bluuebunny/crossref_metadata_2025_split huggingface dataset:
The individual fetal weight/estimated placental weight ratios in monochorionic twins with selective intrauterine growth restriction
Authors: Chang Yao‐Lung , Chang Shuenn‐Dyh , Chao An‐Shine , Hsieh Peter C. C. , Wang Chao‐Nin , Tseng Ling‐Hong 
Published: February 2008

AbstractObjectivesTo evaluate the individual fetal weight/estimated placental weight ratios (F/P ratio) of the two fetuses in monochorionic (MC) twins with selective intrauterine growth restriction (IUGR).Material and MethodsMC twin with selective IUGR was defined as an estimated fetal weight below the 10th percentile in one twin of MC pregnancy. The estimated individual placental weight was obtained by cutting the placenta along the vascular equator into two territories. A total of 15 MC twins with selective IUGR and 18 MC twins without selective IUGR were included in this study.ResultsThe individual F/P ratio in the IUGR twin is significantly higher than that in the appropriate for gestational age (AGA) one in MC twin with selective IUGR (6.4 vs 4.0 respectively, p < 0.001). In MC twin without IUGR, the F/P ratios are not significantly different between the two fetuses (5.4 vs 5.1, respectively).ConclusionThe high F/P ratio in the IUGR twin in MC with selective IUGR may be due to the placental reserve phenomenon, so that a smaller placental territory may suffice to perfuse the IUGR twin. In other words, in MC twin gestations with an IUGR twin, the fetal weights are not proportional to the placental masses. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of maternal smoking on prenatal screening for Down syndrome and trisomy 18 in the first trimester of pregnancy
Authors: Miron Pierre , Côté Yvan P. , Lambert Jean 
Published: February 2008

AbstractObjectivesTo assess the impact of maternal smoking on first‐trimester prenatal screening results for Down syndrome and trisomy 18.MethodsData on maternal smoking status, maternal age, gestational dating, levels of free beta‐human chorionic gonadotrophin (β‐hCG) and pregnancy‐associated plasma protein A (PAPP‐A) in maternal blood and fetal nuchal translucency (NT) thickness were analyzed from a cohort of 53 114 women. Statistical analyses were carried out for crude and adjusted comparisons between smoking and nonsmoking groups.ResultsIn women who smoked during the first trimester of pregnancy, PAPP‐A and free β‐hCG levels from dried blood were significantly decreased (p < 0.001) and fetal NT thickness was significantly increased (p < 0.001). For an overall risk assessment combining maternal age and biochemical and ultrasound markers, no significant changes for Down syndrome were found with smoking, but significant increases in average risk as well as in positive rates were found for trisomy 18 (p < 0.001). A potential association between maternal smoking and trisomy 18 remains to be clarified.ConclusionAdjustment for smoking is recommended in first‐trimester prenatal screening for trisomy 18 and probably not warranted for Down syndrome because of the cancelling effects of decreased free β‐hCG and increased NT. Further research is required to demonstrate a biological association between maternal smoking and trisomy 18. Copyright © 2008 John Wiley & Sons, Ltd.
Expected performance of second trimester maternal serum testing followed by a ‘genetic sonogram’ in screening of fetal Down syndrome
Authors: Benn Peter A. , Egan James F. X. 
Published: February 2008

AbstractObjectiveTo assess the efficacy of screening for fetal Down syndrome through the sequential provision of second trimester maternal serum tests and fetal ultrasound (the ‘genetic sonogram’).MethodsMonte Carlo modeling was used to generate typical results for second trimester serum screening. Serum test likelihood ratios were then multiplied by likelihood ratios associated with the provision of a genetic sonogram. The impact of adding the genetic sonogram on the detection rate (DR) and false‐positive rate (FPR) were assessed for typical protocols that are currently in use. The effect of expanding the number of women who receive the genetic sonogram, variation in the marker frequencies in the genetic sonogram, and a multivariate Gaussian model that incorporated both serum and ultrasound measurements as continuous variables were also considered.ResultsWhen the genetic sonogram is offered only to those women who are screen‐positive by serum testing, there can be a substantial reduction in the number of women with an indication for amniocentesis but also some loss in detection. The extent of these changes will partially depend on the serum tests and cutoff used. Providing the genetic sonogram to more women can reduce loss in detection without resulting in high amniocentesis rates. As a sequential screening tool, the genetic sonogram can be improved by incorporating markers that have a high frequency in affected pregnancies and by using ultrasound measurements as continuous variables.ConclusionIt should be possible to provide highly effective multistep screening protocols that maximize the benefits of both maternal serum and ultrasound while minimizing the amount of testing offered. Copyright © 2008 John Wiley & Sons, Ltd.
Smoking in pregnancy is associated with increased total maternal serum cell‐free DNA levels
Authors: Urato Adam C. , Peter Inga , Canick Jacob , Lambert‐Messerlian Geralyn , Pulkkinen Andrea , Knight George , Jeong Young‐Ju , Johnson Kirby L. , Bianchi Diana W. 
Published: February 2008

AbstractObjectiveCell‐free DNA is a marker of cellular apoptosis and necrosis. We wished to determine if maternal smoking affects maternal and fetal serum cell‐free DNA levels.MethodsCase–control sets of stored second‐trimester serum‐screening samples from 27 smoking and 90 nonsmoking pregnant women were developed. Smoking status was confirmed by measuring serum cotinine levels. Glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) and DYS1 levels were determined using real‐time polymerase chain reaction (PCR) to measure total and fetal cell‐free DNA, respectively. At delivery, medical records were reviewed to confirm gender and determine other factors that could affect DNA values.ResultsSmoking was associated with significantly elevated GAPDH levels compared with nonsmokers (median: 97 662 genome equivalents (GE)/mL vs 38 217 GE/mL; p = 0.018). DYS1 levels were not statistically significantly elevated in smokers (p = 0.29). Other factors that affected DYS1 levels included maternal age in nonsmokers only (r2 = 0.30, p = 0.013) and maternal Synthroid use (p = 0.0045)ConclusionPregnant smokers have threefold higher levels of total cell‐free DNA compared with pregnant nonsmokers. Maternal age and Synthroid exposure may also affect circulating cell‐free fetal DNA levels. Copyright © 2008 John Wiley & Sons, Ltd.
Correlation between referral ultrasound with suspected foetal anomalies and autopsy examination in two prenatal diagnosis centres. Impact of the routine use of 3D/4D scan
Authors: Picone Olivier , Levaillant Jean‐Marc , Hirt Raphael , Frydman René , Boulvain Michel , Senat Marie‐Victoire 
Published: February 2008

AbstractObjectiveTo compare ultrasound diagnosis with autopsy findings in two tertiary referral foetal medicine centres, only one routinely using 3D and 4D ultrasound, and to compare results between the centres.MethodsA retrospective study of 138 cases with a termination of pregnancy for foetal abnormalities after 21 weeks' gestation from January 2004 through May 2006 was carried out. We compared prenatal ultrasound and autopsy findings for each organ, calculating the sensitivity, specificity, positive predictive and negative predictive values, and false‐positive and false‐negative rates for ultrasound.ResultsAbnormalities were found most frequently in the brain (48.9%), heart and thorax (34.0%), limbs (31.9%), face (15.9%), and abdomen, urogenital tract and spine (14.5%). Sensitivity between centres did not differ statistically for the brain, spine, limbs and abdomen, but was different for the face (p = 0.005) and heart (p = 0.007). The detection rate was higher for facial malformations at the centre with routine 3D and 4D scans, and better for the heart and thorax at the other centre.ConclusionDiagnostic ultrasound cannot give a complete assessment of foetal anatomy. Autopsy examination is always strongly recommended for accurate genetic counselling. As already reported, 3D and 4D ultrasound may improve ultrasound performance in facial anomalies. Copyright © 2008 John Wiley & Sons, Ltd.
ADAM12s in maternal serum as a potential marker of pre‐eclampsia
Authors: Spencer Kevin , Cowans Nicholas J. , Stamatopoulou Anastasia 
Published: February 2008

AbstractObjectiveTo examine whether maternal serum ADAM12s, a potential first‐ and second‐trimester marker of fetal aneuploidy and fetal growth, had altered concentrations in the first or second trimester of pregnancies subsequently developing pre‐eclampsia.MethodsADAM12s was measured by a time‐resolved fluoroimmunoassay developed by PerkinElmer Life Science. Maternal serum samples from women taking part in early first‐trimester aneuploidy screening in whom the pregnancy resulted in pre‐eclampsia (64) were identified from a cohort of 4390 singleton pregnancies in which uterine artery Doppler mean Pulsatility Index (PI) had been measured at 22–24 weeks. From amongst those cases delivering a normal term infant with birth weight greater than the 10th centile for gestational age 240 cases were selected as gestational age‐matched controls. A second study group consisting of maternal serum taken at 22–24 weeks at the time of uterine artery Doppler in a group of 12 women developing pre‐eclampsia were compared with 86 matched controls from a previously studied cohort of 24 cases and 144 controls. Serum ADAM12s concentrations were converted to multiple of the median (MoM) to take account of gestational age variation.ResultsFirst‐trimester maternal serum ADAM12s levels in women who developed pre‐eclampsia were reduced with a median MoM of 0.71 which was further reduced in those delivering prior to 35 weeks (0.50). At the 5th centile of normal (0.48 MoM) ADAM12s identified 27% of cases with pre‐eclampsia and 47% of those with early pre‐eclampsia. Combining ADAM12s with PAPP‐A from a previous study only resulted in a further 1% increase in detection of all women developing pre‐eclampsia. However combining ADAM12s with mean PI increased the detection rate to 66%. In the second trimester at 22–24 weeks the maternal serum ADAM12s levels were increased in those women developing pre‐eclampsia compared to controls (709 vs 486 ug/L, p = 0.045).ConclusionADAM12s in addition to being a potential marker of aneuploidy may also be a marker of pre‐eclampsia. Further studies are required to see if this can improve on the clinical discrimination already provided by PAPP‐A in the early first trimester. Copyright © 2008 John Wiley & Sons, Ltd.
Sustainable use of glyphosate in North American cropping systems
Authors: Gustafson David I 
Published: February 2008

AbstractRoundup Ready (glyphosate‐resistant) cropping systems enable the use of glyphosate, a non‐selective herbicide that offers growers several benefits, including superior weed control, flexibility in weed control timing and economic advantages. The rapid adoption of such crops in North America has resulted in greater glyphosate use and concern over the potential for weed resistance to erode the sustainability of its efficacy. Computer modeling is one method that can be used to explore the sustainability of glyphosate when used in glyphosate‐resistant cropping systems. Field tests should help strengthen the assumptions on which the models are based, and have been initiated for this purpose. Empirical evaluations of published data show that glyphosate‐resistant weeds have an appearance rate of 0.007, defined as the number of newly resistant species per million acres treated, which ranks low among herbicides used in North America. Modeling calculations and ongoing field tests support a practical recommendation for growers occasionally to include other herbicides in glyphosate‐resistant cropping systems, to lower further the potential for new resistance to occur. The presented data suggest that the sustainability of glyphosate in North America would be enhanced by prudent use of additional herbicides in glyphosate‐resistant cropping systems. Copyright © 2008 Society of Chemical Industry
On the properties of auxetic meta‐tetrachiral structures
Authors: Grima Joseph N. , Gatt Ruben , Farrugia Pierre‐Sandre 
Published: February 2008

AbstractAuxetics are systems which get fatter when stretched and thinner when compressed i.e. they exhibit a negative Poisson's ratio. Here, we present an analysis of a novel class of structures (referred to as ‘meta‐chiral') which belong to the class of auxetics constructed using chiral building blocks. We show through analytical modelling that some of these systems can exhibit negative Poisson's ratios, the extent of which will depend, amongst other things, on the geometry of the system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the auxetic properties of rotating rhombi and parallelograms: A preliminary investigation
Authors: Grima Joseph N. , Farrugia Pierre‐Sandre , Gatt Ruben , Attard Daphne 
Published: February 2008

AbstractAuxetics exhibit the unusual property of expanding when uniaxially stretched (negative Poisson's ratio), a property that is usually linked to particular geometric features and deformation mechanisms. One of the mechanisms which results in auxetic behaviour is the one involving rotating rigid units, for which, systems made from triangles, squares or rectangles have already been considered. In this work we extend this study by considering systems which can be constructed from either connected rhombi or connected parallelograms. We show that various types of such systems can exist and we discuss in detail the properties of one type of ‘rotating rhombi' and one type of ‘rotating parallelograms'. We also show that the Poisson's ratio of these systems, which can be positive or negative, is anisotropic and dependent on the shape of the parallelograms/rhombi and the degree of openness of the system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Initial growth of W‐based films deposited on Si studied with ARXPS
Authors: Oswald S. , Rittrich D. , Zahn W. 
Published: February 2008

AbstractW and WN films with thicknesses of less than one monolayer up to some nanometers were deposited by magnetron sputtering. The samples were transferred after deposition immediately into an analysis chamber without breaking the vacuum to avoid oxide formation and contamination. Analysis was done by means of XPS for elemental and bonding state characterization and angle‐resolved XPS (ARXPS) for nondestructive depth profiling. Phase formation and morphology were studied during the first stages of layer growth. Influences of the residual gas atmosphere are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
The morphological, optical and electrical properties of SnO2:F thin films prepared by spray pyrolysis
Authors: Zhi Xiao , Zhao Gaoyang , Zhu Tao , Li Ying 
Published: February 2008

AbstractCombining the spray pyrolysis and the sol–gel techniques gives the possibility to produce Fluorine doped Tin oxide (SnO2:F) thin films. Transparent conducting SnO2:F thin films have been deposited on glass substrates by the spray pyrolysis technique. This technique for the fabrication of SnO2:F filmsby combining sol–gel process and the spray pyrolysis technique ispresented in this paper. The Sol–gel precursors have been successfully prepared using SnCl2·5H2O and (Ac)F3. The structural, electrical, and optical properties of these films were investigated. The high resolution transmission electron microscopy (HRTEM) and selected area diffraction (SAD) patterns of SnO2:F films show that the gel films lead to a tetragonal structure. The X‐ray diffraction pattern of the films deposited at substrate temperature 530° , the orientation of the films was predominantly [110]. In addition, the surface chemical components were also examined by X‐ray photoelectron spectroscopy (XPS) showing the SnO2:F deposited with the atomic concentration ratios Sn/F 1.82:1. The minimum sheet resistance was 50 Ω and average transmission in the visible wavelength range of 300 to 800 nm was 87.25%. Copyright © 2008 John Wiley & Sons, Ltd.
Contact angle and biocompatibility of sol‐gel prepared TiO2 thin films for their use as semiconductor‐based cell‐viability sensors
Authors: Ozasa Kazunari , Nemoto Shigeyuki , Li Yuanzhi , Hara Masahiko , Maeda Mizuo , Mochitate Katsumi 
Published: February 2008

AbstractWe have investigated the surface, biocompatibility, and H2O2 sensitivity of TiO2 thin films prepared by sol‐gel technique, from the viewpoints of aptitude for a gate‐oxide film on field‐effect transistors (FETs) for cell‐viability sensors. The surface of TiO2 thin films had nanometer‐scale roughness (approximately 1 nm in height), but was uniform and flat in micrometer scale. The contact angle of the TiO2 thin films increases with time, when the TiO2/GaAs samples were preserved in air at room temperature, probably because of hydrophobic contaminates. A stretched exponential dependence fits well to the temporal evolution of the TiO2 contact angle. Scattered data obtained in cell‐adhesion experiments show that the cell adhesion is mostly independent of the contact angle of the TiO2 surfaces. In order to evaluate TiO2 thin films for biosensor use, TiO2 thin films were formed on two‐dimensional electron‐gas (2DEG) FETs as the gate‐oxide film. TiO2/2DEG‐FETs exhibit a high H2O2 sensitivity up to 4.5 mV/µM, whereas conventional ISFET (Ta2O5/Si‐FET)is insensitive to H2O2. Copyright © 2008 John Wiley & Sons, Ltd.
Characterisation of the silicon nitride thin films deposited by plasma magnetron
Authors: Batan A. , Franquet A. , Vereecken J. , Reniers F. 
Published: February 2008

AbstractSilicon nitride thin films were deposited by reactive DC magnetron sputtering on different substrates in a home‐made planar DC sputtering system. The sputtering was performed from a silicon target in a sputtering atmosphere of (Ar, H2, N2) mixture. The gas composition could be varied from 0 to 100% for Ar and N2, and from 0 to 10% for H2. The structure and purity of the coatings have been investigated as a function of the process parameters, such as the composition of the sputtering atmosphere and the total pressure. The deposited films were characterised by optical interferometry (thickness measurement), Fourier transformed infrared spectroscopy (FTIR), X‐ray diffraction (XRD) and XPS. The XPS spectra indicated that Si3N4 was obtained for a molar fraction of nitrogen larger than 0.1, and also indicated that the sputtered silicon nitride films were uncontaminated with oxygen and carbon. The N/Si ratio of the nitride films could be tuned between 0.56 and 1.33 depending on the deposition conditions. The presence of the transverse optical (TO) and longitudinal optical (LO) phonons in infrared reflection absorption spectroscopy (IRRAS) attest for the presence of SiN bonds. For the stoichiometric films no change in the LO phonon peak position was observed, indicating that there is no variation in the film composition. Copyright © 2008 John Wiley & Sons, Ltd.
Electrochemical studies on the stability and corrosion resistance of new zirconium‐based alloys for biomedical applications
Authors: Branzoi Ioan Viorel , Iordoc Mihai , Codescu Mirela 
Published: February 2008

AbstractThe biocompatibility of commercially pure zirconium and its alloys is closely related to their surface properties with both the composition of the protecting oxide film and the surface topography playing an important role. This article is a study of corrosion behavior of new zirconium alloys for orthopedic implants, which are supposed to be used instead of some implant materials that have a higher citotoxicity. For this reason, zirconium and its alloys will be employed widely in biomedical applications. The higher stability and corrosion resistance exhibited by zirconium are due to the spontaneous formation of a passive zirconium oxide film, which protects the metal from further oxidation. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) are used as electrochemical techniques. Measurements were carried out to investigate the corrosion behavior of zirconium and Zr2.5Nb, Zr3Ta, and Zr2.5Nb3Ta alloys in aerated Hank solution at 37 ± 0.2 °C. The results of EIS were compared with those obtained by potentiodynamic polarization techniques. Impedance spectra were represented both in complex impedance diagram (Nyquist plot) and Bode plots. The EIS measurements have confirmed this stability range and pointed out the formation of oxide layers on the electrode surfaces. Copyright © 2008 John Wiley & Sons, Ltd.
Ultrasound assessment of cervical length in prolonged pregnancy: prediction of spontaneous onset of labor and successful vaginal delivery
Authors: Vankayalapati P. , Sethna F. , Roberts N. , Ngeh N. , Thilaganathan B. , Bhide A. 
Published: February 2008

AbstractObjectivesTo evaluate the usefulness of sonographic assessment of cervical length in the prediction of spontaneous onset of labor and of vaginal delivery.MethodsTwo hundred and six women who attended a dedicated postdates clinic at 41 + 3 weeks of pregnancy and agreed to the assessment of cervical length using transvaginal ultrasound imaging were included in the study. Those who had not delivered at 42 weeks were offered induction of labor. The labor details were recorded prospectively, and the onset of spontaneous labor and mode of delivery were correlated with cervical length data.ResultsWomen who underwent spontaneous onset of labor (n = 112) had a significantly shorter cervical length (mean (SD) 25.0 (8.3) mm) than had women whose labor was induced (n = 67; mean (SD) 29.7 (8.5) mm). Logistic regression analysis showed that cervical length was an independent predictor of the likelihood of spontaneous labor in nulliparous women, and of vaginal delivery in both nulliparous and parous women. Parity had no independent effect on the onset of spontaneous labor, but was an independent predictor of the likelihood of vaginal delivery.ConclusionsSonographic assessment of cervical length is a significant independent predictor of the likelihood of the onset of spontaneous labor in nulliparous women, and of successful vaginal delivery in both nulliparous and parous women with prolonged pregnancy. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Hypothermia/Warming Protocols: Why Are They Not Widely Used in the OR?
Authors: Weirich Tara Lynn 
Published: February 2008

ABSTRACTHYPOTHERMIA, A COMMON PROBLEM for patients having surgery, adversely affects multiple organ systems and physiologic functions. Research indicates that maintaining normothermia can reduce infection rates, operative blood loss, and length of hospital stay.OFTEN, PREVENTING HYPOTHERMIA is not a high priority to surgical staff members because forced‐air warming systems may cause field contamination and passive warming may increase the ambient OR temperature. In addition, inconsistent practices and lack of guidelines may affect team members' efforts.SURGICAL TEAM AWARENESS, education, and understanding of the effects of hypothermia are necessary components to enhance the ways clinicians provide quality, cost‐effective patient care. AORN J 87 (February 2008) 333‐344. © AORN, Inc, 2008.