Objective: The purpose of the present study was to build a database of reference ranges of fetal nasal bone length (NBL) in a Chinese population. The accuracy rate of detecting Down syndrome was ...also analyzed using fetal NBL as a marker.
Methods: The control group of fetuses included 342 normal singleton pregnancies with no chromosomal or congenital anomalies. The present study was a cross‐section study and the control group was used to construct percentile values of NBL from 13 to 29 gestational weeks of age. Two‐dimensional ultrasonography was used for the nasal bone studies. Measurements of NBL were collected and each fetus contributed a single value to the reference sample. During the study period, 14 fetuses with Down syndrome were examined. Measurement of fetal NBL was made during amniocentesis, with gestational age ranging from 13 to 19 weeks.
Results: From 342 normal fetuses with gestational age ranging from 13 to 29 weeks, reference ranges of NBL were constructed. The reference ranges were constructed from the 100(1 − p)% reference range: , where Ŷ = 25 − exp(3.58 − 0.044 × t + 0.0006 × t2), with Ŷ being the fitted mean of regression model and t being gestational age (weeks). Using fetal NBL, the regression model was Pr(Down syndrome) = exp(W)/1 + exp(W), where W = 0.62–4.80 × NBL (multiples of the median) in predicting Down syndrome. Fetal NBL was found to have a sensitivity and specificity of 0.78 and 0.78, respectively, in predicting Down syndrome in the second trimester of pregnancy.
Conclusions: Fetal NBL measurement can provide a simple and useful algorithm to predict Down syndrome during the second trimester of pregnancy.
Abstract Objective Assessment of the fetal medulla oblongata volume (MOV) and blood flow might be important in the evaluation of fetal brain growth. We used three-dimensional power Doppler ultrasound ...(3DPDUS) to assess the fetal MOV and blood flow index in normal gestation. The relationships between these parameters were further analyzed. Methods We assessed the total volume and blood flow index of the fetal MO in normal pregnancies using a 3DPDUS (Voluson 730 Expert). The true sagittal plane over the fetal occipital area was measured by a 3D transabdominal probe to scan the fetal MO under the power Doppler mode. Then, we quantitatively assessed the total volume of the fetal MOV, mean gray area (MG), vascularization index (VI), and flow index (FI). Results A total of 106 fetuses, ranging from 19 weeks to 39 weeks of gestation, were involved in our study. The volume of the fetal MO was highly positively correlated with gestational age correlation coefficient ( r ) = 0.686, p < 0.0001. The MG was negatively correlated with gestational age r = −0.544, p < 0.0001). VI and FI showed no significant correlation with gestational age ( p = 0.123 and p = 0.219, respectively). Conclusion 3DPDUS can be used to assess the fetal MOV and blood flow development quantitatively. Our study indicated that fetal MOV and blood flow correlated significantly with the advancement of gestational age. This information may serve as reference data for further studies of the fetal brain and blood flow under abnormal conditions.
Transmission Electron Microscopy Observation
A sophisticated transmission electron microscopy holder with both the advantages of conventional open‐cell and liquid cell approaches is realized by ...Tetsuya Tsuda, Susumu Kuwabata, and co‐workers in article number 2100018. Its usage facilitates to accurately monitor Li metal anode reactions under realistic operation conditions.
Heat treatment on multi-wall carbon nanotubes (CNTs) in ammonia gas was performed in this study. Effects of heating temperature (up to 1000 °C) on material characteristics of the CNTs were ...systematically investigated. Microstructure of the CNTs was examined using a transmission electron microscope. In addition, their crystallinity and specific surface area were evaluated with a Raman spectrometer and a nitrogen gas sorption analyzer, respectively. It was found that hydrogen storage performance of the CNTs clearly depended on their microstructure and crystallinity, which can be modified by the heat treatment. The hydrogen storage capacity of the as-received CNTs, measured with a high-pressure microbalance under 6.89 MPa, was only 0.39 wt.%. However, this value can be significantly improved to be 2.9 wt.% when the CNTs underwent a heat treatment conducted in the ammonia atmosphere at 1000 °C.
Nano transparent heat insulating coating is applied to window glass in this study. The heat insulating coating absorbs thermal radiation, and reduces the thermal radiation transmittance of glass, ...thus, preventing the building heat load from increasing in summer, or reducing the consumption of heat energy in winter. Therefore, this study will design a scaled down building model room, where heat insulating coating is coated on the inner side of the window glass of the model room, and the thermal radiation isolation effect is tested. Finally, the building energy-saving benefit of outdoor heat insulation in summer and indoor heat preservation in winter is discussed.
Abstract Objective This study assesses the performance of noninvasive prenatal testing (NIPT) for fetal aneuploidies in a mixed risk factors pregnancy population. Materials and methods Data review of ...169 pregnant women undergoing prenatal aneuploidy screening in a single tertiary medical center was conducted. Indications included maternal anxiety, advanced maternal age, abnormal nuchal translucency, and high/moderate risk of first trimester Down syndrome screening. Multifetal pregnancies and patients receiving in vitro fertilization were also enrolled for analysis. Results A total of 169 patients were enrolled in this study during a time period from July 2012 to June 2014. For patients' ≥ 34 years, anxiety about amniocentesis was the most common reason for patients selecting NIPT for fetal aneuploidy screening, with 107 (88.4%) patients choosing NIPT for this reason. Among the total patient population, two patients showed a positive result from NIPT. One patient displayed 47, XXY, which was confirmed to be a false-positive result. The other patient displayed trisomy 18, which was confirmed by an amniotic cell culture. The sensitivity for NIPT is 100% with the specificity 99.4%. Conclusions NIPT for fetal aneuploidy in a mixed risk factors pregnancy population showed high accuracy. NIPT applied to the low risk population might reassure the anxious family.
Infection and preterm birth Yeh, Chang-Chin; Chen, Chih-Yao; Wang, Peng-Hui
Journal of the Chinese Medical Association,
09/2017, Letnik:
80, Številka:
9
Journal Article
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