• Journal of the Korean Geotechnical Society
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• v.26 no.1
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• pp.63-73
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• 2010

The supply of high quality filling materials for pavement base course or reclamation is getting harder. So, there is an attempt to use soft mudstones as an earth filling material in Pohang area. But the engineering properties of the soil deposit placed with soft mudstones have not been clearly evaluated yet. We investigated the water absorption and softening, the slaking behavior and the geological mechanism in order to obtain an effective way of estimating the magnitude of land subsidence and the reduction of soil strength. The applicability of soft mudstones is examined by a variety of laboratory tests and pilot-scale field tests. In addition, it is necessary to consider the environmental characteristics of soft mudstones as a reclaiming material, Consequently, the results from the current study can be used to prevent any construction defects due to the careless use of soft mudstones for the pavement base course or reclamation.

• The Journal of Korean Medicine
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• v.43 no.3
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• pp.1-15
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• 2022

Objectives: Myrrh have been used as a traditional remedy to treat infectious and inflammatory diseases. However, it is largely unknown whether myrrh ethanol extract could exhibit the inhibitory activities against particulate matter (PM)-induced skin injury on human keratinocytes, HaCaT cells. Therefore, this study was aimed to investigate the inhibitory activity of myrrh ethanol extract on PM-induced skin injury in HaCaT cells. Methods: To investigate the inhibitory effects of myrrh ethanol extract in HaCaT cells, the skin injury model of HaCaT cells was established under PM treatment. HaCaT keratinocyte cells were pre-treated with myrrh ethanol extract for 1 h, and then stimulated with PM. Then, the cells were harvested to measure the cell viability, reactive oxygen species (ROS), pro-inflammatory cytokines including interleukin (IL) 1-beta, IL-6, and tumor necrosis factor (TNF)-𝛼, hyaluronidase, collagen, MMPs. In addition, we examined the mitogen activated protein kinases (MAPKs) and inhibitory kappa B alpha (I𝜅-B𝛼) as inhibitory mechanisms of myrrh ethanol extract. Results: The treatment of myrrh ethanol extract inhibited the PM-induced cell death and ROS production in HaCaT cells. In addition, myrrh ethanol extract treatment inhibited the PM-induced elevation of IL-1beta, IL-6, and TNF-𝛼. Also, myrrh ethanol extract treatment inhibited the increase of hyaluronidase, MMP and decrease of collagen. Furthermore, myrrh ethanol extract treatment inhibited the activation of MAPKs and the degradation of I𝜅-B𝛼. Conclusions: Our result suggest that treatment of myrrh ethanol extract could inhibit the PM-induced skin injury via deactivation of MAPKs and nuclear factor (NF)-𝜅B in HaCaT cells. This study could suggest that myrrh ethanol extract could be a beneficial agent to prevent skin damage or inflammation.

• Clinical and Experimental Pediatrics
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• v.50 no.9
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• pp.882-890
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• 2007

Purpose : Preterm very low birth weight infant have high rate of adverse neurodevelopmental sequale. Recently, there have been lots of reports that human umbilical cord blood transplantation ameliorates functional deficits in animal models as hypoxic ischemic injury. This pilot study was undertaken to determine the clinical efficacy and safety of autologous umbilical cord blood cell transplantation for preventing neurodevelopmental sequale in perterm VLBW. Methods : Subjects were 26 preterm infants whose birth weight are less than 1,500 g and delivered under the intrauterine period 34 weeks. Autologous umbilical mononuclear cells (about $5.87{\times}10^7/kg$) were injected to neonate via the umbilical vein on the postnatal 24-48 hour. The therapeutic efficacy was assessed by numbers of nucleated RBC, urinary uric acid/creatinine ratio, concentration of neuron specific enolase (NSE), interleukin 6 (IL6), interleukin-$1{\beta}$ ($IL-1{\beta}$), and glial cell derived neurotrophic factor (GDNF) in serum and cerebrospinal fluid on day 1 and 7. Results : There were no significant differences in the numbers of the nucleated RBC, urinary uric acid/creatinine ratio, concentration of creatine kinase between the transplanted infants and controls. But the nucleated RBC is more likely to be rapidly discharged in the transplanted group. In the transplanted group, the concentrations of IL6, $IL-1{\beta}$, and GDNF were no significant difference between day 1 and 7, although GDNF seemed to be elevated. Serum NSE concentration was significantly elevated after transplantation, but not in CSF. Conclusion : It is suggested that autologous umbilical cord blood transplantation in preterm very low birth weight infant is safe to apply clinical practice. Long term follow up study should be needed to evaluate the potential therapeutic effect of umbilical cord blood transplantation for neuroprotection.

• Neonatal Medicine
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• v.18 no.1
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• pp.76-81
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• 2011

Purpose: The object of this study was to evaluate the efficacy of early total parenteral nutrition with early amino acid in extremely low birth weight infant (ELBWI). Methods: We retrospectively analyzed the medical records of all ELBWIs who were born and admitted to Samsung Medical Center from January 2003 to December 2003 and January 2009 to December 2009 and alive at the time of discharge. Data for nutritional status and morbidities were compared between period 1 (2003, n=22), in which parenteral nutritional support was started gradually over several days and period 2 (2009, n=38), in which parenteral nutrition with amino acid was started as soon as possible after birth. Results: Compared to period 1, birth weight and Apgar score were lower in period 2. The intake amount of glucose, amino acid and total calorie was higher and the level of blood urea nitrogen was increased more from 7th day to 14th day after birth in period 2 when compared than period 1. The weight gain velocity was faster at 7th and 14th postnatal day in period 2. There were no differences in the incidence of necrotizing enterocolitis, moderate to severe bronchopulmonary dysplasia, and severe intraventricular hemorrhage (${\geq}$ Gr III) between two periods but, the incidence of periventricular leukomalacia(PVL) was significantly lower in period 2. Conclusion: Early initiation of total parenteral nutrition with early amino acid in ELBWIs was beneficial at weight gain with lowering catabolism and increasing anabolism. And it could be related with reducing the incidence of PVL.

• Economic and Environmental Geology
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• v.12 no.2
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• pp.51-73
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• 1979

The zinc-lead deposits at the Yeonhwa I mine were investigated in terms of ore-forming geologic setting, structural style of ore control, geometry of individual orebodies, zoning, paragenesis and chemical composition of skarn minerals, as well as metal grades and ratios of selected orebodies. The Yeonhwa I mine is characterized by a large swarm of chimney type massive orebodies with thin skarn envelopes, boldly developed through a thick sequence of Pungchon Limestone, the overlying Hwajeol Formation, and the underlying Myobong Slate of Cambrian age. Nearly 20 orebodies of similar shape, but of varying size are arranged in a V-shaped pattern with northwest and northeast trends, clearly indicating an outstanding ore control by a conjugate system of fractures with these trends. Important orebodies are the Wolam 1, 2, 3, and 5 orebodies in the west, and the Namsan 1, 2, 3. and 5 orebodies in the east, among others. The Wolam 1 orebody, which was observed from the -360 level through the -240, -120, and 0 levels to the surface outcrops (totaling a vertical height of about 500m), shows a vertical variation in skarn mineralogy, ranging from pyroxene-garnet zone on the lower levels. through pyroxene (without garnet) zone on the intermediate levels, and finally to rhodochrosite vein on the upper levels and surface. Microprobe analyses of pyroxene and garnet on a total of 14 mineral grains revealed that pyroxenes are manganoan salitic in most samples, with downward increase of Fe and Mn, whereas garnets are highly andraditic, containing fractions of subordinate grossular with downward decrease of Fe. This indicates a reverse relationship of Fe-contents between pyroxene and garnet with depth. Ore minerals are major sphalerite, subordinate galena, and minor chalcopyrite. Sulfide gangue minerals include major pyrrhotite, and minor pyrite and marcasite of later age. Two types of variational trends in metal grades and ratios with depth are present on the plots of assay data from the Wolam orebodies: one is a steady upward increase in Pb, Zn, and Pb:Zn ratios, with a terminal decline at the top of orebody: the other is an irregular or sinusoidal change. The former is characteristic of chimney-type orebodies, whereas the latter is of vein· shaped orebodies. The Pb grades show large variations among orebodies and from level to level, whereas the Zn grades are relatively constand or less variable.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.1
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• pp.40-52
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• 2020

The purpose of this study is to explore ways to change high school earth science elective courses with the introduction of the high school credit system in 2025, and ways to restructure them in preparation for the next curriculum revision. For this purpose, Delphi surveys with earth science education experts, a survey with in-service earth science teachers, and in-depth interviews with experts were conducted. According to the results, we need to consider four keywords such as cultivation of earth science literacy, connection with student career paths, emphasis on the fun of earth science itself, and student selection rate and college entrance exam in restructuring Earth science electives. Based on this direction, we composed four subjects: Earth System Science emphasizing earth science literacy, and three such subjects reinforcing career connection as Solid Earth Science, Atmospheric and Ocean Science, and Space Science. To resolve concerns about falling selection rate of earth science courses with the introduction of the high school credit system, it is necessary to re-establish the status of the earth science subjects including enhancing the career connection of the earth science electives. Follow-up studies are necessary to elaborate and publicize the titles and core concepts of Earth science electives.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2002.05a
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• pp.3-42
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• 2002

21세기에는 인구의 폭발적 증가와 함께 가속화된 산업화로 말미암아 경지 면적은 줄고 농업 환경은 더욱 피폐해질 것으로 예상된다. 지금도 이미 화석 에너지원의 고갈로 대체 에너지 개발이 시급히 요구되고 있으며, 지구의 자연 환경 보존 목소리도 그 어느 때 보다 높다. 한마디로 식량, 에너지, 환경 문제가 새 세기에 우리가 시급히 해결해야할 과제로 주어져 있다. 이에 과학계에서는 식량 및 대체 에너지원의 공급을 증대시키고 환경을 보존할 수 있는 보편적인 수단으로 환경 친화적 유전자 변형 (GM)작물의 활용이 제시되고있다. 따라서 선진국들은 이의 기반이 되는 식물유전체 연구에 대규모 투자를 아끼지 않고 있으며, 이를 이 용한 식물 생명공학산업을 국가 전략 산업으로 집중 육성하고 있다. GM작물 제조 기술은 유용 유전자의 발굴 및 재조합, 식물세포로의 이식 및 재분화를 통한 완전한 식물체 재생, 이를 품종으로 실용화하는 단계로 구성되어 있다. GM작물은 1983년 항생제 저항성 담배가 개발된 것을 시점으로 하여, 1994년에는 연화지 연 토마토 Flaver Saver이후 지금까지 개발 실용화된 작물은 제초제 저항성 콩, 카놀라, 목화, 그리고 해충 저항성 옥수수 등이 있으며,2001년까지 세계적으로 상품화 승인을 얻은 경우는 15 작물 68품종에 이른다. 2001년 경우 GM작물 종자시장은 약 30억 달러에 달하고 있으며, 미국, 아르헨티나, 캐나다 등 세계적으로 52.6백만 ha에 이르는 면적에서 재배되었다. 그러나 GM농산물의 식품 및 환경 안전성에 대한 의구심이 일기 시작하였고, 따라서 이의 생산 및 소비에 대한 전반적 인 문제가 뜨거운 쟁점으로 부각되기도 하였다. 이 에 각국 정부는 객관적 인 안전성을 확보하기 위한 제도적인 장치를 마련하고 있으며, 아울러 과학기술자들은 더욱 안전한 형질전환 기술 개발을 도모하고 있다. 다음 세대의 GM작물은 단순한 제초제 및 병해충 저항성을 넘어서서 특정 영양 또는 건강기능성을 향상시켜 부가가치를 증가시킨 신품종 맞춤작물이 지속적으로 개발 상업화될 것이다. 따라서 고유성을 가진 유용 유전자의 대량 확보 여부가 산업적 경쟁력을 결정하게 될 것이다. 지금까지 개별 유전자 중심으로 이루어지던 유용 유전자 발굴 작업은 유전체학의 출현으로 규모가 대량화되고 그 효율이 증진되었다. 따라서 진 각국은 유용 유전자 발굴에 국가적 차원의 역량을 집중하고 있다. 그러나 우리나라는 정부와 민간의 소규모 지원으로 근근히 기술 습득 차원에 머물러 왔으며, 산업적 경쟁력의 무기가 될 고유한 유용 유전자와 형질전환 기술이 거의 없는 어려운 상황에 놓여 있다. 최근 정부가 시작한 생명공학 분야 대규모 연구지원 사업 기대를 모아 보며 이 분야 과학기술자들의 노력을 촉구한다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.130-138
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• 1981

Discoloration of canned boiled oysters during storage is one of the serious problems which affect the quality of the products as well as the nutritive value. Usually the factors influencing the quality of canned boiled oysters are the process of pretreatments and the storage temperature of the products. In the present work, the changes of the total chlorophylls and carotenoids in the meat and the viscera of oysters were determined in order to make certain the procedure of the discoloration. In addition, the amino-N and the available lysine as factors of the nutritive value were also checked. In case of treatment with additives, direct addition of syrups containing additives just before seaming or soaking boiled oysters into the solution of additives seemed to have mild effects on retardation of discoloration. The migration of carotenoids from the viscera into the meat was faster than that of chlorophyll resulting in yellowing of the Products preceded greening caused by the chlorophylls. Treatment with $0.5\%\; Na_{2}EDTA\;of\;2.5\%$ brine retarded discoloration and available lysine loss of the Products while sodium-polyphosphate accelerated them. It was probably due to that sodium-polyphosphate could affect the softening or breakdown of the muscle of oysters. But most of all, storage temperature of canned boiled oysters seemed to be the major factor influencing the discoloration and nutritive loss of the products.

• Radiation Oncology Journal
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• v.24 no.1
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• pp.67-76
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• 2006

Purpose: Oral mucositis is a common toxicity of radiation or chemotherapy, which is used a treatment for head and neck cancer. We investigated effects of recombinant human epidermal growth factor (rhEGF) on radiation-induced oral mucositis in rat model. Materials and Methods: Spraque-Dawley rats (7 per group) exposed to a single dose of 25 Gy (day 0) on their head, except for one group, were randomly divided into un-treated, vehicle-treated, and two rhEGF-treated groups. Rats were topically applied with rhEGF (15 or $30{\mu}g/oral$ cavity/day) or vehicle to their oral mucosa. Survival rate of rats, weight changes, and food intakes were examined from day 0 to 18 after radiation. Histology study was performed from oral mucosa of rats at day 7 and 18 after radiation. Results: rhEGF-treated groups (15 or $30{\mu}g/oral$) showed all survival rate 33%, whereas un-treated and vehicle-treated groups showed all survival rate 0% at the end of experiment. rhEGF-treated groups statistically had less weight loss compared to vehicle-treated group from day 2 to 7 after radiation. Food intake of rats with rhEGF treatment turned to increase at day 14 after radiation. At 7 day after radiation, un-treated and vehicle-treated groups showed severe pseudomembraneous or ulcerative oral mucositis. On the other hand, rhEGF-treated groups had no more than cellular swelling and degeneration of epidermal cells in oral mucosa of rats. Conclusion: These results suggest that rhEGF has significantly positive effects on radiation-induced oral mucositis in rats. rhEGF display a therapeutic potential on a clinical level.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1194-1199
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• 2003

Purpose : To determine the change in the limit of viability in fetal infants and the incidence of major complications in neonatal intensive care unit(NICU) at Samsung Medical Center(SMC). Methods : Sevety-three infants weighing less than 800 g at birth and 117 infants born earlier than 27 weeks gestational age, who were admitted to NICU at SMC between November 1994 and December 2002, were enrolled. Their medical records were reviewed with a focus on the survival and major complications, including chronic lung disease, retinopathy of prematurity, intraventricular hemorrhage, and periventricular leukomalacia. The limit of viability in fetal infants was defined as the birth weight or gestational age at which a 50% survival rate is reached and the incidence of major complications were compared by period(period I : Nov. 1994-Dec. 1998, period II : Jan. 1999-Dec. 2002). Results : The limit of viability in fetal infants was markedly lowered from birth weight range of 800-900 g or gestational age range of $26^{+0}-26^{+6}$ weeks in period I to birth weight range of 600-700 g or gestational age range of $24^{+0}-24^{+6}$ weeks in period II. The incidence rates of major complications at the limit of viability were all less than 50% in period II. There was no definite trend toward increased incidence of major complications as birth weight get smaller and gestational age get younger. Conclusion : Our results indicate that at present, fetal infants whose body weight is over 600 g, or whose gestational age is over 24 weeks should be resuscitated vigorously. The risk of major complications at this birth weight or gestational age seems to be not greater than that at a bigger birth weight or an older gestational age.