bluuebunny/crossref_metadata_2025 huggingface dataset:
Neutralizing monoclonal antibody to human connective tissue growth factor ameliorates transforming growth factor‐β‐induced mouse fibrosis
Authors: Ikawa Yuka , Ng Poh‐Sing , Endo Koki , Kondo Miki , Chujo Sonoko , Ishida Wataru , Shirasaki Fumiaki , Fujimoto Manabu , Takehara Kazuhiko
Published: May 2008

Skin fibrotic disorders such as systemic sclerosis (SSc) are characterized by an excessive accumulation of extracellular matrix (ECM) and are understood to develop under the influence of fibrogenic growth factors. To better understand the detailed mechanisms of persistent fibrosis in SSc, we have previously established an animal model of skin fibrosis induced by exogenous application of growth factors. In this model, transforming growth factor‐β (TGF‐β) transiently induced subcutaneous fibrosis and serial injections of connective tissue growth factor (CTGF) after TGF‐β caused persistent fibrosis. These results suggest that CTGF plays an important role in the development of persistent skin fibrosis and that CTGF may be a potential and specific therapeutic target in skin fibrosis. Therefore, the aim of the current study is to develop a neutralizing monoclonal antibody against human CTGF. We also investigated the neutralizing effect of the antibodies in our animal model. Firstly, by using the DNA immunization method, we developed a panel of anti‐CTGF antibodies recognizing the native conformation of human CTGF. Next, to examine the anti‐fibrosing effects of these antibodies, newborn B6 mice received subcutaneous injections of TGF‐β for 3 days with either anti‐CTGF neutralizing antibodies or control purified immunoglobulin. Anti‐CTGF antibodies significantly reduced skin fibrosis and collagen contents compared with the control group. These results suggest that our anti‐CTGF antibodies are capable of blocking the development of skin fibrosis at least partially and these anti‐CTGF neutralizing antibodies may be useful as the feasible strategy to treat skin fibrotic diseases as SSc. J. Cell. Physiol. 216: 680–687, 2008, © 2008 Wiley‐Liss, Inc.
Cancer stem cells in prostate adenocarcinoma: a target for new anticancer strategies
Authors: Fioriti D. , Mischitelli M. , Monaco F. Di , Silverio F. Di , Petrangeli E. , Russo G. , Giordano A. , Pietropaolo V.
Published: May 2008

Prostate cancer (PC) is major common malignancy in males in most industrialized Western countries, where it is the most commonly diagnosed cancer affecting men after middle age (>50 years). Over 90% of PC patients with incurable disease respond to primary treatment, which consists of intervention to lower serum testosterone. However, the duration of response is short (12–33 months) and in almost all patients, is followed by the emergence of a phenotype resistant to androgen deprivation in therapy (known as hormone or androgen‐resistant PC). Considerable research efforts have been directed towards the identification of markers associated with the initiation and progression of PC, yet there is little consensus about the target cell within prostate epithelium that is susceptible to malignant transformation. Stem cells may represent a major target for mutations leading to cancer as their longevity assures continued presence during the long latency between carcinogenic agents exposure and cancer development. Therefore in order to allow the development of more effective treatment strategies for PC, a better understanding of the molecular changes that underlie cancer stem cells is required. J. Cell. Physiol. 216: 571–575, 2008, © 2008 Wiley‐Liss, Inc.
Estradiol, a key endocrine signal in the sexual differentiation and activation of reproductive behavior in quail
Authors: Balthazart Jacques , Cornil Charlotte A. , Charlier Thierry D. , Taziaux Mélanie , Ball Gregory F.
Published: May 2008

In Japanese quail, estrogen's effects on sexual behavior can be divided into three classes based on the underlying mechanisms and time‐course of action and release. During embryonic life, the embryonic ovary secretes large amounts of estrogens. In contrast to what is observed in mammals where sexual differentiation essentially proceeds via masculinization of the males, in quail, females are demasculinized by their endogenous ovarian estrogens, an effect that can be blocked by injection of an aromatase inhibitor and mimicked in male embryos by an injection of estradiol. In adulthood, testosterone secreted by the testes is converted into estrogens by the preoptic aromatase. Locally produced estrogens activate male sexual behavior largely through the activation of estrogen receptors resulting in the transcription of a variety of genes, including brain aromatase (genomic effect). Both changes in estrogen production and action are observed within latencies ranging from a few hours to a few days, and are completely reversible. Additionally, brain aromatase activity can be modulated within minutes by calcium‐dependent phosphorylations, triggered by variations in glutamatergic neurotransmission. These rapid changes in aromatase activity affect with relatively short latencies (10–15 min) the expression of male sexual behavior in quail and also in mice. Overall, the effects of estrogens on sexual behavior can thus be categorized into three classes: organizational (irreversible genomic action during ontogeny), activational (reversible genomic action during adulthood) and rapid nongenomic effects. Rapid and slower changes in brain aromatase activity match well with the two modes of estrogen action on behavior and provide temporal variations in the estrogens' bioavailability that should be able to support the entire range of established effects for this steroid. J. Exp. Zool. 311A:323–345, 2009. © 2008 Wiley‐Liss, Inc.
Evolution of the placenta and associated reproductive characters in bats
Authors: Carter Anthony M. , Mess Andrea
Published: May 2008

Recent advances in molecular phylogenetics indicate that the order Chiroptera is monophyletic and that one of four lineages of microbats (Rhinolophoidea) shares a common origin with megabats. Against this background we undertook a comprehensive analysis of placental evolution in bats. We defined a range of characters and character states associated with female reproduction, early development, placentation and the neonate. These were then mapped on a pre‐existing hypothesis of bat relationships that represents the current view from molecular studies. Our purpose was threefold. First, on the assumption of bat monophyly, we wished to establish the stem species pattern of extant chiropterans. Secondly, we asked whether there are derived character conditions in support of a common origin for Rhinolophoidea and the megabats. Thirdly, we looked for evolutionary character transformations that characterize higher‐level clades within Chiroptera, i.e. the megabats and the four lineages of microbats. The character condition occurring in the last common ancestor of Chiroptera was unequivocal for 21 of the 25 characters included in the analysis. The data did not offer support for a megabat‐rhinolophoid clade or the implication that microbats are paraphyletic. However, analysis of early development, placentation and other reproductive parameters resulted in derived character conditions for the megabats as well as for each of the four major lineages of microbats. J. Exp. Zool. (Mol. Dev. Evol.) 310B:428–449, 2008. © 2008 Wiley‐Liss, Inc.
Electrospun Zein Fibers Using Glutaraldehyde as the Crosslinking Reagent: Effect of Time and Temperature
Authors: Selling Gordon W. , Woods Kristen Kruger , Sessa David , Biswas Atanu
Published: May 2008

Glutaraldehyde was used as a crosslinking reagent to produce electrospun zein fibers with improved physical properties and solvent resistance. Using 8% glutaraldehyde, round and ribbon fibers were produced with diameters between 1 and 70 µm. All fibers readily dissolved in acetic acid. Heating the zein/glutaraldehyde fibers at temperatures from 80 to 180 °C for different times provided various degrees of insolubility to the fibers. A model was developed relating the extent of dissolution with the amount of glutaraldehyde used and the temperature/time at which the fiber was exposed. The fibers were found to be birefringent; upon heating, the amount of α‐helix in the fiber was reduced.

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Carbanions on Tap – Living Anionic Polymerization in a Microstructured Reactor
Authors: Wurm Frederik , Wilms Daniel , Klos Johannes , Löwe Holger , Frey Holger
Published: May 2008

The paper describes the living anionic polymerization of styrenes to homo‐ and diblock copolymers in continuous flow, using a microstructured mixing set‐up (“microreactor”). Reaction times and experimental effort are significantly reduced compared to classical batch methods that often require stringent reaction conditions and strict drying of the apparatus by “break‐seal” and “high vacuum” techniques. In continuous flow, residual impurities can be removed by purging the reactor with monomer and initiator solution before polymer samples are collected at the device outlet on a scale of up to 200 g · h−1. Facile molecular weight adjustment is achieved by variation of the flow rates of initiator or monomer solutions. The polymerization of styrene in THF and cyclohexane was studied with respect to control of molecular weight and polydispersity. Furthermore, diblock copolymers with different block lengths and low polydispersities, consisting of styrene‐ and 4‐tert‐butoxystyrene blocks were synthesized, employing a second micromixer for a delayed introduction of the additional monomer. All materials were investigated by NMR‐spectroscopy, SEC/MALLS, and MALDI‐TOF mass spectrometry, confirming narrow molecular weight distributions (MWDs; $\overline M _{\rm w} /\overline M _{\rm n}$ 1.09–1.25), molecular weights in the range of 500–70 000 g · mol−1, and complete end‐functionalization. No dimerization due to side reactions that would occur in the presence of oxygen was observed, evidencing efficient shielding of the apparatus from environmental influences.

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Electrospray Deposition of Photoresist: A Low Impact Method for the Fabrication of Multilayered Films
Authors: Rietveld Ivo B. , Suganuma Naotoshi , Kobayashi Kei , Yamada Hirofumi , Matsushige Kazumi
Published: May 2008

Electrospray deposition has been investigated as a substitute for photoresist spin coating. The morphology of Microposit S1813 photoresist films has been studied as a function of several spray conditions including resist concentration, substrate surface, and flow rate. Film morphology is controlled by three process parameters: the surface energy determines the equilibrium conditions of resist on the substrate; the viscosity and volume flux determine the relaxation time for the depositing resist solution after impact on the substrate. Electrosprayed photoresist films have been used for photolithographic patterning and it has been demonstrated that electrospray deposition is an effective method for deposition of photoresist on top of fragile, thin films, which can be used for multilayered thin film fabrication.

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Self‐Assembling of SBS Block Copolymers as Templates for Conductive Silver Nanocomposites
Authors: Peponi Laura , Tercjak Agnieszka , Gutierrez Junkal , Stadler Hartmut , Torre Luigi , Kenny Josè M. , Mondragon Iñaki
Published: May 2008

Novel nanocomposites based on conductive Ag nanoparticles and a self‐assembled polystyrene‐block‐polybutadiene‐block‐polystyrene (SBS) block copolymer were investigated. Good confinement of the nanoparticles into polystyrene microphase was achieved by the addition of DT as surfactant. The polymeric matrix kept its hexagonal order packed cylindrical structure up to 7 wt.‐% content of Ag nanoparticles. An electrostatic force microscopy (EFM) analysis of well‐dispersed metal‐organic hybrid Ag/SBS films was used to characterize the electric behavior of the conductive nanocomposites.

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Synthesis of ABC and CABAC Triphilic Block Copolymers by ATRP Combined with ‘Click’ Chemistry
Authors: Kyeremateng Samuel Oppong , Amado Elkin , Blume Alfred , Kressler Jörg
Published: May 2008

ATRP using poly(propylene oxide) monofunctional macroinitiator was carried out with solketal methacrylate (SMA) and the non‐reactive PPO having two N3 terminal groups was removed by dissolution in an excess of n‐hexane. The resulting azido terminated AB diblock copolymer was ‘clicked’ with an α‐alkyne fluorinated compound, followed by acid hydrolysis of the SMA units, a triphilic ABC triblock copolymer was prepared. ATRP of SMA with a difunctional PPO macroinitiator to give ABA triblock copolymer was also carried out. The terminal Br was again exchanged with N3, ‘clicked’ with the α‐alkyne fluorinated compound and likewise hydrolyzed to give a triphilic CABAC pentablock copolymer, i.e., hydrophilic, oleophilic, and fluorophilic blocks were combined.

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Shrinking Behavior of Surfactant‐Grafted Thermosensitive Gels and the Mechanism of Rapid Shrinking
Authors: Okeyoshi Kosuke , Abe Tetsuya , Noguchi Yuji , Furukawa Hidemitsu , Yoshida Ryo
Published: May 2008

Surfactant‐grafted hydrogels with a fast response to temperature were prepared. In order to clarify the mechanism of rapid shrinking, the effects of the grafted surfactant and the homogeneity of the main chain were investigated. Poly(NIPAAm‐co‐S180A) gels prepared using a chemical cross‐linker (bis‐PNS gels) exhibited rapid shrinking, as did PNS gels prepared by γ‐ray irradiation (γ‐PNS gels). This suggested that the rapid shrinking of the PNS gel did not depend on the homogeneity of the main‐chain structure. The shrinking kinetics of the bis‐PNS gels depended on the amount of the introduced surfactant, which means that shrinking is enhanced by micelle formation as a dynamic driving force. From the analysis by dynamic light scattering (DLS) and scanning microscopic light scattering (SMILS), it was suggested that the micelle structure, which induced rapid shrinking, existed in the bis‐PNS gel.

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Tuning Surface Wettability of Poly(3‐sulfopropyl methacrylate) Brushes by Cationic Surfactant‐Driven Interactions
Authors: Döbbelin Markus , Arias Garciela , Loinaz Iraida , Llarena Irantzu , Mecerreyes David , Moya Sergio
Published: May 2008

In this communication, polyanionic poly(potassium 3‐sulfopropyl methacrylate) (PSPM) brushes were switched from hydrophilic to hydrophobic by exchange of the counter cations. First, poly(potassium 3‐sulfopropyl methacrylate) brushes were grown by means of atom transfer radical polymerization (ATRP) from thiol monolayers of initiating ω‐mercaptoundecyl bromoisobutyrate and mixed monolayers of thiol initiator and 1‐undecanothiol (blank thiol) attached to gold surfaces. The kinetics of the polymerization reaction were followed by means of the quartz microbalance technique with dissipation (QCM‐D). The collapse of PSPM brushes in the presence of cationic surfactants like quaternary ammonium salts (tetraethylammonium bromide, hexadecyltrimethylammonium bromide) and imidazolium salts (1‐dodecyl‐3‐methylimidazolium bromide, 1H,1H,2H,2H‐perfluoro‐1‐decyl‐3‐methylimidazolium bromide) was shown by QCM‐D. Water contact angle measurements proved that the wettability of the surface could be tuned reversibly from hydrophilic values (<30 °) to hydrophobic ones (>85 °).

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Design of a Linear Poly(3‐hexylthiophene)/Fullerene‐Based Donor‐Acceptor Rod‐Coil Block Copolymer
Authors: Richard Fanny , Brochon Cyril , Leclerc Nicolas , Eckhardt Doreen , Heiser Thomas , Hadziioannou Georges
Published: May 2008

Novel fullerene‐grafted poly(3‐hexylthiophene) (P3HT)‐based rod‐coil block copolymers have been synthesized. The regioregular P3HT rod block has been synthesized by a modified Grignard metathesis reaction (GRIM). An original in situ end‐capping reaction has been developed in order to convert the P3HT block into an efficient macro‐initiator for the nitroxide‐mediated radical polymerization (NMRP) of the coil block. Controlled radical polymerization of the second poly(butylacrylate‐stat‐chloromethylstyrene) [P(BA‐stat‐CMS)] block has been done through various conditions leading to different coil block lengths. The final electron donor‐acceptor block copolymer has been obtained after C60 grafting in soft conditions. Copolymers have been characterized by 1H NMR and size exclusion chromatography. Optical characterizations, before and after C60 grafting, are reported.

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Matrix Representation of Polymer Chain Size Distributions, 3 – Case Studies for Linear Polymerization Mechanisms at Transient Conditions
Authors: Sanches Heloísa L. , Melo Príamo A. , Pinto José Carlos
Published: May 2008

The mass balance equations used to describe different polymerization systems are represented and analyzed with the help of a general matrix framework previously developed. Some of its properties were presented in previous works and are illustrated here in three examples. The first example regards the dynamics of a copolymerization reactor. It is shown that terminal and penultimate models may predict qualitatively different responses in batch reactions. The second example also regards the dynamics of copolymerization reactions. It is shown how manipulation of initial conditions and monomer feed rates can be used to keep copolymer composition constant throughout the batch. The third example concerns the existence of oscillating chain size distributions when there are multiple monomer insertion steps.

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Membrane‐tethered proteins for basic research, imaging, and therapy
Authors: Cheng Tian‐Lu , Roffler Steve
Published: May 2008

Secreted and intracellular proteins including antibodies, cytokines, major histocompatibility complex molecules, antigens, and enzymes can be redirected to and anchored on the surface of mammalian cells to reveal novel functions and properties such as reducing systemic toxicity, altering the in vivo distribution of drugs and extending the range of useful drugs, creating novel, specific signaling receptors and reshaping protein immunogenicity. The present review highlights progress in designing vectors to target and retain chimeric proteins on the surface of mammalian cells. Comparison of chimeric proteins indicates that selection of the proper cytoplasmic domain and introduction of oligiosaccharides near the cell surface can dramatically enhance surface expression, especially for single‐chain antibodies. We also describe progress and limitations of employing surface‐tethered proteins for preferential activation of prodrugs at cancer cells, imaging gene expression in living animals, performing high‐throughput screening, selectively activating immune cells in tumors, producing new adhesion molecules, creating local immune privileged sites, limiting the distribution of soluble factors such as cytokines, and enhancing polypeptide immunogenicity. Surface‐anchored chimeric proteins represent a rich source for developing new techniques and creating novel therapeutics. © 2008 Wiley Periodicals, Inc. Med Res Rev, 28, No. 6, 885–928, 2008
Regularity of preventive foot care in persons with diabetes: Results from the Nord‐Trøndelag Health Study
Authors: Iversen Marjolein M. , Østbye Truls , Clipp Elizabeth , Midthjell Kristian , Uhlving Sverre , Graue Marit , Hanestad Berit R.
Published: May 2008

The purpose of the present study was to examine the regularity of preventive care for persons with diabetes in the Nord‐Trøndelag Health Study to identify associated demographic, lifestyle, and disease‐related factors. Among 1,972 persons with diabetes, 1,459 (74%) answered questions related to preventive foot care. The final sample included 1,312 persons with known diabetes, but without a self‐reported history of foot ulcer. Almost 85% reported receiving regular clinical diabetes examinations, 31.7% reported regular foot inspection by health care personnel, and 66.3% reported foot self‐inspection. Only 58.8% reported regular clinical diabetes examination combined with foot inspection. Males, patients not using insulin, and those with shorter diabetes duration or macrovascular complications were more likely to report less regular preventive care. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:226–237, 2008
Synthesis, characterization, and evaluation of enzymatically degradable poly(N‐isopropylacrylamide‐co‐acrylic acid) hydrogels for colon‐specific drug delivery
Authors: Li Shengfang , Liu Xianli
Published: May 2008

The enzymatically degradable poly(N‐isopropylacrylamide‐co‐acrylic acid) hydrogels were prepared using 4,4′‐bis(methacryloylamino)azobenzene (BMAAB) as the crosslinker. It was found that the incorporated N‐isopropylacrylamide (NIPAAm) monomer did not change the enzymatic degradation of hydrogel, but remarkably enhanced the loading of protein drug. The hydrogels exhibited a phase transition temperature between 4°C (refrigerator temperature) and 37°C (human body temperature). Bovine serum albumin (BSA) as a model drug was loaded into the hydrogels by soaking the gels in a pH 7.4 buffer solution at 4°C, where the hydrogel was in a swollen status. The high swelling of hydrogels at 4°C enhanced the loading of BSA (loading capability, ca. 144.5 mg BSA/g gel). The drug was released gradually in the pH 7.4 buffer solution at 37°C, where the hydrogel was in a shrunken state. In contrast, the enzymatic degradation of hydrogels resulted in complete release of BSA in pH 7.4 buffer solution containing the cecal suspension at 37°C (cumulative release: ca. 100 mg BSA/g gel after 4 days). Copyright © 2008 John Wiley & Sons, Ltd.
Electrochemical polymerization of imidazolum‐ionic liquids bearing a pyrrole moiety
Authors: Zhang Weixia , Li Yan , Lin Changxu , An Qi , Tao Chengan , Gao Yongbing , Li Guangtao
Published: May 2008

A series of imidazolium‐based ionic liquid monomers bearing a terminal pyrrole moiety were synthesized and electrochemically polymerized. It is found that the polymerizability of the synthesized ionic liquids is strongly dependent on the type of the counteranions. Although bromide monomer is not polymerizable, well‐defined polymeric films can be formed on various substrates in the cases of flour‐containing anions (BF4−, PF6−). The performed characterizations show that all resulting polypyrrole films are electroactive, and the imidazolium‐based ionic liquid moieties are correctly incorporated in polymer films during the electropolymerization process. This work not only provides a facile new method to immobilize ionic liquids on solid surface. Interestingly, without use of any template unique “knit” morphology and nanostructure, even hierarchical structures could also be produced by the electropolymerization of these new functionalized pyrrole monomers. We found that the properties of the pendant ionic liquid units on the surface of the formed polymer films preserved, and by simple anion exchange their surface energy and tension could be easily tuned without loss of the electrical, optical properties, and morphology of the polypyrrole films. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4151–4161, 2008
Synthesis and properties of helical poly(phenylacetylene) derivatives. Effect of chirality combination on the helicity
Authors: Liu Ruiyuan , Sanda Fumio , Masuda Toshio
Published: May 2008

Novel 4‐ethynylphthaloyl amino acid esters carrying different terminal groups, 4‐ethynylphthaloyl glycine (1S,2R,5S)‐menthyl ester (1), 4‐ethynylphthaloyl glycine (1R,2S,5R)‐menthyl ester (2), 4‐ethynylphthaloyl L‐leucine methyl ester (3), 4‐ethynylphthaloyl L‐leucine (1S,2R,5S)‐menthyl ester (4), 4‐ethynylphthaloyl L‐leucine (1R,2S,5R)‐menthyl ester (5) were synthesized and polymerized with a rhodium catalyst. Polymers with high molecular weights were obtained in 71–92% yields. The helical conformation of the polymers could be tuned by the chirality of the amino acid connected to the backbone, together with the chirality and bulkiness of the terminal pendent groups. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4183–4192, 2008
Cyclometalated 2‐phenylpyridine complex [RuII(o‐C6H4‐py)(MeCN)4]PF6 as a tunable catalyst for living radical polymerization
Authors: Diaz Camacho F. , Le Lagadec R. , Ryabov Alexander D. , Alexandrova L.
Published: May 2008

The cyclometalated complex [RuII(o‐C6H4‐py)(MeCN)4]PF6 (1) with a σ‐RuC bond and four substitutionally labile acetonitrile ligands mediates radical polymerization of different vinyl monomers, viz. n‐butyl acrylate, methyl methacrylate, and styrene, initiated by three alkyl bromides: ethyl 2‐bromoisobutyrate, methyl 2‐bromopropionate, and 1‐phenylethyl bromide. The polymerization requires the presence of Al(OiPr)3 and occurs uncontrollably as a conventional radical process. The variation of the molar ratio of the components of the reaction mixture, such as initiator, Al(OiPr)3 and catalyst, affected the polymerization rates and the molecular weights but did not improve the control. A certain level of control has been achieved by adding 0.5 eq of SnCl2 as a reducing agent. Tin(II) chloride decreased the rate of polymerization and simultaneously the molecular weights became conversion‐dependent and the polydispersities were also narrowed. Remarkably, the level of control was radically improved in the presence of excess of the poorly soluble catalyst (1), when the added amount of (1) was not soluble any more, i.e., under heterogeneous conditions, the system became adjustable and the living polymerization of all three monomers was finally achieved. Possible mechanisms of the (1)‐catalyzed polymerization are discussed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4193–4204, 2008
Plasma Polymerization of Organovanadium Oxides onto Flexible PET/ITO Substrates for Flexible Electrochromic Devices
Authors: Lin Yung‐Sen , Chen Ching‐Lun
Published: May 2008

The electrochromic properties of VOxCy films deposited onto 40 Ω · square−1 flexible PET/ITO substrates by low‐temperature plasma polymerization were investigated. The organic precursor was carried by Ar/O2 and polymerized by r.f. power at room temperature; the plasma‐polymerized films were proven to provide extraordinary electrochromic properties of light modulation with up to 35.8% of transmittance variance. Cyclic voltammetry and cyclic potentiostatic switching measurements demonstrated that only low driving voltages from −0.6 to 1 V were needed to provide reversible Li+ ion insertion and extraction.

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Formation of self‐assembled metal/silicon nanocomposites
Authors: Granitzer P. , Rumpf K. , Pölt P. , Šimić S. , Krenn H.
Published: May 2008

The fabrication of nanoscopic silicon based membranes has been carried out by using a non‐expensive electrochemical preparation technique. For these purposes an n+‐silicon wafer is anodized to create oriented pores with typical diameters around 50 nm. The length of the channels is up to 50 μm which yields to an aspect ratio of 1000. The channels of these templates are partially filled with a metal, especially a ferromagnetic one to obtain an array of nanostructures. Metal‐deposition within such high aspect ratio pores is a great challenge but could be realized in some extent. The introduced silicon based nanocomposite offers the opportunity to change between different nano‐architectures by accurate adjustment of the electrochemical fabrication parameters. Also the size and spatial distribution of the precipitated metal‐structures within the pores can be varied by altering the galvanic deposition process. Different morphologies and varying metal fillings modify the physical properties (e.g. magnetic behaviour) of the nanocomposite system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of ultra‐thin glass‐coated amorphous microwires for HF magnetic sensor applications
Authors: Zhukov A. , Ipatov M. , Zhukova V. , García C. , Gonzalez J. , Blanco J. M.
Published: May 2008

In this paper we report novel results on magnetic properties and giant magnetoimpedance (GMI) effect at frequencies between 10 MHz and 500 MHz in ultra‐thin Co–Fe‐rich amorphous glass‐coated microwires with near‐zero magnetostriction constant and with metallic nucleus diameter ranging between 5 μm and 22 μm. Co67.05Fe3.84Ni1.44Si14.47B11.51Mo1.69 glass‐coated amorphous microwires with metallic nucleus diameter ranging between 5 μm and 22 μm and total diameter between 10 μm and 23 μm with vanishing magnetostriction constant of the order of –(1–3) × 10–7 fabricated by the Taylor–Ulitovsky method were studied. Most of the samples studied exhibited excellent soft magnetic behaviour and a large GMI effect. Off‐diagonal components, real and imaginary parts of the GMI were analysed. Even in the thicker samples (metallic nucleus 22 μm) the penetration skin depth calculated from the GMI curves at 30 MHz was about 1 μm. Therefore the surface magnetization process and surface defects are of special importance to achieve good HF properties in these wires. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New non‐volatile logic based on spin‐MTJ
Authors: Zhao Weisheng , Belhaire Eric , Chappert Claude , Jacquet François , Mazoyer Pascale
Published: May 2008

As the minimum dimensions of complementary metal oxide semiconductor (CMOS) transistors shrink down to 90 nm and below, some physical obstacles have been observed which prevent rigidly this miniaturization. For example, high transistor leakage currents lead to an important increase of the ‘idle’ power consumption of CMOS memory arrays. Many nanodevices are therefore the subject of research and development to help CMOS technology continue to downscale by Moore's law. Among them, the magnetic tunnel junction (MTJ) is one of the most promising candidates, because its non‐volatility offers the possibility to power off the chip to greatly reduce the ‘idle’ energy dissipation of conventional CMOS circuits. Moreover, its resistance value property (several kΩ), compatible with CMOS transistor conductivity, allows its states to be sensed easily with CMOS circuits. The novel spin transfer torque (STT) writing approach, which has been recently introduced and developed, reduces significantly the switching energy and data disturbance when compared with the conventional MTJ writing approach. It makes the MTJ technology much more suitable than other nanodevices for commercial applications. In this paper, hybrid STT‐based MTJ (spin‐MTJ)/CMOS logic circuits and some design techniques are proposed based on STMicroelectronics 90 nm CMOS technology and the published Hitachi spin‐MTJ technology. A first prototype has been simulated and evaluated. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrodeposition study of ODN:SWCNT hybrids on gold substrates
Authors: Lahiji Roya R. , Dolash Bridget D. , McDonald Jennifer , Zemlyanov Dmitry , Bergstrom Donald E. , Reifenberger R.
Published: May 2008

Sonication of short single‐stranded DNA (oligodeoxyribonucleotide; ODN) with Single‐Walled Carbon Nanotubes (SWCNTs) greatly facilitates the dispersion of SWCNTs from entangled ropes in an aqueous solution, creating ODN:SWCNT hybrids. Electrodeposition has been investigated to determine if well‐dispersed ODN:SWCNT hybrids on a metal substrate can be created. Preliminary studies indicate that electrodeposition using an Au substrate held at +0.5 V produces ODN:SWCNT hybrids that are uniformly deposited across the Au substrate. This result can be compared to samples produced by drop casting and evaporation techniques which yield a thick tangled mat of ODN:SWCNT hybrids across the substrate. The resulting electrodeposited samples were characterized using Scanning Probe Microscope (SPM) and X‐ray Photoemission Spectroscopy (XPS) techniques. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pharmacokinetic parameters estimation using adaptive Bayesian P‐splines models
Authors: Jullion Astrid , Lambert Philippe , Beck Benoit , Vandenhende F.
Published: May 2008

In preclinical and clinical experiments, pharmacokinetic (PK) studies are designed to analyse the evolution of drug concentration in plasma over time i.e. the PK profile. Some PK parameters are estimated in order to summarize the complete drug's kinetic profile: area under the curve (AUC), maximal concentration (Cmax), time at which the maximal concentration occurs (tmax) and half‐life time (t1/2).

Several methods have been proposed to estimate these PK parameters. A first method relies on interpolating between observed concentrations. The interpolation method is often chosen linear. This method is simple and fast. Another method relies on compartmental modelling. In this case, nonlinear methods are used to estimate parameters of a chosen compartmental model. This method provides generally good results. However, if the data are sparse and noisy, two difficulties can arise with this method. The first one is related to the choice of the suitable compartmental model given the small number of data available in preclinical experiment for instance. Second, nonlinear methods can fail to converge. Much work has been done recently to circumvent these problems (J. Pharmacokinet. Pharmacodyn. 2007; 34:229–249, Stat. Comput., to appear, Biometrical J., to appear, ESAIM P&S 2004; 8:115–131).

In this paper, we propose a Bayesian nonparametric model based on P‐splines. This method provides good PK parameters estimation, whatever be the number of available observations and the level of noise in the data. Simulations show that the proposed method provides better PK parameters estimations than the interpolation method, both in terms of bias and precision. The Bayesian nonparametric method provides also better AUC and t1/2 estimations than a correctly specified compartmental model, whereas this last method performs better in tmax and Cmax estimations.

We extend the basic model to a hierarchical one that treats the case where we have concentrations from different subjects. We are then able to get individual PK parameter estimations. Finally, with Bayesian methods, we can get easily some uncertainty measures by obtaining credibility sets for each PK parameter. Copyright © 2008 John Wiley & Sons, Ltd.
Introducing the coupling information in a limited‐area variational assimilation
Authors: Guidard Vincent , Fischer Claude
Published: May 2008

We address the problem of how to take advantage, in a limited‐area variational assimilation, of the previously‐performed global data analysis of the coupling system. We expect this information to add value to the limited‐area analysis, since, for example, the global analysis can deal with observations close to but outside the domain of interest. The global analysis is treated as an extra source of information, and we derive the full least‐square error problem for the augmented information vector. We are left with the specifications of a global analysis‐error covariance matrix and extra cross‐covariance terms, expressed in a lower‐resolution grid covering all of the coupled domain. Simplifications are proposed to make the problem algorithmically more tractable, especially in order to benefit from the advances in the ‘modelization’ of the background‐error covariance matrix. Further, we obtain a more classical minimization problem for the sum of three, instead of two, additive cost functions.

We have tested the formulation in the framework of the coupled ARPÈGE 4D‐Var and ALADIN‐France 3D‐Var systems. Objective scores with respect to radiosonde and aircraft observations give neutral or slightly positive results for the proposed method. The information‐augmented assimilation cycle produces background 6 h forecasts that are slightly closer to the verifying observations. Subjective case‐by‐case verification does not reveal a visible systematic beneficial impact on the quality of the forecasts, especially for small‐scale parameters such as precipitation. We nevertheless propose to apply the method in future to very high‐resolution assimilation systems, which are likely to be operated on fairly small domains. Copyright © 2008 Royal Meteorological Society
A linear‐stability analysis of the semi‐implicit semi‐Lagrangian discretization of the fully‐compressible equations
Authors: Payne T. J.
Published: May 2008

We give a linear‐stability analysis of the two‐time‐level semi‐implicit discretization of the adiabatic fully‐compressible equations on anf‐plane. Previous work has shown that the scheme is stable with respect to perturbations to a hydrostatic and isothermal basic state if the same time‐implicit weight is used throughout and is greater than ½. In this note, we generalize this result to the case where different time weights are used for different terms. © Crown Copyright 2008. Reproduced with the permission of the Controller of HMSO and the Queen's Printer for Scotland. Published by John Wiley & Sons, Ltd.
Limited‐memory preconditioners, with application to incremental four‐dimensional variational data assimilation
Authors: Tshimanga J. , Gratton S. , Weaver A. T. , Sartenaer A.
Published: May 2008

Incremental four‐dimensional variational assimilation (4D‐Var) is an algorithm that approximately solves a nonlinear minimization problem by solving a sequence of linearized (quadratic) minimization problems of the form

where x is the control vector, A is a symmetric positive‐definite matrix, b is a vector containing data and prior information, and c is a constant. This paper proposes a family of limited‐memory preconditioners (LMPs) for accelerating the convergence of conjugate‐gradient (CG) methods used to solve quadratic minimization problems such as those encountered in incremental 4D‐Var. The family is constructed from a set of vectors {si : i = 1, …, l}, where each si is assumed to be conjugate with respect to the (Hessian) matrix A. In incremental 4D‐Var, approximate LMPs from this family can be built using conjugate vectors generated during the CG minimization on previous outer iterations. The spectral and quasi‐Newton LMPs employed in many operational 4D‐Var systems are shown to be special cases of the family of LMPs proposed here. In addition, a new LMP based on Ritz vectors (approximate eigenvectors) is derived. The Ritz LMP can be interpreted as a stabilized version of the spectral LMP. Numerical experiments performed with a realistic global ocean 4D‐Var system are presented, to test the impact of the three different preconditioners. The Ritz LMP is shown to be more effective than, or at least as effective as, the spectral and quasi‐Newton LMPs in our 4D‐Var experiments. Our experiments also demonstrate the importance of limiting the number of CG (inner) iterations on certain outer iterations to avoid possible divergence of the cost function on the outer loop. The optimal number of CG iterations will depend on the specific preconditioner used, and can be computed a priori, albeit at the expense of several evaluations of the cost function on the outer loop. In a cycled 4D‐Var system, it may be necessary to perform this computation periodically to account for changes in the Hessian matrix arising from changes in the observing system and background‐flow field. Copyright © 2008 Royal Meteorological Society
Large‐eddy simulations of the diurnal cycle of shallow convection and cloudiness over the tropical Indian Ocean
Authors: Wang Hailong , McFarquhar Greg M.
Published: May 2008

A 3‐D non‐hydrostatic model (EULAG) with warm‐rain bulk microphysics was used to study the diurnal cycle of shallow convection and cloudiness in the trade wind boundary layer over the Indian Ocean. Simulations were initialized with soundings obtained during the Indian Ocean Experiment (INDOEX). In the absence of diurnally varying large‐scale forcing, the simulated diurnal cycles of vertical velocities, turbulent fluxes, condensation rate and cloudiness were characterized by distinct daytime reductions. Solar heating in the boundary layer stabilized the air, decreased the relative humidity and, therefore, suppressed cloud‐layer turbulence and shallow cumulus convection. As a result, the condensation rate and cloud amount were reduced. Stronger thermal updraughts and turbulent fluxes caused by solar heating in the mixed layer triggered the recovery of cloudiness in the afternoon when the instability in the cloud layer increased.

Sensitivity experiments showed that the principal cause of the daytime heating of the atmosphere and reductions in convection and cloudiness was not the diurnally varying surface fluxes nor the cloud radiative effects, but rather the gaseous absorption of solar radiation due mainly to water vapour in the spectral band of 2500–14 500 cm−1 and ozone in the ultraviolet and visible bands. Compared to the average short‐wave heating of 0.1 K day−1 due to cloud droplets, gases enhanced solar heating by about 2.0 K day−1 in the cloud layer. However, depending on its direction and magnitude, large‐scale vertical motion can highly modulate the diurnal cycles driven by solar heating, representing a big uncertainty in observing the diurnal cycle of shallow cumuli. Copyright © 2008 Royal Meteorological Society
The impact of mountain wakes on the drag exerted on downstream mountains
Authors: Wells H. , Vosper S. B. , Webster S. , Ross A. N. , Brown A. R.
Published: May 2008

The pressure drag exerted on two identical high idealised mountain ridges aligned perpendicular to the mean flow, with the second mountain lying directly downstream of the first, is investigated using a numerical model. The drag is measured for a variety of different distances between the two peaks, mountain heights and lengths and incident flows. Each two‐mountain simulation has a companion single mountain simulation, with an identical mountain and identical upstream flow, with which to compare the drag. The maximum modelled drag in the two‐mountain simulations is close to two times the drag in the single mountain case, while the minimum two‐mountain drag is similar to that exerted on the single mountain. This change in drag is a result of the wake behind the first mountain reducing the speed of the flow impacting on the second mountain. A parametrization of this effect is suggested which combines the distance between the two mountain peaks, a measure of the velocity deficit in the wake of the first mountain and the wake decay‐scale, a measure of the length‐scale over which the flow perturbation generated by the first mountain decays downwind. Copyright © 2008 Royal Meteorological Society and Crown Copyright 2008, published by John Wiley & Sons, Ltd.
A note on propagating rainfall episodes over the Bay of Bengal
Authors: Liu Changhai , Moncrieff Mitchell W. , Tuttle John D.
Published: May 2008

An observational analysis of precipitation episodes over the Bay of Bengal and the adjacent coastal region is conducted using the TRMM Real‐Time Multi‐Satellite Precipitation Analysis (MPA‐RT) products for three warm seasons (i.e. May to September for 2002–2004). Time–distance diagrams (Hovmüller diagrams) of rainfall episodes reveal frequent travelling precipitation episodes having lifetimes greatly exceeding those of individual convective systems. The majority of the episodes translate southward and many do not appear to have a steering level (i.e. they propagate in a hydraulic‐like manner), unlike those previously documented over midlatitude and tropical continents which usually have a steering level. On average, the coherent systems have a latitudinal span of 5 degrees and a 1‐day duration and a meridional propagation speed of 8 m s−1, approximately. The episodes mostly initiate over the coastal land around midday and offshore around midnight. Copyright © 2008 Royal Meteorological Society
Wind direction effects on orographic drag
Authors: Wells H. , Vosper S. B. , Ross A. N. , Brown A. R. , Webster S.
Published: May 2008

A series of idealised numerical simulations is performed to investigate the effect of wind direction on the pressure forces exerted on a high elliptical mesoscale ridge in the presence of Coriolis effects. At the Rossby number considered here (Ro ∼ 13), rotational effects have a significant impact on the flow fields, however the primary effect of rotation on the drag is to provide the asymmetry required to initiate vortex shedding when the flow is perpendicular to the mountain ridge. It is found that linear theory, although not valid for such high mountains, provides a useful scaling for the variation of drag with wind direction. For a large range of wind directions, the flow is in a high‐ (super‐linear) drag state and wave breaking, vortex shedding and upstream flow blocking are observed. However, when the flow is close to being parallel to the major axis of the mountain ridge, the drag becomes sub‐linear, and none of the above processes are seen. We show that the change from a high‐drag state to a low‐drag state can be explained in terms of the aspect ratio of the mountain, that is the ratio of the across‐flow mountain length to the along‐flow length. Finally we demonstrate that the results found for the idealised elliptical mountains also apply to a real mountain of similar dimensions. Copyright © 2008 Royal Meteorological Society and Crown Copyright 2008, published by John Wiley & Sons, Ltd.
A comparison of the static SIMS and G‐SIMS spectra of biodegradable homo‐polyesters
Authors: Ogaki R. , Green F. M. , Li S. , Vert M. , Alexander M. R. , Gilmore I. S. , Davies M. C.
Published: May 2008

Static SIMS (SSIMS) is a surface analytical technique capable of providing molecular chemical information from solids. A major barrier to the wider take‐up of the technique is the complexity associated with the interpretation of SSIMS spectra. Quality of the interpretation depends on the expertise of analysts and making references to the limited mass spectral libraries. For many materials, there are no SSIMS library spectra. A new library‐independent method, G‐SIMS, is capable of facilitating the interpretation of SSIMS data. G‐SIMS spectra contain parent fragments, which are formed without substantial degradation or rearrangements, and highlight molecular fragments, which are directly related to the surface. In our study, G‐SIMS has been tested on medically relevant biodegradable polyester series, including poly (glycolic acid) (PGA), poly‐l‐(lactic acid) (PLA), poly‐β‐(hydroxybutyrate) (PHB) and poly‐ε‐(caprolactone) (PCL). The polyester series chosen here have closely related structures, which allow us to explore the capabilities of G‐SIMS. The G‐SIMS spectra have facilitated the identification of different polyesters by exhibiting mainly characteristic ions, representative of the polymers' molecular structures. The results also indicated that for the chosen polyester series, the larger the repeating monomer structures, the smaller the maximum number of repeat units were seen in the G‐SIMS spectra. The G‐SIMS spectra for the homologous polyester series have provided an insight into the fragmentation mechanisms as a function of repeating monomer molecular weights and structures. Copyright © 2008 John Wiley & Sons, Ltd.
Keeping properties of edible oils. III. identity of trace materials adsorbed from peanut oil by chromatography on alumina
Authors: Crossley A. , Thomas A.
Published: May 2008

A peanut oil of improved quality was obtained by replacing active earth bleaching in the refining process by treatment with alumina. To determine which components of the oil were removed and modified by this treatment, the material adsorbed on the alumina was examined. Off‐flavor precursors were not concentrated, but chemical modification of precursors had taken place. Alumina treatment probably owes its effectiveness in part to removal of off‐flavor precursors and pro‐oxidants, and in part to suppression of undesirable side reactions which occur in bleaching earths. Hydroperoxides originally present in the oil were almost entirely destroyed on the alumina, and the adsorbate was found to be enriched in oxidized, hydroxylated, and unsaponifiable material. The presence of glycer‐ides containing both saturated and ॅ,ॆ unsat‐urated (and possibly traces of a,ॆ, े, ै diunsat‐urated) aldehyde groups was demonstrated. The adsorbate also contained a considerable proportion of glycerides containing polar groups, e.g. hydroxyl, in the fatty acid radicals; the bulk of these appeared to be hydroxydienoic acid. Gas liquid chromatography (GLC) of the methyl esters of the fatty acids of the adsorbate was used to detect simple oxidized fatty acids such as keto, epoxy, and hydroxy acids. Adsorption on alumina may prove to be a powerful tool for the isolation of aldehydoglycerides and glycerides of hydroxy‐acids from oils and fats.