bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of macrophage‐colony stimulating factor in normal and inflammatory bowel disease intestine
Authors: Klebl F. H. , Olsen J. E. , Jain S. , Doe W. F.
Published: August 2002

Mucosal macrophages have been implicated in the pathogenesis of inflammatory bowel disease (IBD). Macrophage‐colony stimulating factor (M‐CSF) influences monocyte/macrophage proliferation, differentiation, and activation. Serum levels are increased in active IBD, but little is known about its role in mucosal inflammation. This study was undertaken to determine the distribution, frequency, and level of M‐CSF expression in normal and IBD‐affected intestine. RNA and tissue were studied from patients with Crohn's disease (CD) and ulcerative colitis (UC) as well as from histologically normal colon. Tissue from intestinal tuberculosis and ischaemic colitis patients served as controls. M‐CSF mRNA and protein were examined by semi‐quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR), in situ hybridisation, and immunohistochemistry, respectively. M‐CSF mRNA and protein were detected in histologically normal intestine, but their expression was largely confined to the mucosa. In active IBD, the frequency of M‐CSF‐expressing cells was significantly increased and their distribution markedly altered, although no increase in mucosal M‐CSF mRNA levels in intestinal tissue was observed. The changes were not specific to IBD, as there were similar findings in intestinal tuberculosis and ischaemic colitis. The marked alteration observed in M‐CSF expression in IBD and the importance of this cytokine in stimulating macrophage functions suggest that M‐CSF may contribute to the pathogenesis of the IBD lesion. Copyright © 2001 John Wiley & Sons, Ltd.
Screening of Plant Extracts for Antioxidant Activity: a Comparative Study on Three Testing Methods
Authors: Koleva Irina I. , van Beek Teris A. , Linssen Jozef P. H. , Groot Aede de , Evstatieva Lyuba N.
Published: August 2002

Three methods widely employed in the evaluation of antioxidant activity, namely 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging method, static headspace gas chromatography (HS‐GC) and β‐carotene bleaching test (BCBT), have been compared with regard to their application in the screening of plant extracts. The strengths and limitations of each method have been illustrated by testing a number of extracts, of differing polarity, from plants of the genus Sideritis, and two known antioxidants (butylated hydroxytoluene and rosmarinic acid). The sample polarity was important for the exhibited activity in the BCBT and HS‐GC methods but not for the DPPH method. The complex composition of the extracts and partition phenomena affected their activity in each assay. The value of the BCBT method appears to be limited to less polar samples. Although slow, the HS‐GC method is preferable for assessing the antioxidant inhibitory properties on the formation of unwanted secondary volatile products. Being rapid, simple and independent of sample polarity, the DPPH method is very convenient for the quick screening of many samples for radical scavenging activity. Copyright © 2001 John Wiley & Sons, Ltd.
First‐trimester fetal sex determination in maternal serum using real‐time PCR
Authors: Costa Jean‐Marc , Benachi Alexandra , Gautier Evelyne , Jouannic Jean‐Marie , Ernault Pauline , Dumez Yves
Published: August 2002

An Erratum has been published for this article in Prenatal Diagnosis 22(13) 2002, 1241.

Fetal sex prediction can be achieved using PCR targeted at the SRY gene by analysing cell‐free fetal DNA in maternal serum. Unfortunately, the results reported to date show a lack of sensitivity, especially during the first trimester of pregnancy. Therefore, determination of fetal sex by maternal serum analysis could not replace karyotype analysis following chorionic villus sampling.

A new highly sensitive real‐time PCR was developped to detect an SRY gene sequence in maternal serum. Analysis was performed on 121 pregnant women during the first trimester of pregnancy (mean gestational age: 11.8 weeks). Among them, 51 had at least one previous male‐bearing pregnancy. Results were compared with fetal sex.

SRY PCR analysis of maternal serum was in complete concordance with fetal sex. Among the 121 pregnant women, 61 were bearing a male fetus and 60 a female fetus. No false‐negative results were observed. Furthermore, no false‐positive results occurred, even though 27 women carrying a female fetus during the current pregnancy had at least one previous male‐bearing pregnancy.

This study demonstrates that a reliable, non‐invasive sex determination can be achieved by PCR analysis of maternal serum during the first trimester of pregnancy. This non‐invasive approach for fetal sex prediction should have great implications in the management of pregnant women who are carriers of an X‐linked genetic disorder. Prenatal diagnosis might thus be performed for male fetuses only, avoiding invasive procedures and the risk of the loss of female fetuses. Copyright © 2001 John Wiley & Sons, Ltd.
Rapid prenatal diagnosis of trisomy 21 in 5049 consecutive uncultured amniotic fluid samples by fluorescence in situ hybridisation (FISH)
Authors: Witters Ingrid , Devriendt K. , Legius E. , Matthijs G. , Van Schoubroeck D. , Van Assche F. A. , Fryns Jean‐Pierre
Published: August 2002

Objectives

This was a retrospective study on the results of interphase fluorescence in situ hybridization (FISH), performed routinely for chromosome 21 and on ultrasonographic indications for chromosomes 13, 18, X and Y in a series of 5049 amniotic fluid samples.

Methods

Interphase FISH for chromosome 21 was performed in 5049 consecutive amniotic fluid samples for the rapid prenatal diagnosis of Down syndrome. Aneuploidy for four other chromosomes (13, 18, X and Y) was tested following ultrasonographic indications. Karyotypes from standard cytogenetic analysis were compared to the FISH results.

Results

Using conventional cytogenetics 3.6% (183/5049) chromosomal anomalies were detected. After exclusion of familial chromosome rearrangements, i.e. balanced autosomal reciprocal or Robertsonian translocations (30/5049) and inversions (19/5049), 2.65% chromosomal anomalies (134/5049) were diagnosed. Of this group 0.18% (9/5049) were chromosomal rearrangements not detectable by FISH and 2.47% (125/5049) were numerical chromosomal anomalies detectable by interphase FISH for chromosomes 13, 18, 21, X and Y. With routine interphase FISH for chromosome 21 and FISH on echographic indication for the other four chromosomes we detected 107/125 of these numerical chromosomal anomalies, i.e. 85.6%. All 70 cases of trisomy 21 were detected by FISH and confirmed with conventional cytogenetics (sensitivity=100%) and there were no false‐positive results (specificity=100%). Maternal cell contamination of amniotic fluid samples occurred in 1.27% (64/5049) of samples; 0.26% (13/5049) of these samples were uninformative by FISH due to maternal cell contamination (12/5049) or absence of nuclei in one sample (1/5049).

Conclusion

In this group of 5049 samples we found that FISH is a reliable technique for the rapid prenatal diagnosis of trisomy 21. The number of uninformative cases due to maternal cell contamination was low. The strategy to perform FISH for chromosome 21 in all samples and only on ultrasonographic indication for the four other chromosomes (13, 18, X and Y) followed by standard cytogenetics is effective. Copyright © 2002 John Wiley & Sons, Ltd.
Hydrogen‐bonding interaction between poly(ε‐caprolactone) and low‐molecular‐weight amino compounds
Authors: Watanabe Takumi , He Yong , Asakawa Naoki , Yoshie Naoko , Inoue Yoshio
Published: August 2002

The specific interactions between several low‐molecular‐weight diamino compounds and poly(ε‐caprolactone) (PCL) have been investigated by FT‐IR. It was found that PCL and 3,3′‐diaminodiphenylmethane (3,3′‐DADPM) interact through strong intermolecular hydrogen bonds in the blend. Thermal and mechanical properties of PCL/3,3′‐DADPM blends were investigated by DSC and tensile measurements, respectively. The glass transition temperature of the blend increases while both the melting point and the elongation‐at‐break of the blend decrease with the increase of 3,3′‐DADPM content. Besides 3,3′‐DADPM, several other low‐molecular‐weight compounds containing two amino groups, such as o‐phenylenediamine or 1,6‐diaminohexane, were also added into PCL and the corresponding blend systems were investigated by FT‐IR and DSC. The effect of the chemical structure of the additives on the properties of PCL is discussed.

© 2001 Society of Chemical Industry
Effects of a quaternary ammonium salt on the properties of carbon‐black‐filled natural rubber compounds
Authors: Ismail H , Ahmad Z , Mohd Ishak Z A
Published: August 2002

The effects of a quaternary ammonium salt, cetyltrimethylammonium maleate (CTMAM) on the curing characteristics and mechanical properties of carbon‐black‐filled natural rubber compounds are determined. Results indicate that CTMAM increases the rate of vulcanization to a maximum at 1 phr (part per hundred parts of rubber) followed by a decrease as the concentration of CTMAM is further increased. The incorporation of CTMAM also improves mechanical properties such as tensile and tear strengths, tensile modulus, hardness and resilience, whilst elongation at break shows a decreasing trend. CTMAM also improves filler dispersion and increases the extent of crosslinking of carbon‐black‐filled natural rubber compounds.

© 2001 Society of Chemical Industry
Urethanes and polyurethanes based on oxypropylated cork: 1. Appraisal and reactivity of products
Authors: Evtiouguina Margarita , Gandini Alessandro , Neto Carlos Pascoal , Belgacem Naceur M
Published: August 2002

The reaction of various polyols derived from the oxypropylation of cork with aliphatic and aromatic mono‐ and diisocyanates was studied in solution at room temperature. In all instances, good second‐order kinetics were observed and the corresponding rate constant determined. The reactivity of the aromatic isocyanate was found to be much higher than that of aliphatic counterparts. The ensuing urethanes and polyurethanes were characterised by FTIR and 1H NMR spectroscopy, DSC and sol/gel distribution.

© 2001 Society of Chemical Industry
Structure and composition of the surface of urethane/acrylic composite latex films
Authors: Wu Limin , Yu Hongkun , Yan Jian , You Bo
Published: August 2002

Polyurethane dispersions were prepared and urethane/acrylic composite latices were synthesized with polyurethane dispersions as the seed, and core‐shell emulsion polymerization. Fourier‐transform infrared spectroscopy coupled with attenuated total reflectance (FTIR‐ATR) analyses showed that the films obtained from the composite latices were rich in polyurethane component or segments at air‐facing and substrate‐facing surfaces, in comparison with their average composition. Moreover, the substrate‐facing surface contained even more polyurethane component or segments than the air‐facing surface. X‐ray photoelectron spectroscopy (XPS) detection also indicated that the polyurethane component or segments preferentially migrated to the surface layer of the films from the bulk, and that the films from blend latices displayed more polyurethane component or segments near the surface layer. Both FTIR‐ATR and XPS analyses suggested that some reorientation had happened in synthesizing the composite latices and/or after film formation. This structure and composition endow urethane/acrylic composite films with both surface properties (such as mar‐resistance, adhesion, wettability) from pure polyurethane, and film hardness from acrylic copolymers.

© 2001 Society of Chemical Industry
Analysis of quantum efficiency and optical enhancement in amorphous Sip–i–nsolar cells
Authors: Hegedus Steven S. , Kaplan Ruhi
Published: August 2002

The effect ofi‐layer thickness, tin oxide texture, and back reflector (BR) on optical enhancement has been systematically studied in a series of 20 a‐Si p–i–n solar cells. The internal quantum efficiency has been analyzed by a simple model based on the work of Schade and Smith. The enhancement of optical absorption is characterized bym, a wavelength‐dependent fitting parameter representing the increase in optical pathlength relative to thei‐layer thicknessd. Solar cells with an Al BR have negligible optical enhancement, withm < 1.5, consistent with large parasitic absorption at the Al/Si interface as reported by others. Solar cells on highly textured SnO2with ZnO/Al or ZnO/Ag BR have peak values ofm ∼ 3–4, with ZnO/Ag having slightly larger values than ZnO/Al. It was found thatmhas a strong dependence on the product αd, and that maximum values ofmincrease with reflectivity of the BR. It is shown that a major source of parasitic absorption loss at long wavelengths is light trapping in the textured SnO2front contact. Copyright © 2002 John Wiley & Sons, Ltd.
Influence of wafer thickness on the performance of multicrystalline Si solar cells: an experimental study
Authors: Tool C. J. J. , Burgers A. R. , Manshanden P. , Weeber A. W. , van Straaten B. H. M.
Published: August 2002

The influence of the thickness of silicon solar cells has been investigated using neighbouring multicrystalline silicon wafers with thickness ranging from 150 to 325 μm. For silicon solar cell structures with a high minority‐carrier diffusion length one expects that Jscwould decrease as the wafer becomes thinner due to a shorter optical path length. It was found experimentally that Jscis nearly independent of the thickness of the solar cell, even when the minority‐carrier diffusion length is about 300 μm. This indicates that the Al rear metallisation acts as a good back surface reflector. A decrease in Jscis observed only if the wafer thickness becomes less than about 200 μm. The observed trend in Vocas a function of the wafer thickness has been explained with PC1D modelling by a minority‐carrier diffusion length in the Al‐oped BSF which is small in relation to the thickness of the BSF. This effectively increases the recombination velocity at the rear of the cell. We have shown that the efficiency of solar cells made with standard industrial processing is hardly reduced by reducing the wafer thickness. Solar cell efficiencies might be increased by better rear surface passivation. Copyright © 2002 John Wiley & Sons, Ltd.
Predicting violence from school misbehavior: Promises and perils
Authors: Morrison Gale M. , Skiba Russell
Published: August 2002

This article considers the issue of predicting violence committed by students on school campuses through the use of school discipline indices such as office referrals, suspensions, and expulsions. The existing research on incidents of school discipline markers is reviewed as well as sources of variation due to student characteristics and classroom or school‐wide practices. Challenges in making accurate predictions about future behavior at school are outlined. © 2001 John Wiley & Sons, Inc.
Resource consultation and collaboration in gifted education
Authors: Landrum Mary S.
Published: August 2002

Recent changes in the field of gifted education, including calls for redefining the gifted education specialist's role and the classroom teacher's desire to collaborate, have led to consultative and collaborative approaches to serving gifted learners. Resource consultation and collaboration, the pooling of expertise among all school staff in order to do more for students, is emerging as a popular service delivery strategy in gifted education programming. This article reveals much about the nature and context of the processes only recently applied to gifted learners. Specifically, it contains a description of the consultation and collaboration processes, management issues for related programming, delineation of consultation and collaboration activities, and presents the educational implications for their implementation. © 2001 John Wiley & Sons, Inc.
Calorimetric and NMR studies on the direct correlation between supramolecular complex structure and the thermodynamics of N‐benzyloxycarbonyl‐L‐aspartic and ‐glutamic acid inclusion complexes with mono‐ and bis(trimethylammonio)‐β‐cyclodextrins
Authors: Yamamura Hatsuo , Rekharsky Mikhail , Akasaki Asako , Araki Schuki , Kawai Masao , Inoue Yoshihisa
Published: August 2002

The stability constants and standard Gibbs energy, enthalpy and entropy changes for the 1:1 inclusion complexation of N‐benzyloxycarbonyl‐L‐aspartic and ‐glutamic acids with native β‐cyclodextrin (β‐CD), mono(6‐amino‐6‐deoxy)‐β‐CD, mono(6‐trimethylammonio‐6‐deoxy)‐β‐CD and A,B‐, A,C‐ and A,D‐bis(6‐trimethylammonio‐6‐deoxy)‐β‐CDs were determined in aqueous phosphate buffer (pH 6.9) at 298.15 K by titration microcalorimetry. The supramolecular complex structures were elucidated from 1D and 2D NMR spectra, including ROESY, COSY and HOHAHA techniques. Combining the results obtained from the microcalorimetric and NMR studies, we elucidated not only the detailed complex structures and the thermodynamic consequences, but also the mutual dependence between the complex structure and the overall complexation thermodynamics. Copyright © 2001 John Wiley & Sons, Ltd.
Photocrosslinking reaction of vinyl‐functional polyphenylsilsesquioxane sensitized with aromatic bisazide compounds
Authors: Yasuda Naoki , Yamamoto Shigeyuki , Wada Yuji , Yanagida Shozo
Published: August 2002

Photochemical reactions of aromatic azide groups were applied for a novel photosensitive silicone ladder polymer, that is, partially vinyl‐substituted polyphenylsilsesquioxane sensitized with aromatic bisazide compounds as a photocrosslinker. The photocrosslinking reaction in this system was investigated from the viewpoint of the efficiency of the photocrosslinker, that is, the ratio of the photocrosslinker consumed for crosslinking. The numbers of photodecomposed azide groups and crosslinks in the polymer were determined by Fourier transform infrared measurements. At a higher bisazide concentration, the predominant reaction of nitrenes formed as the intermediary radical by the photolysis of azide was a coupling reaction that could not contribute to the gelation of the polymer. The ratio of the bisazide compound consumed for crosslinking showed the highest value at its concentration of 3 wt % and decreased with the addition of a larger amount. The semiempirical molecular orbital calculations were applied to the theoretical analysis of the photoreaction of nitrenes using phenylnitrene as a model structure. The calculation results indicated that the coupling reaction of nitrenes should proceed more easily than the photocrosslinking reaction in N2 atmosphere, and the fact that the oxidation of nitrenes should proceed exclusively in the atmosphere including O2 agreed with the experimental results. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4196–4205, 2001
Synthesis and characterization of two new aryl cyclobutyl ketoethyl methacrylate monomers and their polymers
Authors: Erol Ibrahim , Ilter Zulfiye , Coskun Mehmet , Ahmedzade Misir
Published: August 2002

Two new methacrylate monomers, 2‐[3‐(6‐tetralino)‐3‐methylcyclobutyl]‐2‐ketoethyl methacrylate (TKEMA) and 2‐(3‐mesityl‐3‐methylcyclobutyl)‐2‐ketoethyl methacrylate (MKEMA), were obtained from the reaction of 1‐chloroacetyl‐3‐methyl‐3‐arylcyclobutane with sodium methacrylate. The oxime and hydrazone derivatives of poly(TKEMA) and poly(MKEMA) were prepared with hydroxylamine and 2,4‐dinitrophenyl hydrazine. Poly(TKEMA) and poly(MKEMA), their oxime and hydrazone derivatives, and the monomers were characterized with Fourier transform infrared and NMR techniques. The glass‐transition temperatures and thermal stability of the polymers and their oxime and hydrazone derivatives were compared. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4167–4173, 2001
Synthesis and characterization of biodegradable poly(ϵ‐caprolactone urethane)s. I. Effect of the polyol molecular weight, catalyst, and chain extender on the molecular and physical characteristics
Authors: Gorna Katarzyna , Polowinski Stefan , Gogolewski Sylwester
Published: August 2002

Biodegradable polyurethanes with potential for applications in medical implants were synthesized in bulk with aliphatic hexamethylene diisocyanate, isophorone diisocyanate, poly(ϵ‐caprolactone) diols of various molecular weights, 1,4‐butane diol, 2‐amino‐1‐butanol, thiodiethylene diol, and 2‐mercaptoethyl ether chain extenders. The catalysts used were stannous octoate, dibutyltin dilaurate, ferric acetyl acetonate, magnesium methoxide, zinc octoate, and manganese 2‐ethyl hexanoate. The synthesis reactions were second‐order. All the materials had narrow, unimodal molecular weight distributions and polydispersity indices of 1.5–1.9. The chemical structures of the polyurethanes, as assessed from1H NMR and13C NMR spectra, were in good agreement with the monomer stoichiometric ratios. The glass‐transition temperatures of the materials ranged from −38 to −57 °C and were higher for polymers based on isophorone diisocyanate and with higher hard‐segment contents. For polyurethanes with the same hard‐segment content, there was no effect of the material molecular weight on the thermal properties. The tensile strengths of the materials were 12–63 MPa, and the tensile moduli were 8–107 MPa. These increased with an increasing hard‐segment content. The least effective catalyst was magnesium methoxide, and the most effective was ferric acetyl acetonate. Stannous octoate and manganese 2‐ethyl hexanoate were less effective than dibutyltin dilaurate and zinc octoate. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 156–170, 2002
Photoinitiated polymerization of methacrylic monomers in a poly(methyl methacrylate) matrix: A comparative study with other matrices (styrene–butadiene–styrene, polystyrene, and polybutadiene)
Authors: Mateo J. L. , Calvo M. , Bosch P.
Published: August 2002

The kinetics and mechanism of the photoinitiated polymerization of 1,6‐hexanediol dimethacrylate (HDDMA) in a poly(methyl methacrylate) (PMMA) matrix were studied. The maximum double‐bond conversion, the maximum polymerization rate, the intrinsic reactivity, and the kinetic constants for propagation and termination were calculated. For this system, a reaction‐diffusion termination mechanism occurred from the start of the polymerization, and it was predominantly maintained until high monomer concentrations, probably because of the relatively high intermolecular attraction force between the PMMA matrix and HDDMA monomer. In addition, a comparative study of the photoinitiated polymerization of methacrylic monomers in four different polymeric matrices [styrene–butadiene–styrene (SBS), polystyrene (PS), polybutadiene (PB), and PMMA] was carried out. The aggregation state, vitreous or rubbery, of the monomer–matrix system and the intermolecular strength of attraction in the monomer–matrix system and growing macroradical and matrix systems were the principal factors influencing the kinetic and mechanistic behavior of these systems. When PB and SBS were used as matrices, crosslinked polymerized products were obtained as a result of the participation of double bonds of the matrix in the polymerization process (copolymerization). PS sequences in the SBS and PS matrices also took part in the polymerization process through the coupling of the benzylic radical to the growing macroradical. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 120–127, 2002
Investigations of thermal polymerization in the stable free‐radical polymerization of 2‐vinylnaphthalene
Authors: Lizotte Jeremy R. , Erwin Brian M. , Colby Ralph H. , Long Timothy E.
Published: August 2002

The feasibility of utilizing stable free‐radical polymerization (SFRP) in the synthesis of well‐defined poly(2‐vinylnaphthalene) homopolymers has been investigated. Efforts to control molecular weight by manipulating initiator concentration while maintaining a 2,2,6,6‐tetramethylpiperidinyl‐1‐oxy (TEMPO):benzoyl peroxide (BPO) molar ratio of 1.2:1 proved unsuccessful. In addition, systematic variations of the TEMPO: BPO molar ratio did not result in narrow molecular weight distributions. In situ Fourier transform infrared spectroscopy (FTIR) indicated that the rate of monomer disappearance under SFRP and thermal conditions were identical. This observation indicated a lack of control in the presence of the stable free radical, TEMPO. The similarities in chemical structure between styrene and 2‐vinylnaphthalene suggested thermally initiated polymerization occurred via the Mayo mechanism. A kinetic analysis of the thermal polymerization of styrene and 2‐vinylnaphthalene suggested that the additional fused ring in 2‐vinylnaphthalene increased the propensity for thermal polymerization. The observed rate constant for thermal polymerization of 2‐vinylnaphthalene was determined using in situ FTIR spectroscopy and was one order of magnitude greater than styrene, assuming pseudo‐first‐order kinetics. Also, an Arrhenius analysis indicated that the activation energy for the thermal polymerization of 2‐vinylnaphthalene was 30 kJ/mol less than styrene. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 583–590, 2002; DOI 10.1002/pola.10131
Isotopically pure uniform polymers: The final step toward true uniformity in macromolecules
Authors: Vogl Otto , Jaycox Gary D. , Simonsick William J.
Published: August 2002

Computer‐based calculations were used to simulate the mass spectra for a number of uniform macromolecules having fixed, well‐defined chain lengths. The presence of naturally occurring carbon, hydrogen, oxygen, and halogen isotopes introduced significant levels of mass heterogeneity into these systems. For a given polymer, mass variability was demonstrated to be a function of both the elemental composition and degree of polymerization of the polymer chain. In many cases, these natural variations in mass exceeded the molecular weight of one or more monomeric repeat units along the polymer backbone, effectively blurring the mass distinction between uniform polymer constructs formed from N and N+1 repeat units. The significance of isotopic diversity and its potential impact on the synthesis and physiochemical properties of highly uniform macromolecules is also discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 923–935, 2002
Synthesis and properties of photoluminescent polymers bearing electron‐facilitating oxadiazole derivative side groups
Authors: Kim J. J. , Kim K.‐S. , Baek S. , Kim H. C. , Ree M.
Published: August 2002

Poly(p‐divinylene phenylene) derivatives bearing fluorene and carbazole units in the main chain and 5‐phenyl‐1,3,4‐oxadiazole moieties as side groups were prepared by the polycondensation of a newly synthesized monomer, [2‐(5′‐phenyl‐1′,3′,4′‐oxadiazole‐2′‐yl)‐1,4‐xylylene]bis(triphenyl phosphonium bromide) (OXAD), with 9,9‐dibutylfluorene‐2,2′‐dicarbaldehyde (DBFDA) and 9‐(2‐ethylhexyl)carbazole‐3,6‐dicarbaldehyde (EHCDA), which gave DBFDA–OXAD and EHCDA–OXAD. Analogues of these polymers without the side groups were also synthesized by the reaction of 1,4‐xylene bis(triphenyl phosphonium bromide) (PXYL) with the dicarbaldehydes, which gave DBFDA–PXYL and EHCDA–PXYL. All the synthesized polymers are soluble in organic solvents, giving films of good quality. The polymers are stable beyond 375 °C. They emit blue and blue‐green light, and their quantum yields are 38–79% in solution and 1–24% in film, depending on the fluorene and carbazole units as well as the side groups. In particular, the OXAD‐based polymers contain hole‐facilitating backbones and electron‐facilitating side groups, perhaps allowing these polymers to transport both holes and electrons. Overall, the synthesized polymers are potential candidates for the fabrication of light‐emitting devices. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1173–1183, 2002
Effects of salts and copolymer composition on the lower critical solution temperature of poly(methyl 2‐acetamidoacrylate‐co‐methyl methacrylate) solutions
Authors: Okamura Hirokazu , Morihara Yasushi , Masuda Seizo , Minagawa Keiji , Mori Takeshi , Tanaka Masami
Published: August 2002

Copolymerizations of methyl 2‐acetamidoacrylate (MAA) with methyl methacrylate (MMA) were carried out at 60 °C in chloroform. Copolymers containing MAA units in the range of 83–90 mol % exhibited a lower critical solution temperature (LCST), although homopolymers of MAA and MMA did not. The LCST of polymer solutions decreased with (1) an increase in the concentration of the copolymer, (2) a decrease in the MAA content in the copolymer, and (3) an increase in the concentration of salts added. The effectiveness of anionic species for reducing the LCST is NO < Cl− < SO < SO. Divalent anion is more effective for lowering the LCST than monovalent anion. However, there is no difference between cationic species in the salting‐out effect. Sodium carbonate and sodium phosphate had a salting‐in effect. Salting‐out coefficients were evaluated from the relationship between the logarithm of solubility of the copolymers and the salt concentration. Salting‐out coefficients of the copolymer depended not on the composition of the copolymers but on the salt added. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1945–1951, 2002
Synthesis and characterization of new organosoluble polyamides derived from bis[4‐(4‐carboxyphenoxy) phenyl]diphenylmethane
Authors: Liaw Der‐Jang , Liaw Been‐Yang , Yang Chao‐Min , Hsu Pei‐Nan , Hwang Chieh‐Ying
Published: August 2002

A new dicarboxylic acid containing a diphenylmethylene linkage, bis[4‐(4‐carboxyphenoxy)phenyl]diphenylmethane (BCAPD), was prepared from bis(4‐hydroxphenyl)diphenylmethane and p‐fluorobenzonitrile via an aromatic nucleophilic substitution reaction followed by hydrolysis. A series of novel polyamides were prepared by the direct polycondensation of BCAPD and various aromatic diamines. The polymers were produced with moderate to high inherent viscosities of 0.80–0.85 dL g−1. Nearly all the polymers were readily soluble in polar solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfoxide, in less polar solvents such as pyridine and cyclohexanone, and in tetrahydrofuran. All the polymers were amorphous, and the polyamide films had a tensile strength and a tensile modulus greater than 80 MPa and 2.0 GPa, respectively. These polyamides had glass‐transition temperatures between 249 and 274 °C, and their temperatures at a 10% weight loss were 477–538 and 483–540 °C in nitrogen and air atmospheres, respectively. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1156–1161, 2001
Synthesis and characterization of new soluble polyamides containing phthalimide pendent group
Authors: Liaw Der‐Jang , Hsu Pei‐Nan , Chen Jao‐Jin , Liaw Been‐Yang , Hwang Chieh‐Ying
Published: August 2002

A dicarboxylic acid monomer, 5‐phthalimidoisophthalic acid, containing a phthalimide pendent group was prepared by the condensation of 5‐aminoisophthalic acid and phthalic anhydride in glacial acetic anhydride. The monomer was reacted with various aromatic diamines to produce polyamides using triphenyl phosphite and pyridine as condensing agents. These polyamides were produced with inherent viscosities of 0.64–1.14 dL · g−1. All the polymers, characterized by wide‐angle X‐ray diffraction, revealed an amorphous nature resulting from the presence of the bulky pendent group. These polyamides exhibited excellent solubility in a variety of solvents such as N‐ methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide (DMAc), N,N‐dimethylformamide, dimethyl sulfoxide, pyridine, and cyclohexanone. These polyamides showed glass‐transition temperatures (Tg's) between 247 and 273 °C (by DSC) and 248 and 337 °C (by a dynamic mechanical analyzer). The thermogravimetric analytic measurement revealed the decomposition temperature at 10% weight‐loss temperatures (Td10) ranging from 442 to 530 °C in nitrogen. The polyamides containing phthalimide groups exhibited higher Tg and Td10 values than those having no phthalimide groups. Transparent, tough, and flexible films of these polyamides could be cast from the DMAc solutions. These casting films had tensile strengths ranging from 81 to 126 MPa, elongations at break ranging from 7 to 13%, and tensile moduli ranging from 2.0 to 2.9 GPa. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1557–1563, 2001
New biodegradable polymers from renewable sources: Polyester‐carbonates based on 1,3‐propylene‐co‐1,4‐cyclohexanedimethylene succinate
Authors: Liu Yan , Ranucci Elisabetta , Söderqvist Lindblad Margaretha , Albertsson Ann‐Christine
Published: August 2002

α,ω‐Dihydroxy‐terminated copolymeric oligomers of a 1,3‐propylene/1,4‐cyclohexanedimethylene succinate structure were obtained by the thermal polycondensation of 1,3‐propanediol/1,4‐cyclohexanedimethanol/succinic acid mixtures. They were subsequently chain‐extended via phosgene synthesis to high molecular weight aliphatic/alicyclic copolyester‐carbonates. These new polymers, besides having a biodegradable backbone, originate from two monomers, namely, 1,3‐propanediol and succinic acid, which can be obtained by renewable sources. Therefore, they have a potential as environmentally friendly materials. All synthesized materials were characterized in reference to their molecular structure by 1H NMR and 13C NMR. Their molecular weights and molecular weight distributions were determined by size exclusion chromatography, and their main thermal properties were measured by DSC. Spectroscopic characterizations were in full agreement with the proposed structures. 1,4‐Cyclohexanedimethanol was used as a diol comonomer to improve the overall thermal properties of poly(1,3‐propylene succinate). The results of the characterization performed show that the initial expectations were only partially satisfied. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2508–2519, 2001
Polyethylene‐poly(L‐lactide) diblock copolymers: Synthesis and compatibilization of poly(L‐lactide)/polyethylene blends
Authors: Wang Yunbing , Hillmyer Marc A.
Published: August 2002

A model polyethylene‐poly(L‐lactide) diblock copolymer (PE‐b‐PLLA) was synthesized using hydroxyl‐terminated PE (PE‐OH) as a macroinitiator for the ring‐opening polymerization of L‐lactide. Binary blends, which contained poly(L‐lactide) (PLLA) and very low‐density polyethylene (LDPE), and ternary blends, which contained PLLA, LDPE, and PE‐b‐PLLA, were prepared by solution blending followed by precipitation and compression molding. Particle size analysis and scanning electron microscopy results showed that the particle size and distribution of the LDPE dispersed in the PLLA matrix was sharply decreased upon the addition of PE‐b‐PLLA. The tensile and Izod impact testing results on the ternary blends showed significantly improved toughness as compared to the PLLA homopolymer or the corresponding PLLA/LDPE binary blends. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2755–2766, 2001
Swelling of dextran gel and osmotic pressure of soluble dextran in the presence of salts
Authors: Livney Yoav D. , Ramon Ory , Kesselman Ellina , Cogan Uri , Mizrahi Shimon , Cohen Yachin
Published: August 2002

The swelling of dextran gels (Sephadex) in salt solutions with a water activity of 0.937, compared with the swelling in pure water, exhibited anion specificity as evidenced by an increased swelling ratio in the following order: Na2SO4 < H2O < NaCl < NaSCN. The swelling ratio showed a good linear correlation with the osmotic pressure of dextran (500 kD) in these solutions. The salt‐concentration difference (imbalance) between the polymer‐solution side of the membrane and the polymer‐free permeate side during the osmotic‐pressure measurements positively correlated with the effect of the salt on the polymer osmotic pressure. These phenomena conform to Hofmeister‐type (or lyotropic) behavior. The diminishing augmentation of dextran osmotic pressure and the change in the salt‐concentration imbalance with rising NaSCN concentration imply a positive preferential interaction and adsorption of the salt onto the polymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2740–2750, 2001
Sorption and diffusion of carbon dioxide in wood‐fiber/polystyrene composites
Authors: Doroudiani Saeed , Chaffey Charles E. , Kortschot Mark T.
Published: August 2002

In this study, sorption and diffusion of carbon dioxide (CO2) in wood‐fiber/polystyrene composites were investigated. The effects of gas pressure and fiber content on the solubility and diffusion coefficients were evaluated. A statistical analysis indicated that pressure is more important than fiber content in determining the solubility and diffusivity of CO2. An increase in saturation pressure causes an increase in the solubility and diffusion coefficients, whereas inclusion of the fibers decreases both of these properties. Models were developed to predict the uptake and diffusion coefficients of CO2 in the composite samples as functions of pressure and fiber content. A theoretical model based on Henry's law and the Langmuir equation compared favorably to the experimental data for CO2 solubility. This dual mode model also described both the transient sorption and desorption data, but only if the concentration‐dependent value of diffusivity was treated as a history‐dependent parameter. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 723–735, 2002
Influence of humidity cycling parameters on the moisture‐accelerated creep of polymeric fibers
Authors: Habeger C. C. , Coffin D. W. , Hojjatie B.
Published: August 2002

Accelerated creep is a curious and poorly understood transient moisture effect. The creep rates of most hydrophilic materials increase greatly with moisture content. However, when these same materials are subjected to creep loads in cyclic humidity environments, they often exhibit much higher creep rates than in a constantly humid state. This is called accelerated creep. Previous experimenters reported that accelerated creep was less likely to occur in polymeric fibers. We demonstrate experimentally that this happened only because of their choice of humidity cycling parameters. New results are given for Kevlar, lyocell, nylon‐6,6, and ramie fibers. Other paper scientists have argued that the absence of accelerated creep in single fibers supports a explanation based on fiber network effects for accelerated creep in paper. We argue here that accelerated creep is a more general phenomenon consistent with sorption‐induced stress‐gradient explanations. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2048–2062, 2001
Art therapy with adult bone marrow transplant patients in isolation: a pilot study
Authors: Gabriel Bonnie , Bromberg Elissa , Vandenbovenkamp Jackie , Walka Patricia , Kornblith Alice B. , Luzzatto Paola
Published: August 2002

Psycho‐social interventions for cancer patients in isolation for bone marrow transplant (BMT) have been advocated in the recent literature. It is not clear what type of interventions would be most appropriate. This study was conducted at Memorial Sloan‐Kettering Cancer Center (MSKCC), with three aims. (1) To test the feasibility of introducing art therapy as a supportive intervention for adult BMT patients in isolation. Nine patients were seen in art therapy sessions twice a week while in isolation, and were helped to develop free personal images. The three art therapists used the same art therapy program as a model. (2) To assess how patients would use the program. Forty‐two images were made by the nine patients during the art therapy sessions. A thematic analysis of the images showed that the patients used art therapy effectively in three ways: (a) to strengthen their positive feelings, (b) to alleviate their distress, and (c) to clarify their existential/spiritual issues. (3) The third aim was to identify which patients would most benefit from art therapy. Our results suggest that the non‐verbal metaphorical modality of art therapy may be especially beneficial for patients who need to deal with emotional conflicts, and with feelings about life and death, in a safe setting. Copyright © 2001 John Wiley & Sons, Ltd.
Personality and exercise participation across the breast cancer experience
Authors: Rhodes Ryan E. , Courneya Kerry S. , Bobick Todd M.
Published: August 2002

The purpose of this study was to investigate the relationship between personality and exercise participation across the breast cancer experience. Based on the Five‐Factor Model and previous exercise research, it was hypothesized that high scores of extraversion (E) and conscientiousness (C), and low scores of neuroticism (N) would discriminate exercise stage during and following cancer treatment as well as changes in exercise stage across the cancer experience (i.e. from prediagnosis through treatment to posttreatment). Participants were 175 non‐metastatic breast cancer survivors who completed a mailed questionnaire that assessed demographic and medical information, personality (the NEO‐Five Factor Inventory), and exercise stage recalled for three time periods (prediagnosis, during treatment, and posttreatment). Multivariate analysis of variance showed differences in personality based on exercise stage both during cancer treatment and posttreatment and also for exercise pattern across the cancer experience. Univariate F‐tests and post hoc analyses identified N, E, and C as the key personality dimensions. N was associated with earlier exercise stages and a maladaptive exercise pattern whereas E and C were associated with more advanced exercise stages and adaptive exercise patterns. It was concluded that personality may be an important determinant of exercise following breast cancer diagnosis. Copyright © 2001 John Wiley & Sons, Ltd.
The effectiveness of relaxation training in reducing treatment‐related symptoms and improving emotional adjustment in acute non‐surgical cancer treatment: a meta‐analytical review
Authors: Luebbert Karin , Dahme Bernhard , Hasenbring Monika
Published: August 2002

Cancer patients often have to deal with severe side effects and psychological distress during cancer treatment, which have a substantial impact on their quality of life. Among psychosocial interventions for reducing treatment‐related side effects, relaxation and imagery were most investigated in controlled trials. In this study, meta‐analytic methods were used to synthesize published, randomized intervention–control studies aiming to improve patients' treatment‐related symptoms and emotional adjustment by relaxation training. Mean weighted effect sizes were calculated for 12 categories, treatment‐related symptoms (nausea, pain, blood pressure, pulse rate) and emotional adjustment (anxiety, depression, hostility, tension, fatigue, confusion, vigor, overall mood). Significant positive effects were found for the treatment‐related symptoms. Relaxation training also proved to have a significant effect on the emotional adjustment variables depression, anxiety and hostility. Additionally, two studies point to a significant effect of relaxation on the reduction of tension and amelioration of the overall mood. Intervention features of the relaxation training, the time the professional spent with the patient overall (intervention intensity) and the schedule of the intervention (offered in conjunction with or independent of medical treatment to the cancer patient) were relevant to the effect of relaxation on anxiety. The interventions offered independently of medical treatment proved to be significantly more effective for the outcome variable anxiety. Relaxation seems to be equally effective for patients undergoing different medical procedures (chemotherapy, radiotherapy, bone marrow transplantation, hyperthermia). According to these results relaxation training should be implemented into clinical routine for cancer patients in acute medical treatment. Copyright © 2001 John Wiley & Sons, Ltd.
Sensory and affective dimensions of advanced cancer pain
Authors: Sela Rami A. , Bruera Eduardo , Conner‐spady Barbara , Cumming Ceinwen , Walker Candace
Published: August 2002

The present study was designed to explore the extent to which advanced cancer pain is explicable in terms of both physical pain intensity and affect. Most notably, it expanded on previous findings by more clearly elucidating the relationship between several discrete emotional states and the total experience of cancer pain. One hundred and eleven patients with cancer pain attending a Pain and Symptom Control Clinic were studied. Visual Analogue Scales (VASs) were used to quantify overall pain intensity and the accompanying affect. Then, correlations were calculated to evaluate the relationships both between and within these two variables. Overall, the participants rated both the pain intensity and the negative affect associated with that pain as high. Of the examined affective components of pain, frustration and exhaustion were found to be the most significant. In addition, some gender differences were identified in terms of frustration, anger, fear, exhaustion, helplessness, and hopelessness. Copyright © 2002 John Wiley & Sons, Ltd.
The first year after breast cancer diagnosis: hope and coping strategies as predictors of adjustment
Authors: Stanton Annette L. , Danoff‐burg Sharon , Huggins Melissa E.
Published: August 2002

Given the marked individual variability in psychological adjustment in response to breast cancer, it is important to specify factors contributing to adaptive survivorship. This longitudinal study of 70 women with Stage I or II breast cancer tested the ability of situation‐specific coping strategies and a more stable attribute, hope, to predict adjustment prospectively from the point shortly following diagnosis through the first year. Consonant with previous studies, coping through active acceptance at diagnosis predicted more positive adjustment across time, and avoidance‐oriented coping predicted greater fear of cancer recurrence, over and above participant age and initial status on dependent variables. The hypothesis that coping through turning to religion would be more effective for less hopeful women was supported, and mixed support emerged for the hypothesis that approach‐oriented coping strategies would yield greater adaptational benefits for women high in hope. Findings suggest that risk and protective factors for adjustment across the first year of survivorship can be identified even prior to definitive surgery for breast cancer, particularly when both dispositional characteristics such as hope and situation‐specific coping strategies are considered. Copyright © 2002 John Wiley & Sons, Ltd.