• Proceedings of the Korean Society for Environmental Edudation Conference
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• 2001.11a
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• pp.23-24
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• 2001

• Journal of Korean Electronics
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• v.4 no.12
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• pp.96-100
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• 1984

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.509-518
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• 2019

To monitor the levels of antimicrobials, allergens, pathogens and other contaminants in foods meant for human consumption, it is imperative to have quick, accurate and low-cost tests. Advanced techniques (e.g. label-free biosensor assays) have been developed over the past 10-15 years to solve some of these problems. As biosensors, immunosensors can provide real-time measurements, a high degree of automation, and improved throughput and sensitivity. By comparison with conventional methods, immunosensors are less expensive, less sophisticated physicochemical instruments that require less time for analysis while also being more user-friendly. In this review, we discuss our current knowledge about immunosensors, their strengths and weaknesses, as well as the future of these biosensors in food safety.

• The Journal of Korean Association of Computer Education
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• v.10 no.6
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• pp.11-18
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• 2007

The proposed virtual laboratory system for digital logic circuits is composed of two main sessions, which are concept-learning session and virtual experiment session by virtual digital kit. During concept-learning session the learners can easily understand the important principles in the digital circuits to be performed. In addition, during virtual laboratory session the virtual experiments are performed by assembling and connecting the circuits on the virtual bread board, applying input voltages, making the output measurements, and comparing and transmitting the virtual experimental data. Every activity done during the virtual laboratory session is recorded on database and will be provided with the learners as a preliminary report form including personal information. Thus, the educators may check out the submitted preliminary report to estimate how well the learners understand the circuit operations. Finally, in order to show the validity of our virtual laboratory system we investigated and analysed the damage rate of real experimental equipment during class and assessed student performance on the five quizzes for one semester.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.263-269
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• 2010

This paper describes real-time detection and tracking of moving objects for unmanned visual surveillance. Using images obtained from the fixed camera it detects moving objects within the image and tracks them with displaying rectangle boxes enclosing the objects. Tracking method is implemented on an embedded system which consists of TI DSK645.5 kit and the FPGA board connected on the DSP kit. The DSP kit processes image processing algorithms for detection and tracking of moving objects. The FPGA board designed for image acquisition and display reads the image line-by-line and sends the image data to DSP processor, and also sends the processed data to VGA monitor by DMA data transfer. Experimental results show that the tracking of moving objects is working satisfactorily. The tracking speed is 30 frames/sec with 320x240 image resolution.

• Journal of Life Science
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• v.28 no.7
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• pp.835-840
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• 2018

Quantitative determination of the protein expression levels is one of the most important parts in assessment of the safety of foods derived from genetically modified (GM) crops. Overexpression of AtCYP78A7, a gene encoding cytochrome P450 protein, has been reported to improve tolerance to abiotic stress, such as drought and salt stress, in transgenic rice (Oryza sativa L.). In the present study, an enzyme-linked immunosorbent assay (ELISA) kit for diagnosing AtCYP78A7 protein including AtCYP78A7-specific monoclonal antibody was developed. GST-AtCYP78A7 recombinant protein was induced and purified by affinity column. Four monoclonal antibodies (mAb 6A7, mAb 4C2, mAb 11H6, and mAb 7E8) against recombinant protein were also produced and biotinylated with avidin-HRP. After pairing test using GST-AtCYP78A7 protein and lysate of rice samples, mAb 4C2 and mAb 7E8 were selected as a capture antibody and a detecting antibody, respectively, for ELISA kit. Product test using rice samples indicated that percentages of detected protein in total protein were greater than 0.1% in AtCYP78A7-overexpressing transgenic rice (Line 10B-5 and 18A-4), whereas those in negative control non-transgenic rice (Ilpum and Hwayoung) were less than 0.1%. The ELISA kit developed in this study can be useful for the rapid detection and safety assessment of transgenic rice overexpressing AtCYP78A7.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.121-125
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• 2011

Purpose: The DNA-type virus HBV, discovered by D. Dane and others in 1976, is approximately 42nm big and known as the main cause of liver-related diseases around the world. HBsAg has 4 kinds of subtypes including adw, adr, ayw and ayr and besides common antigen factor a, there are d, y, r, w. From the methods of serologically testing HBV, IRMA, EIA and CLIa were developed for testing HBsAg and are being used in examining the surface antigen of HBV. In this study, among the methods for testing HBV, the recently developed RIAKEY Ultrasensitive HBsAg IRMA kit's sensitivity level and performance in detection of mutant forms were measured and compared with CLIA. Materials and methods: Two certified reference materials, which are WHO 1st International Standard 1985(80/549) and WHO 2nd International Standard 2003(00/588. subtype adw2, genotypeA), were used in the examination and the sensitivity level was measured by diluting these materials from 0.08 IU/ml to 0.005 IU/ml. The materials for examining the detection of mutant forms included 9 kinds of subtype 'ad' and one kind of subtype 'ay' purchased from DSI company. Also, with the use of positive and negative samples, they was compared with CLIA. Result: Ultrasensitive HBsAg kit based on IRMA method showed the detection of up to 0.01 IU/ml not only for WHO 1st International Standard 1985(80/549) but also for WHO 2nd International Standard 2003(00/588. subtype adw2, genotypeA) and the sensitivity level was measured as 0.01 IU/ml by WHO standard. In testing the performance for detection of mutant forms, the 9 kinds of subtype 'ad' and one kind of subtype 'ay' mutant materials were detected, demonstrating the capacity of detecting various types of mutant forms. Conclusions: With the clinical importance of sensitivity level and performance in detection of mutant forms increasing in the field of HBsAg diagnosis, the examination of IRMA's effectiveness using RIA method in the aspects of the sensitivity level and performance in detection of mutant forms was carried out and its result is as follows. The sensitivity level was measured as 0.01 IU/ml by WHO standard and it was possible to measure various types of mutant forms with high sensitivity. Thus it is suggested that more speedy and accurate reports could be produced from a nuclear medicine laboratory for clinical practitioners requiring results of various situations.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.87-96
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• 2022

Recently, the purchase of fresh-cut produce and meal kits has increased. Ready-to-eat (RTE) fresh-cut products have potentially hazard of cross-contamination of various microorganisms in the processes of peeling, slicing, dicing, and shredding. There are frequent cases of protozoa food poisoning, such as Cyclospora and Cryptosporidium, caused by fresh-cut products. The objective of the study is to investigate the microbiological qualities of various types of RTE fresh-cut products in the domestic on/offline markets. RTE fresh-cut fruits cup (n=100), fresh-cut vegetables (n=50), and vegetables in meal kits (Vietnamese spring rolls and white radish rolls kits, n=50) were seasonally analyzed. The contamination levels of hygienic indicator organisms, yeast and mold (YM), and foodborne pathogens (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7) were monitored. Overall, the lowest microbiological qualities of meal kits vegetables were observed, followed by RTE fresh-cut fruits cup and fresh-cut vegetables. Contamination levels of total aerobic bacteria, coliforms, and YM in meal kits vegetables were 5.91, 3.90, and 4.71 logs CFU/g, respectively. From the qualitative analysis, 6 out of 200 RTE fresh-cut products (3%) returned positive result for S. aureus. From the quantitative analysis, the contamination levels of S. aureus in purple cabbage from a meal-kit and fresh-cut pineapple were below the acceptable limit (100 CFU/g). Staphylococcus enterotoxin seg and sei genes were detected in RTE fresh-cut celery and red cabbage from meal-kits, respectively. S. aureus contamination must be carefully controlled during the manufacturing processes of RTE fresh-cut products. Neither Cyclospora cayetanensis nor Cryptosporidium parvum was detected in the samples of RTE fresh-cut products and vegetables from meal-kits from the Korean retail markets.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.457-463
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• 2023

To investigate residual pesticide levels in agricultural products contained in Meal-kits, 27 Meal-kit products were collected from marts, Meal-kit shops, and online stores in Incheon City, South Korea. Seventy-six vegetable and thirty-seven mushroom products were analyzed for residual levels of 339 pesticides. Residual pesticides were detected in 23 out of 76 vegetables and were not present in the 37 mushroom products. The residual pesticide detection rate was 20.4% (23/113 cases). The pesticides famoxadone 0.034 mg/kg (standard: 0.01 mg/kg or less, PLS) and fenpyroximate 0.302 mg/kg (standard: 0.01 mg/kg or less, PLS) exceeded their maximum residue levels (MRL). This survey revealed that various types of pesticides remain in agricultural products in Meal-kits. Due to the nature of Meal-kit products, there is no separate standard for residual pesticides in agricultural products. Therefore, continuous monitoring of residual pesticides is necessary.

• Analytical Science and Technology
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• v.29 no.2
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• pp.79-84
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• 2016

A small and inexpensive thermal cycler (PCR machine), known as the MiniPCR^TM Mini8 Thermal Cycler (Amplyus, Cambridge, MA, USA), was developed. In this study, the performance of this PCR machine was compared with the GeneAmp^® PCR system 9700 (Applied Biosystems) using four autosomal short tandem repeat (STR) kits, a Y-chromosome STR kit, and a mitochondrial DNA HV1/HV2 sequence analysis. The sensitivity and stochastic effects of the STR multiplex kits and the quality of the DNA sequence analysis were similar between the two PCR machines. The MiniPCR^TM Mini8 Thermal Cycler could be used for analyses at forensic DNA laboratories and crime scenes. The cost of the PCR is so economical that school laboratories and individuals could use the machines.