bluuebunny/crossref_metadata_2025 huggingface dataset:
Tracking Neuronal Migration in Adult Brain Slices
Authors: Bakhshetyan Karen , Saghatelyan Armen
Published: April 2015

Neuronal migration is one of the fundamental processes underlying the proper assembly and function of neural circuitry. The majority of neuronal precursors are generated far away from their sites of integration and need to migrate substantial distances to reach their final destination. Neuronal migration occurs not only in the embryonic brain but also in a few regions of the adult brain such as the olfactory bulb (OB). The mechanisms orchestrating cell migration in the adult brain are, however, poorly understood, despite their clinical relevance. Here we describe a method for time‐lapse imaging of cell migration in acute brain slices. This method, combined with genetic and/or pharmacological manipulations of different molecular pathways, makes it possible to determine the dynamics and molecular mechanisms of cell migration in the adult brain. In addition, time‐lapse imaging in acute brain slices makes it possible to monitor cell movement in a microenvironment that closely resembles in vivo conditions and to study neuroblast displacement along with other cellular elements such as astrocytes and blood vessels. © 2015 by John Wiley & Sons, Inc.
Mapping Regulatory Factors by Immunoprecipitation from Native Chromatin
Authors: Orsi Guillermo A. , Kasinathan Sivakanthan , Zentner Gabriel E. , Henikoff Steven , Ahmad Kami
Published: April 2015

Occupied Regions of Genomes from Affinity‐purified Naturally Isolated Chromatin (ORGANIC) is a high‐resolution method that can be used to quantitatively map protein‐DNA interactions with high specificity and sensitivity. This method uses micrococcal nuclease (MNase) digestion of chromatin and low‐salt solubilization to preserve protein‐DNA complexes, followed by immunoprecipitation and paired‐end sequencing for genome‐wide mapping of binding sites. In this unit, we describe methods for isolation of nuclei and MNase digestion of unfixed chromatin, immunoprecipitation of protein‐DNA complexes, and high‐throughput sequencing to map sites of bound factors. © 2015 by John Wiley & Sons, Inc.
Toll‐Like Receptors
Authors: Takeda Kiyoshi , Akira Shizuo
Published: April 2015

The mammalian Toll‐like receptor (TLR) family consists of 13 members, and recognizes specific patterns of microbial components, called pathogen‐associated molecular patterns (PAMPs). TLR‐dependent recognition of PAMPs leads to activation of the innate immune system, which subsequently leads to activation of antigen‐specific adaptive immunity. The TLR‐mediated signaling pathways consist of the MyD88‐dependent pathway and TRIF‐dependent pathway, both of which induce gene expression. This unit discusses mammalian TLRs (TLR1 to 13) that have an essential role in the innate immune recognition of microorganisms. Also discussed are TLR‐mediated signaling pathways and antibodies that are available to detect specific TLRs. © 2015 by John Wiley & Sons, Inc.
Effects of injected ice particles in the lower stratosphere on the Antarctic ozone hole
Authors: Nagase H. , Kinnison D. E. , Petersen A. K. , Vitt F. , Brasseur G. P.
Published: March 2015

The Antarctic ozone hole will continue to be observed in the next 35–50 years, although the emissions of chlorofluorocarbons (CFCs) have gradually been phased out during the last two decades. In this paper, we suggest a geo‐engineering approach that will remove substantial amounts of hydrogen chloride (HCl) from the lower stratosphere in fall, and hence limit the formation of the Antarctic ozone hole in late winter and early spring. HCl will be removed by ice from the atmosphere at temperatures higher than the threshold under which polar stratospheric clouds (PSCs) are formed if sufficiently large amounts of ice are supplied to produce water saturation. A detailed chemical‐climate numerical model is used to assess the expected efficiency of the proposed geo‐engineering method, and specifically to calculate the removal of HCl by ice particles. The size of ice particles appears to be a key parameter: larger particles (with a radius between 10 and 100 µm) appear to be most efficient for removing HCl. Sensitivity studies lead to the conclusions that the ozone recovery is effective when ice particles are supplied during May and June in the latitude band ranging from 70°S to 90°S and in the altitude layer ranging from 10 to 26 km. It appears, therefore, that supplying ice particles to the Antarctic lower stratosphere could be effective in reducing the depth of the ozone hole. In addition, photodegradation of CFCs might be accelerated when ice is supplied due to enhanced vertical transport of this efficient greenhouse gas.
Parameters controlling dynamically self‐consistent plate tectonics and single‐sided subduction in global models of mantle convection
Authors: Crameri Fabio , Tackley Paul J.
Published: March 2015

Recent advances in numerical modeling allow global models of mantle convection to more realistically reproduce the behavior at convergent plate boundaries; in particular, the inclusion of a free surface at the outer boundary has been shown to facilitate self‐consistent development of single‐sided subduction. This allows for a more extensive study of subduction in the context of global mantle convection, as opposed to commonly used regional models. Our first study already indicated important differences between mantle convection with single‐sided subduction and mantle convection with double‐sided subduction. Here we further investigate the effect of various physical parameters and complexities on inducing Earth‐like plate tectonics and its evolution in time. Results reinforce the previous finding that using a free surface instead of a free‐slip outer boundary dramatically changes subduction style, with free surface cases displaying many episodes of single‐sided subduction, which leads to more realistic slab dip, stress state, trench retreat rate, and slab‐induced mantle flow. Longevity of single‐sided subduction is promoted by a layer of hydrated crust with a low yield strength to lubricate the subduction channel, a low‐viscosity asthenosphere, and a high strength of the slab (determined by a combination of high‐diffusion creep viscosity and intermediate friction coefficient), although its effective viscosity is in the observationally constrained range in the bending region. The time evolution displays interesting events including subduction polarity reversals, subduction shut‐off, and slab break‐off.
Impact of Shanghai urban land surface forcing on downstream city ozone chemistry
Authors: Zhu Bin , Kang Hanqing , Zhu Tong , Su Jifeng , Hou Xuewei , Gao Jinhui
Published: March 2015

The urban land surface has a significant impact on local urban heat island effects and air quality. In addition, it influences the atmospheric conditions and air quality in the downwind cities. In this study, the impact of Shanghai urban land surface forcing on weather conditions and air quality over Kunshan was investigated using the Weather Research and Forecasting model coupled with a multilayer urban canopy model and the Community Multiscale Air Quality model. Two simulations were conducted to identify the impact of upstream effects with and without upstream urban land surfaces in control and sensitivity experiments. The results show that the near‐surface temperature and boundary layer height over Kunshan increased significantly with the appearance of the upstream urban land surface. Horizontal transport of O3 and its precursors, from Shanghai to Kunshan, are suppressed in the lower boundary layer but are strengthened in the upper boundary layer because of strong urban heat island circulation. As a result, O3 chemical production is decreased in the lower boundary layer of Kunshan but is increased in the upper boundary layer. On average, daytime O3 concentrations over Kunshan are decreased by approximately 2 ppbv in the lower boundary layer but are increased by as much as 40 ppbv in the upper air.
An active heat tracer experiment to determine groundwater velocities using fiber optic cables installed with direct push equipment
Authors: Bakker Mark , Caljé Ruben , Schaars Frans , van der Made Kees‐Jan , de Haas Sander
Published: April 2015

A new approach is developed to insert fiber optic cables vertically into the ground with direct push equipment. Groundwater temperatures may be measured along the cables with high spatial and temporal resolution using a Distributed Temperature Sensing system. The cables may be inserted up to depths of tens of meters in unconsolidated sedimentary aquifers. The main advantages of the method are that the cables are in direct contact with the aquifer material, the disturbance of the aquifer is minor, and no borehole is needed. This cost‐effective approach may be applied to both passive and active heat tracer experiments. An active heat tracer experiment was conducted to estimate horizontal groundwater velocities in a managed aquifer recharge system in the Netherlands. Six fiber optic cables and a separate heating cable were inserted with a 1 m spacing at the surface. The heating cable was turned on for 4 days and temperatures were measured during both heating and cooling of the aquifer. Temperature measurements at the heating cable alone were used to estimate the magnitude of the groundwater velocity and the thermal conductivity of the solids. The direction of the velocity and heat capacity of the solids were estimated by including temperature measurements at the other fiber optic cables in the analysis. The latter analysis suffered from the fact that the cables were not inserted exactly vertical. The three‐dimensional position of the fiber optic cables must be measured for future active heat tracer experiments.
SMILES observations of mesospheric ozone during the solar eclipse
Authors: Imai Koji , Imamura Takashi , Takahashi Kenshi , Akiyoshi Hideharu , Yamashita Yousuke , Suzuki Makoto , Ebisawa Ken , Shiotani Masato
Published: April 2015

The Superconducting Submillimeter‐Wave Limb‐Emission Sounder (SMILES) successfully observed vertical distributions of ozone (O3) concentration in the middle atmosphere during the annular solar eclipse that occurred on 15 January 2010. In the mesosphere, where the photochemical lifetime of O3 is relatively short (approximately 100 s), altitude‐dependent changes in O3 concentration under reduced solar radiation and their temporal variations were clearly observed as a function of the eclipse obscuration. This study reports the vertical distributions of mesospheric O3 during a solar eclipse event and analyzes theoretically the eclipse‐induced changes. We show that simple analytical expressions for O3 concentration, which assume that O3 and O are in a photochemically steady state, can be used to describe the O3 concentration under reduced solar radiation. The SMILES data obtained during the eclipse provide a unique opportunity to test our current understanding of mesospheric O3 photochemistry.
Evolution and Future Trends
Authors: Vits André J.
Published: April 2015

The development over recent few decades of information and telecommunication technologies (ICT) has changed dramatically the transportation sector and the way it operates. This chapter highlights some major outcomes of cooperative research, mainly in Europe, which have been the basis for future systems and services and their way to full deployment. Three topics are looked at in more detail: in‐car safety and fuel efficiency, navigation systems, and traffic management. In‐car safety and recently energy efficiency systems have fundamentally changed the design and operation of vehicles, the “connected car” will provide over its communication channels access to a whole range of services. Positioning technologies made it possible to develop navigation systems providing high quality route guidance to drivers. Dynamic traffic information across transport modes is the key service in keeping and brings another level of services using brought route guidance the map and traffic information into the car and continue to do. Traffic management, traditionally the responsibility of the road operator, is changing rapidly its scope network management within a mode and across modes in becoming possible making best use of telematics.
Adaptive enhanced sliding mode control for permanent magnet synchronous motor drives
Authors: Quan Zou , Lin‐fang Qian , Jian‐shou Kong
Published: April 2015

An adaptive enhanced sliding mode control (AESMC) scheme for the position tracking control of permanent magnet synchronous motor drives is proposed in this paper. The AESMC system is composed of three controllers: the adaptive model compensation controller, which is used to compensate for the parameter perturbations to achieve perfect tracking; the hitting controller, which is considered to attenuate the effect of external load disturbance and the compensation error; and the robust feedback controller, which is used to enhance the stability of the closed‐loop system and to improve the transient performance while the AESMC is in the learning process. Moreover, the bound of the lumped disturbance is assumed to be unknown, and an adaptive mechanism is investigated to estimate this bound. Simulation results show that the proposed AESMC scheme has a favorable tracking performance in spite of various model uncertainties. Copyright © 2015 John Wiley & Sons, Ltd.
Symmetric and Asymmetric Decoration of Graphene: Bimetal‐Graphene Sandwiches
Authors: Toth Peter S. , Velický Matěj , Ramasse Quentin M. , Kepaptsoglou Despoina M. , Dryfe Robert A. W.
Published: March 2015

Low‐dimensional carbon materials, i.e., graphene and its functionalization with a number of semiconductor or conductor materials, such as noble metal nanostructures, have primary importance for their potential exploitation as electro‐active materials, i.e., as new generation catalysts. Here, low‐cost, solution chemistry‐based, two‐step functionalization of an individual, free‐standing, chemical vapor‐deposited graphene monolayer is reported, with noble metal (Au, Pt, Pd) nanoparticles to build up two‐side decorated graphene‐based metal nanoclusters. Either the same metal (symmetric decoration) or different metals (asymmetric decoration) are used for the preparation of bimetal graphene sandwiches, which are adsorbed at the liquid/liquid (organic/water) interface. The successful fabrication of such dual‐decorated graphene‐based metal nanocomposites is confirmed using various microscopic techniques (scanning electron and atomic force microscopies) and several spectroscopic methods (x‐ray photoelectron, energy dispersive x‐ray, mapping mode Raman spectroscopy, and electron energy loss spectroscopy). Taken together, it is inferred from these techniques that the location of deposited metal nanoparticles is on opposite sides of the graphene.
Oxygen Vacancy Creation, Drift, and Aggregation in TiO2‐Based Resistive Switches at Low Temperature and Voltage
Authors: Kwon Jonghan , Sharma Abhishek A. , Bain James A. , Picard Yoosuf N. , Skowronski Marek
Published: March 2015

Transmission electron microscopy with in situ biasing has been performed on TiN/single‐crystal rutile TiO2/Pt resistive switching structures. Three elementary processes essential for switching: i) creation of oxygen vacancies by electrochemical reactions at low temperatures (<150 °C), ii) their drift in the electric field, and iii) their coalescence into planar faults (and dissociation from them) have been documented. The faults have a form of vacancy discs in {110} and {121} planes, are bound by partial dislocation loops, and are identical to Wadsley defects observed in nonstoichiometric TiO2 annealed at high temperatures. The faults can be regarded as a precursor to the formation of oxygen‐deficient Magnéli phases, but 3D secondary phase inclusions have not been detected. Together, the observations shed light on the behavior of oxygen vacancies in relatively low electric fields and temperatures, suggesting that, in addition to the rather accepted notion of oxygen vacancy motion during the writing processes in resistive switching devices, such motion may occur even during reading, and may be accompanied by significant oxygen vacancy creation at modest device excitation levels.
Bio‐Interface of Conducting Polymer‐Based Materials for Neuroregeneration
Authors: Weng Bo , Diao Jianglin , Xu Qun , Liu Yuqing , Li Changming , Ding Ailing , Chen Jun
Published: April 2015

Nerve system diseases like Parkinson's disease, Huntington's disease, Alzheimer's disease, etc. seriously affect thousands of patients' lives every year, making them suffer from pains and inconvenience. Recently, bio‐interfaces between neural cells/tissues and polymer based biomaterials attracted worldwide attention due to the ability of polymer based biomaterials to serve as nerve conduits, drug carriers and neurites guidance platform in neuroregeneration. The role that bio‐interface played and the way it interacted with neural tissues and cells have been thoroughly investigated by the researchers. In this paper we mainly focus on reviewing the bio‐interface between nerve tissues/cells and advanced functional biocompatible polymers, such as conducting polymers and advanced carbon composite materials. These advanced polymers can provide combined interfacial stimulations including interfacial external neurotrophic factors (NTFs) delivery, electrical stimulation, surface guidance and molecules decoration to lesion cells and tissues to promote neuroregeneration in vitro and in vivo, and have contributed greatly to nerve diseases therapy. At the end of this review, the criteria of polymer based biomaterials utilized in neuroregeneration are summarized and the perspectives for future development of bio‐interfaces are also discussed.
Random Lasing in Novel Dye‐Doped White Paints with Shape Memory
Authors: Espinha André , Serrano María Concepción , Blanco Alvaro , López Cefe
Published: April 2015

Although enormous advances are accomplished using shape memory polymers (SMPs) and their derived composites, the application of these media in optics and photonics is still restricted to a few systems. The present work addresses the fabrication and characterization of novel composites based on polydiolcitrates doped with titania nanoparticles, aiming at expanding the capabilities of the original elastomer. They constitute advanced photonic white paints, which incorporate the shape memory effect as an additional functionality. In these materials, light propagation is diffusive and it is possible to tailor its transport mean free path by acting on the titania fillers concentration. Optical gain is introduced by additionally doping the composites with organic dyes. This allows the shape recovery process to be monitored by luminescence and, conversely, the composites can perform as configurable shape active media. Their application in nonresonant feedback random lasers is demonstrated by systematic photoluminescence studies. The threshold for stimulated emission is shown to depend on both the fillers and dye concentrations. The so‐obtained multifunctional composites are promising candidates for establishing synergies between applications from the domain of SMPs with those typically restricted to random photonic media, leading to novel self‐reporting sensors/actuators or responsive illumination devices, for example.
Synthesis, Characterization, and Biological Evaluation of a 4,7‐Dihydroxy‐1,10‐Phenanthroline‐Based Epoxy Resin and Its Polymer–Metal Complexes
Authors: Alshehri Saad M. , Aldalbahi Ali , Ahamad Tansir
Published: March 2015

An epoxy polymeric ligand (EPL) was synthesized via polycondensation of 4,7‐dihydroxy‐1,10‐phenanthroline with epichlorohydrin under basic conditions and used to prepare polymer–metal complexes [EPL‐M(II)] with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) ions. The synthesized polymers were characterized via elemental and magnetic moment analyses, UV–vis, ESR, FTIR, 1H NMR and 13C NMR spectroscopy, and thermal analyses (TGA/DTA/DSC). The results of polymeric ligand indicated that the molar ratio of 4,7‐dihydroxy‐1,10‐phenanthroline and epichlorohydrin was 1:2, respectively, and in the case of EPL‐M(II), the molar ratio of EPL and metal chloride was 2:1, respectively. The TGA/DTA results revealed higher thermal stability in all EPL‐M(II) relative to EPL. The thermal kinetic and thermodynamic parameters of the synthesized polymers were evaluated for the polymer metal complexes using the Coats–Redfern equation. In addition, the antimicrobial activities of EPL and EPL‐M(II) were measured against several bacteria and fungi using the agar well diffusion method, and the results were compared with kanamycin and miconazole as standard drugs for antibacterial and antifungal activities, respectively.
Obstructive heart defects associated with candidate genes, maternal obesity, and folic acid supplementation
Authors: Tang Xinyu , Cleves Mario A. , Nick Todd G. , Li Ming , MacLeod Stewart L. , Erickson Stephen W. , Li Jingyun , Shaw Gary M. , Mosley Bridget S. , Hobbs Charlotte A. ,   National Birth Defects Prevention Study
Published: April 2015

Right‐sided and left‐sided obstructive heart defects (OHDs) are subtypes of congenital heart defects, in which the heart valves, arteries, or veins are abnormally narrow or blocked. Previous studies have suggested that the development of OHDs involved a complex interplay between genetic variants and maternal factors. Using the data from 569 OHD case families and 1,644 control families enrolled in the National Birth Defects Prevention Study (NBDPS) between 1997 and 2008, we conducted an analysis to investigate the genetic effects of 877 single nucleotide polymorphisms (SNPs) in 60 candidate genes for association with the risk of OHDs, and their interactions with maternal use of folic acid supplements, and pre‐pregnancy obesity. Applying log‐linear models based on the hybrid design, we identified a SNP in methylenetetrahydrofolate reductase (MTHFR) gene (C677T polymorphism) with a main genetic effect on the occurrence of OHDs. In addition, multiple SNPs in betaine‐homocysteine methyltransferase (BHMT and BHMT2) were also identified to be associated with the occurrence of OHDs through significant main infant genetic effects and interaction effects with maternal use of folic acid supplements. We also identified multiple SNPs in glutamate‐cysteine ligase, catalytic subunit (GCLC) and DNA (cytosine‐5‐)‐methyltransferase 3 beta (DNMT3B) that were associated with elevated risk of OHDs among obese women. Our findings suggested that the risk of OHDs was closely related to a combined effect of variations in genes in the folate, homocysteine, or glutathione/transsulfuration pathways, maternal use of folic acid supplements and pre‐pregnancy obesity. © 2015 Wiley Periodicals, Inc.
ELP2 is a novel gene implicated in neurodevelopmental disabilities
Authors: Cohen Julie S. , Srivastava Siddharth , Farwell Kelly D. , Lu Hsiao‐Mei , Zeng Wenqi , Lu Hong , Chao Elizabeth C. , Fatemi Ali
Published: April 2015

Elongator is a multi‐subunit protein complex essential to transcription elongation, histone acetylation, and tRNA modification. The complex consists of six highly conserved protein subunits, called Elongator Proteins (ELP) 1–6. Apart from an association with intellectual disability (ID), there is limited clinical information about patients with ELP2 variants. Here we report on two brothers with severe ID, spastic diplegia, and self‐injury whose presentation eluded a diagnosis for over 20 years. In both brothers, whole exome sequencing revealed a likely pathogenic, compound heterozygous missense variant in ELP2. We describe the phenotype and natural history of the ELP2‐related disorder in these brothers. © 2015 Wiley Periodicals, Inc.
Persistence of müllerian duct structures in a genetic male with distal monosomy 10q
Authors: Tosur Mustafa , Geary Cara A. , Matalon Reuben , Radhakrishnan Ravi S. , Swischuk Leonard E. , Tarry William F. , Dong Jianli , Lee Phillip D. K.
Published: March 2015

Persistent müllerian duct syndrome (PMD) with antimüllerian hormone (AMH) deficiency is usually associated with mutations or deletions of the AMH gene, although many cases have no identified gene association. We report on a genetic male with PMD and AMH deficiency associated with distal monosomy 10q. A term 3,230 g infant was born to a healthy 27‐year‐old. Fetal ultrasound had shown possible genital ambiguity. Postnatal exam showed a 0.5 cm phallus with basal meatus, normal scrotum with no palpable gonads, no vaginal orifice, and a rectal fistula with an imperforate anus. Voiding cystourethrogram with ultrasound, cystoscopy, and laparoscopy showed normal bladder, urethral orifice, distal vagina, cervix, and bilateral abdominal testis. At 24 hours of life, testosterone was within normal range with low AMH level. Chromosome microarray analysis showed 46, XY, del10(10q25.3q26.13) involving an 8.2 MB interstitial deletion. Whole exome sequencing identified a NOTCH2 variant (1p11.2). AMH sequencing revealed no abnormalities. Following multidisciplinary team and parent discussion, male gender was assigned. Testosterone treatment resulted in penile length of 1.5 cm. Bilateral orchiopexy and posterior sagittal anorectoplasty were performed at 11 months of age; rudimentary müllerian structures were identified. This observation suggests an association of 10qter elements with male differentiation including AMH expression and is similar to a patient with 46, XY, del(10q26.1) in which AMH levels were not reported. Regional candidate genes include FGFR2 (10q26.13). The possible contribution of a NOTCH2 variant cannot be excluded. © 2015 Wiley Periodicals, Inc.
Phenotype of a child with Angelman syndrome born to a woman with Prader–Willi syndrome
Authors: Ostergaard John R.
Published: April 2015

This report describes the phenotype, from early childhood to adolescence, of a girl with Angelman syndrome (AS) born following a maternal transmission of a germline paternal 15q11.2‐q13 deletion. During early childhood, she showed a typical AS phenotype, such as jerky movements, poor sleep, high voltage electroencephalography pattern, epilepsy, and a severe developmental disability. As she grew older, indications of phenotypical traits similar to Prader–Willi syndrome (PWS) appeared, in particular hyperphagic behavior and a body fat distribution similar to that reported in PWS. She generally showed cheerful AS behavior and had the characteristic outbursts of laughter, but her attitude to other people did not reflect the usual shared enjoyment of interaction seen in children with AS. In unfamiliar surroundings, she withdrew socially, similar to children with PWS, and her insistence on the same, rigid routines was similar to behavior patterns in PWS. The dysmorphic facial features that characterize AS were blurred in adolescence. The specified features that this AS patient had in common with PWS were hardly incidental and, if verified by upcoming case reports of children born to women with a paternal 15q11.2‐q13 deletion, they may show new aspects of genetic imprinting. © 2015 Wiley Periodicals, Inc.
Mechanophores with a Reversible Radical System and Freezing‐Induced Mechanochemistry in Polymer Solutions and Gels
Authors: Imato Keiichi , Irie Atsushi , Kosuge Takahiro , Ohishi Tomoyuki , Nishihara Masamichi , Takahara Atsushi , Otsuka Hideyuki
Published: March 2015

Visualization and quantitative evaluation of covalent bond scission in polymeric materials are highly important for understanding failure, fatigue, and deterioration mechanisms and improving the lifetime, durability, toughness, and reliability of the materials. The diarylbibenzofuranone‐based mechanophore radical system enabled, through electron paramagnetic resonance spectroscopy, in situ quantitative evaluation of scission of the mechanophores and estimation of mechanical energy induced along polymer chains by external forces. The coagulation of polymer solutions by freezing probably generated force but did not cleave the mechanophores. On the other hand, cross‐linking led to efficient propagation of the force of more than 80 kJ mol−1 to some mechanophores, resulting their cleavage and generation of colored stable radicals. This mechanoprobe concept has the potential to elucidate other debated issues in the polymer field as well.
Stabilizing Two Classical Antiaromatic Frameworks: Demonstration of Photoacoustic Imaging and the Photothermal Effect in Metalla‐aromatics
Authors: Zhu Congqing , Yang Yuhui , Luo Ming , Yang Caixia , Wu Jingjing , Chen Lina , Liu Gang , Wen Tingbin , Zhu Jun , Xia Haiping
Published: March 2015

Antiaromatic species are substantially less thermodynamically stable than aromatic moieties. Herein, we report the stabilization of two classical antiaromatic frameworks, cyclobutadiene and pentalene, by introducing one metal fragment through the first [2+2] cycloaddition reaction of a late‐transition‐metal carbyne with alkynes. Experimental observations and theoretical calculations reveal that the metal fragment decreases the antiaromaticity in cyclobutadiene and pentalene simultaneously, leading to air‐ and moisture‐stable products. These molecules show broad absorption from the UV to the near‐IR region, resulting in photoacoustic and photothermal effects for metalla‐aromatic compounds for the first time. These results will encourage further efforts into the exploration of organometallic compounds for photoacoustic‐imaging‐guided photothermal therapy.
Electrochemical Assay to Detect Influenza Viruses and Measure Drug Susceptibility
Authors: Zhang Xiaohu , Dhawane Abasaheb N. , Sweeney Joyce , He Yun , Vasireddi Mugdha , Iyer Suri S.
Published: March 2015

An electrochemical assay has been designed to rapidly diagnose influenza viruses. Exposure of a glucose‐bearing substrate to influenza viruses or its enzyme, neuraminidase (NA), releases glucose, which was detected amperometrically. Two methods were used to detect released glucose. First, we used a standard glucose blood meter to detect two viral NAs and three influenza strains. We also demonstrated drug susceptibility of two antivirals, Zanamivir and Oseltamivir, using the assay. Finally, we used disposable test strips to detect nineteen H1N1 and H3N2 influenza strains using this assay in one hour. The limit and range of detection of this first generation assay is 102 and 102–108 plaque forming units (pfu), respectively. Current user‐friendly glucose meters can be repurposed to detect influenza viruses.
Stereoselective Synthesis of the Halaven C14–C26 Fragment from D‐Quinic Acid: Crystallization‐Induced Diastereoselective Transformation of an α‐Methyl Nitrile
Authors: Belanger Francis , Chase Charles E. , Endo Atsushi , Fang Francis G. , Li Jing , Mathieu Steven R. , Wilcoxen Annie Z. , Zhang Huiming
Published: March 2015

Crystallization‐induced diastereoselective transformation (CIDT) of an α‐methyl nitrile completes an entirely non‐chromatographic synthesis of the halichondrin B C14–C26 stereochemical array. The requisite α‐methyl nitrile substrate is derived from D‐quinic acid through a series of substrate‐controlled stereoselective reactions via a number of crystalline intermediates that benefit from a rigid polycyclic template. Therefore, all four stereogenic centers in the Halaven C14–C26 fragment were derived from the single chiral source D‐quinic acid.
In vivo bioactivity of herbal‐drug‐incorporated nanofibrous matrixes
Authors: Agnes Mary S. , Giri Dev V. R.
Published: April 2015

Aloe‐vera‐incorporated polycaprolactone nanofibrous matrixes were prepared by an electrospinning method. These developed matrixes were evaluated for their water absorption capacity, water vapor permeability, and contact angle, and, in an in vivo animal model, wound‐healing ability. The incorporation of the herbal drug made the matrixes hydrophilic with improved water retention and permeability properties. The in vivo studies were carried out in a rat model and showed improved results with respect to healing. Thus, this study confirmed that the developed matrixes could be used for wound‐healing applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42178.
Τhe effect of wood‐fiber type on the thermomechanical performance of a biodegradable polymer matrix
Authors: Georgiopoulos Panayiotis , Kontou Evagelia
Published: April 2015

The effect of type and content of wood fibers on the thermal, mechanical and rheological behavior of the commercial biodegradable polyester product, Ecovio® (BASF) is analytically studied. Ecovio® is basically a blend of poly(butylene adipate‐terephthalate) copolyester (Ecoflex®, BASF) and polylactide. Three different types of wood fibers, based either on raw cellulose (Arbocel) or selected conifers (Lignocel), with varying fiber size at various weight fractions were used for this purpose. The role of these fibers on the thermomechanical performance of Ecovio® was investigated in terms of several experimental techniques including scanning electron microscopy, differential scanning calorimetry, dynamic mechanical analysis, creep, tensile testing, and water uptake at room temperature. At the low wood fiber content (20 wt %), Lignocel composite's properties are predominant compared with the Arbocel composites. It has been found, that at this wood content, an efficient compatibility between matrix and fibers is achieved, leading to superior reinforcement. This trend is completely reversed at higher filler loading, probably due to the poor interfacial adhesion between the matrix and Lignocel occurring at 30 wt %. This behavior was supported by all the experimental methods employed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42185.
Distortive effects of initial‐based name disambiguation on measurements of large‐scale coauthorship networks
Authors: Kim Jinseok , Diesner Jana
Published: April 2015

Scholars have often relied on name initials to resolve name ambiguities in large‐scale coauthorship network research. This approach bears the risk of incorrectly merging or splitting author identities. The use of initial‐based disambiguation has been justified by the assumption that such errors would not affect research findings too much. This paper tests that assumption by analyzing coauthorship networks from five academic fields—biology, computer science, nanoscience, neuroscience, and physics—and an interdisciplinary journal, PNAS. Name instances in data sets of this study were disambiguated based on heuristics gained from previous algorithmic disambiguation solutions. We use disambiguated data as a proxy of ground‐truth to test the performance of three types of initial‐based disambiguation. Our results show that initial‐based disambiguation can misrepresent statistical properties of coauthorship networks: It deflates the number of unique authors, number of components, average shortest paths, clustering coefficient, and assortativity, while it inflates average productivity, density, average coauthor number per author, and largest component size. Also, on average, more than half of top 10 productive or collaborative authors drop off the lists. Asian names were found to account for the majority of misidentification by initial‐based disambiguation due to their common surname and given name initials.
Versuchstechnische Bestimmung der Eignung von Befestigungssystemen unter seismischer Beanspruchung
Authors: Zeman Oliver , Guggenberger Theodor , Bergmeister Konrad , Zimmermann Thomas
Published: April 2015

Das bisher im europäischen Raum gebräuchliche Zulassungssystem von Befestigungssystemen auf Grundlage der European Technical Approval Guideline 001 (ETAG 001) aus dem Jahre 1997 für statische und quasi‐statische Belastungssituationen berücksichtigt Versuche mit wechselnder Rissöffnung bzw. wechselnder zentrischer Belastung nicht unter dem Gesichtspunkt seismischer Beanspruchungen. Darüber hinausgehende seismische Beanspruchungen, wie sie bei der Anwendung von nachträglich angebrachten Befestigungen in Zonen erhöhter seismischer Aktivität zu berücksichtigen sind, werden durch das gegenwärtige europäische Zulassungsverfahren nicht abgedeckt. Unter diesem Gesichtspunkt und den bereits gewonnenen Erfahrungen mit Versuchen nach ACI 355.2 wird nun auch im europäischen Zulassungs‐ bzw. Bewertungsverfahren eine dahingehende Entwicklung vollzogen. Mit dem Annex E zur ETAG 001 wird diese Komponente auch im europäischen Verfahren auf Grundlage der Bestimmungen der Eurocodes ergänzt.

Im ersten Teil dieses Beitrags erfolgt eine Übersicht über das gegenwärtige Zulassungsverfahren. Im zweiten Teil werden die Spezifikationen zu den erforderlichen Zulassungsversuchen nach Annex E der ETAG 001 hinsichtlich Performance Class 1 und Performance Class 2 erläutert. Der dritte Teil dieses Beitrags beschäftigt sich mit Fragestellungen, welche im Rahmen von durchgeführten Versuchen aufgetreten sind.

Evaluation of anchors under seismic actions by means of experimental testing

The current European approval system for anchors for use in concrete is based on the European Technical Approval Guideline 001 (ETAG 001). It is valid for static and quasi‐static loading situations and considers tests with cycling loading situations. Thereby, tests with crack movement and pulsating tension load are just taken into account in a quite reduced range. Explicit seismic loadings are not covered by this European approval system, in contrast to the US. Within the US system tests under pulsating tension load und tests under alternating shear load cycling are required. By means of the experience, taken from tests according to ACI 355.2, the Annex E of ETAG 001 was elaborated for the consideration of seismic aspects in a more severe way in the European approval procedure.

The first part of this article gives an overview of the actual valid approval procedure. In the second part the specifications for the required tests of the Annex E of ETAG 001 regarding the anchor performance class 1 and performance class 2 are pointed out. The third part of this contribution deals with definitions and boundary conditions of the guideline for the individual tests. On the one hand, tests under alternating shear load cycling are considered and on the other hand a few critical points for the performance of tests with tension load and varying crack width are discussed. For each point a recommendation based on available test results is given.
Caffeic acid, a phyto polyphenol mitigates fluoride induced hepatotoxicity in rats: A possible mechanism
Authors: Kanagaraj Vishnu Vignesh , Panneerselvam Lakshmikanthan , Govindarajan Vimal , Ameeramja Jaishabanu , Perumal Ekambaram
Published: April 2015

Fluoride induced hepatotoxicity has been extensively studied in both humans and animals. However, the mechanism underlying in the hepatotoxicity of experimental fluorosis remains obscure. The severity of fluoride toxicity was reduced by oral administration of certain plant derived antioxidants. Caffeic acid (CA) a polyphenolic compound has diverse range of pharmacological activity in the biological system. Therefore, the present study was aimed to investigate the protective mechanism of CA, against fluoride induced hepatotoxicity in rats. The rats were treated with 300 ppm of NaF via drinking water ad libitum alone and in combination with CA at a dose of 50 mg/kg daily for 30 days by oral intubation. CA treatment significantly prevented fluoride induced hepatic damage as evident from the histopathological studies and declined levels of serum fluoride and liver marker enzymes. A significant decrease in the levels of enzymatic (SOD2, CAT, GPx, and GSTpi class) and nonenzymatic (GSH and Vitamin C) antioxidants along with increased ROS, lipid peroxidation, protein carbonyl content, and nitrate levels by fluoride were also prevented in these groups. In addition, CA inhibits fluoride induced apoptosis by altering the Bax and caspase‐3p20 expressions. Further, fluoride induced upregulation of Nox4, p38α MAPK, Hsp60, and downregulation of Hsp27 are the indicators for the detection of oxidative damage, apoptosis, and mitochondrial stress was also modulated by CA. These findings reveal that CA supplementation has a protective effect against fluoride induced hepatotoxicity in rats. © 2015 BioFactors, 41(2):90–100, 2015
Risk factors and consequences of conversion in laparoscopic major liver resection
Authors: Cauchy F , Fuks D , Nomi T , Schwarz L , Barbier L , Dokmak S , Scatton O , Belghiti J , Soubrane O , Gayet B
Published: April 2015

Background

Although recent reports have suggested potential benefits of the laparoscopic approach in patients requiring major hepatectomy, it remains unclear whether conversion to open surgery could offset these advantages. This study aimed to determine the risk factors for and postoperative consequences of conversion in patients undergoing laparoscopic major hepatectomy (LMH).

Methods

Data for all patients undergoing LMH between 2000 and 2013 at two tertiary referral centres were reviewed retrospectively. Risk factors for conversion were determined using multivariable analysis. After propensity score matching, the outcomes of patients who underwent conversion were compared with those of matched patients undergoing laparoscopic hepatectomy who did not have conversion, operated on at the same centres, and also with matched patients operated on at another tertiary centre during the same period by an open laparotomy approach.

Results

Conversion was needed in 30 (13·5 per cent) of the 223 patients undergoing LMH. The most frequent reasons for conversion were bleeding and failure to progress, in 14 (47 per cent) and nine (30 per cent) patients respectively. On multivariable analysis, risk factors for conversion were patient age above 75 years (hazard ratio (HR) 7·72, 95 per cent c.i. 1·67 to 35·70; P = 0·009), diabetes (HR 4·51, 1·16 to 17·57; P = 0·030), body mass index (BMI) above 28 kg/m2 (HR 6·41, 1·56 to 26·37; P = 0·010), tumour diameter greater than 10 cm (HR 8·91, 1·57 to 50·79; P = 0·014) and biliary reconstruction (HR 13·99, 1·82 to 238·13; P = 0·048). After propensity score matching, the complication rate in patients who had conversion was higher than in patients who did not (75 versus 47·3 per cent respectively; P = 0·038), but was not significantly different from the rate in patients treated by planned laparotomy (79 versus 67·9 per cent respectively; P = 0·438).

Conclusion

Conversion during LMH should be anticipated in patients with raised BMI, large lesions and biliary reconstruction. Conversion does not lead to increased morbidity compared with planned laparotomy.
Transcatheter melody valve placement in large diameter bioprostheses and conduits: What is the optimal “Landing zone”?
Authors: Finch Will , Levi Daniel S. , Salem Morris , Hageman Abbie , Aboulhosn Jamil
Published: March 2015

Objectives

This study sought to elucidate the optimal bioprosthetic valve (BPV) size prior to Melody valve implantation. Background: BPVs provide an ideal “landing zone” for future Melody valve insertion. To guide surgical choice of BPV size, it is important to understand which BPV size can serve consistently as substrates for Melody valve placements.

Methods

A database of all patients who underwent Melody implantation at UCLA or Kaiser Permanente Los Angeles from 2010 to 2014 was analyzed retrospectively. Patients with an existing BPV were stratified into those with a valve diameter of ≥27 mm or <27 mm.

Results

One hundred and sixty patients underwent catheterization with the intention to implant a Melody valve. Melody valve implantation was performed in the pulmonary position in 52 patients with prior BPVs. The immediate procedural success rate was 100%. Immediately post‐Melody, the right ventricular to pulmonary artery gradient was significantly higher in the <27 mm group compared to the ≥27 mm group (14.3 ± 3 vs. 8.6 ± 6.8, P = 0.006). There was a significantly shorter time from prior valve replacement to Melody implantation in the <27 mm group. There was one patient in whom transcatheter pulmonary valve implantation was aborted due to inadequate landing zone in the <27 mm group, and no patients in the ≥27 mm group (P = NS).

Conclusions

The results of this study indicate that 27 and 29 mm BPV provide a superior landing zone for Melody valve implantation with excellent immediate and intermediate term hemodynamic results when compared to smaller BPVs less than 27 mm. © 2015 Wiley Periodicals, Inc.
CO2 Adsorption Kinetics of K2CO3/Activated Carbon for Low‐Concentration CO2 Removal from Confined Spaces
Authors: Guo Yafei , Zhao Chuanwen , Li Changhai
Published: April 2015

K2CO3 supported on activated carbon (K2CO3/AC) is a promising means to remove low‐concentration CO2 from confined spaces. In this removal process, physical adsorption plays an important role but it is difficult to quantify the amount of CO2 adsorbed when both H2O and CO2 are present. The linear driving force mass transfer model is adopted to study the CO2 adsorption kinetic characteristics of K2CO3/AC by analyzing the experimental data. The effect of K2CO3 and H2O on the adsorption of CO2 in K2CO3/AC was also evaluated. K2CO3 loaded on the support is found to increase the mass transfer resistance but decrease the activation energy required for the physical adsorption process. The presence of water vapor is disadvantageous to achieve high physical adsorption capacity since it enhances the chemical sorption in the competitive dynamic sorption process.
Interactions of Pt‐ttpy with G‐Quadruplexes Originating from Promoter Region of the c‐myc Gene Deciphered by NMR and Gel Electrophoresis Analysis
Authors: Trajkovski Marko , Morel Elodie , Hamon Florian , Bombard Sophie , Teulade‐Fichou Marie‐Paule , Plavec Janez
Published: April 2015

This study provides insights into the interactions of Pt‐ttpy, that is, a metallo‐organic heterocycle‐comprising platinum(II) complex of terpyridine, and G‐quadruplexes adopted by G‐rich DNA from the transcriptional regulatory element of the c‐myc gene, a well‐known attractive target for artificial modulation of oncogene expression. A previously noted drug‐like potential of Pt‐ttpy relies on its antiproliferative activity on cancer cells and its increased selectivity for G‐quadruplex binding attributed to the combination of distinct interacting modes. The predominant interaction between the herein used models of a parallel G‐quadruplex exhibiting short propeller‐type loops and Pt‐ttpy occurs through stacking to the outer G‐quartets. The presence of adenine versus thymine residue at the 5’‐end overhanging region allows the coordinative binding of Pt‐ttpy to the G‐quadruplex structure. Interestingly, Pt‐ttpy triggers the formation of the G‐quadruplex even in the absence of cations. Furthermore, NMR‐based characterisation revealed common structural features of Pt‐ttpy–G‐quadruplex complexes in the presence and absence of cations, which indicate that cations may be expelled from the cores of the corresponding structures.
ChemInform Abstract: Cesium Carbonate Promoted Direct Arylation of Hydroxylamines and Oximes with Diaryliodonium Salts.
Authors: Yang Yang , Wu Xunshen , Han Jianwei , Mao Song , Qian Xiaofei , Wang Limin
Published: April 2015

The title reaction is efficient, is tolerant to a variety of substituents, and proceeds under mild reaction conditions without any additional transition‐metals.
ChemInform Abstract: A Direct C—H/Ar—H Coupling Approach to Oxindoles, Thio‐Oxindoles, 3,4‐Dihydro‐1H‐quinolin‐2‐ones, and 1,2,3,4‐Tetrahydroquinolines.
Authors: Hurst Timothy E. , Gorman Ryan M. , Drouhin Pauline , Perry Alexis , Taylor Richard J. K.
Published: April 2015

CEH is identified as inexpensive and efficient catalyst for all approaches to the title heterocycles including double cyclizations [cf.
Synthesis of Quaternary α‐Hydroxy Phosphonates via Direct Hydroxylation of Phosphonate Compounds
Authors: Liu Jiyan , Wang Wei , Wang Rui , Gu Lijun
Published: March 2015

It was found for the first time that Cs2CO3 serves as highly efficient catalyst for the direct hydroxylation reactions of phosphonates under mild conditions. This reaction provides an efficient approach to quaternary α‐hydroxy phosphonates, which possess intriguing biological activities and are widely used in many areas.