Flexible air breathable electroluminescent device based on electrospinning process

Ce Li,Shaoqiang Gu,Tao Ma,Dongchan Li 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.6

Alternative current electroluminescent device with excellent air permeability were fabricated by a facile electrospinningmethod, and the optimal fabrication conditions of the device substrate and light-emitting layer, such as voltage, acceptancedistance, concentration, and propulsion rate, were determined. The microscopic morphology, luminance and air permeabilityof the samples were explored and analyzed. The characterization results show that the flexible alternative current electroluminescentdevice fabricated by electrospinning method exhibits excellent mechanical properties and high air permeability. The device can reach 55.74 cd/m2 at a voltage of 130 V and a frequency of 3 kHz, and the air permeability can reach 5.81 g/(h·m2). It is discussed that its excellent breathability is attributed to the overall microns fabric structure. On the basis ofthese results, we believe our electrospinningac process will accelerate development of more comfortable electroluminescentdevices with the flexibility required for real-world applications.

Blood-compatible Polyaniline Coated Electrospun Polyurethane Fiber Scaffolds for Enhanced Adhesion and Proliferation of Human Umbilical Vein Endothelial Cells

Yumei Li,Rui Zhao,Xiang Li,Chuying Wang,Huiwei Bao,Shudan Wang,Jing Fang,Jinqiu Huang,Ce Wang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

The endothelialization and anti-thrombotic abilities of tissue engineered vascular scaffolds are considered to be effective properties for improving the performance small-caliber vascular scaffolds. For this purpose, we designed and developed electrically conductive fibrous scaffolds based on polyaniline coated polyurethane (PANI-PU) electrospun fibersfor vascular tissue engineering applications. The porosity of PANI-PU fibers was 75.27±2.04 %. The obtained PANI-PU fibers were characterized by SEM observations, XPS analysis, water contact angle (WCA) measurement and mechanical property. The PANI functionalization aimed to improve the performance of anticoagulation and endothelialization. The WCA of PAIN-PU decreased to 35 o from 135 o of PU fibers. Blood compatibility and cytocompatibility were compared before and after PANI coating. The adhered platelet cells on PANI-PU was 6.87×105/cm2 and plasma recalcification time was 123 s. Platelet adhesion and plasma recalcification time test showed that the PANI-PU scaffolds had a certain anticoagulant effect. The hemolysis rate of PANI-PU fibers was 0.14 %, which showed that the PANI-PU scaffolds could be used as blood contact materials. The observation of endothelial cell proliferation and morphology in human umbilical vein endothelial cells showed that PANI-PU fibers were more beneficial to cell adhesion, proliferation and extension than that of PU fibers. The results demonstrates the PANI coated electrospun PU fibers have great potential in application as small-diameter vascular grafts and this work shows new insights into conductive scaffolds for vascular tissue engineering.

Microstructure and mechanical properties of rostrum in Cyrtotrachelus longimanus (Coleoptera: Curculionidae)

Longhai Li,Ce Guo,Xin Li,Shun Xu,Cheng Han 한국통합생물학회 2017 Animal cells and systems Vol.21 No.3

The microstructure, composition and mechanical properties of the rostrum in Cyrtotrachelus longimanus (JHC Fabre) were studied utilizing light, fluorescent, scanning electron microscopy (SEM) and energy-dispersive spectroscopy. SEM images show the morphological characteristics of rostrum’s cross section; it is a typical lightweight multilayer structure – one rigid exocuticle layer and dense endocuticle layers, which construct unevenly overlapping fiber structures. The composition analysis of the rostrum shows that it is mainly composed of C, H, N, O, as well as some metal elements and microelements, such as Mg, Si, Zn, Ca and Na, which contribute to its mechanical performance. The mechanical properties of the rostrum were tested by the electronic universal testing machine, which shows it has high-specific strength and is almost the same as that of the stainless steel. The results may provide a biological template to inspire biomimetic lightweight structure design.

Functional morphology and structural characteristics of the hind wings of the bamboo weevil Cyrtotrachelus buqueti (Coleoptera, Curculionidae)

Xin Li,Ce Guo,Longhai Li 한국통합생물학회 2019 Animal cells and systems Vol.23 No.2

Research data of the microstructure and surface morphology of insect wings have been used to help design micro air vehicles (MAV) and coating materials. The present study aimed to examine the microstructure and morphology of the hind wings of Cyrtotrachelus buqueti using inverted fluorescence microscopy (IFM), scanning electron microscopy (SEM), and a mechanical testing system. IFM was used to investigate the distribution of resilin in the hind wing, and SEM was performed to assess the functional characteristics and cross-sectional microstructure of the wings. Moreover, mechanical properties regarding the intersecting location of folding lines and the bending zone (BZ) were examined. Resilin, a rubber-like protein, was found in several mobile joints and in veins walls that are connected to the wing membranes. Taken together, structural data, unfolding motions, and results of tensile testing suggest two conclusions on resilin in the hind wing of C. buqueti: firstly, the resilin distribution is likely associated with specific folding mechanisms of the hind wings, and secondly, resilin occurs at positions where additional elasticity is needed, such as in the bending zone, in order to prevent structural damage during repeated folding and unfolding of the hind wings. The functional significance of resilin joints may shed light on the evolutionary relationship between morphological and structural hind wing properties.

Closed T-Spline Surface Reconstruction from Medical Image Data

Ce Shang,Jianzhong Fu,Zhiwei Lin,Jiawei Feng,Bin Li 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.11

The reconstruction from medical image data to CAD model is an essential process of Bio-medical engineering. So far, it is still challenging to create medical model which is suitable for both design and manufacturing. This paper introduces a process of constructing a single-patched closed T-spline surface model based on medical image data. The image data is first converted into triangular mesh and then parameterized onto a rectangular domain. An iterative least-squares fitting process is proposed to finally obtain the T-spline surface model with a user-specified tolerance. In this fitting process, the smoothing part of the algorithm is redesigned, considering the flexible structure of T-mesh and the geometric complexity of the T-spline surface. Local smoothness weighting factors are introduced to the fitting formula to locally adjust the smoothness of the surface. An adaptive smoothness checking points distribution method is proposed to reduce the computational cost. These algorithms are easy to implement and the obtained model is simple in form. Compared with the STL and NURBS model, the T-spline surface model requires less storage space and can be easily modified. The obtained model is suitable for Bio-medical engineering applications like bone scaffolds design, surgical planning and related manufacturing process.

Investigations on the effect of guide vane thickness and solidity on shock and unsteady flow characteristic of VNT

Dengfeng Yang,Li’ang Cao,Ce Yang,Dazhong Lao,Harold Sun 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.6

In this work, the influence of thickness and solidity of guide vane on the unsteady flow of a radial inflow turbine with variable nozzle has been numerically studied. Three vanes with the thickness changes from 0.3 to 0.1 and the solidity changes from 1.43 to 2.86, were chosen for this study. By investigating the unsteady flow field, it is found that the vane with low thickness and high solidity (vane B) can reduce shock by 75 % compared to the vane with high thickness and low solidity (base model); meanwhile, it can also mitigate the nozzle endwall leakage flow thus improves the flow uniformity of rotor inlet. As the intensity of shock and nozzle leakage flow were mitigated, the aerodynamic loading fluctuation of rotor blade can be weakened effectively, which will lead to improved rotor blades forced response. However, at small opening, vane B shows about 0.5 % lower efficiency than the base model; at large open condition, the efficiency degradation of vane B is up to 1.4 %. Therefore, there is a trade-off between the efficiency and forced response when choosing the nozzle vane solidity and thickness.

Multiple Network-on-Chip Model for High Performance Neural Network

Yiping Dong,Ce Li, Zhen Lin,Takahiro Watanabe 대한전자공학회 2010 Journal of semiconductor technology and science Vol.10 No.1

Hardware implementation methods for Artificial Neural Network (ANN) have been researched for a long time to achieve high performance. We have proposed a Network on Chip (NoC) for ANN, and this architecture can reduce communication load and increase performance when an implemented ANN is small. In this paper, a multiple NoC models are proposed for ANN, which can implement both a small size ANN and a large size one. The simulation result shows that the proposed multiple NoC models can reduce communication load, increase system performance of connection-per-second (CPS), and reduce system running time compared with the existing hardware ANN. Furthermore, this architecture is reconfigurable and reparable. It can be used to implement different applications of ANN.

Multiple Network-on-Chip Model for High Performance Neural Network

Dong, Yiping,Li, Ce,Lin, Zhen,Watanabe, Takahiro The Institute of Electronics and Information Engin 2010 Journal of semiconductor technology and science Vol.10 No.1

Hardware implementation methods for Artificial Neural Network (ANN) have been researched for a long time to achieve high performance. We have proposed a Network on Chip (NoC) for ANN, and this architecture can reduce communication load and increase performance when an implemented ANN is small. In this paper, a multiple NoC models are proposed for ANN, which can implement both a small size ANN and a large size one. The simulation result shows that the proposed multiple NoC models can reduce communication load, increase system performance of connection-per-second (CPS), and reduce system running time compared with the existing hardware ANN. Furthermore, this architecture is reconfigurable and reparable. It can be used to implement different applications of ANN.

Cordycepin inhibits chondrocyte hypertrophy of mesenchymal stem cells through PI3K/Bapx1 and Notch signaling pathway

( Zhen Cao ),( Ce Dou ),( Jianmei Li ),( Xiangyu Tang ),( Junyu Xiang ),( Chunrong Zhao ),( Lingyu Zhu ),( Yun Bai ),( Qiang Xiang ),( Shiwu Dong ) 생화학분자생물학회(구 한국생화학분자생물학회) 2016 BMB Reports Vol.49 No.10

Mesenchymal stem cells (MSCs) are widely used in cartilage tissue engineering to repair articular cartilage defects. However, hypertrophy of chondrocytes derived from MSCs might hinder the stabilization of hyaline cartilage. Thus, it is very important to find a suitable way to maintain the chondrogenic phenotype of chondrocytes. It has been reported that cordycepin has anti-inflammatory and anti-tumor functions. However, the role of cordycepin in chondrocyte hypertrophy remains unclear. Therefore, the objective of this study was to determine the effect of cordycepin on chondrogenesis and chondrocyte hypertrophy in MSCs and ATDC5 cells. Cordycepin upregulated chondrogenic markers including Sox9 and collagen type II while down-regulated hypertrophic markers including Runx2 and collagen type X. Further exploration showed that cordycepin promoted chondrogenesis through inhibiting Nrf2 while activating BMP signaling. Besides, cordycepin suppressed chondrocyte hypertrophy through PI3K/Bapx1 pathway and Notch signaling. Our results indicated cordycepin had the potential to maintain chondrocyte phenotype and reconstruct engineered cartilage. [BMB Reports 2016; 49(10): 548-553]

A novel clocking effect between inlet bend and volute in an automotive turbocharging system

Ben Zhao,Ce Yang,Liangjun Hu,Du Li,Shan Chen 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.5

Numerical methods were carried out on a turbocharger compressor with inlet bent pipe to research a novel clocking effect between the inlet bend and the volute. It was found that the clocking effect with 3.4 percent of variations (1.9 percentage points) in compressor efficiency positively exists at the research point near chock. The reason for the changed efficiency loss is that the inlet bend induces a serious distortion of approaching flow to impeller inlet on one hand, and the downstream volute causes a circumferentially non-uniform distribution of pressure in vaneless diffuser. By adjusting the clocking positions between inlet bend and volute, not only is the unsteadiness of the flow rate through single impeller channel changed, but the uniformity of the incoming flow at the vaneless diffuser inlet is modulated as well. It is the dominant reason for the novel clocking effect that the bad uniformity causes more flow loss in both diffuser and volute.