Advantages of time-resolved fluorescent nanobeads compared with fluorescent submicrospheres, quantum dots, and colloidal gold as label in lateral flow assays for detection of ractopamine.

Label selection is a critical factor for improving the sensitivity of lateral flow assay. Time-resolved fluorescent nanobeads, fluorescent submicrospheres, quantum dots, and colloidal gold-based lateral flow assay (TRFN-LFA, FM-LFA, QD-LFA, and CG-LFA) were first systematically compared for the quantitative detection of ractopamine in swine urine based on competitive format. The limits of detection (LOD) of TRFN-LFA, FM-LFA, QD-LFA, and CG-LFA were 7.

Sesquiterpenoids from the roots of Vladimiria muliensis.

An unusual aromadendrane-type sesquiterpenoid with a rare hemiketal-containing 10/3 ring system, named vladimuliecin C (1), and one new eudesmane-type sesquiterpenoid, named vladimuliecin D (4), together with four known sesquiterpenoids, were isolated from the roots of Vladimiria muliensis. The structures of these compounds were elucidated by analysis of spectroscopic data. The absolute configuration of 1 was assigned by X-ray diffraction analysis.