2,580 research outputs found

    Evaluating the Effects of Bisphenols F and S with Respect to Bisphenol A on Primordial Germ Cell Migration in Zebrafish (Danio rerio) Embryos Using Immunofluorescence Microscopy

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    Primordial Germ Cell (PGC) migration occurs in early embryonic development and is highly conserved across taxa. PGC migration occurs within the first 24 hours post fertilization (hpf) in zebrafish, making the organism an efficient model for observing the migration pathway. Proper PGC migration is necessary for normal gonad development and, in some species, sex determination. Disruption of this process leads to defects in gonad formation and abnormal sex determination and differentiation. Studies show that endocrine-disrupting chemicals such as bisphenol A (BPA) disrupt PGC migration in zebrafish. BPA is an estrogenic compound that has been linked to a variety of human diseases, including various cancers, diabetes, reproductive disorders, obesity, and cardiovascular diseases. It is one of the most widely used synthetic compounds worldwide, as it is used to make polycarbonate plastics. Many studies provide evidence of the harmful effects of BPA on living organisms. In response, manufacturers have started to use replacements such as bisphenol F (BPF) and bisphenol S (BPS). However, due to their structural similarity, it is likely that BPF and BPS are just as harmful to organisms as BPA. In this study, we use antibody staining and immunofluorescence microscopy to confirm that BPA exposure results in abnormal PGC migration in zebrafish embryos, as previously studied, and to illustrate that BPF and BPS exposure results in similar PGC migration defects

    Using zebrafish (Danio rerio) to study the behavioral impacts of early bisphenol F exposure reveals decreased swim speed, increased distance between fish, and increased freezing behaviors

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    The widespread use of endocrine disrupting chemicals (EDCs) has been a source of concern because of their various effects on the endocrine system. These effects include metabolic disorders, complications in reproductive health, hormone-related cancers, and neurodevelopmental disorders. Of particular concern is bisphenol A (BPA), a synthetic compound commonly found in consumer products such as water bottles, thermal receipt paper, and epoxy resins used in processed food packaging. Previous studies have shown that BPA can mimic estrogen through a variety of mechanisms and thus elicit an endocrine response. Some manufacturers have responded by removing BPA from their products; however, studies using a replacement compound bisphenol S have reported it to be just as, if not more, dangerous. The use of zebrafish (Danio rerio) larvae as a model organism allows for the effects of bisphenol exposure to be rapidly quantified through a simple behavioral assay. In studies involving bisphenol exposure, the use of zebrafish has demonstrated reproductive, developmental, endocrine, and behavioral effects. The study of bisphenol F, yet another endocrine disruptor that has become a replacement for BPA in consumer products, is highly important to public safety

    Fetal exposure to bisphenols and phthalates and childhood bone mass: a population-based prospective cohort study.

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    Background: Exposure to bisphenols and phthalates might influence bone health. We hypothesized that exposure to bisphenols and phthalates during fetal life has persistent effects on bone development. Objectives: To analyze the associations of fetal exposure to bisphenols and phthalates with bone health in school-aged children. Methods: Among 1,362 mother-child pairs participating in a population-based cohort study, we measured maternal urinary concentrations of bisphenols and phthalates at first, second and third trimester with high performance liquid chromatography electrospray ionizatio

    Bisphenols

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    Bisphenols are a group of abundant environmental chemicals. Many bisphenol derivatives, including bisphenol A (BPA), are used to manufacture plastics, epoxy resins, and other products. Thus, human exposure to bisphenols is inevitable. BPA may cause reproductive, developmental, and systemic toxic effects and there are questions about its potential impact, particularly on children’s health and the environment. Due to these concerns, new alternatives are now being used; however, these alternatives also have a bisphenol chemical structure and may lead to toxicity in humans. This book focuses on the toxicity mechanisms, pathological conditions, detection methods, and regulations of bisphenol derivatives. It presents the latest findings on the toxic effects of BPA, diseases that may be related to bisphenol exposure, and the regulations of the US Food and Drug Administration, European Food Safety Authority, and European Union

    Poly(arylene ether)s containing pendent ethynyl groups

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    Poly(arylene ether)s containing pendent ethynyl and substituted ethynyl groups and poly(arylene ether) copolymers containing pendent ethynyl and substituted ethynyl groups are readily prepared from bisphenols containing ethynyl and substituted ethynyl groups. The resulting polymers are cured up to 350.degree. C. to provide crosslinked poly(arylene ether)s with good solvent resistance, high strength and modulus

    EPOXY POLYMERS BASED ON DIGLYCIDYL ETHERS WITH CYCLIC GROUPS

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    Glycidyl ethers of polycyclic bisphenols of norbornan type and their phenyl substituted derivatives were obtained and studied. They were solidified by diaminodiphenylsulphon and methyltetrahydrophthalic anhydride. The data of the termogravimetric analysis of the obtained polymers showed that they are characterizes by high thermal – and heat stability.The properties of polymers depend on the structure of the hardener and its chemical nature as well. The properties of polymers were sharply changed when glycidyl derivatives of bisphenols were cured by hardeners of different chemical structure. The presence of cyclic structures in the hardener molecule causes considerable increase of their thermal stability. Polymers on the basis of chlorine substituted glycidyl ethers of polycyclic bisphenols are characterized by incombustibility.Glycidyl ethers of polycyclic bisphenols of norbornan type and their phenyl substituted derivatives were obtained and studied. They were solidified by diaminodiphenylsulphon and methyltetrahydrophthalic anhydride. The data of the termogravimetric analysis of the obtained polymers showed that they are characterizes by high thermal – and heat stability.The properties of polymers depend on the structure of the hardener and its chemical nature as well. The properties of polymers were sharply changed when glycidyl derivatives of bisphenols were cured by hardeners of different chemical structure. The presence of cyclic structures in the hardener molecule causes considerable increase of their thermal stability. Polymers on the basis of chlorine substituted glycidyl ethers of polycyclic bisphenols are characterized by incombustibility

    Bacteriostatic conformal coating and methods of application Patent

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    Development of bacteriostatic conformal coating and methods of applicatio

    Presence of Parabens and Bisphenols in Food Commonly Consumed in Spain

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    Given the widespread use of bisphenols and parabens in consumer products, the assessment of their intake is crucial and represents the first step towards the assessment of the potential risks that these compounds may pose to human health. In the present study, a total of 98 samples of food items commonly consumed by the Spanish population were collected from different national supermarkets and grocery stores for the determination of parabens and bisphenols. Our analysis demonstrated that 56 of the 98 food samples contained detectable levels of parabens with limits of quantification (LOQ) between 0.4 and 0.9 ng g-1. The total concentration of parabens (sum of four parabens: ĂĄparabens) ranged from below the LOQ to 281.7 ng g-1, with a mean value of 73.86 ng g-1. A total of 52% of the samples showed detectable concentrations of bisphenols. Bisphenol A (BPA) was the most frequently detected bisphenol in the food samples analysed, followed by bisphenol S (BPS) and bisphenol E (BPE). Bisphenol AF (BPAF), bisphenol B (BPB) and bisphenol P (BPP) were not found in any of the analysed samples. LOQ for these bisphenols were between 0.4 and 4.0 ng g-1
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