bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peri‐ and intraventricular cerebral sonography in second‐ and third‐trimester high‐risk fetuses: a comparison with neonatal ultrasound and relation to neurological development
Authors: van Gelder‐Hasker M. R. , van Wezel‐Meijler G. , de Groot L. , van Geijn H. P. , de Vries J. I. P. 
Published: August 2003

AbstractObjectivesTo determine whether periventricular leukomalacia (PVL) and peri‐ and intraventricular hemorrhages can be detected in fetuses at risk for preterm birth and to establish the clinical significance of this finding.MethodsPrenatal cerebral sonography was performed in 26 fetuses at risk for uteroplacental insufficiency on the day of inclusion into the study and weekly until delivery. Neonatal cerebral ultrasound examination was performed within 24 h of birth and biweekly until discharge. The infants underwent standardized neurological examinations.ResultsDuring 30 observations, 21/26 fetuses presented in a cephalic position. Successful visualization in the coronal and sagittal planes was significantly correlated with that of a control population (r = 0.615; 95% CI, 0.390–0.771). In 20/21 fetuses at least one observation was adequate for analysis. Eleven cerebral abnormalities were found in nine fetuses, periventricular echodensities in four, intraventricular hemorrhage in two, and localized thalamic densities in five. In six of these infants ultrasound abnormalities persisted after birth. Neurological follow‐up at 24 months demonstrated abnormalities in three infants, two infants were normal and one was lost to follow‐up. The three infants with normal ultrasound results after birth had a normal follow‐up. Five infants with normal antenatal ultrasound results showed ultrasound abnormalities during the neonatal period; four of them developed PVL Grade 1 and one developed PVL Grade 2. The follow‐up of two of these infants was normal, two died and one developed spastic tetraplegia. Abnormal antenatal brain sonography was significantly correlated with gestational age at birth (r = 0.487; P = 0.029).ConclusionPeri‐ and intraventricular echodensities can be detected reliably before birth in fetuses at high risk for uteroplacental insufficiency. When abnormalities persist, there is a high risk for an adverse outcome. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Intra‐ and interoperator variability in fetal nasal bone assessment at 11–14 weeks of gestation
Authors: Senat M. V. , Bernard J. P. , Boulvain M. , Ville Y. 
Published: August 2003

AbstractObjectivesExamination of the fetal nasal bones by ultrasound between 11 and 14 weeks of gestation has been proposed as an additional tool in the detection of trisomy 21 in a high‐risk population. However the variability in the identification of fetal nasal bones by ultrasound has not yet been investigated. The aim of this study was to assess the intraobserver and interobserver reproducibility of fetal nasal bone identification by ultrasound between 11 and 14 weeks of gestation.MethodsA total of 1040 consecutive ultrasound examinations were performed at 11–14 weeks of gestation for nuchal translucency (NT) measurement and nasal bone identification by ultrasound. A total of 657 consecutive video‐loops were assessed by three experienced operators. Each operator assigned cases to one of three categories, namely present, uncertain or absent nasal bones, and the results were compared between operators. To assess the intraoperator variability each operator reviewed 100 randomly selected videos out of the 657 loops and again used the same classification. Results were compared by pairwise unweighted and weighted Kappa index to evaluate the inter‐ and intraoperator variability.ResultsAmong the 1040 fetuses, there were 51 (4.9%) with an NT measurement above the 95th centile. Nasal bones were identified by ultrasound in 948, not seen in eight and impossible to assess in 84 fetuses. Four fetuses had trisomy 21 including three with absent nasal bones and increased NT and one with present nasal bones and normal NT. The Kappa and weighted Kappa values for interoperator variability between the three operators were between 0.26 and 0.37 and 0.33 and 0.44, respectively. The Kappa and weighted Kappa values for intraoperator variability were between 0.35 and 0.48 and 0.43 and 0.55, respectively.ConclusionThe assessment of fetal nasal bones is only fairly reproducible. Although the performance of the test in fetuses at high risk for trisomy 21 has been reported to be good, its implementation as an additional screening technique in the general population must be accompanied by teaching and quality control programs. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Conjoined twins in a triplet pregnancy: early prenatal diagnosis with three‐dimensional ultrasound and review of the literature
Authors: Sepulveda W. , Munoz H. , Alcalde J. L. 
Published: August 2003

AbstractWe report two cases of conjoined twins complicating a triplet pregnancy diagnosed by two‐dimensional ultrasound in the first trimester and evaluated further by three‐dimensional ultrasound. A review of the literature over the last 30 years revealed 11 other cases diagnosed prenatally by ultrasound. Overall, three (23%) of these 13 pregnancies were achieved by assisted reproductive techniques and 10 (77%) were diagnosed before 18 weeks. Four women opted for termination of the whole pregnancy and three were managed expectantly, with two delivering before 32 weeks. Two monochorionic pregnancies underwent selective feticide with intrauterine demise of the non‐conjoined fetus in both cases. All four dichorionic pregnancies undergoing selective termination or spontaneous embryo reduction to singleton in the first trimester resulted in term delivery of the non‐conjoined fetus. The rare condition of conjoined twins in a triplet pregnancy poses a significant obstetric challenge from both diagnostic and management points of view. Accurate determination of chorionicity in these cases plays a critical role in determining management and outcome. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Delta‐NT or NT MoM: which is the most appropriate method for calculating accurate patient‐specific risks for trisomy 21 in the first trimester?
Authors: Spencer K. , Bindra R. , Nix A. B. J. , Heath V. , Nicolaides K. H. 
Published: August 2003

AbstractObjectiveTo assess whether in screening for trisomy 21 by nuchal translucency (NT) the delta or the multiples of the median (MoM) approach is the most appropriate method for calculating accurate individual patient‐specific risks.MethodsData on fetal NT and crown–rump length from 128 030 unaffected and 428 trisomy 21 pregnancies, measured by sonographers who had obtained The Fetal Medicine Foundation Certificate of Competence in the 11–14‐Week Scan, were used. We examined first, if the distribution of NT MoM and log10(NT MoM) was Gaussian; second, if the standard deviation of the distributions did not change with gestation; and third, if the median MoM in the affected population was a constant proportion of the median for unaffected pregnancies. All of these features are required to underpin the MoM approach. NT distributions and those of delta‐NT were also analyzed. A non‐parametric kernel density method was then used to assess the validity of both methods. Errors in the estimation of individual patient‐specific risks using the MoM approach were assessed.ResultsIn the unaffected pregnancies, the distributions of NT MoM and log10(NT MoM) were not Gaussian and the standard deviation of log10(NT MoM) decreased with gestation. In the trisomy 21 pregnancies, the median NT MoM decreased significantly with gestation, whereas the median delta‐NT did not change with gestation. The non‐parametric density approach showed that contours of constant likelihood ratio were parallel to the gestational age‐dependent median NT values, thus supporting the delta‐NT approach. The NT MoM approach resulted in women being given an overestimate of risk for trisomy at 11 weeks and a considerable underestimate of risk at 13 weeks.ConclusionIn the calculation of risk for trisomy 21 by NT the NT MoM approach is inaccurate and inappropriate because the underlying assumptions are not valid. In contrast, the delta‐NT approach gives accurate estimates of risks. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Is there a relationship between estimated fetal weight and umbilical artery Doppler impedance indices?
Authors: Owen P. , Murphy J. , Farrell T. 
Published: August 2003

AbstractObjectiveTo establish whether there is a relationship between estimated fetal weight (EFW) and umbilical artery Doppler waveform impedance indices in the third trimester.MethodsThe pulsatility index (PI) and S/D (systolic/diastolic) ratio were obtained together with the EFW from 274 low‐risk pregnancies. Measurements were made at fortnightly intervals from 30 weeks' gestation until delivery. A relationship between the two impedance indices and EFW was sought at gestational age ranges of 30–32, 33–35, 36–38 and 39–41 weeks.ResultsThere were 918 pairs of PI (with S/D) and EFW available for analysis. The mean of the impedance indices decreased with advancing gestational age as expected. There was no clinically relevant correlation between impedance indices and EFW within any of the gestational age ranges.ConclusionImpedance indices from the umbilical artery Doppler waveform decrease with advancing gestational age due, at least partially, to expansion of the placental vascular tree. Within narrow gestational age ranges in the third trimester, there is no meaningful correlation between fetal weight and impedance indices. It is therefore not necessary to adjust umbilical artery Doppler impedance indices to account for fetal size. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Doppler sonography for predicting fetal anemia caused by massive fetomaternal hemorrhage
Authors: Sueters M. , Arabin B. , Oepkes D. 
Published: August 2003

AbstractFetomaternal hemorrhage (FMH) can cause severe anemia in the fetus. Untreated, this may cause hydrops or even fetal death. However, correct diagnosis of FMH followed by blood transfusion can prevent these life‐threatening consequences. We describe two cases in which fetal anemia was suspected because of maternal reporting of decreased or absent fetal movements, the detection of a sinusoidal heart rate pattern and increased blood flow velocities of the middle cerebral artery and umbilical vein. Together with the Betke–Kleihauer test showing fetal cells in the maternal circulation, this led to the correct diagnosis of severe fetal anemia caused by FMH. A Cesarean section was performed within a few hours. Both neonates were severely anemic and received immediate blood transfusions. They are currently alive and well. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Reference leaks for sniffer leak detectors
Authors: Jitschin W. 
Published: August 2003

AbstractBei der Dichtheitsprüfung und Lecksuche mit Prüfgas muss die ordnungsgemäße Funktion und die Empfindlichkeit des benutzten Gerätes mittels zertifizierter Prüflecks überwacht werden. Beim sogenannten Schnüffelbetrieb wird das zu testende Bauteil mit dem Prüfgas unter Überdruck gesetzt, so dass bei Vorhandensein eines Lecks das Prüfgas nach Atmosphäre ausströmt. Das atmosphärische Gas wird vom benutzten Gerät angesaugt und auf den Gehalt an Prüfgas untersucht. Zur Überwachung der Gerätefunktion gibt es kommerzielle Prüflecks für verschiedene Gase, die einen definierten Leckagestrom liefern. Aufbau und Eigenschaften eines derartigen kommerziellen Prüflecks werden beschrieben. Das Prüfleck besitzt einen internen Gasvorrat und eine Kapillare als Leckelement. Da der Eingangsdruck der Kapillare mittels eines Druckreglers konstant gehalten wird, bleibt der Leckagestrom über mehrere Jahre konstant, auch wenn der Druck im Gasvorrat allmählich abnimmt. Die Kalibrierung des Leckagestroms mittels Volumenstrommessung wird detailliert diskutiert. Die Messung des Volumenstroms kann mit einem Flüssigkeitstropfen in einer Messkapillare oder mit einem Verdrängerkolben in einer Dosierspritze erfolgen.
Applications of surface technology in space
Authors: Luther Wolfgang 
Published: August 2003

AbstractImmer anspruchsvollere Missionen zur wissenschaftlichen Erkundung des Weltraums und die zunehmende Nutzung satellitengestützter Dienstleistungen in den Bereichen Telekommunikation, Navigation und Erdbeobachtung erfordern in Zukunft die Entwicklung effizienterer, kostengünstigerer und widerstandsfähigerer Raumfahrttechniken und ‐systeme. Eine vom Deutschen Zentrum für Luft‐ und Raumfahrt (DLR e.V.) in Auftrag gegebene Untersuchung des VDI‐Technologiezentrums in Düsseldorf zeigt, dass die Nanotechnologie, insbesondere im Bereich der Oberflächentechnik, signifikante Lösungsbeiträge und technologische Durchbrüche für die Entwicklung zukünftiger Raumfahrtsysteme liefern könnte. Anwendungsbeispiele in den Bereichen reibungs‐ und verschleißmindernde Schichten, thermische Schutzschichten, Magnetoelektronik, Röntgenastronomie und Dünnschichtechnologien für Raumfahrtstrukturen werden vorgestellt.
Developments and trends in the coating industry
Authors: Wijngaard Jan H. , Schütze Andreas 
Published: August 2003

AbstractDie technische Entwicklung von PVD‐Beschichtungen eröffnete in den letzten Jahrzehnten einen breiten Markt mit weiter großen Wachstumsraten. Neben dem traditionellen Markt für Werkzeuge in der Zerspanung stehen zunehmend Märkte wie das Stanzen und Umformen sowie Großserienbeschichtungen von Bauteilen im Mittelpunkt des Interesses. Nach Jahren starken Wachstums mit gesteigertem Wettbewerbsdruck gilt es nun das Produktportfolio sowie die Produktivität an die strategische Ausrichtung des jeweiligen Unternehmens anzupassen.
Superhard amorphous carbon films
Authors: Schultrich Bernd 
Published: August 2003

AbstractKohlenstoffschichten zeichnen sich durch die mit ihnen erreichbaren besonderen Eigenschaften und durch ihre strukturelle Vielfalt aus. Amorphe Kohlenstoffschichten mit überwiegend tetragonaler Bindung (ta‐C‐Schichten) haben durch die Kombination von extremer Härte und geringer Adhäsionsneigung ein hohes Anwendungspotential als tribologische Schutzschichten. Mit den gepulsten Vakuumbogenverfahren stehen industriell einsetzbare Technologien zur Abscheidung derartiger Schichten zur Verfügung.
Distributional analysis of boundary value problems in half‐spaces – exemplified by Melan's problem of elastostatics
Authors: Kirchner G. 
Published: August 2003

AbstractUsing a result on the ${\cal C}^\infty$‐dependence (with respect to a distinguished variable) of solutions to partially hypoelliptic operators, we present a definition for Green's function which allows to prove a representation theorem. Afterwards we discuss the construction of a Green's matrix for Melan's problem of elastostatics using the reflection principle and single layer potentials. This involves the solution of convolution equations as well as the explicit computation of convolutions. In this special case also the question of uniqueness is investigated.
The linear stability of a viscoelastic jet (liquid cylinder) surrounded by another viscoelastic fluid
Authors: Brunn P.O. , Ryssel E. 
Published: August 2003

AbstractThe linear stability of a viscoelastic liquid thread surrounded by another viscoelastic liquid is studied. If in the undisturbed state there is no relative motion between the two liquids the results hold without requiring any rheological modeling of the liquids. The complex viscosity, or equivalently the complex modulus will govern the stability behaviour. If in the undisturbed state there is a relative motion (say of velocity u), then model fluids are required and the present analysis will be the model‐free u → 0 limit of such studies.
On the lack of analytic solutions of the Van der Pol oscillator
Authors: Panayotounakos D.E. , Panayotounakou N.D. , Vakakis A.F. 
Published: August 2003

AbstractIn this work it is shown that by a series of transformations the classical Van der Pol oscillator can be exactly reduced to Abel's equations of the second kind. The absence of exact analytic solutions in terms of known (tabulated) functions of the reduced equations leads to the conclusion that there are no exact solutions of the Van der Pol oscillator in terms of known (tabulated) functions. In the limits or small or large values of the parameter ϵ the reduced equations are amenable to asymptotic analysis. For the case of large values of the parameter (relaxation oscillations) an analytic solution to the problem is provided that is exact up to O(ϵ‐2).
Finite difference methods for multi time scale differential algebraic equations
Authors: Pulch R. 
Published: August 2003

AbstractIn radio frequency applications, electronic circuits include oscillatory signals with widely separated time scales. Thus transient analysis demands a large amount of computation. A multidimensional signal model yields an alternative approach. This strategy causes savings in computation time and memory, if the arising partial differential algebraic equation (PDAE) is solved efficiently. For this purpose, we construct a specific finite difference method, which is based on the information transport in the PDAE system. Test results confirm that both PDAE model and corresponding finite difference technique are suitable for simulating driven oscillators.
Steady two‐dimensional asymmetric stagnation point flow of a micropolar fluid
Authors: Lok Y.Y. , Amin N. , Pop I. 
Published: August 2003

AbstractNumerical solutions are presented for the steady two‐dimensional boundary‐layer flow of a micropolar fluid near an asymmetric plane stagnation point. The transformed non‐similar boundary‐layer equations are solved numerically using an implicit finite‐difference method known as Keller‐box method. Numerical results are given for the reduced velocity and microrotation profiles, as well as for the reduced skin friction coefficient when the material parameter K takes the value K = 0 (Newtonian fluid), 0.5, 1, 1.5, 2, 2.5, and 3. Important features of these flow characteristics are shown on graphs and in tables. Comparisons with existing solutions for both symmetric and asymmetric stagnation point flow cases are given and it is shown that these results are in very good agreement. Discussion of the flow characteristics is also made.
New results for the normal shock in inviscid flow at a curved surface
Authors: Zierep J. 
Published: August 2003

AbstractThe well known problem of a normal shock in inviscid flow at a curved wall is discussed again. Behind the shock we have in general a singularity for the gradients of velocity and pressure. This singularity is discussed on the one hand for the full Euler equations with shock equations and on the other hand for the Small Disturbance Transonic equations. Some misunderstandings and open questions in the past are corrected and answered. The solutions are of interest for similar problems in Gasdynamics and for adaption of the local grids for CFD‐methods.
Semicontinuity of multifunctions and a stochastic fluid oscillator
Authors: Fritsch H. 
Published: August 2003

AbstractIn this paper on stochastic differential inclusions with set‐valued drift, we will consider the possible existence of strong solutions in the case of a kind of lower semicontinuous multifunctions as well as of upper semicontinuous ones. The dispersion matrix conditions are weakened in the classical way. To show existence results for such inclusions, we will use a locally Lipschitzean approximation of lower semicontinuous multifunctions. A set‐valued stochastic system with an upper semicontinuous drift will be used to describe the motion of a fluid oscillator with small random perturbations.
Erratum
Authors: Wright Elizabeth R. , Conticello Vincent P. , Apkarian Robert P. 
Published: August 2003

The following shows the correction to Figure 7 that appeared
on page 179 of Microscopy and Microanalysis, 9:3,
June 2003, in the article by Wright et al. The double image
in Figure 7 represents a stereo pair, and the corrected figure shown
below gives the proper 3-dimensional effect.The Editor and Cambridge University Press regret the inconvenience
that this inadvertent error may have caused.
Welcome to San Antonio
Authors: Osten Ev 
Published: August 2003

The Microscopy Society of America, the Microbeam Analysis Society, the
International Metallographic Society and the Congress of InterAmerican
Societies of Electron Microscopy invite you to Microscopy and Microanalysis
2003, which is also the VII InterAmerican Congress on Electron
Microscopy/VII Congreso InterAmericano de Microscopía
Electrónica.The city of San Antonio with its location, history, and culture is an ideal
host for this Pan American meeting. The Convention Center and three of the
participating hotels are located downtown on the amazing River Walk. Many
restaurants and shops are clustered around the River Walk as is La Villita, an
arts village and a National Register Historical District. A few blocks from
the River Walk is Market Square, which is a center of the Mexican culture
featuring patio restaurants, a farmers market, and El Mercado, the largest
Mexican marketplace outside of Mexico. You will find that downtown San Antonio
is a very convenient, interesting, and unique venue for our meeting. For
transportation information, maps, visitor's guides, and much more, see
http://www.sanantoniovisit.com/.
Pet‐keeping in early childhood and airway, nose and skin symptoms later in life
Authors: Bornehag C. G. , Sundell J. , Hagerhed L. , Janson S. ,   the DBH Study Group
Published: August 2003

Background: It is discussed whether exposure to pets during childhood is a risk or a protective factor for sensitization and allergic symptoms. The aim of this study was to investigate the association between pet‐keeping at time of birth and allergic symptoms in airways, nose and skin among young children in Sweden.Method: A questionnaire was sent to the parents of 14 077 children (1–6 years), the focus being on allergic symptoms, home environment and other background factors including pet‐keeping and avoidance behaviour. The response rate was 79%.Results: Almost one‐tenth of the population had got rid of pets because of allergy in the family, and 27.3% reported ‘avoidance’ behaviour towards pets. In a cross‐sectional analysis current pet‐keeping was ‘protective’, but this may be due to the fact that people avoid exposing their child to something that they believe is a risk factor for allergies. Pet‐keeping at the time of birth was associated with ‘wheezing’, ‘asthma’ and ‘rhinitis on pet‐exposure’ later in life for children from families with an ‘avoidance’ behaviour, and was not ‘protective’ for other children. There was also an indication of a dose–response relationship between the number of types of furred pets at time of birth and later symptoms in analyses adjusted for avoidance behaviour or current pet‐keeping.Conclusion: The distribution of pet‐keeping in the population is largely explained by avoidance behaviour, meaning that those who have pets mainly are those who can stand them, indicating a ‘healthy pet‐keeping effect’.