• 한국환경보건학회지
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• 제47권1호
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• pp.1-19
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• 2021

Objectives: Phthalates, which are widely used as plasticizers, have been recognized as endocrine disruptors. In the present study, we provided information on the regulation of these chemicals and summarized the information available on their detection and toxicity in children's products and those of their alternatives. Methods: The regulatory frameworks related to phthalates in children's products in Korea, the United States (US), and the European Union (EU) were compared. Data on the detection concentration of 16 phthalates and seven phthalate alternatives that could be used in polyvinyl chloride (PVC) plastic products for children as well as on their toxicity classification and endocrine disruption toxicity were collected from the literature. Results: Korea adopted US and EU chemical standards for six phthalates (DEHP, BBP, DBP, DINP, DIDP, and DNOP), but not others (e.g., DIBP, DPP, DHP, and DCHP). Among the ten phthalates and seven substitutes for which regulatory standards were not determined, DIBP, DHP, DEHA, DIBA, DINA, and DEHT were detected in children's products made from PVC plastic. DIBP and DHP, which have a reproductive toxicity classification of 1B, were frequently detected in PVC toys. The reproductive toxicity, estrogenicity, and anti-androgenic activity of the unregulated phthalates and their alternatives have been reported in diverse in vitro and in vivo assays. Conclusion: The use of unregulated phthalates and their substitutes in children's products is increasing. Further monitoring and toxicological information on phthalate alternatives is required to develop proper management plans.

• 한국농공학회논문집
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• 제64권2호
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• pp.37-45
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• 2022

In-situ pilot experiment was carried out to establish a countermeasure on the soil loss from the hill side uplands that was rehabilitated by soil remediation method nearby abandoned mine sites for 2 years. It was considered that the affect of an inclination of cover surface, a stabilization treatment of cover layer by lime and steel refining slag (SRS) and a vegetation of soil surface as an effect factors in the experiment. It was constructed 4 lysimeters (plots, 22 m long, 4 m width) on the hilly side (37% inclination). One plot was control and two plots was treated by 1% lime and SRS. A remind one plot was modified a inclination to 27% to compare the affect of inclination on the amount of cover soil loss. It was attached a reservior tank and water level gauge in the end of lysimeters to measure the amount of the surface water flow and soil loss. It was also installed the automated sensors that could be collect the precipitation, soil moisture content, tension of cover layer in each plots. It was observed that the event of precipitation were caused the soil loss and it were related the physical and chemical properties of cover soil and inclination of surface layer of plots. During the experiment, it was exceeded the national regulation (50 t/ha/yr) in 37% inclination plots even though it was vegetated on the cover soil surface. However, in 27% inclination plot, it was shown that the amount of soil loss was maintained below the national regulation and, more ever, vegetation could reduce the the amount of soil loss. Therefore it was expected that such results could be applied to the future design of rehabilitation projects on the polluted farmland nearby abandoned mine sites.

• 분석과학
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• 제21권3호
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• pp.201-211
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• 2008

본 연구에서는 PCBs 함유 폐기물의 분해 전후의 처리효율을 검토하고 반응 부산물을 확인하고자 물리화학적 처리기술을 적용한 전자빔과 탈염소화 처리 전후의 시료를 분석하였다. 전자빔으로 물리적 처리를 한 시료는 절연유 중의 PCBs 피크패턴을 유지하고 있지 않아 폐기물공정시험방법으로 정량하기 어려워 HRGC/HRMS을 이용하여 정량한 결과, PCBs의 제품이 가지고 있는 피크패턴이 분해되어 저염화물인 3-chlorobiphenyls이 생성되는 것으로 확인 되었다. 또한, 탈염소화 분해로 화학적 처리한 경우에도 PCBs 농도는 폐기물관리법 및 잔류성유기물질 관리법의 규제기준 이하로 POPs 관리법의 처리 종료 기준을 만족하는 것으로 나타났으며, PCBs 함유 폐기물을 물리화학적으로 처리하는 과정 중 분석 대상 모든 시료에서 다이옥신류가 불검출되어 다이옥신은 생성되지 않는 것으로 나타났다.

• Animal Bioscience
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• 제37권2_spc호
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• pp.337-345
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• 2024

Ruminants possess a specialized four-compartment forestomach, consisting of the reticulum, rumen, omasum, and abomasum. The rumen, the primary fermentative chamber, harbours a dynamic ecosystem comprising bacteria, protozoa, fungi, archaea, and bacteriophages. These microorganisms engage in diverse ecological interactions within the rumen microbiome, primarily benefiting the host animal by deriving energy from plant material breakdown. These interactions encompass symbiosis, such as mutualism and commensalism, as well as parasitism, predation, and competition. These ecological interactions are dependent on many factors, including the production of diverse molecules, such as those involved in quorum sensing (QS). QS is a density-dependent signalling mechanism involving the release of autoinducer (AIs) compounds, when cell density increases AIs bind to receptors causing the altered expression of certain genes. These AIs are classified as mainly being N-acyl-homoserine lactones (AHL; commonly used by Gram-negative bacteria) or autoinducer-2 based systems (AI-2; used by Gram-positive and Gram-negative bacteria); although other less common AI systems exist. Most of our understanding of QS at a gene-level comes from pure culture in vitro studies using bacterial pathogens, with much being unknown on a commensal bacterial and ecosystem level, especially in the context of the rumen microbiome. A small number of studies have explored QS in the rumen using 'omic' technologies, revealing a prevalence of AI-2 QS systems among rumen bacteria. Nevertheless, the implications of these signalling systems on gene regulation, rumen ecology, and ruminant characteristics are largely uncharted territory. Metatranscriptome data tracking the colonization of perennial ryegrass by rumen microbes suggest that these chemicals may influence transitions in bacterial diversity during colonization. The likelihood of undiscovered chemicals within the rumen microbial arsenal is high, with the identified chemicals representing only the tip of the iceberg. A comprehensive grasp of rumen microbial chemical signalling is crucial for addressing the challenges of food security and climate targets.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권5호
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• pp.432-443
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• 2005

Microarray technology has contributed Significantly to the understanding of bacterial genetics and transcriptional regulation. One neglected aspect of this technology has been optimization of microarray-generated signals and quality of generated information. Full genome microarrays were developed for Clostridium acetobutylicum through spotting of PCR products that were designed with minimal homology with all other genes within the genome. Using statistical analyses it is demonstrated that Signal quality is significantly improved by increasing the hybridization volume. possibly increasing the effective number of transcripts available to bind to a given spot, while changes in labeled probe amounts were found to be less sensitive to improving signal quality. In addition to Q-RT-PCR, array validation was tested by examining the transcriptional program of a mutant (M5) strain lacking the pSOL1 178-gene megaplasmid relative to the wildtype (WT) strain. Under optimal conditions, it is demonstrated that the fraction of false positive genes is 1% when considering differentially expressed genes and 7% when considering all genes with signal above background. To enhance genomic-scale understanding of organismal physiology, using data from these microarrays we estimated that $40{\sim}55%$ of the C. acetobutylicum genome is expressed at any time during batch culture, similar to estimates made for Bacillus subtilis.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권7호
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• pp.18-24
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• 2013

The influences of various operating parameters on physico-chemical techniques were evaluated to remediate petroleum-contaminated sandy soil including S/L ratio, kinetic, and effect of soil particle size. The simple extraction using tap water removed only 20.6% of total petroleum hydrocarbon (TPH), and addition of NaOH enhanced the removal of TPH to approximately 30%. To meet the regulation levels, a surfactant, sodium dodecyl sulfate, was added, and the removal of TPH increased to 4 times. Probably, the carbonate minerals affected chemical aging and soprtion of petroleum, which inhibited the extraction of TPH. The soil with smaller particle size contained more TPH, and the removal of TPH was obstructed with smaller particle size. However, NaOH addition increased the removal of TPH in the smaller particles. The physico-chemical properties of soil influenced greatly the removal of petroleum even in sandy soil.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제19권4호
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• pp.221-228
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• 2016

The gastrointestinal exposome represents the integration of all xenobiotic components and host-derived endogenous components affecting the host health, disease progression and ultimately clinical outcomes during the lifespan. The human gut microbiome as a dynamic exposome of commensalism continuously interacts with other exogenous exposome as well as host sentineling components including the immune and neuroendocrine circuit. The composition and diversity of the microbiome are established on the basis of the luminal environment (physical, chemical and biological exposome) and host surveillance at each part of the gastrointestinal lining. Whereas the chemical exposome derived from nutrients and other xenobiotics can influence the dynamics of microbiome community (the stability, diversity, or resilience), the microbiomes reciprocally alter the bioavailability and activities of the chemical exposome in the mucosa. In particular, xenobiotic metabolites by the gut microbial enzymes can be either beneficial or detrimental to the host health although xenobiotics can alter the composition and diversity of the gut microbiome. The integration of the mucosal crosstalk in the exposome determines the fate of microbiome community and host response to the etiologic factors of disease. Therefore, the network between microbiome and other mucosal exposome would provide new insights into the clinical intervention against the mucosal or systemic disorders via regulation of the gut-associated immunological, metabolic, or neuroendocrine system.

• 한국물환경학회지
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• 제20권1호
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• pp.37-41
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• 2004

This paper was studied about the characteristics of treatment by ionized gas for livestock wastewater, aiming at the effects of ionized gas on organic matter, hydrophobic and hydrophilic organic matter in livestock wastewater when the new process of advanced oxidation process was applied for meeting the improved the quality of effluent. The organic matter within treated livestock wastewater by ionized gas was partially mineralized according to the time increasement. The $TCOD_{Mn}$ in the livestock wastewater was decreased from 840mg/L to 340mg/L when treated by ionized gas by the enhancement of time. We occupied the equations of $TCOD_{Cr}$, $SCOD_{Cr}$, $TCOD_{Mn}$ and $SCOD_{Mn}$ as to ionized gas treated time. As $TCOD_{Mn}$ increasing ionized gas treated time, the concentration did not meet the water quality, $COD_{Mn}$ 4Omg/L. So, for removing of the remaining organic matter in the efflent after ionized gas, following process is necessary. After treating the livestock wastewater by ionized gas, coagulation was considerable for organic matter removal up to regulation water quality. From UV scans of the treated livestock wastewater by ionized gas, the wastewater has low aromaticity and good colour.

• 대한의생명과학회지
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• 제24권1호
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• pp.50-54
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• 2018

N-nitroso-N-methylurea (NMU) and N-nitroso-N-ethylurea (NEU), direct alkylating chemical mutagens and carcinogens, are shown to be the upregulators of cellular $NF-{\kappa}B$, regulating various genes that mediate tumorigenesis and carcinogenesis. Nitric oxide (NO), a toxic reactive radical gas, has been known to induce programmed cell death or apoptosis in various cells. Therefore, the assessment of NO production was examined to elucidate the possible contribution of NO release to the chemical carcinogenic potency of NMU and NEU in human skin cells. NMU and NEU did not alter the NO production, but they caused a significant downregulation of the NO generation on lipopolysaccharide (LPS)-induced NO production at concentrations ranging from $2{\sim}5{\mu}M$. The degree of downregulation of NO by NMU and NEU decreased up to 15% and 20%, respectively, compared to the control. These results demonstrate that the LPS-inducible keratinocytes NO synthase is involved in modulating carcinogenic potency by NMU and NEU, and the regulation of the cellular $NF-{\kappa}B$ activity by NMU and NEU is negatively correlated with the level of LPS-induced NO production in human skin cells. The findings of this study suggest the hypothesis that NMU and NEU-induced carcinogenesis may be associated with the downregulation of NO production, and the inducible NO may play an important role in NMU and NEU-induced carcinogenicity in human epidermal keratinocytes.

• Biomolecules & Therapeutics
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• 제22권4호
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• pp.341-346
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• 2014

Paeonol is a major phenolic micromolecular component of Moutan cortex Radicis, a traditional Chinese Medicine. It has shown antitumor effects in previous studies; however, the underlying mechanisms remain unknown. This study investigated the mechanism by giving treatments of placebo, cyclophosphamide, paeonol of 150 and 300 mg/kg to 4 groups of mice bearing EMT6 breast cancer. Apoptosis in tumor cells were confirmed by morphology analysis, including hematoxylin, eosin staining and TUNEL staining. The results showed that the weight of EMT6 breast tumor was significantly reduced in the groups treated with both 150 and 300 mg/kg of paeonol. Immunohistochemical and Western blot results showed that the expression of Bcl-2 was down-regulated while the expression of Bax, caspase 8 and caspase 3 was up-regulated respectively. These results suggest that paeonol exhibits antitumor effects and the mechanism of the inhibition is via induction of apoptosis, regulation of Bcl-2 and Bax expression, and activation of caspase 8 and caspase 3.