• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.89-91
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• 2000

Polynuclear aromatic hydrocarbon (PAH) compounds are highly carcinogenic chemicals and common groundwater contaminants that are observed to persist in soils. The adherence and slow release of PAHs in soil is an obstacle to remediation and complicates the assessment of cleanup standards and risks. Biological degradation of PAHs in soil has been an area of active research because biological treatment may be less costly than conventional pumping technologies or excavation and thermal treatment. Biological degradation also offers the advantage to transform PAHs into non-toxic products such as biomass and carbon dioxide. Ample evidence exists for aerobic biodegradation of PAHs and many bacteria capable of degrading PAHs have been isolated and characterized. However, the microbial degradation of PAHs in sediments is impaired due to the anaerobic conditions that result from the typically high oxygen demand of the organic material present in the soil, the low solubility of oxygen in water, and the slow mass transfer of oxygen from overlying water to the soil environment. For these reasons, anaerobic microbial degradation technologies could help alleviate sediment PAH contamination and offer significant advantages for cost-efficient in-situ treatment. But very little is known about the potential for anaerobic degradation of PAHs in field soils. The objectives of this research were to assess: (1) the potential for biodegradation of PAH in field aged soils under denitrification conditions, (2) to assess the potential for biodegradation of naphthalene in soil microcosms under denitrifying conditions, and (3) to assess for the existence of microorganisms in field sediments capable of degrading naphthalene via denitrification. Two kinds of soils were used in this research: Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS). Results presented in this seminar indicate possible degradation of PAHs in soil under denitrifying conditions. During the two months of anaerobic degradation, total PAH removal was modest probably due to both the low availability of the PAHs and competition with other more easily degradable sources of carbon in the sediments. For both Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS), PAH reduction was confined to 3- and 4-ring PAHs. Comparing PAH reductions during two months of aerobic and anaerobic biotreatment of MHS, it was found that extent of PAHreduction for anaerobic treatment was compatible with that for aerobic treatment. Interestingly, removal of PAHs from sediment particle classes (by size and density) followed similar trends for aerobic and anaerobic treatment of MHS. The majority of the PAHs removed during biotreatment came from the clay/silt fraction. In an earlier study it was shown that PAHs associated with the clay/silt fraction in MHS were more available than PAHs associated with coal-derived fraction. Therefore, although total PAH reductions were small, the removal of PAHs from the more easily available sediment fraction (clay/silt) may result in a significant environmental benefit owing to a reduction in total PAH bioavailability. By using naphthalene as a model PAH compound, biodegradation of naphthalene under denitrifying condition was assessed in microcosms containing MHS. Naphthalene spiked into MHS was degraded below detection limit within 20 days with the accompanying reduction of nitrate. With repeated addition of naphthalene and nitrate, naphthalene degradation under nitrate reducing conditions was stable over one month. Nitrite, one of the intermediates of denitrification was detected during the incubation. Also the denitrification activity of the enrichment culture from MHS slurries was verified by monitoring the production of nitrogen gas in solid fluorescence denitrification medium. Microorganisms capable of degrading naphthalene via denitrification were isolated from this enrichment culture.

• BMB Reports
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• v.51 no.11
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• pp.584-589
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• 2018

Secondary prevention via earlier detection would afford the greatest chance for a cure in premalignant lesions. We investigated the exomic profiles of non-malignant and malignant changes in head and neck squamous cell carcinoma (HNSCC) and the genomic blueprint of human papillomavirus (HPV)-driven carcinogenesis in oropharyngeal squamous cell carcinoma (OPSCC). Whole-exome (WES) and whole-genome (WGS) sequencing were performed on peripheral blood and adjacent non-tumor and tumor specimens obtained from eight Korean HNSCC patients from 2013 to 2015. Next-generation sequencing yielded an average coverage of $94.3{\times}$ for WES and $35.3{\times}$ for WGS. In comparative genomic analysis of non-tumor and tumor tissue pairs, we were unable to identify common cancer-associated early mutations and copy number alterations (CNA) except in one pair. Interestingly, in this case, we observed that non-tumor tonsillar crypts adjacent to HPV-positive OPSCC appeared normal under a microscope; however, this tissue also showed weak p16 expression. WGS revealed the infection and integration of high-risk type HPV16 in this tissue as well as in the matched tumor. Furthermore, WES identified shared and tumor-specific genomic alterations for this pair. Clonal analysis enabled us to infer the process by which this transitional crypt epithelium (TrCE) evolved into a tumor; this evolution was accompanied by the subsequent accumulation of genomic alterations, including an ERBB3 mutation and large-scale CNAs, such as 3q27-qter amplification and 9p deletion. We suggest that HPV16-driven OPSCC carcinogenesis is a stepwise evolutionary process that is consistent with a multistep carcinogenesis model. Our results highlight the carcinogenic changes driven by HPV16 infection and provide a basis for the secondary prevention of OPSCC.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.555-560
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• 1994

Among the permanent teeth. the first permanent molars play the greatest role in occlusion and function. So, the congenital missing, abnormal reuption or abnormal formation of the first permanent molars in the course of arch development would inflict normal development of dental arches. Therefore, early detection of abnormal cases related to first permanent molars and understanding of current and predictable clinical problems are essential for proper occlusal guidance in children. With the aim of investigating the clinical patterns of delayed eruption of first permanent molars in children, panoramic tomograms of the childern in mixed and early permanent dentition were observed and analyzed. The results were as follows: 1. Among the delayed eruption of first permanent molars, on tooth or bilateral teeths were affected most frequently. Delayed eruption was more prevalent in maxilla than in mandible. 2. The formation of tardily erupted teeth were also delayed. 3. Delayed eruption was generally limited in first molars or molar segments. 4. Delayed eruption of first permanent molars is accompanied by abnormal position of tooth germs, for example, ectopic eruption, delayed dental age, delayed localized tooth formation and generalized congenital missing. 5. There was a tendency of delayed formation or congenital missing of second molars distal to tardily erupted 1st molars. And that was more marked in maxilla than in mandible. 6. There was reported that affected 1st molars show various size and shapes. Maxillary 1st molars showing delayed eruption showed a tendency of having 3 cusps. But, tardily erupted mandibular 1st molars showed no significant reduction in mesiodistal dimension, as reported. 7. In some cases, the delayed eruption of 1st permanent molars was associated with ectopic eruption, but their formation was not usually retarded. 8. In skeletal class III cases, there showed a tendency of mandibular 1st molars to erupt earlier than maxillary 1st molars with greater interval than in normal occlusion.

• Korean Journal of Cognitive Science
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• v.16 no.1
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• pp.1-15
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• 2005

Since human visual system has limited capacity for visual information processing, it should select goal-relevant information for further processing. There have been several studies that emphasized the possible involvement of memory in spatial shift of selective attention (Chun & Jiang, 1998, 1999; Klein, 1988; Klein & MacInnes, 1999). However, other studies suggested the inferiority of human visual memory in change detection(Rensink, O'Regan, & Clark, 1997; Simons & Levin, 1997) and in visual search(Hotowitz & Wolfe, 1998). The present study examined the involvement of memory in visual search; whether memory for the previously searched items guides selective attentional shift or not. We investigated how search works by comparing visual search performances in three different conditions; full exposure condition, partial exposure condition, and partial-to-full exposure condition. Revisiting searched items was allowed only in full exposure condition and not in either partial or partial-to-full exposure condition. The results showed that the efficiencies of attentional shift were nearly identical for all conditions. This finding implies that even in full exposure condition the participants scarcely re-examined the previously searched items. The results suggest that instant memory can be formed and used in visual search process. These results disagree with the earlier studies claiming thar visual search has no memory. We discussed the problems of the previous research paradigms and suggested some alternative accounts.

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.242-250
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• 2016

This study was conducted to investigate whether Stroop-related cognitive task will be affected according to the preceding affective valence factored by matchedness in response time(RT) and whether facial recognition will be indexed by specific event-related potentials(ERPs) signature in normal person as in patients suffering from affective disorder. ERPs primed by subliminal(30ms) facial stimuli were recorded when presented with four pairs of affect(positive or negative) and cognitive task(matched or mismatched) to get ERP effects(N2 and P300) in terms of its amplitude and peak latency variations. Behavioral response analysis based on RTs confirmed that subliminal affective stimuli primed the target processing in all affective condition except for the neutral stimulus. Additional results for the ERPs performed in the negative affect with mismatched condition reached significance of emotional-face specificity named N2 showing more amplitude and delayed peak latency compared to the positive counterpart. Furthermore the condition shows more positive amplitude and earlier peak latency of P300 effect denoting cognitive closure than the corresponding positive affect condition. These results are suggested to reflect that negative affect stimulus in subliminal level is automatically inhibited such that this effect had influence on accelerating detection of the affect and facilitating response allowing adequate reallocation of attentional resources. The functional and cognitive significance with these findings was implied in terms of subliminal effect and affect-related recognition modulating the cognitive tasks.

• Korean Journal of Ichthyology
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• v.17 no.3
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• pp.187-194
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• 2005

Feeding of the maiden goby, Pterogobius virgo and multicolorfin rainbowfish, Halichoeres poecilopterus, was studied at Kurahashi Island in the Seto Inland Sea, Japan. P. virgo foraged on only benthic invertebrates in a pit on the bottom by spot-fixed fin digging. Territory size of P. virgo was very small, because they only defended the excavated pit. H. poecilopterus frequently intruded into the feeding territory of P. virgo and fed on benthic invertebrates flushed out by the fin digging of P. virgo. Feeding activity and vigilance time of P. virgo tended to decrease significantly more in such an association than when solitary. Frequency of aggression of P. virgo when H.poecilopterus intruded into the territory was higher the intruder came from the front of the territory than when the invasion was from the side and back, regardless of the size of the intruder. In small H.poecilopterus, feeding success rate was greater from the side and back of the territory than from the front. However, similar-sized H.poecilopterus were more successful in feeding from the front and side. Feeding association provides an antipredatory benefit to P. virgo because of less alert time against predators and earlier detection of predators, although their cost is great because of territory defense and decrease of feeding activity.

• Journal of Preventive Medicine and Public Health
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• v.39 no.6
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• pp.511-519
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• 2006

Objectives : As the disabled have higher prevalence rates and earlier onsets of chronic diseases than the non-disabled, their participation in mass screening is important for the early detection and intervention of chronic diseases. Nevertheless, in Korea, the disabled have lower participation rates in mass screening services than the non-disabled. The purpose of the study was to find determinants for the participation in the National Health Insurance (NHI) mass screening program among the disabled. Methods : In this study, the NHI mass screening data of 423,076 disabled people, which were identified using the National Disability Registry (2003), were analyzed. Of the factors affecting the participation rates in mass screenings, the following variables were included for the analysis: socioeconomic stati, such as sex, age, category of health insurance program, region and income, disability characteristics, such as disability type, and severity. A multiple logistic regression analysis was used to evaluate the association between the participation rates, disability characteristics variables and demographic variables. Results : The participation rate in mass screening of the disabled was 41.3%, but was lower in females, an age of more than 70 years, self-employed and for those with an average monthly insurance premium over 133,500 Won and in metropolitan legions. The participation rate was 1.31 times lower in females than males (95% CI=1.29-1.33); 3.50 times lower in the elderly (more than 70 years) than the younger (95% CI=3.33-3.67); 1.43 times lower in those who live in metropolitan areas (95% CI=1.40-1.46); 2.59 times lower for those in a health Insurance program for the self-employed than for employees (95% CI=2.56-2.63), 1.19 times lower for the higher income (more than 133,500) than the lower income group (4,400-22,000) for the average monthly insurance premium (95% CI=1.15-1.23): 2.04 times lower for those with brain palsy and stroke disabilities than with auditory impairments (95% CI: 1.97-2.11) and 3.27 times for those with severe compared to mild disabilities (95% CI=3.15-3.40). Conclusions : The disabled with high severity, and locomotive and communication disabilities have lower participation rates in mass screening services in Korea.

• The Journal of Korean Society of Virology
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• v.27 no.2
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• pp.161-168
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• 1997

The present study was designed to estimate the seroprevalence of NLVs among diarrheagenic children and in healthy adults in Seoul and its vicinity with the use of an EIA and an Western blot (WB) based on recombinant Norwalk virus capsid protein (rNV) and crude virus preparations as antigen. Seroconversion was observed in 34 (83%) of 41 tested using the EIA and in 21 (54%) of 39 using the WB, suggesting that the NLVs with epitopes common to rNV are prevalent in Seoul area. Diarrheal children who were known to have been infected with several other strains of the NLVs showed no significant antibody response to the rNV. Infection with rNV occurred earlier in life: primary infections with rNV were common before the age of 6 months and over 91 % of children had evidence of infection by that age by the EIA. Since the amount of the NLV antigens available for seroepidemiologic surveys is limited, we tried to detect NLV antibody by using crude virus preparations as antigen. One crude virus preparation of a child whose stool yielded genetically distinct NLV revealed the presence of the plural number of bands upon SDS-PAGE, but precipitated only one band (62 kDa) after the WB with a serum (collected 10 days after the onset of symptoms) of another diarrheal child. The WB assay we present in this report revealed that the NLVs are prevalent among Korean population and that the sera contained antibody to a single major structural protein, with molecular sizes of 58 to 62 kDa, compatible with the sizes reported for the Norwalk virus and Snow Mountain agent proteins, respectively. When the results of the WB were compared with those obtained by the EIA, the EIA antibody assay was sensitive enough to detect an antibody rise of as much as 4096-fold but not as specific as the WB. The WB assay presented in this paper will provide a powerful tool to elucidate not only antigenic structures of the NL Vs but also seroepidemiology of the NLV infection. The availability of an unlimited source of antigen will enable a large scale serologic studies that will greatly increase our understanding of the role of NLVs in human enteric illness.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5095-5099
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• 2013

Background: The overall incidence of breast cancer in South Asian countries, including Nepal, is low compared to Western countries. However, the incidence of breast cancer among young women is relatively high. Breast cancer in such cases is characterized by a relatively unfavorable prognosis and unusual pathological features. The aim of this study was to investigate clinico-pathological and biological characteristics in younger breast cancer patients (<40 years) and compare these with their older counterparts. Materials and Methods: Nine hundred and forty four consecutive female breast cancer patients, admitted to the Department of Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal between November 1997 and October 2012, were retrospectively analyzed. Results: Out of the 944 female breast cancer patients, 263 (27.9%) were <40 years. The mean age was $34.6{\pm}5.0$ years among younger patients compared to $54.1{\pm}9.9$ for those ${\geq}40$ years. The mean age at menarche was also significantly lower ($13.5{\pm}1.5$ vs $14.2{\pm}1.5$ years p=0.001) while the mean duration of symptoms was significantly longer (7.6 vs 6.5 months p=0.004). Family history of breast cancer was evident in 3.0% of the young women versus 0.3% in the older one. Mammography was performed less frequently in younger patients (59.7%), compared to older (74.4%), and was of diagnostic benefit in only 20% of younger patients compared to 85% of older ones. At diagnosis, the mean tumor diameter was significantly larger in young women ($5.0{\pm}2.5$ vs $4.5{\pm}2.4cm$, p=0.005). Axillary lymph nodes were positive in 73% of younger patients and 59% of older patients. In the younger group, the proportion of stage III or IV disease was higher (55.1% vs 47.1%, $p{\leq}0.05$). The proportion of breast conserving surgery was higher in young patients (25.1% vs 8.7%) and a higher proportion of younger patients receive neoadjuvant chemotherapy (9.9% vs 2.8%). The most common histological type was ductal carcinoma (93.1% vs 86%). The proportion of histological grade II or III was higher in younger patients (55.9% vs 24.5%). Similarly, in the younger group, lymphatic and vascular invasion was more common (63.2% vs 34.3% and 39.8% vs 25.4%, respectively). Patients in the younger age group exhibited lower estrogen and/or progesterone receptor positivity (34.7% vs 49.8%). Although statistically not significant, the proportion of triple negative tumors in younger age group was higher (22.4% vs 13.6%). Conclusions: Breast cancer in young Nepalese women represents over one quarter of all female breast cancers, many being diagnosed at an advanced stage. Tumors in young women exhibit more aggressive biological features. Hence, breast cancer in young women is worth special attention for earlier detection.

• Journal of KIISE:Software and Applications
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• v.33 no.9
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• pp.787-801
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• 2006

Ontology merging describes the process of integrating two ontologies into a new ontology. How this is done best is a subject of ongoing research in the Semantic Web, Data Integration, Knowledge Management System, and other ontology-related application systems. Earlier research on ontology merging, however, has studied for developing effective ontology matching approaches but missed analyzing and solving methods of problems of merging two ontologies given correspondences between them. In this paper, we propose a specific ontology merging process and a generic operator, T-MERGE, for integrating two source ontologies into a new ontology. Also, we define a taxonomy of merging conflicts which is derived from differing representations between input ontologies and a method for detecting and resolving them. Our T-MERGE operator encapsulates the process of detection and resolution of conflicts and merging two entities based on given correspondences between them. We define a data structure, MergeLog, for logging the execution of T-MERGE operator. MergeLog is used to inform detailed results of execution of merging to users or recover errors. For our experiments, we used oriental philosophy ontologies, western philosophy ontologies, Yahoo western philosophy dictionary, and Naver philosophy dictionary as input ontologies. Our experiments show that the automatic merging module compared with manual merging by a expert has advantages in terms of time and effort.