• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.229-239
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• 2018

Currently, in Korea, a dry food simulant has not been designated for the migration testing of paper and board, food contact materials (FCMs) being used in dry foods, and foods heated at ultra-high temperature. Considering the diverse usage of FCMs, in order to secure reliable and confident safety evaluation and to overcome the non-trade barrier tariff in worldwide trade, migration testing methods of what should be more clearly defined for securing and overcoming. This article delves into the available literature on the use of $Tenax^{(R)}$ as a simulant for dry foods as well as its suitability and limitations, and examines the feasibility of its introduction into Korean FCMs regulation. Most experimental studies using $Tenax^{(R)}$ showed overestimated migration values when used in real foods, which reflects the potential of $Tenax^{(R)}$ as a dry food simulant in a worst-case scenario. However, more studies are required to optimize migration testing using $Tenax^{(R)}$ by standardizing the solvent type and the extraction method for surrogates of various FCMs and foods, and to resolve the potential drawbacks in the use of $Tenax^{(R)}$.

• Journal of Preventive Medicine and Public Health
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• v.37 no.2
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• pp.182-189
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• 2004

Objectives : The objective of this study is to compare the circadian patterns of heart rate variability assessed by 24-hour ambulatory electrocardiographic (ECG) recordings during day shift and night shift among the workers in the 5 days-concecutive-12-hour shift in an automobile factory in Korea. Methods : The study population consisted 300 workers, who were randomly selected among the 8700 total workers in one car factory. To analyse circadian variation, the 24-hour ECG recordings (Marquette) were measured during day shift (08:00-20:00 h) and night shift (20:00-08:00 h). Analysis was performed for all time and frequency domain measures of HRV. 233 workers completed taking 24-hour ECG recordings. Results : This study shows that the 24 hourcircadian variation mainly follows work/sleep cycle rather than day/night cycle among shift workers. This study also shows that among the night shift, the circadian variation between work and sleep cycle decreased compared to the work/sleep cycle among day shift workers. All time and frequency domain parameters (except LF/HF ratio) show significantly different between work and sleep in the day shift and night shift. Conclusion : These changes in heart rate variability circadian rhythms reflect significant reductions in cardiac parasympathetic activity with the most marked reduction in normal vagal activity among the shift workers. Especially, it suggests the circadian rhytm has blunted among the night workers. The quantification of the circadian variation in HRV can be a surrogates of workers' potential health risk, as well as suggests possible mechanisms through which the shift works compromise workers' health.

• Development and Reproduction
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• v.21 no.2
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• pp.157-165
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• 2017

One of the reasons to causing blood coagulation in the tissue of xenografted organs was known to incompatibility of the blood coagulation and anti-coagulation regulatory system between TG pigs and primates. Thus, overexpression of human CD73 (hCD73) in the pig endothelial cells is considered as a method to reduce coagulopathy after pig-to-non-human-primate xenotransplantation. This study was performed to produce and breed transgenic pigs expressing hCD73 for the studies immune rejection responses and could provide a successful application of xenotransplantation. The transgenic cells were constructed an hCD73 expression vector under control porcine Icam2 promoter (pIcam2-hCD73) and established donor cell lines expressing hCD73. The numbers of transferred reconstructed embryos were $127{\pm}18.9$. The pregnancy and delivery rate of surrogates were 8/18 (44%) and 3/18 (16%). The total number of delivered cloned pigs were 10 (2 alive, 7 mummy, and 1 died after birth). Among them, three live hCD73-pigs were successfully delivered by Caesarean section, but one was dead after birth. The two hCD73 TG cloned pigs had normal reproductive ability. They mated with wild type (WT) MGH (Massachusetts General Hospital) female sows and produced totally 16 piglets. Among them, 5 piglets were identified as hCD73 TG pigs. In conclusion, we successfully generated the hCD73 transgenic cloned pigs and produced their litters by natural mating. It can be possible to use a mate for the production of multiple transgenic pigs such as ${\alpha}-1,3-galactosyltransferase$ knock-out /hCD46 for xenotransplantation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.183-183
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• 2017

In the early part of rice growth, root volume primarily limits the amount of plant-accessible nitrogen (N). Therefore, knowledge of the root development is important for modeling N uptake of rice. The timing when the volume of rhizosphere cover the whole soil is also important to carry out timely top dressing. However, information about initial root expansion and associated N uptake is limited due to intrinsic technical difficulties in assessing below-ground processes. Some studies, however, showed a close relationship between below-ground root and above-ground leaf development, suggesting a possibility that above-ground attributes could serve as surrogates for the root processes. In this study, we investigated the relationship between below-ground and above-ground development of rice. Field experiments were conducted where we cultivated Koshihikari (a leading cultivar in Japan) for four different cropping schedules in 2012. In 2016, Gimbozu (HEG4) and three flowering time mutant lines of Gimbozu (X61 (se13), HS276 (ef7), DMG9 (se13, ef7)) were examined for a single season. Experiments were performed with three replications in a completely randomized design. We monitored ammonium-N concentration ([NH4+-N]) in soil solution by repeatedly taking samples from a porous tubing (10-cm long) vertically inserted at the most distant point from surrounding rice hills. Samples were taken in triplicate (= triplicate tubes) and every three days from transplanting in each experimental unit. For above-ground attributes, leaf area index (LAI) was measured in 2012, whereas soil coverage ratio was estimated by image processing in 2016. Results showed that [NH4+-N] increased gradually after transplanting and then rapidly decreased from a certain day. This distinct drop in [NH4+-N] informed us the timing at which the rice root system reached the point of porous tubing and thus essentially covered the whole soil volume. The LAI at the dropping point was about 0.43 regardless of the cropping schedules in 2012 experiment. In 2016, the coverage ratio at the N dropping point was within the range of 0.12 to 0.19 for four genotypes having different growth durations. In addition, the coverage ratios at seven weeks after the transplanting showed a good correspondence to LAI across the four genotypes. We therefore conclude that both LAI and coverage ratio may serve as robust indicators for root development and might be useful to estimate the timing when the root system fully cover the soil volume. Results obtained here will also contribute to develop models that can predict not only above-ground canopy development but also associated below-ground processes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5522-5529
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• 2013

The purpose of this study was to look into the marketing strategies of social commerce companies by analyzing the relationships among the environment, strategy and performance in social commerce. For that, the environment condition and components of marketing strategy were derived based on the marketing mix by analyzing the related contents published in 3,783 articles on newspapers dated from April 2010 to March 2013. UV(Unique Visitor) and PV(Page View) for each social commerce site were used as surrogates for performance. The results of study revealed the relationship of the marketing strategies to the changes in environment conditions towards negative conditions such as the spread of buyer anxiety. In the "strategy-performance" relations, the product element and external sales promotion element had high correlation with the performance. Finally, a difference was found in the marketing strategies of social commerce companies. High correlation was found in all aspects between the UV and PV marketing elements in the case of Coupang, while the correlation with the UV was low and the environment also showed relatively low correlation level in the case of WEmakePRICE. Thus, this study is considered to provide useful basis for the social commerce companies to map out and implement the marketing strategies, and is significant in that it applied the marketing mix to the special market environment such as social marketing.

• Journal of Embryo Transfer
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• v.31 no.1
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• pp.1-7
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• 2016

Xenotransplantation involves multiple steps of immune rejection. The present study was designed to produce nuclear transfer embryos, prior to the production of transgenic pigs, using fibroblasts carrying transgenes human complement regulatory protein hCD59 and interleukin-18 binding protein (hIL-18BP) to reduce hyperacute rejection (HAR) and cellular rejection in pig-to-human xenotransplantation. In addition to the hCD59-mediated reduction of HAR, hIL-18BP may prevent cellular rejection by inhibiting the activation of natural killer cells, activated T-cell proliferation, and induction of $IFN-{\gamma}$. Transgene construct including hCD59 and ILI-18BP was introduced into miniature pig fetal fibroblasts. After antibiotic selection of double transgenic fibroblasts, integration of the transgene was screened by PCR, and the transgene expression was confirmed by RT-PCR. Treatment of human serum did not affect the survival of double-transgenic fibroblasts, whereas the treatment significantly reduced the survival of non-transgenic fibroblasts (p<0.01), suggesting alleviation of HAR. Among 337 reconstituted oocytes produced by nuclear transfer using the double transgenic fibroblasts, 28 (15.3%) developed to the blastocyst stage. Analysis of individual embryos indicated that 53.6% (15/28) of embryos contained the transgene. The result of the present study demonstrates the resistance of hCD59 and IL-18BP double-transgenic fibroblasts against HAR, and the usefulness of the transgenic approach may be predicted by RT-PCR and cytolytic assessment prior to actual production of transgenic pigs. Further study on the transfer of these embryos to surrogates may produce transgenic clone miniature pigs expressing hCD59 and hIL-18BP for xenotransplantation.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.1-11
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• 2021

In this review, recent foodborne outbreaks caused by viruses in the Republic of Korea (2010-2019) were analyzed. The human norovirus was found to be the major foodborne virus causing an average of 94.9% of the viral outbreaks. Reverse-transcription polymerase chain reaction (PCR) with electrophoresis has been widely used to detect viruses, but several rapid detection methods, including real-time PCR, multiplex PCR, and quantum dot assay, have also been suggested. For norovirus inactivation studies, surrogates such as murine norovirus and feline calicivirus have been widely used to identify the reduction rate owing to the limitations in laboratory cultivation. Conversely, direct cell infection studies have been conducted for other foodborne viruses such as adenovirus, astrovirus, rotavirus, and hepatitis A or E virus. Moreover, virucidal mechanisms using various physical and chemical treatments have been revealed. These recent studies suggest that rapid in situ detection and effective control are valuable for ensuring food safety against viral infections.

• Korean Journal of Radiology
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• v.23 no.1
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• pp.112-123
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• 2022

Objective: To investigate the relationship between ¹⁸F-FDG PET/CT semi-quantitative parameters and the International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histopathologic classification, including histological subtypes, proliferation activity, and somatic mutations. Materials and Methods: This retrospective study included 419 patients (150 males, 269 females; median age, 59.0 years; age range, 23.0-84.0 years) who had undergone surgical removal of stage IA-IIIA lung adenocarcinoma and had preoperative PET/CT data of lung tumors. The maximum standardized uptake values (SUVmax), background-subtracted volume (BSV), and background-subtracted lesion activity (BSL) derived from PET/CT were measured. The IASLC/ATS/ERS subtypes, Ki67 score, and epidermal growth factor/anaplastic lymphoma kinase (EGFR/ALK) mutation status were evaluated. The PET/CT semi-quantitative parameters were compared between the tumor subtypes using the Mann-Whitney U test or the Kruskal-Wallis test. The optimum cutoff values of the PET/CT semi-quantitative parameters for distinguishing the IASLC/ATS/ERS subtypes were calculated using receiver operating characteristic curve analysis. The correlation between the PET/CT semi-quantitative parameters and pathological parameters was analyzed using Spearman's correlation. Statistical significance was set at p < 0.05. Results: SUVmax, BSV, and BSL values were significantly higher in invasive adenocarcinoma (IA) than in minimally IA (MIA), and the values were higher in MIA than in adenocarcinoma in situ (AIS) (all p < 0.05). Remarkably, an SUVmax of 0.90 and a BSL of 3.62 were shown to be the optimal cutoff values for differentiating MIA from AIS, manifesting as pure ground-glass nodules with 100% sensitivity and specificity. Metabolic-volumetric parameters (BSV and BSL) were better potential independent factors than metabolic parameters (SUVmax) in differentiating growth patterns. SUVmax and BSL, rather than BSV, were strongly or moderately correlated with Ki67 in most subtypes, except for the micropapillary and solid predominant groups. PET/CT parameters were not correlated with EGFR/ALK mutation status. Conclusion: As noninvasive surrogates, preoperative PET/CT semi-quantitative parameters could imply IASLC/ATS/ERS subtypes and Ki67 index and thus may contribute to improved management of precise surgery and postoperative adjuvant therapy.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.73-78
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• 2015

Purpose : Under the assumption of change to the amplitude based sorting, the study will use four dimensional computed tomography imaging (4DCT) arrayed using the phase based sorting to analyze the respiratory phase difference. Materials and Methods : The study analyzed the 4DCT (4-dimensional computed tomography) images of 10 liver cancer patients that were treated with respiratory gated radiotherapy from 2015 February to March. Using RPM respiratory gating (RPM 1.7.5, Varian, USA) equipment, imaging according to respiratory cycle of phase based sorting was acquired and using a treatment planning system (Pinnacle 9.2, Philips, USA) the acquired imaging according to respiratory cycle was used to measure the abdominal movement value by respiratory cycle. The measuring point was the point where the center point of the Marker Block and the body surface met in the 50% phase image and here the coordinate values Lateral, Vertical, Longitudinal (X, Y, Z) were set as reference points, and on the X, Z plane identical to the reference point, using the identical method the Y axis coordinate value of each 0%, 30%, 40%, 50%, 60%, 80% phase images were acquired to quantitatively measure the variation of distance to the Y axis. The abdominal movement value according to respiration was applied to the theoretical model that the value decreases linearly from maximum inhalation to maximum exhalation to divide the variation of my value to predict as amplitude value by respiratory cycle and conversely the variation in amplitude was recalculated with the phase variation deviation value to analyze. Results : The deviation value between expected value and actual location was the largest in the 30% phase with 0.24 cm, and standard deviation was also the largest in 30% phase with 0.13 cm. The effective value of the deviation value derived from the average of the deviation squared value of each patient appeared as minimum 0.7 cm, maximum 0.18 cm, average 0.12 cm, and standard deviation 0.4 cm. Also by dividing the actual movement distance value with the peak expiration value then converting it into %Phase, the deviation value with actual phase 16.5% in 30% phase, 10.0% and 40% phase, 10.0% and 60% phase, 15.4% and 80% phase, and overall average about 13%, and arraying based on amplitude, phase shift occurred and further it was from peak expiration the chance of deviation occurrence was increasingly measured. Conclusion : Based on the results of the study there were differences between value acquired based on theoretical model and actual value. Therefore in respiratory gated radiotherapy using external surrogates, there needs to be establishment of respiration gated radiation system that avoids the combination of two Sorting methods considering that there will be occurrence of treatment and corresponding clinical differences due to the phase difference that occur due to the Amplitude based Phase Sorting.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.507-516
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• 1999

Background : Patients with lung cancer and their relatives often ask the advice of relative or friends who are doctors on the treatment and prognosis of the disease. Therefore a doctor's opinion may play a role in determining the treatment modality and affect therapeutic compliance of patients. The purpose of this study was to find the opinion of general practitioners on lung cancer treatment. Method : A mail survey for general practitioners in Taegu City and Northern Kyungsang Province was performed. Each individual was sent a written questionnaire in which he or she was asked for ten questions about management and prognosis of lung cancer. Results : Two hundred and twenty eight doctors filled in the questionnaire. Of the respondents, 68% had the experience of being asked about lung cancer by their friends or relatives. About 52% replied that it was better to tell the patient of his or her disease. And about 22% considered it better to follow the relatives' opinion. On the question about choosing the treatment modality, following the doctors' plan was most appropriate in 86.9%, showing that most respondents favored actively recommending doctors. Nonsurgical treatment was preferable in patients over 80 years old with resectable lung cancer and with an increase in age, significant increase was observed in respondents recommending nonsurgical treatment. Most respondents said that they would actively recommend or advise following the doctors' plan about radiotherapy and chemotherapy. But a large percent of the respondents had a negative view on the effect of radiotherapy and chemotherapy. Conclusion : The opinions of general practitioners on the treatment and prognosis of lung cancer was variable. And they did not prefer active treatment for patients with old age or advanced lung cancer.