bluuebunny/crossref_metadata_2025 huggingface dataset:
Projections from the accessory olfactory organ into the medial region of the olfactory bulb in the sea lamprey (Petromyzon marinus): A novel vertebrate sensory structure?
Authors: Ren Xiang , Chang Steven , Laframboise Alyson , Green Warren , Dubuc Réjean , Zielinski Barbara
Published: May 2009

Although four different primary olfactory pathways have been described in tetrapod vertebrates, polymorphic olfactory sensory neurons comingle in the olfactory epithelium and project axons into separate bulbar regions in teleost fish. However, spatially segregated neurons may exist in the peripheral olfactory organ of lampreys, extant representatives of ancestral jawless vertebrates. In lampreys, the caudoventral portion of the peripheral olfactory organ contains tubular diverticula, named the accessory olfactory organ (AOO). Short, ciliated AOO cells were retrogradely labelled following application of biocytin or carbocyanine dyes to the medial region of the olfactory bulb. Tracer application to eight radial locations within the layer of glomeruli with mitral cells, of the olfactory bulb, showed that AOO projections were restricted to the medial region of the olfactory bulb. The outer boundary of the AOO projection extended to the ventromedial region of glomerular neuropil in 43% of the specimens. The olfactory sensory neurons in the main olfactory epithelium projected to glomerular neuropil throughout the olfactory bulb, including sparse projections to the medial region of the olfactory bulb. This study shows that these AOO neurons and their projections in the medial region of the olfactory bulb are anatomically distinct regions of the primary olfactory pathway in the sea lamprey. J. Comp. Neurol. 516:105–116, 2009. © 2009 Wiley‐Liss, Inc.
Efferent innervation to the auditory basilar papilla of scincid lizards
Authors: Wibowo Erik , Brockhausen Jennifer , Köppl Christine
Published: May 2009

Hair cells of the inner ear of vertebrates are innervated by afferent neurons that transmit sensory information to the brain as well as efferent neurons that receive feedback from the brainstem. The function of the efferent feedback system is poorly understood and may have changed during evolution when different tetrapod groups acquired sensitivity to airborne sound and extended their hearing ranges to higher frequencies. Lizards show a unique subdivision of their basilar papilla (homologous to the mammalian organ of Corti) into a low‐frequency (<1 kHz) and a high‐frequency (approximately 1–5 kHz) region. The high‐frequency region was reported to have lost its efferent innervation, suggesting it was insignificant or even functionally detrimental at higher frequencies. We re‐examined the innervation to the basilar papilla of five species of Australian scincid lizards, by using immunohistochemistry. Anti‐choline acetyltransferase (ChAT) was used as an efferent marker. Co‐localization with anti‐synaptic vesicle protein 2 confirmed the synaptic identity of label. Cholinergic terminals were observed along the whole length of the basilar papilla, including the regions that had previously been described as devoid of efferent innervation. However, there was a clear decrease in terminal density from apical, low‐frequency to basal, high‐frequency locations. Our findings suggest that efferent innervation is a general feature of the hair cells in the basilar papilla of lizards, irrespective of tonotopic location. This re‐enforces the notion that efferent feedback control of hair cells is a fundamental and important property of all vertebrate hearing organs. J. Comp. Neurol. 516:74–85, 2009. © 2009 Wiley‐Liss, Inc.
Protein kinase D isoforms are expressed in rat and mouse primary sensory neurons and are activated by agonists of protease‐activated receptor 2
Authors: Amadesi Silvia , Grant Andrew D. , Cottrell Graeme S. , Vaksman Natalya , Poole Daniel P. , Rozengurt Enrique , Bunnett Nigel W.
Published: May 2009

Serine proteases generated during injury and inflammation cleave protease‐activated receptor 2 (PAR2) on primary sensory neurons to induce neurogenic inflammation and hyperalgesia. Hyperalgesia requires sensitization of transient receptor potential vanilloid (TRPV) ion channels by mechanisms involving phospholipase C and protein kinase C (PKC). The protein kinase D (PKD) serine/threonine kinases are activated by diacylglycerol and PKCs and can phosphorylate TRPV1. Thus, PKDs may participate in novel signal transduction pathways triggered by serine proteases during inflammation and pain. However, it is not known whether PAR2 activates PKD, and the expression of PKD isoforms by nociceptive neurons is poorly characterized. By using HEK293 cells transfected with PKDs, we found that PAR2 stimulation promoted plasma membrane translocation and phosphorylation of PKD1, PKD2, and PKD3, indicating activation. This effect was partially dependent on PKCϵ. By immunofluorescence and confocal microscopy, with antibodies against PKD1/PKD2 and PKD3 and neuronal markers, we found that PKDs were expressed in rat and mouse dorsal root ganglia (DRG) neurons, including nociceptive neurons that expressed TRPV1, PAR2, and neuropeptides. PAR2 agonist induced phosphorylation of PKD in cultured DRG neurons, indicating PKD activation. Intraplantar injection of PAR2 agonist also caused phosphorylation of PKD in neurons of lumbar DRG, confirming activation in vivo. Thus, PKD1, PKD2, and PKD3 are expressed in primary sensory neurons that mediate neurogenic inflammation and pain transmission, and PAR2 agonists activate PKDs in HEK293 cells and DRG neurons in culture and in intact animals. PKD may be a novel component of a signal transduction pathway for protease‐induced activation of nociceptive neurons and an important new target for antiinflammatory and analgesic therapies. J. Comp. Neurol. 516:141–156, 2009. © 2009 Wiley‐Liss, Inc.
Excited State Intramolecular Proton Transfer and Photophysics of a New Fluorenyl Two‐Photon Fluorescent Probe
Authors: Morales Alma R. , Schafer‐Hales Katherine J. , Yanez Ciceron O. , Bondar Mykhailo V. , Przhonska Olga V. , Marcus Adam I. , Belfield Kevin D.
Published: May 2009

The steady‐state photophysical, NMR, and two‐photon absorption (2PA) properties of a new fluorene derivative (1) containing the 2‐(2′‐hydroxyphenyl)benzothiazole (HBT) terminal construct is investigated for use as a fluorescence probe in bioimaging. A comprehensive analysis of the linear spectral properties reveals inter‐ and intramolecular hydrogen bonding and excited state intramolecular proton transfer (ESIPT) processes in the HBT substituent. A specific electronic model with a double minimum potential energy surface is consistent with the observed spectral properties. The 2PA spectra are obtained using a standard two‐photon induced fluorescence method with a femtosecond kHz laser system, affording a maximum 2PA cross section of ∼600 GM, a sufficiently high value for two‐photon fluorescence imaging. No dependence of two‐photon absorption efficiency on solvent properties and hydrogen bonding in the HBT substituent is observed. The potential use of this fluorenyl probe in bioimaging is demonstrated via one‐ and two‐photon fluorescence imaging of COS‐7 cells.
An opportunistic routing mechanism for real‐time voice service in mobile ad hoc networks
Authors: Zhen Y. , Wu M. Q. , Wu D. P. , Sun B. , Li X. Y. , Xu C. X.
Published: May 2009

The opportunistic routing mechanism can use several lossy broadcast links to support reliable transmission. In this paper, a simple opportunistic routing mechanism for real‐time multimedia services is proposed. This mechanism is based on the dynamic source routing protocol with some modifications, multiple route request, and route reply messages are used to construct the forwarder list, and the nodes within the forwarder list forward the packets which they overhear. The forwarder list is placed on the packet header in the form of a Bloom filter, which will restrict the size of the forwarder list to a constant value. There are no strict scheduling mechanisms for the forwarding order of the forwarder nodes, thus our opportunistic routing mechanism can be scalable for multiple simultaneous flows. Simulations show that our mechanism can effectively decrease the transmission times and the amount of the control messages for each packet and reduce the end‐to‐end delay for real‐time voice service, the quality of service for these services can be supported well over the unstable wireless channel. Copyright © 2009 John Wiley & Sons, Ltd.
Watching moving images specifically promotes development of medial area of secondary visual cortex in rat
Authors: Sun Baonan , Lv Bing , Dong Qiping , Wang Shiqiang , Chai Zhen
Published: May 2009

It is generally accepted that the cortex can be divided into numerous regions depending on the type of information each processes, and that specific input is effective in improving the development of related regions. In visual cortex, many subareas are distinguished on the basis of their adequate information. However, whether the development of a subarea can be specifically improved by its particular input is still largely unknown. Here, we show the specific effects of motion information on the development of the medial area of secondary visual cortex (V2M), a subarea associated with processing the movement component of visual information. Although watching a moving or a still image had similar effects in primary visual cortex, the moving image induced multistage development of V2M in dark‐reared rats: both mRNA and protein levels of GluR2 were upregulated, the density and protein content of GluR2‐positive synapses increased, and the spine density and the frequency of spontaneous excitatory postsynaptic currents (EPSCs) of pyramidal neurons in Layer 5 were elevated. Our results suggest that rats are able to identify motion information, distribute it to V2M, and then use this input to specifically improve the development of V2M. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2009
A New Synthesis of Push‐Pull Pyrroles, Their Oxidation to Stable 3H‐Pyrroles and an Unexpected Anellation Reaction
Authors: Buehrdel Gunther , Beckert Rainer , Herzigova Petra , Petrlikova Eva , Schuch Dirk , Birckner Eckhard , Goerls Helmar
Published: May 2009

A new synthesis of push‐pull pyrroles of type 5 was developed starting from bis(imidoyl chlorides) 1 and various iminodiacetic acid derivatives 3. The use of appropriate N‐trifluoroacetyl residues as protecting/activating group proved to be the method of choice for the straightforward preparation of the 3,4‐diarylamino‐1H‐pyrroles 5. When benzothiazole substructures are present in 2,5‐position of heterocycles 5, a two‐electron oxidation leads to 3H‐pyrroles of type 6 in excellent yields. However, in the case of cyano or ester groups, a further oxidative process immediately led to the new 3H‐pyrrolo[3,4‐b]quinoxalines 7 via intramolecular ring anellation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Mutagenic potency of MMS‐induced 1meA/3meC lesions in E. coli
Authors: Nieminuszczy Jadwiga , Mielecki Damian , Sikora Anna , Wrzesiński Michał , Chojnacka Aleksandra , Krwawicz Joanna , Janion Celina , Grzesiuk Elżbieta
Published: May 2009

The mutagenic activity of MMS in E. coli depends on the susceptibility of DNA bases to methylation and their repair by cellular defense systems. Among the lesions in methylated DNA is 1meA/3meC, which is recently recognized as being mutagenic. In this report, special attention is focused on the mutagenic properties of 1meA/3meC which, by the activity of AlkB‐dioxygenase, are quickly and efficiently converted to natural A/C bases in the DNA of E. coli alkB+ strains, preventing 1meA/3meC‐induced mutations. We have found that in the absence of AlkB‐mediated repair, MMS treatment results in an increased frequency of four types of base substitutions: GC→CG, GC→TA, AT→CG, and AT→TA, whereas overproduction of PolV in CC101–106 alkB−/pRW134 strains leads to a markedly elevated level of GC→TA, GC→CG, and AT→TA transversions. It has been observed that in the case of AB1157 alkB− strains, the MMS‐induced and 1meA/3meC‐dependent argE3→Arg+ reversion occurs efficiently, whereas lacZ−→ Lac+ reversion in a set of CC101–106 alkB− strains occurs with much lower frequency. We considered several reasons for this discrepancy, namely, the possible variance in the level of the PolV activity, the effect of the PolIV contents that is higher in CC101–106 than in AB1157 strains and the different genetic cell backgrounds in CC101–106 alkB− and AB1157 alkB− strains, respectively. We postulate that the difference in the number of targets undergoing mutation and different reactivity of MMS with ssDNA and dsDNA are responsible for the high (argE3→Arg+) and low (lacZ− → Lac+) frequency of MMS—induced mutations. Environ. Mol. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.
Reform of the East China power market and assessment of the market structure
Authors: Meng Qian , Haubrich Hans‐Jürgen , Tersteegen Bernd
Published: May 2009

The liberalization of the power market in East China has made much progress. From May 2004 until today, the power market in East China stepped into the stages of simulation and trial operation. In this paper, the market design is introduced and the market structure is assessed by aspects of horizontal concentration, vertical integration, and market barriers. Copyright © 2009 John Wiley & Sons, Ltd.
Electricity pricing and market power—evidence from Germany
Authors: Janssen M. , Wobben M.
Published: May 2009

The aim of this paper is to develop a methodology for measuring the exercise of potential market power in liberalized electricity markets. We therefore investigate producer behavior in the context of electricity pricing with respect to fundamental time‐dependent marginal cost (TMC), i.e., CO2‐ and fuel cost. In doing so, we do not—in contrast to most current approaches to market power investigation—rely on an estimate of the entire generation cost, which inevitably suffers from the lack of appropriate available data. Applying an analytical model of a day‐ahead electricity market, we derive work‐on rates, which provide information about the impact of TMC variations on electricity prices in the market constellations of perfect competition, quasi‐monopoly, and monopoly. Comparing these model‐based work‐on rates with actual work‐on rates, estimated by an adjusted first‐differences regression model of German power prices on the cost for hard coal, natural gas, and emission allowances, we find evidence of the exercise of market power in the period 2006–2008. However, our results reveal that German market competitiveness increases marginally. We confirm our results by simulating a TMC‐driven diffusion model of futures power prices estimated by maximum‐likelihood. Copyright © 2009 John Wiley & Sons, Ltd.
Algorithmic challenges and current problems in market coupling regimes
Authors: Tersteegen Bernd , Schröders Christian , Stein Sebastian , Haubrich Hans‐Jürgen
Published: May 2009

Increasing cross‐border trade at European borders has lead to the necessity of an efficient allocation of scarce cross‐border capacities. Explicit auctions used to be the commonly applied auction method in the past at most borders, but due to the separation of the trade of electrical energy and the allocation of cross‐border capacity, market inefficiencies arise. As a consequence, a trend toward a market coupling, which combines the trade of electrical energy with the allocation of cross‐border capacity, can be observed across Europe. The most convincing approach to solve the complex optimization task associated with market couplings solves the problem by a maximization of the system‐wide welfare based on a closed‐form optimization. Practical experience shows that problems remain with such an approach. This paper thoroughly analyzes problems that may occur in market coupling regimes with a closed‐form optimization. In this paper an extension of formerly presented formulations of the optimization problem is presented, which avoids the described problems. The extended formulation still assures practically feasible calculation times of far less than 10 minutes even for systems with up to 12 market areas. Further, a fair and transparent approach to determine feasible market clearing prices not neglecting the time and market coupling relationship between prices is shown in this paper and it is demonstrated that this approach does not lead to practically infeasible calculation times. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of manure and mineral fertilisation on pepper nutritional quality
Authors: Flores Pilar , Hellin Pilar , Fenoll Jose
Published: May 2009

BACKGROUND: The influence of farming systems on fruit quality remains controversial and the different aspects associated with each agricultural management system need to be studied separately to elucidate any specific effect on fruit quality. To this end, a greenhouse experiment was conducted to examine the effect of the usual fertilisation guidelines for pepper cultivation on the nutritional quality of fruits (sugars, vitamin C, total phenolic compounds, chlorophylls, total carotenoids and antioxidant activities in the hydrophilic (HAA) and lipophilic (LAA) fractions). Treatments included manure amendment combined with synthetic fertiliser applied at the rates recommended for organic (T1), low‐input (T2) and conventional (T3) practices.

RESULTS: Pepper composition was not affected by increasing mineral fertilisation. In addition, treatment had no significant effect on HAA or LAA. The antioxidant activity of both the hydrophilic and lipophilic fractions increased from the green to the red stage of ripening. HAA contributed about 80% of the total antioxidant activity.

CONCLUSION: Pepper response to mineral fertilisation seems to be less pronounced than that of other fruits, since antioxidant concentrations did not increase with increasing fertiliser application. Antioxidant activity in pepper was mainly linked to hydrophilic compounds (vitamin C and phenolic compounds). Ripening was the most important factor determining the fruit antioxidant composition. Copyright © 2009 Society of Chemical Industry
Inhibition action of tween‐80 on the corrosion of cold rolled steel in sulfuric acid
Authors: Li X. H. , Deng S. D. , Fu H. , Mu G. N.
Published: May 2009

The inhibition action of a nonionic surfactant of tween‐80 on the corrosion of cold rolled steel (CRS) in sulfuric acid (H2SO4) has been investigated by weight loss and potentiodynamic polarization methods. Atomic force microscope (AFM) provided the CRS surface conditions. The results show that tween‐80 is a good inhibitor in 1.0 M H2SO4, and its adsorption obeys Langmuir adsorption isotherm. Effects of temperature (20–50 °C) and acid concentration (0.5–7.0 M) on the inhibition action were investigated. Polarization curves show that tween‐80 is a mixed‐type inhibitor in sulfuric acid, but prominently inhibits the cathodic reaction. The results obtained from weight loss and potentiodynamic polarization are consistent, and the inhibition action could also be evidenced by AFM images.
Quantum chemical studies of some amino acids on the corrosion of cobalt in sulfuric acid solution
Authors: Gece G. , Bilgiç S. , Türkşen Ö.
Published: May 2009

The inhibitive effect of some amino acids, glycine (Gly), alanine (Ala), valine (Val), leucine (Leu), isoleucine (Ile), serine (Ser), threonine (Thr), methionine (Met), phenylalanine (Phe), tyrosine (Tyr), trytophan (Try), aspartic acid (Asp), asparagine (Asn), glutamic acid (Glu), and lysine (Lys) against the corrosion of cobalt surface is studied by means of semiempirical and density functional methods. The calculated quantum chemical parameters correlated to the inhibition efficiency are, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), the energy gap (ΔE), and Mulliken charges. It is found that the calculated results satisfactorily support the experimental findings.
Modal‐type orthomodular logic
Authors: Domenech Graciela , Freytes Hector , de Ronde Christian
Published: May 2009

In this paper we enrich the orthomodular structure by adding a modal operator, following a physical motivation. A logical system is developed, obtaining algebraic completeness and completeness with respect to a Kripkestyle semantic founded on Baer*‐semigroups as in [22] (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Weak‐quasi‐Stone algebras
Authors: Celani Sergio A. , Cabrer Leonardo M.
Published: May 2009

In this paper we shall introduce the variety WQS of weak‐quasi‐Stone algebras as a generalization of the variety QS of quasi‐Stone algebras introduced in [9]. We shall apply the Priestley duality developed in [4] for the variety N of ¬‐lattices to give a duality for WQS. We prove that a weak‐quasi‐Stone algebra is characterized by a property of the set of its regular elements, as well by mean of some principal lattice congruences. We will also determine the simple and subdirectly irreducible algebras (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elementary explicit types and polynomial time operations
Authors: Spescha Daria , Strahm Thomas
Published: May 2009

This paper studies systems of explicit mathematics as introduced by Feferman [9, 11]. In particular, we propose weak explicit type systems with a restricted form of elementary comprehension whose provably terminating operations coincide with the functions on binary words that are computable in polynomial time. The systems considered are natural extensions of the first‐order applicative theories introduced in Strahm [19, 20] (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Splitting stationary sets from weak forms of Choice
Authors: Larson Paul , Shelah Saharon
Published: May 2009

Working in the context of restricted forms of the Axiom of Choice, we consider the problem of splitting the ordinals below λ of cofinality θ into λ many stationary sets, where θ < λ are regular cardinals. This is a continuation of [4] (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Distributed control of performance management traffic with accuracy objectives
Authors: Jagadish Chundury , Gonsalves Timothy A.
Published: May 2009

One of the important functions of a network management system (NMS) is performance management (PM). PM deals with collecting statistical information to track the effectiveness and utilization of the network and network elements (NE). While this may be done offline, it is often necessary to monitor the network statistics online in real time. The aim of real‐time monitoring is to achieve high accuracy of the statistics while minimizing the use of scarce network bandwidth. The accuracy objective can vary depending on the priority and dynamic severity state of the NE. We define cost, which needs to be optimized, as a function of network traffic and achieved accuracy. Based on the cost, a comparison of push and pull data collection alternatives is done. We have developed a push‐based distributed data collection system that tunes the accuracy objectives, based on the network traffic and the dynamic severity state of the NE. Copyright © 2009 John Wiley & Sons, Ltd.
Characterization of bulk agro‐green composites: Sisal fiber reinforced wheat flour thermoplastics
Authors: Sreekumar P.A.  , Leblanc Nathalie , Saiter Jean M.
Published: May 2009

Starch based thermoplastic composites reinforced by short sisal fibers having length less than 1 mm were fabricated by extrusion followed by compression molding. The sisal fiber content varied from 0 to 10% w/w keeping the amount of glycerol (plasticizer) as constant (23% w/w). Investigation proved that an increase in the amount of sisal fibers will decrease the ductile nature of composites. The Young's modulus and hardness value increases as a function of fiber content. The impact strength varied as a function of fiber content. Contact angle analysis showed that incorporation of sisal fibers to the matrix increases its hydrophilic nature. The polar factor and total surface energy increases as a function of fiber content whereas dispersive factor decreases. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Melt‐blowing thermoplastic polyurethane and polyether‐block‐amide elastomers: Effect of processing conditions and crystallization on web properties
Authors: Begenir Asli , Michielsen Stephen , Pourdeyhimi Behnam
Published: May 2009

Melt‐blown webs from ester and ether thermoplastic polyurethanes and polyether‐block‐amide (PEBA) elastomers were produced at different die‐to‐collector distances (DCD) to study the correlation between the polymer type and hardness, melt‐blowing process conditions, and web properties. An experimental set up was built to measure the air temperature and velocity profiles below and across the melt‐blowing die to correlate the fiber formation process and polymer crystallization behavior to process conditions and web properties. It was shown that air temperature and velocity profiles follow similar trends with increasing distance below the melt‐blowing die: both drop rapidly until reaching a plateau region approximately 5–6 cm below the die. Thereafter, they remain relatively constant with further increasing distance. It was found that crystallization onset and peak temperatures of all block copolymers in this study fall within this region of rapid velocity and temperature drop. This suggests that the polymers have already started to crystallize and solidify before reaching the collector, the extent of which depends on the crystallization kinetics of the polymer. The strong influence of the crystallization kinetics on web strength was clearly demonstrated in the PEBA series. In particular, the hardest grade produced the lowest web strength mainly because of its high crystallization rate and crystallization onset temperature. It is concluded that the melt‐blown web strength is strongly dependent on the degree of fiber‐to‐fiber adhesion within the web, which is determined by the amount of fiber solidification that occurs prior to the collector. The crystallization kinetics of the polymer and the distances traveled between the die and collector or the exposure time of the polymer melt to process and ambient air were shown to be critical in the amount of fiber solidification attained. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Study on the creep behavior of polypropylene
Authors: Liu Xiaolin , Huang Yajiang , Deng Cong , Wang Xiaojun , Tong Wei , Liu Yuxin , Huang Jianqian , Yang Qi , Liao Xia , Li Guangxian
Published: May 2009

The creep behavior and creep failure law of polypropylene (PP) were investigated by using a multifunctional stress‐aging testing machine under different aging environmental conditions (temperature, UV, and stress). Photoinduced changes in samples were studied using gel permeation chromatography and X‐ray photoelectron spectrometer. Surface morphologies were also observed by scanning electron microscopy. It was found that there is a critical failure strain (εcrit) for PP during the creep course. Once the creep deformation exceeds the εcrit, creep failure of PP takes place very rapidly. The value of εcrit is independent of the tensile stress and UV irradiation, whereas it is only affected by the temperature and the nature of the PP, such as molecular weight and molecular structure. With increasing temperature, the value of εcrit increases gradually. In addition, the creep rate of PP increases rapidly with increasing tensile stress and temperature as well as under irradiation with UV light. This study may provide a new way to predict the service lifetime of PP. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
In‐situ synthesis of poly(ethylene terephthalate)/clay nanocomposites using TiO2/SiO2 sol‐intercalated montmorillonite as polycondensation catalyst
Authors: Yin Ming , Li Chuncheng , Guan Guohu , Yuan Xuepei , Zhang Dong , Xiao Yaonan
Published: May 2009

A novel organic montmorillonite, which could act as both polycondensation catalyst of poly(ethylene terephthalate) (PET) and filler of PET/clay nanocomposites, was prepared. Original montmorillonite was first treated with different amounts of poly(vinylpyrrolidone) (PVP), and then intercalated by TiO2/SiO2 sol to gain polycondensation catalytic activity. The acquired clay possessed excellent thermal stability and would not degrade during the polycondensation step. PET/clay nanocomposites were prepared via in‐situ polymerization using the organo‐clay as polycondensation catalysts. The morphologies of the nanocomposites were characterized by X‐ray diffraction and transmission electron microscope. The results indicated that the amount of PVP and TiO2/SiO2 sol strongly affected the dispersion state of the clay, and finally, partially exfoliated PET/clay nanocomposites were obtained. The nanocomposites had better properties than pure PET due to the incorporation of the delaminated clay layers. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Monomer/polymer Schiff base copper(II) complexes for catalytic oxidative polymerization of 2,2′‐dihydroxybiphenyl
Authors: Bi̇li̇ci̇ Ali̇ , Kaya İsmet , Doğan Fati̇h
Published: May 2009

Catalytic oxidative polymerization of 2,2′‐dihydroxybiphenyl (DHBP) was performed by using both the Schiff base monomer‐Cu(II) complex and Schiff base polymer‐Cu(II) complex compounds as catalysts and hydrogen peroxide as oxidant, respectively. The dependence of monomer conversion and molecular weight distribution on various reaction parameters, including time, temperature, solvent as well as the amount of catalyst and oxidant were investigated. The structure of the poly‐2,2′‐dihydroxybiphenyl (PDHBP) was confirmed by UV‐vis, IR, 1H and 13C NMR spectroscopy techniques. The electrochemical and thermal properties of PDHBP were also studied. DSC data revealed that PDHBP was amorphous. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2977–2984, 2009
Electrochemical synthesis of PEDOT derivatives bearing imidazolium‐ionic liquid moieties
Authors: Döbbelin Markus , Pozo‐Gonzalo Cristina , Marcilla Rebeca , Blanco Raúl , Segura José L. , Pomposo Jose A. , Mecerreyes David
Published: May 2009

Novel poly(3,4‐ethylenedioxythiophene) (PEDOT) polymers bearing imidazolium‐ionic liquid moieties were synthesized by electrochemical polymerizations. For this purpose, new functional monomers were synthesized having an 3,4‐ethylenedioxythiophene (EDOT) unit and an imidazolium‐ionic liquid with different anions such as tetrafluoroborate (BF), bis(trifluoromethane)sulfonimide ((CF3SO2)2N−), and hexafluorophosphate (PF). Next, polymer films were obtained by electrochemical synthesis in dicholoromethane solutions. Obtained polymers were characterized, revealing the characteristics of PEDOT in terms of electrochemical and spectroelectrochemical properties, FTIR, 1H NMR, and AFM microscopy. Interestingly, the hydrophobic character of electropolymerized films could be modified depending on the anion type. The hydrophobicity followed the trend PF > (CF3SO2)2N− > BF > pure PEDOT as determined by water contact angle measurements. Furthermore, the polymers could be dissolved in a range of polar organic solvents such as dimethylformamide, propylene carbonate, and dimethyl sulfoxide making these polymers interesting candidates for wet processing methods. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3010–3021, 2009
Synthesis and characterization of amphiphilic poly(N‐vinyl pyrrolidone)‐b‐poly(ε‐caprolactone) copolymers by a combination of cobalt‐mediated radical polymerization and ring‐opening polymerization
Authors: Jeon Hyun Jeong , You Young Chang , Youk Ji Ho
Published: May 2009

An amphiphilic block copolymer of poly(N‐vinyl pyrrolidone)‐b‐poly(ε‐caprolactone) (PVP‐b‐PCL) was synthesized by a combination of cobalt‐mediated radical polymerization (CMRP) and ring‐opening polymerization (ROP). The micellar characteristics of this copolymer were subsequently investigated. PVP (Mn = 11,400, Mw/Mn = 1.32) was synthesized at 20 °C via CMRP using a molar ratio of [VP]0/[V‐70]0/[Co]0 = 150/8/1. The PVP was then reacted with 2,2′‐azobis[2‐methyl‐N‐(2‐hydroxyethyl)propionamide] (VA‐086) to modify its cobalt complex chain end to a hydroxyl group. The cobalt (Co) content in the resulting PVP‐OH was 1.2 ppm, indicating that all of the covalent CoC bonds were cleaved and reacted with VA‐086, and that the separated cobalt complexes were successfully removed. The ROP of CL was subsequently carried out using the produced PVP‐OH as a macroinitiator at 110 °C. The GPC trace of PVP‐b‐PCL was monomodal without any tailing caused by the residual PVP‐OH, indicating that the initiation efficiency was very high. The critical micelle concentration (CMC) of PVP‐b‐PCL (Mn = 18,000, Mw/Mn = 1.35) was 0.015 mg/mL. The PVP‐b‐PCL micelles were spherical in shape with an average diameter of 105 nm. The nanosized PVP‐b‐PCL micelles show promise as novel drug carriers in biomedical and pharmaceutical applications. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3078–3085, 2009
PPEGMEA‐g‐PDEAEMA: Double hydrophilic double‐grafted copolymer stimuli‐responsive to both pH and salinity
Authors: Gu Lina , Feng Chun , Yang Dong , Li Yaogong , Hu Jianhua , Lu Guolin , Huang Xiaoyu
Published: May 2009

A series of well‐defined double hydrophilic double‐grafted copolymers, consisting of polyacrylate backbone, hydrophilic poly(2‐(diethylamino)ethyl methacrylate) and poly(ethylene glycol) side chains, were synthesized by successive atom transfer radical polymerization. The backbone, poly[poly(ethylene glycol) methyl ether acrylate] (PPEGMEA) comb copolymer, was firstly prepared by ATRP of PEGMEA macromonomer via the grafting‐through route followed by reacting with lithium diisopropylamide and 2‐bromopropionyl chloride to give PPEGMEA‐Br macroinitiator of ATRP. Finally, poly[poly(ethylene glycol) methyl ether acrylate]‐g‐poly(2‐(diethylamino)ethyl methacrylate) graft copolymers were synthesized by ATRP of 2‐(diethylamino)ethyl methacrylate using PPEGMEA‐Br macroinitiator via the grafting‐from route. Poly(2‐(diethylamino)ethyl methacrylate) side chains were connected to polyacrylate backbone through stable CC bonds instead of ester connections, which is tolerant of both acidic and basic environment. The molecular weights of both backbone and side chains were controllable and the molecular weight distributions kept relatively narrow (Mw/Mn ≤ 1.39). The results of fluorescence spectroscopy, dynamic laser light scattering and transmission electron microscopy showed this double hydrophilic copolymer was stimuli‐responsive to both pH and salinity. It can aggregate to form reversible micelles in basic surroundings which can be conveniently dissociated with the addition of salt at room temperature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3142–3153, 2009
Toll‐like receptor 4‐mediated immunoregulation by the aqueous extract of Mori Fructus
Authors: Yang Xin‐Ying , Park Gil‐Soon , Lee Moo Hyung , Chang In Ae , Kim Youn Chul , Kim Sung Yeon , Lee Joo Young , Yun Yong Gab , Park Hyun
Published: May 2009

The aqueous extract of Mori Fructus (MF) exerts a change of phenotype and a cytoprotective effect in macrophages. The present study was carried out to investigate the immunomodulating activity of MF on the expression of nitric oxide (NO), tumor necrosis factor alpha (TNF‐α), co‐stimulatory molecules and also interferon‐gamma (IFN‐γ) in macrophages and splenocytes. Toll‐like receptor 4 (TLR4) is a promising molecular target for immune‐modulating drugs. It was hypothesized that one possible upstream signaling pathway leading to immunoregulation of MF may be mediated by TLRs. Multiple signaling molecules (NF‐κB, ERK1/2, p38 and JNK) of the TLR4 signaling pathway were also detected. It was found that MF increased NO production and TNF‐α secretion in RAW 264.7 and peritoneal macrophages, co‐stimulatory molecules expression in peritoneal macrophages and IFN‐γ expression in splenocytes. Further studies indicated that MF could significantly induce the phosphorylation of signal molecules of MAPKs and the degradation of IκBα which finally led to the activation and nuclear translocation of nuclear factor‐κB (NF‐κB) for the target gene expression. All those notions disclosed that the aqueous extract MF is a new TLR4 activator, which induces a Th1 immune response as a consequence of induction of cytokines secretion, especially TNF‐α and IFN‐γ. Copyright © 2009 John Wiley & Sons, Ltd.
Danshen extracts decrease blood c reactive protein and prevent ischemic stroke recurrence: a controlled pilot study
Authors: Xu Gelin , Zhao Wenxin , Zhou Zhiming , Zhang Renliang , Zhu Wusheng , Liu Xinfeng
Published: May 2009

The efficacy of a danshen (Salvia miltiorrhiza) dripping pill (DDP) for secondary stroke prevention was evaluated in patients with ischemic cerebrovascular disease. The preparation also contained Panax notoginseng (sanqi) and Dryobalanops camphor. Patients who had suffered from ischemic stroke or a transient ischemic attack (TIA) within the previous 20 days were managed according to established guidelines, and were divided into groups to receive either DDP or non‐DDP treatment according to their time of enrolment. Mortality, cerebrovascular events and any suspected adverse reactions during the 1‐year follow‐up were recorded and analysed. Hematological and hemorheological parameters were measured at the start of the study (baseline) and the end of the follow‐up period. A total of 106 patients with ischemic stroke/TIA were enrolled, of which 52 were allocated to take DDP and 54 were in the control group. Recurrent stroke/TIA was observed in five patients (9.6%) with DDP and in 13 patients (24.1%) without DDP during the follow‐up. Recurrence in the patient group taking DDP was lower than that in the control group (p < 0.05). No significant differences in intracranial hemorrhage and mortality were detected between groups (p > 0.05). Blood C reactive protein decreased significantly in patients with DDP compared with patients without DDP. These results indicate that DDP treatment may reduce the risk for stroke/TIA recurrence, and this reduction of risk may be associated with its antiinflammatory effects. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of palm oil on doxorubicin induced cytotoxicity in normal and tumor cell cultures
Authors: Dan Postescu Ion , Virag Piroska , Achim Marcela , Fischer‐Fodor Eva
Published: May 2009

The vitamin E of palm oil, unlike most other vegetal fats, consists largely of tocotrienols (TT), products previously reported as having antioxidant and tumor‐inhibitory properties. A tocotrienols containing palm oil, in the form of liposomes entrapping dosages of 0.5–0.05 µgTT/mL, was studied in combined treatments with doxorubicin (30 min before drug administration). The IC50 values of doxorubicin, at 24 h, showed that its cytotoxic effects were decreased by palm oil, in a dose effect relationship (p < 0.01, ANOVA), in both normal (Hfl‐1, Huvec) and tumor (HepG2, Mls) cells. These results demonstrated an unselective protective activity of tocotrienols, in vitro, on some normal and tumor cultured cells treated with doxorubicin. Copyright © 2009 John Wiley & Sons, Ltd.
A simple strategy for linearizing complex moist convective schemes
Authors: Mahfouf J.‐F. , Bilodeau B.
Published: May 2009

Variational data assimilation methods and related applications depend on the validity of the tangent‐linear approximation, which is truly challenging when applied to deep moist convection. A simple strategy for linearizing complex moist convective schemes in numerical weather prediction models is proposed. This strategy represents a trade‐off between code development and maintenance on the one hand and expected benefit on the other hand. The generic linearized scheme described hereafter can be used in conjunction with any nonlinear moist convective scheme, thus eliminating the need to linearize complex codes. The universality of the scheme stems from the fact that conditional triggers and cloud vertical extent are supplied by the trajectory of the nonlinear scheme. In active columns, the convective tendencies cancel the large‐scale dynamical tendencies. Potential uses of the scheme include variational data assimilation and diagnostic studies such as tropical singular vectors and key analysis errors with precipitation. The relevance of the methodology is examined with the Global Environmental Multiscale model using the Kain–Fritsch mass‐flux scheme that is operational at the Canadian Meteorological Centre. It is shown that the tangent‐linear approximation is improved when compared to a linearized convection scheme having its own trigger functions. The improvement is particularly noticeable for the partition between stratiform and convective components of surface precipitation. Finally the examination of adjoint sensitivities of surface precipitation with the simplified linearized scheme triggered by the Kain–Fritsch scheme reveals a more pronounced sensitivity to midlatitude baroclinic instability and less predictability for tropical systems when compared to a Kuo‐type scheme. Copyright © 2009 Royal Meteorological Society and Crown in the Right of Canada
Physical layer security in broadcast networks
Authors: Liang Yingbin , Poor H. Vincent , Shamai (Shitz) Shlomo
Published: May 2009

This paper reviews the information theoretic characterization of security in broadcast channels, in which a transmitter has both public and confidential messages intended for multiple receivers. All messages must be successfully received by their intended receivers, and the confidential messages must be kept as secret as possible from non‐intended recipients. Various scenarios are considered in the context of two‐user broadcast channels, for which known results on the secrecy capacity region are reviewed and corresponding coding schemes for achieving rates in these regions are described. Copyright © 2009 John Wiley & Sons, Ltd.
A multilevel perspective on knowledge transfer: evidence from the Chinese automotive industry
Authors: Jane Zhao Zheng , Anand Jaideep
Published: May 2009

We adopt a multilevel perspective to study the transfer of collective and individual knowledge. By making a clear theoretical distinction between collective and individual attributes in concepts such as knowledge, teaching approach, and absorptive capacity, this study extends the knowledge transfer literature and provides fresh insights into the ways in which collective and individual knowledge are transferred. Based on a survey of the capability transfer activities of 161 engineering units of multinationals in the Chinese automotive industry, we empirically validate the distinction between individual and collective teaching activities and absorptive capacity. More importantly, we find that the largely underexplored collective‐level mechanisms, such as collective teaching and collective absorptive capacity, are more effective in transferring both collective knowledge and individual knowledge in comparison to their individual‐based counterparts. Our findings also have important implications for management of multinationals and international joint ventures, particularly in emerging economies. Copyright © 2009 John Wiley & Sons, Ltd.
Exercise Increases Neural Stem Cell Number in a Growth Hormone-Dependent Manner, Augmenting the Regenerative Response in Aged Mice
Authors: Blackmore Daniel G. , Golmohammadi Mohammad G. , Large Beatrice , Waters Michael J. , Rietze Rodney L.
Published: May 2009

The exercise-induced enhancement of learning and memory, and its ability to slow age-related cognitive decline in humans led us to investigate whether running stimulates periventricular (PVR) neural stem cells (NSCs) in aging mice, thereby augmenting the regenerative capacity of the brain. To establish a benchmark of normal aging on endogenous NSCs, we harvested the PVR from serial vibratome sections through the lateral ventricles of juvenile (6-8 weeks), 6-, 12-, 18-, and 24-month-old mice, culturing the cells in the neural colony-forming cell assay. A significant decline in NSC frequency was apparent by 6 months (∼40%), ultimately resulting in a ∼90% reduction by 24 months. Concurrent with this decline was a progressive loss in regenerative capacity, as reflected by an incomplete repopulation of neurosphere-forming cells following gamma cell irradiation-induced depletion of the PVR. However, voluntary exercise (i.e., 21 days of running) significantly increased NSC frequency in mice ≥ 18 months of age, augmenting the regeneration of irradiation-ablated periventricular cells and restoring NSC numbers to youthful levels. Importantly, and consistent with the demonstrated ability of growth hormone (GH) to increase NSC proliferation, and the elevated secretion of GH during exercise, exercise failed to stimulate NSCs in GH receptor-null mice. These findings now provide a novel basis for understanding the ability of exercise to delay the onset and rate of decline in neurodegenerative conditions not typically associated with the hippocampus and suggest that the GH-dependent activation of endogenous NSCs may be effective in reversing or preventing age-related neurodegeneration in humans.

Disclosure of potential conflicts of interest is found at the end of this article.
Lagrangean relaxation for service location in large‐scale networks with QoS constraints
Authors: Kamal Zille Huma , Al‐Fuqaha Ala , Gupta Ajay
Published: May 2009

Current trends in computing indicate that there is a great potential for service‐oriented computing and similar technologies, such as application‐oriented networks (AONs), where services can relocate to adapt to the conditions of the underlying network. In such environments, providing and consuming services and establishing a relationship between consumers (users of services) and producers (providers of services) are still challenging and vastly researched aspects.

Bearing this in mind, we define a service location and planning (SLP) problem that uniquely matches producers to consumers and accounts for realistic parameters such as, quality of service (QoS) constraints of throughput and delay, and network constraints of underlying link layer bandwidth capacities, and cost of meeting consumer requests.

Our contribution lies in the mathematical formulation of the SLP problem as an integer linear programming (ILP) problem that can be solved optimally for small‐scale networks and extending this work using Lagrangean relaxation (LR) approximation techniques to solve the SLP problem for large‐scale networks. Copyright © 2009 John Wiley & Sons, Ltd.
Up‐regulation of ZO‐1 expression and barrier function in cultured human corneal epithelial cells by substance P
Authors: Ko Ji-Ae , Yanai Ryoji , Nishida Teruo
Published: May 2009

The effects of the sensory neurotransmitter substance P on the expression of tight junction proteins and on barrier function in human corneal epithelial cells were investigated. The expression of ZO‐1, but not that of occludin or claudin‐1, was increased by substance P in a concentration‐ and time‐dependent manner. This effect was inhibited by the NK‐1 receptor antagonist GR82334 and by KN62, an inhibitor of Ca2+‐ and calmodulin‐dependent protein kinase II. Substance P also increased the transepithelial electrical resistance of a cell monolayer in a manner sensitive to GR82334. Substance P may therefore play a role in maintenance of tight junctions in the corneal epithelium.