bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunoblotting and Immunodetection
Authors: Gallagher Sean , Winston (tank transfer systems) Scott E. , Fuller (tank transfer systems) Steven A. , Hurrell (tank transfer systems; reversible staining of prote John G.R.
Published: November 2008

Immunoblotting (western blotting) is used to identify specific antigens recognized by polyclonal or monoclonal antibodies. This unit provides protocols for all steps, starting with solubilization of the protein samples, usually by means of SDS and reducing agents. Following solubilization, the material is separated by SDS‐PAGE and the antigens are electrophoretically transferred to a membrane, a process that can be monitored by reversible staining with Ponceau S. The transferred proteins are bound to the surface of the membrane, providing access to immunodetection reagents. After nonspecific binding sites are blocked, the membrane is probed with the primary antibody and washed. The antibody‐antigen complexes are tagged with horseradish peroxidase or alkaline phosphatase coupled to a secondary anti‐IgG antibody, and detected using appropriate chromogenic or luminescent substrates. Finally, membranes may be stripped and reprobed. Curr. Protoc. Immunol. 83:8.10.1‐8.10.28. © 2008 by John Wiley & Sons, Inc.
Endoglycosidase and Glycoamidase Release of N‐Linked Glycans
Authors: Freeze Hudson H. , Kranz Christian
Published: November 2008

Nearly all proteins entering the lumen of the endoplasmic reticulum (ER) become glycosylated en route to a cellular organelle, the plasma membrane, or the extracellular space. Many glycans can be attached to proteins, but the most common are the N‐linked glycans (oligosaccharides). These chains are added very soon after a protein enters the ER, but they undergo extensive remodeling (processing), especially in the Golgi. Processing changes the sensitivity of the N‐glycan to enzymes that cleave entire sugar chains or individual monosaccharides, which also changes the migration of the protein on SDS gels. These changes can be used to indicate when a protein has passed a particular subcellular location. This unit details some of the methods used to track a protein as it traffics from the ER to the Golgi toward its final location. Curr. Protoc. Immunol. 83:8.15.1‐8.15.26. © 2008 by John Wiley & Sons, Inc.
Colon Cancer Stem Cells
Authors: Kreso Antonija , O'Brien Catherine Adell
Published: November 2008

This unit describes protocols for working with colon cancer stem cells. To work with these cells one must start by generating single‐cell suspensions from human colon cancer tissue. These cell suspensions are sorted using flow cytometry–assisted cell sorting to fractionate the cells into tumor‐initiating and nontumor‐initiating subsets. Once the cells have been fractionated, they must be functionally tested to determine tumor‐forming capacity, the gold standard being the in vivo xenograft assay. Methods have also been developed to grow these cells in vitro in a sphere‐forming assay. This unit will describe how to isolate and functionally test colon cancer stem cells, as well as provide advice on the potential challenges of the research. Curr. Protoc. Stem Cell Biol. 7:3.1.1‐3.1.12. © 2008 by John Wiley & Sons, Inc.
Laboratory Maintenance of Moraxella catarrhalis
Authors: Balder Rachel , Lafontaine Eric R.
Published: November 2008

Moraxella catarrhalis is a Gram‐negative bacterium that has recently emerged as the third leading cause of bacterial ear infections in children. This organism is also responsible for a variety of upper respiratory tract illnesses in adults, including ∼10% of all cases of respiratory exacerbations in patients with chronic obstructive pulmonary disease (COPD). There is interest in studying M. catarrhalis for vaccine development, and this unit provides guidelines for the laboratory maintenance of the organism. The three Basic Protocols presented in this unit describe how to culture and prepare M. catarrhalis cells for use in experiments pertaining to various biological aspects of this important respiratory pathogen. Curr. Protoc. Microbiol. 11:6B.1.1‐6B.1.11. © 2008 by John Wiley & Sons, Inc.
Experimental Chick Colonization by Campylobacter jejuni
Authors: Davis Lindsay , DiRita Victor
Published: November 2008

Campylobacter jejuni is commonly isolated from animals, including rodents, farm animals, and especially birds. The most common route of infection for humans is through the ingestion of contaminated chicken. Although C. jejuni commonly inhabits a number of animals, it does so asymptomatically. Many animals have been explored for use in pathogenic models; however, the most commonly used and established animal model is the chick colonization model described in this unit. Curr. Protoc. Microbiol. 11:8A.3.1‐8A.3.7. © 2008 by John Wiley & Sons, Inc.
Aseptic Technique
Authors: Bykowski Tomasz , Stevenson Brian
Published: November 2008

This chapter describes common laboratory procedures that can reduce the risk of culture contaminations (sepsis), collectively referred as “aseptic technique.” Two major strategies of aseptic work are described: using a Bunsen burner and a laminar flow hood. Both methods are presented in the form of general protocols applicable to a variety of laboratory tasks such as pipetting and dispensing aliquots, preparing growth media, and inoculating, passaging, and spreading microorganisms on petri dishes. Curr. Protoc. Microbiol. 11:A.4D.1‐A.4D.11. © 2008 by John Wiley & Sons, Inc.
Growth and Maintenance of Vero Cell Lines
Authors: Ammerman Nicole C. , Beier‐Sexton Magda , Azad Abdu F.
Published: November 2008

Vero cells are derived from the kidney of an African green monkey, and are one of the more commonly used mammalian continuous cell lines in microbiology and molecular and cell biology research. This unit includes protocols for the growth and maintenance of Vero cell lines in a research laboratory setting. Curr. Protoc. Microbiol. 11:A.4E.1‐A.4E.7. © 2008 by John Wiley & Sons, Inc.
Commentary a few can catch a liar, sometimes: Comments on Ekman and O'Sullivan (1991), as well as Ekman, O'Sullivan, and Frank (1999)
Authors: Bond Charles F.
Published: November 2008

In two influential articles, Paul Ekman and associates have determined ‘who can catch a liar’ and reported that ‘a few can catch a liar’. The current article seeks to clarify these contributions. It provides information that was not mentioned in Ekman's journal articles. Copyright © 2008 John Wiley & Sons, Ltd.
Do textual features affect credibility judgment? It all depends on who is the judge
Authors: Nahari Galit , Glicksohn Joseph , Nachson Israel
Published: November 2008

This study examined the moderating role of absorption (a disposition associated with vivid imagination and rich mental experiences) in the process of interpersonal reality monitoring. Seventy five participants were assessed for absorption, and read a text describing an event that was either rich or poor in perceptual–emotional–contextual detail. They were asked to assess the credibility of the narrator; that is, the likelihood that he or she had actually experienced the event. For a text poor in detail, high‐absorption individuals believed the narrator more than low‐absorption individuals, whereas for a text rich in detail, no group differences appeared. The data seem to suggest that for high‐absorption individuals, credibility judgment depends on the degree to which the text can be assimilated into their own vivid imagination. Consideration of the judges' characteristics might therefore bring about a better understanding of the biases and errors involved in interpersonal reality monitoring. Copyright © 2008 John Wiley & Sons, Ltd.
Forensic interviews with children in CSA cases: A large‐sample study of Norwegian police interviews
Authors: Thoresen Christian , Lønnum Kyrre , Melinder Annika , Magnussen Svein
Published: November 2008

The study was designed to investigate changes in how children are interviewed in cases of child sexual abuse over a fairly long period of time. The interviewers' utterances were analysed in a large sample of forensic interviews conducted in Norway during the period of 1990–2002. The results indicate that interviewer strategies have improved during this period; there is a decrease in the proportion of suggestive, yes/no and option‐posing utterances, accompanied by a comparable increase in directive utterances. However, the frequency of open‐ended utterances is low, and has not changed much over time. An index of the overall quality of the interviews likewise showed a positive trend, with an increase in the proportion of interviews that were labelled ‘good’. However, even in recent years, interviews rated as ‘inadequate’ or ‘poor’ constituted half of the interviews conducted. Copyright © 2008 John Wiley & Sons, Ltd.
Robust fault diagnosis of networked control systems
Authors: Sauter Dominique , Li Shanbin , Aubrun Christophe
Published: November 2008

The fault detection problem is studied in this paper for a class of linear networked control systems (NCS) with communication delays. The aim is to generate residual signals which, in the fault‐free case, are supposed to be identical to zero. In practice, this condition is not respected due to various factors such as measurements noises, model uncertainties, and in particular for NCS communication‐induced delays. In this work, the communication delays are described as a random Markov jump process and a fault isolation filter is developed. Directional residuals, decoupled from the disturbance, are generated to ensure the treatment of multiple faults appearing simultaneously or sequentially. The parameters of the filter are determined to satisfyH∞disturbance attenuation and poles assignment constraints in the frame of Markov jump linear systems. Sufficient conditions for the existence of the fault detection filter are set in terms of linear matrix inequalities. An illustrative example is given to show the efficiency of the proposed method for NCS. Copyright © 2008 John Wiley & Sons, Ltd.
The Dielectric Constant of Self‐Assembled Monolayers
Authors: Romaner Lorenz , Heimel Georg , Ambrosch‐Draxl Claudia , Zojer Egbert
Published: November 2008

Self‐assembled monolayers (SAMs) are fundamental building blocks of molecular electronics and find numerous applications in organic (opto)electronic devices. Their properties are decisively determined by their response to electric fields, which are either applied externally (e.g., when biasing devices) or originate from within the monolayer itself in case it consists of dipolar molecules (which are used to tune charge‐injection barriers). This response is typically described by the dielectric constant of the monolayer. In this work it is explicitly show that there is no “general” dielectric constant that simultaneously applies to both cases. This is first derived on the basis of density‐functional theory (DFT) calculations for substituted biphenyl‐thiol SAMs at varying packing densities. Depolarization effects, which play a crucial role for the dielectric properties of the monolayers, are subsequently analyzed on the basis of packing‐dependent charge rearrangements. Finally, the DFT results are rationalized using an electrostatic model. In this context, the importance of finite‐size effects is highlighted and a connection between the macroscopic dielectric properties and the molecular polarizability is established providing a monolayer equivalent to the Clausius–Mossotti relationship. This allows deriving general trends for the packing‐density dependent dielectric response of monolayers to both external and internal electric fields.
Ultra Low‐k Films Derived from Hyperbranched Polycarbosilanes (HBPCS)
Authors: Rathore Jitendra S. , Interrante Leonard V. , Dubois Geraud
Published: November 2008

Dense and porous hyperbranched carbosiloxane thin films (HBCSO) are obtained by sol–gel processing using methylene‐bridged hyperbranched polycarbosilanes (HBPCSs) with the general compositional formula {(OMe)2Si(CH2)}. Introduction of porosity is achieved using a porogen templating approach, allowing the control of the films' dielectric constant from 2.9 to as low as 1.8. Over the entire dielectric range, the HBCSO films exhibit exceptional mechanical properties, 2–3 times superior to those obtained for non‐alkylene bridged organosiloxanes such as methylsilsesquioxanes (MSSQs) of similar densities and k‐values.
Biological Assemblies Provide Novel Templates for the Synthesis of Biocomposites and Facilitate Cell Adhesion
Authors: Gajjeraman Sivakumar , He Gen , Narayanan Karthikeyan , George Anne
Published: November 2008

Mechanical mismatch and the lack of interactions between implants and the natural tissue environment are major drawbacks in bone tissue engineering. Biomaterials mimicking the self‐assembly process and the composition of the bone matrix should provide new routes for fabricating biomaterials possessing novel osteoconductive and osteoinductive properties for bone repair. In the present study, bioinspired strategies are employed to design de novo self‐assembled chimeric protein hydrogels comprising leucine zipper motifs flanking a dentin matrix protein 1 domain, which is characterized as a mineralization nucleator. Results show that this chimeric protein could function as a hydroxyapatite nucleator in pseudo‐physiological buffer with the formation of highly oriented apatites similar to biogenic bone mineral. It could also function as an inductive substrate for osteoblast adhesion, promote cell surface integrin presentation and clustering, and modulate the formation of focal contacts. Such biomimetic “bottom‐up” construction with dual osteoconductive and osteoinductive properties should open new avenues for bone tissue engineering.
On the implementation of linear diffusion in transconductance‐based cellular nonlinear networks
Authors: Fernández‐Berni J. , Carmona‐Galán R.
Published: November 2008

In theory, cellular nonlinear networks (CNN) are well capable of implementing discrete‐space linear diffusion by means of the appropriate templates. In practice, good results have not been demonstrated with transconductance‐based circuits. In this paper, we prove that inherent mismatch to very large scale integration implementation is the reason. Although previous works consider that the small perturbations of the network parameters lead to small deviations from the ideal behavior, we consider that this is over optimistic. When interactions between nodes are supported by unidirectional building blocks, originally balanced current paths are realized by mismatched elements. In the case of linear diffusion, the singular location of natural frequencies of the system implies that a small perturbation of balanced current paths renders qualitatively different network dynamics. We analyze and compare a set of linear templates performing unconstrained and constrained linear diffusion in transconductance‐based CNN hardware. Several numerical examples are also presented to visualize the consequences of mismatch on the processing. Finally, in order to emphasize the importance of having balanced current paths, we tested the influence of mismatch in a grid built with MOS transistors. In spite of their nonlinearity, the resulting network is much more robust to mismatch. This last result coincides with previous studies. Copyright © 2008 John Wiley & Sons, Ltd.
Simulation of 2D inviscid, adiabatic, compressible flows on emulated digital CNN‐UM
Authors: Kocsárdi Sándor , Nagy Zoltán , Csík Árpád , Szolgay Péter
Published: November 2008

In the area of mechanical, aerospace, chemical and civil engineering the solution of partial differential equations has been one of the most important problems in mathematics for a long time. In this field, one of the most exciting areas is the simulation of fluid flow, which involves for example, problems of air, sea and land vehicle motion. In this paper a CNN‐UM based solver of 2D inviscid, adiabatic, compressible fluids will be presented. The governing equations are solved by using first‐ and second‐order numerical methods. Unfortunately the necessity of the coupled multi‐layered computational structure with nonlinear, space‐variant templates does not make it possible to utilize the huge computing power of the analog CNN‐UM chips. To improve the performance of our solution emulated digital CNN‐UM implemented on FPGA has been used. Properties of the implemented specialized architecture is examined in terms of area, speed and accuracy. Copyright © 2008 John Wiley & Sons, Ltd.
The winnerless competition paradigm in cellular nonlinear networks: Models and applications
Authors: Arena Paolo , Fortuna Luigi , Lombardo Davide , Patanè Luca , Velarde Manuel G.
Published: November 2008

Starting from the biological background on the olfactory architecture of both insects and mammalians, different nonlinear systems able to respond to spatial‐distributed external stimuli with spatial–temporal dynamics have been investigated in the last decade. Among these, there is a class of neural networks that produces quasi‐periodic trajectories that pass near heteroclinic contours and prove to be global attractors for the system. For this reason, these networks are calledwinnerless competition(WLC) networks. The sequence of saddle points crossed by each trajectory depends on the spatial input presented to the network and can be used as a ‘code’ representing a specific class of stimuli. Thanks to the intrinsic discrimination, WLC networks are often used for classification. In this paper, this capability is exploited within a framework for action‐oriented perception. WLC networks are here used as bio‐inspired architectures for the association between stimuli and ‘percepts’. After presenting the theoretical basis of the WLC network in the classic Lotka–Volterra system, we investigate how WLC networks can be formalized in terms of cellular nonlinear networks (CNNs) hosting different kinds of cells: the FitzHugh–Nagumo neuron, the Izhikevich neuron and the single layer CNN standard cell. In order to find efficient ways to code environmental stimuli for action generation, we analyze and compare these WLC‐based CNNs in terms of number of generated classes and robustness against the initial conditions. Based on the simulation results, we apply the best‐performing system to solve a perceptual task involving navigation and obstacle avoidance. We demonstrate how the large memory capacity shown by the WLC–CNN is able to contribute to the new perceptual framework for autonomous artificial agents, where the association between stimuli and sequences is learned through the experience. Copyright © 2008 John Wiley & Sons, Ltd.
Structural Studies on (–)‐Sparteine‐Coordinated Lithiosilanes
Authors: Däschlein Christian , Strohmann Carsten
Published: November 2008

A series of (–)‐sparteine‐coordinated lithiosilanes was synthesised and studied by X‐ray structural analysis. All lithiosilanes are monomers in the solid state; yet, increasing sizes of substituents at silicon significantly influences their molecular structures. Due to the given stereochemistry of the dinitrogen (–)‐sparteine ligand, all systems possess stereoinformation. NMR spectroscopic studies were used to obtain deeper insight into the structures of these compounds in solution. Observed coupling between the silicon and lithium atoms as well as the presence of only one signal for each atom in the NMR spectra are indicative of monomeric structures of the lithiosilanes in solution. Additional quantum chemical calculations on one of the examined (–)‐sparteine‐coordinated systems provided very small energy differences between the diastereomers.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthetic and Theoretical Investigations on the Construction of Oxanorbornenes by a Michael Addition and Intramolecular Diels–Alder Furan Reaction
Authors: Dadwal Mamta , Kesharwani Manoj K. , Danayak Vaishalee , Ganguly Bishwajit , Mobin Shaikh M. , Muruganantham Rajendran , Namboothiri Irishi N. N.
Published: November 2008

The conjugate addition of nucleophiles such as allylmercaptan, allyl‐ and homoallylmalonate and diallylamine to β‐furyl enones and acrylate, provides the Michael adducts in good yield. A facile intramolecular Diels–Alder reaction between the unsaturated tether and the furan diene ensues when these adducts are heated in a solvent such as toluene orxylene to afford the cycloadducts in good yield and excellent stereoselectivity in most cases. The structure and stereochemistry of these cycloadducts were confirmed by extensive NMR experiments and X‐ray crystallography. Quantum chemical calculations on the transition state and product geometries suggest that the formation of the cycloadducts, in which the newly formed ring is exo‐fused to the oxanorbornene framework, is favored over the endo‐fused product due to less strain in the former and its transition state.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The Grignard Reagent Formation Reaction of 2‐Chloro‐1,1,1‐triphenylethane Revisited
Authors: Bickelhaupt Friedrich , Newcomb Martin , DeZutter Christopher B. , de Boer Henk J. R.
Published: November 2008

The reaction of 2‐chloro‐1,1,1‐triphenylethane (1) with magnesium in THF has been reinvestigated. The reaction produced a dark‐red solution and after deuterolysis with D2O, 1,1,1‐triphenylethane (2; 16 %), 2‐D‐1,1,1‐triphenylethane (3; 52 %) and 1,1,2‐triphenylethene (4; 26 %) were isolated. Rate constants for phenyl migration in the 2,2,2‐triphenylethyl radical were measured directly between 23 °C and 55 °C; the reaction is described by log k = 11.2 – 7.5/2.3 RT [kcal/mol] and the rate constant for rearrangement at 20 °C is 4.0 × 105 s–1. The combined results support the intermediate formation of radicals in the reaction of chloride 1 with magnesium. The red colour of the reaction mixture, however, indicates the formation of a carbanionic species, which has not yet been identified. The diffusion model for Grignard formation reactions of Garst et al. is in line with the product distribution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Stable‐Ion Studies of Regioisomeric Acetylnitropyrenes and Nitropyrenyl Carbinols and GIAO‐DFT Study of Nitro Substituent Effects on α‐Pyrenyl Carbocations
Authors: Laali Kenneth K. , Arrica Maria A. , Okazaki Takao , Bunge Scott D.
Published: November 2008

Several regioisomeric acetylnitropyrenes were synthesized from isomeric acetylpyrenes by mild protic nitration. Nitration of 1‐acetylpyrene gave the 3‐, 6‐, and 8‐nitro derivatives (with 8‐nitro as the major isomer), from which the corresponding carbinols [NO2‐Py‐CH(OH)CH3; Py = pyrene] were synthesized. Isomeric 4‐acetylnitropyrenes and their corresponding carbinols were synthesized by starting from hexahydropyrene through nitration/aromatization/reduction or aromatization/nitration/reduction sequences. The molecular structures of 4‐acetyl‐3‐nitropyrene and 1‐(6‐nitropyren‐1‐yl)ethanol were established by X‐ray analysis. Tetrahydropyrene was the starting point for the synthesis of isomeric nitro‐2‐acetylpyrenes. Low‐temperature protonation of 1‐acetyl‐8‐nitropyrene, 4‐acetyl‐3‐nitropyrene, and 2‐acetyl‐6‐nitropyrene in FSO3H/SO2ClF or in FSO3H/SbF5 (1:1)/SO2ClF resulted in the formation of onium dications (by C=O and NO2 protonation). Charge delocalization (pyrenium ion character) in the carboxonium ions is strongly influenced by the position of the carboxonium group, with the 4‐acetyl‐3‐nitropyrene dication being the most delocalized. Superacid protonation of 1‐(3‐nitropyren‐4‐yl)ethanol gave a persistent onium dication rather than an α‐pyrenyl carbocation. With all other isolated nitropyrenyl carbinol isomers, low‐temperature protonation (with FSO3H/SO2ClF) led to polymerization within 5 min standing at dry‐ice–acetone temperature. For these cases, nitro substituent effects on the α‐pyrenyl carbocations were gauged by DFT and GIAO‐DFT studies. An interesting relationship between the computed nitro tilt angles and the GIAO‐derived charge delocalization modes was observed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Development of New Pyrrolocoumarin Derivatives with Satisfactory Fluorescent Properties and Notably Large Stokes Shifts
Authors: Chen Lei , Hu Tai‐Shan , Yao Zhu‐Jun
Published: November 2008

Small, organic, fluorescent molecules with large Stokes shifts and long emission wavelengths are ideal dyes for various modern fluorescent imaging technologies such as FRET. In this study, we designed and synthesized a number of new fluorescent molecules on the basic structures of two pyrrolocoumarin skeletons where Fischer's indole synthesis and the Suzuki coupling successfully served as the efficient molecular editing protocols. The examination of the fluorescent properties and further structural optimization of these compounds afforded three new pyrrolocoumarin dyes with notably large Stokes shifts and satisfactory fluorescent properties. Among these, 30 showed a large Stokes shift (113 nm) and intense fluorescence (φ = 0.55, λem = 523 nm), and thus showed great potential in biological imaging studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Desulfurization Mediated by Hypervalent Iodine(III): A Novel Strategy for the Construction of Heterocycles
Authors: Ghosh Harisadhan , Yella Ramesh , Nath Jayashree , Patel Bhisma K.
Published: November 2008

The desulfurization ability of diacetoxyiodobenzene (DIB) has been explored in the preparation of isothiocyanates from the corresponding dithiocarbamate salts. The in situ generated isothiocyanates reacted with o‐phenylenediamine and o‐aminophenol to form monothioureas, which, on treatment with a further equivalent of DIB in one pot, gave benzimidazoles and aminobenzoxazoles, respectively. Aliphatic 1,2‐diamines on reaction with 2 equiv. of isothiocyanate followed by treatment with DIB gave imidazolidenecarbothioamides, whereas the treatment of aromatic 1,2‐diaminebis(thioureas) yielded benzimidazoles with the concurrent formation of isothiocyanate. The driving force for the formation of the latter is the aromatization of the product. The use of DIB makes these methods simpler and more efficient, giving high yields of the desired products in one pot.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A methodology for simulating power system vulnerability to cascading failures in the steady state
Authors: Kumbale Murali , Hardiman Rod , Makarov Yuri
Published: November 2008

Simulations of power system conditions and event sequences leading to either local or widespread blackout has acquired increasing importance following wide‐impact network collapses that have occurred over the past several years in North America and Europe. This paper summarizes an analytical framework that has been developed, implemented, and practically used by Southern Company to evaluate system vulnerability to cascading failures using the steady state model. This methodology was first used by Southern Company in 1999. The studies performed at Southern Company have already influenced and motivated certain transmission development projects. Future improvements to the method could include better modeling and sequencing of cascading steps, including time sequence of failures using equipment response time. Significant interest exists in developing preventive methods and procedures and in the application of this technology in the infrastructure security arena. Copyright © 2008 John Wiley & Sons, Ltd.
A Sb‐doped SnP2O7 Solid Proton Conductor for Intermediate Temperature Fuel Cells
Authors: Wu X. , Verma A. , Scott K.
Published: November 2008

Sb‐doped SnP2O7 were prepared and characterised with XRD, FTIR, SEM and EIS. The preparation parameters were optimised taking into consideration the influence of H3PO4 content in the reactants and PmOn impurities. Conductivities of SnP2O7 with different Sb doping levels were studied from 100 to 300 °C in un‐humidified air. The conductivity of 20 mol‐% Sb‐doped SnP2O7 was greater than 0.1 S cm–1 at 300 °C. The effect of heat treatment was identified as an important factor in the preparation of the proton conductors. The time dependence of the conductivity demonstrated Sb‐doped SnP2O7 as a promising intermediate temperature solid proton conductor.
A Membraneless Direct Borohydride Fuel Cell Using LaNiO3‐Catalysed Cathode
Authors: Ma J. , Liu Y. , Liu Y. , Yan Y. , Zhang P.
Published: November 2008

Direct borohydride fuel cell (DBFC) is one of the most exciting energy technologies that solve the hydrogen storage and safety issues by using aqueous solution of KBH4 or NaBH4. Here, we present a membraneless DBFC with perovskite‐type oxide LaNiO3/C‐catalysed cathode. A significant finding from the electrochemical experiments is that it obviously shows that the existence of $ {\rm BH}_4^- $ ions has almost no negative influence on the discharge performances of the LaNiO3‐catalysed cathode. Therefore, the DBFC is designed without using an ion exchange membrane. The maximal power density of 127 mW cm–2 is obtained at 65 °C under atmospheric pressure. A 500 h life test shows that the DBFC has good stability.
Late Alpine tectonics in the Ligurian Alps: constraints from the Tertiary Piedmont Basin conglomerates
Authors: Capponi Giovanni , Crispini Laura , Federico Laura , Piazza Michele , Fabbri Barbara
Published: November 2008

The Tertiary Piedmont Basin (TPB) is a syn‐tectonic Neoalpine–Apennine basin with an upper Eocene–upper Miocene sedimentary succession. It has an inner position with respect to the arcuate belt of the Western and Ligurian Alps, in northwestern Italy. In the area north of Genova, the Scrivia Valley separates two distinct sectors where the TPB basal conglomerates display a differentiated clast provenance: in the western sector conglomerates are fed by the metamorphic units of central Liguria, whereas in the eastern sector most of the conglomerate clasts come from the Antola flysch Unit. Observations on clast lithology demonstrate that the transition between the two types of conglomerates is abrupt and roughly coincides with the Scrivia River Valley. An explanation of the different clast provenance as due to a progressive deepening of the erosional level appears to be possible in the eastern sector, but it is not feasible in the western sector, where the flysch units appear to have been protected from erosion. We propose that the northwards thrusting of the Ligurian Alps metamorphic units onto the Antola flysch units, made the latter not available to erosion and led the Scrivia Fault and other equivalent tectonic lineaments to act as tear faults.

Field data suggest that the Tertiary geodynamics of the Ligurian Alps was dominated by the Corsica–Sardinia anticlockwise rotation, that caused the northwards backthrusting of the Ligurian Alps, accommodated by a complex strike‐slip fault system, that segmented the TPB, affecting the sedimentation and the clast provenance of the conglomerates. Copyright © 2008 John Wiley & Sons, Ltd.
Synthetic polymeric substrates as potent pro‐oxidant versus anti‐oxidant regulators of cytoskeletal remodeling and cell apoptosis
Authors: Sung Hak‐Joon , Chandra Prafulla , Treiser Matthew D. , Liu Er , Iovine Carmine P. , Moghe Prabhas V. , Kohn Joachim
Published: November 2008

The role of reactive oxygen species (ROS)‐mediated cell signal transduction pathways emanating from engineered cell substrates remains unclear. To elucidate the role, polymers derived from the amino acid L‐tyrosine were used as synthetic matrix substrates. Variations in their chemical properties were created by co‐polymerizing hydrophobic L‐tyrosine derivatives with uncharged hydrophilic poly(ethylene glycol) (PEG, Mw = 1,000 Da), and negatively charged desaminotyrosyl‐tyrosine (DT). These substrates were characterized for their intrinsic ability to generate ROS, as well as their ability to elicit Saos‐2 cell responses in terms of intracellular ROS production, actin remodeling, and apoptosis. PEG‐containing substrates induced both exogenous and intracellular ROS production, whereas the charged substrates reduced production of both types, indicating a coupling of exogenous ROS generation and intracellular ROS production. Furthermore, PEG‐mediated ROS induction caused nuclear translocation of glyceraldehyde‐3‐phosphate dehydrogenase and an increase in caspase‐3 activity, confirming a link with apoptosis. PEG‐rich pro‐oxidant substrates caused cytoskeletal actin remodeling through β‐actin cleavage by caspase‐3 into fractins. The fractins co‐localized to the mitochondria and reduced the mitochondrial membrane potential. The remnant cytosolic β‐actin was polymerized and condensed, events consistent with apoptotic cell shrinkage. The cytoskeletal remodeling was integral to the further augmentation of intracellular ROS production. Conversely, the anti‐oxidant DT‐containing charged substrates suppressed the entire cascade of apoptotic progression. We demonstrate that ROS activity serves an important role in “outside‐in” signaling for cells grown on substrates: the ROS activity couples exogenous stress, driven by substrate composition, to changes in intracellular signaling. This signaling causes cell apoptosis, which is mediated by actin remodeling. J. Cell. Physiol. 218: 549–557, 2009. © 2008 Wiley‐Liss, Inc.
Skeletal muscle contractions uncoupled from gravitational loading directly increase cortical bone blood flow rates in vivo
Authors: Caulkins Carrie , Ebramzadeh Edward , Winet Howard
Published: November 2008

The direct and indirect effects of muscle contraction on bone microcirculation and fluid flow are neither well documented nor explained. However, skeletal muscle contractions may affect the acquisition and maintenance of bone via stimulation of bone circulatory and interstitial fluid flow parameters. The purposes of this study were to assess the effects of transcutaneous electrical neuromuscular stimulation (TENS)‐induced muscle contractions on cortical bone blood flow and bone mineral content, and to demonstrate that alterations in blood flow could occur independently of mechanical loading and systemic circulatory mechanisms. Bone chamber implants were used in a rabbit model to observe real‐time blood flow rates and TENS‐induced muscle contractions. Video recording of fluorescent microspheres injected into the blood circulation was used to calculate changes in cortical blood flow rates. TENS‐induced repetitive muscle contractions uncoupled from mechanical loading instantaneously increased cortical microcirculatory flow, directly increased bone blood flow rates by 130%, and significantly increased bone mineral content over 7 weeks. Heart rates and blood pressure did not significantly increase due to TENS treatment. Our findings suggest that muscle contraction therapies have potential clinical applications for improving blood flow to cortical bone in the appendicular skeleton. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 651–656, 2009
Poly(amidoamine) Conjugates Containing Doxorubicin Bound via an Acid‐Sensitive Linker
Authors: Lavignac Nathalie , Nicholls Johanna L. , Ferruti Paolo , Duncan Ruth
Published: November 2008

Poly(amidoamine)s with amino pendant groups were prepared by hydrogen‐transfer polyaddition of primary and secondary amines to bis‐acrylamines. Dansyl cadaverine (DC) doxorubicin (Dox) were bound to the polymers via acis‐aconityl spacer to give conjugates containing 3 µg of DC per mg of polymer and 28 to 35 µg of Dox per mg of polymer. Release of DC and Dox at physiological and acidic pH varied from 0 to 35% over 48 h and was pH dependent. Although the ISA1Dox conjugate (IC50 = 6 µg Dox · mL−1) presented similar toxicity as the parent polymer without Dox, ISA23Dox showed increased toxicity (IC50 = 10 µg Dox · mL−1). These results suggest that ISA23Dox is able to release biologically active Doxin vitroand that this conjugate might be suitable for further development.

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Molecular Structure of Physiologically‐Responsive Hydrogels Controls Diffusive Behavior
Authors: Carr Daniel A. , Peppas Nicholas A.
Published: November 2008

Polymeric networks and the ensuing hydrogels of MAA and NVP were successfully synthesized using a UV‐initiated free radical polymerization and characterized to assess their applicability as carriers for directed drug delivery. FT‐IR spectroscopy revealed shifts in peak absorbances that indicated the presence of hydrogen bonding complexes between functional groups, while SEM imaging showed that the different comonomers affect the surface morphology of the microparticles. Dynamic pH swelling studies demonstrated the pH responsiveness of the carriers in gastric and intestinal conditions and revealed that systems containing higher concentrations of MAA experienced the highest degree of hydrogen bonding complexation in gastric conditions. The presence of NVP in the systems enhanced swelling. Equilibrium swelling studies revealed that the mesh size was sufficiently large to allow drug diffusion across the networks.

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Effect of Nanoplatelets on the Rheological Behavior of Epoxy Monomers
Authors: Sun Luyi , Boo Woong‐Jae , Liu Jia , Clearfield Abraham , Sue Hung‐Jue , Verghese Nikhil E. , Pham Ha Q. , Bicerano Jozef
Published: November 2008

The effect of nanoplatelets on the rheological behavior of epoxy monomers with variations in nanoplatelet exfoliation level and aspect ratio was investigated. The results show that the presence of exfoliated nanoplatelets in epoxy can significantly influence viscosity and lead to shear‐thinning phenomena, especially when the aspect ratio of the nanoplatelets is high. By employing the Krieger‐Dougherty model, the effectiveness of nanoplatelets in altering epoxy rheological behavior was quantitatively described and compared with experimental findings. Possible physical reasons for the observed rheological behaviors are discussed. The implication of the present study for polymer nanocomposites processing is also addressed.

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Synthesis of Crosslinked Sulfonated Poly(phenylene sulfide sulfone nitrile) for Direct Methanol Fuel Cell Applications
Authors: Phu Duong Sang , Lee Chang Hyun , Park Chi Hoon , Lee So Young , Lee Young Moo
Published: November 2008

With a view towards direct methanol fuel cell applications, novel sulfonated poly(phenylene sulfide sulfone nitrile) (sPPSSfN) has been prepared and subsequently crosslinked by a Friedel‐Craft reaction using 4,4′‐oxybis(benzoic acid) as a crosslinker to achieve lower water swelling and lower methanol permeability. The dimensional change of SPPSSfN40 is 43.7% in 90 °C liquid water but that of the crosslinked membrane, XsPPSSfN40, is 23.3% while maintaining proton conductivity at 0.22 S · cm−1. These results show that the Friedel‐Craft crosslinking of the novel sPPSSfN membrane effectively reduces water uptake and the degree of swelling while improving the dimensional stability and maintaining high proton conductivity.

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Large Deformable Multiwalled Carbon Nanotube Core–Shell Structure on Polystyrene Beads
Authors: Lee Jun‐Ho , Lee Youngkwan , Nam Jae‐Do
Published: November 2008

Multiwalled carbon nanotube (MWCNT)‐coated polystyrene (PS) beads have been prepared by dispersion polymerization followed by a layer‐by‐layer self‐assembly method. The concentration of carboxylic acid groups on the MWCNTs increased from 1.81 × 1021 to 3.43 × 1022 COO− per g as the treatment time was increased from 3 to 9 h. The sulfonated polystyrene (SPS) beads changed from being negatively charged to positively charged when the cationic polyelectrolyte was self‐assembled on their surface. The surface morphology of the adsorbed polyelectrolyte was smooth without any aggregation and the thickness of the polyelectrolyte coating on the SPS beads was ≈0.6 µm. The electrical conductivity and resistance of the MWCNT‐coated SPS beads were measured to be 4.0 × 10−2 S · cm−1 and 12.8 Ω at a volume fraction of 91%, respectively.

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Medial plantar nerve testing facilitates identification of polyneuropathy
Authors: Sylantiev Constantin , Schwartz Roseline , Chapman Joab , Buchman Aron S.
Published: November 2008

Many studies have used sural nerve action potential (NAP) as an electrophysiological marker for distal symmetrical polyneuropathy (DSP). We examined the role of medial plantar nerve testing for identifying DSP by comparing amplitudes from sural, superficial peroneal, and medial plantar nerves in 85 participants with symptoms and clinical signs of DSP and 204 participants without DSP. Receiver‐operating characteristic curves were used to determine the sensitivity of all three sensory conduction studies for the diagnosis of DSP. All three nerves could be used to discriminate between subjects with and without DSP with an area under the curve of more than 85% of cases. Sural and superficial peroneal nerve testing sensitivities were about 55%, whereas medial plantar nerve testing sensitivity was more than 90%. These findings suggest that testing the medial plantar nerve may increase the diagnostic yield of nerve conduction studies for DSP. Muscle Nerve 38: 1595–1598, 2008
Needlestick injuries among electromyographers
Authors: Mateen Farrah J. , Grant Ian A. , Sorenson Eric J.
Published: November 2008

The objective of this study was to determine the self‐reported prevalence of needlestick injuries among practicing electromyographers. In January 2008, an anonymous electronic survey was sent to all active members of the American Association for Neuromuscular and Electrodiagnostic Medicine (AANEM) who provided e‐mail addresses to the Association. Eight hundred and eight members (56% neurologists, 43% physiatrists; 97% practicing physicians, 3% trainees) responded, with a response rate of 22% (808 of 3659). The mean number of years in practice, involving electromyography (EMG) at least 1 day per week, was 16 years. A majority of physicians (64%) reported at least one needlestick injury involving EMG, and 8% reported five or more injuries. Needlestick injuries involving patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), hepatitis B, and/or hepatitis C occurred in 1 of every 11 electromyographers. Nearly half of all respondents (44%) who experienced a needlestick injury stated that they did not report at least one injury event to official centers. Injuries were most likely to occur during a routine procedure (45%) or when a patient moved (26%). The most common preventable reason for injury was a perceived lack of time. Muscle Nerve 38: 1541–1545, 2008
Complete recovery of an aged patient with Guillain–Barré syndrome associated with multiple IgM anti‐ganglioside antibodies
Authors: Furiya Yoshiko , Hirano Makito , Kusunoki Susumu , Ueda Masami , Sugie Kazuma , Nishiwaki Tomohisa , Ueno Satoshi
Published: November 2008

In this report we describe a 72‐year‐old woman who had cytomegalovirus infection–related Guillain–Barré syndrome (GBS) associated with multiple immunoglobulin M (IgM) anti‐ganglioside antibodies. She became tetraplegic with respiratory failure, but recovered completely after intravenous immunoglobulin therapy and plasmapheresis. The serum contained high‐titer IgM antibody activities to several gangliosides with disialosyl residues (GD1b, GD3, GT1b, GQ1b, and GT1a) and GD1a. These antibodies are often found in sera from patients with chronic sensory ataxic neuropathy, but they occur rarely in GBS. Muscle Nerve 38: 1630–1633, 2008
Ultrasound‐guided needle EMG of the diaphragm: Technique description and case report
Authors: Boon Andrea J. , Alsharif Kais I. , Harper C. Michel , Smith Jay
Published: November 2008

We describe an ultrasound (US)‐guided technique for needle examination of the diaphragm and report a case in which the adjuvant use of diagnostic US in conjunction with electrophysiologic studies provided additional information regarding the motion of the diaphragm in a patient who was a potential candidate for phrenic nerve pacing. US imaging provides excellent direct and real‐time visualization of soft tissue, anatomic landmarks, fascial planes, and neurovascular structures. It thereby enhances safety by avoiding accidental needle puncture of vital organs, and it also increases the diagnostic utility of the needle examination. Muscle Nerve 38: 1623–1626, 2008
Development of a finite element contact analysis algorithm for charged‐hydrated soft tissues with large sliding
Authors: Chen Xian , Sunagawa Kenji , Hisada Toshiaki
Published: November 2008

This paper focuses on a finite element analysis of contact phenomena with large sliding between charged‐hydrated biological soft tissues, such as articular cartilages, based on the triphasic theory. The impenetrability constraint between the contacting bodies and the continuity of the interstitial fluid and ion phases at the contact surfaces are imposed by applying a Lagrange multiplier approach with the contact pressure, chemical potential of the fluid and electrochemical potentials of ions as Lagrange multipliers. A node‐to‐segment one‐pass approach is adopted to cope with large deformations and sliding between the contact surfaces. To pass the contact patch test, contact boundary integrations are performed on both the master and slave contact surfaces. On the other hand, the degrees of freedom of the multipliers at the master nodes are eliminated by projecting the master nodes onto the slave surface to avoid overconstraint. The effectiveness of the proposed algorithm is verified by a couple of numerical examples, in which continuous distributions of displacement, fluid flow, ionic molar flow and Lagrange multipliers on or across the contact surface are confirmed. Copyright © 2008 John Wiley & Sons, Ltd.
Analysis of composite beams with partial interaction using the direct stiffness approach accounting for time effects
Authors: Ranzi Gianluca , Bradford M. A.
Published: November 2008

This paper presents a modelling technique based on the direct stiffness method (DSM) to describe the behaviour in time of composite beams with partial shear interaction accounting for creep and shrinkage of the slab. The time‐dependent behaviour of the concrete is modelled using algebraic representations, such as the age‐adjusted effective modulus method and the mean stress method, while the steel joist, the reinforcement and the shear connection are assumed to behave in a linear‐elastic manner. Only one discretization (i.e. in the time domain) is required by the proposed stiffness formulations to perform a time analysis, while two discretizations (i.e. one in the time domain and the other in the spatial domain along the beam axis) are required by other modelling techniques available in the literature. The ability of the derived elements to overcome curvature locking problems observed to occur in some conventional displacement formulations is also highlighted. The proposed DSM approach is then validated against analytical solutions derived by the authors for simple structural systems. The applicability of this method for the time analysis of continuous composite beams is also illustrated. Copyright © 2008 John Wiley & Sons, Ltd.