bluuebunny/crossref_metadata_2025_split huggingface dataset:
DSC solution for flow in a staggered double lid driven cavity
Authors: Zhou Y. C. , Patnaik B. S. V. , Wan D. C. , Wei G. W. 
Published: April 2003

AbstractA benchmark quality solution is presented for flow in a staggered double lid driven cavity obtained by using the wavelet‐based discrete singular convolution (DSC). The proposed wavelet based algorithm combines local methods' flexibility and global methods' accuracy, and hence, is a promising approach for achieving the high accuracy solution of the Navier–Stokes equations. Block structured grids with pseudo‐overlapping subdomains are employed in the present simulation. A third order Runge–Kutta scheme is used for the temporal discretization. Quantitative results are presented, apart from the qualitative fluid flow patterns. The prevalence of rich features of flow morphology, such as two primary vortex patterns, merged single primary vortex patterns, and secondary eddies, makes this problem very attractive and interesting. The problem is quite challenging for the possible existence of numerically induced asymmetric flow patterns and elliptic instability. Important computational issues like consistence, convergence and reliability of the numerical scheme are examined. The DSC algorithm is tested on the single lid driven cavity flow and the Taylor problem with a closed form solution. The double lid driven cavity simulations are cross‐validated with the standard second order finite volume method. Copyright © 2003 John Wiley & Sons, Ltd.
Meshless local boundary integral equation method for 2D elastodynamic problems
Authors: Sladek J. , Sladek V. , Van Keer R. 
Published: April 2003

AbstractA new meshless method for solving transient elastodynamic boundary value problems, based on the local boundary integral equation (LBIE) method and the moving least squares approximation (MLS), is proposed in this paper. The LBIE with the MLS is applied to both transient and steady‐state (Laplace transformed) elastodynamics. Applying the MLS approximation for spatially dependent terms in the first approach, the LBIEs are transformed into a system of ordinary differential equations for nodal unknowns. This system of ordinary differential equations is solved by the Houbolt finite difference scheme. In the second formulation, the time variable is eliminated by using the Laplace transformation. Unknown Laplace transforms of displacements and traction vectors are computed from the LBIEs with the MLS approximation. The time‐dependent values are obtained by the Durbin inversion technique. Copyright © 2003 John Wiley & Sons, Ltd.
A two‐dimensional BEM/FEM coupling applied to viscoelastic analysis of composite domains
Authors: Mesquita A. D. , Coda H. B. 
Published: April 2003

AbstractA coupling between the boundary‐element and finite‐element methods is studied for the viscoelastic analysis of reinforced media. The viscous behaviour of the composed body is taken into account by an alternative BEM methodology developed for the Boltzmann model. This methodology is based on differential constitutive relations for viscoelasticity. The reinforcements are modelled by finite elements and are considered elastic. The coupling is based on the sub‐region technique due to its generality and easy implementation. The resulting time‐marching process is able to represent both the instantaneous and the time‐dependent behaviour of a body subjected to general boundary conditions. The method is validated by an experimental result and its accuracy tested by comparing numerical results with analytical solutions. The generality of the method is proved by an infinite domain application. Copyright © 2003 John Wiley & Sons, Ltd.
On the computation of design derivatives for Huber–Mises plasticity with non‐linear hardening
Authors: Wisniewski K. , Kowalczyk P. , Turska E. 
Published: April 2003

AbstractThis paper concerns design sensitivity analysis (DSA) for an elasto–plastic material, with material parameters depending on, or serving as, design variables. The considered constitutive model is Huber–Mises deviatoric plasticity with non‐linear isotropic/kinematic hardening, one which is applicable to metals.The standard radial return algorithm for linear hardening is generalized to account for non‐linear hardening functions. Two generalizations are presented; in both the non‐linearity is treated iteratively, but the iteration loop contains either a scalar equation or a group of tensorial equations. It is proven that the second formulation, which is the one used in some parallel codes, can be equivalently brought to a scalar form, more suitable for design differentiation. The design derivatives of both the algorithms are given explicitly, enabling thus calculation of the ‘explicit’ design derivative of stresses entering the global sensitivity equation.The paper addresses several issues related to the implementation and testing of the DSA module; among them the concept of verification tests, both outside and inside a FE code, as well as the data handling implied by the algorithm. The numerical tests, which are used for verification of the DSA module, are described. They shed light on (a) the accuracy of the design derivatives, by comparison with finite difference computations and (b) the effect of the finite element formulation on the design derivatives for an isochoric plastic flow. Copyright © 2003 John Wiley & Sons, Ltd.
Prenatal diagnosis of laryngeal atresia
Authors: Önderoǧlu L. , Saygan Karamürsel B. , Bulun A. , Kale G. , Tunçbilek E. 
Published: April 2003

AbstractPrenatal diagnosis of congenital atresia of the larynx is difficult but is possible by the findings of increased lung echogenicity and size coexisting with fetal ascites in ultrasonography. Sonographic findings may not always be typical. We report on a case of congenital laryngeal atresia diagnosed prenatally by the findings of fetal hydrops and hyperechogenic lungs. Our case presented with oligohydramnios. We also review syndromes that demonstrate laryngeal anomalies. Copyright © 2003 John Wiley & Sons, Ltd.
Antenatal manifestation of congenital pancreatoblastoma in a fetus with Beckwith–Wiedemann syndrome
Authors: Pelizzo Gloria , Conoscenti Giancarlo , Kalache Karim D. , Vesce Francesco , Guerrini Paolo , Cavazzini Luigi 
Published: April 2003

AbstractAn Erratum has been published for this article in Prenatal Diagnosis 23(9) 2003, 771
Antenatal detection of an isolated abdominal cyst was found to be a pancreatoblastoma in a female fetus with Beckwith–Wiedemann syndrome. Prenatal and post‐natal features and management of this very rare tumour are discussed. Molecular investigation disclosed a mosaic paternal 11p15 uniparental disomy in the tumoral cells. The prognosis of a congenital pancreatoblastoma is good if complete surgical excision is achieved. However, the association with Beckwith–Wiedemann syndrome requires a prolonged follow‐up because of the increased risk of developing malignant tumours. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of the 100‐g oral glucose tolerance test on fetal acid–base balance
Authors: Weissman Amir , Lowenstein Lior , Drugan Arie , Zimmer Etan Z. 
Published: April 2003

AbstractObjectivePrevious studies have shown that maternal hyperglycemia may lead to fetal hypoxia and acidosis. The aim of the present study was to examine the impact of an oral 100‐g glucose tolerance test on the fetal acid–base balance at mid‐gestation.MethodsThe study was conducted in healthy women who were scheduled for termination of pregnancy. The study group (n = 18) received an oral solution containing 100‐g glucose and the control group (n = 18) received only water 1 h prior to termination of pregnancy. Termination of pregnancy was performed by fetal intracardiac injection of potassium chloride (KCl) and intraamniotic instillation of PGF2α. Acid–base variables were evaluated in the fetal blood and the amniotic fluid.ResultsThe glucose levels differed significantly between the study group and the control group with regard to maternal blood (127 ± 28 versus 69 ± 11 mg/dL, p < 0.001), fetal blood (128 ± 24 versus 71 ± 17 mg/dL, p < 0.001) and amniotic fluid (39 ± 13 versus 28 ± 5 mg/dL, p < 0.006). A linear relationship was found between maternal, fetal and amniotic fluid levels of glucose after maternal glucose ingestion. No significant changes were observed in the acid–base balance variables (pH, base excess, bicarbonate, lactate) in the fetal blood and the amniotic fluid of the study and control groups.ConclusionThe 100‐g oral glucose tolerance test has no adverse effect on the fetal acid–base balance when glucose levels reach a peak 1 h after the test in normal pregnancies. Copyright © 2003 John Wiley & Sons, Ltd.
The effect of image size on nuchal translucency measurement
Authors: Edwards Andrew , Mulvey Sheila , Wallace Euan M. 
Published: April 2003

AbstractObjectivesTo assess the effect of altering image size on the absolute nuchal translucency (NT) measurement.MethodsNT was measured at three image magnifications (60%, 100% and 200%) in 120 singleton pregnancies.ResultsThe mean ± SD NT measurements were 1.52 ± 0.57 mm, 1.35 ± 0.53 mm and 1.18 ± 0.48 mm at 60%, 100% and 200% magnification, respectively (p = 0.00001).ConclusionsThe measurement of NT decreases significantly with increasing image size. Optimisation of NT as a method of screening will require agreed standardisation of image magnification. Copyright © 2003 John Wiley & Sons, Ltd.
Feasibility, accuracy and safety of chorionic villus sampling: a report of 10 741 cases
Authors: Brun Jean‐Luc , Mangione Raphaelle , Gangbo Flore , Guyon Frederic , Taine Laurence , Roux Denis , Maugey‐Laulom Brigitte , Horovitz Jacques , Saura Robert 
Published: April 2003

AbstractObjectivesTo evaluate the feasibility, accuracy and safety of chorionic villus sampling (CVS).MethodsTen thousand seven hundred and forty one singleton pregnancies at risk of chromosome abnormalities (96.3%) and gene disorders (2.8%) were referred from 1990 to 1999 to the fetal medicine unit of a teaching hospital. CVS was performed transabdominally after 11 weeks, using a modified freehand ultrasonographically guided technique by 5 operators. Fetal karyotyping was obtained using a direct method before 1995 and was completed by cell culture after 1996. Failed results, feto‐placental discrepancy and fetal loss were assessed.ResultsVilli were sampled using extra‐amniotic puncture (89.4%) and one sampling‐device insertion (92.3%). The mean weight of the specimen was 15.2 ± 6.0 mg. All attempts at sampling were successful, except eight (0.07%). The number of failed results following direct preparation, cell culture and both methods was 20 (0.19%), 23 (0.21%) and 2 (0.02%), respectively. Light maternal cell contamination occurred in less than 1% of the samplings after microscopic selection of the villi, and never interfered with the assessment of karyotyping. All 3 false‐negative results (0.03%) were recorded after direct preparation and 2 were corrected by culture. The rate of chromosomal abnormalities confined to the placenta decreased from 1.08% before 1995 to 0.73% after 1996. True fetal mosaicisms were recorded in 7 cases (0.06%). The rate of fetal loss at <28 weeks was 1.64% in all pregnancies and 1.92% when CVS was performed before 13 weeks. Advanced maternal age was the single factor significantly associated with fetal loss.ConclusionsCVS was feasible, accurate and safe in our institution, as a result of the increasing experience of the operators and the cytogeneticists. Copyright © 2003 John Wiley & Sons, Ltd.
Detection of trisomy 21 by quantitative fluorescent–polymerase chain reaction in uncultured amniocytes
Authors: Solassol Jérôme , Rahil Haíssam , Sapin Vincent , Lemery Didier , Dastugue Bernard , Boespflug‐Tanguy Odile , Creveaux Isabelle 
Published: April 2003

AbstractPrenatal diagnosis of fetal trisomy 21 is usually performed by cytogenetic analysis. This requires lengthy laboratory procedures, high costs and is unsuitable for large‐scale screening of pregnant women. Today, trisomy 21 can be rapidly diagnosed within 24 h by molecular analysis of uncultured fetal cells using the semi‐quantification of fluorescent PCR products from short tandem repeat (STR) polymorphic markers. The aim of our study was to test a chromosome quantification method on the basis of the analysis of fluorescent PCR products derived from non‐polymorphic target genes. Co‐amplification of a portion of DSCR1 (Down syndrome Critical Region 1) and the reference gene, CFTR (cystic fibrosis transmembrane regulator) enabled molecular detection of trisomy 21. Our method was successfully tested on a total of 154 amniotic fluids in a blind prospective study. Calculation of the DSCR1/CFTR ratio allowed us to distinguish between 152 normal amniotic fluids (mean ratio 0.99) and 2 amniotic fluids presenting a trisomy 21 status (DSCR1/CFTR ratio of 1.53 and 1.61, respectively). The results obtained by conventional cytogenetic analysis and our quantitative PCR method were concordant in every case. Our gene‐based fluorescent PCR approach represents an alternative molecular method for rapid and reliable detection of trisomy 21, which can be helpful in the prenatal diagnosis of women at high risk of fetal trisomy 21. Copyright © 2003 John Wiley & Sons, Ltd.
Unusual case of a fetus with congenital cystic adenomatoid malformation of the lung associated with trisomy 13
Authors: Heling Kai‐Sven , Tennstedt Cornelia , Chaoui R. 
Published: April 2003

AbstractCongenital cystic adenomatoid malformation of the lung can be detected with antenatal ultrasound as hyperechogenic areas in the fetal chest. Associated extrapulmonary malformations as well as chromosomal aberrations are described as very rare.We present a case report of a fetus in the 23rd week of gestation who showed in the course of a routine ultrasound screening a large number of malformations: holoprosencephaly, arrhinencephaly, cleft palate, CCAM type III of the right inferior pulmonary lobe, ventricular septal defect and bilateral clubfeet. Chromosome analysis confirmed the suspicion of trisomy 13.The present case shows how important it is—even with malformations that are rarely accompanied by associated anomalies and which have a very good prognosis—to carry out a directed diagnosis including a fetal karyotyping. Copyright © 2003 John Wiley & Sons, Ltd.
Association between prenatal sonographic findings and post‐natal outcomes in 30 cases of isolated spina bifida aperta
Authors: Peralta Cleisson Fábio A. , Bunduki Victor , Plese José Píndaro P. , Figueiredo Eberval Gadelha , Miguelez Javier , Zugaib Marcelo 
Published: April 2003

AbstractThis study presents 30 cases of fetal isolated spina bifida aperta (SBA) to identify prenatal ultrasound findings that could predict the prognosis. Comparisons between surviving patients who had normal (group 1) and abnormal (group 2) post‐natal neurological outcomes were made for three different prenatal signs, that is, site of vertebral lesion, presence and degree of ventriculomegaly and presence of talipes. The site of the lesion was the most significant outcome predictor, as high spinal dysraphisms were observed in 2 patients (2/7–28.6%) in group 1 and in 15 patients (15/19–79.0%) in group 2 (p = 0.03). The presence of fetal ventriculomegaly was associated with impaired post‐natal neurological development, as it occurred in 4 patients (4/7–57.1%) in group 1 and in 18 patients (18/19–94.7%) in group 2 (p = 0.04). The presence of talipes did not significantly differ between the two groups. Patients with abnormal intellectual outcome (8/26–30.8%) had significantly greater (p = 0.018) lateral ventricle/hemisphere ratios (mean = 0.74, standard deviation = 0.13) than those with normal intellectual development (mean = 0.54, standard deviation = 0.18). Mean post‐natal follow‐up was at 23 months (standard deviation = 15 months). Copyright © 2003 John Wiley & Sons, Ltd.
Correlation between biomagnetic and Doppler findings of umbilical artery in fetal growth restriction
Authors: Kotini A. , Avgidou K. , Koutlaki N. , Sigalas J. , Anninos P. , Anastasiadis P. 
Published: April 2003

AbstractObjectiveTo assess the value of biomagnetic recordings of the umbilical artery over Doppler ultrasound screening in order to predict complications of impaired uteroplacental blood flow in fetuses with intrauterine growth restriction (IUGR).MethodsOur study population included 11 IUGR preeclamptic (34–37‐weeks gestation; birth weight 1969 ± 129 g) and 19 normal pregnancies (34–37‐weeks gestation; birth weight 3195 ± 229 g). Umbilical artery Doppler ultrasound waveform measurements were expressed in terms of pulsatility index (PI). Biomagnetic signals (waveforms) recorded from the IUGR umbilical artery were expressed in terms of magnetic power spectral amplitudes.ResultsIn all cases, the frequency band considered was 2 to 7 Hz. The spectral amplitudes were low (mean: 117±24 fT/√Hz) in most (90.9%) IUGR pregnancies and high (mean: 224±37 fT/√Hz) in most normal pregnancies (89.5%). There was a statistically significant difference between normal and IUGR pregnancies with respect to spectral amplitudes (p < 0.0001), Doppler PI (p < 0.0005), pH (p < 0.0005) and Apgar score (p < 0.0005). Multiple linear regression analysis revealed an influence of PI, pH and Apgar scores on the biomagnetic values (ANOVA: p < 0.0005).ConclusionOur data imply that biomagnetic values of the umbilical artery flow could prove to be a helpful method for the evaluation of fetal well being especially in pregnancies complicated with preeclampsia and growth restriction. Copyright © 2003 John Wiley & Sons, Ltd.
A new approach to antenatal screening for Fragile X syndrome
Authors: Wald N. J. , Morris J. K. 
Published: April 2003

AbstractObjectivesTo describe a new approach to antenatal screening for Fragile X syndrome and to evaluate its effectiveness.MethodsWe propose that Fragile X syndrome should be considered as a different disorder in males and in females. We also propose that only male Fragile X syndrome should be screened for, so the initial screening test would be the determination of fetal sex. This can now be performed from eight‐weeks gestation using a polymerase chain reaction (PCR) analysis on maternal serum. If this test reveals a male fetus, then the same blood sample can be used to determine the CGG repeat length in the DNA of the mother, again using the PCR technique and a Southern blot analysis where necessary. Mothers with positive results (>58 repeats) would be offered antenatal diagnosis (chorionic villus sampling or amniocentesis) to determine the CGG repeat length in cells from the fetus. The screening performance of this strategy was determined using the performance of the component tests.ResultsThe proposed strategy for screening for male Fragile X syndrome would have a 99% detection rate and a 0.1% false‐positive rate.ConclusionAfter antenatal screening for Down syndrome, the proposed screening strategy would be the most effective method of preventing the birth of males with severe mental retardation. It would have a higher detection rate and a lower false‐positive rate than any other antenatal screening programme currently being undertaken, and there would be virtually no prenatal diagnosis of female Fragile X syndrome, which, because such a high proportion are phenotypically normal, has been a barrier to the introduction of screening. Copyright © 2003 John Wiley & Sons, Ltd.
False‐positive diagnosis of trisomy 21 using fluorescence in situ hybridisation (FISH) on uncultured amniotic fluid cells
Authors: George Alice M. , Oei Paul , Winship Ingrid 
Published: April 2003

AbstractAn amniocentesis was performed on a 22‐week pregnancy following the detection of foetal abnormalities on ultrasound. A rapid aneuploid screen using fluorescence in situ hybridisation on uncultured amniotic fluid cells revealed 3 signals for chromosome 21, consistent with trisomy 21. In situ metaphase cultures revealed a 46,XY normal male karyotype. These discordant results may be explained by a sub‐standard batch of the commercially available probe or alternatively, a very specific variation within the sample interacting with the probe. Alternative strategies are proposed in order to safeguard against inappropriate clinical action as a consequence of discordant results. Copyright © 2003 John Wiley & Sons, Ltd.
Integrated ultrasound and biochemical screening for trisomy 21 using fetal nuchal translucency, absent fetal nasal bone, free β‐hCG and PAPP‐A at 11 to 14 weeks
Authors: Cicero Simona , Bindra Renu , Rembouskos Georgios , Spencer Kevin , Nicolaides Kypros H. 
Published: April 2003

AbstractBackgroundScreening for trisomy 21 by a combination of maternal age, fetal nuchal translucency (NT) thickness and maternal serum free β‐hCG and pregnancy‐associated plasma protein‐A (PAPP‐A) at 11 to 14 weeks of gestation is associated with a detection rate of 90% for a false‐positive rate of 5%. Recent evidence suggests that in about 70% of fetuses with trisomy 21, the nasal bone is not visible at the 11th‐ to 14th‐week scan (Cicero et al., 2001). The aim of this study was to examine whether fetal NT thickness and the level of maternal serum biochemical markers is independent of the presence or absence of the nasal bone, and to estimate the performance of a screening test that integrates the two sonographic and the two biochemical markers.MethodsThis was a retrospective case‐control study comprising 100 trisomy 21 and 400 chromosomally normal singleton pregnancies at 11 to 14 weeks of gestation. Ultrasound examination was carried out for measurement of fetal NT and assessment of the presence or absence of the fetal nasal bone. Maternal serum free β‐hCG and PAPP‐A were measured using the Kryptor rapid random‐access immunoassay analyser (Brahms Diagnostica GmbH, Berlin). The distribution of fetal NT, maternal serum free β‐hCG and PAPP‐A in trisomy 21 fetuses with absent and present nasal bone was examined.ResultsThe nasal bone was absent in 69 and present in 31 of the trisomy 21 fetuses. There were no significant differences in median maternal age, median gestational age, NT delta, free β‐hCG MoM and PAPP‐A MoM in trisomy 21 fetuses with and without a visible nasal bone. For a false‐positive rate of 5%, it was estimated that screening with the four markers in combination with maternal age would be associated with a detection rate of 97%. For a false‐positive rate of 0.5%, the detection rate was 90.5%.ConclusionsAn integrated sonographic and biochemical test at 11 to 14 weeks can potentially identify about 90% of trisomy 21 fetuses for a false‐positive rate of 0.5%. Copyright © 2003 John Wiley & Sons, Ltd.
Fetoplacental discrepancy involving structural abnormalities of chromosome 8 detected by prenatal diagnosis
Authors: Soler Anna , Sánchez Aurora , Carrió Ana , Badenas Cèlia , Milà Montserrat , Borrell Antoni 
Published: April 2003

AbstractWe describe the finding of three cell lines involving different structural abnormalities of chromosome 8 detected in a prenatal diagnosis. Chorionic villi sampling (CVS) was performed on a pregnant woman because of advanced maternal age. Semidirect cytogenetic analysis showed a mos46,XX,i(8q)/46,XX,del(8)(p11.2) karyotype, confirmed by fluorescence in situ hybridization (FISH). Amniocentesis was subsequently performed, and the karyotype obtained was 46,XX,dup(8)(p23p11.2). The pregnancy was terminated; pathologic findings included clubfeet, clenched left hand, subcutaneous edema and bilateral hydrocephalus. Molecular studies using chromosome 8 microsatellites performed on parents' blood and fetal tissues revealed a maternal meiotic origin of the inv dup(8p) with deletion of the distal p23 region and duplication of the remaining 8p. We propose a model to explain the cytogenetic findings, which includes a first maternal meiotic error giving rise to a large dicentric isochromosome 8 present in the ovum, a second error in one of the first zygote divisions with misdivision of the dicentric 8 giving rise to a cell line with del(8p) confined to the trophoblast and another cell line with inv dup(8p) confined to the fetal tissue and a third error in the trophoblast giving rise to a further cell line with isochromosome 8q. Copyright © 2003 John Wiley & Sons, Ltd.