Get Rid of Constraint

Yuhan Chen 한국콘텐츠학회 2016 ICCC International Digital Design Invitation Exhib Vol.2016 No.5

Mechanism and Coping Strategies towards the Evolution of Chemical Hazards Incidents during Transportation

Yuhan Lin,An Chen 위기관리 이론과 실천 2014 Journal of Safety and Crisis Management Vol.4 No.1

(Abstact) The accident, accident evolution and disaster are further investigated. Subsequently the synergistic coupling of the various vulnerability factors among the system and their effect on evolution of the initial accident are discussed viewing the possible interactions between the elements within the system during hazardous chemicals transportation links. The evolution mechanism is elaborated by a series of emergency intervention model and the strategies for preparedness and response to preventing from the incident evolution are provided.

Axial compression mechanical properties of steel reinforced recycled concrete column exposure to temperatures up to 800ºC

Zongping Chen,Yuhan Liang,Linlin Mo,Maogen Ban 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.5

The purpose of this paper is to investigate the axial bearing capacity and residual properties of steel reinforced recycled aggregate concrete (SRC) column after elevated temperature. A total of 48 SRC columns were designed for the static loading test after elevated temperature. The variables include replacement ratios, designed temperature, target duration, thicknesses of cover concrete, steel ratios and stirrup spacing. From this test, the mass loss ratio and stress load-deformation curve were obtained, and the influence of various parameters on residual bearing capacity were analyzed. ABAQUS was used to calculate the temperature field of specimens, and then got temperature damage distribution on the cross-section concrete. It was shown that increasing of the elevated temperatures leaded to the change of concrete color from smoky-gray to grayish brown and results in reducing the bearing capacity of SRC columns. The axial damage and mechanism of SRC columns were similar to those of reinforced natural aggregate concrete columns at the same temperatures. Finally, the calculation method of axial compressive residual bearing capacity of SRC columns recycled concrete columns after high temperature was reported based on the test results and finite element analysis.

Therapeutic luminal coating of the intestine

Lee, Yuhan,Deelman, Tara E.,Chen, Keyue,Lin, Dawn S. Y.,Tavakkoli, Ali,Karp, Jeffrey M. Springer Science and Business Media LLC 2018 NATURE MATERIALS Vol.17 No.9

Controlled synthesis of PEI-coated gold nanoparticles using reductive catechol chemistry for siRNA delivery

Lee, Yuhan,Lee, Soo Hyeon,Kim, Jee Seon,Maruyama, Atsushi,Chen, Xuesi,Park, Tae Gwan Elsevier 2011 Journal of controlled release Vol.155 No.1

<P><B>Abstract</B></P><P>Development of nano-sized gene delivery vehicles for small interfering RNA (siRNA) delivery is of great importance for their clinical applications such as cancer therapy. Herein, we demonstrate the controlled synthesis of polyethyleneimine (PEI)-coated gold nanoparticles (AuNPs) using catechol-conjugated PEI (PEI-C) for siRNA delivery. Since the conjugated catechol groups are reductive and moderately hydrophobic, PEI-C formed spherical multi-cored micelles in aqueous solution and served as reductive templates for the growth and synthesis of spherical AuNPs with tunable sizes and surface charges. PEI-C was stably anchored on the surface of growing crystal gold seeds with crosslinking, resulting in robust cationic AuNPs. The fabricated PEI-coated AuNPs formed stable complexes with siRNA, and the complexes showed an excellent gene silencing effect in cancer cells. Size and surface charge values of the synthesized AuNPs had a great influence on intracellular uptake and unpacking of siRNA, and the resultant gene silencing efficiency. The PEI-coated AuNPs exhibited an extremely low cytotoxicity due to the reduced density of primary amine groups and the absence of uncomplexed PEI fraction in aqueous solution.</P> <P><B>Graphical Abstract</B></P><P><ce:figure id='f0035'></ce:figure></P>

The involvement of Parkin-dependent mitophagy in the anti-cancer activity of Ginsenoside

Xin Sun,Yeting Hong,Yuhan Shu,Caixia Wu,Guiqin Ye,Hanxiao Chen,Hongying Zhou,Ruilan Gao,Jianbin Zhang 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.2

Colon cancer, the third most frequent occurred cancer, has high mortality and extremely poor prognosis. Ginsenoside, the active components of traditional Chinese herbal medicine Panax ginseng, exerts antitumor effect in various cancers, including colon cancer. However, the detailed molecular mechanism of Ginsenoside in the tumor suppression have not been fully elucidated. Here, we chose the representative ginsenoside Rg3 and reported for the first time that Rg3 induces mitophagy in human colon cancer cells, which is responsible for its anticancer effect. Rg3 treatment leads to mitochondria damage and the formation of mitophagosome; when autophagy is inhibited, the clearance of damaged mitochondria can be reversed. Next, our results showed that Rg3 treatment activates the PINK1-Parkin signaling pathway and recruits Parkin and ubiquitin proteins to mitochondria to induce mitophagy. GO analysis of Parkin targets showed that Parkin interacts with a large number of mitochondrial proteins and regulates the molecular function of mitochondria. The cellular energy metabolism enzyme GAPDH is validated as a novel substrate of Parkin, which is ubiquitinated by Parkin. Moreover, GAPDH participates in the Rg3-induced mitophagy and regulates the translocation of Parkin to mitochondria. Functionally, Rg3 exerts the inhibitory effect through regulating the nonglycolytic activity of GAPDH, which could be associated with the cellular oxidative stress. Thus, our results revealed GAPDH ubiquitination by Parkin as a crucial mechanism for mitophagy induction that contributes to the tumor-suppressive function of ginsenoside, which could be a novel treatment strategy for colon cancer.

si-Tgfbr1-loading liposomes inhibit shoulder capsule fibrosis via mimicking the protective function of exosomes from patients with adhesive capsulitis

Yaying Sun,Yisheng Chen,Jinrong Lin,Yuhan Zhang,Beijie Qi,Jiwu Chen 한국생체재료학회 2022 생체재료학회지 Vol.26 No.3

Background: Adhesive capsulitis is a common shoulder disorder inducing joint capsule fibrosis and pain. When combined with rotator cuff tear (RCT), treatments can be more complex. Currently, targeted therapy is lacking. Since adhesive capsulitis is reported to be related to circulating materials, we analyzed the contents and biology of circulating exosomes from RCT patients with and without adhesive capsulitis, in an attempt to developing a targeting treatment. Methods: Samples from a consecutive cohort of patients with RCT for surgery were collected. Circulating exosomal miRNAs sequencing were used to detect differentially expressed miRNAs in patients with and without adhesive capsulitis. For experiments in vitro, Brdu staining, CCK-8 assay, wound healing test, collagen contraction test, real-time quantitative polymerase chain reaction, and western blot were conducted. Histological and immunofluorescent staining, and biomechanical analysis were applied in a mouse model of shoulder stiffness. The characteristics of liposomes loaded with siRNA were measured via dynamic light scattering or electron microscopy. Results: Circulating exosomal miRNAs sequencing showed that, compared to exosomes from patients without adhesive capsulitis, miR-142 was significantly up-regulated in exosomes from adhesive capsulitis (Exo-S). Both Exo-S and miR-142 could inhibit fibrogenesis, and the anti-fibrotic effect of Exo-S relied on miR-142. The target of miR-142 was proven to be transforming growth factor β receptor 1 (Tgfbr1). Then, liposomes were developed and loaded with si-Tgfbr1. The si-Tgfbr1-loading liposomes exhibited promising therapeutic effect against shoulder stiffness in mouse model with no evidence toxicity. Conclusion: This study showed that, in RCT patients with adhesive capsulitis, circulating exosomes are protective and have anti-fibrotic potential. This effect is related to the contained miR-142, which targets Tgfbr1. By mimicking this biological function, liposomes loaded with si-Tgfbr1 can mitigate shoulder stiffness pre-clinically

Protective effect of hepatocyte-enriched lncRNA-Mir122hg by promoting hepatocyte proliferation in acute liver injury

Yu Zhenjun,Li Yuhan,Shao Shuai,Guo Beichen,Zhang Mengxia,Zheng Lina,Zhang Kun,Zhou Feng,Zhang Li,Chen Chiyi,Jiang Wentao,Hong Wei,Han Tao 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Some long noncoding RNAs (lncRNAs), which harbor microRNAs in their gene sequence and are also known as microRNA host gene derived lncRNAs (lnc-MIRHGs), play a dominant role alongside miRNAs, or both perform biological functions synergistically or independently. However, only a small number of lnc-MIRHGs have been identified. Here, multiple liver injury datasets were analyzed to screen and identify the target lncRNA Mir122hg. Mir122hg was mainly enriched in liver tissues with human-mouse homology. In both CCl4-induced acute liver injury and Dgal/LPS-induced fulminant liver failure in mice, Mir122hg was sharply downregulated at the early stage, while a subsequent significant increase was only found in the CCl4 group with liver recovery. Overexpression and silencing assays confirmed that Mir122hg played a protective role in acute injury by promoting hepatocyte proliferation in vivo and in vitro. Consistent with the results of gene enrichment analysis, Mir122hg binding to C/EBPα affected its transcriptional repression, promoted gene transcription of downstream chemokines, Cxcl2, Cxcl3, and Cxcl5, and exerted pro-proliferative effects on hepatocytes through activation of the AKT/GSK-3β/p27 signaling pathway by CXC/CXCR2 complexes. This study identifies a novel lncRNA with protective effects in acute liver injury and demonstrates that the binding of Mir122hg-C/EBPα promotes hepatocyte proliferation via upregulation of CXC chemokine and activation of AKT signaling.

Characterization, activity and selectivity of ethylenediamine modified Co/SiO2 FT catalyst prepared by sol-gel method

Yuelun Wang,Bo Hou,Jiangang Chen,Litao Jia,Debao Li,Yuhan Sun 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.3

Co/SiO2 catalysts were prepared by sol-gel method with varied en (ethylenediamine)/Co molar ratios under the same pH. Their physical-chemical properties were compared with those prepared with similar en/Co molar ratios at natural pH or without adding ethylenediamine. Regardless of pH, the catalysts prepared using ethylenediamine possessed high microporosity, which led to a better selectivity to C5-18 hydrocarbons, versus the catalyst possessing higher mesoporosity which showed slightly higher C18+ selectivity. As enough positions in the coordination sphere were blocked by ethanediamine ligands, the formation of cobalt silicate disfavored for (en/Co=2) catalysts, which resulted in the higher activity in FT reaction. Whereas the catalysts prepared with lower or higher en/Co molar ratio both showed lower activity due to the formation of [(SiO)Co(en)(EtOH)3] species or the electronic adsorption of cobalt complexes in the negatively charged silica surface, respectively. However, for the catalyst without using ethylenediamine, the lowest activity and the highest CH4 selectivity obtained due to its much lower reducibility.

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.