bluuebunny/crossref_metadata_2025 huggingface dataset:
A sixteenth‐century warrior grave from Uppsala, Sweden: the Battle of Good Friday
Authors: Kjellström A.
Published: September 2004

Little is known about the Battle of Good Friday in Uppsala. The historical records are scarce and of limited extent. Moreover, the more spectacular event of the Stockholm Bloodbath has drawn most of the attention from both the contemporary public and later historians. This is why the discovery of a mass grave in the steep slope of Uppsala Castle in 2001 has provoked much interest. An analysis of the osseous material showed that the remains of at least 60 male individuals, mostly between 25–34 years of age, were buried in the excavated area. The demographic profile is largely similar to other European war‐related skeletal assemblages of the same era. Sharp force trauma was exhibited primarily on the skulls, with no obvious dominance to either side. The trauma distribution pattern suggests that the battle was not fought face‐to‐face. Blade wounds concentrated in specific regions imply a standardised technique when delivering the blows. The combination of commingled bones and articulated elements suggests that the individuals were in different stages of skeletonisation when buried. Copyright © 2004 John Wiley & Sons, Ltd.
Identification of historical human skeletal remains: a case study using skeletal and dental age, history and DNA
Authors: Katzenberg M. A. , Oetelaar G. , Oetelaar J. , Fitzgerald C. , Yang D. , Saunders S. R.
Published: September 2004

Excavation of an early historical (circa 1900) church cemetery in Cochrane, Alberta, Canada, revealed the graves of six individuals. All but one had been previously excavated and the individuals were re‐interred elsewhere. The remaining grave contained a coffin burial of an infant including most of the skeleton, crowns of forming deciduous teeth, scalp and hair. The remains were excavated and historical research was carried out to determine possible families who had used the cemetery. Skeletal and dental age estimates pointed to a particular individual described in historical records. This identification was confirmed through more precise ageing by dental microstructure, sex determination using DNA, and finally, maternal relatedness by comparison of mtDNA with a living female relative. In addition to describing the analytical methods used, this paper demonstrates the importance of accurately identifying historical burials, particularly when living relatives remain in the community. Copyright © 2004 John Wiley & Sons, Ltd.
Prenatal diagnosis and characterization of an analphoid marker chromosome 16
Authors: Tabet A. C. , Gosset P. , Elghezal H. , Fontaine S. , Martinovic J. , Encha Razavi F. , Romana S. , Vekemans M. , Morichon‐Delvallez N.
Published: September 2004

We report on a fetus with intrauterine growth retardation and multiple malformations diagnosed on ultrasound at 32 weeks. Examination of amniotic fluid cells in culture showed a 47,XY, i(16)(q10), +mar karyotype. Chromosome analysis of both parents was normal. Using spectral karyotyping, we identified the marker chromosome as a mitotically stable acentric marker chromosome derived from chromosome 16. Further studies using subtelomeric fluorescent probes confirmed the presence of an isochromosome for the long arm of chromosome 16 and showed that the acentric marker chromosome derived from the short arm of chromosome 16 leading to a trisomy for the long arm of chromosome 16. After genetic counseling, the parents decided to terminate the pregnancy. Fetal autopsy showed a male fetus with ambiguous external genitalia, cardiac malformation, megacystis and limbs anomalies as observed in other cases of trisomy for the long arm of chromosome 16. In addition, fetal brain examination showed vermian and olfactory bulb hypoplasia. Copyright © 2004 John Wiley & Sons, Ltd.
Focal sonographic periventricular pattern associated with mild ventriculomegaly in foetal cytomegalic infection revealing cytomegalic encephalitis in the third trimester of pregnancy
Authors: Guibaud Laurent , Attia‐Sobol Jocelyne , Buenerd Annie , Foray Patrice , Jacquet Catherine , Champion Fabienne , Arnould Pierre , Pracros Jean‐Pierre , Golfier François
Published: September 2004

Objectives

To report focal sonographic periventricular pattern related to residual germinal matrix lesions in foetal cytomegalic infection in association with mild ventriculomegaly seen during the third trimester of pregnancy correlating with neuropathological findings of encephalitis.

Methods

We reviewed prenatal cerebral sonographic examination performed in three patients, during the third trimester of pregnancy, looking for either late ‘isolated’ ventriculomegaly (n = 2) or sonographic follow‐up of cerebral structures following a known primary CMV infection in the early stage of pregnancy (n = 1). In cases of isolated ventriculomegaly, serological examination identified prenatal CMV infection. Magnetic resonance imaging (MRI) was performed in all cases. Imaging findings were compared with those following neuropathological examination.

Results

In all cases, ultrasound examination revealed an abnormal focal symmetrical bilateral periventricular pattern on the mid‐lateral border of the lateral ventricles, including a mainly hyperechogenic lesion containing a few microcysts (case 1), a mixture of echogenic tissue and cysts (case 2) and mainly cystic areas (case 3). No alteration of cephalic biometry was noted. Neuropathological examination correlated these abnormal areas with lesions of the residual germinal matrix including inflammation and necrosis, but revealed also an extensive inflammatory process of the whole foetal brain.

Conclusions

This focal sonographic periventricular pattern associated with mild ventriculomegaly without any abnormalities of the cerebral and cerebellar organogenesis nor cephalic biometry alteration in the third trimester of pregnancy should be considered as a marker of encephalitis following CMV infection of the foetal brain. Copyright © 2004 John Wiley & Sons, Ltd.
The ductus venosus in early pregnancy and congenital anomalies
Authors: Borrell Antoni
Published: September 2004

The ductus venosus (DV) is a tiny vessel leading oxygenated blood from the placenta to the fetal heart and its flow assessment has been used as an indicator of fetal acidemia. At 11 to 14 weeks, the fetuses with increased nuchal translucency also showing an abnormal DV blood flow were consistently found to be aneuploid. Early cardiac dysfunction, signaled by abnormal DV blood flow, was suggested as the underlying cause of increased nuchal translucency. Detection rates for aneuploidy with the use of DV blood flow studies range from 59 to 93% with 2 to 21% false‐positive rates. In fetuses with normal karyotype, an abnormal DV flow pattern signals cardiac defects or adverse perinatal outcome. Copyright © 2004 John Wiley & Sons, Ltd.
Germline mosaicism complicates molecular diagnosis of Lesch–Nyhan syndrome
Authors: Willers Ingrid
Published: September 2004

A healthy female with a brother suffering from Lesch–Nyhan syndrome was assigned a carrier status on the basis of haplotype analysis employing flanking and intragenic polymorphic markers of the HPRT gene. Her mother has been confirmed as a definite carrier by cell growth selection studies in cultured fibroblasts. In our proposita's first pregnancy, a male fetus was identified carrying the risk allele. Afterwards, the underlying novel mutation A161E (GCA→GAA at position c482) could be identified in the affected brother and in the heterozygous mother but not in the DNA of the pregnant sister and fetus. The fetus was also confirmed to be normal by uptake of 14C‐hypoxanthine in cultured amniotic cells. To test the discrepancy, the investigation was extended by recruiting additional family members. The data obtained showed that the mother had passed her risk haplotype to the affected son as well as to her mutation‐carrying and non–mutation‐carrying daughters. This provides the first evidence of concomitant somatic and germline mosaicism in Lesch–Nyhan syndrome. The study has a bearing on genetic counselling and cautions against the reliability of only using indirect genetic diagnosis even with intragenic markers. Copyright © 2004 John Wiley & Sons, Ltd.
Prenatal molecular diagnosis in hypertrophic cardiomyopathy: report of the first case
Authors: Charron Philippe , Héron Delphine , Gargiulo Marcela , Feingold Josué , Oury Jean‐François , Richard Pascale , Komajda Michel
Published: September 2004

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease that may cause premature sudden death, especially in teenagers and young adults. The recent progress in the molecular genetics of the disease has made genetic testing sometimes available in clinical practice. We report the case of a couple who still requested prenatal molecular testing after detailed information had been given through a multidisciplinary consultation. Prenatal diagnosis in HCM is associated with complex medical and psychological implications, in addition to general ethical considerations, as the potential value of the diagnosis is counterbalanced by the highly variable expression of the disease and the difficulty in predicting its evolution. The R403L mutation in the MYH7 gene had been previously identified in this family, characterized by a malignant form of HCM. In the specific context of this case, we decided to agree to the request of the parents and performed the prenatal diagnosis. To the best of our knowledge, this is the first report of a prenatal molecular diagnosis performed in the context of HCM. Copyright © 2004 John Wiley & Sons, Ltd.
Use of time‐dependent measures to estimate benefits of β‐blockers after myocardial infarction
Authors: Levy Adrian R. , Tamblyn Robyn M. , Abrahamowicz Michal , McLeod Peter J. , Fitchett David
Published: September 2004

Purpose

To estimate the reduction in all‐cause mortality conferred by β‐blockers in a population‐based cohort of elderly survivors of myocardial infarction during the year following hospital discharge.

Methods

A dynamic retrospective cohort was assembled from persons aged 66 years and over surviving myocardial infarction in Quebec between 1990 and 1993. Information on hospitalizations was linked to medication and physician claims, demographic characteristics and vital status. Subjects prescribed β‐blockers at hospital discharge had fewer comorbid medical conditions, less pre‐existing cardiovascular disease and less severe infarcts. To control for these differences, analyzes were restricted to subjects receiving at least one β‐blocker and mortality was compared between periods with and without β‐blocker exposure using Cox proportional hazard models.

Results

Among 14 547 survivors of myocardial infarction, 41% were dispensed at least one β‐blocker. Among those subjects, the risk of dying during periods of β‐blocker use was reduced 40% (hazard ratio = 0.6; 95% CI: 0.5, 0.7).

Conclusion

Confounding by indication threatens the validity of observational studies of intended effects of medications. For elderly survivors of myocardial infarction, the estimated benefit of β‐blockers from observational studies is greater than the estimate from randomized trials. Greater benefits do not seem to be an artifact arising from systematically prescribing β‐blockers to subjects with better prognosis. Reducing confounding by indication can enhance the validity of observational studies of medications and widen research applications of administrative health databases. While the actual benefits of medications are never truly known these studies can provide a credible range that brackets the truth. Copyright © 2004 John Wiley & Sons, Ltd.
Allergen‐induced proteolytic cleavage of annexin‐1 and activation of cytosolic phospholipase A2 in the lungs of a mouse model of asthma
Authors: Chung Youn Wook , Oh Hae Yeun , Kim Ji Yeong , Kim Jae‐Hong , Kim Ick Young
Published: September 2004

To identify proteins that might play an important role in allergen‐induced asthma, we analyzed lung extracts prepared from allergen (ovalbumin)‐challenged animals in a mouse model of this condition. The combination of two‐dimensional gel electrophoresis and mass spectrometry revealed that annexin‐1, a 37 kDa anti‐inflammatory protein that inhibits the activity of cytosolic phospholipase A2 (cPLA2), was down‐regulated by allergen challenge in the lungs of ovalbumin‐sensitized mice. Immunoblot analysis showed that this effect of ovalbumin challenge was attributable to proteolytic cleavage of annexin‐1. The ovalbumin‐induced degradation of annexin‐1 was blocked by pretreatment of mice with the antioxidant N‐acetylcysteine (NAC) or with sodium selenite, both of which have previously been shown to exert anti‐inflammatory effects in this asthma model. Ovalbumin challenge also both increased the expression of cPLA2 in lung tissue and reduced the extent of the interaction between cPLA2 and annexin‐1, and these effects were inhibited by NAC or selenite. Moreover, the concentrations of cysteinyl leukotrienes in bronchoalveolar lavage fluid and of leukotriene B4 in lung tissue were increased by ovalbumin challenge in a NAC‐ or selenite‐sensitive manner. Together, these results suggest that allergen‐induced oxidative stress results in proteolysis of annexin‐1 and consequent up‐regulation of cPLA2 activity and leukotriene production in this mouse model of asthma, and that the anti‐inflammatory effects of selenite may provide a basis for the development of new antiasthmatic drugs.
A targeted proteomics approach to the rapid identification of bacterial cell mixtures by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Warscheid Bettina , Fenselau Catherine
Published: September 2004

A proteomic approach to the rapid identification of bacteria is presented, which relies on the solubilization of a limited number of proteins from intact cells combined with on‐probe tryptic digestion. Within 20 min, complete cleavage products of a limited set of bacterial proteins with molecular masses of about 4–125 kDa were obtained by on‐probe digestion with immobilized trypsin. Bacterial peptides suitable for unimolecular decomposition analysis were generated within 5 min, and the sequence information obtained allowed identification of abundant proteins, and accordingly, their bacterial sources via searches in the NCBI database. Analysis of fragmentation products was also shown to allow for identification of bacterial peptides identical in mass but differing slightly in amino acid sequence by manual data analysis. In this work, Bacillus subtilis 168, B. globigii, B. sphaericus 14577, B. cereus T, and B. anthracis Sterne were examined, and various cold shock proteins were identified in all species. In addition, DNA‐binding, 60 kDa‐heat shock, surface‐related and other stress‐protective proteins were identified in the bacterial cell digests, and species‐specific tryptic peptides could be generated from each of the Bacillus species studied. Bacterial peptides could be analyzed with greater sensitivity and mass accuracy than the parent proteins. The applicability of this targeted proteomics approach to the rapid identification of Bacillus species was further established by analyzing binary cell mixtures.
Proteomic analysis of the sarcosine‐insoluble outer membrane fraction of the bacterial pathogen Bartonella henselae
Authors: Rhomberg Thomas A. , Karlberg Olof , Mini Thierry , Zimny‐Arndt Ursula , Wickenberg Ulrika , Röttgen Marlene , Jungblut Peter R. , Jenö Paul , Andersson Siv G. E. , Dehio Christoph
Published: September 2004

Bartonella henselae is an emerging zoonotic pathogen causing a wide range of disease manifestations in humans. In this study, we report on the analysis of the sarcosine‐insoluble outer membrane fraction of B. henselae ATCC 49882 Houston‐1 by one‐dimensional sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (1‐D SDS‐PAGE) and two‐dimensional nonequilibrium pH gradient polyacrylamide gel electrophoresis (2‐D NEPHGE). Protein species were identified by matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF‐MS) and subsequent database query against the B. henselae genome sequence. Subcellular fractionation, application of the ionic detergent lauryl sarcosine, assessment of trypsin sensitivity, and heat modifiability of surface‐exposed proteins represented valuable tools for the analysis of the outer membrane subproteome of B. henselae. 2‐D NEPHGE was applied to display and catalogue a substantial number of proteins associated with the B. henselae sarcosine‐insoluble outer membrane fraction, resulting in the establishment of a first 2‐D reference map of this compartment. Thus, 53 distinct protein species associated with the outer membrane subproteome fraction were identified. This study provides novel insights into the membrane biology and the associated putative virulence factors of this pathogen of increasing medical importance.
Proteome comparison of Vibrio cholerae cultured in aerobic and anaerobic conditions
Authors: Kan Biao , Habibi Hajar , Schmid Monika , Liang Weili , Wang Ruibai , Wang Duochun , Jungblut Peter R.
Published: September 2004

The pathogen Vibrio cholerae causes severe diarrheal disease in humans. This environmental inhabitant has two distinct life cycles, in the environment and in the human small intestine, in which it differs in its multiplication behavior and virulence expression. Anaerobiosis, limitation of some nutrient elements, and excess burden from host metabolism reactants are the major stresses for V. cholerae living in intestine, in comparison to conditions in the environment and laboratory medium. For an insight into the response of V. cholerae to different microenvironments, we cultured the bacteria in aerobic and anaerobic conditions, and compared the whole cell proteome by two‐dimensional electrophoresis. Among the protein spots identified, some protein species involved in aerobic respiration and the nutrient carbohydrate transporters were found to be more abundant in aerobic conditions, and some enzymes for anaerobic respiration and some stress response proteins were found more abundant in anaerobic culture. One spot corresponding to flagellin B subunit was decreased in anaerobic conditions, which suggests correlation with the meticulous regulation of bacterial motility during infection in the host intestine. This proteome analysis is the starting point for in‐depth understanding of V. cholerae behavior in different environments.
Proteome analysis of Neisseria meningitidis serogroup A
Authors: Bernardini Giulia , Renzone Giovanni , Comanducci Maurizio , Mini Roberta , Arena Simona , D'Ambrosio Chiara , Bambini Stefania , Trabalzini Lorenza , Grandi Guido , Martelli Paola , Achtman Mark , Scaloni Andrea , Ratti Giulio , Santucci Annalisa
Published: September 2004

Neisseria meningitidis is an encapsulated Gram‐negative bacterium responsible for significant morbidity and mortality worldwide. Meningococci are opportunistic pathogens, carried in the nasopharynx of approximately 10% of asymptomatic adults. Occasionally they enter the bloodstream to cause septicaemia and meningitis. Meningococci are classified into serogroups on the basis of polysaccharide capsule diversity, and serogroup A strains have caused major epidemics mainly in the developing world. Here we describe a two‐dimensional gel electrophoresis protein map of the serogroup A strain Z4970, a clinical isolate classified as ancestral to several pandemic waves. To our knowledge this is the first systematically annotated proteomic map for N. meningitidis. Total protein samples from bacteria grown on GC‐agar were electrophoretically separated and protein species were identified by matrix‐assisted laser desorption/ionization time of flight spectrometry. We identified the products of 273 genes, covering several functional classes, including 94 proteins so far considered as hypothetical. We also describe several protein species encoded by genes reported by DNA microarray studies as being regulated in physiological conditions which are relevant to natural meningococcal pathogenicity. Since menA differs from other serogroups by having a fairly stable clonal population structure (i.e. with a low degree of variability), we envisaged comparative mapping as a useful tool for microevolution studies, in conjunction with established genotyping methods. As a proof of principle, we performed a comparative analysis on the B subunit of the meningococcal transferrin receptor, a vaccine candidate encoded by the tbpB gene, and a known marker of population diversity in meningococci. The results show that TbpB spot pattern variation observed in the maps of nine clinical isolates from diverse epidemic spreads, fits previous analyses based on allelic variations of the tbpB gene.
Synthesis of functionalized amine oligomers by free‐radical telomerization of methyl methacrylate with a peculiar telogen: 2‐Aminoethanethiol hydrochloride
Authors: Boyer Cyrille , Loubat Cédric , Robin Jean Jacques , Boutevin Bernard
Published: September 2004

The Telomerization of methyl methacrylate with 2‐aminoethanethiol hydrochloride initiated by 2,2′‐azobisisobutyronitrile, was investigated in dimethylformamide (DMF). First, the peculiar behavior of 2‐aminoethanethiol was highlighted because it behaves as a peculiar transfer agent; this is because its transfer constant (CT) is weak compared with that of other thiols. The presence of the amine function greatly disturbs the free radical telomerization reaction. Telomerization was performed in the presence of hydrochloric acid (HCl) to protect the amine group. The transfer constant was strongly influenced by the acid and water concentration. This work emphasized that the nature of the solvent plays an important role in the determination of the transfer constant. Thus, the value of CT increased from 0.23 in DMF to 0.56 in the HCl/DMF mixture. The primary and secondary amines were recovered after the reaction. The functionality of the primary and secondary amines was measured by titration. The influence of the concentration of HCl on the resulting amine functionality was investigated. The acid presence prevents the formation of secondary amines, arising from Michael's reaction, on methyl methacrylate. Finally, these results were applied to the synthesis of amine‐functionalized telomers with molecular masses of 2000 to 15,000 g/mol. The amine function was correlated with the decrease of R0 ([telogen]/[monomer]). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5146–5160, 2004
Polymers derived from N‐isopropylacrylamide and azobenzene‐containing acrylamides: Photoresponsive affinity to water
Authors: Akiyama Haruhisa , Tamaoki Nobuyuki
Published: September 2004

N‐Isopropylacryamide was copolymerized by free‐radical polymerization with N‐[2‐(4‐phenylazophenoxy)ethyl]acrylamide derivatives that were substituted at their 4′‐position with ethoxy, methoxyethoxy, or isopropyl units, or with N‐{2‐[4‐(pyridin‐2‐ylazo)phenoxy]ethyl}acrylamide. The polymers were soluble in cold water and possessed lower critical solution temperatures (LCSTs). The value of the LCST rose a few degrees after UV irradiation and dropped after irradiation with visible light, reversibly, in processes that corresponded to the isomerization of the azobenzene units. The polymers became increasingly hydrophobic after increasing their azobenzene content. The difference of hydrophobicity correlates with the absorption band height at about 400 nm. The structure of the substituent on the azobenzene unit affected both the transition temperature and the hydrophobicity. A change in photoinduced wettability for water was observed to occur on a prepared film at a temperature different from the LCST determined in water. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5200–5214, 2004
Ethylene/1‐pentene copolymers synthesized using the metaloxycarbene complex catalyst system [(CO)5W=C(Me)OZr(Cp)2Cl]/MAO
Authors: Luruli Nyambeni , Grumel Valérie , Brüll Robert , du Toit Aletta , Pasch Harald , van Reenen Albert J. , Raubenheimer Helgard G.
Published: September 2004

Ethylene/1‐pentene copolymers were prepared using a [(CO)5W= C(Me)OZr(Cp)2Cl] (1)/MAO catalyst system. 1‐Pentene incorporation in the copolymer was monitored using 13C‐NMR spectroscopic methods. The weight average molecular weights (Mw) of the copolymers were between 142,000 and 629,000 g/mol, with polydispersity indexes (PDIs) ranging from ≈ 2 to 90, as analyzed by size exclusion chromatography (SEC). Melting and crystallization temperatures, determined using differential scanning calorimetry (DSC) and crystallization analysis fractionation (CRYSTAF), decreased linearly as the amount of 1‐pentene in the copolymer increased. SEC‐FTIR revealed that the 1‐pentene is predominantly incorporated in the low molecular weight fraction. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5121–5133, 2004
Initiator efficiency of 2,2′‐azobis(isobutyronitrile) in bulk dodecyl acrylate free‐radical polymerizations over a wide conversion and molecular weight range
Authors: Charton Nathalie , Feldermann Achim , Theis Alexander , Stenzel Martina H. , Davis Thomas P. , Barner‐Kowollik Christopher
Published: September 2004

An Erratum has been published for this article in J. Polym. Sci. Part A: Polym. Chem. (2004) 42(21) 5559.

The initiator efficiency, f, of 2,2′‐azobis(isobutyronitrile) (AIBN) in dodecyl acrylate (DA) bulk free‐radical polymerizations has been determined over a wide range of monomer conversion in high‐molecular‐weight regimes (Mn ≅ 106 g mol−1 [≅ 4160 units of DA)] with time‐dependent conversion data obtained via online Fourier transform near infrared spectroscopy (FTNIR) at 60 °C. In addition, the required initiator decomposition rate coefficient, kd, was determined via online UV spectrometry and was found to be 8.4 · 10−6 s−1 (±0.5 · 10−6 s−1) in dodecane, n‐butyl acetate, and n‐dodecyl acetate at 60 °C. The initiator efficiency at low monomer conversions is relatively low (f = 0.13) and decreases with increasing monomer to polymer conversions. The evolution of f with monomer conversion (in high‐molecular‐weight regimes), x, at 60 °C can be summarized by the following functionality: f60 °C (x) = 0.13–0.22 · x + 0.25 · x2 (for x ≤ 0.45). The reported efficiency data are believed to have an error of >50%. The ratio of the initiator efficiency and the average termination rate coefficient, 〈kt±, (f/〈kt〉) has been determined at various molecular weights for the generated polydodecyl acrylate (Mn = 1900 g mol−1 (≅ 8 units of DA) up to Mn = 36,500 g mol−1 (≅ 152 units of DA). The (f/〈kt〉) data may be indicative of a chain length‐dependent termination rate coefficient decreasing with (average) chain length. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5170–5179, 2004
Synthesis and characterization of novel thermoresponsive‐co‐biodegradable hydrogels composed of N‐isopropylacrylamide, poly(L‐lactic acid), and dextran
Authors: Huang Xiao , Nayak Bishwa Ranjan , Lowe Tao Lu
Published: September 2004

A series of novel multifunctional hydrogels that combined the merits of both thermoresponsive and biodegradable polymeric materials were designed, synthesized, and characterized. The hydrogels were copolymeric networks composed of N‐isopropylacrylamide (NIPAAM) as a thermoresponsive component, poly(L‐lactic acid) (PLLA) as a hydrolytically degradable and hydrophobic component, and dextran as an enzymatically degradable and hydrophilic component. The chemical structures of the hydrogels were characterized by an attenuated total reflection–Fourier transform infrared spectroscopy (ATR–FTIR) technique. The hydrogels were thermoresponsive, showing a lower critical solution temperature (LCST) at approximately 32 °C, and their swelling properties strongly depended on temperature changes, the balance of the hydrophilic/hydrophobic components, and the degradation of the PLLA component. The degradation of the hydrogels caused by hydrolytic cleavage of ester bonds in the PLLA component was faster at 25 °C below the LCST than at 37 °C above the LCST, determined by the ATR–FTIR technique. Due to their multifunctional properties, the designed hydrogels show great potential for biomedical applications, including drug delivery and tissue engineering. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5054–5066, 2004
Cationic copolymerization behavior of cyclic ether monomers with norbornene‐containing cyclic carbonate or spiro–orthoether structure
Authors: Hino Tetsuo , Inoue Naoto , Endo Takeshi
Published: September 2004

Cationic ring‐opening copolymerizations of various cyclic ether compounds with volume expanding monomers bearing norbornene backbones [norbornene‐spiro orthocarbonate (N‐SOC) and norbornene‐cyclic carbonate (N‐CC)] were carried out in the presence of a thermally latent initiator 1. The 10% weight loss decomposition temperatures (Td10) and the volume changes on the copolymerizations were measured for these resultant products. In the comparison between copolymerizations of bifunctional epoxide 2 with N‐SOC and with N‐CC, it was found that N‐CC served as a more useful volume controllable comonomer than N‐SOC. The copolymerizations with N‐CC yielded the products with a decrease in the volume change (volume shrinkage) and with an increase in the monomer feed ratio of N‐CC; Td10 was relatively similar to the homopolymer of epoxide 2 and was observed except when the proportion of N‐CC was more than 20% in the monomer feed ratio of N‐CC. In contrast, similar copolymerizations with N‐SOC did not exhibit such tendencies, probably because of the low efficiency of the copolymerization derived from the low miscibility of N‐SOC for the epoxide. The other copolymerization systems of other bi‐ and monocyclic ether compounds (3–6 and phenyl glycidyl ether) with N‐CC also indicated an almost similar tendency toward that of the copolymerization with epoxide 2. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5113–5120, 2004
Antimicrobial activity on the copolymers of 2,4‐dichlorophenyl methacrylate with methyl methacrylate: Synthesis and characterization
Authors: Patel Milan V. , Patel Samir A. , Ray Arabinda , Patel Rajni M.
Published: September 2004

Copolymers of monomers 2,4‐dichlorophenyl methacrylate (2,4‐DMA) and methyl methacrylate (MMA) were synthesized with different monomer feed ratios using toluene as a solvent and 2,2′‐azobisisobutyronitrile (AIBN) as an initiator at 70 °C. The copolymers were characterized by IR‐spectroscopy, and copolymer composition was determined with UV‐spectroscopy. The linearization method of Fineman–Ross was employed to obtain the monomer reactivity ratios. The molecular weights and polydispersity indexes were determined by gel permeation chromatography (GPC). Thermogravimetric analyses of polymers were carried out in nitrogen atmosphere. The homo‐ and copolymers were tested for their antimicrobial properties against selected microorganisms. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5227–5234, 2004
Polyelectrolyte complexes. VII. Complex nanoparticles based on poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate) tailored by the titrant addition rate
Authors: Dragan Ecaterina Stela , Schwarz Simona
Published: September 2004

Nonstoichiometric interpolyelectrolyte complexes (IPECs) as colloidal dispersions have been widely used for the past decade as reactive materials for flocculation and surface modification. In this context, some new aspects of the preparation and properties of IPEC nanoparticles based on NaPAMPS, in salt‐free aqueous solutions, are reported in this article. IPEC dispersions with different characteristics, z‐averaged particle sizes, polydispersity indices, and colloidal stabilities were tailored by the addition rate of the titrant, a less investigated factor in the synthesis of IPECs as nanoparticles. Poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate) (NaPAMPS) and two polycations bearing positive charges in the backbone, poly(diallyldimethylammonium chloride) and a polycation containing 95 mol % N,N‐dimethyl‐2‐hydroxypropyleneammonium chloride units, were used for this purpose. The complex nanoparticle characteristics and storage stability were monitored via the optical density at 500 nm and dynamic light scattering. IPEC nanoparticles with z‐averaged particle sizes of 100–250 nm resulted from the same polyion pair and the same polyion concentrations when the addition rate of the titrant, either the polyanion or polycation, varied within the range of 0.1–1.5 mL/mL of the starting polyion × h. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5244–5252, 2004
The effect of salts on the conformation and microstructure of poly(N‐isopropylacrylamide) (PNIPA) in aqueous solution
Authors: Krasovitski Elena , Cohen Yachin , Bianco‐Peled Havazelet
Published: September 2004

We present an experimental investigation of the conformation and microstructure of Poly(N‐isopropylacrylamide) (PNIPA) in aqueous solution in the presence of salts. As a model, a strong salting–out salt (Na2SO4) and a strong salting–in salt (NaSCN) were chosen. Light scattering measurements show that Na2SO4 decreases the radius of gyration of PNIPA compared to its value in water, whereas NaSCN increases it. Moreover, the NaSCN solution was found to be a better solvent for PNIPA compared to water, whereas Na2SO4 solution is worse. Small‐angle neutron scattering measurements of semidilute PNIPA solutions, at temperatures well below the phase‐transition temperature, exhibit the behavior predicted by the model of dynamic concentration fluctuations characterized by a single correlation length. Excess scattering at low angles is observed in salt solutions at temperatures that are near, yet below, the phase‐transition temperature. This may indicate intrachain heterogeneities on the scale of 6–8 nm. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3713–3720, 2004
Influence of solvents on the formation of ultrathin uniform poly(vinyl pyrrolidone) nanofibers with electrospinning
Authors: Yang Qingbiao , Li Zhenyu , Hong Youliang , Zhao Yiyang , Qiu Shilun , Wang Ce , Wei Yen
Published: September 2004

Although there have been many reports on the preparation and applications of various polymer nanofibers with the electrospinning technique, the understanding of synthetic parameters in electrospinning remains limited. In this article, we investigate experimentally the influence of solvents on the morphology of the poly(vinyl pyrrolidone) (PVP) micro/nanofibers prepared by electrospinning PVP solution in different solvents, including ethanol, dichloromethane (MC) and N,N‐dimethylformamide (DMF). Using 4 wt % PVP solutions, the PVP fibers prepared from MC and DMF solvents had a shape like a bead‐on‐a‐string. In contrast, smooth PVP nanofibers were obtained with ethanol as a solvent although the size distribution of the fibers was somewhat broadened. In an effort to prepare PVP nanofibers with small diameters and narrow size distributions, we developed a strategy of using mixed solvents. The experimental results showed that when the ratio of DMF to ethanol was 50:50 (w/w), regular cylindrical PVP nanofibers with a diameter of 20 nm were successfully prepared. The formation of these thinnest nanofibers could be attributed to the combined effects of ethanol and DMF solvents that optimize the solution viscosity and charge density of the polymer jet. In addition, an interesting helical‐shaped fiber was obtained from 20 wt % PVP solution in a 50:50 (w/w) mixed ethanol/DMF solvent. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3721–3726, 2004
Isothermal and nonisothermal crystallization kinetics of poly(propylene terephthalate)
Authors: Achilias Dimitris S. , Papageorgiou George Z. , Karayannidis George P.
Published: September 2004

The kinetics of crystallization of poly(propylene terephthalate) (PPT) samples of different molecular weights were studied under both isothermal and nonisothermal conditions. The Avrami and Lauritzen–Hoffmann treatments were applied to evaluate kinetic parameters of PPT isothermal crystallization. It was found that crystallization is faster for low‐molecular‐weight samples. The modified Avrami equation, and the combined Avrami–Ozawa method were found to successfully describe the nonisothermal crystallization process. Also, the analysis of Lauritzen–Hoffmmann was tested and it resulted in values close to those obtained with isothermal crystallization data. The nonisothermal kinetic data were corrected for the effect of the temperature lag and shifted alone with the isothermal kinetic data to obtain a single master curve, according to the method of Chan and Isayev, testifying to the consistency between the isothermal and corrected nonisothermal data. A new method for ranking of polymers, referring to the crystallization rates, was also introduced. This involved a new index that combines the maximum crystallization rate observed during cooling with the average crystallization rates over the temperature range of the crystallization peak. Furthermore, the effective energy barrier of the dynamic process was evaluated with the isoconversional methods of Flynn and Friedmann. It was found that the energy barrier is lower for the low‐molecular‐weight PPT. The effect of the catalyst remnants on the crystallization kinetics was also investigated and it was found that this is significant only for low‐molecular‐weight samples. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3775–3796, 2004
Electrically conductive, melt‐processed ternary blends of polyaniline/dodecylbenzene sulfonic acid, ethylene/vinyl acetate, and low‐density polyethylene
Authors: Zhang Qing‐Hua , Wang Xian‐Hong , Chen Da‐Jun , Jing Xia‐Bin
Published: September 2004

Although polyaniline (PANI) has high conductivity and relatively good environmental and thermal stability and is easily synthesized, the intractability of this intrinsically conducting polymer with a melting procedure prevents extensive applications. This work was designed to process PANI with a melting blend method with current thermoplastic polymers. PANI in an emeraldine base form was plasticized and doped with dodecylbenzene sulfonic acid (DBSA) to prepare a conductive complex (PANI–DBSA). PANI–DBSA, low‐density polyethylene (LDPE), and an ethylene/vinyl acetate copolymer (EVA) were blended in a twin‐rotor mixer. The blending procedure was monitored, including the changes in the temperature, torque moment, and work. As expected, the conductivity of ternary PANI–DBSA/LDPE/EVA was higher by one order of magnitude than that of binary PANI–DBSA/LDPE, and this was attributed to the PANI–DBSA phase being preferentially located in the EVA phase. An investigation of the morphology of the polymer blends with high‐resolution optical microscopy indicated that PANI–DBSA formed a conducting network at a high concentration of PANI–DBSA. The thermal and crystalline properties of the polymer blends were measured with differential scanning calorimetry. The mechanical properties were also measured. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3750–3758, 2004
Metallocenic copolymers of ethylene and 5,7‐dimethylocta‐1,6‐diene: Structural characterization and mechanical behavior
Authors: Cerrada María L. , Benavente Rosario , Pérez Ernesto , Moniz‐Santos Jorge , Ribeiro M. Rosário
Published: September 2004

The relationship between the structure and mechanical properties has been established for several copolymers of ethylene and 5,7‐dimethylocta‐1,6‐diene synthesized with a metallocene catalyst. A dependence on the composition and polymerization temperature has been found. The branches cannot be incorporated into the orthorhombic crystal lattice, and consequently, structural parameters such as the crystallinity and crystal size are considerably affected as the 5,7‐dimethylocta‐1,6‐diene content increases in the copolymers. The viscoelastic relaxations have been analyzed and compared with those exhibited by high‐density polyethylene (HDPE). The β relaxation does not appear in HDPE and is exclusively seen in the copolymers. As the 5,7‐dimethylocta‐1,6‐diene content rises, the intensity of this process is increased, and its location is shifted to a lower temperature up to comonomer contents of approximately 6–8 mol % in the copolymers. On the other hand, the α mechanism associated with motion within the crystalline regions is also moved to a lower temperature and its intensity is diminished as the 5,7‐dimethylocta‐1,6‐diene molar fraction increases in the copolymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3797–3808, 2004
Interfacial toughness in polymer‐layered laminar composites
Authors: Devasahayam Sheila
Published: September 2004

The investigation of the interfacial toughness of polymer layered laminar composites with two different approaches produced results differing by up to an order of magnitude and following opposite trends with respect to the strain rates. The flexural modulus and neutral axis of a constrained epoxy‐adhesive layer bound to a painted metal substrate varied with the thickness of the adhesive layer. The adhesion energy depended on the rate at which the force was transmitted to the adhesion bonds—not just on the strength of the adhesion bonds—and on the concomitant strain hardening at high strain rates. As the strain rate and thickness of the polymer layer increased, the transition from a cohesive mode to an adhesive–cohesive (polymer–polymer interface) mode of debonding led to the observed high adhesion energy. The high adhesion energy and increased strain hardening were attributed to the formation of organic–inorganic composites and nanocomposites within the polymer matrix, which evolved as a result of the interactions between the metal oxide pigments and fillers with the polymer matrix during curing. Scission of the polymer chains at the interface was proposed to be the predominant fracture mechanism; it was based on the high relaxation time (∼1017 s) and the high activation energy (∼175 kJ mol−1). © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3822–3835, 2004
Surface Analysis of Plasma‐Deposited Polymer Films, 2
Authors: Swaraj Sufal , Oran Umut , Lippitz Andreas , Schulze Rolf‐Dieter , Friedrich Jörg F. , Unger Wolfgang E. S.
Published: September 2004

Summary: Chemical properties of plasma‐polymerized styrene films can be effectively controlled by the appropriate choice of external plasma parameters, such as duty cycle, power and monomer pressure. Chemical properties here are the regularity of the primary structure, the amount of long living radicals and branching or cross‐linking or both in plasma polymerized styrene films, which can be indirectly monitored by X‐ray photoelectron spectroscopy (XPS) and near edge X‐ray absorption fine structure (NEXAFS) spectroscopy. Principally, XPS and NEXAFS spectra of plasma‐polymerized styrene show all the spectroscopic fingerprints characteristic of atactic polystyrene indicating an inherent similarity of the respective primary chemical structures. There is an increase in irregularity and radical concentration for the plasma deposited films with increasing duty cycle or power. With an increase in monomer pressure, a decreased level of monomer fragmentation and, consequently, an increase in regularity must be concluded from the experimental data. The applied power regulates the fragmentation of the monomers as monitored by spectroscopic signals correlated to the aromatic rings. A trend in the extent of the post‐plasma oxygen incorporation according to the variation of the various external plasma parameters was deduced, which agrees with earlier ToF‐SIMS findings (Plasma Process. Polym., 2004, 1, 123).

Total electron yield NEXAFS spectra of atactic polystyrene reference film (a) and a selected pulsed plasma‐polymerized styrene film (b).

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Total electron yield NEXAFS spectra of atactic polystyrene reference film (a) and a selected pulsed plasma‐polymerized styrene film (b).
PBS 180 – A New Standard in Plasma Technology
Authors: Preiß Gregor
Published: September 2004

Plasma News: This section contains news of the plasma community all over the world. Articles about, for example, people, projects, and market trends are welcome. Suggestions should be sent to the editorial office of the Plasma Processes and Polymers, preferably by E‐mail to plasma@wiley‐vch.de. The editorial office decides which articles will be published.
Geophysical surveys designed to delineate the altitudinal limit of mountain permafrost: an example from Jotunheimen, Norway
Authors: Hauck Christian , Isaksen Ketil , Vonder Mühll Daniel , Sollid Johan Ludvig
Published: September 2004

Three geophysical methods have been applied to delineate the altitudinal limit of permafrost at Juvvasshøe/Jotunheimen in southern Norway. By using each method in a complementary way according to its applicability, the permafrost distribution could be analysed on both large and small scales. In addition, temperature‐based methods such as the BTS method (bottom temperature of snow cover) were used to validate the results. On a large scale, electromagnetic induction profiling with the EM‐31 was used to detect the location of the transition area between frozen and unfrozen ground. Within this area direct‐current (DC) resistivity and refraction seismic tomography were also applied to further characterize and visualize the permafrost transition. The large scale surveys revealed a sharp increase in conductivity, indicating an increase in unfrozen water content, near 1400 m a.s.l., with a possible transition zone between 1500 m a.s.l. and 1380 m a.s.l. The small scale investigation delineated the altitudinal limit of permafrost between 1470 m a.s.l. and 1410 m a.s.l., with sporadic ground ice occurrences and temperatures near the freezing point. Copyright © 2004 John Wiley & Sons, Ltd.
Permafrost and Little Ice Age glacier relationships, Posets Massif, Central Pyrenees, Spain
Authors: Lugon Ralph , Delaloye Reynald , Serrano Enrique , Reynard Emmanuel , Lambiel Christophe , González‐Trueba Juan J.
Published: September 2004

This paper contributes to the study of permafrost in the Pyrenees by reporting geoelectrical investigations and thermal measurement on the Little Ice Age (LIA) forefields of two glaciers. The aim was to assess the internal composition of sedimentary bodies (debris rock glaciers and moraine deposits) located in this proglacial environment. Ground ice was prospected using two DC resistivity techniques: vertical electrical soundings and resistivity mapping at a fixed pseudo‐depth. Extreme specific resistivities ranging between 1 and 25 MΩ m were detected under a thin (1–2 m) unfrozen layer, indicating the presence of a massive ice layer, certainly buried glacier ice. This ice of glacial origin probably covers former permafrost bodies, i.e. a much thicker layer of perennially frozen sediments. Low subsurface temperatures measured on the deposits indicate that buried glacier ice could have been preserved on top of permafrost since the end of the LIA or earlier Holocene glacier advances. This stratigraphy demonstrates that glaciers and pre‐existing perennially frozen sediments (permafrost) were in contact during the LIA. Copyright © 2004 John Wiley & Sons, Ltd.