A simplified vortex model for the mechanism of vortex-induced vibrations in a streamlined closed-box girder

Chuanxin Hu,Lin Zhao,Yao-Jun Ge 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.4

The vortex-drift pattern over a girder surface, actually demonstrating the complex fluid-structure interactions between the structure and surrounding flow, is strongly correlated with the VIVs but has still not been elucidated and may be useful for modeling VIVs. The complex fluid-structure interactions between the structure and surrounding flow are considerably simplified in constructing a vortex model to describe the vortex-drift pattern characterized by the ratio of the vortex-drift velocity to the oncoming flow velocity, considering the aerodynamic work. A spring-suspended sectional model (SSSM) is used to measure the pressure in wind tunnel tests, and the aerodynamic parameters for a typical streamlined closed-box girder are obtained from the spatial distribution of the phase lags between the distributed aerodynamic forces at each pressure point and the vortex-excited forces (VEFs). The results show that the ratio of the vortex-drift velocity to the oncoming flow velocity is inversely proportional to the vibration amplitude in the lock-in region and therefore attributed to the “lock-in” phenomena of the VIVs. Installing spoilers on handrails can destroy the regular vortex-drift pattern along the girder surface and thus suppress vertical VIVs.

Effects of types of bridge decks on competitive relationships between aerostatic and flutter stability for a super long cable-stayed bridge

Chuanxin Hu,Zhiyong Zhou,Baosong Jiang 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.28 No.4

Aerodynamic configurations of bridge decks have significant effects on the aerostatic torsional divergence and flutter for super long-span bridges, which are onset for selection of suitable bridge decks for those bridges. Based on a cable-stayed bridge with double main spans of 1500 m, considering typical twin-box, stiffening truss and closed-box section, which are the most commonly used form of bridge decks and assumed that the rigidity of those section is completely equivalent, are utilized to investigate the effects of aerodynamic configurations of bridge decks on aerodynamic instability performance comprised of the aerostatic torsional divergence and flutter, by means of wind tunnel tests and numerical calculations, including three-dimensional (3D) multimode flutter analysis and nonlinear aerostatic analysis. Regarding the aerostatic torsional divergence, the results obtained in this study show twin-box section is the best, closed-box section the second-best, and the stiffening truss section the worst. Regarding the flutter, the flutter stability of the twin-box section is far better than that of the stiffening truss and closed-box section. Furthermore, wind-resistance design depends on the torsional divergence for the twin-box and stiffening truss section. However, there are obvious competitive relationships between the aerostatic torsional divergence and flutter for the closed-box section. Flutter occur before aerostatic instability at initial attack angle of +3°and 0°, while the aerostatic torsional divergence occur before flutter at initial attack angle of −3°. The twin-box section is the best in terms of both aerostatic and flutter stability among those bridge decks. Then mechanisms of aerostatic torsional divergence are revealed by tracking the cable forces synchronous with deformation of the bridge decks in the instability process. It was also found that the onset wind velocities of these bridge decks are very similar at attack angle of −3°. This indicates that a stable triangular structure made up of the cable planes, the tower, and the bridge deck greatly improves the aerostatic stability of the structure, while the aerodynamic effects associated with the aerodynamic configurations of the bridge decks have little effects on the aerostatic stability at initial attack angle of −3°. In addition, instability patterns of the bridge depend on both the initial attack angles and aerodynamic configurations of the bridge decks. This study is helpful in determining bridge decks for super long-span bridges in future.

The role of microRNAs in tumors

Chuanxin Liu 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.10

The cancers are a series of serious diseases inthe world, and the mechanism involved in many cancershas not yet been fully elucidated. Therefore, it is a verymajor and significant to explore the molecular mechanismsof cancer occurence and development. MicroRNAs (miRNAs),a class of molecules that regulates gene at posttranscriptionexpression, play an important role in tumorigenesis. It has been proved that a number of miRNAsidentified as aberrantly expressed during cancer development. In addition, some of the miRNAs may have prognosticsignificance. It is the aim of this review to describethe important role of miRNAs in cancer initiation anddevelopment as predictive, diagnostic, prognostic biomarkersand novel therapeutic strategies.

Decomposition-based multi-objective firefly algorithm for RFID network planning with uncertainty

Zhao, Chuanxin,Wu, Changzhi,Chai, Jian,Wang, Xiangyu,Yang, Xinmin,Lee, Jae-Myung,Kim, Mi Jeong Elsevier 2017 Applied soft computing Vol.55 No.-

<P>Radio frequency identification (RFID) is widely used for item identification and tracking. Due to the limited communication range between readers and tags, how to configure a RFID system in a large area is important but challenging. To configure a RFID system, most existing results are based on cost minimization through using 0/1 identification model. In practice, the system is interfered by environment and probabilistic model would be more reliable. To make sure the quality of the system, more objectives, such as interference and coverage, should be considered in addition to cost. In this paper, we propose a probabilistic-based multi-objective optimization model to address these challenges. The objectives to be optimized include number of readers, interference level and coverage of tags. A decomposition based firefly algorithm is designed to solve this multi-objective optimization problem. Virtual force is integrated into random walk to guide readers moving in order to enhance exploitation. Numerical simulations are introduced to demonstrate and validate our proposed method. Comparing with existing methods, such as Non-dominated Sorting Genetic Algorithm-II and Multi-objective Particle Swarm Optimization approaches, our proposed method can achieve better performance in terms of quality metric and generational distance under the same computational environment. However, the spacing metric of the proposed method is slightly inferior to those compared methods. (C) 2017 Elsevier B.V. All rights reserved.</P>

Maximizing lifetime of a wireless sensor network via joint optimizing sink placement and sensor-to-sink routing

Zhao, Chuanxin,Wu, Changzhi,Wang, Xiangyu,Ling, Bingo Wing-Kuen,Teo, Kok Lay,Lee, Jae-Myung,Jung, Kwang-Hyo Butterworths [etc.] 2017 Applied mathematical modelling Vol.49 No.-

<P><B>Abstract</B></P> <P>Wireless sensor networks typically contain hundreds of sensors. The sensors collect data and relay it to sinks through single hop or multiple hop paths. Sink deployment significantly influences the performance of a network. Since the energy capacity of each sensor is limited, optimizing sink deployment and sensor-to-sink routing is crucial. In this paper, this problem is modeled as a mixed integer optimization problem. Then, a novel layer-based diffusion particle swarm optimization method is proposed to solve this large-scaled optimization problem. In particular, two sensor-to-sink binding algorithms are combined as inner layer optimization to evaluate the fitness values of the solutions. Compared to existing methods that the sinks are selected from candidate positions, our method can achieve better performance since they can be placed freely within a geometrical plane. Several numerical examples are used to validate and demonstrate the performance of our method. The reported numerical results show that our method is superior to those existing. Furthermore, our method has good scalability which can be used to deploy a large-scaled sensor network.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Model jointly optimal sink placement and sensor-to-sink routing as a mixed integer optimization problem. </LI> <LI> Propose a discrete particle swarm optimization for sensor-to-sink routing. </LI> <LI> Develop a novel diffusion particle swarm optimization for sinks placement. </LI> <LI> Show superiority of our method over existing results through experimental comparisons. </LI> </UL> </P>

Amorphous LaZnSnO Thin Films by a Combustion Solution Process and Application in Thin Film Transistors

Jun Li,Chuanxin Huang,Yi-Zhou Fu,Jianhua Zhang,Xue-Yin Jiang,Zhi-Lin Zhang 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.1

Amorphous LaZnSnO thin films with different La doping concentrationare prepared by a combustion solution process and theelectrical performances of thin film transistors (TFTs) areinvestigated. The influence of La content on the structure, oxygenvacancies, optical and electrical performance of LaZnSnO thinfilms are investigated. At an appropriate amount of La doping(15 mol.%), LaZnSnO-TFT shows a superior electrical performanceincluding a mobility of 4.2 cm2/V s, a subthreshold swing of 0.50 V/decade and an on/off current ratio of 1.9 × 107. The highperformance LaZnSnO-TFT is attributed to the better interfacebetween SiO2 and LaZnSnO channel layer and the suppression ofoxygen vacancies by optimizing La content. It suggests that Ladoping can be a useful technique for fabricating high performancesolution-processed oxide TFTs.

Improved Multi-objective Optimization Evolutionary Algorithm on Chaos

Xue Ding,Chuanxin Zhao 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.3

In this paper, chaos theory and the traditional multi-objective optimization evolutionary algorithm is put forward, "Chaos-based multi-objective evolutionary algorithm", combines a variety of optimization strategies. The traditional multi-objective evolutionary algorithm for repeating individual causes of variation is based on chaotic analysis of multi-objective evolutionary algorithm and demonstration. According to the characteristics of chaotic map tent, NSGA-II algorithm in this paper on the basis of chaotic map was proposed based on chaotic tent initialization and chaotic mutation multi-objective evolutionary algorithm. The original NSGA-II algorithm is improved, and the introduction of adaptive mutation operator and a new crowding distance is calculated and applied to the design of the algorithm. Analysis and experimental results show that these methods can better improve the distribution of population performance.

20(S)-Ginsenoside Rh2 displays efficacy against T-cell acute lymphoblastic leukemia through the PI3K/Akt/mTOR signal pathway

Ting Xia,Jin Zhang,Chuanxin Zhou,Yu Li,Wenhui Duan,Bo Zhang,Min Wang,Jianpei Fang 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.5

Background: T-cell acute lymphoblastic leukemia (T-ALL) is a kind of aggressive hematological cancer, and the PI3K/Akt/mTOR signaling pathway is activated in most patients with T-ALL and responsible for poor prognosis. 20(S)-Ginsenoside Rh2 (20(S)-GRh2) is a major active compound extracted from ginseng, which exhibits anti-cancer effects. However, the underlying anticancer mechanisms of 20(S)-GRh2 targeting the PI3K/Akt/mTOR pathway in T-ALL have not been explored. Methods: Cell growth and cell cycle were determined to investigate the effect of 20(S)-GRh2 on ALL cells. PI3K/Akt/mTOR pathway-related proteins were detected in 20(S)-GRh2-treated Jurkat cells by immunoblotting. Antitumor effect of 20(S)-GRh2 against T-ALL was investigated in xenograft mice. The mechanisms of 20(S)-GRh2 against T-ALL were examined by cell proliferation, apoptosis, and autophagy. Results: In the present study, the results showed that 20(S)-GRh2 decreased cell growth and arrested cell cycle at the G1 phase in ALL cells. 20(S)-GRh2 induced apoptosis through enhancing reactive oxygen species generation and upregulating apoptosis-related proteins. 20(S)-GRh2 significantly elevated the levels of pEGFP-LC3 and autophagy-related proteins in Jurkat cells. Furthermore, the PI3K/Akt/mTOR signaling pathway was effectively blocked by 20(S)-GRh2. 20(S)-GRh2 suppressed cell proliferation and promoted apoptosis and autophagy by suppressing the PI3K/Akt/mTOR pathway in Jurkat cells. Finally, 20(S)-GRh2 alleviated symptoms of leukemia and reduced the number of white blood cells and CD3 staining in the spleen of xenograft mice, indicating antitumor effects against T-ALL in vivo. Conclusion: These findings indicate that 20(S)-GRh2 exhibits beneficial effects against T-ALL through the PI3K/Akt/mTOR pathway and could be a natural product of novel target for T-ALL therapy.

Determination and prediction of the digestible and metabolizable energy contents of corn germ meal in growing pigs

Meng Shi,Zhaoyu Liu,Hong Liang Wang,Chuanxin Shi,Ling Liu,Junjun Wang,Defa Li,Shuai Zhang 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.3

Objective: This experiment was conducted to determine the chemical composition, digestible energy (DE) and metabolizable energy (ME) contents of corn germ meals (CGM) and to develop equations to predict the corresponding energy contents based on the chemical characteristics of individual CGM. Methods: Sixty-six barrows (initial body weight = 51.3±4.6 kg) were allotted to 11 diets including a basal diet and 10 CGM test diets in a completely randomized design. In the test diets, CGM was included in replacement of 30% of the energy-providing ingredients in the basal diet, resulting in a final inclusion rate of 29.1%. Each diet was fed to 6 barrows housed in individual metabolism crates for a 7-d acclimation period followed by a 5-d total but separate collection of feces and urine. Results: Considerable variation was observed in acid-hydrolyzed ether extract, ether extract, ash, calcium (Ca) and total phosphorus contents among the CGM samples. On dry matter (DM) basis, the DE and ME contents of the CGM ranged from 10.22 to 15.83 MJ/kg and from 9.94 to 15.43 MJ/kg, respectively. The acid detergent fiber (ADF) contents were negatively correlated with the DE and ME contents of CGM samples. The best-fit prediction equations for the DE and ME values (MJ/kg DM) of the 10 CGM were: DE = 26.85–0.28 insoluble dietary fiber (%)–17.79 Ca (%); ME = 21.05–0.43 ADF (%)–11.40 Ca (%). Conclusion: The chemical compositions of CGM vary depending on sources, particularly in ether extract and Ca. The DE and ME values of CGM can be predicted based on their chemical composition in growing pigs.

Mechanism of alveolar bone loss in a collagen‐induced arthritis model in mice

Park, Jung‐,Chul,Su, Chuanxin,Jung, Im‐,Hee,Choi, Seong‐,Ho,Cho, Kyoo‐,Sung,Kim, Chong‐,Kwan,Park, Yong‐,Beom,Lee, Soo‐,Kon,Kim, Chang‐,Sung Blackwell Publishing Ltd 2011 Journal of Clinical Periodontology Vol.38 No.2

<P>Park J‐C, Su C, Jung I‐H, Choi S‐H, Cho K‐S, Kim C‐K, Park Y‐B, Lee S‐K, Kim C‐S: Mechanism of alveolar bone loss in a collagen‐induced arthritis model in mice. J Clin Periodontol 2011; 38: 122–130. doi: 10.1111/j.1600‐051X.2010.01645.x</P><P><B>Abstract</B></P><P><B>Objective: </B> The aim of this study was to understand the cellular/molecular mechanisms of periodontal breakdown in a collagen‐induced arthritis (CIA) model in mice to enhance the understanding of rheumatoid arthritis (RA)‐associated alveolar bone loss in humans.</P><P><B>Materials and Methods: </B> All analyses were performed on paired samples from CIA and control group mice. Mandibles were retrieved for micro‐computed tomography (micro‐CT), histomorphometric analysis, and isolation of alveolar bone cells (ABCs). In vitro osteoclastogenic/osteogenic/adipogenic potentials of ABCs were evaluated and the mRNA expression of downstream effector genes was assessed. Bone formation of ABCs was assessed using an ectopic transplantation model.</P><P><B>Results: </B> Histomorphometric and micro‐CT data showed that alveolar bone loss was significantly increased in the CIA group (<I>p</I><0.05). Osteoclastogenesis was significantly increased in the CIA group in vivo (<I>p</I><0.05), with upregulated mRNA expressions of osteoclastogenesis‐associated genes. Osteoblasts appeared to undergo increased apoptosis, and the bone‐forming activity of ABCs concomitantly decreased with in vitro osteogenic differentiation and in vivo ectopic transplantation (<I>p</I><0.05). Also, adipogenesis‐associated mRNA expression was highly expressed in the CIA group, resulting in significantly enhanced adipocyte differentiation in vitro (<I>p</I><0.05).</P><P><B>Conclusions: </B> These data demonstrate that increased osteoclastic activity, decreased bone‐forming activity and enhanced adipogenesis promote alveolar bone loss in a CIA model in mice, and they suggest that these mechanisms could account for the same outcome in human RA.</P>