Mda-9/syntenin Promotes Human Brain Glioma Migration through Focal Adhesion Kinase (FAK)-JNK and FAK-AKT Signaling

Zhong, Dong,Ran, Jian-Hua,Tang, Wen-Yuan,Zhang, Xiao-Dong,Tan, Yun,Chen, Gui-Jie,Li, Xiao-Song,Yan, Yi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Invasion is usually recognized as the main reason for the high recurrence and death rates of glioma and restricts the efficacy of surgery and other therapies. Therefore, we aimed to investigate the mechanism involved in promotion effects of mda-9/syntenin on human glioma cell migration. The wound healing method was used to test the migration ability of human glioma cells CHG-5 and CHG-hS, stably overexpressing mda-9/syntenin. Western blotting was performed to determine the expression and phosphorylation of focal adhesion kinase (FAK) and JNK in CHG-5 and CHG-hS cells. The migration ability of CHG-hS cells was significantly higher than that of CHG-5 cells in fibronectin (FN)-coated culture plates. Phosphorylation of FAK on tyrosine 397, 576, and 925 sites was increased with time elapsed in CHG-hS cells. However, phosphorylated FAK on the tyrosine 861 site was not changed. Phosphorylated Src, JNK and Akt levels in CHG-hS cells were also significantly upregulated. Phosphorylation of JNK and Akt were abolished by the specific inhibitors SP600125 and LY294002, respectively, and the migration ability of CHG-hS cells was decreased, indicating that the JNK and PI3K/Akt pathways play important roles in regulating mda-9/syntenin-induced human brain glioma migration. Our results indicate Mda-9/syntenin overexpression could activate FAK-JNK and FAK-Akt signaling and then enhance the migration capacity of human brain glioma cells.

Numerical simulation of water flow in an axial flow pump with adjustable guide vanes

Zhongdong QIAN,Yan WANG,Wenxin HUAI,이영호 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.4

A new adjustable guide vane (AGV) is proposed in this paper. This vane can reduce hydraulic losses and improve the performance of an axial flow pump. The formula of AGV adjustment was obtained after theoretical analysis. The fluid flow inside the axial flow pump with a fixed guide vane and adjustable guide vane was simulated. The calculated Q-H curves for the fixed guide vane agreed well with the experimental ones. The results show that the attack angle and flow separation have an important contribution to the vortices which create hydraulic losses in the guide vane channel. The AGV can decrease hydraulic losses and significantly enhance the pump head and efficiency by changing the guide vane angle.

Anti-Aging Scheduling in Single-Server Queues: A Systematic and Comparative Study

Zhongdong Liu,Liang Huang,Bin Li,Bo Ji 한국통신학회 2021 Journal of communications and networks Vol.23 No.2

The age of information (AoI) is a new performance met ric recently proposed for measuring the freshness of information ininformation-update systems. In this work, we conduct a systematicand comparative study to investigate the impact of scheduling poli cies on the AoI performance in single-server queues and provideuseful guidelines for the design of AoI-efficient scheduling poli cies. Specifically, we first perform extensive simulations to demon strate that the update-size information can be leveraged for achiev ing a substantially improved AoI compared to non-size-based (orarrival-time-based) policies. Then, by utilizing both the update-sizeand arrival-time information, we propose three AoI-based policies. Observing improved AoI performance of policies that allow ser vice preemption and that prioritize informative updates, we fur ther propose preemptive, informative, AoI-based scheduling poli cies. Our simulation results show that such policies empiricallyachieve the best AoI performance among all the considered poli cies. However, compared to the best delay-efficient policies (suchas shortest remaining processing time (SRPT)), the AoI improve ment is rather marginal in the settings with exogenous arrivals. In terestingly, we also prove sample-path equivalence between somesize-based policies and AoI-based policies. This provides an intu itive explanation for why some size-based policies (such as SRPT)achieve a very good AoI performance.

LARGE EDDY SIMULATION OF VORTEXING FLOW IN THE MOLD WITH DC MAGNETIC FIELD

Zhongdong Qian,Yulin Wu Korea Society of Computational Fluids Engineering 2005 한국전산유체공학회지 Vol.10 No.1

Large eddy simulation of vortexing flow of molten steel in the continuous casting mold with and without DC magnetic field was conducted. The influence of the position of magnetic field to the residence time and depth of the vortex was analyzed. The mechanism of the influence of magnetic field to the vortexing flow was found. The computational results show that the vortexing flow is the result of shearing of the two un-symmetric surface flows from the mold narrow faces when they meet adjacent to the SEN; the un-symmetric flow for turbulent vortex is caused by turbulent energy of the fluid and that for biased vortex is caused by biased flow and the turbulent energy of fluid; with the moving of the magnetic field from the centerline of the outlet of the SEN to the free surface, the surface velocity is decreased gradually and the depth of the turbulent vortex and the biased vortex is decreased, the residence time is increased with the magnetic field moves from DL=120mm to DL=60mm and then decreased; the turbulent vortex and the biased vortex can be eliminated when the magnetic field is located at the free surface.

LARGE EDDY SIMULATION OF VORTEXING FLOW IN THE MOLD WITH DC MAGNETIC FIELD

Qian Zhongdong,Wu Yulin 한국전산유체공학회 2005 한국전산유체공학회지 Vol.10 No.1

Large eddy simulation of vortexing flow of molten steel in the continuous casting mold with and without DC magnetic field was conducted. The influence of the position of magnetic field to the residence time and depth of the vortex was analyzed. The mechanism of the influence of magnetic field to the vortexing flow was found. The computational results show that the vortexing flow is the result of shearing of the two un-symmetric surface flows from the mold narrow faces when they meet adjacent to the SEN; the un-symmetric flow for turbulent vortex is caused by turbulent energy of the fluid and that for biased vortex is caused by biased flow and the turbulent energy of fluid; with the moving of the magnetic field from the centerline of the outlet of the SEN to the free surface, the surface velocity is decreased gradually and the depth of the turbulent vortex and the biased vortex is decreased, the residence time is increased with the magnetic field moves from DL=120mm to DL=60mm and then decreased; the turbulent vortex and the biased vortex can be eliminated when the magnetic field is located at the free surface.

Bubble formation in a step-emulsification microdevice: hydrodynamic effects in the cavity

Zhiwei Zhang,Zhongdong Wang,Fengrui Bao,Mengyu Fan,Shaokun Jiang,Chunying Zhu,Youguang Ma,Taotao Fu 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

This study focuses on the generation of bubbles in a step-emulsification microdevice via a two-anglephotography method. It's found that the bubble generation mechanism is controlled by the interfacialtension, below a critical capillary number; while controlled by viscous force, inertial force and thedisturbance induced by the bubble swarm, above the critical capillary number. From the two-anglephotography method, a model is established for predicting the bubble size, by taking into account of thedynamic contact angle between gas-liquid interface and wall, and the hydrodynamic feedback of thecavity on bubble formation via the quantification of resistance by the volume fraction of gas in the cavity.

Damage detection for beam structures using an angle-between-string-and-horizon flexibility matrix

Guirong Yan,Zhongdong Duan,Jinping Ou 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.5

The classical flexibility difference method detects damage by observing the difference of conventional deflection flexibility matrices between pre- and post-damaged states of a structure. This method is not able to identify multiple damage scenarios, and its criteria to identify damage depend upon the boundary conditions of structures. The key point behind the inability and dependence is revealed in this study. A more feasible flexibility for damage detection, the Angle-between-String-and-Horizon (ASH) flexibility, is proposed. The physical meaning of the new flexibility is given, and synthesis of the new flexibility matrix by modal frequencies and translational mode shapes is formulated. The damage indicators are extracted from the difference of ASH flexibility matrices between the pre- and postdamaged structures. One feature of the ASH flexibility is that the components in the ASH flexibility matrix are associated with elements instead of Nodes or DOFs. Therefore, the damage indicators based on the ASH flexibility are mapped to structural elements directly, and thus they can pinpoint the damaged elements, which is appealing to damage detection for complex structures. In addition, the change in the ASH flexibility caused by damage is not affected by boundary conditions, which simplifies the criteria to identify damage. Moreover, the proposed method can determine relatively the damage severity. Because the proposed damage indicator of an element mainly reflects the deflection change within the element itself, which significantly reduces the influence of the damage in one element on the damage indicators of other damaged elements, the proposed method can identify multiple damage locations. The viability of the proposed approach has been demonstrated by numerical examples and experimental tests on a cantilever beam and a simply supported beam.

Damage detection for truss or frame structures using an axial strain flexibility

Guirong Yan,Zhongdong Duan,Jinping Ou 국제구조공학회 2009 Smart Structures and Systems, An International Jou Vol.5 No.3

Damage detection using structural classical deflection flexibility has received considerable attention due to the unique features of the flexibility in the last two decades. However, for relatively complex structures, most methods based on classical deflection flexibility fail to locate damage sites to the exact members. In this study, for structures whose members are dominated by axial forces, such as truss structures, a more feasible flexibility for damage detection is proposed, which is called the Axial Strain (AS) flexibility. It is synthesized from measured modal frequencies and axial strain mode shapes which are expressed in terms of translational mode shapes. A damage indicator based on AS flexibility is proposed. In addition, how to integrate the AS flexibility into the Damage Location Vector (DLV) approach (Bernal and Gunes 2004) to improve its performance of damage localization is presented. The methods based on AS flexbility localize multiple damages to the exact members and they are suitable for the cases where the baseline data of the intact structure is not available. The proposed methods are demonstrated by numerical simulations of a 14-bay planar truss and a five-story steel frame and experiments on a five-story steel frame.

Modal parameter identification with compressed samples by sparse decomposition using the free vibration function as dictionary

Jie Kang,Zhongdong Duan 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.2

Compressive sensing (CS) is a newly developed data acquisition and processing technique that takes advantage of the sparse structure in signals. Normally signals in their primitive space or format are reconstructed from their compressed measurements for further treatments, such as modal analysis for vibration data. This approach causes problems such as leakage, loss of fidelity, etc., and the computation of reconstruction itself is costly as well. Therefore, it is appealing to directly work on the compressed data without prior reconstruction of the original data. In this paper, a direct approach for modal analysis of damped systems is proposed by decomposing the compressed measurements with an appropriate dictionary. The damped free vibration function is adopted to form atoms in the dictionary for the following sparse decomposition. Compared with the normally used Fourier bases, the damped free vibration function spans a space with both the frequency and damping as the control variables. In order to efficiently search the enormous two-dimension dictionary with frequency and damping as variables, a two-step strategy is implemented combined with the Orthogonal Matching Pursuit (OMP) to determine the optimal atom in the dictionary, which greatly reduces the computation of the sparse decomposition. The performance of the proposed method is demonstrated by a numerical and an experimental example, and advantages of the method are revealed by comparison with another such kind method using POD technique.

Ontology-Based Cutting Tool Configuration Considering Carbon Emissions

Guanghui Zhou,Qi Lu,Zhongdong Xiao,Ce Zhou,Shengze Yuan,Chao Zhang 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.11

In order to improve the precision and efficiency of cutting tool configuration and reduce carbon emissions during manufacturing process, an ontology-based cutting tool configuration process considering carbon emissions is put forward in the paper. Firstly, the architecture of ontology-based cutting tool configuration is established and key functional modules are described. Secondly, ontology is applied to describe the complex knowledge of cutting tool configuration and the Semantic Web Rule Language (SWRL) is used to build inference rules to reason feasible cutting tool configuration schemes according to machining requirements. Thirdly, taking carbon emissions as the objective, an evaluation method based on the c-PBOM-T (carbon emissions-Process Bill of Material for cutting Tools) table is studied to decide an optimal cutting tool configuration scheme from the feasible ones in the previous step for part machining. Finally, the proposed method is applied to a vortex shell workpiece to demonstrate its feasibility. The results show that the proposed method can improve the cutting tool configuration and reduce carbon emissions effectively for the machining processes. The presented method provides a valuable insight into the intelligent cutting tool configuration to support low-carbon manufacturing.