ABSTRACT
Based on melamine-Cu conjugate and subsequent interruption of formation of polythymine (Poly T)-templated copper nanoclusters (CuNCs), a novel fluorescent strategy was developed for detection of melamine.The method relied on the principle that the coordination of melamine to copper would be unfavorable for the reduction of Cu2+ in the poly T-CuNCs synthesis process, and thereby resulting in the decrease of fluorescence intensity of CuNCs.By this method, the fluorescence response of CuNCs displayed an linear relationship with melamine concentration in the range from 5 μmol/L to 120 μmol/L.The detection limit was 1.5 μmol/L.Furthermore, the assay was successfully applied in the detection of melamine in milk samples with good recoveries.
ABSTRACT
A novel fluorescence homogeneous biosensing strategy was developed for simple, rapid and sensitive detection of melamine in milk by using the polythymine oligonucleotide T24 and SYBR Green Ⅰ. In the absence of melamine, the fluorescence of SYBR Green Ⅰ was weak. The interactions between the single strand oligonucleotide T24 and SYBR Green Ⅰ were weak. In contrast, the presence of melamine drove the formation of T-melamine-T folded structure and enabled the SYBR Green Ⅰ to intercalate into double-strand DNA, resulting in the enhancement of fluorescence intensity. The results revealed that the method allowed a sensitive, simple, and rapid assay of melamine with a linear response range from 0. 1 μmol/L to 10 μmol/L and a detection limit of 35 nmol/L.
ABSTRACT
Objective To observe the protective effects of the extracts of Rhizoma Zingiberis and Pericarpium Citri Reticulatae on myocardial ischemia reduced by isoproterenol(ISO) in rats,and to explore their optimal ratio.Methods Acute myocardial ischemia rat model was established by continuously subcutaneous injection of large-dose.Then the content of the serum creatine kinase(CK) within 24 hours in rats were detected,and the optiaml ratio of Rhizoma Zingiberis and Pericarpium Citri Reticulatae was optimized by uniform design.Results Compared with the control group,the content of CK in the model group was significantly increased(P
ABSTRACT
Objective To observe the analgesic action and anti-inflammation effect of borneol. Methods The analgesic action and anti-inflammation effect of borneol were observed by mouse hot-plate test,mouse acetic-acid-induced twisting test,mouse abdominal cavity capillary permeability increase test induced by acetic acid,and rat pedal swelling test induced by carrageenin. Results Borneol reduced the pedal swelling of rats,ED50=0.3242 g?kg-1,increased pain threshold in mice ED50=0.3870 g?kg-1,inhibited twisting response of mice obviously,ED50=0.5813 g?kg-1. In the same dose,the analgesic action of borneol was stronger than the anti-inflammatory effect. Conclusion Borneol has certain analgesic action and anti-inflammation effect.