bluuebunny/crossref_metadata_2025 huggingface dataset:
Organization of Multisynaptic Inputs from Prefrontal Cortex to Primary Motor Cortex as Revealed by Retrograde Transneuronal Transport of Rabies Virus
Authors: Miyachi Shigehiro , Lu Xiaofeng , Inoue Satoshi , Iwasaki Takuya , Koike Satoshi , Nambu Atsushi , Takada Masahiko
Published: March 2005

The organization of multisynaptic projections from the prefrontal cortex to the primary motor cortex (MI) was examined in macaque monkeys by retrograde transneuronal transport of rabies virus. In the first series of experiments, the virus was injected into the MI forelimb region, and the time-dependent distribution patterns of transsynaptic labeling were analyzed in the frontal lobe with various survivals (2-4 d). Two days after the viral injection, neuronal labeling emerged in the caudal aspects of the nonprimary motor-related areas that are known to project to the MI directly. At the same time, the motor thalamus contained labeled neurons. On the third day, cortical labeling extended into the rostral motor-related areas and, also, prearcuate area 8. Moreover, a number of labeled neurons were located in the internal pallidum and the cerebellar nuclei. At the 4 d postinjection period, neuronal labeling occurred widely in prefrontal areas as well as in the putamen and the cerebellar cortex. In the second series of experiments, the viral injection was made into the MI hindlimb region, and the distribution pattern of prefrontal labeling on the fourth day was compared with that in the forelimb-injection case. The labeled neurons in each prefrontal area were much fewer in the hindlimb-injection case than in the forelimb-injection case. Whereas ventral area 46 was most densely labeled from the forelimb region, only sparse labeling from the hindlimb region was observed in this prefrontal area. The present results suggest the importance of ventral area 46 in the cognitive control of forelimb movements.
Fluorescent Tagging of Rhythmically Active Respiratory Neurons within the Pre-Bötzinger Complex of Rat Medullary Slice Preparations
Authors: Pagliardini Silvia , Adachi Tadafumi , Ren Jun , Funk Gregory D. , Greer John J.
Published: March 2005

Elucidation of the neuronal mechanisms underlying respiratory rhythmogenesis is a major focal point in respiratory physiology. An area of the ventrolateral medulla, the pre-Bötzinger complex (preBötC), is a critical site. Attention is now focused on understanding the cellular and network properties within the preBötC that underlie this critical function. The inability to clearly identify key “rhythm-generating” neurons within the heterogeneous population of preBötC neurons has been a significant limitation. Here we report an advancement allowing precise targeting of neurons expressing neurokinin-1 receptors (NK1Rs), which are hypothesized to be essential for respiratory rhythmogenesis. The internalization of tetramethylrhodamine conjugated substance P in rhythmically active medullary slice preparations provided clear visualization of NK1R-expressing neurons for subsequent whole-cell patch-clamp recordings. Among labeled neurons, 82% were inspiratory modulated, and 25% had pacemaker properties. We propose that this approach can be used to greatly expedite progress toward understanding the neuronal processes underlying the control of breathing.
Cortical Metabotropic Glutamate Receptors Contribute to Habituation of a Simple Odor-Evoked Behavior
Authors: Best Aaron R. , Thompson Jason V. , Fletcher Max L. , Wilson Donald A.
Published: March 2005

Defining the circuits that are involved in production and cessation of specific behaviors is an ultimate goal of neuroscience. Short-term behavioral habituation is the response decrement observed in many behaviors that occurs during repeated presentation of non-reinforced stimuli. Within a number of invertebrate models of short-term behavioral habituation, depression of a defined synapse has been implicated as the mechanism. However, the synaptic mechanisms of short-term behavioral habituation have not been identified within mammals. We have shown previously that a presynaptic metabotropic glutamate receptor (mGluR)-dependent depression of synapses formed by olfactory bulb afferents to the piriform (olfactory) cortex significantly contributes to adaptation of cortical odor responses. Here we show that blockade of mGluRs within the olfactory cortex of awake, behaving rats diminishes habituation of a simple odor-induced behavior, strongly implicating a central mechanism for sensory gating in olfaction.
Haptisches Telepräsenzsystem zur Unterstützung bei Entschärfungstätigkeiten: Systemgestaltung, Regelung und Evaluation (Haptic Telepresence System for Support of Disposal of Explosive Ordnances: Design Issues, Control, and Evaluation)
Authors: Kron Alexander , Schmidt Günther
Published: March 2005

Bei der Entschärfung explosiver Objekte aus sicherem Abstand werden Experten durch ein Telepräsenzsystem unterstützt, das beidhändige und mehrfingrige Manipulationen sowie die Rückmeldung detaillierter haptischer Informationen aus der entfernten Zielumgebung ermöglicht. Dieser Beitrag geht auf Aspekte der Systemgestaltung, auf Regelungsverfahren für die kinästhetischen Teilsysteme sowie auf Maßnahmen für eine sichere Handhabung des Gesamtsystems ein. Die praktische Umsetzung theoretischer Vorüberlegungen und Maßnahmen wird an einem neu entwickelten bimanuellen Telepräsenzsystem demonstriert. Seine Eignung für den praktischen Einsatz wurde in Kooperation mit Experten der Kampfmittelbeseitigung im Rahmen eines realistischen Applikationsszenarios, nämlich der Entschärfung des Prototyps einer Splittermine, erprobt und evaluiert.
Fluorine Compounds, Inorganic, Hydrogen
Authors: Smith Robert A.
Published: March 2005

Hydrogen fluoride is the most important manufactured fluorine compound, having the greatest production volume and serving as the raw material for most other fluorine‐containing chemicals. It is produced from sulfuric acid and fluorspar (calcium fluoride ore) at elevated temperatures in a rotating kiln. It is used for the production of fluorocarbons and inorganic fluorides, as a catalyst in the production of high octane gasoline, in aluminum manufacture, as an etchant in the electronic industry, in uranium fuel processing, and in stainless steel pickling. Hydrogen fluoride is a colorless liquid or gas that strongly associates to form polymers in both the liquid and gaseous states, and exhibits highly nonideal physical properties. It is a fairly weak acid as a solute, but is highly acidic as a solvent. Among its unusual chemical properties is its reactivity with silica and silicates, including glass. It is a corrosive, hazardous material, but can be handled safely provided rigorous safety precautions are followed. Properties of both the aqueous and anhydrous material are described.
What attracts attention during police pursuit driving?
Authors: Crundall David , Chapman Peter , France Emma , Underwood Geoffrey , Phelps Nicola
Published: March 2005

Efficient deployment of attention is important to the safe execution of tasks with a high content of visual information, such as driving. Chasing a lead vehicle is an extremely demanding and dangerous task, though little is known of the visual skills required. A study is reported that recorded the eye movements of police drivers and two control groups (novices and age‐ and experienced‐ matched controls) while watching a series of video clips of driving. The clips included pursuits, emergency response drives, and control drives (at normal speeds) around Nottinghamshire, UK. Analysis of gaze durations within certain categories of stimuli revealed that daytime pursuit drives correspond with an increase in gaze durations on a lead car (controlled for exposure), though police drivers direct their attention to other sources of potential hazards, such as pedestrians, more so than other drivers. Copyright © 2005 John Wiley & Sons, Ltd.
The role of deliberate practice in chess expertise
Authors: Charness Neil , Tuffiash Michael , Krampe Ralf , Reingold Eyal , Vasyukova Ekaterina
Published: March 2005

Two large, diverse samples of tournament‐rated chess players were asked to estimate the frequency and duration of their engagement in a variety of chess‐related activities. Variables representing accumulated time spent on serious study alone, tournament play, and formal instruction were all significant bivariate correlates of chess skill as measured by tournament performance ratings. Multivariate regression analyses revealed that among the activities measured, serious study alone was the strongest predictor of chess skill in both samples, and that a combination of various chess‐related activities accounted for about 40% of the variance in chess skill ratings. However, the relevance of tournament play and formal instruction to skill varied as a function of skill measurement time (peak vs. current) and age group (above vs. below 40 years). Chess players at the highest skill level (i.e. grandmasters) expended about 5000 hours on serious study alone during their first decade of serious chess play—nearly five times the average amount reported by intermediate‐level players. These results provide further evidence to support the argument that deliberate practice plays a critical role in the acquisition of chess expertise, and may be useful in addressing pedagogical issues concerning the optimal allocation of time to different chess learning activities. Copyright © 2005 John Wiley & Sons, Ltd.
Biomedical knowledge: encapsulated or two worlds apart?
Authors: Rikers Remy M. J. P. , Schmidt Henk G. , Moulaert Véronique
Published: March 2005

The present study investigated the role of biomedical knowledge in clinical case representations of experienced family physicians and advanced medical students. Two views on the role of biomedical knowledge were compared: The knowledge encapsulation and the two‐worlds view. According to the knowledge encapsulation view, biomedical knowledge still plays a role in the physician's clinical case representation, whereas the two‐worlds view assumes that it does not. In order to investigate this issue, participants were instructed to carefully study a short case description that was associated with a particular disease. Subsequently, medical students and family physicians were instructed to judge whether or not a presented target item was related to the case description. Targets were biomedical or diagnostic items that were either related or unrelated to the case. Findings were more in line with the knowledge encapsulation than with the two‐worlds view, in that physicians judged related biomedical items faster than unrelated items, and physicians outperformed medical students in judging related biomedical and diagnostic items. Copyright © 2005 John Wiley & Sons, Ltd.
Recent advances in expertise research
Authors: Rikers Remy M. J. P. , Paas Fred
Published: March 2005

During the 55th meeting of the American Educational Research Association (AERA, 2004) in San Diego, a symposium was organized on Recent Advances in Expertise Research. Most papers in this special issue of Applied Cognitive Psychology were presented in this symposium. The aim of this special issue is to provide a representative overview of recent developments and current directions in expertise research and to discuss their implications for theoretical and applied cognitive psychology, particularly, for learning and instruction. In addition, it covers some new and innovative theoretical and methodological approaches to the study of expertise. This introductory paper presents a short introduction on expertise research, and provides an overview of the contributions to the special issue. Copyright © 2005 John Wiley & Sons, Ltd.
Monitoring accuracy and self‐regulation when learning to play a chess endgame
Authors: De Bruin Anique B. H. , Rikers Remy M. J. P. , Schmidt Henk G.
Published: March 2005

In order to examine the effect of monitoring and self‐regulation on skill acquisition, the present study asked novice chess players to provide judgments of learning (JOLs) and to select moves for restudy after studying an endgame of chess. In four groups, we varied the JOL instruction (present versus absent) and the selection instruction (free number of move selections versus selection of at least two moves per chess exercise). After four learning trials, participants were required to play against a chess computer. In the learning phase, participants who were forced to select moves for restudy outperformed those who were free to select moves for restudy when predicting the next computer move, even after controlling for the actual number of restudied moves. Although the groups that did provide JOLs showed better self‐regulatory behaviour, there were no or even negative performance differences between the groups that did provide JOLs and the groups that did not provide JOLs. This same pattern emerged in the test phase: Although no differences were found between the groups with and without JOLs, the groups that were forced to select moves for restudy outperformed the groups that were free in the number of move selections. These data show that, for novice chess players, the instruction to provide JOLs possibly places a high and ineffective load on working memory and therefore has no effect on learning a chess endgame. To examine the relation between prior knowledge and quality of self‐regulation, further research is needed that examines the effect of the JOL and selection instruction in groups that differ in chess experience. Copyright © 2005 John Wiley & Sons, Ltd.
Chunking models of expertise: implications for education
Authors: Gobet Fernand
Published: March 2005

Chunking models offer a parsimonious explanation of how people acquire knowledge and have been validated in domains such as expert behaviour and the acquisition of language. In this paper, we review two computational theories based on chunking mechanisms (the chunking theory and the template theory) and show what insight they offer for instruction and training. The suggested implications include the importance of perception in learning, the cost of acquiring knowledge, the significance of segmenting and ordering instruction material, the role of the variability of the instructional material in acquiring schemata, and the importance of taking individual differences into account. Copyright © 2005 John Wiley & Sons, Ltd.
Recent advances in expertise research: a commentary on the contributions to the special issue
Authors: Ericsson K. Anders
Published: March 2005

A brief historical background on scientific studies of expert performance describes how the articles published in this special issue relate to recent advances in the study of expertise. This commentary reviews how research on expertise originally focused on testing chess experts' memory as a convenient substitute for studies of actual performance, such as selecting the best move for chess positions. Most of the articles in the special issue illustrate a new trend towards capturing the expert performance with representative tasks in the laboratory and focus on how this superior performance is acquired through training and extended deliberate practice. With these and other advances in our knowledge of how experts acquire their superior skills, the study of expertise is establishing its most important implications for theoretical and applied cognitive psychology. Copyright © 2005 John Wiley & Sons, Ltd.
Uncovering expertise‐related differences in troubleshooting performance: combining eye movement and concurrent verbal protocol data
Authors: Van Gog Tamara , Paas Fred , Van Merriënboer Jeroen J. G.
Published: March 2005

This study explored the value of eye movement data for uncovering relatively small expertise‐related differences in electrical circuit‐troubleshooting performance, and describes that value in relation to concurrent verbal protocols. Results show that in the ‘problem orientation’ phase, higher expertise participants spent relatively more time, had a shorter mean fixation duration, and fixated more on a major fault‐related component than lower expertise participants. In the ‘problem formulation’ part of the ‘problem formulation and action decision’ phase, the mean fixation duration of the higher expertise participants was longer. In the ‘action evaluation and next action decision’ phase, higher expertise participants spent relatively more time than the lower expertise participants. Over the different phases, only the mean fixation duration of the higher expertise participants differed significantly. The relation between the eye movement and concurrent verbal protocol data is qualitatively described. The results are discussed in perspective of the combined value of eye tracking and concurrent reports for expertise research and instructional design. Copyright © 2005 John Wiley & Sons, Ltd.
Thermomechanics of the variation of interfaces in heterogeneous lyophobic systems
Authors: Coiffard Loïc , Eroshenko Valentin A. , Grolier Jean‐Pierre E.
Published: March 2005

A comprehensive investigation aimed at elucidating thermodynamic and mechanical behavior of heterogeneous systems, featuring an association of solid hydrophobic matrices (micro‐ or mesoporous) and water, has been undertaken. Scanning transitiometry techniques were applied for measurements of mechanical work and heat effects during cycles of isothermal compression/decompression. The interface variation during forced intrusion of water into the matrix porous space and its spontaneous expulsion show complicated thermal behavior patterns. Typical exothermic intrusion and expulsion are confirmed for certain categories of systems, whereas for others strong endothermic intrusion is detected. A simple thermodynamic model involving variable irreversibility in the liquid flow and in the contact line movement is proposed to explain such an original thermomechanical behavior. Consequences for mechanical devices based on these heterogeneous systems are fully discussed. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Analysis and control of heteroazeotropic batch distillation
Authors: Skouras S. , Skogestad S. , Kiva V.
Published: March 2005

The separation of close‐boiling and azeotropic mixtures by heterogeneous azeotropic distillation is addressed in batch columns. Both a common rectifier and a multivessel batch column are considered. Theoretical and graphical analyses of the process are presented for both column configurations and different separation strategies are presented. A simple control scheme is proposed for the practical operation of the columns, the implementation of different separation strategies and the realization of the final results. Dynamic simulations for mixtures classified under Serafimov's topological classes 2.0‐2b and 3.1‐2 verify the theoretical findings. The results show that heteroazeotropic batch distillation exhibits substantial flexibility. The column profile can be totally restored during the process and lie in regions different from those of the initial feed. The still path can cross distillation boundaries and the still product does not have to be the stable node of the feed region. Such results cannot be obtained by homogeneous azeotropic batch distillation. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Natural convection of a paramagnetic liquid controlled by magnetization force
Authors: Maki Syou , Ataka Mitsuo , Tagawa Toshio , Ozoe Hiroyuki , Mori Wasuke
Published: March 2005

Rayleigh–Benard natural convection of aqueous gadolinium nitrate solution (paramagnetic) was studied experimentally and numerically in the presence of upward magnetization force in a framework similar to that proposed by Braithwaite et al. With the magnetic susceptibility of the gadolinium nitrate solution reevaluated by the Gouy method, the measured heat transfer rates were found to agree with Silveston's experimental curve, which represents the relationship between the Nusselt number (Nu) and the magnetic Rayleigh number (Ram). Furthermore, three‐dimensional numerical computations were also carried out. Every convection flow pattern became axisymmetric, and the computed Nu agreed with Silveston's curve when Ram was used in place of the Rayleigh number. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Mutation analysis of the NSD1 gene in a group of 59 patients with congenital overgrowth
Authors: Cecconi M. , Forzano F. , Milani D. , Cavani S. , Baldo C. , Selicorni A. , Pantaleoni C. , Silengo M. , Ferrero G.B. , Scarano G. , Della Monica M. , Fischetto R. , Grammatico P. , Majore S. , Zampino G. , Memo L. , Cordisco E. Lucci , Neri G. , Pierluigi M. , Bricarelli F. Dagna , Grasso M. , Faravelli Francesca
Published: March 2005

Sotos syndrome is characterized by pre‐ and post‐natal overgrowth, typical craniofacial features, advanced bone age, and developmental delay. Some degree of phenotypic overlap exists with other overgrowth syndromes, in particular with Weaver syndrome. Sotos syndrome is caused by haploinsufficiency of the NSD1 (nuclear receptor SET domain containing gene 1) gene. Microdeletions involving the gene are the major cause of the syndrome in Japanese patients, whereas intragenic mutations are more frequent in nonJapanese patients. NSD1 aberrations have also been described in some patients diagnosed as Weaver syndrome. Some authors have suggested a certain degree of genotype–phenotype correlation, with a milder degree of overgrowth, a more severe mental retardation, and a higher frequency of congenital anomalies in microdeleted patients. Data on larger series are needed to confirm this suggestion. We report here on microdeletion and mutation analysis of NSD1 in 59 patients with congenital overgrowth. Fourteen novel mutations, two previously described and one microdeletion were identified. All patients with a NSD1 mutation had been clinically classified as “classical Sotos,” although their phenotype analysis demonstrated that some major criteria, such as overgrowth and macrocephaly, could be absent. All patients with confirmed mutations shared the typical Sotos facial gestalt. A high frequency of congenital heart defects was present in patients with intragenic mutations, supporting the relevance of the NSD1 gene in the pathogenesis of this particular defect. © 2005 Wiley‐Liss, Inc.
Unrelated patients with a rearrangement of chromosome 2 causing duplication of 2p23 and deletion of 2q37
Authors: Armstrong Linlea , Allanson Judith E. , Weaver David D. , Bevan Carole J. , Hobart Holly H.
Published: March 2005

We describe two unrelated patients who each have a similar chromosome 2 with duplication of 2p23 to pter, and deletion of 2q37 to qter. In one, the abnormality was derived from his mother with a pericentric inversion. Both individuals have frontal bossing; abnormally formed, low set and posteriorly rotated ears; redundant nuchal skin; inversion of the nipple(s); fleshy fingertips with prominent pads; a sacral dimple; significant developmental delay/mental retardation; and G‐tube dependency. Most of these features are present in previously described individuals with either duplication of the 2p terminus or deletion of the 2q terminus. This report is the first that documents postnatal viability of individuals with concurrent duplication of 2p and deletion of 2q, and also generation of this imbalance through rearrangement of a maternally inherited pericentrically inverted 2. This report should be considered in the reproductive counseling of individuals with pericentric inversions of chromosome 2. © 2005 Wiley‐Liss, Inc.
Elevated fibroblast growth factor‐23 in hypophosphatemic linear nevus sebaceous syndrome
Authors: Hoffman William H. , Jueppner Harald W. , DeYoung Barry R. , O'Dorisio M. Sue , Given Keena S.
Published: March 2005

We report on an adolescent who experienced the onset of linear nevus sebaceous syndrome (LNSS) prior to 1 year of age. At 7 years of age he was diagnosed to have hypophosphatemic rickets. He was suboptimally controlled with phosphate and calcitriol treatment and sustained numerous insufficiency fractures ipsilateral to the linear sebaceous nevus. Fibroblast growth factor‐23 (FGF‐23), the phosphaturic peptide, was elevated in the plasma. Treamtent with the somatostatin agonist, octreotide, and excision of the nevus were followed by normalization of FGF‐23 and clinical improvement. The patient also had hyperimmunoglobulinemia E, which responded to octreotide and surgery. We speculate that in some patients with LNSS there may be more than one mediator of hypophosphatemia and that FGF‐23 is the mediator of hyperphosphaturia in this and other hypophosphatemic syndromes. © 2005 Wiley‐Liss, Inc.
Bilateral preaxial polydactyly in a WAGR syndrome patient
Authors: Manoukian Siranoush , Crolla John A. , Mammoliti Palma M.A. , Testi Maria Adele , Zanini Rinaldo , Carpanelli Maria Luisa , Piozzi Elena , Sozzi Gabriella , De Vecchi Giovanna , Terenziani Monica , Spreafico Filippo , Collini Paola , Radice Paolo , Perotti Daniela
Published: March 2005

We report on a 30‐month‐old baby girl with typical clinical features of WAGR syndrome. In addition, the patient showed bilateral preaxial polydactyly of the feet. Cytogenetic and fluorescent in situ hybridization (FISH) analyses identified a deletion, del(11)(p13p14.1), extending from 6.1 to 21.7 Mb in size. Although the simultaneous appearance of WAGR and polydactyly has been already described, to our knowledge this is the first case in which the characterization at the cytogenetic molecular level of a patient with these phenotypes is reported. These observations indicate that preaxial polydactyly may be another feature of the WAGR syndrome and suggest the existence of a related gene in the WAGR critical region or in its proximity. © 2005 Wiley‐Liss, Inc.
Titelbild: Eisenkatalysierte Aryl‐Aryl‐Kreuzkupplungen mit Kupferreagentien (Angew. Chem. 11/2005)
Authors: Sapountzis Ioannis , Lin Wenwei , Kofink Christiane C. , Despotopoulou Christina , Knochel Paul
Published: March 2005

Aryl‐Aryl‐Kreuzkupplungen zählen zu den wichtigsten C‐C‐Verknüpfungen, aber die Katalysatoren für diese Reaktion sind oft teuer (Pd) oder giftig (Ni). Eisensalze werden nur selten eingesetzt, da sie mit Arylmagnesiumreagentien zur unerwünschten Homokupplung führen. P. Knochel und Mitarbeiter beschreiben nun in ihrer Zuschrift auf S. 1682 ff. eine effiziente und umweltverträgliche [Fe(acac)3]‐katalysierte Kreuzkupplung von Organokupferspezies ArCu(CN)MgCl mit Aryliodiden, die polyfunktionalisierte Biphenyle in 50–93 % Ausbeute zugänglich macht.
Cover Picture: Iron‐Catalyzed Aryl–Aryl Cross‐Couplings with Magnesium‐Derived Copper Reagents (Angew. Chem. Int. Ed. 11/2005)
Authors: Sapountzis Ioannis , Lin Wenwei , Kofink Christiane C. , Despotopoulou Christina , Knochel Paul
Published: March 2005

Aryl–aryl cross‐couplings are among the most important CC bond‐forming reactions. Catalysts for this reaction tend to be expensive (Pd) or toxic (Ni). Fe salts are not usually employed as they promote homocoupling of the aryl magnesium reagent. In their Communication on page 1654 ff., P. Knochel and co‐workers report an efficient and environmentally benign [Fe(acac)3]‐catalyzed cross‐coupling of organocopper species ArCu(CN)MgCl with aryl iodides to give a wide range of polyfunctional biphenyl compounds in 50–93 % yield.
Role of molecular weight of atactic poly(vinyl alcohol) (PVA) in the polarizing efficiency of PVA/azo dye complex film with high durability
Authors: Lyoo Won Seok , Yeum Jeong Hyun , Park Joo Min , Kwak Jin Woo , Kim Joon Ho , Kim Sam Soo , Ji Byung Chul , Noh Seok Kyun
Published: March 2005

To precisely identify the effect of molecular weight of atactic poly(vinyl alcohol) (a‐PVA) on the durability and polarizing efficiency (PE) of a‐PVA/dye polarizing film, we prepared two (a‐PVA)s with similar syndiotactic diad contents of 54.0%, degrees of saponification of 99.9%, and with different number‐average degrees of polymerization [(Pn)s] of 1700 and 4000, respectively. Through a series of experiments, it was found that molecular weight of a‐PVA had a significant influence on the durability of a‐PVA/dye film in heat and humidity conditions (relative humidity of 80% and temperature of 90°C). That is, both desorption of dye in a‐PVA/dye film and transmittance of film decreased with increasing molecular weight of PVA. The change of PE (durability) of a‐PVA/dye film in heat and humidity conditions was limited to about below 5%. The change of PE of PVA/dye film having Pn of 4000 especially was limited to 1%, whereas that of a‐PVA/iodine film with Pn of 4000, was almost 80% under the same condition. Also, transmittance of the drawn a‐PVA/dye film was far higher than that of the undrawn one. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 967–974, 2005
Effect of additives on durable‐press cotton fabrics treated with a glyoxal/glycol mixture
Authors: Lee Eui So , Kim Seung Il
Published: March 2005

Cotton fabrics were treated with a glyoxal/glycol mixture for a nonformaldehyde durable‐press finish by a pad–dry–cure method. Aluminum sulfate was used as a catalyst. The effects of additives such as sodium hydrogen sulfate, polyurethane, and a silicone softener were examined. Sodium hydrogen sulfate improved the whiteness and strength retention of the treated fabrics. The degree of whiteness of the treated fabrics was similar to that of fabrics treated with 1,2,3,4‐butanetetracarboxylic acid. Polyurethane improved the wrinkle recovery angle and tearing strength retention of the treated fabrics significantly but impaired the whiteness. The softening agent increased the retention of the tearing strength and abrasion resistance significantly. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 975–978, 2005
Polymerization of N‐phenylmaleimide with a rare‐earth coordination catalyst
Authors: Lu Yanbing , Sun Weilin , Shen Zhiquan
Published: March 2005

The polymerization of N‐phenylmaleimide was carried out with the binary rare‐earth coordination catalyst lanthanum phosphonate [La(P507)]–trisobutyl aluminum [Al(i‐Bu)3] in toluene at 60°C. The dependence of the polymerization on the polymerization time, the molar ratio of Al(i‐Bu)3 to La(P507), and the concentration of the catalyst were studied. The structures of the resultant polymer were characterized with 1H‐NMR, 13C‐NMR, and Fourier transform infrared spectrophotometry, and the thermal properties of the polymer were measured with thermogravimetric analysis. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 979–982, 2005
Preparation of conducting nylon‐6 electrospun fiber webs by the in situ polymerization of polyaniline
Authors: Hong Kyung Hwa , Oh Kyung Wha , Kang Tae Jin
Published: March 2005

For the preparation of conducting polyaniline (PANI)/nylon composites with high electrical conductivity as well as superior mechanical properties such as flexibility and lightness, PANI/nylon‐6 composite nanofiber webs were prepared via the electrospinning process with a nylon‐6/formic acid polymer solution, and then PANI on the surface of the nylon‐6 electrospun nanofiber webs was chemically polymerized. The electrical conductivity measurements showed that the conductivity of the PANI/nylon‐6 composite electrospun fiber webs was superior to that of PANI/nylon‐6 plain‐weave fabrics because of the high surface‐area/volume ratios. On the other hand, the volume conductivities of the PANI/nylon‐6 composite electrospun fiber webs increased from 0.5 to 1.5 S/cm as the diffusion time increased from 10 min to 4 h because of the even distribution of PANI in the electrospun fiber webs. However, the surface conductivities of the PANI/nylon‐6 composite electrospun fiber webs somewhat decreased from 0.22 to 0.14 S/cm as the diffusion time increased because of PANI contaminated with aniline monomers, aniline oligomers, and some alkyl chains, which served as electrical resistants. These results were confirmed with Fourier transform infrared, electron spectroscopy for chemical analysis, and morphology analysis. It was concluded that the diffusion time for the in situ polymerization of PANI in electrospun fiber webs was optimized at approximately 3 h. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 983–991, 2005
Plasticization of poly(lactic acid) with oligomeric malonate esteramides: Dynamic mechanical and thermal film properties
Authors: Ljungberg Nadia , Colombini Didier , Wesslén Bengt
Published: March 2005

Two oligomeric malonate esteramides and an oligomeric malonate ester were synthesized with the intention to plasticize poly(lactic acid), PLA. The synthesis was performed by reacting diethyl bishydroxymethyl malonate (DBM) with adipoyl dichloride and one of two diamines, that is, triethylene glycol diamine (TA) and polyoxypropylene glycol diamine (PA), or triethylene glycol (TEG), giving three platicizing agents denoted as DBMATA, DBMAPA, and DBMAT, respectively. The synthesis products were characterized by size exclusion chromatography and Fourier transform infrared spectroscopy, and blended with PLA at a concentration of 15 wt %. Dynamic mechanical analysis, differential scanning calorimetry, and tensile testing were used to investigate the physical properties of films from the resulting blends. All three plasticizers decreased the glass transition temperature of PLA, and the largest decrement was observed for PLA/DBMATA. Films of DBMATA and DBMAT showed enhanced flexibility in strain at break as compared to neat PLA. Subsequently, it was found that thermal annealing of the plasticized materials (4 h at 100°C) encouraged cold crystallization, inducing phase separation in the blends, and caused them to regain the brittleness of neat PLA. On the other hand, by aging (6 weeks) the blends at ambient conditions, cold crystallization could be avoided and the flexibility in the films maintained. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 992–1002, 2005
Effect of various morphology and testing conditions on fiber infrared spectrum
Authors: Yu Weidong , Xiong Lei
Published: March 2005

A series of measurements verify that the accuracy, reproducibility, and quality of fiber infrared spectra strongly rely on fiber thickness and morphology, the aperture size and direction, and instrument parameters, despite the use of high resolution in microscopy by using the Continuμm microscope. The effect of fiber cross section and testing parameters on the characteristics of the FTIR microscope spectra is discussed systematically. Meanwhile, the reproducibility of the spectra has also been tested using the transmission and mapping methods. The experimental results show that the size selection of the aperture, fiber flattening, and proper contact between attenuated total reflection crystal and fiber are vitally important for high quality and accuracy of FTIR microscope spectra. Through reasonable parameter setting and sample preparation, in fact, the IR spectra of single fibers can be obtained quickly and reproducibly. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1003–1010, 2005
Enzyme‐mediated grafting of acrylamide to ultrahigh molecular weight polyethylene fiber: A novel radical initiation system
Authors: Zhao Jingchan , Guo Zhian , Liang Guozheng , Wang Junlong , Zhang Gangshen
Published: March 2005

The enzyme‐mediated grafting of acrylamide (AM) to ultrahigh molecular weight polyethylene (UHMWPE) fibers using horseradish peroxidase (HRP) was demonstrated. To optimize the reaction condition, the concentrations of monomer, H2O2, the initiator, and time were varied. The grafting results were discussed and a reaction mechanism was proposed. Function groups and structural change of the graft copolymer were determined by FTIR spectroscopic and scanning electron microscopy micrographs for proof of grafting and the results were discussed. Results show that the surface of treated fiber becomes rougher than the untreated surface. Compared to unmodified fiber, modified fiber surface had significantly increased the interfacial shear strength, and carbonyl‐stretching regions in the IR spectra. The interfacial shear strength of the UHMWPE fiber increased, clearly indicating that enzymatic‐grafted acrylamide could significantly increase the hydrophilicity of the surfaces of UHMWPE fibers. Moreover, the hydrophilicity of treated fiber depends on the monomer concentration, the initiator concentration, and oxidizing agent concentration as well as the time of the reaction. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1011–1016, 2005
High modulus/tenacity filaments from blends of different molecular weights of polypropylene
Authors: Chatterjee A. , Deopura B. L.
Published: March 2005

Polypropylene (PP) filaments are prepared by blending two different molecular weight components of PP. A melt‐spinning process to produce filaments includes mixing of components, extrusion, and two‐stage drawing, followed by a unique Gradient Drawing™ process. Blending results in highly deformable as‐spun filaments with high draw ratios. For 90:10 blends of PP samples with melt flow indexes of 35 and 3, a high level of crystallinity and crystalline and amorphous orientations are obtained. A sonic modulus of 28 GPa, dynamic modulus of 20 GPa, tensile modulus of 16 GPa, and tenacity of 667 MPa are achieved. These samples are dimensionally stable up to ∼100°C. All steps in the production of the filaments are continuous. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1021–1028, 2005
Influence of tension on the oxidative stabilization process of polyacrylonitrile fibers
Authors: Wu Gangping , Lu Chunxiang , Ling Licheng , Hao Aimin , He Fu
Published: March 2005

Polyacrylonitrile fibers were heat‐treated in air, and a series of stretching experiments were conducted in different temperature zones. The effects of tension on the microstructure of the heat‐treated fibers and the tensile strength of the resultant carbon fibers were investigated. The results show the variations in morphological characteristics affected by stretching were different as stabilization proceeded. A possible mechanism of tension on cyclization and, thus, stabilization was elucidated. During stabilization, tension at low temperatures led to a great increase in the tensile strength of the carbon fibers, whereas tension at high temperatures resulted in only small improvement in the tensile strength of the carbon fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1029–1034, 2005
Novel conducting polyaniline blends with cyanoresin
Authors: Kim Seong Hun , Oh Kyung Wha , Kim Tae Kyun
Published: March 2005

Novel conducting polyaniline (PANI)/cyanoresin (Cyan) blends were prepared by the addition of Cyan/dimethylformamide solutions to aniline monomer/dopant solutions and the in situ chemical oxidative polymerization of aniline with ammonium persulfate as an oxidant in aqueous p‐toluene sulfonic acid solutions. The PANI/Cyan blends were prepared with various compositions (5:95, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, and 70:30), and blend films of PANI/Cyan were obtained with a casting method. The conductivity of the PANI/Cyan blend films was 10−7 to 10−2 S/cm, which was measured by a four‐probe technique. The tensile strength of the blend films was maintained with an increasing amount of PANI (up to 50 wt %), and this was attributed to intermolecular interactions such as hydrogen bonding between PANI and Cyan and a reinforcing effect through blending. This hypothesis was corroborated by Fourier transform infrared spectroscopy. Field emission scanning electron microscopy and thermogravimetric analysis were also used to investigate the morphology and thermal properties of the conducting PANI/Cyan blend films, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1035–1042, 2005
Structure and relaxation properties of medical‐purposed polyacrylamide gels
Authors: Lopatin Vladislav V. , Askadskii Andrei A. , Peregudov Alexander S. , Vasil'ev Viktor G.
Published: March 2005

By IR and NMR spectroscopy methods, thermomechanical analysis, mechanical relaxation measurements, and computational simulation the effect of production conditions of acrylamide copolymer and N,N′‐methylenebisacrylamide derived hydrogels with respect to their properties were studied. Four hydrogel samples, prepared under different production conditions (γ‐radiation dose and autoclaving), were investigated. It was found that autoclaving and γ‐radiation lead to a slight increase of the crosslinking degree in the polymeric network and formation of alkene structures in polymeric chains. Stress relaxation and creep processes under axial compression of gel cylindrical samples were studied in detail. To approximate stress relaxation and creep curves new memory functions were used, based on the analysis of entropy production in the system during the relaxation process. It was found that primary γ‐radiation of initial gels induces an increase of quasi‐equilibrium rubbery elasticity modulus, and quasi‐equilibrium compliance is decreased. The opposite situation is observed during further autoclaving at 120°C. After autoclaving, required to sterilize the gels, their treatment by γ‐radiation again induced a noticeable increase of the modulus and compliance decrease. The mechanism of relaxation processes was found to be associated with the limiting stage of physical interaction between relaxants, representing different micro‐inhomogeneities in the material. The investigation results were compared with the data obtained by histology and morphology methods. A hydrogel obtained under additional γ‐radiation treatment and autoclaving did not swell when implanted into a living organism, and the tissue reaction to implantation of such gel was minimal. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1043–1058, 2005
Soil burial test for poly(ethylene‐co‐vinyl alcohol)‐graft‐polycaprolactone
Authors: Park Eun‐Soo , Kim Hun‐Sik , Kim Mal‐Nam , Yoon Jin‐San
Published: March 2005

The ring‐opening polymerization of ε‐caprolactone was carried out with poly(ethylene‐co‐vinyl alcohol) as a macroinitiator to synthesize poly(ethylene‐co‐vinyl alcohol)‐graft‐polycaprolactone (EVOH‐g‐PCL). A simple low‐density polyethylene (LDPE)/polycaprolactone (PCL) (64/36) blend lost 5.3 wt % of its original weight after 90 days of a soil burial test. However, the elongation at break of the LDPE/PCL blend remained almost invariable even after the solid burial test because the tensile properties depended mostly on the LDPE phase on account of the poor interaction between the continuous LDPE matrix and the dispersed PCL phase. For EVOH‐g‐PCL, the elongation at break decreased drastically as a result of the soil burial test, and the reduction of the elongation at break was more pronounced for EVOH‐g‐PCL with a higher PCL concentration, even though the weight loss of EVOH‐g‐PCL after the soil burial test was as low as 1.2–1.3% and was nearly independent of the PCL concentration. Few holes were observed in EVOH‐g‐PCL when the PCL concentration was less than 26 wt % after an accelerated hydrolysis experiment at 60°C for 7 days in a 0.1M KOH solution. In contrast, the hydrolysis formed small holes in EVOH‐g‐PCL with a PCL concentration of 36 wt %. The LDPE/PCL blend was much better percolated, as a result of the hydrolysis, than EVOH‐g‐PCL with the same PCL concentration; the soil burial test showed the same results. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1064–1071, 2005
Experimental results and modeling of solvent activities in binary polymer solutions
Authors: Taghizadeh Majid , Eliassi Ali , Rahbari‐Sisakht Masoud
Published: March 2005

A new model based on Eyring's absolute rate theory for the prediction of solvent activities in binary polymer solutions is presented. This model requires experimental viscosity and density data. The model results for various solutions of poly(ethylene glycol)s with molecular weights of 200, 300, and 6000 in water and for poly(propylene glycol) with a molecular weight of 2025 in ethanol are compared with experimental data at different temperatures and concentrations. There is good agreement between the calculated and experimental results, and the overall average mean relative deviation of the model is less than 1.2%. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1059–1063, 2005
Biodegradable and functionally superior starch–polyester nanocomposites from reactive extrusion
Authors: Kalambur Sathya , Rizvi Syed S. H.
Published: March 2005

Biodegradable starch‐polyester polymer composites are useful in many applications ranging from numerous packaging end‐uses to tissue engineering. However the amount of starch that can form composites with polyesters without significant property deterioration is typically less than 25% because of thermodynamic immiscibility between the two polymers. We have developed a reactive extrusion process in which high amounts of starch (approx. 40 wt%) can be blended with a biodegradable polyester (polycaprolactone, PCL) resulting in tough nanocomposite blends with elongational properties approaching that of 100% PCL. We hypothesize that starch was oxidized and then crosslinked with PCL in the presence of an oxidizing/crosslinking agent and modified montmorillonite (MMT) organoclay, thus compatibilizing the two polymers. Starch, PCL, plasticizer, MMT organoclay, oxidizing/crosslinking agent and catalysts were extruded in a co‐rotating twin‐screw extruder and injection molded at 120° C. Elongational properties of reactively extruded starch‐PCL nanocomposite blends approached that of 100% PCL at 3 and 6 wt% organoclay. Strength and modulus remained the same as starch‐PCL composites prepared from simple physical mixing without any crosslinking. X‐ray diffraction results showed mainly intercalated flocculated behavior of clay at 1,3,6, and 9wt% organoclay. Scanning electron microscopy (SEM) showed that there was improved starch‐PCL interfacial adhesion in reactively extruded blends with crosslinking than in starch‐PCL composites without crosslinking. Dynamic mechanical analysis showed changes in primary α‐transition temperatures for both the starch and PCL fractions, reflecting crosslinking changes in the nanocomposite blends at different organoclay contents. Also starch‐polytetramethylene adipate‐co‐terephthalate (PAT) blends prepared by the above reactive extrusion process showed the same trend of elongational properties approaching that of 100% PAT. The reactive extrusion concept can be extended to other starch‐PCL like polymer blends with polymers like polyvinyl alcohol on one side and polybutylene succinate, polyhydroxy butyrate‐valerate and polylactic acid on the other to create cheap, novel and compatible biodegradable polymer blends with increased toughness. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1072–1082, 2005
Preparation of poly(ethylene glycol)/chitosan membranes by a glucose‐mediating process and in vitro drug release
Authors: Wang Jian‐Wen , Hon Min‐Hsiung
Published: March 2005

Novel pH‐dependent chitosan/poly(ethylene glycol) (PEG) membranes were developed for oral drug delivery. The preparation of these membranes involved a solution‐mediating process with glucose addition at different pHs. Fourier transform infrared/attenuated total reflectance showed that the Schiff‐base reaction was favored at high pHs and high glucose concentrations. X‐ray diffraction analysis showed a continuous increase in the glucose addition transformed the chitosan/PEG samples into amorphous polymers. The equilibrium swelling measurements showed that the swelling ratio of the solution‐mediated membranes decreased as the glucose concentration increased, and this was demonstrated by degree‐of‐mediation analysis. The glucose‐mediated membranes had different degrees of mediation, which depended on the pH and glucose concentration. The in vitro release profiles of theophylline‐loaded, pH 6 treated, glucose‐mediated membranes showed that the theophylline release decreased as the glucose concentration increased. Also, the release behavior of the theophylline from the glucose‐mediated membranes varied with the pH of the release medium, the glucose concentration, and the final pH of the glucose‐mediated chitosan/PEG gels. Chitosan/PEG membranes prepared by a basic glucose‐mediated process could lead to successful applications in localized drug delivery to the intestine. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1083–1094, 2005