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Comparative Genomics of Vibrio cholerae

  • Chun, Jong-Sik;Jeon, Yoon-Seong;Lee, Je-Hee;Choi, Seon-Young;Kim, Dong-Wook;Grim, Christopher J.;Hasan, Nur A.;Colwell, Rita R.
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2009.05a
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    • pp.57-57
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    • 2009
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Evanescent Wave-Based Fiber Bragg Grating Biosensors

  • Lee, Sang-Mae;Kim, Deug;Dagenais, Mario;Chryssis, Athanasios N.;Saini, Simarjeet Singh;Yi, Hyunmin;Bentley, William E.
    • Proceedings of the Optical Society of Korea Conference
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    • 2006.07a
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    • pp.399-400
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    • 2006
  • Etched fiber Bragg grating, Sensitivity of fiber-Bragg-grating sensors to index of surrounding, Hybridization of DNA

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The Influence of Environmental Conditions on the Production of Pigment by Serratia marcescens

  • Hardjito, Linawati;Huq, Anwar;Colwell, Rita R.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.2
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    • pp.100-104
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    • 2002
  • Serratia marcescens biovar A2/A6, isolated from an Indonesian freshwater source, was identified based on extensive morphological, biochemical and genetic characterization. Formation of pigment was found to be strongly influenced by environmental conditions. Placket-Burman design was used to analyze the effect of carbon and nitrogen sources. Based on results of physiological and biochemical studies, the optimum conditions for growth and pigment formation were incubation 30$^{\circ}C$ in a neutral to slightly alkaline medium containing lactic acid and beef extract.

Reduced Addamycin Cytotoxicity in RIF-1 Multicell Spheroid Due to an Acidic Microenvironment

  • Um, Kyung-Il;Cheston, Sally B.;Suntharalingam, Mohan;Rhee, Juong-G.
    • Environmental Mutagens and Carcinogens
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    • v.17 no.1
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    • pp.7-11
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    • 1997
  • Variations in adriamycin uptake and cytotoxicity were studied in tumor cells that were grown in different growth states and microenvironments. RIF-1 tumor cells were maintained in an RPMI 1640 medium, and grown in either a monolayer or multicell spheroids. For exponentially growing cells, adriamycin cytotoxicity increased with increased dosage up to 2.5 $\mu$g/ml, and this cytotoxicity was reduced when the cells were grown in a plateau phase or in an acidic microenvironment (pH 6.6). This reduced cytotoxicity was correlated with the uptake of the drug. For multicell spheroids, the cytotoxicity of the drug was reduced dramatically, and this reduction was also correlated with a reduced uptake of the drug and an acidic pH inside of the spheroids. When the drug cytotoxicity was evaluated at different locations within the spheroids, the cells in the inner regions were least affected by the drug, suggesting that both an acidic microenvironment and noncycling plateau phase cells are contributing factors in decreasing the efficacy of the drug in an organized tissue, such as multicell spheroids.

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Errors in light-emitting diodes positioning when curing bulk fill and incremental composites: impact on properties after aging

  • Abdulrahman A. Balhaddad;Isadora M. Garcia;Haifa Maktabi;Maria Salem Ibrahim;Qoot Alkhubaizi;Howard Strassler;Fabricio M. Collares;Mary Anne S. Melo
    • Restorative Dentistry and Endodontics
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    • v.46 no.4
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    • pp.51.1-51.13
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    • 2021
  • Objectives: This study aimed to evaluate the effect of improper positioning single-peak and multi-peak lights on color change, microhardness of bottom and top, and surface topography of bulk fill and incremental composites after artificial aging for 1 year. Materials and Methods: Bulk fill and incremental composites were cured using multi-peak and single-peak light-emitting diode (LED) following 4 clinical conditions: (1) optimal condition (no angulation or tip displacement), (2) tip-displacement (2 mm), (3) slight tip angulation (α = 20°) and (4) moderate tip angulation (α = 35°). After 1-year of water aging, the specimens were analyzed for color changes (ΔE), Vickers hardness, surface topography (Ra, Rt, and Rv), and scanning electron microscopy. Results: For samples cured by single-peak LED, the improper positioning significantly increases the color change compared to the optimal position regardless of the type of composite (p < 0.001). For multi-peak LED, the type of resin composite and the curing condition displayed a significant effect on ΔE (p < 0.001). For both LEDs, the Vickers hardness and bottom/top ratio of Vickers hardness were affected by the type of composite and the curing condition (p < 0.01). Conclusions: The bulk fill composite presented greater resistance to wear, higher color stability, and better microhardness than the incremental composite when subjected to improper curing. The multi-peak LED improves curing under improper conditions compared to single-peak LED. Prevention of errors when curing composites requires the attention of all personnel involved in the patient's care once the clinical relevance of the appropriate polymerization reflects on reliable long-term outcomes.