bluuebunny/crossref_metadata_2025 huggingface dataset:
Indwelling urinary catheters in cesarean delivery
Authors: Ghoreishi J.
Published: November 2003

Objectives:A prospective randomized study was used to determine the effect of urinary bladder catheterization on first‐void discomfort, time of ambulation, hospital stay, and urinary tract infection in women undergoing cesarean delivery.Methods:We randomly assigned 270 women delivered by cesarean section to urinary bladder catheterization or no catheterization. Prospective methods were used to assess patient discomfort with the first postoperative void after, time of ambulation, time of hospital stay, and need for recatheterization.Results:Of 135 women who did not receive an indwelling urinary catheter after cesarean delivery, six (4.4%) patients needed postoperation urinary catheterization. The time of first postoperative voiding was 8–11 h in 54 (42.5%) of cases. The ambulation time in the uncatheterized group was 6.8 h, vs. 12.9 h in the control group. Uncatheterized patients had a shorter hospital stay. Urinary tract infection was not assessed in this study.Conclusions:Routine use of indwelling urinary catheter in cesarean delivery patients with a stable hemodynamic condition is not necessary.
Serum levels of insulin, IGF‐1, and IGFBP‐1 in pre‐eclampsia and eclampsia
Authors: Ingec M. , Gursoy H.G. , Yildiz L. , Kumtepe Y. , Kadanali S.
Published: November 2003

Objectives: To investigate whether the serum concentrations of insulin, insulin‐like growth factor‐1 (IGF‐1), and insulin‐like growth factor binding protein‐1 (IGFBP‐1) were altered in women with mild pre‐eclampsia, severe pre‐eclampsia, and eclampsia. Methods: In this prospective study, we investigated 20 mild pre‐eclamptic, 20 severe pre‐eclamptic, and 20 eclamptic patients in the third trimester. The control group consisted of 20 healthy pregnant women. Serum levels of insulin, IGF‐1, and IGFBP‐1 were measured. Results: In patients with eclampsia, serum levels of IGF‐1 were lower, and IGFBP‐1 were higher, respectively, than control and other study groups (P<0.001) The values of IGF‐1 in mild pre‐eclampsia and severe pre‐eclampsia were lower compared with control groups (both P<0.01), but there were no differences between mild and severe pre‐eclampsia. The serum levels of IGFBP‐1 in severe pre‐eclampsia were higher compared with control groups (P<0.01), but there was no statistical difference between mild pre‐eclampsia and other groups. Conclusions: IGF‐1 was lower, and IGFBP‐1 was higher in pre‐eclamptic and eclamptic patients than controls, these alterations were related to the severity of pre‐eclampsia.
Behavioral profile of L–741,741, a selective D4 dopamine receptor antagonist, in social encounters between male mice
Authors: Navarro J.F. , Luna G. , Pedraza C.
Published: October 2003

Although the role of dopamine D1–D2–D3 receptors in the modulation of aggression has been extensively documented, there is not information with respect to the implication of D4 receptor. The aim of this study was to examine the acute effects of L–741,741 (0.75, 1.5 and 3 mg/kg, i.p), a selective D4 receptor antagonist, on social encounters between male mice using an ethopharmacological approach. Ten min of diadic interactions were staged between a singly housed and an anosmic mouse in a neutral area. These encounters were videotaped and the accumulated time allocated by subjects to ten broad behavioral categories was estimated. Besides other behaviors, the aggressive and motor behaviors were evaluated 30 min after injection using an ethologically based analysis. L–741,741 did not affect significantly offensive behaviors (threat and attack), as compared with the control group. Likewise, motor and anxiety‐related behaviors (such as social investigation, avoidance/flee or defense submission) were not altered after drug administration. These results suggest that dopamine D4 receptor is not involved in the modulation of aggressive behavior. Aggr. Behav. 29:552–557, 2003. © 2003 Wiley‐Liss, Inc.
Moral emotions and bullying: A cross‐national comparison of differences between bullies, victims and outsiders
Authors: Menesini Ersilia , Sanchez Virginia , Fonzi Ada , Ortega Rosario , Costabile Angela , Lo Feudo Giorgio
Published: October 2003

This study aims to analyse the role of moral emotions and reasoning in relation to children's behaviour in a bullying situation. On the basis of a peer nomination questionnaire [Salmivalli et al., 1996; Sutton and Smith, 1999], children from three different cities (Seville, Florence, and Cosenza) were assigned to one of three different status groups: bullies, victims, or outsiders. Subsequently they were interviewed about their feelings in relation to the task of putting themselves in the role of the bully in a bullying scenario. Specifically, emotions such as guilt and shame, expressed in a sense of moral responsibility, and indifference and pride, expressed in an attitude of moral disengagement, were investigated. Results showed significant differences between bullies, victims, and outsiders, with regard to moral disengagement, at both the affective and cognitive levels. Across the three cities, bullies, as compared to victims and outsiders, showed a higher level of disengagement emotions and motives when they were asked to put themselves in the role of bully. At a more detailed level, analyses of specific mechanisms of moral disengagement revealed that bullies possessed a main profile of egocentric reasoning. Besides the differences between bullies and victims, cross‐cultural differences were also present. Compared to children from Seville, children from the south of Italy (Cosenza) attributed higher disengagement to the bullies. Findings are discussed in relation to specific cultural characteristics of this area. Aggr. Behav. 29:515–530, 2003. © 2003 Wiley‐Liss, Inc.
Rough‐and‐tumble play in human children
Authors: Scott Eric , Panksepp Jaak
Published: October 2003

Rough and tumble (R&T) play is a unique set of behaviors that can be reliably distinguished from aggression and other childhood activities. Although it may be the most fundamental form of play, it has received comparatively little experimental attention in the human species. Forty children, ages three to six, were allowed to play in pairs (10 male pairs, 10 female pairs) during a 30 minute videotaped session with no toys available while music played in the background during every other five‐minute time period. The incidence frequency of children's play and related behavioral activities were scored using 20 behavioral categories. The major findings show only modest gender differences in the frequency of play behaviors in such controlled social encounters; the main difference is that boys engaged in slightly more physical play solicitations than girls. Music facilitated General Motor Activities (e.g., Running and Walking behaviors), but not specific R&T play actions (e.g., Wrestling, Ventral and Dorsal contacts). Finally, most play behaviors as well as general activities declined systematically over the course of each recording session. This experiment highlights how human social play can be systematically studied in a controlled laboratory setting. Aggr. Behav. 29:539–551, 2003. © 2003 Wiley‐Liss, Inc.
Examining antisocial behavior through the lens of the five factor model of personality
Authors: Miller Joshua D. , Lynam Donald , Leukefeld Carl
Published: October 2003

The current study attempts to provide greater precision in understanding how personality is related to antisocial behavior. Specifically, we examined the relations between the facets (subordinate traits) from three domains (superordinate dimensions): Neuroticism, Agreeableness, and Conscientiousness, of the Five Factor Model and five outcome variables: stability of conduct problems, variety of conduct problems, onset of conduct problems, aggression, and antisocial personality disorder symptoms. These relations were examined in a community sample of 481 individuals. These three personality dimensions were chosen for exploration due to their consistent relations, at the domain level, with antisocial behaviors. The results from this study suggest that the facets from the dimension of Agreeableness are the most consistently related to all five outcomes. However, the facets from all three domains made significant contributions. Overall, three personality traits stood out as being the strongest and most consistent predictors: low straightforwardness, low compliance, and low deliberation. Implications for prevention and intervention are discussed. Aggr. Behav. 29:497–514, 2003. © 2003 Wiley‐Liss, Inc.
Bindungsaffinitäten von Wirt‐Gast‐, Protein‐Ligand‐ und Protein‐Übergangszustands‐Komplexen
Authors: Houk Kendall N. , Leach Andrew G. , Kim Susanna P. , Zhang Xiyun
Published: October 2003

Die Affinitäten von Wirten – ausgehend von kleinen synthetischen Cavitanten bis hin zu großen Proteinen – für organische Moleküle sind gut dokumentiert. Die mittleren Assoziationskonstanten für die Bindung organischer Moleküle durch Cyclodextrine, synthetische Wirte und Albumine in Wasser sowie von katalytischen Antikörpern oder Enzymen für Substrate betragen im Allgemeinen 103.5±2.5 M−1. Die Bindungsaffinitäten steigen bei der Komplexierung von Übergangszuständen und biologischen Antigenen durch Antikörper oder von Enzymen durch Inhibitoren auf 108±2 M−1 und auf 1016±4 M−1 für Enzym‐Übergangszustands‐Komplexe. Die Gründe für die unterschiedlichen Stabilitäten dieser Wirt‐Gast‐Systeme sollen hier untersucht werden, und wir beschreiben Ansätze zur computergestützten Analyse der Wirt‐Gast‐Komplexbildung in Lösung. Bei vielen Komplexklassen besteht eine ungefähre Korrelation der Bindungsaffinität mit der Größe der Oberfläche, die bei der Komplexierung vergraben wird. Enzyme folgen dieser Korrelation nicht, sondern binden Übergangszustände sehr viel stärker als es anhand der Oberfläche zu erwarten wäre.
Elektrochemische und photochemische Steuerung der Wirt‐Gast‐Komplexierung an Oberflächen
Authors: Cooke Graeme
Published: October 2003

Der Einsatz von Elektro‐ und Photochemie zur Modulation supramolekularer Wechselwirkungen zwischen Wirt‐Gast‐Systemen in Lösung ist ein aktuelles Forschungsgebiet. Die Geschwindigkeit und Reversibilität elektrochemisch oder photochemisch ausgelöster Wechselwirkungen ermöglichten Aufbau und Modulation neuartiger molekularer Maschinen in Lösung. In den letzten Jahren wurden große Fortschritte bei der Übertragung dieser Systeme auf die Festphase erzielt. Dadurch wurde die Entwicklung von Bausteinen erleichtert, die auf einen Reiz als elektronische Einheit reagieren. So können Oberflächen aufgebaut werden, die auf äußere Signale reagieren. Diese Systeme können in hoch entwickelten Materialien für die Nanotechnologie eingesetzt werden.
Titelbild: Organocatalytic Asymmetric Michael Reaction of Cyclic 1,3‐Dicarbonyl Compounds and α,β‐Unsaturated Ketones—A Highly Atom‐Economic Catalytic One‐Step Formation of Optically Active Warfarin Anticoagulant (Angew. Chem. 40/2003)
Authors: Halland Nis , Hansen Tore , Jørgensen Karl Anker
Published: October 2003

Chirale Antikoagulantien können durch eine organokatalytische asymmetrische Michael‐Reaktion erhalten werden. Als Beispiel ist die Synthese von enantiomerenreinem Warfarin aus einfachen Ausgangsverbindungen gezeigt, das CT‐Bild einer Lunge, in der Thrombosen auftreten können, dient als Hintergrund. Links unten ist ein Herz mit Thrombus abgebildet, rechts oben dasselbe Herz nach einer Operation und Behandlung mit einem Antikoagulans (Filme dazu sind als Hintergrundinformationen verfügbar). Weitere Details liefert die Zuschrift von K. A. Jørgensen et al. auf S. 5105 ff.
Cover Picture: Organocatalytic Asymmetric Michael Reaction of Cyclic 1,3‐Dicarbonyl Compounds and α,β‐Unsaturated Ketones—A Highly Atom‐Economic Catalytic One‐Step Formation of Optically Active Warfarin Anticoagulant (Angew. Chem. Int. Ed. 40/2003)
Authors: Halland Nis , Hansen Tore , Jørgensen Karl Anker
Published: October 2003

Optically active anticoagulants are formed in a new one‐step organocatalytic asymmetric Michael reaction. The synthesis of the optically active warfarin from simple starting materials is shown. The background is a CT‐scanning image of the lungs, where thrombosis can occur. The other images show a heart with a thrombus (left), and the same heart after surgery and treatment with anticoagulant (right), these images can be seen as films in the Supporting Information. Full details are in the Communication by K. A. Jørgensen et al. on page 4955 ff.
Crystallographic report: Bis(tetraphenylphosphonium) bis(dichloro‐nitratophenylstannate)methane, [Ph4P+]2 [(PhCl2(NO3)Sn)2CH2]2−
Authors: Jurkschat Klaus , Reeske Gregor , Schürmann Marcus , Tiekink Edward R. T.
Published: October 2003

Each tin atom of the title compound is five‐coordinate, defined by 2C, 2Cl and 1O atoms, and shows a distorted square pyramidal configuration stabilized by intramolecular Sn· · ·O or Sn· · ·Cl interactions. Both nitrate anions coordinate the tin atoms in a monodentate mode. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis and characterization of triarylphosphine complexes of zinc(II) halides
Authors: Chauhan Ashok K. S. , Singh Narendra , Srivastava Ramesh C.
Published: October 2003

Both 1:1 and 1:2 complexes are formed by zinc(II) halides and triarylphosphines unless electronic and/or steric factors intervene. Tri‐p‐chlorophosphine (a weaker base than PPh3) forms only a 1:1 complex, whereas bulky tri‐(ortho‐substituted phenyl)phosphines do not react. The complexes ZnX2PR3 and ZnX2(PR3)2 have been characterized by elemental analyses, conductance, far‐IR and (in a few cases) Raman spectral studies. The Zn–X and Zn–P stretching and Zn–X bending vibrational frequencies have been assigned in the complexes with a pseudo‐tetrahedral structure of C2v symmetry. Copyright © 2003 John Wiley & Sons, Ltd.
1,1‐Organoboration of bis(trimethylstannyl)ethyne with trimethylsilyl‐ and dimethylsilyl‐dialkylboryl‐substituted alkenes: organometallic‐substituted allenes
Authors: Wrackmeyer Bernd , Tok Oleg L. , Bhatti Moazzam H. , Ali Saqib
Published: October 2003

The reactions of bis(trimethylstannyl)ethyne, Me3Sn–CC–SnMe3 (4), with trimethylsilyl‐ or dimethylsilyl‐dialkylboryl‐substituted alkenes 1–3 afford organometallic‐substituted allenes 5, 6 and 8, 9 in high yield. In the case of (E)‐2‐trimethylsilyl‐3‐diethylboryl‐2‐pentene (1), a butadiene derivative 7 could be detected as an intermediate prior to rearrangement into the allene. All reactions were monitored by 29Si and 119Sn NMR, and the products were characterized by an extensive NMR data set (1H, 11B, 13C, 29Si, 119Sn NMR). Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis and cytotoxicity of silylalkylthio‐substituted N‐heterocycles and their hydroselenites
Authors: Arsenyan Pavel , Rubina Kira , Shestakova Irina , Abele Edgars , Abele Ramona , Domracheva Ilona , Nesterova Alena , Popelis Juris , Lukevics Edmunds
Published: October 2003

New hydroselenites of the different silylalkylthio‐substituted N‐heterocycles have been prepared by the reaction of selenium dioxide with N‐heterocycles in an aqueous medium. Their structure was confirmed by 1H, 13C, and 77Se NMR data. Most of these silylalkylthio‐substituted N‐heterocycles and their hydroselenites have an expressed cytotoxic activity on the MG‐22A (mouse hepatoma), HT‐1080 (human fibrosarcoma), B16 (mouse melanoma), and Neuro 2A (mouse neuroblastoma) cell lines. Some of the hydroselenites exhibit free‐radical protection simultaneously with a high cytotoxic effect. The substances studied were also active in vivoagainst sarcoma S‐180. Copyright © 2003 John Wiley & Sons, Ltd.
Practical generation of 3,5‐dimethoxybenzyllithium: application to the synthesis of 5‐substituted‐resorcinols
Authors: Azzena Ugo , Dettori Giovanna , Idini Maria Vittoria , Pisano Luisa , Sechi Grazia
Published: October 2003

Reductive lithiation of 3,5‐dimethoxybenzyl methyl ether was successfully performed with lithium wire and a catalytic amount of naphthalene in dry tetrahydrofuran at −15°C, leading to the quantitative generation of 3,5‐dimethoxybenzyllithium. This organometallic compound, which can be stored for at least 24 h, was trapped with a variety of different electrophiles, including, besides aldehydes, non‐functionalized and functionalized alkyl halides and an epoxide. Accordingly, it is a useful intermediate in the synthesis of 5‐substituted natural and non‐natural resorcinols. Copyright © 2003 John Wiley & Sons, Ltd.
Aminoethynyl‐silanes, ‐germanes and ‐stannanes: novel organometallic‐substituted enamines via 1,1‐organoboration
Authors: Wrackmeyer Bernd , Tok Oleg L. , Guldner Gudrun , Gruener Sergej V.
Published: October 2003

The reactions of diethylaminoethynyl(trimethyl)silane (1), bis(diethylaminoethynyl)methylsilane (2), diethylaminoethynyl(trimethyl)germane (3), dimethylaminoethynyl(triethyl)germane (4), diethylaminoethynyl(trimethyl)stannane (5) and methyl(phenyl)aminoethynyl(trimethyl)stannane (6) with trialkylboranes [BEt3 (7b), BPr3 (7c), BiPr3 (7d) and 9‐alkyl‐9‐borabicyclo[3.3.1]nonanes 9‐Me‐9‐BBN (8a) and 9‐Et‐9‐BBN (8b)] were studied. The alkynes 1 and 2 did not react even with boiling BEt3, whereas the reactions of 3–6 afforded mainly novel enamines [(E)‐1‐amino‐1‐trialkylgermyl‐2‐dialkylboryl‐alkenes (9, 10), (E)‐1‐diethylamino‐1‐trimethylstannyl‐2‐dialkylboryl‐alkenes (11, 12), (E)‐1‐methyl(phenyl)amino‐1‐trimethylstannyl‐2‐dialkylboryl‐alkenes (13, 14)]. This particular stereochemistry is unusual for products from 1,1‐organoboration reactions, indicating a special influence of the amino group. The starting materials and products were characterized by multinuclear magnetic resonance spectroscopy (1H, 11B, 13C, 15N, 29Si, 119Sn NMR). Copyright © 2003 John Wiley & Sons, Ltd.
The interaction of zinc pyrithione with mitochondria from rat liver and a study of the mechanism of inhibition of ATP synthesis
Authors: Bragadin Marcantonio , Manente Sabrina , Marton Daniele , Cima Francesca , Rigobello Maria Pia , Bindoli Alberto
Published: October 2003

The interactions of zinc pyrithione (ZnPT) with rat liver mitochondria were investigated. Since most of the organometals, principally the triorganotin compounds, induce the inhibition of ATP synthesis in rat liver mitochondria, the efficiency of the ATP synthesis was measured in the presence of ZnPT. The results indicate that ZnPT inhibits ATP synthesis. In order to individuate the molecular mechanism responsible for a failure in ATP synthesis, all of the steps involved in ATP synthesis or in its inhibition were investigated separately, i.e. the respiratory chain, the uncoupling effect, the ATPase and the opening of a permeability pore. All of the steps are inhibited by ZnPT, but the crucial one, the one responsible for the inhibition of ATP synthesis, seems to be the opening of a small‐size cyclosporine‐sensitive pore. The results are different from those obtained using other organometallic compounds, but are similar to those obtained when using methylmercury and Zn2+, both of which also induce the opening of a cyclosporine‐sensitive pore. However, although Hg2+ and Zn2+ would seem to induce the opening of large‐size pores, in the case of ZnPT the pores involved are of a small size. This action mechanism seems to exclude the possibility that ZnPT is a deliverer of Zn2+. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Bis(triphenyltin) oxalate
Authors: Diop Libasse , Mahieu Bernard , Mahon Mary F. , Molloy Kieran C. , Okio Kochikpa Y. A.
Published: October 2003

The centrosymmetric structure of bis(triphenyltin) oxalate contains essentially four‐coordinated tin and monodentate carboxylate moieties despite a Mössbauer quadrupole splitting of 2.8 mm s−1 and a 119Sn NMR chemical shift of −503 ppm. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Bis(norfloxacin)dilead(II) tetranitrate, [Pb2(H‐Norf)2(ONO2)4]
Authors: Chen Zhen‐Feng , Zhou Hong‐Li , Liang Hong , Li Yan , Xiong Ren‐Gen , You Xiao‐Zeng
Published: October 2003

The centrosymmetric binuclear structure of [Pb2(H‐Norf)2(ONO2)4]shows the geometry around each lead(II) atom to be distorted trigonal bipyramidal with Pb–O distances ranging from 2.357(3) to 2.769(4) Å. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Crystal structure of the first alkaline earth metal compound with the antibacterial drug sulfasalazine: [Sr(H‐Sulf)(H2O)6](H‐Sulf)·3H2O
Authors: Chen Zhen‐Feng , Kang Shu , Liang Hong , Yi Feng , Yu Kai‐Bei , Xiong Ren‐Gen , You Xiao‐Zeng
Published: October 2003

The structure of [Sr(H‐Sulf)(H2O)6](H‐Sulf)·3H2O features a seven‐coordinated distorted capped octahedral geometry around strontium(II) with SrO distances ranging from 2.445(5) to 2.606(5) Å. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Bis(indole‐3‐acetato)(1,10‐phenanthroline) cadmium(II)
Authors: Chen Zhen‐Feng , Huang Ling , Liang Hong , Hu Rui‐Xiang , Shi Shao‐Ming , Fun Hoong‐Kun
Published: October 2003

The structure of Cd(phen)(indole‐3‐acetato)2 has twofold symmetry and features a six‐coordinated distorted octahedral geometry around cadmium(II), defined by an N2O4 donor set, with Cd–O distances ranging from 2.214(3) to 2.526(3) Å. Copyright © 2003 John Wiley & Sons, Ltd.
Short communication: Carbon–Silicon coupling between fluorenyl Grignard reagents and dichlorosilanes for synthesis of novel copolymers and chemical properties of the copolymers
Authors: Kitamura Naoyuki , Yamamoto Takakazu
Published: October 2003

A series of novel silicon‐containing fluorene polymers has been prepared by carbon–silicon (C–Si) coupling between fluorenyl Grignard reagents and dichlorosilanes, and their optical and thermal properties have been studied. Copyright © 2003 John Wiley & Sons, Ltd.
Palladium‐catalysed cyclocarbonylation reactions in dimethyl carbonate, an eco‐friendly solvent and ring‐opening reagent
Authors: Vasapollo Giuseppe , Mele Giuseppe , Maffei Annamaria , Sole Roberta Del
Published: October 2003

Dimethyl carbonate (DMC) is used as an alternative and eco‐friendly solvent for selective cyclocarbonylation reactions of allyl phenol derivatives for the synthesis of lactones; in some cases, depending on the reaction condition, DMC behaves as a ring‐opening reagent producing methoxycarbonyl compounds. Copyright © 2003 John Wiley & Sons, Ltd.
Demethylation of methylarsenic species by Mycobacterium neoaurum
Authors: Lehr Corinne R. , Polishchuk Elena , Radoja Una , Cullen William R.
Published: October 2003

Mycobacterium neoaurum demethylates both methylarsonic acid and methylarsonous acid to mixtures of arsenate and arsenite. After 28 days of incubation, the yields of inorganic arsenic were 27% from arsenate and 43% from arsenite. A time study of the demethylation of methylarsonic acid by M. neoaurum showed that demethylation occurs rapidly during the growth and stationary phases of the bacterium, and indicates that MMA(V) is reductively demethylated to arsenite. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Crystal structure of a two‐dimensional coordination polymer: tetraaqua‐1,2,4,5‐benzenetetracarboxylato(pyrazine)dizinc(II) dihydrate
Authors: Yang Shi‐Yao , Long La‐Sheng , Huang Rong‐Bin , Zheng Lan‐Sun , Ng Seik Weng
Published: October 2003

The structure of {[Zn2(1,2,4,5‐btc)(pz)(H2O)4]·2(H2O)}n (1,2,4,5‐btc = 1, 2, 4, 5‐benzenetetracarboxylate, pz = pyrazine) is a two‐dimensional coordination network. The zinc(II) center is in a distorted octahedral NO5 coordination environment that is defined by one nitrogen atom of pyrazine, three oxygen atoms of carboxyl groups from 1,2,4,5‐benzenetetracarboxylate tetraanions and two water molecules. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Tris(η5‐cyclopentadienyl)‐tetrahydrofuran‐praseodymium
Authors: Junk Peter C.
Published: October 2003

The title compound is mononuclear with three η5‐cyclopentadienyl ligands and one tetrahydrofuran ligand. If the centroids of the cyclopentadienyl ligands are taken as the point of binding to praseodymium, then the environment about the metal centre is considered as a distorted tetrahedron. Copyright © 2003 John Wiley & Sons, Ltd.
Efficiency of ultraviolet/ozone treatments in the improvement of the dyeability and light fastness of wool
Authors: Micheal M. N. , El‐Zaher N. A.
Published: October 2003

In this study, we evaluated the effect of ultraviolet/ozone treatments for different times on the characteristics of wool fabrics with respect to wettability, permeability, yellowness index, and weight loss. The beneficial effects of this treatment on dyeability, color parameters, light fastness characteristics, and the change in color difference after exposure of the treated dyed samples to artificial daylight for about 150 h was investigated. The results indicated that the improvement in wetting processes may have been due to to surface modifications; this meant that an increase in the amorphousity of the treated samples, the oxidation of the cystine linkage on the surface of the fabrics, and the formation of free‐radical species encouraged dye penetration and aggregation inside the fiber pores as well as bond formation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3668–3675, 2003
Surface plasmon resonance spectroscopic comparison of spiroxazine monolayer and polymeric thin film
Authors: Hur Youngjune , Lee Minsu , Jin Sung‐Ho , Gal Yeong‐Soon , Kim Jae‐Ho , Kim Sung‐Hoon , Koh Kwangnak
Published: October 2003

Photochromic dye has recently attracted much interest in optical applications because of its reversible photoswitching properties by light irradiation. To apply those aspects of photochromism to actual photonic devices, the form of the thin film must be favorable to the photochromic molecular system. In this study, a polymeric thin film and self‐assembled monolayer were constructed with a photochromic spiroxazine derivative that is well known for its good fatigue properties. Their photoisomerization properties were characterized through surface plasmon resonance (SPR). As a result of ultraviolet irradiation to these thin films, the SPR angle shift clearly appeared as the optical thickness (Refractive index × Geometrical thickness) change in both of the films. The Fresnel calculation based on measurement results showed that the angle shift of the polymeric thin film mainly corresponded to the change of the refractive index. For the spiroxazine monolayer, the geometrical thickness change caused the resonance angle to shift dominantly. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3459–3465, 2003
Tentative study on kinetics of bulk polymerization of methyl methacrylate in presence of montmorillonite
Authors: Liu Guo‐Dong , Zhang Liu‐Cheng , Qu Xiong‐Wei , Wang Bo‐Tao , Zhang Yan
Published: October 2003

The kinetics of the bulk polymerization of methyl methacrylate (MMA) in the presence of montmorillonite (MMT) were studied. The effect of MMT on the radical polymerization of MMA was researched by determining the polymerization rate dilatometrically. It was assumed that there were both bimolecular and monomolecular termination processes involved in the termination of the radicals in the polymerization. It was found that a lower benzoyl peroxide (BPO) concentration promotes a higher fraction of monomolecular mode in chain termination. The results show that there is an optimal ratio of MMT to initiator that increases the bulk polymerization rate of MMA. The X‐ray results show that the layer structure of the formed PMMA–MMT composites was also affected by the BPO concentration. With lower initiator concentration, less pronounced layer structure will be observed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3690–3695, 2003
A rheological and morphological study of treated PVC
Authors: Place S. , Fugit J. L. , Prochazka F. , Taverdet J. L.
Published: October 2003

This article reports a rheological and morphological study of poly(vinyl chloride) (PVC) that was subjected to a treatment capable of decreasing the simultaneous mass transfers occurring between liquid food (or simulant) and PVC packaging. The storage modulus (G′), loss modulus (G″), and the loss angle (tan δ), have been used to determine the glass transition temperature using a Rheometric Scientific Dynamic Analyzer. Young's modulus was measured on a dynamometer, and a morphological characterization was carried out with an optical microscope. The obtained results show that treated PVC behaves like a composite material, which is in agreement with a previously established model. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3497–3502, 2003
Effect of ultrafine, fully vulcanized acrylate powdered rubber on the mechanical properties and crystallization behavior of nylon 6
Authors: Ding Xuejia , Xu Riwei , Yu Dingsheng , Chen Hong , Fan Run
Published: October 2003

Nylon 6 (PA6) is a widely used engineering plastic. However, its poor toughness limits its applications. Therefore, toughening PA6 has been a point of interest in the field of PA6 modification. Generally, toughening a plastic with an elastomer reduces the stiffness and heat distortion temperature of the matrix. It has been an important goal of polymer researchers to find a way of toughening PA6 without reductions in its stiffness and heat distortion temperature. In this study, a new kind of material—an ultrafine, fully vulcanized acrylate powdered rubber (UFAPR)—was used to toughen PA6 through melt blending. The influence of UFAPR on the isothermal crystallization kinetics and nonisothermal crystallization behavior of PA was studied with differential scanning calorimetry. The results showed that, with the addition of a little UFAPR, the crystallization rate of PA could be increased, the crystallization temperature could be augmented, and the crystal size distribution of the crystal grain could be narrowed. The changes in the free energy perpendicular to the crystal nucleus were consistent with the results of an Avrami equation according to the theory of Hoffman. The unit surface free energy of the radially developing crystal spherulites decreased with an increasing amount of UFAPR. The results for the mechanical properties, crystalline structure, and crystallization kinetics of PA6/UFAPR composites showed that UFAPR was not only a good toughening agent for PA6 but also an excellent nucleation agent for PA6. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3503–3511, 2003
Morphology of nylon 6/acrylonitrile–butadiene–styrene blends compatibilized by a methyl methacrylate/maleic anhydride copolymer
Authors: Araújo E. M. , Hage E. , Carvalho A. J. F.
Published: October 2003

The morphologies of nylon 6/acrylonitrile–butadiene–styrene blends compatibilized with a methyl methacrylate/maleic anhydride copolymer, with 3–20 wt % maleic anhydride, were examined by transmission electron microscopy. Some staining techniques were employed for identifying the various phases. The binary blends were immiscible and exhibited poor mechanical properties that stemmed from the unfavorable interactions among their molecular segments. This produced an unstable and coarse phase morphology and weak interfaces among the phases in the solid state. The presence of the copolymer in the blends clearly led to a more efficient dispersion of the acrylonitrile–butadiene–styrene phase and consequently optimized Izod impact properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3512–3518, 2003
Metal‐ion‐retention properties of the poly(2‐acrylamido‐2‐methyl‐1‐propanosulfonic acid‐co‐4‐vinyl pyridine) resin
Authors: Rivas Bernabé L. , Villegas Sandra
Published: October 2003

The water‐insoluble resin poly(2‐acrylamido‐2‐methyl‐1‐propanosulfonic acid‐co‐4‐vinyl pyridine), through a radical polymerization solution, was synthesized with ammonium persulfate as an initiator and N,N‐methylene bisacrylamide as a crosslinking reagent. The metal‐ion‐retention properties were studied by batch and column equilibrium procedures for the following metal ions: Hg(II), Cu(II), Cd(II), Zn(II), Pb(II), and Cr(III). These properties were investigated under competitive and noncompetitive conditions. The effects of the pH, maximum retention capacity, and regeneration capacity were studied. The resin showed a high retention ability for Hg(II) ions at pH 2.0. The retention of Hg(II) ions from a mixture of ions was greater than 90%. The resin showed a high selectivity for Hg(II) with respect to other metal ions. The Hg(II)‐loaded resin was able to be recovered with 4M HClO4. The retention capacity was kept after four cycles of adsorption and desorption. The retention properties for Hg(II) were very similar with the batch and column methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3556–3562, 2003
Kinetics and parameters affecting degradation of purified natural rubber
Authors: Phetphaisit Chor. Wayakron , Phinyocheep Pranee
Published: October 2003

Purified natural rubber (PNR) was obtained by treatment of high ammonia NR latex with proteinase enzyme for 24 h, followed by double centrifugation. The PNR was later redispersed into latex form with 0.5% (w/v) sodium dodecyl sulfate. The degradation of PNR was performed in latex form by using a combination of the radical initiator potassium persulfate (K2S2O8) and propanal. The intrinsic viscosity [η] of the degraded rubber or liquid rubber that was obtained depended on various parameters such as the initiator concentration, amount of propanal, dry rubber content, reaction time, and temperature. It was found that the [η] of the rubber can be reduced from 4.31 to 0.19 for the PNR after a 25‐h reaction time using 5% dry rubber content PNR latex, 1 part per hundred rubber (phr) of K2S2O8, and 32 phr of propanal at 80°C. The kinetics of the degradation reaction were investigated. The highest rate constant found was 11.33 × 10−2 s−1. The activation energy of the degradation reaction was 76.56 kJ mol−1. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3546–3555, 2003
Synthesis, thermal behavior, and cone calorimetry of organophosphorus epoxy materials
Authors: Hussain M. , Varley R. J. , Zenka M. , Simon G. P.
Published: October 2003

An organophosphorus epoxy resin with diglycidyl ether of bisphenol A (DGEBA), which has improved fire performance, was synthesized from the reaction of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide and DGEBA. The epoxy resin was then cured with an isomeric mixture of 3,5‐diethyltoluene‐2,4‐diamine and 3,5‐diethyltoluene‐2,6‐diamine. The reaction kinetics were measured by Fourier transform IR, 1H‐NMR, and differential scanning calorimetry. The effect of the incorporation of a phosphorus species into the epoxy network structures was also measured using thermogravimetric, thermal conductivity, and dynamic mechanical thermal analyses. The fire performance was measured using cone calorimetry, which showed that a significant improvement was achieved by the addition of only 1–4% phosphorus into the epoxy backbone. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3696–3707, 2003
Morphology and properties of soy protein plastics modified with chitin
Authors: Zheng Hua , Tan Zhan'ao , Ran Zhan Yuan , Huang Jin
Published: October 2003

A series of bioplastics from isolated soy protein (SPI) and chitin (CH) was prepared with glycerol as a plasticizer by blending and compression molding. Their morphology and properties were investigated by wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), dynamical mechanical thermal analysis (DMTA), scanning electron microscopy (SEM), and tensile and water‐absorption tests. The added CH as a filler cannot strongly interact with SPI molecules and, hence, this results in phase separation in blends. However, the rigid nature of the CH molecules enhanced the tensile strength and Young's modulus, but decreased the breaking elongation of the materials. When the CH content was higher than 10 wt %, the water absorption of the blends were obviously lower than that of the sheets without CH, resulting from the formation of a CH framework in the blends. Both soy protein and CH exhibit good biodegradability, biocompatibility, and bioactivity, and their composites may become a promising biomaterial. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3676–3682, 2003
Preparation and characterization of poly(ether ester) thermoplastic elastomers containing the 2,6‐naphthalenedicarboxyl group
Authors: Ahn Tae Hwan , Park Yun Heum , Kim Seong Hun , Baik Doo Hyun
Published: October 2003

Poly(ether ester) elastomers (PEEs) were synthesized in which dimethyl terephthalate (DMT) was the primary diester compound in the hard segment (H/S) and dimethyl 2,6‐naphthalene dicarboxylate (NDC), which has a more rigid aromatic chemical structure than DMT, was the secondary diester in the H/S. The block PEEs with poly(tetramethylene terephthalate) (PTMT) and/or poly(tetramethylene 2,6‐naphthalate) (PTMN) as the H/S and poly(tetramethylene ether glycol terephthalate) (PTMEGT) as the soft segment (S/S) were synthesized through transesterification and polycondensation of DMT, NDC, 1,4‐butanediol (BD), and poly(tetramethylene ether) glycol (PTMEG) of molecular weight 1000. The melting temperature and heat of fusion of the PEEs decreased with increasing NDC content up to an NDC content of 44.4% in the H/S, but increased on further increase of the NDC content. In addition, the higher the fraction of NDC in the H/S, the higher the glass transition temperature of the copolymer. X‐ray diffraction analysis revealed that the crystallinity of the sample decreases as the NDC content in the H/S is increased relative to that of DMT. Increasing the PTMN content in the H/S reduced the effect of UV photodegradation on the elongation at break. The results show that the introduction of the NDC component into the H/S as a secondary diester compound improves the UV resistance of the resulting PEE. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3473–3480, 2003
Synthesis and properties of the copolymer of acrylamide with 2‐acrylamido‐2‐methylpropanesulfonic acid
Authors: Liu Yang , Xie Jian‐Jun , Zhang Xin‐Ying
Published: October 2003

A cross‐linked copolymer of acrylamide (AM) with 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS) was prepared by solution polymerization. In this reaction, potassium persulfate (PPS) and N,N′‐methylenebisacrylamide (NMBA) were used as initiator and cross‐linker, respectively. This copolymer, poly(acrylamide‐co‐2‐acrylamido‐2‐methylpropanesulfonic acid) (PAMA), can absorb up to 1749 g/g of dry polymer in distilled water and 87 g/g of dry polymer in 0.9 wt % NaCl aqueous solution at room temperature. The PAMA also has excellent performance in absorbing pure alcohols. Its absorbencies in methanol and glycol are about 310 g/g and 660 g/g, respectively. The effects of various salt solutions on the swelling properties were studied systematically, and the relationship between the absorbency and the concentrations of the different salt solutions can be expressed as Q = kcn. Experimental results indicate that the absorbencies were stable at different water temperatures. The swelling rates of the copolymer in distilled water and a water/ethanol mixture (Vwater:Valcohol = 1:1) were also investigated, and the results showed that PAMA could absorb 992 g of distilled water per gram of dry polymer and 739 g of water/ethanol mixture per gram of dry polymer in five minutes. The PAMA has such good water retention at higher temperatures that the swollen gel can retain 71.6 and 49.5% of the maximum absorbency after being heated for 9 hours at 60 and 80 °C, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3481–3487, 2003
Synthesis and characterization of calcium‐containing poly(urethane‐urea)s
Authors: Jayakumar R. , Lee Y.‐S. , Nanjundan S.
Published: October 2003

A calcium salt of mono(hydroxyethoxyethyl)phthalate [Ca(HEEP)2] was synthesized by the reaction of diethylene glycol, phthalic anhydride, and calcium acetate. Four different bisureas like hexamethylene bis(ω,N‐hydroxyethylurea), tolylene 2,4‐bis(ω,N‐hydroxyethylurea), hexamethylene bis(ω,N‐hydroxypropylurea), and tolylene 2,4‐bis(ω,N‐hydroxypropylurea) were prepared by reacting ethanolamine or propanolamine with hexamethylene diisocyanate (HMDI) or tolylene 2,4‐diisocyanate (TDI). Calcium‐containing poly(urethane‐urea)s (PUUs) were synthesized by reacting HMDI or TDI with 1:1 mixtures of Ca(HEEP)2 and each of the bisureas using di‐n‐butyltin dilaurate as a catalyst. The PUUs were well characterized by Fourier transform infrared, 1H‐ and 13C‐NMR (nuclear magnetic resonance), solid‐state 13C cross‐polarization–magic angle spinning NMR, viscosity, solubility, elemental, and X‐ray diffraction studies. Thermal properties of the polymers were also studied by using thermogravimetric analysis and differential scanning calorimetry. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3488–3496, 2003
Polymer hybrids from self‐emulsified PU anionomer and water‐reducible acrylate copolymer via a postcuring reaction
Authors: Lai Jian‐Zei , Ling Hao‐Jan , Chen Guan‐Nan , Yeh Jen‐Taut , Chen Kan‐Nan
Published: October 2003

Water‐reducible acrylate copolymer is obtained from a free‐radical copolymerization of n‐butyl acrylate, acrylic acid, and methacrylic acid. Self‐emulsified aqueous‐based polyurethane (PU) anionomer is prepared by the conventional method. The latent curing agents (di‐ and triaziridinyl compounds, HDDA‐AZ and TMPTA‐AZ) are synthesized from the reaction of aziridine with hexandiol diacrylate and trimethylolpropane triacrylate, respectively. These two polymers and the latent curing agent are miscible in each other and become a single component and self‐curable polymer dispersion. The carboxyl ions of polymers not only stabilize the aqueous polymer dispersions but also serve the curing site toward latent curing agent in the drying process. These two polymers blend with a curing agent, which results in new polymer hybrid formation. These polymer hybrids have the improvements on performance properties and the cost/performance benefits. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3578–3587, 2003
Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan
Authors: Tsaih Min Larng , Chen Rong Huei
Published: October 2003

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003
Synthesis and characterization of temperature‐ and pH‐sensitive poly(N,N‐diethylacrylamide‐co‐methacrylic acid)
Authors: Liu Shouxin , Liu Mingzhu
Published: October 2003

A series of pH‐ and temperature‐responsive (N,N‐diethylacrylamide‐co‐methacrylic acid) (DEAM–MAA) random copolymers were synthesized by free‐radical copolymerization techniques, and their lower critical solution temperatures (LCSTs) at different pH values and their critical phase‐transition pH values at different temperatures were determined by transmittance measurements, respectively. The LCSTs of DEAM–MAA copolymers depend on the MAA content in the copolymers and are significantly affected by the pH of the aqueous solution. Similarly, the critical phase‐transition pH values also depend on the MAA content of the DEAM–MAA copolymers and are significantly affected by the temperature of the aqueous solution. The LCST of DEAM–MAA copolymers increases with an increase in the MAA content. The critical phase‐transition pH increases with increasing MAA content in the copolymer and also increases with increasing aqueous solution temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3563–3568, 2003
Feasibility of conducting semi‐interpenetrating networks based on a poly(ethylene oxide) network and poly(3,4‐ethylenedioxythiophene) in actuator design
Authors: Vidal F. , Popp J.‐F. , Plesse C. , Chevrot C. , Teyssié D.
Published: October 2003

A new type of synthetic pathway—the use of interpenetrating polymer networks (IPNs)—is proposed to design conducting polymer‐based actuators. Two types of materials with interesting conducting properties were prepared: (1) a semi‐IPN between poly(3,4‐ethylenedioxythiophene) (PEDOT) and branched poly(ethylene oxide) (PEO) network; (2) a tricomponent IPN between PEDOT and a PEO/polycarbonate (PC)–based network as the ionic conducting partner. In the first case, the influence of the amount of branching in the PEO network on the EDOT uptake and electrochemical properties was studied. A maximum conductivity (15 S cm−1) was obtained for 60 wt % branched PEO in the material. Moreover, the dispersion profile of PEDOT in the material was shown by elemental analysis and energy dispersion spectroscopy to follow a gradient through the thickness of the film leading to a built‐in three‐layered device. With respect to PEO/PC materials, the best results were obtained for about 80 wt % PEO in the matrix where the material remains sufficiently elastomeric. In this case, the conductivity reaches about 1 S cm−1 for a 10 to 30 wt % polycarbonate content. These materials are capable of reversible 45° angular deflections under a 0.5V potential difference. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3569–3577, 2003
Rheological and mechanical properties of natural rubber reinforced with agricultural byproduct
Authors: Imanah J. E. , Okieimen F. E.
Published: October 2003

Cocoa pod powdered (CP) and Carbonized Cocoa pod powdered (CCP) sieved through 150 μm mesh were characterized in terms of loss on ignition, surface area, moisture content, and oil absorption and used as filler in compounding natural rubber and vulcanized using efficient vulcanization system. The processing and curing characteristics of the compound mixes were determined on a Monsanto Rheometer. Physical‐mechanical properties of the vulcanizates were measured as a function of filler loading. It was found that vulcanizates with 40–50% filler loading showed maximum tensile strength of 8.4 MPa for CP, and 9.5 MPa for CCP. Hardness showed increased with increased filler loading for all the compounds. The reinforcing ability of the cocoa pod husk is not much inferior when compared to Carbon Black, N330. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3718–3722, 2003