• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.345-345
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• 2011

최근 대기압 플라즈마 젯을 이용한 바이오/메디컬의 활발한 응용연구가 진행 중이다. 박테리아 및 세균의 살균은 물론 암세포 세포예정사에 핵심적인 역할을 하는 활성산소종(Reactive Oxygen Species, ROS) 또는 다양한 라디칼들은 대기압 플라즈마의 다양한 변수를 이용하여 조절할 수 있다고 알려져 있다. 수십 kHz의 고전압에서 발생된 마이크로 헬륨 플라즈마 젯에서 질소종의 제어를 통해 같은 부피의 플라즈마 젯에서의 방출광을 살펴보았다. 또한 광섬유센서를 이용하여 플라즈마의 기체온도를 측정하고 Boltzmann plot method를 통해 전자의 여기온도 변화를 관찰하였다. 실험의 결과, 같은 부피의 플라즈마에서 질소종이 증가할 때 기체온도는 큰 변함이 없지만 여기온도가 증가하는 것을 관찰하였다. 시간분해 이미지 촬영으로 질소종의 양에 따른 플라즈마 불릿의 속도 변화를 분석을 하였고, 최종적으로 대기압 플라즈마 젯의 질소종 변화에 따른 대장균의 비활성화 정도를 관찰하였다.

• Development and Reproduction
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• v.15 no.2
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• pp.159-166
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• 2011

Simazine (6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine) is a triazine herbicide that has been applied worldwide including Korea for agricultural purposes. Simazine is the second most commonly detected pesticide in surfaceand ground-water in the United States, Europe and Australia. It has been shown that simazine is a potent endocrine disruptor in wildlife and laboratory animals. Although many endocrine disruptors can induce apoptosis in various types of cells, the effects of simazine on apoptosis and on the expression of Bcl-2 family genes are not known. Also it is unknown the effect of simazine on the expression of steroidogenesis-regulating genes in testicular cells. In this study, we investigated the effect of simazine on the expression levels of apoptosis- and steroidogenesis-regulating genes in testicular cells. We found that a low concentration of simazine can alter the mRNA expression levels of steroidogenesis-related genes and Bcl-2 family genes in mouse Sertoli cells and rat Leydig cells. Thus, our results suggest that simazine can disturb normal testicular development and reproductive function by altering the expression of genes that are critical for the regulation of apoptosis and steroidogenesis.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.111-118
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• 2015

Probiotic, prebiotic, and synbiotic substances as well as microorganisms were added to infant formula in an attempt to influence the intestinal microflora with an aim to stimulate the growth of lactic acid bacteria, especially bifidobacteria and lactobacilli. Over the last 10 years, new synbiotic infant formulas containing probiotics and prebiotics have been proposed in order to simulate the effect of breast-feeding on the intestinal microflora. Owing to their synergistic effect, the new synbiotics are expected to be more helpful than using probiotics and prebiotics individually. Maintenance of the viability of the probiotics during food processing and the passage through the gastrointestinal tract should be the most important consideration, since a sufficient number of bacteria ($10^8cfu/g$) should reach the intended location to have a positive effect on the host. Storage conditions and the processing technology used for the manufacture of products such as infant formula adversely affect the viability of the probiotics. When an appropriate and cost-effective microencapsulation methodology using the generally recognized as safe (GRAS) status and substances with high biological value are developed, the quality of infant formulas would improve. The effect of probiotics may be called a double-effect, where one is an immunomodulatory effect, induced by live probiotics that advantageously alter the gastrointestinal microflora, and the other comprises anti-inflammatory responses elicited by dead cells. At present, a new terminology is required to define the dead microorganisms or crude microbial fractions that positively affect health. The term "paraprobiotics" (or ghost probiotics) has been proposed to define dead microbial cells (not damaged or broken) or crude cell extracts (i.e., cell extracts with complex chemical composition) that are beneficial to humans and animals when a sufficient amount is orally or topically administered. The fecal microflora of bottle-fed infants is altered when the milk-based infant formula is supplemented with probiotics or prebiotics. Thus, by increasing the proportion of beneficial bacteria such as bifidobacteria and lactobacilli, prebiotics modify the fecal microbial composition and accordingly regulate the activity of the immune system. Therefore, considerable attention has been focused on the improvement of infant formula quality such that its beneficial effects are comparable to those of human milk, using prebiotics such as inulin and oligosaccharides and potential specific probiotics such as bifidobacteria, which selectively stimulate the proliferation of beneficial bacteria in the microflora and the indigenous intestinal metabolic activity of the microflora.