• Title/Summary/Keyword: m-transformation

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Oxidative Transformation of Triclosan by Laccase (Laccase를 이용한 Triclosan의 처리)

  • Kim, Young-Jin
    • Journal of Environmental Health Sciences
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    • v.31 no.1
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    • pp.61-65
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    • 2005
  • The oxidative transformation of triclosan with laccase from Trametes versicolor was conducted in a closed, temperature controlled system containing phosphate buffer for pH control. The optimum pH for triclosan transformation showed about 5. Despite the observation that elevated temperatures tended to inactivate the enzyme, increased transformation of triclosan was observed up to $50^{\circ}C$. Of the mediators studied, ABTS was most successful at enhancing triclosan transformation. About 80% of the toxicity of the initial mixture was reduced after the enzymatic treatment. In the presence of 1.0 mM of anions such as sulfite, sulfide, and cyanide, triclosan transformation was greatly inhibited. Chloride and fluoride ions exhibited inhibition of triclosan transformation at 25 mM. Ferric ion substantially inhibited triclosan transformation at 1.0 mM.

Agrobacterium-Mediated Co-transformation of Multiple Genes in Metarhizium robertsii

  • Padilla-Guerrero, Israel Enrique;Bidochka, Michael J.
    • Mycobiology
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    • v.45 no.2
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    • pp.84-89
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    • 2017
  • Fungi of the Metarhizium genus are a very versatile model for understanding pathogenicity in insects and their symbiotic relationship with plants. To establish a co-transformation system for the transformation of multiple M. robertsii genes using Agrobacterium tumefaciens, we evaluated whether the antibiotic nourseothricin has the same marker selection efficiency as phosphinothricin using separate vectors. Subsequently, in the two vectors containing the nourseothricin and phosphinothricin resistance cassettes were inserted eGFP and mCherry expression cassettes, respectively. These new vectors were then introduced independently into A. tumefaciens and used to transform M. robertsii either in independent events or in one single co-transformation event using an equimolar mixture of A. tumefaciens cultures. The number of transformants obtained by co-transformation was similar to that obtained by the individual transformation events. This method provides an additional strategy for the simultaneous insertion of multiple genes into M. robertsii.

Transformation of Bacillus brevis P176-2 with Plasmid DNA by Electroporation (전기천공법에 의한 Bacillus brevis P176-2의 형질전환)

  • 채기수;엄경일
    • The Korean Journal of Food And Nutrition
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    • v.5 no.2
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    • pp.77-83
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    • 1992
  • The optimum conditions and mechanisms for the plasmid-mediated genetic transformation of intact cells of Bacillus brevis Pl76-2, an extracellular protein producing bacterium by electroporation were investigated. It was found that pUB110 Plasmid DNA can be introduced into intact bacterial cells by electroporation. The frequency of transformation by this electroporation system depended upon the initial electric field strength, the capacity of the electric discharge capacitor, growth stage, number of successive pulses and composition of electroporation buffer. It was effective for transformation that cells were harvested, washed and resuspended with HSM [7M HEPES(PH 7.4), 272mM sucrose, 1 mM MgCl2] electroporation buffer when cell growth was attained to 1.2 at OD660. A maximum frequency of transformation of 2.40$\times$104 transformants per$\mu$g plasmid DNA was obtained by two succesive Pulses with an initial electric field strength of 12.5kV/cm and with a capacitance of 7.3uF.

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Study on predictive model and mechanism analysis for martensite transformation temperatures through explainable artificial intelligence (설명가능한 인공지능을 통한 마르텐사이트 변태 온도 예측 모델 및 거동 분석 연구)

  • Junhyub Jeon;Seung Bae Son;Jae-Gil Jung;Seok-Jae Lee
    • Journal of the Korean Society for Heat Treatment
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    • v.37 no.3
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    • pp.103-113
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    • 2024
  • Martensite volume fraction significantly affects the mechanical properties of alloy steels. Martensite start temperature (Ms), transformation temperature for martensite 50 vol.% (M50), and transformation temperature for martensite 90 vol.% (M90) are important transformation temperatures to control the martensite phase fraction. Several researchers proposed empirical equations and machine learning models to predict the Ms temperature. These numerical approaches can easily predict the Ms temperature without additional experiment and cost. However, to control martensite phase fraction more precisely, we need to reduce prediction error of the Ms model and propose prediction models for other martensite transformation temperatures (M50, M90). In the present study, machine learning model was applied to suggest the predictive model for the Ms, M50, M90 temperatures. To explain prediction mechanisms and suggest feature importance on martensite transformation temperature of machine learning models, the explainable artificial intelligence (XAI) is employed. Random forest regression (RFR) showed the best performance for predicting the Ms, M50, M90 temperatures using different machine learning models. The feature importance was proposed and the prediction mechanisms were discussed by XAI.

Transformation of Antagonistic Pseudomonas stutzeri YPL-1 against Root Rotting Fungi Fusarium solani by Plasmid DNA (생물방제균 Pseudomonas stutzeri YPL-1의 형질전환 조건)

  • 김용수;김상달
    • Microbiology and Biotechnology Letters
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    • v.18 no.5
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    • pp.454-459
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    • 1990
  • For the genetic multipurpose of antagonistic abilities of Pseudomom etutzeri YPL-1 aganist Fusarium solani causing root rot of many important crops by genetic engineering, optimal conditions for transformation of P-stutzeri YPL-1 by pKT230 were investigated. Maxium frequency of the transformation was achieved when cells were harvested at early exponential growth phase. The highest transformation efficiency was obtained when the competent cells were exposed to chilled transformation buffer containing 20 mM RbCI, 100 mM $CaCl_2$ and added l${\mu}g$/ml of plasmid DNA. The pH optimum for transformation was 6.5. When the bacterial cells that were incubated during 60 minutes for the competence were brought in contact with plasmid DNA, the transformations were obtained in the best frequency. It was formed that transformation frequency was 2 ~$6 \times 10^{-6}$ under the optimal conditions.

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Comparison between Two Coordinate Transformation-Based Orientation Alignment Methods (좌표변환 기반의 두 자세 정렬 기법 비교)

  • Lee, Jung-Keun;Jung, Woo-Chang
    • Journal of Sensor Science and Technology
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    • v.28 no.1
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    • pp.30-35
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    • 2019
  • Inertial measurement units (IMUs) are widely used for wearable motion-capturing systems in the fields of biomechanics and robotics. When the IMUs are combined with optical motion sensors (hereafter, OPTs) for their complementary capabilities, it is necessary to align the coordinate system orientations between the IMU and OPT. In this study, we compare the application of two coordinate transformation-based orientation alignment methods between two coordinate systems. The first method (M1) applies angular velocity coordinate transformation, while the other method (M2) applies gyroscopic angle coordinate transformation. In M1 and M2, the angular velocities and angles, respectively, are acquired during random movement for a least-square algorithm to determine the alignment matrix between the two coordinate systems. The performance of each method is evaluated under various conditions according to the type of motion during measurement, number of data points, amount of noise, and the alignment matrix. The results show that M1 is free from drift errors, while drift errors are present in most cases where M2 is applied. Thus, this study indicates that M1 has a far superior performance than M2 for the alignment of IMU and OPT coordinate systems for motion analysis.

Driving Forces for γ→ε Martensitic Transformation of Fe-Mn Alloys (Fe-Mn 합금의 γ→ε 마르텐사이트변태에 필요한 구동력)

  • Lee, Young-Kook;Choi, Chong-Sool
    • Journal of the Korean Society for Heat Treatment
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    • v.9 no.4
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    • pp.243-251
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    • 1996
  • Dilatometric experiment and thermodynamic calculation have been performed to determine $M_s$, $A_s$ and driving forces for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation of Fe-Mn alloys. The transformation temperatures($M_s$, $A_s$, $T_o) were decreased with increasing manganese content and were newly formulated as a function of manganese content. Driving force for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation was increased from -75J/mole to -105J/mole with increasing manganese content from 15wt.% to 25wt.%. Transformation temperature hysteresis($A_s-M_s$) was also increased from 50K to 80K with increasing mangenese content from 15wt.% to 25wt.%. The small driving force(-75J/mole~-105J/mole) and small ${\Delta}T$(50K~80K) for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation indicated that Fe-Mn alloys behave like thermoelastic martensitic alloys : We would like to call them semi-thermoelastic martensitic alloys.

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Digital Transformation, Manipulation of Asset Evaluation and M&A Performance: Discussion on the Intermediary Effect of Internal Control

  • Chen Chen;Hee-Jung Lee;Nan Hui;Xue-Hua Qian
    • Asia-Pacific Journal of Business
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    • v.14 no.1
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    • pp.1-19
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    • 2023
  • Purpose - The purpose of this study was to examine the internal relevance between digital transformation, manipulation of asset evaluation and corporate M&A performance and further explores the impact path of manipulation of asset valuation on corporate M&A performance. Design/methodology/approach - This study based on the financial data of A-share listed companies in Shanghai and Shenzhen Stock Exchanges from 2013 to 2021. Findings - First, manipulation of asset evaluation is negatively correlated with M&A performance. Second, Digital transformation significantly weakens the negative correlation between manipulation of asset evaluation and corporate M&A performance. Third, The effectiveness of internal control plays a partially intermediary role in the process of manipulation of asset evaluation affecting M&A performance. Research implications or Originality - Enriching the existing literature on the subject, the study can also provide useful reference for improving the performance of corporate mergers and acquisitions, regulating asset valuation, promoting the digital transformation of enterprises and improving internal control mechanisms, with both theoretical and practical implications.

A NOTE ON COMPACT MÖBIUS HOMOGENEOUS SUBMANIFOLDS IN 𝕊n+1

  • Ji, Xiu;Li, TongZhu
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.3
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    • pp.681-689
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    • 2019
  • The $M{\ddot{o}}bius$ homogeneous submanifold in ${\mathbb{S}}^{n+1}$ is an orbit of a subgroup of the $M{\ddot{o}}bius$ transformation group of ${\mathbb{S}}^{n+1}$. In this note, We prove that a compact $M{\ddot{o}}bius$ homogeneous submanifold in ${\mathbb{S}}^{n+1}$ is the image of a $M{\ddot{o}}bius$ transformation of the isometric homogeneous submanifold in ${\mathbb{S}}^{n+1}$.