• Journal of Microbiology and Biotechnology
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• 제24권3호
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• pp.379-385
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• 2014

The purpose of this study was to compare the ability of an engineered Escherichia coli to degrade chlorpyrifos (Cp) using an organophosphorus hydrolase enzyme, encoded in both Flavobacterium sp. ATCC 27551 or Pseudomonas diminuta, by employing the Lpp-OmpA chimera and the N-terminal domain of the ice nucleation protein as anchoring motifs. Tracing of the expression location of the recombinant protein using SDS-PAGE showed the presentation of OPH by both anchors on the outer membrane. This is the first report on the presentation of OPH on the cell surface by Lpp-OmpA under the control of the T7 promoter. The results showed cell growth in the presence of Cp as the sole source of energy, without growth inhibition, and with higher whole-cell activity for both cells harboring plasmids pENVO and pELMO, at approximately 10,342.85 and 10,857.14 U/mg, respectively. Noticeably, the protein displayed by pELMO was lower than the protein displayed by pENVO. It can be concluded that Lpp-OmpA can display less protein, but more functional OPH protein. These results highlight the high potential, of both engineered bacteria, for use in the bioremediation of pesticide-contaminated sources in the environment.

• 한국발생생물학회지:발생과생식
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• 제23권3호
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• pp.285-295
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• 2019

Junction-mediating and regulatory protein (JMY) is a regulator of both transcription and actin filament assembly. The actin-regulatory activity of JMY is based on a cluster of three actin-binding Wiskott-Aldrich syndrome protein homology 2 (WH2) domains that nucleate actin filaments directly and promote nucleation of the Arp2/3 complex. In addition to these activities, we examined the activity of JMY generation in early embryo of mice carrying mutations in the JMY gene by CRISPR/Cas9 mediated genome engineering. We demonstrated that JMY protein shuttled expression between the cytoplasm and the nucleus. Knockout of exon 2, CA (central domain and Arp2/3-binding acidic domain) and NLS-2 (nuclear localization signal domain) on the JMY gene by CRISPR/Cas9 system was effective and markedly impeded embryonic development. Additionally, it impaired transcription and zygotic genome activation (ZGA)-related genes. These results suggest that JMY acts as a transcription factor, which is essential for the early embryonic development in mice.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.139.1-139.1
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• 2013

Graphene and graphene oxide (GO) have been modified with palladium nanoparticles (Pd NPs) to develop high performance catalysts for the Sonogashira cross coupling reaction. To understand catalytic performance of Pd NPs on graphene (Pd/G) and Pd NPs on GO (Pd/GO), we monitored their morphological and electronic structural changes before/after Sonogashira reaction using FT-IR, XRD, XPS, and XAFS. Here, we demonstrate that both Pd/G and Pd/GO show high catalytic efficiency toward the Sonogashira reaction, but only Pd/GO revealed excellent recyclability. The remarkable catalytic efficiency of both catalysts is attributed to the high degree of the Pd NP dispersions on supports and thus smaller Pd NPs can provide highly reactive low coordinated Pd atoms. However, we attributed the excellent recyclability of Pd/GO to the presence of oxygen functionalities on GO, which can provide nucleation sites for the detached Pd atoms during the Sonogashira reaction and prevent agglomeration of the Pd NPs since the oxygen functional groups are very reactive to mobile Pd adatoms.

• 대한화학회지
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• 제66권4호
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• pp.284-297
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• 2022

The antibacterial activity of metallic nanoparticles (NPs), especially silver (Ag), has been investigated during the course of time in various chemical reactions for antibiotics free agents. Green synthesis of metallic NPs using either microorganisms or plant-extracts has appeared as a simple and replacement to chemical and physical methods. The synthesizing of these NPs through ecofriendly methods signifies an exceedingly applicable approach for offering economical, preferring scalability and possessing negligible ecological influences. Essential-oils are among the subordinate metabolites of plants and their antibacterial anti-inflammatory characteristics have been investigated widely and are commonly attained from the aromatic plants. The usage of essential-oils as reducing agents in biosynthesizing of Ag NPs bring together the interaction of a vital antibacterial agent that simplify the nucleation and growth process within the NPs formation. This review article is offering a progressive process of Ag NPs synthesis using essential oils along with proposing the most applicable formation mechanisms and their antibacterial activities.

• 미생물학회지
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• 제39권2호
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• pp.76-82
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• 2003

Alcaligenes faecalis T1의 Poly(3-hydroxybutyrate)(PHB) depolymerase활성 증진을 위해 DNA shuffling방법을 이용하였다. 제조된 A. faecalis T1의 PHB depolymerase 돌연변이 유전자의 library를 Pseudomonas syringae의 icenucleation protein유전자를 포함하는 발현벡터 pJHCll에 클로닝하여 약 7,000개의 형질전환체를 얻었다. 탄소원으로 PHB또는 poly(3-hydroxybutyrate-co-3-hydroxyvalerate)를 포함하는 M9최소배지를 이용하여 형질전환체들로부터 활성이 서로 다른 돌연변이주들을 선별하였다. 이들의 PHB depolymease 활성은 평판배지에서의 halo형성 및 배양 상등액을 이용한 탁도 감소 실험으로 확인하였으며,형질전환체들 중에서 shuffling전의 대조군에 비하여 사용된 기질에 따라 효소활성이 1.8-3.2배 증진된 II-4 돌연변이주를 얻었다. DNA 염기서열의 분석을 통하여 II-4의 PHB depolymease에는 3개의 아미노산 치환(A1a209Va1, Leu258Phe, Asp263Thr)이 이루어졌음을 확인하였다. 여러 가지 돌연변이주의 아미노산 서열의 변화를 분석한 결과, PHB depolymerase의 catalytictriad주위에 기존 아미노산에 비하여 보다 소수성인 아미노산으로의 치환이 소수성 기질인 PHB에 대한분해 활성 중진에 기여하는 것으로 추정되었다.

• Advances in nano research
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• 제16권1호
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• pp.71-79
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• 2024

Nanotechnology is the latest technology developed by humanity, trying to use the molecular properties of materials found in nature to create devices that solve the problems plaguing humanity and their efficiency. Man is also trying to change the meaning of molecules to nano so that a body made up of these particles has all the properties of these particles. Nanotechnology is not a new field but a new approach in all areas. A new perspective in concrete technology has been created by the use of nanoparticles in recent years. Adding silica nanoparticles to concrete mixes improves its properties and increases its strength. However, different results and reported mechanisms explain the behavior of nanoparticles in the mixture; Therefore, it took much work to generalize the results and predict the behavior of nano concretes. This article is about the construction simulation technology of civil engineering based on artificial intelligence, which deals with the effect of nanoparticles on improving concrete properties. This was demonstrated by analyzing laboratory samples in various mixture configurations and observing how silica nanoparticles affected their microstructure with scanning electron microscopy (SEM). Based on SEM measurements, silica nanoparticles have a powerful effect because of their specific surface area. Their increase and decrease must be sought in interacting with the filling and nucleation mechanism and the pozzolanic activity. Each of these mechanisms dominates at different ages of hydration and affects the microstructure and mechanical properties of concrete.

• Journal of Microbiology and Biotechnology
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• 제21권12호
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• pp.1330-1335
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• 2011

N-Acyl homoserine lactones (AHLs) serve as the vital quorum-sensing signals that regulate the virulence of the pathogenic bacterium Erwinia carotovora. In the present study, an approach to efficiently restrain the pathogenicity of E. carotovora-induced soft rot disease is described. Bacillus thuringiensis-derived N-acyl homoserine lactonase (AiiA) was projected onto the surface of Pseudomonas putida cells, and inoculation with both strains was challenged. The previously identified N-terminal moiety of the ice nucleation protein, InaQ-N, was applied as the anchoring motif. A surface display cassette with inaQ-N/aiiA was constructed and expressed under the control of a constitutive promoter in P. putida AB92019. Surface localization of the fusion protein was confirmed by Western blot analysis, flow cytometry, and immunofluorescence microscopy. The antagonistic activity of P. putida MB116 expressing InaQ-N/AiiA toward E. carotovora ATCC25270 was evaluated by challenge inoculation in potato slices at different ratios. The results revealed a remarkable suppressing effect on E. carotovora infection. The active component was further analyzed using different cell fractions, and the cell surface-projected fusion protein was found to correspond to the suppressing effect.

• 대한화학회지
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• 제57권4호
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• pp.483-488
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• 2013

$CuCl_2$로부터 용액합성법에 의해 CuO를 제조하였다. $CuCl_2$를 용액에 첨가하기 전에 용액내에 anatase형 $TiO_2$ 입자를 분산시켜 CuO가 형성되는 과정에서 $TiO_2$/CuO 결합입자를 합성하였다. 얻어진 $TiO_2$/CuO에 적당량의 글루코스를 가하여 반응시켜 CuO의 일부를 $Cu_2O$로 환원시켰다. 얻어진 시료 $TiO_2/Cu_xO$ (1$TiO_2/Cu_xO$ 복합체는 anatase와는 다르게 가시광선 전 영역에서 흡광이 발생했으며 당연한 결과로 태양광선에서 $TiO_2/Cu_xO$ 복합체의 광촉매 활성은 anatase $TiO_2$에 비하여 매우 뛰어난 것으로 나타났다. 또한 $TiO_2/Cu_xO$ 복합체의 항균성이 대단히 뛰어난 것으로 나타났다.

• 한국가축번식학회지
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• 제26권4호
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• pp.361-368
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• 2002

The onset of pronucleus formation and DNA synthesis in porcine oocytes following the injection of porcine or murine sperm was determined in order to obtain insights into species-specific paternal factors that contribute to fertilization. After 44h in vitro maturation, spermatozoa was injected into the cytoplasm of oocytes. After injection, all oocytes were transferred to NCSU23 medium and cultured at 39'E under 5% CO2 in air. Similar frequencies of oocytes with female pronuclei were observed after injection with porcine sperm or with murine sperm. In contrast, male pronuclei formed 8 to 9 h following the injection of porcine sperm, and 6 to 8 h following the injection of murine sperm. After pronucleus formation maternally derived microtubules were assembled and appeared to move both male and female pronuclei to the oocyte center. A few porcine oocytes entered metaphase 22 h after the injection of murine sperm, but normal cell division was not observed. The mean time of onset of S-phase in male pronuclei was 9.7 h following porcine sperm injection and 7.4 h following mouse sperm injection. These results suggested that DNA synthesis was delayed in both pronuclei until the sperm chromatin fully decondensed, and the sperm nuclear decondensing activity and microtubule nucleation abilities of the male centrosome are cell cycle dependent.

• 청정기술
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• 제28권2호
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• pp.147-154
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• 2022

Titanate nanotubes (TNTs) were synthesized via alkaline hydrothermal treatment using commercial TiO₂ nanoparticles (P25). The TNTs were prepared at various TiO₂/NaOH ratios, hydrothermal temperatures, and hydrothermal times. The synthesized catalysts were characterized by X-ray diffraction, field-emission scanning electron microscopy, N₂ adsorption-desorption isotherms, field-emission transmission electron microscopy, and ultraviolet-visible spectroscopy. TNTs were generated upon a decrease in the TiO₂/NaOH ratio due to the dissolution of TiO₂ in the alkaline solution and the generation of new Ti-O-Ti bonds to form titanate nanoplates and nanotubes. The hydrothermal treatment temperature and time were important factors for promoting the nucleation and growth of TNTs. The TNT catalyst with the largest surface area (389.32 m² g^-1) was obtained with a TiO₂/NaOH ratio of 0.25, a hydrothermal treatment temperature of 130 ℃, and a hydrothermal treatment time of 36 h. Additionally, we investigated the photocatalytic activity of methyl violet 2B (MV) over the TNT catalysts under UV irradiation and found that the degradation efficiencies of the TNTs were higher than that of P25. Among the TNT catalysts, the TNT catalyst that was hydrothermally synthesized for 36 h (TNT 36 h) exhibited a 96.9% degradation efficiency and a degradation rate constant that was 4.8 times higher than P25 due to its large surface area, which allowed for more contact between the MV molecules and TNT surfaces and facilitated rapid electron transfer. Finally, these results were correlated with the specific surface area.