• Title/Summary/Keyword: acid-resistance

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Evaluation of Properties of Sulfur-Oxidizing Bacteria Growth and Resistance to Biochemical Corrosion by Simulation Test (시뮬레이션 시험에 의한 황산화세균의 생장 특성 및 생화학적 부식 저항성 평가)

  • Kim, Gyu-Yong;Lee, Eui-Bae;Khil, Bae-Su;Lee, Seung-Hun
    • Journal of the Korea Concrete Institute
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    • v.20 no.4
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    • pp.495-502
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    • 2008
  • To analyze the growth of SOB(Thiobacillus novellus) and biochemical corrosion of concrete, simulation test method and device were developed, and basic conditions for SOB growth were established. Two types of simulation tests were conducted according to a transplant method and a concentration of $H_2SO_4$. As a result, the SOB growth in distinct manners and antibiosis of specimen were observed. In the case of the specimens indirectly transplanted with SOB through culture solution submersion at a hydrogen sulfide level of 120 ppm, the rapid activation of SOB and the resulting sulfuric acid production were observed. However, SOB were shown to grow rapidly and then die out in a relative short period of time. Meanwhile, in the case of the specimens directly transplanted with SOB at a hydrogen sulfide level of 50 ppm, the long-term growth of SOB was possible, but the production of sulfuric acid by SOB did not progress. In the case of the antibiotic metal-mixed specimens, SOB with destroyed cell membranes and internal organizations were observed.

Molecular Typing of Salmonella enterica serovar Typhi Strains Isolated in Busan by Pulsed-Field Gel Electrophoresis (부산지역에서 분리된 Salmonella enterica serovar Typhi균에 대한 PFGE를 이용한 Molecular typing)

  • Min, Sang-Kee;Lee, Ju-Hyun;Park, Eun-Hee;Kim, Jung-Ah;Kim, Kyu-Won
    • Journal of Life Science
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    • v.16 no.4
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    • pp.664-671
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    • 2006
  • We obtained 424 Salmonella enterica serovar Typhi isolates from sporadic cases of infection in Busan during 1996 to 2005. We investigated the trend of antimicrobial resistance and molecular typing by pulsed-field gel electrophoresis (PFGE). Of the total 424 isolates, 6 strains (1.4%) were multidrug-resistant (MDR) S. enterica serovar Typhi isolates, 2 strains (0.5%) were resistant to only nalidixic acid, and the remaining 416 strains (98.1%) were fully susceptible to the 18 antimicrobial agent. PFGE of XbaI-digested chromosomal DNA was performed on 50 sporadic S. enterica serovar Typhi isolates with the objective of investigating the extent of genetic diversity of these isolates in our region. We could find that these isolates were much more heterogeneous and at least 32 different PFGE patterns were generated according by dice coefficient, between 0.69 and 1.0. Restriction fragment patterns consisted of 13 to 18 fragments ranged in size from 20 to 630 kb. The results confirmed that PFGE would be an useful tool for investigating surveillance of sporadic or outbreak case and assessing clonality for S. enterica serovar Typhi in Busan area. Our finding will be valuable in developing rational strategies to control this pathogen and setting the basis of an effective PulseNet system in Korea.

Isolation and Antimicrobial Susceptibility of Campylobacter jejuni from Diarrhea Patients (설사환자에서 Campylobacter jejuni의 분리 및 항생제 감수성 특성)

  • Park, Eun-Hee;Kim, Joung-A;Choi, Seung-Hwa;Bin, Jae-Hun;Cheigh, Hong-Sik;Suk, Dong-Hee;Lee, Su-Chul;Kim, Young-Hui
    • Journal of Life Science
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    • v.17 no.6 s.86
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    • pp.811-815
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    • 2007
  • ln this study we isolated 27 isolates of Campylobacter jejuni from stool samples of 882 diarrheal patients. The seasonal distribution of patients was highest at July (11.7%). All the isolates of C. jejuni hydrolyzing sodium hippurate were serotyped on basis of heat-stable antigens, and identified with the use of passive hemagglutination assay. A total of 59.3% among 27 C. jejuni isolates were identified into 6 different serotypes, which serotype HS2, HSl/44, and HS2l were dominant. Antibiotics resistant rates of C. jejuni isolates were shown to be 100%, 63.0%, 51.9%, 37.0%, 33.3%, 25.9% and 7.4% to cephalothin, trimethoprim- sulfamethoxazole, tetracycline, ciprofloxacin, ampicillin, gentamycin and clindamycin, respectively. All isolates were sensitive to the erythromycin and imipenem.

Enhancement of Tomato Tolerance to Biotic and Abiotic Stresses by Variovorax sp. PMC12 (Variovorax sp. PMC12 균주에 의한 토마토의 생물학 및 비생물학적 스트레스 저항성 증진)

  • Kim, Hyeon Su;Lee, Shin Ae;Kim, Yiseul;Sang, Mee kyung;Song, Jaekyeong;Chae, Jong-Chan;Weon, Hang-Yeon
    • Research in Plant Disease
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    • v.24 no.3
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    • pp.221-232
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    • 2018
  • Rhizobacteria play important roles in plant growth and health enhancement and render them resistant to not only biotic stresses but also abiotic stresses, such as low/high temperature, drought, and salinity. This study aimed to select plant growth promoting rhizobacteria (PGPR) with the capability to mitigate biotic and abiotic stress effects on tomato plants. We isolated a novel PGPR strain, Variovorax sp. PMC12 from tomato rhizosphere. An in vitro assay indicated that strain PMC12 produced ammonia, indole-3-acetic acid (IAA), siderophore, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, which are well-known traits of PGPR. The aboveground fresh weight was significantly higher in tomato plants treated with strain PMC12 than in non-treated tomato plants under various abiotic stress conditions including salinity, low temperature, and drought. Furthermore, strain PMC12 also enhanced the resistance to bacterial wilt disease caused by Ralstonia solanacearum. Taken together, these results indicated that strain PMC12 is a promising biocontrol agent and a biostimulant to reduce the susceptibility of plants to both abiotic and biotic stresses.

Prevention of Protein Loss Using A Shield Coating According to Moisture Behavior in Human Hair (수분거동 패턴에 따른 차폐막 설정을 통한 모발단백질 소실방지)

  • Song, Sang-Hun;Lim, Byung Tack;Son, Seong Kil;Kang, Nae-Gyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.46 no.1
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    • pp.57-65
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    • 2020
  • To prevent loss of hair protein during hair washing process by water through, a shield coating the pathway of water molecules was studied. Hydrophobic virgin hair, hydrophilic hair, which was damaged only methyleicosanoic acid (18-MEA) on the surface, and a repaired hair re-bound 18-MEA, were prepared and water mass changes by as heat were measured. Results showed that hydrophobic hairs followed bi-exponential function of 39 s and 151 s and other two hairs exhibited fast- and mono-exponential decay with 83 s, reflecting the extraction of water molecules without any resistance at the hydrophobic surface. On the assumption that hydrophobic surface resists an extraction of protein in water during the wash, the protein concentrations were compared from the hair of hydrophobic and hydrophilic surface. The extracted hair proteins were 179 and 148 ㎍/mL from the hair coated with hydrophilic polyethylene glycol (PEG) and hydrophobic polydimethylsiloxane (PDMS), respectively. This study suggested that hydrophobic coating on the hair surface could be used to prevent protein loss in wash, represented by LFM. In conclusion, this research provides some useful information to contribute to the development of hair washing products that can prevent protein loss in the cleaning process by granting hydrophobic coatings.

Changes in physical characteristics of white pan bread by addition of GABA rice bran and its extract (GABA 미강 및 미강추출물 첨가에 의한 식빵의 텍스처 및 저장성의 변화)

  • Oh, Su-Jin;Kwon, Young-Hoi;Shin, Hae-Hun;Kim, Hyun Soo;Choi, Hee-Don;Lim, Seung-Taik
    • Korean Journal of Food Science and Technology
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    • v.50 no.6
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    • pp.614-620
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    • 2018
  • A rice bran physically treated to increase the residual gamma amino butyric acid (GABA) content (200 mg/100 g) or its hot-water extract (200 mg/100 g) was added into a white pan bread, and changes in the physical properties including color, and volume and texture changes during storage at room temperature were examined. The addition of bran powders had negative effects on bread quality and storage stability whereas that of rice bran extract (RBE) improved the storage stability of bread. The lightness of bread crumbs decreased but the volume of bread slightly increased after addition of the RBE. The increase in crumb hardness during storage was retarded by the RBE addition. The residual concentration of GABA in bread was increased 38-fold when 20% of RBE was added. The addition of RBE to white pan bread improved the resistance to staling and health-promoting function because of GABA.

Synthesis of SiO2/Ag Core-shell Nanoparticles for Conductive Paste Application (SiO2/Ag 코어-쉘 나노입자의 합성 및 전도성 페이스트 적용)

  • Sim, Sang-Bo;Han, Jong-Dae
    • Applied Chemistry for Engineering
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    • v.32 no.1
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    • pp.28-34
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    • 2021
  • SiO2/Ag core-shell nanoparticles were synthesized by combining modified Stöber process and reverse micelle method using acetoxime as a reducing agent in water/dodecylbenzenesulfonic acid (DDBA)/cyclohexane reverse micells. The SiO2/Ag core-shells were studied for structure, morphology and size using UV-visible spectroscopy, XRD, SEM and TEM. The size of a SiO2/Ag core-shell could be controlled by changing the [water]/[DDBA] molar ratio (WR) values. The size and the polydispersity of SiO2/Ag core-shells increased with increase of the WR value. The resultant Ag nanoparticles exhibit a strong surface plasmon resonance (SPR) peak at 430 nm over the amorphous SiO2 nanoparticles. The SPR peak shifted to the red side with increase in nanoparticle size. Conductive pastes with 70 wt% SiO2/Ag core-shell were prepared, and the pastes were coated on the PET films using a screen-printing method. The printed paste film of the SiO2/Ag core-shell showed higher surface resistance than the commercial Ag paste in the range of 460~750 µΩ/sq.

Core-shell TiO2/Ag Nanoparticle Synthesis and Characterization for Conductive Paste (전도성 페이스트용 코어-쉘 TiO2/Ag 나노입자의 합성 및 특성 연구)

  • Sang-Bo, Sim;Jong-Dae, Han
    • Applied Chemistry for Engineering
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    • v.34 no.1
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    • pp.36-44
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    • 2023
  • Core-shell TiO2/Ag nanoparticles were synthesized by a modified sol-gel process and the reverse micelle method using acetoxime as a reducing agent in water/dodecylbenzenesulfonic acid (DDBA)/cyclohexane. The structure, shape, and size of the TiO2/Ag nanoparticles were investigated using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), and thermogravimetric analysis (TGA). The size of TiO2/Ag nanoparticles could be controlled by changing the [water]/[DDBA] molar ratio values. The size and the polydispersity of TiO2/Ag nanoparticles increased when the [water]/[DDBA] molar ratio rose. The resultant Ag nanoparticles over the anatase crystal TiO2 nanoparticles exhibited a strong surface plasmon resonance (SPR) peak at about 430 nm. The SPR peak shifted to the red side with the increase in nanoparticle size. Conductive pastes with 70 wt% TiO2/Ag nanoparticles were prepared, and the pastes were coated on the PET films using a screen-printing method. The printed paste films of the TiO2/Ag nanoparticles demonstrated greater surface resistance than conventional Ag paste in the range of 405~630 μΩ/sq.

Pytotoxicity by Continuous Spraying of Fruit Fire Blight Disinfectant During Growing Season of Apple and Pear (과수 화상병 방제약제의 사과·배 생육기 연용 살포에 의한 약해)

  • Se Hee Kim;Song-Hee Ryu;Byeonghyeon Yun;Kang Hee Cho;Sang-Yun Cho;Jung Gwan Park
    • Korean Journal of Plant Resources
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    • v.36 no.1
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    • pp.100-106
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    • 2023
  • In order to control the fire blight disease, all plants within the radius of the diseased orchard were removed in the early stage of the outbreak, or antibiotics control was performed for prevention. Since the beginning of antibiotics use on plants, the potential for development of resistance to antibiotics by the plant pathogen and unintended detrimental effects on the fruit trees and environment has become a problem. The purpose of this study is to determine the degree of phytotoxicity to fruit trees caused by excessive spraying of the fire blight disease disinfectant and to establish basic data for safe disinfectant guide. We analyzed whether damage to the fruit tree and the maximum residual limit of fruit was exceeded when three kinds of the fire blight disease disinfectants were continuously sprayed in excess of the number of safe use during the growing season. There was no phytotoxicity in apple 'Fuji' and pear 'Niitaka', and oxolinic acid was detected beyond the limit of quantitation in 'Fuji' grown without a bag, and the other disinfectants were detected below the maximum residue limit. When these disinfectants are continuously sprayed in excess of the number of safe, phytotoxicity may remain on the fruit. Therefore, it is necessary to observe the prescribed dilution factor and observe the safe frequency and the timing of use.

In-silico annotation of the chemical composition of Tibetan tea and its mechanism on antioxidant and lipid-lowering in mice

  • Ning Wang ;Linman Li ;Puyu Zhang;Muhammad Aamer Mehmood ;Chaohua Lan;Tian Gan ;Zaixin Li ;Zhi Zhang ;Kewei Xu ;Shan Mo ;Gang Xia ;Tao Wu ;Hui Zhu
    • Nutrition Research and Practice
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    • v.17 no.4
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    • pp.682-697
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    • 2023
  • BACKGROUND/OBJECTIVES: Tibetan tea is a kind of dark tea, due to the inherent complexity of natural products, the chemical composition and beneficial effects of Tibetan tea are not fully understood. The objective of this study was to unravel the composition of Tibetan tea using knowledge-guided multilayer network (KGMN) techniques and explore its potential antioxidant and hypolipidemic mechanisms in mice. MATERIALS/METHODS: The C57BL/6J mice were continuously gavaged with Tibetan tea extract (T group), green tea extract (G group) and ddH2O (H group) for 15 days. The activity of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) in mice was detected. Transcriptome sequencing technology was used to investigate the molecular mechanisms underlying the antioxidant and lipid-lowering effects of Tibetan tea in mice. Furthermore, the expression levels of liver antioxidant and lipid metabolism related genes in various groups were detected by the real-time quantitative polymerase chain reaction (qPCR) method. RESULTS: The results showed that a total of 42 flavonoids are provisionally annotated in Tibetan tea using KGMN strategies. Tibetan tea significantly reduced body weight gain and increased T-AOC and SOD activities in mice compared with the H group. Based on the results of transcriptome and qPCR, it was confirmed that Tibetan tea could play a key role in antioxidant and lipid lowering by regulating oxidative stress and lipid metabolism related pathways such as insulin resistance, P53 signaling pathway, insulin signaling pathway, fatty acid elongation and fatty acid metabolism. CONCLUSIONS: This study was the first to use computational tools to deeply explore the composition of Tibetan tea and revealed its potential antioxidant and hypolipidemic mechanisms, and it provides new insights into the composition and bioactivity of Tibetan tea.