• Analytical Science and Technology
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• v.21 no.5
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• pp.375-382
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• 2008

Bisphenol A (BPA) and di-2-ethyhexyl phthalate (DEHP) is the considerably hazardous materials, endocrine disrupting chemicals (EDCs), which is accumulated to the human's fat and tissue. We studied the relationship between the concentrations of BPA and DEHP in the precocious puberty and the normal controls using GC/MSD. BPA concentrations of the precocious puberty are lower than that of normal controls. But DEHP concentrations of the precocious puberty are higher than that of normal controls. From these results, BPA is not related to the precocious puberty. Otherwise, DEHP is somewhat related to the precocious puberty and the concentrations of the precocious puberty are approximately 45% higher than that of normal controls.

• Biomolecules & Therapeutics
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• v.18 no.2
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• pp.125-134
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• 2010

Bisphenol A (BPA) is one of the most common endocrine disrupters. In the last decade, the number of studies concerning the effects of chronic treatment with BPA on the development of the central nervous system (CNS) has increased. However, little is known about the effects of chronic exposure to BPA on higher brain functions such as memory or psychomotor functions. Here, we report our following findings: (1) Prenatal and neonatal exposure to BPA enhances psychostimulant-induced rewarding effects, results in the up- or downregulation of dopamine receptors, causes memory impairment, and decreases choline acetyltransferase (ChAT) activity. (2) BPA activates astrocytes in vivo and in vitro. These findings suggest that prenatal and neonatal exposure to BPA affects the development of the CNS.

• Journal of Environmental Health Sciences
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• v.30 no.1
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• pp.59-64
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• 2004

This study was carried out to investigate influencing factors of bisphenol A(BPA) removal characteristic in conventional water treatment systems to be connected with coagulation, sedimentation, filtration and disinfection. The result are summarized as follows; In BPA removal, optimal doses of PAC, alum, ferric chloride were 7.5 mg Al/L, 10.0 mg AI/L, 15.0 mg Fek. PAC was most effective coagulant to remove BPA. In coagulation process, BPA removal efficiency were increased about 2％ by adjusting pH of raw water as 6. At temperature rise 1$0^{\circ}C$, BPA removal efficiency were increased 0.94％. but BPA removal efficiency in sand filtration process were under 1 ％ie, so that BPA was almost not removed. At free chlorine dose 1, 2 mg/L, the reaction rate constant k in the BPA removal have been calculated to be 0.397, 0.953 min$^{-1}$ . At free chlorine dose 1, 2 mg/1-, degradation reaction of BPA was completed during 10 min and BFA removal efficiencies were 97.66, 99.99％ at this time.

• Journal of fish pathology
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• v.19 no.3
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• pp.189-195
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• 2006

A subtracted cDNA library of a marine scuticociliate, Philasterides dicentrarchii, in response to 17β-estradiol exposure was constructed using suppression subtractive hybridization (SSH). As a result of SSH, 275 clones were isolated, and among them, only glutathione peroxidase (GPX) gene was isolated as an antioxidative enzyme responding to 17β-estradiol. The semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis revealed that the transcription of GPX gene of P. dicentrarchii was clearly increased by exposure to 17β-estradiol. The GPX transcription was also clearly increased by exposure to xenoestrogens such as bisphenol A (BPA) and genistein.

• Journal of the Korean Applied Science and Technology
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• v.24 no.3
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• pp.309-318
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• 2007

Novolac is widely used as the primary solid component of most photoresists in semiconductor and microelectronic devices. In this study, novolac resins were prepared by condensation of 35% formaldehyde with phenolic compounds such as m-/p-cresol, 2,5-dimethylphenol and bisphenol A in the presence of oxalic acid as catalyst. The average molecular weight $(M_w)$ of these novolac resins has been varied on the changing of mixing ratio of m-/p-cresol/2,5-dimethylphenol/bisphenol A or formaldehyde/phenolic compound. Also, thermal properties of novolac were observed by TGA.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2560-2564
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• 2011

Mesoporous silicon dioxide (meso-$SiO_2$) was prepared using cetyltrimethylammonium bromide as the structure-directing reagent and tetraethyl orthosicate as the silicon source. The influence of pH value on the adsorption behavior of bisphenol A (BPA) was investigated. The adsorption capacity of BPA onto meso-$SiO_2$ increases slightly with pH value from 2 to 6, and then gradually decreases as further improving pH value. The effect of temperature was also studied, and the adsorption capacity of BPA gradually declines with increasing temperature. The adsorption kinetics and thermodynamics of BPA were examined. It is found that the adsorption of BPA onto meso-$SiO_2$ is in good agreement with Langmuir adsorption model. The rate constant of adsorption is $5.17{\times}10^{-3}g\;mg^{-1}\;min^{-1}$, and the maximum adsorption capacity is as high as 353.4 $mg\;g^{-1}$ at 20 $^{\circ}C$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.22-23
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• 2017

The purpose of this study is to ascertain self-healing function on microcracks in bisphenol F-type epoxy-modified mortars using expansive admixtures. The specimens are prepared with various polymer-binder ratios of 0, 5, 10, 20%, expansive admixture contents of 0% and 10%, a sodium carbonate content of 0.25%, and subjected to exposure conditions of CR1, CR2, CR3 and CR4. The specimens are tested for self-healing effect, porosity and FE-SEM analysis. As a result, self-healing effects of bisphenol F-type EPMMs with expansive admixtures are visible in all of the outdoor exposure conditions. In particular, exposure conditions of CR3 and CR4 are most noticeable. And the porosity of EPMMs is reduced with an increase in the polymer-binder ratio, and is considerably smaller than that of unmodified mortar.

• Analytical Science and Technology
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• v.30 no.1
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• pp.20-25
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• 2017

An analytical method for determining potential endocrine disruptors (bisphenol A, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, p-t-butylphenol, p-pentylphenol, p-hexylphenol, p-t-octylphenol, p-heptylphenol, nonylphenol) by solid-phase extraction (SPE) and High Perfomance Liquid Chromatography(HPLC) equipped with fluorescence and variable wavelength detector has been developed. The SPE process for sample concentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of elution solvent and elution volume on the recoveries of the analytes were investigated with HPLC. Average recovery of >85% was achieved with 60mg sorbents using 5mL of methanol as elution solvent. Phenolic compounds in canned drinks, beverages and water samples were surveyed by this proposed method.

• Textile Coloration and Finishing
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• v.9 no.2
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• pp.17-24
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• 1997

PET/PHE blends were prepared by the mixing of poly(ethylene terephthalate) and poly(hydroxyether of bisphenol A) at melt state above PET melting temperature and modified PET fibers having less than 5 wt% of PHE were also prepared by the melt spinning of the PET/PHE blends. The PET/PHE blends were able to prepare by means of physical mixing concept, except the chemical interaction between hydroxyl groups of PHE and ester groups of PET. It has been revealed that the modified PET fibers have some hydrophilic properties such as low contact angle and easy-dyeable characters.

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.275-280
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• 2005

Development of the fourth-instar larvae of Chironomus riparius has a sensitive to ecdysteroid hormones. The 2D/E gel analysis for polypeptide expression reflecting early-ecdysterone inducible gene has conducted the emerged female from larval phase exposure to bisphenol A (BPA). In the 2D/E gel 1108 protein spots were identified. The visualized protein spots allowed extraction of 17 protein spots differed more than 3 fold in BPA treated animals, which was approximately $1.6\%$ of the total protein spots. However, polypeptide expression reflecting early-ecdysterone inducible gene didn't change after treatments. In addition, detection for the damages or changes in mitogenome level was observed. The conserved cytochrome oxidase I in DNA level affected exposure to BPA $(1{\mu}gL^{-1})$ in this preliminary study.