• 정보관리연구
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• 제7권4호
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• pp.103-114
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• 1974

• 대한의생명과학회지
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• 제28권1호
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• pp.50-57
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• 2022

In this study, we tried to examine the possibility of developing a dental product such as tooth decay prevention and oral hygiene by manufacturing a natural polymer film for oral use. Natural polymer films were prepared from shark byproduct extract (SBE) and gellan gum (GG). As an antibacterial substance, the antibacterial activity of green tea extract against tooth decay-causing bacteria was measured. An film was prepared by adding green tea extract to the composition of SBE and GG. The mechanical, solubility, moisture content and antibacterial function of the prepared film were investigated in detail. Also, the incorporation of GTE into the SBE/GG film improved the physical performance of the film. Increasing the content of GTE improved the antioxidant and antibacterial properties of the film. Formulation of antimicrobial SBE/GG film containing green tea extract was established and these results evidently showed potential for cavity prevention products application.

• 한국유체기계학회 논문집
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• 제9권5호
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• pp.60-63
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• 2006

• 한국식품저장유통학회지
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• 제8권2호
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• pp.206-212
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• 2001

Water extract of green tea(GTW) and 70% ethanol extract of green tea(GTE) were prepared for the test of antibacterial activity. The sensitivity of Staphylococcus aureus and Salmonella typhimurium to the green tea extracts in various pH of culture broth was tested. Tryptic soy broth(TSB) containing 0∼2%(w/v) of green tea extracts was adjusted to pH 5.0∼7.0 and inoculated with 10$\^$5/∼10$\^$6/ cells/ml of each bacteria. The plate counting method and clear zone test were used to determine inhibitory effect of green tea extracts. Green tea extracts completely inhibited the growth of S. aureus at 0.5% level and bactercidal at 0.5∼1.0% level of GTW and GTE at pH 5.0∼7.0. Green tea extracts were bactercidal to S. typhimurium at 1.5∼2.0% level of GTW and 1.0∼2.0% level of GTE at pH 7.0. Sal. typhimurium was more resistant than S. aureus. in same concentration of green tea extracts at same pH. The resistance of S. aureus and Sal. typhimurium was increased with decreasing pH of culture broth. The morphology of S. aureus cells treated with green tea extracts showed damage of cell wall and cytoplasmic membrane. Severely damaged cells of S. aureus lost electron dense material and cytoplasm. Green tea extracts stimulated autolysis and cell death of S. aureus. This result suggests that green tea extracts can be used as an effective natural antibacterial agent in food.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.281-286
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• 2000

2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD), a ubiquitous environmental contaminant, causes a variety of adverse effects on the male reproductive system in rats. The effect of green tea extract (GTE) was investigated on the testicular function in Spragure-Dawley rats after a single exposure of 10$\mu\textrm{g}$ TCDD/kg body weight. The exposure of rat to TCDD significantly increased the weights of the epididymis and ventral prostate, yet significantly decresed the weight of the seminal vesicle when compared to the controls (p<0.05). In a combined treatment of TCDD with GTE, the organ weight changes caused by TCDD treatment disappeared. Significant decreases in sperm motility and sperm numbers were observed in the TCDD-treated rats, when compared to the control (p<0.05). GTE treatment reversed the decrease of sperm motility and sperm numbers caused by TCDD. There were no differences in sperm morphology, histological changes of the reproductive organs, and spermatogenesis between all the treated groups. In the ventral prostate and seminal vesicle, TCDD increased the CYP1A1 mRNA level, however, it did not affect the estrogen receptor $\beta$ (ER-$\beta$) mRNA level. GTE treatment did not influence the effect of TCDD on the levels of CYP1A1 and Er-$\beta$ mRNA. These results seem to indicate that green tea protects the testicular function against TCDD-induced reproductive toxicity, not because of a receptor-mediated mechanism but rather due to a secondary change of testes or accessory sex organs.

• 한국식품과학회지
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• 제31권3호
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• pp.823-830
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• 1999

배양 CHO cell에 SCE법을 이용하여 실제로 음용하는 조건에서 추출한 시판 감잎차, 녹차, 우롱차 추출물의 돌연변이 억제효과를 보기 위하여 실험하였다. 돌연변이 물질로 사용한 MMC에 의하여 유발된 SCE 빈도에 미치는 각 차 추출물의 돌연변이 억제 효과를 본 결과, 감잎차는 MMC 처리 후 S9 mix와 함께 고농도$(1000\;{\mu}g/mL)$로 세포에 처리되었을 때 SCE 빈도를 유의하게 감소시켰다. S9 mix 없이 감잎차 추출물만을 후처리한 경우는 저농도$(20{\sim}80\;{\mu}g/mL)$에서 SCE 유발빈도를 유의하게 감소시켰다. 우롱차는 MMC처리 후 S9 mix와 함께 저농도$(10{\sim}20\;{\mu}g/mL)$로 처리 시 SCE 유발빈도를 감소시키는 효과가 있었으며, 녹차는 MMC 처리 후 S9 mix와 함께 추출물 농도 $160\;{\mu}g/mL$로 처리 시 SCE 유발빈도를 감소시키는 효과가 있었다. 감잎차, 녹차, 우롱차 모두 농도는 다르나 각 추출물을 S9 mix와 함께 세포분열 주기 중 G1기에 후 처리 되었을 때에 SCE 빈도를 감소시키는 효과가 있었으며, 감잎차는 S9 mix 없이 단독으로 후처리 되었을 때에도 용량 상관성은 없지만 SCE 빈도를 감소시키는 효과가 있었다. 결론적으로, 시판 감잎차, 녹차, 우롱차 추출물에는 MMC로 유발된 돌연변이를 억제시키는 효과가 있는 것을 확인할 수 있었으며, 감잎차의 경우 S9 mix 없이도 SCE 빈도를 감소시키는 효과가 있었던 것으로 보아 다른 두 차와는 다른 기전의 돌연변이 억제 작용을 하는 성분이 있는 것으로 사료된다.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.115-115
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• 2001

Regular green tea consumption has been associated with a reduced risk of cancer, partly via antioxidant effects of green tea in protecting cellular components against free radical. In the present study, we evaluated the effect of green tea extract (GTE) on oxidative damage to DNA in CHL cells.(omitted)

• Applied Microscopy
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• 제21권1호
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• pp.108-120
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• 1991

Principles of electron diffraction patterns in transmission electron microscope are described for beginners in terms of reciprocal lattices and Ewald sphere. Analysis of both ring patterns and spot patterns are illustrated with practical examples as well as basic calibrations of TEM. Especially convergent beam electron diffraction method is emphasized for the determination of lattice parameters, microstrains, and thickness of thin foil followed by a review of microcomputer programs for the electron diffraction analyses explained in this paper.

• 한국수정란이식학회지
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• 제32권4호
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• pp.337-342
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• 2017

The present study was aimed to determine the effects of green tea extract (GTE) and beta-mercaptoethanol (${\beta}-ME$) supplementation in boar sperm freezing extender on in vitro fertilization (IVF) and reactive oxygen species (ROS) and glutathione (GSH) levels of presumptive zygotes (PZs). Experimental groups were allocated into lactose egg yolk (LEY) without antioxidant (control), GTE (1,000 mg/l in LEY) and ${\beta}-ME$ ($50{\mu}M$ in LEY). In freezing, spermatozoa extended with LEY were cooled to $5^{\circ}C$ for 3 h and then kept at $5^{\circ}C$ for 30 min following dilution with LEY containing 9% glycerol and 1.5% Equex STM. The final sperm concentration was $1{\times}10^8/ml$. Spermatozoa were loaded into straws and frozen in nitrogen vapor for 20 min. For IVF, oocytes were matured in NCSU-23 medium and co-cultured with spermatozoa following thawing at $37^{\circ}C$ for 25 sec. At 12 h following IVF, IVF parameters (sperm penetration and monospermy) were evaluated. In addition, GSH and ROS levels of PZs were determined by Cell Tracker Blue CMF2HC and DCHFDA, respectively. IVF parameters did not show any significant difference among the experimental groups. GSH and ROS levels of PZs were not significantly different between groups. In conclusion, antioxidant supplementation in boar sperm freezing could not influence IVF parameters, ROS and GSH levels of PZs.

• 대한한방내과학회지
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• 제45권1호
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• pp.55-74
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• 2024

Objectives: This study reviewed the status of adverse event (AE) reporting in VigiAccess using anti-obesity agents as examples and explored the possibility of its use and future challenges. Methods: AE reports related to some representative drugs among herbal medicines (HMs), complex HM prescriptions, ingredients of supplements, and over-the-counter and prescription medicines were investigated using VigiAccess on February 1, 2024. Results: AE reports on prescription drugs were overwhelmingly higher than those on HMs or supplements. Although most reports were submitted from North America, reports on Ephedra sinica and green tea extract (GTE) were more from Asia and Europe, respectively. The female population reported more, and the difference in the sex ratio was the smallest for Ephedra spp. The age group was concentrated on young adults, but many older patients reported GLP-1 receptor agonist-related AEs. Symptoms related to the gastrointestinal and nervous systems were most commonly reported, but mental and cardiac disorders were common in Ephedra-type HMs. Hepatobiliary disorders are also commonly found in GTE-related reports. Conclusions: VigiAccess was useful for easily checking the global status of AE reporting for prescription drugs. However, several limitations were observed in using VigiAccess for HMs because of the few reports. Thus, it is necessary to increase the number of reports by education and to promote AE reporting among HM prescribers and users. The full range of HMs should be included in the pharmacovigilance system, and the coding and classification of HMs should be revised.