bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergism and catalysis in flame retardancy of polymers
Authors: Lewin Menachem
Published: September 2002

Synergististic and catalytic effects in flame retardancy technology are reviewed. An attempt is reported to define and determine the synergistic effectivity (SE) and the catalytic effectivity (CAT‐EFF) of a number of systems operating according to the accepted mechanism. Synergistic effects in the halogen based gas phase systems involving Br/Sb
2O
3, Cl/Sb
2O
3, Br/NH
3, Br/Cl, Br/P, and of the condensed phase based intumescent systems— ammonium polyphosphate/pentaerythritol/N derivatives are discussed and compared. Recently discovered catalysis of intumescent systems by divalent and transition metal compounds involving a maximum effect catalyst concentration is discussed in the light of thermoanalytical data. Recent work on catalysis of endothermic flame retardancy systems based on aluminum trihydrate and magnesium hydroxide are also reviewed. Copyright­© 2001 John Wiley & Sons, Ltd.
Synthesis of CuII‐complexed polymers and use as catalysts in the hydrolytic decontamination of Sarin nerve agent†
Authors: Blacker N. C. , Findlay P. H. , Sherrington D. C.
Published: September 2002

A range of polymer‐supported bidentate amine Cu
II complexes have been synthesized based on linear polymers, crosslinked resins and hydrogels as precursor species. Linear styrene, acrylate and methacrylate structures have been examined along with reactive crosslinked resins derived from vinylbenzyl chloride, glycidyl methacrylate and methacrylic acid (Amberlite IRC‐50). Hydrogels based on hydroxyethyl methacrylate, hydroxyethyl acrylate and hydroxypropyl acrylate, each copolymerized with a diamine containing monomer, have also been prepared.

Each Cu
II‐complexed polymer has been assessed as a catalyst in the hydrolytic decomposition of the nerve agent, Sarin, as a possible strategy for developing self‐decontaminating materials and coatings for both personnel and equipment in the event of a nerve agent challenge in the field.

Based on the measured half‐lives for hydrolysis of Sarin all of the polymer Cu
II complexes show remarkable catalytic activity relative to the rate of the uncatalyzed hydrolysis reaction. The linear polymethacrylate‐based catalysts are the most active followed by the linear polystyrene‐based species, the macroporous polymethacrylates and the polystyrene resins. The polymethacrylate hydrogels are the least effective. It seems therefore that the hydrophilic/hydrophobic balance is important in controlling Sarin access to the catalytic sites, and this seems to be optimal in the linear polymethacrylate‐based catalysts. The results are discussed further in the context of the existing literature. Copyright © 2001 John Wiley & Sons, Ltd.
Metal complexes with linear and crosslinked polysaccharides as mediators of angiogenesis
Authors: Barbucci R , Lamponi S , Magnani A , Peluso G , Petillo O
Published: September 2002

Bioactive macromolecules resulting from chemical modification of hyaluronic acid (Hyal) have been designed to improve the compatibility of biomaterials used for cardiovascular prostheses. Hyal has been sulphated to obtain derivatives (HyalS) with a number of sulphate groups ranging from 1 to 4 per disaccharide unit. Hydrogels of Hyal have been obtained by cross‐linking the free polysaccharide. An appropriate Hyal/cross‐linking agent ratio has produced a hydrogel with a degree of crosslinking of 50%.

In the present study, the ability to stimulate endothelial cell adhesion and migration was evaluated for free Hyal, HyalS3.5 and their complexes with Cu(II) and Zn(II) ions. The results revealed that Hyal and [Cu(OH)2HyalS3.5](4.5)− induced cell adhesion, while [ZnHyalS3.5](2.5)− and [Zn(OH)2HyalS3.5](4.5)− inhibited the process. The chemotactic activity of increasing concentrations of the above complexes was also evaluated, demonstrating that [Cu(OH)2HyalS3.5](4.5)− complex at 1 µM concentration was the most active in inducing cell migration. These results were also confirmed by analysing cell migration in agarose. The 50% hydrogel bound Cu(II) and Zn(II) and the in vivo biocompatibility of the complexes was found to be good. Copyright © 2001 John Wiley & Sons, Ltd.
Atomic force microscopy study of the polymer growth in a polymer stabilized liquid crystal
Authors: Guillard H. , Sixou P. , Tottreau O.
Published: September 2002

The growth of a cholesteric polymer network in a polymer stabilized cholesteric texture (PSCT) was studied by atomic force microscopy (AFM). The liquid crystal is removed by dipping the samples into a solvent bath and the polymer network remaining on each strip is analyzed. Several aspects of the polymer growth were studied: irradiation time, use of an orientation layer and application of an electric field during polymerization. AFM has proved to be an accurate means to study polymer networks thanks to its high resolution. The pitch of the cholesteric polymer is observable under special conditions of polymerization. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of poly[(2‐oxo‐1,3‐dioxolane‐ 4‐yl)methyl methacrylate‐co‐styrene] by addition reaction of carbon dioxide and its compatibility with poly(methyl methacrylate) or poly(vinyl chloride)
Authors: Park Sung‐Young , Park Hee‐Young , Woo Hang‐Soo , Ha Chang‐Sik , Park Dae‐Won
Published: September 2002

We investigated the chemical fixation of carbon dioxide (CO
2) to a copolymer bearing epoxide and the application of the cyclic carbonate group containing copolymer to polymer blends. In the synthesis of poly[(2‐oxo‐1,3‐dioxolane‐4‐yl)methyl methacrylate‐co‐styrene] [poly(DOMA‐co‐St)] from the addition of CO
2 to poly(glycidyl methacrylate‐co‐styrene) [poly(GMA‐co‐St)], quaternary ammonium salts showed good catalytic activity at mild reaction conditions. The CO
2 addition reaction followed pseudo first‐order kinetics with the concentration of poly(GMA‐co‐St). In order to expand the applications of the CO
2 fixed copolymer, polymer blends of this copolymer with poly(methyl methacrylate) (PMMA) or poly(vinyl chloride) (PVC) were cast from N,N′‐dimethylformamide (DMF) solution. Miscibility of blends of poly(DOMA‐co‐St) with PMMA or PVC have been investigated both by differential scanning calorimetry (DSC) and visual inspection of the blends, and the blends were miscible over the whole composition ranges. The miscibility behaviors were also discussed in terms of FT‐IR spectra. Copyright © 2002 John Wiley & Sons, Ltd.
Cellulose membranes grafted with vinyl monomers in a homogeneous system
Authors: Ibrahim Maha M. , Flefel Eman M. , El‐Zawawy Waleed K.
Published: September 2002

The homogeneous grafting of hydrophilic monomer onto cellulose derivatives was carried out in an aqueous system at 30, 50, 70 and 90 °C during reaction periods of 30 to 180 min. The graft polymer was isolated by ethanol from the reaction mixture, dried, and weigh. The grafted polymer was characterized by IR spectroscopy as well as microscopic sample morphology detected by electron scanning microscopy. The water absorption capacities and grafting values of grafted cellulose derivatives were also determined. The maximum grafting yield was obtained at 30 °C. Copyright © 2002 John Wiley & Sons, Ltd.
Microsatellite analysis provides efficient confirmation of fetal trophoblast isolation from maternal circulation
Authors: Koumantaki Yvoni , Sifakis Stavros , Dragatis Georgios , Matalliotakis Ioannis , Froudarakis Georgios , Papadopoulou Eleftheria , Koumantakis Eugenios
Published: September 2002

Fetal trophoblasts can be found in maternal circulation from an early stage of pregnancy and thus provide a potential source of DNA for non‐invasive prenatal diagnosis. We have developed a two‐step method for trophoblast isolation between the 8th and 12th week of pregnancy. Blood was sampled from 14 women undergoing termination of pregnancy or spontaneous abortion. Immunomagnetic beads precoated with HLA class I and II, and with anti‐cytokeratin‐18 monoclonal antibodies, were used to remove CD8+ and other maternal cells, and to select for fetal trophoblasts, respectively. Microsatellite analysis was performed on DNA extracted from the isolated, maternal, paternal and placental cells after PCR amplification. Recovery of the trophoblasts was confirmed in 13/14 cases (93%) by the identification of an identical microsatellite pattern for fetal and placental cells. Further evidence was the presence of heterozygous alleles of both maternal and paternal origin. The correct prediction of gender in all five male fetuses was an additional confirmation of trophoblast recovery. We conclude that trophoblasts can be effectively isolated from maternal blood in the first trimester, and by using polymorphic microsatellite markers to confirm sample purity, this method has potential future application in prenatal diagnosis. Copyright © 2001 John Wiley & Sons, Ltd.
Two unbalanced segregation products due to a maternal t(7;16)inv(16)
Authors: Leegte Beike , Sikkema‐Raddatz Birgit , Hordijk Roel , Davelaar Inge , van der Veen Anneke , Cobben JanMaarten
Published: September 2002

We report a prenatal case of a maternally inherited abnormal chromosome 16, originally interpreted as a pericentric inversion only, but after family studies re‐interpreted as a pericentric inversion (16) accompanied by an unbalanced (7;16) translocation. Because of the inversion 16 and an elder son with developmental delay and craniofacial dysmorphic features, in the past karyotyped as 46,XY, the chromosomes 16 of the mother and son were carefully re‐examined. Using a whole chromosome 16 paint and sub‐telomere probes of 16p and 16q, the karyotype of the mother was shown to be 46,XX,inv(16)(p11.2q23.2).ish t(7;16)(q36;p13.3)inv(16). Subsequently one chromosome 16 of the elder son appeared to be a der(16)t(7;16)(q36;p13.3). This is probably the result of a meiotic crossover between the chromosomes 16 in the mother. The prenatal karyotype was finally interpreted as 46,XY,inv(16)(p11.2q23.2).ish der(16)t(7;16)(q36;p13.3)inv(16). This is the same cytogenetic imbalance as his elder brother: a partial trisomy of chromosome 7 (q36→qter) and a partial monosomy of chromosome 16 (p13.3→pter). Copyright © 2001 John Wiley & Sons, Ltd.
Karyotypes found in the population declared at increased risk of Down syndrome following maternal serum screening
Authors: G. Ryall Richard , Callen David , Cocciolone Robert , Duvnjak Amra , Esca Renata , Frantzis Niki , M. Gjerde Elizabeth , A. Haan Eric , Hocking Trudy , Sutherland Grant , W. Thomas David , Webb Fiona
Published: September 2002

Of the 65 328 pregnancies of South Australian mothers screened by the South Australian Maternal Serum Antenatal Screening (SAMSAS) Programme between 1 January 1991 and 31 December 1997, 3431 (5.25%) were declared at increased risk of fetal Down syndrome. Fetal or neonatal karyotype was determined in 2737/3431 (79.8%) of these pregnancies, including 16 with early fetal loss. Interrogation of the database of the South Australian Neonatal Screening Service showed 643 live‐born infants whose phenotype was not subsequently questioned among the 694 pregnancies whose karyotype was not determined. Of the remaining 51/3431 pregnancies, 19 ended in early fetal loss without karyotyping and no newborn screening or other records could be found for 32 cases. The 129 instances of abnormal karyotype found were Down syndrome (84), trisomy 18 (four), trisomy 13 (three), triploidy (two), female sex chromosome aneuploidy (six) and male sex chromosome aneuploidy (five), inherited balanced rearrangements (19), mosaic or de novo balanced abnormalities (four) and unbalanced karyotypes (two). In the pregnancies declared at increased risk of fetal Down syndrome, only the karyotype for Down syndrome occurred with a frequency greater than that expected for the general, pregnant population. Copyright © 2001 John Wiley & Sons, Ltd.
Three‐ versus two‐dimensional ultrasound for nuchal translucency thickness measurements: comparison of feasibility and levels of agreement
Authors: Eppel Wolfgang , Worda Christof , Frigo Peter , Lee Andreas
Published: September 2002

We have determined feasibility and levels of agreement for visualizing the nuchal translucency within a time limit with three‐dimensional (3D) and two‐dimensional (2D) transvaginal ultrasound. A total of 213 women of median gestational age 13 weeks (range 11–14 weeks) undergoing first‐trimester nuchal translucency (NT) thickness measurements with 2D transabdominal ultrasound were included in the study. Additionally all women underwent 2D and 3D transvaginal NT examination within a time limit of 90 s. These two methods were compared with each other and with our standard method (2D transabdominal ultrasound) with respect to visualization of fetal nuchal fold and to the levels of agreement. The nuchal fold was visualized by 3D and 2D transvaginal ultrasound in 85.9% (95% CI: 80.5%, 90.3%) and 25.8% (95% CI: 20.1%, 32.2%), respectively (p<0.001). There was a statistically significant underestimation of the NT by 2D transabdominal as compared with 3D transvaginal ultrasound of 0.1 mm (p<0.001), and by 3D transvaginal as compared with 2D transvaginal ultrasound of even 0.1 mm (p<0.001). 3D transvaginal ultrasound of the nuchal fold has increased feasibility to 2D transvaginal ultrasound within a short examination time and with minimal, but significant, measurement differences. Copyright © 2001 John Wiley & Sons, Ltd.
Prenatal diagnosis of respiratory chain deficiency by direct mutation screening
Authors: Amiel Jeanne , Gigarel Nadine , Benacki Alexandra , Benit Paule , Valnot Isabelle , Parfait Béatrice , Von Kleist‐Retzow Jurgen‐Christoph , Raclin Valérie , Hadj‐Rabia Smaïl , Dumez Yves , Rustin Pierre , Bonnefont Jean‐Paul , Munnich Arnold , Rötig Agnès
Published: September 2002

Respiratory chain deficiency (RCD) is responsible for a clinically heterogeneous group of early‐onset untreatable disorders. Enzymological prenatal diagnosis (PD) can only be offered to a fraction of families. Moreover, due to the two‐fold genetic origin of the respiratory chain (nuclear and mitochondrial DNA) and owing to the large number of nuclear genes involved in the respiratory chain assembly, maintenance and functioning, the identification of the disease causing gene in a given family remains challenging. Here, we report on PD of RCD by direct screening of NDUFV1, SDH‐Fp, SCO1 and SURF1 mutations in five unrelated families with complex I, II and IV deficiency, respectively. The identification of the disease‐causing gene in a given family with RCD is a major issue to provide both adequate genetic counselling and early, reliable PD. Copyright © 2001 John Wiley & Sons, Ltd.
Fetal diaphragmatic hernia and upper limb anomalies suggest Brachmann‐de Lange syndrome
Authors: Marino Teresa , Wheeler Patricia G. , Simpson Lynn L. , Craigo Sabrina D. , Bianchi Diana W.
Published: September 2002

We describe two independent cases of Brachmann‐de Lange syndrome (BDLS) in which second trimester fetal sonographic studies showed the presence of a diaphragmatic hernia and upper limb anomalies. In both cases the karyotypes were normal. Intrauterine growth restriction (IUGR) developed in the third trimester. Postnatal and postmortem physical examinations demonstrated typical physical findings associated with BDLS. The prenatal diagnosis of diaphragmatic hernia with associated anomalies should prompt consideration of an underlying genetic etiology. Copyright © 2002 John Wiley & Sons, Ltd.
Fetal gender and aneuploidy detection using fetal cells in maternal blood: analysis of NIFTY I data
Authors: Bianchi D. W. , Simpson J. L. , Jackson L. G. , Elias S. , Holzgreve W. , Evans M. I. , Dukes K. A. , Sullivan L. M. , Klinger K. W. , Bischoff F. Z. , Hahn S. , Johnson K. L. , Lewis D. , Wapner R. J. , Cruz F. de la
Published: September 2002

Objectives

The National Institute of Child Health and Human Development Fetal Cell Isolation Study (NIFTY) is a prospective, multicenter clinical project to develop non‐invasive methods of prenatal diagnosis. The initial objective was to assess the utility of fetal cells in the peripheral blood of pregnant women to diagnose or screen for fetal chromosome abnormalities.

Methods

Results of fluorescence in situ hybridization (FISH) analysis on interphase nuclei of fetal cells recovered from maternal blood were compared to metaphase karyotypes of fetal cells obtained by amniocentesis or chorionic villus sampling (CVS). After the first 5 years of the study we performed a planned analysis of the data. We report here the data from 2744 fully processed pre‐procedural blood samples; 1292 samples were from women carrying singleton male fetuses.

Results

Target cell recovery and fetal cell detection were better using magnetic‐based separation systems (MACS) than with flow‐sorting (FACS). Blinded FISH assessment of samples from women carrying singleton male fetuses found at least one cell with an X and Y signal in 41.4% of cases (95% CI: 37.4%, 45.5%). The false‐positive rate of gender detection was 11.1% (95% CI: 6.1,16.1%). This was higher than expected due to the use of indirectly labeled FISH probes in one center. The detection rate of finding at least one aneuploid cell in cases of fetal aneuploidy was 74.4% (95% CI: 76.0%, 99.0%), with a false‐positive rate estimated to be between 0.6% and 4.1%.

Conclusions

The sensitivity of aneuploidy detection using fetal cell analysis from maternal blood is comparable to single marker prenatal serum screening, but technological advances are needed before fetal cell analysis has clinical application as part of a multiple marker method for non‐invasive prenatal screening. The limitations of the present study, i.e. multiple processing protocols, are being addressed in the ongoing study. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatally detected trisomy 7 mosaicism in a dysmorphic child
Authors: Kivirikko Sirpa , Salonen Riitta , Salo Armi , von Koskull Harriet
Published: September 2002

Trisomy 7 mosaicism was detected prenatally in cultured amniocytes but not in fetal lymphocytes. The child that was born had pigmentary changes of the skin and facial asymmetry suggestive of a chromosomal mosaicism. Skin fibroblasts were studied and trisomy 7 mosaicism was confirmed. At 3 years of age the boy had developed mentally within normal limits. However, dysmorphic findings include sparse hair, short leftpalpebral fissure, ptosis of the left eyelid, strabismus, enamel dysplasia, low‐set and posteriorly rotated ears and undescended testes. These findings share some common features with previously reported cases of trisomy 7 mosaicism. Copyright © 2002 John Wiley & Sons, Ltd.
Mid‐trimester triple test levels in early and late onset severe pre‐eclampsia
Authors: Shenhav Simon , Gemer Ofer , Sassoon Essie , Volodarsky Michael , Peled Ronit , Segal Shmuel
Published: September 2002

Objective

To study whether the degree of elevation of mid‐trimester triple test markers differs in patients with early versus late onset severe pre‐eclampsia.

Methods

A retrospective study of the medical records of 102 patients with severe pre‐eclampsia for whom mid‐trimester triple test result data were available was made. None of these patients had fetuses with abnormal karyotype nor delivered infants with malformations. Pre‐eclampsia was defined as early onset when it presented before 32 weeks' gestation. The levels of mid‐trimester maternal serum alpha‐fetoprotein (MSAFP), human chorionic gonadotrophin (hCG) and unconjugated oestriol (MSuE3) in patients with early and late onset severe pre‐eclampsia were compared.

Results

Twenty‐five patients had early onset and 77 patients had late onset severe pre‐eclampsia. The two groups did not differ significantly with regard to age, weight, parity and severity of pre‐eclampsia. The mean MSAFP in patients with early onset was significantly higher than in patients with late onset severe pre‐eclampsia (1.46 MoM, SE 0.12 versus 1.16 MoM, SE 0.05; p=0.01). The mean hCG in the early onset group was also significantly higher than in the late onset group (1.71 MoM, SE 0.18 versus 1.21 MoM, SE 0.07; p=0.03). Mean MSuE3 levels in patients with early onset were significantly lower than in patients with late onset severe pre‐eclampsia (0.83 MoM, SE 0.05 versus 1.02 MoM, SE 0.03; p=0.04).

Conclusions

Higher MSAFP and hCG, and lower MSuE3, may be more significant markers of early rather than late onset severe pre‐eclampsia. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal diagnosis of extrahepatic biliary duct atresia
Authors: Ben‐Ami Moshe , Perlitz Yuri , Shalev Stavit , Shajrawi Ibrahim , Muller Francoise
Published: September 2002

A rare case of extrahepatic biliary atresia was diagnosed by a combination of prenatal ultrasound and measurements of fetal digestive enzymes in amniotic fluid. Ultrasound at 15 and 18 weeks' gestation failed to detect the gall bladder, and amniotic fluid digestive enzyme values were below the fifth percentile. The patient decided to terminate the pregnancy. Post‐abortal pathological examination confirmed the diagnosis. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal diagnosis of Pierre–Robin sequence as part of Stickler syndrome
Authors: Soulier Marie , Sigaudy Sabine , Chau Cécile , Philip Nicole
Published: September 2002

Stickler syndrome or hereditary progressive arthro‐ophthalmopathy, is an autosomal dominant condition characterized by ocular manifestations, arthritic changes, orofacial features and deafness, in variable degrees.

We report the first case of prenatal diagnosis of Stickler syndrome in a child with a Pierre–Robin sequence (PRS) causing a polyhydramnios. When isolated polyhydramnios is not explained by immunological, metabolic or infectious causes, swallowing difficulty due to PRS must be considered. As PRS is aetiologically heterogenous, the prognosis depends on the cause. Genetic investigations and familial history must be taken into account. Here, in a context of familial Stickler syndrome, making the prenatal diagnosis of PRS as part of Stickler syndrome allowed us to reassure the parents and to anticipate airway trouble at the child's birth. Copyright © 2002 John Wiley & Sons, Ltd.
Psychological impact of the detection of soft markers on routine ultrasound scanning: a pilot study investigating the modifying role of information
Authors: Watson Melanie S. , Hall Sue , Langford Kate , Marteau Theresa M.
Published: September 2002

Objectives

To determine the impact on maternal anxiety of detecting a soft marker, and the association between anxiety and the information given during the scan.

Methods

Routine 20‐week fetal anomaly scans were audiotaped in the obstetric ultrasound unit of a London teaching hospital, across a four month study period. The study sample comprised 28 pregnant women: 14 in whom a soft marker was detected and a comparison group of 14 women in whom no marker was identified. Telephone interviews were conducted within one week of the scan, at 30 weeks' gestation, and one month after the birth of their children. The main outcome was anxiety, assessed using a standardized scale. Information provided during the scan was coded from transcripts.

Results

In the week following the scan, women with soft markers had clinically significant levels of anxiety. At 30 weeks' gestation and one month post‐partum their levels were within the normal range. Women who were told during their scan that their baby would probably be all right, compared with women not told this, were significantly less anxious and worried about their baby.

Conclusions

Results from this small longitudinal study suggest that the detection of soft markers on routine prenatal ultrasound causes considerable short‐term anxiety for women and that providing reassurance during the scan may prevent some of this anxiety. Copyright © 2002 John Wiley & Sons, Ltd.
Attitude of Saudi families affected with hemoglobinopathies towards prenatal screening and abortion and the influence of religious ruling (Fatwa)
Authors: Alkuraya Fowzan S. , Kilani Ramzi A.
Published: September 2002

Hemoglobinopathies are common inherited disorders in Saudi Arabia. Prenatal diagnosis for such diseases is specific and sensitive but not yet implemented in Saudi Arabia. Saudis are Muslims with a very high rate of consanguinity and inherited genetic disorders. To examine the attitude of Saudi families affected with hemoglobinopathies towards prenatal diagnosis and abortion, and to evaluate the effect of education on religious ruling on such attitudes, 32 families were interviewed using a pre‐structured questionnaire. The majority accepted prenatal diagnosis (81.3%). The attitude towards abortion was greatly affected by religious values. Education about religious ruling significantly affected parents' attitude towards accepting abortion and prenatal diagnosis. No other factors were found to influence the outcome. Although the majority of families received some kind of formal genetic counseling [23/32 (71.9%)], none of them was informed about the possibility of prenatal or preimplantation diagnosis prior to the interview. Therefore for prevention of genetic disorders, the emphasis in countries with a vast majority of Muslims such as Saudi Arabia has probably to be placed on public awareness about genetic risks, the risk of consanguinity, availability of services, and so on, while at the same time taking into consideration the religious beliefs and education of the target population Copyright © 2001 John Wiley & Sons, Ltd.
Derivated fetal haemoglobin as a marker for red cell age in the human fetus reflecting stimulated or impaired red blood cell production
Authors: Huisman Margriet , Egberts Johannes , van Loon Jenny
Published: September 2002

We have determined whether derivated fetal haemoglobin (dHbF, consisting of glycated and acetylated HbF) can be used as a cell age marker for fetal red blood cells (RBCs). Cord blood was obtained between 19 and 39 weeks of gestation from 28 alloimmunised anaemic fetuses (23 RhD+ and 5 Kell) and from 20 non‐anaemic fetuses and newborns (controls). Density gradient centrifugation was applied to 36 samples (20 RhD+, 15 controls and 1 Kell) to obtain fractions of increasing cell age. Blood samples were used for measurements of mean cellular volume (MCV), mean cell haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), pyruvate kinase activity (PK) and derivated fetal haemoglobin (dHbF) by cation‐exchange HPLC. Reticulocytes were counted only in the whole blood samples. In all density gradient separated RBC fractions, the values for MCV, MCH and PK activity decreased and those of MCHC and dHbF increased with increasing density (equivalent to increasing cell age). The mean density was lower for RBCs of the anaemic RHD group (1.072±0.007 g/ml) than for the non‐anaemic controls (1.077±0.005 g/ml) (p<0.05) The RBC density of the Kell sensitised fetus did not differ from those of the controls. In the control group, the values of the cell age markers in whole blood changed significantly with the gestational age, showing an increase of mean age of the erythrocyte population. The best linear relationship was found for dHbF (y=6.28+0.17*weeks; r=0.84; p<0.001). In the anaemic RhD+ fetuses, the RBC age markers did not change with gestational age; the dHbF percentages were lower, and the MCV, MCH, PK values and the reticulocyte counts were higher than in the controls (0.05<p<0.001). The dHbF values of the Kell sensitised fetuses were above (p<0.01) and the reticulocyte counts were below normal (p<0.05) for gestational age. For the anaemic fetuses, a significant number of the dHbF values (86%) and of the reticulocyte counts (78%) differed from the values of the controls (p<0.01). The dHbF percentages in RhD+ fetuses showed the best correlation with the Hb deficit, which is a measure for anaemia (r=−0.81, p<0.0001). We conclude that the percentage derivated HbF may indicate whether the RBC production is normal for gestational age. It may in that sense reflect stimulated or impaired erythropoiesis in alloimmunised haemolytic anaemia. Copyright © 2001 John Wiley & Sons, Ltd.
A rapid and quantitative mass spectrometry method for determining the concentration of acylcarnitines and aminoacids in amniotic fluid
Authors: Braida Laura , Crovella Sergio , Boniotto Michele , Luchesi Ariella , de Vonderweid Umberto , Casetta Bruno , Amoroso Antonio
Published: September 2002

We describe a quantitative, rapid, sensitive and reproducible tandem mass spectrometry (MSMS) method for the one‐step detection of aminoacid (AAs) and acylcarnitine (ACs) concentrations in amniotic fluid. This technology is quicker and more sensitive than other methods used to date since it is possible to determine very low AA and AC concentrations in samples simultaneously in a single run. The high degree of automation allows a large number of pregnancies to be screened for metabolic defects in a very short time. Copyright © 2001 John Wiley & Sons, Ltd.
Improved diabetes control after prolonged fasting — the Ramadan model
Authors: Maislos Maximo , Abou‐Rabiah Yunes , Zuili Irenne , Shany Shraga
Published: September 2002

We studied the effect of one large evening meal (gorging‐type diet) on patients with diabetes mellitus, during the month of Ramadan. Observant Muslims refrain from food and drink during the day and eat a large meal after sundown. It was an observational study carried out under field conditions in the Bedouin town of Rahat, in the northern Negev area of Israel. Fasting diabetic subjects were studied before, at the end of, and one month after Ramadan. Body weight, changes in medication, frequency of acute complications, plasma glucose and hemoglobin A1c were determined. Sixty‐seven fasting Muslim diabetic patients were studied. A significant decrease in hemoglobin A1c (HbA1c; p<0.001) was observed at the end of the month of fasting. There was no significant change in the total daily dose of antidiabetic agents, or in the incidence of acute diabetic complications. The gorging‐type diet, followed for one month, was well tolerated and safe. A statistically significant decrease in HbA1c suggests a beneficial effect of the Ramadan fast in these patients. Copyright © 2001 John Wiley & Sons, Ltd.
Changes in the care of the diabetic foot: part two
Authors: Foster A
Published: September 2002

This two‐part paper (the first part is in the previous issue of Practical Diabetes International) describes how specialised foot care for people with diabetes has developed over the ages. Until the 1980s, uncontrolled infections, ‘salami’ procedures (where patients first lose a toe, then more toes, then a foot and then a leg), major amputations and deaths were alarmingly common. The last two decades of the 20th Century saw an uspsurge in interest in the management of the diabetic foot, and the development of new treatments delivered by multidisciplinary teams led to halving of major amputations in a number of centres. New approaches included the development of modern podiatry offering preventative foot care and also debridement, antibiotics to control infections, shoes, insoles and casts to relieve abnormal mechanical forces, preventative education and surgical and radiological procedures to re‐perfuse the ischaemic limb. However, the new techniques are not universally applied and the diabetic foot remains a major public health problem. All over the world, public health systems have failed the diabetic foot and many patients have no rapid access to expert care from experienced teams. The incidence of diabetes is increasing epidemic proportions, and amputations are also on the increase. Copyright © 2001 John Wiley & Sons, Ltd.
A pharmacodynamic assessment of the impact of antihypertensive non‐adherence on blood pressure control
Authors: Choo Peter W. , Rand Cynthia S. , Inui Thomas S. , Lee Mei‐Ling Ting , Canning Claire , Platt Richard
Published: September 2002

Objectives

To evaluate if antihypertensive regimens that conform to present FDA guidelines by maintaining ≥ 50% of their peak effect at the end of the dosing interval protect patients during sporadic lapses in adherence.

Methods

169 patients on monotherapy for high blood pressure underwent electronic adherence monitoring for 3 months. Blood pressures were measured during non‐study office visits and were retrieved from automated medical records. Questionnaires were used to obtain other covariate information. The ratio of the dosing interval to the half‐life of drug activity (I′) was used to capture conformity with FDA guidelines. Data analysis focused on the interaction between I′ and the impact on blood pressure of delayed dosing.

Results

The average ( ± standard deviation) blood pressure during the study was 139.0 ( ± 12.0)/85.0 ( ± 6.9) mm Hg. Lisinopril followed by sustained‐release verapamil, atenolol, and hydrochlorothiazide were the most frequently prescribed agents. The majority of regimens (99%) conformed to FDA dosing guidelines. Of the patients 23% missed a dose before their blood pressure check. Non‐adherence, however, did not have a direct impact on blood pressure, and no interaction with I′ of was detected.

Conclusions

Among patients with relatively mild hypertension on single‐drug therapy, regimens that conform to current FDA dosing guidelines may prevent losses of blood pressure control during episodic lapses of adherence. These findings should be replicated in other patient populations with standardized blood pressure measurement to confirm their validity. Copyright © 2000 John Wiley & Sons, Ltd.
Radiofrequency and microwave (10 kHz–8 GHz) electrical properties of polypyrrole and polypyrrole–poly(methyl methacrylate) composites
Authors: Mohamed A Bel Hadj , Miane J L , Zangar H
Published: September 2002

The complex permittivity ϵ = ϵ′ −j ϵ″ of polypyrrole (PPY) samples and polypyrrole–poly(methyl methacrylate) (PPY‐PMMA) composites is calculated from measurements in the radiofrequency and microwave range (F = 103–8 × 109 Hz) at room temperature. A relaxation phenomenon is observed in PPY‐PMMA composites with polypyrrole concentration p = 6–12% by weight. The frequency Fmax corresponding to the maximum of ϵ″ appears in the radiofrequency domain and increases with the PPY concentration from 104 to 2 × 106 Hz. This relaxation is caused by space charge moving into the conductive clusters of PPY. At low frequency F ≪ Fmax, the real part of the permittivity ϵ′ becomes very high. For F ≪ Fmax, PPY‐PMMA composites have a percolative behaviour, the percolation threshold pc being 3.85%. For F ≫ Fmax, in the microwave domain, an ac component of the conductivity σac appears. σac varies as a power function of the frequency, σac ∝ ω
x; with x < 1, x independent of p.

© 2001 Society of Chemical Industry
Pyroelectric and dielectric properties of spin‐coated thin films of vinylidene fluoride–trifluoroethylene copolymers
Authors: Akcan M I , Topacli C
Published: September 2002

This work emphasizes the use of vinylidene fluoride and trifluoroethylene copolymer P(VDF‐TrFE) as a pyroelectric sensor. The pyroelectric and dielectric properties of the copolymer have been investigated in the temperature interval 150–350 K. The samples were prepared by using a spin‐coating technique with 70/30 mol% VDF/TrFE copolymer. The final film thickness of the samples, which is mainly determined by the concentration of the copolymer, spinning rate and spin time, was measured with a surface profiler. The samples were annealed at 150 °C for 10 min to improve the crystallinity of the copolymer. The crystallinity of the annealed and non‐annealed samples was compared by IR spectroscopy. The most effective process by which to improve the pyroelectric response of the material is to pole the sample with huge poling field‐strengths at elevated temperatures. Both pyroelectric and dielectric activities of the samples were measured after each successful poling process. It was observed that while the pyroelectric activity of the material increases, the dielectric activity decreases, so the figure‐of‐merit of the material, which shows the sensor capability of the material, was increased by a significant amount. It was found that the pyroelectric coefficient of VDF/TrFE (70/30 mol%) copolymer is 68.7 µC m−2 K−1 at 300 K.

© 2001 Society of Chemical Industry
Breakeven criteria for the GaInNAs junction in GaInP/GaAs/GaInNAs/Ge four‐junction solar cells
Authors: Friedman D. J. , Kurtz Sarah R.
Published: September 2002

The four‐junction GaInP/GaAs/GaInNAs/Ge solar cell structure holds the promise of efficiencies exceeding those of the GaInP/GaAs/Ge three‐junction cell, which at present is the benchmark for high‐efficiency multijunction cell performance. The performance of GaInNAs junctions demonstrated to date has been insufficient for the realization of these projected efficiency gains, owing to poor minority‐carrier properties in the GaInNAs. However, incremental improvements in the GaInNAs junctions have brought this breakeven point within sight. In this paper, we use a semiempirical approach to estimate the efficiency of the GaInP/GaAs/GaInNAs/Ge four‐junction solar cell structure as a function of the performance parameters of the GaInNAs third junction. The results provide guidance on the extent to which the current and voltage of present‐day GaInNAs junctions will need to be improved in order for the resulting four‐junction cell to realize its potential for efficiencies higher than that of GaInP/GaAs/Ge benchmark. Published in 2002 by John Wiley & Sons, Ltd.
Synthesis of polymers by template polymerization. I. Template polymerization of poly(methacrylic acid) with β‐cyclodextrin
Authors: Saito Reiko , Okuno Yoshiki , Kobayashi Hiroaki
Published: September 2002

A novel template monomer with multiple methacryloyl groups was synthesized with β‐cyclodextrin by the acetylation of primary hydroxyl groups and the esterification of secondary hydroxyl groups with methacrylic acid anhydride. The average number of methacryloyl groups in the monomer was 11. The radical polymerization of the monomer was carried out with the following initiators: α,α′‐azobisisobutylonitrile, H2O2Fe2+ redox initiator, p‐xylyl‐N,N‐dimethyldithiocarbamate (XDC), and α‐bromo‐p‐xylyl‐N,N‐dimethyldithiocarbamate (BXDC). When the concentration of the monomer was less than 4.12 × 10−3 M, polymerization was limited inside the molecule, and gelation of the system was hindered. For controlled radical photopolymerization with XDC and BXDC, the methacryloyl groups of the monomer were homogeneously polymerized, and poly(methacrylic acid) with a narrow molecular weight distribution was obtained by the hydrolysis of the polymerized products. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3539–3546, 2001
Asymmetric anionic polymerization of N‐1‐naphthylmaleimide with chiral ligand‐organometal complexes in toluene
Authors: Isobe Yukio , Onimura Kenjiro , Tsutsumi Hiromori , Oishi Tsutomu
Published: September 2002

Asymmetric anionic homopolymerizations of N‐1‐naphthylmaleimide (1‐NMI) were performed with chiral ligand/organometal complexes to form optically active polymers. Poly(1‐NMI)s obtained with methylene‐bridged bisoxazoline derivatives (Rbox)‐diethylzinc (Et2Zn) complexes showed high specific optical rotations ([α]) from +152.3 to +191.4°. Circular dichroism spectra of the polymers exhibited a split Cotton effect in the UV absorption‐band region. According to the exciton chirality method, the absolute configuration of the polymer main chain was determined according to the following method: (+)‐poly[N‐substituted maleimides (RMI)] main chains can contain more (S,S)‐ than (R,R)‐configurations. (−)‐Poly(RMI) main chains can contain more (R,R)‐ than (S,S)‐configurations. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3556–3565, 2001
Effect of the chemical nature and length of spacer arms on the covalent grafting of fluorinated molecular probes at the surface of poly(ethylene terephthalate) membrane
Authors: Biltresse Stéphane , Descamps Dimitri , Henneuse‐Boxus Cathy , Marchand‐Brynaert Jacqueline
Published: September 2002

A series of fluorinated molecular probes were synthesized that are characterized by spacer arms of various lengths and polarities. Previous molecules (1, 2a, 2b, 2c, 3a, 3b) were covalently fixed on the surface of poly(ethylene terephthalate) (PET) membranes via activated hydroxyl chain endings. X‐ray photoelectron microscopic analysis of the grafted samples allowed us to quantify the PET surface reactivity; the results were within 40–50 pmol/cm2 of fixed probes, independent of the length and hydrophilicity of the spacer arms. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 770–781, 2002; DOI 10.1002/pola.10156
Effect of glyoxylic oxime ether on radical polymerization of styrene
Authors: Sato Tsuneyuki , Sato Nobuyuki , Seno Makiko , Hirano Tomohiro
Published: September 2002

Methyl benzyloxyiminoacetate (MBOIA), a glyoxylic oxime ether, revealed different behaviors depending on the kinds of monomers used in the radical polymerization. MBOIA served as a retarder for styrene (St) and an inhibitor for vinyl acetate, whereas it showed little effect on the polymerization of methyl methacrylate. The retardation effect of MBOIA on the polymerization of St with dimethyl 2,2′‐azobisisobutyrate (MAIB) was examined in detail in benzene. The rate constant (kx) of the reaction of MBOIA with polystyrene (PS) radical was 92 L/mol s at 50 °C, 112 L/mol s at 60 °C, and 143 L/mol s at 70 °C, indicating that the reactivity of MBOIA toward PS radical is less than that of St by a factor of about 3. The Arrhenius plot of kx gave an activation energy of 20.3 kJ/mol. A nitrogen‐centered radical of a stationary state was observed by electron spin resonance (ESR) in the polymerization of St with MAIB at 60 °C in benzene in the presence of MBOIA, which is assignable to the radical (MBOIA ·) formed by addition of PS radical to MBOIA. The stationary MBOIA · concentration increased with increasing MBOIA concentration and then tended to be saturated at high concentrations. The rate constant of termination between MBOIA · radicals was 1.87 × l05 L/mol s at 60 °C with ESR. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2772–2781, 2002
Second‐harmonic response of a series of chiral polyesters: A joint experimental and theoretical study
Authors: Philip Biju , Sreekumar K.
Published: September 2002

A series of polyesters with π‐conjugated donor–acceptor segments was synthesized by the condensation of azobenzene‐4,4′‐dicarbonylchloride with 1,4:3,6‐dianhydro‐D‐sorbitol ([α] = + 42.5°) and biphenolic chromophores, bis(4‐hydroxyphenylazo)‐2,2′‐dinitrodiphenylmethane and bis(4‐hydroxyphenylazo)‐2,2′‐dinitrodiphenylsulfone. The polymers were characterized by spectral methods (IR, ultraviolet–visible, and NMR), thermal methods (thermogravimetry and differential scanning calorimetry), wide‐angle X‐ray scattering, and polarimetry. The polymers containing isosorbide units were optically active and crystalline. They exhibited glass‐transition temperature values between 100 and 160 °C and were stable up to 400 °C. The second‐harmonic generation (SHG) efficiency of the polymers was experimentally verified by a powder‐reflection technique with 2‐methyl‐4‐nitroaniline as a reference. The SHG efficiencies of the polymers were compared to those of the chromophores and explained as a function of the percentage of chiral composition. The hyperpolarizability β values were also determined by a two‐level model solvatochromic method and computational methods. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2868–2877, 2002
Influence of camphorsulfonic acid in nitroxide‐mediated styrene miniemulsion polymerization
Authors: Cunningham Michael F. , Tortosa Karine , Lin Marcus , Keoshkerian Barkev , Georges Michael K.
Published: September 2002

The rate‐accelerating effects of camphorsulfonic acid (CSA) on nitroxide‐mediated styrene miniemulsion polymerization were studied. Polymerizations were initiated with benzoyl peroxide (BPO) as an initiator and mediated with either 2,2,6,6‐tetramethylpiperidinyloxy (TEMPO) or 4‐hydroxy‐2,2,6,6‐tetramethylpiperidinyloxy (OH‐TEMPO). Although CSA has been used to accelerate the rate in bulk nitroxide‐mediated polymerizations, it has not been well studied in emulsion/miniemulsion. With dispersed systems, the effectiveness of CSA is likely to be affected by partitioning between the aqueous and organic phases. In styrene miniemulsion experiments performed over a range of conditions, the effect of adding CSA varied from negligible to significantly increasing the final conversion and molecular weight, depending on the nitroxide:BPO ratio. At a ratio of nitroxide:BPO = 1.7, the effect of CSA addition is small, whereas the final conversion and molecular weight are dramatically enhanced by CSA addition when the nitroxide:BPO ratio is 3.6. CSA is most effective in enhancing the rate and molecular weight when the initial free‐nitroxide concentration is higher. The magnitude of the rate and molecular weight enhancement was similar for TEMPO and OH‐TEMPO despite their differences in water solubility. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2828–2841, 2002
Synthesis of poly(p‐phenylene) macromonomers and multiblock copolymers
Authors: Bloom Paul D. , Sheares Valerie V.
Published: September 2002

Rigid‐rod poly(4′‐methyl‐2,5‐benzophenone) macromonomers were synthesized by Ni(0) catalytic coupling of 2,5‐dichloro‐4′‐methylbenzophenone and end‐capping agent 4‐chloro‐4′‐fluorobenzophenone. The macromonomers produced were labile to nucleophilic aromatic substitution. The molecular weight of poly(4′‐methyl‐2,5‐benzophenone) was controlled by varying the amount of the end‐capping agent in the reaction mixture. Glass‐transition temperatures of the macromonomers increased with increasing molecular weight and ranged from 117 to 213 °C. Substitution of the macromonomer end groups was determined to be nearly quantitative by 1H NMR and gel permeation chromatography. The polymerization of a poly(4′‐methyl‐2,5‐benzophenone) macromonomer [number‐average molecular weight (Mn) = 1.90 × 103 g/mol; polydispersity (Mw)/Mn = 2.04] with hydroxy end‐capped bisphenol A polyaryletherketone (Mn = 4.50 × 103 g/mol; Mw/Mn = 1.92) afforded an alternating multiblock copolymer (Mn = 1.95 × 104 g/mol; Mw/Mn = 6.02) that formed flexible, transparent films that could be creased without cracking. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3505–3512, 2001
Decomposition of model alkoxyamines in simple and polymerizing systems. I. 2,2,6,6‐tetramethylpiperidinyl‐ N‐oxyl‐based compounds
Authors: Ananchenko Gennady S. , Fischer Hanns
Published: September 2002

The thermal decomposition of five alkoxyamines labeled TEMPO–R, where TEMPO was 2,2,6,6‐tetramethylpiperidinyl‐N‐oxyl and R was cumyl (Cum), 2‐tert‐butoxy‐carbonyl‐2‐propyl (PEst), phenylethyl (PhEt), 1‐tert‐butoxy‐carbonylethyl (EEst), or 1‐methoxycarbonyl‐3‐methyl‐3‐phenylbutyl (Acrylate‐Cum), was studied with 1H NMR in the absence and presence of styrene and methyl methacrylate. The major products were alkenes and the hydroxylamine 1‐hydroxy‐2,2,6,6‐tetramethyl‐ piperidine (TEMPOH), and in monomer‐containing solutions, unimeric and polymeric alkoxyamines and alkenes were also found. Furthermore, the reactions between TEMPO and the radicals EEst and PEst were studied with chemically induced dynamic nuclear polarization. In comparison with coupling, TEMPO reacted with the radicals Cum, PEst, PhEt, and EEst and their unimeric styrene adducts by disproportionation to alkenes and TEMPOH only to a minor extent (0.6–3%) but with the radical adducts to methyl methacrylate to a considerable degree (≥20%). Parallel to the radical cleavage, TEMPO–EEst (but not the other alkoxyamines or TEMPO–Acrylate‐Cum) underwent substantial nonradical decay. The consequences for TEMPO‐mediated living radical polymerizations are discussed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3604–3621, 2001