bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autologous peripheral blood progenitor cell transplantation
Authors: Anderson Kenneth C. 
Published: February 2007

AbstractHarvesting of autologous peripheral blood stem cells (PBSCs) has been facilitated by using currently available, efficient apheresis technology at the time of rebound from chemotherapy while patients are receiving recombinant growth factors, i.e., granulocyte (G) or granulocyte‐macrophage (GM) colony stimulating factor (CSF). Ideally pheresis should be done before patients have had extensive stem cell toxins, i.e., alkylating agents or nitrosoureas. This strategy has facilitated the use of high dose chemoradiotherapy given as a single regimen or in a divided dose for patients with solid tumors or hematologic malignancies and results in more rapid engraftment than bone marrow transplantation (BMT). Although mere are no assays which measure repopulating stem cells, enumeration of CD34+ cells within PBSCs is a direct and rapid assay which provides an index of both early and late long‐term reconstitutive capacity, since it correlates with colony‐forming unit (CFU)‐GMs, as well as pre‐progenitor or delta assays and long‐term culture‐initiating cells (LTC‐IC). A threshold of ≥2 × 106 CD34+ cells/kg recipient body weight has been reported to be required for engraftment, but may vary depending upon the clinical setting. Strategies for mobilization of normal PBSCs also increase tumor cell contamination within PB in the setting of both hematologic malignancies and solid tumors, but the significance of these tumor cells in terms of patient outcome is unclear. Recently isolation of CD34+ cells from PBSCs has been done using magnetic beads or immunoabsorption on columns or rigid plates in order to enrich for normal hematopoietic progenitors and potentially decrease tumor cell contamination. As for other cellular blood components, standards have been developed to assure efficient collection and processing, thawing, and reinfusion, and to maintain optimal PBPC viability. Finally, future directions of clinical research include expansion of hematopoietic progenitor cells ex vivo; use of umbilical cord or placenta as rich sources of progenitor cells; syngeneic hematopoietic stem cell transplantation; related and unrelated allogeneic hematopoietic stem cell transplantation; treatment of infections, i.e., Epstein Barr virus, or tumor relapse after allogeneic BMT using donor PBSC infusions; and gene therapy approaches.
Balancing work and family: a field study of multi‐dimensional, multi‐role work‐family conflict
Authors: Premeaux Sonya F. , Adkins Cheryl L. , Mossholder Kevin W. 
Published: February 2007

AbstractLittle is known about the effectiveness of family‐friendly policies (FFPs) in reducing interrole conflicts involving work and family. The present study examined the influence of FFPs, work‐family culture, and family characteristics on salient job outcomes, and multiple dimensions of work‐family conflict (WFC) and family‐work conflict (FWC). Results from a survey of 564 workers, indicate that FFPs exert minimal effects on felt conflict, and that a positive work‐family culture and family support may be more instrumental in helping employees balance work and home roles. Findings also suggest that sources of conflict varied among workers, as did the mechanisms used to address WFC and FWC. This study underscores the importance of examining WFC as a multi‐dimensional phenomenon affecting employees in a variety of family structures, as well as considering the impact of FFPs in conjunction with work‐family culture. Copyright © 2007 John Wiley & Sons, Ltd.
Leader–member social exchange (LMSX): development and validation of a scale
Authors: Bernerth Jeremy B. , Armenakis Achilles A. , Feild Hubert S. , Giles William F. , Walker H. Jack 
Published: February 2007

AbstractIn the last 10 years, research devoted to the construct of leader–member exchange (LMX) has increasingly relied on the tenets of social exchange as a theoretical foundation to propose and test relationships between supervisor‐subordinate dyads and variables of significant consequence. Despite the theory underpinning such relationships, researchers continue to measure LMX with scales developed to assess vertical dyad linkage (VDL), not social exchange. To address this concern, we investigated the content validity of LMX7 (the most widely cited measure of LMX) and LMX‐MDM (a popular multidimensional measure of LMX). Findings from content validity assessments by 25 LMX experts revealed LMX7 and LMX‐MDM items are not representative of the construct of social exchange. As such, we undertook a series of studies to develop a new scale we label, leader–member social exchange (LMSX). Results indicate LMSX is able to assess different, as well as the same, components of the supervisor–subordinate relationship as previous scales while being more theoretically consistent with the notion of social exchange. Copyright © 2007 John Wiley & Sons, Ltd.
Ice‐borne prehistoric finds in the Swiss Alps reflect Holocene glacier fluctuations
Authors: Grosjean Martin , Suter Peter J. , Trachsel Mathias , Wanner Heinz 
Published: February 2007

AbstractDuring the hot summer of 2003, reduction of an ice field in the Swiss Alps (Schnidejoch) uncovered spectacular archaeological hunting gear, fur, leather and woollen clothing and tools from four distinct windows of time: Neolithic Age (4900 to 4450 cal. yr BP), early Bronze Age (4100–3650 cal. yr BP), Roman Age (1st–3rd century AD), and Medieval times (8–9th century AD and 14–15th century AD). Transalpine routes connecting northern Italy with the northern Alps during these slots is consistent with late Holocene maximum glacier retreat. The age cohorts of the artefacts are separated which is indicative of glacier advances when the route was difficult and not used for transit. The preservation of Neolithic leather indicates permanent ice cover at that site from ca. 4900 cal. yr BP until AD 2003, implying that the ice cover was smaller in 2003 than at any time during the last 5000 years. Current glacier retreat is unprecedented since at least that time. This is highly significant regarding the interpretation of the recent warming and the rapid loss of ice in the Alps. Copyright © 2007 John Wiley & Sons, Ltd.
Microwave‐Assisted Esterification of Methacrylic Acid and Polymer‐Analogous Esterification of Poly[ethylene‐co‐(acrylic acid)] with Dissimilar Phenols
Authors: Bezdushna Ella , Ritter Helmut 
Published: February 2007

AbstractPhenyl methacrylate and p‐tolyl methacrylate were synthesized by starting directly from methacrylic acid and the corresponding phenols. Polymer‐analogous esterification on poly[ethylene‐co‐(acrylic acid)] (PEAA) was performed with phenol, p‐methoxyphenol, and 2,4,6‐trimethylphenol. The synthesized compounds were characterized by FT‐IR and 1H NMR measurements. The esterification reactions were performed under solvent‐free conditions using an acid catalyst under microwave irradiation and in an oil‐bath, for comparison. It was shown that MW irradiation effectively promotes the esterification especially on the polymeric system. Differential scanning calorimetry was employed to study the thermal behavior of modified and unmodified PEAA. One pot reaction and reaction time within minutes are the main advantages of the MW method.magnified image
Microwave‐Assisted Homogeneous Polymerizations in Water‐Soluble Ionic Liquids: An Alternative and Green Approach for Polymer Synthesis
Authors: Guerrero‐Sanchez Carlos , Lobert Matthias , Hoogenboom Richard , Schubert Ulrich S. 
Published: February 2007

AbstractWater‐soluble ionic liquids (IL) were used as reaction media to perform homogeneous polymerizations under microwave irradiation. The investigated reaction systems include the free radical polymerization of methyl methacrylate and the cationic ring opening polymerizations of 2‐phenyl‐2‐oxazoline and 2‐(m‐difluorophenyl)‐2‐oxazoline. The incorporation of ILs into the polymerizations showed a more efficient heating profile of the reaction mixtures under microwave irradiation in comparison to the cases without ILs. Moreover, a convenient approach for the polymer isolation and recovery of the ILs for further polymerizations is demonstrated taking advantage of the water solubility of the investigated ILs. This synthetic approach is an alternative, efficient, and green method for the manufacture of hydrophobic polymers which may allow depletion of the emission of volatile organic compounds into the environment and for energy savings.magnified image
Preparation of Novel Metallic and Bimetallic Cross‐Linked Poly(vinyl alcohol) Nanocomposites under Microwave Irradiation
Authors: Nadagouda Mallikarjuna N. , Varma Rajender S. 
Published: February 2007

AbstractA facile method utilizing microwave irradiation is described that accomplishes the cross‐linking reaction of PVA with metallic and bimetallic systems. Nanocomposites of PVA‐cross‐linked metallic systems such as Pt, Cu, and In and bimetallic systems such as Pt‐In, Ag‐Pt, Pt‐Fe, Cu‐Pd, Pt‐Pd and Pd‐Fe were prepared expeditiously by reacting the respective metal salts with 3 wt.‐% PVA under microwave irradiation, maintaining the temperature at 100 °C, a radical improvement over the methods for preparing cross‐linked PVA described in the literature. The general preparative procedure is versatile and provides a simple route to manufacturing useful metallic and bimetallic nanocomposites with various shapes, such as nanospheres, nanodendrites and nanocubes.magnified image
Scale‐Up of Microwave‐Assisted Polymerizations in Continuous‐Flow Mode: Cationic Ring‐Opening Polymerization of 2‐Ethyl‐2‐oxazoline
Authors: Paulus Renzo M. , Erdmenger Tina , Becer C. Remzi , Hoogenboom Richard , Schubert Ulrich S. 
Published: February 2007

AbstractMicrowave‐assisted polymerizations is a growing field of interest because the use of microwave irradiation instead of thermal heating was demonstrated to result in faster, cleaner, and higher yielding reactions. To overcome the one‐at‐a‐time nature of preparing polymerizations in single microwave vials and the possible scale‐up method for microwave‐assisted polymerizations, the use of continuous‐flow reactions under microwave irradiation seems to be ideal. In this contribution, we report for the first time the use of different continuous‐flow microwave reactors for polymerizations, using the cationic ring‐opening polymerizations of 2‐ethyl‐2‐oxazoline as a model system. In addition, the observed broader molecular‐weight distributions were correlated to residence time distributions of the continuous‐flow reactors that were determined using methyl orange as the flow marker.magnified image
Water Diffusion in Glassy Polymers and their Silica Hybrids: an Analysis of State of Water Molecules and of the Effect of Tensile Stress
Authors: Larobina Domenico , Lavorgna Marino , Mensitieri Giuseppe , Musto Pellegrino , Vautrin Alain 
Published: February 2007

AbstractIn‐situ, time‐resolved FTIR spectroscopy along with gravimetric analysis have been used to investigate water sorption and transport in several glassy polymeric matrices, characterized by different levels of interaction with water, as well as on polymer‐silica hybrids. This technique has also been coupled to a dynamical‐mechanical analyser to gather information on the water sorption kinetics and thermodynamics in a polymer sample submitted to stretching deformation and load. Results have been modelled by coupling the mass balance and momentum balance, using a theoretical approach developed for elastic matrices and low sorbed amounts by Larché and Cahn.
Air‐Coupled Ultrasonic Cure Monitoring of Unsaturated Polyester Resins
Authors: Lionetto Francesca , Tarzia Antonella , Coluccia Miriam , Maffezzoli Alfonso 
Published: February 2007

AbstractAir‐coupled ultrasound in one‐side transmission mode has been applied to monitor the curing process of an unsaturated polyester resin, commonly used as a matrix in glass reinforced composites. The evolution of the resin mechanical properties during cure has been measured from the variation of longitudinal velocity. The technique has demonstrated to be a very powerful tool for detecting the structural changes occurring at gelation and vitrification. The no‐contact ultrasonic results have been compared with those obtained using conventional contact ultrasonic measurements, characterized by direct coupling between the transducer and the resin, and with the rheological measurements. The good agreement among the results of the different techniques demonstrates the reliability of air‐coupled ultrasound in monitoring the changes of viscoelastic properties occurring during the cure of thermosetting polymers. A further advantage of the proposed one‐side ultrasonic technique is the absence of physical contact between the transducers and the sample, which is relevant during composite manufacturing, where probe contact could adversely affect the part quality or access from both sides is not practicable. No‐contact ultrasonic cure monitoring is suitable for both stationary and moving liquid or solid samples in several process conditions such as moulding, filament winding, etc., opening the way to new applications of ultrasound in the composite industry.
Rheological and Structure Investigation of Melt Mixed Multi‐Walled Carbon Nanotube/PE Composites
Authors: Nobile Maria R. , Simon George P. , Valentino Olga , Morcom Melanie 
Published: February 2007

AbstractIn this study a series of melt mixed multi‐walled carbon nanotube (MWNT)/Polyethylene composites with several carbon nanotube (CNTs) concentrations were investigated. A good dispersion of the nanotubes in the matrix was seen using scanning electron microscopy. Melt rheological measurements in dynamic mode were used to estimate the percolation state of the CNTs within the polymer and to provide information about the structure of the CNT/polymer composites. The effect of nanotubes on the non‐isothermal crystallization behaviour of the nanocomposites was also studied by differential scanning calorimetry.
Silica‐graft‐polyamidoamine Hybrid Materials: Effect of Constraints on the Polymer Mobility
Authors: Sartore Luciana , Penco Maurizio , Sciucca Stefania Della , D'Amore Alberto 
Published: February 2007

AbstractOrganic‐inorganic hybrid materials with excellent heavy metal ions chelating properties are synthesized by covalent bonding of multifunctional polymers of polyamidoamine (PAA) type onto silica. Two series of polyamidoamine‐silica hybrid materials differing in the PAA chemical structure are prepared and their thermal properties are investigated. Differential Scanning Calorimetry (DSC) is used to study the effects of chain immobilization and ion chelation on the glass‐transition temperature (Tg) of the polymers. The Tg of PAA‐hybrid materials is elevated with respect to ungrafted PAAs, but when the linear and the corresponding hybrid PAAs are in the complex form with metal ions such as Cu2+ and Co2+, the materials arrive to the decomposition temperature and no Tg is detected. To highlight the effect of metal ion on the molecular mobility of these systems, an oligomeric plasticizer is added. The behaviour in the Tg region is analyzed and discussed in term of Tool‐Narayanaswamy‐Moynihan (TNM) model. In particular the apparent activation energy (Δh*) is used to discuss overall segmental co‐operativity in order to better understand the effect of complex formation on structural mobility.
Electrical Properties of Single Walled Carbon Nanotube Reinforced Polystyrene Composites
Authors: Antonucci Vincenza , Faiella Gabriella , Giordano Michele , Nicolais Luigi , Pepe Gianpiero 
Published: February 2007

AbstractComposites of carbon nanotubes (CNT) in polymeric matrices have attracted considerable attention in the research communities due to their good electrical conductivity, high stiffness and high strength at relatively low CNT contents. Effective utilization of CNT in composites depends primarily on the ability to disperse them homogeneously throughout the polymer matrix, avoiding the formation of bundles due to van der Waals interactions existing between the nanotubes. In this work composites of polystyrene at various percentages of SWNT were fabricated using Latex Technology technique, a polymer type‐independent method based on using a surfactant as a dispersing agent. An electrical characterization of SWNT composites was performed both in DC and AC modes. From the analysis of DC data a percolative behavior was found for the conductivity as function of SWNT content. The innovative contribution of this work consists in the modeling of the composite material upon its electrical properties. AC measurements and the analysis of impedance as function of angular frequency lead to the formulation of an equivalent circuit able to model the composite material in correspondence of the percolative threshold.
Modelling and Experimental Characterisation of Hygrothermoelastic Stress in Polymer Matrix Composites
Authors: Gigliotti Marco , Jacquemin Frédéric , Molimard Jérôme , Vautrin Alain 
Published: February 2007

AbstractSummary: The present paper is concerned with the modelling and the simulation of hygrothermal deformation of composite laminates. The temperature and moisture fields are established by employing the Fick's law for transient and cyclical environmental conditions, then the Classical Plate Theory (CLT) adapted for taking into account such conditions is applied. The hygrothermoelastic law of the composite is supposed to be constant but the diffusion coefficients depend on the temperature. The paper shows the ability of the model to handle complex environmental loading, close to service conditions. Finally, a model of plate with moderate rotations is introduced to predict the nonlinear deformations of unsymmetric plates under temperature and moisture cycling conditions.
Coupon Tests on z‐Pinned and Unpinned Composite Samples for Damage Resistant Applications
Authors: Lenzi F. , Riccio A. , Clarke A. , Creemers R. 
Published: February 2007

AbstractThe main objective of the work was to determine the mechanical properties of Z‐pinned and unpinned composites samples. Tensile and interlaminar fracture tests under mode I have been carried out on thermoset polymer matrix composite samples composed of CYTEC 977‐2 and carbon fibre yarn HTA‐12K/35. The presence of the Z‐pins has been found to significantly increase the interlaminar fracture toughness. The crack resistance improvement has been found to be accompanied by a small reduction of the in‐plane stiffness properties for a Z‐pins density of 2%. The results are presented in relation to the size and pinning quality and are rationalised on the basis of the location of Z‐pin block within the sample.
PMMA/PC Blends: Effect of Mixing Conditions on Compatibility
Authors: Penco Maurizio , Sartore Luciana , Sciucca Stefania Della , Di Landro Luca , D'Amore Alberto 
Published: February 2007

AbstractIn this work the effect of melt mixing condition and of a trans‐esterification catalyst on miscibility of poly(methyl methacrylate) (PMMA)/polycarbonate of bisphenol A (PC) blends is studied. In particular, at high temperature chemical reactions between PMMA and PC phases can take place; these strongly change the compatibility in the blend and materials having single Tg can be obtained. FT‐IR analyses, coupled with solvent extraction, suggest that a grafting reaction of PC on PMMA is involved. SEC and DSC data are consistent with spectroscopic results, and some decrement of the molar weight distribution (MWD) of PC phase is observed. On the other hand, the presence of a fraction of modified material having higher MWD of starting PMMA is also noticed. The single Tg characteristic of some materials has been confirmed by experimental data of structural relaxation performed by differential scanning calorimetry (DSC). These materials showed optical clarity and the morphological analysis performed by scanning electron microscopy (SEM) confirm the homogeneity of these materials.
Efficiency and Aging Comparison Between N,N′‐Bis (3‐methylphenyl)‐N,N′‐diphenylbenzidine (TPD) and N,N′‐Di‐[(1‐naphthalenyl)‐N,N′‐diphenyl]‐1,1′‐biphenyl‐4,4′‐diamine (NPD) Based OLED Devices
Authors: Maglione Maria Grazia , Minarini Carla , Miscioscia Riccardo , Nenna Giuseppe , Romanelli Emma , Tassini Paolo 
Published: February 2007

AbstractIn this paper we present and discuss experimental results to evaluate performances and aging behaviour of two Hole Transporting Material (HTM), TPD and NPD, in Organic Light Emitting Device (OLED) with structure: ITO/HTM/Alq3/Al. For each of these HTMs, devices with several thicknesses have been built, to measure and emphasize behaviours of material‐geometry combinations. Electro‐optical properties have been measured to estimate and compare brightness, power efficiency and aging decays.
A Molecular Photosensor Based on Photoswitching of Charge Carrier Mobility
Authors: Weiter Martin , Vala Martin , Zmeškal Oldřch , Nešpůrek Stanislav , Toman Petr 
Published: February 2007

AbstractPolymer photoelectronic device based on interaction between π‐conjugated polymer matrices and photochromic molecules was fabricated. The theoretical and experimental studies proved that the photochromic reaction in studied devices should eventuate in changes of optical and electrical properties of polymers such as luminescence and conductivity. The quantum chemical calculations showed that the presence of dipolar species in the vicinity of a polymer chain modifies the on‐chain site energies and consequently increases the width of the distribution of hopping transport states. Optical switching was studied using standard absorption and photoluminescence spectroscopy. A strong photoluminescence quenching after the photochromic conversion caused by radiative energy transfer was observed. The influence of photoswitchable charge carrier traps on charge transport were evaluated by Space Charge Limited Current (SCLC) method. It was shown that deep traps may significantly affect the energy of the transport level, and thus modulate the transport of charge carriers.
A Study on Thermal Degradation of Organic LEDs Using IR Imaging
Authors: Nenna G. , Flaminio G. , Fasolino T. , Minarini C. , Miscioscia R. , Palumbo D. , Pellegrino M. 
Published: February 2007

AbstractIn this paper, we present a correlation study between the working temperature of OLEDs (Organic Light Emitting Diodes) and the electroluminescence and driving voltage changes. The aim is to investigate the relationship between the operating temperature and the aging mechanisms. We have found that performances degradation of devices is strictly related to the glass transition temperature (Tg) of organic layers, and that electrical failure is reached only for temperatures higher than Tg.