• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.1-7
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• 2020

This study aims to evaluate the effect of artificial facilities constructed afterthe release of the civilian controlled zone (CCZ) in Cheorwon on the inhabitation of cranes. The study site was released from the CCZ in 2012, and several barns have been built since 2017. The average number of Red-crowned Cranes was 9.3±4.3 individuals (±Standard Deviation) in the period before the release of the CCZ from 2009 to 2012, and it decreased by ca. one third of Red-crowned Crane's average individuals were showing 3.5±0.5 individuals after release. The average number of White-naped Cranes also appeared to be decreased by ca. 90% from 63.3±24.6 to 6.0±6.0 individuals. This results suggest that the construction of greenhouses and barns after the releasing of the CCZ affected the decrease of the population of these two crane species. In the case of Red-crowned Crane, the core area tended to move away from the area where barns were built. However, the distribution range of Red-crowned Cranes did not change significantly we expected because the study area was not their favorite place since 2012 when the area was released from the CCZ. The density of the White-naped Crane was relatively high even in the area where greenhouses were built, but after 2017 when the barn was built intensively, core habitat of crane became shrink and fragmented. These results suggest that both Red-crowned Cranes and White-naped Cranes response sensitively against habitat change due to the construction of barns. Since the release of the CCZ, the construction of the greenhouse has been influenced on the distribution of cranes, but subsequently, the construction of the barn seems to have caused a bigger change in their core habitat because the passage of people to barns is more frequent than the greenhouses.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.166-174
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• 2006

To determine the proper processing and storage conditions, physico-chemical, microbial and sensory properties of venison jerky under different dry times were measured during storage at $30^{\circ}C$ for 28 days. Samples were dried for 3 hr (T1), 4 hr (T2) and 5 hr (T3) at $75^{\circ}C$ in the smoke chamber, respectively. The pH of T1 was slightly lower than those of T2 and T3 as storage time increased. As dry and storage time increased, TBARS of T2 and T3 were significantly higher (p<0.05) than that of T1. In meat color, $L^*$ values of T3 showed slightly higher than those of T1 and T2, while at values were not clearly tendency by the passage of storage time. $b^*$ values of T2 and T3 were higher than that of T1. The water activity were significantly lower (p<0.05) in ,the order of T3$log_{10}$ CFU/g until 28 days and its number were accepted by sensory evaluation. In conclusions, T2 and T3 showed slightly high overall acceptability and lipid oxidative stability compared to T1 conditions. These results indicated that longer dry time ($4{\sim}5 hr$) of venison jerky would be better characteristics as compared to shorter dry time (3 hr) with increased storage time at $30^{\circ}C$.

• Journal of radiological science and technology
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• v.28 no.2
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• pp.105-110
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• 2005

Background/Aim : Common bile duct (CBD) stones may cause jaundice, cholangitis, or pancreatitis. Extracorporeal shock wave lithotripsy (ESWL) may be needed whenever endoscopic procedure are failed to extract common bile duct stones. The aim of this study is to provide the standard for patient's best choice on ESWL for treatment of CBD stones resistant to endoscopic extraction. Materials and Methods : Fourty-six patients failed in endoscopic stone extraction including mechanical lithotripsy were treated by ESWL. In all patients, endoscopic sphincterotomy and nasobiliary drainage tube was done before ESWL using the ultrasonography for stone localization with a spark-gap type lithotriptor. Patients were sedated with an intravenous injection of 50 mg of Demerol. None were treated under general anesthesia. Results : Overall complete clearance rate of CBD stone was 89.1% (41/46). In 82.6% of the patients, the stones were extracted endoscopically after ESWL, and spontaneous passage was observed in 6.5%. In the clearance rate after ESWL, there were no noticeable differences with regard to number (single: 82.8%, two or three: 100%, more than three: 100%) and size of the stone (less than 33mm: 92.9%, 33 mm or larger: 83.3%), whereas there were significant differences with regard to the ratio of sum of long-axis length of the all stones to sum of long-axis length of the CBD excluding stone (1:2.4, 1:2.1) and diameter of the largest stone to diameter of CBD excluding stone (1:0.9, 1:0.4) for patients with complete clearance compared with those without. Conclusion : We propose that stones without the fragments are travelable sufficient space in CBD or extractable sufficient diameter of CBD regardless of stone size and number should be treated by other technique to prevent time and cost consuming, such as percutaneous transhepatic cholangioscopylithotomy.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.59-93
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• 2006

Wolseong in Gyeongju is a historic fortress site of Silla constructed under the reign of Pasanisageum that played politically and militarily important roles. The moat surrounding Wolseong had a function of protecting the fortress in wartimes but became a part of gardening in the unified Silla era. Lots of relics have been excavated from Wolseong moat since 1985. Among them a great number and kinds of convex roofing tiles are regarded as invaluable sources to show different aspects of Silla, from its earlier time through to the unified and on. Roofing tiles were widely used for national buildings such as royal palaces, temples and fortresses and even for other popular architecture and have been dug out a lot more than any other relics. Research on them, however, has been done poorly. Vigorous study is in progress with increasing number of roofing tiles coming from many recent excavations, though it has been limited to the studies on general genealogy of patterns and manufacture processes. Thus this essay seeks to find which are dongbeomwas, roofing tiles of a same mold, out of convex tiles with the pattern of a unilobed lotus flower dug out of Wolseong moat. It also attempts to identify dongbeomwas by examining detail characteristics of roofing tiles which have been confusingly termed as yusawa, similar roofing tiles, or donghyeongwa, roofing tiles of the same shape. The significance of identifying dongbeomwas could be emphasized by various facts resulting from researches on dongbeomwas; the ways to identify them correctly, their time sequence and their excavated sites. In conclusion, dongbeomwas were identified out of many kinds of convex tiles. If they were excavated from the same site, they share some common features. The sites where they were dug out also tell what changes were made with passage of time and what relations they had with neighboring Anapji. Since roofing tile molds haven't been found yet, the only way to identify dongbeomwas is to examine details of roofing tiles. Dongbeomwas excavated in Wolseong moat help to discuss the time of each district of it. Meanwhile it should be noted that the term 'dongbeomwa' be used only after exact examining.

• Journal of Astronomy and Space Sciences
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• v.36 no.1
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• pp.21-33
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• 2019

This paper focuses on the interpretation of radiation fluxes from active galactic nuclei. The advantage of positron annihilation spectroscopy over other methods of spectral diagnostics of active galactic nuclei (therefore AGN) is demonstrated. A relationship between regular and random components in both bolometric and spectral composition of fluxes of quanta and particles generated in AGN is found. We consider their diffuse component separately and also detect radiative feedback after the passage of high-velocity cosmic rays and hard quanta through gas-and-dust aggregates surrounding massive black holes in AGN. The motion of relativistic positrons and electrons in such complex systems produces secondary radiation throughout the whole investigated region of active galactic nuclei in form of cylinder with radius R= 400-1000 pc and height H=200-400 pc, thus causing their visible luminescence across all spectral bands. We obtain radiation and electron energy distribution functions depending on the spatial distribution of the investigated bulk of matter in AGN. Radiation luminescence of the non-central part of AGN is a response to the effects of particles and quanta falling from its center created by atoms, molecules and dust of its diffuse component. The cross-sections for the single-photon annihilation of positrons of different energies with atoms in these active galactic nuclei are determined. For the first time we use the data on the change in chemical composition due to spallation reactions induced by high-energy particles. We establish or define more accurately how the energies of the incident positron, emitted ${\gamma}-quantum$ and recoiling nucleus correlate with the atomic number and weight of the target nucleus. For light elements, we provide detailed tables of all indicated parameters. A new criterion is proposed, based on the use of the ratio of the fluxes of ${\gamma}-quanta$ formed in one- and two-photon annihilation of positrons in a diffuse medium. It is concluded that, as is the case in young supernova remnants, the two-photon annihilation tends to occur in solid-state grains as a result of active loss of kinetic energy of positrons due to ionisation down to thermal energy of free electrons. The single-photon annihilation of positrons manifests itself in the gas component of active galactic nuclei. Such annihilation occurs as interaction between positrons and K-shell electrons; hence, it is suitable for identification of the chemical state of substances comprising the gas component of the investigated media. Specific physical media producing high fluxes of positrons are discussed; it allowed a significant reduction in the number of reaction channels generating positrons. We estimate the brightness distribution in the ${\gamma}-ray$ spectra of the gas-and-dust media through which positron fluxes travel with the energy range similar to that recorded by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) research module. Based on the results of our calculations, we analyse the reasons for such a high power of positrons to penetrate through gas-and-dust aggregates. The energy loss of positrons by ionisation is compared to the production of secondary positrons by high-energy cosmic rays in order to determine the depth of their penetration into gas-and-dust aggregations clustered in active galactic nuclei. The relationship between the energy of ${\gamma}-quanta$ emitted upon the single-photon annihilation and the energy of incident electrons is established. The obtained cross sections for positron interactions with bound electrons of the diffuse component of the non-central, peripheral AGN regions allowed us to obtain new spectroscopic characteristics of the atoms involved in single-photon annihilation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.279-288
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• 2007

In the present study, we focused on stem cells in the dental papilla of the tooth germ. The tooth germ, sometimes called the tooth bud, is the primordial structure from which a tooth is formed. The tooth germ consists of the enamel organ, the dental papilla, and the dental follicle. The dental papilla lies below a cellular aggregation of the enamel organ. Mesenchymal cells within the dental papilla are responsible for formation of dentin and pulp of a tooth. Tooth germ disappears as a tooth is formed, but that of a third molar stays in the jawbone of a human until the age of 10 to 16, because third molars grow slowly. Impacted third molar tooth germs from young adults are sometimes extracted for orthodontic treatment. In the present study, we evaluated the osteogenic activity and mineralization of cultured human dental papilla-derived cells. Dental papillas were harvested from mandible during surgical extraction of lower impacted third molar from 3 patients aged 13-15 years. After passage 3, the dental papilla-derived cells were trypsinized and subsequently suspended in the osteogenic induction DMEM medium supplemented with 10% fetal bovine serum, 50 g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate at a density of $1\;{\times}10^6\;cells/dish$ in a 100-mm culture dish. The dental papilla-derived cells were then cultured for 6 weeks and the medium was changes every 3 days during the incubation period. Dental papilla-derived cells showed positive alkaline phosphatase (ALP) staining during 42 days of culture period. The formation of ALP stain showed its maximal manifestation at day 7 of culture period, then decreased in intensity during the culture period. ALP mRNA level was largely elevated at 1 weeks and gradually decreased with culture time. Osteocalcin mRNA expression appeared at day 14 in culture, after that its expression continuously increased in a time-dependent manner up to day 28. The expression remained constant thereafter. Runx2 expression appeared at day 7 with no detection thereafter. Von Kossa-positive mineralization nodules were first present at day 14 in culture followed by an increased number of positive nodules during the entire duration of the culture period. Osteocalcin secretion was detectable in the culture medium from 1 week. The secretion of osteocalcin from dental papilla-derived cells into the medium greatly increased after 3 weeks although it showed a shallow increase by then. In conclusion, our study showed that cultured human dental papilla-derived cells differentiated into active osteoblastic cells that were involved in synthesis of bone matrix and the subsequent mineralization of the matrix.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.79-88
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• 1968

For the purpose of assessing the influence of the mamillary bodies on the general activity and stress response, mamillary body·damaged rats(mamillary body group), operated control rats, and normal control animals were prepared and 2 experiments were carried out. The mamillary bodies. were damaged electrolytically by passing 0.3 ma d.c. current through stereotaxically implanted electrodes. The operated control group received the same treatment except passage of current. In the 1st experiment, each subject belonging to the mamillary body group .(9 rats) or the operated control group (13 animals) was put individually into an activity cage across which an infrared beam traversed. The number of beam interruptions by the movement of the subject in the cage was. recorded hourly for 48 hours and was regarded as an index of general activity. In the 2nd experiment, each of the mamillary body group (52 animals), the operated control group (45 rats), and the normal control group (37 animals) was further divided into 4 subgroups and the adrenal ascorbic acid content of one of the 4 subgroups was measured before, another subgroup immediately after, a third subgroup 2 hours after, and the remaining subgroup 4 hours after termination of a cold stress ($-10^{\circ}C$ for 1 hour). Following results were obtained: 1. Though the total activities in 48 hours of the mamillary body group and the operated control group were not significantly different, the activities of the malnillary body group for a few hours. at the beginning of the measurement and also in the evenings of both the 1st and the 2nd experimental days were significantly greater than those of the operated control group. 2. Judged by the significant reduction in adrenal ascorbic acid content, the stress response of the mamillary body group was as marked as that of the operated control or the normal control group-immediately after termination of cold exposure. Recovery from the stress was accelerated significantly in the mamillary body group and insignificantly in the operated control group compared with that of the normal control group, the intergroup difference of the former two groups being insignificant. It was inferred from the above results that the mamillary bodies may exert an inconspicuous inhibitory influence upon the central mechanism of general activity, and that the mamillaryies bodies may not be the main seat of the stress mechanism, although more works are desirable to confirm the results.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.197-205
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• 2007

Angiogenesis is a essential part for bone formation and bone fracture healing. Vascular endothelial growth factor (VEGF), one of the most important molecules among many angiogenic factors, is a specific mitogen for vascular endothelial cells. VEGF-mediated angiogenesis is required for bone formation and repair. However, the effect of VEGF on osteoblastic cells during osteogenesis is still controversial. In recent days, substantial progress have been made toward developing tissue-engineered alternatives to autologous bone grafting for maxillofacial bony defects. Periosteum has received considerable interest as a better source of adult stem cells. Periosteum has the advantage of easy harvest and contains various cell types and progenitor cells that are able to differentiate into a several mesenchymal lineages, including bone. Several studies have reported the bone formation potential of periosteal cells, however, the correlation between VEGF signaling and cultured human periosteal cell-derived osteogenesis has not been fully investigated yet. The purpose of this study was to examine the correlation between VEGF signaling and cultured human periosteal-derived cells osteogenesis. Periosteal tissues of $5\;{\times}\;20\;mm$ were obtained from mandible during surgical extraction of lower impacted third molar from 3 patients. Periosteal-derived cells were introduced into the cell culture and were subcultured once they reached confluence. After passage 3, the periosteal-derived cells were further cultured for 42 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and ${\beta}-glycerophosphate$. We evaluated the alkaline phosphatase (ALP) activity, the expression of Runx2 and VEGF, alizarin red S staining, and the quantification of osteocalcin and VEGF secretion in the periosteal-derived cells. The ALP activity increased rapidly up to day 14, followed by decrease in activity to day 35. Runx2 was expressed strongly at day 7, followed by decreased expression at day 14, and its expression was not observed thereafter. Both VEGF 165 and VEGF 121 were expressed strongly at day 35 and 42 of culture, particularly during the later stages of differentiation. Alizarin red S-positive nodules were first observed on day 14 and then increased in number during the entire culture period. Osteocalcin and VEGF were first detected in the culture medium on day 14, and their levels increased thereafter in a time-dependent manner. These results suggest that VEGF secretion from cultured human periosteal-derived cells increases along with mineralization process of the extracellular matrix. The level of VEGF secretion from periosteal-derived cells might depend on the extent of osteoblastic differentiation.

• Clinical and Experimental Pediatrics
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• v.50 no.10
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• pp.1011-1017
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• 2007

Purpose : We tried to assess the optimal conditions to improve low transduction efficiency and their effect on target cells. Methods : Cultured NIH 3T3 cells were incubated with retroviral vectors bearing an enhanced green fluorescent protein (eGFP) gene. We varied the ratio of viral vectors to target cells (1:1-1:8) and the number of transfections (${\times}1$, ${\times}2$), and compared transduction efficiencies. Also, the effects of polybrene on transduction efficiency and viability of target cells were assessed. Transduction of the eGFP gene was evaluated by observing NIH 3T3 cells under a fluorescence microscope and efficiencies were measured by the percentage of eGFP positive cells using FACscan. Results : As the ratio of retroviral vectors to target cells increased, transduction efficiency was greatly improved, from 7% (1:1) to 38% (1:4). However, transduction efficiency did not increase any more when the ratio increased from 1:4 to 1:8. Cells transfected twice showed higher transduction efficiencies than cells transfected once, at a ratio of 1:8. The eGFP gene transduced to NIH 3T3 cells sustained its expression during repeated passages. However, after the third passage (day 9), the percentage of eGFP positive cells began to decline. The degree of this decline in eGFP expression was lower in cells transfected twice than in cells transfected once (P<0.05). The addition of polybrene did not have any toxic effect on NIH 3T3 cells and greatly increased transduction efficiency (P=0.007). In addition to vector component, transduction efficiency was very sensitive to culture confluence. Cells cultured and transfected in 24-well plate showed higher transduction efficiency, although cells cultured in 6- well plate proliferated more (P=0.024). Conclusion : Our data could be used as a basis for retrovirus-based gene therapy. Further study will follow using human cells as target cells.

• Journal of Environmental Impact Assessment
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• v.25 no.4
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• pp.233-247
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• 2016

The purpose of this study is to offer the basic data for management of National Park by surveying and analysing the change of flora of damaged lands in Juwangsan National Park, Korea. In cause of occurring the damaged lands, site-1 was the vegetation damage by stamping, the removing Gwangamsa of site-2, 3, 4 and the removing Naewon village of site-5, 6, 7. Whole sites are caused by the artificial disturbance and interference. The numbers of flora were summarized as 135 taxa including 52 families, 109 genera, 116 species, 2 subspecies and 17 varieties in whole sites. The status of flora by sites, site-6 is the largest number of 52 taxa, site-1 is the lowest of 23 taxa. The rare plant is 1 taxa, 4 taxa of endemic plants, 10 taxa of specific plants by floristic region, 9 taxa of naturalized plants and 1 taxa of invasive alien plant. In the results of analysis about the change of coverage ratio, for this shrub layer, site-7 was changed to the most $0%{\rightarrow}50%$, and the herb layer, site-5 was changed to the most $75%{\rightarrow}95%$. In case of the change of species numbers, most sites tended to increase in the sites introduced different species or generated by the growth. It is contemplated that is similar to the restoration with the surrounding natural vegetation that is in progress is a transition occurs with the passage of time. In the dominant species, the shrub layer is Fraxinus sieboldiana, Lespedeza bicolor, Rhus javanica, Lespedezamaximowiczii, Salix koreensis and Zelkova serrata, and Miscanthus sinensis var. purpurascens, Oplismenus undulatifolius, Artemisia princeps, Bothriochloa ischaemum and Erigeron annuus of herb layer. In the results of analysing Naturalized Index(NI) and Urbanized Index(UI), NI was increased or decreased this phenomenon with the lapse of time, UI was the most increase. In particular, the increase in UI is due to the transition process, the pioneering plant, naturalized plant was imported to continue.