• Title/Summary/Keyword: Bacterial size

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A Study on the Performance Appraisal for Copper Sheet as Root Barrier Material Appling to Green Roof System (옥상녹화 및 인공지반녹화용 구리시트 방근재의 성능평가에 관한 연구)

  • Cho, Il-Kyu;Kwon, Shi-Won;Kwak, Kyu-Sung;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.04a
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    • pp.5-8
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    • 2007
  • Selection of proper root barrier as destination part of greening is very important in Root penetration resistance plan. To select proper root barrier, it need to understand composition of greening part, size, kind of plant, connection with waterproofing layer. In this point of view, we have establish greening on the roof or concrete structure, not been understand the structural mechanism. It means that we misunderstood about purpose of greening and using it. So, chosen materials and construction method was not proper for greening, it caused water leakage and decrease performance of concrete structure. Therefore, we examine the practical use of copper sheet considering environmental condition for green roof. Watertightness by water of greening part, root penetration resistance test by root penetration, bacteria resistance by must or bacteria in soil, chemical resistance by rain and chemical agent of fertilizer, and load resistance by soil depth, sire of plant. These suggested test methods could be referred as guideline to test in green roof system because of not exist any performance appraisal guideline or standard. Consequently, it should be analysis as technical and institutional subdividing test methods and it need to study constantly as varied angles.

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Polycarprolactone Ultrafine Fiber Membrane Fabricated Using a Charge-reduced Electrohydrodynamic Process

  • Kim, Geun-Hyung;Yoon, Hyeon;Lee, Haeng-Nam;Park, Gil-Moon;Koh, Young-Ho
    • Macromolecular Research
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    • v.17 no.7
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    • pp.533-537
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    • 2009
  • This paper introduces a modified electro spinning system for biomedical wound-healing applications. The conventional electrospinning process requires a grounded electrode on which highly charged electro spun ultrafine fibers are deposited. Biomedical wound-healing membranes, however, require a very low charge and a low level of remnant solvent on the electrospun membrane, which the conventional process cannot provide. An electrohydrodynamic process complemented with field-controllable electrodes (an auxiliary electrode and guiding electrodes) and an air blowing system was used to produce a membrane, with a considerably reduced charge and low remnant solvent concentration compared to one fabricated using the conventional method. The membrane had a small average pore size (102 nm) and high porosity (85.1%) for prevention of bacterial contamination. In vivo tests on rats showed that these directly electro spun fibrous membranes produced using the modified electro spinning process supported the good healing of skin bums.

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.

Understanding Drug-Protein Interactions in Escherichia coli FabI and Various FabI Inhibitor Complexes

  • Lee, Han-Myoung;Singh, N. Jiten
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.162-168
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    • 2011
  • Many ligands have been experimentally designed and tested for their activities as inhibitors against bacterial enoyl-ACP reductase (FabI), ENR. Here the binding energies of the reported ligands with the E. coli ENR-$NAD^+$ were calculated, analyzed and compared, and their molecular dynamics (MD) simulation study was performed. IDN, ZAM and AYM ligands were calculated to have larger binding energies than TCL and IDN has the largest binding energy among the considered ligands (TCL, S54, E26, ZAM, AYM and IDN). The contribution of residues to the ligand binding energy is larger in E. coli ENR-NAD+-IDN than in E. coli ENR-$NAD^+$-TCL, while the contribution of $NAD^+$ is smaller for IDN than for TCL. The large-size ligands having considerable interactions with residues and $NAD^+$ have many effective functional groups such as aromatic $\pi$ rings, acidic hydroxyl groups, and polarizable amide carbonyl groups in common. The cation-$\pi$ interactions have large binding energies, positively charged residues strongly interact with polarisable amide carbonyl group, and the acidic phenoxyl group has strong H-bond interactions. The residues which have strong interactions with the ligands in common are Y146, Y156, M159 and K163. This study of the reported inhibitor candidates is expected to assist the design of feasible ENR inhibitors.

Prevalence and Diversity of MBL Gene-Containing Integrons in Metallo-β-Lactamase (MBL)-Producing Pseudomonas spp. Isolates Disseminated in a Korean Hospital

  • Yum, Jong Hwa
    • Biomedical Science Letters
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    • v.25 no.4
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    • pp.321-330
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    • 2019
  • Carbapenem is recently considered as the last resort of the therapeutics for gram negative bacterial infection. Increasing of organisms producing metallo-β-lactamase (MBL), we have difficulty in choosing the antimicrobial agents. Among 345 clinical isolates of Pseudomonas spp., 61 isolates (17.7%) were positive for the modified imipenem or meropenem-Hodge test and 55 isolates (15.9%) were positive for the imipenem-EDTA + SMA double disk synergy test (DDS). PCR and sequencing of blaVIM-2-allele and blaIMP-1-allele showed that 17 isolates of Pseudomonas aeruginosa, 9 isolates of Pseudomonas taiwnensis and 2 Pseudomonas plecoglossicida had blaVIM-2, and 22 isolates of P. aeruginosa and one Pseudomonas otitidis had blaIMP-6. These MBL genes were all in class 1 integron. The size of class 1 integron with blaVIM-2 ranged from 3.5 kb to 5.5 kb in clinical isolates of Pseudomonas spp. including P. aeruginosa. blaVIM-2 was most often located first in the class 1 integron, sometimes in the second or third position, and these integrons often had aacA4 or aadA1. Strict infection control measures are needed to more effectively prevent further spread of these MBL-producing Pseudomonas spp. In addition, MBL-producing Pseudomonas spp. is expected to continue to spread in various countries and regions.

The BNR-MBR(Biological Nutrient Removal-Membrane Bioreactor) for nutrient removal from high-rise building in hot climate region

  • Ratanatamskul, C.;Glingeysorn, N.;Yamamoto, K.
    • Membrane and Water Treatment
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    • v.3 no.2
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    • pp.133-140
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    • 2012
  • The overall performance of BNR-MBR, so-called Anoxic-Anaerobic-Aerobic Membrane Bioreactor ($A^3$-MBR), developed for nutrient removal was studied to determine the efficiencies and mechanisms under different solid retention time (SRT). The reactor was fed by synthetic high-rise building wastewater with a COD:N:P ratio of 100:10:2.5. The results showed that TKN, TN and phosphorus removal by the system was higher than 95%, 93% and 80%, respectively. Nitrogen removal in the system was related to the simultaneous nitrification-denitrification (SND) reaction which removed all nitrogen forms in aerobic condition. SND reaction in the system occurred because of the large floc size formation. Phosphorus removal in the system related to the high phosphorus content in bacterial cells and the little effects of nitrate nitrogen on phosphorus release in the anaerobic condition. Therefore, high quality of treated effluent could be achieved with the $A^3$-MBR system for various water reuse purposes.

Antibacterial Activity of Ethanol Extract of Saussurea lappa (목향(木香) 에탄올추출물의 항균효과(抗菌效果))

  • Lee, Sung-Jin;Kim, Dae-Sung;Mun, Yeun-Ja;Woo, Won-Hong;Lee, Jang-Cheon;Lim, Kyu-Sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.1
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    • pp.100-107
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    • 2009
  • Objective : The purpose of this study is to investigate the antibacterial activity of Saussurea lappa for the applications of herb-based extracts to both cosmetic and medicinal industries. Methods : Antibacterial activity of ethanol extract of Saussutes lappa (ESL) was assessed using agar diffusion and broth dilution methods, and determined by whether clear zone was formed around paper disc and in terms of the size (mm) of clear zone, Results : ESL provided activity against Staphylococcus aureus KCTC 1927 in concentration of 1 mg/ml with an clear zone of 16 mm, and showed an activity against Staphylococcus epidermids KCTC 1917 in concentration of 1 mg/ml with an clear zone of 18mm. Moreover, the minimum inhibitory concentration (MIC) of ESL against S. sureus and S. epidermidls were 1 mg/ml for both bacterial species. However, ESL showed no growth inhibition against Pseudomonas aeruginosa KCTC 12513, Enterobactet aerogenes KCTC 2190, Escherichia coli KCTC 2571, Salmonella typhimurium KCTC 1925 and Propionibacterium acnes KCCM 41747. Conclusions : Antibacterial activity of ESL against Staphylococcus sureus and Staphylococcus epidermids causing eye and skin diseases was proved. The result suggest that ESL may be useful as a natural preservative on behalf of synthetic preservatives.

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Expression of Helicobacter pylori Urease Subunit A in Plant (Helicobacter pylori urease subunit A 단백질의 식물체내에서의 발현)

  • 이효정;이만형;신동일;정일경;최성진;박희성
    • Korean Journal of Plant Tissue Culture
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    • v.27 no.3
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    • pp.239-243
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    • 2000
  • Helicobacter pylori, an etiologic agent of gastritis and peptic ulceration, produces urease which elicits a powerful immunoglobulin response in H. pylori-infected individuals. To establish a model plant vaccine agains H. pylori, 750 bp -ureA DNA amplified by polymerase chain reaction from pH 808 plasmid harboring urease gene cluster was cloned and manipulated to be expressed in tobacco plants. From the regenerated transgenic tobacco plants, ureA DNA integration,m its mRNA expression and protein synthesis were analyzed and confirmed by standard molecular techniques. The CaMV 35S promoter-driving ureA construct was expressed to produce a 30 kDa protein which was identical with bacterial UreA in size when detected on immunoblot of SDS polyacrylamide gel electrophoresis.

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Medicinal aspects of Murraya koenigii mediated silver nanoparticles

  • Mumtaz, Sumaira;Nadeem, Raziya;Sarfraz, Raja A.;Shahid, Muhammad
    • Advances in nano research
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    • v.11 no.6
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    • pp.657-665
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    • 2021
  • The present work aimed to explore green approach via aqueous leaves extract of Murraya koenigii (ALEMk) for the synthesis of silver nanoparticles (AgNPsMk) in single step. The synthesis process was visualized with a color change and monitored by employing UV/Visible spectroscopy and a clear peak attained at 420 nm confirming the synthesis of AgNPsMk. The possible functional groups present in the extract which participated in the synthesis of AgNPsMk were identified with the help of FTIR spectroscopy. Further characterization using TEM images revealed the spherical shape of AgNPsMk with average particle size of 20 nm displaying well dispersion throughout the solution. Pronounced antioxidant activities of AgNPsMk at increased concentrations observed which evidencing strong radical scavenging ability. Moreover, AgNPsMk exhibited strong antibacterial behavior when tested against bacterial strains of Escherichia coli and Bacillus subtilis. Moving ahead, in vitro cytotoxicity work revealed potent cell viability loss appearing in AU565 and HeLa cancer cell lines on exposure to AgNPsMk at increased concentration. Finally, in vivo assessment carried out inside male Wistar rats indicated non toxic effect on examined liver tissues besides biochemical analysis including bilirubin, alkaline phosphtase (ALP) and serum glutamate pyruvate transaminase (SGPT) which found within the normal range when compared with control. The prior research work profoundly apprises the potential of green synthesized AgNPsMk to play a significant role in biomedical applications and formulations.

A New Soybean Cultivar 'Daewang' with High Quality and Large Seed Size (장류용 고품질, 대립 콩 신품종 '대왕')

  • Choi, Jae-Keun;Ha, Keon-Soo;Byun, Hak-Soo;Heo, Nam-Ki;Jang, Eun-Ha;Kim, Sang-Soo;Lee, Se-Jong;Sa, Jong-Goo
    • Korean Journal of Breeding Science
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    • v.43 no.3
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    • pp.177-179
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    • 2011
  • A new soybean cultivar 'Daewang' was released by Agricultural Research & Extension Services, Gangwon Province in 2008. The Goals of breeding the variety was for large seed size, high yield, lodging tolerance and resistance to diseases such as soybean mosaic virus (SMV) and bacterial pustule. 'Daewang' was derived from the cross of GWS91, which has yellow seed coat, large seed size and late maturity, and 'Seokryang-putkong', which has large seed size and early maturity. The preliminary, advanced and regional yield trials for evaluation and selection were carried out from 2002 to 2007. It has a determinate growth habit with purple flower, yellow seed coat, yellow hilum and large seed weight (33.6 g per 100 seeds). The maturity date of 'Daewang' is 16 days later than the 'Taekwang'. It has a high content of total isoflavone ($1,851{\mu}g/g$). The average yield of 'Daewang' was 2.68 MT/ha in the regional yield trials (RYT) carried out in four locations in Gangwon province from 2004 to 2007 which was 4 percent higher than the check cultivar 'Taekwang'.