Pulse Compression Shape-Based ADC/DAC Chain Synchronization Measurement Algorithm with Sub-Sampling Resolution.

In this article, we address the problem of synchronizing multiple analog-to-digital converter (ADC) and digital-to-analog converter (DAC) chains in a multi-channel system, which is constrained by the sampling frequency and inconsistencies among the components during system integration. To evaluate and compensate for the synchronization differences, we propose a pulse compression shape-based algorithm to measure the entire delay parameter of the ADC/DAC chain, which achieves sub-sampling resolution by mapping the shape of the discrete pulse compression peak to the signal propagation delay. Moreover, owing to the matched filtering in the pulse compression process, the algorithm exhibits good noise performance and is suitable for wireless scenarios. Experiments verified that the algorithm can achieve precise measurements with sub-sampling resolution in scenarios where the signal-to-noise ratio (SNR) is greater than -10 dB.

Exposure to perfluoroalkyl substances was associated with estrogen homeostasis in pregnant women.

Previous studies have suggested that perfluoroalkyl substances (PFASs) can act as endocrine disruptors, but few studies have investigated the effects of serum PFASs on estrogen homeostasis during pregnancy. The present study included 557 pregnant women in Tangshan City, North China, and determined 11 serum PFASs in the early term of pregnancy and three typical estrogens (estrone (E1), estradiol (E2) and estriol (E3)) in the early (n = 557), middle (n = 339), and late (n = 286) terms of pregnancy. Sociodemographic factors and diet information were obtained by structured questionnaires. After adjusting for potential confounders, multiple linear regression model demonstrated negative associations of natural logarithmic transformed serum perfluoroundecanoic acid (Ln PFUdA) with Ln E1and Ln E3 in the early term of pregnancy with ß coefficients of -0.060 (95% confidence interval (CI): -0.101 to -0.019) and -0.041 (95% CI: -0.070 to -0.011), respectively. Ln perfluorodecanoic acid (PFDA) was negatively associated with averaged E1 in the early and middle (EM) terms of pregnancy with a ß coefficient of -0.205 (95% CI: -0.357 to -0.053). Ln perfluorononanoic acid (PFNA) tended to be negatively associated with E2 in the late term of pregnancy with a ß coefficient of -0.134 (95% CI: -0.253 to -0.016) although p-value was slightly greater than 0.05 after false discovery rate (FDR) correction. Mixed effect model found that serum PFDA was negatively associated with E1 (ß = -0.123, 95% CI: -0.235 to -0.012) during the entire pregnancy. These findings suggested that exposure to PFASs disturbed estrogen homeostasis in pregnant women and the effects varied with the terms of pregnancy.

Association of triclosan and triclocarban in urine with obesity risk in Chinese school children.

BACKGROUND: Laboratory studies have suggested that triclosan and triclocarban can influence energy metabolism by multiple mechanisms and are potential obesogens, but the effect on obesity risk has not been well investigated in human. OBJECTIVE: To examine the associations of triclosan and triclocarban in urine with childhood obesity. METHODS: We investigated 458 school children aged 7-11 years who entered a dynamic cohort of children established in Shanghai in 2019 and 2020. Triclosan and triclocarban were determined in first morning urine by liquid chromatography coupled to mass spectrometry. Body mass index (BMI) and waist circumference (WC) were used to identify general overweight/obesity and central obesity, respectively. Logistic regression and linear models of generalized estimating equations (GEE) were used to investigate the association between urinary triclosan and triclocarban with obesity prevalence. RESULTS: After adjusting for potential confounders, children with detectable triclocarban in urine had a higher proportion of general overweight/obesity (odds ratio (OR): 1.84; 95% confidential interval (95% CI): 1.19, 2.85) or central obesity (OR: 1.71; 95% CI: 1.03, 2.84). Compared to the low tertile, children in the median tertile of triclosan showed a higher proportion of central obesity (OR: 1.78; 95 %CI: 0.98, 3.24) and children in the high tertile of triclocarban had a higher proportion of general overweight/obesity (OR: 2.25; 95 %CI: 1.31, 3.88) and central obesity (OR: 2.08; 95 %CI: 1.12, 3.87). When the tertiles of triclocarban in urine were treated as a continuous variable, a positive exposure-response relationship was found with general overweight/obesity (OR: 1.50; 95 %CI: 1.15, 1.96) and central obesity (OR: 1.44; 95 %CI: 1.06, 1.95). Multiple linear regression showed a positive exposure-response relationship between triclocarban and BMI (ß: 0.45; 95 %CI: 0.11, 0.80) values. CONCLUSION: Exposure to triclosan and triclocarban was associated with increased risk of childhood obesity. Given the cross-sectional design, more studies are needed to interrogate these findings.

Serum perfluoroalkyl substances in relation to lipid metabolism in Chinese pregnant women.

Laboratory and epidemiologic studies suggested that exposure to perfluoroalkyl substances (PFASs) could affect lipid metabolisms, but data remain limited for pregnant women. A total of 436 pregnant women were selected in Tangshan City, North China. Serum levels of 11 PFASs were determined in the early term of pregnancy. Four lipids (total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL)) were measured in the late term of pregnancy. Of 11 PFASs, seven had a detection rate of greater than 70%. After adjusting for potential confounders, natural log-transformed perfluororohexanesulfonic acid (ln PFHxS) was positively associated with TC (ß: 0.184, 95% CI: 0.045-0.321), HDL (ß: 0.040, 95% CI: 0.001-0.083), and LDL (ß: 0.091, 95% CI: 0.001-0.185). Ln perfluoroundecanoic acid (PFUdA) was positively associated with HDL (ß: 0.021, 95% CI: 0.001-0.044), while Ln perfluorodecanoic acid (PFDA) was negatively associated with LDL (ß: -0.053, 95% CI: -0.098∼-0.009) and ln perfluorootanoic acid (PFOA) was negatively associated with LDL/HDL (ß: -0.042, 95% CI: -0.075∼-0.009). In principal component analysis, the component with a large loading of 31.3% for PFOA, perfluorononanoic acid (PFNA), PFDA and PFUdA showed a negative association with LDL/HDL. After serum concentrations of PFASs were categorized into quartiles, a higher level of TC was seen in the second quartile of PFOA or PFNA than the first quartile, but a lower LDL/HDL ratio was seen in the fourth quartile of PFOA, PFUdA or PFDA. These results suggested that exposure to PFASs has a potential to influence lipid metabolisms in pregnant women.

Predictors, sources, and health risk of exposure to neonicotinoids in Chinese school children: A biomonitoring-based study.

BACKGROUND: Recent studies have suggested an extensive exposure to neonicotinoids in human, but the information on predictors, sources, and health risk remains limited in children. OBJECTIVE: To explore the predictors, sources, and health risk for exposure of Chinese school children to neonicotinoids by biomonitoring method. METHODS: In 2019, 309 school children aged 7-11 years were selected from a dynamic cohort of children established in Shanghai, East China. Eight neonicotinoids and four metabolites were determined in first morning urine. After detailed information on demographic and socioeconomic indices, intake of drinking water, food consumption, and anthropometric measurements was collected, the predictors and sources of exposure to neonicotinoids were explored by binary and ordinal logistic regression models. Health risk was assessed by the hazard quotient (HQ) and hazard index (HI) based on estimated daily exposure dose. RESULTS: Six neonicotinoids (thiamethoxam, clothianidin, imidacloprid, acetamiprid, nitenpyram, and dinotefuran) and three metabolites (N-desmethyl-thiamethoxam, N-desmethyl-clothianidin, and N-desmethyl-acetamiprid) were detected in 81.3% of urine samples. Children in nuclear family or girls had a higher detection frequency of thiamethoxam. N-desmethyl-acetamiprid was more likely to be detected in children who were older, physically active, or obese. Parents' occupation was heterogeneously associated with the detection of thiamethoxam and clothianidin. Thiamethoxam and clothianidin were more likely to be detected in children consuming more fresh vegetables in all or its specific items of cabbage, nori, and kelp. N-desmethyl-acetamiprid was more likely to be detected in children who drank more tap water. The maximum HQ and HI were 0.3522 and 0.5187, respectively, and 2.8% of children had a HI between 0.1 and 1. CONCLUSION: Predictors for the exposure of children to neonicotinoids included demographic and socioeconomic factors, physical exercise, and relative body weight. Tap water and fresh vegetables were potential sources. A low risk was posed on children's health by the neonicotinoids.