Search

The design of foundations is often governed by the serviceability limit state (SLS) requirements of the supported structure, particularly for large spread foundations. This paper aims to develop a reliability-based SLS design method for spread foundations under uplift loading in cohesionless soils. A probabilistic framework was adopted for the empirical characterisation of the compiled load-displacement curves and the quantification of the associated uncertainties. By using the obtained statistics of the curves, reliability analysis was carried out with Monte-Carlo simulations to calibrate the resistance factors within the load and resistance factor design (LRFD) framework. The calibration results showed that the embedment ratio of the foundation and the fitting errors of the empirical model, which were previously unaddressed in the literature, had notable effects on the calibrated SLS resistance factors. The relationship of the SLS with the ultimate limit state was assessed, including the governing limit state at each allowable displacement level, and the probability of ultimate failure of the foundation at the SLS condition. By considering the relationship between the limit states, the procedures for determining the design resistance factor and foundation capacity were proposed.

This study proposed a virtual reality (VR) course that addresses the overall understanding and application of VR technology. After investigating previous studies, we found that two technologies must be applied to design a VR course that fits the latest trends. One is hardware technology dealing with the technical background, while the other is software utilization and development using the merits of VR technology. To accommodate these needs, we designed a VR course consisting of three steps: VR-related theory, TA-led content creation training, and team projects. Through this course, students will improve their ability to develop applications that apply to their research fields after studying the technical background and courses of VR. We conducted a semester-long study with nine students to verify the proposed method and then evaluated them through an in-depth interview and a questionnaire with a five-point Likert scale consisting of nine items. Considering this feedback, we have added several steps to improve the educational effect among students.

The objective of this study was to discover a panel of microRNAs (miRNAs) as potential biomarkers for noninvasive prenatal testing (NIPT) of trisomy 21 (T21) and to predict the biological functions of identified biomarkers using bioinformatics tools.Using microarray-based genome-wide expression profiling, we compared the expression levels of miRNAs in whole blood samples from non-pregnant women, whole blood samples from pregnant women with euploid or T21 fetuses, and placenta samples from euploid or T21 fetuses. We analyzed the differentially expressed miRNAs according to disease and tissue type (P value0.05 and two-fold expression change). To predict functions of target genes of miRNAs, the functional annotation tools were used.We identified 299 miRNAs which reasonably separate the whole blood from the placenta. Among the identified miRNAs, 150 miRNAs were up-regulated in the placenta, and 149 miRNAs were down-regulated. Most of the up-regulated miRNAs in the placenta were members of the mir-498, mir-379, and mir-127 clusters. Among the up-regulated miRNAs in the placenta, mir-1973 and mir-3196 were expressed at higher levels in the T21 placenta than in the euploid placenta. The two miRNAs potentially regulate 203 target genes that are involved in development of brain, central nervous system, and nervous system. The genes are significantly associated with T21-related disorder such as congenital abnormalities, mental disorders, and nervous system diseases.Our study indicates placenta-specific miRNAs that may be potential biomarkers for NIPT of fetal T21 and provides new insights into the molecular mechanisms of T21 via regulation of miRNAs.

Non-invasive prenatal test of trisomy 21 (T21) is being researched using fetal specific epigenetic biomarkers present in maternal plasma. We applied a methyl-CpG binding domain-based protein (MBD) method based on epigenetic characteristics of fetal specific-methylated regions with a high CpG density in HLCS on chromosome 21 and RASSF1A on chromosome 3 for the non-invasive detection of fetal T21 and estimated the diagnostic accuracy of the method.A nested case-control study was conducted with maternal plasma collected from 50 pregnant women carrying 40 normal and 10 T21 fetuses. A MBD method was used for enrichment of methylated DNA regions in maternal plasma. The levels of methylated HLCS (M-HLCS) and methylated RASSF1A (M-RASSF1A) were simultaneously measured by multiplex qPCR.Levels of M-HLCS and M-RASSF1A were obtained in all cases. Levels were not different according to fetal gender (p0.05 in both). The level of M-HLCS was significantly increased in women with a T21 fetus compared with controls (p0.001). The level of M-RASSF1A was not different between two groups (p0.05). In non-invasive fetal T21 detection, the specificity of M-HLCS level and the epigenetic-epigenetic ratio (EER) using M-HLCS and M-RASSF1A levels were 82.5% and 92.5%, respectively, at 90.0% sensitivity.Our findings suggest that the EER may be useful as a potential biomarker for the non-invasive detection of fetal T21, regardless of fetal gender. The MBD method can be used as an effective tool in the detection of methylated fetal specific markers with a high CpG density in maternal plasma.