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• Lead intoxication decreased serum TSH level in school- age children. • Lead intoxication increased serum GABA level in school- age girls. • BLL and serum Glu level were negatively correlated with school- aged children's IQ. • The frequency of mother smoking and drinking un-boiled stagnant tap water were risk factors of lead intoxication. • Eating fresh fruits, vegetables and soy products regularly may protect against lead intoxication. Lead exposure is one of the most concerning public health problems worldwide, particularly among children. Yet the impact of chronic lead exposure on the thyroid status and related intelligence quotient performance among school-age children remained elusive. The aim of this study was to evaluate the influence of lead exposure on the thyroid hormones, amino acid neurotransmitters balances, and intelligence quotient (IQ) among school-age children living nearby a lead-zinc mining site. Other factors such as rice lead levels, mothers' smoking behavior, and diet intake were also investigated. A total of 255 children aged 7-12 years old were recruited in this study. Blood lead level (BLL), thyroid hormones including free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH), and amino acid neurotransmitters such as glutamate (Glu), glutamine (Gln), and γ-aminobutyric acid (GABA) were measured using graphite furnace atomic absorption spectroscopy (GFAAS), chemiluminescence immunoassay, high performance liquid chromatography (HPLC). Raven's standard progressive matrices (SPM) and the questionnaire were used to determine IQ and collect related influence factors. The average BLL of children was 84.8 μg/L. The occurrence of lead intoxication (defined as the BLL ≥ 100 μg/L) was 31.8%. Serum TSH levels and IQ of lead-intoxicated children were significantly lower than those without lead toxicity. The GABA level of girls with the lead intoxication was higher than those with no lead-exposed group. Correlation analyses revealed that BLL were inversely associated with the serum TSH levels (R= -0.186, p < 0.05), but positively related with IQ grades (R = 0.147, p < 0.05). Moreover, BLL and Glu were inversely correlated with IQ. In addition, this study revealed four factors that may contribute to the incidence of lead intoxication among children, including the frequency of mother smoking (OR = 3.587, p < 0.05) and drinking un-boiled stagnant tap water (OR = 3.716, p < 0.05); eating fresh fruits and vegetables (OR = 0.323, p < 0.05) and soy products regularly (OR = 0.181, p < 0.05) may protect against lead intoxication. Lead exposure affects the serum TSH, GABA levels and IQ of school-aged children. Developing good living habits, improving environment, increasing the intake of high-quality protein and fresh vegetable and fruit may improve the condition of lead intoxication. [ABSTRACT FROM AUTHOR]

Abstract: Microstructural evolution and deformation mechanism of a Fe–12Mn–8Al–0.8C steel were investigated. The steel exhibited a good combination of strength over 900MPa and ductility about 46%. The microstructure of the Fe–12Mn–8Al–0.8C steel in solid solution state was a mixture of the (α+γ+κ) phases. The κ phase carbides ((Fe,Mn)3AlC x ) were formed by a spinodal decomposition during quenching. The deformation behavior of the austenite in the early deformation stage was fully determined by the size of the dislocation substructure, namely, dislocations alignment and Taylor lattices. With strain increasing, a gradual transition from Taylor lattices to highly dense dislocation walls and microbands was observed in austenite. Ferrite exhibited randomly distributed dislocations at a low strain and high dense dislocation tangles at a strain of 20%. TEM observations revealed ordered κ-carbide precipitates were sheared by slip bands at a strain of 30%. The present steel presented a multiple-stage strain hardening behavior which was associated with the changes of such dislocation substructures. The steel also exhibited a high initial strain hardening rate and a high specific strength about 130.5MPacm3/g. [Copyright &y& Elsevier]