Effective synthesis to fabricate a giant dielectric-constant material CaCu3Ti4O12 via solid state reactions

Wen Xiang Yuan,Wai Ning Mei,Sui Kong Hark 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.5

In this study, we effectively synthesized a giant dielectric-constant material CaCu3Ti4O12 (CCTO) by using a solid-state reaction method that was composed of two main chemical reactions. Comparing with typical calcining conditions, our procedures are much less energy- and time-consuming. When preparing our CCTO, we applied a momentarily high temperature heating at the end of the calcination, then followed it by a typical sintering process. We found this additional heating converts the otherwise mixed-phase products into a pure phase and the CCTO samples prepared this special way possess a large dielectric constant, up to 19,000. In this study, we effectively synthesized a giant dielectric-constant material CaCu3Ti4O12 (CCTO) by using a solid-state reaction method that was composed of two main chemical reactions. Comparing with typical calcining conditions, our procedures are much less energy- and time-consuming. When preparing our CCTO, we applied a momentarily high temperature heating at the end of the calcination, then followed it by a typical sintering process. We found this additional heating converts the otherwise mixed-phase products into a pure phase and the CCTO samples prepared this special way possess a large dielectric constant, up to 19,000.

The Effect of Obstacle Number, Shape and Blockage Degree in Flow Field of PEMFC on its Performance

Zongxi Zhang,Xiang Fan,Wenhao Lu,Jian Yao,Zhike Sui The Korean Electrochemical Society 2024 Journal of electrochemical science and technology Vol.15 No.1

Proton exchange membrane fuel cell (PEMFC) has received extensive attention as it is the most common hydrogen energy utilization device. This research not only investigated the effect of obstacle number and shape on PEMFC performance, but also studied the effect of the blockage degree in the channel of PEMFC on its performance. It was found that compared with traditional scheme, longitudinally distributed obstacles scheme can significantly promote reactants transfer to catalyst layer, and the blockage degree in the channel effect PEMFC performance most. The scheme with 10 rectangular obstacles in single channel and 60% channel blockage had the best output performance and the most uniform distribution of reactants and products. Obstacle height distribution can significantly affect PEMFC performance, the blockage degree in the whole basin was large, particularly as the channel was blocked to higher degree in region 2 and region 3, higher net power density and better mass transfer effect can be obtained. Among them, the fuel cell with the blockage degree of 40%, 60% and 60% in region 1, region 2 and region 3 have the best PEMFC output performance and mass transfer, the net power density was 29.8% higher than that of traditional scheme.

Anti-metastasis Activity of Black Rice Anthocyanins Against Breast Cancer: Analyses Using an ErbB2 Positive Breast Cancer Cell Line and Tumoral Xenograft Model

Luo, Li-Ping,Han, Bin,Yu, Xiao-Ping,Chen, Xiang-Yan,Zhou, Jie,Chen, Wei,Zhu, Yan-Feng,Peng, Xiao-Li,Zou, Qiang,Li, Sui-Yan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: Increasing evidence from animal, epidemiological and clinical investigations suggest that dietary anthocyanins have potential to prevent chronic diseases, including cancers. It is also noteworthy that human epidermal growth factor receptor 2 (ErbB2) protein overexpression or ErbB2 gene amplification has been included as an indicator for metastasis and higher risk of recurrence for breast cancer. Materials and Methods: The present experiments investigated the anti-metastasis effects of black rice anthocyanins (BRACs) on ErbB2 positive breast cancer cells in vivo and in vitro. Results: Oral administration of BRACs (150 mg/kg/day) reduced transplanted tumor growth, inhibited pulmonary metastasis, and decreased lung tumor nodules in BALB/c nude mice bearing ErbB2 positive breast cancer cell MDA-MB-453 xenografts. The capacity for migration, adhesion, motility and invasion was also inhibited by BRACs in MDA-MB-453 cells in a concentration dependent manner, accompanied by decreased activity of a transfer promoting factor, urokinase-type plasminogen activator (u-PA). Conclusions: Together, our results indicated that BRACs possess anti-metastasis potential against ErbB2 positive human breast cancer cells in vivo and in vitro through inhibition of metastasis promoting molecules.

The role of extracellular vesicles in osteoarthritis treatment via microenvironment regulation

Han Yin,Muzhe Li,Guangzhao Tian,Yang Ma,Chao Ning,Zineng Yan,Jiang Wu,Qian Ge,Xiang Sui,Shu-Yun Liu,Jinxuan Zheng,Weimin Guo,Quan-Yi Guo 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Osteoarthritis (OA) is a degenerative joint disease that is common among the middle-aged and older populations, causes patients to experience recurrent pain in their joints and negatively affects their quality of life. Currently, therapeutic options for patients with OA consist of medications to alleviate pain and treat the symptoms; however, due to typically poor outcomes, patients with advanced OA are unlikely to avoid joint replacement. In recent years, several studies have linked disrupted homeostasis of the joint cavity microenvironment to the development of OA. Recently, extracellular vesicles (EVs) have received increasing attention in the field of OA. EVs are natural nano-microcarrier materials with unique biological activity that are produced by cells through paracrine action. They are composed of lipid bilayers that contain physiologically active molecules, such as nucleic acids and proteins. Moreover, EVs may participate in local and distal intercellular and intracellular communication. EVs have also recently been shown to influence OA development by regulating biochemical factors in the OA microenvironmental. In this article, we first describe the microenvironment of OA. Then, we provide an overview of EVs, summarize the main types used for the treatment of OA, and describe their mechanisms. Next, we review clinical studies using EVs for OA treatment. Finally, the specific mechanism underlying the application of miRNA-enriched EVs in OA therapy is described.

Construction and Expression of an Eukaryotic Expression Vector Containing the IER3 Gene

Wang, Zhen,Yu, Hong-Sheng,Yao, Ru-Yong,Qiu, Wen-Sheng,Yue, Lu,Sui, Ai-Hua,Liu, Xiang-Ping,Liu, Shi-Hai Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Background: More and more research indicate that the immediately early response gene 3 (IER3) is involved inmany biological provesses, such as apoptosis and immunoreaction, as well as viral infection, tumorigenesis and tumour progression. Methods: Here we describe the construction of an eukaryotic expression vector containing IER3 gene and its expression in A549 cells as assessed through fluorescence microscopyand Western-blotting. Results: Fluorescence detection displayed that GFP in cytoplasm was high during 48 and 72 hours post-transfection. In addition, Western blotting showed significant increase in IER3 gene expression in the transfected cells compared with controls. Conclusion: The recombinate plasmid expression vector was constructed successfully, which may provide a basis for further exploration of function of IER3 in lung cancer.

Hierarchical porous ECM scaffolds incorporating GDF-5 fabricated by cryogenic 3D printing to promote articular cartilage regeneration

Wu Jiang,Fu Liwei,Yan Zineng,Yang Yu,Yin Han,Li Pinxue,Yuan Xun,Ding Zhengang,Kang Teng,Tian Zhuang,Liao Zhiyao,Tian Guangzhao,Ning Chao,Li Yuguo,Sui Xiang,Chen Mingxue,Liu Shuyun,Guo Quanyi 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

In recent years, there has been significant research progress on in situ articular cartilage (AC) tissue engineering with endogenous stem cells, which uses biological materials or bioactive factors to improve the regeneration microenvironment and recruit more endogenous stem cells from the joint cavity to the defect area to promote cartilage regeneration.In this study, we used ECM alone as a bioink in low-temperature deposition manufacturing (LDM) 3D printing and then successfully fabricated a hierarchical porous ECM scaffold incorporating GDF-5.Comparative in vitro experiments showed that the 7% ECM scaffolds had the best biocompatibility. After the addition of GDF-5 protein, the ECM scaffolds significantly improved bone marrow mesenchymal stem cell (BMSC) migration and chondrogenic differentiation. Most importantly, the in vivo results showed that the ECM/GDF-5 scaffold significantly enhanced in situ cartilage repair.In conclusion, this study reports the construction of a new scaffold based on the concept of in situ regeneration, and we believe that our findings will provide a new treatment strategy for AC defect repair.