A comparative study to measure the sagittal condylar inclination using mechanical articulator, virtual articulator and jaw tracking device

Liya Ma,Fei Liu,Jiansong Mei,Jiarui Chao,Zhenyu Wang,Jiefei Shen 대한치과보철학회 2023 The Journal of Advanced Prosthodontics Vol.15 No.1

Purpose. To compare the sagittal condylar inclination (SCI) in dentate individuals measured by the different methods with mechanical articulator (MA), virtual articulator (VA), and a jaw tracking device (JTD) system. Materials and methods. A total of 22 healthy dentate participants were enrolled in this study. For MA workflow, the SCI was obtained by a semi-adjustable articulator with protrusive interocclusal records. The SCI was also set on a VA by aligning intraoral scan (IOS) with cone beam computed tomography (CBCT) and facial scan (FS), respectively. These virtual workflows were conducted in a dental design software, namely VAIOS-CBCT and VAIOS-FS. Meanwhile, a JTD system was also utilized to perform the measurement. Intraclass correlation was used to assess the repeatability within workflows. The bilateral SCI values were compared by Wilcoxon matched-pairs signed rank test for each workflow, and Kruskal-Wallis test and post hoc p-value Bonferroni correction were used to compare the differences among four workflows. The agreement of VAIOS-CBCT, VAIOS-FS, and JTD compared with MA was evaluated by Bland-Altman analysis. Results. Intraclass correlation of the SCI revealed a high degree of repeatability for each workflow. There were no significant differences between the left and right sides (P > .05), except for VAIOS-CBCT (P = .028). Significant differences were not found between MA and VAIOS-FS (P > .05). Bland-Altman plots indicated VAIOS-CBCT, VAIOS-FS, and JTD were considered to substitute MA with high 95% limits of agreement. Conclusion. The workflow of VAIOS-FS provided an alternative approach to measure the SCI compared with MA.

Study of Deformation Mechanisms of a High-Purity α-Titanium Plate Under Monotonic Loading with the EVPSC-TDT Model

Chao Ma,Xing Duan,Xiaoqian Guo,Hua Qiao,Lianying Zhang,Xianbiao Mao,Peidong Wu 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.2

The deformation mechanisms of a rolled high-purity α-titanium plate under monotonic loading along the rolling direction(RD), transverse direction (TD), and normal direction (ND) are investigated by the Elastic Visco-Plastic Self-Consistent(EVPSC) model, which incorporates a Twinning and De-Twinning (TDT) scheme to describe twinning behavior duringstraining. In the EVPSC-TDT model, plastic deformation is assumed to be accommodated by prismatic, basal and pyramidal⟨c + a⟩ slip modes as well as the 10̄12 extension and 11̄22 contraction twin modes. Numerical results based on theEVPSC-TDT model are in good agreement with the corresponding experimental data. The tension–compression asymmetry,anisotropic initial yielding and strain hardening behavior are interpreted in terms of the predicted relative activities of variousdeformation modes, twin volume fractions and texture evolutions. It is demonstrated that twinning plays an important rolein tension–compression asymmetry and plastic anisotropy, which is closely related to the loading direction with respect tocrystal orientations in the initial texture. In addition, it can be concluded that the TDT scheme permits better performancein describing twinning-associated deformation behavior for the rolled high-purity α-titanium plate than the PredominantTwin Reorientation (PTR) model even when detwinning is not involved.

Data Access Control Scheme Based on Blockchain and Outsourced Verifiable Attribute-Based Encryption in Edge Computing

Chao Ma,Xiaojun Jin,Song Luo,Yifei Wei,Xiao-jun Wang 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.7

The arrival of the Internet of Things and 5G technology enables users to rely on edge computing platforms to process massive data. Data sharing based on edge computing refines the efficiency of data collection and analysis, saves the communication cost of data transmission back and forth, but also causes the privacy leakage of a lot of user data. Based on attribute-based encryption and blockchain technology, we design a fine-grained access control scheme for data in edge computing, which has the characteristics of verifiability, support for outsourcing decryption and user attribute revocation. User attributes are authorized by multi-attribute authorization, and the calculation of outsourcing decryption in attribute encryption is completed by edge server, which reduces the computing cost of end users. Meanwhile, We implemented the user's attribute revocation process through the dual encryption process of attribute authority and blockchain. Compared with other schemes, our scheme can manage users' attributes more flexibly. Blockchain technology also ensures the verifiability in the process of outsourcing decryption, which reduces the space occupied by ciphertext compared with other schemes. Meanwhile, the user attribute revocation scheme realizes the dynamic management of user attribute and protects the privacy of user attribute.

CCL12 induces trabecular bone loss by stimulating RANKL production in BMSCs during acute lung injury

Ma Chao,Gao Juan,Liang Jun,Wang Feizhen,Xu Long,Bu Jinhui,He Bo,Liu Guangpu,Niu Ru,Liu Guangwang 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

In the last three years, the capacity of health care systems and the public health policies of governments worldwide were challenged by the spread of SARS-CoV-2. Mortality due to SARS-CoV-2 mainly resulted from the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Moreover, millions of people who survived ALI/ARDS in SARS-CoV-2 infection suffer from multiple lung inflammation-induced complications that lead to disability and even death. The lung-bone axis refers to the relationship between lung inflammatory diseases (COPD, asthma, and cystic fibrosis) and bone diseases, including osteopenia/osteoporosis. Compared to chronic lung diseases, the influence of ALI on the skeleton has not been investigated until now. Therefore, we investigated the effect of ALI on bone phenotypes in mice to elucidate the underlying mechanisms. In vivo bone resorption enhancement and trabecular bone loss were observed in LPS-induced ALI mice. Moreover, chemokine (C-C motif) ligand 12 (CCL12) accumulated in the serum and bone marrow. In vivo global ablation of CCL12 or conditional ablation of CCR2 in bone marrow stromal cells (BMSCs) inhibited bone resorption and abrogated trabecular bone loss in ALI mice. Furthermore, we provided evidence that CCL12 promoted bone resorption by stimulating RANKL production in BMSCs, and the CCR2/Jak2/STAT4 axis played an essential role in this process. Our study provides information regarding the pathogenesis of ALI and lays the groundwork for future research to identify new targets to treat lung inflammation-induced bone loss.

A Study on the Design Principle of Battery Capacity for x-EVs

Chao Ma,Minseok Song,Kiyun Jeong,Hyunsoo Kim 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

Axial Hole Air-Entraining Cooling Technique of Radial-Flow Turbines

Ma Chao,Zhang Jianjian,Wang Ningning,Zhu Zhifu 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.5

In response to the continually increasing thermal load caused by the rising gas temperature in the inlet of radial-flow turbines, this paper proposes the use of axial hole air-entraining cooling to cool the turbine shaft and turbo wheel back-disc. The cooling effect of this technique, as well as its influence on the aerodynamic performance of turbines, were investigated through numerical simulations. The results demonstrate that the axial hole air-entraining cooling technique can significantly improve the local cooling efficiency of the turbine back-disc. Under a blowing ratio of 0.25 %, the local cooling efficiency increased by 154 %, and the temperature decreased by up to 233 K. The maximum temperature on the surface of the turbine shaft at the floating bearing location decreased significantly, thus reducing the coking risk of the lubricating oil. When the blowing ratio was within 0.5 %, the impact of this cooling technique on the overall turbine performance was negligible.

Robust Stability Analysis of Time-varying Delay Systems via an Augmented States Approach

Chao-Yang Dong,Ming-Yu Ma,Qing Wang,Si-Qian Ma 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

This paper focuses on the robust stability analysis of linear systems with time varying delays. The second derivative of the state is used to construct a novel Lyapunov-Krasovskii functional (LKF). Then, both the integrals and derivatives of the states along with the delayed states could be taken into consideration in handling of the LKF. We introduce these augmented variables and establish correlations between them. Moreover, our approach makes it available that quadratic convex combination can be applied not only to the time delay, but also to the derivative of it. Robust stability criteria are presented, and numerical examples illustrate that the methods are less conservative.

Memory-based Human Postural Regulation Control: An Asynchronous Semi-Markov Model Approach

Chao Ma,Hang Fu,Wei Wu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.10

This article investigates the human postural regulation problem from the dynamical system perspective, which is also applicable for human-like robotics. More precisely, since the dynamical human posture parameters may change caused by varying load or environment abrupt, the semi-Markov jump process is employed to model the human standing postural dynamics with multiple modes. Furthermore, a novel memorized regulation strategy is developed for guaranteeing the stable standing such that the past memory information can be well utilized. In particular, the asynchronous regulation procedure is considered for better describing the human postural model with mismatched jumping modes. By model transformation and stochastic analysis, mode-dependent regulation criteria with state feedback model are established by convex optimization approach, based on which the mode-dependent regulation gains are designed accordingly. Finally, the feasibility and effectiveness of our proposed regulation strategy is verified via an illustrative example of quiet upright standing posture.

Carrageenan Oligosaccharides Extend Life Span and Health Span in Male Drosophila Melanogaster by Modulating Antioxidant Activity, Immunity, and Gut Microbiota

Chao Ma,Qiaowei Li,Xianjun Dai 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.1

Carrageenan oligosaccharide (CAO), the hydrolysate of carrageenan from marine red algae, is used as a prebiotic additive or medical material. In this study, male Drosophila melanogaster was used as an animal model to explore the possibility that CAO can extend the life span through its relationship with antioxidation, immunity, and gut microbiota in vivo. The results show that a certain amount of CAO effectively prolonged the average life span and improved the climbing vitality and fecundity of male Drosophila. In addition, 0.125% CAO in the diet significantly increased the activity of Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and catalase (CAT), reduced the content of malondialdehyde (MDA), and significantly repressed the expression of nuclear factor kappa B (NF-κB) gene in old male Drosophila tissues. In the intestinal microbiota analysis, 0.125% CAO in the diet increased the diversity of gut microbiota and improved the abundance of Commensalibacter at the genus level in Drosophila on the 40th day. The above results indicated that CAO supplementation could extend the life span of male Drosophila by improving antioxidant activity, immunity, and by regulating intestinal microflora.

A meso-scale approach to modeling thermal cracking of concrete induced by water-cooling pipes

Chao Zhang,Wei Zhou,Gang Ma,Chao Hu,Shaolin Li 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.15 No.4

Cooling by the flow of water through an embedded cooling pipe has become a common and effective artificial thermal control measure for massive concrete structures. However, an extreme thermal gradient induces significant thermal stress, resulting in thermal cracking. Using a mesoscopic finite-element (FE) mesh, three-phase composites of concrete namely aggregate, mortar matrix and interfacial transition zone (ITZ) are modeled. An equivalent probabilistic model is presented for failure study of concrete by assuming that the material properties conform to the Weibull distribution law. Meanwhile, the correlation coefficient introduced by the statistical method is incorporated into the Weibull distribution formula. Subsequently, a series of numerical analyses are used for investigating the influence of the correlation coefficient on tensile strength and the failure process of concrete based on the equivalent probabilistic model. Finally, as an engineering application, damage and failure behavior of concrete cracks induced by a water-cooling pipe are analyzed in-depth by the presented model. Results show that the random distribution of concrete mechanical parameters and the temperature gradient near water-cooling pipe have a significant influence on the pattern and failure progress of temperature-induced micro-cracking in concrete.