• Research in Plant Disease
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• v.20 no.2
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• pp.112-118
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• 2014

A liquid bio-formulation containing chitinolytic bacteria, chitin and their products was assessed for its potential biological control against root-knot nematodes on cucumber. The bio-formulation was prepared by cultures of three chitinolytic bacteria, Chromobacterium sp. strain C-61, Lysobacter engymogenes and Serratia plymuthica in minimal medium supplemented with chitin. Under pot conditions, the bio-formulation showed better growth of cucumber plants, and less root galls and population density of Meloidogyne spp. than control media without the bio-formulation. In a greenhouse, 75-fold diluted bio-formulations were treated instead of water around cucumber plants through hoses for drip irrigation six times at 5-day intervals from the transplanting date. After 30 and 60 days, the treatment provided about 7% and 10% enhancement in the plant height and about 78% and 69% reduction in population density of Meloidogyne spp. in the rhizosphere, respectively. In addition, the experiments showed that the control effects occurred only in the soils contacted with the bio-formulation. Undiluted bio-formulations were drenched three times at 10-day intervals around cucumber plants severely infested with Meloidogyne spp. The treatment showed about 37% plant enhancement without dead plants compared with 37% death in the untreated control, and about 82% nematode reduction. These results suggest that the bio-formulation can be practically used to control the root-knot nematode on cucumber.

• Parasites, Hosts and Diseases
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• v.29 no.2
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• pp.129-138
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• 1991

Tetrahymena pyriformis is a free-living ciliate protozoan in the freshwater system. Experiments were carried out to determine whether intraperitoneal administration of T. pyriformis (GL strain) to mice activates macrophages to be able to kill Toxoplasma gondii tachyzoites in vitro. Mice were also injected intraperitoneally with several synthetic activators; dimethyldioctadecylammonium bromide (DDA), dextran sulfate, complete Freund's adjutant (CFA) as well as Toxoplasma and Tetrehymena Iysates in order to activate mouse peritoneal macrophages. One week after the administration of activators, peritoneal cells were harvested and the adherent macrophages were challenged with Toxoplasma tachyzoites. Macrophage monolayers were then fixed with absolute methanol after washing, and stained with Giemsa solution. The percentage of the adherent cells infected and total number of organisms per 100 macrophages were calculated to make toxoplasma-cidal activity of macrophages according to the cultivation time. Peritoneal macrophages from mice administered with Tetrahymena exhibited significant protection against target parasites as compared with those treated with synthetic activators. Among non-biological synthetic activators, DDA was evaluated as an ellcellent activator.

• Journal of the korean veterinary medical association
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• v.25 no.10
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• pp.595-606
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• 1989

항원제시세포(APC)와 보조T세포 간의 협력작용에 의하여 활성화된 작동세포(NK세포, CTL, K세포, 대식세포, 과립구 등)의 종양세포, 이식장기 및 세포내기생세균에 감염된 각종 세포에 대한 세포독성작용은 생체방어를 위한 중요한 세포성면역기전이다. 지난 몇 년간 세포성면역기전에 관한 많은 연구에도 불구하고 T림파구매개성 세포독성작용의 면역생물학적기전은 확실히 밝혀있지 않다. 지금까지 알려진 중요한 연구내용을 요약하면 다음과 같다. 1. 세포독성작용을 나타내는 작동세포로는 NK세포, CTL, K세포, 대식세포/단핵구 및 과립구가 있다. 2. T세포의 세포표면항원분자군(CD)으로는 $CD_{2},\;CD_{3},\;CD_{4}[Ly_{3}T_{4}],\;CD_{5}[=Ly_{1}],\;CD_{7},\;CD_{8}[Ly_{2,3}]$가 있으며 $CD_{4}$는 보조Ttpvhdml 특이마커이고 $CD_{8}$는 세포독성 T세포 및 억압T세포의 특이마커이다. 주요 T세포수용체(TCR)는 $CD_{4}$ 또는 $CD_{8}$ 분자와 가까이 연합된 이향체($TCR-{\alpha}{\beta}/TCR-{\gamma}{\delta}$이며 보조 T세포 $CD_{4}$(마우스 $L_{3}T_{4}$)는 수용체와 연합되어 있는반면 억압 T세포 $CD_{8}(Ly+_{2,3})$는 항원수용체와 연합되어 있다. 3. T세포는 Ti-$CD_{3}$(항원/MHC) 복합체를 통한 '항원가교'에 의한 자극(항원인식)과 $CD_{2}$를 통한 비특이경로에 의하여 활성화(분화증식)된다. 비특이경로를 통한 활성경로에서 T세포($CD_{4}$ 및 $CD_{8}$)가 활성화되기 위하여는 보조T세포가 생산하는 IL-2을 요구하며 IL-2의 자극으로 분화증식된 $CD_{8}$는 세포독성능을 나타내지만 $CD_{4}^{+}$는 여전히 세포독성능을 나타내지 못한다. 4. 보조T세포는 class II MHC분자와 연합된 항원을 식별하는 반면 세포독성T세포는 class I MHC 분자와 연합된 항원을 식별한다. 5. 림파구 매개성 세포독성은 접촉(conjugati-on), 탈분극(depolarization), 용해계획(progra-mming), 용해(lysis) 및 재순환(recycling)의 단계를 거쳐 진행된다. 6. 표적세포살해매체로는 perforin / PFP / cy-tolysin, lymphopores, lymphotoxins, protone, cytolytic enzymes가 알려졌으며 세포독성작용은 이들 이외에도 여러 가지 매체를 통한 복합작용으로 추정된다. 7. CTL 매개성 표적세포의 주요 대사변화는 actomyocin ATPase의 증가, phosphocreatine과 ATPase의 소모, ATP 의존성 $Na^{+}/K^{+}$ 펌프작용의 중지, ATP 의존성 $Ca^{2+}$ 유출감소 및 세포내 축적이 관찰된다. 8. $Ca^{2+}$의 축적으로 세포막 교질 침투손상을 주어 수분의 유입을 증가시킴으로써 수포형성, 핵붕괴, 사립체팽화 및 정상세포 구조상실(Zeiosis)이 있다. 결론적으로 CTL 매개성 세포독성작용은 PFP, LT, TNF, 유사 TNF / LT 및 기타 매체를 통한 복합작용이며 세포살해기전은 지속적 대사소모와 정형적 세포구조(핵 및 세포질)의 파괴에 의한 것이다.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.351-355
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• 2017

Tolaasin, peptide toxin produced by Pseudomonas tolaasii, causes a brown blotch disease on the cultivated mushrooms. Tolaasin peptides form membrane pores and disrupt cellular membrane structure. Molecular actions of tolaasin consist of the aggregation of peptide molecules, binding to the cell membrane, and formation of membrane pores. Therefore, the inhibitions of any of these actions are able to suppress the blotch disease. We have isolated and identified several tolaasin inhibitors (named tolaasin inhibitory factors, TIF) from food additives. TIFs were able to suppress the blotch-formation by the pathogen inoculated to the mushrooms. In this study, TIFs were incubated under various conditions and their activities for the inhibition of tolaasin-induced hemolytic activity were investigated. Since TIFs are unsaturated carbon compounds, they were sensitive to the air exposure and light irradiation. In the anaerobic conditions, TIFs were stable and their activities were decreased by 10% for three months. However, near 90% of TIF activity was suppressed by two weeks in the presence of air and sun light. Temperature did not show any significant effects on the activity of TIF, since storages at 5, 25, $45^{\circ}C$ did not show any difference. Therefore, for the stable storage of TIF compounds, container should be designed to be dark and air-tight.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.490-497
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• 2016

This study compared and analyzed the pollution levels of radiation shielding aprons and ways to sterilize them using 30 lead aprons. After collecting samples from the center of the lead apron, where contact is most frequent, experiments were conducted employing Coagula and Latex methods. Using the culture medium where bacteria grew, measurements of the pathogen count and identification were performed. The greatest number of pathogens were $7.16{\pm}10$, which were detected on the lead apron from general X-ray room #2, but there was no significant difference according to the facilities (p > 0.05). Compared to how many pathogens remained between using the disinfectant ethanol and tissue, the pathogens decreased by $0.01{\pm}0.4$ (p < 0.05) after using disinfectant ethanol and by $0.87{\pm}1.7$(p < 0.05) after using disinfectant tissue. The Pearson correlation test revealed a significant correlation (-0.296, p < 0.05) between them. According to this research, there were pathogens on the lead aprons and the number of pathogens was determined by statistical analysis. It is expected that the rate of radiology technologists, patients, and medical equipment infected by pathogens will be reduced by the proper use of sterilization with a disinfectant ethanol.

• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.186-193
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• 2015

Purpose: The aim of study was to estimate the hand hygiene (HH) compliance of healthcare workers (HCWs) in a children's hospital. Methods: This study was conducted in a hospital which is a tertiary and educational children's hospital with 313 beds and 533 HCWs. Data were collected by direct observation methods from November 1, 2010 to December 31, 2010. Results: A total of 2,999 opportunities for HH were observed, and the overall HH rate was 95.3%. HH rate of the registered nurse, physicians and transferer was 97.7%, 89.2%, and 72.1%, respectively (P<0.001). Among physicians, HH rate of the fellows, professors, residents and interns was 97.5%, 93.9%, 89.7%, and 80.9%, respectively (P<0.001). HH rate in the emergency room, operation room, outpatient department (OPD), and the intensive care unit (ICU) was 97.2%, 97.2%, 95.4%, and 92.5%, respectively (P<0.001). Hand rubbing was the most frequently used (81.1%), and hand washing was frequently used in the case of 'after body fluids exposure risk' (37.7%) and 'after touching patient surroundings' (28.5%). HH methods were not statistically different from each departments (P =0.083), however, they were significantly different according to the World Health Organization (WHO) 5 Moments (P<0.001). Distributions in WHO 5 Moments by the job titles were significantly different (P<0.001). The odds ratio of physicians, ICU and OPD was 0.353 (95% CI, 0.241-0.519), 0.291 (95% CI, 0.174-0.487), and 0.484 (95% CI, 0.281-0.834), respectively. Conclusions: Compliance of HH was different by the job titles and departments. Effective custom-tailored HH programs for each job title and department need to be developed.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1647-1656
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• 2021

In order to reduce the spread of infection due to COVID-19, South Korea has established a four-step social distancing standard and implemented it by changing the steps based on the rate of confirmed cases. The implementation of social distancing brought about a change in the amount of activity of citizens by limiting social contact such as movement and gathering of people. One of the data that can intuitively confirm this is Night Time Light (NTL). NTL is a variable that can measure the size of the national economy measured using lights captured by satellites, and can be used to understand people's social activities during the night. The NTL visible data is obtained via the Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB) onboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite. 1023 of Suomi data from 1 January 2019 until 26 October 2021 were collected to generate time series of NTL radiance change over Seoul to analyze the correlation with social distancing policy. The results show that implementing the level of social distancing generally decreased the NTL radiance both in spatial disparities and temporal patterns. The higher level of policy, limiting human activities combined with the low number of people who have been vaccinated and the closure of various facilities. Because of social distancing, the differences in human activities affected the nighttime light during the COVID-19 pandemic, especially in Seoul, South Korea. Therefore, this study can be used as a reference for the government in evaluating and improving policies related to efforts reducing the transmission of COVID-19.

• The Journal of Bigdata
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• v.5 no.2
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• pp.187-199
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• 2020

The World Health Organization declared COVID-19 a pandemic on March 11. South Korea recorded 27,000 cases of the coronavirus illness, and more than 50 million coronavirus cases were confirmed all over the world. An epidemiological investigation becomes important once again due to the spread of COVID-19 infections. However, there were a number of confirmed coronavirus cases from Deagu and Gyeongbuk. Limitations of the epidemiological investigation methods were recognized. The Korea Disease Control and Prevention Agency developed the Epidemiological Investigation Support System(EISS) to utilize the smart city data hub technology and utilized the system in the epidemiological investigation. As a part of EISS, The proposed system is big-data bsed epidemiological investigation support system processing mobile network data. The established system is the epidemiological investigation support system based on big data to process mobile carriers' big data. Processing abnormal values of mobile carriers' data which was impossible with existing staff or creating hotspot regions where more than two people were in contact with an infected person were realized. As a result, our system processes outlier of mobile network data in 30 seconds, while processes hotspot around in 10 minutes. as a first time to adapt and support bigdata system into epidemiological investigation, our system proposes the practical utilizability of big-data system into epidemiological investigation.

• Journal of the Korean Society of Radiology
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• v.83 no.2
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• pp.265-283
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• 2022

To develop Korean coronavirus disease (COVID-19) chest imaging justification guidelines, eight key questions were selected and the following recommendations were made with the evidence-based clinical imaging guideline adaptation methodology. It is appropriate not to use chest imaging tests (chest radiograph or CT) for the diagnosis of COVID-19 in asymptomatic patients. If reverse transcription-polymerase chain reaction testing is not available or if results are delayed or are initially negative in the presence of symptoms suggestive of COVID-19, chest imaging tests may be considered. In addition to clinical evaluations and laboratory tests, chest imaging may be contemplated to determine hospital admission for asymptomatic or mildly symptomatic un-hospitalized patients with confirmed COVID-19. In hospitalized patients with confirmed COVID-19, chest imaging may be advised to determine or modify treatment alternatives. CT angiography may be considered if hemoptysis or pulmonary embolism is clinically suspected in a patient with confirmed COVID-19. For COVID-19 patients with improved symptoms, chest imaging is not recommended to make decisions regarding hospital discharge. For patients with functional impairment after recovery from COVID-19, chest imaging may be considered to distinguish a potentially treatable disease.

• Tuberculosis and Respiratory Diseases
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• v.53 no.4
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• pp.389-400
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• 2002

Background : The rapid diagnostic tests for tuberculosis are needed to facilitate early treatment of tuberculosis and prevention of Mycobacterium tuberculosis transmission. The Xeniss Rapid TB kit is a rapid, card-based immunochromatographic test for the detection of antibodies directed against M. tuberculosis antigens including antigen 5(38-kDa antigen). The objective of this study was to evaluate the performance of the Xeniss Rapid TB kit for the diagnosis of active tuberculosis with serums from patients, asymptomatic healthy and close contact controls. Methods : 188 patients with active tuberculosis were tested; 177 with pulmonary tuberculosis(18 with combined pleurisy), and 11 with extrapulmonary tuberculosis. The control groups were composed of 82 close contacts and 57 healthy adults. Study subject were drawn from one national tuberculosis hospital for patients and close contacts, and another private hospital for healthy adults in Masan city, Korea. The Xeniss Rapid TB kit(Xeniss Life Science Co., Ltd., Seoul, Korea) was evaluated by using serum samples according to the instructions of the manufacturer by an investigator masked to the clinical and microbiological status of the study subjects. Results : The diagnostic sensitivity of the Xeniss Rapid TB kit was 73.9% in patients and specificities were 73.2% and 93.0% in close contact and healthy adults respectively. The positive predictive value in patients was 84.2% and the negative predictive value in controls was 85.8%. Conclusion : This study shows that the Xeniss Rapid TB test is a simple and fast method to diagnose active TB. The results of the sensitivity and specificites suggest that serodiagnosis using this point of care testing(POCT) device would be valuable and advantageous for screening tuberculosis in the clinical field.