ABSTRACT
A colorimetric method was developed for detection of mercury based on the inhibition of oxidation of peroxidase substrates. The as-prepared gold nanoclusters ( Au NCs), which has been stabilized and reduced by Glutathione (GSH), can effectively catalyze the H2 O2-TMB to generate a blue color signal. It is interestingly that Hg2+ can inhibit the oxidation of peroxidase substrates, thus causing a color diminished. Taking advantage of the inhibitive effect of Hg2+, a novel Hg2+ sensor has been developed. In this system, sensing conditions, including pH of the buffer solution, substrate concentration and time, were optimized. Under the optimal conditions, the probe showed a linear range of 10 - 300 nmol/ L ( R2 = 0. 997) with a detection limit of 6. 26 nmol/ L. In addition, this sensor exhibited good selectivity and sensitivity for Hg2+against other common environmental mental ions, providing a new method for water analysis.
ABSTRACT
Objective To explore the association between metabolic syndromes (MS) and carotid atherosclerosis and to estimate the predictive effects of MS under 3 different definitions.Methods A cross-sectional study was conducted in 2 community-based populations in Beijing,in 2008.1266 subjects (598 men,668 women),aged 45-69,were included in the analyses.MS was defined by the criteria of International Diabetes Federation (IDF),the revised NCEPATPm (ATP Ⅲ-R) and "The Guidelines of Dyslipidemia Control for Chinese Adult" ( "Guidelines" ) in 2007.Results The prevalence rates of MS by the 3 criteria were 39.0%,43.3% and 30.9% respectively.The Kappa value for the measure of the agreement between each pair of the 3 definitions were 0.911,0.719 and 0.730 respectively.The intima-media thickness in common carotid artery (CCA-IMT) was significantly higher (P＜0.001) in all MS groups than in non-MS groups,diagnosed with the 3 criteria independent of age,gender,LDL-C,and current smoking status.After adjustment of age,gender,LDL-C,and current smoking status,the classification of MS significantly increased the risk of prevalence of carotid atberosclerotic plaques,compared to the non-MS group.OR value were 1.499 (95% CI:1.157-1.942) for IDF,1.696 (95% CI:1.314-2.189) for NCEP-R,1.763 (95% CI:1.344-2.312) for "Guideline" respectively.Conclusion Our research findings indicated that,when MS were defined with the 3 definitions,prediction on the risk of sub-clinical atberosclerosis would work beyond some of the conventional cardiovascular risk factors such as smoking,LDL-C.There might exist some differences in gender issue on the strength of association between MS when diagnosed by different criteria and carotid plaque.