Morphology, Crystallization and Mechanical Properties of Biodegradable Poly(butylene succinate-co-butylene carbonate)/Multi-Walled Carbon Nanotubes Nanocomposites

Yuanyuan Zhao,Zhaobin Qiu 한국고분자학회 2014 Macromolecular Research Vol.22 No.7

Biodegradable poly(butylene succinate-co-butylene carbonate) (PBSC)/carboxyl-functionalized multiwalledcarbon nanotubes (f-MWCNTs) nanocomposites were prepared through a solution and casting method at lowf-MWCNTs loadings. Scanning electron microscopy observations revealed a fine dispersion of f-MWCNTs in the PBSCmatrix. Both the nonisothermal and isothermal melt crystallization processes of PBSC were enhanced, apparently by thepresence of f-MWCNTs in the nanocomposites, because f-MWCNTs acted as an efficient heterogeneous nucleation agentfor the crystallization of PBSC. The crystallization mechanism remained unchanged for both neat PBSC and the PBSC/f-MWCNTs nanocomposites, regardless of crystallization temperature; moreover, the crystal structures of PBSCwere not modified by f-MWCNTs in the nanocomposites. The dynamical mechanical properties were also improvedin the nanocomposites. Upon incorporating only 1 wt% of f-MWCNTs, the storage modulus of PBSC improved byabout 30% at -60 oC. In addition, the glass transition temperature values of PBSC were increased slightly in the nanocomposites,relative to that of neat PBSC.

Simulating the Exposure of Urban Areas to Seismic Hazard in Beijing-Tianjin-Tangshan Metropolitan Area, China

Zhao Yuanyuan,Chunyang He 대한지리학회 2011 대한지리학회 컨퍼런스 자료집 Vol.- No.6

The Effect of Enhanced UV-B Radiation and Drought on the Growth and Physiology in Artemisia sphaerocephala

Yuanyuan Zhao,Xiaowei Hu,Xiumei Miao,Shuzhen Nan,Guoqin Duan,Pengfang Yang,Xiaolong Chen,Lijing zhang,Hua Fu 한국초지조사료학회 2016 한국초지조사료학회 학술대회논문집 Vol.2016 No.08

The Expectations and Acceptability of a Smart Nursing Home Model Among Chinese Older Adults and Family Members: A Qualitative Study

Zhao Yuanyuan,Sazlina Shariff-Ghazali,Rokhani Fakhrul Z.,Su Jing,Chew Boon-How 한국간호과학회 2023 Asian Nursing Research Vol.17 No.4

Purpose This study aims to explore the expectations and acceptability of a smart nursing home model among Chinese older adults and their family members based on a scoping review that defines the concept of smart nursing homes. Methods A qualitative case study was employed for this research. Semi-structured, in-depth interviews and focus group discussions were conducted on WeChat. Participants were purposively sampled through snowball sampling in Hainan and Dalian, China. A total of 28 older adults aged 60–75 and six adult children were interviewed until data saturation was achieved, followed by a thematic analysis. Results The expectations of smart nursing homes include: 1) quality of care supported by governments and societies; 2) smart technology applications; 3) the presence of a skilled healthcare professional team; 4) access to and scope of basic medical services; and 5) integration of medical services. The acceptability of smart nursing homes included factors such as stakeholders’ perceived efficaciousness, usability, and collateral damages of using smart technologies, and the coping process of adoption was influenced by factors such as age, economic status, health status, education, and openness to smart technologies among older adults. Conclusions Chinese older adults and their family members have a positive perception of the smart nursing home model. The qualitative evidence regarding their expectations and acceptability of smart nursing homes contributes valuable insights for a wide range of stakeholders involved in the planning and implementation of smart nursing homes.

Direct Electrochemistry and Electrocatalysis of Myoglobin with CoMoO₄ Nanorods Modified Carbon Ionic Liquid Electrode

Zhao, Zengying,Cao, Lili,Hu, Anhui,Zhang, Weili,Ju, Xiaomei,Zhang, Yuanyuan,Sun, Wei Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.2

By using ionic liquid 1-hexylpyridinium hexafluorophosphate ($HPPF_6$) based carbon ionic liquid electrode (CILE) as the substrate electrode, a $CoMoO_4$ nanorods and myoglobin (Mb) composite was casted on the surface of CILE with chitosan (CTS) as the film forming material to obtain the modified electrode (CTS/$CoMoO_4$-Mb/CILE). Spectroscopic results indicated that Mb retained its native structures without any conformational changes after mixed with $CoMoO_4$ nanorods and CTS. Electrochemical behaviors of Mb on the electrode were carefully investigated by cyclic voltammetry with a pair of well-defined redox peaks from the heme Fe(III)/Fe(II) redox center of Mb appeared, which indicated that direct electron transfer between Mb and CILE was realized. Electrochemical parameters such as the electron transfer number (n), charge transfer coefficient (${\alpha}$) and electron transfer rate constant ($k_s$) were estimated by cyclic voltammetry with the results as 1.09, 0.53 and 1.16 $s^{-1}$, respectively. The Mb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid in the concentration range from 0.1 to 32.0 mmol $L^{-1}$ with the detection limit as 0.036 mmol $L^{-1}$ ($3{\sigma}$), and the reduction of $H_2O_2$ in the concentration range from 0.12 to 397.0 ${\mu}mol\;L^{-1}$ with the detection limit as 0.0426 ${\mu}mol\;L^{-1}$ ($3{\sigma}$).

One-pot Synthesis of Hierarchical Mesoporous ZSM-5 from the Assembly of Nanocrystals Using Urea as Additive

Yuanyuan Ma,Zhifang Li,Nan Zhao,Fuzhong Han,Qiubin Kan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.03

A hierarchical mesoporous ZSM-5 catalyst with aggregated nanocrystals structure was one-pot hydrothermally synthesized by using urea as the additive. The crystalline phase, morphology and hierarchical architectures were characterized by the XRD, SEM, TEM and N2 adsorption/desorption analyses. The nano-aggregates showed MFI crystalline phase and were composed of connected nanoparticles. The samples had the high surface area and the pore volume from intercrystalline among the nanoparticles due to spontaneously stacking of nanocrystals. The pyridine-adsorbed FTIR and the catalytic performances in the alkylation of phenol and tert-butyl alcohol were applied to evaluate the accessibility of acid sites and the catalytic activities for the hierarchical mesoporous ZSM-5 samples. The samples possessed high accessibility of acid sites which resulted from their large amount of mesopores, and its catalytic activity was improved dramatically. The phenol conversion could reach up to 95.6%, and the corresponding selectivity of 4-TBP and 2,4-DTBP was 44% and 51.5%, respectively.

Optimum synthesis of esomeprazole catalyzed by Rhodococcus rhodochrous ATCC 4276 through response surface methodology

Yuanyuan Zhang,Qiuxiang Zhao,Hui Tang,Huiling Li,Depeng Li,Zhiyong Wang,Xin Gao,Fanye Wang 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.5

Enantiopure esomeprazole is an important drug in the treatment of gastric ulcer. The asymmetric sulfoxidation of omeprazole thioether was catalyzed by immobilized cells of a mutant of Rhodococcus rhodocrous ATCC 4276 to synthesize esomeprazole. The bioreaction was carried out in a biphasic system (chloroform-water), at a high substrate concentration (200mM), and optimized using response surface methodology (RSM). The optimal yield of esomeprazole obtained was 94.8% with e.e. (>99%) without the formation of the sulfone form as a byproduct, under the optimal conditions: the concentration of immobilized cells, 283.5 g/L, the incubation temperature, 37.05 oC, and pH of phosphate buffer, 7.35, respectively. A quadratic polynomial model was developed with R2 of 0.9998, which indicates that the model predicts the observed data with very high accuracy. The mutant exhibited a high enantioselective activity and substrate and product tolerance. The small size of immobilized cell beads (0.5-1 mm) creates a large reaction interface. The aerated flask provides enough oxygen for a high concentration of cells. The significant improvement of substrate tolerance may mainly be attributed to employing the chloroform-water biphasic system because organic substrates may be partitioned in the organic phase, eliminating potential damage and inhibition to cells. Based on the above, the asymmetric sulfoxidation catalyzed by immobilized bacterial cells is therefore more promising for efficient synthesis of chiral sulfoxides.

STRESS AND CONSUMER ETHICAL BELIEFS: THE ROLE OF CONSTRUAL LEVEL AND MATERIALISM

Yuanyuan Liu,Yeyi Liu,Xi Zhao 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

Understanding why individuals behave unethically is an important topic for both theory and practice, especially in the current environment where people experience much more stressful events. The current research aims to examine the relationship between peoples’ experienced stress and their attitude towards unethical consumption behavior, as well as the underlying mechanism. Empirical findings from a survey of 451 participants suggest perceived stress serves as an important indicator of people’s tolerance of unethical activities, and that this relationship is mediated by chronic construal level and materialism value. Specifically, stressed individuals tend to develop low-construal mindsets and more materialism values, both of which further increase their tolerance of ethically questionable behaviors. The present research highlights the importance of stress on consumer ethics and contributes to prior literature in three ways. Firstly, the current study adds to the literature on consumer ethics by examining a new predictor of consumers’ ethical beliefs, which enriches the understanding of why some consumers act more ethically than others do. Secondly, to the best of our knowledge, little prior literature has examined the effect stress on ethical beliefs. The current research for the first time examines the effect and the mechanism and reveals the mediating roles of construal level and materialism value. Thirdly, the present research finds that stress increases low-level construal, leading to unethical beliefs. This finding broadens the scope in construal level theory by suggesting that chronic construal level predicts individual ethical judgments.

Histone demethylase KDM4A plays an oncogenic role in nasopharyngeal carcinoma by promoting cell migration and invasion

Zhao Jingyi,Li Bingyan,Ren Yongxia,Liang Tiansong,Wang Juan,Zhai Suna,Zhang Xiqian,Zhou Pengcheng,Zhang Xiangxian,Pan Yuanyuan,Gao Fangfang,Zhang Sulan,Li Liming,Yang Yongqiang,Deng Xiaoyu,Li Xiaole,C 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Compelling evidence has indicated the vital role of lysine-specific demethylase 4 A (KDM4A), hypoxia-inducible factor-1α (HIF1α) and the mechanistic target of rapamycin (mTOR) signaling pathway in nasopharyngeal carcinoma (NPC). Therefore, we aimed to investigate whether KDM4A affects NPC progression by regulating the HIF1α/DDIT4/mTOR signaling pathway. First, NPC and adjacent tissue samples were collected, and KDM4A protein expression was examined by immunohistochemistry. Then, the interactions among KDM4A, HIF1α and DDIT4 were assessed. Gain- and loss-of-function approaches were used to alter KDM4A, HIF1α and DDIT4 expression in NPC cells. The mechanism of KDM4A in NPC was evaluated both in vivo and in vitro via RT-qPCR, Western blot analysis, MTT assay, Transwell assay, flow cytometry and tumor formation experiments. KDM4A, HIF1α, and DDIT4 were highly expressed in NPC tissues and cells. Mechanistically, KDM4A inhibited the enrichment of histone H3 lysine 9 trimethylation (H3K9me3) in the HIF1α promoter region and thus inhibited the methylation of HIF1α to promote HIF1α expression, thus upregulating DDIT4 and activating the mTOR signaling pathway. Overexpression of KDM4A, HIF1α, or DDIT4 or activation of the mTOR signaling pathway promoted SUNE1 cell proliferation, migration, and invasion but inhibited apoptosis. KDM4A silencing blocked the mTOR signaling pathway by inhibiting the HIF1α/DDIT4 axis to inhibit the growth of SUNE1 cells in vivo. Collectively, KDM4A silencing could inhibit NPC progression by blocking the activation of the HIF1α/DDIT4/mTOR signaling pathway by increasing H3K9me3, highlighting a promising therapeutic target for NPC.

Direct Electrochemistry and Electrocatalysis of Myoglobin with CoMoO4 Nanorods Modified Carbon Ionic Liquid Electrode

Zengying Zhao,Lili Cao,Anhui Hu,Weili Zhang,Xiaomei Ju,Yuanyuan Zhang,Wei Sun 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.2

By using ionic liquid 1-hexylpyridinium hexafluorophosphate (HPPF6) based carbon ionic liquid electrode (CILE) as the substrate electrode, a CoMoO4 nanorods and myoglobin (Mb) composite was casted on the surface of CILE with chitosan (CTS) as the film forming material to obtain the modified electrode (CTS/ CoMoO4-Mb/CILE). Spectroscopic results indicated that Mb retained its native structures without any conformational changes after mixed with CoMoO4 nanorods and CTS. Electrochemical behaviors of Mb on the electrode were carefully investigated by cyclic voltammetry with a pair of well-defined redox peaks from the heme Fe(III)/Fe(II) redox center of Mb appeared, which indicated that direct electron transfer between Mb and CILE was realized. Electrochemical parameters such as the electron transfer number (n), charge transfer coefficient (α) and electron transfer rate constant (ks) were estimated by cyclic voltammetry with the results as 1.09, 0.53 and 1.16 s−1, respectively. The Mb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid in the concentration range from 0.1 to 32.0 mmol L−1 with the detection limit as 0.036 mmol L−1 (3σ), and the reduction of H2O2 in the concentration range from 0.12 to 397.0 μmol L− 1 with the detection limit as 0.0426 μmol L−1 (3σ).