• Title/Summary/Keyword: detection technique

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Photo-induced inter-protein interaction changes in the time domain; a blue light sensor protein PixD

  • Terazima, Masahide
    • Rapid Communication in Photoscience
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    • v.4 no.1
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    • pp.1-8
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    • 2015
  • For understanding molecular mechanisms of photochemical reactions, in particular reactions of proteins with biological functions, it is important to elucidate both the initial reactions from the photoexcited states and the series of subsequent chemical reactions, e.g., conformation, intermolecular interactions (hydrogen bonding, hydrophobic interactions), and inter-protein interactions (oligomer formation, dissociation reactions). Although time-resolved detection of such dynamics is essential, these dynamics have been very difficult to track by traditional spectroscopic techniques. Here, relatively new approaches for probing the dynamics of protein photochemical reactions using time-resolved transient grating (TG) are reviewed. By using this method, a variety of spectrally silent dynamics can be detected and such data provide a valuable description about the reaction scheme. Herein, a blue light sensor protein TePixD is the exemplar. The initial photochemistry for TePixD occurs around the chromophore and is detected readily by light absorption, but subsequent reactions are spectrally silent. The TG experiments revealed conformational changes and changes in inter-protein interactions, which are essential for TePixD function. The TG experiments also showed the importance of fluctuations of the intermediates as the driving force of the reaction. This technique is complementary to optical absorption detection methods. The TG signal contains a variety of unique information, which is difficult to obtain by other methods. The advantages and methods for signal analyses are described in detail in this review.

Analysis of Residual Solvents in Food Packaging Materials Using Solid Phase Microextraction Method (Solid Phase Microextraction법을 이용한 식품포장재 중의 잔류용제 분석)

  • 서택교;박상현;이윤수;김정한;권익부
    • Journal of Food Hygiene and Safety
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    • v.14 no.1
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    • pp.76-83
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    • 1999
  • Solid phase microextraction (SPME) was used for the determination of 6 standard solvents (methanol, isopropanol, methyl ethyl ketone, ethyl acetate, cyclohexane, toluene) in food packaging materials. SPME method is a solvent-free sample preparation technique in which a fused silica fiber coated with polymeric organic liquid is introduced into the headspace above the sample. SPME method using fiber coated polydimethylisiloxane (PDMS) was compared with static headspace (SHS) method used as a reference. It was found that the optimal adsorption condition using PDMS-SPME method was 2$0^{\circ}C$ for 15 minutes for the standard solvents. Detection limits, linearity, reproducibility and recovery of both SHS and PDMS-SPME methods have been determined using 6 standard solvents. Both methods were characterized by high reproducibility and good linearity. Using SHS methods, the mean recovery of the 6 standard solvents was ranged from 75.5% to 105.8% with a mean relative standard deviation (RSD) of 0.3% to 4.8%. With PDMS-SPME method, the mean recovery of the 6 standard solvents was ranged from 86.7% to 108.3% with a mean RSD of 0.4% to 2.5%. The detection limits of both methods were the same for toluene, cyclohexane and methyl ethyl ketone; those of PDMS-SPME method were higher than those of SHS method for methanol, isopropanol and ethyl acetate. PDMS-SPME fiber shoed excellent adsorption for non-polar solvents such as toluene, while it showed relatively low adsorption for polar solvents such as methanol.

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Detection of Adulteration of Sesame Oil(I) Chromatographic Determination for Soybean Oil, Linseed Oil and Perilla Oil in Sesame Oil (참기름의 진위 판정에 관하여 - (I) 참기름중의 대두유, 아마인유 및 들깨기름의 검출)

  • 천석조;임영희;송인상;노정배
    • Journal of Food Hygiene and Safety
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    • v.3 no.2
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    • pp.59-63
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    • 1988
  • A technique of high-performance liquid chromatography (HPLC) was applied to tbe detection and estimation for composition of linseed oil, perilla oil and soybean oil in edible sesame oil. Tbe triglycerides were separated into five peaks in sesame 011, seven peaks in linseed oil, perilla oil and soybean oil by HPLC. From the resulls separated by HPLC on the basis of PN (partition number), tbese observations indicate tbat adullerants linseed oil, perilla oil and soybean oil in sesame oil for the ratio of minimum 4%, respectively can be detected. As a resull, it was suggested that tbe use of HPLC can provide more detailed Information concerning adulteration of sesame all.

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Interactive 3D Pattern Design Using Real-time Pattern Deformation and Relative Human Body Coordinate System (실시간 패턴 변형과 인체 상대좌표계를 이용한 대화형 3D 패턴 디자인)

  • Sul, In-Hwan;Han, Hyun-Sook;Nam, Yun-Ja;Park, Chang-Kyu
    • Fashion & Textile Research Journal
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    • v.12 no.5
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    • pp.582-590
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    • 2010
  • Garment design needs an iterative manipulation of 2D patterns to generate a final sloper. Traditionally there have been two kinds of design methodologies such as the flat pattern method and the pattern draping method. But today, it is possible to combine the advantages from the two methods due to the realistic cloth simulation techniques. We devised a new garment design system which starts from 3D initial drape simulation result and then modifies the garment by editing the 2D flat patterns synchronously. With this interactive methodology using real-time pattern deformation technique, the designer can freely change a pattern shape by watching its 3D outlook in real-time. Also the final garment data were given relative coordinates with respect to the human anthropometric feature points detected by an automatic body feature detection algorithm. Using the relative human body coordinate system, the final garments can be re-used to an arbitrary body data without repositioning in the drape simulation. A female shirt was used for an example and a 3D body scan data was used for an illustration of the feature point detection algorithm.

Detection of Lawsonia intracellularis in swine feces by polymerase chain reaction (돼지분변에서 PCR에 의한 Lawsonia intracellularis 검색)

  • 장성준;김정화;김영태;김기향;김중규;김영욱;최일영
    • Korean Journal of Veterinary Service
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    • v.24 no.1
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    • pp.43-50
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    • 2001
  • Swine proliferative enteritis(SPE) caused by inかsoma intracellularis is a common enteric disaese of grower and finisher pig. Swine affected with SPE show variable clinical signs including diarrhea, weight loss, aberrant growth and death. The characteristic lesion of ileitis at necropsy is marked thickening of the last section of the small intestine. The inner lining of the thickened intestine proliferates almost like a cancer and curved rod bacteria(L intracellularis) are always seen inside the intestinal wall. Infected swine shed the organism in the feces. Isolation and growth of pure L intracellularis in vitro requires a suitable cell culture. This procedure is difficult and not a practical means of diagnosis, thus the polymerase chain reaction(PCR) test of feces can be used to determine whether a pig is shedding the infective organism. A sensitive assay based on amplification of a 319bp DffA fragment of the L intracellularis of Swine proliferative enteritis was attempted for the detection of the organism in the 62 feces of swine. L intracellularis was identified on three herds and detected in 6 fecal samples, representing a infection rate of 9.7%. The PCR was very sensitive and specific on the individual level. The PCR technique could be very useful for the diagnosis of this disease.

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Detection of viral-like particles in feces of Korean indigenous calves with diarrhea by negative staining (음성대조 염색법을 이용한 설사 한우송아지 분변내 바이러스양 입자 검색)

  • 임종수;강춘원;이태욱;김내영;정용운;강문일;한동운;최현성;이채용
    • Korean Journal of Veterinary Service
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    • v.22 no.1
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    • pp.43-52
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    • 1999
  • Presently, viral isolation in the diarrheal feces can be reached by many tools such as fluorescent antibody test(FA), negative contrast electron microscopy(NCEM), virus neutralization test, cell culture, and so on. The purpose of the study was to aimed at the establishment of simplified NCEM technique which can be efficiently applied for diarrheal feces and also the understanding on prevalence of viral-induced diarrhea in calves. One hundred fourty-seven korean indigenous calves with diarrhea were examined to their feces by the modified NCEM. Among them, 98(66.7%) were confirmed to have one or more viruses in feces. The viruses detected were identified as rotavirus(33.3%), coronavirus(16.3% ), togavirus(10.2%) and herpesvirus(0.7%). Ten cases of combined viral infection were consisted of 8 with rotavirus+coronavirus, one with rotavirus+togavlrus and one with rotavirus+herpesvirus. Dirrheal types could classified by yello-wish watery(44.9a ), blood-tinged(19.7% ), white watery(17.7% ) , brownish watery(14.3%), greenish watery(3.4%) diarrhea, respectively. Yellowish watery diarrhea(66cases) was frequently included rotavirus(31.8%), coronavirus(15.2%), and togavirus(13.6%), respectively. Consequently, these results suggest that the modified NCEM is reliable and efficient diagnostic tool for detection of viruses in the diarrheal feces and many calves rearing in Chonnam province have been exposed to some enteric viral agents mainly including rotavirus and coronavirus.

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Detection Algorithm for Cracks on the Surface of Tomatoes using Multispectral Vis/NIR Reflectance Imagery

  • Jeong, Danhee;Kim, Moon S.;Lee, Hoonsoo;Lee, Hoyoung;Cho, Byoung-Kwan
    • Journal of Biosystems Engineering
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    • v.38 no.3
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    • pp.199-207
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    • 2013
  • Purpose: Tomatoes, an important agricultural product in fresh-cut markets, are sometimes a source of foodborne illness, mainly Salmonella spp. Growth cracks on tomatoes can be a pathway for bacteria, so its detection prior to consumption is important for public health. In this study, multispectral Visible/Near-Infrared (NIR) reflectance imaging techniques were used to determine optimal wavebands for the classification of defect tomatoes. Methods: Hyperspectral reflectance images were collected from samples of naturally cracked tomatoes. To classify the resulting images, the selected wavelength bands were subjected to two-band permutations, and a supervised classification method was used. Results: The results showed that two optimal wavelengths, 713.8 nm and 718.6 nm, could be used to identify cracked spots on tomato surfaces with a correct classification rate of 91.1%. The result indicates that multispectral reflectance imaging with optimized wavebands from hyperspectral images is an effective technique for the classification of defective tomatoes. Conclusions: Although it can be susceptible to specular interference, the multispectral reflectance imaging is an appropriate method for commercial applications because it is faster and much less expensive than Near-Infrared or fluorescence imaging techniques.

The Significance of the Analytical Sciences In Environmental Assessment

  • Chung, Yong;Ahn, Hye-Won
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.1079-1087
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    • 1995
  • The quality of human life is directly related to the quality of the environment. To assess environmental quality we must first determine the MCLG(Maximum Contaminant Level Goal), MCL(Maximum Contaminant Level), environmental impact and so on. The MCLG is the concentration at which no known adverse health effects occur. The MCLG is determined by risk assessment identifying which process is hazardous assessing, dose-response, human exposure, and characteristics of risk. With consideration of analytical methods, treatment technology, cost and regulatory impact, the MCL is set as close to the MCLG as possible. In this way, determination of the concentration and national distribution of contaminants is important for assessment of environmental quality The analytical sciences pose potential problems in assessing environmental quality. Continuing improvement in the performance of analytical instruments and operating technique has been lowering the limits of detectability. Contaminant concentration below the detection limit has usually been reported as ND(Not-Detected) and this has often been misunderstood as equivalent to zero. Because of this, more the contaminant concentration in the past was below the detection limit, whereas contaminants can be quantified now even though the contaminant concentration might remain the same or may even have decreased. In addition, environmental sampling has various components due to heterogeneous matrices. These samples are used to overestimate the concentration of the contaminant due to large variability, resulting in excess readings for MCL. In this paper, the significance of the analytical sciences is emphasized in both a conceptual and a technical approach to environmental assessment.

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A Real-Time Inspection System for Digital Textile Printing (디지털 프린팅을 위한 실시간 직물 결점 검출 시스템)

  • Kim, Kyung-Joon;Lee, Chae-Jung;Park, Yoon-Cheol;Kim, Joo-Yong
    • Textile Coloration and Finishing
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    • v.20 no.1
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    • pp.48-56
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    • 2008
  • A real-time inspection system has been developed by combining CCD based image processing algorithm and a standard lighting equipment. The system was tested for defective fabrics showing nozzle contact scratch marks, which are one of the frequently occurring defects. Two algorithms used were compared according to both their processing time and detection rate. First algorithm (algorithm A) was based on morphological image processing such as dilation and opening for effective treatment of defective printing areas while second one (algorithm B) mainly employs well-defined edge detection technique based on canny detector and Zermike moment. It was concluded' that although both algorithms were quite successful, algorithm B showed relatively consistent performance than algorithm A in detecting complex patterns.

Nano Scale Compositional Analysis by Atom Probe Tomography: I. Fundamental Principles and Instruments (Atom Probe Tomography를 이용한 나노 스케일의 조성분석: I. 이론과 설비)

  • Jung, Woo-Young;Bang, Chan-Woo;Gu, Gil-Ho;Park, Chan-Gyung
    • Applied Microscopy
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    • v.41 no.2
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    • pp.81-88
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    • 2011
  • Even though importance of nano-scale structure and compositional analysis have been getting increased, existing analysis tools have been reached to their limitations. Recent development of Atom Probe Tomography (APT), providing 3-dimensional elemental distribution and compositional information with sub-nm scale special resolution and tens of ppm detection limit, is one of key technique which can overcome these limitations. However, due to the fact that APT is not well known yet in the domestic research area, it has been rarely utilized so far. Therefore, in this article, the theoretical background of APT was briefly introduced with sample preparation to help understanding APT analysis.