Total oxy-radical scavenging capacity assay를 이용한 taurine과 hypotaurine의 항산화 활성 측정

오정민,주홍매,김상겸,김봉희 忠南大學校 生命科學硏究院 醫藥品開發硏究所 2006 藥學論文集 Vol.21 No.-

Taurine, a sulfur containing non-amino acid, is one of the most abundant intracellular amino acid in humans, and hypotaurine is a precursor of the synthesis of taurine. While it is widely believed that taurine may play an important role in protecting cells against toxic injury by functioning as an antioxidant, there is a lack of evidence to support this hypothesis. In this study, total oxy-radical scavenging capacity(TOSC) assay was used to evaluate antioxidant activity of taurine and hypotaurine against peroxyl radical, hydroxyl radical and peroxynitrite. The present results show that taurine does not have oxy-radical scavenging activity and hypotaurine is comparable to glutathione, an antioxidant substance, in oxy-radical scavenging activity. The results suggest that protective effects of taurine against oxidative stress may not be associated with its direct oxy-radical scavenging activity. Difference in oxy-radical scavenging capacity between taurine and hypotaurine may be ascribed to their sulfur oxidation state.

대장에 발생한 샘암종에서 MUC1과 MUC2 점소 발현의 의의

이윤경,이주호,이용,심재영,박정훈,오수섭,박진실,기근홍 朝鮮大學校 附設 醫學硏究所 2004 The Medical Journal of Chosun University Vol.29 No.2

Background : Mucins possess the unique function of protecting and lubricating the epithelial surface and other important functions such as call growth, direct implication in the fetal development, the epithelial renewal and differentiation, the epithelial integrity, carcinogenesis, immune regulation, cellular adhesion and metastasis. Purpose : This study was done to provide the significance of alteration of MUC1 and MUC2 expression in colorectal adenocarcinoma, A series of 131 colorectal adenocarcinomas including 11 mucinous carcinomas were screened immunohistochemically for their expression of MUCI and MUC2, Materials and mehtods : Of 131 carcinomas, 76 (58,5%) were MUCI positive and 91 (68, 9%) were MUC2 positive, In normal colonic goblet cells, MUCl was not expressed but MUC2 was expressed in cytoplasm, Conclusion There were up-regulation of MUCI and down-regulation of MUC2 in colorectal carcinomas, The frequency of MUC2 positivity according to differentiation was statistically reliable. (p=0.0001)

Damage identification of vehicle-track coupling system from dynamic responses of moving vehicles

Zhu, Hong-Ping,Ye, Ling,Weng, Shun,Tian, Wei Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.5

The structural responses are often used to identify the structural local damages. However, it is usually difficult to gain the responses of the track, as the sensors cannot be installed on the track directly. The vehicles running on a track excite track vibration and can also serve as response receivers because the vehicle dynamic response contains the vibration information of the track. A damage identification method using the vehicle responses and sensitivity analysis is proposed for the vehicle-track coupling system in this paper. Different from most damage identification methods of vehicle-track coupling system, which require the structural responses, only the vehicle responses are required in the proposed method. The local damages are identified by a sensitivity-based model updating process. In the vehicle-track coupling system, the track is modeled as a discrete point supported Euler-Bernoulli beam, and two vehicle models are proposed to investigate the accuracy and efficiency of damage identification. The measured track irregularity is considered in the calculation of vehicle dynamic responses. The measurement noises are also considered to study their effects to the damage identification results. The identified results demonstrate that the proposed method is capable to identify the local damages of the track accurately in different noise levels with only the vehicle responses.

Click Synthesis of Hydrogels by Metal-Free 1,3-Dipolar Cycloaddition Reaction Between Maleimide and Azide Functionalized Polymers

Hong-Zheng Zhu,Gang Wang,Hong-Liang Wei,Hui-Juan Chu,Jing Zhu 한국고분자학회 2016 Macromolecular Research Vol.24 No.9

Herein, a metal-free 1,3-dipolar cycloaddition click reaction was used to prepare hydrogels. First, copolymer of N,N-dimethylacrylamide and 2-hydroxyethyl methacrylate was synthesized via free radical copolymerization with an initiator of 2,2'-azobisisobutyronitrile and a solution of 1,4-dioxane. Second, maleimide-functionalized polymer was obtained by a coupling reaction of the above synthesized copolymer and N-maleoyl alanine with a dehydrating agent of N,N'-dicyclohexylcarbodiimide. Similarly, azido-modified polymer was prepared by the reaction between azidoacetic acid and the as-prepared copolymer. Third, the hydrogels were obtained by the reaction of the azidomodified polymer and maleimide-functionalized copolymer without any initiator or catalyst. Gelation times of different conditions were measured by a cuvette inversion method. The samples of different steps were analysized by means of FTIR, NMR, SEM, etc. The swelling behaviour of the gels was investigated via a general gravimetric method. Finally, release mechanism was explored with a model drug molecule of 5-fluorouracil. It was found temperature, concentration and solvent had an impact on the gelation time. And the swelling behavior and drug-controlled release profiles of the hydrogels were relevant to the concentration of polymers used for the hydrogels.

Physical modelling of sliding failure of concrete gravity dam under overloading condition

Zhu, Hong-Hu,Yin, Jian-Hua,Dong, Jian-Hua,Zhang, Lin Techno-Press 2010 Geomechanics & engineering Vol.2 No.2

Sliding within the dam foundation is one of the key failure modes of a gravity dam. A two-dimensional (2-D) physical model test has been conducted to study the sliding failure of a concrete gravity dam under overloading conditions. This model dam was instrumented with strain rosettes, linear variable displacement transformers (LVDTs), and embedded fiber Bragg grating (FBG) sensing bars. The surface and internal displacements of the dam structure and the strain distributions on the dam body were measured with high accuracy. The setup of the model with instrumentation is described and the monitoring data are presented and analyzed in this paper. The deformation process and failure mechanism of dam sliding within the rock foundation are investigated based on the test results. It is found that the horizontal displacements at the toe and heel indicate the dam stability condition. During overloading, the cracking zone in the foundation can be simplified as a triangle with gradually increased height and vertex angle.

A Parallel-Processing Structure for The Sequential Boltzmann Machine

Hong Bing Zhu,Mamoru Sasaki,Takahiro Inoue,Kenichi Sugitani,Fumio Ueno 대한전자공학회 1998 ITC-CSCC :International Technical Conference on Ci Vol.- No.-

Reversion of Multidrug Resistance by SKI-II in SGC7901/DDP Cells and Exploration of Underlying Mechanisms

Zhu, Zu-An,Zhu, Zheng-Qiu,Cai, Hong-Xing,Liu, Ying Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

In order to investigate whether SKI-II could reverse drug resistance and its possible mechanisms, we treated SGC7901/DDP cells with SKI-II or SKI-II in combination with DDP. Then cell growth, apoptosis, micromorphological changes, and expression of SphK1, P-gp, NF-${\kappa}B$, Bcl-2 and Bax were assessed by MTT assay, flow cytometry, electron microscopy, immunocytochemistry and Western blot assay respectively. SGC7901/DDP cells were insensitive to cisplatin 2.5mg/L, but when pretreated with SKI-II, their proliferation was inhibited by cisplatin 2.5mg/L significantly, the inhibition rate increasing with time and dose. The apoptosis rate was also significantly elevated. Expression of SphK1 and P-gp was decreased significantly, Pearson correlation analysis showing significant correlation between the two (r=0.595, P<0.01). Expression of NF-${\kappa}B$ and Bcl-2 was decreased significantly,while that of Bax was increased, compared to the control group. There were significant correlations between SphK1 and NF-${\kappa}B$(r=0.723, P<0.01), NF-${\kappa}B$ and Bcl-2(r=0.768, P<0.01). All these data indicated that SKI-II could reverse drug resistance of SGC7901/DDP to cisplatin by down-regulating expression of P-gp and up-regulating apoptosis through down-regulation of SphK1. The increased apoptotic sensitivity of SGC7901/DDP to cisplatin was due to the decreasing proportion of Bcl-2/Bax via down-regulating NF-${\kappa}B$.

Microstructure and corrosion resistance of Ni-based alloy laser coatings with nanosize CeO₂ addition

Hong Zhang, Shi,Xi Li, Ming,Hong Yoon, Jae,Yul Cho, Tong,Zhu He, Yi,Gyu Lee, Chan Elsevier 2008 SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS Vol.9 No.3

<P>Micron-size Ni-base alloy (NBA) powders were mixed with both 1.5 wt.% (hereinafter %) micron-size CeO<SUB>2</SUB> (<I>m</I>-CeO<SUB>2</SUB>) and also 1.5% and 3.0% nano-size CeO<SUB>2</SUB> (<I>n</I>- CeO<SUB>2</SUB>) powders. These mixtures were coated on low-carbon steel (Q235) by 2.0 kW CO<SUB>2</SUB> laser cladding. The effects on the microstructures, phases and electrochemical corrosion of the coatings upon the addition of <I>m</I>- and <I>n</I>- CeO<SUB>2</SUB> powders to NBA (<I>m</I>- and <I>n</I>- CeO<SUB>2</SUB> /NBA) have been investigated. The results showed that a smooth coating was prepared under suitable processing parameters (<I>P</I>= 2.0 kW, <I>V</I>= 180 mm min<SUP>- 1</SUP>) by adding 1.5% <I>n</I>- CeO<SUB>2</SUB>. In addition to the primary phases of γ-Ni, Cr<SUB>23</SUB> C<SUB>6</SUB> and Ni<SUB>3</SUB> B in the Ni-base alloy coating, CeNi<SUB>3</SUB> was formed in Ni-base alloy coatings with both <I>n</I>- CeO<SUB>2</SUB> and <I>m</I>-CeO<SUB>2</SUB> particles, and CeNi<SUB>5</SUB> appeared in the coating upon decreasing the size of CeO<SUB>2</SUB> particles. Well-developed dendrites were observed in the Ni-base alloy coating; directional dendrites grew at the interface in the coating upon the addition of <I>m</I>-CeO<SUB>2</SUB>, whereas fine and multioriented dendrites grew upon decreasing the size of CeO<SUB>2</SUB> particles to the nanoscale. Actinomorphic dendrites and compact equiaxed dendrites grew from the interface to near the surface upon increasing the content of <I>n</I>- CeO<SUB>2</SUB> from 1.5 to 3.0%. In strongly acidic HNO<SUB>3</SUB> solution, the severe corrosion of dendrites occurred and there were many corrosion pits in the Ni-base alloy coating; intercrystalline corrosion also has a dominant role upon the addition of <I>m</I>-CeO<SUB>2</SUB>, whereas uniform corrosion occurs in the coating as the size of CeO<SUB>2</SUB> particles is decreased to nanoscale.</P>

MicroRNAs: their involvement in fibrosis pathogenesis and use as diagnostic biomarkers in scleroderma

Hong-Lin Zhu,Hui Luo,Xiao-Xia Zuo 생화학분자생물학회 2013 Experimental and molecular medicine Vol.45 No.9

miRNAs are important post-transcriptional regulators. The aberrant expression of miRNAs is strongly associated with the initiation and progression of pathophysiologic processes in a wide range of human diseases. Scleroderma (systemic sclerosis;SSc) is a highly heterogeneous autoimmune disease that includes the progressive fibrotic replacement of normal tissue architecture in multiple organs. Our previous studies have suggested that SSc skin tissues display a different miRNA expression signature than that found in normal controls. miRNAs with pro- or antifibrotic properties are found to be dysregulated in SSc skin fibrosis. Serum miRNA levels are associated with SSc activity and severity. miRNAs have the potential to be therapeutic targets and serve as biomarkers for SSc diagnosis and assessment of disease state and severity. This review summarizes the SSc miRNA expression signature and the roles of dysregulation of miRNAs in SSc tissues and serum and examines the future therapeutic potential of targeting miRNAs in the management of SSc patients.

The Influence of Relative Humidity, Temperature, Insect Developmental Stages on the Susceptibility of Sweetpotato Whitefly to Conidia of Isaria javanica

Hong Zhu,Jeong Jun Kim,Ji Hee Han,Sang Yeob Lee 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.04

Bemisia tabaci, sweetpotato whitefly, has been recognized one of the most destructive insect pests worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We conducted a study of the influence of relative humidity, temperature and different developmental stages on the susceptibility of sweetpotato whitefly to conidia of Isaria javanica isolate, which had been reported high virulence against Q biotype of B. tabaci. The mortality of tobacco whitefly was low at low constant relative humidities, but was high when kept high humidity for first 24 hours and transferred to low humidity. The Isaria isolate had wide range of temperature (15℃ to 35℃) to control sweetpotato whitefly. The isolate has virulence to the egg and all developmental stages of nymph of B. tabaci. These results indicated that the isolate had good control effects at various environmental conditions and is an excellent candidate to develop a microbial pesticide to control sweetpotato whitefly.