Preimplantation genetic screening (PGS) is widely used to select in vitro-fertilized embryos free of chromosomal abnormalities and to improve the clinical outcome of in vitro fertilization (IVF). A ...disadvantage of PGS is that it requires biopsy of the preimplantation human embryo, which can limit the clinical applicability of PGS due to the invasiveness and complexity of the process. Here, we present and validate a noninvasive chromosome screening (NICS) method based on sequencing the genomic DNA secreted into the culture medium from the human blastocyst. By using multiple annealing and looping-based amplification cycles (MALBAC) forwhole-genome amplification (WGA), we performed next-generation sequencing (NGS) on the spent culture medium used to culture human blastocysts (n = 42) and obtained the ploidy information of all 24 chromosomes. We validated these results by comparing each with their corresponding whole donated embryo and obtained a high correlation for identification of chromosomal abnormalities (sensitivity, 0.882, and specificity, 0.840). With this validated NICS method, we performed chromosome screening on IVF embryos from seven couples with balanced translocation, azoospermia, or recurrent pregnancy loss. Six of them achieved successful clinical pregnancies, and five have already achieved healthy live births thus far. The NICS method avoids the need for embryo biopsy and therefore substantially increases the safety of its use. The method has the potential of much wider chromosome screening applicability in clinical IVF, due to its high accuracy and noninvasiveness.
In recent decades, bearingless switched reluctance motors (BSRMs) have been proposed. However, few researchers focused on the optimal design of the BSRMs. In this paper, the multi-objective optimal ...design of BSRMs is investigated. At first, an analytical design model is derived from the mathematical model of the BSRMs. An initial design is calculated by the analytical design model. The electromagnetic performance is compared with calculation results from the finite-element method (FEM). Then, the objective functions, constraints, and decision variables are also determined. Corresponding sensitivity analysis of the decision variables is implemented. Besides, aiming at solving the optimization problem with disconnected, non-uniformly distributed Pareto front and multiple local optimums, a novel multi-objective genetic particle swarm optimizer (MOGPSO) is presented. The algorithm performance of the proposed MOGPSO is validated by solving the standard test functions. Then the proposed MOGPSO is applied for the optimal design of BSRMs. Optimization results solved by MOGPSO, conventional multi-objective particle swarm optimizer, and non-dominated sorting genetic algorithm II are compared and analyzed. Comparison results reveal that the proposed MOGPSO can achieve more non-dominated solutions in Pareto front and is particularly suitable for optimization of BSRMs. The final optimal design is selected from the obtained Pareto front. The electromagnetic performance is compared with the initial design and verified by the FEM. Verification results show that the optimal design of BSRMs based on the analytical design model and the proposed MOGPSO is feasible and effective.
Ceramifiable silicone rubber composites play important roles in the field of thermal protection systems (TPS) for rocket motor cases due to their advantages. Ceramifiable silicone rubber composites ...filled with different contents of ZrSi
were prepared in this paper. The fffects of ZrSi
on the vulcanization, mechanical and ablation resistance properties of the composites were also investigated. The results showed that the introduction of ZrSi
decreased the vulcanization time of silicone rubber. FTIR spectra showed that ZrSi
did not participate in reactions of the functional groups of silicone rubber. With the increasing content of ZrSi
, the tensile strength increased first and then decreased. The elongation at break decreased and the permanent deformation increased gradually. The thermal conductivity of the composite increased from 0.553 W/(m·K) to 0.694 W/(m·K) as the content of the ZrSi
increased from 0 to 40 phr. In addition, the thermal conductivity of the composite decreased with the increase of temperature. Moreover, thermal analysis showed that the addition of ZrSi
increased the initial decomposition temperature of the composite, but had little effect on the peak decomposition temperature in nitrogen. However, the thermal decomposition temperature of the composite in air was lower than that in nitrogen. The addition of ZrSi
decreased the linear and mass ablation rate, which improved the ablative resistance of the composite. With the ZrSi
content of 30 phr, the linear and mass ablation rate were 0.041 mm/s and 0.029 g/s, decreasing by 57.5% and 46.3% compared with the composite without ZrSi
, respectively. Consequently, the ceramifiable silicone rubber composite filled with ZrSi
is very promising for TPS.
Abstract
The development of technology, in particular, innovations in natural language processing and means to explore big
data, has influenced different aspects in the training of translators and ...interpreters. This paper investigates how learner
corpora and their research contribute to the teaching and learning of translation and interpreting. It starts with a review of the
evolvement of learner corpora in translator and interpreter training. Drawing on data from the Chinese/English Translation and
Interpreting Learner Corpus (CETILC), a learner corpus developed for the study of lexical cohesion, the paper introduces three
case studies to illustrate the possibilities of exploring learner data through human annotation, machine-facilitated human
annotation, and finally human-supervised/edited machine annotation. The findings of the case studies suggest the complexity of
learner language and its intricate relationships with various factors concerning the learner, text, and task. The paper ends with
a discussion of the great potentials of purposely made learner corpora such as the CETILC in translator and interpreter training,
as well as the application of learner corpora in (semi-) automatic processing of learner texts.
To guarantee stable power system operation, a synchronous condenser (SC) is configured in an ultra-high voltage direct current (UHVDC) converter station to provide dynamic reactive power support to ...the power system. The research on the reactive power output modelling of a SC in an UHVDC converter station has important theoretical significance and practical value for the reactive power control of a SC in an UHVDC converter station. Focusing on the reactive power regulation system of the SC with strong coupling, multivariable, and nonlinear features, it is difficult for the universal analytic method to build the SC reactive power output model. A novel reactive power output model of the SC in the UHVDC converter station based on interlaced superposition convolutional neural network-bidirectional long short-term memory (CNN-BiLSTM) is proposed, in which a novel interlaced superposition CNN composed of convolution units with two different structures is built to increase the depth of the network and avoid over-fitting. Particularly the branch channels of convolution units with two different structures are connected by a convolution layer and a skip connection respectively. The interlaced superposition CNN-BiLSTM model is that the combination of the interlaced superposition CNN model and BiLSTM model for improving the model accuracy and generic capability. The Bayesian optimization method is used to optimize its hyperparameters. The application of interlaced Superposition CNN-BiLSTM in SC reactive power output modelling is a new technology. The excitation voltage and excitation current of the SC are used as inputs for the training and testing sampled data, and the reactive power of the SC is used as outputs for the training and testing sampled data. Therefore, the reactive power output model of a SC in an UHVDC converter station based on interlaced superposition CNN-BiLSTM is obtained, and it attains a low root mean square error (RMSE = 0.126750) and a high determination coefficient (
R
2
= 0.999999).
This paper presents a two-dimensional finite element time domain (FETD) algorithm for simulation of ground penetrating radar (GPR) on dispersive and lossy media. The medium of linear dispersion is ...modeled by a multi-pole Debye model, which is incorporated into the FETD scheme through the Fourier transform. We apply the finite element Galerkin method to discretize the computation domain using triangular elements. A perfectly matched layer is extended to match the dispersive media and is used as an absorbing boundary condition to truncate the computation domain. The proposed FETD algorithm is proven to have comparable accuracy with the finite difference time domain (FDTD) method by comparing the simulated electromagnetic waves propagating in a homogeneous dispersive medium with the corresponding analytical solution. At an expense of computational costs, the FETD approach can yield more accurate results when simulating a complex geometry than the FDTD approach, which suffers from the staircase error. Moreover, we analyze the influence of material dispersion on GPR data acquired by different survey geometries. The results demonstrate that material dispersion will bring a great challenge for quantitative interpretation of GPR data. Numerical simulation of GPR data with dispersion does help in accurate interpretation of GPR data.
•A 2D finite element time domain (FETD) algorithm for GPR simulation is proposed.•The medium dispersion is modeled by a multi-pole Debye model.•Numerical simulation of GPR data with dispersion does help in accurate interpretation of GPR data.
Previous studies from this as well as other research groups suggested that non-invasive chromosome screening (NICS) with embryo culture medium can be used to identify chromosomal ploidy and ...chromosomal abnormalities. We here report a series of clinical cases utilizing the technology.
A total of 45 couples underwent in vitro fertilisation during a period between February 2016 and February 2017. Karyotyping revealed normal chromosomes in both partners in 23 couples, and chromosomal rearrangements in at least one partner in 22 couples. Intracytoplasmic sperm injection (ICSI) was used for fertilization. NICS was carried out using embryo culture medium at the blastocyst stage via multiple annealing and looping-based amplification cycles, whole-genome amplification and next-generation sequencing.
A total of 413 embryos were obtained; 170 blastocysts were subjected to NICS. The screening showed euploidy in 79 embryos, aneuploidy in 52 embryos, and mosaic ploidy for 33 embryos. The rate of euploidy was comparable in couples with normal karyotype (50.7%; 38/75) vs. chromosomal rearrangement (43.2%; 41/95). A total of 52 euploid embryos (50 oocyte retrieval cycles) were transferred in 43 women. Biochemical pregnancy rate was 72.0% (36/50). Clinical pregnancy rate was 58.0% (29/50). The rate of spontaneous miscarriage was 3/29 (none with chromosomal aneuploidy). A total of 27 healthy babies were delivered.
NICS could identify embryo chromosomal abnormalities in couples either with or without chromosomal rearrangement, with satisfying clinical outcomes.
Due to the increasing cases of bone damage and bone graft demand, bone-repair technology has great social and economic benefits and the manufacturing of artificial bone implants has become a focus in ...the domain of regenerative therapy. Considering that the traditional manufacturing process cannot effectively control the overall size of the scaffold, the diameter and shape of micropores, and the interoperability of micropores, 3D printing technology has emerged as a focal point of research within the realm of bone tissue engineering. However, the printing accuracy of extrusion-based biological 3D printing techniques is low. In this research, we utilized three-dimensional printing technology to develop high-precision magnesium-containing silicate (CSi-Mg) scaffolds. The precision of this innovative method was scrutinized and the influence of pore size on scaffold strength was systematically analyzed. Furthermore, the influence of the pore architecture on the sidewalls of these 3D-printed scaffolds was evaluated in terms of mechanical properties. The CSi-Mg scaffold, post a 3-week immersion in a simulated body of fluid, demonstrated a high modulus of elasticity (exceeding 404 MPa) and significant compressive strength (beyond 47 MPa). Furthermore, it exhibited commendable bioactivity and biodegradability. These results suggest that the high-precision 3D-printed CSi-Mg scaffolds hold great promise for addressing challenging bone defect cases.
With the rapid development of thermal protection systems for the aerospace industry and power electronics, polyarylacetylene (PAA) resin plays an important role because of its good mechanical ...properties, high glass transition temperature (T
), low water absorption, high char yield (Y
), and the fact that there is no byproduct released in the curing process. In order to further improve the thermal property of PAA based FRP for the thermal protection field, the introduction of a zirconium element into arylacetylene is promising. In this paper, zirconium modified arylacetylene (ZAA) resin was prepared by two-step synthesis. The FTIR analysis characterized its molecular structure and confirmed the products. The viscosity of ZAA was about 6.5 Pa·s when the temperature was above 120 °C. The DSC analysis showed that the ZAA had a low curing temperature, and its apparent activation energy was 103.86 kJ/mol in the Kissinger method and 106.46 kJ/mol in the Ozawa method. The dielectric constant at 1 MHz of poly(zirconium modified arylacetylene) (PZAA) was 3.4. The TG analysis showed that the temperatures of a weight loss of 5% (T
) and char yield (Y
) at 800 °C of PZAA were 407.5 °C and 61.4%, respectively. The XRD results showed the presence of SiO
and ZrO
in the PZAA residue after ablation. The XRF results showed that the contents of SiO
and ZrO
in PZAA residual after ablation were, respectively, 15.3% and 12.4%. The SEM showed that the surface of PZAA after ablation had been covered with a dense and rigid ceramic phase composed of ZrO
and SiO
. Therefore, the introduction of Zr into arylacetylene greatly improved the densification of the surface after ablation, and improved the heat resistant property.
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