• Title/Summary/Keyword: Biological Engineering

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Developing a Testing Method for Antimicrobial Efficacy on TiO2 Photocatalytic Products

  • Kim, Jee-Yeon;Park, Chang-Hun;Yoon, Je-Yong
    • Environmental Engineering Research
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    • v.13 no.3
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    • pp.136-140
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    • 2008
  • $TiO_2$ photocatalyst has been known to exhibit a notable disinfecting activity against a broad spectrum of microorganisms. A lot of commercial $TiO_2$ photocatalyst products have been developed for antimicrobial purposes. However, a standard method has not yet been proposed for use in testing antimicrobial activity. In this study, we developed a $TiO_2$ photocatalytic adhesion test method with film as the standard testing method for the evaluation of antimicrobial activity. This method was devised by modifying the previous antimicrobial products test method, which has been widely used, and considering the characteristics of $TiO_2$ photocatalytic reaction. The apparatus for testing the antimicrobial activity was composed of a Black Light Blue (BLB) lamp as UV-A light source, a Petri dish as the cover material, and a polypropylene film as the adhesion film. The standard $TiO_2$ photocatalyst sample, Degussa P25 $TiO_2$ - coated glass, could only be used once. The optimal initial concentration of the microorganism, proper light intensity, and light irradiation time were determined to be $10^6$ CFU/mL, 1.0 mW/$cm^2$, and 3 hr, respectively, for testing and evaluating antimicrobial activity on the $TiO_2$ surface.

Notes of 15 unrecorded macrofungi in Korea

  • Minseo Cho;Sun Lul Kwon;Seokyoon Jang;Yeonjae Yoo;Sang Hyun Lee;Dae Young Kwon;Changmu Kim;Young Woon Lim;Jae-Jin Kim
    • Journal of Species Research
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    • v.13 no.1
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    • pp.67-88
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    • 2024
  • Macrofungi are essential decomposers in the forest environment. Although more than 70% of the land is mountainous, there has been a lack of research on mushroom diversity in Korea compared to the global species estimation. For this reason, the need for further research became apparent. The surveys were conducted from 2014 to 2022 nationwide. As a result, 15 unrecorded macrofungal species were discovered: Agaricus thiersii, Baorangia alexandri, Boletellus putuoensis, Entoloma bulakhae, Entoloma pygmaeopapillatum, Entoloma subtenuicystidiatum, Gerronema kuruvense, Hyphoderma nudicephalum, Hyphoderma tenue, Macrolepiota subcitrophylla, Mycena jingyinga, Mycena yuezhuoi, Ophiocordyceps vespulae, Scytinostroma acystidiatum, and Steccherinum straminellum. These species are identified based on morphological, molecular, and phylogenetic analyses using the internal transcribed spacer (ITS) region and the nuclear large subunit rRNA (LSU) region. Here, we provided macro- and micro-morphological figures with phylogenetic trees to support 15 species as unrecorded to Korea.

Gene Expression using nar Promoter under Anaerobic Condition with Recombinant E. coli

  • Kim, Kwang-Soo;Lee, Jong-Won;Hong, Eock-Kee
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.2 no.2
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    • pp.82-85
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    • 1997
  • The nar promoter as an inducible promoter was characterized for the process development for the gene expression and the protein production under anaerobic condition. The LB medium was selected as a main culture medium showing the enzyme activity of 18,000 units/min/g cell in the flask cultivation. The optimum concentration of nitrate was 1%. Under anaerobic conditions, the gene expression was fully induced in the presence of nitrate.

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Thermal Distribution and Development of RF Hyperthermia for Cancer Treatment (암치료를 위한 고주파 온열장치의 개발과 가온특성)

  • 추성실;김귀언
    • Journal of Biomedical Engineering Research
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    • v.8 no.1
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    • pp.63-68
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    • 1987
  • The biological effects for the use of hypertherinla to treat malignant tumors has been well studied and encouraging clinical results have been reported. However, the engineering and technical aspects of hyperthermia for the deepseated tumors has not been satisfactory. We have developed the FF capacitive hyperthermia device(GHT RF8)by cooporation with Yonsei Cancer Center and Green Cross Medical Equipment Corporation. It was composed with 8.10 MHz RF generator, capacitive electrode, matching system, cooling system, temperature measuring thermocouples and control PC computer. We have measured the temperature and thermal distribution in agar phantom, animals and human tumors.

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