• Korean Journal of Remote Sensing
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• v.36 no.5_3
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• pp.1109-1123
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• 2020

In South Korea with forest as a major land cover class (over 60% of the country), many wildfires occur every year. Wildfires weaken the shear strength of the soil, forming a layer of soil that is vulnerable to landslides. It is important to identify the severity of a wildfire as well as the burned area to sustainably manage the forest. Although satellite remote sensing has been widely used to map wildfire severity, it is often difficult to determine the severity using only the temporal change of satellite-derived indices such as Normalized Difference Vegetation Index (NDVI) and Normalized Burn Ratio (NBR). In this study, we proposed an approach for determining wildfire severity based on machine learning through the synergistic use of Sentinel-1A Synthetic Aperture Radar-C data and Sentinel-2A Multi Spectral Instrument data. Three wildfire cases-Samcheok in May 2017, Gangreung·Donghae in April 2019, and Gosung·Sokcho in April 2019-were used for developing wildfire severity mapping models with three machine learning algorithms (i.e., Random Forest, Logistic Regression, and Support Vector Machine). The results showed that the random forest model yielded the best performance, resulting in an overall accuracy of 82.3%. The cross-site validation to examine the spatiotemporal transferability of the machine learning models showed that the models were highly sensitive to temporal differences between the training and validation sites, especially in the early growing season. This implies that a more robust model with high spatiotemporal transferability can be developed when more wildfire cases with different seasons and areas are added in the future.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.11-18
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• 2004

Background: We tested the effect of indomethacine and total spinal anesthesia on the improvement of placental flow during cardiopulmonary bypass on fetal lamb. Material and Method: Twenty fetuses at 120 to 150 days of gestation were subjected to bypass via trans-sternal approach with a 12 G pulmonary arterial cannula and 14 to 18 F venous cannula for 30 minutes. All ewes received general anesthesia with ketamine. In all the fetuses, no anesthetic agents were used except muscle relaxant. Ten served as a control group in which placenta was worked as an oxygenator during bypass (Control group). The remainder worked as an experimental group in which pretreatment with indomethacine and total spinal anesthesia was performed before bypass with the same extracorporeal circulation technique as control group (Experimental group). Observations were made every 10 minutes during a 30-minute bypass and 30-minute post bypass period. Result: Weights of the fetuses ranged from 2.2 to 5.2 kg. In Control group, means of arterial pressure decreased from 44.7 to 14.4 mmHg and means of Pa$CO_2$ increased from 61.9 to 129.6 mmHg at each time points during bypass. Flow rate was suboptimal (74.3 to 97.0 $m\ell$/kg/min) during bypass. All hearts fibrillated immediately after the discontinuation of bypass. On the contrary, in Experimental group, means of arterial pressure reamined higher (45.8 to 30 mmHg) during bypass (p<0.05). Means of Pa$CO_2$ were less ranging from 59.8 to 79.4 mmHg during bypass (P<0.05). Flow rates were higher (78.8 to 120.2 $m\ell$/kg/min) during bypass (p<0.05). There were slower deterioration of cardiac function after cessation of bypass. Conclusion: In this study, we demonstrated that the placental flow was increased during fetal cardiopulmonary bypass in the group pretreated with indomethacine and total spinal anesthesia. However, further studies with modifications of the bypass including a creation of more concise bypass circuit, and a use of axial pump are mandatory for the clinical application.

• Journal of Chest Surgery
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• v.33 no.9
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• pp.697-706
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• 2000

Background: Isolated lung perfusion(ILP) was developed as a new treatment approach to non-resectable primary or metastatic lung cancer, because of its ability to reduce systemic toxicity while delivering high-dose chemotherapeutic agents to the target organs. This research was planned to evaluate the direct toxic effect of high-dose cisplatin to the lung tissue during isolated lung perfusion. Material and Method: Fifteen mongrel dogs were divided in the perfusate for 40 minutes. The second group was composed of 5 mongrel dogs which underwent ILP with cisplatin 2.5 mg/Kg added to the perfusate for 30 minutes and 10 minutes with washing solution without cisplatin. The third group underwent the same procedure as the second group except cisplatin 5.0 mg/Kg in the perfusate. Activities of serum angiotensin converting enzyme(ACE), tumor necrosis factor-$\alpha$(TNF-$\alpha$), and concentration of serum lactate dehydrogenase(LDH) and blood urea nitrogen/creatinine (BUN/Cr) were analyzed in each groups at the time of pre-perfusion, 1 hour, 1 day, 1 week, and 2 weeks after ILP. Result: Serum ACE activities before and 1 hour, 1 day, 1 week, and 2 weeks after ILP in control group were 45.1$\pm$6.3, 44.6$\pm$9.3, 46.7$\pm$9.5, 50.8$\pm$9.1, 46.1$\pm$4.3 U/L. Those in cisplatin 2.5 and 5.0 mg/Kg groups were 49.4$\pm$12.6, 39.0$\pm$8.6, 42.3$\pm$15.9, 50.0$\pm$2.6, 53.8$\pm$8.3 and 55.5$\pm$12.3, 47.0$\pm$6.3, 45.1$\pm$6.9, 74.8$\pm$19.5, 60.2$\pm$12.0 U/L, respectively. Serum TNF-$\alpha$ activities in each group before and after ILP were 5.0$\pm$1.5 / 7.7$\pm$2.2 / 6.6$\pm$2.5 / 4.3$\pm$1.3 / 5.2$\pm$1.1(control), 8.7$\pm$1.6 / 9.9$\pm$2.2 / 7.9$\pm$1.5 / 6.3$\pm$2.2 / 7.4$\pm$2.4 (cisplatin 2.5 mg/Kg), and 6.9$\pm$0.7 / 8.9$\pm$3.4 / 7.9$\pm$4.0 / 3.3$\pm$0.9 / 5.8$\pm$1.3 pg/ml(cisplatin 5.0 mg/Kg). Mean LDH levels of each group were 225.7 / 271.3 / 328.9 / 350.8 / 255.7(control), 235.7 / 265.7 / 336.0 / 379.5 / 299.2 (cisplatin 2.5 mg/Kg), and 259.6 / 285.2 / 340.6 / 433.4 / 292.4 IU/L(cisplatin 5.0 mg/Kg). So there was no significant difference in serum ACE, TNF-$\alpha$, and LDH activity changes after ILP between the 3 groups. And, there was no significant changes in BUN/Cr in each groups, which was independent of ILP and perfused concentration of cisplatin. In addition, all dogs survived the ILP and there was no significant evidence of pulmonary vascular injury after 2 weeks of ILP with cisplatin. Conclusion: There was no harmful effect of cisplatin to the lund tissue of the mongrel dog up to 5.0 mg/Kg in perfusate. Therefore, it is perceived to be safe and effective to deliver high-dose cisplatin to the lung without pulmonary toxicity and renal damage with ILP.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.5
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• pp.359-363
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• 2007

Purpose: Incidental parotid lesions on F-18 FDG-PET can mimic distant metastasis of underlying malignancy. The prevalence and the clinico-pathologic findings of PET positive parotid lesions have not been known. We investigated how often incidental parotid lesions are found on clinical FDG-PET studies and what the clinico-pathologic characteristics of those parotid lesions are in the present study. Materials and Methods: We retrospectively reviewed 3,344 cases of FDG-PET which had been obtained in our hospital from May 2003 to Dec 2006. The indications of FDG-PET were: evaluation of known/suspected cancer (n= 3,212) or screening of cancer in healthy subjects (n=132). Incidental parotid lesion on FDG-PET was defined as an un-expected FDG uptake in one of parotid glands which was not primary target lesion of current FDG-PET. FDG uptake was represented by maximum standardized uptake value (maxSUV). Final diagnosis was made by pathologic analysis or clinical follow-up assessment. Results: Fifteen (0.45% = 15/3,344) incidental parotid lesions were found and they were all benign lesions. The maxSUV ranged from 1.7 to 8.6 (mean${\pm}$s.d. = $3.7{\pm}1.9$). Final diagnoses of the incidental parotid lesions were; Warthin's tumor (n=2), pleomorphic adenoma (n=1), other un-specified benign lesion (n=1), and benign lesions under bases of imaging studies (n=3) and of clinical follow-up (n=8). Conclusion: All of incidentally found parotid lesions in clinical FDG-PET studies were confirmed as benign lesions with prevalence of 0.45%. Close follow up using PET or CT might be a reasonable approach for determining the nature of incidentally found parotid lesions.

• Journal of Hospice and Palliative Care
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• v.15 no.1
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• pp.18-29
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• 2012

Purpose: We analyzed how clinical nurses in Korea perceive terminally ill patients' medical decision-making. Methods: The Q-methodology which analyzes the subjectivity of each item was used. We selected 34 Q-statements among those provided by each of 37 subjects and grouped them into a shape of normal distribution using a 9 point scale. The collected data were analyzed using a QUANL PC program. Results: Four types of perception toward medical decision-making were identified. Type I focuses on patient participation, and Type II emphasizes the role of health professionals. Type III is characterized by an open-minded culture toward death, and Type IV values the role of family members. Conclusion: The results of this study indicate the need for development of a multi-disciplinary curriculum medical decision-making and death for medical and nursing students.

• Journal of Hospice and Palliative Care
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• v.15 no.1
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• pp.10-17
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• 2012

Purpose: This study was conducted to identify the perception regarding palliative care among Korean doctors and referral barriers toward palliative care for terminal cancer patients. Methods: Between May and June 2010, 477 specialists mainly caring cancer patients using a web-based, self-administered questionnaire. Results: A total of 128 doctors (26.8%) responded. All respondents (100%) deemed palliative care a necessary service for terminal cancer patients. More than 80% of the respondents agreed to each of the following statements: all cancer centers should provide palliative care service (80.5%); all terminal cancer patients should receive concurrent palliative care along with anti-cancer therapies (89.1%) and caring for terminal cancer patients requires interdisciplinary approach (96.9). While more than 58% of the respondents were satisfied with their performance of physical and psychological symptoms management and emotional support provided by patient's family members, 64% of the responded answered that their general management of the end-of-life care was less than satisfactory. Doctors without prior experience in referring their patients to palliative care specialists accounted for 26.6% of the respondents. The most common barrier to hospice referral, cited by 47.7% of the respondents, was "refusal of patient or family member", followed by "lack of available palliative care resources" (46.1%). Conclusion: Although most doctors do recognize the importance of palliative care for advanced cancer patients, comprehensive and sufficient palliative medicine, including interdisciplinary cooperation and end-of-life care, has not been put into practice. Thus, more active palliative consultation or referral is needed for effective care of terminal cancer patients.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.187-196
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• 2000

This paper describes a simple method that uses differences among Carlson's (1977) trophic state index (TSI) values based on total phosphorus (TP), chlorophyll a (CHL) and Secchi depth (SD) to draw inferences regarding the factors that are limiting to phytoplankton growth and the composition of lake seston. Examples are provided regarding seasonal and spatial patterns in a large subtropical lake (Lake Okeechobee, Florida, USA) and inter- and intra-lake variations from a multilake data set developed from published studies. Once an investigator has collected routine water quality data and established TSI values based on TP, CHL, and SD, a number of inferences can be made. Additional information can be provided where it also is possible to calculate a TSI based on total nitrogen (TN). Where TSI (CHL)<>TSI (SD), light attenuating particles are large (large filaments or colonies of algae), and the phytoplankton may be limited by zooplankton grazing. Other limiting conditions are inferred by different relationships between the TSI values. Results of this study indicate that the analysis is quite robust, and that it generally gives good agreement with conclusions based on more direct methods (e.g., nutrientaddition bioassays, zooplankton size data, zooplankton removal experiments). The TSI approach, when validated periodically with these more costly and time-intensive methods, provides an effective, low cost method for tracking long-term changes in pelagic structure and function with potential value in monitoring lake ecology and responses to management.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.31-45
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• 2020

The biological indices based on the community structure with species richness and/or abundance are commonly used to assess aquatic ecosystem health. Meanwhile, recently functional traits-based approach is considered in ecosystem health assessment to reflect ecosystem functioning. In this study, we developed a database of biological traits for 136 taxa consisting of major stream insects (Ephemeroptera, Plecoptera, Trichoptera, Coleoptera, and Odonata) collected at Korean streams on the nationwide scale. In addition, we obtained environmental variables in five categories (geography, climate, land use, hydrology and physicochemistry) measured at each sampling site. We evaluated the relationships between community indices based on taxonomic diversity and functional diversity estimated from biological traits. We classified sampling sites based on similarities of their environmental variables and evaluated relations between clusters of sampling sites and diversity indices and biological traits. Our results showed that functional diversity was highly correlated with Shannon diversity index and species richness. The six clusters of sampling sites defined by a hierarchical cluster analysis reflected differences of their environmental variables. Samples in cluster 1 were mostly from high altitude areas, whereas samples in cluster 6 were from lowland areas. Non-metric multidimensional scaling (NMDS) displayed similar patterns with cluster analysis and presented variation of taxonomic diversity and functional diversity. Based on NMDS and community-weighted mean trait value matrix, species in clusters 1-3 displayed the resistance strategy in the life history strategy to the environmental variables whereas species in clusters 4-6 presented the resilience strategy. These results suggest that functional diversity can complement the biological monitoring assessment based on taxonomic diversity and can be used as biological monitoring assessment tool reflecting changes of ecosystem functioning responding to environmental changes.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.533-540
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• 1995

Attenuation correction is important in producing quantitative positron emission tomography (PET) images. Conventionally, photon attenuation effects are corrected using transmission measurements performed before tracer administration. The pre-injection transmission measurement approach may require a time delay between transmission and emission scans for the tracer studies requiring a long uptake period, about 45 minutes for F-18 deoxyglucose study. The time delay will limit patient throughput and increase the likelihood of patient motion. A technique lot performing simultaneous transmission and emission scans (T+E method) after the tracer injection has been validated. The T+E method substracts the emission counts contaminating the transmission measurements to produce accurate attenuation correction coefficients. This method has been evaluated in experiments using a cylindrical phantom filled with background water (5750 cc) containing $0.4{\mu}Ci/cc$ of F-18 fluoride ion and one insert cylinder (276 cc) containing $4.3{\mu}Ci/cc$. GE $Advance^{TM}$ PET scanner and Ge-68 rotating pin sources for transmission scanning were used for this investigation. Post-injection transmission scan and emission scan were peformed alternatively over time. The error in emission images corrected using post-infection transmission scan to emission images corrected transmission scan was 2.6% at the concentration of $1.0{\mu}Ci/cc$. No obvious differences in image quality and noise were apparent between the two images. The attenuation correction can be accomplished with post-injection transmission measurement using rotating pin sources and this method can significantly shorten the time between transmission and omission scans and thereby reduce the likelihood of patient motion and increase scanning throughput in PET.

• Korean Journal of Organic Agriculture
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• v.27 no.4
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• pp.479-499
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• 2019

This study was conducted to investigate the responses of soil properties and microbial communities to different agricultural management and soil types, including organic management in Andisols (Org-A), organic management in Non-andisols (Org-NA), conventional management in Andisols (Con-A) and conventional management in Non-andisols (Con-NA) by using a pyrosequencing approach of 16S rRNA gene amplicon in Radish farms of volcanic ash soil in Jeju island. The results showed that agricultural management systems had a little influence on the soil chemical properties but had significant influence on microbial communities. In addition, soil types had significant influences on both the soil chemical properties and microbial communities. Organic farming increased the microbial density of bacteria and biomass C compared to conventional farming, regardless of soil types. Additionally, Org-NA had the highest dehydrogenase activity among treatments, whereas no difference was found between Org-A, Con-A and Con-NA and had the highest species richness (Chao 1) and diversity (Phyrogenetic diversity). Particularly, Chao 1 and Phyrogenetic diversity were increased in organic plots by 12% and 20%, compared with conventional plots, respectively. Also, regardless of agricultural management and soil types, Proteobacteria was the most abundant bacterial phylum, accounting for 21.9-25.9% of the bacterial 16S rRNAs. The relative abundance of putative copiotroph such as Firmicutes was highest in Org-NA plot by 21.0%, as follows Con-NA (13.1%), Con-A (6.7%) and Org-A (5.1%.), respectively and those of putative oligotrophs such as Acidobacteria and Planctomycetes were higher in Con-A than those in the other plots. Furthermore, LEfSe indicated that organic system enhanced the abundance of Fumicutes, while conventional system increased the abundance of Acidobacteria, especially in Non-andisols. Correlation analysis showed that total organic carbon (TOC) and nutrient levels (e.g. available P and exchangeable K) were significantly correlated to the structure of the microbial community and microbial activity. Overall, our results showed that the continuous organic farming systems without chemical materials, as well as the soil types made by long-term environmental factors might influence on soil properties and increase microbial abundances and diversity.