32 research outputs found

    Effect of pH on the Radical Quenching Capacity of Tea Infusions Using the ABTS•+ Assay

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    Aims: The aims of this study were to assess the impact of pH on the free radical quenching activity of tea infusions using a modified 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay and three antioxidant compounds as reference. Study Design: In-vitro method. Place and Duration of Study: Faculty of Life and Health Science, School of Biomedical Sciences, Ulster University, UK. From Sept 2014 and May 2016. Methodology: Free radical quenching capacity of tea (Earl grey, black tea, Ceylon tea, & green tea) infusions were investigated using persulfate activated ABTS with acetate buffer (pH 4.5) or phosphate buffer saline (pH 7.0) as solvent. Tests were performed using 96-well microplates, 20 µl of sample and 280 µl of ABTS reagent, and calibrated using ascorbic acid, trolox or gallic acid as reference antioxidants. Results: Gallic acid free radical quenching was pH dependent and unsuitable as reference. The free radical quenching capacity of trolox and ascorbic acid was not significantly different at pH 4.5 and pH 7.0. The radical quenching capacity of tea infusions expressed as Trolox Equivalent Antioxidant Capacity (TEAC) or Ascorbic Acid Equivalent Antioxidant Capacity (AAEAC) was greater by 50-300% at pH 7 compared to pH 4.5. Conclusion: The modified ABTS assay is suitable for examining the influence of pH on free radical quenching ability of tea samples. Gallic acid was not a suitable reference compound. The radical quenching capacity of tea infusions increases with rising pH

    Early exclusion of major adverse cardiac events in emergency department chest pain patients: A prospective observational study

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    Background The current evaluation of patients with chest pain presenting to an emergency department (ED) with suspected acute coronary syndrome (ACS) is a lengthy process involving serial measurements of troponin. Objective We aimed to validate the diagnostic accuracy of a Thrombolysis in Myocardial Infarction (TIMI) score with single high-sensitive cardiac troponin T (hs-cTnT) for early rule out of 30-day major adverse cardiac events (MACE), and to compare the TIMI score with combinations of heart-type fatty acid binding protein (H-FABP) and a modified HEART (history, electrocardiogram, age, risk factors, troponin) score. Methods We recruited 602 consecutive adult patients with chest pain and suspected ACS in the ED. Each patient had TIMI and HEART scores, and a point-of-care H-FABP test. Results MACE occurred in 42 (7.0%) patients within 30 days. A low risk for 30-day MACE was identified by a modified TIMI score of 0 in 65 (11%) patients, and by a HEART score ≤ 2 in 96 (16%) patients. No MACE occurred in these groups, giving both scores a sensitivity of 100% (95% confidence interval [CI] 91.6–100%), and specificity of 11.6% (95% CI 9.2–14.5%) and 17.1% (95% CI 14.2–20.5%), respectively. Use of combined TIMI and HEART scores improved the specificity further to 22.0% (95% CI 18.7–25.6%) without lowering sensitivity. Early H-FABP measurement > 7 μg/L had a sensitivity of 41.5% (95% CI 27.8–56.6%) and a specificity of 91.1% (95% CI 88.4–93.2%) for predicting 30-day MACE. Conclusions A modified TIMI score of 0 or a HEART score of ≤ 2, incorporating a single hs-cTnT level, will identify patients with low risk of 30-day MACE for early discharge within 2 h of ED arrival

    Gestalt for shock and mortality in the emergency department: A prospective study

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    Objective The diagnosis of shock in patients presenting to the emergency department (ED) is often challenging. We aimed to compare the accuracy of experienced emergency physician gestalt against Li's pragmatic shock (LiPS) tool for predicting the likelihood of shock in the emergency department, using 30-day mortality as an objective standard. Method In a prospective observational study conducted in an urban, academic ED in Hong Kong, adult patients aged 18 years or older admitted to the resuscitation room or high dependency unit were recruited. Eligible patients had a standard ED workup for shock. The emergency physician treating the patient was asked whether he or she considered shock to be probable, and this was compared with LiPS. The proxy ‘gold’ or reference standard was 30-day mortality. The area under the receiver operating curve (AUROC) was used to predict prognosis. The primary outcome measure was 30-day mortality. Results A total of 220 patients fulfilled the inclusion criteria and were included in the analysis. The AUROC for LiPS (0.722; sensitivity = 0.733, specificity = 0.711, P < 0.0001) was greater than emergency physician gestalt (0.620, sensitivity = 0.467, specificity = 0.774, P = 0.0137) for diagnosing shock using 30-day mortality as a proxy (difference P = 0.0229). LiPS shock patients were 6.750 times (95%CI = 2.834–16.076, P < 0.0001) more likely to die within 30-days compared with non-shock patients. Patients diagnosed by emergency physicians were 2.991 times (95%CI = 1.353–6.615, P = 0.007) more likely to die compared with the same reference. Conclusions LiPS has a higher diagnostic accuracy than emergency physician gestalt for shock when compared against an outcome of 30-day mortality

    Cardioprotective Actions of the Annexin-A1 N-Terminal Peptide, Ac2-26, Against Myocardial Infarction

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    The anti-inflammatory, pro-resolving annexin-A1 protein acts as an endogenous brake against exaggerated cardiac necrosis, inflammation, and fibrosis following myocardial infarction (MI) in vivo. Little is known, however, regarding the cardioprotective actions of the N-terminal-derived peptide of annexin A1, Ac2-26, particularly beyond its anti-necrotic actions in the first few hours after an ischemic insult. In this study, we tested the hypothesis that exogenous Ac2-26 limits cardiac injury in vitro and in vivo. Firstly, we demonstrated that Ac2-26 limits cardiomyocyte death both in vitro and in mice subjected to ischemia-reperfusion (I-R) injury in vivo (Ac2-26, 1 mg/kg, i.v. just prior to post-ischemic reperfusion). Further, Ac2-26 (1 mg/kg i.v.) reduced cardiac inflammation (after 48 h reperfusion), as well as both cardiac fibrosis and apoptosis (after 7-days reperfusion). Lastly, we investigated whether Ac2-26 preserved cardiac function after MI. Ac2-26 (1 mg/kg/day s.c., osmotic pump) delayed early cardiac dysfunction 1 week post MI, but elicited no further improvement 4 weeks after MI. Taken together, our data demonstrate the first evidence that Ac2-26 not only preserves cardiomyocyte survival in vitro, but also offers cardioprotection beyond the first few hours after an ischemic insult in vivo. Annexin-A1 mimetics thus represent a potential new therapy to improve cardiac outcomes after MI

    Hypoxia Impairs Primordial Germ Cell Migration in Zebrafish (Danio rerio) Embryos

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    Background: As a global environmental concern, hypoxia is known to be associated with many biological and physiological impairments in aquatic ecosystems. Previous studies have mainly focused on the effect of hypoxia in adult animals. However, the effect of hypoxia and the underlying mechanism of how hypoxia affects embryonic development of aquatic animals remain unclear. Methodology/Principal Findings: In the current study, the effect of hypoxia on primordial germ cell (PGC) migration in zebrafish embryos was investigated. Hypoxic embryos showed PGC migration defect as indicated by the presence of mis-migrated ectopic PGCs. Insulin-like growth factor (IGF) signaling is required for embryonic germ line development. Using real-time PCR, we found that the mRNA expression levels of insulin-like growth factor binding protein (IGFBP-1), an inhibitor of IGF bioactivity, were significantly increased in hypoxic embryos. Morpholino knockdown of IGFBP-1 rescued the PGC migration defect phenotype in hypoxic embryos, suggesting the role of IGFBP-1 in inducing PGC mis-migration. Conclusions/Significance: This study provides novel evidence that hypoxia disrupts PGC migration during embryonic development in fish. IGF signaling is shown to be one of the possible mechanisms for the causal link between hypoxia and PGC migration. We propose that hypoxia causes PGC migration defect by inhibiting IGF signaling through the induction of IGFBP-1

    Brainwashing or nurturing positive values : competing voices in Hong Kong\u27s national education debate

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    This corpus-based discourse analytical study compares the use of collocations, semantic preferences, semantic prosodies and metaphors in the news reports and Hong Kong Government press releases concerning the introduction of the school subject Moral and National Education in Hong Kong in 2012. The analysis of word co-occurrences with the phrase ‘national education’ in the two corpora shows that journalists use various FIGHT metaphors to describe the attitudes and actions of protesters and the responses of the government. However, the government press releases are much more literal, showing a neutral to positive tone and implying that when the planned introduction was shelved, national education will be re-introduced in the future

    Hong Kong government's financial assistance for maintenance scheme (FAMS) for privately-owned graded historic buildings : the case of the repair and maintenance works for Fung Chi Tsuen Tin Hau Temple, Yuen Long

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    The Conserve and Revitalize Hong Kong Heritage of Bureau department (BD) implement a Financial Assistance for Maintenance Scheme (FAMS) in 2007. The objective of this scheme is to provide financial assistance in the form of grants for the owner of privately-owned graded historic buildings in Hong Kong to process minor works by themselves from deterioration due to lack of maintenance. This dissertation will evaluate the scheme to find out what works and what does not work as the FAMS has been in operation for seven years (from 2008 to 2015). Up to September 2015, there are fifty successful applications to grant under the financial assistance on privately-owned graded historic buildings. There are twelve applications being processed including nine applications obtained Stage one approval. (AAB, 2015). This dissertation uses the author’s professional experience as a conservation contractor in Ding Hsung Construction Company, to identify the actual scope of work and actual costs involved in the repair and maintenance of a Chinese heritage building in Hong Kong, in order to evaluate the FAMS and make recommendations to make it work better for conservation. This dissertation will focus on the FAMS as applied to the repair and maintenance of the Fung Chi Tsuen Tin Hau Temple, Yuen Long as a case-study. As the author has been involved in the actual repair and maintenance work for the case-study building using grant from the FAMS, she is in a good position to provide in-depth information and analysis for the research.published_or_final_versionConservationMasterMaster of Science in Conservatio

    Metaphors in financial analysis reports : how are emotions expressed?

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    This study critically investigates the use of emotion metaphors in a corpus of BNP Paribas financial analysis reports produced during the credit crisis from 2011 to 2012. The corpus was examined to identify constituent words in the semantic category of ‘Emotion’. Concordances for selected words in ‘Emotion’ were examined by adopting the Metaphor Identification Procedure in order to identify metaphors in the corpus. The emotion metaphors identified were then classified into different semantic domains, underpinned by Conceptual Metaphor Theory. The main findings of the study revolve around the conceptualisation of emotion words reflecting the market turbulence circa 2011. In addition, the findings show that BNP Paribas\u27 corporate culture is revealed by the use of emotion metaphors in their financial analysis reports. The bank also uses varied metaphors to describe the emotions of investors. The study concludes that the identification of emotion terms for a conceptual metaphor analysis can be more effectively carried out by combining the methods of corpus linguistics, semantic annotation and Metaphor Identification Procedure. The study suggests important pedagogical implications for both ESP teachers and members of the financial services profession
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