• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.477-488
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• 2020

Recently, foodborne illness outbreaks linked to fresh produce are being increasingly reported in the United States, the EU, and Korea as well. Some of this increase may be due to improved surveillance, increase in consumption, change in consumers' habits, and complex distribution systems. Garlic chive is a green, fresh-cut vegetable consumed year-round as a nutrition-rich herb in Korea. It is also prone to contamination with foodborne pathogens during pre-harvest, as amendment with high amounts of livestock manure or compost to soil is required in its cultivation. Our aim in this study was to evaluate microbial contamination of garlic chives, garlic chives cultivation soil, compost, and irrigation water in the southern part of Korea. Samples were collected in A, B, and C regions in 2019 and 2020, and 69, 72, 27, and 40 of garlic chives, soil, compost, and irrigated water, respectively, were analyzed for the presence of sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), Bacillus cereus, Staphylococcus aureus, pathogenic E. coli, E. coli O157:H7, Listeria monocytogenes, and Salmonella spp. In A, B, and C regions, levels of total aerobic bacteria, coliform, B. cereus, and S. aureus on all samples were between 1.14 and 8.83 log CFU/g, 0.43 and 5.01 log CFU/g, 0.41 and 5.55 log CFU/g, and 1.81 and 6.27 log CFU/g, respectively. B. cereus isolated from garlic chives and environmental samples showed β-hemolysis activity. Incidence of S. aureus in garlic chive and its production environments in 2020 was different from 2019. In this study, B. cereus and S. aureus were the only pathogenic microorganisms detected in all samples. As a result, this work suggests that continuous monitoring in the production and pre-harvest environment is required to improve hthe hygiene and safety of garlic chive.

• Journal of fish pathology
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• v.11 no.1
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• pp.77-81
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• 1998

By standardized method, Bacillus subtilis BGA, Bacillus cereus var. mycoides ATCC 11778, and Micrococcus luteus ATCC 9341 were seeded on the muller hinton agar (Difco) plate, and pH was adjusted to 6.0, 7.2, and 8.0. Five agar plates, B. subtilis (pH 6.0), B. cereus (pH 6.0), B. subtilis (pH 7.2), B. subtilis (pH 8.0), and M. luteus (pH 8.0), were employed as test plates of modified EEC 4-plate method. Oxytetracycline (OTC) with a diet was orally administered to flounder, Paralichthys olivaceus, at 100 mg/kg once a day. After oral administration, modified EEC 4-plate method by the three screening test using muscle-direct, extraction-disk and direct-disk methods was conducted for 3 fish at 1, 3, 5, 10, 15, 20, 25 and 30 days. Muscle-direct treatment of B. subtilis (pH 6.0) was found to be dubious positive (${\pm}$) at the 1st day after the administration; thereafter, it was found to be negative to the last day of the experiment. Extraction-disk and direct-disk treatment of B. subtilis (pH 6.0) were found to be negative from the 1st day to the last day after the administration. B. subtilis (pH 7.2), B. subtilis (pH 8.0), and M. luteus (pH 8.0) by the three screening tests, were found to be negative all the way after the administration. On the other hand, B. cereus (pH 6.0) by the three screening tests was clearly found to be positive for the first 15 days after the administration, and then muscle-direct and direct-disk treatment of B. cereus (pH 6.0) were found to be dubious positive at 20th days after the administration. However extraction-disk treatment of B. cereus (pH 6.0) was clearly found to be negative at the same stage; thereafter, the three screening tests of B. cereus (pH 6.0) were found negative to the last of the experiment. These findings showed that to have equal sensitivity to those determination for the residual detection of OTC, and also confirmed that B. cereus was effective test organism for the monitoring of OTC.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.400-407
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• 2014

Urban farming supplies emotional stability and fresh vegetables to participating persons, however, no information regarding the biosafety of agricultural products from urban farming is available. Here, we collected 260 samples of Chinese cabbages and lettuce from 4 urban community gardens and 6 roof gardens in Seoul from September through October 2012, and monitored the microbiological and parasitological contamination quantitatively and/or qualitatively. The mean counts of total aerobic bacteria and coliforms were $6.1{\pm}0.8\;log\;CFU{\cdot}g^{-1}$ ( range, $5.4{\pm}0.6{\sim}7.1{\pm}0.8\;log\;CFU{\cdot}g^{-1}$) and $4.0{\pm}0.7\;log\;CFU{\cdot}g^{-1}$ (range, $2.3{\pm}0.6{\sim}6.1{\pm}0.9\;log\;CFU{\cdot}g^{-1}$), respectively. Coliforms were detected on 59.6% among 260 vegetable samples. There were no significant differences in the contamination levels of total aerobic bacteria and coliforms between the Chinese cabbages and lettuce, whereas both levels of vegetables from urban community gardens were higher than those of roof gardens (p > 0.05). Escherichia coli was isolated at 3.1% among whole vegetables, and contamination level was $1.5{\pm}0.2\;log\;CFU{\cdot}g^{-1}$. Among foodborne pathogens, Staphylococcus aureus was detected in 1.5%, however, Salmonella spp., Listeria monocytogenes and E. coli O157:H7 were not detected on any of the vegetable samples. We also found undefined parasite eggs from two samples of Chinese cabbages (0.8% of total vegetables we tested). From these study, we found the presence of microbial contamination of agricultural products from urban farming, thus we need further concern to improve the biosafety during production of agricultural products.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.33-40
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• 2013

From March 2012 to January 2013, this study was conducted as a part of the project for making a precise electronic ecological zoning map of vegetation on a highly reduced scale of 1 to 5,000 with a view to improving management efficiency of national parks and enlarging the availability of the data produced from the basic research monitoring the resources of national parks. For the research accuracy and rapidity, a vegetation map was specially created for the on-the-site-vegetation research. To make the map more meticulous, we categorized the vegetation database into five groups: broadleaved forest, coniferous forest, mixed forest, rock vegetation and miscellaneous one. After comparing the results of the data built for the vegetation research and the actual research findings, it was made clear that vegetation of both categories was almost the same in case of broad-leaved forest with 72.20% and 78.45% respectively, and also equivalent in other groups like, for example, coniferous forest (16.70%, 13.41%), mixed forest (9.50%, 7.49%) and rock vegetation (0.60%, 0.15%). According to the precise vegetation map produced from the research, the deciduous broad-leaved forest was the most widely prevalent type in the correlated hierarchical classification of vegetation, occupying 65.78% of the overall vegetation. It was followed by mountain valley forest (15.17%), coniferous forest (10.90%), and plantation forest (7.00%) in order. It is particularly noteworthy that Mt. Deogyusan national park has retained a very stable and versatile forest vegetation in the outstanding state since approximately 20% of the mountain turns out to belong to the I grade vegetation conservation classification which contains climax forests, unique vegetation, subalpine vegetation, matured stands which are older than 50 years and etc.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.148-154
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• 2012

It was carried out to detect anti-impotence drug-like compounds, sibutramine and their analogues in dietary supplements, which are doubtful whether they include illegal compounds. A total of 51 food products were bought online and have been investigated. The separation was achieved on a C18 column, with the mobile phase made up of water (5 mM sodium hexanesulfonate and 0.1% phosphoric acid) and 95% acetonitrile, at a flow rate of 1.2 mL/min with gradient elution using by HPLC-DAD. The UV signals were monitored at 220 nm and 291 nm. LC-ESI-tandom MS was utilized to confirm that detected compounds in samples are the same as the reference materials. Two nutrient supplement foods and ginseng products were found to contain 1.3-82.1 mg of sildenafil, dimethylthiolsildenafil and pseudovardenafil per serving size. In addition, two other processed products were detected to contain 1.7 and 2.2 mg of didesmethylsibutramine, derived from sibutramine per serving size.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.27-32
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• 2010

This study was conducted to monitor aflatoxins in various medicinal herbs, providing available data for the safety of those products. To monitor aflatoxins in medicinal herbs, a total of 400 samples of 40 different herbs were collected in commercial retailers in Seoul, Daejeon, Gwangju, Daegu, and Busan from March to August, 2008. The samples that passed the sensory evaluation were tested for aflatoxins. Aflatoxins in samples were analyzed by HPLC-florescence coupled with photochemical enhancement. Samples were extracted with 70% methanol and then diluted to the appropriate concentration. A refining process was performed using an immunoaffinity column. The analytical method used in this study was validated. The $R^2$ value for aflatoxin $B_1$ was 0.99946, and the detection range was from 0.25 to 10.0 ng/mL. The accuracy of the analysis was ranged from 83.2% to 101.8%. The relative standard deviation (RSD) in the aflatoxin $B_1$ analysis was 3.4%, demonstrating the precision of this method. In addition, the detection limit and quantitative analysis limit of aflatoxin $B_1$ was $0.53\;{\mu}g/kg$ and $1.76\;{\mu}g/kg$, respectively. These results indicated that the analytical method used in this study was appropriate. The results of HPLC showed that 1% (4 samples) of the samples may contain aflatoxins. The concentration of quantified aflatoxin was $2.3\;{\mu}g/kg$ for both Quisqualis fructus and Remotiflori radix samples. The other samples were below the limit of quantification. Moreover, the concentration of aflatoxin $B_1$ which is made by specific fungi were below the level of regulation. Only 20% of aflatoxin $B_1$ were transferred to hot water. Therefore, the levels of aflatoxins in medicinal herbs were considered to be safe especially considering the aflatoxin transfer ratio.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.391-402
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• 2013

Pesticide residues in agricultural products in Korea were evaluated to create a data base to inform food policy. Pesticide residues were investigated in 17 commodities collected from 9 provinces in 2012. Our analytical method of multiresidue analysis, involved the analysis of individual recovery, linearity, limit of detection, and limit of quantitation of 60 pesticides in six matrices. The pesticides, including acetamiprid and forchlorofenuron, were evaluated in 358 agricultural samples by liquid chromatography/tandem mass spectrometry. Twenty three pesticides were detected from 67 samples. The results showed that the ratio of estimated daily intake to acceptable daily intake was 0.00009-0.0861% by the intake assessment, which means that residual pesticides in agricultural products in Korea are properly controlled.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.268-273
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• 2006

차세대 무선 네트워크 (4G)는 새로운 무선 접속 기술의 개발과 함께 많은 연구가 필요한 분야이다. 그 중에서 특히 단말의 끊김없는 이동성을 제공해 주기 위한 핸드오버 기술이 가장 중요하다고 할 수 있다. 차세대 무선 네트워크는 새로운 무선 접속 기술과 함께 기존의 무선랜이나 이동통신망 등과 같이 사용될 것으로 예상되며, 네트워크 계층에서의 이동성 지원을 위하여 Mobile IPv6를 사용할 것으로 예상되는 네트워크이다. 이러한 네트워크에서 끊김없는 이동성을 제공해 주기 위해서는 현재까지 연구된 핸드오버 기능 및 구조에 대한 연구와 함께 보다 다양해진 네트워크 환경과 QoS 등을 고려한 종합적인 핸드오버 기능에 대한 연구가 필요하다. 본 논문에서는 차세대 무선 네트워크에서 단말의 끊김없는 핸드오버를 제공해 주기 위하여 필요한 기능들을 도출하고, 이들간의 유기적인 연관관계를 정의하여 다양한 네트워크 환경과 사용자의 우선순위, 어플리케이션의 QoS 요구 조건 등을 고려한 종합적인 핸드오버 기능 구조를 제안하고자 한다. 제안하는 핸드오버 구조는 Monitoring, Triggering, Handover의 세 가지 module로 나뉘어져 있으며, 각각은 필요에 따라 sub-module로 다시 세분화된다. 제안하는 핸드오버 구조의 가장 큰 특징은 핸드오버를 유발시킬 수 있는 여러 가지 요소를 종합적으로 고려하며 이들간의 수평적인 비교가 아닌 다단계 비교를 수행하여 보다 정확한 triggering이 가능하도록 한다. 또한 단말의 QoS 요구 사항을 보장하고 네트워크의 혼잡도(congestion) 및 부하 조절 (load balancing)을 위한 기능을 핸드오버 기능에 추가하여 효율적인 네트워크의 자원 사용이 가능하도록 설계하였다.서버로 분산처리하게 함으로써 성능에 대한 신뢰성을 향상 시킬 수 있는 Load Balancing System을 제안한다.할 때 가장 효과적인 라우팅 프로토콜이라고 할 수 있다.iRNA 상의 의존관계를 분석할 수 있었다.수안보 등 지역에서 나타난다 이러한 이상대 주변에는 대개 온천이 발달되어 있었거나 새로 개발되어 있는 곳이다. 온천에 이용하고 있는 시추공의 자료는 배제하였으나 온천이응으로 직접적으로 영향을 받지 않은 시추공의 자료는 사용하였다 이러한 온천 주변 지역이라 하더라도 실제는 온천의 pumping 으로 인한 대류현상으로 주변 일대의 온도를 올려놓았기 때문에 비교적 높은 지열류량 값을 보인다. 한편 한반도 남동부 일대는 이번 추가된 자료에 의해 새로운 지열류량 분포 변화가 나타났다 강원 북부 오색온천지역 부근에서 높은 지열류량 분포를 보이며 또한 우리나라 대단층 중의 하나인 양산단층과 같은 방향으로 발달한 밀양단층, 모량단층, 동래단층 등 주변부로 NNE-SSW 방향의 지열류량 이상대가 발달한다. 이것으로 볼 때 지열류량은 지질구조와 무관하지 않음을 파악할 수 있다. 특히 이러한 단층대 주변은 지열수의 순환이 깊은 심도까지 가능하므로 이러한 대류현상으로 지표부근까지 높은 지온 전달이 되어 나타나는 것으로 판단된다.의 안정된 방사성표지효율을 보였다. $^{99m}Tc$-transferrin을 이용한 감염영상을 성공적으로 얻을 수 있었으며, $^{67}Ga$-citrate 영상과 비교하여 더 빠른 시간 안에 우수한 영상을 얻을 수 있었다. 그러므로 $^{99m}Tc$-transierrin이 감염 병소의 영상진단에 사용될 수 있을 것으로 기대된다.리를 정량화 하였다. 특히 선

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.3
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• pp.212-223
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• 2014

For the better understanding of long-term and seasonal variations of water quality in Masan Bay, South Sea of Korea, we analyzed the archive data monitored at three stations of the bay during the last 13 years (2000-2012). The average concentrations of the chemical oxygen demand (COD), the dissolved inorganic nitrogen (DIN) and the dissolved inorganic phosphorus (DIP) during the monitoring period are $2.70{\pm}0.09{\mu}/L$, $19.66{\pm}1.84{\mu}m$ and $1.39{\pm}0.13{\mu}m$ in surface water, respectively, and $2.22{\pm}0.07{\mu}/L$, $18.53{\pm}1.36{\mu}m$ and $1.47{\pm}0.12{\mu}m$ in bottom water, respectively. The trophic state of the surface water was the eutrophic level in Masan Bay during the four seasons. The DIN concentrations of both surface and bottom waters increased from August to November and showed the highest average in November. However, The DIN decreased from February to May and showed the lowest average in May. The concentrations of the DIP and the dissolved silicate (DSi) in bottom waters had the highest averages in August because of the high water temperature and oxygen deficient condition. The results of correlation analysis and factor analysis showed that the main factors of surface waters were inflow of nutrients from terrestrial areas and internal production, and the main factors of bottom waters were the variations of the dissolved oxygen (DO), the DIP, and the DSi. The DIN and DIP average concentrations (2007~2012) had decreased in range of 68.1%~76.0% and 66.2~76.6%, respectively from 2007 in which the "Regulation of Total Emission" was established in Masan Bay. Therefore, it could have had positive effects on water quality improvement to take the "Regulation of Total Emission" and other actions such as reducing water pollutions in Masan Bay from 2007.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.148-153
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• 2005

Malaria is a re-emerging infectious disease that is spreading to areas where it had been eradicated, such as Eastern Europe and Central Asia. To avoid the mortality from malaria, early detection of the parasite is a very important issue. The peripheral blood smear has been the gold standard method for the diagnosis of malaria infection. Recently, several other methods have been introduced for quantitative detection of malaria parasites. Real time PCR that employs fluorescent labels to enable the continuous monitoring of PCR product formation throughout the reaction has recently been used to detect several human malaria parasites. 18S rRNA sequences from malaria parasites have been amplified using Taqman real time PCR assay. Here, a SYBR Green-based real time quantitative PCR assay for the detection of malaria parasite-especially, Plasmodium vivax - was applied for the evaluation of 26 blood samples from Korean malaria patients. Even though SYBR Green-based real time PCR is easier and cheaper than Taqman-based assay, SYBR Green-based assay cannot be used because 18S rRNA cannot be specifically amplified using 1 primer set. Therefore, we used DBP gene sequences from Plasmodium vivax, which is specific for the SYBR Green based assays. We amplified the DBP gene from the 26 blood samples of malaria patients using SYBR Green based assay and obtained the copy numbers of DBP genes for each sample. Also, we selected optimal reference gene between ACTB and B2M using real time assay to get the stable genes regardless of Malaria titer. Using selected ACTB reference genes, we successfully converted the copy numbers from samples into titer, ${\sharp}$ of parasites per microliter. Using the resultant titer from DBP based SYBER Green assay with ACTB reference gene, we compared the results from our study with the titer from Taqman-based assay. We found that our results showed identical tendency with the results of 18S rRNA Taqman assay, especially in lower titer range. Thus, our DBP gene-utilized real time assay can detect Plasmodium vivax in Korean patient group semi-quantitatively and easily.