• Title/Summary/Keyword: acid-resistance

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Clinical Study of Augmentin (Augmentin 의 임상효과)

  • Kim, Hyeong-Muk;Im, Chang-Yeong
    • Journal of Chest Surgery
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    • v.19 no.1
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    • pp.174-179
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    • 1986
  • Augmentin is a formulation of amoxycillin trihydrate and potassium clavulanate, a fused beta-lactam molecule produced by the fermentation of Streptomyces clavuligerus. Most clinically important resistance is due to the production by bacteria of antibiotic destroying enzymes. In the case of penicillins and cephalosporins these enzymes are termed beta-lactamase as they destroy the beta-lectern ring of these antibiotics, completely inactivating them. The presence of clavulanic acid extends the spectrum of amoxycillin to include bet On clinical study of the intravenous Augmentin in the field of thoracic and cardiovascular surgical cases, we selected randomly 30 patients, 21 male and 9 female, age from 13 to 72, in the period from April to December 1985. Among the total 30 patients, 22 were preoperatively infected [11 thoracic empyema, 5 lobar pneumonia, 2 lung abscess, 2 bronchiectasis, one acute pyelonephritis with ureter stone and one rheumatic carditis], and 8 were not infected preoperatively [Table 1, 2]. Of the preoperatively infected group, 11 cases [50%] were culture positive [4 staphylococcus, 3 pseudomonas, 2 Serratia group, and one E. coli], and preoperatively non-infected group [8 cases] revealed expectedly negative findings on bacterial culture. All of the culture positive bacteria were sensitive to Augmentin on disc culture sensitivity test except one case of E. coli. Daily doses of intravenous Augmentin were 2.-1-6.0gm divided in 2-5 injections. Every injection administered [1.2gm at Augmentin dissolved in 20ml distilled water] slowly for more than 20 minutes. Duration of injection was variable according to the clinical conditions from minimum 5 to maximum 31 days. The results of antibiotic treatment with Augmentin and some other antibiotic combinations pre- and postoperatively were subgrouped as EXCELLENT, EFFECTIVE, and FAILURE. Clinical criteria of the therapeutic result were symptomatic, objective and laboratory improvement. 8 cases were excellent, 13 effective, and one failure among the preoperatively infected group, and all 8 cases of the preoperatively non-infected group were effective as pro;hylactive antibiotic therapy. Overall effective ratio was 97% in both subgroup. There was no side effect clinically and laboratory study including liver and kidney function test during and after the I.V. administration of Augmentin. Oral swallow tablets which were administered after discharge from hospital also revealed good effects with some degree of gastrointestinal trouble.

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Effect of Amine-Based Antioxidants as Stabilizers for Biodiesel (바이오디젤용 산화방지제인 아민안정제들의 효과)

  • Park, Soo-Youl;Kim, Hun-Soo;Kim, Seung-Hoi
    • Tribology and Lubricants
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    • v.31 no.6
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    • pp.258-263
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    • 2015
  • Biodiesel is an environmentally-friendly fuel with low smoke emission because it contains about 10% oxygen. Biodiesel fuel prepared by transesterification of vegetable oil or animal fats is susceptible to auto-oxidation. The rate of auto-oxidation depends on the number of methylene double bonds contained within the fatty acid methyl or ethyl ester groups. Biodiesel may be easily oxidized under several conditions, i.e., upon exposure to sunlight, temperature, oxygen environment. Maintenance of the fuel quality of biodiesel requires the development of technologies to increase the resistance of biodiesel to oxidation. Treatment with antioxidants is a promising approach for extending the shelf-life or storage time of biodiesel. The chemical properties of various amine-based antioxidants were evaluated after synthesis of the antioxidants by condensation of phenylenediamine with alkylamines at room temperature. In general, the oxidative stability can be assessed based on various experimental parameters. Such parameters may include temperature, pressure, and the flow rate of air through the samples. The Rancimat method (EN14112) was selected because it is a rapid technique that requires very little sample and provides good precision for oxidative degradation analysis. Specifically, the EN 14112 technique provides enhanced efficiency for oxidative stability evaluation when a larger ester head group is utilized. Therefore, this technique was employed for evaluation of the oxidation stability of biodiesel by the Rancimat method (EN14112).

Fabrication of 2-layer Flexible Copper Clad Laminate by Vacuum Web Coater with a Low Energy Ion Source for Surface Modification (저 에너지 표면 개질 이온원이 설치된 진공 웹 공정을 이용한 2층 flexible copper clad laminate 제작)

  • Choi, Hyoung-Wook;Park, Dong-Hee;Choi, Won-Kook
    • Korean Journal of Materials Research
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    • v.17 no.10
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    • pp.509-515
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    • 2007
  • In order to fabricate adhesiveless 2-layer flexible copper clad laminate (FCCL) used for COF (chip on film) with high peel strength, polyimide (PI; Kapton-EN, $38\;{\mu}m$) surface was modified by reactive $O_2^+$ and $N_2O^+$ ion beam irradiation. 300 mm-long linear electron-Hall drift ion source was used for ion irradiation with ion current density (J) higher than $0.5\;mA/cm^2$ and energy lower than 200 eV. By vacuum web coating process, PI surface was modified by linear ion source and then 10-20 nm thick Ni-Cr and 200 nm thick Cu film were in-situ sputtered as a tie layer and seed layer, respectively. Above this sputtered layer, another $8-9{\mu}m$ thick Cu layer was grown by electroplating and subsequently acid and base resistance and thermal stability were tested for examining the change of peel strength. Peel strength for the FCCLs treated by both $O_2^+$ and $N_2O^+$ ion irradiation showed similar magnitudes and increased as the thickness of tie layer increased. FCCL with Cu (200 nm)/Ni-Cr (20 nm)/PI structure irradiated with $N_2O^+$ at $1{\times}10^{16}/cm^2$ ion fluence was proved to have a strong peel strength of 0.73 kgf/cm for as-received and 0.34 kgf/cm after thermal test.

Suppression of tobamovirus movement toward upper leaves in the tomato plant over-expressing a maize calreticulin (옥수수 calreticulin 과발현 토마토에서 tobamovirus의 상엽 이동 억제)

  • Han, Jeung-Sul
    • Journal of Plant Biotechnology
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    • v.37 no.4
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    • pp.567-573
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    • 2010
  • To ascertain the effect of over-expressed maize calreticulin in tomato plant on tobamovirus movement in addition to validating potentiality of the gene (ZmCRT) as a means for the virus-resistance resource, four ZmCRT-expressing homozygous lines were generated from the T0 plants as using an Agrobacterium-mediated transformation, nucleic acid analyses, and a conventional breeding method. Of them, a line was subjected to the bioassay for tolerances to tobacco mosaic virus-U1 (TMV-U1) and tomato mosaic virus (ToMV) followed by RT-PCR and a chlorophyll fluorescence quenching analyses. Both transgenic plants transcribing ZmCRT and wild-type plants showed no symptom by 20 days after viruses inoculation, however the photosystem II quantum yield parameter measured from the upper leaves of ToMV-inoculated plants revealed that ZmCRT transgenic plants have higher photosynthetic ability than wild-type ones at that time, which indirectly implies that over-expressed ZmCRT product acts as a barrier to the cell-to-cell and/or systemic movement of ToMV. Moreover, ZmCRT transgenic plants showed remarkably longer shoot length than wild-type ones in 40 days after TMV-U1 or ToMV inoculation each, which might be resulted from higher photosynthetic ability during the phase not yet showing any external symptoms. Collectively, over-expressed ZmCRT protein in tomato plants is able to interrupt the systemic movement of infected TMV-U1 and ToMV even though not perfect.

Expression of prune dwarf Ilarvirus coat protein sequences in Nicotiana benthamiana plants interferes with PDV systemic proliferation

  • Raquel, Helena;Lourenco, Tiago;Moita, Catarina;Oliveira, M. Margarida
    • Plant Biotechnology Reports
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    • v.2 no.1
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    • pp.75-85
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    • 2008
  • Prune dwarf virus (PDV) is an Ilarvirus systemically infecting almond trees and other Prunus species and spreading through pollen, among other means. We have studied strategies based on coat protein (cp) gene to block PDV replication in host plant cells. A Portuguese isolate of PDV was obtained from infected almond leaves and used to produce the cDNA of the cp gene. Various constructs were prepared based on this sequence, aiming for the transgenic expression of the original or modified PDV coat protein (cpPDVSense and cpPDVMutated) or for the expression of cpPDV RNA (cpPDVAntisense and cpPDVwithout start codon). All constructs were tested in a PDV host model, Nicotiana benthamiana, and extensive molecular characterization and controlled infections were performed on transformants and their progenies. Transgenic plants expressing the coat protein RNA were able to block the proliferation of a PDV isolate sharing only 91% homology with the isolate used for cpPDV cloning, as evaluated by DAS-ELISA on newly developed leaves. With cp expression, the blockage of PDV proliferation in newly developed leaves was only achieved with the construct cpPDV Mutated, where the coat protein has a substitution in the 14th aa residue, with arginine replaced by alanine. This result points to a possible role of the mutated amino acid in the virus ability to replicate and proliferate. This work reveals the possibility of achieving protection against PDV through either coat protein RNA or mutated cp sequence.

$PPAR_{\gamma}$ Ligand-binding Activity of Fragrin A Isolated from Mace (the Aril of Myristica fragrans Houtt.)

  • Lee, Jae-Young;Kim, Ba-Reum;Oh, Hyun-In;Shen, Lingai;Kim, Naeung-Bae;Hwang, Jae-Kwan
    • Food Science and Biotechnology
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    • v.17 no.6
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    • pp.1146-1150
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    • 2008
  • Peroxisome proliferator-activated receptor-gamma ($PPAR_{\gamma}$), a member of the nuclear receptor of ligand-activated transcription factors, plays a key role in lipid and glucose metabolism or adipocytes differentiation. A lignan compound was isolated from mace (the aril of Myristica fragrans Houtt.) as a $PPAR_{\gamma}$ ligand, which was identified as fragrin A or 2-(4-allyl-2,6-dimethoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)-propane. To ascertain whether fragrin A has $PPAR_{\gamma}$ ligand-binding activity, it was performed that GAL-4/$PPAR_{\gamma}$ transactivation assay. $PPAR_{\gamma}$ ligand-binding activity of fragrin A increased 4.7, 6.6, and 7.3-fold at 3, 5, and $10{\mu}M$, respectively, when compared with a vehicle control. Fragrin A also enhanced adipocytes differentiation and increased the expression of $PPAR_{\gamma}$ target genes such as adipocytes fatty acid-binding protein (aP2), lipoprotein lipase (LPL), and phosphoenol pyruvate carboxykinase (PEPCK). Furthermore, it significantly increased the expression level of glucose transporter 4 (GLUT4). These results indicate that fragrin A can be developed as a $PPAR_{\gamma}$ agonist for the improvement of insulin resistance associated with type 2 diabetes.

Screening of Antimicrobial Lactic Acid Bacteria against Bovine Mastitis (여러 분리원으로부터 유방염 원인균에 대한 항균력을 가진 유산균의 분리)

  • Lee, Na-Kyoung;Choi, In-Ae;Park, Yong-Ho;Kim, Jong-Man;Kim, Jae-Myung;Jung, Suk-Chan;Paik, Hyun-Dong
    • Food Science of Animal Resources
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    • v.27 no.4
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    • pp.543-547
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    • 2007
  • Bovine mastitis is costly infectious disease of dairy cattle, being responsible for significant economic losses all over the world. Also, mastitis has troubled about resistance to antibiotics. The purpose of this study was to screen a novel antimicrobial strain from various sources (raw milk and feeds (from farm of Paju, Dangjin, and Hwasung), commercial milk, Korean traditional fermented foods, and chicken feces). The isolate was screened using triple agar layer method and deferred method was used for confirmation of antimicrobial effect. Seventy six of isolates were screened using triple agar layer method. In these strain, 42 isolates were shown a broad spectrum of autimicrobial activity against mastitis pathogens. Especially, fourteen isolates were shown over 20 mm inhibition zone against S. aureous ATCC 25923. These results suggest that these novel antimicrobial strains could be used for the alternative of antibiotics.

Spectroscopic and Electrochemical Study on the Citrate-based CuNi Codeposition (구연산 기반 구리-니켈 합금도금에 대한 분광학적/전기화학적 특성 연구)

  • Lee, Joo-Yul;Yim, Seong-Bong;Kim, Man;Jeong, Yong-Soo
    • Journal of the Korean institute of surface engineering
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    • v.44 no.3
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    • pp.117-123
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    • 2011
  • We investigated the spectroscopic and electrochemical properties of the citrate-based CuNi solution at different solution pH and analyzed various surface properties of CuNi codeposition layer. By combining UV-Visible spectroscopic data with potentiodynamic polarization curves, it could be found that the complexation of $Ni^{2+}$-citrate pair was completed at lower solution pH than $Cu^{2+}$-citrate pair and was affected by the coexistent $Cu^{2+}$ ions, while the complexation between $Cu^{2+}$ ions and citrate was not sensitive to the presence of $Ni^{2+}$ ions. Also, the electron transfer from cathode to $Cu^{2+}$-citrate and$Ni^{2+}$-citrate was hindered by strong complexation between $Cu^{2+}/Ni^{2+}$ ions and citrate and so apparent codeposition current densities were reduced as the solution pH increases. CuNi codeposited layers had a higher Cu content when they were prepared at high pH solution due to the suppression of Ni deposition, and when codeposition was executed in an agitated condition due to the acceleration of mass transfer of $Cu^{2+}$ ions in the solution. Actually, solution pH had little effect on the surface morphology and deposits orientation, but greatly influenced the corrosion resistance in 3.5% NaCl solution by modifying the chemical composition of CuNi layers and so pH 3 was expected as the most suitable solution pH in the viewpoint of corrosion coatings.

A Novel Plasmid-Mediated ${\beta}-lactamase$ that Hydrolyzes Broad-Spectrum Cephalosporins in a Clinical Isolate of Klebsiella pneumoniae

  • Kwak, Jin-Hwan;Kim, Mu-Yong;Chol, Eung-Chil
    • Archives of Pharmacal Research
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    • v.24 no.6
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    • pp.590-596
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    • 2001
  • A new extended-spectrum ${\beta}-lactamase$ with an isoelectric point (pl) of 6.2 was detected in Klebsiella pneumoniae Fl 61 that was isolated from a patient with infection. This strain was highly resistant to the third or fourth generation cephalosporins such as cceftazidime ceftriaxone, cefoperzaone, and cefpirome. Analysis of this strain by the double disk diffusion test showed synergies between amoxicillin-clavulanate (AMX-CA) and cefotaxime, and AMX-CA and aztreonam, which suggested that this strain produced a extended-spectrum ${\beta}-lactamase$ (ESBL). Cenetic analysis revealed that the resistance was due to the presence of a 9.4-kb plasmic, designated as pkpl 61, encoding for new ${\beta}-lactamase$ gene (bla). Sequence analysis showed that a new bla gene of pkpl 61 differed from $bla_{TEM-1}$ by three mutations leading to the following amino acid substitutions: $Val_{84}{\rightarrow}lie,{\;}Ala_{184}{\rightarrow}Val,{\;}and{\;}Gly_{238}{\rightarrow}Ser$. These mutations have not been reported previously in the TIM type ${\beta}-lactamases$ produced by clinical strains. The novel ${\beta}-lactamase$ was overexpressed in E. coli and purified by ion exchange chromatography on Q-Sepharose and CM-Sepharose, and then further purified by gel filtration on Sehadex G-200. The catalytic activity of th8 purified ${\beta}-lactamase$ was confirmed by the nitrocefin disk.

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Spray coating of electrochemically exfoliated graphene/conducting polymer hybrid electrode for organic field effect transistor

  • Kim, Youn;Kwon, Yeon Ju;Hong, Jin-Yong;Park, Minwoo;Lee, Cheol Jin;Lee, Jea Uk
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.399-405
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    • 2018
  • We report the fabrication of organic field-effect transistors (OFETs) via spray coating of electrochemically exfoliated graphene (EEG) and conducting polymer hybrid as electrodes. To reduce the roughness and sheet resistance of the EEG electrodes, subsequent coating of conducting polymer (poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)) and acid treatment was performed. After that, active channel layer was developed by spin coating of semiconducting poly(3-hexylthiophene) on the hybrid electrodes to define the bottom gate bottom contact configuration. The OFET devices with the EEG/PEDOT:PSS hybrid electrodes showed a reasonable electrical performances (field effect mobility = $0.15cm^2V^{-1}\;s^{-1}$, on/off current ratio = $10^2$, and threshold voltage = -1.57V). Furthermore, the flexible OFET devices based on the Polydimethlsiloxane (PDMS) substrate and ion gel dielectric layer exhibited higher electrical performances (field effect mobility = $6.32cm^2V^{-1}\;s^{-1}$, on/off current ratio = $10^3$, and threshold voltage = -1.06V) and excellent electrical stability until 1000 cycles of bending test, which means that the hybrid electrode is applicable to various organic electronic devices, such as flexible OFETs, supercapacitors, organic sensors, and actuators.