ABSTRACT
The reaction conditions for the determination of bovine serum albumin (BSA) using o-hydroxyphenylfluorone (o-HPF) as fluorescence probe reagent were studied. In the B-R medium at pH 7.90, o-HPF could react with BSA, producing a stable complex compound which resulted in fluorescent quenching of this binary system. The quantitative assay was carried out based on the relation between the degree of fluorescent quenching and the additional amount of BSA. The method has advantages of good selectivity, stability and simplicity. The linear range of o-HPF fluorescence spectrophotometric method was 1.32-18.54 microg x mL(-1). Moreover, the mechanism of the reaction BSA and o-HPF was discussed, and the quenching constant, and the ther modynamics constant of the fluorescence effects were calculated. The results showed that the nonconvalent binding forces were the binding force between o-HPF and BSA, and the quenching of BSA to o-HPF was probably a single static quenching process.
Subject(s)
Fluoresceins/chemistry , Fluorescent Dyes/chemistry , Serum Albumin, Bovine/analysis , Spectrometry, Fluorescence , Animals , Cattle , Fluoresceins/analysis , Fluorescent Dyes/analysis , Serum Albumin, Bovine/chemistryABSTRACT
The reactions were studied for the determination of bovine serum albumin (BSA) using o-hydroxyphenylfluorone (o-HPF) as fluorescence probe reagent with fluorescence spectrophotometry. In the B-R medium, o-HPF reacts with BSA to form the stable complex compound. The reaction system of o-HPF and BSA was binary system, and the method for the determination of BSA was of good selectivity and stability and simplicity. The linear range of o-HPF fluorescence spectrophotometric method was 1.32-18.54 microg x mL(-1) The quenching constant and thermodynamics constant of the fluorescence effects between BSA and o-HPF were calculated. The results showed that the non-covalent binding forces were the binding force between o-HPF and BSA.
Subject(s)
Fluorescent Dyes/chemistry , Serum Albumin, Bovine/analysis , Spectrometry, Fluorescence/methods , Hydrogen-Ion Concentration , Temperature , ThermodynamicsABSTRACT
OBJECTIVE: To investigate the stability of upper molars with the application of micro-screw implant anchorage during orthodontic treatment. METHODS: Fifteen adult patients with severe maxillary protrusion were included. Upper first premolars were extracted and upper posterior anchorage was reinforced with micro-screw implant in all patients. The average treatment period to close the extraction space was 10.5 months. Cephalometric and cast analysis were carried out. RESULTS: During the treatment, the micro-screw implants kept stable in sagittal plane; neither the mesial-distal movement nor the rotation or tipping of the upper molars during the treatment was of statistic significance (P > 0.05); the edge of upper incisors was retracted by 6.99 mm on average, and no significant vertical change was observed (P > 0.05). CONCLUSIONS: Micro-screw implant could provide good anchorage control in the orthodontic treatment.