bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preimplantation genetic diagnosis for aneuploidy screening in early human embryos: a review
Authors: Wilton Leeanda 
Published: October 2002

AbstractEmbryonic aneuploidies may be responsible for pregnancy failure in many IVF patients. In recent years, fluorescent in situ hybridisation (FISH) for multiple chromosomes has been used to document a high frequency of chromosomal errors and aneuploidy in human preimplantation embryos and, after embryo biopsy, to select embryos that are more likely to implant. Such studies suggest that women with recurrent miscarriage and advanced maternal age may benefit most from preimplantation genetic diagnosis with aneuploidy screening (PGD‐AS). The success of PGD‐AS is likely to be enhanced by new technologies, such as comparative genomic hybridisation, which enable full karyotyping of single cells. Copyright © 2002 John Wiley & Sons, Ltd.
First application of preimplantation genetic diagnosis to neurofibromatosis type 2 (NF2)
Authors: Abou‐Sleiman P. M. , Apessos A. , Harper J. C. , Serhal P. , Winston R. M. L. , Delhanty J. D. A. 
Published: October 2002

AbstractNeurofibromatosis type 2 (NF2) is a dominantly inherited cancer predisposition syndrome that is caused bymutations in the NF2 gene. We report here the first clinical preimplantation genetic diagnosis (PGD) forNF2. A protocol was developed to simultaneously amplify the mutation and a single nucleotide polymorphism (SNP) located within the gene. The mutation and polymorphism were analysed by simultaneous fluorescent single‐strand conformation polymorphism (SSCP) on an automated DNA sequencer. The mutation, carried by the male partner, was a single base pair substitution affecting a splice site in intron 4 of the gene. The female partner was infertile due to polycystic ovary syndrome and would require IVF to conceive. The couple was found to be informative at a linked intragenic SNP situated in the 5′ untranslated region of the gene. The SNP was included in the assay to reduce the risk of misdiagnosis due to allele dropout (ADO). The couple underwent three cycles of treatment during which a total of 43 blastomeres were biopsied from 31 embryos. Amplification at both loci was obtained in 35 cells (81%). A total of five embryos were transferred, two in the first cycle, two in the second and one in the third. No pregnancy ensued. The results of the diagnoses indicated that, in this couple, the inheritance of the mutation may be non‐Mendelian. Out of a total of 32 embryos tested only four were found not to carry the mutation. The reasons for this apparent skew remain unknown. Copyright © 2002 John Wiley & Sons, Ltd.
Prescription behaviours of office‐based doctors to standardized common cold patients in Korea
Authors: Cho H. J. , Kim C. B. 
Published: October 2002

AbstractPurposeTo investigate real pictures of prescription behaviours of office‐based doctors in Korea, especially focusing on the prescription of oral antibiotics and injections.MethodsPrescription information was collected from 18 standardized patients (SPs) with the symptoms of the common cold who visited doctors' office.ResultsFor these patients antibiotics were prescribed by 96 doctors (64.7%) out of 148 and the rate of antibiotic prescription increased with age of doctors, increasing number of medicines, and cost of medicines. Analgesics were most frequently prescribed (91.8%), and gastrointestinal drugs (81.6%), antitussivies (61.2%), antithistamines (61.2%), decongestants (59.2%), mucolytics (51.0%) and proteolytic enzymes (32.7%) followed. More than half of the doctors intended to give injections to the patients, which was higher among internists and doctors prescribed more medicines.ConclusionsAntibiotics and injections were frequently prescribed for mild common colds in Korea. Action to ensure judicious use of antibiotics and injection is urgent. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of poly(aryl ether sulfone)‐graft‐polystyrene and poly(aryl ether sulfone)‐graft‐[polystyrene‐block‐poly(methyl methacrylate)] through atom transfer radical polymerization
Authors: Xiao Guyu , Zhu Shenmin , Yan Deyue , Xu Jialian 
Published: October 2002

AbstractA new graft copolymers poly(aryl ether sulfone)‐graft‐polystyrene (PSF‐g‐PS) and poly(aryl ether sulfone)‐graft‐[polystyrene‐block‐poly(methyl methacrylate)] (PSF‐g‐(PS‐b‐PMMA)) were successfully prepared via atom transfer radical polymerisation (ATRP) catalyzed by FeCl2/isophthalic acid in N,N‐dimethyl formamide. The products were characterized by GPC, DSC, IR, TGA and NMR. The characterization data indicated that the graft copolymerization was accomplished via conventional ATRP mechanism. The effect of chloride content of the macroinitiator on the graft copolymerization was investigated. Only one glass transition temperature (Tg) was detected by DSC for the graft copolymer PSF‐g‐PS and two glass transition temperatures were observed in the DSC curve of PSF‐g‐(PS‐b‐PMMA). The presence of PSF in PSF‐b‐PS or PSF‐g‐(PS‐b‐PMMA) was found to improve thermal stabilities.© 2002 Society of Chemical Industry
Kinetic behaviour of styrene–2‐hydroxyethyl methacrylate copolymerisation in microemulsion
Authors: Sanghvi Paresh G , Pokhriyal Naveen Kumar , Devi Surekha 
Published: October 2002

AbstractThe copolymerisation of styrene and 2‐hydroxyethyl methacrylate (2‐HEMA) in a three‐component oil‐in‐water microemulsion containing sodium dodecylsulfate as emulsifier was investigated as a function of temperature and concentration of potassium persulfate or hydrogen peroxide/ascorbic acid as initiator. Stable and transparent poly(styrene–2‐HEMA) latexes were produced. The latexes were characterised for particle size and number of particles by dynamic light scattering and transmission electron microscopy. The isolated products were characterised by 1H NMR as well as by thermal analysis. The overall size of particles was observed to be in the range 22–38 nm. Attempts are made to examine the suitability of the existing mathematical models for homopolymerisation to account for the copolymerisation of styrene and 2‐HEMA.© 2002 Society of Chemical Industry
Kinetic investigations of the reactions of hindered­phenols with N‐fluoro‐1,4‐diazoniabicyclo[2.2.2]octane­salt analogues
Authors: Stavber Stojan , Jereb Marjan , Zupan Marko 
Published: October 2002

AbstractThe kinetics of reactions of hindered phenols (2,4,6‐trimethylphenol, 2,6‐di‐tert‐butyl‐4‐methylphenol and 2,4,6‐tri‐tert‐butylphenol) with 1‐fluoro‐4‐chloromethyl‐1,4‐diazoniabicyclo [2.2.2]octane bis(tetrafluoroborate) (Selectfluor™, F‐TEDA‐BF4) in acetonitrile in the absence or presence of various sources of external nucleophile (alcohols, water, trifluoroacetic acid) were studied. The reactions exhibited overall second‐order kinetics, whereas products formation was strongly dependent on reaction conditions. Fluorination took place in neat MeCN; in the presence of water or alcohols, para quinols or para quinol ethers were formed exclusively; under acidic conditions (TFA), Ritter‐type amidation was found to be the predominant process. Values for second‐order rate constants k2 were found to be dependent on the structure of the target phenol and decreased with bulkiness of the substrate. Methanol slightly increased the rate, whereas water decreased it considerably. Activation enthalpies (between 72 and 78 kJ mol−1) and activation entropies (between −5 and −42 J mol−1 K−1) were obtained. Activation entropies were found to be higher for less‐hindered substrates, indicating that the rate‐determining steps were mainly regulated by steric factors. Grunwald–Winstein correlation of log k2 with solvent ionizing power Y revealed a relatively small correlation factor m. An electron‐transfer‐type process following the rate‐determining formation of substrate–reagent complex was postulated as the key step of the reaction pathway. Copyright © 2001 John Wiley & Sons, Ltd.
Tautomerism studies of 3‐(ω‐sulphoalkylamino)benzoic acids. Substituent effects
Authors: Jesús Marcelo Nunes de , Hioka Noboru , Costa Willian Ferreira da , Maionchi Florângela 
Published: October 2002

AbstractTwo SAABA [3‐ and 4‐(ω‐sulphoalkylamino)benzoic acid] derivatives, 3‐(3‐sulphopropylamino)benzoic acid and 3‐(4‐sulphobutylamino)benzoic acid, were studied by a potentiometric method to determine two macroscopic constants (K and K) for each derivative. The combination of these values with 13C NMR spectroscopic titration data was used to determine their tautomeric (KT) microscopic constants at 25.0 °C and ionic strength 1.00 mol dm−3 (KCl). From these results, it was possible to estimate the other microscopic constants and consequently the Hammett substituent constants (σm) for two m‐aminoalkylsulphonates and the electronic effects of two alkylsulphonate substituents separately. For the m‐aminoalkylsulphonate substituents the σm values are −0.12 for m‐aminopropylsulphonate and −0.27 for m‐aminobutylsulphonate, and therefore the electron‐donating effect prevails when three methylene units are present. On the other hand, in alkylsulphonate substituents, this effect prevails only for four methylene units. Copyright © 2002 John Wiley & Sons, Ltd.
Ring‐opening polymerization of ϵ‐caprolactam and ϵ‐caprolactone via microwave irradiation
Authors: Fang Xiaomei , Simone Christopher D. , Vaccaro Eleonora , Huang Samuel J. , Scola Daniel A. 
Published: October 2002

AbstractA novel process for synthesizing nylon‐6 and poly(ϵ‐caprolactone) by microwave irradiation of the respective monomers, ϵ‐caprolactam and ϵ‐caprolactone, is described. The ring opening of ϵ‐caprolactam to produce nylon‐6 was performed in a microwave oven by the forward power being controlled to about 90–135 W in the presence of an ω‐aminocaproic acid catalyst (10 mol %) and for periods of 1–3 h at temperatures varying from 250 to 280 °C. The ring opening of ϵ‐caprolactone to produce poly(ϵ‐caprolactone) was performed in a microwave oven by the forward power being controlled to about 70–100 W for a period of 2 h in the presence of stannous octoate with and without 1,4‐butanediol over a temperature range of 150–200 °C. The yields, conditions of the reactions, and properties of the products generated relative to the thermal processes are discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2264–2275, 2002
Vinyltitanium as an initiator for the polymerization of acetylene
Authors: Takagi Yasuhiro , Saeki Naoko , Tsubouchi Akira , Murakami Hisashi , Kumagai Yoshinao , Takeda Takeshi 
Published: October 2002

AbstractThe preparation of lustrous conducting polyacetylene films by the polymerization of acetylene with vinyltitanium species as initiators was studied. Organotitanium species were generated by the alkylation of titanium vinylcarbene complexes with tert‐butyl chloride. Solid‐state 13C NMR and IR analyses of the obtained polyacetylene indicated that polyacetylene with a trans configuration was produced. The use of titanocene(II) species Cp2Ti[P(OEt)3]2 and titanium vinylcarbene complexes for the preparation of polyacetylene films was also studied. The morphology of the films and the mechanisms of polymerization are discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2663–2669, 2002
Cocrystallization in blends of random tetrafluoroethylene fluorinated copolymers: The effect of the chain structure and crystallization conditions
Authors: Pucciariello Rachele , Villani Vincenzo , Ruiz De Ballesteros Odda 
Published: October 2002

AbstractThe possibility of the cocrystallization of random fluorinated tetrafluoroethylene copolymers was investigated with differential scanning calorimetry and wide‐angle X‐ray scattering. In particular, mixtures composed of poly(tetrafluoroethylene)‐co‐(hexafluoropropylene) containing 8 or 1 mol % comonomer or poly(tetrafluoroethylene)‐co‐perfluoromethylvinylether (2–10 mol % comonomer) were examined. The extent of cocrystallization was determined by the difference in the comonomer content, being higher when the difference was lower, and it was favored when quenching from the melt state was adopted. Nevertheless, a key to determining the extent of cocrystallization was the behavior of counits with respect to inclusion or exclusion from the crystal lattice: when the components were different with respect to this behavior, they were not likely to be miscible in the crystal state even if the difference in the comonomer content was low. Moreover, the similarity in the crystallization rates between the components played an important role: the cocrystallization decreased as the difference in the crystallization rate increased until, when the difference became high enough, the blend became immiscible. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1477–1489, 2002
Effect of amino and polysiloxane groups on the chemical adsorption of polymers containing thiophosphate at the oil/metal interface under extreme pressure
Authors: Ni Sheng‐Chung , Kuo Ping‐Lin 
Published: October 2002

AbstractCopolymers that separately contained thiophosphate–polysiloxane, thiophosphate–amino, and thiophosphate–polysiloxane–amino groups were synthesized and characterized. The performances of these synthesized copolymers on metal surfaces under a high load and rotary velocity were examined by the measurement of the oil temperature, frictional coefficient, and electrical contact resistance between two metal surfaces. The configuration of the adsorption layer was studied with energy‐dispersive spectrometry (EDS) and scanning electron microscopy (SEM). Copolymers that contained amino–thiophosphate groups reduced the frictional coefficient between two metal surfaces and markedly limit the increase in the oil temperature. Notably, a higher content of polysiloxane groups in the copolymer corresponded to an increased operating time to establish the adsorption layer on the metal surface. However, a higher content of amino groups reduced the time required for the layer to form. The adsorption layers that formed on the metal surfaces were investigated by EDS as phosphides produced by a chemical reaction of the thiophosphate‐containing copolymer with the metal surface. These adsorption layers on the metal surface were directly observed with SEM. The layer that formed on the metal surface of copolymers containing less polysiloxane and more amino groups was the thickest layer for all the synthesized copolymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1795–1803, 2002
Isothermal and nonisothermal crystallization kinetics of nylon‐46
Authors: Zhang Qingxin , Zhang Zhihao , Zhang Hongfang , Mo Zhishen 
Published: October 2002

AbstractIsothermal and nonisothermal crystallization kinetics of nylon‐46 were investigated with differential scanning calorimetry. The equilibrium melting enthalpy and the equilibrium melting temperature of nylon‐46 were determined to be 155.58 J/g and 307.10 °C, respectively. The isothermal crystallization process was described by the Avrami equation. The lateral surface free energy and the end surface free energy of nylon‐46 were calculated to be 8.28 and 138.54 erg/cm2, respectively. The work of chain folding was determined to be 7.12 kcal/mol. The activation energies were determined to be 568.25 and 337.80 kJ/mol for isothermal and nonisothermal crystallization, respectively. A convenient method was applied to describe the nonisothermal crystallization kinetics of nylon‐46 by a combination of the Avrami and Ozawa equations. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1784–1793, 2002
Crystalline poly(4‐methyl‐1‐pentene): Structure and solubility of gas molecules
Authors: Zanuy David , Alemán Carlos , Muñoz‐Guerra Sebastián 
Published: October 2002

AbstractMonte Carlo (MC) simulations have been used to study the crystal structure of isotactic poly(4‐methyl‐1‐pentene). Four different tetragonal packing models, each one containing two right‐handed and two left‐handed 7/2 helices, have been considered in an investigation of the up‐and‐down chain statistical disorder proposed on the basis of X‐ray data. Simulations have been performed with the isotropic united‐atom parameterization of the AMBER force field. The influence on the more stable packing models of the force‐field parameterization has been investigated with respect to the anisotropic united‐atom and all‐atom models. Results reveal that packing consisting of two upward and two downward helices arranged at random is more stable than packing with three or four helices with the same sense. Furthermore, the fiber period length for the 7/2 helix is predicted to be 0.56 Å larger than that experimentally determined. The microstructures generated from MC simulations have been employed to study the solubility of gas molecules (He, H2, Ar, O2, CH4, and CO2) with Widom's test‐particle insertion method. Special attention has been paid to the solubility of CH4 and CO2 because experimental data are available for these penetrants, the latter being described by both spherical and explicit models. The results are in good agreement with experimental measures only when a suitable model is used for the penetrant. The solubility of gas molecules in crystalline poly(4‐methyl‐1‐pentene) has been correlated with that measured for the crystal phases of other helical polymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2037–2049, 2002
Degradation of talus‐derived rock glaciers in the Upper Engadin, Swiss Alps
Authors: Ikeda Atsushi , Matsuoka Norikazu 
Published: October 2002

AbstractActive and inactive rock glaciers differ from relict rock glaciers in the presence of subsurface permafrost, as indicated by high seismic velocity, high DC resistivity and low bottom temperature of the winter snow cover. The lack of vegetation on the frontal slope and negative mean annual surface temperatures (MAST) distinguish active rock glaciers from inactive rock glaciers. Increasing MAST induces melting of ice‐rich permafrost, which is followed by the subsidence of rock glaciers. As a result, convex‐up transverse profiles are replaced by flat or depressed profiles. Permafrost degradation inactivates rock glaciers by decreasing shear stress, within or at the base of the deforming ice/rock mixture, causing stabilization and declination of the frontal slope. Relict rock glaciers are usually associated with soil development over the surficial clasts, which is responsible for further declination of the frontal slope and a more rounded topography. Copyright © 2002 John Wiley & Sons, Ltd.
Cytokine secretion in children with acute Mycoplasma pneumoniae infection and wheeze
Authors: Esposito Susanna , Droghetti Roberta , Bosis Samantha , Claut Laura , Marchisio Paola , Principi Nicola 
Published: October 2002

AbstractThe aim of this study was to evaluate cytokine secretion in children with acute Mycoplasma pneumoniae infection and wheeze. We studied 25 patients aged 2–14 years with an acute episode of wheezing (15 with acute M. pneumoniae infection) and 16 healthy controls of similar gender and age (8 with laboratory evidence of asymptomatic acute M. pneumoniae infection). Serum interleukin (IL)‐2, interferon (IFN)‐γ, IL‐4, and IL‐5 concentrations were measured in samples obtained at enrollment, using enzyme‐linked immunosorbent assay kits.In the presence of wheezing, IL‐5 concentrations were significantly higher in subjects with acute M. pneumoniae infection (33.415 ± 22.138 pg/mL) than in those without such infection (2.320 ± 1.846 pg/mL, P < 0.0001). The children with acute M. pneumoniae infection and wheeze had higher IL‐5 concentrations (33.415±22.138 pg/mL) than those with asymptomatic acute infection and without wheeze (1.740 ± 2.299 pg/mL, P < 0.0001). No significant between‐group differences were observed in terms of IL‐2, IFN‐γ, or IL‐4 levels, or the prevalence of atopy.Our results show that children with wheezing and acute M. pneumoniae infection have a specific cytokine profile characterized by a significant increase in serum levels of IL‐5. This immune response may be important for understanding the pathophysiological mechanisms by which this pathogen contributes to the development of wheeze‐related symptoms, and for identifying new treatment strategies. Pediatr Pulmonol. 2002; 34:122–127. © 2002 Wiley‐Liss, Inc.
Peripheral blood lymphopenia and neutrophilia in children with severe respiratory syncytial virus disease
Authors: O'Donnell Diarmuid R. , Carrington David 
Published: October 2002

AbstractIt is not known why respiratory syncytial virus (RSV) is associated with prolonged sequelae in many children. Measles virus (also a paramyxovirus), acute stress in sepsis, and cardiac bypass all cause lymphopenia.Using a retrospective analysis of records of children in Bristol with RSV infections over 5 years, we found that children with RSV had lower lymphocyte counts than unstressed, stable children prior to cardiac surgery. Children who required intensive care had the lowest lymphocyte counts. Neutrophil counts were raised in RSV‐infected children.These data may offer an insight into pathological mechanisms, and suggest new research avenues. Pediatr Pulmonol. 2002; 34:128–130. © 2002 Wiley‐Liss, Inc.
Alcaligenes infection in cystic fibrosis
Authors: Tan Kenneth , Conway Steven P. , Brownlee Keith G. , Etherington Christine , Peckham Daniel G. 
Published: October 2002

AbstractThe aim of this study was to investigate the effect of chronic Alcaligenes species infection of the respiratory tract on the clinical status of patients with cystic fibrosis. We conducted a retrospective case‐controlled study. The microbiological records of all patients attending the Leeds Regional Pediatric and Adult Cystic Fibrosis Units from 1992–1999 were examined. Chronic Alcaligenes infection was defined as a positive sputum culture on at least three occasions over a 6‐month period. These patients were compared with controls matched for age, gender, respiratory function, and Pseudomonas aeruginosa infection status. Respiratory function tests, anthropometric data, Shwachman‐Kulczycki score, Northern chest x‐ray score, intravenous and nebulized antibiotic treatment, and corticosteroid treatment were compared from 2 years before to 2 years after Alcaligenes infection.From a clinic population of 557, 13 (2.3%) fulfilled the criteria for chronic infection. The median age at acquisition of infection was 17.2 years (range, 6.5–33.6). There was no significant difference in the changes of percentage predicted values for FEV1, FVC, FEF25–75, or Shwachman‐Kulczycki and Northern chest x‐ray scores, or in weight, height, and body mass index z‐scores between Alcaligenes‐infected cases and controls. There was also no significant difference in the use of antibiotics (intravenous and nebulized) or corticosteroids (inhaled and oral).We conclude that in our clinic, chronic infection with Alcaligenes species was uncommon. Chronically infected patients showed no excess deterioration in clinical or pulmonary function status from 2 years before to 2 years after primary acquisition. Pediatr Pulmonol. 2002; 34:101–104. © 2002 Wiley‐Liss, Inc.