• Title/Summary/Keyword: acid-resistance

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항 결핵제, 리팜피신에 내성인 유산균의 개발 (Development of Lactobacillus casei Resistant to Rifampicin, an Antituberculosis Agent)

  • 이승희;최응칠;김병각
    • 약학회지
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    • 제32권6호
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    • pp.394-401
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    • 1988
  • Lactobacillus casei was treated with N-methyl-N'-nitro-N-nitrosoguanidine(NTG) to obtain resistant mutants to rifampicin. Freshly grown cells of the strain suspended in tris-maleic acid buffer were exposed to NTG of $50{\mu}g/ml$ for 30min. Five colonies of the NTG-induced mutants showed distinct resistance to rifampicin. They also exhibited identical characteristics with the original Lactobacillus casei when they were tested for growth, titrable acidity and sugar fermentation. It is suggested that they can be utilized as efficieient starter cultures for fermented milk.

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Study of the Application of Gel Electrolyte in the Reference Electrode of $Cu/CuSO_4$

  • Lin, Cunguo;Xu, Likun;Liu, Yang
    • Corrosion Science and Technology
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    • 제7권3호
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    • pp.179-181
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    • 2008
  • With nano-$SiO_2$ and sulphate acid, a kind of colloid electrolyte is synthesized by sol-gel method. It is placed outside the reference electrode as a layer of gel electrolyte so as to decrease the leaching of $Cu^{2+}$ and increase the life of the reference electrode. The performance of the gel electrode in simulating soil solution is measured as follows: the potential of the electrodes ranging from 60 mV to 80 mV (vs. SCE) with potential variation no more than $\pm10mV$, enough resistance to polarization. The $Cu^{2+}$ effusion rate of the reference electrode without gel electrolyte is 3 times that with colloid electrolyte, which means that gel electrolyte can extend the life of the reference electrode significantly.

Effect of Catalyst Type and NCO Index on the Synthesis and Thermal Properties of Poly(urethane-isocyanurate) Foams

  • Shin, Hye-Kyeong;Lee, Sang-Ho
    • Elastomers and Composites
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    • 제53권2호
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    • pp.86-94
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    • 2018
  • The effect of the NCO index and catalyst type on the thermal stability of poly(urethane-isocyanurate) (PUIR) foams was investigated to identify a method for enhancing the flame resistance of PUIR. PUIR foams were prepared using 4,4-diphenylmethane diisocyanate (MDI) and [(diethylene glycol)adipate]diol, which were synthesized by esterification of adipic acid and diethylene glycol. Dabco K-15, Dabco TMR-30, and Toyocat RX-5 were used as the catalysts for trimerization and gelation. The amount of urea and isocyanurate groups in PUIR was semi-quantitatively determined by normalizing their absorbance with the phenyl absorbance measured by FT-IR. The normalization data showed that Dabco TMR-30 effectively generated isocyanurate groups in PUIR. As a result, Dabco TMR-30 effectively raised the decomposition temperature and increased the 800 K and 900 K residues of the PUIR foam synthesized with an NCO index of 200.

Probiotic Characteristics of Lactobacillus plantarum FH185 Isolated from Human Feces

  • Park, Sun-Young;Lim, Sang-Dong
    • 한국축산식품학회지
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    • 제35권5호
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    • pp.615-621
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    • 2015
  • Lactobacillus plantarum FH185 was isolated from the feces of healthy adults. In our previous study, L. plantarum FH185 was demonstrated that it has anti-obesity effect in the in vitro and in vivo test. In order to determine its potential for use as a probiotic, we investigated the physiological characteristics of L. plantarum FH185. The optimum growth temperature of L. plantarum FH185 was 40℃. L. plantarum FH185 showed higher sensitivity to novobiocin in a comparison of fifteen different antibiotics and showed higher resistance to polymyxin B and vancomycin. It also showed higher β-galactosidase and N-acetyl-β-glucosaminidase activities. Moreover, it was comparatively tolerant to bile juice and acid, and inhibited the growths of Salmonella Typhimurium and Staphylococcus aureus with rates of 44.76% and 53.88%, respectively. It also showed high adhesion activity to HT-29 cells compared to L. rhamnosus GG.

플라이 애시를 혼입한 콘크리트의 물리.역학적 특성에 관한 실험적 연구 (Experimental Study on physical and Mechanical Properties of Concrete with Fly Ash)

  • 성찬용
    • 한국농공학회지
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    • 제42권3호
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    • pp.107-113
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    • 2000
  • This study is performed to examine the physical and mechanical properties of concrete with fly ash. Test results show that the unit weights of concrete with fly ash are decreased 1-3% and the highest strength is achieved by 10% filled fly ash concrete with it is increased 7% than that of the normal cement concrete. the ultrasonic pulse velocity is in the range of 3.705~4.204m/s and the dynamic and static modulus of elasticity is in the range of 271$\times$103 ~289$\times$103kgf/cm2 and 208$\times$103 ~262$\times$103kgf/cm2 respectively. The acid-resistance is increased with increase of the content of fly ash. It is 1.2 times of the normal cement concrete by 10% filled fly ash concrete and 1.7 times by 30% filled fly ash concrete respectively.

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Comparison of the Nutritional Compositions of Insect-Resistant and Glufosinate-Tolerant Rice and Conventional Rice

  • Park, Soo-Yun;Lee, Si Myung;Yeo, Yunsoo;Kweon, Soon Jong;Cho, Hyun Suk;Kim, Jae Kwang
    • Journal of Applied Biological Chemistry
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    • 제56권1호
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    • pp.5-9
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    • 2013
  • The nutritional composition of transgenic rice (Agb0101) with bar and modified cry1Ac1 genes grown with herbicides was compared with that of its non-transgenic counterpart. The analyzed components (proximates, amino acids, fatty acids, minerals, vitamins, trypsin inhibitors, and phytic acid) in the herbicide-treated Agb0101 brown rice were substantially equivalent to those of its non-transgenic counterpart.

포토리소그래피 공정으로 제작된 터치스크린패널용 금속메시 (Thin Metal Meshes for Touch Screen Panel Prepared by Photolithography)

  • 김서한;송풍근
    • 한국표면공학회지
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    • 제49권6호
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    • pp.575-579
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    • 2016
  • The metal mesh films with thickness of 1.0, 1.5, $2.0{\mu}m$ were prepared by photolithography using Ag, Al, and Cu metals. Every metal films were showed C(111) preferred orientation and Ag showed the lowest resistivity and followed by Al and Cu. The transmittance of almost films were higher than 90%. But, the Ag film with thickness of $2.0{\mu}m$ was delaminated during photolithography process due to low adhesion. So, Cu and Ti metal films were introduced under Ag film to improve adhesion property. The Cu film showed higher adhesion properties compared to Ti film. Furthermore, the Ti films that deposited on Ag film showed higher acid resistance.

나노합성 무기질 폴리머계 표면처리제를 적용한 콘크리트의 내구성능 평가에 관한 실험적 연구 (An experimental study on durability evaluation of the concrete applied nano level inorganic polymer based coatings)

  • 백종명;김은겸
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.1014-1020
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    • 2004
  • In this study, durability of the nano-level inorganic polymer based coatings which can provide a barrier against the ingress of moisture or aggressive ions to concrete is discussed. For the durability evaluation of the coatings, chloride penetration test, accelerating carbonation test, freezing and thawing test, and sulfate ponding test are conducted. As the result of this study, concrete applied nano-level inorganic polymer based coatings has a much higher resistance to the ingress of chloride ion, carbon dioxide, moisture and aggressive acid than plain concrete and epoxy resin based paint by means of crosslinking three-dimensional structure with concrete structure.

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Homology Modelling of Chemerin like Receptor-1 (CMKLR1): Potential Target for Treating Type II Diabetes

  • B, Sathya.
    • 통합자연과학논문집
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    • 제10권1호
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    • pp.20-26
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    • 2017
  • Chemerin receptor, which predominantly expressed in immune cells as well as adipose tissue, was found to stimulate chemotaxis of dendritic cells and macrophages to the site of inflammation. Chemerin is a widely distributed multifunctional secreted protein implicated in immune cell migration, adipogenesis, osteoblastogenesis, angiogenesis, myogenesis, and glucose homeostasis. Recent studies suggest chemerin may play an important role in the pathogenesis of obesity and insulin resistance and it becomes a potential therapeutic target for treating type II diabetes. The crystal structure of chemerin receptor has not yet been resolved. Therefore, in the present study, homology modelling of CMKLR1 was done utilizing the crystal structure of human angiotension receptor in complex with inverse agonist olmesartan as the template. Since the template has low sequence identity, we have incorporated both threading and comparative modelling approach to generate the three dimensional structure. 3D models were generated and validated. The reported models can be used to characterize the critical amino acid residues in the binding site of CMKLR1.

위식도역류질환과 인후두역류질환의 대한 최신지견 (Update of Pathophysiology in GERO/LPR)

  • 우정수
    • 대한기관식도과학회지
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    • 제16권2호
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    • pp.83-90
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    • 2010
  • The pathophysiology of Gastroesophageal reflux disease (GERD) has been known that it is developed when the offense-primarily the gastric acid-pepsin content of the refluxate-overcomes a 3-tiered esophageal protective defense. consisting of antireflux mechanisms, luminal clearance mechanisms, and tissue resistance. Laryngopharyngeal reflux (LPR), which is known as an extraesophageal variant of GERD, has been considered to be developed by transient lower esophageal sphincter relaxation (TLESR), direct mucosal injury by gastric contents, more sensitive mucosa compared to esophagus, and absence of buffering effect and aggravation of the injury due to pepsin. However, hypothesis of the pathophysiology in both entities are numerous and still lack of understanding for being a theory. There is no conflict that understanding the pathophysiology is necessary for resolving the problems of these diseases and numerous studies and results have been releasing. This review could provide clinicians dealing with GERD and LPR with applicable new information and help for overcoming the clinical obstruction.

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