• Title/Summary/Keyword: Harmful media

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Sterilization of Bacteria, Yeast, and Bacterial Endospores by Atmospheric-Pressure Cold Plasma using Helium and Oxygen

  • Lee Kye-Nam;Paek Kwang-Hyun;Ju Won-Tae;Lee Yeon-Hee
    • Journal of Microbiology
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    • v.44 no.3
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    • pp.269-275
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    • 2006
  • Atmospheric-pressure cold plasma (APCP) using helium/oxygen was developed and tested as a suitable sterilization method in a clinical environment. The sterilizing effect of this method is not due to UV light, which is known to be the major sterilization factor of APCP, but instead results from the action of reactive oxygen radicals. Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae deposited on a nitrocellulose filter membrane or Bacillus subtilis spores deposited on polypropylene plates were exposed to helium/oxygen plasma generated with AC input power at 10 kHz, 6 kV. After Plasma treatment, nitrocellulose filter membranes were overlaid on fresh solid media and CFUs were counted after incubation overnight. D-values were 18 sec for E. coli, 19 sec for S. aureus, 1 min 55 sec for S. cerevisiae, and 14 min for B. subtilis spores. D-values of bacteria and yeast were dependent on the initial inoculation concentration, while the D-value of B. subtilis spores showed no correlation. When treated cells were observed with a scanning electron microscope, E. coli was more heavily damaged than S. aureus, S. cevevisiae exhibited peeling, and B. subtilis spores exhibited shrunken morphology. Results showed that APCP using helium/oxygen has many advantages as a sterilization method, especially in a clinical environment with conditions such as stable temperature, unlimited sample size, and no harmful gas production.

Robustness Analysis of Flash Memory Software using Fault Injection Tests (폴트 삽입 테스트를 이용한 플래시 메모리 소프트웨어의 강건성 분석)

  • Lee, Dong-Hee
    • Journal of KIISE:Computing Practices and Letters
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    • v.11 no.4
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    • pp.305-311
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    • 2005
  • Flash memory software running on cellular phones and PDAs need to be tested extensively to cope with abrupt power and media faults. For those tests, we designed and implemented a Flash memory emulator with fault injection features. The fault injection tester has provided a helpful framework for designing fault recovery schemes and also for analyzing fault damages to the FTL (Flash Translation Layer) and file system for a Flash memory based system. In this paper, we discuss Plash memory fault types and fault injection features implemented on this Flash memory emulator. We then discuss in detail a design flaw revealed during fault injection tests. Specifically, it was revealed that a scheme that was believed to improve reliability instead, turned out to be harmful. In addition, we discuss post-fault behaviors of the FTL and the file system.

Development of wrinkled skin-on-a-chip (WSOC) by cyclic uniaxial stretching

  • Lim, Ho Yeong;Kim, Jaewon;Song, Hyun Jeong;Kim, Kyunghee;Choi, Kyung Chan;Park, Sungsu;Sung, Gun Yong
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.238-245
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    • 2018
  • The skin experiences constant physical stimuli, such as stretching. Exposure to excessive physical stimuli stresses the skin and can accelerate aging. In this study, we applied a method that allowed human fibroblasts and keratinocytes to be perfused with media to form 3D skin equivalents that were then uniaxially 10%-stretched for 12 h per day (at either 0.01 or 0.05 Hz) for up to 7 days to form wrinkled skin-on-a-chip (WSOC). There was more wrinkling seen in skin equivalents under 0.01 Hz uniaxial stretching than there was for non-stretched skin equivalents. At 0.05 Hz, the stratum corneum almost disappeared from the skin equivalents, indicating that stretching was harmful for the epidermis. At both frequencies, the production of collagen and related proteins in the skin equivalents, such as fibronectin 10 and keratin, decreased more than those in the non-stretched equivalents, indicating that the dermis also suffered from the repeated tensile stress. These results suggest that WSOCs can be used to examine skin aging and as an in vitro tool to evaluate the efficacy of anti-wrinkle cosmetics and medicines.

The Role of Visual Communication for Emotional Marketing Strategy

  • HAN, Jung-Im
    • The Journal of Industrial Distribution & Business
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    • v.13 no.11
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    • pp.39-46
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    • 2022
  • Purpose: Visual communication is the act of using elements and components that can be seen. Some of the elements include images, illustrations, drawings, and videos. The purpose of this research is to check if there is the meaningful role of visual communication for emotional marketing plan. Research design, data and methodology: The present author firstly tried to obtain prior knowledge based on numerous previous literature through qualitative content method, investigating and searching related topic in 'Scopus' and 'Google Scholar' which is one of the most famous database. This methodology has already been proved the credibility and conformability by prior researchers. Results: The current study looks at four basic aspects that will assist in analyzing the findings and results from different peer-review articles. The section will cover social media, videos, podcasts, and ads. Conclusions: Several studies also affirmed that increased use of the internet and internet for marketing causes psychological issues among adolescents. Only adults should view some of the marketing ads, but if they pop into an adolescent browser, it may cause some harmful effects. Therefore, the study concluded that moderation of online visual adverts should be done to ensure only the targeted customers view the advert.

Effect of Cu Addition on the Properties of Duplex Stainless Steels

  • Hwangbo, D.;Yoo, Y.R.;Choi, S.H.;Choi, S.J.;Kim, Y.S.
    • Corrosion Science and Technology
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    • v.21 no.4
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    • pp.273-281
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    • 2022
  • The effect of addition of Cu on the localized corrosion performance of aged duplex stainless steel in chloride media has yet to be explained in a consistent manner, and there is some controversy in the literature regarding the composition of stainless steel and the experimental conditions (pH, temperature, chloride concentration, etc.) used. In this work, the effect of the addition of Cu on the microstructure, hardness, and corrosion resistance of duplex stainless steel in an acidic chloride or high concentration sulfuric acid solutions was investigated for annealed and aged alloys. The Cu addition of annealed duplex stainless steel strengthened the alloy and reduced the ferrite contents of the alloy, and it also increased the polarization behavior in chloride or sulfuric solutions, except for the case of a high potential in acidic chloride solution. However, the Cu addition of aged duplex stainless steel reduced the formation of harmful phases such as sigma and kai and increased the polarization behavior in acidic chloride or sulfuric solutions up to 0.8 wt% of the Cu content, after which it slightly decreased at 0.8 wt% Cu or more.

The 2018 US Midterm Elections and the Latino Voting: Diversity and Change (미국의 2018년 중간선거와 라티노 투표: 다양성과 변화)

  • Lee, Byung-Jae
    • Korean Journal of Legislative Studies
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    • v.25 no.1
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    • pp.5-44
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    • 2019
  • The 2018 midterm elections were considered a referendum for Trump Presidency, especially because Latino community has been feeling that the anti-immigration, anti-Latino policies of Trump administration are harmful to the community. News Media and pundits predicted the boost of the Latino turnout and its positive effects on Democratic candidates at all levels. The purpose of this paper is to provide an overview of Latino demographics and Latino public opinion and to analyze the election results with exit poll data and actual aggregate data. The data analysis shows that, compared to 2014 midterm elections, Latino turnout and the support for Democratic candidates actually increased in most counties and precincts, which is more salient in the areas with heavy Latino concentration.

Investigation of bacteria in the agricultural by-products imported for the use as media materials in mushroom cultivation (버섯재배 배지재료용 수입 농업부산물에서의 세균 조사 연구)

  • Kim, Jun Young;Kim, Susan;Kim, Seong Hwan
    • Korean Journal of Microbiology
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    • v.54 no.4
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    • pp.410-419
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    • 2018
  • It is urgently required to construct safety data on agricultural by-products imported for use as medium materials for domestic mushroom production. However, research on microorganisms is insufficient. This study was conducted to investigate the presence of bacteria that have the possibility of harmful effects on human, plants and mushroom in wheat straw, peatmoss, cottonseed hull, cottonseed meal, and beet pulp imported from Australia, Canada, China, Egypt, Germany. Bacteria were found in the range of $1.35{\times}10^2$ to $8.34{\times}10^6CFU/g$. As a result of 16S rDNA sequence analysis, total of 19 genera and 45 species of bacteria were identified. Bacillus genus was dominant, followed by Paenibacillus genus. At the species level, diverse species was in the order of Firmicute, Proteobacteria and Actinobacteria. Regarding the agricultural by-products, straw and peat moss had more diverse bacteria than other agricultural by-products. Among the indentified bacteria, 6 species of 5 genera (Enterobacter asburiae, Enterobacter ludwigii, Stenotrophomonas maltophilia, Pseudomonas monteilii, Bacillus anthracis, and Cellulosimicrobium funkei) were present as potent harmful bacteria to human. Surprisingly, both the human and plant pathogenic Klebsiella pneumoniae subsp. pneumonia was present. Bacillus altitudinis was present as a plant pathogen. Lysinibacillus sphaericus, an insect pathogen, and Ochrobactrum pseudogrignonense, a mushroom pathogen, were also present. The results of this study confirmed that several kinds of pathogenic bacteria were present in the agricultural by-products for the mushroom cultivation medium imported into Korea. Our work suggests that hygiene inspection and management is urgently needed for imported agricultural by-products to be safely used for mushroom production.

Investigation of some harmful bacteria in commercial Kimchi (시판김치 중 유해세균의 조사)

  • Shin Sun-Mi;Park Ju-Yeon;Kim Eun-Joung;Hahn Young-Sook
    • Korean journal of food and cookery science
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    • v.21 no.2 s.86
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    • pp.195-200
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    • 2005
  • Three different commercial Kimchi industry-made packaged, department store-made and ordinary market-made were analyzed for their pH, acidity and microbiological characteristics including certain harmful bacteria on selective media during a storage-fermentation period of 7 days at $2^{\circ}C\;or\;20^{\circ}C$ The pH of all the Kimchi samples wasdecreased from 5.85 to 3.82 and their total acidities increased from 0.2 to 1.18 as the fermentation continued during the storage-fermentation. E. coli and Salmonella sp. of $0\~1101$ cfu/mL were found in the industry-made Kimchi just after purchase time. As the storage-fermentation proceeded, the viable numbers of these bacteria had been reduced in all Kimchi samples tested and no bacteria were detected after 5 days at $2^{\circ}C$ and 2 days at $20^{\circ}C$, respectively. On the other hand, a range of $7.9102\~2.9103$ cfu/mL of Staphylococcus sp. was detected in the department store-made and ordinary market-made Kimchi samples at the purchase time, which was higher than that of the industry-made Kimchi, and this range wasn't reduced during storage-fermentation. The viable number of yeasts in the market-made Kimchi was 2.1103 cfu/mL. These results suggest that some commercial Kimchis were contaminated by some harmful bacteria and that a portion of these bacteria remained alive in the Kimchi, even with high acidity during the edible period.

Investigation of Microbial Communities in Sulculus diversicolor supertexta Through 16S rRNA Sequencing and Antibacterial Monitoring of Harmful Strains (16S rRNA 염기서열 분석을 통한 오분자기(Sulculus diversicolor supertexta)내 미생물 군집 조사 및 인체유해 질병세균에 대한 항균활성 모니터링)

  • Kim, Min-Seon;Lee, Seung-Jong;Heo, Moon-Soo
    • Journal of Life Science
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    • v.28 no.12
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    • pp.1477-1488
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    • 2018
  • This study investigated the muscles, intestines, and gonads of Sulculus diversicolor supertexta to examine the diversity of microbial communities within examples collected from the Jeju Coast. Using different media, initial pure isolation in MA, 1% BHIA, and 1% TSA indicated that the muscles, intestines, and gonads supported more communities, respectively. In analysis of relative similarity with 16s rRNA sequencing, 190 pure colonies were isolated, and further analysis with NBLAST identified 71 species, 39 genera, 25 families, and five phyla. Homogeny with the reference strain was 91-100%. Microbial communities in S. supertexta consisted of gamma and alpha Proteobacteria (48%), Actinobacteria (32.5%), Firmicutes (16.9%), Deinococcus-Thermus (1.3%), and Bacteroides (1.3%). In all tissue, Psychrobacter cibarius in Moraxellaceae was dominant. Alteromonadaceae, Enterobacteriaceae, Pasturellaceae, Moraxellaceae, Rhodobacteraceae, Geminicoccaceae, Dietziaceae, Intrasporangiaceae, Microbacteriaceae, Micrococcaceae, Micromonosporaceae, Streptomycetaceae, Aerococcaceae, Bacillaceae, Paenibacillaceae, Planococcaceae, and Staphylcoccaceae were commonly isolated across all tissues, and Flavobacteriaceae, Corynebacteriaceae, Yesiniaceae, Vibrionaceae, Hahellaceae, Pseudomonadaceae were also identified from the intestines. In microbial monitoring of four harmful bacteria, Streptomyces albus (96%) showed antibacterial activity against all four strains, and Agrococcus baldri (99%) and Psychrobacter nivimaris (99%) presented against E. Coli and E. aerogens. In addition, some strains with low homogeny were isolated and further experiments are therefore required, for example to refine the antimicrobial substances including new strain investigations. These additional experiments would aim to establish generic resources for the microbial communities in S. Supertexta and provide basic data for applied microbiological research.

The Survey on the Degree of Link with Internet Space and a Internet Addiction Disposition of Adolescents (청소년의 인터넷 접촉 정도와 중독성향에 대한 조사)

  • Sang-chul Han
    • Korean Journal of Culture and Social Issue
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    • v.9 no.2
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    • pp.19-39
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    • 2003
  • The purpose of this study was to investigate the degree of link with internet media and a internet addiction disposition of adolescents. The subjects were 500 students attending to middle and high schools consisted of male and female. The instruments were "the questionnaire on the present conditions of internet use" consisted of 14 items(Cronbach's α=.71) and "the internet addiction rating scale" consisted of 20 items(Cronbach's α=.73). These questionnaire were revised by this researcher. For data analysis, chisqure and ANOVA were used. The main results were as follows. First, a boy students and the vocational high school and the middle school each have more negative response than a girl students and the humanistic high schools in the present conditions of internet use and the judgement on a harmful object of internet space. Second, a boy students have higher than a girl students in an internet addiction disposition. Third, an internet addiction related with the times link with internet, the type of internet game, and the content of internet space(a lustful and violent objects). The various methods for the prevent with the internet addiction of adolescents discussed with based on the previous studies.

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