bluuebunny/crossref_metadata_2025_split huggingface dataset:
A note on the robust control of Markov jump linear uncertain systems
Authors: de Farias D. P. , Geromel J. C. , do Val J. B. R. 
Published: August 2002

AbstractThis note addresses a robust control problem of continuous‐time jump linear Markovian systems subject to norm‐bounded parametric uncertainties. The problem is expressed in terms of a H∞ control problem as in the purely deterministic case. The present formulation is simpler and it contains previous results in the literature as particular cases. Robust state feedback controllers are parameterized by means of a set of linear matrix inequalities. The result is illustrated by solving some examples numerically. Copyright © 2002 John Wiley & Sons, Ltd.
Grafting of hyperbranched poly(amidoamine) onto carbon black surfaces using dendrimer synthesis methodology
Authors: Tsubokawa Norio , Satoh Toshiya , Murota Masamichi , Sato Shimpei , Shimizu Hiroshi 
Published: August 2002

AbstractTo modify carbon black surface, the surface grafting of hyperbranched poly(amidoamine) onto the surface by using dendrimer synthesis methodology was investigated. Carbon black having amino groups (initiator sites) was prepared by the reduction of surface nitro groups introduced by nitration of aromatic rings. It was found that hyperbranched poly(amidoamine) was propagated from carbon black surface by repeating two processes: (1) Michael addition of methyl acrylate (MA) to surface amino groups and (2) amidation of the resulting esters with ethylenediamine: the percentage of poly(amidoamine) grafting reached to 96.2% after 10th‐generation. The grafting of hyperbranched poly(amidoamine) onto polystyrene‐bead as a model compound of carbon black was also achieved by the above procedures. However, the theoretical propagation of poly(amidoamine) dendrimer was not achieved, because of steric hindrance of grafted polymer. Hyperbranched poly(amidoamine)‐grafted carbon black gave a stable dispersion in a good solvent for poly(amidoamine). Copyright © 2001 John Wiley & Sons, Ltd.
The first trimester ‘combined test’ for the detection of Down syndrome pregnancies in 4939 unselected pregnancies
Authors: Schuchter K. , Hafner E. , Stangl G. , Metzenbauer M. , Höfinger D. , Philipp K. 
Published: August 2002

AbstractThe high detection rate (DR) for Down syndrome (DS) pregnancies which can be achieved by measuring fetal nuchal translucency (NT) early in pregnancy can be improved by combining it with placental hormones [pregnancy‐associated plasma protein A (PAPP‐A) and free β‐human chorionic gonadotrophin (fβ‐hCG)] and maternal age (‘combined test’). In this study we wanted to assess the DR using the ‘combined test’ in an unselected population of self‐referred pregnant women at a false‐positive rate (FPR) of about 5%. NT, PAPP‐A, fβ‐hCG and maternal age were measured in all women with singleton pregnancies who booked for delivery in our hospital from 1 December 1997 to 31 April 2000 and who were between 10 and 13 completed weeks of gestation [crown–rump length (CRL) 35–70 mm]. The specific DS risk was calculated using the computer program Alpha Version 5aa (Logical Medical Systems, London, UK). A total of 4939 women were tested. Out of 14 DS pregnancies that occurred during this period of time, 12 were detected with the test. A total of 246 women had a false‐positive test result in a non‐DS pregnancy (FPR 5.0%). This makes the ‘combined test’ by far the best test for the detection of DS pregnancies in a low‐risk population. The constant increase in maternal age at the time of delivery can also lead to an improved DR if a simple age‐dependant protocol for DS detection is used, but only at the price of a much higher number of amniocenteses and subsequent abortions. The DR for DS can be increased much more markedly using the ‘combined test’ with a FPR that still remains at the level as it was in the early 1970s. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal diagnosis of partial monosomy 18p(18p11.2→pter) and trisomy 21q(21q22.3→qter) with alobar holoprosencephaly and premaxillary agenesis
Authors: Chen Chih‐Ping , Chern Schu‐Rern , Wang Wayseen , Lee Chen‐Chi , Chen Wen‐Lin , Chen Li‐Feng , Chang Tung‐Yao , Tzen Chin‐Yuan 
Published: August 2002

AbstractA prenatal diagnosis of partial monosomy 18p(18p11.2→pter) and trisomy 21q(21q22.3→qter) in a fetus with alobar holoprosencephaly (HPE) and premaxillary agenesis (PMA) but without the classical Down syndrome phenotype is reported. A 27‐year‐old primigravida woman was referred for genetic counselling at 21 weeks' gestation due to sonographic findings of craniofacial abnormalities. Level II ultrasonograms manifested alobar HPE and median orofacial cleft. Cytogenetic analysis and fluorescence in situ hybridization (FISH) on cells obtained from amniocentesis revealed partial monosomy 18p and a cryptic duplication of 21q,46,XY,der(18)t(18;21)(p11.2;q22.3), resulting from a maternal t(18;21) reciprocal translocation. The breakpoints were ascertained by molecular genetic analysis. The pregnancy was terminated. Autopsy showed alobar HPE with PMA, pituitary dysplasia, clinodactyly and classical 18p deletion phenotype but without the presence of major typical phenotypic features of Down syndrome. The phenotype of this antenatally diagnosed case is compared with those observed in six previously reported cases with monosomy 18p due to 18;21 translocation. The present study is the first report of concomitant deletion of HPE critical region of chromosome 18p11.3 and cryptic duplication of a small segment of distal chromosome 21q22.3 outside Down syndrome critical region. The present study shows that cytogenetic analyses are important in detecting chromosomal aberrations in pregnancies with prenatally detected craniofacial abnormalities, and adjunctive molecular investigations are useful in elucidating the genetic pathogenesis of dysmorphism. Copyright © 2001 John Wiley & Sons, Ltd.
Troglitazone (Rezulin) and hepatic injury
Authors: Faich Gerald A. , Moseley Richard H. 
Published: August 2002

AbstractPurposeAnalyze US rates of reported severe liver disease for the oral hypoglycemic agent troglitazone from March 1997 through February 2000 and the possible effects of publicity on reporting.MethodsThe number of troglitazone reports with liver failure and or hospitalization with jaundice or hyperbilirubinemia, made to the FDA and/or Parke‐Davis are used as numerators. The denominators are numbers of patients and person‐time estimates of exposure. Additionally, the amount of publicity about troglitazone during its marketing is quantified.ResultsApproximately 1.92 million patients were treated with troglitazone from March 1997 through the end of February 2000 resulting in 1.6 million person‐years of exposure. Reports of 83 cases of liver failure associated with troglitazone were received (1 in 23 000 patients or 1 in 20 000 person‐years). Of the 83 cases, only 49 (59%) were classified by a hepatologist to be ‘possibly’ or ‘probably’ attributed to troglitazone. For the first, second, and third years of marketing, rates of reported hepatic failure per 100 000 person years exposure to troglitazone were 8.3, 5.3, and 2.7 respectively. Rates of reported liver disease involving hospitalizations with mention of jaundice and hyperbilirubinemia per 100 000 person‐years were 16.0, 6.1, and 3.6 respectively for these years. During the 3‐year marketing history of troglitazone, there were 470 lay press and 158 medical literature articles with mentions of hepatotoxicity for the drug.ConclusionsRates of reported severe liver disease declined substantially during the second and third years of marketing of troglitazone. The decline followed increasingly stringent requirements for liver function test monitoring and may have been due to improved patient selection and management as a result of the widely publicized association between troglitazone and hepatotoxicity. Copyright © 2001 John Wiley & Sons, Ltd.
Electrochemically stimulated 2‐ethylhexyl phosphate (EHP) release through redox switching of conducting polypyrrole film and polypyrrole/poly (N‐methylpyrrole) or self‐doped polyaniline bilayers
Authors: Massoumi Bakhshali , Entezami Ali Akbar 
Published: August 2002

Abstract2‐Ethylhexyl phosphate (EHP) released from poly(pyrrole 2‐ethylhexyl phosphate) (PP‐EHP) was investigated at open circuit and compared with electrochemically stimulated release during potential cycling. It was found that the fast EHP release from the PP‐EHP single layer is substantially retarded and that amounts of spontaneously and electrochemically released EHP can be reduced by constructing bilayers, consisting of a PP‐EHP inner layer and a poly(N‐methylpyrrole)‐poly(styrene sulfonate) (PNMP‐PSS) or self‐doped poly(aniline) sulfonate (SPANI) as the outer films. The presence of outer film over the PP‐EHP allowed surface‐property modification, as well as the control of the rate of EHP release, while electrochemically stimulated EHP release from inner films was not substantially hampered by the outer layer. The quantity of the EHP released was investigated using UV‐vis spectrophotometery and an electrochemical quartz‐crystal microbalance (EQCM) during reduction of PP‐EHP from single layer and bilayers through electrochemical stimulation. EHP was reincorporated to the inner film by applying an anodic potential and then the release of EHP was performed again. The results showed that the outer film could act as a barrier to ion‐and solvent‐transport between the inner film and electrolyte, yielding a more balanced counter‐directional movement of anions.© 2002 Society of Chemical Industry
Observing collaborative problem‐solving processes and outcomes
Authors: Wilczenski Felicia L. , Bontrager Terry , Ventrone Paula , Correia Margaret 
Published: August 2002

AbstractThis study examined the problem of assessing group process in a collaborative problem‐solving situation. Students in seven collaborative groups worked on a two‐part math and logic problem—first individually, then in groups, and finally, individually again. Groups engaging in behaviors that facilitated collaboration obtained higher group and individual accuracy scores on a challenging problem set. High‐achieving students were influential in group problem‐solving outcomes. Group scores did not reflect the individual achievement of low‐achieving students. Examining collaborative group process and outcomes offers a new direction in functional and contextualized assessment for school psychologists. © 2001 John Wiley & Sons, Inc.
Probing the influence of stereoelectronic effects on lithium affinity in 1,3‐ and 1,4‐dioxa systems
Authors: Ganguly Bishwajit , Fuchs Benzion 
Published: August 2002

AbstractA combined computational and structural study of the lithium affinity (LA) of O—C—O systems exhibiting the anomeric effect and of O— C—C—O systems exhibiting the gauche effect is presented. QM ab initio calculations using the MP2/6–31G* basis set were carried out on the gas‐phase lithium affinities of dimethoxymethane (DMOM), dimethoxyethane (DMOE), 1,3‐dioxane (DOX) and cis‐ and trans‐tetraoxadecalin (TOD), along with that of dimethyl ether and of its dimer as reference compounds. Structural parameters were retrieved from the Cambridge Structural Database (CSD) for diethyl ether dimer and O—C—C—O lithium complexes and these agreed well with the calculated data. The computed lithium affinities of dimethoxymethane and dimethoxyethane were found to be conformationally dependent. The LAs are conformationally dependent (wherever applicable) and decrease in the order: (Me2O)2 > DMOE > DMOM > DOD > DOX > trans‐TOD, but cis‐TOD restores the high LA (better than DMOE) by virtue of multiple coordination. Copyright © 2001 John Wiley & Sons, Ltd.
Preparation and properties of novel polyimides derived from 4‐aryl‐2,6 bis(4‐amino phenyl)pyridine
Authors: Tamami Bahman , Yeganeh Hamid 
Published: August 2002

AbstractTo prepare novel polyimides with enhanced thermal stability and high solubility in common organic solvents, diamine monomers, 4‐aryl‐2,6 bis‐(4‐amino phenyl)pyridine, were introduced. The diamines were reacted with three different conventional aromatic dianhydrides including pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, and hexafluoroisopropylidene‐2,2‐bis(phthalic‐dianhydride) (6FDA) in dimethylacetamide solvent to obtain the corresponding polyimides via the polyamic acid precursors and chemical imidization. The monomers and polymers were characterized by Fourier transform infrared spectroscopy, 1H NMR, mass spectroscopy, and elemental analysis; and the best condition of polymerization and imidization were obtained via the study of model compound. The polyimides showed little or no weight loss by thermogravimetric analysis up to 500 °C, and those derived from 6FDA exhibited good solubility in various polar solvents. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3826–3831, 2001
Free‐radical copolymerization of 3‐phthalimido‐2‐hydroxypropyl methacrylate with styrene: The determination of monomer reactivity ratios and thermal analysis studies
Authors: Coşkun M. Fatih , Demirelli Kadir , Güzel Dilek , Coşkun Mehmet 
Published: August 2002

AbstractFree‐radical copolymerizations of styrene and phthalimido‐2‐hydroxypropyl methacrylate (PHPMA) were carried out at 60 °C in a 1,4‐dioxane solution in the presence of 2,2′‐azobisisobutyronitrile at low conversions (<15%). The copolymer compositions were established by elemental analysis. The monomer reactivity ratios r1 (PHPMA) and r2 (styrene) were determined with the linearized copolymerization equations of the Kelen–Tüdös and inverted Fineman–Ross methods and with the nonlinear relationship of the Mayo–Lewis method to be r1 = 1.41 and r2 = 0.24, r1 = 1.52 and r2 = 0.26, and r1 = 1.15 and r2 = 0.16, respectively. The monomer reactivity ratios and glass‐transition temperatures of the copolymers as functions of the copolymer composition are discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 650–658, 2002; DOI 10.1002/pola.10140
Effect of the structure of amphiphilic poly(ethylene glycol)‐containing graft copolymers on styrene emulsion polymerization
Authors: Chern Chorng‐Shyan , Lee Cheng 
Published: August 2002

AbstractAmphiphilic graft copolymers consisting of monomeric units of poly(ethylene glycol) monomethyl ether acrylate, lauryl or stearyl methacrylate, and 2‐hydroxyethyl methacrylate were synthesized and characterized. The effectiveness of these poly(ethylene glycol)‐containing graft copolymers in stabilizing styrene emulsion polymerization was evaluated. The polymerization rate (Rp) increases with increasing graft copolymer concentration, initiator concentration, or temperature. At a constant graft copolymer concentration, Rp increases, and the amount of coagulum decreases with the increasing hydrophilicity of graft copolymers. The polymerization system does not follow Smith–Ewart case II kinetics. The desorption of free radicals out of latex particles plays an important role in the polymerization kinetics. The overall activation energy and the activation energy for the radical desorption process are 85.4 and 34.3 kJ/mol, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1608–1624, 2002
Radical and cationic polymerizations of 3‐ethyl‐3‐methacryloyloxymethyloxetane
Authors: Sato Tsuneyuki , Oki Takayuki , Seno Makiko , Hirano Tomohiro 
Published: August 2002

Abstract3‐Ethyl‐3‐methacryloyloxymethyloxetane (EMO) was easily polymerized by dimethyl 2,2′‐azobisisobutyrate (MAIB) as the radical initiator through the opening of the vinyl group. The initial polymerization rate (Rp) at 50 °C in benzene was given by Rp = k[MAIB]0.55 [EMO]1.2. The overall activation energy of the polymerization was estimated to be 87 kJ/mol. The number‐average molecular weight (M̄n) of the resulting poly(EMO)s was in the range of 1–3.3 × 105. The polymerization system was found to involve electron spin resonance (ESR) observable propagating poly(EMO) radicals under practical polymerization conditions. ESR‐determined rate constants of propagation (kp) and termination (kt) at 60 °C are 120 and 2.41 × 105 L/mol s, respectively—much lower than those of the usual methacrylate esters such as methyl methacrylate and glycidyl methacrylate. The radical copolymerization of EMO (M1) with styrene (M2) at 60 °C gave the following copolymerization parameters: r1 = 0.53, r2 = 0.43, Q1 = 0.87, and e1 = +0.42. EMO was also observed to be polymerized by BF3OEt2 as the cationic initiator through the opening of the oxetane ring. The M̄n of the resulting polymer was in the range of 650–3100. The cationic polymerization of radically formed poly(EMO) provided a crosslinked polymer showing distinguishably different thermal behaviors from those of the radical and cationic poly(EMO)s. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1269–1279, 2001
Synthesis of new photoresponsive polyesters containing norbornadiene residues by the polyaddition of donor–acceptor norbornadiene dicarboxylic acid diglycidyl ester with dicarboxylic acids and their photochemical properties
Authors: Konno Yousuke , Kameyama Atsushi , Nishikubo Tadatomi , Nagai Takabumi 
Published: August 2002

AbstractA donor–acceptor norbornadiene derivative, 5‐(4‐methoxyphenyl)‐1,4,6,7,7‐pentamethyl‐2,5‐norbornadiene‐2,3‐dicarboxylic acid diglycidyl ester (D–A NDGE), was synthesized by the reaction of the cesium salt of 5‐(4‐methoxyphenyl)‐1,4,6,7,7‐pentamethyl‐2,5‐norbornadiene‐2,3‐dicarboxylic acid with epibromohydrin in N‐methyl‐ pyrrolidone (NMP). The polyaddition reactions of D–A NDGE with certain dicarboxylic acids were carried out with tetrabutylammonium bromide as a catalyst in NMP, producing corresponding polyesters containing D–A norbornadiene (NBD) residues in the main chain in fair to good yields. The photoisomerization of the D–A NBD residues in the polyesters proceeded very smoothly, forming the corresponding quadricyclane groups. The photoreactivities of the D–A NBD residues in the polymer were 50 times higher than those of the NBD residues in the film state and 60 times higher than those in a tetrahydrofuran solution. The stored energy in the quadricyclane groups of the polymers was about 45–55 kJ/mol according to differential scanning calorimetry analysis of the irradiated polymer films. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2683–2690, 2001
Morphology and crystallization kinetics of dilute binary blends of two monodisperse n‐alkanes with a length ratio of two
Authors: Hosier I. L. , Bassett D. C. 
Published: August 2002

AbstractThe crystallization kinetics and morphologies of dilute binary blends of the monodisperse alkane n‐C122H246 in n‐C246H494 and vice versa have been investigated. With a molecular length ratio close to two, this pair of n‐alkanes does not produce permanent cilia when once‐folded C246H494 molecules cocrystallize with extended chains of C122H246. In this condition, the supplementary splaying of adjacent dominant lamellae and the consequently more spherulitic textures, which are present in previous blends for which a longer guest molecule gives permanent cilia, are absent, although other features of blend crystallization remain. Specifically, the isothermal radial growth rate is constant for cocrystallizing blends, although less than for their pure hosts, but becomes nonlinear with cellulation when C122H246 forms a segregated population within extended‐chain C246H494. Increased nucleation in the blends give smaller scale textures than for the host materials, but the presence of a second component reduces splaying and thereby disfavors spherulitic growth. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2874–2887, 2001
Rubbing‐induced molecular alignment and its relaxation in polystyrene thin films
Authors: Tsang O. C. , Xie Fengchao , Tsui O. K. C. , Yang Z. , Zhang Jianmin , Shen Deyan , Yang Xiaozhen 
Published: August 2002

AbstractRubbing‐induced molecular alignment and its relaxation in polystyrene (PS) thin films are studied with optical birefringence. A novel relaxation of the alignment is observed that is distinctly different from the known relaxation processes of PS. First, it is not the Kohlrausch–Williams–Watts type but instead is characterized by two single exponentials plus a temperature‐dependent constant. At temperatures several degrees or more below the glass‐transition temperature (Tg), the relaxation time falls between that of the α and β relaxations. Second, the decay time constants are the same within 40% for PS with weight‐average molecular weights (Mw's) of 13,700–550,000 Da at temperatures well below the sample Tg's, indicating that the molecular relaxations involved are mostly local within the entanglement distance. Nonetheless, the temperature at which the rubbing‐induced molecular alignment disappears (T0) exhibits a strong Mw dependence and closely approximates the Tg of the sample. Furthermore, T0 depends notably on the thickness of the polymer in much the same way as previously found for the Tg of supported PS films. This suggests that the α process becomes dominant near Tg. Preliminary spectroscopic studies in the mid‐infrared range show a significant degree of bending of the phenyl ring toward the sample surface, with the CC bond connecting the phenyl ring and the main chain tends to lie along the rubbing direction, which indicates that the relaxation is connected with the reorientation of this CC bond. We exclude the observed relaxation, as predominantly a near‐surface one, because detailed studies on the effects of rubbing conditions on the degree of molecular alignment indicate that the alignment is not local to the polymer–air surface. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2906–2914, 2001
Predictors of affective responses of mothers and fathers of children with cancer
Authors: Frank Natalie C. , Brown Ronald T. , Blount Ronald L. , Bunke Victoria 
Published: August 2002

AbstractWe investigated predictors of affective responses for 125 parents (77 mothers, 48 fathers) of children with various types of cancer who varied in time of diagnosis from newly diagnosed to 13 years following cancer treatment. The primary rationale of the investigation was to determine whether cognitive appraisals, perceived social supports, and caregivers' perceptions of children's behavior would predict affective responses differentially for mothers and fathers. We defined affectivity as self‐reported depressive symptoms, and state and trait anxiety symptoms. Parents did not differ on any of the variables, including affective responses, although differential predictors of affective responses were revealed for mothers and fathers. Affiliation‐related attributions were associated with affective responses for mothers, and achievement‐related attributions and perceived social support were associated with affective responses for fathers. Copyright © 2001 John Wiley & Sons, Ltd.
Stratified scree in the Central Spanish Pyrenees: palaeoenvironmental implications
Authors: García‐Ruiz J. M. , Valero‐Garcés B. , González‐Sampériz P. , Lorente A. , Martí‐Bono C. , Beguería S. , Edwards L. 
Published: August 2002

AbstractSedimentological, geomorphological and palynological study of three stratified screes from two environments in the central Spanish Pyrenees allows reconstruction of climate and vegetational change since the last glacial maximum. In both localities (at 700 and 1000 m a.s.l.) the deposits show a similar stratigraphy: (i) a basal stratified scree, in one case fossilized by speleothems; (ii) a palaeosol, with abundant charcoal and evidence of human activity; and (iii) a massive coarse scree. The stratified scree developed during the glacial maximum and late glacial. A humid period during the early Holocene was characterized by speleothem formation and carbonate cementation in some screes. Forest fires around 3300 BP were widespread in the Pyrenees and were probably related to human impact. Recent scree reactivation due to an increase in clast supply is limited to cold stages during the late Holocene. Copyright © 2001 John Wiley & Sons, Ltd.