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Nitrogen-doped graphene nanosheets as reactive water purification membranes

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Nano Research 2016年第7期9卷 1983-1993页

作者： Yanbiao Liu Ling Yu choon nam ong Jianping Xie NUS Environmental Research Institute National University of Singapore 117411 Singapore Department of Chemical and Biomolecular Engineering National University of Singapore 117585 Singapore

Oxidation of organic pollutants by sulfate radicals produced via activation of persulfate has emerged as a promising advanced oxidation technology to address various challenging environmental issues. The development of an effective, environmentally-friendly, metal-free catalyst is the key to this technology. Additionally, a supported catalyst design is more advantageous than conventional suspended powder catalysts from the point of view of mass transfer and practical engineering applications （e.g. post-use separation）. In this study, a metal-free N-doped reduced graphene oxide （N-rGO） catalyst was prepared via a facile hydrothermal method. N-rGO filters were then synthesized by facile vacuum filtration, such that water can flow through nanochannels within the filters. Various advanced characterization techniques were employed to obtain structural and compositional information of the as-synthesized N-rGO filters. An optimized phenol oxidative flux of 0.036 ＋_ 0.002 mmol.h ~ was obtained by metal-flee catalytic activation of persulfate at an influent persulfate concentration of 1.0 mmol-L 1 and filter weight of 15 rag, while a N-free rGO filter demonstrated negligible phenol oxidation capability under similar conditions. Compared to a conventional batch system, the flow-through design demonstrates obviously enhanced oxidation kinetics （0.036 vs. 0.010 retool-h-I）, mainly due to the liquid flow through the filter leading to convection-enhanced transfer of the target molecule to the filter active sites. Overall, the results exemplified the advantages of organic compound removal by catalytic activation of persulfate using a metal-free catalyst in flow- through mode, and demonstrated the potential of N-rGO filters for practical environmental applications.

关键词： persulfate activation nitrogen-doped graphene phenol oxidation convective flow batch system

Metabolites change of Scenedesmus obliquus exerted by AgNPs

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Journal of Environmental Sciences 2019年第2期31卷 310-318页

作者： Pu Wang Bo Zhang Hui Zhang Yiliang He choon nam ong Jun Yang School of Environmental Science & Engineering Shanghai Jiaotong University School of Municipal and Environmental Engineering Lanzhou Jiaotong University NUS Environmental Research Institute National University of Singapore

With increasing emission of silver nanoparticles(AgNPs) into the environment, it is important to understand the effects of ambient concentration of AgNPs. The biological effects of AgNPs on Scenedesmus obliquus, a ubiquitous freshwater microalgae, was evaluated. AgNPs exerted a minor inhibitory effect at low doses. Non-targeted metabolomic studies were conducted to understand and analyze the effect of AgNPs on algal cells from a molecular perspective. During the 48 hr of exposure to AgNPs, 30 metabolites were identified, of which nine had significant changes compared to the control group. These include D-galactose, sucrose, and *** carbohydrates are involved in the synthesis and repair of cell walls. Glycine, an important constituent amino acid of glutathione, increased with AgNP exposure concentration increasing, likely to counteract an increased intracellular oxidative stress. These results provide a new understanding of the toxicity effects and mechanism of AgNPs. These metabolites could be useful biomarkers for future research, employed in the early detection of environmental risk from AgNPs.

关键词： Silver nanoparticles (AgNPs) Scenedesmus obliquus Metabolomics Molecular mechanism

Protective effects of Asian green vegetables against oxidant induced cytotoxicity

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World Journal of Gastroenterology 2005年第48期11卷 7607-7614页

作者： Peter Rose choon nam ong Matt Whiteman Department of Biochemistry Department of Community

AIM: To evaluate the antioxidant and phase Ⅱ detoxification enzyme inducing ability of green leaf vegetables consumed in ***: The antioxidant properties of six commonly consumed Asian vegetables were determined using the ABTS, DPPH, deoxyribose, PR bleaching and ironascorbate induced lipid peroxidation assay. Induce of phase Ⅱ detoxification enzymes was also determined for each respective vegetable extract. Protection against authentic ONOO- and HOCI mediated cytotoxicity in human colon HCT116 cells was determined using the MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide) viability ***: All of the extracts derived from green leaf vegetables exhibited antioxidant properties, while also having cytoprotective effects against ONOO- and HOCI mediated cytotoxicity. In addition, evaluation of the phase Ⅱ enzyme inducing ability of each extract,as assessed by quinone reductase and glutathioneS-transferase activities, showed significant variation between the vegetables ***: Green leaf vegetables are potential sources of antioxidants and phase Ⅱ detoxification enzyme inducers in the Asian diet. It is likely that consumption of such vegetables is a major source of beneficial phytochemical constituents that may protect against colonic damage.

关键词：保护作用亚洲绿色蔬菜细胞毒性异硫氰酸酯

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职业工效学与卫生

科学对社会的影响 1993年第1期42卷 11-19页

作者： choon-nam ong 张雁新加坡国立大学社区职业及家庭医学系

工效学包括预防职业病和提高健康水平两个方面。新近的一些研究表明,许多职业病与工具、机器和作业场所的不良设计有关。为了防止不必要的失误和暴露性及累积性损伤,工效学通过制造适应于使用者和劳动者能力的工具或机器,在提高工作效... 详细信息

工效学包括预防职业病和提高健康水平两个方面。新近的一些研究表明,许多职业病与工具、机器和作业场所的不良设计有关。为了防止不必要的失误和暴露性及累积性损伤,工效学通过制造适应于使用者和劳动者能力的工具或机器,在提高工作效率和生产力方面具有关键作用。

关键词：工效学职业工效学卫生

Chrysin sensitizes tumor necrosis factor-α-induced apoptosis in human tumor cells via suppression of nuclear factor-kappaB

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Chrysin sensitizes tumor necrosis factor-α-induced apoptosi...

广西原发性肝细胞癌与p53基因72密码子单核苷酸多态性密切相关

2011广东省预防医学会学术年会

作者： Xin Li Qing Huang choon-nam ong Xing-Fen Yang Han-Ming Shen Center for Disease Control and Prevention of Guangdong Province NUS Graduate School for Integrative Sciences and Engineering National University of Singapore

Chrysin(5.7-dihydroxyflavone) is a natural flavonoid commonly found in many *** anti-cancer property of chrysin has been demonstrated although the molecular mechanisms remain to be further *** the present study,we found that,pretreatment with chrysin greatly sensitized various human cancer cells to tumor necrosis factor-alpha (TNFα)-induced *** the search of the molecular mechanisms responsible for the sensitization effect of chrysin,we discovered that such sensitization is closely associated with the inhibitory effect of chrysin on TNFα-mediared nuclear transcription factor-kappaB (NF-κB) *** with chrysin inhibited TNFα-induced degradation of Inhibitor of kappaB(lκB) protein and subsequent nuclear translocation of *** a result, chrysin suppressed the expression of NF-κB-targeted anti-apoptotic *** role of c-FUP-L was further confirmed by its ectopic expression,which significantly protecred cell death induced by combined treatment with chrysin and TNFα.Data from this study thus reveal a novel function of chrysin and enhance the value of chrysin as an anti-cancer agent.

关键词： Chrysin TNFα NF-κB Apoptosis Cancer

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中华外科杂志 2004年第5期42卷 313-314页

作者：彭涛严律南刘志明 Hanming shen choon nam ong 彭民浩黎乐群李家荃 530021 南宁广西医科大学附属第一医院普外科四川大学华西医院普外科新加坡国立大学社区职业与家庭医学部

临床分子流行病学资料提示,肿瘤抑制基因p53-72密码子的单核苷酸多态性(single nucleotide polymorphism,SNP)与某些与人类乳头瘤病毒(human papillomavirus,HPV)感染有关的肿瘤密切相关[1,2];这一多态性还可能增加丙型肝炎病毒(hepatit... 详细信息

临床分子流行病学资料提示,肿瘤抑制基因p53-72密码子的单核苷酸多态性(single nucleotide polymorphism,SNP)与某些与人类乳头瘤病毒(human papillomavirus,HPV)感染有关的肿瘤密切相关[1,2];这一多态性还可能增加丙型肝炎病毒(hepatitis C virus, HCV)某些亚型感染的易感性[3],并与慢性肝病等一些因素共同增加原发性肝细胞癌(hepatocellular carcinoma, HCC)的发病危险度[4].我们对这一多态性在广西HCC中的分布进行了初步的研究探讨,现报告如下。

关键词：原发性肝细胞癌基因单核苷酸多态性 p53-72密码子

Public Health and Water Resources

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Public Health and Water Resources

Bacterial microbiome of Coptotermes curvignathus （Isoptera： Rhinotermitidae） reflects the coevolution of species and dietary pattern

北京论坛（2005）文明的和谐与共同繁荣——全球化视野中亚洲的机遇与发展

作者： ong choon nam Dept.of Community Occupational and Family Medicine Yong Loo Lin School of Medicine National University of Singapore 10 Kent Ridge Crescent Singapore 117597

Fresh water is quickly becoming a precious item,with only 2.5%of available water in the world is fresh *** access to clean and safe water is a fundamental human need,yet over a billion people in our planet do not have access to clean and safe *** 2015,it is estimated that at least 40%of the world’s population or about 3 billion people will not have water for basic *** 2001,the World Health Organization(WHO) and United Nations

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Insect Science 2014年第5期21卷 584-596页

作者： Jie Hung Patricia King Nor Muhammad Mahadi choon Fah Joseph Bong Kian Huat ong Osman Hassan Faculty of Agriculture and Food Sciences Universiti Putra Malaysia Bintulu Sarawak Campus Sarawak Malaysia Genome Institute Jalan Bangi Lama 43000 Kajang Faculty of Science and Technology UniversiU Kebangsaan Malaysia 43600 UKM BangiSelangor Malaysia

Coptotermes curvignathus Holmgren is capable of feeding on living trees. This ability is attributed to their effective digestive system that is furnished by the termite＇s own cellulolytic enzymes and cooperative enzymes produced by their gut microbes. In this study, the identity of an array of diverse microbes residing in the gut of C. curvignathus was revealed by sequencing the near-full-length 16S rRNA genes. A total of 154 bacterial phylotypes were found. The Bacteroidetes was the most abundant phylum and accounted for about 65% of the gut microbial profile. This is followed by Firmicutes, Actinobacteria, Spirochetes, Proteobacteria, TM7, Deferribacteres, Planctomycetes, Ferrucomicrobia, and Termite Group 1. Based on the phylogenetic study, this symbiosis can be a result of long coevolution of gut enterotypes with the phylogenic distribution, strong selection pressure in the gut, and other speculative pressures that determine bacterial biome to follow. The phylogenetic distribution of cloned rRNA genes in the bacterial domain that was considerably different from other termite reflects the strong selection pressures in the gut where a proportional composition of gut microbiome of C. curvignathus has established. The selection pressures could be linked to the unique diet preference of C. curvignathus that profoundly feeds on living trees. The delicate gut microbiome composition may provide available nutrients to the host as well as potential protection against opportunistic pathogen.

关键词： Coptotermes curvignathus diet preference gut microbiome selection

菊花倍半萜烯内酯诱导的鼻咽癌细胞毒性和凋亡

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菊花倍半萜烯内酯诱导的鼻咽癌细胞毒性和凋亡