bluuebunny/crossref_metadata_2025 huggingface dataset:
Johnson Solids: Anion‐Templated Silver Thiolate Clusters Capped by Sulfonate
Authors: Wang Zhi , Su Hai‐Feng , Wang Xing‐Po , Zhao Quan‐Qin , Tung Chen‐Ho , Sun Di , Zheng Lan‐Sun
Published: December 2017

Sulfonates were incorporated into six novel high‐nuclearity silver(I) thiolate clusters under the guidance of anion templates varied from S2−, SO42−, α‐[Mo5O18]6−, β‐[Mo5O18]6−, [Mo2O8]4−, to [Mo4O14(SO4)]6−. Single crystal X‐ray analysis revealed that SD/Ag1, SD/Ag3, SD/Ag5, and SD/Ag6 are discrete [S@Ag60], [α‐Mo5O18@Ag36], [Mo2O8@Ag30]2, and [Mo4O14(SO4)@Ag73] clusters, respectively, whereas SD/Ag2 and SD/Ag4 are one‐dimensional (1D) chains based on the [SO4@Ag20] and [β‐Mo5O18@Ag36] cluster subunits, respectively. Their silver skeletons are protected exteriorly by thiolates and sulfonates and interiorly supported by diverse anions as templates. Structurally, cluster SD/Ag1 is a typical core–shell structure comprised of an inner Ag12 cuboctahedron and an outer Ag48 shell. The sulfate‐templated drum‐like Ag20 cluster subunits are bridged by PhSO3− to give a 1D chain of SD/Ag2. Complex SD/Ag3 and SD/Ag4 are spindle‐like Ag36 clusters with isomeric [Mo5O18]6− inside, and the latter is further extended to a 1D chain through PhSO3− bridges. A pair of [Mo2O8]4− templated gourd‐like Ag30 clusters are dimerized in a head‐to‐head fashion to form SD/Ag5. Complex SD/Ag6 is the largest cluster in this family and doubly templated by unprecedented [Mo4O14(SO4)]6− anions. Geometrically, the silver shells of SD/Ag1–SD/Ag5 show the polyhedral features of Johnson solids, instead of the usual Platonic or Archimedean solids. Solution behaviors and luminescent properties were also investigated in detail.
Efficient Reduction of CO2 to CO Using Cobalt–Cobalt Oxide Core–Shell Catalysts
Authors: Yin Guoheng , Yuan Xiaotao , Du Xianlong , Zhao Wei , Bi Qingyuan , Huang Fuqiang
Published: December 2017

The route of converting CO2 to CO by reverse water‐gas shift (RWGS) reaction is of particular interest due to the direct use of CO as feedstock in many significant industrial processes. Here, an engineered cobalt–cobalt oxide core–shell catalyst (Co@CoO) with nanochains structure has been made for the efficient reduction of CO2 to useful CO. Owing to the excellent performance for H2 activation of metal nanoparticles and the enhanced absorption and activation for CO2 molecule of defective metal oxides, the unique synergistic effect of metallic Co and encapsulating coordinatively unsaturated CoO species shows high performance for clean generation of CO under moderate and practical conditions. Furthermore, with N‐dopant into the defective CoO shell, the Co@CoO‐N achieves the highest conversion of 19.2 % and an exceptional CO evolution rate of 96 mL min−1 gcat−1 at 523 K with a gas hourly space velocity (GHSV) of 42,000 mL gcat−1 h−1, which is comparable with the previously reported materials under identical conditions.
Selective Transformation of Well‐Defined Alkenyllithiums to Alkenylmagnesiums via Transmetalation
Authors: Zhu Miaomiao , Liu Liang , Zhang Yongliang , Yu Hai‐Tao , Zhang Wen‐Xiong , Xi Zhenfeng
Published: December 2017

A series of butadienyl organomagnesium complexes, including 1‐Li‐4‐(MgR)‐butadienes, 1,4‐bis(MgR)‐butadienes, and 1‐Mg‐4‐(MgR)‐butadiene were synthesized starting with 1,4‐dilithio butadienes via the transmetalation reaction between alkenyllithium bond and alkenylmagnesium bond. Single‐crystal X‐ray structural analysis of these butadienyl organomagnesiates revealed unique bonding modes. Study on their structural transformation demonstrated that 1‐Li‐4‐(MgR)‐butadiene is the key intermediate in the reaction process leading to the formation of 1,4‐bis(MgR)‐butadiene and 1‐Mg‐4‐(MgR)‐butadiene.
Bandgap Optimization of Perovskite Semiconductors for Photovoltaic Applications
Authors: Xiao Zewen , Zhou Yuanyuan , Hosono Hideo , Kamiya Toshio , Padture Nitin P.
Published: December 2017

The bandgap is the most important physical property that determines the potential of semiconductors for photovoltaic (PV) applications. This Minireview discusses the parameters affecting the bandgap of perovskite semiconductors that are being widely studied for PV applications, and the recent progress in the optimization of the bandgaps of these materials. Perspectives are also provided for guiding future research in this area.
A Direct Proof of the Resonance‐Impaired Hydrogen Bond (RIHB) Concept
Authors: Lin Xuhui , Wu Wei , Mo Yirong
Published: December 2017

The concept of resonance‐enhanced hydrogen bond (RAHB) has been widely accepted and applied as it highlights the positive impact of π‐conjugation on intramolecular H‐bonds. However, electron delocalization is directional and there is a possibility that π‐resonance goes from the H‐bond acceptor to the H‐bond donor, leading to a negative impact on H‐bonds. Here we used the block‐localized wavefunction (BLW) method which is a variant of ab initio valence bond (VB) theory and able to derive strictly electron‐localized structures self‐consistently, to quantify the interplay between H‐bond and π‐resonance in the terms of geometry, energetics and spectral properties. The comparison of geometrical optimizations with and without π‐resonance shows that conjugation can indeed either enhance or weaken intramolecular H‐bonds. We further experimented with various substituents attached to either the H‐bond acceptor and/or H‐bond donor side(s) to tune the H‐bonding strength in both directions.
An Exfoliated 2D Egyptian Blue Nanosheet for Highly Selective Enrichment of Multi‐Phosphorylated Peptides in Mass Spectrometric Analysis
Authors: Yang Shi‐Shu , Yu Hai‐Xia , Wang Zi‐Zhen , Liu Hai‐Long , Zhang Hao , Yu Xizhong , Shang Wenbin , Chen Gui‐Quan , Gu Zhi‐Yuan
Published: December 2017

Invited for the cover of this issue are the group of Zhi‐Yuan Gu at Nanjing Normal University, and co‐workers at Nanjing University of Chinese Medicine and Nanjing University. The image depicts a 2D CaCuSi4O10 nanosheet as an intriguing adsorbent towards highly selective enrichment of multi‐phosphopeptides Read the full text of the article at 10.1002/chem.201704138.
Real‐time feedback control of SAGD wells using model predictive control to optimize steam chamber development under uncertainty
Authors: Vembadi Shiv S. , Patel Rajan G. , Trivedi Japan J. , Prasad Vinay
Published: December 2017

The efficiency of steam assisted gravity drainage (SAGD) operation depends on developing a uniform steam chamber by maintaining an optimal subcool temperature along the length of the well pair. Implementing operational parameters obtained from model‐based optimization directly in the field may not lead to the desired subcool temperature. Based on the real‐time measurements from surface and downhole sensors, along with other well and surface constraint information, a real‐time feedback control of SAGD well pairs can be implemented to optimize subcool and steam chamber development. Model predictive control (MPC), which is a multivariable constrained controller, provides a framework for such control. To evaluate the use of MPC for real‐time control of SAGD wells, a case study is performed using a 3D heterogeneous reservoir model. Porosity and permeability realizations are created and ranked based on net present value (NPV). One of the realizations is considered as the ‘true’ reservoir, and two other realizations are selected to represent different cases of uncertain reservoir models. For each model, a reservoir simulator is used to find the optimum rates and subcool temperature, which become the set‐points for MPC to operate the wells. We compare the steam chamber growth and NPV calculated using MPC with the base case where no MPC is used and discuss the implementation advantages. Since MPC led to expedited and accurate tracking of optimized operating targets obtained using reservoir models, ∼18 % improvement in NPV is achieved compared to manual open‐loop application of optimum rates, a practice used commonly in the field.
Modelling of water transport through mixed‐ion conducting dense ceramics
Authors: Al Selgin , Song Feng , Zhang Guangru
Published: December 2017

This study develops and demonstrates a model that characterizes defect transports, responsible for water transport within dense ceramics, and calculates the diffusion coefficients for those defects. The multi‐species mass transfer processes within yttrium doped barium cerates are modelled by applying the Nernst‐Planck equation to the system. The Nernst‐Planck equation with suitable boundary conditions is adopted to compute defect diffusion coefficients in COMSOL Multiphysics. All related equations, based on charge and defect conservation, are solved numerically and validated experimentally. The model also predicts the concentration distribution of the defects and potential profiles throughout the membranes. The results provided convenient insights about the water transport and charge distribution as a function of membrane thickness.
Analysis of the multi‐echo spin‐echo pulse sequence
Authors: Zur Yuval
Published: December 2017

The multi‐echo spin‐echo sequence is a series of operators, referred to as periodic operators. Each periodic operator consists of a free rotation (no RF), a refocusing RF pulse, and another free rotation, identical to the first one. A preparation operator that precedes the periodic operators converts the equilibrium magnetization Mz into an initial magnetization Mi. It is shown that a multi‐echo sequence is equivalent to a simple rotation of the magnetization about a tilted axis. The component of Mi along the rotation axis is stationary and provides a stable signal, denoted pseudo steady‐state. The perpendicular component rotates and eventually de‐phases. Using this model, we derive analytic expressions to the signal for different preparation operators, and show how to align Mi with the rotation axis such that the signal is maximized. A simple and efficient algorithm is presented to calculate the Fourier coefficients of the magnetization during the sequence using the discrete Fourier transform. Finally, formulas of the echo signal when unavoidable phase errors are generated are derived. We show how to eliminate artifacts caused by these errors and restore the original image.
Photoinduced Intermolecular Electron Transfer Mediated by the Colloidal Tyrosyl Bolaamphiphile Assembly
Authors: Cho Junghyun , Kwak Jinyoung , Oh Juwon , Kim Dongho , Lee Sang‐Yup
Published: December 2017

The self‐assembly of tyrosyl bolaamphiphiles is exploited to create a colloidal protein‐like host matrix, upon which sacrificial electron‐donor molecules associate to create a photosystem II (PSII) mimetic electron‐relay system. This system harnesses the tyrosine phenol groups abundant on the surface of the assemblies to mediate photoinduced intermolecular electron transfer. Compared with the l‐tyrosine molecules, the tyrosyl bolaamphiphile assembly facilitates electron transfer from the sacrificial electron donor to the oxidized photosensitizer. The enhanced electron relay is likely to be driven by the host function of the assembly associated with the sacrificial electron donor and by the suppression of the oxidative cross‐linking of phenoxyl radicals. The tyrosyl bolaamphiphile assembly is advantageous in the construction of a PSII mimetic system with a protein‐like nature and displaying biochemical functions.
A Chemical View on X‐ray Photoelectron Spectroscopy: the ESCA Molecule and Surface‐to‐Bulk XPS Shifts
Authors: Delesma Francisco A. , Van den Bossche Maxime , Grönbeck Henrik , Calaminici Patrizia , Köster Andreas M. , Pettersson Lars G. M.
Published: December 2017

In this paper we remind the reader of a simple, intuitive picture of chemical shifts in X‐ray photoelectron spectroscopy (XPS) as the difference in chemical bonding between the probed atom and its neighbor to the right in the periodic table, the so called Z+1 approximation. We use the classical ESCA molecule, ethyl trifluoroacetate, and 4d‐transition metals to explicitly demonstrate agreement between core‐level shifts computed as differences between final core‐hole states and the approach where each core‐ionized atom is replaced by a Z+1 atom. In this final state, or total energy picture, the XPS shift arises due to the more or less unfavorable chemical bonding of the effective nitrogen in the carbon geometry for the ESCA molecule. Surface core level shifts in metals are determined by whether the Z+1 atom as an alloy segregates to the surface or is more soluble in the bulk. As further illustration of this more chemical picture, we compare the geometry of C 1s and O 1s core‐ionized CO with that of, respectively, NO+ and CF+. The scope is not to propose a new method to compute XPS shifts but rather to stress the validity of this simple interpretation.
Unprecedented Ionization Processes in Mass Spectrometry Provide Missing Link between ESI and MALDI
Authors: Trimpin Sarah , Lee Chuping , Weidner Steffen M. , El‐Baba Tarick J. , Lutomski Corinne A. , Inutan Ellen D. , Foley Casey D. , Ni Chi‐Kung , McEwen Charles N.
Published: December 2017

In the field of mass spectrometry, producing intact, highly‐charged protein ions from surfaces is a conundrum with significant potential payoff in application areas ranging from biomedical to clinical research. Here, we report on the ability to form intact, highly‐charged protein ions on high vacuum time‐of‐flight mass spectrometers in the linear and reflectron modes achievable using experimental conditions that allow effective matrix removal from both the sample surfaces and from the charged clusters formed by the laser ablation event. The charge states are the highest reported on high vacuum mass spectrometers, yet they remain at only around a third of the highest charge obtained using laser ablation with a suitable matrix at atmospheric pressure. Other than physical instrument modifications, the key to forming abundant and stable highly‐charged ions appears to be the volatility of the matrix used. Cumulative results suggest mechanistic links between the ionization process reported here and traditional ionization methods of electrospray ionization and matrix‐assisted laser desorption/ionization.
Overview of the European Medicines Agency's Development of Product‐Specific Bioequivalence Guidelines
Authors: Sullivan Jane O' , Blake Kevin , Berntgen Michael , Salmonson Tomas , Welink Jan ,   on behalf of the Pharmacokinetics Working Party
Published: December 2017

The European Medicines Agency's (EMA) product‐specific bioequivalence guidelines outline harmonized regulatory requirements for studies to demonstrate bioequivalence for products that may have particular needs due to their pharmacokinetics, in addition to those outlined in general guidance. As such they are potentially very useful to the pharmaceutical industry in the development of generic medicinal products and to regulatory authorities for harmonized decision‐making. Since their introduction in 2013, EMA product‐specific bioequivalence guidelines continue to increase in number, and as of June 2017, encompass a number of different pharmacotherapeutic groups and pharmaceutical forms. This article further elucidates the processes involved for stakeholders and reviews the Agency's experience with the development of these guidelines, including the scientific issues witnessed with their advancement. A comparison with the United States Food and Drug Administration approach to similar guidelines is also provided.
Kinematic Modeling of Mechanocatalytic Depolymerization of α‐Cellulose and Beechwood
Authors: Kessler Martin , Woodward Robert T. , Wong Narumi , Rinaldi Roberto
Published: December 2017

Mechanocatalytic depolymerization of lignocellulose presents a promising method for the solid‐state transformation of acidified raw biomass into water‐soluble products (WSPs). However, the mechanisms underlining the utilization of mechanical forces in the depolymerization are poorly understood. A kinematic model of the milling process is applied to assess the energy dose transferred to cellulose during its mechanocatalytic depolymerization under varied conditions (rotational speed, milling time, ball size, and substrate loading). The data set is compared to the apparent energy dose calculated from the kinematic model and reveals key features of the mechanocatalytic process. At low energy doses, a rapid rise in the WSP yield associated with the apparent energy dose is observed. However, at a higher energy dose obtained by extended milling duration or high milling speeds, the formation of a substrate cake layer on the mill vials appear to buffer the mechanical forces, preventing full cellulose conversion into WSPs. By contrast, for beechwood, there exists a good linear dependence between the WSP yield and the energy dose provided to the substrate over the entire range of WSP yields. As the formation of a substrate cake in depolymerization of beechwood is less severe than that for the cellulose experiments, the current results verify the hypothesis regarding the negative effect of a substrate layer formed on the mill vials upon the depolymerization process. Overall, the current findings provide valuable insight into relationships between the energy dose and the extent of cellulose depolymerization effected by the mechanocatalytic process.
An integrative mating system assessment of a nonmodel, economically important Pacific rockfish (Sebastes melanops) reveals nonterritorial polygamy and conservation implications for a large species flock
Authors: Karageorge Kurt W. , Wilson Raymond R.
Published: December 2017

Characterizing the mating systems of long‐lived, economically important Pacific rockfishes comprising the viviparousSebastesspecies flock is crucial for their conservation. However, direct assignment of mating success to sires is precluded by open, offshore populations and high female fecundity. We addressed this challenge by integrating paternity‐assigned mating success of females with the adult sex ratio (ASR) of the population, male evolutionary responses to receptive females, and reproductive life history traits—in the framework of sexual selection theory—to assess the mating system ofSebastes melanops. Microsatellite parentage analysis of 17 pregnant females, 1,256 of their progeny, and 106 adults from the population yielded one to four sires per brood, a mean of two sires, and a female mate frequency distribution with a truncated normal (random) pattern. The 11 multiple paternity broods all contained higher median allele richness than the six single paternity broods (Wilcoxon test:W = 0,p < .001), despite similar levels of average heterozygosity. By sampling sperm and alleles from different males, polyandrous females gain opportunities to enhance their sperm supply and to lower the cost of mating with genetically incompatible males through reproductive compensation. A mean of two mates per mated female with a variance of one, anASR = 1.2 females per male, and the expected population mean of 2.4 mates for mated males (and the estimated 35 unavailable sires), fits polygamous male mate frequency distributions that distinguish polygynandry and polyandrogyny mating systems, that is, variations of polygamy, but not polyandry. Inference for polygamy is consistent with weak premating sexual selection on males, expected in mid‐water, schoolingS. melanops, owing to polyandrous mating, moderately aggregated receptive females, an evenASR, and no territories and nests used for reproduction. Each of these characteristics facilitates more mating males and erodes conspicuous sexual dimorphism. Evaluation of male evolutionary responses of demersal congeners that express reproductively territorial behavior revealed they have more potential mechanisms for producing premating sexual selection, greater variation in reproductive success, and a reduced breeding effective population size of adults and annual effective size of a cohort, compared toS. melanopsmodeled with two mates per adult. Such divergence in behavior and mating system by territorial species may differentially lower their per capita birth rates, subsequent population growth, and slow their recovery from exploitation.
Nutrient stoichiometry and land use rather than species richness determine plant functional diversity
Authors: Busch Verena , Klaus Valentin H. , Penone Caterina , Schäfer Deborah , Boch Steffen , Prati Daniel , Müller Jörg , Socher Stephanie A. , Niinemets Ülo , Peñuelas Josep , Hölzel Norbert , Fischer Markus , Kleinebecker Till
Published: December 2017

Plant functional traits reflect individual and community ecological strategies. They allow the detection of directional changes in community dynamics and ecosystemic processes, being an additional tool to assess biodiversity than species richness. Analysis of functional patterns in plant communities provides mechanistic insight into biodiversity alterations due to anthropogenic activity. Although studies have consi‐dered of either anthropogenic management or nutrient availability on functional traits in temperate grasslands, studies combining effects of both drivers are scarce. Here, we assessed the impacts of management intensity (fertilization, mowing, grazing), nutrient stoichiometry (C, N, P, K), and vegetation composition on community‐weighted means (CWMs) and functional diversity (Rao's Q) from seven plant traits in 150 grasslands in three regions in Germany, using data of 6 years. Land use and nutrient stoichiometry accounted for larger proportions of model variance of CWM and Rao's Q than species richness and productivity. Grazing affected all analyzed trait groups; fertilization and mowing only impacted generative traits. Grazing was clearly associated with nutrient retention strategies, that is, investing in durable structures and production of fewer, less variable seed. Phenological variability was increased. Fertilization and mowing decreased seed number/mass variability, indicating competition‐related effects. Impacts of nutrient stoichiometry on trait syndromes varied. Nutrient limitation (large N:P, C:N ratios) promoted species with conservative strategies, that is, investment in durable plant structures rather than fast growth, fewer seed, and delayed flowering onset. In contrast to seed mass, leaf‐economics variability was reduced under P shortage. Species diversity was positively associated with the variability of generative traits. Synthesis. Here, land use, nutrient availability, species richness, and plant functional strategies have been shown to interact complexly, driving community composition, and vegetation responses to management intensity. We suggest that deeper understanding of underlying mechanisms shaping community assembly and biodiversity will require analyzing all these parameters.
Sap flow characteristics and responses to summer rainfall for Pinus tabulaeformis and Hippophae rhamnoides in the Loess hilly region of China
Authors: Wu Xu , Tang Yakun , Chen Yunming , Wen Jie , Xie Yuli , Lu Senbao
Published: December 2017

As a major driving element of the structure and function of arid and semiarid ecosystems, rainfall is the essential factor limiting plant biological processes. To clarify the characteristics of transpiration and responses to summer rainfall, sap flow density (Fd) of Pinus tabulaeformis and Hippophae rhamnoides was monitored using thermal dissipation probes. In addition, midday leaf water potential (ψm) and leaf stomatal conductance (Gs) were also analyzed to determine water use strategies. The results indicated that the diurnal variation in the normalized Fd values exhibited a single‐peak curve for P. tabulaeformis, while H. rhamnoides showed multiple peaks. The normalized Fd for P. tabulaeformis remained relatively stable regardless of rainfall events. However, there was also a significant increase in the normalized Fd for H. rhamnoides in response to rainfall in June and August (p < .05), although no significant differences were observed in July. The normalized Fd values for P. tabulaeformis and H. rhamnoides fitted well with the derived variable of transpiration, an integrated index calculated from the vapor pressure deficit and solar radiation (Rs), using an exponential saturation function. The differences in fitting coefficients suggested that H. rhamnoides showed more sensitivity to summer rainfall (p < .01) than P. tabulaeformis. Furthermore, during the study period, P. tabulaeformis reduced Gs as soil water decreased, maintaining a relatively constant ψm; while H. rhamnoides allowed large fluctuations in ψm to maintain Gs. Therefore, P. tabulaeformis and H. rhamnoides should be considered isohydric and anisohydric species, respectively. And more consideration should be taken for H. rhamnoides in the afforestation activities and the local plantation management under the context of the frequently seasonal drought in the loess hilly region.
Silicon amendment to rice plants contributes to reduced feeding in a phloem‐sucking insect through modulation of callose deposition
Authors: Yang Lang , Li Pei , Li Fei , Ali Shahbaz , Sun Xiaoqin , Hou Maolin
Published: December 2017

Silicon (Si) uptake by Poaceae plants has beneficial effects on herbivore defense. Increased plant physical barrier and altered herbivorous feeding behaviors are documented to reduce herbivorous arthropod feeding and contribute to enhanced plant defense. Here, we show that Si amendment to rice (Oryza sativa) plants contributes to reduced feeding in a phloem feeder, the brown planthopper (Nilaparvata lugens, BPH), through modulation of callose deposition. We associated the temporal dynamics of BPH feeding with callose deposition on sieve plates and further with callose synthase and hydrolase gene expression in plants amended with Si. Biological assays revealed that BPH feeding was lower in Si‐amended than in nonamended plants in the early stages post‐BPH infestation. Histological observation showed that BPH infestation triggered fast and strong callose deposition in Si‐amended plants compared with nonamended plants. Analysis using qRT‐PCR revealed that expression of the callose synthase gene OsGSL1 was up‐regulated more and that the callose hydrolase (β‐1,3‐glucanase) gene Gns5 was up‐regulated less in Si‐amended than in nonamended plants during the initial stages of BPH infestation. These dynamic expression levels of OsGSL1 and Gns5 in response to BPH infestation correspond to callose deposition patterns in Si‐amended versus nonamended plants. It is demonstrated here that BPH infestation triggers differential gene expression associated with callose synthesis and hydrolysis in Si‐amended and nonamended rice plants, which allows callose to be deposited more on sieve tubes and sieve tube occlusions to be maintained more thus contributing to reduced BPH feeding on Si‐amended plants.
Early phenology and growth trait variation in closely related European pine species
Authors: Wachowiak Witold , Perry Annika , Donnelly Kevin , Cavers Stephen
Published: December 2017

Closely related taxa occupying different environments are valuable systems for studying evolution. In this study, we examined differences in early phenology (bud set, bud burst) and early growth in a common garden trial of closely related pine species: Pinus sylvestris, P. mugo, and P. uncinata. Seeds for the trial were sourced from populations across the ranges of each species in Europe. Over first 4 years of development, clear differences were observed between species, while the most significant intraspecific differentiation was observed among plants from P. sylvestris populations from continental European locations. Trait differences within P. sylvestris were highly correlated with altitude and latitude of the site of origin. Meanwhile, P. mugo populations from the Carpathians had the earliest bud set and bud flush compared to other populations of the species. Overall, populations from the P. mugo complex from heterogeneous mountain environments and P. sylvestris from the Scottish Highlands showed the highest within‐population variation for the focal traits. Although the three species have been shown to be genetically highly similar, this study reveals large differences in key adaptive traits both among and within species.
A Study for Sensitivity Improvement of 3‐D Lab‐on‐a‐CD‐Based Immunosensor
Authors: KATAOKA CHIWA , AZETA TSUKASA , SAWADAISHI KAZUYUKI , UKITA YOSHIAKI , YAMAGUCHI AKINOBU , UTSUMI YUICHI
Published: December 2017

We have developed a three‐dimensional (3D) Lab‐on‐a‐CD immunosensor based on a competitive/noncompetitive assay for small endocrine disruptors and biomolecules. To improve the sensitivity of the 3D Lab‐on‐a‐CD immunosensor, an immobilizing method of capturing‐type antibody on the sensor surface was investigated. The method is based on the introduction of a highly reactive amino group to a P(MMA/CEMA) copolymer surface having chlorine, and utilizing a biotin‐streptavidin system. The functionality of the 3D Lab‐on‐a‐CD immunosensor was evaluated by measuring mouse IgG. The detection limit was found to be 3 f g/assay (3 × 10‐12 g/assay). After further modification, the 3D Lab‐on‐a‐CD immunosensor, having some characteristics such as a substrate with highly integrated antibodies, is expected to be applicable for highly sensitive immunoassay.
Fitness consequences of occasional outcrossing in a functionally asexual plant (Oenothera biennis)
Authors: Maron John L. , Johnson Marc T. J. , Hastings Amy P. , Agrawal Anurag A.
Published: December 2017

Many clonal organisms occasionally outcross, but the long‐term consequences of such infrequent events are often unknown. During five years, representing three to five plant generations, we followed 16 experimental field populations of the forb, Oenothera biennis, originally planted with the same 18 original genotypes. Oenothera biennis usually self fertilizes, which, due to its genetic system (permanent translocation heterozygosity), results in seeds that are clones of the maternal plant. However, rare outcrossing produces genetically novel offspring (but without recombination or increased heterozygosity). We sought to understand whether novel genotypes produced through natural outcrossing had greater fecundity or different multigenerational dynamics compared to our original genotypes. We further assessed whether any differences in fitness or abundances through time between original and novel genotypes were exaggerated in the presence vs. absence of insect herbivores. Over the course of the experiment, we genotyped >12,500 plants using microsatellite DNA markers to identify and track the frequency of specific genotypes and estimated fecundity on a subset (>3,000) of plants. The effective outcrossing rate was 7.3% in the first year and ultimately 50% of the plants were of outcrossed origin by the final year of the experiment. Lifetime fruit production per plant was on average 32% higher across all novel genotypes produced via outcrossing compared to the original genotypes, and this fecundity advantage was significantly enhanced in populations lacking herbivores. Among 43 novel genotypes that were abundant enough to phenotype with replication, plants produced nearly 30% more fruits than the average of their specific two parental genotypes, and marginally more fruits (8%) than their most fecund parent. Mean per capita fecundity of novel genotypes predicted their relative frequencies at the end of the experiment. Novel genotypes increased more dramatically in herbivore‐present compared to suppressed populations (45% vs. 27% of all plants), countering the increased competition from dandelions (Taraxacum officinale) that resulted from herbivore suppression. Increased interspecific competition likely also lead to the lower realized fitness of novel vs. original genotypes in herbivore‐suppressed populations. These results demonstrate that rare outcrossing and the generation of novel genotypes can create high‐fecundity progeny, with the biotic environment influencing the dynamical outcome of such advantages.
Growing competitive or tolerant? Significance of apical dominance in the overcompensating herb Gentianella campestris
Authors: Lennartsson Tommy , Ramula Satu , Tuomi Juha
Published: December 2017

As a compensatory response to herbivory, plants may branch vigorously when the growth of dormant meristems is triggered by shoot damage. Undamaged plants, on the other hand, often restrain branching, and this limitation on growth can be considered a cost of tolerance to herbivory. Restrained branching is caused by apical dominance and may, alternatively, be associated with fitness benefits in competitive environments that favor fast vertical growth. To test these hypotheses regarding selection for restrained branching, we compared the performance of two subspecies of the biennial grassland herb Gentianella campestris; the tall, apically dominant ssp. campestris and the short, multi‐stemmed ssp. islandica, which shows reduced apical dominance. For both subspecies, we manipulated the height of surrounding vegetation (competition) and damage intensity in grasslands of differing productivity (high, medium, low), and examined population growth rates using matrix population models combined with life table response experiments. In the absence of damage, ssp. campestris exhibited a higher population growth rate than ssp. islandica in the tallest vegetation, however with the growth rate still being below one. In the medium and low productivity environments where the vegetation was shorter, the population growth rate of ssp. islandica was considerably higher than that of ssp. campestris as long as no more than about 50% of the plants were damaged. When plants were damaged, the apically dominant ssp. campestris showed a positive population growth rate (λ > 1) and often overcompensatory seed production in all productivity levels, while ssp. islandica showed no compensation and therefore the population was predicted to decline (λ < 1). We conclude that restrained branching in Gentianella cannot be selected for by competition alone, but that episodes of apical damage are required to maintain the trait. Furthermore, because of the costs of restrained branching, apical dominance should be selected against in grasslands where competition and disturbance are low.
Osmium Complexes Coordinated with Poly(pyridylmethyl)diamine‐Based Hexadentate Ligands
Authors: Sugimoto Hideki , Kiriyama Kahori , Itoh Shinobu
Published: December 2017

Osmium(II) and osmium(III) complexes with a potentially hexadentate ligand [N,N,N′,N′‐tetrakis(2‐pyridylmethyl)ethylenediamine, (TPEN)] are synthesized. The X‐ray structural analysis of [OsII/III(TPEN)](PF6)2/3 complexes reveals that the chelating ligand exhibits a hexadentate coordination fashion and induces distortion from a regular octahedron to the osmium centers. Due to this distortion, the osmium(III) center becomes labile toward substitution by chloride and bromide anions. The osmium(III) complex, [OsIII(TPEN)](PF6)3, reacts with Cl– and Br– to give the anion bound six coordinated osmium(III) complex {[OsIII(Cl/Br)(κ5‐TPEN)]2+}, in which one of the equatorial pyridine donor groups is dissociated from the osmium(III) center. Kinetic and spectroscopic studies on the reaction with Br– at a low temperature suggest that the ligand substitution involves an associative mechanism via a seven coordinate osmium(III) complex intermediate involving Br–, [OsIIIBr(κ6‐TPEN)]2+. On the other hand, when the propylenediamine analogue [N,N,N′,N′‐tetrakis(2‐pyridylmethyl)propylenediamine, TPPN] is employed for the preparation of osmium(III) complex, [OsIII(TPPN)](PF6)3, the osmium(III) center displays a less distorted octahedral structure due to the longer alkylene tether. In contrast to the TPEN system, the osmium(III) complex of TPPN is reduced to the osmium(II) complex, [OsII(TPPN)](PF6)2, upon the reaction with Cl– and Br– yielding Cl2 or Br2. In this TPPN ligand system, associative mechanism involving an anion bound seven‐coordinate osmium(III) intermediate with the κ6‐hexadentate ligand is suggested to be operated as in the case of the TPEN ligand system.
Pd Nanoparticles Dispersed on ZrIV Organophosphonate: A Robust and Reusable Catalyst for Suzuki–Miyaura Cross‐Coupling Reactions
Authors: Borah Suchibrata , Mishra Shashank , Cardenas Luis , Gogoi Nayanmoni
Published: December 2017

A mesoporous zirconium(IV) phosphonate was synthesized by the hydrothermal reaction of ZrOCl2·8H2O with a trisphosphonic acid ligand, mesityl‐1,3,5‐tris(methylenephosphonic acid). Treatment of the mesoporous ZrIV phosphonate framework with Pd(OAc)2 and subsequent reduction produced a nanocomposite where Pd nanoparticles of average size ca. 7–8 nm were found to be homogeneously and abundantly dispersed over the phosphonate framework. The composite acts as an efficient and reusable heterogeneous catalyst in the Suzuki–Miyaura cross coupling reaction of aryl bromides with aryl boronic acids.
Risk of cancer in children exposed to antiretroviral nucleoside analogues in utero: The french experience
Authors: Hleyhel Mira , Goujon Stéphanie , Sibiude Jeanne , Tubiana Roland , Dollfus Catherine , Faye Albert , Mandelbrot Laurent , Clavel Jacqueline , Warszawski Josiane , Blanche Stéphane ,   on behalf of the ANRS French Perinatal Cohort study Group
Published: December 2017

All nucleoside analogues for treating HIV infection, due to their capacity to integrate into and alter human DNA, are experimentally genotoxic to some extent. The long‐term oncogenic risk after in utero exposure remains to be determined. Cancer incidence in uninfected children exposed to nucleos(t)ide reverse transcriptase inhibitors (NRTIs) was evaluated, by cross‐checking against the National Cancer Registry, in the French perinatal study of children born to HIV+ mothers. Twenty‐one cancers were identified in 15,163 children (median age: 9.9 years [interquartile range (IQR): 5.8–14.2]) exposed to at least one NRTI in utero between 1990 and 2014. Five of these children were exposed to zidovudine monotherapy, and 15 to various combinations, seven of which included didanosine. Overall, the total number of cases was not significantly different from that expected for the general population (SIR = 0.8[0.47–1.24]), but the number of cases after didanosine exposure was twice that expected (SIR = 2.5 [1.01–5.19]). Didanosine accounted for only 10% of prescriptions but was associated with one‐third of cancers. In multivariate analysis, didanosine exposure was significantly associated with higher risk (HR = 3.0 [0.9–9.8]). This risk was specifically linked to first‐trimester exposure (HR = 5.5 [2.1–14.4]). Three cases of pineoblastoma, a very rare cancer, were observed, whereas 0.03 were expected. Two were associated with didanosine exposure. Despite reassuring data overall, there is strong evidence to suggest that didanosine displays transplacental oncogenicity. These findings cannot be extrapolated to other NRTIs, but they highlight the need for comprehensive evaluations of the transplacental genotoxicity of this antiretroviral class. Environ. Mol. Mutagen., 60:404–409, 2019. © 2017 Wiley Periodicals, Inc.
Permanent earthquake‐induced actions in buried pipelines: Numerical modeling and experimental verification
Authors: Sarvanis Gregory C. , Karamanos Spyros A. , Vazouras Polynikis , Mecozzi Elisabetta , Lucci Antonio , Dakoulas Panos
Published: December 2017

Buried pipelines are often constructed in seismic and other geohazard areas, where severe ground deformations may induce severe strains in the pipeline. Calculation of those strains is essential for assessing pipeline integrity, and therefore, the development of efficient models accounting for soil‐pipe interaction is required. The present paper is aiming at developing efficient tools for calculating ground‐induced deformation on buried pipelines, often triggered by earthquake action, in the form of fault rupture, liquefaction‐induced lateral spreading, soil subsidence, or landslide. Soil‐pipe interaction is investigated by using advanced numerical tools, which employ solid elements for the soil, shell elements for the pipe, and account for soil‐pipe interaction, supported by large‐scale experiments. Soil‐pipe interaction in axial and transverse directions is evaluated first, using results from special‐purpose experiments and finite element simulations. The comparison between experimental and numerical results offers valuable information on key material parameters, necessary for accurate simulation of soil‐pipe interaction. Furthermore, reference is made to relevant provisions of design recommendations. Using the finite element models, calibrated from these experiments, pipeline performance at seismic‐fault crossings is analyzed, emphasizing on soil‐pipe interaction effects in the axial direction. The second part refers to full‐scale experiments, performed on a unique testing device. These experiments are modeled with the finite element tools to verify their efficiency in simulating soil‐pipe response under landslide or strike‐slip fault movement. The large‐scale experimental results compare very well with the numerical predictions, verifying the capability of the finite element models for accurate prediction of pipeline response under permanent earthquake‐induced ground deformations.
An Exploratory Study of Teaching Tasks in English as a Foreign Language Education
Authors: Turkan Sultan , Timpe-Laughlin Veronika , Papageorgiou Spiros
Published: December 2017

Due to rising demand for qualified teachers of English as a foreign language (EFL), interest in issues pertaining to the language proficiency of these teachers has increased. However, research focusing on the teaching tasks that EFL teachers engage in for the purposes of EFL instruction is scant. The present study aims to address this gap in the literature by identifying the teaching tasks and exploring the teaching practices reported in logs kept by 5 EFL teachers over the course of a 2‐week period. Findings suggest that the majority of language teaching tasks observed in the teachers' logs were related to the instructional stages of (a) presenting subject material and communicating lesson content and (b) planning, developing, and organizing instruction.
Self‐perceptions of aging mediate the longitudinal relationship of hopelessness and depressive symptoms
Authors: Gum Amber M. , Ayalon Liat
Published: December 2017

Objectives

The purpose of the current study was to examine the hypothesis that the prospective relationship between hopelessness and depressive symptoms is mediated by self‐perceptions of aging.

Methods

Data from 3 waves of the US Health and Retirement Study (2008, 2012, and 2014) were used (N = 4606; age M = 65.3, 55.5% female). In mediation analyses, hopelessness in 2008 was the independent variable, self‐perceptions of aging in 2012 were the mediator, and depressive symptoms in 2014 were the outcome variable.

Results

After controlling for covariates, hopelessness in 2008 was an independent predictor of self‐perceptions of aging in 2012 (β = −.10, P < .001), and self‐perceptions of aging in 2012 was an independent predictor of depressive symptoms in 2014 (β = −.41, P < .001). Hopelessness in 2008 showed both direct (β = .09, P < .001) and indirect (β = .03, P < .001) effects on depressive symptoms in 2014, indicating partial mediation by change in self‐perceptions of aging.

Conclusions

As hypothesized, change in self‐perceptions of aging partially mediated the relationship of hopelessness with depressive symptoms 6 years later. Findings are consistent with a conceptualization of hopelessness as broad negative expectations about the future that may contribute to negative self‐perceptions of aging and subsequent changes in depressive symptoms. Reducing hopelessness, increasing hope, and improving self‐perceptions of aging have potential to reduce and prevent depressive symptoms for older adults. Future research should examine the mechanisms of these interrelationships and other aging outcomes.
Factors affecting operative time in robotic thyroidectomy
Authors: Song Chang Myeon , Jang Youn Il , Ji Yong Bae , Park Jeong Seon , Kim Dong Sun , Tae Kyung
Published: December 2017

Background

The purpose of this study was to evaluate factors related to operative time in robotic thyroidectomy.

Methods

We retrospectively analyzed 240 patients who underwent robotic thyroidectomy. The total thyroidectomy cases and lobectomy cases were both categorized into those with long operative times (LOTs; upper 25% of cases) and those with short operative times (SOTs; lower 25%).

Results

Among the total thyroidectomy cases, body mass index (BMI) ≥23 kg/m2 (hazard ratio [HR] 5.34; P = .008) and bilateral central neck dissection (CND; HR 14.92; P = .028) were more frequent in the LOT group in multivariate analysis. Among the lobectomy cases, BMI ≥23 kg/m2 (HR 12.92; P = .003) and unilateral CND (HR 21.38; P = .017) were the only independent risk factors for prolonged operative time.

Conclusion

Body habitus and clinical nodal status in the central compartment should be considered in deciding the indications for robotic thyroidectomy.
Numerical Evaluation of the Effects of Increasing Ratio of Cropped to Uncropped Width on Dry Drainage Efficiency in Salty Soils
Authors: Soltani Masoud , Rahimikhoob Ali , Sotoodehnia Abbas , Mendicino Giuseppe , Akram Mojtaba , Senatore Alfonso
Published: December 2017

Sustainable agriculture can contribute to food security in arid and semi‐arid regions if soil salinity in the root zone is kept under control. Recently, experts have been concentrating their research towrds alternative and environmentally friendly solutions. In this study, dry drainage was evaluated as a sustainable and cost‐effective alternative technique, by means of both field experiments and a numeric approach based on the HYDRUS‐2D modelling environment. Results showed that soil salinity in the cropped area increased from the soil surface to the bottom, and soil salinity movement (transport direction) was from the cropped to uncropped area. Increasing the ratio of cropped to uncropped width led to an increase in soil salinity of the cropped root zone and lack of stabilization of salinity concentration. Results of modelling showed that there are no significant differences between observed and modelled data, even though HYDRUS‐2D simulated soil water content better than soil salinity. Averages of performance indices for simulated soil water content (SE = 0.08, NRMSE = 0.133) were better in comparison with simulated soil salinity (SE = 0.28, NRMSE = 0.262). Soil surface salinity in the cropped area increased 2.7 times (from 2.1 to 5.7 dS m−1) during the experiment for equal cropped to uncropped width (1 (cropped): 1 (uncropped)), and by increasing cropped width (2 (cropped): 1 (uncropped)) it increased 7.5 times (from 2.3 to 17.3 dS m−1). Copyright © 2017 John Wiley & Sons, Ltd.
On the Suitability of 6TiSCH for wireless seismic data streaming
Authors: Vilajosana Xavier , Martinez Borja , Vilajosana Ignasi , Watteyne Thomas
Published: December 2017

Seismic tomography is a technique for imaging the subsurface of the Earth with seismic waves produced by earthquakes (passive) or explosions (active). A typical instrumentation deployment involves hundreds or even thousands of equally distributed data‐loggers, reading from geophones, that sample typically between 250 and 2000 Hz in a synchronized manner. This data is streamed outside the data‐logger network for postexperiment processing. In this letter, we evaluate the suitability of IETF 6TiSCH technology for a standards‐based real‐time data streaming solution, and highlight the benefits of standardization in this market sector.