bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk factors for back pain among male farmers: Analysis of Iowa Farm Family Health and Hazard Surveillance Study
Authors: Park Hyesook , Sprince Nancy L. , Whitten Paul S. , Burmeister Leon F. , Zwerling Craig
Published: August 2002

Background

Back pain causes considerable morbidity, disability, and economic loss among workers. Farmers handle heavy objects, often in awkward postures. However, the prevalence of back pain among farmers and the risk factors associated with back pain are not well known.

Methods

In this study, we assess the frequency of risk factors for back pain among 287 Iowa male farmers. From 1992 to 1994, using a mail questionnaire, we collected data on potential risk factors for back pain. Eighteen months later, we surveyed occurrence of back pain as the outcome measure.

Results

Thirty‐one percent of farmers reported having daily back pain for a week or more during the past 12 months compared to 18.5% in the general working population. Using a multiple logistic regression model, we found two factors associated with back pain: 45–59 years of age (OR = 2.13, 95% CI 1.02–4.43) and having a non‐agricultural job as the major occupation (OR = 2.02, 95% CI 0.98–4.17, P = 0.055).

Conclusions

Farmers had a significantly higher prevalence of back pain than the general working population. Middle‐aged farmers and those with additional non‐agricultural jobs had the highest risk for back pain. Am. J. Ind. Med. 40:646–654, 2001. © 2001 Wiley‐Liss, Inc
Epidemiology of occupational injuries and illnesses in a university population: A focus on age and gender differences
Authors: Saleh Shadi S. , Fuortes Laurence , Vaughn Thomas , Bauer Eric P.
Published: August 2002

Background

Occupational injuries and illnesses are a major preventable public health problem.

Methods

This study evaluated the incidence, nature, and cause of awarded workers' compensation claims for a large state university and teaching hospital. Rates and types of injury were compared across age and gender.

Results

Rates of injury varied over twofold with age, with those 16–25 having the lowest rates of injury and those 36–45 having the highest rates. Claims rates were 1.36‐fold higher for women than men. Women had higher rates for injury resulting from lifting, falling, noxious exposures, repetitive motion, and carpal tunnel syndrome. Similarly women had significantly higher rates of claims for pain, sprains, bruises, burns, concussion, and inhalation injury; with lower rates of cuts, ligament injury, and jammed joints.

Conclusions

These group differences suggest the need to examine age and gender job distributions and relevant ergonomic and environmental causative factors. Am. J. Ind. Med. 39:581–586, 2001. © 2001 Wiley‐Liss, Inc.
The social consequences of occupational injuries and illnesses
Authors: Dembe Allard E.
Published: August 2002

Background

Most outcome studies of occupational injuries and illnesses have tended to focus on direct economic costs and duration of work disability. Rarely have the broader social consequences of work‐related disorders or their impacts on injured workers' families, coworkers, and community been investigated. This paper examines a wide range of social consequences including workers' psychological and behavioral responses, vocational function, and family and community relationships

Methods

Literature review and development of conceptual framework

Results

Complex and multifactorial relationships are described whereby occupational injuries and illnesses produce a variety of social consequences involving filing and administration of workers' compensation insurance claims, medical care experiences, domestic function and activities of daily living, psychological and behavioral responses, stress, vocational function, rehabilitation and return to work, and equity and social justice

Conclusion

A research agenda is proposed for guiding future investigations in this field. Am. J. Ind. Med. 40:403–417, 2001. © 2001 Wiley‐Liss, Inc.
Dispermic chimerism with two abnormal cell lines, 47,XY, +21 and 47,XX, +12
Authors: Wiley John E. , Madigan Merle , Christie John D. , Smith April W.
Published: August 2002

Chimerism in humans appears to be a rare phenomenon that is usually discovered by accident. Here we describe a stillborn male fetus with multiple congenital anomalies which was found to have two cytogenetically abnormal cell lines, 47,XY, +21 and 47, XX, +12. The difference in sex chromosome constitution between the cell lines indicated that the fetus had dispermic chimerism. To our knowledge, this is the first report of chimerism with two abnormal cell lines. © 2001 Wiley‐Liss, Inc.
Full genome screen for Alzheimer disease: Stage II analysis*
Authors: Myers Amanda , Wavrant De‐Vrieze Fabienne , Holmans Peter , Hamshere Marian , Crook Richard , Compton Danielle , Marshall Helen , Meyer David , Shears Shantia , Booth Jeremy , Ramic Dzanan , Knowles Heather , Morris John C. , Williams Nigel , Norton Nadine , Abraham Richard , Kehoe Pat , Williams Hywel , Rudrasingham Varuni , Rice Francis , Giles Peter , Tunstall Nigel , Jones Lesley , Lovestone Simon , Williams Julie , Owen Michael J. , Hardy John , Goate Alison
Published: August 2002

We performed a two‐stage genome screen to search for novel risk factors for late‐onset Alzheimer disease (AD). The first stage involved genotyping 292 affected sibling pairs using 237 markers spaced at approximately 20 cM intervals throughout the genome. In the second stage, we genotyped 451 affected sibling pairs (ASPs) with an additional 91 markers, in the 16 regions where the multipoint LOD score was greater than 1 in stage I. Ten regions maintained LOD scores in excess of 1 in stage II, on chromosomes 1 (peak B), 5, 6, 9 (peaks A and B), 10, 12, 19, 21, and X. Our strongest evidence for linkage was on chromosome 10, where we obtained a peak multipoint LOD score (MLS) of 3.9. The linked region on chromosome 10 spans approximately 44 cM from D10S1426 (59 cM) to D10S2327 (103 cM). To narrow this region, we tested for linkage disequilibrium with several of the stage II microsatellite markers. Of the seven markers we tested in family‐based and case control samples, the only nominally positive association we found was with the 167 bp allele of marker D10S1217 (chi‐square = 7.11, P = 0.045, df = 1). © 2002 Wiley‐Liss, Inc.
Heterogeneity in familial dominant Paget disease of bone and muscular dystrophy
Authors: Waggoner Brook , Kovach Margaret J. , Winkelman Marc , Cai Dan , Khardori Romesh , Gelber David , Kimonis Virginia E.
Published: August 2002

The combination of autosomal dominant, early onset Paget disease of bone (PDB) and muscular dystrophy is an unusual disorder. We recently mapped the disorder in a large family from central Illinois with PDB and proximal limb‐girdle type of muscular dystrophy (LGMD), and in 3 additional families with hereditary inclusion body myopathy (HIBM), Paget disease of bone and frontotemporal dementia, to a unique locus on chromosome 9p21.1‐q12. The present study describes an unrelated 10‐member family with autosomal dominant PDB and a scapuloperoneal type of muscular dystrophy. Clinical, biochemical, and radiological evaluations were performed to delineate clinical features in this family. Progression of the muscular dystrophy begins with weakness in the distal muscles of the legs accompanied by foot drop. EMG and muscle biopsy are compatible with a primary dystrophy. Onset of Paget disease is early, at a mean age of 41 years, with initial distribution in the long bones and eventual infiltration of the spine and pelvis. Creatine phosphokinase (CPK) and alkaline phosphatase levels are elevated in affected individuals. Molecular analyses excluded all known loci for Paget disease of bone, scapuloperoneal muscular dystrophy (SPMD), fascioscapulohumeral muscular dystrophy (FSH), amyotrophic lateral sclerosis (ALS), Bethlem myopathy, two forms of autosomal dominant limb‐girdle muscular dystrophy (LGMD), and the critical region for LGMD or HIBM/PDB on chromosome 9p21.1‐q12, thus providing evidence for genetic heterogeneity among families with the unique combination of muscular dystrophy and Paget disease of bone. © 2002 Wiley‐Liss, Inc.
Sequencing of the GRIK1 gene in patients with juvenile absence epilepsy does not reveal mutations affecting receptor structure
Authors: Izzi Claudia , Barbon Alessandro , Kretz Rebekka , Sander Thomas , Barlati Sergio
Published: August 2002

Hereditary factors play a major role in the etiology of juvenile absence epilepsy (JAE) that is a common subtype of idiopathic generalized epilepsy (IGE). Sander et al. [1997: Am J Med Genet 74:416–421] reported an allelic association of JAE with the nine‐copy allele of a tetranucleotide repeat polymorphism in the third intron of the kainate‐selective GluR5 receptor gene (GRIK1) and supportive evidence for linkage of IGE to GRIK1 in families of JAE probands. These findings suggest that a major genetic determinant of GRIK1 confers susceptibility to JAE. Assuming that the GRIK1 tetranucleotide repeat polymorphism is unlikely to have functional relevance itself, we have sequenced the coding regions and regulatory sequences of the GRIK1 gene in eight JAE patients who carry the nine‐repeat allele of the GRIK1 tetranucleotide repeat polymorphism to detect a putative functional GRIK1 mutation that is in linkage disequilibrium with the nine‐repeat allele. Seven of them were derived from families showing positive evidence for linkage to GRIK1. Our mutation analysis of coding regions and splice junctions revealed only two silent polymorphisms (A522C and C1173T) out of the five SNPs present in public databases and no mutations affecting protein structure. No significant differences were found in the allele frequencies of the detected polymorphisms between the JAE patients and controls. High levels of sequence conservation were also found in the promoter, in the 5′ and both the 3′ untranslated regions and in the RNA secondary structure involved in the editing reaction. The results presented indicate that mutations in the coding sequences, in the intron‐exon boundaries and in the main regulatory regions of the GRIK1 are not commonly involved in the etiology of JAE. © 2002 Wiley‐Liss, Inc.
Growth and maturation in Marfan syndrome
Authors: Erkula Gurkan , Jones Kevin B. , Sponseller Paul D. , Dietz Harry C. , Pyeritz Reed E.
Published: August 2002

Understanding the growth pattern in Marfan syndrome is important for prediction of expected growth, prevention of excessive growth by hormone therapy, timing of surgical epiphysiodesis for cessation of growth, and instituting brace treatment for scoliosis. In this study, we analyze growth patterns and generate growth charts for persons with Marfan syndrome. From the charts of 180 clinically diagnosed Marfan patients, longitudinal height and weight measurements were obtained. From this data, growth charts and growth velocity charts were generated for males and females. Skeletal maturation was studied by determining the Risser signs from the x‐rays of 71 males and 56 females. From 22 female patients, age of menarche was available and retrieved either by reviewing the charts or contacting the patients. Mean length at birth was 53 ± 4.4 cm for males and 52.5 ± 3.5 cm for females. Mean final height was 191.3 ± 9 cm for males and 175.4 ± 8.2 cm for females. Mean birth weight was 3.51 ± 0.74 kg for males and 3.48 ± 0.68 kg for females. The puberty‐associated peak in growth velocity was 2.4 years earlier than the gender‐matched general population for males with Marfan syndrome and 2.2 years earlier for females. Age of menarche was 11.7 ± 2 years of age, which is also early compared to the general population. This study suggests that the growth spurt and pubertal skeletal maturation occur early in Marfan syndrome. The growth curves generated should help more accurately predict adult stature, as well as monitor progression toward it. © 2002 Wiley‐Liss, Inc.
No association of the dopamine transporter gene 3′ VNTR polymorphism with ADHD subtypes in a population sample of twins
Authors: Todd Richard D. , Jong Yuh‐Jiin I. , Lobos Elizabeth A. , Reich Wendy , Heath Andrew C. , Neuman Rosalind J.
Published: August 2002

Dopamine pathway genes have been the subject of a variety of studies testing the association of candidate genes and liability for attention‐deficit hyperactivity disorder (ADHD). Due to the known effects of stimulant medications such as methylphenidate on the dopamine transporter, a variety of case control and family‐based transmission distortion genetic studies of ADHD have focused on DAT1 polymorphisms. The most widely reported positive finding has been with a variable number of tandem repeats (VNTR) polymorphism of unknown function in the 3′ untranslated region of the DAT1 gene. In this report, we test for association of alleles of this polymorphism with ADHD using population‐derived samples of twins. We use the transmission disequilibrium test and ADHD subtypes defined by both DSM‐IV and latent class criteria. We fail to demonstrate any significant association or trend for association of any of the VNTR alleles with any of the variously defined ADHD subtypes. © 2001 Wiley‐Liss, Inc.
Evidence for postjunctional serotonin (5‐HT1) receptors in the trigeminocervical complex
Authors: Goadsby Peter J. , Akerman Simon , Storer R. James
Published: August 2002

Units linked to stimulation of the superior sagittal sinus were identified and recorded from in the trigeminocervical complex of the anesthetized cat. Iontophoresis of glutamate NMDA receptor agonists increased the baseline‐firing rate of these neurons. Coejection of sumatriptan, 4991W93, or ergometrine resulted in a significant reduction in NMDA agonist‐induced increases in firing. These data establish the existence of triptan‐sensitive (5‐HT1) receptors on postsynaptic central trigeminal neurones.
Synthesis and characterization of pH‐sensitive networks containing degradable poly(1,3‐dioxolane) segments
Authors: Du Juan , Peng Yuxing , Zhang Tingting , Ding Xiaobin , Zheng Zhaohui
Published: August 2002

pH‐sensitive networks were obtained by radical copolymerization of telechelic poly(1,3‐dioxolane) (PDXLDA) with acrylic acid (AA). PDXLDA was synthesized by acrylation of the corresponding dihydroxylated polyacetal (polyDXL) with AA in pyridine. The copolymer networks of poly(AA‐b‐DXL) showed pH sensitivity due to —COOH groups, which are insoluble in any solvents, but can swell in water or good solvents. The swelling behavior is closely related to the solvents and is composition‐dependent. The networks containing polyDXL segments can be decrosslinked under acidic conditions due to the low ceiling temperature of polyDXL. After degradation, the linear segments of polyDXL became cycled molecules. The networks' structure, swelling behavior, and degradation were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, GC–MS analysis, and swelling data. This kind of material can be potentially used in biosystems, such as in intelligent drug‐delivery systems. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1678–1682, 2002
Characterization of drag reducing guar gum in a rotating disk flow
Authors: Kim C. A. , Lim S. T. , Choi H. J. , Sohn J.‐I. , Jhon M. S.
Published: August 2002

The turbulent drag reduction characteristics in a rotating disk apparatus were investigated by using polysaccharide guar gum in deionized water. The ultrasonic degradation method was adopted to obtain different molecular weight fractions of guar gum for this study. The stability of guar gum over time was observed to be better than the typical synthetic water‐soluble drag reducers [e.g., poly(ethylene oxide)]. A linear correlation between polymer concentration and the concentration/(drag reduction) for different molecular weights of guar gum was obtained, and the universal drag reduction curve for the guar gum/deionized water system was constructed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2938–2944, 2002; DOI 10.1002/app.10300
Role of chain length in degradation process (chain breakdown)
Authors: Vainstein E. F. , Zaikov G. E.
Published: August 2002

The role of molecular weight of a chain in the chain breakdown in diluted solution at a constant concentration of chain molecules and constant temperature is discussed theoretically using the methods of the theory of the activated complex and kinetics of cooperative processes. The reaction starts at the certain molecular weight of the chain. The chain breakdown is the flat increasing function of the chain molecular weight. This function has a limit when chain molecular weight approaches infinity. Such dependence is explained by the increase of flexibility (following two theories) and increase of extra entropy of molecules of different sizes (following kinetics of cooperative processes. Unequal reactivity of chemically identical active centers links to the dependence of chain flexibility on the location of the more flexible part (place of reaction) of the chain. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1810–1817, 2002; DOI 10.1002/app.10356
Deposition of polypyrrole on microporous filtration membranes at air/water interface
Authors: Pyo Myoungho , Cho Chulae
Published: August 2002

Microfiltration membranes were utilized as a template for the preparation of polypyrrole films at the air/water interface. Unlike the formation of polypyrrole tubules (or fibrils) when the membranes are soaked in polymerization media, chemical polymerization on the membrane at the interface resulted in the film formation on the membrane surface in contact with polymerization media, without remaining open micropores. Investigations of electrochemical responses with anthraquinone‐2‐sulfonate and Fe(CN) on fully reduced or oxidized polypyrrole as well as studies of conductivity changes with polypyrrole deposition were carried out to confirm this behavior. Complete coverage of one side of a microfiltration membrane with a polypyrrole layer, remaining micropore walls, and the other side of a membrane intact, could be useful in various applications because it allows further electrochemical treatment/measurements utilizing these open micropores straightforward. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 514–518, 2002
Kinetic studies of crease‐resistant finishing process for cotton fabrics with DMEU/MMEU prepolymer mixture
Authors: Shih Chung‐Yang , Huang Kuo‐Shien
Published: August 2002

The kinetics of the crease‐resistant finishing process for cotton fabrics with DMEU/MMEU prepolymer mixture are studied. The DMEU/MMEU prepolymer resin is made from ethylene urea (EU) and paraformaldehyde (PF) with different mole ratios. The results show that the nitrogen content in the treated fabrics and the reaction rate constant increases with curing temperature and PF mole ratio. The treated fabrics with more PF in the source material have smaller Ea, Δ H*ast;, and ΔS*. The ΔG* was independent of the mole ratio in the source material, but it increases with curing temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 509–513, 2002
Effect of bonding agents on styrene butadiene rubber–aluminum powder composites
Authors: Vinod V. S. , Varghese Siby , Kuriakose Baby
Published: August 2002

Effects of various bonding agents—such as the hexamethylene tetramine–resorcinol system (HR), bis[3‐ (triethoxysilyl) propyl] tetra sulfide (Si‐69), and cobalt naphthenate (CoN)—on the mechanical properties of aluminum powder filled styrene butadiene rubber composites were studied, giving emphasis on concentration of bonding agent and loading of aluminum powder. Shore A hardness, modulus, tensile strength, tear strength, heat buildup, etc., were increased by the loading of aluminum powder, and the presence of bonding agents again increased these properties. Rebound resilience and elongation at break were decreased by the addition of aluminum powder. Equilibrium swelling studies showed an improved adhesion between aluminum powder and styrene butadiene rubber (SBR) in presence of bonding agents. Among the various bonding agents used in this study, silane coupling agent (Si‐69) and hexamethylene tetramine–resorcinol (HR) system were found to be better for aluminum powder filled SBR vulcanizates. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 519–529, 2002
Synthesis and characterization of bisitaconimides. I
Authors: Solanki Anjali , Choudhary Veena , Varma I. K.
Published: August 2002

This article describes the synthesis and characterization of bisitaconimides on the basis of 4,4′‐diaminodiphenylether, 2,2′‐bis[4‐(4‐aminophenoxy)phenyl]propane, 1,3‐bis(4‐aminophenoxy)benzene, and 1,4‐bis (4‐aminophenoxy)benzene. Isomerization of the itaconimides to citraconimides (varying in the range of 25–40%) was observed during synthesis. The curing exotherm and thermal stability of the cured resins depended on the backbone structure of itaconimides. The curing exotherm immediately followed the melting endotherms. These resins cured at lower temperatures than bismaleimides but thermal stability of cured bismaleimides was higher than bisitaconimides. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2277–2282, 2002
Studies on self‐assembly and characterization of polyelectrolytes and organic dyes
Authors: Lin Xianjun , Zhong Anyong , Chen Deben , Zhou Zonghua , He Bobing
Published: August 2002

Four polyelectrolyte complexes were formed through the self‐assembly of poly‐N‐ethyl‐N,N‐ dimethylamino ethyl methacrylate (PEDEM) and poly‐ N‐ethyl‐4‐vinylpyridinium (PEVP) cations with methyl orange (MO) and metanil yellow (MY) anions in water. The FTIR spectra showed that the assembly was formed chiefly through electrostatic force and hydrophobic interaction between polyelectrolytes and organic dyes without new bonds emerging. The fluorescence spectra revealed that the emission waves of the complexes of PEDEM‐MY and PEDEM‐MO in alcohol were blue‐shift in comparison with those of dyes in alcohol, and the emission waves of the PEVP‐MY and PEVP‐MO complexes in alcohol were red‐shift in comparison with those of dyes in alcohol. The structure of the complexes in solid state were also investigated by differential thermal analysis (DTA) and X‐ray diffraction experiments. It was proved that the complexes were new materials formed through weak interactions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 638–644, 2002
Processing characteristics and physicomechanical properties of natural rubber and liquid natural rubber blends
Authors: Okieimen F. E. , Akinlabi A. K
Published: August 2002

Investigations into the processing characteristics and physicomechanical properties of natural rubber (NR) modified with liquid natural rubber (LNR) were carried out. Liquid natural rubber samples (of different molecular weights) were first produced by depolymerization of natural rubber latex (NRL), using nitrobenzene as the depolymerizing agent to lower molecular weight rubbers. The LNRs produced were then mixed with natural rubber in various proportions. The NR/LNR blends showed better processing characteristics by having higher scorch time and lower cure rate, higher molecular mass between crosslinking resulting from the lower volume fraction of the LNR, and good solubility properties; and marginal differences in shear modulus, crosslinking densities, Mooney viscosity, plasticity, and the plasticity retention index compared to properties of an unmodified NR. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1070–1076, 2002
Modification of polyindole by the incorporation of pyrrole unit
Authors: Wan Fen , Li Liang , Wan Xiaobo , Xue Gi
Published: August 2002

Electrochemical copolymerization of pyrrole and indole was performed galvanostatically in a solvent of acetonitrile (AN)/water (vol %: 99/1). The product obtained was characterized by cyclic voltammetry and infrared spectroscopy. The influence of the monomer feed ratio of pyrrole and indole on the synthesis of the copolymer was investigated. The amount of pyrrole units in the copolymer chain increased with increase of the concentration of the pyrrole monomer in the solution. The results showed that the electrochemical activity of the copolymer was improved as the incorporation of pyrrole units increased. Thermogravimetric analysis was carried out to investigate the properties of the copolymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 814–820, 2002
A dynamic mechanical and thermal analysis of unplasticized and plasticized poly(vinyl alcohol)/methylcellulose blends
Authors: Park Jun‐Seo , Park Jang‐Woo , Ruckenstein Eli
Published: August 2002

The miscibility of poly(vinyl alcohol) (PVA)/methylcellulose (MC) blends was investigated over the entire composition range using the dynamic mechanical analyzer (DMA) and the differential scanning calorimeter (DSC). On the basis of the glass transition temperature, determined by DMA, one could conclude that the blends exhibited some miscibility below 80 wt % of MC and a good miscibility above 80 wt % of MC. The highest depressions of the melting and crystallization temperatures of the blends compared to those of PVA, determined via DSC analysis, were observed for MC contents greater than 80 wt %. The miscibility between PVA and MC can be attributed to the hydrogen bonds formed between the two components. The DMA studies showed that water is a good plasticizer for PVA and poly(ethylene glycol) 400 (PEG 400), a good plasticizer for MC. The inclusion of both water and PEG 400 in the blends revealed a synergistic plasticizing effect, which resulted in an increased miscibility between PVA and MC over a greater range of MC compositions (>60 wt %). The elongations of PVA, MC, and their blends were found to increase with the addition of PEG 400, but the tensile strengths to decrease. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1825–1834, 2001
Macromolecular modification of EPDM: Wettability, miscibility, and morphology study
Authors: Ginic‐Markovic Milena , Choudhury Namita Roy , Dimopoulos Maria , Matisons Janis , Kumudinie Chandima
Published: August 2002

The present investigation deals with studies on wettability, miscibility, and morphology of the macromolecularly modified EPDM. Two different maleated EPDM rubbers (grafted rubber) were chosen (0.5 and 1% maleation) for such modification and they were used in various proportions. Wettability of the rubber substrate, as observed from dynamic contact angle measurement, was improved using these grafted rubbers. Results of X‐ray photoelectron spectroscopy showed an increase in oxygen level with higher levels of grafted rubber in the blends. Morphology study by transmission electron microscopy showed a smaller domain size for the blend with higher maleic anhydride content in the grafted rubber. The viscosity versus blend ratio results showed a negative deviation behavior for blends with 1% grafted rubber, whereas a positive negative deviation behavior was observed in blends with 0.5% grafted EPDM. As the strength of interaction increased, the glass transition shifted to a higher temperature. All blends were heterogeneous, as indicated by different degrees of dispersion. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2647–2661, 2001
Polyetherimide‐modified bismaleimide resins. II. Effect of polyetherimide content
Authors: Jin Jianyong , Cui Jun , Tang Xiaolin , Li Shanjun , Wang Jinchen , Zhao Qushen , Hua Xiangyang , Cai Xianqing
Published: August 2002

A novel polyetherimide was prepared and used to improve the toughness of bismaleimide resin composed of bis(4‐maleimidediphenyl) methane and O,O′‐diallyl bisphenol A. The morphologies of the modified resins change from spherical particles to an inverted phase structure, depending on the modifier's content based on the scanning electronic microscopy results. Dynamic mechanical analysis is also used to characterize morphologies of the modified resins. The phase‐separation process of the modified system is traced by time‐resolved light scattering. The change in the light‐scattering profile with curing time showed that the phase separation mechanism depended on the modifier concentration. Phase separation took place via the spinodal decomposition mechanism in the PEI 15‐phr‐ and 20‐phr‐modified system. The fracture energy (GIC) increased with PEI content in the modified system; in the PEI 15‐phr‐modified system, the GIC value was three times greater than that of the unmodified BMI resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 350–358, 2001
Polycondensation of bis(cyanoacetate) and a,10bdihydrobenzofuro[2,3‐b]benzofuran‐2,9‐dicarbaldehyde via knoevenagel reaction: Synthesis of donor–acceptor polymers containing shoulder‐to‐shoulder main chains
Authors: Namazi H. , Assadpour A. , Pourabbas B. , Entezami A.
Published: August 2002

Compound 5a,10b‐dihydrobenzofuro[2,3‐b]benzofuran‐2,9‐dicarbaldehyde (II) was prepared by two‐step reactions from p‐cresol and glyoxal. The bis(cyanoacetate) monomers (III) were prepared in a high yield by reacting ethyl cyanoacetate with the appropriate diol in the presence of tetra‐n‐butyl titanate. The polymers from II and III were synthesized by Knoevenagel polycondensation that was first carried out in anhydrous THF and followed by a solid‐state polycondensation, and main‐chain polymers with good glass transition temperatures in high yield were obtained. The polymerization of II and III afforded polymers IV, which exhibited good solubility in most organic solvents. The structure of all the monomers and polymers were characterized by conventional spectroscopic methods. The synthesized polymers contain acceptor groups (cyanide and carbonyl) and a donor group (benzodihydrofuran) in their main chain. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 505–511, 2001
Surface modification of poly(styrene) by the attachment of an antimicrobial peptide
Authors: Appendini P. , Hotchkiss J. H.
Published: August 2002

Polymers that directly inhibit the growth of microorganisms at their surface are potentially useful. To investigate the feasibility of such materials, poly(styrene) (PS) resin beads that had had poly(ethyleneglycol) (PEG) grafted onto the surface were further derivatized by covalently linking an antimicrobial peptide onto the surface. The antimicrobial peptide was composed of 8 lysine and 7 leucine (6K8L) residues. The resulting surface‐modified polystyrene (SMPS) was microcidal in a concentration and time‐dependent manner against several micro‐organisms includingE. coliO157 : H7,L. monocytogenes, S. aureus, P. fluorescens,andK. marxianuswhen suspended in phosphate buffer. The SMPS inhibited the growth of pathogenicE. coliO157 : H7 in trypticase soy broth. SMPS was bactericidal at pH 3.5 to 7, retained activity after heating to 200°C for 30 min, and could be extensively washed without loss of antimicrobial activity. Bioassays and HPLC analyses of buffer that had been preincubated with SMPS indicated that antimicrobial activity may have been due, at least in part, to the slow release of a peptide–PEG ligand from the PS to the buffer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 609–616, 2001
Electroinduced copolymerization of acrylonitrile–polyethylene glycol compared with chemical copolymerization
Authors: Saraç A. Sezai̇ , Özkara Şerife , Di̇ler Z. İrem
Published: August 2002

Electroinduced copolymerization of acrylonitrile (AN)–polyethylene glycol (PEG‐400) initiated by Ce(IV) was performed in aqueous solution and compared with chemical copolymerization, which allowed Ce(III) to be converted to Ce(IV) electrochemically during the polymerization. The polymer that was insoluble in water was formed in the cathodic compartment. The effect of Ce(IV), H2SO4, monomer, PEG‐400 concentration, temperature, time, and potential on the yield were studied and compared with similar effects under nonelectrolytic conditions. The role of Ce(IV) salt on the copolymerization was followed by spectrophotometric methods during the reaction period. Polymers were characterized by FTIR, UV‐visible spectrophotometry, and NMR. Intrinsic viscosities of polymers were determined. Possible polymerization mechanisms are suggested in the case of electrolytic and nonelectrolytic conditions. The electrolytic process has a demonstrable advantage over the nonelectrolytic method. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1410–1419, 2001
Proton uptake by poly(2‐vinylpyridine) coatings
Authors: Tantavichet Nisit , Pritzker Mark D. , Burns Charles M.
Published: August 2002

A titration technique has been used to directly measure the proton uptake by ion‐exchange poly(2‐vinylpyridine) coatings as a function of solution pH. Contrary to the common assumption that each nitrogen in the pyridine ring is attached to an H+ when the polymer film is fully protonated, the use of the titration technique has shown that the portion of the pyridine sites actually protonated does not exceed 25% anywhere in the pH range where the coating is stable. The pKa value for the poly(2‐vinylpyridine) coating has also been estimated to be 4.5 from the titration curve. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1493–1497, 2001
Free radical polymerization of nitropropyl acrylates and methacrylates. I. Heat of polymerization
Authors: Lee Keundeuk , Kim Jinseuk , Lee Bumjae
Published: August 2002

The heat of polymerization ΔHp, of nitropropyl(meth)acrylate monomers has been studied by differential scanning calorimetry (DSC) in dynamic and isothermal modes. DSC showed that ΔHp of 2‐nitropropyl(meth)acrylate was surprisingly smaller than that of propyl(meth)acrylate but similar to that of 2,2‐dinitropropyl(meth)acrylate. According to molecular structure analysis by a PM3 Hamiltonian in a MOPAC program, the contributing main factor to the lowering of ΔHp of 2‐nitropropyl (meth)acrylate was found to be the hydrogen bond between the O(C) and the H atom attached at position C6. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2929–2935, 2001
Crystallization and melting behavior in syndiotactic polypropylene: Origin of multiple melting phenomenon
Authors: Supaphol Pitt
Published: August 2002

The melting behavior of syndiotactic polypropylene (s‐PP) after isothermal crystallization from the melt state was studied using differential scanning calorimetry (DSC) and wide‐angle X‐ray diffraction (WAXD) techniques. Three melting endotherms were observed for isothermal crystallization at high degrees of undercooling. The minor endotherm, located closed to the corresponding crystallization temperature, was postulated to be the melting of the secondary crystallites formed at the crystallization temperature. The low‐temperature melting peak was found to be the melting of the primary crystallites formed, and the high‐temperature melting peak was a result of the melting of the crystallites recrystallized during a heating scan. The triple‐melting behavior observed in subsequent melting endotherms of s‐PP was therefore described as contributions from melting of the secondary crystallites and their recrystallization, partial melting of the less stable fraction of the primary crystallites and their recrystallization, melting of the primary crystallites, and remelting of the recrystallized crystallites formed during the heating scan. In addition, determination of the equilibrium melting temperature for this s‐PP resin according to the linear and nonlinear Hoffman–Weeks extrapolations provided values of 143.1 and 185.6°C, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1083–1097, 2001
Absorption and desorption of liquid water by a superabsorbent polyelectrolyte: Role of polymer on the capacity for absorption of a ground
Authors: Bakass M. , Mokhlisse A. , Lallemant M.
Published: August 2002

To study the potentialities of a polyelectrolyte superabsorbent for the storage of water, we have studied a ground representative of the area of Haouz (area of Marrakesh, South of Morocco) in the presence of polymer. We sought the optimal proportions allowing the best retention of water by the mixture made up of the polymer and the ground and to prolong the storage period of water in the ground. We have also studied the effect of certain ions and the pH on the capacity for absorption of polymer. These ions can be naturally present in the ground or introduced by the means of manure and pesticides. The presence of polymer in the ground makes it possible to increase the capacity for absorption of the water by the ground, which can thus involve a saving in water while decreasing the frequency of irrigation and by reducing the water losses by the phenomena of evaporation and infiltration. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1541–1548, 2001
In situ and ex situ FTIR–ATR and Raman microscopic studies of organosilane hydrolysis and the effect of hydrolysis on silane diffusion through a polymeric film
Authors: Eaton Peter , Holmes Paul , Yarwood Jack
Published: August 2002

We report combined FTIR–ATR and Raman microscopic studies of the distribution and redistribution of three different silane adhesion promoters in thin (10–20 μm) PVC films deposited on a Si/SiO2/SiOH substrate (a “model” glass surface). It has been shown that the different functionalized silanes diffuse at different rates through the polymer (at 70°C) and therefore have different distributions at the polymer/glass interface. The differences in behavior have been rationalized in terms of their respective abilities to hydrolyze and condense, under the different humidity and temperature conditions used. As the level of humidity rises there is evidence that the diffusion rate (measured using a dual‐mode sorption model) decreases as a result of hydrolysis and condensation in the polymer films. The data are of importance as a direct measure of the relation between humidity levels and the adhesive action of a silane promoter at polymer/glass interfaces. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2016–2026, 2001
Structural organization and transport properties of iPP/LLDPE blends solidified at controlled cooling rates
Authors: Coccorullo Ivano , Gorrasi Giuliana , Pantani Roberto
Published: August 2002

The structural organization of blends of isotactic polypropylene (iPP) and linear low‐density polyethylene (LLDPE), with different compositions, was studied and correlated with the thermal history followed by the samples during solidification from the molten state. The materials were cooled at two extreme controlled rates: 0.1 and 500°C/s. The resulting structure was investigated both in the crystalline and the amorphous phases. In particular, attention was focused toward the analysis of the diffusion parameters of dichloromethane vapors, and the morphological organization of the amorphous phases was interpreted using models that consider them (in terms of resistance to diffusion) combined in series and in parallel. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2237–2244, 2001
Structural changes of bulk polyethylene by stress impact as studied by solid‐state NMR
Authors: Satoh Hidenori , Kuroki Shigeki , Ando Isao
Published: August 2002

Solid‐state 13C‐ and 1H‐NMR spectra of bulk high‐density polyethylene samples, cylindrical in form, to which stress impacts were applied with a home‐made stress‐impact apparatus, were measured. The fraction of the noncrystalline component increases with an increase in the stress‐impact strength. In the crystalline region, the monoclinic crystalline component appear with the stress impact, in addition to the major orthorhombic crystalline component. Furthermore, dynamic characterization was carried out on the basis of the observed values of the relaxation parameters 1H T2 and TCH of the 1H and 13C nuclei. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2268–2272, 2001
Safety assessment of polymeric additives for food packaging: Hydrolysis of polymeric plasticizers by digestive fluids
Authors: Hamdani M. , Thil L. , Gans G. , Feigenbaum A. E.
Published: August 2002

The in vitro hydrolysis of poly(1,2‐propylene adipate) by digestive fluid liquids was studied to assess the safety of polymeric plasticizers that could migrate into food. A high extent of hydrolysis was obtained with freshly prepared intestinal fluid solutions. High performance size exclusion chromatography analysis indicated that the bulk plasticizer completely disappeared and that low molecular weight oligomers were formed within 4 h. Hydrolysis did not result in a significant conversion to the free monomers, like adipic acid, as was shown by gas‐phase chromatography. Measurements by NMR indicated that the cleavage selectively occurred at primary ester linkages. Fractionation of the hydrolysis products on silica gel gave six oligomeric fractions, which were recovered and analyzed. The absolute molecular weight of the plasticizers and the average molecular weight of the hydrolysis products were evaluated using proton NMR. Hydrolysis did not take place (<2%) under simulated gastric and saliva conditions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 956–966, 2002
Comparative analysis of Prx1 and Prx2 expression in mice provides evidence for incomplete compensation
Authors: Chesterman Elizabeth S. , Kern Michael J.
Published: August 2002

The family of paired‐related homeobox genes to which Prx1 and Prx2 belong plays an integral role in limb and craniofacial development, as evidenced by both transgenic mice and in situ hybridization data. However, little is known about protein expression of these homeodomain transcription factors. Recent studies in our lab have established the pattern of Prx1 protein expression during normal mouse embryogenesis. Here we present a comparative analysis of Prx1 and Prx2 protein expression in the developing mouse using a novel anti‐Prx2 antibody reagent. Anat Rec 266:1–4, 2002. © 2002 Wiley‐Liss, Inc.
Using web‐based animations to teach histology
Authors: Brisbourne Marc A.S. , Chin Susan S.‐L. , Melnyk Erica , Begg David A.
Published: August 2002

We have been experimenting with the use of animations to teach histology as part of an interactive multimedia program we are developing to replace the traditional lecture/laboratory‐based histology course in our medical and dental curricula. This program, called HistoQuest, uses animations to illustrate basic histologic principles, explain dynamic processes, integrate histologic structure with physiological function, and assist students in forming mental models with which to organize and integrate new information into their learning. With this article, we first briefly discuss the theory of mental modeling, principles of visual presentation, and how mental modeling and visual presentation can be integrated to create effective animations. We then discuss the major Web‐based animation technologies that are currently available and their suitability for different visual styles and navigational structures. Finally, we describe the process we use to produce animations for our program. The approach described in this study can be used by other developers to create animations for delivery over the Internet for the teaching of histology. Anat Rec (New Anat) 269:11–19, 2002. © 2002 Wiley‐Liss, Inc.
Comparative studies on the expression patterns of three troponin T genes during mouse development
Authors: Wang Qin , Reiter Rebecca S. , Huang Qi‐Quan , Jin Jian‐Ping , Lin Jim Jung‐Ching
Published: August 2002

In vertebrates, three troponin T (TnT) genes, cardiac TnT (cTnT), skeletal muscle fast‐twitch TnT (fTnT), and slow‐twitch TnT (sTnT), have evolved for the regulation of striated muscle contraction. To understand the mechanism for muscle fiber‐specific expression of the TnT genes, we compared their expression patterns during mouse development. Our data revealed that the TnT expression in the developing embryo was not as restricted as that in the adult. In addition to a strong expression in the developing heart beginning at day 7.5 p.c (postcoitum), the cTnT transcript was detected at later stages in some skeletal muscles, where beginning at day 11.75 p.c. the fTnT and sTnT genes were also expressed. Only sTnT but not fTnT was found transiently in the developing heart. At day 13.5 p.c., expressions of all three genes were detected in the developing tongue and this co‐expression continued to day 16.5 p.c. with the fTnT isoform being predominant. At this stage, overlapping and distinct expression patterns of both sTnT and fTnT genes were also evident in many developing skeletal muscles. These data suggest that different muscles during development undergo a complex change in TnT isoforms resulting in different contractile properties. Unexpectedly, the cTnT transcript was persistently found in the developing bladder, where presumably smooth muscle is present. In transgenic mice, expression of a LacZ gene driven by a rat cTnT promoter (−497 to +192 bp) was very similar to that of the endogenous cTnT gene, suggesting that this promoter contained regulatory elements sufficient for the control of tissue‐specific cTnT expression during development. Anat Rec 263:72–84, 2001. © 2001 Wiley‐Liss, Inc.
Ground penetrating radar study of iron age tombs in Southeastern Kazakhstan
Authors: Pipan M. , Baradello L. , Forte E. , Finetti I.
Published: August 2002

An international archaeological and geophysical expedition was carried out to study Iron Age tombs of the Saka culture in southeastern Kazakhstan. Single‐fold and multifold ground‐penetrating radar (GPR) surveys, in two and two and a half dimensions, focused on the identification of burial chambers beneath the mound‐shaped Saka tumuli, named kourgans. Primary objectives of the geophysical study were the testing and optimization of GPR techniques for studying this type of tomb and the reconstruction of subsurface images of use for the design of archaeological excavations. Single‐fold GPR grids with line spacing ranging between 50 and 200 cm were obtained at each of the 13 sites selected. After identification of the sectors of major potential interest from data processing performed directly in the field and interpretation of the single‐fold grids, multifold profiles with average 1200 per cent fold were designed and performed. Processing of the data focused on velocity analyses, pre‐stack coherent noise attenuation by means of FK and KL filters, stacking and analysis of the instantaneous attributes of the complex radar trace. Multifold GPR data processing techniques achieved a substantial increment in the signal to noise ratio at most sites, allowed accurate depth conversions of the stacked profiles (average deviation of estimated target location from the actual target was less than 5% of total depth) and provided indications to identify the characteristic response from the target of interest through the joint interpretation of pre‐stack gathers, velocity analysis and amplitude versus offset analysis. Interpretation of stacked sections and three‐dimensional models obtained from the single‐fold/multifold grid allowed the identification of a burial chamber located at an estimated depth of 140–150 cm, which was excavated successfully by the archaeological team. Further reflectors with similar characteristics are shown from other sites, which will be excavated by the next archaeological expeditions to the area. Copyright © 2001 John Wiley & Sons, Ltd.