The impact of subclinical hypothyroidism on growth and development in infants and young children aged 0 to 5 years.

INTRODUCTION: The objective was to investigate the growth and development of infants and young children with mild subclinical hypothyroidism aged 0 to 5 years, especially those aged 0 to 2 years. MATERIAL AND METHODS: The study was a retrospective analysis of the birth status, physical growth, and neuromotor development of patients aged 0 to 5 years, who were diagnosed with subclinical hypothyroidism during newborn screening (NBS) in Zhongshan between 2016 and 2019. Based on preliminary results, we compared 3 groups: with thyroid-stimulating factor (TSH) value of 5-10 mIU/L (442 cases), TSH value of 10-20 mIU/L (208 cases), and TSH above 20 mIU/L (77 cases). Patients with TSH value above 5 mIU/L were called back for repeat testing and were divided into 4 groups as follows: mild subclinical hypothyroidism group 1 with a TSH value of 5-10 mIU/L in both initial screening and repeat testing; mild subclinical hypothyroidism group 2 with TSH value above 10 mIU/L in initial screening; and TSH value of 5-10 mIU/L in repeat testing; the severe subclinical hypothyroidism group with TSH value of 10-20 mIU/L in both the initial screening and repeat testing and the congenital hypothyroidism group. RESULTS: There were no significant differences in the maternal age, type of delivery, gender, length, and weight at birth between the preliminary groups; however, the gestational age at birth was significantly different (F = 5.268, p = 0.005). The z-score for length at birth was lower in the congenital hypothyroidism group compared to the other 3 groups but showed no difference at 6 months of age. The z-score for length in mild subclinical hypothyroidism group 2 was lower compared to the other 3 groups but showed no difference at 2-5 years of age. At 2 years of age there was no significant difference in the developmental quotient (DQ) of the Gesell Developmental Scale between the groups. CONCLUSION: The gestational age at birth affected the neonatal TSH level. Intrauterine growth in infants with congenital hypothyroidism was retarded compared to that of infants with subclinical hypothyroidism. Neonates with a TSH value of 10-20 mIU/L in the initial screening and a TSH value of 5-10 mIU/L in the repeat testing showed developmental delay at 18 months but caught up at age 2 years. There was no difference in neuromotor development between the groups. Levothyroxine in patients with mild subclinical hypothyroidism is not required, but we recommend that the growth and development of such infants and young children continues to be monitored.

Design and Optimization of Hemispherical Resonators Based on PSO-BP and NSGA-II.

Although one of the poster children of high-performance MEMS (Micro Electro Mechanical Systems) gyroscopes, the MEMS hemispherical resonator gyroscope (HRG) is faced with the barrier of technical and process limits, which makes it unable to form a resonator with the best structure. How to obtain the best resonator under specific technical and process limits is a significant topic for us. In this paper, the optimization of a MEMS polysilicon hemispherical resonator, designed by patterns based on PSO-BP and NSGA-II, was introduced. Firstly, the geometric parameters that significantly contribute to the performance of the resonator were determined via a thermoelastic model and process characteristics. Variety regulation between its performance parameters and geometric characteristics was discovered preliminarily using finite element simulation under a specified range. Then, the mapping between performance parameters and structure parameters was determined and stored in the BP neural network, which was optimized via PSO. Finally, the structure parameters in a specific numerical range corresponding to the best performance were obtained via the selection, heredity, and variation of NSGAII. Additionally, it was demonstrated using commercial finite element soft analysis that the output of the NSGAII, which corresponded to the Q factor of 42,454 and frequency difference of 8539, was a better structure for the resonator (generated by polysilicon under this process within a selected range) than the original. Instead of experimental processing, this study provides an effective and economical alternative for the design and optimization of high-performance HRGs under specific technical and process limits.

Molecular epidemiology investigation of beta-thalassemia in Zhongshan City, Guangdong Province, People's Republic of China.

Beta-THAlassemia (beta-thal) is one of the most common genetic diseases in southern China. In order to obtain detailed epidemiology data to be used for primary prevention programs, we have analyzed 2,055 independent subjects living in Zhongshan City, Guangdong Province, People's Republic of China (P.R. China), by using hematological biochemical screening and DNA technology. The results indicate a higher prevalence (3.07%) of beta-thal and coinheritance of alpha- and beta-thal (0.49%) than previously reported for Guandong Province. Ten beta-thal mutations were found in 63 independent chromosomes. The four most common mutations [codons 41/42 (-TCTT), IVS-II-654 (C>T), -28 (A>G), codon 17 (A>T)] accounted for 90.46% of the total. The uncommon mutations profile was different from that of other cities in Guangdong Province and the rare mutation IVS-II-2 (-T), once reported in Hong Kong, was also detected. This study will contribute to the development of prevention strategies in the region, allowing better genetic counseling and prenatal diagnosis of beta-thal.