bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual stimulation enhances auditory processing in 3‐month‐old infants and adults
Authors: Hyde Daniel C. , Jones Blake L. , Porter Chris L. , Flom Ross
Published: December 2009

Behavioral work demonstrates human infants are sensitive to a host of intersensory properties and this sensitivity promotes early learning and memory. However, little is known regarding the neural basis of this ability in infants. Using event‐related potentials (ERPs) with infants and adults, we show that during passive viewing auditory evoked brain responses are increased with the presence of simultaneous visual stimulation. Results converge with previous adult neuroimaging studies, single‐cell recordings in nonhuman animals, and behavioral studies with human infants to provide evidence for an elevated status of multisensory stimulation in infancy. Furthermore, these results may provide a neural marker of multisensory audio‐visual processing in infants that can be used to test developmental theories of how information is integrated across the senses to form a unitary perception of the world. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 52:181–189, 2010
The effect of taste familiarity on intake and taste reactivity in infant rats
Authors: Diaz‐Cenzano Elena , Chotro M. Gabriela
Published: December 2009

With infant rats, unlike with adults, increased intake of a taste after mere exposure to this stimulus is not consistently found; this has sometimes been interpreted as a failure by the immature subject to recognize tastes as familiar. We studied the effect of preexposure to a tastant, measuring taste reactivity and intake in 14‐day‐old rats. Familiarity increased hedonic response to sucrose, but also increased aversive response to quinine and ethanol. With the sucrose‐quinine compound, familiarity increased both the hedonic and the aversive reaction to the stimulus. In no case was a differential reactivity to water observed. Significant increased intake after familiarization was only found with quinine or the sucrose‐quinine compound. Results indicate that in infant rats, and with the present parameters, taste familiarity enhances responsiveness to these stimuli, an effect not always accompanied by detectable changes in intake. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 52:109–120, 2010
Snowbrush (Ceanothus velutinus Dougl) effects on nitrogen availability in soils and solutions from a Sierran ecosystem
Authors: Stein C. M. , Johnson D. W. , Miller W. W. , Powers R. F. , Young D. A. , Glass D. W.
Published: December 2009

The presence of nitrogen (N) fixing vegetation can have significant deleterious effects on water quality and also soil leaching. This study investigates the effects of snowbrush (Ceanothus velutinus Dougl.), a common post‐disturbance N fixer in the western United States, on water quality and soil leaching. We compared mineral N concentrations in soil solution, runoff, O horizon leachates and resin lysimeters in adjacent snowbrush and Jeffrey pine (Pinus jeffreyii Grev. & Balf) stands in one site in the eastern Sierra Nevada Mountains in Nevada. Soil solutions from snowbrush had slightly but not significantly greater NO3− concentrations than those from Jeffrey pine. Leaching rates of NO3− and NH4+ measured by resin lysimeters were lower in snowbrush than in Jeffrey pine, and leaching rates in mineral soil (15 cm) were not significantly different. Nitrate and NH4+ concentrations in runoff were greater in the snowbrush than Jeffrey pine, and ancillary field column studies confirmed that snowbrush litter was the primary source of this elevated mineral N. Cutting, followed by mastication and herbicide treatments had no effect on mineral N leaching in a snowbrush stand growing on a recently burned (1994) site in the eastern Sierra Nevada Mountains of California. We conclude from this and previous studies that snowbrush, unlike some other post‐disturbance N‐fixing species, has minimal and inconsistent effects on water quality in the eastern Sierra Nevada Mountains. Copyright © 2009 John Wiley & Sons, Ltd.
Water Dissociation and Dioxygen Binding in Phenylalanine Hydroxylase
Authors: Olsson Elaine , Martinez Aurora , Teigen Knut , Jensen Vidar R.
Published: December 2009

Phenylalanine hydroxylase (PAH) catalyzes the hydroxylation of L‐phenylalanine to L‐tyrosine and is dependent on the contribution of electrons from the reduced cofactor tetrahydrobiopterin (BH4). Whereas three ligating water molecules are bound to the central iron atom in the existing crystal structures of binary complexes of the catalytic domain of both the inactive, PAH–FeIII–BH2, and active, PAH–FeII–BH4, forms of the human enzyme, previous spectroscopic studies show that the water molecules dissociate prior to the onset of the catalytic reaction. In the present study, starting from a cluster model of the active FeII center of PAH, three successive water ligand dissociations followed by dioxygen coordination have been investigated by using density functional theory. The calculations show that the formation of the active, water‐free O2 complex from the water‐ligated complex of the PAH–FeII–BH4 crystal structure is remarkably facile (ΔG = 1.5 kcal/mol). Moreover, the initial water dissociation is accompanied by entrance of the cofactor into the first coordination sphere of iron.
Dioxomolybdenum(VI) Epoxidation Catalyst Supported on Mesoporous Silica Containing Phosphane Oxide Groups
Authors: Castro Alichandra , Alonso João C. , Neves Patrícia , Valente Anabela A. , Ferreira Paula
Published: December 2009

A new mesoporous hybrid material (denoted LP‐TEPPPO‐Mo) has been prepared by tethering [MoO2Cl2] onto mesoporous silica previously functionalised with phosphane oxide spacer ligands. The LP‐TEPPPO‐Mo material was tested in the liquid‐phase epoxidation of olefins [cis‐cyclooctene, (R)‐(+)‐limonene, trans‐2‐octene and 1‐octene] with tBuOOH, at 55 °C, and without a co‐solvent, giving at least 90 % selectivity to the corresponding epoxide at 36–77 % conversion: in the case of limonene, regioselectivity favours the epoxidation of the endocyclic double bond, giving mainly 1,2‐epoxy‐p‐menth‐8‐ene. The catalytic system based on a liquid–liquid biphasic system containing the homogeneous complex [MoCl2(O)2{OP(CH2CH3)(Ph)2}2] dissolved in the ionic liquid 1‐butyl‐4‐methylpyridinium tetrafluoroborate leads to lower epoxide selectivity (91 % at 64 % conversion) in the reaction of cyclooctene in comparison to that observed for LP‐TEPPPO‐Mo (100 % at 87 % conversion). The reused solid–liquid and liquid–liquid biphasic catalytic systems show partial loss of catalytic activity.
Subvalent Organometallic Compounds of the Alkaline Earth Metals in Low Oxidation States
Authors: Krieck Sven , Yu Lian , Reiher Markus , Westerhausen Matthias
Published: December 2009

Alkaline earth metals (Ae) are regarded as redox‐inactive, and their chemistry is dominated by the oxidation state +2. Nevertheless, in recent years several compound classes with alkaline earth metals in low oxidation states were investigated. Various concepts proved to be valid for the stabilization of such compounds and are discussed in this review. In the solid state, subvalency can be achieved by offering a matrix that takes over the excess electrons as, for example, in subnitrides. This fact leads to normal‐valent alkaline earth metals with electrons free to move between alkaline‐earth‐metal‐containing cages with or without a metal matrix. Another concept focuses on the synthesis of [Ae2]2+ cations with adequate substituents. The homodinuclear Ae–Ae bonds exhibit binding energies that should allow the synthesis of molecules such as R–Ae–Ae–R. The synthesis of magnesium derivatives succeeded by use of extremely bulky bidentate ligands with a delocalized anionic charge. The heavier alkaline earth metal derivatives are investigated by quantum chemical methods. Another possibility takes advantage of the fact that the first and second ionization potentials of the alkaline earth metals are clearly separated. Therefore, an arene with an extended π‐system having an energy level between the two ionization potentials should be able to overtake only one electron, which leads to Ae+ cations. Sophisticated procedures allowed the synthesis of a calcium(I) derivative, [(thf)3Ca(μ‐η6,η6‐C6H3‐1,3,5‐Ph3)Ca(thf)3], and such structures are investigated by quantum chemical methods also for the other alkaline earth metals.
Enantioselective Michael Addition of Aromatic Ketones to Nitroolefins Catalyzed by Bifunctional Thioureas and Mechanistic Insight
Authors: Li Bai‐Lin , Wang Yi‐Feng , Luo Shu‐Ping , Zhong Ai‐Guo , Li Zhao‐Bo , Du Xiao‐Hua , Xu Dan‐Qian
Published: December 2009

A highly enantioselective Michael reaction of aromatic ketones with nitroolefins was accomplished in the presence of a chiral bifunctional primary amine–thiourea catalyst and 4‐nitrobenzoic acid as the co‐catalyst; the corresponding adducts were obtained in excellent enantioselectivities (up to 99 % ee) and yields (up to 98 %). The catalytic mechanism of the Michael reaction was confirmed through the ESI‐MS detection of proposed reaction intermediates and the 1H NMR detection of hydrogen bonding between thiourea and the nitroolefins. DFT calculations showed that chiral moieties of the thiourea impacted the yields and enantioselectivities of the adducts remarkably, which corresponds to the observed experimental results.
Reactivity‐Controlled Regioselectivity: A Regiospecific Synthesis of 1,2‐Disubstituted Benzimidazoles
Authors: Deng Xiaohu , Mani Neelakandha S.
Published: December 2009

We demonstrate exceptional levels of regioselectivity in the tandem amination reactions between 1,2‐differentiated dihaloarenes and N‐substituted amidines. The regiochemical outcome of this CuI‐catalyzed reaction is achieved through a combination of N1/N2 chemoselectivity on the amidine and reactivity‐controlled X1/X2 chemoselectivity on the 1,2‐dihaloarene. This reaction proves to be fairly general for the regiospecific synthesis of 1,2‐substituted benzimidazoles.
Reusable, Polystyrene‐Resin‐Supported, Palladium‐Catalyzed, Atom‐Efficient Cross‐Coupling Reaction of Aryl Halides with Triarylbismuths
Authors: Zhou Wen‐Jun , Wang Ke‐Hu , Wang Jin‐Xian , Huang Dan‐Feng
Published: December 2009

A rapid, atom‐efficient, cross‐coupling reaction of triarylbismuths with aryl bromides or aryl iodides was reported, and the reaction involves the use of a catalytic amount of polystyrene‐supported palladium in the presence of KF as base in DMSO at 105 °C in an open atmosphere. All three aryl groups of the triarylbismuths participated in the reaction and produced polyfunctional biaryls in excellent yields. The polymeric catalyst can be easily separated from the reaction mixture and reused more than 10 times without showing any obvious decrease in activity.
Sensitive Voltammetric Determination of Methyl Parathion Using a Carbon Paste Electrode Modified with Mesoporous Zirconia
Authors: Tan Xiaohong , Li Buhai , Zhan Guoqing , Li Chunya
Published: December 2009

A mesoporous zirconia modified carbon paste electrode was developed for electrochemical investigations of methyl parathion (MP, Phen‐NO2). The significant increase of the peak currents and the improvement of the redox peak potential indicate that mesoporous zirconia facilitates the electronic transfer of MP. The oxidation peak current was proportional to the MP concentration in the range from 1.0×10−8 to 1.0×10−5 mol L−1 with a detection limit of 4.6×10−9 mol L−1 (S/N=3) after accumulation under open‐circuit for 210 s. The proposed method was successfully applied to the determination of MP in apple samples.
Electrode Modified with Cobalt Cyclohexylbutyrate for the Determination of Low Molecular Weight Thiol Group Bearing Compounds Using Catalytic Stripping Voltammetry
Authors: Jakubec Petr , Halouzka Vladimir , Skopalova Jana , Hrbac Jan
Published: December 2009

Glassy carbon electrode, modified with cobalt(II) cyclohexylbutyrate monohydrate immobilized in polystyrene matrix is usable for determination of thiol group bearing compounds both in oxidized and reduced forms using catalytic stripping voltammetry. The measurements are carried out in acetate buffer (pH 4.3) containing Tween 40. After the accumulation step at −850 mV vs. Ag/AgCl a peak at −170 mV is observed on linear sweep voltammogram, the height of which is proportional to the concentration of added thiol. Addition of carbon nanotubes into polystyrene film enhances the sensitivity of the modified electrode. The detection limit is 1×10−6 mol dm−3 for all studied thiols. The electrode can be regenerated by exposing it to the potential between 300–600 mV.
Solid‐State Electrochemical Method for Determining Core and Shell Size in Pd@PdO Nanoparticles
Authors: Doménech‐Carbó Antonio , Coronado Eugenio , Díaz Pilar , Ribera Antonio
Published: December 2009

Electrochemical characterization of palladium nanoparticles surrounded by a palladium oxide shell (Pd@PdO) is described from a combination of voltammetry plus electrochemical quartz crystal microbalance experiments at nanoparticle deposits on graphite electrodes in contact with aqueous H2SO4 and NaOH solutions. A method for determining the metal core size and oxide shell thickness of the Pd@PdO nanoparticles, based on a combination of conventional voltammetry of nanoparticles in DMSO solution and voltammetry of nanoparticle deposits in contact with 0.10 M aqueous NaOH solution, is described.
Rapid Method for Quantitative Determination of Proteolytic Activity with Cyclic Voltammetry
Authors: Baş Deniz , Hakkı Boyacı İsmail
Published: December 2009

An alternative electrochemical method for the determination of proteolytic activity based on cyclic voltammetry of the electroactive probe ferricyanide (Fe(CN)63−) on the gelatin film coated ITO electrodes was proposed. The gelatin film behaves as a kinetic barrier for Fe(CN)63− and the proteolytic digestion of the gelatin film results an increase in the penetration of the Fe(CN)63−. Thus, by the change of peak potential in cyclic voltammogram of Fe(CN)63−, activity of the enzyme was determined.
Mediated Electron Transfer Across Supported Bilayer Lipid Membrane with TCNQ‐Based Organometallic Compounds
Authors: Qu Meili , Lv Qiying , Yang Bing , Zhang Weide , Zhang Jiaqi , Zhan Shuzhong , Ye Jianshan
Published: December 2009

Supported bilayer lipid membrane (s‐BLM) containing one‐dimensional compound 1, TCNQ‐based (TCNQ=7,7,8,8‐tetracyanoquinodimethane) organometallic compound {(Cu2(μ‐Cl)(μ‐dppm)2)(μ2‐TCNQ)}∞, was prepared and characterized on the self‐assembled monolayer (SAM) of 1‐octadecylmercaptan (C18H37SH) deposited onto Au electrode. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results showed that the compound 1, dotted inside s‐BLM, can act as mediator for electron transfer across the membrane. Two redox peaks and the charge‐transfer resistance of 400 kΩ were observed for compound 1 inside s‐BLM. The mechanism of the electron transfer across s‐BLM by TCNQ is by electron hopping while TCNQ‐based organometallic compound is by conducting. Further conclusion drawn from this finding is that the TCNQ‐based organometallic compound embedded inside s‐BLM exhibits excellent electron transfer ability than that of free TCNQ. This opens a new path for the development of s‐BLM sensor and/or biosensor by incorporation with TCNQ‐based organometallic compounds.
Simple Fabrication of Amperometric Nitric Oxide Microsensors Based on Electropolymerized Membrane Films
Authors: Ho Shim Jun , Do Hyunkyung , Lee Youngmi
Published: December 2009

Demand for highly sensitive, selective, and practically reliable sensors which could be easily fabricated is increasing for various applications in biological and biomedical systems. Thus, here we present a novel and simple amperometric NO microsensor based on electropolymerized polymeric films. The sensor consists of a platinized Pt disk anode (25‐μm diameter) which surface is modified with electropolymerized polymer films and a Ag/AgCl wire cathode coiled around the anode. Three different electropolymerized films prepared from m‐phenylenediamine (m‐PD), 2,3‐diaminonaphthalene (2,3‐DAN), and 5‐amino‐1‐naphthol (5A1N) are compared in terms of their permselectivity for NO over major biological interferents such as anionic nitrite, ascorbic acid, uric acid; neutral acetaminophen; and cationic dopamine. Poly‐5A1N film layer among the three different polymers shows the best anti‐interference characteristics for all the electroactive interferents examined. Indeed, single polymer film of electropolymerized 5A1N without any additional modification as a NO selective membrane is confirmed to be sufficient to reject anionic, neutral, as well as cationic interferents while allowing relatively high permeation of NO through it. Other analytical performance of the NO microsensor fabricated with poly‐5A1N is evaluated: reliable linear dynamic range (a few tens nM to μM); sensitivity of 122.0±2.5 pA/μM; detection limit of <5.8 nM (S/N=3); response time, t90%<5 s, which are excellent when considering the small sensor size. Another sensor design which has both an anode (poly‐5A1N modified platinized Pt) and a cathode (Ag/AgCl disk) embedded in a single sensor body is also presented.
Electrochemical Oxidation of Sanguinarine and of Its Oxidation Products at a Glassy Carbon Electrode – Relevance to Intracellular Effects
Authors: Diculescu Victor Constantin , Enache Teodor Adrian , Oliveira Paulo Jorge , Oliveira‐Brett Ana Maria
Published: December 2009

The electrochemical behavior of sanguinarine, a quaternary benzophenanthridine glycoside alkaloid with antimicrobial, anti‐inflammatory, antioxidant and/or immune‐stimulatory activities, was studied at a glassy carbon electrode using cyclic, differential pulse, and square wave voltammetry. The oxidation of sanguinarine is a quasireversible, diffusion‐controlled process and occurred in a cascade mechanism with the formation of several oxidation products which adsorbed at the electrode surface. The oxidation of sanguinarine is pH dependent and involves the transfer of the same number of electrons and protons. The adsorbed sanguinarine oxidation products are reversibly oxidized at the glassy carbon electrode surface and their oxidation for a wide range of pHs was also studied by differential pulse and square wave voltammetry. A mechanism for the oxidation of sanguinarine at glassy carbon electrode is proposed.
Analysis of the Effect of Potential Cycles on the Reflective Infrared Signals of Nitro Groups in Nanofilms: Application of the Fractional Moments Statistics
Authors: Nigmatulin Raoul R. , Alekhin Alexander P. , Baleanu Dumitru , Dinç Erdal , Üstündağ Zafer , Ekşi Haslet , Solak Ali Osman
Published: December 2009

The effect of the potential cycles on the reflective IR signals of nitro‐groups in nanofilms was studied for the statistical characterization of nitrobenzene (NB) and nitroazobenzene (NAB)‐modified glassy carbon (GC) surfaces. Both NB and NAB nanofilms were obtained by the electrochemical reduction of the diazonium tetrafluoroborate salts in acetonitrile using cyclic voltammetry (CV). The modified surfaces were denoted as GC‐(NB)n and GC‐(NAB)n, respectively, where n indicates the number of CV cycles performed during modification. Reflective IR signals of the normalized NB and NAB nanofilms and GC were used for the quantitative evaluation of the effect of the potential cycles on the reflective IR signals of nitro‐groups in nanofilms. The detection and quantitative ‘reading’ of the influence of number of CV cycles were realized in the frame of a new error controllable approach that was applied for analysis of all available set of data. This approach includes in itself the following basic steps: (a) the procedure of the division (normalization) on the GC spectra, (b) the comparison of the smoothed spectra for their statistical proximity in the frame of the statistics of the fractional moments, (c) extraction of possible calibration parameters for possible calibration of the normalized spectra with respect to the number of CV cycles. These three basic steps are becoming effective for detection of the influence of some external factors. In our case it is important to detect the influence of the factor n characterizing CV cycles.
A Simple Contactless Conductivity Detector Employing a Medium Wave Radio Integrated Circuit for the Signal Treatment
Authors: Opekar František , Štulík Karel , Fenclová Kateřina
Published: December 2009

A new procedure has been tested for the treatment of the alternating signal coming from a contactless conductivity detection cell. The cell consists of a polyethylene (2 mm o.d., 1.5 mm i.d.) or polytetrafluoroethylene (1.6 mm o.d., 0.8 mm i.d.) tubing, with 5 mm wide tubular electrodes placed over the tubing and separated by a 5 mm gap. An unmodulated or an amplitude‐modulated AC voltage is applied to the cell and the AC current passing through the cell is treated by a TDA 1072A integrated circuit, obtaining a signal depending on the conductivity of the quiescent or flowing solution inside the cell. Under optimized conditions, the solution conductance can be measured within a range from ca. 10 to 700 μS cm−1, corresponding to ca. 9×10−5 to 5×10−3 M KCl. The detector was used to measure the conductivities of various drinking waters and the values obtained were in a good agreement with those provided by a commercial contact conductometer. It has been found that the use of unmodulated input voltage is advantageous both experimentally, and from the point of view of the quality of the analytical characteristics. The integrated circuit tested is not, however, sufficiently sensitive for application to capillary detection cells with diameters of a few tens of μm, employed in microseparation procedures.
Electrochemical Assay to Quantify the Hydroxyl Radical Scavenging Activity of Medicinal Plant Extracts
Authors: Hilgemann Maurício , Scholz Fritz , Kahlert Heike , de Carvalho Leandro Machado , da Rosa Marcelo Barcellos , Lindequist Ulrike , Wurster Martina , do Nascimento Paulo C. , Bohrer Denise
Published: December 2009

A new electrochemical assay has been developed which is based on quantifying the attack of OH. radicals on a self‐assembled thiol monolayer on electrodes in the presence and absence of antioxidants. The OH. radicals were produced in Fenton solutions. The radical scavengers diminish the concentration of the OH. radicals in the Fenton solution, and the extent of thiol layer destruction is monitored with the help of a redox probe in solution, the signal of which is only generated at SAM‐free electrode surface. The results of the electrochemical assay were compared with those of the standard DPPH. assay. In case of each plant extract, an excellent linear correlation was observed between the radical scavenging activity and the concentration of plant extracts; however, the scavenging properties of different plants strongly differ in the electrochemical and the DPPH. assay. Since the proposed new method probes the reactivity of radical scavengers towards OH., one of the most important reactive oxygen radicals in tissues, it is supposed to provide much more relevant information than the DPPH. or other assays.
Potential Response of Monolayer‐Modified Indium Tin Oxide Electrodes to Indole Compounds
Authors: Nakanishi Takuya , Ueno Tsubasa , Matsunaga Mariko , Khan Md. Zaved Hossain , Osaka Tetsuya
Published: December 2009

Potential response of indium tin oxide (ITO) electrode modified by treatment with disuccinimidyl suberate (DSS) was investigated to various target molecules. Distinctively, the DSS‐modified ITO electrode exhibited a potential shift to the molecules possessing an indole group such as tryptophan, tryptamine and indole propionic acid, while little response to benzoic acid, phenylalanine, proline, proline amide, and arginine was observed. In addition, the combination of this specificity to indoles and enantioselective affinity of human serum albumin (HSA), which was additionally immobilized on the DSS‐modified ITO electrode, brought about enantioselective potential response to tryptophan.
Modified Electrodes with Switchable Selectivity for Cationic and Anionic Redox Species
Authors: Tam Tsz Kin , Pita Marcos , Motornov Mikhail , Tokarev Ihor , Minko Sergiy , Katz Evgeny
Published: December 2009

The modified electrode functionalized with a mixed‐polymer brush composed of poly(2‐vinylpyridine) and polyacrylic acid tethered to the surface demonstrated switchable interfacial properties discriminating negatively and positively charged redox species. The switchable electrochemical process was characterized by differential pulse voltammetry and Faradaic impedance spectroscopy. The electrochemical system was discussed as a model of an electrochemical multiplexer with two chemical redox inputs, the pH input operating as the selecting signal and one electronic output signal readable by the impedance spectroscopy in the form of the interfacial resistance. The modified electrode represents a novel component for integration with biocatalytic and biocomputing systems aiming at biochemically and electronically controlled actuators.
A Sensitive Electrochemical Immunosensor for α‐Fetoprotein Detection with Colloidal Gold‐Based Dentritical Enzyme Complex Amplification
Authors: Liu Xueping , Wu Huiwang , Zheng Yue , Wu Zaisheng , Jiang Jianhui , Shen Guoli , Yu Ruqin
Published: December 2009

A sensitive and specific electrochemical immunosensor was developed with α‐fetoprotein (AFP) as the model analyte by using gold nanoparticle label for enzymatic catalytic amplification. A self‐assembled monolayer membrane of mercaptopropionic acid (MPA) was firstly formed on the electrode surface through gold‐sulfur interaction. Monoclonal mouse anti‐human AFP was covalently immobilized to serve as the capture antibody. In the presence of the target human AFP, gold nanoparticles coated with polyclonal rabbit anti‐human AFP were bound to the electrode via the formation of a sandwiched complex. With the introduction of goat anti‐rabbit IgG conjugated with alkaline phosphatase, the dentritical enzyme complex was formed through selective interaction of the secondary antibodies with the colloidal gold‐based primary antibody at the electrode, thus affording the possibility of signal amplification for AFP detection. Current response arising from the oxidation of enzymatic product was significantly amplified by the dentritical enzyme complex. The current signal was proportional to the concentration of AFP from 1.0 ng mL−1 to 500 ng mL−1 with a detection limit of 0.8 ng mL−1. This system could be extended to detect other target molecules with the corresponding antibody pairs.
The student athlete experience
Authors: Gayles Joy Gaston
Published: December 2009

This chapter discusses data sources available for studying the experience of student athletes on college campuses and highlights the need for national‐level data to address complex questions concerning this population.
Gender equity, sport sponsorship, and participation
Authors: Yiamouyiannis Athena
Published: December 2009

Data on sport participation rates and gender equity can be useful to colleges and universities for decision making and ensuring compliance.
Data‐driven decision making in practice: The NCAA injury surveillance system
Authors: Klossner David , Corlette Jill , Agel Julie , Marshall Stephen W.
Published: December 2009

Policymakers can use sport injury and exposure data to enhance the student athlete experience and make data‐driven policy, rules, and equipment decisions.
Decision making in hiring: Intercollegiate athletics coaches and staff
Authors: Harrison C. Keith , Lapchick Richard E. , Janson Neza K.
Published: December 2009

How do sport management and higher education scholars discuss access discrimination and the underrepresentation of racial minorities in athletic administration and head coaching positions in college sport?
Group dynamics effectiveness of water user associations under different irrigation systems in an eastern Indian state
Authors: Ghosh Souvik , Kumar Ashwani , Nanda Prabhakar , Anand P.S.B.
Published: December 2009

Most of the irrigation systems in India, whether large or small, are reported to have problems relating to the management of irrigation system at grass‐root level. Therefore, a solution that has been tried in various places is irrigation management transfer to water user groups. However, group dynamics plays a pivotal role in the functioning of groups in an efficient manner. The present study was conducted to study the group dynamics effectiveness of water users' associations (WUAs) under different irrigation systems in the state of Orissa, India. A group dynamics effectiveness index (GDEI) was formulated to measure group effectiveness of selected WUAs, which included 10 parameters. The study was carried out following an interview survey of 159 farmers representing eight WUAs under different irrigation systems. All 10 parameters of the GDEI were highly regarded by the farmers of lift irrigation WUAs, except social support. Most of the parameters of group effectiveness were found to be high in the case of minor irrigation WUAs. Farmers of major irrigation WUAs have perceived many of the parameters (participation, decision‐making procedure, group atmosphere, empathy, interpersonal trust and social support) to be weak. Differential group effectiveness may be attributed to the temporal and spatial variation in the irrigation command areas under the group's jurisdiction. Copyright © 2009 John Wiley & Sons, Ltd.
Dissecting the signal transduction pathways triggered by galectin–glycan interactions in physiological and pathological settings
Authors: Laderach Diego J. , Compagno Daniel , Toscano Marta A. , Croci Diego O. , Dergan‐Dylon Sebastián , Salatino Mariana , Rabinovich Gabriel A.
Published: December 2009

Galectins are a family of evolutionarily conserved animal lectins with pleiotropic functions and widespread distribution. Fifteen members have been identified in a wide variety of cells and tissues. Through recognition of cell surface glycoproteins and glycolipids, these endogenous lectins can trigger a cascade of intracellular signaling pathways capable of modulating cell differentiation, proliferation, survival, and migration. These cellular events are critical in a variety of biological processes including embryogenesis, angiogenesis, neurogenesis, and immunity and are substantially altered during tumorigenesis, neurodegeneration, and inflammation. In addition, galectins can modulate intracellular functions and this effect involves direct interactions with distinct signaling pathways. In this review, we discuss current knowledge on the intracellular signaling pathways triggered by this multifunctional family of β‐galactoside‐binding proteins in selected physiological and pathological settings. Understanding the “galectin signalosome” will be essential to delineate rational therapeutic strategies based on the specific control of galectin expression and function. © 2009 IUBMB IUBMB Life, 62(1):1–13, 2010
Leukemia inhibitory factor promotes Hsp90 association with STAT3 in mouse embryonic stem cells
Authors: Setati Mokgadi M. , Prinsloo Earl , Longshaw Victoria M. , Murray Patricia A. , Edgar David H. , Blatch Gregory L.
Published: December 2009

Self‐renewal of in vitro cultured mouse embryonic stem (mES) cells is dependent on the presence of leukemia inhibitory factor (LIF). LIF induces overexpression and tyrosine phosphorylation of STAT3 (signal transducer and activator of transcription 3) and its subsequent nuclear translocation. The molecular chaperone heat shock protein 90 (Hsp90) is involved in the activation and maturation of a wide variety of substrate proteins. We investigated the effect of LIF withdrawal on the protein expression levels of STAT3 and Hsp90 and on the interactions between STAT3 and Hsp90. Taken together the data presented here suggest that LIF promotes the interaction of Hsp90 with STAT3 during self‐renewal, indicating a potentially pivotal role for Hsp90 in the LIF‐based maintenance of self‐renewal of mouse embryonic stem cells. © 2009 IUBMB IUBMB Life, 62(1):61–66, 2010
Therapy for lysosomal storage disorders
Authors: Beck Michael
Published: December 2009

In the last years, much progress has been achieved in the field of lysosomal storage disorders. In the past, no specific treatment was available for the affected patients; management mainly consisted of supportive care and treatment of complications. As orphan drug regulations, however, encouraged development of drugs for these disorders by granting marketing exclusivity for 10 years and other commercial benefits, enzyme replacement therapy became available for lysosomal storage disorders, such as Gaucher disease, Fabry disease, mucopolysaccharidoses type I, II, and VI, and Pompe disease. This review will summarize the efficacy and clinical status of hematopoietic stem cell transplantation, enzyme replacement, and substrate deprivation therapy, and describe new therapeutic perspectives currently under preclinical investigations such as chaperone‐mediated therapy, stop‐codon read‐through therapy, and gene therapy. © 2009 IUBMB IUBMB Life, 62(1):33–40, 2010
Mycobacterial stress regulation: The Dps “twin sister” defense mechanism and structure‐function relationship
Authors: Chowdhury Rakhi Pait , Saraswathi Ramachandran , Chatterji Dipankar
Published: December 2009

In this work, we have tried to emphasize the connection between mycobacterial growth and regulation of gene expression. Utilization of multiple carbon sources and diauxic growth helps bacteria to regulate gene expression at an optimum level so that the inhospitable conditions encountered during nutrient depletion can be circumvented. These aspects will be discussed with respect to mycobacterial growth in subsequent sections. Identification and characterization of genes induced under such conditions is helpful to understand the physiology of the bacterium. Although it is necessary to compare the total expression profile of proteins as they transit from vegetative growth to stationary phase, at times a lot of insights can be deciphered from the expression pattern of one or two proteins. We have compared the protein expression and sigma factor selectivity of two such proteins in M. smegmatis to understand the differential regulation of genes playing diverse function in the same species. Some newer insights on the structure and function of one of the Dps proteins are also explained. © 2009 IUBMB IUBMB Life, 62(1):67–77, 2010
Micro‐RNA‐375 inhibits lung surfactant secretion by altering cytoskeleton reorganization
Authors: Zhang Honghao , Mishra Amarjit , Chintagari Narendranath Reddy , Gou Deming , Liu Lin
Published: December 2009

Lung surfactant is secreted via exocytosis of lamellar bodies from alveolar epithelial type II cells. Whether micro‐RNAs regulate lung surfactant secretion is unknown. Micro‐RNA‐375 (miR‐375) has been shown to be involved in insulin secretion. In this article, we report that the overexpression of miR‐375 inhibited lung surfactant secretion. However, miR‐125a, miR‐30a, miR‐1, miR‐382 and miR‐101 did not influence lung surfactant secretion. miR‐375 had no effects on surfactant synthesis or the formation of lamellar bodies. However, miR‐375 did abolish the lung surfactant secretagogue‐induced disassembly and reassembly of cytoskeleton. Our results suggest that miR‐375 regulates surfactant secretion via the reorganization of cytoskeleton. © 2009 IUBMB IUBMB Life, 62(1):78–83, 2010
Transforming growth factor‐β activated kinase 1 signaling pathways regulate TNF‐α production by titanium alloy particles in RAW 264.7 cells
Authors: Cheng Tao , Peng Xiao‐Chun , Li Feng‐Feng , Zhang Xian‐Long , Hu Kong‐Zu , Zhu Jun‐Feng , Zeng Bing‐Fang
Published: December 2009

Implant particles may induce inflammatory response by activating the nuclear factor κB (NFκB) and mitogen activated protein kinases (MAPK). Previous studies have shown that these signaling pathways are involved in the transforming growth factor‐β activated kinase 1 (TAK1) in signaling cascades induced by the receptor activator of NFκB ligand (RANKL) and tumor necrosis factor‐α (TNF‐α) as well as interleukin‐1β (IL‐1β). In this study, the roles of the TAK1 pathway in the production of the pro‐inflammatory cytokine TNF‐α in RAW 264.7 cells exposed to titanium alloy particles were investigated. Endogenous TAK1 was phosphorylated upon simulating RAW 264.7 cells by titanium alloy particles. The critical role for TAK1 in p38MAPK and NFκB activation was as well confirmed by the inhibition of p38MAPK and NFκB activity following 5Z‐7‐oxozeaenol, a selective inhibitor of TAK1. Furthermore, it was found that TNF‐α was completely blocked by 5Z‐7‐oxozeaenol in RAW 264.7 cells. These results suggest that the TAK1‐MAPK‐NFκB signaling pathways may be a potential pharmacological target that can prevent instability for arthroplasty prosthesis. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
In vivo evaluation of acellular human dermis for abdominal wall repair
Authors: Eberli Daniel , Rodriguez Sergio , Atala Anthony , Yoo James J.
Published: December 2009

Limitations of synthetic biomaterials for abdominal wall repair have led investigators to seek naturally derived matrices, such as human acellular dermis, because of their excellent biocompatibility and their ability to naturally interface with host tissues with minimal tissue response. In this study, we investigated two different biomaterials derived from human dermis (FlexHD acellular dermis and FlexHD acellular dermis‐thick) in a rabbit abdominal hernia repair model. One quarter of the abdominal wall was replaced with each biomaterial, and the animals were followed for up to 24 weeks. Rabbit hernias repaired with AlloDerm®, a commercially available acellular dermal matrix, and sham operated animals served as controls. Retrieved samples of these implants were assessed grossly and histologically. Collagen production measurements and tension studies were performed. FlexHD acellular dermis, FlexHD acellular dermis‐thick, and AlloDerm® maintained their strength in the rabbit hernia repair model with no incidence of hernia formation or bowel adhesion. The exact size measurements at 24 weeks were 217.0 ± 20.9% for FlexHD acellular dermis, 200.8 ± 23.5% for FlexHD acellular dermis‐thick, and 209.7 ± 32.9% for AlloDerm®. Macroscopic and microscopic evaluation showed excellent integration and tissue formation. All biomaterials studied harbored cells that produced new collagen fibers, and a six‐fold increase in these fibers was observed at 24 weeks. This study shows that acellular biomaterials derived from human dermis are suitable for abdominal hernia repair. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Alveolar ridge augmentation in irradiated rabbit mandibles
Authors: Jegoux Franck , Aguado Eric , Cognet Ronan , Malard Olivier , Moreau Françoise , Daculsi Guy , Goyenvalle Eric
Published: December 2009

Oral carcinomas are frequently treated with a nonsegmental mandibulectomy plus radiotherapy. Improving the quality of life of these patients depends on the possibilities for dental rehabilitation. The aim of this study was to increase the alveolar ridge height. Twelve white New Zealand rabbits underwent surgery to produce a 11 × 9 × 7 mm3 horizontal bicortical full‐thickness defect at the alveolar ridge of the left mandible. Six were implanted with a composite associating resorbable collagen membrane filled with micro‐macroporous biphasic calcium phosphate granules. After a daily radiation delivery schedule for 4 weeks, a total autologous bone marrow graft was injected percutaneously into the center of the implant. All animals were sacrificed at 16 weeks. Successful osseous colonization was observed in all implants. Significant ridge augmentation was observed (p = 0.0349) in the implanted group compared with the control group. This study contributed to producing an experimental model for oncological mandible defects in rabbits. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Growth factor delivery through electrospun nanofibers in scaffolds for tissue engineering applications
Authors: Sahoo Sambit , Ang Lay Teng , Goh James Cho‐Hong , Toh Siew‐Lok
Published: December 2009

Tissue engineering scaffolds should ideally mimic the natural ECM in structure and function. Electrospun nanofibrous scaffolds are easily fabricated and possess a biomimetic nanostructure. Scaffolds can mimic ECM function by acting as a depot for sustained release of growth factors. bFGF, an important growth factor involved in tissue repair and mesenchymal stem cell proliferation and differentiation, is a suitable candidate for sustained delivery from scaffolds. In this study, we present two types of PLGA nanofibers incorporated with bFGF, fabricated using the facile technique of blending and electrospinning (Group I) and by the more complex technique of coaxial electrospinning (Group II). bFGF was randomly dispersed in Group I and distributed as a central core within Group II nanofibers; both scaffolds showed similar protein encapsulation efficiency and release over 1–2 weeks. Although both scaffold groups favored bone marrow stem cell attachment and subsequent proliferation, cells cultured on Group I scaffolds demonstrated increased collagen production and upregulated gene expression of specific ECM proteins, indicating fibroblastic differentiation. The study shows that the electrospinning technique could be used to prolong growth factor release from scaffolds and an appropriately sustained growth factor release profile in combination with a nanofibrous substrate could positively influence stem cell behavior and fate. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
In vitrouptake of amphiphilic, hydrogel nanoparticles by J774A.1 cells
Authors: Missirlis Dimitris , Hubbell Jeffrey A.
Published: December 2009

We here report improved synthesis andin vitrointeractions of amphiphilic hydrogel nanoparticles with the macrophage cell line J774A.1. Nanoparticles comprising dispersed hydrophobic nanodomains of poly(propylene glycol) within a continuous phase of hydrophilic poly (ethylene glycol) (PEG) were prepared via inverse emulsion crosslinking polymerization, using acrylated PEG and Pluronic® F127 as macromonomer blocks. Functionality and fluorescent labeling were achieved through incorporation of reactive comonomers anda posteriorireaction with fluorescein, respectively. When introduced to a static cell culture of adhered J774A.1 macrophages, the cells internalized these hydrogel nanoparticles in a dose‐ and time‐ dependent manner through clathrin‐mediated and other pathways. Amphiphilic nanoparticle uptake was however dramatically lower than that of a model system (Fluospheres®) and similar to PEG‐coated colloids reported in the literature, which are considered “stealth.” Our findings support the potential of the nanoparticles presented here as long‐circulating drug carriers. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Influence of anodization on the adhesion of calcium phosphate coatings on titanium substrates
Authors: Blackwood Daniel J. , Seah Kar Heng W.
Published: December 2009

Electrochemical deposition is an attractive technique for the deposition of calcium phosphate, especially hydroxyapatite, on titanium implants. However, the adhesion of these coatings to the titanium substrates needs to be improved for clinical use. It is demonstrated that anodization of a titanium alloy does marginally increase the adhesion of calcium phosphate coatings. Although scratch test measurements on coatings deposited at a constant potential appear to suggest that adhesion improves with increased thickness of the anodized layer, when a constant current is used to deposit the coatings their adhesion becomes independent of the thickness of the anodized layer. This apparent contradiction is explained by the thicker oxides acting as larger series resistors that reduce the magnitude of the current density when deposition is conducted at a constant potential. The resulting lower current density is responsible for increased adhesion of the calcium phosphate coating. It was also observed that surface roughness affects the interfacial adhesion strength between the coating and the titanium substrate, with a more adherent coating being formed over a rough surface. However, adhesion becomes independent of surface finish at levels smoother than 600 grit, suggesting that mechanical interlocking is not the sole force at play. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Poly(vinyl alcohol)/halloysite nanotubes bionanocomposite films: Properties and in vitro osteoblasts and fibroblasts response
Authors: Zhou Wen You , Guo Baochun , Liu Mingxian , Liao Ruijuan , Rabie A. Bakr M. , Jia Demin
Published: December 2009

In this study, transparent poly(vinyl alcohol) (PVA) and PVA/halloysite nanotubes (HNTs) bionanocomposite films were prepared by solution casting and glutaraldehyde (GA) crosslinking. The surface topography and chemistry of the films were characterized by atomic force microscopy (AFM) and attenuated total reflection Fourier transform infrared (ATR‐FTIR) spectroscopy, respectively. Blending with HNTs induced changes in nanotopography and surface chemistry of PVA films. The mechanical properties of PVA were enhanced by the incorporated HNTs. The stain‐induced crystallization was confirmed by DSC after tensile test. MC3T3‐E1 osteoblast‐like and NIH 3T3 fibroblast cells were cultured on neat PVA and PVA/HNTs films to evaluate the effects of surface nanotopography and composition on cell behavior. The observations indicated that MC3T3‐E1 cell behavior strongly responded to surface nanotopography. On nanotube‐dominant surface, cells exhibited a significantly higher level of adhesion than on neat PVA film, whereas neat PVA showed higher degree of osteoblast proliferation compared with PVA/HNTs. In vitro fibroblasts response demonstrated that both neat PVA and PVA/HNTs nanocomposite films were biocompatible and PVA/HNTs films favored to fibroblasts attach and growth below 7.5 wt % of HNTs incorporated. In summary, these results provided insights into understanding of PVA and PVA/HNTs bionanocomposite films in potential applications in bone tissue engineering and drug delivery systems. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Biocompatibility of porous polyethylene implants tissue‐engineered by extracellular matrix and VEGF
Authors: Strieth Sebastian , Weger Tobias , Bartesch Christian , Bittmann Philipp , Stelter Klaus , Berghaus Alexander
Published: December 2009

Rapid ingrowth of blood vessels and low inflammatory response are considered major prerequisites for successful implantation of biomaterials in reconstructive surgery. Aim of the present study was to evaluate whether tissue‐engineered porous polyethylene (PPE) implants providing extracellular matrix components (ECM) and vascular endothelial growth factor (VEGF) in vivo improve microvascular ingrowth and mechanical integration with regard to initial inflammatory responses. PPE implants (3 × 3 × 0.1 mm3, pore size ∼100–200 μm) were tissue‐engineered by incorporation of ECM components (GFR‐Matrigel) adding recombinant murine VEGF (1 μg/mL) and grafted into dorsal skinfold chamber preparations of C57BL/6 mice. Control animals received uncoated implants or implants coated with ECM components alone (n = 6 per group). Using in vivo fluorescence microscopy angiogenic activity and inflammatory leukocyte‐endothelial cell interactions were analyzed for 2weeks. Finally, mechanical integration was quantified by measurement of dynamic desintegration strengths at the host‐implant border. Functional vessel density, red blood cell velocity, and vessel diameters increased continuously in all groups indicating that rapid microvascular integration of PPE occurred even without incorporation of ECM or VEGF. However, a transient initial inflammatory response with increased leukocyte‐endothelial cell adherence on day 7 in uncoated control implants was efficiently reduced by incorporation of ECM and VEGF. Measurement of dynamic breaking strengths revealed no significant differences between the groups although there was a tendency to improved mechanical integration in tissue‐engineered implants. Therefore, novel tissue‐ engineered constructs of PPE implants providing ECM and VEGF in high local concentrations can increase biocompatibility especially under unfavorable conditions for implantation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010