• Title/Summary/Keyword: Stability Limit

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Rapid and Efficient Detection of 16SrI Group Areca Palm Yellow Leaf Phytoplasma in China by Loop-Mediated Isothermal Amplification

  • Yu, Shao-shuai;Che, Hai-yan;Wang, Sheng-jie;Lin, Cai-li;Lin, Ming-xing;Song, Wei-wei;Tang, Qing-hua;Yan, Wei;Qin, Wei-quan
    • The Plant Pathology Journal
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    • v.36 no.5
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    • pp.459-467
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    • 2020
  • Areca palm yellow leaf (AYL) disease caused by the 16SrI group phytoplasma is a serious threat to the development of the Areca palm industry in China. The 16S rRNA gene sequence was utilized to establish a rapid and efficient detection system efficient for the 16SrI-B subgroup AYL phytoplasma in China by loop-mediated isothermal amplification (LAMP). The results showed that two sets of LAMP detection primers, 16SrDNA-2 and 16SrDNA-3, were efficient for 16SrI-B subgroup AYL phytoplasma in China, with positive results appearing under reaction conditions of 64℃ for 40 min. The lowest detection limit for the two LAMP detection assays was the same at 200 ag/μl, namely approximately 53 copies/μl of the target fragments. Phytoplasma was detected in all AYL disease samples from Baoting, Tunchang, and Wanning counties in Hainan province using the two sets of LAMP primers 16SrDNA-2 and 16SrDNA-3, whereas no phytoplasma was detected in the negative control. The LAMP method established in this study with comparatively high sensitivity and stability, provides reliable results that could be visually detected, making it suitable for application and research in rapid diagnosis of AYL disease, detection of seedlings with the pathogen and breeding of disease-resistant Areca palm varieties.

Validation of a Selective Method for Simultaneous Determination of Doxifluridine and 5-Fluorouracil in Dog Plasma by LC-MS/MS (LC/MS/MS를 이용한 비글견의 혈장 중 Doxifluridine 및 5-Fluorouracil의 동시 분석법 Validation)

  • Kim, Ghee-Hwan;Kim, Won;Kim, Jin-Sung;Jin, Qingri;Kang, Won-Ku;Lee, Jong-Hwa;Ha, Jung-Heun;Jeong, Eun-Ju
    • Journal of Pharmaceutical Investigation
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    • v.37 no.3
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    • pp.179-186
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    • 2007
  • A simple, sensitive and selective liquid chromatographic/tandem mass spectrometric method (LC-MS/MS) was developed and validated for doxifluridine and 5-fluorouracil (5-FU) quantification in dog heparinized plasma. Sample preparation was based on liquid-liquid extraction using a mixture of isopropanol/ethyl acetate (1/9 v/v) to extract doxifluridine, 5-FU and 5-chlorouracil (5-CU, an internal standard) from plasma. Chromatography was performed on a C-18 analytical column and the retention times were 2.7, 1.5 and 1.7 min for doxifluridine, 5-FU and 5-CU, respectively with shorter analysis time within 5 min than previously reported methods. The ionization was optimized using ESI negative mode and selectivity was achieved by tandem mass spectrometric analysis by multiple reaction monitoring (MRM) using the transformations of m/z 244.8>107.6, 129.0>42.0 and 144.9>42.1 for doxifluridine, 5-FU and 5-CU, respectively. The achieved low limit of quantification was 20.0 ng/mL and the assay exhibited linear range of 20-2000 ng/mL ($R^2>0.99957$ for doxifluridine and $R^2>0.99857$ for 5-FU), using $100{\mu}L$ of plasma. Accuracy and precision of quality control samples for both doxifluridine and 5-FU met KFDA and FDA Guidance criteria of 15% for accuracy with coefficients of variation less than 15%. This method demonstrated adequate sensitivity, specificity, accuracy, precision and stability to support the simultaneous analysis of doxifluridine and 5-FU in dog plasma samples in pharmacokinetic and bioequivalence studies.

Detection of the Fungicide Iprovalicarb Residues Using a Surface Plasmon Resonance Biosensor (표면플라즈몬공명 바이오센서를 이용한 살균제 Iprovalicarb 잔류물의 검출)

  • Kim, Woon-Ho;Cho, Han-Keun;Kyung, Kee-Sung;Kim, Gi-Young
    • Journal of Biosystems Engineering
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    • v.34 no.1
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    • pp.50-56
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    • 2009
  • Surface plasmon resonance (SPR) biosensor has been used to detect many biochemical reactions, because this label-free sensor has high sensitivity and rapid response. The reactions are monitored by refractive index changes of the SPR biosensor. Iprovalicarb is protective, curative, and eradicative systemic fungicide introduced by Bayer AG in 1999. It has potential far control of downy mildew infesting onion, cucumber, grape and melon, late blight infesting tomato and potato, and anthracnose infesting watermelon and pepper. It is strictly limited to the maximum residue limit. In this study, the applicability of a portable SPR biosensor (Spreeta, Texas instrument, TX, USA) to detect the iprovalicarb residue was examined. The sensor chip was adopted to detect the reaction of iprovalicarb to immobilized iprovalicarb-antibody. The binding of the iprovalicarb onto the biosensor surface was measured by change of the refractive index (RI). Characteristics of the sensor chip including specificity, sensitivity, stability, and reusability were analyzed. In calibration test for seven levels of iprovalicarb concentration (0.32 to 5,000 mg/L) with three replications, a Sigmoidal model with Hill function was obtained between relative RI value and the iprovalicarb concentration with R-square of 0.998. It took 30 minutes to complete a set of detecting assay with the SPR biosensor.

Optimal Reserve Allocation to Maximize Kinetic Energy in a Wind Power Plant

  • Yoon, Gihwan;Lee, Hyewon;Lee, Jinsik;Yoon, Gi-Gab;Park, Jong Keun;Kang, Yong Cheol
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.1950-1957
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    • 2015
  • Modern wind generators (WGs) are forced or encouraged to participate in frequency control in the form of inertial and/or primary control to improve the frequency stability of power systems. To participate in primary control, WGs should perform deloaded operation that maintains reserve power using speed and/or pitch-angle control. This paper proposes an optimization formulation that allocates the required reserve to WGs to maximize the kinetic energy (KE) stored in a wind power plant (WPP). The proposed optimization formulation considers the rotor speed margin of each WG to the maximum speed limit, which is different from each other because of the wake effects in a WPP. As a result, the proposed formulation allows a WG with a lower rotor speed to retain more KE in the WPP. The performance of the proposed formulation was investigated in a 100-MW WPP consisting of 20 units of 5-MW permanent magnet synchronous generators using an EMTP-RV simulator. The results show that the proposed formulation retains the maximum amount of KE with the same reserve and successfully increases the frequency nadir in a power system by releasing the stored KE in a WPP in the case of a disturbance.

Mitigation of Ammonia Dispersion with Mesh Barrier under Various Atmospheric Stability Conditions

  • Gerdroodbary, M. Barzegar;Mokhtari, Mojtaba;Bishehsari, Shervin;Fallah, Keivan
    • Asian Journal of Atmospheric Environment
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    • v.10 no.3
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    • pp.125-136
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    • 2016
  • In this study, the effects of the mesh barrier on the free dispersion of ammonia were numerically investigated under different atmospheric conditions. This study presents the detail and flow feature of the dispersion of ammonia through the mesh barrier on various free stream conditions to decline and limit the toxic danger of the ammonia. It is assumed that the dispersion of the ammonia occurred through the leakage in the pipeline. Parametric studies were conducted on the performance of the mesh barrier by using the Reynolds-averaged Navier-Stokes equations with realizable k-${\varepsilon}$ turbulence model. Numerical simulations of ammonia dispersion in the presence of mesh barrier revealed significant results in a fully turbulent free stream condition. The results clearly show that the flow behavior was found to be a direct result of mesh size and ammonia dispersion is highly influenced by these changes in flow patterns in downstream. In fact, the flow regime becomes laminar as flow passes through mesh barrier. According to the results, the mesh barrier decreased the maximum concentration of the ammonia gas and limited the risk zone (more than 500 ppm) lower than 2 m height. Furthermore, a significant reduction occurs in the slope of the upper boundary of $NH_3$ risk zone distribution at downstream when a mesh barrier is presented. Thus, this device highly restricts the leak distribution of ammonia in the industrial plan.

The Effects of visuo-perceptual biofeedback training on dynamic postural balance in stroke patients (시지각적 되먹임 훈련이 뇌졸중 환자의 동적자세 균형에 미치는 영향)

  • Lee, Geon-Cheol;Yoon, Jung-Gyu
    • Journal of Korean Physical Therapy Science
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    • v.9 no.2
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    • pp.17-26
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    • 2002
  • This study is aimed to compare the effect of visuo-perceptual biofeedback sitting balance training and conventional sitting balance training using Balance Master on stroke patients with that of program in order to analyze the effect it has on dynamic postural balance. The subjects are twenty-four stroke patients who are receiving physical therapy in Ilsan Paik Hospital and can maintain sitting posture by themselves. These patients were divided to control group and experimental group randomly. In order to compare to control and experimental group before and after the balance training, they were tested with Mann-Whitney U test and in order to compared the changes before and after the balance training, they were tested with Wilcoxon signed-ranks test. The results are as follows: we measured the ability of dynamic posture balance control with limit of stability(LOS) test and rhythmic weight shift test. There was an increasing improvement in the ability of dynamic posture balance control of the experimental group that had visuo-perceptual biofeedback sitting balance control training using the Balance Master(p<0.05, p<0.01). According to the results from above, compared to conventional sitting balance training programs, visuo-perceptual biofeedback sitting balance control training using the Balance Master is considered to be a more valuable therapy in balance control improvement and physical function improvement. It is considered that if the weak points are made up, the training with Balance Master will give help to stroke patients and to patients with balance control disabilities and will further more contribute to successful rehabilitation therapy.

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The Effect of Treadmill and Body Weight Support Treadmill Training on Balance and Gait Ability in Hemiplegia Patients (편마비 환자의 트레드밀과 체중지지의 트레드밀 훈련이 균형능력 및 보행능력에 미치는 영향)

  • Kim, Sung-Chul;Hur, Young-Goo
    • Journal of Korean Physical Therapy Science
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    • v.25 no.1
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    • pp.31-43
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    • 2018
  • Purpose: The purpose of this study is to investigate and to verification of changes that the effect of treadmill and body weight support treadmill training on balance and gait ability for sub-acute stroke patients during 4 week. Method: 16 subjects who was diagnosed stroke were divided into 2 groups(8-treadmill training group, 8-body weight support treadmill group) by randomized control trial. Both training programs were consisted with 40 minuted, 5 times a week for 4 weeks and after training programs. Analysis: We analysed effects and changes on balance and gait ability. Analyses were performed using PASW ver. 18.0 and results were reported as mean ${\pm}$ standard deviation (S.D.). To investigate within group comparisons and to verification on effects of exercise, we did paired t test and repeated measured ANOVA test. Significance was set at p<.05. Result: Both training programs showed positive changes in Limit of Stability but significant results which is area of hemiside, area of intact side, area of posterior, total area were reported in body weight support treadmill training group. Changes of Berg Balance Scale was significantly increase and it had significant correlation between groups. Changes of 6 Minutes Walking Test was significant increase in both groups but there was no significant changes on Foot print and Romberg test. Conclusion: After considering all factors, both training programs showed effect on improvement of balance and gait ability in sub-acute stroke patients, but body weight support treadmill training group had better improvement in dynamic balance than treadmill training group. For the increase of balance and gait ability in sub-acute stroke patients, we need to continues study on difference of treadmill and body weight support treadmill and then we will give stroke patients a better satisfaction if we develop and provide a rehabilitation program for improvement of balance and gait ability.

Structural Studies on RUNX of Caenorhabditis elegans by Spectroscopic Methods

  • Son, Woo-Sung;Kim, Jong-Wan;Ahn, Hee-Chul;Park, Sung-Jean;Bae, Suk-Chul;Lee, Bong-Jin
    • Journal of the Korean Magnetic Resonance Society
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    • v.6 no.1
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    • pp.54-68
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    • 2002
  • PEBP2/CBF (Polyomavirus Enhancer-core Binding Protein 2/Core Binding Factor), represents a new family of heterodimeric transcription factor. Those members play important roles in hematopoiesis and osteogenesis in mouse and human. PEBP2/CBF is a sequence-specific DNA binding protein. Each member of the PEBP2/CBF family of transcription factors is composed of two subunits, ${\alpha}$ and ${\beta}$. The evolutionarily conserved 128 amino acid region in ${\alpha}$ subunit has been called the Runt domain, which harbors two different activities, the ability to bind DNA and interact with the ${\beta}$ subunit. Recently, cDNA clones encoding the C. elegans Runt domain were isolated by screening a cDNA library. This gene was referred to run (Runt homologous gene). In this study, the basic experiments for the structural characterization of RUN protein were performed using spectroscopic methods. We have identified the structural properties of RUN using bioinformatics, CD and NMR. The limit temperature of the structural stability was up to 60$^{\circ}C$ with irreversible thermal process, and the structure of RUN seems to adopt ${\alpha}$ helices and one or more ${\beta}$ sheet or turn. The degree of NMR peak dispersion and intensity was increased by addition of glycine. Therefore, glycine could be used to alleviate the aggregation property of RUN in NMR experiment.

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Surface Flame Patterns and Stability Characteristics of Premixed Burner System for Fuel Reformers (개질기용 예혼합 버너의 화염형태 및 안정성 특성)

  • Lee, Pil-Hyong;Park, Bong-Il;Jo, Soon-Hye;Hwang, Sang-Soon
    • Journal of the Korean Society of Combustion
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    • v.15 no.3
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    • pp.8-14
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    • 2010
  • Fuel processing systems which convert fuel into rich gas (such as stream reforming, partial oxidation, autothermal reforming) need high temperature environment ($600{\sim}1,000^{\circ}$). Generally, anode-off gas or mixture of anode-off gas and LNG is used as input gas of fuel reformer. In order to make efficient and low emission burner system for fuel reformer, it is necessary to elucidate the combustion and emission characteristic of fuel reformer burner. The purpose of this study is to develop a porous premixed flat ceramic burner that can be used for 1~5 kW fuel cell reformer. Ceramic burner experiments using natural gas, hydrogen gas, anode off gas, mixture of natural gas & anode off gas were carried out respectively to investigate the flame characteristics by heating capacity and equivalence ratio. Results show that the stable flat flames can be established for natural gas, hydrogen gas, anode off gas and mixture of natural gas & anode off gas as reformer fuel in the porous ceramic burner. For all of fuels, their burning velocities become smaller as the equivalence ratio goes to the lean mixture ratio, and a lift-off occurs at lean limit. Flame length in hydrogen and anode off gas became longer with increasing the heat capacity. In particular, the blue surface flame is found to be very stable at a very lean equivalence ratio at heat capacity and different fuels. The exhausted NOx and CO measurement shows that the blue surface flame represents the lowest NOx and CO emissions since it remains very stable at a lean equivalence ratio.

A New ZVS Bi-directional CUK DC/DC Converter for a Car Dual Power Supply System (자동차 이중전원 시스템을 위한 새로운 ZVS 양방향 CUK DC/DC 컨버터)

  • Lee S. R.;Lee S. W.;Ko S. H.;Mun J. M.
    • Proceedings of the KIPE Conference
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    • 2004.07a
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    • pp.355-358
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    • 2004
  • Currently, to overcome the limit of a 14V power supply system and to enhance the stability of this system high and to make the fuel efficiency better, a research development of a 42V power supply system is actively the progress. As an intermediate step to change into an unity power supply system, a 42V/14V dual power supply system uses a DC/DC Converter as one of structure elements. Considering the main electric power sources in the next generation of the car is a 42V system a 14V power supply system has advantages as follows : In be managed efficiently and to increase the redundancy at start, to jump start with any vehicles, etc. We need the introduction of a hi-directional converter that can flow the energy each other in a dual 42V-l2V system. This paper proposed the ZVS hi-directional CUK DC/DC converter which decrease the weight with the size of the DC/DC Converter and minimize the loss when the switching happen. In this paper, a circuit design method and an action principle of the circuit was proposed. To verify the proposed circuit, a comprehensive evaluation with theoretical analysis, simulation results is presented.

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