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17,949 result(s) for "Bisphenol A"
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Ten bisphenol analogues in Chinese fresh dairy milk: high contribution ratios of conjugated form, importance of enzyme hydrolysis and risk evaluation
This study investigated concentration levels of ten bisphenols (BPs) in 13 Chinese commercial fresh low temperature dairy milk samples (fresh milk) of main local and national brands with or without enzyme hydrolysis. The results showed that at least two BPs were detected in each fresh milk sample without enzyme hydrolysis and the respective mean concentrations of bisphenol AF (BPAF), bisphenol B (BPB), bisphenol C (BPC), bisphenol F (BPF), bisphenol A (BPA), bisphenol S (BPS), bisphenol AP (BPAP), bisphenol PP (BPP), bisphenol Z (BPZ), and bisphenol E (BPE) were 0.73, 0.61, 1.86, 0.87, 0.42, 0.11, 1.06, 1.42, 1.5, and 0.04 ng/mL, while their respective detection frequencies ranged from 23.1–92.3%. These results indicated the frequent detection of BPs in fresh milk samples. With enzyme hydrolysis, the respective mean concentrations of BPAF, BPA, BPB, BPC, BPF, BPS, and BPAP were increased 7.1–107.1%, indicating the long-ignored importance of enzyme hydrolysis. The respective average estimated daily intakes (EDIs) of BPA by adult and children in China via fresh milk were 32.5 and 37.5 ng/kg bw/d, indicating that BPA in fresh milk was a crucial source to human. Six out of nine other BPs had higher average EDIs than that of BPA, among which the EDI of BPAP was almost three times that of BPA, suggesting the widespread contamination of other BPs in Chinese fresh milk.
Removal of Bisphenol A and Its Potential Substitutes by Biodegradation
The possibility of removing bisphenol A and its five potential substitutes (bisphenols S, F, AF, E, and B) was tested using microorganism consortia from river water and activated sludge from municipal and rural wastewater treatment plants. For most bisphenols, biodegradation with activated sludge was faster than with river water and a greater extent of biodegradation was also achieved. However, only bisphenol A and bisphenol F underwent 100% primary biodegradation while other bisphenols degraded no more than about 50% which has some important implications in case of their increased usage. Metabolic activity in biodegradation liquors was also tested and it showed higher activity in the tests with activated sludge than with river water. However, there was no clear connection between the decline of metabolic activity and the extent of biodegradation as decreased activity was observed for two easily degrading bisphenols and two others with little biodegradability. It can be assumed that two different phenomena are involved in this process including depletion of nutrients for easily degradable bisphenol A and absence of nutrients for bacteria incapable of primary degradation of bisphenol AF and bisphenol S.
Human exposure of bisphenol A and its analogues: understandings from human urinary excretion data and wastewater-based epidemiology
This work evaluated human exposure to bisphenol A (BPA) and its analogues based on human urinary excretion data and wastewater-based epidemiology (WBE). The results showed that the world’s average human daily intake ranked from high to low is in order of bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS), bisphenol P (BPP), bisphenol AP (BPAP), bisphenol B (BPB), bisphenol Z (BPZ), and bisphenol AF (BPAF), and their corresponding human daily intakes are 2.53, 0.68, 0.60, 0.41, 0.36, 0.29, 0.24, and 0.06 μg/p/day, respectively. BPA is clearly the dominant bisphenol for human exposure. However, the results also showed that humans have been widely exposed to BPA analogues as well. Many BPA analogues showed similar estrogenic activities to those of BPA; therefore, the adverse effects of BPA and its analogues on humans should be comprehensively evaluated. The nominal exposure levels obtained based on wastewater-based epidemiology ranked high to low are in order of BPA (513.73 μg/p/day), BPF (10.20 μg/p/day), BPS (5.21 μg/p/day), BPP (1.15 μg/p/day), BPZ (0.66 μg/p/day), BPB (0.61 μg/p/day), BPAF (0.58 μg/p/day), and BPAP (0.35 μg/p/day). The world’s human average daily intakes of BPA and its analogues are only 0.5–47.9% of the intakes of their corresponding human nominal exposures. This study suggests that other sources rather human excretions are important origins in municipal wastewater, which indicates that the WBE method based on parent compounds is inappropriate for evaluations of human daily intakes of BPA and its analogues, neither for other industrial compounds that have multiple important sources. Three main important sources of BPA and its analogues in municipal wastewater are likely effluents of industrial wastewater, discharges of hospital wastewater, and landfill leachates. To decrease discharges of BPA and its analogues to the natural environment, any mixing of industrial and hospital wastewater as well as landfill leachates in municipal wastewater is not favorable.
Toxicity and bioconcentration of bisphenol A alternatives in the freshwater pulmonate snail Planorbella pilsbryi
Bisphenol A (BPA) is an industrial chemical identified as a vertebrate endocrine disruptor. Numerous alternatives have been developed, for which toxicity data are lacking. The present study assessed the toxicity of BPA and its replacement products bisphenol F (BPF), bisphenol S (BPS), and bisphenol AF (BPAF) in freshwater snail ( Planorbella pilsbryi ) embryos and adults. The chronic toxicity of BPA and BPAF was further characterized in 28-day tests with adult snails, followed by 21-day assessments of hatching and survival of embryos produced at the end of the test (F1 generation). In acute tests, BPAF was the most toxic of the substances tested (maximum acceptable toxicant concentration [MATC], 136 µg/L), followed by BPA (MATC, 1404 µg/L), BPF (MATC, 1525 µg/L), and BPS (MATC > 8590 µg/L). In the chronic test with BPA, although we observed no significant effects on adult snails up to 479 µg/L, the hatching and survival of juveniles from the F1 generation decreased (MATC, 13 µg/L), and was delayed by 7.5 days, on average. In contrast, we did not observe any decrease in hatching or survival of juveniles from the F1 generation during exposure to BPAF. Effects were observed at concentrations above most reported environmental exposure concentrations, although there was an overlap between exposure and effect concentrations. Given that concentrations of alternative substances are expected to increase, and in the absence of data on potential effects of mixtures, further research is needed.
Bisphenol A substitutes and childhood obesity at 7 years: a cross-sectional study in Shandong, China
Bisphenol A (BPA) substitutes, such as bisphenol S (BPS) and bisphenol AF (BPAF), are increasingly used due to restrictions on BPA usage, a known endocrine disrupting chemical and putative obesogen. However, little is known about the obesogenic effects of exposure to BPA substitutes in children. A total of 426 children aged 7 years old originally recruited from Laizhou Wan Birth Cohort in Shandong, China, during 2010–2013 participated in the 2019–2020 survey. Urinary BPA and its substitutes including BPS, BPAF, bisphenol B (BPB), bisphenol AP (BPAP), bisphenol Z (BPZ), and bisphenol P (BPP) were determined. Anthropometric measures including height, weight, waist circumference, and body fat percentage were assessed, and overweight/obesity was defined as BMI z -score ≥ 85th percentile. Linear and logistic regressions were used on continuous and binary obesity measures, respectively, and weighted quantile sum (WQS) regression was further used to estimate the mixture effects of exposure to diverse bisphenols, and sex-stratified analysis was performed. BPA substitutes were widely detected (> 75%) in children’s urine samples. A positive association with obesity measures was consistently observed for urinary BPS and BPAF, i.e., BMI z -score, waist circumference, and overweight/obesity. Further analysis from the WQS regression model demonstrated a positive association between bisphenol mixtures and all measures of obesity, with BPAF contributing the greatest weighing to the observed associations. Sex difference might exist as the positive associations were only significant in boys. No significant association was found between obesity and BPA or other BPA substitutes. Our study adds to mounting evidence that BPA substitutes BPS and BPAF are linked to obesity in children, especially in boys. Further longitudinal studies with larger sample size with continued biomonitoring these chemicals and their obesogenic effects are necessary.
Quasilinear Evolution Equations in L.sup.P.sub.mu-Spaces with Lower Regular Initial Data
We study the Cauchy problem of the quasilinear evolution equations in [L.sup.P.sub.[mu]]-spaces. Based on the theories of maximal [L.sup.p]-regularity of sectorial operators, interpolation spaces, and time-weighted [L.sup.p]-spaces, we establish the local posedness for a class of abstract quasilinear evolution equations with lower regular initial data. To illustrate our results, we also deal with the second-order parabolic equations and the Navier-Stokes equations in [L.sup.p,q]-spaces with temporal weights.
Urinary Bisphenols and Obesity Prevalence Among U.S. Children and Adolescents
Bisphenol A (BPA) has been recognized as an endocrine disrupting chemical and identified as an obesogen. Although once ubiquitous, human exposure to BPA has been declining owing to its substitution with other bisphenols. Two structurally similar substitutes, bisphenol S (BPS) and bisphenol F (BPF), have raised similar concerns, although fewer studies have been conducted on these newer derivatives. We used data from the US National Health and Nutrition Examination Surveys from 2013 to 2016 to evaluate associations between BPA, BPS, and BPF and body mass outcomes among children and adolescents aged 6 to 19 years. Concentrations of BPA, BPS, and BPF were measured in spot urine samples using HPLC with tandem mass spectrometry. General obesity was defined as ≥95th percentile of the age- and sex-standardized body mass index (BMI) z-scores according to the 2000 US norms. Abdominal obesity was defined as a waist circumference/height ratio of ≥0.5. BPA, BPS, and BPF were detected in 97.5%, 87.8%, and 55.2% of urine samples, respectively. Log-transformed urinary BPS concentrations were associated with an increased prevalence of general obesity (OR, 1.16; 95% CI, 1.02 to 1.32) and abdominal obesity (OR, 1.13; 95% CI, 1.02 to 1.27). BPF detection (vs not detected) was associated with an increased prevalence of abdominal obesity (OR, 1.29; 95% CI, 1.01 to 1.64) and continuous BMI z-score (β = 0.10; 95% CI, 0.01 to 0.20). BPA and total bisphenols were not statistically significantly associated with general obesity, abdominal obesity, or any body mass outcome. These results suggest that BPA substitute chemicals are correlated with obesity in contemporary children.
Exposure to Bisphenol B and S Increases the Risk of Male Reproductive Dysfunction in Middle Age
Accumulating evidence indicates that bisphenol A (BPA) analogs, including bisphenol B (BPB) and bisphenol S (BPS), disrupt testicular function and contribute to male reproductive dysfunction (MRD). However, whether BPA analogs are involved in MRD among middle-aged men remains inconclusive. Therefore, we selected cryptorchidism, erectile dysfunction, premature ejaculation, and testicular tumors as representative MRD conditions in middle-aged individuals, aiming to explore the molecular mechanisms that may be disrupted by bisphenols (BPs). By using GeneCards, STRING and Cytoscape, TP53, AKT1, and MYC were pinpointed as core targets associated with MRD. Enrichment analysis suggested that BPs may induce MRD by disrupting steroidogenesis. UPLC-MS/MS analysis showed that both BPB and BPS exhibit specific accumulation in the testes. Following 20-day exposure to 0.3 or 0.6 mg/kg body weight/day BPB or BPS, testosterone levels and the expression of hub genes were decreased. The molecular docking results demonstrated that both BPB and BPS can directly bind to members of the cytochrome P450 family, potentially interfering with sex hormone biosynthesis. Our study identified the targets and mechanisms through which BPB and BPS induce MRD in middle-aged males, thereby providing insights for the safety assessment of BPs.