Retrospective analysis of Vitamin A levels in children in Shandong, China

Abstract

Background Vitamin A (VA) levels of children are essential for health. There is a worldwide concern in VA deficiency(VAD), which is associated with some diseases such as dry eyes, respiratory, digestive and immune system diseases in children. Objective The VA levels of children aged 0–14 years who visited our hospital located in Linqing City,Shandong Province, China from February 2019 to January 2020 were screened to provide evidence for prevention and treatment of VAD in children. Methods Children aged 0–14 years were selected as the research objects, and VA levels were determined by liquid chromatography, and the effects of gender, age and different seasons on VA levels were analyzed. Results A total of 1965 children were investigated, ranging from 0 to 14 years old. Among them, 1191 were boys, accounting for 60.61%. 774 were girls, accounting for 39.39%. The normal range of VA levels is 0.3-0.7mg/L. Based on this range, The highest rates of VAD were found in children within 1 year old. 979 (49.8%) of the VA levels were below normal. 211(10.7%)children were deficient and 768(39.1%) children were subclinical deficient. 164(63.3%)children with RRTI and RTI were deficient.467(43.4%)healthy children were deficient.One person (0.05%) exceeded the normal level value. There was no significant difference in serum VA levels between boys and girls (P > 0.05), indicating that gender difference had no effect on VA levels. However, the influence of different seasons on VA levesl were statistically significant in different age groups (P < 0.05). Conclusion Nearly half of the children's VA levels were lower than normal value, which was related to age and season, but not gender. Children with RRTI and RTI had much lower VA levels than healthy children.

Magnetic anomaly of long track detection method based on wavelet combining with fractal for high speed maglev transit

“…Using multifractal spectrum to screen massive data requires low computational complexity and strong robustness. Calculation methods include Box-counting, Moment, WTMM, Wavelet Leader and MF-DFA, in which WTMM based on CWT lacks theoretical basis with large computational complexity, 15 and MF-DFA is prone to poor stability of caculation with different segmentation scale. 17 So, Box-counting, Moment and Wavelet Leader are involved in this paper.…”

“…14 In seismic activity detection, Sanchez et al proposed the EMD-FD algorithm by combining EMD with fractal theory for geomagnetic anomalies caused by low-frequency seismic activity, which uses EMD to remove background noise and combines three fractal dimension of Katz, Higuchi and Box to mine more information. 15 In mineral exploration in surface covered areas, Guoxiong Chen proposed an anomaly extraction and identification method based on wavelet and fractal theory, which provides a new break through direction for identifying hidden ores by using wavelet transform to high light local details and using multiple fractal spectra to the intrinsic structure of the data. 16 The main contributions of this work can be summarized as follows:…”