bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain Systems Mediating Cognitive Interference by Emotional Distraction
Authors: Dolcos Florin , McCarthy Gregory
Published: February 2006

Flexible behavior depends on our ability to cope with distracting stimuli that can interfere with the attainment of goals. Emotional distracters can be particularly disruptive to goal-oriented behavior, but the neural systems through which these detrimental effects are mediated are not known. We used event-related functional magnetic resonance imaging to investigate the effect of emotional and nonemotional distracters on a delayed-response working memory (WM) task. As expected, this task evoked robust activity during the delay period in typical WM regions (dorsolateral prefrontal cortex and lateral parietal cortex). Presentation of emotional distracters during the delay interval evoked strong activity in typical emotional processing regions (amygdala and ventrolateral prefrontal cortex) while simultaneously evoking relative deactivation of the WM regions and impairing WM performance. These results provide the first direct evidence that the detrimental effect of emotional distracters on ongoing cognitive processes entails the interaction between a dorsal neural system associated with “cold” executive processing and a ventral system associated with “hot” emotional processing.
Connexin29 Is Highly Expressed in Cochlear Schwann Cells, and It Is Required for the Normal Development and Function of the Auditory Nerve of Mice
Authors: Tang Wenxue , Zhang Yanping , Chang Qing , Ahmad Shoab , Dahlke Ian , Yi Hong , Chen Ping , Paul David L. , Lin Xi
Published: February 2006

Connexins (Cxs) are a family of protein subunits constituting gap junctions, which facilitate exchanges of molecules important for cellular signaling and metabolic activities intercellularly or between different regions of the cytoplasm in the same cells. Mutations in Cxs are the major cause of nonsyndromic childhood deafness, which are mostly found in Cx26 and Cx30 expressed in cochlear supporting cells and fibrocytes. So far, little is known about the functional contribution of Cxs in other types of cochlear cells. Here, we show that Cx29 was highly expressed in the cochlea. The developmental expression time course of Cx29 was similar to that of a myelin marker [myelin associate glycoprotein (MAG)]. Immunolabeling identified Cx29 exclusively in the Schwann cells myelinating the soma and fiber of spiral ganglion (SG) neurons. The absence of the Cx29 gene in mice (Cx29−/−mice), with a penetrance of ∼50%, caused a delay in the maturation of hearing thresholds, an early loss of high-frequency sensitivities, a prolongation in latency and distortion in the wave I of the auditory brainstem responses, and elevated sensitivity to noise damages. The morphology of sensory hair cells and otoacoustic emissions that depend on the integrity of hair cells were normal in Cx29−/−mice. In contrast, decreases in MAG expression and severe demyelination at the soma of SG neurons were found in Cx29−/−mice. Our findings demonstrated the requirement of Cx29 for normal cochlear functions and suggest that Cx29 is a new candidate gene for studying the auditory neuropathy.
Consumers with a Conscience: Will they Pay More?
Authors: Kimeldorf Howard , Meyer Rachel , Prasad Monica , Robinson Ian
Published: February 2006

Most Americans say they will pay more for clothes not made in sweatshops. Is this just talk, or will they actually put their money where their mouth is? An in-store test of consumer behavior turns up some surprising results.
Fashioning Steel
Authors: Barthel-Bouchier Diane
Published: February 2006

Who designs our cars? Are they artists or mere stylists? American and European designers have disagreed, but global production is eroding the differences between the two traditions.
High‐Throughput Real‐Time Quantitative Reverse Transcription PCR
Authors: Bookout Angie L. , Cummins Carolyn L. , Mangelsdorf David J. , Pesola Jean M. , Kramer Martha F.
Published: February 2006

Extensive detail on the application of the real‐time quantitative polymerase chain reaction (QPCR) for the analysis of gene expression is provided in this unit. The protocols are designed for high‐throughput, 384‐well‐format instruments, such as the Applied Biosystems 7900HT, but may be modified to suit any real‐time PCR instrument. QPCR primer and probe design and validation are discussed, and three relative quantitation methods are described: the standard curve method, the efficiency‐corrected ΔCt method, and the comparative cycle time, or ΔΔCt method. In addition, a method is provided for absolute quantification of RNA in unknown samples. RNA standards are subjected to RT‐PCR in the same manner as the experimental samples, thus accounting for the reaction efficiencies of both procedures. This protocol describes the production and quantitation of synthetic RNA molecules for real‐time and non‐real‐time RT‐PCR applications.
Use of LINKAGE Programs for Linkage Analysis
Authors: Speer Marcy C.
Published: February 2006

Genetic linkage analysis remains a powerful tool for identifying regions of the genome that may harbor suceptibility loci. This unit describes the traditional approach of calculating two‐point and multipoint lod scores when the underlying genetic model is known. Components of the genetic model include whether a trait is dominant, recessive, or codominant, whether it is autosomal or sex linked, and whether there is mutation at the disease gene locus, as well as the disease and marker allele frequencies and the penetrance of the disease allele. The approach to genetic linkage analysis presented in this unit assumes that the markers are loosely spaced, so that there is no linkage disequilibrium between genetic markers. Practical examples and step‐by‐step guidelines are presented.
DNA Mutation Detection Using Denaturing High‐Performance Liquid Chromatography (DHPLC)
Authors: Yu Bing , Sawyer Nicole A. , Chiu Christine , Oefner Peter J. , Underhill Peter A.
Published: February 2006

DHPLC is an efficient method for candidate gene scanning with a high level of automation. Single‐base substitutions and insertions or deletions of up to 1.5 kb in PCR amplified DNA fragments can be detected. The method exploits the differential retention of homoduplex and heteroduplex DNA species under conditions of partial thermal denaturation. DHPLC provides a useful platform for high‐throughput mutation detection and SNP discovery.
Characterization of gas crossover and its implications in PEM fuel cells
Authors: Kocha Shyam S. , Deliang Yang J. , Yi Jung S.
Published: February 2006

With pure hydrogen as the fuel, PEM fuel cell operation at or near 100% fuel utilization is desirable to achieve a high stack efficiency and zero emissions. However, typical membranes used in PEM fuel cells allow a finite amount of permeation rates or crossover of hydrogen, oxygen, and nitrogen across the membrane. The hydrogen and oxygen that permeate through the membrane are consumed with the generation of heat and water but without the generating of useful work, leading to a fuel inefficiency. Nitrogen crossover, on the other hand, from the cathode side to the anode side accumulates at the exit of the anode flow fields, lowering the hydrogen concentration and resulting in local fuel starvation. In this study, an in‐situ electrochemical technique has been applied to determine the magnitude of the hydrogen crossover over a range of relevant fuel cell operating temperatures and pressures. Permeability coefficients thus obtained are compared to values reported in the literature. A mathematical model is developed to predict the extent of nitrogen accumulation along the anode flow fields, and fuel recycle as a mitigation method is simulated by improving hydrogen distribution. The model results were validated by comparison with experimental results. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Dynamic modeling of local reaction conditions in an agitated aerobic fermenter
Authors: Laakkonen Marko , Moilanen Pasi , Alopaeus Ville , Aittamaa Juhani
Published: February 2006

Computational Fluid Dynamics (CFD) can be used to investigate local reaction rates and gas‐liquid mass transfer in agitated aerobic fermenters, but it is too slow for the simulation of a whole fermentation batch at present computational capabilities. This problem is addressed in the present work by developing a dynamic model with 42 subregions for a 0.64 m3 pilot xanthan fermenter. The model considers local reaction and mass transfer rates in the fermenter and the change of liquid flow fields during the fermentation. Gas‐liquid mass transfer fluxes are calculated based on the simplified solution of Maxwell‐Stefan diffusion by assuming the mass transfer resistance in both the gas and the liquid side of the gas‐liquid interface. Gas‐liquid mass transfer areas are obtained from Population Balances (PB) for bubbles. The comparison of model predictions to the laboratory stirred tank experiments with aqueous xanthan shows the need of local bubble size distributions (BSD) for the description of complex gas‐liquid hydrodynamics and mass transfer. The model predicts the effect of operating conditions on the temporal and spatial variation of BSDs, mass transfer coefficients, dissolved oxygen concentrations, and xanthan reaction rates in the fermenter. It can be used to investigate fermenter operating strategies. The model is also useful for the scale‐up studies. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Spondyloenchondrodysplasia with spasticity, cerebral calcifications, and immune dysregulation: Clinical and radiographic delineation of a pleiotropic disorder
Authors: Renella Raffaele , Schaefer Elke , LeMerrer Martine , Alanay Yasemin , Kandemir Nurgun , Eich Georg , Costa Teresa , Ballhausen Diana , Boltshauser Eugen , Bonafé Luisa , Giedion Andres , Unger Sheila , Superti‐Furga Andrea
Published: February 2006

Enchondromas are a feature of several constitutional disorders of bone, and the classification of different nosologic entities is still provisional. Among these disorders, spondyloenchondrodysplasia (SPENCD), as outlined by Schorr et al. [1976], is defined by the presence of radiolucent spondylar and metaphyseal lesions that represent persistence of islands of chondroid tissue within bone. Careful review of radiographic findings is needed to distinguish SPENCD from the many other disorders combining enchondromas with spinal lesions. Even when strict criteria are applied, it appears that SPENCD is clinically heterogeneous, as some SPENCD patients are neurologically intact while others present with spasticity, mental retardation, and cerebral calcifications in different combinations, and it has been suggested that SPENCD should be divided in two types. We herein report ten individuals from six families with SPENCD and illustrate the radiographic changes. Seven individuals had CNS manifestations including spasticity, developmental delay, and late‐onset cerebral calcifications. We also noted that six individuals had clinical manifestations of autoimmunity (auto‐immune thrombocytopenic purpura, auto‐immune hemolytic anemia, auto‐immune thyroiditis, and SLE) and one had been diagnosed with immune deficiency. Neurological and autoimmune manifestations were seen in different combinations within one single family. These observations suggest that SPENCD may be a single entity defined by specific radiographic features, but with remarkably pleiotropic manifestations that include CNS disease (spasticity, mental retardation, and calcifications), as well as immune dysregulation ranging from autoimmunity to immunodeficiency. The notion of recessive inheritance hitherto assumed is challenged by the observation of two apparently dominant pedigrees. © 2006 Wiley‐Liss, Inc.
Case of chromosome 6p25 terminal deletion associated with Axenfeld–Rieger syndrome and persistent hyperplastic primary vitreous
Authors: Suzuki Katsuhiro , Nakamura Makoto , Amano Emi , Mokuno Kumiko , Shirai Shoichiro , Terasaki Hiroko
Published: February 2006

Axenfeld–Rieger syndrome is inherited in an autosomal dominant pattern and is characterized by anomalies of the anterior segment of the eye and systemic signs including craniofacial dysmorphic features and cardiac defects. The disorder is genetically heterogeneous and one causative gene, FOXC1, is located on chromosome 6p25. Persistent hyperplastic primary vitreous (PHPV) is a congenital ocular disorder in which there is a failure of the normal regression of the primary vitreous and a proliferation of fibrous tissue from the remnants of the primary vitreous. Deletions of chromosome 6p25 have been reported in a small number of patients with Axenfeld–Rieger syndrome; however, no case of chromosome 6p25 deletion has been reported with PHPV. We report a newborn girl who had both Axenfeld–Rieger syndrome and the combined type of PHPV, in whom the G‐banding and spectral karyotyping revealed a 6p monosomy of terminal deletion with a breakpoint at chromosome 6p25.1. The karyotype was 46,XX,del(6)(p25.1). We conclude that PHPV in the context of Axenfeld–Rieger syndrome can be caused by 6p25 terminal deletion. © 2006 Wiley‐Liss, Inc.
Delineation of a 2.2 Mb microdeletion at 5q35 associated with microcephaly and congenital heart disease
Authors: Bækvad‐Hansen Marie , Tümer Zeynep , Delicado Alicia , Erdogan Fikret , Tommerup Niels , Larsen Lars A.
Published: February 2006

Fine mapping of chromosomal deletions and genotype–phenotype comparisons of clinically well‐defined patients can be used to confirm or reveal loci and genes associated with human disorders. Eleven patients with cytogenetically visible deletions involving the terminal region of chromosome 5q have been described, but the extent of the deletion was determined only in one case. In this study we describe a 15‐year‐old boy with Ebstein anomaly, atrial septal defect (ASD), atrioventricular (AV) conduction defect, and microcephaly. He had an apparently balanced paracentric inversion of chromosome 5, with the karyotype 46, XY,inv(5)(q13q35) de novo. Further mapping of the chromosome breakpoints using fluorescence in situ hybridization (FISH) revealed a 2.2 Mb microdeletion at the 5q35 breakpoint, which spans 16 genes, including the cardiac homeobox transcription factor gene NKX2‐5. The current data suggest that haploinsufficiency of NKX2‐5 cause Ebstein anomaly and support previous results showing that NKX2‐5 mutations cause ASD and AV conduction defect. Furthermore, we suggest presence of a new microcephaly locus within a 2.2 Mb region at 5q35.1–q35.2. © 2006 Wiley‐Liss, Inc.
Clinical findings in 33 subjects with large supernumerary marker(15) chromosomes and 3 subjects with triplication of 15q11‐q13
Authors: Dennis N.R. , Veltman M.W.M. , Thompson R. , Craig E. , Bolton P.F. , Thomas N.S.
Published: February 2006

We present clinical data on 33 subjects with additional copies of the Prader‐Willi‐Angelman critical region (PWACR) contained in a supernumerary marker chromosome (SMC). Twenty‐three subjects had a typical large non‐mosaic SMC(15) containing two copies of the PWACR. They showed a variable but generally severe phenotype of learning disability and autism, with seizures in approximately two‐thirds. The other 10 differed from this typical pattern in respect of mosaicism, variation in copy number, or arrangement of the PWACR within the SMC or number of SMC per cell. Clinical severity increased with the number of additional copies of the PWACR and decreased with mosaicism for a normal cell line. There was a trend for a larger number of seizures to be associated with more severe learning disability. Three subjects with interstitial triplications of 15q11‐q13 showed a range of phenotypes similar to those of the typical large SMC(15). All additional copies of the PWACR in this series were maternally‐derived. FISH and molecular data localizing the breakpoints of the rearrangements have been previously published or are included in this report. No correlations were found between specific clinical features and variations in breakpoints proximal and distal to the PWACR. © 2006 Wiley‐Liss, Inc.
Molecular cytogenetic analysis of a de novo interstitial deletion of 5q23.3q31.2 and its phenotypic consequences
Authors: Tzschach Andreas , Krause‐Plonka Ines , Menzel Corinna , Kalscheuer Vera , Toennies Holger , Scherthan Harry , Knoblauch Andreas , Radke Michael , Ropers Hans‐Hilger , Hoeltzenbein Maria
Published: February 2006

We report a $2{3 \over {12}}$‐year‐old boy with a constitutional interstitial deletion of 5q,46,XY,del(5)(q23.3q31.2) de novo. Clinical manifestations in this patient included failure to thrive, psychomotor retardation, mild facial dysmorphic features, and long and slender fingers and toes. The precise location and extent (9.5 Mb) of the deletion was determined by fluorescence in situ hybridization (FISH) using 19 YAC and BAC clones. Comparison of the present patient with six other patients with deletions of chromosomal bands 5q22–5q31 allowed further delineation of a constitutional del5q22q31 syndrome. The main features of this syndrome are psychomotor retardation, failure to thrive, hypotonia, hypoplastic muscles, cleft or high arched palate, low‐set and dysplastic ears, flat nasal bridge, downslanting palpebral fissures, hypertelorism, anteverted nostrils, and micro‐ and/or retrognathia. © 2006 Wiley‐Liss, Inc.
Primary palmar hyperhidrosis locus maps to 14q11.2‐q13
Authors: Higashimoto Ikuyo , Yoshiura Koh‐ichiro , Hirakawa Naomi , Higashimoto Ken , Soejima Hidenobu , Totoki Tadahide , Mukai Tsunehiro , Niikawa Norio
Published: February 2006

Primary palmar hyperhidrosis (PPH) is a unique disorder of unknown cause. It is characterized by excessive perspiration of the eccrine sweat gland in the palm, sole, and the axilla. It is presumed that PPH results from overactivation of the cholinergic sympathetic nerve or dysfunction of the autonomic nervous system. There have been no genetic studies on the disease. We performed a linkage analysis of 11 families including 42 affected and 40 unaffected members using genome‐wide DNA polymorphic markers to identify the disease locus. Diagnosis of their PPH was made by direct inspection, interviewing and measurement of the sweating rate with perspirometer. Consequently, from data of three of the 11 families examined, the combined maximum two‐point LOD scores of 3.08 and 3.16 (recombination fraction = 0) were obtained at the D14S283 and D14S264 loci, respectively, on chromosome 14q11.2‐q13, under an assumption that two liability conditions depend on age. These regions were ruled out in eight other families. Haplotype analysis of the three families supported that one of the PPH locus is assigned at minimum to about a 6‐cM interval between D14S1070 and D14S990 and at maximum to about a 30‐cM interval between D14S1070 and D14S70. This is the first report of systemic mapping of the PPH locus. © 2006 Wiley‐Liss, Inc.
Using screening walls and advance waivers to manage mediation conflicts of interest
Authors: Lurie Paul M.
Published: February 2006

How can you be a mediator in a law firm without losing business down the road? Paul M. Lurie, of Chicago, analyzes the tough conflicts issues, and proposes setting up a screen, and getting a waiver, from prospective mediation clients. And he provides a clause form that he uses for incorporation into mediation retainer agreements.
Discounts on Alternative's compilation
Authors: Bleemer Russ
Published: February 2006

Alternatives' compilation, “Mediation: Approaches and Insights,” is offered at a 30% discount for CPR members, and a special 15% discount for nonmembers. Also, information on submitting international cases online with the U.S.‐China Business Mediation Center.
Mediation matters: States, insurers focus on ADR for Katrina relief
Authors: Bleemer Russ
Published: February 2006

Details on the role alternative dispute resolution will play in the recovery from Hurricanes Katrina and Rita in the deep south. Calls for deploying ADR have been answered: Two states have hired the American Arbitration Association to conduct mediation facilities for homeowners' claims, and a third will set up a similar program. At the same time, two large insurers have enlisted 9/11 victims fund special master Kenneth Feinberg to administer their mediation efforts. One of the company programs will focus on mediating commercial claims.
Harmonisierter Leitfaden für die Validierung von Analysenmethoden durch Einzellaboratorien
Authors: Steck Werner
Published: February 2006

Die Validierung einer Methode ist eine der Maßnahmen, die allgemein als notwendiger Bestandteil eines umfassenden Qualitätssicherungssystems in der analytischen Chemie angesehen werden. In der Vergangenheit haben ISO, IUPAC und AOAC INTERNATIONAL zusammengearbeitet, um gegenseitig anerkannte Empfehlungen zur Gestaltung, Durchführung und Interpretation von Untersuchungen zur Leistungsfähigkeit analytisch‐chemischer Methoden,1 für Eignungstests (proficiency testing, PT) von (chemisch‐)analytischen Laboratorien,2 zur internen Qualitätskontrolle in analytisch‐chemischen Laboratorien3 und zur Verwendung von Wiederfindungsdaten bei analytischen Messungen4 zu erstellen. Die Arbeitsgruppe, die all diese Empfehlungen verfasst hat, wurde anschließend von der IUPAC beauftragt, Leitfäden für die Validierung von Analysenmethoden durch Einzellaboratorien zu erstellen. Diese Leitfäden bieten Mindestempfehlungen für Maßnahmen, die im Interesse einer adäquaten Validierung von Analysenmethoden durchgeführt werden sollten. (Generelle Vorbemerkung des Übersetzers: In vielen Texten, so auch hier, wird der Ausdruck “Unsicherheit” manchmal ohne genauen Bezug verwendet. Bei der reinen Messunsicherheit handelt es sich um die Wiederholbarkeitsstreuungen (Reproduzierbarkeit) von Messungen einer bestimmten chemisch vorbereiteten Probe, die hintereinander vermessen wird; diese zufällige Unsicherheit des eigentlichen Messvorganges wird charakterisiert durch den Schätzwert s für die Standardabweichung σ. Beim Vermessen von Parallelproben (run) kommen noch weitere Fehlerquellen hinzu, z. B. unzureichende Probenhomogenität, Aliquotisierungsfehler (unsaubere Pipetten) oder leicht unterschiedliche Behandlung. “Run‐to‐run”‐Fehler können durch den Wechsel des Reagentien‐Loses oder eine neue Kalibrierung vor jeder Messserie ausgelöst werden. Alle diese Fehlerquellen haben einen rein zufälligen, statistisch bedingten Anteil und einen variablen, systematischen Fehler aus den unterschiedlichsten Gründen. In die kombinierte Ergebnisunsicherheit gehen alle bekannten Fehler nach den Gesetzen der Fehlerfortpflanzung ein, also vor allem auch Matrixeffekte und Kalibrierungsfehler (einschließlich Auswertefehler durch ungenaue Algorithmen), aber auch die Probenrepräsentanz und ‐homogenität. Die Ergebnisunsicherheit muss daher stets größer sein als die reine Messunsicherheit des eigentlichen Messvorgangs. In bestimmten Fällen gehört zum analytischen Messergebnis aber auch eine professionelle Abschätzung der Probenrepräsentanz.)
Polymerization of methyl methacrylate using bis(β‐ketoamino)nickel(II)–MAO catalytic systems
Authors: He Xiaohui , Wu Qing
Published: February 2006

The polymerization of methyl methacrylate (MMA) was investigated using a series of bis(β‐ketoamino)nickel(II) complexes in combination with methylaluminoxane in toluene solution. The binary catalyst is necessary for initiating MMA polymerization and producing PMMA with high molecular weights but broad molecular weight distributions. The effects of reaction temperature and Al:Ni molar ratios on the polymerization of MMA were examined in detail. Both steric bulk and electronic effects of the substituents around the imino group in the ligand on MMA polymerization activities could be observed. Relative to electronic effects, the steric hindrance of the ligands displayed a more significant effect on the catalytic activities, with the catalytic activity sequence observed in the order 4 > 1 > 2 > 3 > 5 > 6. Structural analyses of the polymers by 13C NMR spectra indicate that polymerization yields PMMA with a syndiotactic‐rich atactic microstructure. Copyright © 2006 John Wiley & Sons, Ltd.
Novel crosslinked nonlinear optical materials based on cellulose diacetate
Authors: Zhou Limin , Xu Qiang , Wang Dening
Published: February 2006

Preparation of second‐order nonlinear optical (NLO) materials based on cellulose diacetate and melamine derivatives was attempted. The NLO chromophore DR19 was incorporated into the crosslinking network resulting from the reaction of cellulose diacetate with trimethylolmelamine or hexamethylolmelamine. The poled and cured NLO materials exhibited electrooptic coefficient (r13) values of 1.11 or 1.03 pm/V, respectively, at a laser wavelength of 1550 nm, a modulation frequency of 12.7 kHz. The r13 values decreased to 80 or 81.5% of the initial values after 4 days. The laser transmission loss was 0.50 or 0.44 db. The crosslinking materials showed better temporal stability than that of host/guest type materials, and 73% of the initial r13 value remained after keeping the NLO film at 100°C for 15 h. No evident weight loss was found below 250°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2832–2837, 2006
Identification of nucleation loci in emulsion polymerization processes. II. A systematic study of liquid–liquid emulsions
Authors: Shastry Vineet , Garcia‐Rubio L. H.
Published: February 2006

Identification of the main nucleation sites and characterizing them in terms of their size and composition is prime objective of this research effort. Different nucleation sites have been proposed as the most likely nucleation sites by various researchers. Recent advances in the development of the spectroscopic techniques enable comprehensive characterization of the emulsion at the beginning of the reaction. In this paper, we present the experimental evidence of the existence of a previously unidentified nano‐droplet population of size range 30 to 100 nm in diameter using spectroscopy. Presence of about seventy to eighty percent of the dispersed phase in the nano‐droplet population and large interfacial area make them the most probable particle nucleation loci in emulsion polymerization processes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2858–2866, 2006
Grafting of poly(methyl methacrylate) or polyacrylonitrile onto polystyrene using ATRP technique
Authors: Tizpar Salamat , Abbasian Mojtaba , Taromi Faramarz Afshar , Entezami Ali Akbar
Published: February 2006

One of the most useful methods for synthesizing the graft and well‐defined copolymers is the atom transfer radical polymerization (ATRP) method. The polymerization was initiated by polystyrene (PS) carrying chloroacetyl groups as macroinitiator, in the presence of copper chloride (CuCl) and bipyridine (bpy). The macroinitiator (chloroacetylated PS) was prepared by successive chloroacetylation of PS under mild conditions and these reaction conditions overcome the problem of gelation and crosslinking in polymers. Successful graft copolymerizations were performed with methyl methacrylate (MMA) in toluene at 80°C and with acrylonitrile (AN) in tetrahydrofuran/ethylenecarbonate (62.5/37.5 v/v %) mixed solvent at 55°C. The characterization of the copolymers was investigated by 1H‐NMR and FT‐IR spectroscopices. Gel permeation chromatography measurement indicated an increase of the molecular weight of the graft copolymers, as compared to that of the macroinitiator. This measurement also indicated the monomodal molecular weight distribution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2619–2627, 2006
Kinetic analysis of curing behavior of diglycidyl ether of bisphenol A with imidazoles using differential scanning calorimetry techniques
Authors: Ghaemy M. , Sadjady S.
Published: February 2006

The curing kinetics and mechanisms of diglycidyl ether of bisphenol A (DGEBA) using imidazole (H‐NI) and 1‐methyl imidazole (1‐MI) as curing agents are studied with differential scanning calorimetry (DSC) under isothermal (90–120°C) and dynamic conditions (50–250°C). The isothermal DSC thermograms of curing DGEBA with H‐NI and 1‐MI curing agents show two exothermic peaks. These peaks are assigned to the processes of adduct formation and etherification. These results indicate that there is no difference in the initiation mechanism of 1‐unsubstituted (H‐NI) and 1‐substituted (1‐MI) imidazoles in the curing reaction with epoxy resin. A kinetic analysis is performed using different kinetic models. The activation energies obtained from DSC scanning runs using the Ozawa and Kissinger methods are similar and in the range of 75–79 and 76–82 kJ/mol for DGEBA/H‐NI and DGEBA/1‐MI systems, respectively. These values compare well with the activation energies obtained from isothermal DSC experiments using the autocatalytic method (74–77 kJ/mol). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2634–2641, 2006
Sorption studies of propylene in polypropylene. Diffusivity in polymer particles formed by different polymerization processes
Authors: Patzlaff M. , Wittebrock A. , Reichert K. ‐H.
Published: February 2006

Propylene was polymerized in gas phase and liquid phase by using a novel nonporous Ziegler–Natta‐catalyst system. The polymer particles formed at different polymerization times were used for sorption measurements. In both cases it was found that the effective diffusion coefficient is increasing with increasing size of polymer particles and the effective diffusion coefficients of polymer particles formed by liquid‐phase polymerization are larger than those of polymer particles produced by gas‐phase polymerization. The effective diffusion coefficients of polymer particles are in the range of 2 × 10−11 to 1.6 × 10−10 m2/s with activation energies from 34 to 22 kJ/mol. The analyzed polymer particles have average diameters between 250 and 875 μm. The solubility of propylene in polypropylene particles can be described by the law of Henry at conditions studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2642–2648, 2006
Alkylated phenolic resins as antioxidants for rubber
Authors: Malshe V. C. , Elango S. , Rane Shilpa
Published: February 2006

Polymeric antioxidants based on p‐nonyl phenol formaldehyde resin (PNPF) and p‐dodecyl phenol formaldehyde resin (PDPF) were prepared by the condensation reaction of the respective phenols with formaldehyde in the presence of an acid catalyst. The reactions were monitored by thin layer chromatography, and the melting points of the products were determined. These compounds were incorporated in natural rubber mixes to evaluate their antioxidant properties. The compounded mixes were characterized for their rheometric properties. The compression‐molded rubber sheets were tested for their mechanical properties. The effects of aging on the mechanical properties of these molded sheets were evaluated. Both PNPF and PDPF showed better antioxidant properties than the conventional styreneated phenol antioxidant. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2649–2651, 2006
Synthesis and characterization ofN‐acryloylcarbazole/methyl methacrylate copolymers
Authors: Singh Pravin Kumar , Brar Ajaib Singh
Published: February 2006

Copolymers ofN‐acryloylcarbazole (A) and methyl methacrylate (M) were synthesized in different in‐feed ratios. The composition of the copolymer was determined by the help of1H NMR spectrum. The comonomer reactivity ratios determined by Kelen‐Tudos (KT) and nonlinear error‐in‐variables methods wererA= 1.12 ± 0.16,rM= 0.94 ± 0.14, andrA= 1.05,rM= 0.90, respectively. Complete spectral assignments of the1H and13C1H NMR spectra of the copolymers were done by the help of distortionless enhancement by polarization transfer (DEPT) and two‐dimensional NMR techniques, such as heteronuclear single quantum coherence (HSQC), total correlation spectroscopy (TOCSY), and heteronuclear multiple bond correlation (HMBC). The methine, α‐methyl, and carbonyl carbon resonances were found to be sequence sensitive. The signals obtained were broad because of the restricted rotation of bulky carbazole group and the quadrupolar effect of nitrogen present in carbazole moiety. Glass transition temperatures (Tg) were determined by differential scanning calorimetry and were found to be characteristic of copolymer composition. As theN‐acryloylcarbazole content increases, theTgincreases from 378.3 K for poly(methyl methacrylate) to 430.4 K for poly(N‐acryloylcarbazole). Variation inTgwith the copolymer composition were found to be in good agreement with theoretical values obtained from Johnston and Barton equations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2667–2676, 2006
Synthesis and hydrophilicity of poly(butylene 2,6‐naphthalate)/poly(ethylene glycol) copolymers
Authors: Son Jun Sik , Ji Dong Sun
Published: February 2006

Poly(butylene 2,6‐naphthalate) (PBN)/poly(ethylene glycol) (PEG) copolymers were synthesized by the two‐step melt copolymerization process of dimethyl‐2,6‐naphthalenedicarboxylate (2,6‐NDC) with 1,4‐butanediol (BD) and PEG. The copolymers produced had different PEG molecular weights and contents. The structures, thermal properties, and hydrophilicities of these copolymers were studied by 1H NMR, DSC, TGA, and by contact angle and moisture content measurements. In particular, the intrinsic viscosities of PBN/PEG copolymers increased with increasing PEG molecular weights, but the melting temperatures (Tm), the cold crystallization temperatures (Tcc), and the heat of fusion (ΔHf) values of PBN/PEG copolymers decreased on increasing PEG contents or molecular weights. The thermal stabilities of the copolymers were unaffected by PEG content or molecular weight. Hydrophilicities as determined by contact angle and moisture content measurements were found to be significantly increased on increasing PEG contents and molecular weights. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2677–2683, 2006
Interaction of polydiallyldimethylammonium salts with iodine
Authors: Bendoraitiene Joana , Mazoniene Edita , Zemaitaitiene Rima Jule , Zemaitaitis Algirdas
Published: February 2006

The interaction between polydiallyldimethylammonium chloride (PDADMAC) and KI or KBr, followed by changes in conformation of macromolecules, coil compaction, and counterion exchange, was detected by means of turbidimetry and viscometry. In aqueous solutions at presence of KI, PDADMAC rapidly binds iodine by the formation of polymer–iodine complexes PDADMA I− Im (m ≤ 4). Spectrophotometric investigations of the interaction in water without KI prove the formation of complexes of polyquaternary ammonium chloride or bromide with iodine only via iodide. These ions can be generated in the polymer‐catalyzed hydrolysis reaction of iodine. By inducing hydrolysis of iodine and binding the eventually formed iodide, PDADMAC acts as an iodine acceptor with self‐strengthening capacity. For the sorption of gaseous iodine, the possibility of direct interaction of its dipoles with the charged groups of the polyelectrolyte is also reasoned. Polydiallyldimethylammonium halides were used to modify activated carbon and employed in a nuclear power station for treatment of outlet gases containing radioactive iodine. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2710–2716, 2006
Preparation and characterization of low‐density polyethylene/banana starch films containing compatibilizer and photosensitizer
Authors: Ratanakamnuan Usarat , Aht‐Ong Duangdao
Published: February 2006

Composite films containing various percentages of banana starch and low‐density polyethylene (LDPE) were prepared. The effects of the compatibilizer, banana starch content, and photosensitizer content on the thermal and tensile properties of these films were investigated. The banana starch content was varied from 5 to 20 wt % of LDPE, whereas benzophenone was added as a photosensitizer in three different amounts (0.25, 0.5, and 1 wt %) based on LDPE. In these films PE‐graft‐maleic anhydride (PE‐g‐MA) was used as a compatibilizer at 10 wt % banana starch. It was found that the thermal stability of the composite films remained unchanged with respect to the amount of banana starch and benzophenone content. The addition of banana starch had no effect on the melting temperature and degree of crystallinity of the films. Similarly, PE‐g‐MA had no effect on the melting temperature but decreased the degree of crystallinity of the LDPE phase. Benzophenone caused an increase in the melting temperature but decreased the degree of crystallinity of LDPE in the films. Increasing the amount of banana starch decreased the tensile properties of the composite films. The addition of PE‐g‐MA as a compatibilizer increased the tensile properties compared with the uncompatibilized films. However, benzophenone had no effect on the tensile properties of the blend films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2717–2724, 2006
Photobiodegradation of low‐density polyethylene/banana starch films
Authors: Ratanakamnuan Usarat , Aht‐Ong Duangdao
Published: February 2006

The effects of the starch content, photosensitizer content, and compatibilizer on the photobiodegradability of low‐density polyethylene (LDPE) and banana starch polymer blend films were investigated. The compatibilizer and photosensitizer used in the films were PE‐graft‐maleic anhydride (PE‐g‐MA) and benzophenone, respectively. Dried banana starch at 0–20% (w/w) of LDPE, benzophenone at 0–1% (w/w) of LDPE, and PE‐g‐MA at 10% (w/w) of banana starch were added to LDPE. The photodegradation of the blend films was performed with outdoor exposure. The progress of the photodegradation was followed by determining the carbonyl index derived from Fourier transform IR measurements and the changes in tensile properties. Biodegradation of the blend films was investigated by a soil burial test. The biodegradation process was followed by measuring the changes in the physical appearance, weight loss, and tensile properties of the films. The results showed that both photo‐ and biodegradation rates increased with increasing amounts of banana starch, whereas the tensile properties of the films decreased. The blends with higher amounts of benzophenone showed higher rates of photodegradation, although their biodegradation rates were reduced with an increase in benzophenone content. The addition of PE‐g‐MA into polymer blends led to an increase in the tensile properties whereas the photobiodegradation was slightly decreased compared to the films without PE‐g‐MA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2725–2736, 2006
Kinetics and simulation of the imidization of poly(styrene‐co‐maleic anhydride) with amines
Authors: Liu He‐Yang , Cao Kun , Huang Yuan , Yao Zhen , Li Bo‐Geng , Hu Guo‐Hua
Published: February 2006

The imidization of poly(styrene‐co‐maleic anhydride) with amines may improve some of its end‐use properties. The objective of this study was to examine the mechanism and kinetics with aniline (ANL) as an amine of the preparation of poly(styrene‐co‐N‐phenyl maleimide). The reaction was carried out in a tetrahydrofuran solution at 25–55°C and in an ethylbenzene solution at 85–120°C. The extent of the reaction was determined by conductance titration, a new and simple method. Two consecutive reactions were involved in the imidization: ring opening to produce an acido‐amide group and ring closing to form a corresponding imide group. The imidization rate was greatly influenced by the reaction temperature and the molar ratio of ANL to the anhydride. A model for the imidization kinetics over a wide range of reaction temperatures and concentration ranges was developed and validated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2744–2749, 2006
Preparation and properties of new polyurethane gels with a stress‐distributing function for medical applications
Authors: Cha Gook Chan , Lee Sukmin , Song Jeom Sik , Kim Jong Kwon , Kim Kyung Hoon , Mun Mu Seong , Youn Hyoung Soon , Pyun Do Gi , Choi Yoon So
Published: February 2006

The purpose of this study is to prepare new polyurethane gels that can be used as stress‐ or pressure‐distributing materials, particularly by being combined with selective plasticizers for medical or clinical applications. Because low‐molecular‐weight plasticizer molecules in polymer gels intrinsically tend to migrate to the surface of the gels by the so‐called entropy effect in polymer miscibility, the stress‐distributing function may decrease gradually after a certain amount of time. Correspondingly, both the chemical nature of the plasticizer and polymer gels and the compatibility between the polymer segments and plasticizer should be deliberately considered as important factors in determining the thermophysical properties and stress‐distributing performance of polymer gels. New polyurethane gels comprising separated phases of soft and hard segments, the glass‐transition temperature of which was around the ambient temperature, were prepared, and selective plasticizers were combined to obtain an optimized formulation of gels for stress‐relieving properties. The glassy‐to‐rubbery transition of semicrystalline hard segments occurring around the ambient temperature caused the rearrangement of chain conformations, leading to the reduction of the pressure applied to the surface; this indicated that the pressure buildup or loss was somewhat related to the heat regulation by thermal absorption and release in the phase‐transition range. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2750–2758, 2006
Characterization of electron beam irradiated polypropylene: Influence of irradiation temperature on molecular and rheological properties
Authors: Krause Beate , Voigt Dieter , Häuβler Liane , Auhl Dietmar , Münstedt Helmut
Published: February 2006

The aim of the investigations was to analyze the influence of the temperature during the irradiation process of polypropylene on the molar mass, the formation of long chain branching and the final branching topology. A linear isotactic polypropylene homopolymer was modified by electron beam irradiation at different temperatures, with two irradiation doses to insert long chain branching. The samples were analyzed by size exclusion chromatography coupled with a multiangle laser light scattering detector, by differential scanning calorimetry, and by shear and elongational rheology. The shear and elongational flow behavior is discussed in terms of the influence of molecular parameters and used to analyze the topology of the irradiated samples. With increasing temperature, a slight reduction of the molar mass, an increase of long chain branching and an increase of crystallization temperature were found. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2770–2780, 2006
Effect of spinning conditions on the structure and properties of PAN fibers containing nano‐hydroxyapatite
Authors: Mikołajczyk Teresa , Boguń Maciej , Błażewicz Marta , Piekarczyk Izabella
Published: February 2006

Spinning conditions for nano‐hydroxyapatite‐containing precursor polyacrylonitrile (PAN) fibers have been developed and their effects on the structure and properties of nanocomposite PAN fibers have been assessed. The precursor PAN fibers prepared under the developed conditions are characterized by high strength, with their total pore content being at a level of 0.25 cm3/g. After carbonization, these fibers are designed for use as implants that support and stimulate the process of bone reconstruction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2881–2888, 2006
Synergistic effect of halide ions on the corrosion inhibition of aluminum in acidic medium by some polymers
Authors: Ebenso E. E. , Ekpe U. J. , Umoren S. A. , Jackson Ekerete , Abiola O. K. , Oforka N. C.
Published: February 2006

The corrosion inhibition of aluminum in H2SO4 in the presence of polyvinyl alcohol (PVA) and polyethylene glycol (PEG) and the effect of addition of halides (KCl, KBr, KI) was studied using the hydrogen evolution technique at 30 and 40°C. Inhibition efficiency (%I) increases with concentration of PVA and PEG—‐but with PEG having higher %I. The %I decrease with increase in temperature from 30 to 40°C in the absence and presence of inhibitor and halides. PVA and PEG were found to obey Freundlish adsorption isotherm. Phenomenon of physical adsorption is proposed from the obtained Ea, ΔGads, and Qads values obtained. The synergism parameters (SI) obtained were found to be greater than unity for both PVA and PEG, which indicates that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2889–2894, 2006
TGA analysis of γ‐irradiated linear low‐density polyethylene
Authors: Tidjani Adams , Wilkie Charles A.
Published: February 2006

Linear low‐density polyethylene (LLDPE), based on butene‐1 or hexene‐1, was irradiated with γ‐rays under vacuum or in the presence of air. The study focused on the influence of the dose rate and the γ‐dose on the thermal properties of LLDPE. Differential scanning calorimetry, thermogravimetric analysis (TGA), and TGA/FTIR techniques were used to address the thermal behavior as a result of γ‐irradiation. During this irradiation, competition between crosslinking and scission reactions, subsequent to oxidation reactions, occurred in the polymeric material, which strongly depends on the experimental conditions. A decrease of the crystallinity for γ‐irradiated samples was observed in particular for samples irradiated under vacuum. This observation may be explained by increased hindrance of segment mobility due to crosslinking reactions that prevent crystal growth. TGA investigations revealed an enhancement of the thermal stability for samples irradiated under vacuum but not for those irradiated in air. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2790–2795, 2006
A study on the solution behavior of IPBC‐hydrophobically‐modified hydroxyethyl cellulose
Authors: Dai Shanshan , Ye Lin , Huang Ronghua
Published: February 2006

Through the macromolecule reaction method, a series of 4‐isopropylbenzyl chloride (IPBC) hydrophobically‐modified hydroxyethyl cellulose (HAHEC) were synthesized. The use of suitable amount of hydrophobic monomer can ensure both the strong intermolecular association and good water‐solubility of HAHEC. Effects of polymer concentration, shear rates, temperature, and electrolytes on the solution behavior of HAHEC were comprehensively studied, which indicated that the polymers show high viscosification property, excellent viscosity retention in brine water, and surface activity. FTIR, DSC, and UV measurements were applied to characterize the molecular structure and composition of HAHEC to confirm the incorporation of hydrophobic group into the polymer chain. Atomic force microscope (AFM) and fluorescence spectrum measurements were applied to study the formation of the molecule aggregation and hydrophobic microdomain of HAHEC, and revealed the close relationship between the rheological behaviors and the hydrophobic viscosification effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2824–2831, 2006