bluuebunny/crossref_metadata_2025 huggingface dataset:
Giant platelets in a case of deletion 11q24‐qter confirmed by fluorescence in situ hybridization
Authors: Laleye Anatole , Delneste Daniele , Pradier Olivier , Hans Christine , Darboux Raphaël , Ogur Gonul
Published: October 2002

Here we report the association of giant platelets and an increase in platelet volume in a 19‐month‐old black female with de novo del 11q24‐qter. The deletion, which was visible on karyotype, was further confirmed and more precisely localized by fluorescence in situ hybridization studies (FISH) that showed the deletion to lie distal to the MLL gene region (11q23). Clinically, the case presented less severe symptoms than Jacobsen syndrome‐the well known partial deletion of the distal end of chromosome 11. Platelet glycoproteins CD 41, CD 42a, C 42b, CD 61, and PAC‐1 were also assayed and found to be normally expressed. To our knowledge, giant platelets are described for the first time in the relevant deleted region. © 2002 Wiley‐Liss, Inc.
Association of external auditory canal atresia, vertical talus, and hypertelorism: Confirmation of rasmussen syndrome
Authors: Julia Sophie , Pedespan Jean Michel , Boudard Philippe , Barbier Richard , Gavilan‐Cellie Isabelle , Chateil Jean François , Lacombe Didier
Published: October 2002

In 1979, Rasmussen et al. reported six members of a family with congenital, bilateral, symmetrical, and isolated subtotal atresia of the external auditory canal, bilateral foot abnormalities, and increased interocular distance. The family history suggested autosomal dominant inheritance of the syndrome. We report a 3‐year‐old girl whose symptoms are compatible with this diagnosis. Therefore, we suggest confirmation of the description by Rasmussen et al. as a distinct entity and suggest the term Rasmussen syndrome for this condition. © 2002 Wiley‐Liss, Inc.
Chromosome 13q neocentromeres: Molecular cytogenetic characterization of three additional cases and clinical spectrum
Authors: Li Shulan , Malafiej Paul , Levy Brynn , Mahmood Radma , Field Michael , Hughes Thomas , Lockhart Lillian H. , Wu Zhanhe , Huang Melissa , Hirschhorn Kurt , Velagaleti Golpalrao V.N. , Daniel Art , Warburton Peter E.
Published: October 2002

We report three new cases of chromosome 13 derived marker chromosomes, found in unrelated patients with dysmorphisms and/or developmental delay. Molecular cytogenetic analysis was performed using fluorescence in situ hybridization (FISH) with chromosome‐specific painting probes, alpha satellite probes, and physically mapped probes from chromosome 13q, as well as comparative genomic hybridization (CGH). This analysis demonstrated that these markers consisted of inversion duplications of distal portions of chromosome 13q that have separated from the endogenous chromosome 13 centromere and contain no detectable alpha satellite DNA. The presence of a functional neocentromere on these marker chromosomes was confirmed by immunofluorescence with antibodies to centromere protein‐C (CENP‐C). The cytogenetic location of a neocentromere in band 13q32 was confirmed by simultaneous FISH with physically mapped YACs from 13q32 and immunofluorescence with anti‐CENP‐C. The addition of these three new cases brings the total number of described inv dup 13q neocentic chromosomes to 11, representing 21% (11/52) of the current overall total of 52 described cases of human neocentric chromosomes. This higher than expected frequency suggests that chromosome 13q may have an increased propensity for neocentromere formation. The clinical spectrum of all 11 cases is presented, representing a unique collection of polysomy for different portions of chromosome 13q without aneuploidies for additional chromosomal regions. The complexity and variability of the phenotypes seen in these patients does not support a simple reductionist view of phenotype/genotype correlation with polysomy for certain chromosomal regions. © 2002 Wiley‐Liss, Inc.
Possible third case of Lin‐Gettig syndrome
Authors: Hedera Peter , Innis Jeffrey W.
Published: October 2002

We report a patient with craniosynostosis, severe mental retardation, absence of the corpus callosum, camptodactyly, hypogonadism, and ventricular septal defect. We propose that he has Lin‐Gettig syndrome and that he is the third reported patient with this entity. Our patient also had additional phenotypic features, including palatal cleft and absent rapid eye movement (REM) sleep that were not present in the two previously described patients with this syndrome. High‐resolution karyotype and subtelomeric fluorescence in situ hybridization (FISH) for cryptic telomeric rearrangement were normal. The existence of an unrelated patient with Lin‐Gettig syndrome supports that this is a separate and distinct clinical entity. © 2002 Wiley‐Liss, Inc.
Genotype–phenotype correlation in cystic fibrosis: The role of modifier genes
Authors: Salvatore Francesco , Scudiero Olga , Castaldo Giuseppe
Published: October 2002

More than 1,000 mutations have been identified in the cystic fibrosis (CF) transmembrane regulator (CFTR) disease gene. The impact of these mutations on the protein and the wide spectrum of CF phenotypes prompted a series of Genotype–Phenotype correlation studies. The CFTR genotype is invariably correlated with pancreatic status—in about 85% of cases with pancreatic insufficiency and in about 15% of cases with pancreatic sufficiency. The correlations between the CFTR genotype and pulmonary, liver, and gastrointestinal expression are debatable. The heterogeneous phenotype in CF patients bearing the same genotype or homozygotes for nonsense mutations implicated environmental and/or genetic factors in the disease. However, the discordant phenotype observed in CF siblings argued against a major role of environmental factors and suggested that genes other than CFTR modulate the CF phenotype. A locus that modulates gastrointestinal expression was identified in mice and subsequently in humans. By analyzing nine CF patients discordant for meconium ileus we were able to show that this locus had a dominant effect. Moreover, in a collaborative study we found a higher rate of polymorphisms in β‐defensin genes 1 and 2 in CF patients and in controls. In another multicenter study mutations in α‐1 antitrypsin (A1AT) and mannose binding lectin genes were found to be independent risk factors for liver disease in CF patients. The body of evidence available suggests that the variegated CF phenotype results from complex interactions between numerous gene products. © 2002 Wiley‐Liss, Inc.
Generalized abnormal embryonic development in missed abortion: Embryoscopic and cytogenetic findings
Authors: Philipp Tom , Kalousek Dagmar K.
Published: October 2002

A direct view of the embryo by means of transcervical embryoscopy prior to evacuation in 154 cases of missed abortion showed general embryonic maldevelopment in 48 cases (31%). A successful cytogenetic evaluation of these growth‐disorganized embryos was performed in 37. Chromosomal abnormalities were found in 26 cases (70%), with autosomal trisomies in 24 cases (92%). Trisomies involved chromosome 3 (one case), 6 (one case), 8 (two cases), 10 (one case), 12 (two cases), 14 (one case), 16 (11 cases), 20 (one case), and 22 (four cases). Most of these chromosome abnormalities represented nonviable defects, and their presence explained the minimal embryonic development observed embryoscopically. An apparently normal karyotype was observed in 11 growth‐disorganized embryos whose maldevelopment was similar to that resulting from the trisomies listed above. The factors responsible for embryonic maldevelopment with a normal karyotype are presently unknown and require further study, including investigation of imprinting defects, subtelomeric abnormalities, and cryptic mosaicism. © 2002 Wiley‐Liss, Inc.
Cockayne syndrome in three sisters with varying clinical presentation
Authors: Mahmoud Adel A.H. , Yousef George M. , Al‐Hifzi Ibrahim , Diamandis Eleftherios P.
Published: October 2002

We report three sisters showing the clinical features and investigational findings of Cockayne syndrome (CS). In the rehabilitation unit of Northwest Armed Forces Hospital (N.W.A.F.H.), Tabuk, Saudi Arabia, there was a 12‐year‐old girl with typical features of CS. The girl had no apparent problems until the end of the first year when growth and developmental delay prompted medical evaluation. Brain CT, bone X‐rays, auditory and ophthalmological evaluation confirmed the clinical impression of Cockayne syndrome. Two of her 13 sibs, both sisters, were later found to have the same syndrome. The sisters varied in clinical severity, as two of them had cataracts and early global delay and died early of inanition and infection. The third showed the disease manifestations at a relatively later age, did not have cataract, exhibited milder manifestations of the disease, and remains alive. The parents are not related by any way and the father is married to two other wives with 11 unaffected children. This report documents variable degrees of manifestations in sibs who presumably have the same gene mutation. © 2000 Wiley‐Liss, Inc.
Cobalamin disorder Cbl‐C presenting with late‐onset thrombotic microangiopathy
Authors: Van Hove Johan L.K. , Damme‐Lombaerts Rita Van , Grünewald Stephanie , Peters Heidi , Damme Boudewijn Van , Fryns Jean‐Pierre , Arnout Jozef , Wevers Ron , Baumgartner E. Regula , Fowler Brian
Published: October 2002

Two siblings, a boy age 12 and his sister age 4 years, presented with proteinuria and hematuria, hypertension, and chronic hemolytic anemia. At age 13 years, the boy developed an episode of severe hypertensive encephalopathy and transient renal failure. Both children are attending normal school, have no neurologic symptoms, and only minimal pigmentary retinal abnormalities. Renal biopsy showed a chronic thrombotic microangiopathic nephropathy. Both patients had hyperhomocysteinemia and mild methylmalonic aciduria. Fibroblasts showed decreased cobalamin uptake, reduced methyl‐ and adenosyl‐cobalamin formation, and deficient incorporation of formate and propionate, compatible with the Cbl‐C complementation group, but milder than that found in cells from most patients. Both patients and their father carry a balanced reciprocal translocation. Parenteral hydroxycobalamin treatment reduced the homocysteine levels, and methylmalonic acid disappeared. Increasing the dosage of hydroxycobalamin from 1 to 2.5, then 5 mg daily together with betaine, further reduced homocysteine levels (boy from 118 to 23 μM and girl from 59 to 14 μM). With this treatment, hemolysis has stopped, hematuria has disappeared, proteinuria has almost normalized, and creatinine clearance has been stable. Investigations for chronic thrombotic microangiopathy should include testing for this unusual but treatable disorder, regardless of age of presentation. © 2002 Wiley‐Liss, Inc.
Meta‐analysis of the association between tryptophan hydroxylase and suicidal behavior
Authors: Lalovic A. , Turecki G.
Published: October 2002

Tryptophan hydroxylase (TPH) has been the candidate gene of focus in many of the association studies of suicidal behavior in recent years. Initial positive findings with respect to an association between the TPH gene and suicidal behavior have been replicated, but not consistently. Typically, individual studies have investigated small samples, and thus they repeatedly had insufficient statistical power to detect a positive association. Meta‐analysis is one approach that can be used to achieve greater statistical power and may be helpful in providing a more conclusive understanding. We used meta‐analytic techniques to investigate the association between an intron 7 polymorphism in the TPH gene and suicidal behavior. A total of 39 publications were identified and reviewed, 17 of which were selected for inclusion in this study. We performed two meta‐analyses. One compared suicide attempters or completers (N = 1,290) with healthy controls (N = 2,295); the other compared suicide attempters (N = 625) with nonattempters (N = 1,475). None of these studies provided evidence for association (odds ratio (OR) = 1.14, 95% confidence interval (CI) = 0.97–1.34 for the former and OR = 0.96, 95% CI = 0.77–1.20 for the latter). The combined results from comparisons within both groups showed no overall association between suicidal behavior and an intron 7 polymorphism of the TPH gene. © 2002 Wiley‐Liss, Inc.
Morphometric appraisal of the skull of Caroline Crachami, the Sicilian “dwarf” 1815?–1824: A contribution to the study of primordial microcephalic dwarfism
Authors: Jeffery Nathan , Berkovitz B.K.B.
Published: October 2002

The skeleton of Caroline Crachami is a rare historical example of primordial microcephalic dwarfism (PMD). Studies show the condition to be heterogeneous, with at least three types, for which the assessment criteria rely on descriptive evaluations and/or simple measures with regard to cranial features. Advances in noninvasive imaging allow for a more complete morphometric examination of the skull of Caroline Crachami with the aim of clarifying aspects of the condition. In the present study, the skull of Caroline Crachami was three‐dimensionally imaged with computed tomography (CT) and reconstructed in virtual space. Coordinates for a number of measurements were taken to represent interesting anatomies with an emphasis on those measures not easily replicated on the skull itself. Volumes of the endocranial cavity and sella turcica were also computed. These data were compared with normative values taken from the literature and measured from CT images of the Bosma collection. Findings indicate that the general size of the skull is equivalent to that of a 6‐ to 8‐month‐old, that the endocranial volume and cranial base angle are commensurate with that of a newborn, and that the sella volume is the same as that for an 8‐ to 15‐month‐old. Apart from these traits, the skull was well proportioned and within the range of normal variation for a skull aged between 2–9 years. We conclude that further quantitative analysis on related skulls is warranted in the study of PMD using the methods and techniques described. © 2002 Wiley‐Liss, Inc.
Distribution of CGG repeats and FRAXAC1/DXS548 alleles in South American populations
Authors: Mingroni‐Netto Regina Célia , Angeli Claudia B. , Auricchio Maria Teresa B.M. , Leal‐Mesquita Emygdia R. , Ribeiro‐dos‐Santos Ândrea K.C. , Ferrari Iris , Hutz Mara H. , Salzano Francisco M. , Hill Kim , Hurtado A. Magdalena , Vianna‐Morgante Angela M.
Published: October 2002

In order to assess the molecular variability related to fragile X (FMR1 locus), we investigated the distribution of CGG repeats and DXS548/FRAXAC1 haplotypes in normal South American populations of different ethnic backgrounds. Special attention was given to Amerindian Wai‐Wai (Northern Brazil) and Ache (Paraguay), as well as to Brazilian isolated communities of African ancestry, the remnants of quilombos. Comparison of samples from quilombos, Amerindians, and the ethnically mixed, but mainly European‐derived population of São Paulo revealed that the 30‐copy allele of the fragile X gene is the most frequent in all groups. A second peak at 20 repeats was present in the population of São Paulo only, confirming this as a European peculiarity. The distribution of DXS548 and FRAXAC1 alleles led to a high expected heterozygosity in African Brazilians, followed by that observed in the population of São Paulo. Amerindians showed the lowest diversity in CGG repeats and DXS548/FRAXAC1 haplotypes. Some rare alleles, for example, the 148‐bp (FRAXAC1) or 200‐bp (DXS548) variants, which seem to be almost absent in Europe, occurred in higher frequencies among African Brazilians. This suggests a general trend for higher genetic diversity among Africans; these rarer alleles could be African in origin and would have been lost or possibly were not present in the groups that gave rise to the Europeans. © 2002 Wiley‐Liss, Inc.
A dominantly inherited malformation syndrome with short stature, upper limb anomaly, minor craniofacial anomalies, and absence of TBX5 mutations: Report of a Thai family
Authors: Kantaputra Piranit N. , Yamasaki Kentaro , Ishida Takafumi , Kishino Tatsuya , Niikawa Norio
Published: October 2002

We report on a Thai family with dominantly inherited malformation syndrome with upper limb anomalies, short stature, quadricuspid aortic valve, and minor craniofacial anomalies. The affected individuals comprised a mildly affected mother, a moderately affected daughter, and a most severely affected son. The daughter and son had short stature. The craniofacial abnormalities comprised frontal bossing, hypoplastic nasal bones, depressed nasal bridge, and broad nasal alae. The upper limb defects varies among the patients, ranging from radial ray defects in the mother through radial and ulnar ray defects with unilateral humeral hypoplasia in the daughter to radial ray defects with severe oligodactyly and bilateral humeral hypoplasia in the son. All patients in this family had hypoplasia of the shoulder girdle and resembled what is observed in many families with Holt‐Oram syndrome. Moreover, the son showed quadricuspid aortic valve with mild aortic regurgitation. However, the present family did not show any mutation of the TBX5 gene, a disease‐causing gene of Holt‐Oram syndrome. The present family deserves further investigation on other genes that play a role in the development of the upper limbs, particularly of radial rays. © 2002 Wiley‐Liss, Inc.
Partial duplication 4q and deletion 1p36 in monozygotic twins with discordant phenotypes
Authors: Angle Brad , Yen Frank , Hersh Joseph H. , Gowans Gordon , Barch Margaret
Published: October 2002

We report on monozygotic (MZ) twins with a de novo chromosome abnormality consisting of a partial duplication of chromosome 4 (q25‐qter) and deletion of chromosome 1p36. These infants had dysmorphic facial features and other clinical manifestations similar to those described with the previously delineated duplication 4q and deletion 1p36 phenotypes and two other reported cases of combined partial duplication 4q and deletion 1p36. However, the twins were discordant for a number of congenital anomalies. The discordant phenotypes described in these genetically identical infants demonstrate that nongenetic factors may play a significant role in the phenotypic differences in patients with recognized chromosome duplication and deletion syndromes, which are usually attributed to the individual genotypic differences in the duplicated and/or deleted chromosome segments. © 2002 Wiley‐Liss, Inc.
Diseases caused by nuclear genes affecting mtDNA stability
Authors: Suomalainen Anu , Kaukonen Jyrki
Published: October 2002

Diseases caused by nuclear genes that affect mitochondrial DNA (mtDNA) stability are an interesting group of mitochondrial disorders, involving both cellular genomes. In these disorders, a primary nuclear gene defect causes secondary mtDNA loss or deletion formation, which leads to tissue dysfunction. Therefore, the diseases clinically resemble those caused by mtDNA mutations, but follow a Mendelian inheritance pattern. Several clinical entities associated with multiple mtDNA deletions have been characterized, the most frequently described being autosomal dominant progressive external ophthalmoplegia (adPEO). MtDNA depletion syndrome (MDS) is a severe disease of childhood, in which tissue‐specific loss of mtDNA is seen. Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) patients may have multiple mtDNA deletions and/or mtDNA depletion. Recent reports of thymidine phosphorylase mutations in MNGIE and adenine nucleotide translocator mutations in adPEO have given new insights into the mechanisms of mtDNA maintenance in mammals. The common mechanism underlying both of these gene defects could be disturbed mitochondrial nucleoside pools, the building blocks of mtDNA. Future studies on MNGIE and adPEO pathogenesis, and identification of additional gene defects in adPEO and MDS will provide further understanding about the mammalian mtDNA maintenance and the crosstalk between the nuclear and mitochondrial genomes. © 2001 Wiley‐Liss, Inc.
ALFRED: An allele frequency database for anthropology
Authors: Osier Michael V. , Cheung Kei‐Hoi , Kidd Judith R. , Pakstis Andrew J. , Miller Perry L. , Kidd Kenneth K.
Published: October 2002

The deluge of data from the human genome project (HGP) presents new opportunities for molecular anthropologists to study human variation through the promise of vast numbers of new polymorphisms (e.g., single nucleotide polymorphisms or SNPs). Collecting the resulting data into a single, easily accessible resource will be important to facilitate this research. We created a prototype Web‐accessible database named ALFRED (ALelle FREquency Database, http://alfred.med.yale.edu/alfred/) to store and make publicly available allele frequency data on diverse polymorphic sites for many populations. In constructing this database, we considered many different concerns relating to the types of information needed for anthropology, population genetics, molecular genetics, and statistics, as well as issues of data integrity and ease of access to data. We also developed links to other Web‐based databases as well as procedures for others to make links to the data in ALFRED. Here we present an overview of the issues considered and provisional solutions, as well as an example of data already available. It is our hope that this database will be useful for research and teaching in a wide range of fields, and that colleagues from various fields will contribute to making ALFRED an important resource for many studies as yet unforeseen. Am J Phys Anthropol 119:77–83, 2002. © 2002 Wiley‐Liss, Inc.
No mutation in the TRKA (NTRK1) gene encoding a receptor tyrosine kinase for nerve growth factor in a patient with hereditary sensory and autonomic neuropathy type V
Authors: Toscano Ennio , Simonati Alessandro , Indo Yasuhiro , Andria Generoso
Published: October 2002

Hereditary sensory and autonomic neuropathy type IV (HSAN‐IV) and type V (HSAN‐V) are autosomal recessive genetic disorders, both characterized by a lack of pain sensation. We report a girl with clinical and neurophysiological findings consistent with a diagnosis of HSAN‐V. We sequenced her TRKA gene, encoding a receptor tyrosine kinase for nerve growth factor and responsible for HSAN‐IV, but we could not detect any mutation. These data indicate that a gene (or genes) other than TRKA is probably responsible for HSAN‐V in some patients.
Reinforcement of peroxide‐cured styrene–butadiene rubber vulcanizates by mathacrylic acid and magnesium oxide
Authors: Yin Dehui , Zhang Yong , Zhang Yinxi , Peng Zonglin , Fan Yongzhong , Sun Kang
Published: October 2002

Through the neutralization of magnesium oxide (MgO) and methacrylic acid (MAA), magnesium methacrylate [Mg(MAA)2] was in situ prepared in styrene–butadiene rubber (SBR) and used to reinforce the SBR vulcanizates cured by dicumyl peroxide (DCP). The experimental results show that the mechanical properties, dynamic mechanical properties, optical properties, and crosslink structure of the Mg(MAA)2‐reinforced SBR vulcanizates depend on the DCP content, Mg(MAA)2 content, and the mole ratio of MgO/MAA. The formulation containing DCP 0.6–0.9 phr, Mg(MAA)2 30–40 phr, and MgO/MAA mole ratio 0.50–0.75 is recommended for good mechanical properties of the SBR vulcanizates. The tensile strength of the SBR vulcanizates is up to 31.4 MPa when the DCP content is 0.6 phr and the Mg(MAA)2 content is 30 phr. The SBR vulcanizate
have good aging resistance and limited retention of tensile strength at 100°C. The SBR vulcanizates are semitransparent, and have a good combination of high hardness, high tensile strength, and elongation at break. The Tg values of the SBR vulcanizates depend largely on the DCP content, but depend less on the Mg(MAA)2 content and the MgO/MAA mole ratio. The contents of DCP, Mg(MAA)2, and the MgO/MAA mole ratio have also great effects on the E′ values of the vulcanizates. The salt crosslink density is greatly affected by the Mg(MAA)2 content and MgO/MAA mole ratio, but less affected by the DCP content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2667–2676, 2002
Compatibility and thermal properties of poly(acrylonitrile–butadiene–styrene) copolymer blends with poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile)
Authors: Li Qifang , Tian Ming , Kim Donggil , Zhang Liqun , Jin Riguang
Published: October 2002

The mechanical and heat‐resistant properties of acrylonitrile–butadiene–styrene (ABS) binary and ternary blends were investigated. The relationship of compatibility and properties was discussed. The results show that poly(methyl methacrylate) (PMMA) and styrene–maleic anhydride (SMA) can improve the thermal properties of conventional ABS. The Izod impact property of ABS/PMMA blends increases significantly with the addition of PMMA, whereas that of ABS/SMA blends decreases significantly with the addition of SMA. Blends mixed with high‐viscosity PMMA are characterized by higher heat‐distortion temperature (HDT), and their heat resistance is similar to that of blends mixed with SMA. For high‐viscosity PMMA, from 10 to 20%, it is clear that blends appear at the brittle–ductile transition, which is related to the compatibility of the two phases. TEM micrographs show low‐content and high‐viscosity PMMA in large, abnormally shaped forms in the matrix. Compatibility between PMMA and ABS is dependent on both the amount and the viscosity of PMMA. When the amount of high‐viscosity PMMA varied from 10 to 20 wt %, the morphology of the ABS binary blends varied from poor to satisfactory compatibility. As the viscosity of PMMA decreases, the critical amount of PMMA needed for the compatibility of the two phases also decreases. SMA, as a compatibilizer, improved the interfacial adhesiveness of ABS and PMMA, which results in PMMA having good dispersion in the matrix. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2652–2660, 2002
Adhesion of spray primers to plasma polymer coatings
Authors: Yasuda H. K. , Yu Q. S. , Reddy C. M. , Moffitt C. E. , Wieliczka D. M.
Published: October 2002

The adhesion failure of a primer on a plasma‐polymer‐deposited substrate surface could occur at the interface of the substrate/plasma polymer or at the interface of the plasma polymer/primer. We examined the adhesion of spray (solventborne or waterborne) primers on plasma polymer coated substrate with the substrate/plasma polymer systems in which the adhesion of the plasma polymer of trimethylsilane (TMS) to the substrate was good. Waterborne primers adhered well to quite hydrophobic plasma polymer surfaces, except the untreated surface of TMS. The plasma polymer of TMS appeared to contain a significant amount of oligomers, which were not in the three‐dimensional network of the plasma polymer coating and caused poor adhesion of primers. The plasma treatment of the deposited plasma polymer of TMS increased the adhesion characteristics of the primers dramatically. The oxygen‐plasma treatment, however, made the interface water sensitive and made the wet adhesion poor. The argon‐plasma treatment of the plasma polymer of TMS was found to be a viable process that yielded excellent adhesion of spray primers. The plasma polymer of TMS deposited by a closed system, without further plasma treatment, yielded an excellent foundation for the application of spray primers. Waterborne, nonchromated primers adhered exceedingly well and survived 8 h of boiling in water (with a scribed surface) and became virtually nonstrippable by conventional stripping agents. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1443–1457, 2002
Physicochemical investigation of radiation‐grafted poly(acrylic acid)‐graft‐poly(tetrafluoroethylene–ethylene) copolymer membranes and their use in metal recovery from aqueous solution
Authors: El‐Sawy Naeem M. , Al Sagheer Fakhreia A.
Published: October 2002

ET‐g‐PAAc membranes were obtained by radiation grafting of acrylic acid onto poly(tetrafluoroethylene–ethylene) copolymer films using a mutual technique. The ion selectivity of the grafted membranes was determined toward K+, Ag+, Hg2+, Co2+, and Cu2+ in a mixed aqueous solution. The ion‐exchange capacity of the grafted membranes was measured by back titration and atomic absorption spectroscopy. The Hg2+ ion content of the membrane was more than that of either the K+ or Ag+ ions. The presence of metal ions in the membranes was studied by infrared and energy‐dispersive spectroscopy measurements. Scanning electron microscopy of the grafted and metal‐treated grafted membranes showed modification of the morphology of the surface due to the adsorption of K+ and Ag+ ions. No change was observed for the surface of the membrane that was treated with Hg2+ ions. The thermal stability of different membranes was improved more with Ag+ and Hg2+ ions than with K+ ions. It was found that the modified grafted membranes possessed good hydrophilicity, which may make them promising candidates for practical applications, such as for cation‐exchange membranes in the recovery of metals from an aqueous solution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2692–2698, 2002
Synthesis and fluorescence of polymeric triphenylamine obtained by oxidative‐coupling polymerization
Authors: Zhan Caimao , Cheng Zhangang , Zheng Jinyun , Zhang Wei , Xi Yang , Qin Jingui
Published: October 2002

We prepared triphenylamine (TPA)‐containing polymers by a direct oxidative‐coupling method, which showed high thermostability, good solubility, high quantum efficiency, and blue light emission. The polymers are characterized by Fourier transform infrared spectroscopy, 1H‐NMR, ultraviolet–visible spectroscopy, thermogravimetric analysis, elemental analysis, and fluorescence spectra. The homopolymeric TPA (PTPA) was fairly soluble in CCl4 and toluene, with a quantum yield of 0.38 relative to Rhodamine B in toluene solution, and showed blue light emission in solid‐state film. The TPA–stilbene copolymers were more soluble than the PTPA and showed violet to green light emission in solid‐state film, depending on the TPA moiety contents, from which a pure blue light emission could be obtained. The emitting quantum efficiency of the copolymers measured in toluene solution was from 0.57 to 0.78 relative to Rhodamine B. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2718–2724, 2002
Adhesion of the plasma polymer of trimethylsilane to aluminum alloys
Authors: Yasuda H. K. , Yu Q. S. , Reddy C. M. , Moffitt C. E. , Wieliczka D. M.
Published: October 2002

The adhesion of a plasma polymer and the corrosion protection offered to aluminum alloy substrates depends on the cleanliness of the substrate surface and the state of oxides on the aluminum alloy surface. Both factors are dependent on what type of alloy is used, and consequently, the best preparation of the substrate surface differs on the type of aluminum alloy. Oxygen plasma treatment is effective for the elimination of organic surface contamination, but plasma treatment, such as that of mixed argon and hydrogen, cannot be used to modify the surface state of oxides on these alloys. This is because oxides of aluminum are stable and thus resist plasma modification, and prolonged plasma treatment has been observed to change concentrations of alloy components at the surface due to the heating of the alloy. Chemical cleaning of the surface is necessary before the application of the plasma polymer used for corrosion protection enhancement. Once the surface was properly prepared, a plasma polymer of trimethylsilane (TMS), prepared by cathodic polymerization, adhered well to aluminum alloys investigated in this study. Major adhesive failure, however, occurred as a consequence of reactor contamination when hexafluoroethane (HFE) plasma treatment of initially formed TMS plasma polymers was employed. Plasma pretreatment of the substrate with O2 or postplasma treatment of the plasma polymer of TMS with Ar (instead of HFE) was effective in eliminating the surface‐contamination effect on the adhesion. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1387–1398, 2002
Depolymerization of poly(ethylene terephthalate) waste
Authors: Shukla S. R. , Kulkarni K. S.
Published: October 2002

Poly(ethylene terephthalate) waste was depolymerized with ethylene glycol in the presence of different catalysts, two conventional metal catalysts (zinc acetate and lead acetate) and two alkalies (sodium carbonate and sodium bicarbonate). The resulting monomer bis(2‐hydroxy ethylene terephthalate) was characterized by thin layer chromatography, melting point, IR spectroscopy, differential scanning calorimetry, and elemental analysis. The results show that the qualitative and quantitative yields of the monomer obtained with alkalies as catalysts were most comparable with the conventional heavy metal catalysts, thus providing a further advantage for the recycling of polyester waste for the cause of environmental pollution abatement. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1765–1770, 2002
Novel polymeric aromatic lithium sulfonylimides as salts for polymer electrolytes
Authors: Nie Jin , Liu Dan‐Fan , Wang Xu‐Dong , Liu Lie‐Wei
Published: October 2002

Three new polymeric aromatic lithium sulfonylimides were used as salts in high molecular weight poly(ethylene oxide) (PEO) electrolytes. Their conductivity and electrochemical stability behaviors were investigated. The electrolytes with lithium poly[4,4′‐(hexafluoroisopropylidene)diphenoxy]sulfonylimide (LiPHFIPSI) showed a better conductive performance compared with the other two lithium salts. The best conductivity was obtained for PEO/LiPHFIPSI EO/Li = 16 (1.90 × 10−4 S/cm at 60°C). Thermal analysis indicated that the salts effectively decreased the crystallinity of PEO. Moreover, the electrolytes also had good electrochemical stability and their oxidative potential was to 5.5 V versus Li/Li+. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1802–1805, 2002
Rheology of polymeric solutions I. Zero shear conditions
Authors: Yasnovsky V. M.
Published: October 2002

Based on kinetic considerations, the following equation, connecting the zero‐shear viscosity of polymeric solutions with temperature and the molecular weight and concentration of the polymer was derived: RTln ηR = KBφMn /(1 + BφMn), where ηR is relative viscosity (i.e., the ratio of the solution viscosity to the solvent viscosity); K represents a change in enthalpy of viscous flow from a pure solvent to a pure polymer at the same temperature or from a polymer of low molecular weight (M) to one of higher molecular weight, and has the dimensions of energy (e.g., J/mol) because the ratio BφMn/(1 + BφMn) is dimensionless; φ is the volume or molar fraction of a polymer in solution (concentration units can be used in dilute solutions); B is a constant related to the stiffness of the chains of the polymer in a given solvent; and at BφMn >> 1, ln ηR = K/RT. The equation describes published data on the zero‐shear viscosity of four polar and nonpolar polymers in nine solvents with R2 > 0.98. This approach allows the use of solutions of moderate concentrations for the characterization of polymers and opens a way for a single‐point degree of polymerization (DP) determination of polymers at moderate concentrations if constants K, B, and n of the equation are known. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2064–2073, 2002
Preparation of sulfonated novel poly(bis[4‐(3‐aminophenoxy) phenyl]sulfone pyromellite)imide derivatives by heterogeneous sulfonation
Authors: Jeon Jong‐Young , Shim Bomg‐Seob
Published: October 2002

Sulfonated poly(bis[4‐(3‐aminophenoxy)phenyl]sulfone pyromellite)imide derivatives with various ion‐exchange capacities were prepared by heterogeneous sulfonation with chlorosulfonic acid. The effects of sulfonating agent concentration, reaction temperature, and reaction time were investigated. The mechanical and thermal properties, contact angle, change of polydispersity, and solubility were calculated for studying change of their properties. The reactions were effective, when the temperature is <10 °C and the concentration of chlorosulfonic acid is between 0.05 and 0.1 M. The value of ion‐exchange capacity was increased with reaction time, reaction temperature, and concentration of sulfonating reagent. Thermal and mechanical properties were nearly unchanged according to the degree of sulfonation, but the hydrophilicity indirectly measuring contact angle was increased with increasing the value of ion‐exchange capacity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1881–1887, 2002
Influence of filming process on macromolecular structure and organization of a medical segmented polyurethane
Authors: Guignot C. , Betz N. , Legendre B. , Le Moel A. , Yagoubi N.
Published: October 2002

A medical segmented polyurethane, Tecoflex®, based on methylene bis(p‐cyclohexyl isocyanate) and 1,4‐butanediol as hard segments (HS), and poly(tetramethylene glycol) as soft segments (SS), was studied to evaluate the influence of different filming procedures on macromolecular structure and organization. Size‐exclusion chromatography (SEC) and Fourier transform infrared (FTIR) spectroscopy were used to highlight differences between solvent‐cast and hot compression‐molded films (160 to 200°C). For compression‐molded films, FTIR spectra showed weakened vibration bands attributed to HS and SS groups; SEC results indicated a decrease of Mn and Mw molecular weights that was dependent on processing time and temperature. These modifications were the result of both thermooxidation of soft segments and thermal dissociation of urethane linkages. Concerning solvent‐cast films, no chemical or molecular modifications were observed. Moreover, we have highlighted that this procedure enhanced macromolecular organization: the carbonyl stretching region presented several bands assigned to free carbonyls and H‐bonded carbonyls with different environments. Particularly, we observed a band at 1660 cm− 1 reported in only one publication; we demonstrated that it originated from a bonded carbonyl in a well‐ordered structure. We have concluded that solvent casting has to be preferred because it enhances macromolecular ordering without chain degradation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1970–1979, 2002
Enzymatically degradable prodrugs: A novel methodology for drug linkage
Authors: Padmaja T. , Lele B. S. , Deshpande M. C. , Kulkarni M. G.
Published: October 2002

We have synthesized a novel enzymatically degradable prodrug system based on poly(ethylene glycol) (PEG) and tyrosine units by employing a synthetic methodology which eliminated the use of conventional blocking and deblocking methodology used for chemical linkage of drug molecule to the pendant NH2 group of amino acid. A diester of PEG (6 kDa) and tyrosine hydrochloride was synthesized by dicyclohexyl carbodiimide (DCC)‐mediated condensation. In the second stage, oligomers were prepared by condensing phenolic OH groups of tyrosine in the diester with sebacic acid, using DCC. Finally, the hydrochloride salt of tyrosine in the oligomer was treated with triethylamine to activate NH2 groups, which were reacted with benzoyl chloride to obtain a model prodrug system. The products synthesized were characterized by IR, 1H‐NMR, and GPC. The spectral data were in accordance with the proposed structures of products. Chymotrypsin‐catalyzed degradation of the oligomers was characterized by both MW measurements and Ninhydrin assay for free tyrosine. Degradation studies indicated that the rate of main‐chain degradation (ester hydrolysis) is higher than that of the side chain (amide hydrolysis). This new, simple methodology should be useful for conjugating a variety of bioactive molecules to enzymatically degradable PEG–amino acid based polymers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2108–2118, 2002
Microemulsion and conventional emulsion copolymerizations of methyl methacrylate with acrylonitrile
Authors: Ramana Reddy G. V. , Prasad Babu Y. Phani , Rami Reddy N. Subba
Published: October 2002

The microemulsion (ME) and conventional emulsion (CE) copolymerizations of methyl methacrylate (MMA) with acrylonitrile (AN) are carried out at 70°C by employing sodium lauryl sulphate (SLS) and n‐octanol (OA) as surfactant and cosurfactant, respectively, and potassium persulphate (KPS) as initiator. The copolymerization reactions are arrested at lower conversions, and the copolymers prepared are characterized by FTIR, NMR, TG/DTA, and GPC techniques. The reactivity ratios for microemulsion and conventional emulsion copolymerizations are evaluated by Fineman‐Ross (F‐R), Kelen‐Tüdös (K‐T), and Mayo‐Lewis (M‐L) graphical methods. The K‐T method yields the reactivity ratios of MMA (rMMA) and AN (rAN) as 2.03 ± 0.02 and 0.10 ± 0.02, and 1.97 ± 0.02 and 0.13 ± 0.02, respectively, for ME and CE copolymerization methods. The results are compared with the literature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1503–1510, 2002
Morphology and mechanical properties of polypropylene/organoclay nanocomposites
Authors: Svoboda Petr , Zeng Changchun , Wang Hua , Lee L. James , Tomasko David L.
Published: October 2002

Polypropylene (PP) nanocomposites were prepared by melt intercalation in an intermeshing corotating twin‐screw extruder. The effect of molecular weight of PP‐MA (maleic anhydride‐ modified polypropylene) on clay dispersion and mechanical properties of nanocomposites was investigated. After injection molding, the tensile properties and impact strength were measured. The best overall mechanical properties were found for composites containing PP‐MA having the highest molecular weight. The basal spacing of clay in the composites was measured by X‐ray diffraction (XRD). Nanoscale morphology of the samples was observed by transmission electron microscopy (TEM). The crystallization kinetics was measured by differential scanning calorimetry (DSC) and optical microscopy at a fixed crystallization temperature. Increasing the clay content in PP‐ MA330k/clay, a well‐dispersed two‐component system, caused the impact strength to decrease while the crystallization kinetics and the spherulite size remained almost the same. On the other hand, PP/PP‐MA330k/clay, an intercalated three‐component system containing some dispersed clay as well as the clay tactoids, showed a much smaller size of spherulites and a slight increase in impact strength with increasing the clay content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1562–1570, 2002
Preparation and characterization of low molecular weight silk fibroin by high‐temperature and high‐pressure method
Authors: Kang Gyung‐Don , Lee Ki‐Hoon , Shin Bong‐Seob , Nahm Joong‐Hee
Published: October 2002

A low molecular weight silk fibroin powder (LMSF) was prepared through high temperature (200°C) and high pressure (20 kgf/cm2), without any addition of chemicals. The carbonized adducts produced during this process were then removed by treatment with activated charcoal. The yield of LMSF by this preparation method was over 60% after the removal of carbonized adducts by using activated charcoal. Amino acid analysis showed an observable decrease in contents of serine and tyrosine in LMSF prepared by this method, as compared to those prepared by neutral salt. The molecular weight of this LMSF was also observably decreased with an increase in the reaction time. From the measurements of differential scanning calorimeter (DSC) and thermal gravimetric analyzer (TGA), thermal properties of LMSF through high temperature and high pressure were also decreased as compared to those produced by neutral salts. In addition, wide‐angle X‐ray diffraction (WAXD) patterns showed that the crystallinity of LMSF differed from that of the original silk fibroin. It can be said that the preparation method of LMSF in this study is a simple, economical, and environmentally compatible process with many advantages. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2890–2895, 2002
Effect of adding other metal ions on the removal of Cd2+ by the CoAlPO4‐5/polysulfone membrane
Authors: Lin Shiow‐Shyung , Chen Ming‐Ten , Chang Dong‐Jang , Chen Shih‐Hsiung , Tsai Yi‐Ting
Published: October 2002

Based on our previous work, performance of separation of Cd2+ by the CoAlPO4‐5/polysulfone membrane was not as good as that of the other metal ions. This could be significantly improved by the addition of other metal ions into the Cd2+ solution. The metal ions added were those with larger hydrated radius than that of Cd2+. When Mg2+ and Ca2+ were added, the rejection rate of Cd2+ could be increased from about 50% ([Cd2+] = 50 ppm) to nearly 100% and the rate would increase with concentration of Mg2+ and Ca2+. However, when the added ions were Fe2+ and Mn2+, although the performance of Cd2+ removal was still high, the rejection rate would inversely decrease with increasing concentration of Fe2+ and Mn2+. These phenomena were mainly attributable to the effect of hydrated ion and the effect of lowered pH value induced by the hydrolysis of the solution. As to the addition of Al3+, although the rejection rate would decrease with increasing Al3+ concentration up to 100 ppm, an abrupt increase was observed at 150 ppm, which was thought to be attributable to the concentration polarization effect caused by the formation of the high valence [Aln(OH)m](3[supi]n−[supi]m)+ complex. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2172–2177, 2002
Synthesis, spectral properties, and thermal properties of homo‐ and copolymers of 3,5‐dimethylphenyl acrylate with glycidyl methacrylate and determination of reactivity ratios
Authors: Vijayanand P. S. , Arunprasath R. , Balaji R. , Nanjundan S.
Published: October 2002

The new acrylic monomer, 3,5‐dimethylphenyl acrylate, was synthesized by reacting 3,5‐dimethylphenol dissolved in ethyl methyl ketone (EMK) with acryloyl chloride in the presence of triethylamine. The homopolymer and copolymers of different feed compositions of 3,5‐dimethylphenyl acrylate and glycidyl methacrylate were synthesized using free radical polymerization in ethyl methyl ketone solution at 70 ± 1°C using benzoyl peroxide as initiator. The copolymers were characterized by Fourier transform infrared (FTIR), 1H nuclear magnetic resonance (NMR), and 13C‐NMR spectroscopic techniques. The molecular weight (M̄nand M̄w) and polydispersity index of the polymers were determined using gel permeation chromatograph. The glass transition temperatures of the polymers were determined by differential scanning calorimeter. Thermogravimetric analysis of the polymers was performed in air. The solubilities of the polymers were tested in various polar and nonpolar solvents. Copolymer compositions were determined using 1H‐NMR spectra. The monomer reactivity ratios were determined by the application of conventional linearization methods such as Fineman–Ross, Kelen–Tüdös, and extended Kelen–Tüdös. The peel strength of the leather adhesives prepared from the copolymers was also determined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2261–2270, 2002
Characterization of polyethylene/kaolin composites by polymerization filling with Cp2ZrCl2/MAO catalyst system
Authors: Wang Xin , Wu Qiye , Dong Jinyong , Hu Youliang , Qi Zongneng
Published: October 2002

In this work, the preparation and characterization of metallocene‐catalyzed polyethylene (PE)/kaolin composites were presented. The composites was prepared by the so‐called polymerization‐filling method in which the PE matrix was formed directly on the kaolin surface by ethylene polymerization with the prefixed Cp2ZrCl2/methylaluminoxane (MAO) catalyst system on the kaolin surface. SEM, FTIR, and DMA were carried out to characterize the composites. The experimental results showed the new composites had homogeneous distribution of kaolin particles in the PE matrix and strong interfacial interaction between the PE matrix and kaolin particles. At the molecular level, the interfacial interaction caused the decrease of the mobility of PE molecular chains. In addition rheological testing showed that the introduction of kaolin by polymerization filling could improve the rheological behavior of prepared composites. The relationship between the rheological behaviors and the interfacial conditions were discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2913–2921, 2002