RESUMO
In this paper, we study the theory of complements, introduced by Shokurov, for Calabi-Yau type varieties with the coefficient set [0, 1]. We show that there exists a finite set of positive integers N, such that if a threefold pair (X/Z∋z,B) has an R-complement which is klt over a neighborhood of z, then it has an n-complement for some n∈N. We also show the boundedness of complements for R-complementary surface pairs.
RESUMO
A facile strategy has been reported to anchor silver nanoparticles (Ag NPs) onto three-dimensional reduced graphene oxide (3D rGO) via a green and simple method. An accurate and reliable electrochemical sensing platform based on Ag NPs/3D rGO was designed for the ultrasensitive detection of rifampicin (RIF). The morphology and features of Ag NPs/3D rGO were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy and electrochemical measurements. The interface of the modified electrode presented effective electrical activity for the analysis of RIF due to the large electrochemically active surface area and excellent electron transport ability. The sensor exhibited a good linear relationship in the range of 0.01 nM-45 µM and a low detection limit of 0.810 nM (S/N = 3). Crucially, the fabricated Ag NPs/3D rGO sensor was successfully utilized to assess RIF in human blood, drug and aquatic product samples. This sensing platform exhibited outstanding electrochemical performance for RIF detection and showed great potential application in clinical diagnosis, pharmaceutical and food-related fields.
