A Microfluidic Hydrogel Chip with Orthogonal Dual Gradients of Matrix Stiffness and Oxygen for Cytotoxicity Test

Weixing Wang,Lili Li,Mingyu Ding,Guoan Luo,Qionglin Liang 한국바이오칩학회 2018 BioChip Journal Vol.12 No.2

The oxygen tensions and matrix stiffness play important roles in regulating cell response to cytotoxic drugs. In recent years, single spatiotemporal oxygen or matrix stiffness gradient has been established by various technologies for cell studies. However, the synergistic effects of the two factors on tumor cells remained elusive. In this study, we created a highly integrated and easy-to-operate microfluidic device. It was capable of generating more continuous, linear, stable and diffusive hydrogel stiffness gradient over a well-defined oxygen gradient. Sodium hydroxide and pyrogallol were used to scavenge oxygen and generate oxygen gradient, skillfully avoiding the utilization of bulky pressurized gas cylinders and sophisticated flow control by conventional methods. Utilizing the newly developed microfluidic device, we successfully performed drug test with a hypoxia sensitive anti-cancer drug, triapazamine (TPZ), on A549 cells under perpendicular construction of oxygen and spatially hydrogel stiffness gradients. The cell experiment results demonstrated the matrix stiffness-dependent cell drug resistance and hypoxia-induced cytotoxicity of TPZ. In summary, the developed microfluidic device exhibits high potential in the study of matrix stiffness-dependent cell responses and oxygen-sensitive drug cytotoxicity. Furthermore, the design principle can be functionally extended to other dual factors system and will facilitate the study of cell response in complex physiological and pathological conditions.

Preparation and properties of sulfated zirconia for hydrolysis of ethyl lactate

Weixing Li,Yingxiang Ni,Weiwei Liu,Weihong Xing,Nanping Xu 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.6

Sulfated zirconia catalysts are proposed for the reversible hydrolysis of ethyl lactate instead of liquid acids. Sulfated zirconia catalysts were prepared by precipitation-impregnation method. The zirconium hydroxide was produced from zirconium oxychloride by adding aqueous ammonia and then impregnated in sulfuric acid. The solid samples were obtained by filtration and evaporation of the mixtures, respectively. After the samples were calcined, the sulfated zirconia catalysts were prepared. The results showed that the catalyst prepared by evaporation has higher catalytic activity. The physicochemical characteristics of the sulfated zirconia catalysts were studied by thermal analysis, X-ray powder diffraction (XRD), temperature programmed desorption of ammonia (NH3-TPD) and N2 adsorption-desorption,respectively. By the precipitation-impregnation-evaporation method, the optimal sulfated zirconia catalyst of tetragonal phase was prepared under liquid-solid ratio of 5ml/g, 1 mol/L of H2SO4 and calcination at 650 oC for 3 h. The conversion of the ethyl lactate was 87.8% in 3 h at 85 oC with the catalyst loading 2 wt% and initial molar ratio of water to ethyl lactate 20 : 1.

Rock Fracture Centerline Extraction based on Hessian Matrix and Steger algorithm

( Weixing Wang ),( Yanjie Liang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.12

The rock fracture detection by image analysis is significant for fracture measurement and assessment engineering. The paper proposes a novel image segmentation algorithm for the centerline tracing of a rock fracture based on Hessian Matrix at Multi-scales and Steger algorithm. A traditional fracture detection method, which does edge detection first, then makes image binarization, and finally performs noise removal and fracture gap linking, is difficult for images of rough rock surfaces. To overcome the problem, the new algorithm extracts the centerlines directly from a gray level image. It includes three steps: (1) Hessian Matrix and Frangi filter are adopted to enhance the curvilinear structures, then after image binarization, the spurious-fractures and noise are removed by synthesizing the area, circularity and rectangularity; (2) On the binary image, Steger algorithm is used to detect fracture centerline points, then the centerline points or segments are linked according to the gap distance and the angle differences; and (3) Based on the above centerline detection roughly, the centerline points are searched in the original image in a local window along the direction perpendicular to the normal of the centerline, then these points are linked. A number of rock fracture images have been tested, and the testing results show that compared to other traditional algorithms, the proposed algorithm can extract rock fracture centerlines accurately.

Retinex Algorithm on Changing Scales for Haze Removal with Depth Map

Weixing Wang,Lian Xu 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.4

Online Burning Material Pile Detection on Color Clustering and Quaternion based Edge Detection in Boiler

( Weixing Wang ),( Sheng Liu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.1

In the combustion engineering, to decrease pollution and increase production efficiency, and to optimally keep solid burning material amount constant in a burner online, it needs a smart method to detect the amount variation of the burning materials in a high temperature environment. This paper presents an online machine vision system for automatically measuring and detecting the burning material amount inside a burner or a boiler. In the camera-protecting box of the system, a sub-system for cooling is constructed by using the cooling water circulation techqique. In addition, the key and intelligent step in the system is to detect the pile profile of the variable burning material, and the algorithm for the pile profile tracing was studied based on the combination of the gey level (color) discontinuity and similarity based image segmentation methods, the discontinuity based sub-algorithm is made on the quaternion convolution, and the similarity based sub-algorithm is designed according to the region growing with multi-scale clustering. The results of the two sub-algoritms are fused to delineate the final pile profile, and the algorithm has been tested and applied in different industrial burners and boilers. The experiements show that the proposed algorithm works satisfactorily.

Improved Minimum Spanning Tree based Image Segmentation with Guided Matting

( Weixing Wang ),( Angyan Tu ),( Fredrik Bergholm ) 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.1

In image segmentation, for the condition that objects (targets) and background in an image are intertwined or their common boundaries are vague as well as their textures are similar, and the targets in images are greatly variable, the deep learning might be difficult to use. Hence, a new method based on graph theory and guided feathering is proposed. First, it uses a guided feathering algorithm to initially separate the objects from background roughly, then, the image is separated into two different images: foreground image and background image, subsequently, the two images are segmented accurately by using the improved graph-based algorithm respectively, and finally, the two segmented images are merged together as the final segmentation result. For the graph-based new algorithm, it is improved based on MST in three main aspects: (1) the differences between the functions of intra-regional and inter-regional; (2) the function of edge weight; and (3) re-merge mechanism after segmentation in graph mapping. Compared to the traditional algorithms such as region merging, ordinary MST and thresholding, the studied algorithm has the better segmentation accuracy and effect, therefore it has the significant superiority.

miR-582-5p inhibits migration and chemo-resistant capabilities of colorectal cancer cells by targeting TNKS2

Xiao Weixing,Zhou Haijun,Chen Bingrong,Shen Bin,Zhou Jun 한국유전학회 2022 Genes & Genomics Vol.44 No.6

Background: Metastasis and chemo-resistance are still important factors that limit the overall efficacy of colorectal cancer treatment. Understanding the detailed molecular mechanism and identifying potential biomarkers are of great value in prognosis prediction and risk stratification. Objective: We investigated the role of miR-582-5p in colorectal cancer pathogenesis, progression and chemo-resistance. Furthermore, we explored the underlying molecular mechanism of miR-582-5p in modulation of malignant behaviors of colorectal cancer cells. Methods: Clinical samples and colorectal cancer cell lines were applied to explore miR-582-5p expression level and its significance on tumor cell metastasis and chemo-resistance. Transwell study and cellular survivability study were performed to explore the influences of miR-582-5p expression modulation on tumor cell chemo-resistance and invasion/migration. Dual-luciferase reporter gene assay was conducted to explore the influences of miR-582-5p on its target gene TNKS2. Results: Colorectal cancer patients with lymph node or distal organ metastatic diseases exhibited significantly lower level of miR-582-5p. In vitro studies have indicated that miR-582-5p inhibition significantly increased migration and chemo-resistant capabilities of tumor cells. And dual-luciferase reporter gene assay demonstrated that miR-582-5p exhibited its influences on the biological behavior of tumor cells by targeting TNKS2. Conclusions: Our study demonstrated for the first time that miR-582-5p played an important role for colorectal tumor cell metastasis and chemo-resistance. Our research also indicated that miR-582-5p and its target gene TNKS2 could be novel biomarkers for metastatic disease prediction, overall prognosis evaluation, as well as potential therapeutic target for colorectal cancer patients.

Dynamical Analysis and Design of Bearingless Rotor Flexbeam

Shi, Weixing,Wang, Jidong The Society for Aerospace System Engineering 2015 International Journal of Aerospace System Engineer Vol.2 No.1

In helicopter bearingless rotor design, the flexbeam is the key component of rotor system, which plays an importantrole in the blade flapping, lead-lag movement, torsion, and load transfer. Flexbeam must have the minimum torsion stiffness with enough tension strength. In this paper, we first investigated the torsion stiffness of different cross section configurations of the flexbeam through some simple experiments. Then we analyzed a rotor's dynamical characteristics with finite element method and got the rotor's fan plot. After that, we studied the relationship between the frequency changes with the spanwise distribution of mass and stiffness in bearingless rotor. Finally, we analyzed the influence of the flexbeam on dynamical characteristics of the bearingless rotor system, and completed the design of this type of rotor flexbeam.

China's Security Strategy in a Changing World

Hu, Weixing Center for International Studies, Inha University 1993 Pacific Focus Vol.8 No.1

CHINA AND NORTHEAST ASIAN COOPERATION: THE ECONOMIC-SECURITY NEXUS

Hu, Weixing The Institute of East and West Studies 1999 Global economic review Vol.28 No.2

Deepening economic interdependence is bringing about a change in China's perception of regional cooperation in East Asia. China's integration with the world economy in general and Asian economy in particular has greatly increased the productivity and efficiency in the country, leading to a mord favorable attitude in Beijing toward regional integration. The costs associated with such developments are however also raising concerns that China must full consider the possible negative side effects, such as trade dependence, growing economic disparity, and vertical division of regional labor structure among others while proceeding with regional economic integration. In contrast to its more positive policies in the economic front, Chinese response to the growing call in Asia for a multilateral security dialogues complicating its efforts to solve territorial disputes through bilateral means, Beijing maintains there is no need for multilateralism, arguing that the best way to develop security cooperation in the region is through building and managing healthy bilateral relations. Amidst increasing incentives for cooperation with the deepening regional economic networks, it remains to bo seen how such interdependence will further develop the as of now fragile regional security relations in the East Asian region.