bluuebunny/crossref_metadata_2025 huggingface dataset:
A Note on Plots of P‐Values to Evaluate Many Tests Simultaneously
Authors: Koziol James A.
Published: May 2007

Schweder and Spjøtvoll (1982) proposed an informal graphical procedure for simultaneous evaluation of possibly related tests, based on a plot of cumulative p‐values using the observed significance probabilities. We formalize this notion by application of Holm's (1979) sequentially rejective Bonferroni procedure: this maintains an overall experimentwise significance level, and yields an immediate estimate of the number of true hypotheses.
Genetic Group Index on Multiple Traits for Homogeneous Covariance Structure
Authors: Jaiswal U. C. , Jain J. P.
Published: May 2007

A multi‐trait index for ranking different genetic groups/populations with homogeneous covariance structure is developed and illustrated with live data.
A Comparative Statistical Analysis of Genetic Distances. II–Confidence Intervals and Tests of Comparison
Authors: Katz Mariano
Published: May 2007

We present methods for constructing the confidence intervals of the estimations of absolute genetic distance and Nei's minimum and standard genetic distances. Two different estimators of the standard distance are considered: jack‐knife and corrected. A Monte‐Carlo simulation analysis permitted to choose the best adapted confidence interval type for each distance estimator and for each size of the samples of loci and of gametes, taking into account the magnitude of the estimation value. Simulated true confidence levels showed that the best results are obtained using abolute genetic distance. We also give rules for testing the significance of the difference of two distance estimations. Monte‐Carlo simulations were performed in order to obtain the distributions of the difference of two distance estimations under the null hypothesis and consequently the true type I errors of tests. Test powers, obtained by simulation under the alternative hypothesis, also showed the superiority of absolute genetic distance.
Potent Inhibitors of the Human UDP‐Glucuronosyltransferase 2B7 Derived from the Sesquiterpenoid Alcohol Longifolol
Authors: Bichlmaier Ingo , Kurkela Mika , Joshi Tanmaya , Siiskonen Antti , Rüffer Tobias , Lang Heinrich , Finel Moshe , Yli‐Kauhaluoma Jari
Published: May 2007

The tricyclic sesquiterpenol (+)‐longifolol served as a lead structure for the design of inhibitors of the human UDP‐glucuronosyltransferase (UGT) 2B7. Twenty‐four homochiral and epimeric longifolol derivatives were synthesized and screened for their ability to inhibit the enzyme. The absolute configuration at the stereogenic center C1′ was determined by X‐ray crystallography and 2D NMR spectroscopy (gHSQC, gNOESY). The phenyl‐substituted secondary alcohol 16 b (β‐phenyllongifolol) displayed the highest affinity toward UGT2B7, and its inhibitory dissociation constant was 0.91 nM. The mode of inhibition was rapidly reversible and competitive. The inhibitor was not glucuronidated by UGT2B7 or other hepatic UGTs, presumably as a result of the high steric demand exerted by the phenyl group. Inhibition assays employing 14 other UGT isoforms suggested that inhibitor 16 b was highly selective for UGT2B7.
Phase‐rotation in in‐vivo localized spectroscopy
Authors: Ramadan Saadallah
Published: May 2007

Phase‐rotation is an alternative method to phase‐cycling in acquisition of magnetic resonance spectroscopic data. However, there has only been two papers describing its implementation in point resolved spectroscopy (PRESS) and stimulated echo acquisition mode (STEAM) to date. This article aims to introduce and explain the principles of phase‐rotation, describe the implementations that were carried out so far in the current literature, compare phase‐rotation and phase‐cycling experimentally, and introduce the application of phase‐rotation in double‐quantum filtered (DQF) spectroscopy. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part A 30A: 147–153, 2007
NMR application for a study of reversible photochemical kinetics: A multisite case
Authors: Babailov S.P. , Mainichev D.A. , Purtov P.A.
Published: May 2007

Expressions describing the NMR signal shape for photoinduced chemical exchange in a multi‐site system without spin‐spin splitting are obtained by dynamic NMR techniques. The methods provide a framework for planning experimental strategies aimed at studies of photoinduced chemical exchange in dissolved substances. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part A 30A: 140–146, 2007
Introducing dimensionless parameters into the correlation of NMR relaxation time to transport properties of porous media
Authors: Tomadakis Manolis M.
Published: May 2007

Dimensionless parameters representing the viscous permeability (k) and NMR relaxation time (T1) of particle beds, while accounting also for the particle size, are shown to improve drastically the accuracy of k‐T1 correlations in the slow diffusion regime, in the absence of bulk relaxation effects. The finding is based on a regression analysis of numerical results for k and T1 in both random and ordered isotropic and anisotropic beds of fibers. Use of the formation factor (F) improves further the accuracy of the correlations only for the strongly anisotropic unidirectional arrays of fibers. A survey of related literature reveals an extensive effort in recent years in upgrading k‐T1 correlations, driven primarily by applications in petroleum and gas field exploration and recovery. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part A 30A: 154–164, 2007.
Ammonium channel expression is essential for brain development and function in the larva of Ciona intestinalis
Authors: Marino Rita , Melillo Daniela , Di Filippo Miriam , Yamada Atsuko , Pinto Maria Rosaria , De Santis Rosaria , Brown Euan R. , Matassi Giorgio
Published: May 2007

Ammonium uptake into the cell is known to be mediated by ammonium transport (Amt) proteins, which are present in all domains of life. The physiological role of Amt proteins remains elusive; indeed, loss‐of‐function experiments suggested that Amt proteins do not play an essential role in bacteria, yeast, and plants. Here we show that the reverse holds true in the tunicate Ciona intestinalis. The genome of C. intestinalis contains two AMT genes, Ci‐AMT1a and Ci‐AMT1b, which we show derive from an ascidian‐specific gene duplication. We analyzed Ci‐AMT expression during embryo development. Notably, Ci‐AMT1a is expressed in the larval brain in a small number of cells defining a previously unseen V‐shaped territory; these cells connect the brain cavity to the external environment. We show that the knockdown of Ci‐AMT1a impairs the formation of the brain cavity and consequently the function of the otolith, the gravity‐sensing organ contained in it. We speculate that the normal mechanical functioning (flotation and free movement) of the otolith may require a close regulation of ammonium salt(s) concentration in the brain cavity, because ammonium is known to affect both fluid density and viscosity; the cells forming the V territory may act as a conduit in achieving such a regulation. J. Comp. Neurol. 503:135–147, 2007. © 2007 Wiley‐Liss, Inc.
Morphometric analysis of the fiber populations of the rat sciatic nerve, its spinal roots, and its major branches
Authors: Prodanov Dimiter , Feirabend Hans K.P.
Published: May 2007

Correspondence between the nerve composition and the functional characteristics of its fiber populations is not always evident. To investigate such correspondence and to give a systematic picture of the morphology of the rat hind limb nerves, extensive morphometric study was performed on the sciatic nerve, its founding dorsal and ventral spinal roots, and its major branches. Nerve histology was examined in semithin sections via microscopic image analysis. Variation in the density of myelinated fibers, fiber interspace, and nerve cross‐sectional area was studied in individual roots and nerves. In the dorsal roots, fiber numbers and cross‐sectional areas were directly linearly proportional to the spinal root level number. Constituent fiber populations were identified using multicomponent lognormal models, and an optimal model for every nerve or root was selected by using an information theoretic approach. For the dorsal and ventral roots and the sciatic and peroneal nerves, optimal fiber population models consisted of three components, whereas, for the tibial and sural nerves, two components were optimal. Functional identities of the revealed fiber populations were established by using calculations of corresponding conduction velocities according to Arbuthnott et al. (J. Physiol. [1980] 308:125–157) and anatomical considerations. It is anticipated that morphological parameters established in this study would advance the development of neural prostheses in humans. The proximodistal correspondences among the fiber populations of different nerves were established by parametric statistical comparisons. The proposed approach provides a conceptual framework for understanding the comparative anatomy of the peripheral nerves and spinal roots and can be further applied in other species. J. Comp. Neurol. 503:85–100, 2007. © 2007 Wiley‐Liss, Inc.
Reduced axon sprouting after treatment that diminishes microglia accumulation at lesions in the leech CNS
Authors: Ngu Emmanuel Mbaku , Sahley Christie L. , Muller Kenneth J.
Published: May 2007

The role of mammalian microglia in central nervous system (CNS) repair is controversial. Microglia accumulate at lesions where they act as immune cells and phagocytize debris, and they may secrete neurotrophins, but they also produce molecules that can be cytotoxic, like nitric oxide (NO). To determine the importance of microglial accumulation at lesions on growth of severed CNS axons in the leech (Hirudo medicinalis), in which axon and synapse regeneration are notably successful even when isolated in tissue culture medium, microglial migration to lesions was reduced. Pressure (P) sensory neurons were injected with biocytin to reveal the extent of their sprouting 24 hours after lesioning. To reduce microglia accumulation at lesions, cords were treated for 3.5 hours with 3 mM ATP or 2 mM Nω‐nitro‐L‐arginine methyl ester (L‐NAME) or 50 μM Reactive blue‐2 (RB2) beginning 30 minutes before injury. Lesioned controls were either not treated with drug or treated 3 hours later with one of the drugs, after the migration and subsequent accumulation of most microglia had occurred, but before the onset of axon sprouting, for a total of seven separate conditions. There was a significant reduction in total sprout lengths compared with controls when microglial accumulation was reduced. The results suggest that microglial cells are necessary for the usual sprouting of injured axons. J. Comp. Neurol. 503:101–109, 2007. © 2007 Wiley‐Liss, Inc.
Developmental and adult expression of semaphorin 2a in the cricket Gryllus bimaculatus
Authors: Maynard Kristen R. , McCarthy Sarah S. , Sheldon Elizabeth , Horch Hadley Wilson
Published: May 2007

Developmental guidance cues act to direct growth cones to their correct targets in the nervous system. Recent experiments also demonstrate that developmental cues are expressed in the adult mammalian nervous system, although their function in the brain is not yet clear. The semaphorin gene family has been implicated in the growth of dendrites and axons in a number of different species. While the expression of semaphorin and its influence on tibial pioneer neurons in the developing limb bud have been well characterized in the grasshopper, the expression of semaphorin 2a (sema2a) has not been explored in the adult insect. In this study we used polymerase chain reaction (PCR) with degenerate and gene‐specific primers to clone part of the secreted form of sema2a from Gryllus bimaculatus. Using in situ hybridization and immunohistochemistry, we confirmed that sema2a mRNA and protein expression patterns in the embryonic cricket were similar to that seen in the grasshopper. We also showed that tibial neuron development in crickets was comparable to that described in grasshopper. An examination of both developing and adult cricket brains showed that sema2a mRNA and protein were expressed in the Kenyon cells in mushroom bodies, an area involved in learning and memory. Sema2a expression was most obvious near the apex of the mushroom body in a region surrounding the neurogenic tip, which produces neurons throughout the life of the cricket. We discuss the role of neurogenesis in learning and memory and the potential involvement of semaphorin in this process. J. Comp. Neurol. 503:169–181, 2007. © 2007 Wiley‐Liss, Inc.
Chemotopic odorant coding in a mammalian olfactory system
Authors: Johnson Brett A. , Leon Michael
Published: May 2007

Systematic mapping studies involving 365 odorant chemicals have shown that glomerular responses in the rat olfactory bulb are organized spatially in patterns that are related to the chemistry of the odorant stimuli. This organization involves the spatial clustering of principal responses to numerous odorants that share key aspects of chemistry such as functional groups, hydrocarbon structural elements, and/or overall molecular properties related to water solubility. In several of the clusters, responses shift progressively in position according to odorant carbon chain length. These response domains appear to be constructed from orderly projections of sensory neurons in the olfactory epithelium and may also involve chromatography across the nasal mucosa. The spatial clustering of glomerular responses may serve to “tune” the principal responses of bulbar projection neurons by way of inhibitory interneuronal networks, allowing the projection neurons to respond to a narrower range of stimuli than their associated sensory neurons. When glomerular activity patterns are viewed relative to the overall level of glomerular activation, the patterns accurately predict the perception of odor quality, thereby supporting the notion that spatial patterns of activity are the key factors underlying that aspect of the olfactory code. A critical analysis suggests that alternative coding mechanisms for odor quality, such as those based on temporal patterns of responses, enjoy little experimental support. J. Comp. Neurol. 503:1–34, 2007. © 2007 Wiley‐Liss, Inc.
Analysis of a clock‐recovery technique for circuit emulation services over packet networks
Authors: Aweya James , Montuno Delfin Y. , Ouellette Michel , Felske Kent
Published: May 2007

One important requirement of circuit emulation services (CES) over packet networks is clock synchronization and timing distribution among the nodes. CES depends on reliable and high‐quality timing for operations. In the time division multiplexing (TDM) world, whether plesiochronous digital hierarchy (PDH), synchronous digital hierarchy (SDH) or synchronous optical network (SONET) based, timing and synchronization is inherent in the design of the network. However, when timing critical services such PDH and SDH/SONET are carried over packet network (e.g. IP, Ethernet, etc.), the timing element is lost and has to be carried across the packet network by other means. A well‐known and widely implemented technique for clock recovery in CES is one that is based on packet inter‐arrival time (sometimes called time difference of arrival) averaging. The technique is very simple to implement but provides good performance only when packet losses and packet delay variation (PDV) are very low and well controlled. This technique has been extensively analysed through simulations but has not been fully characterized analytically with correlated traffic in the literature. In this paper, we provide a full analytical examination of this well‐known clock recovery technique. We analyse the effects of correlation of the delay variation in the traffic stream on the quality of the clock recovered by a receiver. We prove analytically that, for a general input process, high correlation of the delay variation produces a large variance of the recovered clock. Copyright © 2007 John Wiley & Sons, Ltd.
Structural, Electrochemical, and Spectroscopic Properties of a Class of Dodecasubstituted Iron Porphyrins Bearing Four Positive Charges Close to the Metal
Authors: Renner Mark W. , Bochot Constance , Héroux Annie , Mansuy Daniel , Battioni Pierrette
Published: May 2007

The first iron complexes of the tetracationic 2,3,7,8,12,13,17,18‐octaethyl‐5,10,15,20‐tetra‐N‐pyridiniumylporphyrin, (OEPy4P)4+, in which four pyridine molecules are attached to the meso‐carbon atoms through their nitrogen atoms, were synthesized in three steps starting from Zn(OEP) (Zn‐β‐octaethylporphyrin) with an overall yield of ca. 30 %. The X‐ray structure of [FeII(OEPy4P)(pyridine)2](CF3SO3)3(Br) established that the molecule adopts a severely distorted nonplanar saddle conformation. 1H NMR spectroscopy showed that the [FeII(OEPy4P)(B)2]4+ ligated complexes, B = pyridine (Py) or imidazole (Im), are low‐spin, FeII, S = 0. These complexes exhibit redox potentials for the FeIII/FeII couple that range between 0.62 and 0.38 V (vs. Ag/AgCl) and are shifted by as much as +0.7 V relative to those of the corresponding planar iron complexes of OEP and of the nonplanar complexes of OETPP. Such highly positive redox potentials explain the stability of these iron(II) porphyrins in air. As previously found for dodecasubstituted iron porphyrins bearing electron‐withdrawing groups, the UV/Vis spectra of the[FeII(OEPy4P)(B)2]4+ complexes exhibit Soret and visible bands which are redshifted by ca. 40 nm relative to those of Fe(OEP)(Py)2. These metallo‐OEPy4P4+complexes offer promising synthetic avenues to novel classes of highly charged porphyrins and multiporphyrin arrays, which are soluble in aqueous and polar organic solvents.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Modular N,O‐Chelating Ligands: Group‐4 Amidate Complexes for Catalytic Hydroamination
Authors: Lee Alison V. , Schafer Laurel L.
Published: May 2007

Amidate ligands have been used as a modular ligand set for early transition‐metal complexes, and have been found to exhibit high reactivity in the catalytic hydroamination of alkynes, allenes, and alkenes. This microreview focuses on coordination metal complexes containing amidate functionality including their bonding, structure and reactivity trends. The synthesis and characterization of a number of different group‐4 metal complexes is presented, and their applications in both hydroamination and organic synthesis are discussed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Transfer Hydrogenation Reactions Catalyzed by Free or Silica‐Immobilized [RuCl2(ampy){RN(CH2PPh2)2}] Complexes
Authors: Del Zotto Alessandro , Greco Carla , Baratta Walter , Siega Katia , Rigo Pierluigi
Published: May 2007

The complexes cis‐[RuCl2(ampy){R1N(CH2PPh2)2}] [ampy = (2‐aminomethyl)pyridine, R1 = C6H5 or (CH3CH2O)3Si(CH2)3] showed very high catalytic activity in the homogeneous transfer hydrogenation of acetophenone (TOF > 300000 h–1) with the use of 2‐propanol as the hydrogen donor and in the presence of sodium isopropoxide. The ligand (CH3CH2O)3Si(CH2)3N(CH2PPh2)2 (ATM) was prepared in high yield by reacting (3‐aminopropyl)triethoxysilane, paraformaldehyde, and diphenylphosphane in toluene heated at 80 °C. The –N(CH2PPh2)2 function was attached to the surface of three different kinds of silica by means of two alternative methods. Thus, MA‐Si‐150 and mesoporous MA‐Si‐MCM‐41 were prepared by the reaction of the inorganic matrix with ATM, whereas MA‐Si‐60 was synthesized by reaction of the commercially available 3‐aminopropyl‐functionalized silica gel with HCHO and PHPh2 in refluxing toluene. The –(CH2)3N(CH2PPh2)2 functionalized inorganic materials were used to anchor the RuCl2(ampy) moiety; thus, three different silica‐immobilized versions of the cis‐[RuCl2(ampy)(ATM)] complex were obtained. The silica‐anchored complexes were tested in the transfer hydrogenation of acetophenone, which was found to be fast and quantitative; the effect of the nature of the silica support on the activity of the catalyst was almost negligible. It was possible to reuse the catalytic system for a second cycle without a decrease in the activity, but the efficiency of the catalyst considerably diminished in successive reuses.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Photochromism of Thiazole‐Containing Triangle Terarylenes
Authors: Nakashima Takuya , Atsumi Kazuhiko , Kawai Shigekazu , Nakagawa Tetsuya , Hasegawa Yasuchika , Kawai Tsuyoshi
Published: May 2007

Triangle terarylene derivatives based on the 4,5‐diarylthiazole structure have been synthesized and their photochromic properties have been studied both in solution and in the crystalline state. The thiazolyl‐substituted terarylenes displayed reversible photochromism in solution, with photocyclization quantum yields as high as 60 %, while a 4,5‐dithienylthiazole derivative underwent photochromic reaction even in the single‐crystal state, although a 4,5‐dithiazolylthiazole (terthiazole) showed no photochromic reaction in the crystalline phase. The difference in photochromic reactivity between the 4,5‐dithienylthiazole and the 4,5‐dithiazolylthiazole was found by X‐ray crystallographic analyses to originate from conformational differences in the crystalline state. The thermal cycloreversion activation energies in the solution phase were measured for thiazolyl‐substituted terarylenes and for a corresponding terthiophene derivative. The activation energy for the transition from photogenerated closed‐ring isomer to open‐ring isomer increased with the number of substitutions of thiazole unit for thiophene. The lower aromatic stabilization energy of thiazole in relation to that of thiophene was considered to be responsible for the thermal stability of the closed‐ring isomers of thiazolyl‐substituted terarylenes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
New Amino Endoperoxides Belonging to the Antimalarial G‐Factor Series
Authors: Givelet Cécile , Bernat Virginie , Danel Mathieu , André‐Barrès Christiane , Vial Henri
Published: May 2007

In the search for new antimalarial endoperoxides we developed a direct route for the preparation of new amino compounds belonging to the G‐factor series. During the synthesis, a significant difference in reactivity between two series of diastereoisomers was observed. The final amino endoperoxides were obtained with 58 to 70 % yields, depending on the starting amine, in the “anti” series, but with the “syn” diastereoisomers an unexpected rearrangement occurred during the deprotection step. This was attributed to a transient hexacoordinate fluorosilicon complex allowing the formation of a 1,2‐dioxetane. Its decomposition gave aldehyde 12 and 4‐hydroxybutan‐2‐one; these compounds were also identified when acidic conditions were used in the deprotection step. The anti amino compounds obtained were tested, but in vitro activities were found to be lower than initially expected, and fitted poorly with the previous biological hypothesis.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Electroanalytical Determination of Lidocaine in Pharmaceutical Preparations Using Boron‐Doped Diamond Electrodes
Authors: Oliveira Robson T. S. , Salazar‐Banda Giancarlo R. , Ferreira Valdir S. , Oliveira Silvio C. , Avaca Luis A.
Published: May 2007

A new electroanalytical procedure was developed for the determination of lidocaine in commercial local anesthetics products containing lidocaine as the active ingredient. The procedure is based on the use of electrochemical methods as cyclic and square‐wave voltammetry, with boron‐doped diamond electrodes. The oxidation of lidocaine in Britton–Robinson buffer (0.1 mol L−1) using this type of electrode gives rise to one irreversible peak in 1.68 V (versus Ag/AgCl). The detection and quantification limits obtained from pure water were 10.0 and 34.4 μg/L, respectively. The proposed electrochemical method was also successfully applied to the analysis of commercially available pharmaceutical preparations. The electrochemical responses of pharmaceutical preparations (gels) were identical to those of standard lidocaine. No influence of propyleneglycol present in the gels on the voltammetric responses was observed. Lidocaine recoveries ranged from 97.6% to 99.2%.
A Potentiometric Stripping Analyzer for Multianalyte Screening
Authors: Adami Manuela , Marco Sartore , Nicolini Claudio
Published: May 2007

The paper describes a simple and low‐cost multisensing instrument based on neural network to monitor multiple environmentally significant metals in solution by implementing the potentiometric stripping analysis technique. Our analyzer consists of a measuring unit, implemented on a lap‐top/notebook computer equipped with a simple electronic circuitry, and a reusable sensor, based on glassy‐carbon technology. The current system has been characterized with synthetic samples containing different concentrations of lead, copper, cadmium and zinc, showing detection limits suitable for the first monitoring of metal traces. A linear relationship between peak area and concentration has been observed for all tested metals. Therefore, a simple linear regression can be used by the analyzer to determine the actual metal concentration from the PSA peak area. The presence of a second metal or of a real matrix, often, interferes with stripping measurements in different ways: compounds with oxidation potentials close to that of the analytes of interest may interfere if the instrument does not have sufficient resolution to resolve the overlapping PSA peaks; species which form intermetallic compounds with the analytes may result in erroneously low analyte concentration readings, since the oxidation potential of the intermetallic compound is rarely near that of the original analyte. In order to overcome these problems, the described analyzer has been integrated with a Neural Network algorithm, able to separate the different contributions, after a proper training.
Design and Development of Imprinted Polymer Inclusion Membrane‐Based Field Monitoring Device for Trace Determination of Phorate (O,O‐Diethyl S‐Ethyl Thiomethyl Phophorodithioate) in Natural Waters
Authors: Prasad Karamala , Prathish Krishnapillai Padmajakumari , Gladis Joseph Mary , Naidu Gurijala Ramakrishna , Rao Talasila Prasada
Published: May 2007

A biomimetic potentiometric field monitoring device was developed for the trace determination of phorate (O,O‐diethyl S‐ethyl thiomethyl phophorodithioate) in natural waters. The sensing element was fabricated by the inclusion of phorate imprinted polymer materials in the polyvinyl chloride (PVC) matrix. The sensor surface can be reused without conditioning unlike most other conventional sensors. Operational parameters such as amount and nature of plasticizers sensing material, pH and response time were optimized. The response characteristics of the non‐imprinted (NIPIM) and imprinted polymer inclusion membrane (IPIM) sensors for phorate were compared under optimum conditions. The IPIM sensor responds linearly to phorate in the concentration in the ranges 1×10−9 to 1×10−6 M and 1×10−6 to 1×10−5 M of different slopes with a detection limit of 1×10−9 M. The selectivity was tested with various common organophosphorous (OP) pesticides and herbicides. In addition to superior sensitivity and selectivity of IPIM over NIPIM‐based sensor, IPIM‐based phorate sensor was found to be stable for 3 months and can be used for more than 40 times without any loss in sensitivity. The applicability for analyzing ground, river and tap‐water samples was successfully demonstrated via recovery studies.
Quantized Double‐Layer Charging of Iron Oxide Nanoparticles on a‐Si:H Controlled by Charged Defects in a‐Si:H
Authors: Weis Martin , Gmucová Katarína , Nádaždy Vojtech , Capek Ignác , Šatka Alexander , Kopáni Martin , Cirák Július , Majková Eva
Published: May 2007

Sequential single‐electron charging of iron oxide nanoparticles encapsulated in oleic acid/oleyl amine envelope and deposited by the Langmuir‐Blodgett technique onto Pt electrode covered with undoped hydrogenated amorphous silicon film (a‐Si:H) is reported. Quantized double‐layer charging of nanoparticles is detected by cyclic voltammetry as current peaks and the charging effect can be switched on/off by the excess of negative/positive charged defect states in the a‐Si:H layer. The particular charge states in a‐Si:H are created by the simultaneous application of a suitable bias voltage and illumination before the measurement.
Performance‐based seismic bridge design for damage and loss limit states
Authors: Mackie K. R. , Stojadinović B.
Published: May 2007

Recent efforts in the earthquake engineering community have focused largely on developing a performance‐based earthquake engineering assessment methodology. However, equally important is applying such a methodology to the design of structures. Probabilistic performance‐based seismic design enables design and acceptance criteria to be specified by a continuum of limit states and incorporates uncertainty in all the sources of data. This paper introduces a non‐iterative method, based on the Pacific Earthquake Engineering Research Center framework, for design of bridge structures in terms of single or multiple physical design parameters, such as column height and diameter. Design parameter solutions are obtained from explicit consideration of uncertainty in the hazard, demand, damage, and loss to the structure by way of specifying a level of confidence in the resulting design under different performance objectives. Similar to other performance‐based methodologies, performance objectives consist of a performance level and a hazard level. Design equations are derived for performance levels defined in terms of bridge damage and loss. Examples are presented of both univariate and bivariate design parameter cases for typical reinforced concrete highway overpass bridges in California. Copyright © 2007 John Wiley & Sons, Ltd.
Impact of personality on termination of short‐term group psychotherapy in depressed elderly outpatients
Authors: Canuto Alessandra , Meiler‐Mititelu Corina , Herrmann François , Giannakopoulos Panteleimon , Weber Kerstin
Published: May 2007

Objective

Termination in group psychotherapy is an essential phase of the psychotherapeutic process, yet its clinical determinants remain largely unknown, especially in elderly patients. The aim of this study was to assess how patients' personality traits influence their way of leaving a short‐term psychotherapy group as well as a larger therapeutic community program.

Method

Personality traits were assessed with the NEO Five‐Factor Inventory in 24 elderly depressed outpatients. Patients' terminations from the group as well as from the community were ranked into four classes according to their appropriateness (completeness of experience and ability to deal with feelings of separation).

Results

Neuroticism was not related to the quality of termination. In contrast, agreeableness and openness to experience were strongly associated with successful termination. Conscientiousness and extraversion may have a differential impact depending on the type of group (group psychotherapy versus therapeutic community).

Conclusion

Personality traits may be important clinical determinants of the quality of termination process in both group psychotherapy and therapeutic community settings for elderly depressed patients. Copyright © 2007 John Wiley & Sons, Ltd.
A methodological and operative framework for the evaluation of an e‐health project
Authors: Buccoliero Luca , Calciolari Stefano , Marsilio Marta
Published: May 2007

Assessing public sector ICT investments represents the premise for successful implementation of an e‐health strategy. The recent literature stresses the importance of going beyond the mere financial and/or technical dimensions of the analysis. Consequently, the paper proposes an example of e‐health project evaluation aiming to develop measures which get close to the notion of benefits to the different stakeholders involved: top management, patients, local community. The case study refers to an Italian health care organization that implemented a project of digitalization of its clinical reports production few years ago. Based on on‐field research, different approaches are used to assess costs and benefits from different stakeholders' perspectives. The results of a multidimensional evaluation are reported to emphasize the need for different measures to assess the sustainability of an e‐health project according to the financial convenience, the social role of the organization, and the contingent situation. Copyright © 2007 John Wiley & Sons, Ltd.
Financial profiling of public hospitals: an application by data mining
Authors: Ozgulbas Nermin , Koyuncugil Ali Serhan
Published: May 2007

This paper presents an application of the data mining method to determine the financial profiles of the public hospitals in Turkey. The study is based on the data compiled in 2004, covering 645 public hospitals run by the Ministry of Health (MoH) as the main provider of primary and secondary health services in Turkey. The public hospitals, currently financed by a mixture of funds allocated from the general budget and individually operated revolving funds, need urgent solutions to their financial problems as a part of an ongoing national reform effort. The analysis adopts the Chi‐Square Automatic Interaction Detector (CHAID) decision tree algorithm, as one of the most efficient and up‐to‐date data mining method used for segmentation.

The study has found that the public hospitals could be categorized by the CHAID into 12 different profiles in terms of their financial performance. These profiles have guided us in determining the key financial indicators to be focused upon in the public hospitals and present best practices to improve their respective financial performances. The findings have also allowed policy suggestions as to the financial strategies that may be considered in improving the financial performance of the public hospitals toward a successful health sector reform in Turkey. Copyright © 2007 John Wiley & Sons, Ltd.
Template‐directed patterning of polymers and biomaterials
Authors: Chandekar Amol , Sengupta Sandip K. , Whitten James E.
Published: May 2007

A novel method of patterning surfaces with synthetic or biological polymers is demonstrated. It consists of using microcontact printing to pattern a gold surface with an adsorbate that imparts hydrophilicity; the remainder of the surface is covered with one that imparts hydrophobicity. 16‐Mercaptohexadecanoic acid (MHDA) and 1H,1H,2H,2H‐perfluorodecanethiol, respectively, have been used as the hydrophilic and hydrophobic adsorbates. This functionalized gold surface then serves as a template for patterning hydrophilic polymers and biomaterials, which are either spin‐coated or drop‐cast onto the surface. Using this methodology, it is shown by atomic force microscopy, scanning electron microscopy (SEM), and fluorescence microscopy that micron‐scale patterns of a poly(ethylene)‐block‐poly(ethylene oxide) copolymer, poly‐L‐tryptophan, and bovine collagen can be fabricated, with these mimicking the MHDA patterns. For the block copolymer, it is found by atomic force microscopy that the heights of the polymer patterns decrease as their widths decrease. This is believed to be due to the inherent instability of tall, narrow polymer structures and the tendency of the polymer to minimize its exposed surface area. For poly‐L‐tryptophan, two different molecular weights of this polyamino acid have been studied, and different morphologies within the patterned regions are observed. While oligomeric poly‐L‐tryptophan (1,000–5,000 g/mol) gives smooth MHDA‐covered patterns, the higher molecular weight (15,000–50,000 g/mol) yields fibrous ones. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
AFM studies of nanoparticle deposition via electrospray ionization
Authors: Therrien Joel , Dindar Amir , Smith David
Published: May 2007

Electrospray ionization was used to deposit CdSe nanoparticles on graphite and InP substrates. The charge transferred to the substrate via the deposition was correlated to the number of particles found on the substrate by AFM observation. A charge per nanoparticle was determined from depositions of various lengths of time, which is ∼1 electron per nanoparticle. This value was found to be consistent for concentrations of nanoparticle solutions, which differed by an order of magnitude. Such a value may be used for predicting the density of nanoparticles deposited on a substrate during the deposition. It was found that above a critical concentration, the deposition process produced large clumps of particles rather than individual particles. At lower concentrations, individual particles deposited on the graphite substrates were found to be mobile, arranging themselves on step edges of the graphite. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Nanoparticle scanning and detection on flat and structured surfaces using fluorescence microscopy
Authors: Guldiken Rasim , Makaram Prashanth , Bakhtari Kaveh , Park Jingoo , Busnaina Ahmed A.
Published: May 2007

A new technique is proposed for the scanning and detection of nanoparticles on flat substrates and three‐dimensional structures using fluorescence microscopy. This technique is utilized for particle removal measurements especially in semiconductor and hard disk manufacturing. This fluorescent particle scanning technique enables nanoscale particle detection. The technique shows that single particles down to 63 nm could be detected and counted. The technique is also capable of detecting particles in trenches that are as deep as 500 μm. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Surviving the years of infancy: longevity among small firms in Nigeria, 1971–1997
Authors: Sam Monibo A.
Published: May 2007

It is widely believed that a common pattern exists in the closure of small firms in Africa. Typically, these firms are reported to die in their first three years of life. Like any generalisation, this view fails to take into account probable variations across segments of the small business sector. A few recent reports on small firms in Nigeria and in southern Africa draw attention to this limitation. In this paper, we draw on the experience of privately incorporated firms in Nigeria to report a closure pattern that diverges significantly from that of the sector generally. Our finding that only a small fraction of the closures occurred in the infancy of the firms has implication for research and policy on small businesses. Copyright © 2007 John Wiley & Sons, Ltd.
TFP growth and resource allocation in Singapore, 1965–2002
Authors: Akkemik K. Ali
Published: May 2007

This paper investigates the impact of the reallocations of resources across manufacturing industries on aggregate manufacturing TFP growth in Singapore for the period 1965–2002. This is done by decomposing aggregate TFP growth into its sources, TFP growth arising from within individual industries and from the reallocations of capital and labour. The results show that TFP growth was negative before 1985 but improved remarkably to positive figures after 1985. Resource reallocations are found to account for a large portion of this improvement in aggregate TFP growth. Copyright © 2007 John Wiley & Sons, Ltd.
Hybrid mode-locked, diode-pumped Nd:Gd0.7Y0.3VO4 laser
Authors: Sirotkin A A , Kutovoi S A , Zavartsev Yu D , Mikhailov V A , Zagumennyi A I , Kalachev Yu L , Shcherbakov I A , Renner-Erny R , Lüthy W , Feurer T
Published: May 2007

A Nd:Gd0.7Y0.3VO4 crystal is grown in laser quality. The crystal is diode-pumped at 808 nm. When operated in a Z-shaped resonator with an acousto-optical modulator in combination with a Kerr lens, it produces pulses of 1.7 ps at 140 MHz repetition rate.
Optical coherence tomography using a tapered single mode fiber tip
Authors: Verma Y , Divakar Rao K , Mohanty S K , Gupta P K
Published: May 2007

We report the use of a chemically etched tapered single mode fiber tip for enhancing lateral resolution in optical coherence tomography (OCT). The important advantage of this approach is that high lateral resolution is achieved, without compromising the depth of imaging, as is the case with the use of high numerical aperture objectives. Use of the tapered tip in the sample arm of a single mode fiber based set-up allowed visualization of intracellular structures of Elodea densa plant leaf that could not be seen by the conventional OCT.
Four photon low-frequency Raman spectroscopy of single wall carbon nanotubes
Authors: Bunkin A F , Pershin S M
Published: May 2007

Here we present the data of study of carbon nanotubes at ultra low (less than 0.1 μg/ml) concentration in aqueous surfactant suspension by four photon coherent Raman spectroscopy technique. The spectra have been recorded separately in the two spectral ranges from 100 to 250 cm-1 (3 – 7.5 THz) and ± 10 cm-1 (± 300 GHz). The two nanotube radial breathing modes (RBM) at 235 and 165 cm-1 have been observed. Besides we have detected the increasing of the rotational spectrum amplitude of H2O molecule arising on the water-nanotube interface. In fact, the amplitude increasing is observed mainly for ortho- spin-isomers of H2O.
Evaluation of Endothelial Cell Adhesion onto Different Protein/Gold Electrodes by EIS
Authors: Bouafsoun Amira , Helali Saloua , Othmane Ali , Kerkeni Abdelhamid , Prigent Anne‐France , Jaffrézic‐Renault Nicole , Bessueille François , Léonard Didier , Ponsonnet Laurence
Published: May 2007

To study cell attachment to biomaterials, several proteins such as fibronectin, collagen IV, heparin, immunoglobulin G, and albumin have been deposited onto polystyrene adsorbed on a self‐assembled monolayer (silane or thiol) on glass or gold, respectively. The different steps of this multilayer assembly have been characterized by electrochemical impedance spectroscopy (EIS). These data are compared to those of adhesion rate, viability percentage, and cytoskeleton labeling for a better understanding of the cell adhesion process to each protein. All the proteins are endothelial cell adhering biomolecules but not with the same features. A linear relationship has been established between adhesion rate and resistance of the endothelial cell/protein interface for all negatively charged proteins.

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A Micro/Nanoscale Surface Mechanical Study on Morpho‐Functional Changes in Multilineage‐Differentiated Human Mesenchymal Stem Cells
Authors: Danti Serena , D'Acunto Mario , Trombi Luisa , Berrettini Stefano , Pietrabissa Andrea
Published: May 2007

In recent years MSCs have become a very attractive tool in tissue engineering and regenerative medicine because of their ability to be committed along several lineages through chemical or physical stimuli. Nevertheless their therapeutic potential and plasticity are not yet totally understood. This report describes the use of AFM together with conventional microscopies to obtain mechanical information on cell surfaces and deposited extra cellular matrix molecules, after inducing the differentiation of human MSCs towards three typical mesoderm phenotypes. The aim is to correlate morphological, functional, and mechanical aspects of human MSCs to obtain a deeper understanding of their great potential.

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Chitosan Based Hydrogel Microspheres as Drug Carriers
Authors: Vodná Lucia , Bubeníková Silvia , Bakoš Dušan
Published: May 2007

Chitosan/tripolyphosphate (CHIT/TPP) and chitosan/tripolyphosphate/chondroitin sulfate (CHIT/TPP/CHS) core‐shell type microspheres were prepared by polyelectrolyte complexation in order to develop a biocompatible matrix for drug delivery. The continual method using a multi‐loop reactor under sterile conditions was applied for microsphere preparation. All the types of microspheres produced were spherical in shape and had a porous structure. The mechanical resistance of the microspheres increased in the presence of CHS as the second polyanion, which toughened the microsphere shell structure. For a drug release application, the process of microsphere preparation was modified by dissolving ofloxacin (OFL), the fluoroquinolone antibiotic, in CHIT solution before complex formation. This study shows the difference in OFL release comparing the microspheres CHIT/TPP and CHIT/TPP/CHS and implies the potential to control this process.

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Macromolecular Biomaterials for Scaffold‐Based Vascular Tissue Engineering
Authors: Couet Frédéric , Rajan Navneeta , Mantovani Diego
Published: May 2007

Cardiovascular diseases are increasingly becoming the main cause of death all over the world, which has led to an increase in the economic and social burden of such diseases. Vascular tissue engineering (VTE) is providing a route towards interesting applications, mainly focussing on the in vitro, in vivo, or combined in vitro/in vivo regeneration of small‐diameter blood vessels (<6 mm) for coronary or peripheral vascular substitutions. Although different approaches have been investigated in the past two decades to achieve this aim, the most common method uses a macromolecular‐based structure to scaffold cells during the regeneration process. Therefore, the aim of this work is to comprehensively review macromolecular biomaterials that were designed, developed, fabricated, and tested for scaffolding VTE. In an effort to provide a comprehensive overview, this review will mainly focus on the mechanical properties of the construct and its biological performance that results from the scaffold colonization during cell growth.

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Influence of Coupling Agents on Melt Flow Behavior of Natural Fiber Composites
Authors: Hristov Velichko , Vlachopoulos John
Published: May 2007

The influence of coupling agents on the melt rheological properties of natural fiber composites has been investigated in this work using capillary and rotational rheometers. Scanning electron microscopy was also employed to supplement the rheological data. It was found that molecular weight and molecular weight distribution of the polymer matrix and coupling agent characteristics influence the filler wetting and the melt flow properties of the filled composites. Generally, low molecular weight and narrow molecular weight distribution polyethylene matrix provides relatively larger increase of the viscosity of the composites. Coupling agents tend to increase the resistance to shearing, but wall slip effects may interfere with the measured values, especially at very high filler loadings. Entrance pressure loss in capillaries is also influenced by polymer matrix and coupling agent used.

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Mechanical Properties of Porous Polylactide/Chitosan Blend Membranes
Authors: Wan Ying , Wu Quan , Wang Sheng , Zhang Shengmin , Hu Zhilin
Published: May 2007

Porous membranes were fabricated using chitosan and poly(DL‐lactide) or poly(L‐lactide) blends through a combinatorial technique. Well‐controlled porous structures could be achieved by optimizing processing conditions. The ductility and toughness of dry porous membranes were improved by incorporating an increased amount of chitosan, and the physical strength and dimensional stability of hydrated porous membranes were preserved if the components were used in a suitable ratio. Although there were measurable differences in the pore‐size distributions of membranes with the same composition prepared under identical conditions, this showed no effect in their dry states.

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The Influence of the Irradiation Temperature on the Ratio of Chain Scission to Branching Reactions in Electron Beam Irradiated Polytetrafluoroethylene (PTFE)
Authors: Lappan Uwe , Geißler Uwe , Scheler Ulrich
Published: May 2007

Polytetrafluoroethylene (PTFE) films have been irradiated by electron beam in vacuum at various temperatures ranging from room temperature up to temperatures far above the melting temperature. Changes of the chemical structure have been analyzed by 19F solid‐state NMR and IR spectroscopy. The concentration of several structures generated by irradiation increases with increasing irradiation temperature up to the beginning of the thermal degradation. The molar ratio of >CF branching points to CF3 end groups changes with crossing of the melting temperature. The generation of >CF branching points is accelerated if the PTFE is irradiated in the molten state, where branching reactions become more important.

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