bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning tunnelling microscopy on organic field-effect transistors based on intrinsic pentacene
Authors: Christian Roelofs W. S. , Charrier Dimitri S. H. , Dzwilewski Andrzej , Janssen René A. J. , de Leeuw Dago M. , Kemerink Martijn
Published: July 2014

The full potential of scanning tunnelling microscopy (STM) and scanning tunnelling spectroscopy for in-situ characterization of organic semiconductors has so far not been accessible. Here, we demonstrate that the underlying problem, the low intrinsic conductivity, can be overcome by working in a field-effect geometry. We present high resolution surface topographies obtained by STM on pentacene organic field-effect transistors (OFETs). By virtue of the OFET geometry, the hole accumulation layer that is present at sufficiently negative gate bias acts as back contact, collecting the tunnelling current. The presence of a true tunnelling gap is established, as is the need for the presence of an accumulation layer. The tunnelling current vs. tip bias showed rectifying behaviour, which is rationalized in terms of the tip acting as a second gate on the unipolar semiconductor. An explanatory band diagram is presented. The measurements shown indicate that intrinsic organic semiconductors can be in-situ characterized with high spatial and energetic resolution in functional devices.
Using an ultra-thin non-doped orange emission layer to realize high efficiency white organic light-emitting diodes with low efficiency roll-off
Authors: Zhu Liping , Zhao Yongbiao , Zhang Hongmei , Chen Jiangshan , Ma Dongge
Published: July 2014

By adopting an ultra-thin non-doped orange emission layer sandwiched between two blue emission layers, high efficiency white organic light-emitting diodes (WOLEDs) with reduced efficiency roll-off were fabricated. The optimized devices show a balanced white emission with Internationale de L'Eclairage of (0.41, 0.44) at the luminance of 1000 cd/m2, and the maximum power efficiency, current efficiency (CE), and external quantum efficiency reach 63.2 lm/W, 59.3 cd/A, and 23.1%, which slightly shift to 53.4 lm/W, 57.1 cd/A, and 22.2% at 1000 cd/m2, respectively, showing low efficiency roll-off. Detailed investigations on the recombination zone and the transient electroluminescence (EL) clearly reveal the EL processes of the ultra-thin non-doped orange emission layer in WOLEDs.
Prediction of the adhesive behavior of bio-inspired functionally graded materials against rough surfaces
Authors: Peijian Chen , Juan Peng , Yucheng Zhao , Feng Gao
Published: July 2014

Roughness effect and adhesion properties are important characteristics to be accessed in the development of functionally graded materials for biological and biomimetic applications, particularly for the hierarchical composition in biomimetic gecko robot. A multi-asperities adhesion model to predict the adhesive forces is presented in this work. The effect of surface roughness and graded material properties, which significantly alter the adhesive strength between contact bodies, can be simultaneously considered in the generalized model. It is found that proper interfacial strength can be controlled by adjusting surface roughness σ / R, graded exponent k and material parameter E*R / Δγ. The results should be helpful in the design of new biomimetic materials and useful in application of micro functional instruments.
Introduction to τ-tilting theory
Authors: Iyama Osamu , Reiten Idun
Published: July 2014

Significance

Mutation is an ingredient in the construction of cluster algebras. It deals with replacing an element in the free generating set (x1,x2,..., xn) of the rational function field Q(x1,x2,..., xn) by another element. In module categories for finite dimensional algebras, what is called “support τ-tilting modules” have a similar behavior. They are built up bynparts, and there is an operation of mutation. This plays an important role in categorifying cluster algebras.
Greedy bases in rank 2 quantum cluster algebras
Authors: Lee Kyungyong , Li Li , Rupel Dylan , Zelevinsky Andrei
Published: July 2014

Significance

The quantum cluster algebras are a family of noncommutative rings introduced by Berenstein and Zelevinsky as the quantum deformation of the commutative cluster algebras. At the heart of their definition is a desire to understand bases of quantum algebras arising from the representation theory of nonassociative algebras. Thus a natural and important problem in the study of quantum cluster algebras is to study their bases with good properties. In this paper, we lay out a framework for understanding the interrelationships between various bases of rank two quantum cluster algebras.
Information-based fitness and the emergence of criticality in living systems
Authors: Hidalgo Jorge , Grilli Jacopo , Suweis Samir , Muñoz Miguel A. , Banavar Jayanth R. , Maritan Amos
Published: July 2014

Significance

Recently, evidence has been mounting that biological systems might operate at the borderline between order and disorder, i.e., near a critical point. A general mathematical framework for understanding this common pattern, explaining the possible origin and role of criticality in living adaptive and evolutionary systems, is still missing. We rationalize this apparently ubiquitous criticality in terms of adaptive and evolutionary functional advantages. We provide an analytical framework, which demonstrates that the optimal response to broadly different changing environments occurs in systems organizing spontaneously—through adaptation or evolution—to the vicinity of a critical point. Furthermore, criticality turns out to be the evolutionary stable outcome of a community of individuals aimed at communicating with each other to create a collective entity.
Tribonucleation of bubbles
Authors: Wildeman Sander , Lhuissier Henri , Sun Chao , Lohse Detlef , Prosperetti Andrea
Published: July 2014

Significance

Microscopic gas–vapor bubbles play an important role in various processes in nature, industry, and medicine. Sometimes they are desired: to lower the temperature at which a liquid starts to boil or to enhance the contrast in medical ultrasound applications. In other cases, bubbles are harmful: they cause damage when expanding and collapsing near the propeller blades of ships, and sickness upon expanding in the veins of plants and animals. In spite of their ubiquity, the “nucleation” of bubbles, i.e., the mechanism responsible for their initial formation, has remained mysterious for a long time and, even today, it is not fully understood. Here, we show that bubbles can nucleate when two solids are gently rubbed together in a liquid: “tribonucleation.”
Activity-dependent dendritic spine neck changes are correlated with synaptic strength
Authors: Araya Roberto , Vogels Tim P. , Yuste Rafael
Published: July 2014

Significance

Dendritic spines are the main recipients of excitatory information in the brain, and though it is accepted that they must serve an essential function in neural circuits, their precise role remains ill-defined. Here, using minimal synaptic stimulation, we show that spine neck length correlates inversely with synaptic efficacy. In addition, we discovered a previously unidentified form of spine plasticity following a spike timing-dependent plasticity protocol, characterized by rapid shortening of spine neck length and concomitant increases in synaptic strength. These results provide new insights for our understanding of synaptic plasticity, and could provide an explanation for the presence of thousands of long-necked spines in the dendrites of pyramidal neurons, whose somatic synaptic contribution would otherwise be small or negligible.
Assessment and risk analysis of casing and cement impairment in oil and gas wells in Pennsylvania, 2000–2012
Authors: Ingraffea Anthony R. , Wells Martin T. , Santoro Renee L. , Shonkoff Seth B. C.
Published: July 2014

Significance

Previous research has demonstrated that proximity to unconventional gas development is associated with elevated concentrations of methane in groundwater aquifers in Pennsylvania. To date, the mechanism of this migration is poorly understood. Our study, which looks at more than 41,000 conventional and unconventional oil and gas wells, helps to explain one possible mechanism of methane migration: compromised structural integrity of casing and cement in oil and gas wells. Additionally, methane, being the primary constituent of natural gas, is a strong greenhouse gas. The identification of mechanisms through which methane may migrate to the atmosphere as fugitive emissions is important to understand the climate dimensions of oil and gas development.
Early guenon from the late Miocene Baynunah Formation, Abu Dhabi, with implications for cercopithecoid biogeography and evolution
Authors: Gilbert Christopher C. , Bibi Faysal , Hill Andrew , Beech Mark J.
Published: July 2014

Significance

The primate subfamily Cercopithecinae represents the most diverse and successful living Old World primate group, with a current distribution throughout Africa and Asia. However, how and when these monkeys dispersed out of Africa is not well understood. This paper is significant in its description of a ∼6.5–8.0 million-y-old fossil guenon from Arabia representing the earliest cercopithecine (and only guenon) yet known outside of Africa. Furthermore, this specimen extends the guenon fossil record by at least 2.3 million y and may represent the earliest known cercopithecine as well. Because Old World monkeys appear to have dispersed out of Africa sometime during the Late Miocene, the Arabian fossils also have implications for dispersal scenarios in Old World monkey biogeography and evolution.
Metagenomic scaffolds enable combinatorial lignin transformation
Authors: Strachan Cameron R. , Singh Rahul , VanInsberghe David , Ievdokymenko Kateryna , Budwill Karen , Mohn William W. , Eltis Lindsay D. , Hallam Steven J.
Published: July 2014

Significance

Plant biomass conversion into biofuels and chemicals can reduce human reliance on petroleum and promote sustainable biorefining processes. The structural polymer lignin can comprise up to 40% of plant biomass, but resists decomposition into valuable monoaromatic compounds. In this study, we devised a previously unidentified biosensor responsive to lignin transformation products. We used this biosensor in a functional screen to recover metagenomic scaffolds sourced from coal bed bacterial communities. Genetic and biochemical analyses revealed six functional classes mediating lignin transformation that are mobilized in nature via horizontal gene transfer. Our results suggest that bacterial lignin transformation is an adaptive trait that can be exploited to engineer combinatorial arrays with defined product profiles, a prerequisite for scale-up production using different plant sources.
IL-33/ST2 axis promotes mast cell survival via BCLXL
Authors: Wang Jun-Xia , Kaieda Shinjiro , Ameri Sarah , Fishgal Nadia , Dwyer Daniel , Dellinger Anthony , Kepley Christopher L. , Gurish Michael F. , Nigrovic Peter A.
Published: July 2014

Significance

Mast cells (MC) are long-lived cells that accumulate in inflamed tissues. IL-33 has been characterized extensively as a MC activator, but a contribution of IL-33 and its receptor IL-1 receptor-related protein ST2 to MC survival remains unappreciated. Here, we show that IL-33 attenuates apoptosis of human and murine MC, principally via the antiapoptotic molecule B-cell lymphoma-X large (BCLXL). In vivo, IL-33 and ST2 can confer a cell-intrinsic survival advantage to murine MC, particularly in the context of inflammation. These results identify the IL-33/ST2 axis as an important pathway supporting MC persistence in tissues, raising the possibility that therapeutic targeting of IL-33 could limit the contribution of MC to chronic inflammatory diseases.
Intraoperative mass spectrometry mapping of an onco-metabolite to guide brain tumor surgery
Authors: Santagata Sandro , Eberlin Livia S. , Norton Isaiah , Calligaris David , Feldman Daniel R. , Ide Jennifer L. , Liu Xiaohui , Wiley Joshua S. , Vestal Matthew L. , Ramkissoon Shakti H. , Orringer Daniel A. , Gill Kristen K. , Dunn Ian F. , Dias-Santagata Dora , Ligon Keith L. , Jolesz Ferenc A. , Golby Alexandra J. , Cooks R. Graham , Agar Nathalie Y. R.
Published: July 2014

Significance

The diagnosis of tumors during surgery still relies principally on an approach developed over 150 y ago: frozen section microscopy. We show that a validated molecular marker—2-hydroxyglutarate generated from isocitrate dehydrogenase 1 mutant gliomas—can be rapidly detected from tumors using a form of ambient MS that does not require sample preparation. We use the Advanced Multimodality Image Guided Operating Suite at Brigham and Women’s Hospital to demonstrate that desorption electrospray ionization MS could be used to detect residual tumor that would have been left behind in the patient. The approach paves the way for the clinical testing of MS-based intraoperative monitoring of tumor metabolites, an advance that could revolutionize the care of surgical oncology patients.
Realized niche shift during a global biological invasion
Authors: Tingley Reid , Vallinoto Marcelo , Sequeira Fernando , Kearney Michael R.
Published: July 2014

Significance

Species’ distributions result from dispersal and physiological constraints, interactions with other species, and ultimately, evolution. Biological invasions result from the deliberate or accidental movement of species between regions they would not reach through natural dispersal and can cause major conservation, economic, and human health issues. However, invasions also provide fascinating insights into species’ distribution limits. We investigate the invasion of the cane toad from South America to Australia by comparing the results of two modeling approaches: one considering physiological constraints and the other considering the joint influences of physiology, dispersal, and biotic interactions. Our findings demonstrate that the cane toad is limited in its native distribution by biotic interactions but, in Australia, is free to fill its climatic potential.
Transcription factor induction of human oligodendrocyte progenitor fate and differentiation
Authors: Wang Jing , Pol Suyog U. , Haberman Alexa K. , Wang Chunming , O’Bara Melanie A. , Sim Fraser J.
Published: July 2014

Significance

Transplantation of human myelinogenic cells represents a realizable strategy for treatment of congenital and acquired demyelinating diseases. Although generation of undifferentiated neural stem and progenitors is feasible, the induction of myelinogenic cell fate remains a significant challenge. In this paper, we describe, to our knowledge, the first comprehensive study of transcription factor expression and function by purified neural and oligodendrocyte progenitors obtained directly from human brain tissue. We have identified those transcription factors capable of regulating oligodendrocyte progenitor fate and establish that among these, only SOX10 was capable of comprehensively inducing oligodendrocyte fate both in vitro and following transplantation into a model of human leukodystrophy. Thus, viral and pharmacologic approaches to increasing SOX10 expression likely will improve the outcome of human transplant therapy.
Evolutionary origin of insect–
Wolbachia
nutritional mutualism
Authors: Nikoh Naruo , Hosokawa Takahiro , Moriyama Minoru , Oshima Kenshiro , Hattori Masahira , Fukatsu Takema
Published: July 2014

Significance

How sophisticated mutualism has arisen from less-intimate associations is of general interest. Here we address this evolutionary issue by looking into the bedbug.
Wolbachia
endosymbionts are generally regarded as facultative/parasitic bacterial associates for their insect hosts, but in the bedbug, exceptionally,
Wolbachia
supports the host’s growth and survival via provisioning of vitamins. In the bedbug’s
Wolbachia
genome, we identified a gene cluster encoding the complete synthetic pathway for biotin (vitamin B7), which is not present in other
Wolbachia
genomes and is presumably acquired via lateral transfer from a coinfecting endosymbiont. The
Wolbachia
-provisioned biotin contributes to the bedbug’s fitness significantly, uncovering an evolutionary transition from facultative symbiosis to obligate mutualism facilitated by lateral gene transfer in the endosymbiont lineage.
HelitronScanner uncovers a large overlooked cache of
Helitron
transposons in many plant genomes
Authors: Xiong Wenwei , He Limei , Lai Jinsheng , Dooner Hugo K. , Du Chunguang
Published: July 2014

Significance

Helitrons
are unusual rolling-circle eukaryotic transposons with a remarkable ability to capture gene sequences, which makes them of considerable evolutionary importance. Because
Helitrons
lack typical transposon features, they are challenging to identify and are estimated to comprise at most 2% of sequenced genomes. Here, we describe HelitronScanner, a generalized tool for their identification based on a motif-extracting algorithm proposed initially in a study of natural languages. HelitronScanner overcomes the divergence of
Helitron
termini among species by using conserved nucleotides at potentially variable locations. Many new
Helitrons
were identified in all organisms examined, resulting in a major reassessment of their abundance in eukaryotic genomes. In maize, they make up >6% of the genome and are the most abundant DNA transposons identified.
A framework for multi-scale modelling
Authors: Chopard B. , Borgdorff Joris , Hoekstra A. G.
Published: July 2014

We review a methodology to design, implement and execute multi-scale and multi-science numerical simulations. We identify important ingredients of multi-scale modelling and give a precise definition of them. Our framework assumes that a multi-scale model can be formulated in terms of a collection of coupled single-scale submodels. With concepts such as the scale separation map, the generic submodel execution loop (SEL) and the coupling templates, one can define a multi-scale modelling language which is a bridge between the application design and the computer implementation. Our approach has been successfully applied to an increasing number of applications from different fields of science and technology.
Concurrent multiscale modelling of atomistic and hydrodynamic processes in liquids
Authors: Markesteijn Anton , Karabasov Sergey , Scukins Arturs , Nerukh Dmitry , Glotov Vyacheslav , Goloviznin Vasily
Published: July 2014

Fluctuations of liquids at the scales where the hydrodynamic and atomistic descriptions overlap are considered. The importance of these fluctuations for atomistic motions is discussed and examples of their accurate modelling with a multi-space–time-scale fluctuating hydrodynamics scheme are provided. To resolve microscopic details of liquid systems, including biomolecular solutions, together with macroscopic fluctuations in space–time, a novel hybrid atomistic–fluctuating hydrodynamics approach is introduced. For a smooth transition between the atomistic and continuum representations, an analogy with two-phase hydrodynamics is used that leads to a strict preservation of macroscopic mass and momentum conservation laws. Examples of numerical implementation of the new hybrid approach for the multiscale simulation of liquid argon in equilibrium conditions are provided.
Three-dimensional multi-scale model of deformable platelets adhesion to vessel wall in blood flow
Authors: Wu Ziheng , Xu Zhiliang , Kim Oleg , Alber Mark
Published: July 2014

When a blood vessel ruptures or gets inflamed, the human body responds by rapidly forming a clot to restrict the loss of blood. Platelets aggregation at the injury site of the blood vessel occurring via platelet–platelet adhesion, tethering and rolling on the injured endothelium is a critical initial step in blood clot formation. A novel three-dimensional multi-scale model is introduced and used in this paper to simulate receptor-mediated adhesion of deformable platelets at the site of vascular injury under different shear rates of blood flow. The novelty of the model is based on a new approach of coupling submodels at three biological scales crucial for the early clot formation: novel hybrid cell membrane submodel to represent physiological elastic properties of a platelet, stochastic receptor–ligand binding submodel to describe cell adhesion kinetics and lattice Boltzmann submodel for simulating blood flow. The model implementation on the GPU cluster significantly improved simulation performance. Predictive model simulations revealed that platelet deformation, interactions between platelets in the vicinity of the vessel wall as well as the number of functional GPIbαplatelet receptors played significant roles in platelet adhesion to the injury site. Variation of the number of functional GPIbαplatelet receptors as well as changes of platelet stiffness can represent effects of specific drugs reducing or enhancing platelet activity. Therefore, predictive simulations can improve the search for new drug targets and help to make treatment of thrombosis patient-specific.
Mesoscale dynamic coupling of finite- and discrete-element methods for fluid–particle interactions
Authors: Srivastava S. , Yazdchi K. , Luding S.
Published: July 2014

A new method for two-way fluid–particle coupling on an unstructured mesoscopically coarse mesh is presented. In this approach, we combine a (higher order) finite-element method (FEM) on the moving mesh for the fluid with a soft sphere discrete-element method for the particles. The novel feature of the proposed scheme is that the FEM mesh is a dynamic Delaunay triangulation based on the positions of the moving particles. Thus, the mesh can be multi-purpose: it provides (i) a framework for the discretization of the Navier–Stokes equations, (ii) a simple tool for detecting contacts between moving particles, (iii) a basis for coarse-graining or upscaling, and (iv) coupling with other physical fields (temperature, electromagnetic, etc.). This approach is suitable for a wide range of dilute and dense particulate flows, because the mesh resolution adapts with particle density in a given region. Two-way momentum exchange is implemented using semi-empirical drag laws akin to other popular approaches; for example, the discrete particle method, where a finite-volume solver on a coarser, fixed grid is used. We validate the methodology with several basic test cases, including single- and double-particle settling with analytical and empirical expectations, and flow through ordered and random porous media, when compared against finely resolved FEM simulations of flow through fixed arrays of particles.
MDGRAPE-4: a special-purpose computer system for molecular dynamics simulations
Authors: Ohmura Itta , Morimoto Gentaro , Ohno Yousuke , Hasegawa Aki , Taiji Makoto
Published: July 2014

We are developing the MDGRAPE-4, a special-purpose computer system for molecular dynamics (MD) simulations. MDGRAPE-4 is designed to achieve strong scalability for protein MD simulations through the integration of general-purpose cores, dedicated pipelines, memory banks and network interfaces (NIFs) to create a system on chip (SoC). Each SoC has 64 dedicated pipelines that are used for non-bonded force calculations and run at 0.8 GHz. Additionally, it has 65 Tensilica Xtensa LX cores with single-precision floating-point units that are used for other calculations and run at 0.6 GHz. At peak performance levels, each SoC can evaluate 51.2 G interactions per second. It also has 1.8 MB of embedded shared memory banks and six network units with a peak bandwidth of 7.2 GB s
−1
for the three-dimensional torus network. The system consists of 512 (8×8×8) SoCs in total, which are mounted on 64 node modules with eight SoCs. The optical transmitters/receivers are used for internode communication. The expected maximum power consumption is 50 kW. While MDGRAPE-4 software has still been improved, we plan to run MD simulations on MDGRAPE-4 in 2014. The MDGRAPE-4 system will enable long-time molecular dynamics simulations of small systems. It is also useful for multiscale molecular simulations where the particle simulation parts often become bottlenecks.
Reduced-order modelling numerical homogenization
Authors: Abdulle A. , Bai Y.
Published: July 2014

A general framework to combine numerical homogenization and reduced-order modelling techniques for partial differential equations (PDEs) with multiple scales is described. Numerical homogenization methods are usually efficient to approximate the effective solution of PDEs with multiple scales. However, classical numerical homogenization techniques require the numerical solution of a large number of so-called microproblems to approximate the effective data at selected grid points of the computational domain. Such computations become particularly expensive for high-dimensional, time-dependent or nonlinear problems. In this paper, we explain how numerical homogenization method can benefit from reduced-order modelling techniques that allow one to identify offline and online computational procedures. The effective data are only computed accurately at a carefully selected number of grid points (offline stage) appropriately ‘interpolated’ in the online stage resulting in an online cost comparable to that of a single-scale solver. The methodology is presented for a class of PDEs with multiple scales, including elliptic, parabolic, wave and nonlinear problems. Numerical examples, including wave propagation in inhomogeneous media and solute transport in unsaturated porous media, illustrate the proposed method.
Comparison of D. melanogaster and C. elegans developmental stages, tissues, and cells by modENCODE RNA-seq data
Authors: Li Jingyi Jessica , Huang Haiyan , Bickel Peter J. , Brenner Steven E.
Published: July 2014

We report a statistical study to discover transcriptome similarity of developmental stages from D. melanogaster and C. elegans using modENCODE RNA-seq data. We focus on “stage-associated genes” that capture specific transcriptional activities in each stage and use them to map pairwise stages within and between the two species by a hypergeometric test. Within each species, temporally adjacent stages exhibit high transcriptome similarity, as expected. Additionally, fly female adults and worm adults are mapped with fly and worm embryos, respectively, due to maternal gene expression. Between fly and worm, an unexpected strong collinearity is observed in the time course from early embryos to late larvae. Moreover, a second parallel pattern is found between fly prepupae through adults and worm late embryos through adults, consistent with the second large wave of cell proliferation and differentiation in the fly life cycle. The results indicate a partially duplicated developmental program in fly. Our results constitute the first comprehensive comparison between D. melanogaster and C. elegans developmental time courses and provide new insights into similarities in their development . We use an analogous approach to compare tissues and cells from fly and worm. Findings include strong transcriptome similarity of fly cell lines, clustering of fly adult tissues by origin regardless of sex and age, and clustering of worm tissues and dissected cells by developmental stage. Gene ontology analysis supports our results and gives a detailed functional annotation of different stages, tissues and cells. Finally, we show that standard correlation analyses could not effectively detect the mappings found by our method.
Fluorescence Correlation Spectroscopy: Principles and Applications
Authors: Bacia Kirsten , Haustein Elke , Schwille Petra
Published: July 2014

Fluorescence correlation spectroscopy (FCS) is used to study the movements and the interactions of biomolecules at extremely dilute concentrations, yielding results with good spatial and temporal resolutions. Using a number of technical developments, FCS has become a versatile technique that can be used to study a variety of sample types and can be advantageously combined with other methods. Unlike other fluorescence-based techniques, the analysis of FCS data is not based on the average intensity of the fluorescence emission but examines the minute intensity fluctuations caused by spontaneous deviations from the mean at thermal equilibrium. These fluctuations can result from variations in local concentrations owing to molecular mobility or from characteristic intermolecular or intramolecular reactions of fluorescently labeled biomolecules present at low concentrations. Here, we provide a basic introduction to FCS, including its technical development and theoretical basis, experimental setup of an FCS system, adjustment of a setup, data acquisition, and analysis of FCS measurements. Finally, the application of FCS to the study of lipid bilayer membranes and to living cells is discussed.
Poly[μ6-(naphthalene-2,6-dicarboxylato)-bis(aqualithium)]
Authors: Fédèle Lionel , Sauvage Frédéric , Becuwe Matthieu , Chotard Jean-Noël
Published: July 2014

The title compound, [Li2(C12H6O4)(H2O)2]n, crystallizes with one half of the molecular entities in the asymmetric unit. The second half is gererated by inversion symmetry. The crystal structure has a layered arrangement built from distorted edge-sharing LiO3(OH)2tetrahedra parallel to (100), with naphthalenedicarboxylate bridging the LiO3(OH)2layers along the [100] direction. Hydrogen bonding between the water molecule and adjacent carboxylate groups consolidates the packing.
The 1:1 charge-transfer complex dibenzotetrathiafulvalene–pyromellitic dianhydride (DBTTF–PMDA)
Authors: Payne Margaret E. , Goetz Katelyn P. , Day Cynthia S. , Jurchescu Oana D.
Published: July 2014

The title charge-transfer (CT) complex, C10H2O6·C14H8S4, composed of donor dibenzotetrathiafulvalene (DBTTF) and acceptor pyromellitic dianhydride (PMDA), forms a mixed stacking pattern along the [-110] direction. The constituent molecules occupy crystallographic inversion centers. They are nearly parallel and lieca.3.41 Å from each other. The crystals exhibit a high degree of donor/acceptor overlap [88.20 (4)%] in the long direction of the DBTTF and PMDA molecules as compared with 51.27 (5)% in the shortest direction of the molecules.
(E)-3,4,5-Trimethoxy-N′-[(6-methoxy-4-oxo-4H-chromen-3-yl)methylidene]benzohydrazide monohydrate
Authors: Ishikawa Yoshinobu , Watanabe Kohzoh
Published: July 2014

In the title chromone-tethered benzohydrazide derivative, C21H20N2O7·H2O, the atoms of the 4H-chromen-4-one segment are essentially coplanar (r.m.s. deviation = 0.0073 Å) with the largest deviation from the mean plane [0.012 (3) Å] being found for the benzene C atom. The dihedral angles between the chromone segment and the hydrazide plane and between the chromone segment and the benzene ring of the trimethoxybenzene unit are 24.67 (9) and 41.28 (8) Å, respectively. The molecule is connected to the solvent water molecule by O—H...O hydrogen bonds and weak C—H...O interactions. Additional N—H...O interactions are observed and together they link the molecules into chains forming a two-dimensional network along (011).
3,12-Dimethoxy-5,6,9,10-tetrahydro-[5]helicene-7,8-dicarbonitrile
Authors: Sahasithiwat Somboon , Sooksimuang Thanasat , Kamtonwong Siriporn , Parnchan Waraporn , Kangkaew Laongdao
Published: July 2014

The complete molecule of the title compound, C26H20N2O2, is generated by a crystallographic twofold axis. The torsion angle between the terminal and central benzene rings is −32.5 (2)°. The torsion angle along the inner helical rim of the molecule is −18.8 (2)° with each other. The C...C distance between the terminal rings is 3.016 (2) Å. In the crystal, weak C—H...N hydrogen bonds are observed.
Di-tert-butyl 1-[2-hydroxy-3-(methylsulfanyl)propyl]hydrazine-1,2-dicarboxylate
Authors: Bai Xiao-Guang , Yang Xiao-Yu , Wang Ju-Xian
Published: July 2014

The title compound, C14H28N2O5S, was synthesized by the reaction of 2-[(methylsulfanyl)methyl]oxirane with di-tert-butyl oxalate in hydrazine hydrate. In the crystal, molecules are linked by N—H...O and O—H...O hydrogen bonds into supramolecular chains propagating along theb-axis direction.
Synthetic (+)‐antroquinonol exhibits dual actions against insulin resistance by triggering AMP kinase and inhibiting dipeptidyl peptidase IV activities
Authors: Hsu C Y , Sulake R S , Huang P‐K , Shih H‐Y , Sie H‐W , Lai Y‐K , Chen C , Weng C F
Published: July 2014

Background and Purpose

The fungal product (+)‐antroquinonol activates AMP kinase (AMPK) activity in cancer cell lines. The present study was conducted to examine whether chemically synthesized (+)‐antroquinonol exhibited beneficial metabolic effects in insulin‐resistant states by activating AMPK and inhibiting dipeptidyl peptidase IV (DPP IV) activity.

Experimental Approach

Effects of (+)‐antroquinonol on DPP IV activity were measured with a DPPIV Assay Kit and effects on GLP‐1‐induced PKA were measured in AR42J cells. Translocation of the glucose transporter 4, GLUT4, induced either by insulin‐dependent PI3K/AKT signalling or by insulin‐independent AMPK activation, was assayed in differentiated myotubes. Glucose uptake and GLUT4 translocation were assayed in L6 myocytes. Mice with diet‐induced obesity were used to assess effects of acute and chronic treatment with (+)‐antroquinonol on glycaemic control in vivo.

Key Results

The results showed that of (+)‐antroquinonol (100 μM ) inhibited the DPP IV activity as effectively as the clinically used inhibitor, sitagliptin. The phosphorylation of AMPK Thr172 in differentiated myotubes was significantly increased by (+)‐antroquinonol. In cells simultaneously treated with S961 (insulin receptor antagonist), insulin and (+)‐antroquinonol, the combination of (+)‐antroquinonol plus insulin still increased both GLUT4 translocation and glucose uptake. Further, (+)‐antroquinonol and sitagliptin reduced blood glucose, when given acutely or chronically to DIO mice.

Conclusions and Implications

Chemically synthesized (+)‐antroquinonol exhibits dual effects to ameliorate insulin resistance, by increasing AMPK activity and GLUT4 translocation, along with inhibiting DPP IV activity.
Non‐unique stratal geometries: implications for sequence stratigraphic interpretations
Authors: Burgess Peter M. , Prince Guy D.
Published: July 2014

There is now strong evidence that stratal geometries on basin margins are most likely a consequence of multiple controls, not just variations in accommodation. Consequently, correct sequence stratigraphic interpretation of stratal geometries requires an understanding of how multiple different controls may generate similar geometries. Using a simple numerical stratigraphic forward model, we explore the impact of time variable sediment supply and different sediment transport rates on stratal geometries. We demonstrate how four common types of stratal geometry can form by more than one set of controlling parameter values and are thus likely to be non‐unique, meaning that there may be several sets of controlling factors that can plausibly explain their formation. For example, a maximum transgressive surface can occur in the model due to an increase in rate of relative sea‐level rise during constant sediment supply, and due to a reduction in rate of sediment supply during a constant rate of relative sea‐level rise. Sequence boundaries, topset aggradation and shoreline trajectories are also examples of non‐unique stratal geometries. If the model simulations in this work are sufficiently realistic, then the modelled stratal geometries are important examples of non‐uniqueness, suggesting the need for a shift towards sequence stratigraphic methods based on constructing and evaluating multiple hypotheses and scenarios.
Prevention of cancer recurrence in tumor margins by stopping microcirculation in the tumor and tumor–host interface
Authors: Hori Katsuyoshi , Akita Hirotoshi , Nonaka Hiroi , Sumiyoshi Akira , Taki Yasuyuki
Published: July 2014

Combretastatins interrupt blood flow of solid tumor vascular networks and lead to necrosis by blocking nutrients. However, tumors recover from tumor blood flow interruption‐induced damage and develop viable rims. To investigate why cancer recurs and its prevention, we used a combretastatin derivative, Cderiv (=AC7700), and analyzed changes in tumor–host interface (T‐HI) vessels, which were closest to cancer cells in the tumor margin after tumor vessel disruption, and the microenvironment surrounding them. Treatment with Cderiv (10 mg/kg) interrupted tumor blood flow in all regions of LY80 (a variant of Yoshida sarcoma) tumor, but not T‐HI vessel blood flow. The same Cderiv dose given 72 h after 5 Gy irradiation stopped T‐HI vessel blood flow and prevented cancer recurrence. Treatment in the reverse order, however, did not affect T‐HI vessel blood flow. The greatest difference between the two treatments was the occurrence of gradual T‐HI edema with the former. Severe T‐HI edema compressed T‐HI blood vessels, so that circulation stopped. Thus, the distance between a tumor margin and its nearest functioning host vessel became much larger, and the tumor marginal region became a microenvironment that lacked a nutritional supply. Cancer cells in tumor margins received nutrients through two circulation routes: tumor vessels and T‐HI vessels. Our starvation methods, which involved treatment with Cderiv 72 h after 5 Gy irradiation, blocked both circulation routes and may have great potential as a clinical strategy to prevent cancer recurrence.
Neue Entwicklungen zum Thema Epikutantest – aktuelle Daten aus der Deutschen Kontaktallergie‐Gruppe (DKG) und Informationsverbund Dermatologischer Kliniken (IVDK)
Authors: Mahler Vera , Geier Johannes , Schnuch Axel
Published: July 2014

Hintergrund und Ziele

Die Bedeutung einzelner Kontaktallergene ist einem beständigen Wandel unterworfen, der wesentlich durch veränderte Expositionen aufgrund von Verbrauchervorlieben und der Gesetzesvorgaben beeinflusst wird. Ziele der Arbeit sind, Trends aus dem Epikutantest‐Kollektiv der DKG‐ und IVDK‐Kliniken darzustellen, die zur aktuellen Änderung (gültig ab 1.1.2014) der DKG‐Standardreihe geführt haben und die aktuell geltenden gesetzlichen Rahmenbedingungen darzulegen, die Einfluss auf diese Trends und die Durchführung der Epikutantestung zur Aufklärung von Kontaktallergien haben.

Patienten und Methodik

Das Epikutantestkollektiv aus 56 DKG‐/IVDK‐Kliniken der Jahre 2010 (n = 13 117), 2011 (n = 13 320), 2012 (n = 12 529) wurde bezüglich der Sensibilisierungshäufigkeiten (Hitliste) auf Kontaktallergene und Lokalisationen allergischer Kontaktekzeme ausgewertet.

Ergebnisse

Mit über 15 % Sensibilisierungshäufigkeit stellt Nickel noch immer das am häufigsten erkannte Kontaktallergen dar. Eine Zunahme der Sensibilisierungshäufigkeit auf Duftstoff‐Mix I auf 9,1 % und auf das Konservierungsmittelgemisch aus Chlormethylisothiazolinon/Methylisothiazolinon (MCI/MI) auf 4,5 %, sowie auf Methylisothiazolinon (MI) alleine auf 6,8 % ist zu verzeichnen. Ein Abwärtstrend zeigt sich für Kaliumdichromat von über 6 % (2007) auf 3 % (2012) und für Bufexamac (derzeit bei 0,6 %). Die Hintergründe, gesetzliche Rahmenbedingungen und resultierende Aktualisierung der DKG‐Standardreihe werden dargestellt.

Schlussfolgerungen

Die aufgezeigten Trends demonstrieren die Bedeutung der klinischen Epidemiologie und „Wächterfunktion“ von DKG und IVDK im Hinblick auf öffentliche Gesundheitsfürsorge und die Prävention von Kontaktallergien.
Trichophyton Spezies von Arthroderma benhamiae – ein neuer Infektionserreger in der Dermatologie
Authors: Nenoff Pietro , Uhrlaß Silke , Krüger Constanze , Erhard Marcel , Hipler Uta‐Christina , Seyfarth Florian , Herrmann Jürgen , Wetzig Tino , Schroedl Wieland , Gräser Yvonne
Published: July 2014

In Deutschland kommen seit einigen Jahren Infektionen durch den zoophilen Dermatophyten Trichophyton (T.) Spezies von Arthroderma benhamiae vor. Das Reservoir für diesen neuen Erreger – ein emerging pathogen – überlappt mit dem des zoophilen T. interdigitale. Insbesondere Meerschweinchen sind Carrier. T. Spezies von Arthroderma benhamiae verursacht eine entzündliche Tinea bei Kindern und Jugendlichen. Neben der Tinea capitis werden Tinea corporis und Tinea manus verursacht, vor allem jedoch die Tinea faciei. T. Spezies von Arthroderma benhamiae ist in Deutschland ein häufiger zoophiler Dermatophyt, in manchen Regionen häufiger als Microsporum canis. Die Identifizierung der Isolate mit gelb gefärbten Kolonien ist anhand makro‐ und mikroskopischer Merkmale möglich. Ein Teil der Isolate weist jedoch Koloniemerkmale auf, welche mit denen von T. interdigitale übereinstimmen. Diese Stämme lassen sich nur mittels molekularer Methoden identifizieren. Mit einem PCR‐ELISA oder real‐time PCR kann der Dermatophyt direkt im klinischen Material nachgewiesen werden. Als Kulturbestätigungstest hat sich die Sequenzierung der internal transcribed spacer Region (ITS) der ribosomalen DNA bewährt. Auch die matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI TOF MS) ist dafür geeignet. Die Behandlung von ausgedehnten Dermatophytosen durch T. Spezies von Arthroderma benhamiae, insbesondere der Tinea capitis, erfolgt mit oralen Antimykotika, am besten Terbinafin; Alternativen sind Fluconazol und Itraconazol.
Field cage evaluation of interspecific interaction of two aphelinid parasitoids and biocontrol effect on Bemisia tabaci (Hemiptera: Aleyrodidae) Middle East‐Asia Minor 1
Authors: Xu Hai‐Yun , Yang Nian‐Wan , Wan Fang‐Hao
Published: July 2014

To explore sustainably effective biological control measures to suppress the super pest Bemisia tabaci (Gennadius) Middle East‐Asia Minor 1 and better understand the biological control effects of single and multiple releases of parasitoids, we evaluated the performance and interaction of two aphelinid parasitoids of B. tabaci, Eretmocerus hayati Zolnerowich & Rose (an exotic primary parasitoid) and Encarsia sophia (Girault & Dodd) (an autoparasitoid, which is controversial in a biological control program). Single species or two species were jointly (1:1 density ratio) released in field cages on cotton in Hebei province, China, in 2010. Results of the field cage experiment showed that all parasitoid release treatments were successful in reducing the densities of the host B. tabaci relative to the control in which no parasitoid was released. The combined release of two parasitoid species showed the highest control effect among the treatments. Different population growth trajectories indicated asymmetric competitive effects of En. sophia on Er. hayati. The densities of Er. hayati were significantly higher in the Er. hayati alone treatment than in the combined release treatment, while densities of En. sophia were lower in the En. sophia alone treatment than in the combined release treatment. Our results demonstrated interspecific competition between autoparasitoid En. sophia and exotic primary parasitoid Er. hayati. However, no evidence indicated that autoparasitoid En. sophia disrupted the host suppression achieved by primary parasitoid Er. hayati. The release of the autoparasitoid together with the primary parasitoid may not influence host suppression in biological control.
Novel KRT14 mutation causing epidermolysis bullosa simplex with variable phenotype
Authors: Jankowski Marek , Wertheim‐Tysarowska Katarzyna , Jakubowski Rafal , Sota Justyna , Nowak Wieslaw , Czajkowski Rafal
Published: July 2014

About 75% of cases of epidermolysis bullosa simplex result from mutations in KRT5 and KRT14 genes. Here, we report a family with a novel heterozygous missense mutation p.Leu418Gln in the KRT14 gene causing EBS of phenotype varying from EBS‐loc to EBS‐gen intermed. To the best of our knowledge, the family reported by us is the largest one in which two different phenotypes can be distinguished. The molecular dynamics simulations show that p.Leu418Gln mutation results in clear disruption of intermolecular π‐stacking between KRT14:Tyr415 and KRT5:Tyr470, which in turn may affect putative phosphorylation site at KRT14:Thr414. This study further supports the importance of the EIATYR/KLLEGE motif in maintaining structural stability of KRT14:KRT5 heterodimer and indicates that physical properties of introduced amino acid can modulate the disease severity. The results obtained indicate further need of genotype–phenotype studies in EBS. In conclusion, genotype‐based prognosis should be given to patients with caution.
Eicosapentaenoic acid/arachidonic acid ratio as a possible link between non‐alcoholic fatty liver disease and cardiovascular disease
Authors: Ishitobi Tomokazu , Hyogo Hideyuki , Kan Hiromi , Hiramatsu Akira , Arihiro Koji , Aikata Hiroshi , Chayama Kazuaki
Published: July 2014

Aim

The main causes of mortality from non‐alcoholic fatty liver disease (NAFLD) are cardiovascular disease (CVD) and malignancy. Eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio is known to be associated with CVD. However, a possible link between EPA/AA ratio and NAFLD is not well known. In this study, we investigated EPA/AA ratio in Japanese patients with NAFLD.

Methods

Two hundred and fifty‐four patients with biopsy‐proven NAFLD were retrospectively enrolled. Serum EPA/AA ratios were examined for each generation (<35, 35–44, 45–54, 55–64, ≥65 years), and the differences of EPA/AA ratios were evaluated based on steatotic grades and fibrotic stages.

Results

EPA/AA ratio in NAFLD patients was decreased compared to that reported in age‐matched healthy controls. EPA/AA ratio, body mass index, total cholesterol, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol and steatotic grades in younger NAFLD patients were significantly worse than those in older NAFLD patients. Fasting glucose, hemoglobin A1c and fibrotic stages in older NAFLD patients were significantly higher than those in younger NAFLD patients. No relation was found between EPA/AA ratio and histological findings.

Conclusion

EPA/AA ratio was lower in NAFLD, especially in younger NAFLD patients. Considering the high mortality from CVD in NAFLD patients, low EPA/AA ratio in young age may influence the increased prevalence of CVD in their older age. EPA/AA ratio is suggested to be a possible link between NAFLD and CVD, and would become a useful marker for CVD in NAFLD.
Influence of liver toxicities on prognosis after stereotactic body radiation therapy for hepatocellular carcinoma
Authors: Sanuki Naoko , Takeda Atsuya , Oku Yohei , Eriguchi Takahisa , Nishimura Shuichi , Aoki Yosuke , Kunieda Etsuo
Published: July 2014

Aim

To better define clinically relevant non‐classic radiation‐induced liver disease (RILD) following stereotactic body radiotherapy (SBRT) in patients with small hepatocellular carcinoma (HCC).

Methods

We retrospectively evaluated the influence of acute liver toxicities on fatal hepatic failure in HCC patients treated with SBRT. Between April 2006 and February 2012, 194 HCC were treated with SBRT. Among them, patients followed up for more than 6 months were eligible. Laboratory results and Child–Pugh (CP) scores were obtained before treatment and at monthly follow‐up visits. Toxicities were evaluated by the Common Terminology Criteria for Adverse Events version 4.0. Possible definitions of RILD were evaluated with respect to fatal hepatic failure within 12 months.

Results

One hundred and eighty HCC were evaluated with a median follow‐up of 28.2 months. Fatal hepatic failure within 12 months occurred in eight patients (4%). On univariate analysis, grade 3 or more elevated transaminases, CP score of 8 or more, and/or grade 3 or more decreased platelet count significantly predicted fatal hepatic failure within 12 months. Combinations of these factors (i.e. having at least one criterion) also predicted fatal hepatic failure within 12 months (16% with criteria vs 1% without criteria). Two‐year overall survival rates for patients with and without RILD was 64.9% and 83.8% (P < 0.001), respectively.

Conclusion

We identified three criteria that affected overall survival in HCC patients treated with SBRT. Further prospective studies are warranted to validate the safety and effect of SBRT for HCC.