not needed.
Hunting, Gathering, and Fishing on the Coast of the Atacama Desert: Chinchorro Population Mobility Patterns Inferred from Strontium Isotopes
Authors: Standen Vivien G. , Santoro Calogero M. , Arriaza Bernardo , Coleman Drew
Published: June 2017

We discuss how the Chinchorro population of hunter‐gatherers and fishermen organized their mobility patterns between the rich marine ecosystems of the Pacific coast and the extreme hyperarid core of the Atacama Desert through the application of strontium isotopes (87Sr/86Sr). We analyzed tooth enamel samples of 35 individuals from the coast (n = 28), inland oasis (n = 6), and the Andean highlands (n = 1). The Sr isotopic composition of modern and archaeological bone samples from sea mammals and land herbivores were obtained from 10 localities. Coastal human individuals show a similar Sr signal to sea mammals, confirming that the former were born and raised in the littoral zone. These results along with archaeological data suggest that the Chinchorro maintained logistic mobility along the coast. Similarly, a woman buried in the highlands (Patapatane) has a Sr signal closer to marine values, suggesting that some Chinchorro also maintained a logistic mobility linked to the Andean interior. In contrast, the Sr ratios of individuals from the inland oasis (Tiliviche) are intermediate between marine Sr values and those of local fauna. This seems to indicate that, although these Chinchorro individuals were raised in this oasis, they were part of a broad logistic mobility pattern connected with the coast.
Brenner Base Tunnel: First results of the exploratory tunnels from a geological and geomechanical point of view
Authors: Skuk Stefan , Schierl Heimo
Published: June 2017

The Brenner Base Tunnel (BBT) is a straight, flat railway tunnel between Austria and Italy. It runs from Innsbruck to Fortezza (55 km), crossing the main Alpine crest with an overburden up to 1.7 km. Including the connection to the line around Innsbruck, which has already been built and which is the endpoint for the BBT, the total length of the tunnel will be about 64 km. Once finished, the BBT will be the longest underground rail link in the world. A peculiar feature of the BBT is the exploratory tunnel running from one end to the other. This tunnel lies between the two main tunnels and about 12 m below them and is noticeably smaller than the main tubes.

So far, a total of 60 km of tunnels have already been excavated in Austria and Italy (access tunnels, exploratory tunnel, main tubes and chambers), driven both by blasting and by TBM. Crossing fault zones is a geological and geomechanical challenge, both for TBM and conventional excavation methods. The Periadriatic fault zone, with a total length of 1 km, has already been driven through. This first step of the project provides an interesting look at the comparison of the predicted rock mass conditions with those that were actually encountered, the rock mass behaviour in fault zones and investigation measures ahead of the tunnel face.
Efficacy of first‐trimester ultrasound parameters for prediction of early spontaneous abortion
Authors: Datta Mamta Rath , Raut Ankush
Published: June 2017

Objective

To assess first‐trimester ultrasound measurements for the prediction of early spontaneous abortion.

Methods

In a prospective observational study in Jamshedpur, India, women with singleton pregnancies of 42–76 days were enrolled between November 2014 and April 2016. Inclusion criteria were spontaneous conception, embryonic cardiac activity, and regular menstrual cycle. Fetal crown‐to‐rump length (CRL), gestational sac diameter (GSD), yolk sac diameter (YSD), and fetal heart rate (FHR) were measured by transvaginal ultrasonography. Ultrasonography was repeated at 12 weeks and beyond to determine pregnancy continuation.

Results

Among 800 women, 140 (17.5%) experienced early spontaneous abortion. CRL, GSD, and FHR values below the 5th percentile (odds ratio [OR] 26.48, 26.94, and 100.63, respectively), and YSD above the 95th percentile (OR 1.04) were predictors of early abortion. Normal YSD did not reduce the risk of abortion if the other three parameters were below the 5th percentile (OR 34.27). For every 10‐bpm decrease in FHR below 130, there was 26.7% increased risk of abortion. GSD−CRL difference of less than 5 mm was associated with a higher likelihood of abortion (OR 4.88).

Conclusion

First‐trimester ultrasound measurements are predictors of early abortion. Risk assessment tables based on combinations of abnormal measures might improve prediction rates.
Clinical indications for cesarean delivery among women living with female genital mutilation
Authors: Rodriguez Maria I. , Say Lale , Abdulcadir Jasmine , Hindin Michelle J.
Published: June 2017

Objective

To compare primary indications for cesarean delivery among patients with different female genital mutilation (FGM) status.

Methods

The present secondary analysis included data from women who underwent trial of labor resulting in cesarean delivery at 28 obstetric centers in six African countries between November 1, 2001, and March 31, 2003. Associations between cesarean delivery indications andFGMstatus were assessed using descriptive statistics and multivariable multinomial logistic regression.

Results

Data from 1659 women (480 patients with no type ofFGMand 1179 patients withFGM[any type]) were included; cesarean delivery indications were collapsed into five categories (fetal indications, maternal factors, stage 1 arrest, stage 2 arrest, and other). The incidence of a clear medical indication for cesarean delivery did not differ between the groups (P=0.320). Among patients without a clear indication for cesarean delivery, women withFGMwere more likely to have undergone cesarean delivery for maternal factors (adjusted relative risk ratio [aRRR] 3.92, 95% confidence interval [CI] 1.3–11.71), stage 1 arrest (aRRR7.74, 95%CI1.33–45.07), stage 2 arrest (aRRR6.63, 95%CI3.74–11.73), or other factors (aRRR2.41, 95%CI1.04–5.60) rather than fetal factors compared with women who had no type of FGM.

Conclusion

Among women with unclear medical indications,FGMwas associated with cesarean delivery being performed for maternal factors or arrest disorders.
Blood pressure in adolescent patients with pre‐eclampsia and eclampsia
Authors: Olaya‐Garay Sandra X. , Velásquez‐Trujillo Paula A. , Vigil‐De Gracia Paulino
Published: June 2017

Objective

To compare variables among adolescent and adult patients diagnosed with severe pre‐eclampsia or eclampsia.

Methods

The present cross‐sectional study enrolled patients with severe pre‐eclampsia or eclampsia treated at an intensive care unit in Neiva, Colombia, between January 1 and November 30, 2014. Patients were stratified using age (younger than 20 years [adolescents] and aged at least 20 years [adults]) and patient variables were compared between groups. Maternal age, pregnancy duration at delivery, eclampsia, blood pressure, severe hypertension, maternal organ damage, HELLP syndrome, obstetric hemorrhage, laboratory findings, need for blood transfusion and fetal data were analyzed by group.

Results

There were 171 patients enrolled; 154 (90.1%) with severe pre‐eclampsia and 17 (9.9%) with eclampsia. There were 46 (26.9%) adolescent patients and 125 (73.1%) adults, and 13 (28.3%) and 4 (3.2%) patients had eclampsia in the adolescent and adult groups, respectively (P=0.001). The systolic (P=0.081), diastolic (P=0.174), and mean (P=0.102) blood pressure did not differ significantly between the groups but were higher in the adult group. The incidence of severe hypertension was significantly higher among adult patients (P=0.037).

Conclusion

The blood pressure used in defining pre‐eclampsia and eclampsia should differ for adolescent patients in comparison with the rest of the population.
T lymphocytes dominate local leukocyte infiltration in response to intradermal injection of functionalized graphene‐based nanomaterial
Authors: Erf G. F. , Falcon D. M. , Sullivan K. S. , Bourdo S. E.
Published: June 2017

Graphene‐based nanomaterials (GBN) have many potential biomedical applications. However, information regarding their biological properties and interactions with cells and/or soluble factors within a complex tissue is limited. The objective of this study was to use the growing feather (GF) of chickens as a minimally invasive cutaneous test‐site to assess and monitor leukocyte recruitment in response to intradermal GBN injection. Specifically, the dermis of 20 GFs per chicken was injected with 10 μl of phosphate‐buffered saline (PBS)‐vehicle or 10 μl of 300 μg ml−1 oxygen‐functionalized (f) GBN (6 chickens/treatment). GFs were collected before‐ (0) and at 0.25, 1, 2, 3, 4, 5, and 7 days post‐injection and used for leukocyte‐population analysis of immunofluorescently stained pulp cell suspensions or histological examination. Based on flow‐cytometric cell population analysis, lymphocytes and macrophages were the major leukocyte‐populations infiltrating GFs in response to f‐GBN presence. Compared with PBS‐controls, levels of T cells (γδ‐, αβ‐, CD4‐ and CD8‐T cells) were greatly elevated in f‐GBN‐injected GFs within 6 h and remained elevated throughout the 7‐day examination period. f‐GBN's effects on local tissue leukocyte recruitment were not reflected in the blood, except for a higher percentage of lymphocytes on 7 days. These observations together with a visual examination of f‐GBN‐injected GF tissue‐sections suggest a delayed‐type hypersensitivity‐like, inflammatory cell‐mediated response to the non‐biodegradable f‐GBN. The GF ‘in vivo test‐tube‘system together with blood sampling provided unique insight into the time‐course, qualitative, and quantitative aspects of immune system activities initiated by the presence of f‐GBN in a complex tissue of a living animal. Copyright © 2017 John Wiley & Sons, Ltd.
Identification and characterization of the zebrafish glutathione S‐transferase Pi‐1
Authors: Abunnaja Maryam S. , Kurogi Katsuhisa , Mohammed Yasir I. , Sakakibara Yoichi , Suiko Masahito , Hassoun Ezdihar A. , Liu Ming‐Cheh
Published: June 2017

Zebrafish has in recent years emerged as a popular vertebrate model for use in pharmacological and toxicological studies. While there have been sporadic studies on the zebrafish glutathione S‐transferases (GSTs), the zebrafish GST gene superfamily still awaits to be fully elucidated. We report here the identification of 15 zebrafish cytosolic GST genes in NCBI GenBank database and the expression, purification, and enzymatic characterization of the zebrafish cytosolic GST Pi‐1 (GSTP1). The cDNA encoding the zebrafish GSTP1 was cloned from a 3‐month‐old female zebrafish, expressed in Eschelichia coli host cells, and purified. Purified GSTP1 displayed glutathione‐conjugating activity toward 1‐chloro‐2,4‐dinitrobenzene as a representative substrate. The enzymatic characteristics of the zebrafish GSTP1, including pH‐dependency, effects of metal cations, and kinetic parameters, were studied. Moreover, the expression of zebrafish GSTP1 at different developmental stages during embryogenesis, throughout larval development, onto maturity was examined.
Division Electrosynthesis of Palladium Nanomaterials with Copper–Graphene as Sacrificial Templates and Its Application for Hydrazine Sensing
Authors: He Yaping , Han Quan , Yang Xiaohui , Zhang Changhu , Zheng Jianbin , Huo Yanyan
Published: June 2017

One‐pot electrodeposited copper‐graphene (Cu‐GE) nanocomposite acting as sacrificial template for the division electrosynthesis of palladium nanoparticles (PdNPs) on pyrolytic graphite electrode (PGE) was synthesized. The designed PdNPs‐GE nanocomposite was evaluated as a new material for highly sensitive determination of hydrazine (N2H4). Scanning electron microscopy revealed that the PdNP‐GE‐modified PGE had uniform morphology. The results of energy‐dispersive X‐ray spectrograms confirmed the ingredients of the division electrosynthesis process. Electrochemical experiments were performed to characterize the sensing properties of PdNPs‐GE toward the electrocatalytic oxidation of N2H4 at 0.20 V in sodium phosphate buffered saline (0.1 M pH 7.0). The sensor showed fast response (<3 s), high sensitivity [398 (1 × 10−6 A) (1 × 10−3 M)−1], and broad linearity in the range 2.5 × 10−8–2.7 × 10−4 M with a relatively low detection limit of 1.0 × 10−8 M (S/N = 3).
Facile, Efficient Synthesis of Star‐Shaped π‐Conjugated Systems by Combined Olefin Metathesis with Wittig‐type Coupling
Authors: Fujio Takashi , Miwata Tomohiro , Takase Masayoshi , Sueki Shunsuke , Nomura Kotohiro
Published: June 2017

Precise, efficient one‐pot synthesis of star shaped (tri‐, tetra‐arm) π‐conjugated systems has been achieved by olefin metathesis of 5‐substituted‐2‐propenyl‐thiophene or N‐vinyl carbazole (arm segment) using a molybdenum‐alkylidene reagent and subsequent Wittig‐type cleavage with core segments containing aldehydes [tri(4‐formylphenyl)amine, 2,4,6‐tri(4‐formyl‐biphenyl)benzene, 1,4‐dimethoxy‐2,3,5,6‐tetra(4‐formylphenyl)‐benzene, etc.]; effects of the core and the arm have been clearly demonstrated.
Relationship between skin color and solar elastosis in aged Asian skin: A colorimetric–pathologic correlation
Authors: Kim Dai Hyun , Oh Ga Na , Kwon In Hyuk , Seo Soo Hong , Kye Young Chul , Ahn Hyo Hyun
Published: June 2017

Aged skin is reported to be associated with unattractive skin color changes and solar elastosis. However, comparative studies have not documented the possible correlation between the two factors. This study investigated the plausible relationship between the facial skin color of elderly Asians and solar elastosis. A total of 22 skin specimens were collected from 22 Korean patients who underwent cheek skin biopsies. Skin color was quantitatively measured using colorimetric photography techniques to produce CIE L*a*b* values; the degree of solar elastosis was quantifiably assessed using a histologic grading scale. These values were used to investigate a correlation between the CIE L*a*b* coordinates and solar elastosis grade. The solar elastosis grade increased according to patient age (r = 0.67, p = .0006). However, the extent of solar elastosis was not statistically correlated with the CIE L*a*b* values, including L*, a*, and b* (r = 0.02, p = .95; r = 0.15, p = 0.50; r = −0.07, p = 0.76, respectively). The results showed that the solar elastosis grade increased, according to patient age, because of cumulative actinic damage. However, colorimetric skin color data did not correlate with the degree of solar elastosis. Therefore, cutaneous color changes and solar elastosis are separate, age‐related phenomena. Physicians should be aware of the possible histologic changes in actinically damaged facial skin, regardless of the skin color.