• 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 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 $^{\circ}C$.

• 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.

• Environmental Analysis Health and Toxicology
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• v.21 no.4 s.55
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• pp.301-310
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• 2006

본 연구에서는 내분비계장애물질로 잘 알려진 Bisphenol A와 Ethynyl estradiol(이하 BPA, EE)이 Chironomus riparius에 미치는 영향을 알아보고자 하였다. 수생생태계에서 Chironomus의 생태학적 중요성을 고려하여 연구한 반수치사농도(LC50),효소 활성, 성장/발달 등의 생화학적, 생리학적 독성에 대한 연구는 이들 물질에 대한 잠재적인 생태학적 중요성을 이해하는데 있어 유용한 정보를 제공할 수 있을 것이다. 연구 결과 BPA와 EE에 노출된 후 C. riparius게서 CAT와 GST활성이 증가하였고, EE에 고농도로 노출된 후 성충까지 충분히 성장하지 못했음을 확인하였다 이러한 결과로부터 C. riparius에서 BPA, EE에 대한 중요한 독성정보를 얻을 수 있었다. 그러므로 앞으로 BPA와 EE의 생화학적 효과와 C. riparitis의 개체수준 이상에서의 생리학적 실험을 통한 검증이 필요할 것이다.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.1
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• pp.73-79
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• 2015

Connexins (Cx) are membrane proteins and monomers for forming gap junction (GJ) channels. Cx46 and Cx50 are also known to function as conductive hemichannels. As part of an ongoing effort to find GJ-specific blocker(s), endocrine disruptors were used to examine their effect on Cx46 hemichannels expressed in Xenopus oocytes. Voltage-dependent gating of Cx46 hemichannels was characterized by slowly activating outward currents and relatively fast inward tail currents. Bisphenol A (BPA, 10 nM) reduced outward currents of Cx46 hemichannels up to ~18% of control, and its effect was reversible (n=5). 4-tert-Octylphenol (OP, $1{\mu}M$) reversibly reduced outward hemichannel currents up to ~28% (n=4). However, overall shapes of Cx46 hemichannel current traces (outward and inward currents) were not changed by these drugs. These results suggest that BPA and OP are likely to occupy the pore of Cx46 hemichannels and thus obstruct the ionic fluxes. This finding provides that BPA and OP are potential candidates for GJ channel blockers.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.135-135
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• 2003

Bisphenol A (BPA) mimics estrogen and its activity is one third to one quarter that of estradiol. BPA, an ubiquitous environmental contaminent has been shown to cause development reproductive toxicity and carcinogenic effect. BPA may do physiological action through ER${\alpha}$ and ER${\beta}$ which are expressed in central nerve system.(omitted)

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.19-26
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• 2017

The cure properties of ethoxysilyl bisphenol A type epoxy resin (Ethoxysilyl-DGEBA) systems with different hardeners were investigated, comparing with DGEBA and Diallyl-DGEBA epoxy resin systems. The cure kinetics of these systems were analyzed by differential scanning calorimetry with an isothermal approach, and the kinetic parameters of all systems were reported in generalized kinetic equations with diffusion effects. The Ethoxysilyl-DGEBA epoxy resin system showed lower cure conversion rates than DGEBA and Diallyl-DGEBA epoxy resin systems. The conversion rates of these epoxy resin systems with DDM hardener are lower than those with HF-1M hardener. It can be considered that the optimum hardener for Ethoxysilyl-DGEBA epoxy resin system is Phenol Novolac type. These lower cure conversion rates in the Ethoxysilyl-DGEBA epoxy resin systems could be explained by the retardation of reaction molecule movements according to the formation of organic-inorganic hybrid network structure by epoxy and ethoxysilyl group in Ethoxysilyl- DGEBA epoxy resin system.

• Journal of Mushroom
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• v.17 no.4
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• pp.247-254
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• 2019

Trametes hirsuta, a white rot fungus, exhibits the ability to degrade synthetic aromatic dyes such as congo red (CR), methylene blue (MB), crystal violet (CV), and remazol brilliant blue R (RBBR). The mycelia of T. hirsuta degraded RBBR and CR more efficiently than CV and MB in the PDB liquid medium (supplemented with 0.01% 4 aromatic dyes). In these mycelia the activities of three ligninolytic enzymes-laccase, manganese peroxidase (MnP), and lignin peroxidase (LiP)-were observed. Among these, laccase was identified to be the major enzyme responsible for the degradation of the four aromatic dyes. The degradation of bisphenol A was also investigated by culturing the mycelia of T. hirsuta in YMG medium supplemented with 100 ppm bisphenol A. The mycelia of T. hirsuta were found to degrade bisphenol A by 71.3, 95.3, and 100 % within incubation periods of 12, 24, and 36 hr, respectively. These mycelia also showed ligninolytic enzyme-like activities including those similar to laccase, MnP, and LiP. Therefore, these results indicate that T. hirsuta could emerge as a potential tool for the remediation of environmental contamination by aromatic dyes and bisphenol A.