This study utilizes computer vision and deep learning techniques to accurately capture and correct hand posture errors or inaccuracies in Uyghur dance through an open pose bone recognition method. At the same time, the application design platform of Matlab was used to construct a human-computer interaction interface, which was recognized and corrected through camera capture and video processing, improving the practicality and interactivity of the correction system. Through this system, dancers can better master the techniques and norms of dance movements, improve the accuracy of performances, and enhance the effectiveness of artistic expression. The experiment shows that it still has high efficiency and accuracy in multi angle, low light, and complex background scenes.

The numerical modeling of pile-soil dynamic interaction has been a challenging problem in engineering for many years because of the unbounded domain, which typically involves significant computational cost. This paper develops a novel scaled boundary finite element method (SBFEM) that can accurately calculate the soil dynamic impedance of pile groups with end bearing subjected to horizontal vibration. The three-dimensional (3D) problem is first transformed to a two-dimensional (2D) Helmholtz equation in the horizontal plane, exploiting the analytical solution for the vertical modes using separation of variables. The SBFEM is then applied to solve the 2D computational domain, which is divided into bounded and unbounded domains. Based on the SBFEM, an accurate circular artificial boundary condition (ABC) is formulated to simulate the unbounded domain of the soil. A special hybrid quadtree mesh is devised for this problem, where a high-quality structured quadrilateral mesh is generated surrounding the piles. The accuracy of the proposed method is verified using a single pile problem with known analytical solution. The effects of dimensionless frequency, pile numbers, soil depth and relative distance between piles on the soil dynamic impedance are considered.

Hepatic ischemia reperfusion injury (IRI) is a risk factor for early graft nonfunction and graft rejection after liver transplantation (LT). The process of liver IRI involves inflammatory response, oxidative stress, apoptosis and other pathophysiological processes. So far, there is still a lack of effective drugs to ameliorate liver IRI. Trans-anethole (TA) is an aromatic compound. Many medications as well as natural foods contain TA. TA has multiple effects such as anti-inflammation, anti-oxidative stress and anti-apoptosis. However, the mechanism of TA pretreatment in liver IRI is unclear. The mice hepatic IRI model was constructed after gavage pretreatment with TA (10 mg/kg, 20 mg/kg, 40 mg/kg) for 7 consecutive days. Our study confirmed that TA pretreatment significantly improve liver function and reduce serum AST, ALT in hepatic IRI. HE staining showed that TA pretreatment alleviated liver injury. Meanwhile, TA (20 mg/kg) pretreatment attenuated hepatocyte apoptosis in hepatic IRI. In addition, TA (20 mg/kg) pretreatment reduced the inflammatory factors TNF-α, IL-6 and infiltration of CD11b positive cells in liver tissues during hepatic IRI in mice. TA pretreatment also alleviated oxidative stress in mice hepatic IRI. Our study further indicated that TA pretreatment attenuated mice hepatic IRI through inhibiting NLRP3 inflammasome activation via regulation of soluble epoxide hydrolase (sEH). This study provides a novel and effective potential drug with few side effects for easing liver IRI.

Interaction between underwater shock waves and structures has attracted significant interest of many researchers. This study aims to develop a method to solve two-dimensional (2 D) fluid-structure interaction problems during far-field underwater explosion (UNDEX). The acoustic domain which can undergo small pressure variations is considered to describe the fluid-structure interaction during UNDEX. First, the empirical formula of the incident shock waves is considered as free wave motion of the fluid, and the fluid domain is Discretized by the finite element method. Based on the scaled boundary finite element method (SBFEM) and continued fraction solution, an artificial boundary condition (ABC) with high accuracy in time domain is adopted to simulate the truncated infinite domain, which can be placed very close to the radiating field is adopted to simulate the truncated infinite domain. Third, an internal substructure method (ISM) to calculate the equivalent input shock wave loads is proposed. Finally, the proposed method is used to study the scattered waves on a rigid circular structure due to the shock wave, and the effect of the radiation wave due to the motion of the structure on the dynamic responses of the circular structure during UNDEX is studied.

BACKGROUND:This study aims to construct and verify a nomogram model for microvascular invasion (MVI) based on hepatocellular carcinoma (HCC) tumor characteristics and differential protein expressions, and explore the clinical application value of the prediction model.METHODS:The clinicopathological data of 200 HCC patients were collected and randomly divided into training set and validation set according to the ratio of 7:3. The correlation between MVI occurrence and primary disease, age, gender, tumor size, tumor stage, and immunohistochemical characteristics of 13 proteins, including GPC3, CK19 and vimentin, were statistically analyzed. Univariate and multivariate analyzes identified risk factors and independent risk factors, respectively. A nomogram model that can be used to predict the presence of MVI was subsequently constructed. Then, receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were conducted to assess the performance of the model.RESULTS:Multivariate logistic regression analysis indicated that tumor size, GPC3, P53, RRM1, BRCA1, and ARG were independent risk factors for MVI. A nomogram was constructed based on the above six predictors. ROC curve, calibration, and DCA analysis demonstrated the good performance and the clinical application potential of the nomogram model.CONCLUSIONS:The predictive model constructed based on the clinical characteristics of HCC tumors and differential protein expression patterns could be helpful to improve the accuracy of MVI diagnosis in HCC patients.

An efficient approach for transient exterior vibro-acoustic analysis of power-law functionally graded (FG) shells is developed using the scaled boundary finite element method. In the structural formulation, a shell element is treated as a three-dimensional continuum and its middle surface is represented with a quadrilateral spectral element. Along the thickness, the middle surface is scaled and the displacements are approximated using a quadratic Lagrange interpolation. The assumed natural strain method is applied to treat numerical locking and the integral along the thickness is performed analytically. In the acoustic formulation, velocity potential acts as the basic unknown. An infinite fluid is truncated by a spherical surface. The exterior field is simulated through the improved doubly asymptotic open boundary while the interior region is split into subdomains with their impedance evaluated by the improved continued-fraction method. The structure and fluid are discretized independently. The collocation procedure is utilized to perform the data transfer across the nonconforming interface. A high-order implicit time integration scheme is applied to solve the coupled system of equations. Numerical examples demonstrate that the proposed approach is stable, accurate and highly efficient. The effects of the geometric and material parameters on the vibro-acoustic behaviors of FG shells are systematically studied.

Intestine transplantation (IT) is a critical treatment strategy for irreversible intestinal failure. Among all abdominal solid organ transplants, the intestine was the most vulnerable to ischemia and reperfusion injury (IRI). The static cold storage (SCS) technique is currently the most commonly used graft preservation method, but its hypoxia condition causes metabolic disorders, resulting in the occurrence of IRI, limiting its application in marginal organs. It is especially important to improve preservation techniques in order to minimize damage to marginal donor organs, which draws more attention to machine perfusion (MP). There has been much debate about whether it is necessary to increase oxygen in these conditions to support low levels of metabolism since the use of machine perfusion to preserve organs. There is evidence that oxygenation helps to restore intracellular ATP levels in the intestine after thermal or cold ischemia damage. The goal of this review is to provide an overview of the role of oxygen in maintaining environmental stability in the gut under hypoxic conditions, as well as to investigate the possibilities and mechanisms of oxygen delivery during preservation in intestine transplantation studies and clinical models.

Background Intestinal transplantation (IT) has become an important procedure for the treatment of irreversible intestinal failure. However, IT is extremely vulnerable to ischemia–reperfusion injury (IRI). Due to the limitations of static cold storage (SCS), hypothermic machine perfusion (HMP) is rapidly gaining popularity. In this study, the intestinal HMP system is established and HMP is compared with SCS. Methods An intestinal HMP system was built. Ten miniature pigs were randomly divided into the HMP and SCS groups, and their intestines were perfused using the HMP device and SCS, respectively, followed by orthotopic auto-transplantation. Analysis was done on the grafts between the two groups. Results Operation success rates of the surgery were 100% in both groups. The 7-day survival rate was 100% in the HMP group, which was significantly higher than that of the SCS group (20%, P< 0.05). The pathological results showed that fewer injuries of grafts were in the HMP group. Endotoxin (ET), IL-1, IL-6, IFN-γ and TNF-α levels in the HMP group were significantly lower than in the SCS group (P<0.05), whereas IL-10 levels were significantly higher (P<0.05).The intestinal expression levels of ZO-1 and Occludin were higher in the HMP group compared to the SCS group, whereas Toll-like receptor 4 (TLR4), nuclear factor kappa B (NFκB), and caspase-3 were lower. Conclusions In this study, we established a stable intestinal HMP system and demonstrated that HMP could significantly alleviate intestinal IRI and improve the outcome after IT.

We evaluated the significance of the ultrasound (US) markers shear wave dispersion slope (SWDS) and shear wave velocity (SWV) for identification of non-alcoholic steatohepatitis (NASH) and high-risk NASH; the latter was defined as the presence of steatohepatitis, a non-alcoholic fatty liver disease activity score (NAS) >4 or a fibrosis stage >2. Thirty-six male Sprague-Dawley (SD) rats were assigned to two groups: the study (n = 30) and control (n = 6) groups. To initiate non-alcoholic steatohepatitis, study group rats were fed a diet defi-cient in methionine and choline. All rats were examined using ultrasonography to obtain the SWDS and SWV parameters of the liver at the same time points. Fatty liver pathological grades were determined after euthanasia; the livers were categorized in the normal (n = 6), NAFL (non-alcoholic fatty liver) (n = 10) and NASH (n = 20) subgroups based on the NAS scoring system. They were also categorized into subgroups F0 (n = 22), F1 (n = 3), F2 (n = 7) and F3 (n = 4) on the basis of the METAVIR (Meta-analysis of Histological Data in Viral Hepatitis) scoring system. Measurement differences between various grades were evaluated by analysis of variance (ANOVA) or the Mann -Whitney U-test. We used logistic regression to calculate a combination of the two parameters for combined assessment of parameters. The diagnostic value of SWDS, SWV and the two-variable model was determined by receiver operating characteristic (ROC) curve analysis. This analysis revealed stepwise increases in SWDS and SWV with increasing NAFLD severity. The accuracy of SWDS in diagnosing NASH was good (area under the ROC curve [AUC]: 0.88) and was superior to that of SWV (AUC: 0.76). The combination of SWV and SWDS exhibited higher performance (AUC: 0.90). SWV was higher than SWDS in participants with a fibrosis grade >2 (high-risk NASH). For identification of high-risk NASH, SWV exhibited the best diagnostic performance (AUC: 0.89), which was equivalent to that of the two-variable model (AUC: 0.88) and slightly higher than that of SWDS (AUC: 0.85). This study indicates that of the US-based markers, SWDS outperforms SWV in identifying NASH in rats and that combining the two markers may increase their clinical utility in guiding NAFLD and NASH treatment. (E-mail: drtang2002@aliyun.com) (c) 2022 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

This paper presents new variable-order shell elements that require only the shell mid-surface to be discretized, contain no rotational degree of freedom and adopt the full three-dimensional constitutive relationship. In the formulation, a shell element is treated as a three-dimensional continuum undergoing small deformations and its middle surface is represented by a quadrilateral spectral element. Along the thickness direction, the shell geometry is described by scaling the middle surface and the displacements are expressed approximately by interpolating the displacements on the top, middle and bottom surfaces with quadratic Lagrange shape functions. The assumed natural strain method is applied to eliminate transverse shear locking, membrane locking and curvature thickness locking while the volumetric locking is alleviated by elevating the element order. Numerical examples demonstrate that the developed shell elements are superior in applicability, accuracy and efficiency. (c) 2021 Elsevier Ltd. All rights reserved.

In this study, the Scaled Boundary Finite Element Method (SBFEM) was used to perform analyses and evaluate the objective function in shape optimization of devices relying on acoustic wave propagation. Similar to the Boundary Element Method (BEM), the SBFEM requires only the discretization of the boundary of the computational domain. However, unlike BEM, there is no need for a fundamental solution; thus, the SBFEM provides a flexibility similar to that of the Finite Element Method (FEM). The dimension reduction is achieved by representing the solution analytically inside the domain and numerically on the boundary. Consequently, the SBFEM provides a flexible platform for shape optimization and alleviates the re-meshing difficulties encountered in FEM. It was shown that domain boundaries can be optimized with a minimum number of design variables, while the existing accurate transparent boundary conditions effectively eliminate the artificial numerical reflections for a wide range of frequencies.

With the dawn of organ donation after a citizen's death in China, the use of split-liver transplantation (SLT) can effectively increase the source of donor liver, reduce the waiting time for organ transplantation in patients, and particularly solve the problem of organ shortage in children. In recent years, many transplantation centers have been performing SLT to varying degrees and efficacy. At the current stage, the experiences of countries with advanced transplantation techniques should be used to establish an SLT consensus that is suitable for China to further increase the ratio and efficacy of SLT. In this paper, we combined expert experiences to generate an SLT expert consensus that included donor and donor liver evaluation, recipient selection criteria, donor and recipient matching, selection of splitting form and tools, blood vessels and bile ducts dissection and allocation, perioperative management of SLT, and organ allocation.& COPY; 2020 The Third Affiliated Hospital of Sun Yat-sen University. Publishing Services by Elsevier B. V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

In this paper, a direct time-domain procedure for the seismic analysis of dam–reservoir–foundation interactions is presented based on the scaled boundary finite element method (SBFEM). The SBFEM is a semi-analytical method and requires the discretization of boundary only. The geometric complexity in the bounded dam–reservoir–foundation system is easily handled in the SBFEM using quadtree meshes where each structural component can be discretized independently. The elastic wave fields in the unbounded foundation are rigorously captured through SBFE solutions in terms of displacement unit-impulse response functions, while the acoustic wave propagation in the semi-infinite reservoir is modelled by the SBFE-based doubly asymptotic open boundary. The input of seismic excitations is addressed by incorporating the Domain Reduction Method (DRM) into the SBFEM. Cracks are modelled efficiently and accurately by combining the SBFEM and quadtree meshes. The accuracy and efficiency of the proposed methodology is investigated by studying several benchmarks, Pine Flat dam and Jin'anqiao dam.

This study aimed to investigate whether viscoelasticity measurements can be used to quantitatively analyze and monitor therapy response in hepatic ischemia-reperfusion injury (HIRI). All animals were divided into three groups: a sham operation group (n = 12), an ischemia-reperfusion injury (IRI) group (n = 12) and an andrographolide pre-treatment group (n = 6). To assess the feasibility of using shear-wave velocity (SWV) and shear-wave dispersion (SWD), shear-wave ultrasound elastography was applied onto IRI rats after 4 and 24 h of reperfusion or sham operation (each time point subgroup n = 6). For the verification experiments, six additional rats received andrographolide injection 2 h before IRI and were examined 24 h after reperfusion. The rats were sacrificed for biochemical and histopathological analyses after ultrasound scanning was performed. Compared with the sham group, the IRI group exhibited significantly higher SWD after both 4 and 24 h of reperfusion（10.69 ± 0.69 vs. 15.20 ± 3.23 and 9.01 ± 0.46 vs. 19.35 ± 0.86; p < 0.05). A positive correlation was found between SWD values and Suzuki's score (r = 0.621; p < 0.05). No correlation was found between SWV and Suzuki's score (r = 0.283; p > 0.05), although significant differences were found between the two groups after 24 h of reperfusion. Andrographolide treatment resulted in a significantly decreased SWD (15.24 ± 0.45 vs. 19.35 ± 0.86; p < 0.05), whereas SWV showed no statistically significant difference. This study demonstrated the potential of using viscoelasticity measurements for the diagnosis and therapeutic monitoring of HIRI, and that the use of SWD was significantly more advantageous than SWV.

为研究重叠网格方法在背景网格和局部网格区域插值所引入的额外数值误差,本文结合正交试验方法和ITTC不确定度分析方法,对该数值误差、网格尺度、时间步长和湍流模型进行了多因子不确定度分析.数值计算工况采用L9(34)正交表进行设计,考虑网格形式、网格尺度、时间步长和湍流模型四个因子,每个因子采用3个水平.不确定度分析结果表明,因子时间步长和网格尺度得到了验证和确认.正交试验方法中的方差分析表明,因子湍流模型和网格形式对数值模拟误差的影响相比于时间步长和网格尺度并不显著,即量级相当.

This paper develops an efficient modeling technique based on the scaled boundary finite element method (SBFEM) for transient vibro-acoustic analysis of plates and shells. For simulating the structural dynamic behaviors, a novel shell formulation based on three-dimensional linear elastic theory is presented where only the bottom surface of the shell is discretized with finite elements while the solution along the thickness is expressed analytically as a Padé expansion. A new scaling idea named normal scaling strategy is introduced to enable the formulation to be applicable to geometrically arbitrary shells. The acoustic field is assumed to be infinite and first truncated by a spherical surface into an interior finite region and an exterior unbounded region. The former is further split into a number of bounded subdomains which are analyzed by the improved continued-fraction approach while the latter is simulated by the improved high-order doubly-asymptotic open boundary. These formulations are consistently constructed within the SBFEM framework. The structural and acoustic domains are discretized independently and a simple and reliable coupling scheme is devised. The Bathe time integration method is employed to perform the transient analysis. Numerical examples are presented to demonstrate the validity and performance of the proposed methodology.

A machine learning aided reliability assessment framework is presented for functionally graded material (FGM) structures under plane strain/stress conditions with the consideration of elastoplasticity. The material nonlinearity of the FGM is modelled through the implementation of the Tamura-Tomota-Ozawa (TTO) model. For safety evaluation of FGM structures, the volume fraction of FGM has been modelled through spatially dependent uncertainty as random field for the concerned composite. In order to solve the complex stochastic elastoplastic problem, a further developed machine learning aided technique called the extended support vector regression (X-SVR) with a generalized Dirichlet feature mapping function has been introduced and then, the corresponding probabilistic features, including the statistical moments, probability density functions (PDFs), and cumulative distribution functions (CDFs), of the concerned structural responses can be effectively established for assessing the reliability of FGM structures. Moreover, the proposed approach is competent to deliver critical information regarding the uncertain system inputs which can be beneficial for subsequent safety assessment and structural designs for the FGM. Two test functions and two numerical examples have been adopted to visualise the accuracy, stability and capability of the proposed safety assessment framework for FGM structures.

This paper introduces an automatic way of performing 3D static and dynamic elastoplastic analyses in the framework of the scaled boundary finite element method (SBFEM), which only requires the boundary discretization and thus can provide high flexibility in automatic mesh generation. The input models in this paper are described by Standard Tessellation Language (STL) format due to its simplicity and popularity in computer-aided design. The automatic mesh generation from any input geometry is achieved by utilizing the octree decomposition algorithm and boundary trimming. An efficient approach for 2D static image-based elastoplastic analysis based on SBFEM is extended to 3D static and dynamic elastoplastic analyses in this present work. In this improved approach, the return mapping algorithm is only required to be performed at the scaling center of each subdomain in the yield zone. Constant elastoplastic constitutive matrix and internal stresses are used within each yielded subdomain as well. This will greatly simplify the implementation of elastoplastic formulation and reduce the costs involved in the elastoplastic analysis as the return mapping algorithm is computationally expensive. Meanwhile, stabilization matrix is also introduced in the elastoplastic stiffness matrix to eliminate the spurious modes. Numerical examples are presented in this paper to show the feasibility and accuracy of the proposed approach as well as its capability of modelling complex structures in practical applications.

An automatic approach for 3D analysis of acoustic-structure interaction problems is proposed based on the scaled boundary finite element method (SBFEM). The acoustic domain studied in this paper is assumed to be infinite. The infinite acoustic domain is divided into a near field (bounded domain) and a far field (unbounded domain). The acoustic near field contains structures of arbitrary shape, while the far field represents the unbounded acoustic domain. For modeling the wave propagation accurately and efficiently, continued fractions are employed to evaluate the dynamic stiffness and impedance of subdomains in both structural and acoustic domains. The time-domain equations for both structural and acoustic domains can be obtained by introducing auxiliary variables. Via satisfying the boundary conditions on the acoustic-structure interface, the global system of equations for acoustic-structure interaction system can be constructed. Symmetric formulations can also be obtained for this coupled system. Since the SBFEM requires the discretization of only the boundary, the mesh transition on the acoustic-structure interface is easily addressed by the subdivisions of 2D surface elements. Automatic meshing techniques can be incorporated in the proposed approach to generate meshes directly from the input geometrical models. Numerical examples are presented to demonstrate the accuracy, efficiency and potential of the proposed approach for modeling complex 3D acoustic-structure interaction problems.

Background: Normothermic machine perfusion (NMP) preservation is superior to cold preservation during reduced-size liver transplantation (RSLT) in pigs. However, the mechanism of this protective effect has not been explained. We aimed to compare the effects of NMP preservation with that of cold preservation (CS) in protecting against ischemia-reperfusion injury (IRI) during RSLT in pigs. Material/Methods: Twenty-four healthy Bama miniature pigs were randomized into 2 groups: 1) the NMP group in which donor livers harvested without warm ischemia time and cardiac activity were connected to the NMP system to reduce liver size under normothermic conditions, and 2) the CS group in which donor livers harvested without warm ischemia time and cardiac activity were perfused using the University of Wisconsin (UW) solution and then preserved in the 0-4 degrees C UW solution to reduce liver size under cold conditions. Livers were then transplanted without veno-venous bypass. Amounts of bile secretion for the NMP groups were recorded hourly. The serological indices were measured. Expressions of cytochrome C, caspase 3, and NE-kappa B p65 in liver tissue were observed. Results: The levels of bile secretions were gradually diminished from 16.50 +/- 2.66 mL/h before splitting to 6.35 +/- 1.24 mL/h after splitting. With the exception of TNF-alpha on postoperative day 2, overall, levels of TNF-alpha, IL-1, IL-6, and MDA were significantly lower in the NMP group versus CS group for all 5 days postoperatively. Finally, cytochrome C, caspase 3, and NE-kappa B p65 expressions were all significantly suppressed in the NMP group as compared with the CS group. Conclusions: MP preservation is superior to cold preservation in protecting against liver IRI during RSLT in pigs.