This study aimed to assess the aflatoxin M1 (AFM1) levels in 72 samples of yogurt from eight processing plants in São Paulo, Brazil, and the ability of heat-killed cells of Saccharomyces cerevisiae (1010 yeast cells/g) to reduce AFM1 (0.5 µg/kg) in experimental yogurts (n = 3). Analyses were conducted by high performance liquid chromatogra-phy (HPLC). Only seven samples (9.8%) had AFM1 at a mean level of 0.071 ± 0.08 µg/kg. S. cerevisiae efficiently reduced (P < 0.05) the AFM1 levels in spiked yogurts, with a maximum reduction of 46% after 30 days of storage. Further studies should investigate potential effects of S. cerevisiae on the sensory properties of yogurts.
Precision flow pumps have been widely studied over the last three decades. They have been applied in the areas of Biology, Pharmacy and Medicine in applications usually related to the dosage of medicine and chemical reagents. In addition, thermal management solutions for electronic devices have also been recently developed using these kinds of pumps offering better performance with low noise and low power consumption. In previous works was presented the working principle of a pump based on the use of a bimorph piezoelectric actuator inserted in a fluid channel to generate flow. This work presents a novel configuration of piezoelectric flow pumps using a bimorph piezoelectric actuator of different aspect ratio. Sensibility studies of the rectangular cross-sectional area channel are conducted computationally (CFD) and three parameters are investigated: resonance frequency and oscillation amplitude of the piezoelectric actuator, and pressure inside the channel. Also, experimental tests are conducted to verify the influence of clamps' rigidity and actuator's insulator. The experimental results show that improving these two aspects it is possible to achieve higher flow rates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.