bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychiatric disorders and the use of mental health services among children involved in bullying
Authors: Kumpulainen Kirsti , Räsänen Eila , Puura Kaija
Published: August 2002

This study had two aims: to evaluate the relationship between bullying and psychiatric disorders and to study the probability of using mental health services among children involved in bully/victim problems. The data consisted of interviews with 423 parents and 420 children. Diagnostic measures were based on the Isle of Wight Interview. Children involved in bullying as bullies, bully‐victims, and victims were compared with other children. Children involved in bully/victim problems were more prone to have psychiatric disorders than noninvolved children. The probability of being disturbed was highest among male bullies, followed by male bully‐victims and female victims (9.5‐fold, 7.9‐fold, and 4.3‐fold, respectively) compared with noninvolved same‐sex children. The most common diagnoses among children involved in bully/victim problems were attention deficit disorder, oppositional/conduct disorder, and depression. Furthermore, children involved in bully/victim problems were more likely to have used mental health services at some time during their lives and also during the previous 3 months. Special attention should be paid to children’s mental health when dealing with bullying problems at school. Referral pathways to mental health services and factors affecting the referral processes among children should be further studied. Aggr. Behav. 27:102–110, 2001. © 2001 Wiley‐Liss, Inc.
Weaving our stories as they weave us
Authors: Pritchard Cecilia , Sanders Pamelaia
Published: August 2002

Women of Color graduate students use CI to explore their educational experience within the academy and relate it to their cultural contexts.
Frequency of anti‐heparin‐platelet factor 4 antibodies in hemodialysis patients and correlation with recurrent vascular access thrombosis
Authors: O'Shea Susan I. , Sands Jeffrey J. , Nudo Sybil A. , Ortel Thomas L.
Published: August 2002

Heparin‐induced thrombocytopenia (HIT), characterized by the formation of antibodies to a complex of platelet factor 4 (PF4) and heparin, is a well‐recognized risk factor for thromboembolic complications. The frequency of antibody development varies among patient populations. Hemodialysis patients have repeated heparin exposure and should be at risk of developing HIT. This might, contribute to the development of vascular access thrombosis. We prospectively evaluated 88 hemodialysis patients for the presence of anti‐PF4/heparin antibodies. Eighteen patients (20%) had a prior history of 1 or more prior access thrombosis. One patient (1.14%), without a history of graft thrombosis, tested positive for anti‐PF4/heparin antibodies. In our study, the presence of anti‐PF4/heparin antibodies was rare and was not increased in patients with a history of vascular access thrombosis. Am. J. Hematol. 69:72‐73, 2002. © 2002 Wiley‐Liss, Inc.
Histone deacetylase inhibitors increase p21WAF1 and induce apoptosis of human myeloma cell lines independent of decreased IL‐6 receptor expression
Authors: Lavelle Donald , Chen Yi‐Hsiang , Hankewych Maria , DeSimone Joseph
Published: August 2002

Histone deacetylase (HDAC) inhibitors cause growth arrest and apoptosis of cancer cells by both p21‐dependent and independent mechanisms. Decreased expression of growth factor receptors may be a key factor in the p21‐independent mechanism, although this has not been directly tested. We have tested the effects of sodium butyrate and trichostatin A on human myeloma cell lines and have observed G1 arrest and apoptosis associated with increased expression of p21WAF1, Bax, Rb dephosphorylation, and decreased IL‐6 receptor (IL‐6R) expression. Experiments to determine the role of disruption of IL‐6 signaling as a result of decreased IL‐6 receptor expression in mediating these effects were conducted using a stable transfectant of the OPM‐2 line which constitutively expressed the IL‐6 receptor. Our results indicated that decreased IL‐6R expression was not required for induction of p21WAF1 or apoptosis. Thus, HDAC inhibitors appear to activate multiple cellular pathways, leading to growth arrest and apoptosis, and their use in the treatment of myeloma, particularly in combination with other agents, warrants further investigation. Am. J. Hematol. 68:170–178, 2001. © 2001 Wiley‐Liss, Inc.
Differential workloads of boys and girls in rural Nepal and their association with growth
Authors: Yamanaka Miki , Ashworth Ann
Published: August 2002

In developing countries, heavy workloads of women adversely affect their nutritional status and that of their children. Little is known, however, about the effect of children's heavy workloads on their own well‐being. In Nepal, girls are expected to help their mothers in time‐consuming and energy‐demanding tasks from an early age. The aim of this study was to compare work patterns and anthropometric status of boys and girls age 6–17 years in western rural Nepal. It was hypothesized that girls would work longer and harder than boys and would have poorer growth status. It was also anticipated that children's work patterns might differ between highland and lowland areas. Two study sites were therefore chosen: one in the hills and the other in the lowland terai. A time allocation study was conducted for 237 children. They were observed continuously from 7:00 AM to 7:00 PM to determine the time spent in light, moderate, and heavy activities. Body weights and heights were also measured. On average, girls worked twice as long as boys (5.8 vs. 2.8 h/day, P < 0.001) and undertook more heavy work (1.5 vs. 0.7 h/day, (P < 0.001), but they did not have poorer anthropometric status. Children in the hills worked longer hours and did heavier work than those in the terai and were more stunted in growth. Am. J. Hum. Biol. 14:356–363, 2002. © 2002 Wiley‐Liss, Inc.
Exposures associated with serum organochlorine levels among postmenopausal women from Western New York state
Authors: Moysich Kirsten B. , Ambrosone Christine B. , Mendola Pauline , Kostyniak Paul J. , Greizerstein Hebe B. , Vena John E. , Menezes Ravi J. , Swede Helen , Shields Peter G. , Freudenheim Jo. L.
Published: August 2002

Background

Organochlorines, such as 2,2‐bis (4‐chlorophenyl)‐1,1‐dichloroethylene (DDE), polychlorinated biphenyls (PCBs), and hexachlorobenzene (HCB) are lipophilic compounds that are ubiquitous in the environment and may cause adverse health effects in humans.

Methods

We examined the correlation between epidemiological exposure variables and serum DDE, PCB, and HCB levels in a sample of 192 healthy, female postmenopausal western New York residents; a subset of the control group from a case–control study on breast cancer risk. Usual diet, reproductive and medical histories, and other lifestyle information were obtained by an extensive in person interview. Serum levels (ng/g) of DDE, HCB, and 69 PCB congeners were determined by gas chromatography with electron capture detection. Statistical analyses included computations of crude and age and lipid adjusted correlation coefficients, as well as multiple linear regression analysis.

Results

Results indicated that the strongest predictors for serum DDE levels were age, serum lipids, parity, and fruit and dairy consumption. Statistically significant predictors of PCB levels included age, serum lipids, parity, and fish consumption. Serum HCB levels were related to age, serum lipids, and fruit and red meat consumption.

Conclusions

Our findings are consistent with previous investigations that reported strong associations between organochlorine levels and age and serum lipids. The absence of other data showing an association between fruit intake and organochlorine levels make the importance of this finding unclear. Am. J. Ind. Med. 41:102–110, 2002. © 2002 Wiley‐Liss, Inc.
Occupational stress and work‐related upper extremity disorders: Concepts and models*
Authors: Huang Grant D. , Feuerstein Michael , Sauter Steven L.
Published: August 2002

Background

While research has suggested that interventions targeted at occupational stress (job stress) factors may improve clinical and work outcomes related to work‐related musculoskeletal disorders, the emerging hypotheses relating occupational stress to work‐related upper extremity disorders (WRUEDs) are not particularly well known among occupational health providers and researchers.

Methods

Generic job stress and health models and multivariable models of WRUEDs were described and evaluated.

Results

Models on occupational stress and health/WRUEDs offer unique perspectives on the role of occupational stressors on WRUEDs. However, the limited support for the structure and proposed mechanisms of these models suggest that investigations examining and validating proposed biobehavioral pathways are still needed.

Discussion

Difficulties in conceptualizing occupational stress have, in the past, hindered its systematic incorporation into occupational health research and prevention/intervention strategies. The present paper provides a common basis for researchers and practitioners with diverse backgrounds to understand job stress and its relation to WRUEDs in order to enhance future efforts. Given the present limitations in the field and the need for comprehensive approaches to WRUEDs, there is great potential for occupational health researchers and clinicians to advance knowledge in this area. Am. J. Ind. Med. 41:298–314, 2002. © 2002 Wiley‐Liss, Inc.
Teratogenesis of holoprosencephaly
Authors: Cohen M. Michael , Shiota Kohei
Published: August 2002

Teratogenic causes of holoprosencephaly are critically assessed. A brief general review of holoprosencephaly is followed by four tables summarizing etiologic factors. Subjects evaluated here include: 1) maternal diabetes; 2) ethyl alcohol; 3) retinoic acid; 4) mutated genes and teratogens involving the sonic hedgehog signaling network and cholesterol biosynthesis; and 5) cholesterol trafficking, sterol adducts, target tissue response, and sterol sensing domain. © 2002 Wiley‐Liss, Inc.
Confirmation of existence of a new syndrome: LAPS syndrome
Authors: Lindor Noralane M. , Kasperbauer Jan L. , Hoffman Alan D. , Parisi Joseph E. , Wang Hongwei , Warman Matthew
Published: August 2002

In l998, Hopkin et al. described a new disorder characterized by progressive laryngotracheal stenosis, short stature, and arthropathy. We provide extensive clinical information on two additional unrelated patients with this distinctive disorder and propose the name LAPS syndrome, to reflect the most consistently recognized features, namely, Laryngotracheal stenosis, Arthropathy, Prognathism, and Short stature. © 2002 Wiley‐Liss, Inc.
PTEN mutation in a family with Cowden syndrome and autism
Authors: Goffin Aleide , Hoefsloot Lies H. , Bosgoed Ermanno , Swillen Ann , Fryns Jean‐Pierre
Published: August 2002

We report on a mother and son with Cowden syndrome and a PTEN mutation. The boy also exhibits autistic behavior and mental retardation, while his mother has a normal intelligence and social interaction pattern. We review the scanty literature data on the association of Cowden syndrome and autism and emphasize that the association of progressive macrocephaly and pervasive developmental disorder seems to be an indication for screening for PTEN mutations. © 2001 Wiley‐Liss, Inc.
Chromosome 1q12–q22 linkage results in eastern Québec families affected by schizophrenia
Authors: Maziade Michel , Fournier Alain , Phaneuf Daniel , Cliche Denis , Fournier Jean‐Pierre , Roy Marc‐André , Mérette Chantal
Published: August 2002

An impressive LOD score of 6.5 has recently been reported for schizophrenia on chromosome 1q21–22 in large families from eastern Canada [Brzustowicz et al.,2000: Science 288:678–682]. We did not reproduce such a finding in large pedigrees of eastern Québec based on seven markers spanning the 1p13–1q22 region and using both the models and phenotypes of Brzustowicz et al. and those used in our ongoing genome scan in 21 large French Canadian families. There was no significant total LOD scores in that chromosomal region (a maximum of 0.57) either for schizophrenia or bipolar disorders, nor any signal in individual large pedigrees. However, the samples of Brzustowicz et al. and ours differed in terms of their origins, the latter being of French ancestry and the former of Celtic and German descent. Population difference, genetic heterogeneity, and differences in ascertainment might explain the lack of replication. The result reported by Brzustowicz et al. cannot be discarded and should probably be considered as a susceptibility locus for a subset of the schizophrenic population. © 2001 Wiley‐Liss, Inc.
McLeod neuroacanthocytosis: Genotype and phenotype
Authors: Danek Adrian , Rubio Justin P. , Rampoldi Luca , Ho Mengfatt , Dobson‐Stone Carol , Tison François , Symmans William A. , Oechsner Matthias , Kalckreuth Wolfgang , Watt Julie M. , Corbett Alastair J. , Hamdalla Hisham H. M. , Marshall Andrew G. , Sutton Ian , Dotti Maria Teresa , Malandrini Alessandro , Walker Ruth H. , Daniels Geoff , Monaco Anthony P.
Published: August 2002

McLeod syndrome is caused by mutations of XK, an X‐chromosomal gene of unknown function. Originally defined as a peculiar Kell blood group variant, the disease affects multiple organs, including the nervous system, but is certainly underdiagnosed. We analyzed the mutations and clinical findings of 22 affected men, aged 27 to 72 years. Fifteen different XK mutations were found, nine of which were novel, including the one of the eponymous case McLeod. Their common result is predicted absence or truncation of the XK protein. All patients showed elevated levels of muscle creatine phosphokinase, but clinical myopathy was less common. A peripheral neuropathy with areflexia was found in all but 2 patients. The central nervous system was affected in 15 patients, as obvious from the occurrence of seizures, cognitive impairment, psychopathology, and choreatic movements. Neuroimaging emphasized the particular involvement of the basal ganglia, which was also detected in 1 asymptomatic young patient. Most features develop with age, mainly after the fourth decade. The resemblance of McLeod syndrome with Huntington's disease and with autosomal recessive chorea‐acanthocytosis suggests that the corresponding proteins—XK, huntingtin, and chorein—might belong to a common pathway, the dysfunction of which causes degeneration of the basal ganglia.
Accelerated hippocampal atrophy in Alzheimer's disease with apolipoprotein E ε4 allele
Authors: Mori Etsuro , Lee KangUk , Yasuda Minoru , Hashimoto Mamoru , Kazui Hiroaki , Hirono Nobutsugu , Matsui Mieko
Published: August 2002

Although apolipoprotein E ε4 is an established risk factor for Alzheimer's disease, its effect on the rate of progression of Alzheimer's disease remains unknown. The purpose of this longitudinal study was to elucidate whether the rate of hippocampal atrophy is a function of the apolipoprotein E genotypes and severity of disease. Fifty‐five patients with probable Alzheimer's disease were the subjects. The annual rate of hippocampal atrophy was determined by using magnetic resonance imaging repeated at a 1‐year interval. On a two‐way analysis of variance, the effect of the apolipoprotein E ε4 allele on hippocampal atrophy was significant, but neither the effect of severity nor the interaction term was significant. In further analysis with one‐way analysis of variance, the mean annual rate of hippocampal atrophy was significantly different between the groups of patients with (9.76 ± 4.27%) and without the apolipoprotein E ε4 allele (6.99 ± 4.24%). Apolipoprotein E ε4 dose was significantly correlated with the rate of hippocampal atrophy (rs = 0.277, Spearman rank correlation coefficient), suggesting a gene dose effect. The involvement of the apolipoprotein E ε4 allele in the progression of hippocampal atrophy has implications for therapeutic approaches in Alzheimer's disease and should be taken into consideration in longitudinal studies including clinical drug trials.
Recommended diagnostic criteria for multiple sclerosis: Guidelines from the international panel on the diagnosis of multiple sclerosis
Authors: McDonald W. Ian , Compston Alistair , Edan Gilles , Goodkin Donald , Hartung Hans‐Peter , Lublin Fred D. , McFarland Henry F. , Paty Donald W. , Polman Chris H. , Reingold Stephen C. , Sandberg‐Wollheim Magnhild , Sibley William , Thompson Alan , Van Den Noort Stanley , Weinshenker Brian Y. , Wolinsky Jerry S.
Published: August 2002

The International Panel on MS Diagnosis presents revised diagnostic criteria for multiple sclerosis (MS). The focus remains on the objective demonstration of dissemination of lesions in both time and space. Magnetic resonance imaging is integrated with clinical and other paraclinical diagnostic methods. The revised criteria facilitate the diagnosis of MS in patients with a variety of presentations, including “monosymptomatic” disease suggestive of MS, disease with a typical relapsing‐remitting course, and disease with insidious progression, without clear attacks and remissions. Previously used terms such as “clinically definite” and “probable MS” are no longer recommended. The outcome of a diagnostic evaluation is either MS, “possible MS” (for those at risk for MS, but for whom diagnostic evaluation is equivocal), or “not MS.”
Long‐term hyperexcitability in the hippocampus after experimental head trauma
Authors: Santhakumar Vijayalakshmi , Ratzliff Anna D. H. , Jeng Jade , Toth Zsolt , Soltesz Ivan
Published: August 2002

Head injury is a causative factor in the development of temporal lobe epilepsy. However, whether a single episode of concussive head trauma causes a persistent increase in neuronal excitability in the limbic system has not been unequivocally determined. This study used the rodent fluid percussion injury (FPI) model, in combination with electrophysiological and histochemical techniques, to investigate the early (1 week) and long‐term (1 month or longer) changes in the hippocampus after head trauma. Low‐frequency, single‐shock stimulation of the perforant path revealed an early granule cell hyperexcitability in head‐injured animals that returned to control levels by 1 month. However, there was a persistent decrease in threshold to induction of seizure‐like electrical activity in response to high‐frequency tetanic stimulation in the hippocampus after head injury. Timm staining revealed both early‐ and long‐term mossy fiber sprouting at low to moderate levels in the dentate gyrus of animals that experienced FPI. There was a long‐lasting increase in the frequency of spontaneous inhibitory postsynaptic currents in dentate granule cells after FPI, and ionotropic glutamate receptor antagonists selectively decreased the spontaneous inhibitory postsynaptic current frequency in the head‐injured animals. These results demonstrate that a single episode of experimental closed head trauma induces long‐lasting alterations in the hippocampus. These persistent structural and functional alterations in inhibitory and excitatory circuits are likely to influence the development of hyperexcitable foci in posttraumatic limbic circuits.
Synthesis and characterization of epoxy‐acrylate composite latex
Authors: Pan Guirong , Wu Limin , Zhang Zhuqing , Li Dan
Published: August 2002

A waterborne epoxy‐acrylate composite latex was synthesized. The effects of the concentration of the initiator, surfactant, and epoxy resin on the particle size, molecular weight, and grafting ratios of the composite latex were investigated. The increase of the concentration of the initiator and epoxy resin led to the decrease of the weight‐average molecular weight. The graft ratios increased with an increase in the initiator level and a decrease in the epoxy resin concentration whereas the variation of the concentration of the surfactant did not have much influence on the graft ratios. The increase in the initiator level caused the aggrandizement of the particle size, and the increase of the concentration of the surfactant and epoxy resin caused a decrease in the latex particle size. Fourier transform IR spectroscopy with attenuated total reflectance indicated that the epoxy resin molecules were enriched in the mold‐facing surface in the film from the composite latex. The differential scanning calorimetry analysis, dynamic mechanical analysis, and Instron test showed that the polymer films cast by the composite latex had lower tensile strength and glass transition than those by the blend latex. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1736–1743, 2002
Crystallization behaviors of polypropylene/montmorillonite nanocomposites
Authors: Ma Jisheng , Zhang Shimin , Qi Zongneng , Li Ge , Hu Youliang
Published: August 2002

The isothermal crystallization kinetics of polypropylene/montmorillonite (PP/MMT) nanocomposites synthesized via intercalation polymerization were investigated by using differential scanning calorimeter and polarizing optical microscope (POM). The crystallinity of the nanocomposites decreased with the increase of the montmorillonite content, indicating that the MMT layers dispersed in the PP matrices confined the PP chains and hindered the crystallization of the PP chains. The POM photographs showed that the spherulites of the PP/MMT nanocomposites were greatly decreased in size as MMT was introduced. On the other hand, the crystallization rate increased dramatically with the increasing of MMT content. The interfacial free‐energy per unit area perpendicular to PP chains in PP/MMT nanocomposites decreased with increasing MMT content, suggesting that the MMT layers acted as heterogeneous nuclei in the nucleation of crystallization. The nucleus density increased with the increasing of MMT content, leading to a positive effect on the crystallization. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1978–1985, 2002
Sulfonyl azides—an alternative route to polyolefin modification
Authors: Bateman Stuart A. , Wu Dong Yang
Published: August 2002

Low‐density polyethylene was modified to incorporate aniline moieties by reactive processing with 4‐aminobenzenesulfonyl azide. Under melt‐processing conditions, the loss of nitrogen produces a sulfonyl nitrene which, in the singlet state, interacts with the substrate primarily by C–H insertion. Polymeric blends prepared from aniline‐grafted polyethylene and nylon‐66 showed improved tensile and impact properties over and above nylon blended with virgin polyethylene. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1395–1402, 2002; DOI 10.1002/app.10302
Multiwalled carbon nanotube polymer composites: Synthesis and characterization of thin films
Authors: Safadi B. , Andrews R. , Grulke E. A.
Published: August 2002

The aim of this article was to elucidate the basic relationships between processing conditions and the mechanical and electrical properties of multiwalled carbon nanotube reinforced polymer composites. In conventional chopped fiber reinforced polymer composites, uniform distributions of fibers throughout the matrix are critical to producing materials with superior physical properties. Previous methods have dispersed carbon nanotubes by aggressive chemical modification of the nanotubes or by the use of a surfactant prior to dispersion. 1, 2 Here, ultrasonic energy was used to uniformly disperse multiwalled nanotubes (MWNTs) in solutions and to incorporate them into composites without chemical pretreatment. Polystyrene (PS) solutions containing MWNTs were cast and spun to yield thin film MWNT composites. The rheology of PS/MWNT suspensions was modeled using the Carreau equation. MWNTs were found to align at the shear rates generated by the spin casting process. The tensile modulus and strain to failure of samples compared well to classical micromechanical models, increasing with MWNT loading. The composite films showed lower strains at the yield stress than neat PS films. The presence of MWNTs at 2.5 vol % fraction approximately doubles the tensile modulus, and transforms the film from insulating to conductive (surface resistivity, ρ, approaching 103 Ω/□). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2660–2669, 2002
Phosphorus‐containing epoxy resins: Thermal characterization
Authors: Jain Preeti , Choudhary V. , Varma I. K.
Published: August 2002

Three novel aromatic phosphorylated diamines, i.e., bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl} pyromellitamic acid (AP), 4,4′‐oxo bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl}phthalamic acid (AB) and 4,4′‐hexafluoroisopropylidene‐bis N,N′‐{3‐[(3‐aminophenyl)methyl phosphinoyl] phenyl}phthalamic acid (AF) were synthesized and characterized. These amines were prepared by solution condensation reaction of bis(3‐aminophenyl)methyl phosphine oxide (BAP) with 1,2,4,5‐benzenetetracarboxylic acid anhydride (P)/3,3′,4,4′‐benzophenonetetracarboxylic acid dianhydride (B)/4,4′‐(hexafluoroisopropylidene)diphthalic acid anhydride (F), respectively. The structural characterization of amines was done by elemental analysis, DSC, TGA, 1H‐NMR, 13C‐NMR and FTIR. Amine equivalent weight was determined by the acetylation method. Curing of DGEBA in the presence of phosphorylated amines was studied by DSC and curing exotherm was in the temperature range of 195–267°C, whereas with conventional amine 4,4′‐diamino diphenyl sulphone (D) a broad exotherm in temperature range of 180–310°C was observed. Curing of DGEBA with a mixture of phosphorylated amines and D, resulted in a decrease in characteristic curing temperatures. The effect of phosphorus content on the char residue and thermal stability of epoxy resin cured isothermally in the presence of these amines was evaluated in nitrogen atmosphere. Char residue increased significantly with an increase in the phosphorus content of epoxy network. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2235–2242, 2002
Eco‐friendly durable press finishing of cellulose‐containing fabrics
Authors: Ibrahim N. A. , Abo‐Shosha M. H. , Elnagdy E. I. , Gaffar M. A.
Published: August 2002

To impart easy‐care properties to cellulose‐containing fabrics along with avoiding any harmful effects of formaldehyde on both the health and the environment, attempts have been made to use citric acid (CA) as an ester crosslinking agent along with different catalytic systems in the absence and presence of certain additives. Further, fixation conditions, type of crosslinking agent, as well as type of substrate have been studied. Results revealed that the enhancement in carboxyl content, performance properties, and the decrease in tear strength (TS) as well as in whiteness indices (WI) of the finished fabric samples were increased by increasing CA concentration up to 80 g/L and by raising thermofixation temperature from 140 up to 180°C for 90 s. Inclusion of triethanolamine hydrochloride (TEA. HCl), decreased the carboxyl content, TS, color strength K/S, as well as oily stain release rating (SRR) of the finished fabric samples along with an increase in bound nitrogen (%N), wrinkle recovery angle WRA, and an improvement in WI without affecting the durable press rating (DP). Within the range examined (0–30 g/L), increasing PEG‐600 concentration improved the wet resiliency, TS, as well as WI properties of the finished samples. Increasing DMDHEU ratio in the CA/DMDHEU crosslinking system gave rise to an increase in %N, WRA (dry and wet), DP, as well as in free CH2O of finished fabrics, along with a slight improvement in WI values. On the other hand, the TS, carboxyl content, K/S, SRR values of the finished fabric samples were lower at a higher DMDHEU ratio. Increase in carboxyl content, %N, WRA (dry and wet), DP and SRR, as well as extent of post dyeing (K/S) of the treated fabric samples upon using different ester crosslinking agents followed the descending order: citric acid > pyromellitic dianhydride. The opposite holds true for the TS, and WI values. Among the esterifying catalysts used, and for a given set of finishing conditions, NaH2PO2 · H2O proved to be the most effective one, and the following order of effectiveness may be drawn: NaH2PO2 · H2O > K2HPO4 > Na3–citrate > Na2–tartrate. Inclusion of silicone softener in the finishing formulation brought about an improvement in softeness degree, WRA, %N, DP, TS as well as K/S values along with a decrease in carboxyl content, SRR, and WI values of the treated fabric samples, regardless of the used silicone softener.The performance properties of the finished fabric samples were determined by the type and nature of the substrate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2243–2253, 2002
Influence of carbon fiber surface treatments on the structure and properties of conductive carbon fiber/polyethylene films
Authors: Mironov V. S. , Park Min , Choe Chulrim , Kim Junkyung , Lim Soonho , Ko Hyunhyub
Published: August 2002

Effects of carbon fiber (CF) surface modification on the crystalline structure and both electrical and mechanical properties of conductive CF/high‐density polyethylene (HDPE) films were studied. Three different types of surface‐treated CF, epoxy‐sized, unsized, and sized but thermally treated, were considered. It was found that the uniformity of the transcrystalline zone around CF and the overall crystallinity of the polyethylene matrix decreased when epoxy‐sized CF was used. Epoxy‐sized CF caused a significant reduction not only in electrical resistivity and temperature coefficient of resistivity (TCR) but also tensile strength and coefficient of linear thermal expansion (CLTE) of composite films compared with that of unsized or sized CF that was thermally treated. We observed the systematic changes of TCR and CLTE values in accordance with CF surface modification and CF content in composite films. It was concluded that thermal expansion of the polymer matrix is the main reason for the positive TCR of CF/HDPE films. As the most probable reasons for decreased resistivity and strength of the CF/HDPE films with epoxy‐sized CF, the diffusion of epoxy sizing agent into the polyethylene matrix and the formation of loosened semiconductive interphase structure in the film are considered. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2040–2048, 2002; DOI 10.1002/app.10500
Expandable graphite systems for halogen‐free flame‐retarding of polyolefins. I. Flammability characterization and synergistic effect
Authors: Xie Rongcai , Qu Baojun
Published: August 2002

The use of some types of expandable graphite (EG) as an intumescent flame‐retardant additive in polyolefins was studied using the cone calorimeter test (CCT), thermogravimetric analysis (TGA), the limiting oxygen index (LOI), and the‐UL 94 test and through measurement of EG's mechanical and electrical properties. The present study has shown that some suitable EG systems combined with other organic and inorganic halogen‐free flame‐retardant (HFFR) additives apparently can improve the flame‐retardant capacity with good mechanical properties of polyolefin blends. For linear low‐density polyethylene and/or ethylene vinyl acetate/EG/HFFR blends the limiting oxygen index can reach a rating above 29, and the UL‐94 test can produce a value of V–0. The CCT and TGA data show that the EG and EG/HFFR additives not only promoted the formation of carbonaceous char but also greatly decreased the heat release rate and the effective heat of combustion and increased the residues after burning. The synergistic effect of EG with other HFFR additives, such as zinc borate, the phosphorus–nitrogen compound NP28, and microcapsulated red phosphorus is examined and discussed in detail in this article. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1181–1189, 2001
Mechanism for the plasma oxidation of wool fiber surfaces from XPS studies of self‐assembled monolayers
Authors: Dai X. J. , Elms F. M. , George G. A.
Published: August 2002

The O2 plasma treatment of self‐assembled monolayers (SAMs) of octadecyl mercaptan on gold substrates was investigated as a model for the oxidation of wool fiber surfaces. Three controlled low‐pressure gas‐plasma treatments were employed in which the active species were (i) atomic oxygen, (ii) atomic oxygen plus vacuum UV radiation, and (iii) full plasma treatment (charged particles in addition to the above). X‐ray photoelectron spectroscopy revealed that the plasma treatments differ from each other in the extent of oxidation and etch rate with the full plasma treatment being the most aggressive plasma. The results have confirmed that the charged particles present in a full O2 plasma treatment are responsible for rapid etching of the organic surface and thus play a significant role in the oxidation mechanism due to radical formation during this process. Vacuum UV radiation also contributes to the oxidation process. Only short plasma treatment is necessary for the oxidation of the lipid layer and the SAM is a suitable model for this process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1461–1469, 2001
Studies on high‐speed melt spinning of noncircular cross‐section fibers. III. Modeling of melt spinning process incorporating change in cross‐sectional shape
Authors: Takarada Wataru , Ito Hiroshi , Kikutani Takeshi , Okui Norimasa
Published: August 2002

A numerical analysis program for high‐speed melt spinning of flat and hollow fibers was developed. Change in cross‐sectional shape along the spin line was incorporated adopting a formulation in which energy reduction caused by the reduction of surface area was assumed to be equal to the energy dissipation by viscous flow in the plane perpendicular to the fiber axis. In the case of flat fiber spinning, the development of temperature distribution in the cross section was considered. It was found that the empirical equations for air friction and cooling of the spin line of circular fibers can be applied for the flat fiber spin line if the geometrical mean of long‐axis and short‐axis lengths was adopted, instead of fiber diameter, as the characteristic length for Reynolds number and Nusselt number. Three features expected through the high‐speed spinning of noncircular cross‐section fibers could be reproduced: (1) although cooling of the flat fiber spin line was enhanced, calculated tension at the position of solidification was not affected much by the difference in cross‐sectional shape; (2) change in cross‐sectional shape proceeded steeply near the spinneret; and (3) temperature at the edge became significantly lower than that at the center in the cross section of flat fibers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1589–1600, 2001
Use of silanes and copolymers as adhesion promoters in glass fiber/polyethylene composites
Authors: Bikiaris D. , Matzinos P. , Prinos J. , Flaris V. , Larena A. , Panayiotou C.
Published: August 2002

Two organofunctional silanes and three functionalized copolymers were used as adhesion promoters in glass fiber/polyethylene‐reinforced composites. The performance of the coupling agents was investigated by mechanical property measurements, scanning electron microscopy, and dynamic mechanical analysis. Coupling achieved with the poly(ethylene‐g‐maleic anhydride) copolymer proved to be the most successful compared with the other copolymers (ethylene/vinyl alcohol, ethylene/acrylic acid) and silane agents (γ‐methacryloxypropyltrimethoxy, cationic styryl). The combined coupling performance of the silanes and copolymers examined in this study appears to be controlled by the coupling performance of the copolymer. Effective coupling was reflected in increased mechanical properties. Increased fiber/matrix adhesion is not always associated with effective coupling because structural changes occurring at the interface region can result in a deterioration of the material property. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2877–2888, 2001
Adsorption of heavy‐metal ions on poly(ethylene imine)‐immobilized poly(methyl methacrylate) microspheres
Authors: Duru P. Erol , Bektas Sema , Genç ömer , Pati̇r Süleyman , Denizli Adil
Published: August 2002

Poly(methyl methacrylate) (PMMA) microspheres carrying poly(ethylene imine) (PEI) were prepared for the removal of heavy‐metal ions (copper, cadmium, and lead) from aqueous solutions with different amounts of these ions (50–600 mg/L) and different pH values (3.0–7.0). Ester groups in the PMMA structures were converted to imine groups in a reaction with PEI as a metal‐chelating ligand in the presence of NaH. The adsorption of heavy‐metal ions on the unmodified PMMA microspheres was very low [3.6 μmol/g for Cu(II), 4.6 μmol/g for Cd(II), and 4.2 μmol/g for Pb(II)]. PEI immobilization significantly increased the heavy‐metal adsorption [0.224 mmol/g for Cu(II), 0.276 mmol/g for Cd(II), and 0.126 mmol/g for Pb(II)]. The affinity order of adsorption (in moles) was Cd(II) > Cu(II) > Pb(II). The adsorption of heavy‐metal ions increased with increasing pH and reached a plateau value around pH 5.5. Their adsorption behavior was approximately described with the Langmuir equation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 197–205, 2001
Combustion characteristics of halogen‐free flame‐retarded polyethylene containing magnesium hydroxide and some synergists
Authors: Wang Zhengzhou , Qu Baojun , Fan Weicheng , Huang Ping
Published: August 2002

Halogen‐free flame‐retarded polyethylene materials have been prepared by using magnesium hydroxide (MH) as a flame retardant combined with red phosphorous (RP) and expandable graphite (EG) as synergists. The effects of these additives on the combustion behavior of the filled linear low density polyethylene (LLDPE), such as a limiting oxygen index (LOI), the rate of heat release (RHR), the specific extinction area (SEA), etc., have been studied by the LOI determination and the cone calorimeter test. The results show that RP and EG are good synergists for improving the flame retardancy of LLDPE/MH formulations. In addition, a suitable amount of ethylene and vinyl acetate copolymer (EVA) added in the formulations can increase the LOI values while promoting the char formation and showing almost no effect on the RHR and SEA values. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 206–214, 2001
Thermal characterization of diglycidyl ether of bisphenol‐A/phosphorus containing amines
Authors: Jain Preeti , Choudhary Veena , Varma I. K.
Published: August 2002

In order to improve the thermal resistance of diglycidyl ether of bisphenol‐A (DGEBA), phosphorus‐containing di‐ and tri‐amines, i.e., bis (3‐aminophenyl) methyl phosphine oxide (B) and tris (3‐aminophenyl) phosphine oxide (T), were used as curing agents. The effect of phosphorus content on the curing characteristics and char residue of cured resins in nitrogen atmosphere was evaluated by using different molar ratios of conventional curing agent, i.e. 4, 4′‐diaminodiphenyl sulfone (D) and amine B or T. Activation energy of curing, as evaluated by using the multiple heating rate method, was lowest when triamine T (61.0 kJmol−1) was used as hardener and was highest when D (68.7 kJmol−1) was used. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 390–395, 2001
Properties of rigid polyurethane foams blown by HCFC 141B and distilled water
Authors: Jung H. C. , Ryu S. C. , Kim W. N. , Lee Y.‐B. , Choe K. H. , Kim S.‐B.
Published: August 2002

Rigid polyurethane foams (PUFs) were prepared from polymeric 4,4′‐diphenylmethane diisocyanate, polyester polyol, 1,4‐butane diol, silicone surfactant, hydrochlorofluorocarbon (HCFC) 141B, and distilled water. The properties and structure of the PUFs were investigated with differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and a universal testing machine. The density of the PUF blown by distilled water and/or HCFC 141B decreased from 175.7 to 28.2 kg/m3 with an increase of blowing agents. From the SEM results, the average cell size of the PUF blown by distilled water increased from 150 to 290 μm with the distilled water content. From the DSC results, the glass‐transition temperature (Tg) of the PUF blown by distilled water increased from 85.7 to 101.7°C with increasing distilled water content, whereas the Tg of the PUF blown by HCFC 141B remained unchanged with HCFC 141B content. The compressive strength and modulus of the PUF blown by a mixture of distilled water and HCFC 141B was increased from 0.13 to 0.25 MPa and from 3.00 to 7.23 MPa, respectively, with the distilled water content at the sample density of about 44.0 kg/m3. The increase of the compressive strength and modulus of the PUF at the same density was related to the increase of the Tg from 86.0 to 100.9°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 486–493, 2001
Functionalization of high‐density polyethylene in the molten state by glycidyl methacrylate grafting
Authors: Torres N. , Robin J. J. , Boutevin B.
Published: August 2002

:This study concerns the melt‐free radical grafting of glycidyl methacrylate (GMA) onto high‐density polyethylene (HDPE). We studied the effect of two initiators (tert‐butyl cumyl peroxide and di‐tert‐butyl peroxide) onto HDPE. Crosslinking of polymer was observed in the presence of 0.3 wt % tert‐butyl cumyl peroxide but not with 0.3 wt % di‐tert‐butyl peroxide. The grafting was carried out in a Brabender batch mixer at 190 °C. The grafting yield of GMA onto HDPE (determined by infrared spectrometry) is weak (<1 wt % for an initial concentration in monomer of 6 wt %). Moreover, it was noted that the degree of grafting did not vary with the concentration and the nature of peroxide used. To increase the grafting yield of GMA, we added to the HDPE/peroxide/GMA system an electron‐donating monomer, such as styrene. Adding this comonomer multiplied the rate of grafted GMA 3‐ or 4‐fold, resulting in a ratio [styrene]i/[GMA]i = 1 mol/mol with [GMA]i = 6 wt %. So, the copolymerization is favored compared with the homopolymerization. This kind of copolymer presenting reactive functions is very attractive in the field of compatibilizing immiscible polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 581–590, 2001
AB crosslinked polymers based on cationomeric polyurethane and poly(methyl methacrylate): Static and dynamic mechanical studies
Authors: Sriram V. , Aruna P. , Tharanikkarasu K. , Venkateswarlu U. , Radhakrishnan Ganga
Published: August 2002

Vinyl‐terminated polyurethane (VTPU) was prepared by end‐functionalizing isocyanate‐terminated prepolymers with 2‐bromoethanol and subsequently quartenizing with 4‐vinylpyridine. The vinyl functionality was then effectively utilized for preparing AB crosslinked polymers (ABCPs) with methyl methacrylate (MMA). ABCPs prepared with variable weight ratios on PTMG1000‐based VTPU/MMA (8/2, 6/4, 5/5, 4/6, 2/8) and those prepared at a 5/5 weight ratio with different polyols (PTMG1000, PPG1000, and PCL1250) in VTPU were characterized by Fourier transform infrared spectroscopy (FTIR) and further analyzed for thermal and mechanical properties. FTIR spectral results confirm quartenization of heterocyclic nitrogen, leading to crosslinking. Thermogravimetric analyses show enhanced thermal stability of the crosslinked systems. The stress–strain measurements reveal increasing tensile strength with increasing amounts of MMA. Comparison of dynamic mechanical spectra of ABCPs based on PTMG1000shows that the 5/5 composition exhibits good damping over a broad temperature range. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 813–821, 2001
Preliminary studies on the use of modified ALCELL lignin as a coupling agent in the biofiber composites
Authors: Rozman H. D. , Tan K. W. , Kumar R. N. , Abubakar A.
Published: August 2002

ALCELL lignin has been employed as a coupling agent in empty fruit bunch fiber (EFBF)–polypropylene (PP) composites. The lignin has been chemically modified with toluene diisocyanate (TDI) to various weight loadings. The evidence of the reaction between TDI and lignin has been observed by using Fourier transform infrared (FTIR) analysis. The effect of lignin as a coupling agent on mechanical properties has been studied. The results show that the TDI‐modified lignin is able to impart greater compatibility between EFBF and PP. This is reflected in the greater mechanical properties shown by the composites with TDI‐modified lignin than in those with the unmodified lignin. Scanning electron microscopy (SEM) studies showed that TDI modification of lignin resulted in a better blending and compatibility between lignin and PP matrix. The glass‐transition temperature of the lignin increases as the WPG is increased. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1333–1340, 2001
Study on morphology of ternary polymer blends. II. Effect of composition
Authors: Hemmati M. , Nazokdast H. , Shariat Panahi H.
Published: August 2002

The composition effect on morphology of polypropylene/ethylene–propylene–diene terpolymer/polyethylene (PP/EPDM/PE) and polypropylene/ethylene–propylene–diene terpolymer/polystyrene (PP/EPDM/PS) ternary blends has been investigated. In all of the blends, polypropylene as the major phase was blended with two minor phases, that is, EPDM and PE or PS. From morphological studies using the SEM technique a core–shell morphology for PP/EPDM/PE and separated dispersed morphology for PP/EPDM/PS were observed. These results were found to be in agreement with the theoretical predictions. The composition of components affected only the size of dispersed phases and had no appreciable effect on the type of morphology. The size of each dispersed phase, whether it forms core or shell or disperses separately in matrix, can be related directly to its composition in the blend. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1138–1146, 2001
Influence of cooling rate on pVT‐data of semicrystalline polymers
Authors: Zuidema H. , Peters G. W. M. , Meijer H. E. H.
Published: August 2002

For numerical simulations of the injection‐molding process, an accurate description of the specific volume is needed to predict differential shrinkage during and after molding, which causes thermally induced stresses and controls the dimensional accuracy and long‐term dimensional stability. For amorphous polymers, for which it can often be assumed that cooling‐rate dependence can be ignored, standard techniques enable measurements of the specific volume as a function of temperature and pressure. For semicrystalline polymers, the situation is more complicated since the specific volume depends strongly on the degree of crystallinity, which itself depends on the thermomechanical history, that is, temperature and pressure (for quiescent crystallization). This requires the use of a combined experimental–numerical technique to interpret the data and to determine the specific volume. Standard equipment can only be used at relatively low cooling rates. Since high cooling rates are present during injection molding, improved experimental techniques must be designed. A setup based on the confining fluid technique is built, which can reach cooling rates to 60 Ks−1 and pressures to 20 × 106 Pa. During an experiment, the specific volume is measured together with the temperature history and pressure. Using an accurate model to calculate the crystalline structure, together with a specific‐volume model which depends on this structure, enables the determination of model parameters. Comparing both the measurements and the model predictions, leads to the conclusion that modeling of the crystallization kinetics results in accurate predictions of the specific volume. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1170–1186, 2001
Chorioallantoic membrane capillary bed: A useful target for studying angiogenesis and anti‐angiogenesis in vivo
Authors: Ribatti Domenico , Nico Beatrice , Vacca Angelo , Roncali Luisa , Burri Peter H. , Djonov Valentin
Published: August 2002

The chick embryo chorioallantoic membrane (CAM) is an extraembryonic membrane that is commonly used in vivo to study both angiogenesis and anti‐angiogenesis. This review 1) summarizes the current knowledge about the structure of the CAM's capillary bed; 2) discusses the controversy about the existence of a single blood sinus or a capillary plexus underlying the chorionic epithelium; 3) describes a new model of the CAM vascular growth, namely the intussusceptive mode; 4) reports findings regarding the role played by endogenous fibroblast growth factor‐2 in CAM vascularization; and 5) addresses the use and limitations of the CAM as a model for studying angiogenesis and anti‐angiogenesis. Anat Rec 264:317–324, 2001. © 2001 Wiley‐Liss, Inc.