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41.
Abdul Hamid HAFIZAH Zakaria ZAITON Amom ZULKHAIRI Adenan MOHD ILHAM Megat Mohd Nordin NOR ANITA Abdullah Mahdy ZALEHA 《Journal of Zhejiang University. Science. B》2010,11(5):357-365
Endothelial cell death due to increased reactive oxygen species(ROS) may contribute to the initial endothelial injury,which promotes atherosclerotic lesion formation.Piper sarmentosum(PS),a natural product,has been shown to have an antioxidant property,which is hypothesized to inhibit production of ROS and prevent cell injury.Thus,the present study was designed to determine the effects of PS on the hydrogen peroxide(H2O2)-induced oxidative cell damage in cultured human umbilical vein endothelial cells(HUVECs).In this experiment,HUVECs were obtained by collagenase perfusion of the large vein in the umbilical cord and cultured in medium M200 supplemented with low serum growth supplementation(LSGS).HUVECs were treated with various concentrations of H2O2(0-1000 μmol/L) and it was observed that 180 μmol/L H2O2 reduced cell viability by 50% as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay.Using the above concentration as the positive control,the H2O2-induced HUVECs were concomitantly treated with various concentrations(100,150,250 and 300 μg/ml) of three different extracts(aqueous,methanol and hexane) of PS.Malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GPX) levels showed a significant increase(P0.05) in HUVECs compared to the negative control.However,PS extracts showed a protective effect on HUVECs from H2O2-induced cell apoptosis with a significant reduction in MDA,SOD,CAT and GPX levels(P0.05).Furthermore,PS had exhibited ferric reducing antioxidant power with its high phenolic content.Hence,it was concluded that PS plays a beneficial role in reducing oxidative stress in H2O2-induced HUVECs. 相似文献
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In many historical and monumental Italian buildings, frescoes or stuccoes of artistic and historical value are present on the lower surface of flat light vaults, made by wooden arches, reeds and plaster. These vaults are often suspended by wooden or metallic ties to the upper bearing structures. When differential settlements of the wooden arches happen (i.e.: due to a bad working of their hangings) cracks appear on these precious surfaces. This paper experimentally and numerically investigates on this issue, pointing out which constructive parameters mainly influence the cracking behaviour of the frescoed or stuccoed lower surface, and thus providing guide lines for designing compatible conservation and retrofitting interventions. 相似文献
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The Communication Supporting Classroom Observation Tool (CSCOT) is used in the UK to identify how teachers support children's communication development. This study evaluates the feasibility and impact of collaborative training for teachers using the CSCOT, delivered by specialist teachers and a speech and language therapist. Classroom practice was observed twice using the CSCOT before the collaborative training (repeated baseline). Five teachers then received the collaborative training, informed by their baseline CSCOT results. The training consisted of detailed feedback, target setting and support from the school Special Educational Needs Assistant (SENA) over a period of 20 weeks. Five further teachers did not participate in this training but acted as a control group. The CSCOT observations were then repeated for all 10 classroom teachers. The total score of the CSCOT significantly increased for the five teachers who received training only. There was no increase during the repeated baseline phase, suggesting that the increase was due to the training. All five teachers who participated in training increased their use of their targeted communication-supporting strategies. The CSCOT can be used as part of collaborative training to increase teachers' use of communication-supporting strategies in primary schools in Brunei. 相似文献
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Lee Sharon Jia Chian Abdul Rabu Siti Nazleen 《Education and Information Technologies》2022,27(3):3651-3681
Education and Information Technologies - This study explores the types of online interaction used and levels of reflection achieved by undergraduate students, including the influence of the former... 相似文献
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Ingólfur Ásgeir Jóhannesson Kristín Norðdahl Gunnhildur Óskarsdóttir Auður Pálsdóttir Björg Pétursdóttir 《Environmental Education Research》2011,17(3):375-391
The article explores how the Icelandic public school curriculum for early childhood, compulsory and upper secondary school deals with education for sustainable development. As the curriculum does not often mention the term sustainability, a key with which to investigate signs of education for sustainable development in the three curricula was created. The key encourages a holistic view of sustainable development, where economic, environmental and social factors are not treated as separate entities. It was designed to reflect the goals of the United Nations Decade of Education for Sustainable Development (2005–2014) with research on environmental education and education for sustainable development in mind. The key has seven characteristics: values, opinions and emotions about nature and environment; knowledge contributing to a sensible use of nature; welfare and public health; democracy, participation, and action competence; equality and multicultural issues; global awareness; and finally, economic development and future prospects. Using the key, a variety of signs and indicators that provide a space for teachers and schools to deal with issues of sustainable development were identified. 相似文献
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Siti Balkis Budin Seri Masran Siti Nor Ain Baharuddin Omar Izatus Shima Taib Othman Hidayatulfathi 《Journal of Zhejiang University. Science. B》2012,13(10):783-790
Litsea elliptica Blume has been traditionally used to treat headache, fever, and stomach ulcer, and has also been used as an insect repellent. The acute and subacute toxicities of L. elliptica essential oil were evaluated orally by gavage in female Sprague-Dawley rats. For the acute toxicity study, L. elliptica essential oil was administered in doses from 500 to 4 000 mg/kg (single dose), and in the subacute toxicity test, the following doses were used: 125, 250, and 500 mg/kg, for 28 consecutive days. In the acute toxicity study, L. elliptica essential oil caused dose-dependent adverse behaviours and mortality. The median lethal dose value was 3 488.86 mg/kg and the acute non-observed-adversed-effect level value was found to be 500 mg/kg. The subacute toxicity study of L. elliptica essential oil did not reveal alterations in body weight, and food and water consumptions. The haematological and biochemical analyses did not show significant differences between control and treated groups in most of the parameters examined, except for the hemoglobin, mean cell hemoglobin concentration, mean cell volume, mean cell hemoglobin, serum albumin, and serum sodium. However, these differences were still within the normal range. No abnormalities or histopathological changes were observed in the liver, pancreatic islet of Langerhans, and renal glomerulous and tubular cells of all treated groups. In conclusion, L. elliptica essential oil can be classified in the U group, which is defined as a group unlikely to present an acute hazard according to World Health Organization (WHO) classification. 相似文献
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Zariyantey Abdul Hamid Siti Balkis Budin Ng Wen Jie Asmah Hamid Khairana Husain Jamaludin Mohamed 《Journal of Zhejiang University. Science. B》2012,13(3):176-185
Paracetamol (PCM) overdose can cause nephrotoxicity with oxidative stress as one of the possible mechanisms mediating the
event. In this study, the effects of ethyl acetate extract of Zingiber zerumbet rhizome [200 mg per kg of body weight (mg/kg) and 400 mg/kg] on PCM-induced nephrotoxicity were examined. Rats were divided
into five groups containing 10 rats each. The control group received distilled water while other groups were treated with
extract alone (400 mg/kg), PCM alone (750 mg/kg), 750 mg/kg PCM+200 mg/kg extract (PCM+ 200-extract), and 750 mg/kg PCM+400
mg/kg extract (PCM+400-extract), respectively, for seven consecutive days. The Z. zerumbet extract was given intraperitoneally concurrent with oral administration of PCM. Treatment with Z. zerumbet extract at doses of 200 and 400 mg/kg prevented the PCM-induced nephrotoxicity and oxidative impairments of the kidney, as
evidenced by a significantly reduced (P<0.05) level of plasma creatinine, plasma and renal malondialdehyde (MDA), plasma protein carbonyl, and renal advanced oxidation
protein product (AOPP). Furthermore, both doses were also able to induce a significant increment (P<0.05) of plasma and renal levels of glutathione (GSH) and plasma superoxide dismutase (SOD) activity. The nephroprotective
effects of Z. zerumbet extract were confirmed by a reduced intensity of renal cellular damage, as evidenced by histological findings. Moreover,
Z. zerumbet extract administered at 400 mg/kg was found to show greater protective effects than that at 200 mg/kg. In conclusion, ethyl
acetate extract of Z. zerumbet rhizome has a protective role against PCM-induced nephrotoxicity and the process is probably mediated through its antioxidant
properties. 相似文献
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In this study, the authors examine the influence of ethnic-related diversity experiences on intercultural sensitivity among Malaysian students at a multiethnic, multicultural and multilingual Malaysian public university. Results reveal a significant differential level of ethnic-related diversity experiences (but not at the level of intercultural sensitivity) across ethnic groups studied. In comparison, the minority ethnic group of Indian students had a significantly higher level of ethnic-related diversity experiences than the Chinese and Malay students. The hypothesized significant main effect of level of ethnic-related diversity experiences on the level of intercultural sensitivity among the students is supported. The high-level ethnic-diversity experiences group significantly shows a higher level of intercultural sensitivity than the moderate and low-level groups, and the moderate level group is significantly higher than the low-level group. However, no significant interaction effect of ethnicity and ethnic-related diversity experiences on intercultural sensitivity is found. The implications of these findings are discussed further in the paper. 相似文献