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ObjectiveThe aim of our study was to compare the reference intervals (RIs) [median (2.5th-97.5th percentiles)] for thyroid-stimulating hormone (TSH) between subgroups stratified by ethnicity and iodine status in a global context.Design and MethodsPrimary data were derived from a recently published cross-sectional study in mainland China. Secondary data were obtained from online databases. The RIs for TSH were calculated in the reference population according to the National Academy of Clinical Biochemistry (NACB) standard and in the disease-free population. A meta-analysis of ethnicity- and iodine status-specific TSH RIs was performed.ResultsThe primary data showed that the TSH RI (mU/L) in the disease-free population was 2.33 (0.67, 7.87), which is wider than the published RI [2.28 (0.74, 7.04)] in the reference population. The meta-analysis showed that whether in the reference or disease-free population, the RIs in Yellows were much higher than those in Caucasians. In the reference population, the median and 2.5th percentile in the iodine-sufficient subgroup were both lower than the iodine-deficient or more-than-adequate subgroup, while the 97.5th percentile showed a positive trend with increasing sufficiency of iodine. However, in the disease-free population, the iodine-sufficient subgroup had a lower median and 97.5th percentile but higher 2.5th percentile than the iodine-deficient subgroup.ConclusionYellows have a higher TSH RI than Caucasians. In the reference population, both the median and 2.5th percentile TSH in the iodine-sufficient population were the lowest among the different iodine status subgroups, while the 97.5th percentile of TSH showed an upward trend with increasing iodine sufficiency.

Marginal iodine deficiency is a common health problem in pregnant women. Epidemiological and animal studies had shown that marginally maternal iodine deficiency could cause the mild changes of maternal thyroid function, eventually lead to a negative effect on neurodevelopment. But the underlying mechanisms responsible for the neurological impairment remain unclear. The aim of this study is to explore whether marginally maternal iodine deficiency could produce subtle changes in cell migration and cognitive function of offspring, and the optimal time of giving intervention to minimize the adverse effects. In the present study, we established a marginal iodine deficiency model, and iodine supplement was performed on pre-pregnancy (PP), G13 (gestation day 13), and postnatal day 0 (P0). Our data showed that there were changes in the cytoarchitecture and the percentage of bromodeoxyuridine (BrdU)-labeled cells in the cerebral cortex in marginal iodine deficiency rats. The Reelin expression was significantly lower, but Tenascin-C was higher in the cerebral cortex of marginal iodine deficiency group on P7 than the normal group, respectively. When iodine supplement, especially before G13 could reverse the abnormal expression of the two proteins involved in cell migration, which was consistent with the results of Morris Water Maze test. The three intervention groups had shorter escape latencies than the marginal iodine deficiency rats. The earlier that iodine is supplied, the better behavior performance would reach. Our findings suggested that iodine supplement in early stage of pregnancy could improve the cell migration of cerebral cortex and neurodevelopment of offspring.

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Gray mapping is a well-known way to improve the performance of regular constellation modulation, but it is challenging to be applied directly for irregular alternative. To address this issue, in this paper, a unified bit-to-symbol mapping method is designed for generalized constellation modulation (i.e., regular and irregular shaping). The objective of the proposed approach is to minimize the average bit error probability by reducing the hamming distance (HD) of symbols with larger values of pairwise error probability. Simulation results show that the conventional constellation modulation(i.e., phase shift keying and quadrature amplitude modulation (QAM) with the proposed mapping rule yield the same performance as that of classical gray mapping. Moreover, the recently developed golden angle modulation (GAM) with the proposed mapping method is capable of providing around 1 dB gain over the conventional mapping counterpart and offers comparable performance to QAM with Gray mapping.