Search

2D/3D multimodal alignment plays an important role in medical image navigation surgery, which is mainly used to provide real-time information of preoperative 3D images and intraoperative 2D images to help doctors accurately locate the lesions and plan the surgical paths, so as to improve the safety and efficiency of surgery. A 2D/3D multimodal medical image alignment algorithm was proposed, which firstly utilized the excellent feature extraction capability of Swin Transformer to construct an initial pose estimation model to realize the fast prediction of pose parameters. Then, in order to improve the robustness of the whole alignment method, a coarse alignment method based on the Grangeat relation was introduced. Finally,a fine alignment module based on gradient descent was designed. A fine alignment module based on gradient descent was designed to improve the accuracy of the whole alignment process, and the Sobel differential operator was combined with normalized correlation in this module to improve the sensitivity of the parameter optimization process. The experimental results show that the proposed alignment method meets the alignment requirements in the orthogonal and lateral alignment errors, and the alignment success rate is significantly improved.

The environment in the flood discharge tunnel of tailings pond is complex, and the existing positioning algorithm of detection robot has the problem of positioning failure in weak texture indoor scene, which is difficult to be applied to the precise positioning and accumulative error elimination of detection robot in this kind of environment. In order to solve the above problems, a multi-sensor fusion positioning algorithm of detection robot for tailings flood discharge tunnel is proposed. Based on the odometry method and graph theory, the algorithm simplifies the long-distance positioning in the flood discharge tunnel environment to multi-segment short-distance positioning by using the ArUco code. Firstly, the odometer is calibrated by UMBmark algorithm, which effectively eliminates two types of system errors of wheel diameter and axle diameter. Secondly, the extended Kalman filter (EKF) algorithm is used to fuse the information of the odometer and the inertial measurement unit (IMU), and the odometry method is used to realize the calculation of the position and attitude information of the detection robot during the movement process. Finally, the ArUco code is used as a road sign and fixed inside the tunnel. The detection robot carries the calibrated camera to identify and process the ArUco code information. The robot uses the measurement values of each sensor to form constraints, and combines constraints with the graph optimization method to achieve position and attitude optimization. And according to the information carried by the ArUco code, the accumulative error is eliminated so as to realize the long-distance high-precision positioning of the detection robot in the narrow and long space and weak texture scene. The multi-sensor fusion positioning algorithm is operated and closed in the actual scene of the tailings pond flood discharge tunnel, and 10 groups of repeated positioning experiments traveling 40 m are carried out respectively. The results show that the multi-sensor fusion positioning algorithm has high stability and precision, can correct the accumulative error effectively and realize the precise positioning of the detection robot in the flood discharge tunnel environment. The average positioning error of traveling 20 m is 19.77 cm, the average positioning error of traveling 40 m is 21.23 cm, and the average corrected error of traveling 20 m is 4.2 mm.

ObjectiveMethodsResultsConclusionsThe study aims to explore the relationship between serum uric acid (UA) levels in the first trimester and pregnancy outcomes.The clinical data of 1381 pregnant women who delivered in the Department of Obstetrics and Gynecology of Beijing Chao-Yang Hospital from June 2021 to July 2022 were collected. All patients were categorized into four groups (Q1-Q4) according to quartiles of UA, using the first quartile of UA as the reference group. Logistic regression analysis was used to observe the correlation between UA and pregnancy outcomes. Restricted cubic spline (RCS) was drawn to observe the dose-response relationship between UA and pregnancy outcomes.The numbers of GDM patients in Q1-Q4 were 40 (11.70%), 46 (13.49%), 60 (17.29%) and 83 (23.65%), respectively (p < 0.001). Logistic regression analysis showed that higher quartiles of UA were significantly associated with an increased prevalence of gestational diabetes mellitus (GDM). After adjusting for confounding factors (maternal age, prepregnancy BMI, gestational weight gain, and gestational age), compared with the lowest quartile of UA, the highest quartile of UA had 2.06 times odds of GDM (OR, 2.06; 95% CI, 1.34, 3.18; p = 0.001) in Q4. RCS suggested that the risk of GDM increased slowly until UA levels reached 219.43 µmol/L and then began to increase rapidly afterward (overall p = 0.0037).Increased uric acid concentrations in the first trimester are associated with an increased risk of GDM and gestational hypertension. [ABSTRACT FROM AUTHOR]

This is a summary of a consensus statement on the introduction of "Ultrasound microvasculomics" produced by The Chinese Artificial Intelligence Alliance for Thyroid and Breast Ultrasound. The evaluation of microvessels is a very important part for the assessment of diseases. Super-resolution ultrasound (SRUS) microvascular imaging surpasses traditional ultrasound imaging in the morphological and functional analysis of microcirculation. SRUS microvascular imaging relies on contrast microbubbles to gain sensitivity to microvessels and improves the spatial resolution of ultrasound blood flow imaging for a more detailed depiction of vascular structures and hemodynamics. This method has been applied in preclinical animal models and pilot clinical studies, involving areas including neurology, oncology, nephrology, and cardiology. However, the current quantitative parameters of SRUS images are not enough for precise evaluation of microvessels. Therefore, by employing omics methods, more quantification indicators can be obtained, enabling a more precise and personalized assessment of microvascular status. Ultrasound microvasculomics - a high-throughput extraction of image features from SRUS images - is one novel approach that holds great promise but needs further validation in both bench and clinical settings. Clinical relevance statement: Super-resolution Ultrasound (SRUS) blood flow imaging improves spatial resolution. Ultrasound microvasculomics is possible to acquire high-throughput information of features from SRUS images. It provides more precise and abundant micro-blood flow information in clinical medicine. Key Points: This consensus statement reviews the development and application of super-resolution ultrasound (SRUS). The shortcomings of the current quantification indicators of SRUS and strengths of the omics methodology are addressed. "Ultrasound microvasculomics" is introduced for a high-throughput extraction of image features from SRUS images. [ABSTRACT FROM AUTHOR]

To investigate the hydraulic characteristics during the start-up process of a full-flow pumped storage unit under low-head conditions, numerical simulations were conducted to study the dynamic characteristics during the process, providing a detailed analysis of the dynamic behavior of the internal flow field during the transition period as well as the associated variation in external performance parameters. Study results revealed a vortex-shedding phenomenon during the initial phase of the start-up process. These vortices restrict the flow, initiating a water hammer effect that abruptly elevates the upstream pressure within the runner. As the high-pressure water hammer dissipated, the flow rate rapidly increased, leading to a secondary but relatively weaker water hammer effect, which caused a momentary drop in pressure. This series of events ultimately resulted in significant oscillations in the unit's head. After the guide vanes stop opening, the vortex structures at the runner inlet and outlet gradually weaken. As the runner torque continues to decline, the unit gradually approaches a no-load condition and enters the S-shaped region. Concurrently, pressure pulsations intensify, and unstable vortex formations reemerge along the leading and trailing edges of the runner blades. The escalated flow velocity at the runner's exit contributes to the elongation of the vortex band within the draft tube, ultimately configuring a double-layer vortex structure around the central region and the pipe walls. This configuration of vortices precipitates the no-load instability phenomenon experienced by the unit. [ABSTRACT FROM AUTHOR]

Cemented paste backfill (CPB) is prevented from freezing by antifreeze during transport in subzero temperatures. However, there is yet to be a study on the mechanical properties of CPB with CaCl2 and NaCl antifreeze. This study investigated the effects of antifreeze (CaCl2 and NaCl) on the strength development of CPB curing in above-zero underground environments with a pre-cured at − 12 °C for 1 h. CPB samples with CaCl2 and NaCl antifreeze were prepared and cured under above-zero underground temperatures (2, 20, and 35 °C). Compressive strength tests were implemented after specific curing time (1, 3, 7, and 28 d). Moreover, microstructural analyses and monitoring experiments were performed. The strength of the sample with 15 g/L CaCl2 and NaCl decreased with curing at underground temperatures 20 °C for 1, 3, and 7 d, and increased at 28 d, which was attributed to the competition between the CaCl2 and NaCl antifreeze-induced strength enhancement, that is, increased hydration products, and strength weakening, that is, coarsened pore structure. The development of the CPB strength with the curing time depends on the concentrations of CaCl2 and NaCl and the above-zero underground environments. The findings elucidates on antifreeze CPB in engineering practice. [ABSTRACT FROM AUTHOR]

Halogenation of Y‐series small‐molecule acceptors (Y‐SMAs) is identified as an effective strategy to optimize photoelectric properties for achieving improved power‐conversion‐efficiencies (PCEs) in binary organic solar cells (OSCs). However, the effect of different halogenation in the 2D‐structured large π‐fused core of guest Y‐SMAs on ternary OSCs has not yet been systematically studied. Herein, four 2D‐conjugated Y‐SMAs (X‐QTP‐4F, including halogen‐free H‐QTP‐4F, chlorinated Cl‐QTP‐4F, brominated Br‐QTP‐4F, and iodinated I‐QTP‐4F) by attaching different halogens into 2D‐conjugation extended dibenzo[f,h]quinoxaline core are developed. Among these X‐QTP‐4F, Cl‐QTP‐4F has a higher absorption coefficient, optimized molecular crystallinity and packing, suitable cascade energy levels, and complementary absorption with PM6:L8‐BO host. Moreover, among ternary PM6:L8‐BO:X‐QTP‐4F blends, PM6:L8‐BO:Cl‐QTP‐4F obtains a more uniform and size‐suitable fibrillary network morphology, improved molecular crystallinity and packing, as well as optimized vertical phase distribution, thus boosting charge generation, transport, extraction, and suppressing energy loss of OSCs. Consequently, the PM6:L8‐BO:Cl‐QTP‐4F‐based OSCs achieve a 19.0% efficiency, which is among the state‐of‐the‐art OSCs based on 2D‐conjugated Y‐SMAs and superior to these devices based on PM6:L8‐BO host (17.70%) and with guests of H‐QTP‐4F (18.23%), Br‐QTP‐4F (18.39%), and I‐QTP‐4F (17.62%). The work indicates that halogenation in 2D‐structured dibenzo[f,h]quinoxaline core of Y‐SMAs guests is a promising strategy to gain efficient ternary OSCs. [ABSTRACT FROM AUTHOR]