Objective To assess iron bioavailability of three iron-biofortified maizes using an in vitro digestion/ Caco-2 cell culture model. Method Three maize varieties rich in iron (Zhongtie 2, 3 and 4) and two maize varieties with lower content of iron (Zhengda 818 and 619) were pulverized, and the content of iron and phosphorus in each maize variety was measured. After digestion the iron bioavailability per g food was determined by using Caco-2 cell ferritin formation per mg cell protein as indicator. Results The iron content (33.250 mg/kg), iron bioavailability and the iron bioavailability per g food of Zhongtie 2 maize was the highest among all varieties, but its phosphorus content was lower. The maize varieties with the next higher iron bioavailability were Zhongtie 3 and Zhengda 818, and the lowest was Zhengda 619. Conclusion Zhongtie 2 maize contained the hightest content and bioavailability of iron,so it was optimal to use for the following human trials.

Transoral incisionless fundoplication (TIF)has been used for the treatment of gastroesophageal reflux disease (GERD)via repairing the gastroesophageal junction valve. Both the clinical report and control study confirmed that,with the prerequisite of rational selection of patients,TIF as an emerging technology can effectively cure or improve the clinical symptoms of GERD,esophagitis,and level of esophageal acid exposure. Compared with the traditional treatment,TIF is more effective,safe and having lasting effect for the rationally selected GERD patients. This article reviewed advances in study on TIF for the treatment of GERD.

Targeted replacement genome editing refers to DNA modification and engineering technology that could induce and achieve mutations of targeted gene replacement or knockin at a target gene or DNA region. In this review, the principles, implementation methods, factors that influence efficiency and accuracy, and applications of gene replacement editing were summarized and discussed. It provides the reference for gene functional characterization and genetic improvements through gene replacement strategies in higher plant especially crops.