Mesoporous Carbon as a Metal-Free Catalyst for the Reduction of Nitroaromatics with Hydrazine Hydrate

Hui-Chun Wang,Bao-Lin Li,Yan-Jun Zheng,Wen-Ying Wang 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.9

Mesoporous carbons with tailored pore size were prepared by using sucrose as the carbon source and silicas as the templates. The silica templates were obtained from a hydroxypropyl-β-cyclodextrin-silica hybrids using ammonium perchlorate oxidation at different temperatures to remove the organic matter. The structures and surface chemistry properties of these carbon materials were characterized by N2 adsorption, TEM, SEM and FTIR measurements. The catalytic performances of these carbon materials were investigated through the reduction of nitroaromatic using hydrazine hydrate as the reducing agent. Compared with other carbon materials, such as active carbon, and carbon materials from the silica templates obtained by using calcination to remove the organic matter, these carbon materials exhibited much higher catalytic activity, no obvious deactivation was observed after recycling the catalyst four times. Higher surface area and pore volume, and the presence of abundant surface oxygen-containing functional groups, which originate from the special preparation process of carbon material, are likely responsible for the high catalytic property of these mesoporous carbon materials.

Mesoporous Carbon as a Metal-Free Catalyst for the Reduction of Nitroaromatics with Hydrazine Hydrate

Wang, Hui-Chun,Li, Bao-Lin,Zheng, Yan-Jun,Wang, Wen-Ying Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.9

Mesoporous carbons with tailored pore size were prepared by using sucrose as the carbon source and silicas as the templates. The silica templates were obtained from a hydroxypropyl-${\beta}$-cyclodextrin-silica hybrids using ammonium perchlorate oxidation at different temperatures to remove the organic matter. The structures and surface chemistry properties of these carbon materials were characterized by $N_2$ adsorption, TEM, SEM and FTIR measurements. The catalytic performances of these carbon materials were investigated through the reduction of nitroaromatic using hydrazine hydrate as the reducing agent. Compared with other carbon materials, such as active carbon, and carbon materials from the silica templates obtained by using calcination to remove the organic matter, these carbon materials exhibited much higher catalytic activity, no obvious deactivation was observed after recycling the catalyst four times. Higher surface area and pore volume, and the presence of abundant surface oxygen-containing functional groups, which originate from the special preparation process of carbon material, are likely responsible for the high catalytic property of these mesoporous carbon materials.

A FACILE SYNTHESIS OF SHAPE- AND SIZE-CONTROLLED α-Fe_2O_3 NANOPARTICLES THROUGH HYDROTHERMAL METHOD

GUANG-HUI WANG,WEN-CUI LI,KUN-MING JIA,AN-HUI LU,MATHIAS FEYEN,BERND SPLIETHOFF,FERDI SCHÜTH 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.5

α-Fe_2O_3 nanoparticles have wide-ranging applications such as in catalysis, sensoring, painting, etc. This is the reason to study their controlled synthesis. Here we have investigated the synthesis of uniform α-Fe_2O_3nanoparticles using amino acids as morphology control agents. The products were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA). It was found that the type and the amount of amino acids as well as the reaction temperatures have significant influence on the shape and size of the obtainedα-Fe_2O_3nanoparticles. The use of acidic amino acids (always contain C=O in the side chain) typically leads to the formation of α-Fe_2O_3nanoparticles with spindle shape. However, rhombohedrally shaped α-Fe_2O_3nanoparticles were formed in presence of basic amino acids (always contain -NH_2 in the side chain). Increasing the amount of amino acid generally results in α-Fe_2O_3nanoparticles with decreasing particle sizes.

miR-638 is a new biomarker for outcome prediction of non-small cell lung cancer patients receiving chemotherapy

Fang Wang,Jian-fang Lou,Yan Cao,Xin-hui Shi,Peng Wang,Jian Xu,Er-fu Xie,Ting Xu,Rui-hong Sun,Jianyu Rao,Pu-wen Huang,Shi-yang Pan,Hong Wang 생화학분자생물학회 2015 Experimental and molecular medicine Vol.47 No.-

MicroRNAs (miRNAs), a class of small non-coding RNAs, mediate gene expression by either cleaving target mRNAs or inhibiting their translation. They have key roles in the tumorigenesis of several cancers, including non-small cell lung cancer (NSCLC). The aim of this study was to investigate the clinical significance of miR-638 in the evaluation of NSCLC patient prognosis in response to chemotherapy. First, we detected miR-638 expression levels in vitro in the culture supernatants of the NSCLC cell line SPC-A1 treated with cisplatin, as well as the apoptosis rates of SPC-A1. Second, serum miR-638 expression levels were detected in vivo by using nude mice xenograft models bearing SPC-A1 with and without cisplatin treatment. In the clinic, the serum miR-638 levels of 200 cases of NSCLC patients before and after chemotherapy were determined by quantitative real-time PCR, and the associations of clinicopathological features with miR-638 expression patterns after chemotherapy were analyzed. Our data helped in demonstrating that cisplatin induced apoptosis of the SPC-A1 cells in a dose- and time-dependent manner accompanied by increased miR-638 expression levels in the culture supernatants. In vivo data further revealed that cisplatin induced miR-638 upregulation in the serum derived from mice xenograft models, and in NSCLC patient sera, miR-638 expression patterns after chemotherapy significantly correlated with lymph node metastasis. Moreover, survival analyses revealed that patients who had increased miR-638 levels after chemotherapy showed significantly longer survival time than those who had decreased miR-638 levels. Our findings suggest that serum miR-638 levels are associated with the survival of NSCLC patients and may be considered a potential independent predictor for NSCLC prognosis.

Limonoids from the roots of Trichilia sinensis and their cytotoxicities

Zhu-Nian Wang,Wen-Li Mei,Hui-Qin Chen,Jun Wang,Zhu-Nian Wang,Hao Fu Dai 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.12

Six new compounds (1–4, 8, 10), along with six known limonoids (5–7, 9, 11, 12), were isolated from the roots of Trichilia sinensis. Their structures were elucidated on the basis of extensive spectroscopic methods including 1H NMR, 13C NMR, DEPT, HSQC, HMBC, 1H–1H COSY and ROESY experiments, as well as by comparison with the literature. All the compounds were evaluated for cytotoxicities against K562, SGC-7901 and BEL-7402 cell lines. Compounds 2, 7, 10, 11, and 12 showed weak inhibitory activity to the selected cell lines.

Crocetin Induces Cytotoxicity in Colon Cancer Cells Via p53-independent Mechanisms

Li, Cai-Yan,Huang, Wen-Feng,Wang, Qun-Li,Wang, Fan,Cai, E.,Hu, Bing,Du, Jia-Cheng,Wang, Jing,Chen, Rong,Cai, Xiao-Jing,Feng, Jing,Li, Hui-Hui Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Objective: Crocin has been proposed as a promising candidate for cancer chemoprevention. The purpose of this investigation was to investigate the chemopreventive action and the possible mechanisms of crocin against human colon cancer cells in vitro. Methods: Cell proliferation was examined using MTT assay and the cell cycle distribution fractions were analyzed using fow cytometric analysis after propidium iodide staining. Apoptosis was detected using theTUNEL Apoptosis Detection Kit with laser scanning confocal microscope. DNA damage was assessed using the alkaline single-cell gel electrophoresis assay, while expression levels of p53, cdk2, cyclinA and P21 were examined by Western blot analysis. Results: Treatment of SW480 cells with crocetin (0.2, 0.4, 0.8 mmol/L) for 48 h signifcantly inhibited their proliferation in a concentration-dependent manner. Crocetin (0.8 mmol/L) signifcantly induced cell cycle arrest through p53-independent mechanisms accompanied by P21 induction. Crocetin (0.8 mmol/L) caused cytotoxicity in the SW480 cells by enhancing apoptosis and decreasing DNA repair capacity in a time-dependent manner. Conclusions: This report provides evidence that crocetin is a potential anticancer agent, which may be used as a chemotherapeutic drug.

Determinants of Consumer Participation in Online Group Buying:

Hui-Tzu Lin,Hyun-Jee Kim,Li-Wen Wang 한국무역연구원 2016 무역연구 Vol.12 No.4

Under the rise of network group-buying, consumers can form groups of strangers through the Internet, under the leadership of an coordinator, to integrate internal opinions and negotiate with vendors. Therefore, the coordinator gradually becomes a business. In this newly developed business, the coordinators compete with each other. In the past, most of research studies with regard to Internet group-buying focused on exploring the internet factors of consumer willingness or intention to repurchase. However, studies about applying the characteristics of an coordinator as a moderator to determine the impact of the repurchase intention were rare and thus, this is what this study set out to do. In this study, data was collected through an online questionnaire to examine the relationship between commodity eWOM, the features of the coordinator, online contexts and consumer repurchase intention. Empirical results show that: (1) eWOM has a significant impact on repurchase intention, (2) the features of the coordinator have a significant impact on repurchase intention, (3) online contexts have a significant impact on repurchase intention, (4) the features of coordinator have a negative moderate effect on eWOM and repurchase intention, and (5) online contexts do not have a moderating effect on eWOM and repurchase intention.

A quantitative analysis of the wing outlines of owlflies (Insecta: Neuroptera: Ascalaphidae)

Hui Wen,Heping Yang,Xinli Wang 한국통합생물학회 2015 Animal cells and systems Vol.19 No.2

We quantitatively described and analyzed variation in the wing outlines of owlflies using 135 forewings and 135 hindwings from eight species in five genera. We captured and digitized images of the wing outlines from 135 individual specimens and subjected them to Elliptic Fourier analysis to produce matrices of Fourier coefficients based on 20 harmonics. The first five principal components extracted from the Fourier coefficient matrices described the wing outlines, explaining 94.87% of the total forewing variation and 95.06% of the total hindwing variation. Relationships among species were estimated using multivariate analysis of variance, principal component analysis, and cluster analysis. The results indicated highly significant differences in the wing outlines among the eight owlfly species. Pair-wise comparisons indicated significant differences between 96% of the species pairs based on the forewing outlines and between 100% of the species pairs based on the hindwing outlines. The results of the cluster analysis were partially consistent with the existing classification system of Ascalaphidae. Our results show that quantitative data of wing outlines can effectively differentiate Libelloides from the other four owlfly genera.

Vibration response analysis caused by rubbing between rotating blade and casing

Hui Ma,Fanli Yin,Xingyu Tai,Di Wang,Bang-chun Wen 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.5

Two types of blade-tip rubbing due to the static misalignment of the bladed-disk center and casing center and casing deformation are simulated. By applying aerodynamic load in the blade lateral/flexural direction, vibration responses due to blade-casing rubbing are analyzed under the run-up process with constant angular acceleration and the steady-state process at 10000 rev/min. The effects of some parameters, such as the static misalignment e c , casing stiffness k c and casing deformation n p , on the system vibration responses are also illustrated by spectrum cascades, time-domain waveforms of displacement, normal rubbing forces, amplitude spectra and the impulse P in a single blade-casing rubbing period. The results show that blade-tip rubbing will cause amplitude amplification and harmonic resonance phenomena when the multiple frequencies (nf r ) of rotational frequency (f r ) coincide with the first three flexural dynamic frequencies of the blade (f n1 , f n2 and f n3 ). For example, the displacement amplitudes at 3f r , 14f r and 38f r are large and the vibration is dominant near f n1 . In addition, the casing deformation mainly excites the dominant Blade passing frequency (BPF), which is related to the casing deformation coefficient n p . By comparing these impulse values, for the selected parameters in this paper, the casing stiffness has a greater effect on impulse than the static misalignment and casing deformation coefficient. The impulse shows a linear increase trend with the increasing static misalignment, and it decreases under the large n p because the contact time decreases with the increase of n p .

Inhibitory effects of piceatannol on human cytomegalovirus (hCMV) in vitro

Wang San-Ying,Zhang Jing,Xu Xiao-Gang,Su Hui-Li,Xing Wen-Min,Zhang Zhong-Shan,Jin Wei-Hua,Dai Ji-Huan,Wang Ya-Zhen,He Xin-Yue,Sun Chuan,Yan Jing,Mao Gen-Xiang 한국미생물학회 2020 The journal of microbiology Vol.58 No.8

Human cytomegalovirus (hCMV) is a ubiquitous herpesvirus, which results in the establishment of a latent infection that persists throughout the life of the host and can be reactivated when the immunity is low. Currently, there is no vaccine for hCMV infection, and the licensed antiviral drugs mainly target the viral enzymes and have obvious adverse reactions. Thus, it is important to search for compounds with antihCMV properties. The present study aimed to investigate the suppressive effects of piceatannol on hCMV Towne strain infection and the putative underlying mechanisms using human diploid fibroblast WI-38 cells. Piceatannol supplementation prevented the lytic changes induced by hCMV infection in WI-38 cells. Furthermore, piceatannol suppressed the expression of hCMV immediate-early (IE) and early (E) proteins as well as the replication of hCMV DNA in a dose-dependent manner. Moreover, hCMV-induced cellular senescence was suppressed by piceatannol, as shown by a decline in the senescence-associated β-galactosidase (SA-β-Gal) activity and decreased production of intracellular reactive oxygen species (ROS). p16INK4a, a major senescence-associated molecule, was dramatically elevated by current hCMV infection that was attenuated by pre-incubation with piceatannol in a dose-dependent manner. These results demonstrated that piceatannol suppressed the hCMV infection via inhibition of the activation of p16INK4a and cellular senescence induced by hCMV. Together, these findings indicate piceatannol as a novel and potent anti-hCMV agent with the potential to be developed as an effective treatment for chronic hCMV infection.