• Title/Summary/Keyword: field samples

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Application of a nested-polymerase chain reaction assay to differentiate the genotypes of porcine circovirus 2 (돼지 써코바이러스 2형 유전형 분류를 위한 nested-PCR 적용)

  • Chu, Keum-Suk
    • Korean Journal of Veterinary Service
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    • v.34 no.1
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    • pp.13-18
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    • 2011
  • The purpose of this study was to apply a nested-polymerase chain reaction (nPCR) assay to detect and differentiate PCV 2a and PCV 2b. The compared with nPCR and one-step PCR and nPCR showed more sensitive in the detection of PCV-2 from tissue and blood samples. The total of 52 tissue samples was collected from postweanning pigs from 2006 to 2010. All tissue samples showed positive for PCV-2 in one-step PCR and nPCR, followed by the nPCR in order to identify the genotypes of PCV-2. 2 samples (3.8%) showed positive for PCV 2a, and 35 samples were positive for PCV 2b (67.3%), 15 samples (28.9%) were positive the dual genotypes. In addition, 42 blood samples which were collected from the 5 different swine farms were compared figure out the detection rates of nPCR and one-step PCR. The PCV 2 was positive by one-step PCR in 21 samples (50.0%) and nPCR was positive in 37 samples (88.1%). The PCV 2 genotypes in blood samples and 32 samples (76.2%) were positive for PCV 2b and none were positive for PCV 2a, 5 samples (11.9%) were positive for dual genotypes. These results suggest that the nPCR is very efficient for genotyping blood samples and differentiating the genotypes of PCV-2 from field samples.

Studies on the Hydrolysis of Seaweed Using Microorganisms and Its Application -I. Screening of Microfloras Involved in Hydrolysis of Sea Tangle (Laminaria japonica) and Sea Mustard (Undaria pinnatifida) (미생물을 이용한 해조류의 가수분해 및 이용 -I. 다시마와 미역을 가수분해시키는 미생물군의 탐색-)

  • Kim Hae Sub;Bae Tae Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.4
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    • pp.438-444
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    • 2002
  • The purpose of this study is screening of microfloras involved in hydrolysis of sea tangle (Laminaria japonica) and sea mustard ( Undaria pinnatifida), This is a part of studies on the hydrolysis of seaweed using microorganisms. General process is difficult to extract of the useful constituent parts as intercellular mucilage, storage polysaccharide and mineral from seafood. It was screening to thirty-three microflora samples as destructed of tissue in sea tangle and sea mustard to about two hundred microflora samples from mountain, rice field, dry field, sea, seaside and fish market etc. in the neighborhood of Yeosu. Sufficient results of the naked eye observation were obtained at eight microflora samples as a feces of bull, a decayed pine tree, a soil of dry field, the mud of the banks in a rice Held, the water of a ditch in a rice Held, the weed of the banks in a rice field, the water in a rice field and leaved in the air, And the value of chemical analysis of the sample is much better in comparison with control. Accordingly, the hydrolysis of seaweed using microorganisms in the inside of these microflora samples can possibility.

An improvement of real-time polymerase chain reaction system based on probe modification is required for accurate detection of African swine fever virus in clinical samples in Vietnam

  • Tran, Ha Thi Thanh;Dang, Anh Kieu;Ly, Duc Viet;Vu, Hao Thi;Hoang, Tuan Van;Nguyen, Chinh Thi;Chu, Nhu Thi;Nguyen, Vinh The;Nguyen, Huyen Thi;Truong, Anh Duc;Pham, Ngoc Thi;Dang, Hoang Vu
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.10
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    • pp.1683-1690
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    • 2020
  • Objective: The rapid and reliable detection of the African swine fever virus (ASFV) plays an important role in emergency control and preventive measures of ASF. Some methods have been recommended by FAO/OIE to detect ASFV in clinical samples, including realtime polymerase chain reaction (PCR). However, mismatches in primer and probe binding regions may cause a false-negative result. Here, a slight modification in probe sequence has been conducted to improve the qualification of real-time PCR based on World Organization for Animal Health (OIE) protocol for accurate detection of ASFV in field samples in Vietnam. Methods: Seven positive confirmed samples (four samples have no mismatch, and three samples contained one mutation in probe binding sites) were used to establish novel real-time PCR with slightly modified probe (Y = C or T) in comparison with original probe recommended by OIE. Results: Both real-time PCRs using the OIE-recommended probe and novel modified probe can detect ASFV in clinical samples without mismatch in probe binding site. A high correlation of cycle quantification (Cq) values was observed in which Cq values obtained from both probes arranged from 22 to 25, suggesting that modified probe sequence does not impede the qualification of real-time PCR to detect ASFV in clinical samples. However, the samples with one mutation in probe binding sites were ASFV negative with OIE recommended probe but positive with our modified probe (Cq value ranked between 33.12-35.78). Conclusion: We demonstrated for the first time that a mismatch in probe binding regions caused a false negative result by OIE recommended real-time PCR, and a slightly modified probe is required to enhance the sensitivity and obtain an ASF accurate diagnosis in field samples in Vietnam.

Varistor Properties and Aging Behavior of V/Mn/Co/ La/Dy Co-doped Zinc Oxide Ceramics Modified with Various Additives

  • Nahm, Choon-Woo
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.5
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    • pp.284-289
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    • 2014
  • The effects of additives (Nb, Bi and Cr) on the microstructure, varistor properties, and aging behavior of V/Mn/Co/ La/Dy co-doped zinc oxide ceramics were systematically investigated. An analysis of the microstructure showed that all of the ceramics that were modified with various additives were composed of zinc oxide grain as the main phase, and secondary phases such as $Zn_3(VO_4)_2$, $ZnV_2O_4$, and $DyVO_4$. The $Bi_2O_3$-modified samples exhibited the lowest density, the $Nb_2O_5$-modified sample exhibited the largest average grain size, and the $Cr_2O_3$-modified samples exhibited the highest breakdown field. All additives improved the non-ohmic coefficient (${\alpha}$) by either a small or a large margin, and in particular an $Nb_2O_5$ additive noticeably increased the non-ohmic coefficient to be as large as 36. The $Bi_2O_3$-modified samples exhibited the highest stability with variation rates for the breakdown field and for the non-ohmic coefficient (${\alpha}$) of -1.2% and -26.3%, respectively, after application of a DC accelerated aging stress of 0.85 EB/$85^{\circ}C$/24 h.

Characteristics of Atmospheric Concentrations of Toxic Volatile Organic Compounds in Korea ( I ) - Evaluation of Sampling and Analytical Methodology (국내 대기 중 독성 휘발성 유기화합물의 오염 특성(I) - 측정 방법론 평가 -)

  • 백성옥;김미현;김수현;박상곤
    • Environmental Analysis Health and Toxicology
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    • v.17 no.2
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    • pp.95-107
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    • 2002
  • This study was designed to investigate the characteristics of atmospheric concentrations of toxic volatile organic compounds (VOCs) in Korea. Target compounds included 1,3-butadiene, aromatics such as BTEX, and a number of carbonyl compounds. In this paper, as the first part of the study, the performance of sampling and analytical methods was evaluated for the measurement of selected VOCs and carbonyl compounds in the ambient air. VOCs were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/MSD analysis, while carbonyls by the DNPH-silica cartridge sampling with HPLC analysis. The methodology was investigated with a wide range of performance criteria such as repeatability, linearity. lower detection limits, collection efficiency, thermal conditioning, breakthrough volume and calibration methods using internal standards. In addition, the sampling and analytical methods established in this study were applied to real field samples duplicately collected in various ambient environments. Precisions for the duplicate samples appeared to be comparable with the performance criteria recommended by USEPA TO-17. The overall precision of the sampling and analytical methods was estimated to be within 20 ∼ 30% for major aromatic VOCs such as BTEX, whereas the precision for major carbonyl compounds such as formaldehyde and acetaldehyde was within 10 ∼ 20% for field samples. This study demonstrated that the adsorbent sampling and thermal desorption method can be reliably applied for the measurement of BTEX in ppb levels frequently occurred in common indoor and ambient environments.

A Study on the Constitution and the Application of FIA System for Measurement of Nitrite (The Field Water Samples at Kwangju) (아질산성질소 축정용 FIA의 제작 및 용용에 관한 연구 (광주광역시 광주천 시료를 대상으로))

  • Rhee, J.S.;Park, W.C.;Lee, S.W.;Kim, Y.J.
    • Journal of Korean Society on Water Environment
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    • v.18 no.3
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    • pp.283-290
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    • 2002
  • In this study, home-made detection system by means of noble FIA is introduced on the measurement of toxic nitrite in the water samples collected from the area of Kwangju. As the standard calibration between 30 to 1000 ppb, the linearity has been shown more than 0.9999 as the correlation coefficient($R^2$) with the detection limit 1.5 ppb(S/N>2). The distribution of sample concentration was monitored as N.D. - 123 ppb which is wide span of concentrations in field water samples. The low level of nitrite is hardly detectable with other expensive sophisticated instruments including ion chromatography. Whereas the result of high concentration brings forth the necessity monitoring constantly our precious water resources. Successfully, the FIA system has played a very important role detecting wide span of nitrite in water sample. This technique can be adopted for controlling our environment in the near future.

Magnetic Properties of Helicobacter Pylori Ferritins Genetically Prepared Under Different Biomineralization Conditions

  • Son, K.;Park, J.N.;Yoon, Sungwon;Suh, B.J.;Cho, K.J.;Kim, K.H.;Jang, Z.H.
    • Journal of Magnetics
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    • v.21 no.1
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    • pp.20-24
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    • 2016
  • Magnetic properties of bio-magnetic molecule ferritin have been investigated. Two ferritin samples were synthesized under different magnetic fields, 0 and 9.4 T, respectively. This work is focused on the influence of magnetic field on biomineralization process. While magnetization vs. temperature (M-T) data of both samples measured at 1000 Oe are almost identical except for low temperature region (T < 6 K), magnetization vs. field (M-H) data show noticeable difference. From an analysis of M-H data by using a modified Langevin function, we could extract the saturation magnetization $m_0$(T), the effective magnetic moment ${\mu}_{eff}$(T) and the linear susceptibility x(T). The difference between the samples is most prominent in the x(T), whereby the x(T) of the sample prepared at 9.4 T is 1.7 times bigger than that of the other. In addition, from hysteresis and relaxation measurements, we found the sample prepared at 9.4 T showed strikingly smaller coercivity and slower relaxation.

A Study on the Comfortability of Wearing Pantyhose (시판 Stocking의 착용에 따른 쾌적성 연구)

  • Sim, Bu-Ja;Park, Hye-Jun
    • Journal of the Ergonomics Society of Korea
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    • v.18 no.1
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    • pp.71-90
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    • 1999
  • This study was conducted to examine the comfortability of wearing pantyhose in summer. To satisfy this purpose. 4 types of pantyhose were chosen from the market: a Mono type(M), a Wooly type(W), and two Support types(Sl, S2), were chosen. After the performances of samples were measured, these were worn by 8 healthy adult women. Under the summer field environment, psychological comfort ability was examined through the 5 steps of SD method. Physiological comfort ability was examined by measuring the body reactions(clothing pressure, skin temperature, total body weight loss, rectal temperature, pulse rates, and blood pressure), under the artificial environment($28.5{\pm}0.5^{\circ}C$, $82{\pm}3%$). The results of this examination were as follows : The order of comfortability which people felt in the field was W>M>S1>S2. The number of items which showed the highest correlation with comfort ability decreased and the correlation was lowered on the whole as time went by. There was positive high correlation between the performances of samples and comfort ability in compressibility, air permeability, water vapor permeability, while a negative high correlation in thickness, weight, compressional resiliency, strain (course) and moisture regain. The mean skin temperature was in the comfort zone, and rectal temperature, pulse rates, blood pressure were mostly in the normal range. Also it was showed that the correlation between the performance of samples and body reactions, except total body weight loss, was low.

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Nanotube Shape Variation on the Ti-xNb Alloys with Alloying Elements and Applied Potentials

  • Byeon, In-Seop;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.05a
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    • pp.112-112
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    • 2015
  • The purposed of this work was to determine nanotube shape variation on the Ti-xNb alloys with alloying elements and applied potentials. Samples were prepared by arc melting, followed by followed by homogenization for 12 hr at $1000^{\circ}C$ in argon atmosphere. This study was evaluated the phase and microstructure of Ti-xNb alloys using an X-ray diffraction (XRD) and optical microscopy (OM). The morphology of the samples was investigated with a field-emission scanning electron microscope (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). The nanotube on the alloy surface was formed in 1 M $H_3PO_4$ with small additions of NaF 0.8 wt.%. All anodization treatments were carried out using a scanning potentiostat (Model 362, EG&G, USA) at constant voltage 30 V for 120 min, respectively. The morphology of the samples was investigated with a field-emission scanning electron microscope (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Surface characteristics of nanotbue formed on Ti-xNb alloys was investigated by potentiodynamic test and potentiostatic in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. It was observed that the changed ${\alpha}$ phase to ${\beta}$ phase with Nb content.

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Simulation combined transfer learning model for missing data recovery of nonstationary wind speed

  • Qiushuang Lin;Xuming Bao;Ying Lei;Chunxiang Li
    • Wind and Structures
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    • v.37 no.5
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    • pp.383-397
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    • 2023
  • In the Structural Health Monitoring (SHM) system of civil engineering, data missing inevitably occurs during the data acquisition and transmission process, which brings great difficulties to data analysis and poses challenges to structural health monitoring. In this paper, Convolution Neural Network (CNN) is used to recover the nonstationary wind speed data missing randomly at sampling points. Given the technical constraints and financial implications, field monitoring data samples are often insufficient to train a deep learning model for the task at hand. Thus, simulation combined transfer learning strategy is proposed to address issues of overfitting and instability of the deep learning model caused by the paucity of training samples. According to a portion of target data samples, a substantial quantity of simulated data consistent with the characteristics of target data can be obtained by nonstationary wind-field simulation and are subsequently deployed for training an auxiliary CNN model. Afterwards, parameters of the pretrained auxiliary model are transferred to the target model as initial parameters, greatly enhancing training efficiency for the target task. Simulation synergy strategy effectively promotes the accuracy and stability of the target model to a great extent. Finally, the structural dynamic response analysis verifies the efficiency of the simulation synergy strategy.