Room-temperature Synthesis of Cu2O Nanostructures and Their Morphology-dependent Adsorption Properties

Yanyan Xu,Ping Liu,Yanyan Cao,Yaqiu Sun,Guoying Zhang 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.7

Three different Cu2O nanostructures, namely porous nanospheres, nanoparticles, and nanocubes, were synthesized through a facile solution route at room temperature. Structure and morphology of the products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), and nitrogen adsorption–desorption isotherms. The adsorption behavior of Methyl Orange (MO) onto these Cu2O nanostructures was investigated, considering the effect of initial methyl orange concentration and the additive amount of Cu2O products. The kinetic and equilibrium investigations suggested that the adsorption process of MO followed a pseudo-second order rate equation and the Langmuir isotherm model. The maximum adsorption capacity of the three samples followed the sequence: porous nanospheres > nanoparticles > nanocubes, which was in accordance of the BET specific surface of the samples. In addition, further investigations indicated that the as-prepared Cu2O nanostructures also show good adsorption properties for other anionic dyes including Congo red and Methyl blue.

Cell Growth Inhibition and Gene Expression Regulation by (-)-Epigallocatechin-3-Gallate in Human Cervical Cancer Cells

Yanyan Qiao,Xiaolin Shi,Jinyan Cao,Liangqun Xie 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.9

EGCG [(-)-epigallocatechin-3-gallate] has shown its antitumor ability and perhaps a potential regimen for cancer patients. The goal of this study was to investigate the effect of EGCG on human papilloma virus (HPV) positive cervical cancer cell lines. EGCG inhibited the growth of CaSki (HPV16 positive) and HeLa (HPV18 positive) cells in a time- and concentration-dependent manner. Cell cycle arrest and apoptosis were observed in two cell lines after EGCG exposure. More importantly, we focused on EGCG regulation ability on pivotal genes involved in cervical cancer: viral oncogenes E6/E7, estrogen receptor (ER) and aromatase. Our results suggested that EGCG may be suitable for prevention and treatment of cervical cancer.

Comparative Study on Inclusions in Mg-Nd-Zn-Zr Melt Employing Flux and Fluxless Purification Approach

Hanxue Cao,Hao Jiang,Yanyan Huang,Chengzhi Yang,Siyuan Long 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.11

Two purification approaches, flux approach (flux shielding and flux refining) and fluxless approach (protective atmospheres and inert gas bubbling), are implemented to remove the inclusions in Mg-Nd-Zn-Zr melt. The purification effects are assessed by studying structural properties, chemical composition and the origin of the inclusions. The amount and the average size of the inclusions raise at first, then decrease during flux (or fluxless) refining process, which include 15 min flux refining (or gas bubbling) and 10 min settling. Both approaches have the effect to protect Mg melt and separate inclusions from the melt, but fluxless approach is not as effective as flux approach in the control of inclusions. Either way, oxides and carbides can be found in magnesium (Mg) melt, and the former are the most predominant non-metallic inclusions. Undissolved zirconium (Zr) particles are observed over the process of both techniques, which is a characteristic of Zr alloying Mg alloys, and these particles are easy to settle due to high density. The emergence of chlorine (Cl) atoms in inclusions implies flux inclusions are formed during flux purification, while sulphur (S) is detected in fluxless purification indicates sulphides or sulphates occur in Mg melt as a result of the usage of fire extinguishing sulfur powder.

INDIRECT CUSTOMER-TO-CUSTOMER INTERACTION IN TECHNOLOGY-BASED SELF-SERVICE

Zhongpeng Cao,Yanyan Zhang 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

In service encounter, value creation comes not only from customer-to- service provider interaction but also from customer-to-customer interaction (CCI). A number of studies have demonstrated that the CCI plays an important role in perceived service quality, value creation, and customer satisfaction. Although prior researcher have explored the effect of CCI, they have focused more on traditional service encounter which service employee is present than on technology-based self-service (TBSS) encounter without employee presence. TBSS is an activity or benefit based on hard technologies that service providers offer so that customers can perform the service, or parts of the service by themselves. Focal customers can be influenced directly or indirectly by other customers in service encounter. To examine the effect of ICCI on service quality in TBSS, we conducted two studies. Study 1 focus on the impact of ICCI on service quality and the mediation of service experience. Study 2 explore whether the service failure moderates the relationship between ICCI and service experience. In experiment 1, a single factor (other customers: presence VS. absence) experiment was conducted with two different level of ICCI. Results show that compared with other customer absences when other customer presences focal customer perceived service quality is lower. That is, ICCI has a significant main effect on service quality. In addition, Experiment 1 provided evidence that a partial mediating factor underlying the relationship between ICCI and service quality was customers’s emotion. In experiment 2, A 2 (other customers: presence VS. absence) × 2 (service failure: yes VS. no) between subject design was conducted. An ANOVA on negative emotion yielded a significant ICCI × service failure interaction. The participants in the other customer presence condition experienced service was more discomfortable when the service was failed than when the service was succeeded. However, this effect was strengthened for the other customer absence condition. With advances in information technology, there has been a proliferation of self-service technologies across the services sector in the past decade. The quality and experience of technology-based self-service are very much worth the attention of service providers. Our study reveals the effect of ICCI on service quality and the mechanism by the mediation of negavtive emotion and the boundary condition of the link between ICCI and negative emotion. These results suggest that service providers should avoid ICCI, such as providing closed ATM, kiosk, and so on. In addition, the firms should try their best to guide customer to ensure the production and delivery of self-service to reduce service failures.

Two new triterpenoid saponins derived from the leaves of Panax ginseng and their antiinflammatory activity

Li, Fu,Cao, Yufeng,Luo, Yanyan,Liu, Tingwu,Yan, Guilong,Chen, Liang,Ji, Lilian,Wang, Lun,Chen, Bin,Yaseen, Aftab,Khan, Ashfaq A.,Zhang, Guolin,Jiang, Yunyao,Liu, Jianxun,Wang, Gongcheng,Wang, Ming-Kui The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.4

Background: The leaves and roots of Panax ginseng are rich in ginsenosides. However, the chemical compositions of the leaves and roots of P. ginseng differ, resulting in different medicinal functions. In recent years, the aerial parts of members of the Panax genus have received great attention from natural product chemists as producers of bioactive ginsenosides. The aim of this study was the isolation and structural elucidation of novel, minor ginsenosides in the leaves of P. ginseng and evaluation of their antiinflammatory activity in vitro. Methods: Various chromatographic techniques were applied to obtain pure individual compounds, and their structures were determined by nuclear magnetic resonance and high-resolution mass spectrometry, as well as chemical methods. The antiinflammatory effect of the new compounds was evaluated on lipopolysaccharide-stimulated RAW 264.7 cells. Results and conclusions: Two novel, minor triterpenoid saponins, ginsenoside $LS_1$ (1) and 5,6-didehydroginsenoside $Rg_3$ (2), were isolated from the leaves of P. ginseng. The isolated compounds 1 and 2 were assayed for their inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7 cells, and Compound 2 showed a significant inhibitory effect with $IC_{50}$ of $37.38{\mu}M$ compared with that of NG-monomethyl-L-arginine ($IC_{50}=90.76{\mu}M$). Moreover, Compound 2 significantly decreased secretion of cytokines such as prostaglandin $E_2$ and tumor necrosis factor-${\alpha}$. In addition, Compound 2 significantly suppressed protein expression of inducible nitric oxide synthase and cyclooxygenase-2. These results suggested that Compound 2 could be used as a valuable candidate for medicinal use or functional food, and the mechanism is warranted for further exploration.

3D Bioprinted GelMA/PEGDA Hybrid Scaffold for Establishing an In Vitro Model of Melanoma

( Jiahui Duan ),( Yanyan Cao ),( Zhizhong Shen ),( Yongqiang Cheng ),( Zhuwei Ma ),( Lijing Wang ),( Yating Zhang ),( Yuchuan An ),( Shengbo Sang ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.4

Due to the high incidence of malignant melanoma, the establishment of in vitro models that recapitulate the tumor microenvironment is of great biological and clinical importance for tumor treatment and drug research. In this study, 3D printing technology was used to prepare GelMA/PEGDA composite scaffolds that mimic the microenvironment of human malignant melanoma cell (A375) growth and construct in vitro melanoma micro-models. The GelMA/PEGDA hybrid scaffold was tested by the mechanical property, cell live/dead assay, cell proliferation assay, cytoskeleton staining and drug loading assay. The growth of tumor cells in two- and three-dimensional culture systems and the anti-cancer effect of luteolin were evaluated using the live/dead staining method and the Cell Counting Kit-8 (CCK-8) method. The results showed a high aggregation of tumor cells on the 3D scaffold, which was suitable for long-term culture. Cytoskeleton staining and immunofluorescent protein staining were used to evaluate the degree of differentiation of tumor cells under 2D and 3D culture systems. The results indicated that 3D bioprinted scaffolds were more suitable for tumor cell expansion and differentiation, and the tumor cells were more aggressive. In addition, luteolin was time- and dose-dependent on tumor cells, and tumor cells in the 3D culture system were more resistant to the drug.

Preparation and In Vitro Characterization of Gelatin Methacrylate for Corneal Tissue Engineering

Yan Yayun,Cao Yanyan,Cheng Rong,Shen Zhizhong,Zhao Yajing,Zhang Yixia,Zhou Guohong,Sang Shengbo 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.1

BACKGROUND: Corneal disease is second only to cataract considered as the leading cause of blindness in the world, with high morbidity. Construction of corneal substitutes in vitro by tissue engineering technology to achieve corneal regeneration has become a research hotspot in recent years. We conducted in-depth research on the biocompatibility, physicochemical and mechanical properties of rat bone marrow mesenchymal stem cells (rBM-MSCs)-seeded gelatin methacrylate (GelMA) as a bioengineered cornea. METHODS: Four kinds of GelMA with different concentrations (7, 10, 15 and 30%) were prepared, and their physicchemical, optical properties, and biocompatibility with rBM-MSCs were characterized. MTT, live/dead staining, cell morphology, immunofluorescence staining and gene expression of keratocyte markers were performed. RESULTS: 7%GelMA hydrogel had higher equilibrium water content and porosity, better optical properties and hydrophilicity. In addition, it is more beneficial to the growth and proliferation of rBM-MSCs. However, the 30%GelMA hydrogel had the best mechanical properties, and could be more conducive to promote the differentiation of rBM-MSCs into keratocyte-like cells. CONCLUSION: As a natural biological scaffold, GelMA hydrogel has good biocompatibility. And it has the ability to promote the differentiation of rBM-MSCs into keratocyte-like cells, which laid a theoretical and experimental foundation for further tissue-engineered corneal stromal transplantation, and provided a new idea for the source of seeded cells in corneal tissue engineering.

Effect of lactoferrin on ram sperm motility after cryopreservation

Su Jie,Wang Caiyun,Song Yongli,Yang Yanyan,Cao Guifang 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.9

Objective: The objective of this study was to analyse the differentially abundant proteins caused by freeze–thawing of ram sperm and explore candidate proteins of interest for their ability to improve ram sperm cryopreservation outcomes in vitro. Methods: Sperm were from three mature Dorper. Fresh and frozen sperm proteins were extracted, and the differentially abundant proteins were analysed by mass spectrometry. Among these proteins, lactoferrin (LTF) was selected to be added before cryopreservation. Next, sperm samples were diluted in Tris extender, with the addition of 0, 10, 100, 500, and 1,000 μg/mL of LTF. After thawing, sperm quality was evaluated by motility, plasma membrane integrity, mitochondrial activity and reactive oxygen species (ROS). Results: Cryopreservation significantly altered the abundance of 40 proteins; the abundance of 16 proteins was increased, while that of 24 proteins was decreased. Next, LTF was added to Tris extender applied to ram sperm. The results showed that sperm motility and plasma membrane integrity were significantly improved (p<0.05) by supplementation with 10 μg/mL LTF compared to those in the control group. There was no significant difference in mitochondrial activity between the 0 μg/mL group and other groups (p>0.05). Supplementation of the cryoprotective extender with 10 μg/mL LTF led to decreased ROS levels compared with those in the control and other groups (p<0.05). Conclusion: The LTF is an important protein during cryopreservation, and the addition of 10 μg/mL LTF to a cryoprotective extender can significantly improve the function of frozen ram sperm. Objective: The objective of this study was to analyse the differentially abundant proteins caused by freeze–thawing of ram sperm and explore candidate proteins of interest for their ability to improve ram sperm cryopreservation outcomes in vitro.Methods: Sperm were from three mature Dorper. Fresh and frozen sperm proteins were extracted, and the differentially abundant proteins were analysed by mass spectrometry. Among these proteins, lactoferrin (LTF) was selected to be added before cryopreservation. Next, sperm samples were diluted in Tris extender, with the addition of 0, 10, 100, 500, and 1,000 μg/mL of LTF. After thawing, sperm quality was evaluated by motility, plasma membrane integrity, mitochondrial activity and reactive oxygen species (ROS).Results: Cryopreservation significantly altered the abundance of 40 proteins; the abundance of 16 proteins was increased, while that of 24 proteins was decreased. Next, LTF was added to Tris extender applied to ram sperm. The results showed that sperm motility and plasma membrane integrity were significantly improved (p<0.05) by supplementation with 10 μg/mL LTF compared to those in the control group. There was no significant difference in mitochondrial activity between the 0 μg/mL group and other groups (p>0.05). Supplementation of the cryoprotective extender with 10 μg/mL LTF led to decreased ROS levels compared with those in the control and other groups (p<0.05).Conclusion: The LTF is an important protein during cryopreservation, and the addition of 10 μg/mL LTF to a cryoprotective extender can significantly improve the function of frozen ram sperm.