FUNCTIONALIZED MULTIWALLED CARBON NANOTUBES BY GRAFTING HYPERBRANCHED POLYSILOXANE

HONGXIA YAN,YUAN JIA,LEI MA,YANLI WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.3

Multi-walled carbon nanotubes (MWCNTs) are grafted with hyperbranched polysiloxane(HBPSi) by an e±cient hydrosilylation method. In this hydrosilylation process, hydroxylatedMWCNTs (HO-MWCNTs) are ¯rst functionalized by triethoxyvinylsilane to introduce carbon –carbon double bonds (C ¼ C) on the surface of MWCNTs. The C ¼ C is then reacted with themonomer of methylbis(dimethylvinylsiloxy)silane in the presence of the platinum – carbon cata-lyst, thus HBPSi is ultimately grafted on the surface of MWCNTs. Fourier transform infraredspectrometry (FTIR), Transmission electron microscope (TEM) and X-ray photoelectron spec-troscopy (XPS) are employed to characterize the changes in MWCNTs surface morphology,chemistry and physical conditions at di®erent processing stages. The content of HBPSi on thesurface of MWCNTs was also measured by the thermogravimetric analysis (TGA). The resultsindicate that the HBPSi successfully grafted on the surface of MWCNTs, and the dispersion ofMWCNTs in organic solvent is also improved after functionalization.

VIRTUAL DESIGN OF INDUSTRY PRODUCT AND ENVIRONMENT BASED ON VRML

Yan Zhang,Mingming Chen,Hongxia Wang 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

With the development of computer graphics, visualization technology, software project, hardware and software technology, the application of Visual Reality (VR) has become increasingly used. The emergence of virtual reality modeling language (VRML) makes application of VR more extended. The VR design method of industry product and environment is described, and a practical example is given in this paper. The main contents include ① environment and scene design based on VRML. A design example of street lamp is given. ② Solid modeling design of industry product. ③ 3D fractal design of virtual objects. It is realized to design basso-relievo Sierpinski tetrahedron and hollow Sierpinski tetrahedron. The system takes product, scene, texture and music into account synthetically. The implementing technology provides the foundation for virtual design of industry product. Especially, it can offer technical assurance for scheme argumentation before large-scale pipelining equipment is to go on stream. Also, it is the significance of new product development.

A three-dimensional in vitro culture model for primary neonatal rat ventricular myocytes

Hongxia Zheng,Shanshan Liu,Wei-ming Tian,Hong-ji Yan,Yao Zhang,Yu Li 한국물리학회 2012 Current Applied Physics Vol.12 No.3

To overcome bad prognosis of patients with heart failure and the lack of organ donors, cardiac tissue engineering has developed as a biomimetic approach to repair, replace, and regenerate the damaged cardiac tissue. During the past decade years, researchers are devoted to find different natural and/or synthetic materials that can build appropriate physical structures to contain and organize implanted cells. In this study, we present a new method for primary neonatal rat cardiomyocytes culture in vitro using alginate/collagen/chitosan hydrogel. To investigate the feasibility of this material as scaffold for cardiac myocytes, neonatal rat ventricular myocytes were isolated and encapsulated in alginate-based beads cross-linked with calcium ion. The growth of cells was evaluated by staining with a-Sarcomeric actin (a-SCA) and Troponin T type 2 (TNNT2), and the viability of cardiomyocytes was studied in vitro by assessing the expression levels of several cardiac ion channels, including CACNL1A1, Connexin 43 and SCN5A. The results showed a significant increase in cardiac myocytes number, and the expression levels of CACNL1A1, Connexin 43 (Cx43) were up-regulated significantly except SCN5A, as compared with twodimensional cultures. Moreover, extracellular matrix produced by the seeded cells themselves was observed by staining with fibronectin. Taken together, these findings indicate that this alginate/collagen/chitosan hydrogel bead is suitable for supporting the growth and retaining the morphologic and electrophysiologic characteristics of primary cultured rat cardiac muscle cells.

Influencing Factors of Research Collaboration Intention in Virtual Academic Communities in China

Yan, Chunlai,Li, Hongxia Korea Institute of Science and Technology Informat 2021 Journal of Information Science Theory and Practice Vol.9 No.2

Research collaboration is an important strategy to improve research output, and virtual academic communities (VACs) have become an important platform to collaborate on. This paper reveals the influencing factors of researchers' collaboration intention in VACs from two attributes: individual, and inter-members. On the basis of the Social Cognitive Theory, Social Exchange Theory, social network theory, and Five-Factor Model, this paper constructed a model demonstrating the influencing factors of VACs researchers' collaboration intention. A self-administered questionnaire was employed on members of four VACs in China to collect data; subsequently, 558 usable responses were analyzed using structural equation modeling. The result showed that openness, conscientiousness, reciprocity, trust, and the social network characteristic had a significant influence on the collaboration intention of researchers in VACs, while self-efficacy, agreeableness, extroversion, neuroticism, and experience had no significant effects on the collaboration intention of researchers in VACs. This model plays a positive role in promoting the research collaboration intention of Chinese VACs researchers and in guiding the construction of VAC platforms.

Tribology Property of Benzoxazine–Bismaleimide Composites with Hyperbranched Polysilane-Grafted Multi-Walled Carbon Nanotubes

YUAN JIA,HONGXIA YAN,Song Li,Tianye Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.6

To reveal the wear mechanism of hyperbranched polysilane (HBPSi) grafted multi-walled carbon nanotubes (HBPSi–MWCNTs) modified benzoxazine–bismaleimide (BOZ–BMI) resin (HBPSi– MWCNTs/BOZ–BMI), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) were employed. The results indicated that the suitable addition of HBPSi–MWCNTs could largely enhance the tribological properties of BOZ– BMI composites. The worn surface of the composites showed that the severe wear of the BOZ– BMI resin was converted from adhesive wear to abrasive wear with the addition of HBPSi– MWCNTs. The excellent tribological properties can be attributed to the improved interfacial adhesion between HBPSi–MWCNTs and the BOZ–BMI resin matrix. The TGA demonstrated that the composite with 0.8 wt.% HBPSi–MWCNTs exhibits better thermal resistance; thus, it can inhibit adhesive wear during the friction process. The XPS spectra and the surface energy showed that the HBPSi–MWCNTs could be exposed on the worn surface of the composite to improve the anti-wear capacity of the composites further.

Carbon Nanotubes Grafted with Hyperbranched Triazine Compounds

Tingting Li,HONGXIA YAN,Tianye Liu,Chao Liu,Zhengyan Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.1

In order to improve the dispersibility of carbon nanotubes (CNTs) in the resin matrix, CNTs grafted with hyperbranched triazine compound (HPTC–CNTs) was produced by four generations condensation reaction using cyanuric chloride and hexamethylenediamine. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), UV-Vis spectroscopy (UV-Vis) and transmission electron microscopes (TEM) were used to characterize the obtained HPTC–CNTs. The FTIR, XPS, UV-Vis and TEM analysis showed that CNTs had been successfully grafted with HPTC. The TGA showed that the content of HPTC on the surface of CNTs was about 58 wt.%. And the HPTC–CNTs had good dispersion both in water and acetone.

Genome Sequencing Highlights the Plant Cell Wall Degrading Capacity of Edible Mushroom Stropharia rugosoannulata

Guo Mengpei,Ma Xiaolong,Zhou Yan,Bian Yinbing,Liu Gaolei,Cai Yingli,Huang Tianji,Dong Hongxia,Cai Dingjun,Wan Xueji,Wang Zhihong,Xiao Yang,Kang Heng 한국미생물학회 2023 The journal of microbiology Vol.61 No.1

The basidiomycetous edible mushroom Stropharia rugosoannulata has excellent nutrition, medicine, bioremediation, and biocontrol properties. S. rugosoannulata has been widely and easily cultivated using agricultural by-products showing strong lignocellulose degradation capacity. However, the unavailable high-quality genome information has hindered the research on gene function and molecular breeding of S. rugosoannulata. This study provided a high-quality genome assembly and annotation from S. rugosoannulata monokaryotic strain QGU27 based on combined Illumina-Nanopore data. The genome size was about 47.97 Mb and consisted of 20 scaffolds, with an N50 of 3.73 Mb and a GC content of 47.9%. The repetitive sequences accounted for 17.41% of the genome, mostly long terminal repeats (LTRs). A total of 15,726 coding gene sequences were putatively identified with the BUSCO score of 98.7%. There are 142 genes encoding plant cell wall degrading enzymes (PCWDEs) in the genome, and 52, 39, 30, 11, 8, and 2 genes related to lignin, cellulose, hemicellulose, pectin, chitin, and cutin degradation, respectively. Comparative genomic analysis revealed that S. rugosoannulata is superior in utilizing aldehyde-containing lignins and is possible to utilize algae during the cultivation.

Intestinal segment and vitamin D3 concentration affect gene expression levels of calcium and phosphorus transporters in broiler chickens

Jincheng Han,Lihua Wu,Xianliang Lv,Mengyuan Liu,Yan Zhang,Lei He,Junfang Hao,Li Xi,Hongxia Qu,Chuanxin Shi,Zhiqiang Li,Zhixiang Wang,Fei Tang,Yingying Qiao 한국축산학회 2023 한국축산학회지 Vol.65 No.2

Two experiments were conducted in this research. Experiment 1 investigated the spatial expression characteristics of calcium (Ca) and phosphorus (P) transporters in the duodenum, jejunum, and ileum of 21-day-old broilers provided with adequate nutrient feed. Experiment 2 evaluated the effects of dietary vitamin D3 (VD3) concentration (0, 125, 250, 500, 1,000, and 2,000 IU/kg) on growth performance, bone development, and gene expression levels of intestinal Ca and P transporters in 1–21-day-old broilers provided with the negative control diet without supplemental VD3. Results in experiment 1 showed that the mRNA levels of calcium- binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), plasma membrane calcium ATPase 1b (PMCA1b), and IIb sodium-phosphate cotransporter (NaPi-IIb) were the highest in the broiler duodenum. By contrast, the mRNA levels of inorganic phosphate transporter 1 (PiT-1) and 2 (PiT-2) were the highest in the ileum. Results in experiment 2 showed that adding 125 IU/kg VD3 increased body weight gain (BWG), feed intake (FI), bone weight, and percentage and weight of Ca and P in the tibia and femur of 1–21-day-old broilers compared with the negative control diet (p < 0.05). The rise in dietary VD3 levels from 125 to 1,000 IU/kg further increased the BWG, FI, and weights of the bone, ash, Ca, and P (p < 0.05). No difference in growth rate and leg bone quality was noted in the broilers provided with 1,000 and 2,000 IU/kg VD3 (p > 0.05). Supplementation with 125–2,000 IU/kg VD3 increased the mRNA abundances of intestinal Ca and P transporters to varying degrees. The mRNA level of CaBP-D28k increased by 536, 1,161, and 28 folds in the duodenum, jejunum, and ileum, respectively, after adding 1,000 IU/kg VD3. The mRNA levels of other Ca and P transporters (PMCA1b, NCX1, NaPi-IIb, PiT-1, and PiT-2) increased by 0.57–1.74 folds by adding 1,000–2,000 IU/kg VD3. These data suggest that intestinal Ca and P transporters are mainly expressed in the duodenum of broilers. Moreover, the addition of VD3 stimulates the two mineral transporter transcription in broiler intestines.

Suppression of Aurora-A oncogenic potential by c-Myc downregulation

Yang, Shangbin,He, Shun,Zhou, Xiaobo,Liu, Mei,Zhu, Hongxia,Wang, Yihua,Zhang, Wei,Yan, Shuang,Quan, Lanping,Bai, Jingfeng,Xu, Ningzhi Korean Society for Biochemistry and Molecular Bion 2010 Experimental and molecular medicine Vol.42 No.11

The abnormality of serine/threonine kinase Aurora-A is seen in many types of cancers. Although in physiological context it has been shown to play a vital role in cellular mitosis, how this oncogene contributes to tumorigenesis remains unclear. Here we demonstrate that Aurora-A overexpression enhances both the expression level and transcriptional activity of c-Myc. The inhibition of c-Myc expression by RNA interference significantly impaired the oncogenic potential of Aurora-A, resulting in attenuated cellular proliferation and transformation rates as well as fewer centrosomal aberrations. Furthermore, downregulation of c-Myc effectively overcame Aurora-A-induced resistance to cisplatin in esophageal cancer cells. Taken together, our results suggest an important role for c-Myc in mediating the oncogenic activity of Aurora-A, which may in turn allow for future targeting of c-Myc as a potential therapeutic strategy for tumors with Aurora-A overexpression.

Suppression of Aurora-A oncogenic potential by c-Myc downregulation

Shangbin Yang,Shun He,Xiaobo Zhou,Mei Liu,Hongxia Zhu,Yihua Wang,Wei Zhang,Shuang Yan,Lanping Quan,Jingfeng Bai,Ningzhi Xu 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.11

The abnormality of serine/threonine kinase Aurora-A is seen in many types of cancers. Although in physiological context it has been shown to play a vital role in cellular mitosis, how this oncogene contributes to tumorigenesis remains unclear. Here we demonstrate that Aurora-A overexpression enhances both the expression level and transcriptional activity of c-Myc. The inhibition of c-Myc expression by RNA interference significantly impaired the oncogenic potential of Aurora-A, resulting in attenuated cellular proliferation and transformation rates as well as fewer centrosomal aberrations. Furthermore, downregulation of c-Myc effectively overcame Aurora-A-induced resistance to cisplatin in esophageal cancer cells. Taken together,our results suggest an important role for c-Myc in mediating the oncogenic activity of Aurora-A, which may in turn allow for future targeting of c-Myc as a potential therapeutic strategy for tumors with Aurora-A overexpression.