• Title/Summary/Keyword: $K_{s}$

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Antibiofilm Activity and Binding Specificity of Polyclonal DNA Aptamers on Staphylococcus aureus and Escherichia coli

  • Arizah Kusumawati;Apon Zaenal Mustopa;Rifqiyah Nur Umami;Adi Santoso;I Wayan Teguh Wibawan;Agus Setiyono;Mirnawati Bachrum Sudarwanto
    • Microbiology and Biotechnology Letters
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    • v.50 no.3
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    • pp.328-336
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    • 2022
  • Aptamers are short, chemically synthesized, single-stranded DNA or RNA oligonucleotides that fold into unique three-dimensional structures. In this study, we aim to determine the antibiofilm activity and binding specificity of the six polyclonal DNA aptamers (S15K3, S15K4, S15K6, S15K13, S15K15, and S15K20) on Staphylococcus aureus BPA-12 and Escherichia coli EPEC 4. Aptamer S15K6 showed the highest percentage of antibiofilm activity against S. aureus BPA-12 (37.4%) as shown by the lowest OD570 value of 0.313. Aptamer S15K20 showed the highest percentage of antibiofilm activity against E. coli EPEC 4 (15.4%) as shown by the lowest OD570 value of 0.515. Aptamers S15K13 and S15K20 showed antibiofilm activities against both S. aureus BPA-12 and E. coli EPEC4, and thus potentially have broad reactivity. Furthermore, based on the binding capacity and Kd values from our previous study, the binding specificity assay of selected polyclonal DNA aptamers (S15K3 and S15K15) against S. aureus BPA-12, E. coli EPEC 4, S. aureus BPA-6, S. agalactiae, E. coli MHA-6, and Listeria monocytogenes were performed using qPCR. Aptamers S15K3 and S15K15 showed specific binding to S. aureus BPA-12, E. coli EPEC 4, S. aureus BPA-6, and S. agalactiae, but could not bind to E. coli MHA-6 and L. monocytogenes. Therefore, this study showed that the polyclonal DNA aptamers have antibiofilm activity and were able to bind to S. aureus BPA-12 and E. coli EPEC 4 bacteria.

Spectral Properties of k-quasi-class A(s, t) Operators

  • Mecheri, Salah;Braha, Naim Latif
    • Kyungpook Mathematical Journal
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    • v.59 no.3
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    • pp.415-431
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    • 2019
  • In this paper we introduce a new class of operators which will be called the class of k-quasi-class A(s, t) operators. An operator $T{\in}B(H)$ is said to be k-quasi-class A(s, t) if $$T^{*k}(({\mid}T^*{\mid}^t{\mid}T{\mid}^{2s}{\mid}T^*{\mid}^t)^{\frac{1}{t+s}}-{\mid}T^*{\mid}^{2t})T^k{\geq}0$$, where s > 0, t > 0 and k is a natural number. We show that an algebraically k-quasi-class A(s, t) operator T is polaroid, has Bishop's property ${\beta}$ and we prove that Weyl type theorems for k-quasi-class A(s, t) operators. In particular, we prove that if $T^*$ is algebraically k-quasi-class A(s, t), then the generalized a-Weyl's theorem holds for T. Using these results we show that $T^*$ satisfies generalized the Weyl's theorem if and only if T satisfies the generalized Weyl's theorem if and only if T satisfies Weyl's theorem. We also examine the hyperinvariant subspace problem for k-quasi-class A(s, t) operators.

Development of high-precision high-voltage CCPS (4세대 가속기 고정밀 고전압CCPS 개발)

  • Moon, Yong-Jo;Park, Soung-Soo;Kim, Sang-Hee;Kwon, S.J.;Jang, S.D.;Lee, B.J.;Lee, H.S.;Kang, H.S.;Whaung, J.Y.;Kim, D.S.;Lee, S.Y.;Shin, H.S.;Jang, K.Y.;Roh, S.C.
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.172-173
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    • 2012
  • 포항가속기 연구소에서는 4세대 가속기의 전자를 가속시키기 위해서 100ppm(0.01%) 이하의 고전압 안정도를 가진 200MW 펄스 모듈레이터가 요구된다. 그러므로 본 연구소에서는 고전압 안정도를 가진 고정밀 고전압 CCPS를 일반 CCPS와 병행하여 산업체와 함께 공동 개발을 진행하였다. 개발된 일반 CCPS의 사양은 50 kV, 30 kJ/sec, 600mA, 1000ppm이하이고, 고정밀 CCPS의 사양은 50 kV, 5 kJ/sec, 100mA, 100ppm이하이다. 본 논문에서는 CCPS의 개발 및 실제 모듈레이터에 설치하여 시험한 결과를 발표하고자 한다.

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Characteristics of antimicrobial activity of Streptococcus salivarius K12 by culture condition (Streptococcus salivarius K12의 배양조건에 따른 항균활성의 특징)

  • Song, Young-Gyun;Lee, Sung-Hoon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.37 no.4
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    • pp.244-250
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    • 2021
  • Purpose: The purpose of this study was to examine effects of culture conditions on the growth and antibacterial activity of Streptococcus salivarius K12. Materials and Methods: S. salivarius K12 was cultivated in medium containing animal and plant protein or in medium of neutral and acidic conditions. The growth of S. salivarius K12 was measured every 2 hours by a spectrophotometer. The antimicrobial activity of S. salivarius K12 against Streptococcus mutans and Porphyromonas gingivalis was investigated by the susceptibility assay using the spent culture medium. Results: the growth of S. salivarius K12 showed faster in medium containing plant protein and neutral pH condition. The antimicrobial and antifungal activity of S. salivarius K12 appeared stronger in medium containing plant protein than animal proteins. Conclusion: For application of S. salivarius K12 to bacterial oral disease, co-substances may be needed for S. salivarius K12 to colonize in the oral cavity and enhance the antimicrobial activity.

XFEL Pulse Modulator Test using High Precision High Voltage CCPS (고정밀 고전압 CCPS을 이용한 XFEL 200MW 펄스 모듈레이터 시험)

  • Park, S.S.;Kim, S.H.;Kwon, S.J.;Lee, H.S.;Kang, H.S.;Kim, D.S.;Shin, H.S.
    • Proceedings of the KIPE Conference
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    • 2014.07a
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    • pp.97-99
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    • 2014
  • 포항가속기 연구소에서 4세대 전자를 가속시키기 위하여 RF 공급원으로 사용하는 펄스 모듈레이터의 고전압 안정도는 50ppm 이하의 고전압이 요구된다. 200 MW 모듈레이터에 공급하기 위하여 개발된 고전압 CCPS사양은 50 kV, 120 kJ/sec, 2400mA, 20ppm이하이다. XFEL용 모듈레이터는 고정밀 고전압 CCPS를 적용하여 운전하였으며 모듈레이터 사양은 400kV, 500A, 8us, 60Hz, beam voltage stability 0.005(%)이다. 본 논문에서는 개발한 고정밀 고전압 CCPS를 사용하여 시험한 모듈레이터의 시험 결과에 대하여 발표하고자 한다.

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Development of High Precision High Voltage CCPS for PAL-XFEL (PAL-XFEL 200MW 펄스 모듈레이터용 고정밀 고전압 CCPS 개발)

  • Park, S.S.;Kim, S.H.;Kwon, S.J.;Lee, B.J.;Lee, H.S.;Kang, H.S.;Ko, I.S.;Kim, D.S.;S., M. Ho;Lee, S.Y.;Shin, H.S.;Jang, K.Y.;Roh, S.C.
    • Proceedings of the KIPE Conference
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    • 2013.07a
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    • pp.132-134
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    • 2013
  • 포항가속기 연구소에서 4세대 전자를 가속시키기 위하여 RF 공급원으로 사용하는 펄스 모듈레이터의 고전압 안정도는 100ppm 이하의 고전압이 요구된다. 따라서 본 연구소에서 산업체와 연계하여 인버터를 적용한 고정밀 고전압 CCPS를 개발하였다. 개발된 고정밀 고전압 CCPS의 사양은 50 kV, 5 kJ/sec, 100 ppm 이하 1set와 50 kV, 30 kJ/sec, 1000 ppm 4set이다. 고정밀 고전압 CCPS를 시험하기 위하여 4세대용 200 MW 모듈레이터를 설치하여 시험하였다. 본 논문에서는 고정밀 고전압 CCPS의 개발하고 제작하여 모듈레이터에 적용하여 시험한 내용을 보이고자 한다.

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