Association of Genetic Variants of Melatonin Receptor 1B with Gestational Plasma Glucose Level and Risk of Glucose Intolerance in Pregnant Chinese Women

BACKGROUND: This study aimed to explore the association of MTNR1B genetic variants with gestational plasma glucose homeostasis in pregnant Chinese women. METHODS: A total of 1,985 pregnant Han Chinese women were recruited and evaluated for gestational glucose tolerance status with a two-step approach. The four MTNR1B variants rs10830963, rs1387153, rs1447352, and rs2166706 which had been reported to associate with glucose levels in general non-pregnant populations, were genotyped in these women. Using an additive model adjusted for age and body mass index (BMI), association of these variants with gestational fasting and postprandial plasma glucose (FPG and PPG) levels were analyzed by multiple linear regression; relative risk of developing gestational glucose intolerance was calculated by logistic regression. Hardy-Weinberg Equilibrium was tested by Chi-square and linkage disequilibrium (LD) between these variants was estimated by measures of D' and r(2). RESULTS: In the pregnant Chinese women, the MTNR1B variant rs10830963, rs1387153, rs2166706 and rs1447352 were shown to be associated with the increased 1 hour PPG level (p=8.04 × 10(-10), 5.49 × 10(-6), 1.89 × 10(-5) and 0.02, respectively). The alleles were also shown to be associated with gestational glucose intolerance with odds ratios (OR) of 1.64 (p=8.03 × 10(-11)), 1.43 (p=1.94 × 10(-6)), 1.38 (p=1.63 × 10(-5)) and 1.24 (p=0.007), respectively. MTNR1B rs1387153, rs2166706 were shown to be associated with gestational FPG levels (p=0.04). Our data also suggested that, the LD pattern of these variants in the studied women conformed to that in the general populations: rs1387153 and rs2166706 were in high LD, they linked moderately with rs10830963, but might not linked with rs1447352;rs10830963 might not link with rs1447352, either. In addition, the MTNR1B variants were not found to be associated with any other traits tested. CONCLUSIONS: The MTNR1B is likely to be involved in the regulation of glucose homeostasis during pregnancy

Nonlinear truss modeling and strain-based evaluation of RC walls considering lap-splice failure effects

This paper presents a simulation-based method to evaluate the seismic performance of RC walls with lap splices. Computational analyses are conducted using a recent implementation of the nonlinear truss model. The uniaxial steel law used in the truss model is modified to account for lap-splice failure of vertical bars using a simple tensile strain criterion. Performance evaluation is conducted using a novel method that employs strain limits associated to damage in concrete and steel. The computational models and strain-based evaluation method are verified with experimental data from tests on wall components with lap splices at their base. Truss models are shown to accurately capture the force-displacement response and failures observed in these tests. The proposed evaluation approach allows for consideration of the post-yield capacity of lap-spliced bars, and the strain-based limits are shown to be consistent with the strength and stiffness deterioration of the walls.The study presented in this paper was supported by the National Institute of Standards and Technology (NIST) under award No. 70NANB19H060. Any opinions and findings presented in this paper are those of the authors alone, and do not necessarily reflect the opinions of the sponsor.Postprint (published version

Nonlinear truss models for strain-based seismic evaluation of planar RC walls

This paper introduces a new approach for the seismic performance evaluation of planar RC walls. Compared to existing assessment guidelines, such as those in ASCE/SEI 41-17, where performance limits are described by plastic rotation or lateral drift, the proposed method uses local (strain) quantities, obtained from computational models. The analyses rely on a user-friendly implementation of the nonlinear truss model for RC structures, which eliminates the need to manually create a line-element representation of a wall and includes a material law for steel accounting for buckling and rupture of reinforcement. The capability of the models to capture common failure patterns for planar walls is validated for a set of six previously tested wall components which experienced a variety of damage modes (bar rupture, boundary element failure, diagonal compression and tension failures). The analytical models accurately predict the lateral strength, deformation capacity and failure modes observed in the tests. A set of acceptance criteria, based on the analytically obtained concrete and steel strains, is then established for the immediate occupancy, life safety and collapse prevention levels, consistent with different levels and types of damage. An initial calibration of the limit values associated with these criteria is proposed and verified using the analytical results for the six walls considered. The results of the proposed assessment methodology applied to the six walls are compared to those obtained using the nonlinear procedures in ASCE/SEI 41-17. The results indicate that ASCE/SEI 41-17 may not accurately describe the deformability of walls exhibiting mixed flexure-shear inelastic deformations.The research presented in this paper is supported by the National Institute of Standards and Technology (NIST) under award No. 70NANB19H060. Any opinions and findings presented in this paper are those of the authors alone, and do not necessarily reflect the opinions of the sponsor.Peer ReviewedPostprint (published version

Advanced seismic evaluation of RC structural walls using nonlinear truss models

This paper presents a method to evaluate the seismic performance of RC walls, based on the local (material) response obtained from computational simulation. The latter relies on a recent implementation of the nonlinear truss model, which has been shown capable of capturing all important RC wall failure modes. An enhancement to the method is presented herein, enabling the accurate reproduction of lap-splice failures. The seismic evaluation procedure relies on establishing strain-like acceptance criteria for all significant material damage modes related to Immediate Occupancy, Life Safety and Collapse Prevention performance levels. Truss models are shown to accurately capture the force-displacement response and failure patterns observed in these tests. The threshold limit values for each performance level obtained with the proposed strain-based criteria are consistent with the physical damage and deterioration of the load-carrying capacity of the walls.The study presented in this paper was supported by the National Institute of Standards and Technology (NIST) under award No. 70NANB19H060. Any opinions and findings presented in this paper are those of the authors alone, and do not necessarily reflect the opinions of the sponsor.Postprint (published version

Nonlinear Beam-Truss Model (BTM) for seismic performance evaluation of reinforced concrete wall buildings

This paper presents an accurate, simple and computationally efficient method called the beam-truss model (BTM), for the computational seismic performance assessment and design of reinforced concrete (RC) structural wall buildings. The BTM has been extensively validated through a number of prior studies, and its capability to enable the accurate simulation of planar and flanged walls, coupled walls and entire building systems, has been demonstrated. A recent implementation of the BTM as a four-node shell macroelement substantially facilitates the definition and post-processing of analysis. The method is currently used for transforming the modeling and seismic performance evaluation of existing RC walls, enabling the formulation and use of performance acceptance criteria based on local material damage states. Furthermore, the BTM enables the fully nonlinear static and dynamic analysis of entire buildings including three-dimensional ground motions improving substantially the predicting capabilities of nonlinear analysis practice for performance-based seismic design (PBSD) and assessment.Postprint (published version

Association between genetic variants of <i>MNTR1B</i> and gestational plasma glucose in pregnant Chinese woman.

<p>Data are presented as (mean ± SD); Location information downloaded from <a href="http://asia.ensemble.org" target="_blank">http://asia.ensemble.org</a>; the risk allele of the variant is showed in bold; No transformation was applied to normalize the glucose levels (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040113#pone.0040113.s001" target="_blank">Fig. S1</a>); <i>p</i> values were not corrected for multiple comparisons.</p>a<p>Calculated using multiple regression, assuming an additive model adjusted for age and BMI.</p>b<p>Calculated using logistic regression, assuming an additive model adjusted for age and BMI.</p

Graphitization of graphene oxide films under pressure

Lightweight, flexible graphite foils that are chemically inert, high-temperature resistant, and highly electrically and thermally conductive can be used as component materials in numerous applications. ???Graphenic??? foils can be prepared by thermally transforming graphene oxide films. For this transformation, it is desirable to maintain a densely packed film structure at high heating rates as well as to lower the graphitizing temperatures. In this work, we discuss the pressure-assisted thermal decomposition of graphene oxide films by hot pressing at different temperatures (i.e., 300 ??C, 1000 ??C, or 2000 ??C). The films pressed at 1000 ??C or 2000 ??C were subsequently heated at 2750 ??C to achieve a higher degree of graphitization. The combination of heating and pressing promotes the simultaneous thermal decomposition and graphitic transformation of G-O films. Films pressed at 2000 ??C as well as films further graphitized at 2750 ??C show high chemical purity, uniformity, and retain their flexibility. For films pressed at 2000 ??C and then further heated at 2750 ??C, the mechanical performances outperform the reported values of the ???graphite??? foils prepared by calendering exfoliated graphite flakes; the electrical conductivity is ???3.1 ?? 105 S/m and the in-plane thermal conductivity is ???1.2 ?? 103 W/(m??K)

Comparison of Characteristics in pregnant Chinese women.

<p>Data are presented as (mean ± SD).</p

The <i>MTNR1B</i> gene structure and Haploview plot for 4 <i>MTNR1B</i> variants.

<p>The <i>MTNR1B</i> gene structure with the location of the variants studied (A) and pairwise D′ Haploview plot for the 4 <i>MTNR1B</i> variants was shown; R-squared was also displayed for LD values. B. based on our data for glucose tolerance status in pregnant Chinese women. C. Europeans. D. Han Chinese in Beijing. E. Chinese in Metropolitan Denver. 88×68 mm (600×600DPI).</p