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The China birth cohort study (CBCS) is a prospective longitudinal, mega-cohort study and the first national-based birth cohort study, aiming to establish a birth cohort covering representative geographical areas of the whole of China to investigate risk factors for birth defects and develop strategies for their reduction. Pregnant women who are of Chinese nationality, are 6–13+6 weeks of gestation, plan to attend the routine antenatal examination and deliver in the study site, and give their informed, written consent are eligible to participate in this study. All participants are followed-up through an in-person interview at 20–23+6 weeks and again at 28–33+6 weeks of gestation, and at delivery, respectively. CBCS has been divided into three phases from 20th November 2017 to 31st December 2021, and the first two phases have now been completed on 29th February 2020, enrolling 120 377 eligible pregnant women during this period. During the same period a total of 40 837 participants had been followed up to the end of pregnancy. Study recruitment will continue until December 2021 to achieve the target of 500 000 participants. Meanwhile, biological samples including peripheral blood, amniocytes, cord blood, placenta, or umbilical cord tissue have been collected from participants according to various conditions. The incidence of birth defects in this group is 2.5% and congenital heart disease is the most common type of birth defect seen so far. A website is in the advanced stages of planning, to allow seamless data transfer and facilitate collaboration with groups around the world.

The effects of 1-methylcyclopropene (1-MCP), an ethylene action inhibitor, on the senescence of broccoli (Brassica oleracea, L. var. italica) after harvest were studied, and its possible molecular mechanism was discussed. The results showed that 1-MCP treatment delayed the yellowing of broccoli florets, inhibited the activities of 1-aminocyclopropane-1-carboxylate acid (ACC) oxidase (ACO), and delayed the peaks in the ACC synthase (ACS) activity and ACC concentration. In addition, exogenous ethylene treatment did not accelerate yellowing in the florets pretreated with 1-MCP. The gene expression pattern of enzymes involved in ethylene biosynthesis and ethylene receptors in broccoli florets after harvest was investigated. 1-MCP treatment significantly decreased the expression of BO-ACS1, BO-ACS2, BO-ACO1, BO-ERS, BO-ETR1 and BO-ETR2. 1-MCP delayed the senescing process of broccoli by inhibiting the activities of enzymes involved in ethylene biosynthesis and gene expression of these enzymes and of ethylene receptors at the transcript level.