bluuebunny/crossref_metadata_2025 huggingface dataset:
The lichen-forming fungi of the Xanthoparmelia pulla group (Parmeliaceae, Ascomycota) in Poland
Authors: Szczepańska Katarzyna , Kossowska Maria
Published: February 2014

The paper presents the results of studies of Xanthoparmelia pulla group in Poland. The morphological and chemical analysis of herbarium materials confirmed the presence of four species of this group reported from Poland before. The study however, revealed considerable changes it the partiuclular species distribution. X. verruculifera, so far considered the most endangered species in the country, turned out to be the most frequent taxon. X. loxodes, regarded as common, has much less known localities than previously thought. This species was usually confused with X. verruculifera. Xanthoparmelia pulla is the rarest species and should be considered critically endangered in Poland. Most specimens of X. pulla collected in the country belong to X. delisei, which so far had only two historical records in Poland. All these taxa are characterized in terms of morphology, the content of secondary metabolites, ecology and distribution.
Espacements
Authors: Ferro Antonino , Civitarese Giuseppe
Published: February 2014

Le thème de la temporalité, si important en psychanalyse, représente un de ces carrefours où se croisent d’autres concepts extraordinairement importants tels que le setting, la subjectivité, les théories du travail clinique, l’interprétation et la conception des facteurs thérapeutiques, l’institution psychanalytique. Nous abordons ici le concept de l’espace-temps en relation avec la théorie du champ analytique de Bion. L’hypothèse que nous avançons est que le champ est l’instrument conceptuel qui permet de moduler de façon plus fine et plus sûre la distance qui s’établit entre le patient et l’analyste pour atteindre et étendre l’unisson émotionnel qui, selon nous, est le facteur thérapeutique central.
Éloge de l’humide. Vertu de l’intermédiaire, du pré-conscient et du clair-obscur
Authors: Jacques André
Published: February 2014

Ce texte aborde de façon métaphorique la notion de préconscient en tant que « zone intermédiaire », et le rôle de cette instance dans le fonctionnement de l’appareil psychique. Un cas de figure tiré de l’histoire contemporaine et la référence à une facette de la société technologique actuelle, permettent d’illustrer la résistance de plusieurs à l’égard de cette zone claire-obscure de la psyché. La psychothérapie psychanalytique de groupe est évoquée comme moyen privilégié d’approcher l’« humide ».
Mobile display technologies: Past developments, present technologies, and future opportunities
Authors: Ohshima Hiroyuki
Published: February 2014

It has been thirty years since the first active matrix (AM) flat panel display (FPD) was industrialized for portable televisions (TVs) in 1984. The AM FPD has become a dominant electronic display technology widely used from mobile displays to large TVs. The development of AM FPDs for mobile displays has significantly changed our lives by enabling new applications, such as notebook personal computers (PCs), smartphones and tablet PCs. In the future, the role of mobile displays will become even more important, since mobile displays are the live interface for the world of mobile communications in the era of ubiquitous networks. Various developments are being conducted to improve visual performance, reduce power consumption and add new functionality. At the same time, innovative display concepts and novel manufacturing technologies are being investigated to create new values.
Photoconductivity of Si films after blue multi-laser diode annealing for photosensor applications
Authors: Koswaththage Charith Jayanada , Chinen Satoshi , Sugihara Kouya , Okada Tatsuya , Noguchi Takashi
Published: February 2014

The photoconductivity of Si films after blue multi-laser diode annealing (BLDA) has been investigated for photosensor applications. It was found that, as the laser power increases from 4 to 6 W, the crystal structure changed from micrograins to large grains, and that the photoconductivity increases. After sintering the Si films in H2/N2 (4%) ambient at 450 °C, a photosensitivity ratio of 94 was obtained under white light exposure of 100 mW/cm2 for the Si film after the BLDA at 6 W owing to the reduction in the defects density in the Si films. These results suggest that BLDA is promising for photosensor applications in a multifunctional system on panels.
Lacustrine turbidites as a tool for quantitative earthquake reconstruction: New evidence for a variable rupture mode in south central Chile
Authors: Moernaut Jasper , Daele Maarten Van , Heirman Katrien , Fontijn Karen , Strasser Michael , Pino Mario , Urrutia Roberto , De Batist Marc
Published: February 2014

Understanding the long‐term earthquake recurrence pattern at subduction zones requires continuous paleoseismic records with excellent temporal and spatial resolution and stable threshold conditions. South central Chilean lakes are typically characterized by laminated sediments providing a quasi‐annual resolution. Our sedimentary data show that lacustrine turbidite sequences accurately reflect the historical record of large interplate earthquakes (among others the 2010 and 1960 events). Furthermore, we found that a turbidite's spatial extent and thickness are a function of the local seismic intensity and can be used for reconstructing paleo‐intensities. Consequently, our multilake turbidite record aids in pinpointing magnitudes, rupture locations, and extent of past subduction earthquakes in south central Chile. Comparison of the lacustrine turbidite records with historical reports, a paleotsunami/subsidence record, and a marine megaturbidite record demonstrates that the Valdivia Segment is characterized by a variable rupture mode over the last 900 years including (i) full ruptures (Mw ~9.5: 1960, 1575, 1319 ± 9, 1127 ± 44), (ii) ruptures covering half of the Valdivia Segment (Mw ~9: 1837), and (iii) partial ruptures of much smaller coseismic slip and extent (Mw ~7.5–8: 1737, 1466 ± 4). Also, distant or smaller local earthquakes can leave a specific sedimentary imprint which may resolve subtle differences in seismic intensity values. For instance, the 2010 event at the Maule Segment produced higher seismic intensities toward southeastern localities compared to previous megathrust ruptures of similar size and extent near Concepciόn.
Present‐day deformation of northern Pakistan from Salt Ranges to Karakorum Ranges
Authors: Jouanne F. , Awan A. , Pêcher A. , Kausar A. , Mugnier J. L. , Khan I. , Khan N. A. , Van Melle J.
Published: February 2014

Episodic GPS measurements are used to quantify the present‐day velocity field in the northwestern Himalaya from the southern Pamir to the Himalayan foreland. We report large postseismic displacements following the 2005 Kashmir earthquake and several mm/yr thrusting of the central segment of the Salt Ranges and Potwar Plateau over the foreland, westward thrusting of Nanga Parbat above the Kohistan Plateau, and ~12 mm/yr SSE velocities of the Karakorum Ranges and of the Deosai and Kohistan Plateaus relative to the Indian Plate. Numerical simulations allow to determine a first approximation of slip along active faults: (1) substantial creep of ~87 mm/yr between 2006 and 2012 along the flat northeast of the Balakot‐Bagh Thrust affected by the 2005 earthquake; (2) ~5 mm/yr slip of the central segment of the Salt Ranges and Potwar Plateau, whereas their western boundaries are clearly inactive over the time span covered by our measurements; (3) 13 mm/yr ductile slip along the Main Himalayan Thrust modeled by a dislocation dipping 7° northward, locked at a depth of 15 km; and (4) ~20 mm/yr slip along the shear zone forming the western boundary of Nanga Parbat, between depths of 1.6 and 6.5 km. Residuals velocities suggest the existence of left‐lateral strike slip along the Jhelum Fault.
Design and Synthesis of Chiral Nematic Liquid Crystals
Authors: Taugerbeck Andreas , Booth Christopher J.
Published: February 2014

The article contains sections titled:

Introduction to the Chiral Nematic Phase and Its Properties

Formulation and Application of Chiral Nematic Liquid Crystal Mixtures

Applications of Chiral Nematic Phases

Classification of Chiral Nematic Liquid‐Crystalline Compounds

Aspects of Molecular Symmetry for Chiral Nematic Phases

TypeIChiral Nematic Liquid Crystals

Azobenzenes and Related Mesogens

Azomethine (Schiff's Base) Mesogens

Stable Phenyl, Biphenyl, Terphenyl, and Phenylethylbiphenyl Mesogens

Ester Mesogens

Derivatives of Chiral Alcohols

TypeIIChiral Nematic Liquid Crystals

TypeIIaTwin Systems Using Chiral Flexible Spacers

TypeIIbMaterials Using Achiral Flexible Spacers and Chiral Terminal Groups

TypeIIcanddMaterials Using One or Two Chiral Cores

TypeIIIChiral Nematic Liquid Crystals

Cholesteryl Esters

Chiral Mesogens Derived from Cyclohexane

Chiral Heterocyclic Mesogens

Axially Chiral Liquid Crystals

Axially Chiral Alkenes and Overcrowded Alkenes

Allenes

Tricyclo[4.4.0.03,8]decane or Twistane Derived Mesogens

Sterically Hindered Biphenyl Derivatives

Spirobiindane Derivatives

Concluding Remarks
The Structures of the Blue Phases
Authors: Collings Peter John
Published: February 2014

The article contains sections titled:

Introduction

Fundamental Concepts

Theory

Bragg Scattering

Crystal Morphology

Optical Activity

Phase Diagram

Heat Capacity

Electric Field Effects

Wide Temperature Range Blue Phases

Smectic Blue Phases

Conclusion
Virus Particle‐Based Liquid Crystals
Authors: Lydon John
Published: February 2014

The mesogenic properties of tobacco mosaic virus (
TMV
) were apparent as soon as reasonable quantities of pure material became available. The nematic phase formed by aqueous solutions was extensively investigated by Bernal and Fankuchen using optical microscopy and X‐ray diffraction in the 1930s and 1940s. Early electron microscopy confirmed that the virus particles were long, thin, straight rods. Later, the work of Klug and others gave a detailed picture of the structure of the capsid protein and led to an understanding of the complex processes of self‐assembly of the virus
in vivo
. Because of its simple shape and monodispersity,
TMV
was used as the definitive test case for the Onsager theory. Mixtures of virus rods and polymer spheres produce interesting mesophases and have rich phase diagrams.

In addition to filamentous viruses such as
TMV
, there are “spherical” viruses (which are actually icosahedral). Examples are the virus responsible for poliomyelitis and the adenoviruses. These readily form cubic, colloidal liquid crystalline phases. When the particles are of optical dimensions, the ordered phase has the structure and iridescent properties of gem opal. Techniques have been developed to produce inverse opals using virus particles as sacrificial templates.

Viruses are the classic self‐ordering structures and infectious viruses will spontaneously assemble
in vitro
from their component proteins and nucleic acid. Using contemporary genetic engineering techniques, it is now virtually a routine matter to modify the molecular structures of the components and hence exert a considerable degree of control over the properties of the capsid. Genetically modified viruses offer a general route for the production of materials with complex nanoscale detail, for use either directly or as templates. It appears likely that modified viruses will feature prominently in the nanotechnology of the immediate future. The possible commercial exploitation of virus‐templated materials includes nanowires, high surface area materials for battery electrodes, detectors, catalytic material, light harvesting devices, quantum dots, and tunable photonic devices.
Structure and Properties of Side Group Thermotropic Liquid Crystal Polymers
Authors: Ujiie Seiji , Orihara Hiroshi
Published: February 2014

The liquid crystalline behavior of side‐chain liquid crystal polymers (LCPs) resembles that of low‐molecular‐weight liquid crystals, because it is mainly dependent on interactions between mesogenic side groups. The flexibility of the polymer backbone and the length of the spacer are important factors determining the physical properties because the dynamic properties of the mesogenic groups are influenced by nonmesogenic parts of both the polymer backbone and the spacer chain. The orientational order of the mesogenic groups and the thermal stability of the liquid crystalline states increase when the side‐chain LCPs have a highly flexible polymer backbone and a long spacer.

The influence of these structures on the physical properties of the side‐chain LCPs is examined in this chapter. The thermal, mechanical, optical, electric, and electronic properties of side‐chain LCPs depend on the orientational order and molecular dynamics properties of the side‐chain LCPs. The dielectric properties and electro‐optical effects provide important information about the dynamics and the orientational order. These properties are mainly determined by the characters of the mesogenic side groups, and in the side‐chain LCPs, the mesogenic side groups are dominantly assembled into strongly coupled units through the influence of the polymer backbone.

In this chapter, the structure and properties of the side‐chain LCPs are discussed. In particular, their phase transitions, dielectric properties, and ferroelectric response are revealed.
Recent Advances in Nematic Liquid Crystal Nonlinear Optics
Authors: Tabiryan Nelson V. , Khoo Iam‐Choon
Published: February 2014

A critical review of recent advances in liquid crystal nonlinear optics is presented. We begin by reviewing the fundamental mechanisms responsible for the extraordinarily large nonlinear optical responses of this mesophase of liquid crystals, including laser‐induced director axis reorientation, order parameter, and birefringence modification and their dynamical characteristics.
Redox‐Active (Electrochromic) Liquid Crystals
Authors: Isoda Kyosuke , Yasuda Takuma , Funahashi Masahiro , Kato Takashi
Published: February 2014

Redox‐active liquid‐crystalline materials are expected to function as anisotropic redox‐active materials in the films. These materials can be applied into electrochromic and electronic devices. In this chapter, recent researches of redox‐active liquid‐crystalline materials such as TCNQ, viologen, truxene, oligothiophene, fullerene, and rotaxane derivatives and metallomesogens are overviewed.
Ultrahigh Responsivity of Ternary Sb–Bi–Se Nanowire Photodetectors
Authors: Huang Rong , Zhang Jie , Wei Fenfen , Shi Lin , Kong Tao , Cheng Guosheng
Published: February 2014

High‐quality single‐crystalline ternary (Sb1‐xBix)2Se3 nanowires (NWs) (x = 0–0.88) are synthesized by chemical vapor deposition. Nanowires with x from 0 to 0.75 are indexed as an orthorhombic structure. With increasing Bi incorporation ratio, (Sb1‐xBix)2Se3 NWs exhibit remarkable photoresponsivities, which originate from growing surface Se vacancies and augmented oxygen chemisorptions. Notably, spectra responsivity and external quantum efficiency of an (Sb0.44Bi0.56)2Se3 NW photodetector reach as high as ≈8261.4 A/W and ≈1.6 × 106 %, respectively. Those excellent performances unambiguously demonstrate that Sb–Bi–Se NWs are promising for the utilizations of high‐sensitivity and high‐speed photodetectors and photoelectronic switches.
Understanding the role of oxygen in the segregation of sodium at the surface of molybdenum coated soda‐lime glass
Authors: Forest Robert V. , Eser Erten , McCandless Brian E. , Birkmire Robert W. , Chen Jingguang G.
Published: February 2014

Molybdenum (Mo) coated soda‐lime glass is a commonly used substrate for Cu(InGa)Se2 solar cells as it also acts as the sodium (Na) source, which improves the efficiency of these devices. In this work, we investigate how oxygen controls the segregation and accumulation of Na on the Mo surface. A direct relationship between the concentration of surface oxygen and the amount of Na accumulation is showed. Values for the surface segregation ratio and grain boundary diffusion coefficient for Na in Mo are obtained by fitting diffusion data at several temperatures to a model for grain boundary diffusion. The results of this model reveal that surface oxygen controls the Na saturation level through its effect on the surface segregation of Na. An activation energy for grain boundary diffusion of Na is estimated and is similar to that of MoO bond dissociation in MoO3 suggesting the involvement of this bond during Na transport. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2365–2372, 2014
Dismutatives und globales Minimumisomer der schwereren 1,4‐Dimetallatetrasilabenzole der Gruppe 14
Authors: Jana Anukul , Huch Volker , Repisky Michal , Berger Raphael J. F. , Scheschkewitz David
Published: February 2014

Arene mit schwereren Gruppe‐14‐Elementen zeigen oft bemerkenswerte Unterschiede in Struktur und Reaktivität. Wir berichten hier über unsere experimentellen und theoretischen Untersuchungen zu verschiedenen Isomeren Ge‐ und Sn‐haltiger Benzol‐analoger Verbindungen E2Si4R6 (E=Ge, Sn). Das Ge‐substituierte dismutative Isomer mit tricyclischem sechsgliedrigem Ringgerüst kann isoliert werden, lagert sich aber im Unterschied zum homonuklearen Si6‐Analogon sogar bei Raumtemperatur langsam zum Propellan‐artigen globalen Minimumisomer um. Bei E=Sn könnte das dismutative Isomer zwar ein Intermediat bei der Bildung der isolierbaren Propellan‐artigen Spezies sein, es kann jedoch nicht einmal bei tiefen Temperaturen nachgewiesen werden. Beispiellos große chemische Verschiebungsanisotropien in den 29Si‐NMR‐Spektren, die in der Reihe von Si6 über Ge2Si4 zu Sn2Si4 sukzessive ansteigen, können durch steigende paramagnetische Terme in den chemischen Verschiebungen erklärt werden. Deren Größe ist bedingt durch sinkende HOMO‐LUMO‐Abstände, die auch in den Absorptionsspektren ihren Niederschlag finden, sowie durch Form und Symmetrie der Grenzorbitale.
Modification of Fluorescent Photoinduced Electron Transfer (PET) Sensors/Switches To Produce Molecular Photo‐Ionic Triode Action
Authors: Huxley Allen J. M. , Schroeder Marc , Nimal Gunaratne H. Q. , Prasanna de Silva A.
Published: February 2014

The fluorophore‐spacer1‐receptor1‐spacer2‐receptor2 system (where receptor2 alone is photoredox‐inactive) shows ionically tunable proton‐induced fluorescence off‐on switching, which is reminiscent of thermionic triode behavior. This also represents a new extension to modular switch systems based on photoinduced electron transfer (PET) towards the emulation of analogue electronic devices.
Gas‐Phase Peptide Structures Unraveled by Far‐IR Spectroscopy: Combining IR‐UV Ion‐Dip Experiments with Born–Oppenheimer Molecular Dynamics Simulations
Authors: Jaeqx Sander , Oomens Jos , Cimas Alvaro , Gaigeot Marie‐Pierre , Rijs Anouk M.
Published: February 2014

Vibrational spectroscopy provides an important probe of the three‐dimensional structures of peptides. With increasing size, these IR spectra become very complex and to extract structural information, comparison with theoretical spectra is essential. Harmonic DFT calculations have become a common workhorse for predicting vibrational frequencies of small neutral and ionized gaseous peptides.1 Although the far‐IR region (<500 cm−1) may contain a wealth of structural information, as recognized in condensed phase studies,2 DFT often performs poorly in predicting the far‐IR spectra of peptides. Here, Born–Oppenheimer molecular dynamics (BOMD) is applied to predict the far‐IR signatures of two γ‐turn peptides. Combining experiments and simulations, far‐IR spectra can provide structural information on gas‐phase peptides superior to that extracted from mid‐IR and amide A features.
Electrochemistry of Nanoparticles
Authors: Kleijn Steven E. F. , Lai Stanley C. S. , Koper Marc T. M. , Unwin Patrick R.
Published: February 2014

Metal nanoparticles (NPs) find widespread application as a result of their unique physical and chemical properties. NPs have generated considerable interest in catalysis and electrocatalysis, where they provide a high surface area to mass ratio and can be tailored to promote particular reaction pathways. The activity of NPs can be analyzed especially well using electrochemistry, which probes interfacial chemistry directly. In this Review, we discuss key issues related to the electrochemistry of NPs. We highlight model studies that demonstrate exceptional control over the NP shape and size, or mass‐transport conditions, which can provide key insights into the behavior of ensembles of NPs. Particular focus is on the challenge of ultimately measuring reactions at individual NPs, and relating the response to their structure, which is leading to imaginative experiments that have an impact on electrochemistry in general as well as broader surface and colloid science.
Unexpected Formation of a [4]Radialene and Dendralenes by Addition of Tetracyanoethylene to a Tetraaryl[5]cumulene
Authors: Januszewski Johanna A. , Hampel Frank , Neiss Christian , Görling Andreas , Tykwinski Rik R.
Published: February 2014

The use of cumulenes in synthetic transformations offers the possibility to form structurally interesting and potentially useful conjugated molecules. The cycloaddition reaction of a tetraaryl[5]cumulene with the electron‐deficient olefin tetracyanoethylene affords unusual products, including functionalized dendralenes and alkylidene cyclobutanes, as well as a symmetric [4]radialene that shows unique solvatochromism, with λmax values approaching the near‐IR region. These carbon‐rich products have been investigated spectroscopically and by X‐ray crystallographic analysis (five structures). The cycloaddition reaction sequence has also been explored by mechanistic and theoretical studies. The obtained results clearly demonstrate the potential of [5]cumulenes to serve as precursors for unprecedented conjugated structures.
Nanosized Heterostructures of Au@Prussian Blue Analogues: Towards Multifunctionality at the Nanoscale
Authors: Maurin‐Pasturel Guillaume , Long Jérôme , Guari Yannick , Godiard Franck , Willinger Marc‐Georg , Guerin Christian , Larionova Joulia
Published: February 2014

Access to multifunctionality at the nanoscale requires the development of hybrid nanostructures that combine materials of different natures. In this line of thought, current research on coordination polymers is not only focusing on their synthesis at the nanoscale, but also on combining these polymers with other materials. According to a novel and rational approach, single‐layer Au@Prussian blue analogue (PBA) and double‐layer Au@PBA@PBA′ core–shell nanoparticles (NPs) may be obtained through the growth of a cyano‐bridged coordination network on the gold surface. The nanosized heterostructures combine the plasmonic optical properties of the gold core and the magnetic properties of the PBA shell. Whereas the single‐layer nanoparticles are paramagnetic, the double‐layer nanostructures display ferromagnetism; therefore, the overall structural motif may be considered as multifunctional. The developed synthetic concept also includes an easy access to hollow PBA NPs.
Dismutational and Global‐Minimum Isomers of Heavier 1,4‐Dimetallatetrasilabenzenes of Group 14
Authors: Jana Anukul , Huch Volker , Repisky Michal , Berger Raphael J. F. , Scheschkewitz David
Published: February 2014

Aromatic species with heavier Group 14 elements show remarkable differences in terms of stability, structure, and reactivity. Herein we report our experimental and theoretical investigations regarding isomers of germanium‐ and tin‐containing benzene analogues E2Si4R6 (E=Ge, Sn). The germanium‐substituted dismutational isomer with a tricyclic six‐membered scaffold is isolable, but unlike the homonuclear Si6 analogue slowly rearranges even at room temperature to give the propellane‐type global minimum isomer. In case of E=Sn the dismutational isomer may be an intermediate on the pathway to the propellane‐type species obtained, but cannot be detected even at low temperature. Unprecedentedly large chemical shift anisotropies in the 29Si NMR spectra that increase from the Si6 species through Ge2Si4 to Sn2Si4 are rationalized by progressively larger paramagnetic‐term contributions to the chemical shift tensor as a result of diminishing HOMO–LUMO gaps, which are also reflected in the absorption spectra, as well as by appearance and symmetry of these frontier orbitals.
Superconducting Double Perovskite Bismuth Oxide Prepared by a Low‐Temperature Hydrothermal Reaction
Authors: Rubel Mirza H. K. , Miura Akira , Takei Takahiro , Kumada Nobuhiro , Mozahar Ali M. , Nagao Masanori , Watauchi Satoshi , Tanaka Isao , Oka Kengo , Azuma Masaki , Magome Eisuke , Moriyoshi Chikako , Kuroiwa Yoshihiro , Azharul Islam A. K. M.
Published: February 2014

Perovskite‐type structures (ABO3) have received significant attention because of their crystallographic aspects and physical properties, but there has been no clear evidence of a superconductor with a double‐perovskite‐type structure, whose different elements occupy A and/or B sites in ordered ways. In this report, hydrothermal synthesis at 220 °C produced a new superconductor with an A‐site‐ordered double perovskite structure, (Na0.25K0.45)(Ba1.00)3(Bi1.00)4O12, with a maximum Tc  of about 27 K.
Microsoft academic search and Google scholar citations: Comparative analysis of author profiles
Authors: Ortega José Luis , Aguillo Isidro F.
Published: February 2014

This article offers a comparative analysis of the personal profiling capabilities of the two most important free citation‐based academic search engines, namely, Microsoft Academic Search (MAS) and Google Scholar Citations (GSC). Author profiles can be useful for evaluation purposes once the advantages and the shortcomings of these services are described and taken into consideration. In total, 771 personal profiles appearing in both the MAS and the GSC databases were analyzed. Results show that the GSC profiles include more documents and citations than those in MAS but with a strong bias toward the information and computing sciences, whereas the MAS profiles are disciplinarily better balanced. MAS shows technical problems such as a higher number of duplicated profiles and a lower updating rate than GSC. It is concluded that both services could be used for evaluation proposes only if they are applied along with other citation indices as a way to supplement that information.
An integrated examination of collaboration coauthorship networks through structural cohesion, holes, hierarchy, and percolating clusters
Authors: Ghosh Jaideep , Kshitij Avinash
Published: February 2014

Structural cohesion, hierarchy, holes, and percolating clusters share a complementary existence in many social networks. Although the individual influences of these attributes on the structure and function of a network have been analyzed in detail, a more accurate picture emerges in proper perspective and context only when research methods are employed to integrate their collective impacts on the network. In a major research project, we have undertaken this examination. This paper presents an extract from this project, using a global network assessment of these characteristics. We apply our methods to analyze the collaboration networks of a subset of researchers in India through their coauthored papers in peer‐reviewed journals and conference proceedings in management science, including related areas of information technology and economics. We find the Indian networks to be currently suffering from a high degree of fragmentation, which severely restricts researchers' long‐rage connectivities in the networks. Comparisons are made with networks of a similar sample of researchers working in the United States.
Time Estimation Among Low‐Functioning Individuals With Autism Spectrum Disorders: Evidence of Poor Sensitivity to Variability of Short Durations
Authors: Brodeur Darlene A. , Gordon Green Cathryn , Flores Heidi , Burack Jacob A.
Published: February 2014

Time estimation of short durations (under 1 sec) was examined in low‐functioning individuals with autism spectrum disorder (ASD) and typically developing (TD) children matched on mental age. Temporal bisection and generalization tasks were used to examine basic perceptual timing mechanisms. For both tasks, the participants with ASD demonstrated less sensitivity to variability in short durations than the TD children, adding to a growing body of literature suggesting deficits in timing exist for longer durations. The results highlight the need to examine multiple levels of processing of time‐related information from basic perceptual mechanisms to higher level cognitive mechanisms. Autism Res 2014, 7: 237–244. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.
New biodiesel additives from glycerol and isoamylenes
Authors: Izquierdo José Felipe , Outón Pablo R. , Galán Maribel , Jutglar Luis , Villarrubia Miguel , Ariza Xavier
Published: February 2014

The etherification of glycerol and isoamylenes was performed using several macromolecularion‐exchange resins in order to find the best catalyst which would provide the maximum conversion of glycerol and higher selectivities to ethers. Some different organic solvents (tert‐amyl alcohol, 1,4‐dioxane, acetonitrile, n‐hexane, dichloromethane, diisopropylamine and dimethylformamide) were used in the etherification of glycerol. Reactions were carried out in a batch autoclave reactor at 1.5 MPa in the temperature range from 25 to 100 °C for 24 h of contact time. It was found that resins with a greater pore volume and greater pore diameter showed a better performance in solventless reactions, but when employing solvents their polarity was responsible for the distinct results obtained in the conversion of glycerol: relative abundance and composition of the polar and non‐polar phases in the final reaction mixture. The solubilization of glycerol and isoamylenes in the reaction mixture seems to be the main factor in the progress of the reaction, which is reflected in the different amount of ethers primarily obtained in the non‐polar phase. tert‐Amyl alcohol showed the best results in terms of conversion of glycerol due to the total miscibility of both reactants but it must be employed at temperatures below 50 °C in order to avoid its dehydration reaction that reduces the catalyst activity.
Clustered and genome‐wide transient mutagenesis in human cancers: Hypermutation without permanent mutators or loss of fitness
Authors: Roberts Steven A. , Gordenin Dmitry A.
Published: February 2014

The gain of a selective advantage in cancer as well as the establishment of complex traits during evolution require multiple genetic alterations, but how these mutations accumulate over time is currently unclear. There is increasing evidence that a mutator phenotype perpetuates the development of many human cancers. While in some cases the increased mutation rate is the result of a genetic disruption of DNA repair and replication or environmental exposures, other evidence suggests that endogenous DNA damage induced by AID/APOBEC cytidine deaminases can result in transient localized hypermutation generating simultaneous, closely spaced (i.e. “clustered”) multiple mutations. Here, we discuss mechanisms that lead to mutation cluster formation, the biological consequences of their formation in cancer and evidence suggesting that APOBEC mutagenesis can also occur genome‐wide. This raises the possibility that dysregulation of these enzymes may enable rapid malignant transformation by increasing mutation rates without the loss of fitness associated with permanent mutators.
Genetic instability is prevented by Mrc1‐dependent spatio‐temporal separation of replicative and repair activities of homologous recombination
Authors: Prado Félix
Published: February 2014

Homologous recombination (HR) is required to protect and restart stressed replication forks. Paradoxically, the Mrc1 branch of the S phase checkpoints, which is activated by replicative stress, prevents HR repair at breaks and arrested forks. Indeed, the mechanisms underlying HR can threaten genome integrity if not properly regulated. Thus, understanding how cells avoid genetic instability associated with replicative stress, a hallmark of cancer, is still a challenge. Here I discuss recent results that support a model by which HR responds to replication stress through replicative and repair activities that operate at different stages of the cell cycle (S and G2, respectively) and in distinct subnuclear structures. Remarkably, the replication checkpoint appears to control this scenario by inhibiting the assembly of HR repair centers at stressed forks during S phase, thereby avoiding genetic instability.
Reasons for non-participation in population-based abdominal aortic aneurysm screening
Authors: Linne A , Leander K , Lindström D , Törnberg S , Hultgren R
Published: February 2014

Background

A population-based screening programme for abdominal aortic aneurysm (AAA) started in 2010 in Stockholm County, Sweden. This present study used individual data from Sweden's extensive healthcare registries to identify the reasons for non-participation in the AAA screening programme.

Methods

All 65-year-old men in Stockholm are invited to screening for AAA; this study included all men invited from July 2010 to July 2012. Participants and non-participants were compared for socioeconomic factors, travel distance to the examination centre and healthcare use. The influence of these factors on participation was analysed using univariable and multivariable logistic regression models.

Results

The participation rate for AAA screening was 77·6 per cent (18 876 of 24 319 men invited). The prevalence of AAA (aortic diameter more than 2·9 cm) among participants was 1·4 per cent. The most important reasons for non-participation in the multivariable regression analyses were: recent immigration (within 5 years) (odds ratio (OR) 3·25, 95 per cent confidence interval 1·94 to 5·47), low income (OR 2·76, 2·46 to 3·10), marital status single or divorced (OR 2·23, 2·08 to 2·39), low level of education (OR 1·28, 1·16 to 1·40) and long travel distance (OR 1·23, 1·10 to 1·37). Non-participants had a higher incidence of stroke (4·5 versus 2·8 per cent; P < 0·001) and chronic pulmonary disease (2·9 versus 1·3 per cent; P < 0·001). Daily smoking was more common in residential areas where the participation rate for AAA screening was low.

Conclusion

Efforts to improve participation in AAA screening should target the groups with low income, a low level of education and immigrants. The higher morbidity in the non-participant group, together with a higher rate of smoking, make it probable that this group also has a high risk of AAA.
Outcomes reported in high-impact surgical journals
Authors: Antonescu I , Mueller C L , Fried G M , Vassiliou M C , Mayo N E , Feldman L S
Published: February 2014

Background

With advances in operative technique and perioperative care, traditional endpoints such as morbidity and mortality provide an incomplete description of surgical outcomes. There is increasing emphasis on the need for patient-reported outcomes (PROs) to evaluate fully the effectiveness and quality of surgical interventions. The objective of this study was to identify the outcomes reported in clinical studies published in high-impact surgical journals and the frequency with which PROs are used.

Methods

Electronic versions of material published between 2008 and 2012 in the four highest-impact non-subspecialty surgical journals (Annals of Surgery, British Journal of Surgery (BJS), Journal of the American College of Surgeons (JACS), Journal of the American Medical Association (JAMA) Surgery) were hand-searched. Clinical studies of adult patients undergoing planned abdominal, thoracic or vascular surgery were included. Reported outcomes were classified into five categories using Wilson and Cleary's conceptual model.

Results

A total of 893 articles were assessed, of which 770 were included in the analysis. Some 91·6 per cent of studies reported biological and physiological outcomes, 36·0 per cent symptoms, 13·4 per cent direct indicators of functional status, 10·6 per cent general health perception and 14·8 per cent overall quality of life (QoL). The proportion of studies with at least one PRO was 38·7 per cent overall and 73·4 per cent in BJS (P < 0·001). The proportion of studies using a formal measure of health-related QoL ranged from 8·9 per cent (JAMA Surgery) to 33·8 per cent (BJS).

Conclusion

The predominant reporting of clinical endpoints and the inconsistent use of PROs underscore the need for further research and education to enhance the applicability of these measures in specific surgical settings.
Impact of risk scoring on decision-making in symptomatic moderate carotid atherosclerosis
Authors: Dharmarajah B , Thapar A , Salem J , Lane T R A , Leen E L S , Davies A H
Published: February 2014

Background

Benefit from carotid endarterectomy (CEA) in symptomatic moderate (50–69 per cent) carotid stenosis remains marginal. The Fourth National Clinical Guideline for Stroke recommends use of the risk score from the European Carotid Surgery Trial (ECST) to aid decision-making in symptomatic carotid disease. It is not known whether clinicians are, in fact, influenced by it.

Methods

Using the ECST risk prediction model, three scenarios of patients with a low (less than 10 per cent), moderate (20–25 per cent) and high (40–45 per cent) 5-year risk of stroke were devised and validated. Invitations to complete an online survey were sent by e-mail to vascular surgeons and stroke physicians, with responses gathered. The questionnaire was then repeated with the addition of the ECST risk score.

Results

Two hundred and one completed surveys were analysed (21·5 per cent response rate): 107 by stroke physicians and 94 by vascular surgeons. The high-risk scenario after the introduction of the ECST risk score showed an increased use of CEA (66·7 versus 80·1 per cent; P = 0·009). The low-risk scenario after risk score analysis demonstrated a swing towards best medical therapy (23·4 versus 57·2 per cent; P < 0·001). CEA was preferred in the moderate-risk scenario and this was not altered significantly by introduction of the risk score (71·6 versus 75·6 per cent; P = 0·609). Vascular surgeons exhibited a preference towards CEA compared with stroke physicians in both low- and moderate-risk scenarios (P < 0·001 and P = 0·003 respectively).

Conclusion

The addition of a risk score appeared to influence clinicians in their decision-making towards CEA in high-risk patients and towards best medical therapy in low-risk patients.
Metabolite profiling of ginsenoside Rg1 after oral administration in rat
Authors: Wang Xiaoying , Wang Chengcheng , Pu Feifei , Lin Peiyan , Qian Tianxiu
Published: February 2014

The goal of this study is to investigate the biotransformation of ginsenoside Rg1 in vivo. A highly sensitive and specific LC‐MS/MS method was developed and used for metabolite identification in rat feces and urine after oral administration of ginsenoside Rg1. Four metabolites of Rg1 were detected in rat feces and three metabolites of Rg1 were detected in rat urine. Deglycosylation and oxygenation were found to be the major metabolic pathways of ginsenoside Rg1 after oral administration in rat. Except for the reported metabolites Rh1 and protopanaxatriol, mono‐oxygenated Rg1 and mono‐oxygenated protopanaxatriol were detected for the first time after oral administration of Rg1. The in vivo metabolite profiling of ginsenoside Rg1 in rat was proposed. Viewed collectively, Rg1 was metabolized to mono‐oxygenated Rg1, Rh1, protopanaxatriol and the secondary metabolite mono‐oxygenated protopanaxatriol in rat. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis of Aliphatic and α‐Halogenated Ketone Cyanohydrins with the Hydroxynitrile Lyase from Manihot esculenta
Authors: Diebler Johannes , von Langermann Jan , Mell Annett , Hein Martin , Langer Peter , Kragl Udo
Published: February 2014

The potential of the hydroxynitrile lyase from Manihot esculenta towards ketone substrates was investigated. It was observed that the length of the aliphatic chain is a key parameter for the conversion of aliphatic, non‐branched ketones. Smaller substrates are readily converted with high enantioselectivites, but the elongation of the chain length causes a significant loss in enzyme activity. For a number of halogenated, herein especially fluorinated, acetophenone derivatives the corresponding cyanohydrins have been synthesized with good to moderate enantioselectivities.
Minor Enantiomer Recycling: Application to Enantioselective Syntheses of Beta Blockers
Authors: Wen Ye‐Qian , Hertzberg Robin , Gonzalez Inanllely , Moberg Christina
Published: February 2014

Continuous recycling of the minor product enantiomer obtained from the acetylcyanation of prochiral aldehydes provided access to highly enantiomerically enriched products. Cyanohydrin derivatives, which under normal conditions are obtained with modest or poor enantiomeric ratios, were formed with high enantiomeric purity by using a reinforcing combination of a chiral Lewis acid catalyst and a biocatalyst. The primarily obtained products were transformed into β‐adrenergic antagonists (S)‐propanolol, (R)‐dichloroisoproterenol, and (R)‐pronethalol by means of a two‐step procedure.
C,C‐ and N,C‐Coupled Dimers of 2‐Aminotetraphenylporphyrins: Regiocontrolled Synthesis, Spectroscopic Properties, and Quantum‐Chemical Calculations
Authors: Bruhn Torsten , Witterauf Franziska , Götz Daniel C. G. , Grimmer Carina T. , Würtemberger Max , Radius Udo , Bringmann Gerhard
Published: February 2014

β,β′‐Bisporphyrins are intrinsically chiral porphyrin dimers with fascinating properties. The configurational stability at their axes can be directed by variation of the central metal atoms. Herein, we present a regioselective functionalization of the monomeric 2‐amino‐tetraphenyl‐porphyrin as a versatile substrate for dimerization by oxidative coupling. By simple variation of the reaction conditions (solvent and oxidant), the oxidation selectively gave either the axially chiral C,C‐coupled diaminobisporphyrin in high yields or, under Ullmann conditions, the twofold N,C‐linked achiral dimer, also in good yields. A generalized mechanism for the coupling reaction is proposed based on DFT calculations. The axially chiral β,β′‐coupled porphyrin dimers were isolated as racemic mixtures, but can be resolved by HPLC on a chiral phase. TDDFT and coupled‐cluster calculations were used to explain the spectroscopic properties of the aminoporphyrins and their dimers and to elucidate the absolute configurations of the C,C‐coupled bisporphyrins.
Distance Dependence of Bidirectional Concerted Proton–Electron Transfer in Phenol‐Ru(2,2′‐bipyridine)32+ Dyads
Authors: Chen Jing , Kuss‐Petermann Martin , Wenger Oliver S.
Published: February 2014

Proton‐coupled electron transfer (PCET) was investigated in three covalent donor–bridge–acceptor molecules with different bridge lengths. Upon photoexcitation of their Ru(bpy)32+ (bpy=2,2′‐bipyridine) photosensitizer in acetonitrile, intramolecular long‐range electron transfer from a phenolic unit to Ru(bpy)32+ occurs in concert with release of the phenolic proton to pyrrolidine base. The kinetics of this bidirectional concerted proton–electron transfer (CPET) reaction were studied as a function of phenol–Ru(bpy)32+ distance by increasing the number of bridging p‐xylene units. A distance decay constant (β) of 0.67±0.23 Å−1 was determined. The distance dependence of the rates for CPET is thus not significantly steeper than that for ordinary (i.e., not proton coupled) electron transfer across the same bridges, despite the concerted motion of oppositely charged particles into different directions. Long‐range bidirectional CPET is an important reaction in many proteins and plays a key role in photosynthesis; our results are relevant in the context of photoinduced separation of protons and electrons as a means of light‐to‐chemical energy conversion. This is the first determination of β for a bidirectional CPET reaction.
Inorganic–Organic Heteropolyacid–Gold(I) Hybrids: Structures and Catalytic Applications
Authors: Hueber Damien , Hoffmann Marie , Louis Benoît , Pale Patrick , Blanc Aurélien
Published: February 2014

Gold(I)‐polyoxometalate hybrid complexes 1–4 ([PPh3AuMeCN]xH4−xSiW12O40, x=1–4) were synthesized and characterized. The structure of the primary gold(I)–polyoxometalate 1 (x=1) was fully ascertained by XRD, FTIR, 31P and 29Si magic‐angle spinning (MAS) NMR, mass spectroscopy, and SEM–energy dispersive X‐ray spectroscopy (EDX) techniques. Moreover, this complex exhibited better catalytic activity and selectivity compared with standard, homogeneous, gold catalysts in the new rearrangement of propargylic gem‐diesters.
Pd‐Catalyzed Decarboxylative Cross‐Coupling of 2‐Carboxyazine N‐Oxides with Various (Hetero)aryl Halides
Authors: Rouchet Jean‐Baptiste , Schneider Cédric , Spitz Cédric , Lefèvre Johan , Dupas George , Fruit Corinne , Hoarau Christophe
Published: February 2014

Decarboxylative cross‐coupling reactions of substituted 2‐carboxyazine N‐oxides, with a variety of (hetero)aryl halides, by bimetallic Pd0/CuI and Pd0/AgI catalysis are reported. Two possible pathways, a conventional bimetallic‐catalyzed decarboxylative arylation, as well as a protodecarboxylative/direct CH arylation sequence have been considered. These methods provide the first general decarboxylative arylation methodology for the 2‐carboxyazine series.
Fixed‐Bed Reactor Optimization for the Synthesis of Dimethyl Ether Using a 2D Model
Authors: Zander Hans‐Jörg , Bloch Gregor , Monnin Thibaut
Published: February 2014

Dimethyl ether is typically produced from synthesis gas by conversion to methanol and subsequent etherification. Compared to this classical approach, the direct synthesis has the advantage of higher equilibrium conversion and a simpler single‐stage process. The heat release of the strongly exothermic reactions requires a careful thermal reactor design. Pure axial models are not sufficient, as they neglect the important radial heat transport resistance. Therefore, a 2D model including axial and radial gradients was implemented and used for design optimization.
In Situ Investigations of Catalytic NO Reduction Inside an Optically Accessible Flow Reactor
Authors: Zellner Alexander , Suntz Rainer , Deutschmann Olaf
Published: February 2014

Die katalytische Reduktion von NO wurde in einem optisch zugänglichen Strömungskanal mittels planarer laserinduzierter Fluoreszenz (PLIF) in situ und nicht‐invasiv untersucht. Der Aufbau des Versuchsreaktors und dessen Adaption an die PLIF‐Methode werden präsentiert. Die Ergebnisse zeigen die zweidimensionalen Fluoreszenzverteilungen von NO über einer Katalysatorscheibe sowohl unter reaktiven als auch nicht‐reaktiven Bedingungen. Ein Pt/Al2O3‐beschichteter Monolith eines Dieseloxidationskatalysators diente dabei zur Herstellung selbstgefertigter Katalysatorscheiben.
Optimization of Catalysts for Fischer‐Tropsch Synthesis by Introduction of Transport Pores
Authors: Becker Henning , Güttel Robert , Turek Thomas
Published: February 2014

Diffusional restrictions in the porous network of Fischer‐Tropsch catalysts strongly affect activity and product selectivity. Especially small pores hamper the diffusion of reactants. In order to overcome the diffusion restrictions, the introduction of transport pores into the catalyst and the resulting effect on reaction rate and selectivities were studied. It was shown that transport pores allow for an increase in diffusion length, maintaining high reaction rate and C5+ selectivity. Overall, the productivity can be increased through optimization of the transport pore fraction.