bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of dummy molecularly imprinted solid‐phase extraction in the analysis of cyproheptadine in bovine urine
Authors: Feás Xesús , Ye Lei , Regal Patricia , Fente Cristina A. , Hosseini Seyed V. , Cepeda Alberto
Published: May 2009

Due to the difficulty of monitoring trace levels of cyproheptadine (CYP) residues in complicated biological matrices, specific adsorption materials for the preconcentration and clean‐up of CYP are indispensable. In this work, CYP was extracted from urine using dummy molecularly imprinted SPE (DMISPE) to avoid leakage of the imprinting molecules during the desorption phase. For synthesis of DMISPE, azatadine (AZA) was employed as the dummy template, methacrylic acid (MAA) as the monomer, ethylene glycol dimethacrylate (EGDMA) as the cross‐linker, 2,2′‐azobis(2‐methylpropionitrile) (AIBN) as the initiator, and dichloromethane as the porogen solvent. An LC‐MS/MS method was used to analyze CYP. Two MRM (multiple reaction monitoring) transitions for each analyte were monitored using diphenylpyraline hydrochloride (DPP·HCl), which was used as an internal standard. The advantages of DMISPE include obtaining less complex chromatograms and reducing ion suppression in ESI. The process efficiencies for DMISPE and SPE were 80% and 12%, respectively. In addition, the demonstrated reusability of the DMISPE cartridges is an advantage compared with single‐use SPE cartridges or immunoaffinity materials.
Use of correction factors in mobility shift affinity capillary electrophoresis for weak analyte – ligand interactions
Authors: Østergaard Jesper , Jensen Henrik , Holm René
Published: May 2009

The practical and theoretical problems associated with interpretation of binding isotherms obtained by the investigation of weak analyte – ligand interactions using mobility shift affinity CE were investigated with special emphasis on various correction methods to compensate for media effects due to high additive concentrations. The interaction between 2‐hydroxypropyl‐α‐CD and two bile salts (glycocholate and glycodeoxycholate) was studied applying correction factors based on viscosity, CE based conductance and separately measured conductivities. Accurate measurement of the stability constants proved to be difficult; several points of general nature relating to the investigation of the weak analyte – ligand interactions were identified. These included undesired dilution of the BGE due to the high amounts of additive, avoidance of temperature effects by maintaining a constant power during the separations and limited validity of Walden's rule. The relative sizes of the buffer constituents, the nonelectrolyte ligand additive, and the analytes as well as noninteracting marker substances should be considered in order to minimize errors in the correction factors when significant deviation from Walden's rule is observed. Under such conditions, the mobilities should preferably be corrected by the use of a noninteracting marker; and the most generally applicable corrections may be based on conductance measurements.
Immuno‐ultrafiltration as a new strategy in sample clean‐up of aflatoxins
Authors: Reiter Elisabeth Viktoria , Cichna‐Markl Margit , Chung Duck‐Hwa , Zentek Jürgen , Razzazi‐Fazeli Ebrahim
Published: May 2009

The present paper describes the development of a new clean‐up strategy for the analysis of aflatoxins (AFs) in food. The sample preparation method is based on immuno‐ultrafiltration (IUF) which, in contrast to immunoaffinity chromatography, makes use of antibodies in free form. After selecting an appropriate ultrafiltration (UF) device and optimizing different operation conditions the IUF method was applied to the clean‐up of maize and rice. Quantification of AFs was carried out by HPLC and fluorescence detection, after postcolumn derivatization in a Kobracell. The IUF method was shown to be as selective as sample clean‐up using commercial immunoaffinity columns. Recovery rates and RSD for the AFs G2, G1, B2 and B1 in spiked rice were found to be 76 ± 3, 76 ± 2, 83 ± 5 and 99 ± 14%, respectively. The analysis of a FAPAS (food analysis performance assessment scheme) maize material resulted in AFs concentrations which were in the range assigned by the producer of the reference material.
Biotechnological valorization of biodiesel derived glycerol waste through production of single cell oil and citric acid by Yarrowia lipolytica
Authors: Papanikolaou Seraphim , Aggelis George
Published: May 2009

Continuous energy crises and increasing demand for conventional fuels has resulted in the need for biofuels on a commercial scale. Transesterification of oils to yield biodiesel – one of the principal biofuels currently produced in large‐scale operations – is coupled with significant production of a glycerol‐rich water (so‐called “crude” or “raw” glycerol), as an important side‐product of the process. The increasing demand for biodiesel leads to abundant quantities of this glycerol‐rich material on the market. Therefore, glycerol valorization has much to offer in the cost reduction of biodiesel production. To this end, various chemical or biotechnological strategies have been developed to obtain added‐value products using crude glycerol as substrate. This review combines an account of our attempts to achieve a biotechnological valorization of raw glycerol with a review of appropriate literature.
Directing the Self‐Assembly of Mesostructured Hybrid Materials: Effect of Polymer Concentration and Solvent Type
Authors: Pietsch Torsten , Metwalli Ezzeldin , Roth Stephan Volker , Gebhardt Ronald , Gindy Nabil , Müller‐Buschbaum Peter , Fahmi Amir
Published: May 2009

Herein we explore the possibility to control the fabrication of non‐equilibrium nano‐patterns of spin‐coated organic‐inorganic hybrid materials based on diblock copolymers and metal nanoparticles in thin films. It is demonstrated that the type of solvent and the initial solution concentration, among other factors, can serve as tools to direct the morphology of spin‐coated thin films. The driving forces leading to the pattern formation are reviewed with respect to these parameters—type of solvents and polymer concentration. As a result well‐defined surface patterns of functional hybrid materials are obtained. Moreover, the same tools used to direct the pattern formation can be applied to gain control over the particle size and size distribution.

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Decorating Polypyrrole Nanotubes with Au Nanoparticles by an In Situ Reduction Process
Authors: Xu Jingjing , Hu Jianchen , Quan Baogang , Wei Zhixiang
Published: May 2009

Au nanoparticle‐decorated polypyrrole nanotubes (defined as PPy/Au nanocomposites) are prepared by an in situ reduction process. Polypyrrole (PPy) nanotubes are prepared by a self‐degraded template method, and Au nanoparticles are deposited in situ by the reduction of HAuCl4. The size and uniformity of the Au nanoparticles that decorate the PPy nanotubes can be controlled by adjusting the experimental conditions, such as the stabilizers used and the reaction temperature. The morphologies and optical properties of the nanocomposites have been characterized by scanning electron microscopy, transmission electron microscopy, UV‐vis, and FT‐IR spectroscopy. Conductivity measurements show that the conductivities of the nanocomposites decrease with a decrease of temperature, and the conductivity–temperature relationship obeys the quasi‐one dimensional variable range hopping model.

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Synthesis of a Fluorescent Polymer Bearing Covalently Linked Thienylene Moieties and Rhodamine for Efficient Sensing
Authors: Zhu Mei , Zhou Chunjie , Zhao Yingjie , Li Yongjun , Liu Huibiao , Li Yuliang
Published: May 2009

A novel conjugated polymer (RB‐PPETE) of poly[p‐(phenylene ethynylene)‐alt‐(thienylene ethynylene)] (PPETE) bearing covalently linked thienylene rings and Rhodamine B units has been synthesized and successfully used to detect metal ions. The Rhodamine B exists as a lactone, which is colorless and non‐fluorescent. Hg2+ ions can induce the Rhodamine group to form a ring‐opened state. The fluorescence resonance energy transfer (FRET) was demonstrated in the polymer, and in the presence of Hg2+ ions the excitation energy along the backbone of the conjugated polymer is transferred to the energy acceptor (Rhodamine B), which leads to a visual color change of the solution from slight yellow to orange. Meanwhile, this new system shows outstanding Hg2+‐selective FRET off–on type fluoroionophoric properties among the representative metal ions in tetrahydrofuran.

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First Preparations and Characterization of Conductive Polymer Crystalline Nanoneedles
Authors: Su Kai , Nuraje Nurxat , Zhang Lingzhi , Chu I‐Wei , Matsui Hiroshi , Yang Nan‐Loh
Published: May 2009

Single crystalline nanoneedles of three families of the most studied conductive organic polymers ‐ polythiophene, polyaniline and polypyrrole ‐ were synthesized for the first time using an interfacial polymerization process that takes place with simultaneous crystallization. As the crystal growth is concurrent with polymerization, more ordered crystal packing can be expected. Most of the bulk conducting‐polymer systems studied contains regions that are inhomogeneous. Single nanocrystals of conducting polymers have not been reported, although needle‐shaped bulk crystals of the quarterphenyl cation radical salt have previously been studied. The investigation of processes in a nanodomain of a single crystal is critical in ascertaining the inherent electronic properties of polymer nanoelements. The organic conductive nanoneedles were characterized using TEM, HRTEM, electron diffraction, EDS, and EPR to establish their crystal structure and composition. Scanning tunneling microscopy/spectroscopy (STM/STS) investigation were conducted to examine their electronic behaviors, leading to the discovery of a field‐induced conductance switching with response times on the millisecond level. The switch voltages are in the range of 3 to 4 volts in STM experiments, consistent with the trend of the band gap of the three polymers. The organic conductive nanoneedles with nano‐tip having high density of mobile electron may serve as interesting elements for nanoscale electronics.
Living Anionic Polymerization of N‐Methacryloyl‐2‐methylaziridine
Authors: Ishizone Takashi , Kusakabe Jun‐ichi , Suzuki Takashi
Published: May 2009

Anionic polymerization of N‐methacryloyl‐2‐methylaziridine (1) proceeded with 1,1‐diphenyl‐3‐methylpentyllithium (DMPLi) in the presence of LiCl or Et2Zn to give the polymers possessing predicted molecular weights and narrow molecular weight distributions (Mw/Mn < 1.1) at −78 ∼ −40 °C in THF. In each polymerization initiated with DMPLi/LiCl at the various temperatures ranging from −40 to −60 °C, the linear relationship between polymerization time and conversion of monomer was obtained from the GLC analysis. The rate constant and the activation energy of the anionic polymerization for 1 were determined as follows: ln k = −5.85 × 103/T + 23.3 L mol−1 s−1 and 49 ± 4 kJ mol−1, respectively. Poly(1) showed the glass transition temperature at 98 °C, and gave the insoluble product at higher temperature around 150 °C through the thermal cross‐linking of highly strained N‐acyl‐aziridine moiety.
Counterion Association and Structural Conformation Change of Charged PAMAM Dendrimer in Aqueous Solutions Revealed by Small Angle Neutron Scattering
Authors: Porcar Lionel , Liu Yun , Hong Kunlun , Butler Paul D. , Huang E‐Wen , Chen Wei‐Ren
Published: May 2009

Our previous study of the structure change of poly(amidoamine) starburst dendrimers (PAMAM) dendrimer of generation 5 (G5) have demonstrated that although the overall molecular size is practically unaffected by increasing DCl concentration, a configurational transformation, from a diffusive density profile to a more uniform density distribution, is clearly observed. In the current paper, the focus is placed on understanding the effect of counterion identity on the inter‐molecular structure and the conformational properties by studying the effect due to DBr using small angle neutron scattering (SANS) and integral equation theory. While the overall molecular size is found to be essentially unaffected by the change in the pD of solutions, it is surprising that the intra‐molecular configurational transformation is not observed when DBr is used. The overall effective charge of a dendrimer is nearly the same for α < 1, independent of the type of acids. However, when α > 1, the effect of counterion identity becomes significant, the effective charge carried by a charged G5 PAPAM protonated by DBr becomes smaller than that of solutions with DCl. As a consequence, a counterion identity dependence of counterion association is revealed: Under the same level of molecular protonation, the specific counterion association, which is defined as the ratio of bound chloride anions to positively charged amines per molecule, is larger for the G5 PAMAM dendrimer charged by DBr than the one by DCl.
Structure and Surface Properties of High‐density Polyelectrolyte Brushes at the Interface of Aqueous Solution
Authors: Kobayashi Motoyasu , Yamaguchi Hiroki , Terayama Yuki , Wang Zhe , Ishihara Kazuhiko , Hino Masahiro , Takahara Atsushi
Published: May 2009

Zwitterionic and cationic polyelectrolyte brushes were prepared by surface‐initiated atom transfer radical polymerization of 2‐methacryloyloxy‐ ethyl phosphorylcholine (MPC) and 2‐(N,N‐dimethylamino)ethyl methacrylate (DMAEMA), respectively. The poly(DMAEMA) brush was treated with methyl iodide to form poly[2‐(methacryloyloxy) ethyltrimethylammonium iodide] [poly(METAI)]. The effects of ionic strength on brush structure and surface properties of densely grafted polyelectrolyte brushes were analyzed by contact angle measurements, neutron reflectivity (NR) and macroscopic friction tests. Both polyelectrolyte brushes exhibited hydrophilic properties. The contact angle of the poly(MPC) brush surface against water was ca. 0° in air and the contact angle of the air bubble in water was ca. 170°. The air bubble in water hardly attached to the poly(MPC) brush surface, indicating super hydrophilic characteristics. NR measurements of poly(MPC) and poly(METAI) brushes showed that the grafted polymer chains were extended from the substrate surface in a good solvent such as water. Interestingly, NR study did not reveal the shrinkage of the brush chain in salt solution. The polyelectrolyte brushes immersed in both water and NaCl solution at various concentrations showed a low friction coefficient and low adhesion force.
Fascinating Morphological Behavior of A2‐star‐(B‐alt‐C) Molecules in the Melts and Solutions
Authors: Huang Ching‐I , Chang Yu‐Lung , Chen Chih‐Ming
Published: May 2009

We employ dissipative particle dynamics (DPD) to examine the self‐assembling behavior of A2‐star‐(B‐alt‐C) molecules in the melt and solution states. When these molecules are in the melts, we successfully observe various types of hierarchical structure‐within‐structures, such as A‐formed spheres in the matrix formed by B and C alternating layers, hexagonally packed A‐formed cylinders in the matrix with B and C segregated layers, B and C alternating layers‐within‐lamellae, coaxial B and C alternating domains within hexagonally packed BC‐formed cylinders, and concentric BC‐alternating domains within BC‐formed spheres, by increasing the A composition. These hierarchical structures by varying the composition are reported theoretically for the first time in the copolymer systems consisting of the alternating blocks, and in good agreement with the most recent experimental work by Matsushita and co‐workers (Macromolecules 2007, 40, 4023). Generally speaking, the small‐length‐scale B and C segregated domains are in parallel to the large‐length‐scale structures for the melt case. While when a selective solvent is added, we find that varying the solvent selectivity and the amount of solvent can induce the molecules to form quite different morphological patterns, such as the so‐called segmented worm like micelles.
Hydrophobic Intercalation of Layered Silicate Clays and Hierarchical Self‐Assemblies via Platelet‐Shape Directing
Authors: Lin Jiang‐Jen , Chen Yu‐Min , Tsai Wei‐Cheng
Published: May 2009

Most clay research in recent years has centered on the development of polymer/layered‐silicate nanocomposites besides the conventional applications such as catalyst and adsorbents for organics. Recently, we have reported the hydrophobic modification of the naturally‐occurring sodium montmorillonite clay (d spacing = 12 Å) by exchanging with hydrophobic poly(oxypropylene)‐diamine salts (POP‐salt) to afford the space‐enlarged silicates (d spacing up to 50–60 Å). Owing to the geometrically plate‐like shape and surface ionic charges, the organoclays enabled to self‐assemble into rod‐shape morphologies. For example, unique formation of lengthy rod (ca. 0.3 µm in diameter and up to 40 µm in length) was observed by using scanning electron microscopy (SEM). The self‐assembling mechanism may involve the piling of the primary stack units by face‐to‐face and edge‐to‐edge alignments. The clay primary stacks intercalated by POP‐salt and the hydrophilic analog of poly(oxyethylene)‐diamine salts were observed by AFM.
Size‐Selective Encapsulation Property of Unimolecular Reverse Micelle Consisting of Hyperbranched D‐Glucan Core and L‐Leucine Ethyl Ether Shell
Authors: Satoh Toshifumi , Kitajyo Yoshikazu , Sakai Ryosuke , Narumi Atsushi , Takahashi Kenji , Kaga Harumi , Kaneko Noriaki , Kakuchi Toyoji
Published: May 2009

The synthesis of a unimolecular reverse micelle (3) consisting of hyperbranched D‐glucan as the core and L‐leucine ethyl ester as the shell was accomplished through the carbamation reaction of the hyperbranched D‐glucan (1) with the N‐carbonyl L‐leucine ethyl ester (2) in pyridine at 100 °C. The polymer 3 was soluble in a large variety of organic solvents, such as methanol, acetone, chloroform, and ethyl acetate, and insoluble in water, which remarkably differed from the solubility of 1. The solubilities of 3 were also changed by the substitution degrees of the L‐leucine moiety. The encapsulation ability of 3 toward water‐soluble dyes has been investigated. These results indicated that 3 was a unimolecular reverse micelle with an encapsulation ability toward hydrophilic dye molecules. In addition, 3 showed an molecular size‐selective encapsulation ability.
Chitosan Cross‐Linked Films for Drug Delivery Application
Authors: Campos Maria G. N. , Satsangi Neera , Rawls Henry R. , Mei Lucia H. I.
Published: May 2009

This work evaluated such a cross‐linked chitosan based controlled release device to be later used for sustained drug release. Cross linking was required to control chitosan swelling/deswelling rate. Hexamethylene 1,6‐Bis (aminocarboxysulfonate), a bisulfite blocked diisocyanate obtained by the reaction of 1,6 Hexamethylene Diisocyanate and Sodium bisulfite, was used as cross linking agent. Two films formulations were tested: 30 and 50% cross‐linked, and they were prepared by solvent evaporation technique. Chitosan cross‐linked films were characterized for cross linkage by FTIR, for hydrophilicity by Contact Angle and for swelling behavior by Gravimetric method. Cross linking reaction was confirmed by FTIR. Moreover, cross linking increased the hydrophilic character of cross‐linked films and suppressed swelling. However, 30% cross‐linked film swollen less than the 50% one, while 50% cross‐linked film swollen less than chitosan film itself. This behavior was attributed to the hydrophilic character of the cross linking agent and to the polymeric network formation by cross linking.
Fabrication of Ordered Arrays of Biodegradable Polymer Pincushions Using Self‐Organized Honeycomb‐Patterned Films
Authors: Tanaka Masaru , Takebayashi Masafumi , Shimomura Masatsugu
Published: May 2009

Nano‐ and micropatterned structures of tissue engineering scaffolds made of biodegradable and biocompatible polymers profoundly influence cell behavior. The present study describes a technically simple and inexpensive method to rapidly fabricate hexagonal arrays of biodegradable polymer pillars (pincushions). As precursors to these polymer pincushion arrays, highly regular porous biodegradable polymer films (self‐organized honeycomb‐patterned films, called honeycomb films) were prepared on a glass substrate using a simple casting technique. Scanning electron microscope observations revealed that the honeycomb film was composed of a top and bottom layer. This double‐layered structure is attributable to the self‐organization of hexagonally packed arrays of water droplets that form the template. When we peeled off the top layer of the honeycomb film under ambient conditions using adhesive tape, we obtained arrays of polymer pincushions on both side of the glass substrate and on the adhesive tape. Each air hole is surrounded by six pincushions, each with a diameter of 0.1‐1 µm. We also studied factors that determine the morphology of the pincushions, such as the thermal and mechanical properties of the polymers used. It was shown that the heights, widths, and distances of separation between the pincushions could be controlled by the choice of polymer and the pore structure of the original honeycomb film. Such well‐ordered, biologically inspired pincushion structures could find application in biomedical, photonic, and electronic materials.
The Use of In‐line Quantitative Analysis to Follow Polymer Processing
Authors: Canevarolo Sebastião V. , Bertolino Marcelo K. , Pinheiro Luís A. , Palermo Vincenzo , Piccarolo Stefano
Published: May 2009

In this work it is presented three applications of real time analysis during extrusion process using an optical device developed by our research group, which applies the concepts of light extinction. Monitoring of polymer blends morphology takes place to infer data concerned to dispersed phase size and concentration. The detector also enables information about melting temperature of polymer during extrusion and the level of viscous heating, and the exfoliation step during processing of a polymer‐clay nanocomposite.
Passive and Active Mixing in Microfluidic Devices
Authors: Meijer Han E.H. , Singh Mrityunjay K. , Kang Tae Gong , den Toonder Jaap M.J. , Anderson Patrick D.
Published: May 2009

In microfluidics the Reynolds number is small, preventing turbulence as a tool for mixing, while diffusion is that slow that time does not yield an alternative. Mixing in microfluidics therefore must rely on chaotic advection, as well‐known from polymer technology practice where on macroscale the high viscosity makes the Reynolds numbers low and diffusion slow. The mapping method is used to analyze and optimize mixing also in microfluidic devices. We investigate passive mixers like the staggered herringbone micromixer (SHM), the barrier embedded micromixer (BEM) and a three‐dimensional serpentine channel (3D‐SC). Active mixing is obtained via incorporating particles that introduce a hyperbolic flow in e.g. two dimensional serpentine channels. Magnetic beads chains‐up in a flow after switching on a magnetic field. Rotating the field creates a physical rotor moving the flow field. The Mason number represents the ratio of viscous forces to the magnetic field strength and its value determines the fate of the rotor: a single, an alternating single and double, or a multiple part chain‐rotor results. The type of rotor determines the mixing quality with best results in the alternating case where crossing streamlines introduce chaotic advection. Finally, an active mixing device is proposed that mimics the cilia in nature. The transverse flow induced by their motion indeed enhances mixing at the microscale.
Water‐Soluble Polyacids with Capability to Remove Metal Ions in Homogenous Phase by Using the Liquid Phase Polymer‐Based Retention Technique
Authors: Rivas Bernabé L. , Maureira Antonio , Pereira Eduardo D.
Published: May 2009

Water‐soluble polymers containing carboxylic acid and sulfonic acid groups were investigated as polychelatogens under different experimental conditions in view to study their metal ion binding properties, using the liquid‐phase polymer‐based retention technique. The divalent metal ions investigated were: Co2+, Cu2+, Zn2+, and Cd2+. When the pH increased above 3, and especially at pH 5, metal ion retention capability increased as the majority of the functional groups are carboxylate, which can form more stable complexes with the metal ions. The retention capability also depended on the structure of the polyacid and the filtration factor, Z.
Macromol. Symp. 279
Authors: Meijer Han E.H. , Singh Mrityunjay K. , Kang Tae Gong , den Toonder Jaap M.J. , Anderson Patrick D.
Published: May 2009

Cover: The 42nd World Polymer Congress (MACRO 2008) was held in Taipei in 2008. The aim of this biannually held conference series is to bring polymer scientists and engineers from around the globe to address recent developments and urgent issues in polymer science. The cover shows the evolution of mixing patterns in the BEM at several down‐channel positions (from Han E.H. Meijer, et.al., p 201).
Corporate borrowing and profitability in India
Authors: Majumdar Sumit , Sen Kunal
Published: May 2009

This paper examines effects of different types of corporate borrowing on firm profitability in India. We show that in contrast to the conventional thinking on the importance of monitored debt in determining firm performance, what matters more is arm's‐length lending in the form of fixed deposits in influencing firm profitability. We argue that the strategic implications of fixed deposits can be mainly attributed to the fact that they are both unsecured and privately held, which make the creditors associated with this type of debt the most likely to monitor firms' performance. The results suggest that debt structure matters, and it is important to take into account institutional differences and the heterogeneity of debt in the analysis of capital structure on firm performance. Copyright © 2009 John Wiley & Sons, Ltd.
Quantifying spatial heterogeneity in dynamic contrast‐enhanced MRI parameter maps
Authors: Rose Chris J. , Mills Samantha J. , O'Connor James P. B. , Buonaccorsi Giovanni A. , Roberts Caleb , Watson Yvonne , Cheung Susan , Zhao Sha , Whitcher Brandon , Jackson Alan , Parker Geoffrey J. M.
Published: May 2009

Dynamic contrast‐enhanced MRI is becoming a standard tool for imaging‐based trials of anti‐vascular/angiogenic agents in cancer. So far, however, biomarkers derived from DCE‐MRI parameter maps have largely neglected the fact that the maps have spatial structure and instead focussed on distributional summary statistics. Such statistics—e.g., biomarkers based on median values—neglect the spatial arrangement of parameters, which may carry important diagnostic and prognostic information. This article describes two types of heterogeneity biomarker that are sensitive to both parameter values and their spatial arrangement. Methods based on Rényi fractal dimensions and geometrical properties are developed, both of which attempt to describe the complexity of DCE‐MRI parameter maps. Experiments using simulated data show that the proposed biomarkers are sensitive to changes that distribution‐based summary statistics cannot detect and demonstrate that heterogeneity biomarkers could be applied in the drug trial setting. An experiment using 23 DCE‐MRI parameter maps of gliomas—a class of tumour that is graded on the basis of heterogeneity—shows that the proposed heterogeneity biomarkers are able to differentiate between low‐ and high‐grade tumours. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Two formulations for dynamic response of a cylindrical cavity in cross‐anisotropic porous media
Authors: Eslami Hashem , Gatmiri Behrooz
Published: May 2009

Two formulations for calculating dynamic response of a cylindrical cavity in cross‐anisotropic porous media based on complex functions theory are presented. The basis of the method is the solution of Biot's consolidation equations in the complex plane. Employing two groups of potential functions for solid skeleton and pore fluid (each group includes three functions), the u–w formulation of Biot's equations are solved. Difference of these two solutions refers to use of two various potential functions. Equations for calculating stress, displacement and pore pressure fields of the medium are mentioned based on each two formulations. Copyright © 2009 John Wiley & Sons, Ltd.
Cribra orbitalia: a non‐human primate perspective
Authors: DeGusta D.
Published: May 2009

Cribra orbitalia, a porous lesion involving the orbital roofs, is one of the most‐studied skeletal pathologies in bioarchaeology, and yet uncertainty still exists regarding its aetiology and significance. In contrast to the hundreds of reports of cribra orbitalia in human skeletal remains, little is known of this condition in non‐human primates. Previously, cribra orbitalia has only been reported in catarrhines, with just two cases in cercopithecoids. To provide a broader, phylogenetic perspective on cribra orbitalia, a sample of primate skeletal material was examined to evaluate the occurrence of this condition. The taxonomically diverse sample consists of 380 non‐hominoid (non‐ape) modern primates from both wild and captive populations. Cribra orbitalia is present in 16 individuals, including cercopithecines, colobines, platyrrhines and a prosimian, substantially expanding the known taxonomic range of this condition. Modern primates—with their varied habitats, diets, levels of parasitism, etc.—provide a set of natural experiments regarding conditions and physiologies which may influence the aetiology and impact of cribra orbitalia. More generally, it is suggested here that studies of non‐human primate skeletal pathologies have the potential for providing significant insight on human paleopathologies. Copyright © 2009 John Wiley & Sons, Ltd.
Enhanced number and activity of mitochondria in multiple sclerosis lesions
Authors: Witte Maarten E , Bø Lars , Rodenburg Richard J , Belien Jeroen A , Musters Rene , Hazes Thierry , Wintjes Liesbeth T , Smeitink Jan A , Geurts Jeroen JG , De Vries Helga E , van der Valk Paul , van Horssen Jack
Published: May 2009

Mitochondrial dysfunction has been implicated in the development and progression of multiple sclerosis (MS) lesions. Mitochondrial alterations might occur as a response to demyelination and inflammation, since demyelination leads to an increased energy demand in axons and could thereby affect the number, distribution and activity of mitochondria. We have studied the expression of mitochondrial proteins and mitochondrial enzyme activity in active demyelinating and chronic inactive MS lesions. Mitochondrial protein expression and enzyme activity in active and chronic inactive MS lesions was investigated using (immuno)histochemical and biochemical techniques. The number of mitochondria and their co‐localization with axons and astrocytes within MS lesions and adjacent normal‐appearing white matter (NAWM) was quantitatively assessed. In both active and inactive lesions we observed an increase in mitochondrial protein expression as well as a significant increase in the number of mitochondria. Mitochondrial density in axons and astrocytes was significantly enhanced in active lesions compared to adjacent NAWM, whereas a trend was observed in inactive lesions. Complex IV activity was strikingly up‐regulated in MS lesions compared to control white matter and, to a lesser extent, NAWM. Finally, we demonstrated increased immunoreactivity of the mitochondrial stress protein mtHSP70 in MS lesions, particularly in astrocytes and axons. Our data indicate the occurrence of severe mitochondrial alterations in MS lesions, which coincides with enhanced mitochondrial oxidative stress. Together, these findings support a mechanism whereby enhanced density of mitochondria in MS lesions might contribute to the formation of free radicals and subsequent tissue damage. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Dominant negative factors in health and disease
Authors: Veitia Reiner A
Published: May 2009

The idea of dominant mutations that interfere with the activity of a normal gene product has been known for more than 80 years—the famous Muller's antimorphs. However, only over half a century later, the mechanistic bases of dominant negative mutations (DNMs) were defined in a systematic way by Ira Herskowitz. Most analyses of DNMs consider only intralocus (interallelic) interactions. The typical textbook explanation invokes a defective subunit, which poisons a homo‐dimer or a homo‐oligomer. More complex cases exist and the quantitative dimension of this phenomenon will be explored here. The basic ideas underlying DN effects can be (and should be) extended to included epistatic (interloci) interactions. Indeed, poisoning heteromeric macromolecular complexes is per se a matter of ‘transdominant’ negative effects. In this context, non‐allelic non‐complementation is also considered. Given the importance of DNMs in human disease and in the study of gene function, understanding how they work is essential for understanding pathology and for the design of effective DN molecules that can also prove useful in therapeutics. Finally, the existence and potential relevance of an increasing number of physiological DN protein isoforms is briefly discussed. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Neuropsychological functioning and quality of life during the first year after completing chemotherapy for breast cancer
Authors: Reid‐Arndt Stephanie A. , Hsieh Catherine , Perry Michael C.
Published: May 2009

Objective: Research has documented modest cognitive difficulties among women treated for breast cancer. The present study was designed to evaluate the effects of these subtle cognitive changes on quality of life after treatment.

Methods: Data are presented from women breast cancer patients who completed neuropsychological tests and questionnaires regarding quality of life 6 and 12 months post‐chemotherapy (n's=39 and 33). Neuropsychological test scores were examined for evidence of cognitive difficulties at each time point; repeated measures ANOVAs were used to identify changes over time. Regression analyses assessed relationships of quality of life outcomes with cognitive functioning, social support seeking, and fatigue.

Results: Small percentages of participants (<20% across tests) evidenced deficits in delayed memory, processing speed, response inhibition, and verbal fluency (VF) at each time point. Reliable change index analyses suggested statistically reliable improvements in each cognitive domain for a modest portion of participants. Regressions revealed hesitation to seek social support and fatigue as the most consistent predictors of quality of life at 6 and 12 months post‐chemotherapy. Cognitive complaints and VF difficulties were also significantly related to quality of life at 12 months.

Conclusions: In addition to confirming the importance of fatigue and social support in quality of life, these data offer preliminary indications that weaker VF skills and self‐reported cognitive complaints may be associated with poorer functional outcomes among cancer survivors. Further research is needed to validate these potential relationships, which suggest that cognitive difficulties among cancer survivors may warrant monitoring and possible intervention. Copyright © 2009 John Wiley & Sons, Ltd.
Psychological adjustment among male partners in response to women's breast/ovarian cancer risk: a theoretical review of the literature
Authors: Sherman Kerry A. , Kasparian Nadine A. , Mireskandari Shab
Published: May 2009

Objective: For women at high risk of developing hereditary breast and/or ovarian cancer the process of undergoing genetic testing is anxiety provoking and stressful, entailing difficult and complex decisions. Partners of high‐risk women are frequently perceived by the women as a source of support during this challenging time. Utilising Self Regulatory Theory, this paper provides a theoretically guided overview of existing data to delineate how partners respond emotionally and behaviourally to the woman's high‐risk status.

Methods: An extensive literature search was undertaken. Online searches of MEDLINE, CINAHL and PsycINFO databases were conducted, reference lists of all publications identified were examined; and the databases were searched for authors identified in these publications.

Results: The systematic search yielded 10 published studies on at‐risk women and their male partners; one study did not investigate male partner distress as an outcome variable. Heterogeneity of methodology in this literature precluded quantitative meta‐analyses of study outcomes. Review of the evidence suggests that the genetic testing process may be distressing for some partners, particularly for partners of women identified as mutation carriers. Associations were identified between partner distress and partner beliefs about the woman's perceived breast cancer risk; partner feelings of social separation and lack of couple communication; and partner perceptions of being alienated from the testing process. Lack of partner support was found to be associated with increased distress of the tested woman at the time of testing and following results disclosure. Data are lacking on the role of partner beliefs about breast cancer, partner perceived consequences of genetic testing, and personality factors such as information processing style, on partner distress.

Conclusions: The high level of behavioural and psychological interdependence that exists between a tested woman and her partner means that future research seeking to understand the coping and adjustment processes of partners needs to adopt a dyadic, transactional approach that is grounded in psychological theory. Specific suggestions for future research in this context are delineated. Copyright © 2009 John Wiley & Sons, Ltd.
The Effect of Samples Geometry and Thermal Cycling Test Type on the Thermal Shock Behaviour of Plasma Sprayed TBCs
Authors: Altuncu Ekrem , Karaalİ Emin İrfan , Erdogan Garip , Ustel Fatih , Turk Ahmet
Published: May 2009

Thermal barrier coatings (TBCs) are effective in protecting gas turbine blades by insulating them from hot gas passing through. In addition, they provide prevention of thermal shock, oxidation resistance and improved engine efficiency. A major life‐limiting weakness of TBCs is their susceptibility to get damaged by thermally‐induced stresses. The thermal shock behaviour of TBC systems subjected to thermal shock loading and the influence of the cracks on the coating durability was investigated experimentally. In this study, TBCs (NiCrAlY + YSZ), which have different sample geometry were subjected to both of gas burner and furnace thermal cycle tests. Sample geometry and cycle test type effect on the correlation of thermal shock behaviour of TBC coatings were characterized by macroscopic and microstructural investigations.
Effective knowledge‐based potentials
Authors: Ferrada Evandro , Melo Francisco
Published: May 2009

Empirical or knowledge‐based potentials have many applications in structural biology such as the prediction of protein structure, protein–protein, and protein–ligand interactions and in the evaluation of stability for mutant proteins, the assessment of errors in experimentally solved structures, and the design of new proteins. Here, we describe a simple procedure to derive and use pairwise distance‐dependent potentials that rely on the definition of effective atomic interactions, which attempt to capture interactions that are more likely to be physically relevant. Based on a difficult benchmark test composed of proteins with different secondary structure composition and representing many different folds, we show that the use of effective atomic interactions significantly improves the performance of potentials at discriminating between native and near‐native conformations. We also found that, in agreement with previous reports, the potentials derived from the observed effective atomic interactions in native protein structures contain a larger amount of mutual information. A detailed analysis of the effective energy functions shows that atom connectivity effects, which mostly arise when deriving the potential by the incorporation of those indirect atomic interactions occurring beyond the first atomic shell, are clearly filtered out. The shape of the energy functions for direct atomic interactions representing hydrogen bonding and disulfide and salt bridges formation is almost unaffected when effective interactions are taken into account. On the contrary, the shape of the energy functions for indirect atom interactions (i.e., those describing the interaction between two atoms bound to a direct interacting pair) is clearly different when effective interactions are considered. Effective energy functions for indirect interacting atom pairs are not influenced by the shape or the energy minimum observed for the corresponding direct interacting atom pair. Our results suggest that the dependency between the signals in different energy functions is a key aspect that need to be addressed when empirical energy functions are derived and used, and also highlight the importance of additivity assumptions in the use of potential energy functions.
Recent developments in the analysis of fires, explosions, and production disruption incidents in chemical plants and oil refineries
Authors: McIntyre Dale R. , Ford Emory
Published: May 2009

Significant changes in computing power, regulatory climate, safety culture and globalization of business ventures have occurred since the original publication of MTI Publication No. 30, Guidelines for Assessing Fire and Explosion Damage. The implications of these changes are reviewed with regard to the work of investigators charged with the analysis of fires, explosions and major production disruption incidents in chemical processing plants and refineries. A review of advances in computer modeling of large‐scale energy release events is presented. Storm damage assessment and the analysis of incidents involving sabotage are discussed. © 2009 American Institute of Chemical Engineers Process Saf Prog 2009
Large area mapping of the alloy composition of Alx Ga1–xN using infrared reflectivity
Authors: Henry A. , Lundskog A. , Janzén E.
Published: May 2009

The energy position of a dip observed in the IR‐reflectance spectra recorded from wurtzite c ‐plane Alx Ga1–x N epitaxial films grown on SiC substrate reflects the composition of the alloy. A calibration procedure is presented with the possibility of mapping for large area wafer. The technique is non‐destructive, scalable and fast. The limitations are discussed and comparisons with other techniques are made. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phytotherapy used in orissa state, india for treating malaria
Authors: Kantamreddi Venkata Siva Satyanarayana , Parida Sagarika , Kommula Suryanarayana Murty , Wright Colin W.
Published: May 2009

This paper reports 35 medicinal plants belonging to 25 families used in the treatment of malaria by the people inhabiting the forests located near to Bhubaneswar, the capital city of Orissa, a south‐eastern state in India. The methods adopted for the preparation of plant parts are discussed along with their family and local name(s). The majority of the herbal preparations were made in the form of juices or by using water as the medium in the form of decoctions or infusions. Various plant parts, such as leaves, flowers, fruits, barks, stems, roots, and in some cases the whole plants are used to prepare these remedies each of which contains a single species. Copyright © 2009 John Wiley & Sons, Ltd.
Antinociceptive and antiinflammatory activities of grandisin extracted from Virola surinamensis
Authors: Carvalho Adryano A. V. , Galdino Pablinny M. , Nascimento Marcus V. M. , Kato Massuo J. , Valadares Marize C. , Cunha Luiz C. , Costa Elson A.
Published: May 2009

The antinociceptive and antiinflammatory properties of the neolignan, grandisin, isolated from Virola surinamensis (Myristicaceae) were investigated. Grandisin (GRA) is present in several plant species from Brazil used in popular medicine for the treatment of disorders such as colic, inflammation, rheumatism, dyspepsia and liver dysfunction. These studies demonstrated that GRA is able to inhibit the acetic acid‐induced writhing in mice dose‐dependently, and that this effect is not caused by motor incoordination or sedation due to depressant effect in the CNS. Through the formalin test the antiinflammatory activity of GRA was characterized, this substance reduced the time licking the paw by 60.5% (only in the second phase (inflammatory pain). This activity was also verified by the oil‐induced ear oedema test, where GRA 10.0 mg/kg reduced the oedema by 36.4%. The results suggest that GRA has antinociceptive effects arising from antiinflammatory activity. Copyright © 2009 John Wiley & Sons, Ltd.
Antioxidant activities of coumarins from Korean medicinal plants and their structure–activity relationships
Authors: Thuong Phuong Thien , Hung Tran Manh , Ngoc Tran Minh , Ha Do Thi , Min Byung Sun , Kwack Seung Jun , Kang Tae Suk , Choi Jae Sue , Bae KiHwan
Published: May 2009

The aim of this work was to study the structure–activity relationships of the antioxidant activity of natural coumarins isolated from four Korean medicinal plants (1–17) and four purchased coumarins (18–21). The free radical scavenging and lipid peroxidation assays revealed that five phenolic coumarins, scopoletin (1), aesculetin (2), fraxetin (3), umbelliferone (18) and daphnetin (19), possessed considerable antioxidant activities. The coumarins having a catechol group, 2, 3 and 19, showed significant free radical scavenging activity and inhibitory effects on lipid peroxidation, indicating that the catechol group significantly contributed to the antioxidant activities of coumarins. In contrast, the sugar moiety markedly reduced the activities of coumarin glycosides. The results also demonstrate that the α‐pyrone ring of coumarins significantly enhanced the capacity of inhibiting oxidative reactions of coumarins. Copyright © 2009 John Wiley & Sons, Ltd.
Restrained optimization of broken‐symmetry determinants
Authors: Herrmann Carmen , Podewitz Maren , Reiher Markus
Published: May 2009

The goal of this work is to provide an overview on how Lagrange multipliers can be used in self‐consistent‐field algorithms for convergence control. In particular, a restrained optimization scheme is proposed with the purpose to guide any set of initial guess molecular orbitals to those of a Slater determinant which (1) has certain expectation values (i.e., molecular properties) within a predefined range and (2) corresponds to a true (local) energy minimum, if such a minimum exists within the property range chosen. The most important practical application of such an algorithm is the calculation of minimum‐energy broken‐symmetry determinants, which are often used in Kohn‐Sham density functional calculations to model antiferromagnetically coupled states. This is achieved by (a) combining a constrained optimization with a subsequent optimization where the constraints are released, i.e., the Lagrange multipliers are set to zero. Alternatively, (b) a modified scheme may be employed, where the constraints are released as soon as the energy starts to rise in the SCF algorithm. Both alternatives are combined with both intermediate and final automatic control of whether the properties of interest are within the desired range. A parameter study using scheme (a) is carried out for a set of small test systems. Applications to a synthetically available trinuclear copper complex and to Crabtree and Brudvig's water‐oxidizing complex demonstrate the value and limitations of restrained optimization. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009