P–267 Characterising a novel embryo grading system for 4-cell embryos including symmetry, fragmentation, cell configuration, cell contacts per cell, distance between cells, and cell adhesion strength

Study question What other cell junction factors can be easily characterised from imagery of 4-cell embryos to assist in embryo classification and prediction of viability? Summary answer 4-cell embryo grading should not only account for symmetry and fragmentation, but also cell configuration and cell adhesion quality. What is known already 4-cell embryos are clinically classified according to cell number, symmetry and fragmentation without accounting for cell orientation or quality of cell junctions. Our previous work has focused on classification of 4-cell embryos according to overall embryo shape (“tetrahedral” versus “planar”) using artificial intelligence. Our work, as confirmed by others, has demonstrated that embryo shape at the 4-cell stage is an important determinant of the ability of the embryo to reach blastocyst, utilisation, pregnancy and live birth. This is thought to be because of variations in intracellular communication between cells in embryos with different orientations, and consequently, different intracellular junction phenotypes. Study design, size, duration Using geometrical principles, possible permutations of 4-cell embryos (excluding redundant mirrored permutations) were identified and further classified based on shape and number of cell junctions. For ease of calculations, cells were assumed to be spherical, with at least one intracellular cell contact and symmetrical in size with other cells in the same embryo. Participants/materials, setting, methods The six distances between centroids of permutations for each configuration were calculated relative to the size of the cell, and the shortest distance between cell membranes. Adhesion was characterised from embryo imagery based on the overall shape of the cell, external angle between cells and the length of cell contact (the more spherical the cell, the larger the angle and the longer the cell contact point, the stronger the adhesion, adapted from Winklbauer,2015). Main results and the role of chance 4-cell embryos may be classified into 13 variant configurations: 1 typical Tetrahedral, 2 quasi-tetrahedral, 10 planar. These variants were classified according to number of cells with 0,1,2 and 3 intracellular contacts, leading to six possible configurations: 0004(tetrahedral), 0022(quasi tetrahedral/planar), 0040 (planar), 0121(quasi tetrahedral/planar), 0301(planar), 0220(planar). The number of total cell junctions in the embryo in each of these configurations was 12,10,8,8,6,6 respectively, with tetrahedral embryos (0004) having twice the cell contacts compared to planar embryos (p < 0.001). Tetrahedral embryos have an advantage over the other embryo configurations in terms of better embryo communication, as demonstrated by the lower average and variation in distance and shorter sum of all intracellular distances between centroids (mean: 0.78 vs 0.94,0.98,1.04,1.09,1.19; stdev:0.06 vs 0.2,0.3,0.3,0.4,0.4,0.3; sum:4.7 vs 5.2,6.3,6.1,6.7,7.0,6.0 cell lengths) and between cells (mean: 0 vs 0.34,0.07,0.39,0.42,0.56; stdev: 0 vs 0.56,0.11,0.51,0.53,0.66; sum: 0 vs 2.71,0.43,3.13,3.38,4.46 cell lengths) observed in tetrahedral embryos versus other five configurations respectively (p < 0.001). Cell junctions were classified according to degree of cell adhesion: A:none (cells remain spherical in shape); B:weak (external angle between the cells is acute, there is a narrow visible cell junction); C:strong (external angle between the cells is obtuse with a wide visible cell junction). Limitations, reasons for caution: Follow-up studies will evaluate the impact of different cell shapes,cells without intracellular contact,and asymmetrical embryos. The proposed classification will be validated against a database of known outcome from 8 clinics from 6 countries to quantify the clinical implications of this classification,and the consistency of assessment by humans and AI . Wider implications of the findings: It is clear that differences in intracellular communication between cells in embryos with different orientations, and different intracellular junction phenotypes is an important determinant of embryo viability. Our classification system allows for an easy to use and mathematically sound criteria for classifying 4-cell embryo cell junction quality. Trial registration number NA

IP-Dip-Based SPR Structure for Refractive Index Sensing of Liquid Analytes

In this paper, we present a two-dimensional surface plasmon resonance structure for refractive index sensing of liquid analytes. The polymer structure was designed with a period of 500 nm and prepared in a novel IP-Dip polymer by direct laser writing lithography based on a mechanism of two-photon absorption. The sample with a set of prepared IP-Dip structures was coated by 40 nm thin gold layer. The sample was encapsulated into a prototyped chip with inlet and outlet. The sensing properties were investigated by angular measurement using the prepared solutions of isopropyl alcohol in deionized water of different concentrations. Sensitivity of 478–617 nm per refractive index unit was achieved in angular arrangement at external angle of incidence of 20°.

Sagittal bending of the optic nerve at the entrance from the intracranial to the optic canal and ipsilateral visual acuity in patients with sellar and suprasellar lesions

OBJECTIVEVisual acuity impairment due to sellar and suprasellar tumors is not fully understood. The relationship between these tumors and disturbance of visual function was examined using preoperative MRI.METHODSThis study reviewed 93 consecutive patients with sellar and suprasellar tumors. Best-corrected visual acuity (BCVA) and visual impairment score (VIS) were used for estimation of visual impairments. Preoperative MR images were examined to obtain several values for estimation of chiasmatic compression. Additionally, the optic nerve–canal bending angle (ONCBA) was newly defined as the external angle formed by the optic nerve in the optic canal and the optic nerve in the intracranial subarachnoid space at the junction, using preoperative sagittal T2-weighted MR images.RESULTSThe mean ONCBA was about the same on the right (44° ± 25°) and the left (44° ± 24°). Sagittal ONCBA was defined as large (> 45°) and moderate (≤ 45°) on each side. Preoperative VIS was found to be significantly worse if the right or left ONCBA (or both) was large (right side: ONCBA large [median 20, IQR 8–30] > ONCBA moderate [median 10, IQR 3–17], p = 0.003, Mann-Whitney U-test; left side: ONCBA large [median 22, IQR 9–30] > ONCBA moderate [median 10, IQR 2–16], p = 0.001). A large ONCBA showed a significant relationship with unfavorable ipsilateral BCVA (> logMAR, 0; right side, p = 0.001, left side, p = 0.001, chi-square test). The ONCBA had a positive correlation with ipsilateral BCVA (right: r = 0.297, p = 0.031; left: r = 0.451, p = 0.000, Pearson’s correlation coefficient). Preoperative BCVA was significantly lower on the same side in the large ONCBA group compared with the moderate ONCBA group (right side: large ONCBA 0.169 ± 0.333 [logMAR, mean ± standard deviation] vs moderate ONCBA 0.045 ± 0.359, p = 0.026, Student t-test; left side: large ONCBA 0.245 ± 0.346 vs moderate ONCBA 0.025 ± 0.333, p = 0.000). This visual acuity impairment improved after resection of the tumors.CONCLUSIONSSagittal bending of the optic nerve at the entrance from the intracranial subarachnoid space to the optic canal may be related to ipsilateral deterioration of visual acuity in sellar and suprasellar lesions. Sagittal T2-weighted MRI is recommended for preoperative estimation of the optic nerve bending.

Test Study on Composite Strengthened Beam with CFRP Board, Angle Steel and External Prestressed Steel Strand

The composite strengthening beam combined with a variety of reinforcement technology, complementary advantages.In order to study the mechanical behavior of T-beam strengthened with CFRP board, external angle steel and external prestressed steel strand, six reinforced test beams were fabricated to compare and analyze the structural characteristics of bending stiffness, crack development and bearing capacity. The research shows that the beam strengthened by CFRP board, external angle steel and external prestressed steel strand has good working performance. The rebound force of the bending deformation of the external angle steel and the upward force of the external prestressed steel strand reliably anchor the carbon fiber board, avoiding the bond failure and slippage of the CFRP.The three kinds of reinforcing materials work together and complement each other, which can give full play to their respective strength. The composite strengthened beam with CFRP board, external angle steel and external prestressed steel strand can greatly improve the cracking load, structural stiffness and ultimate bearing capacity of the original beam, and the reinforcement effect is optima.

Mechanical behavior of sealed waterproof for shield tunnel segment joint under different assembling ellipticity

During the construction and assembling stages of shield tunnels, the ellipticity of segment assembly, and the angle between segments are the main reasons for joint leakage of shield tunnel. In this paper, taking Chengdu Metro shield tunnel as the research background, the relationship between assembling ellipticity and segment opening angle is obtained by geometric calculation, and the waterproof effect of gasket under different segment joint angle is studied by finite element analysis method. Results of the nonlinear numerical analyses, there is a linear positive relationship between the opening angle of segments and the ellipticity degree. Meanwhile, the different side joint opening angles of the segments have different effects on the waterproof effect of the gasket, which is manifested as the external angle is greater than the internal. Based on the above research results, this article can provide some references for the design, production, processing, and quality inspection of shield tunnel gasket in the future.

Effects of soft tissue surgery on transverse kinematics in patients with cerebral palsy

Background Gait disturbances, including flexed knee gait, stiff knee gait, and tip-toeing gait, are common in patients with cerebral palsy (CP). There has been no reports regarding kinematic changes in the transverse plane after soft tissue surgeries, such as distal hamstring lengthening (DHL), rectus femoris transfer (RFT), and tendo-Achilles lengthening (TAL). This study aimed to evaluate changes in the transverse plane after soft tissue surgery in patients with CP by assessing the effects of the DHL, RFT, and TAL. Methods The study enrolled 156 consecutive patients (mean age, 8.4 years; range, 4.4 to 20.9), representing 213 operated limbs, who underwent soft tissue surgery including DHL with semitendinosus transfer, RFT, and TAL. All patients were assessed by preoperative and 1-year postoperative three-dimensional gait analysis. Changes in transverse plane kinematics after soft tissue surgery and affecting factors were analyzed. Results Sagittal kinematics including knee flexion at initial contact, ankle dorsiflexion at initial contact, and mean ankle dorsiflexion in the stance phase were significantly improved after single event multilevel surgery (all p < 0.001). Transverse kinematics, including mean tibial rotation and foot progression angle, were significantly improved to a more external angle after soft tissue surgeries (− 2.9°, p = 0.004 and − 9.5°, p < 0.001). The mean hip rotation was significantly improved to a more external angle by RFT (− 4.7°, p = 0.010) and the foot progression angle was significantly improved to a more external angle by TAL (− 3.9°, p = 0.028). Conclusions This study found that the transverse kinematics were improved to a more external angle after soft tissue surgery in patients with CP. Therefore, clinicians should consider that soft tissue surgery can affect the transverse plane kinematics in patients with CP. To confirm our findings, further research regarding the natural history of femoral and tibial torsion in children with CP is needed.

The helicoidal modulated nematic phases in a model system of V-shaped molecules

The phase behavior of the melt of the symmetric V-shaped molecules has been inspected within the Landau–de Gennes approach. The arms of V-shaped molecule are modeled by rod-like segments connected at an external angle [Formula: see text]; these segments are assumed to be composed of monomer units. The phase diagram of the system contains regions of stability of the isotropic, homogeneous nematic, and modulated nematic phases: nematic twist bend (N[Formula: see text]) phase that is characterized by the three directors which move on a helix and one of these directors forms a fixed nonzero cone angle with the helix axis, and the N0 modulated phase in which one director is parallel to the helix axis while two others are orthogonal to the helix axis. The characteristic periods of modulated structures were found to be of order a few molecular lengths.

FAMILY OF INVARIANT CANTOR SETS AS ORBITS OF DIFFERENTIAL EQUATIONS II: JULIA SETS

The Julia set of the quadratic map fμ(z) = μz(1 - z) for μ not belonging to the Mandelbrot set is hyperbolic, thus varies continuously. It follows that a continuous curve in the exterior of the Mandelbrot set induces a continuous family of Julia sets. The focus of this article is to show that this family can be obtained explicitly by solving the initial value problem of a system of infinitely coupled differential equations. A key point is that the required initial values can be obtained from the anti-integrable limit μ → ∞. The system of infinitely coupled differential equations reduces to a finitely coupled one if we are only concerned with some invariant finite subset of the Julia set. Therefore, it can be employed to find periodic orbits as well. We conduct numerical approximations to the Julia sets when parameter μ is located at the Misiurewicz points with external angle 1/2, 1/6, or 5/12. We approximate these Julia sets by their invariant finite subsets that are integrated along the reciprocal of corresponding external rays of the Mandelbrot set starting from the anti-integrable limit μ = ∞. When μ is at the Misiurewicz point of angle 1/128, a 98-period orbit of prescribed itinerary obtained by this method is presented, without having to find a root of a 298-degree polynomial. The Julia sets (or their subsets) obtained are independent of integral curves, but in order to make sure that the integral curves are contained in the exterior of the Mandelbrot set, we use the external rays of the Mandelbrot set as integral curves. Two ways of obtaining the external rays are discussed, one based on the series expansion (the Jungreis–Ewing–Schober algorithm), the other based on Newton's method (the OTIS algorithm). We establish tables comparing the values of some Misiurewicz points of small denominators obtained by these two algorithms with the theoretical values.