miR-1301/TRIAP1 Axis Participates in Epirubicin-Mediated Anti-Proliferation and Pro-Apoptosis in Osteosarcoma

Lijun Yu,Min Meng,Yun Bao,Chao Zhang,Bei Gao,Rina Sa,Wenyuan Luo 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.9

Purpose: Epirubicin is one of the most effective drugs against osteosarcoma. miR-1301 is involved in the occurrence and developmentof osteosarcoma. Whether miR-1301 is responsible for the chemosensitivity of osteosarcoma cells to epirubicin remainslargely unknown. Materials and Methods: U2OS and SAOS-2 cells were treated with various concentrations of epirubicin. Flow cytometry was employedto evaluate cell apoptotic rate. Cell proliferation was measured by Cell Counting Kit-8 assay. Western blot and quantitativereal-time polymerase chain reaction were utilized to detect the expressions of B-cell lymphoma-2 (Bcl-2), Bcl-2 assaciated X protein(Bax), cleaved-caspase-3, cleaved-poly (ADP-ribose) polymerases (PARP1), TP53-regulated inhibitor of apoptosis 1 (TRIAP1),and microRNA-1301 (miR-1301). The relationship between miR-1301 and TRIAP1 was determined by luciferase reporter assay. Results: Epirubicin inhibited proliferation in a dose-dependent manner, induced apoptosis, decreased the expression of Bcl-2,and increased the expressions of Bax, cleaved-caspase-3, and cleaved-PARP1 in osteosarcoma cells. miR-1301 was downregulatedin U2OS and SAOS-2 cells. Importantly, epirubicin significantly increased the levels of miR-1301. Overexpression of miR-1301suppressed proliferation and promoted apoptosis. Interestingly, those effects were enhanced by epirubicin. In contrast, miR-1301depletion attenuated the epirubicin-mediated anti-osteosarcoma effect. miR-1301 negatively regulated the expression of TRIAP1in U2OS and SAOS-2 cells. Furthermore, epirubicin inhibited the mRNA and protein levels of TRIAP1 by upregulating miR-1301levels. Epirubicin suppressed cell proliferation by downregulating TRIAP1. Conclusion: miR-1301 was implicated in the chemosensitivity of osteosarcoma to epirubicin by modulating TRIAP1.

Temporal Instability of a Charged Viscoelastic Jet Subjected to an Axial Magnetic Field

( Luo Xie ),( Xiao Cui ),( Lijun Yang ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

The breakup and instability of charged viscoelastic jets are of great importance both for academic interests and practical applications, such as ink-jet printing, fuel injection spraying, and fiber spinning. Although associated technique of electric viscoelastic jets have recently widely applied, the inevitable and uncontrolled motion of the jets due to various instability mechanisms have limited the practical application of charged jets. For example, the non-axisymmetric instability triggered by the electrostatic force on the jet surface would prevent the formation of uniform drops, which is adverse for ink-jet printer; the rapidly whipping motion caused by the bending instability would hinder the oriented alignment of nanofibers in electrospinning process. Therefore, Wu et al. (“Controlling stability of the electrospun fiber by magnetic field,” Chaos, Solitons & Fractals, 32(2007)) suggested that the magnetic approach is the most effective and economical way to inhibit the onset of unstable motion in electrospinning. The objective of the present work is to investigate the mechanisms of instability of charged viscoelastic jets under an axial magnetic field, and to find whether a linear stability analysis would result in conclusions similar to charged Newtonian jets under an axial magnetic field. Based on the assumption that the magnetic force is comparable to the electric force, while the variation in magnetic field induced by the electrical current is insignificant compared with the applied axial magnetic field, the corresponding dispersion, according to the governing equations and boundary conditions, has been obtained and solved numerically. Results show that an increase of the magnetic strength suppresses the growth rate of both the axisymmetric and non-axisymmetric mode, while the unstable range remains nearly unchanged. However, this stabilizing effect is not significant until the magnetic strength exceeds a critical value.

NiCoSe4@CFF with excellent properties prepared by microwave method for flexible supercapacitors and oxygen evolution reaction

Lijun Du,Ning Lv,Jiashuai Li,Jiayi Zhang,Yilan Chen,Yalin Zhang,Zhen Li,Xianqiang Huang,Jujie Luo 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

NiCoSe4 nanoflowers were synthesized on carbon fiber felt (CFF) by microwave method, and the effects ofmicrowave time and microwave power on the morphology, physical phase and performance ofNiCoSe4@CFF were explored. The results display that the nanostructured NiCoSe4 prepared under themicrowave irradiation of 1000 W for 120 s is uniformly loaded on the CFF. The NiCoSe4@CFF electrodeexhibits a superior specific capacity of 1653.6F g1 at 1A/g and maintains a superior cycling performanceof 87.05 % of the initial capacitance over 150,000 cycles. In addition, the flexible supercapacitor fabricatedwith NiCoSe4@CFF as the cathode exhibits excellent flexibility and flexural strength. As an effective catalystfor oxygen evolution reaction (OER), NiCoSe4@CFF demonstrates a low overpotential of 0.358 V, arelatively small Tafel slope of 115.93 mV dec1 and an excellent lifetime at 10 mA cm2.

Performance of Tunnel Feet-Lock Pipe (TFP) in Sharing Vertical Foundation Load

Lijun Chen,Jianxun Chen,Yao Li,Yanbin Luo,Yongjun Mu,Taotao Hu,Chuanwu Wang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.3

During the tunnel construction in soft ground, the insufficient bearing capacity of tunnel foundation usually causes a series of settlement problems. Tunnel feet-lock pipe (TFP) has been widely used to take the vertical load acting at the foundation of a tunnel foot. However, the detailed bearing performance of TFP is still not clear, and there is a lack of quantitative research. In this paper, a simple analytical approach is adopted to evaluate the performance of the TFP, and the main parameters affecting the supporting performance of the TFP are analyzed. The results show that the ϕ42 − ϕ140 TFP with the angle of 10° can take 3.8% −40.4% of vertical load. TFP has an effective length of 1.7 m − 2.8 m, which is related to the relative stiffness between the TFP and the stratum. With the increase of the installation angle, the TFP shares more vertical load. This trend is more obvious when the angle of the TFP is greater than 20°. If the proportion coefficient of the subgrade reaction coefficient is doubled, the vertical load shared by the TFP can be increased by 34% − 38%. For every 10 cm increase in overbreak behind the steel rib, the vertical load shared by TFP is reduced by 16%.

Back-Calculation Method of Rock Mass Pressure in a Shallow-Buried Super Large-Span Tunnel Using Upper-Bench CD Method

Yanbin Luo,Yunfei Wu,Jianxun Chen,Fangfang Dong,Weiwei Liu,Lijun Chen,Yao Li,Zhou Shi 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.1

Rock mass pressure has always been a research hotspot in the field of tunnel engineering, especially in the super large-span tunnel, which is characterized by flat section, large excavation span, and complex stress field. Based on the Letuan Tunnel (a bi-directional tunnel with eight traffic lanes) of Binlai expressway expansion project in Shandong Province, China, this paper focused on the calculation method of rock mass pressure and the evolution law of load release in the construction process of the super large-span tunnel excavated by upper-bench central diaphragm (CD) method. Based on field measured data of Letuan Tunnel, the deformation behavior of primary lining and the distribution state of rock mass pressure during the tunnel construction were analyzed. According to the bearing mode of supporting structure, the mechanical models of different construction stages were established. Then, the rock mass pressures in different construction stages were back-calculated using mechanical models and compared with the measured values, and the evolution law of load release during the tunnel construction was discussed. The study results show that the tunnel deformation and rock mass pressure were significantly affected by the construction process and support form, and the excavation span was the key factor affecting the stability of rock mass. For the shallow-buried super large-span tunnel constructed by upper-bench CD method, the primary support of upper bench was under eccentric pressure. The comparison between the back-calculated value and the field measured value indicated that they were similar, and the average relative error was 17.23%. According to the concept of load release coefficient proposed in this paper, the load release coefficient after the pilot tunnel ahead (Part I) excavation reached 63%, and the load release coefficient after the pilot tunnel behind excavation (Part II) was 37%, which means that the rock mass pressure of Part I is increased about 59% due to the excavation of Part II.

Instability of a Viscoelastic Jet Containing Micro-nano Bubbles

( Xiao Cui ),( Luo Xie ),( Lijun Yang ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

An effervescent atomizer is a valid applications to obtain small droplets. It can potentially solve the problem of clogging, erosion, high injection pressure, huge gas consumption. To further improve the atomization performance of effervescent atomizer, it is critical to explore the theory behind the onset of instability of viscoelastic jet containing micro-nano bubbles. This paper study the linear instability of that jet surrounded by inviscid gas. Compressibility and viscoelasticity caused by micro-nano gas bubbles are taken into account, since that is consistent with the actual rheological property of jet (Llewellin E W, Mader H M, Sdr W. “The rheology of a bubbly liquid,” Proceedings Mathematical Physical & Engineering Sciences,(2020) 2002). Adopting the method of linear instability to analyze the temporal development of disturbance for jet and obtaining the relationship of wave number and growth rate by utilizing spectral method. It is found that a viscoelastic jet is more unstable than a Newtonian one. Moreover, results show that there exist two instable areas by considering the variation of the radii of gas bubbles and gas volume fraction of bubbles make a great influence of the instability of viscoelastic. The viscoelasticity and compressibility of the jet also make it unstable. To make out the deep mechanism of above results, an analysis of the energy budget of destabilization process is performed, in which a formulation from momentum conservation equation. The formulation is observed to provide a quantitative analysis of the contribution of each physical factor (e.g., release of surface energy, viscous dissipation and compressibility work).The energy analysis reveals that the viscous force, aerodynamic, surface tense common rules the instability of the bubble jet. The two unstable areas because of the competition of these forces.

Failure Mechanisms and Modes of Tunnels in Monoclinic and Soft-Hard Interbedded Rocks: A Case Study

Jianxun Chen,Weiwei Liu,Lijun Chen,Yanbin Luo,Yao Li,Haijiang Gao,Daochuan Zhong 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.4

The issue of large deformation mechanism in soft rock tunnels has puzzled tunnel scholars for decades. Previous studies have not evolved a clear and common understanding. Therefore, detailed on-site measurement, full investigation and statistical analysis have been conducted on the instability and failure of Muzhailing Tunnel since its construction, whose length is beyond 15 km. The study aims at systematically analyzing the failure mechanisms and modes of Muzhailing Tunnel in monoclinic and soft-hard interbedded rock strata. Study results show that the angle between strata strike and tunnel axis greatly determines the magnitude of deformation, the dip direction significantly controls the bias direction and maximum deformation direction, and the dip angle deeply affects the deformation form. The failure modes of surrounding rock mainly include four types: spalling and overturning failure, bending failure, shear slip failure and buckling failure. Large deformation characteristics are summarized from six aspects: failure form, groundwater, sensitivity to influencing factors, deformation degree, deformation speed and deformation duration. The instability modes of primary lining include in-plane (transverse) instability and out-plane (longitudinal) instability. Finally, the causes of large deformation are analyzed from geological, structural, engineering and human factors.

Overexpression of AtNHX1, a Vacuolar Na+/H+ Antiporter from Arabidopsis thalina, in Petunia hybrida Enhances Salt and Drought Tolerance

Kai Xu,Ping Hong,Lijun Luo,Tao Xia 한국식물학회 2009 Journal of Plant Biology Vol.52 No.5

PlantNa+/H+ antiporter plays a critical role in plant salt tolerance. In this study, AtNHX1, a vacuolar Na+ /H+ antiporter from Arabidopsis thalina, was introduced into Petunia hybrida using Agrobacterium-mediated methods. Polymerase chain reaction (PCR) and DNA gel blot analysis confirmed that AtNHX1 was successfully integrated into the P. hybrida genomes. Reverse transcription (RT)-PCR analysis indicated that AtNHX1 expressed highly in transgenic plants. It was found that the 35S::AtNHX1 transgenic P. hybrida plants showed much more resistant to high concentrations of NaCl and to water deprivation than the isogenic wild-type (WT) Petunia plants. The transgenic plants accumulated more Na+, K+, and proline in their leaf tissue than that of the WT Petunia plants and maintained high water contents and high ratio of K+/Na+. These results demonstrated that overexpression of the vacuolar Na+/H+ antiporter conferred both salt tolerance and drought tolerance to the transgenic Petunia plants.

Hand-eye Calibration of Dual Mechanical Arms of Explosive Ordnance Disposal Robot

Jianfeng Jiang,Xiao Luo,Qingsheng Luo,Lijun Qiao,Yuhan Chen 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.7

The explosive ordnance disposal (EOD) robot works in a special environment, which requires dual robotic arms to work together for removing the bomb. Therefore, the coordinate calibration accuracy is the prerequisite for realizing the coordinated movement and visual positioning of the dual robotic arms. A basic problem encountered in the collaborative work of the dual robotic arms system is to determine the homogeneous transformation matrix of the frame, including: hand-eye, base-base, and gripper-camera. We formulate the hand-eye calibration problem of the dual robotic arm as the matrix equation AXB = YCZD. 1) An improved closed solution for singlerobotic arm hand-eye calibration is proposed. This closed solution of the single-robotic arm is used to quickly obtain the initial estimate of the iterative method to improve the efficiency and accuracy of the iteration. 2) The iterative solution of dual robotic arms hand-eye calibration based on the rotation vector is proposed. 3) In addition, a motion trajectory plan of the mechanical gripper is proposed to guide the operator to select the appropriate robot posture during the calibration process. In order to show the feasibility and superiority of the proposed method, a real EOD robot experiment is carried out. The comparison results from experiments show that the proposed simultaneous calibration method has higher accuracy and efficiency.

Accurate measurement of residual stresses of 2219-T87 aluminum alloy friction stir welding joints based on properties of joints

Yang Du,Huan Li,Lijun Yang,Chuanguang Luo 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.1

In order to avoid the deviation caused by calculating the residual stresses of welding joints with the release coefficients of the same parent metal, a new method has been proposed based on the properties of weld joints. Since the mechanical property of 2195-F Al alloy is close to that of 2219-T87 Al alloy Friction stir welding (FSW) joint, 2195-F Al alloy is selected as the substitute material of 2219-T87 Al alloy FSW joint in the calibration test. Release coefficients of 2195-F Al alloy and proper correction coefficient are used to calculate the residual stresses of 2219-T87 Al alloy FSW joints. Compared to the results calculated with release coefficients of its parent metal, it has been proved that the proposed correction method is more precise in residual stresses measurement of weld joints. The mathematical analysis and the results of verification tests have shown that this new method is reliable, and it will provide guidance in academic research and engineering application of the spherical indentation strain-gauge method.