• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.175-179
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• 2018

Study Design: Case report. Objectives: We report 3 cases of loss of disc height after spontaneous regression of a herniated lumbar disc. Summary of Literature Review: Reports of spontaneous regression of a herniated lumbar disc were identified. Materials and Methods: We conservatively treated 3 patients who were diagnosed with a herniated lumbar disc. During outpatient follow-up, radiating pain improved in all patients, but they complained of chronic lower back pain. Magnetic resonance imaging (MRI) was performed for diagnostic purposes. Results: On MRI, spontaneous regression of the herniated lumbar discs was observed, but loss of disc height was also found. Conclusions: A herniated lumbar disc may be a risk factor for loss of disc height. It is important to recognize that a patient with a herniated lumbar disc can struggle with chronic lower back pain even if spontaneous regression of the herniated lumbar disc occurs.

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.161-168
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• 1998

Purpose : Lots of congenital anomalies of urinary tract including hydronephrosis are detected in fetus and neworn by popular use of prenatal ultrasonography. But there are little data available in Korea about natural course of hydronephrosis diagnosed antenatally by ultrasonography. So we intended to help management of these patients by analizing the follow up data of the neonates with hydronephrosis diagnosed antenatally. Methods : We evaluated 22 patients with neonatal hydronephrosis(33 renal units) who were diagnosed prenatally and confirmed postnatally. Especially patients with suspected ureteropelvic junction obstruction were followed regulary with renal ultrasonography and diuretic renography for 8-24 months. Results : 1) The etiologies of neonatal hydronephrosis diagnosed prenatally were suspected ureteropelvic junction obstruction($69.9\%$), vesicoureteral reflux($15.1\%$), primary megaureter($3.0\%$), double ureter with ureterocele($3.0\%$), ureteral stricture($3.0\%$), multicystic dysplastic kidney(3.0$\%$), and ureterovesical junction obstruction(3.0$\%$). 2) The follow up results of 23 renal units of suspected ureteropelvic junction obsruction: Except 4 renal units with palpable abdominal mass, of the remained 19 renal units, 14 units($73.6\%$) were improved spontaneously, 3 units($15.7\%$) remained stable, only2 units($10.5\%$) were aggravated. Conclusion : We concluded that in most cases of hydronephrosis there is no need for immediate surgery, and that nonoperative approach, using serial ultrasonography and diuretic renogram, is safe management of neonatal hydronephrosis diagnosed anteratally.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.21-26
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• 1996

Commercially available Chines oriental lacquer was treated to get two fractions, hexane soluble fraction and hexane insoluble fraction. Hexane soluble fraction was subjected to thermal curing process. Films obtained from the lacquer under normal conditions and obtained from thermal curing were compared. The compounds in hexane soluble fraction were copolymerized with 1,6-diisocyanohexane, and toluendiisocyanate(TDI). Films obtained by thermal curing were highly brittle and hydrophobic while the films obtained under normal conditions were hydrophilic. Curing reaction did not occur when oxygen was not available.Some of the major component in the lacquer was isolated by HPLC and UV spectrum of each compound was recorded.

• Parasites, Hosts and Diseases
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• v.22 no.2
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• pp.267-272
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• 1984

In June of 1983 authors had investigated the occurrence of the avian malaria in the Humboldt penguins imported from Japan to the Farmland Zoo in central district of Korea. The disease was characterized by acute course and high mortality. The peripheral blood smears from the affected penguins demonstrated different developmental stages of Plasmodium sp. in the mature erythrocytes. The predominant gross lesions noticed were pulmonary and epicardial edema and hepato-splenomegaly. Microscopically the lesions were characterized by extensive reticuloendothelial cell hyperplasia with striking feature of exoerythrocytic schizogony affecting a variety of tissues. The report also signifies the first description of a disastrous epizootic of avian malaria in Korea.

• Journal of Advanced Marine Engineering and Technology
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• v.16 no.3
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• pp.42-50
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• 1992

다공성 물질이 충전된 밀폐용기 내에서 수용성 이원혼합용액($H_2O{+}NaCl$)이 수평한 상부전열면으로 부터 동결될 때 혼합용액의 초기농도, 액체의 과열 및 다공성물질의 입자직경 크기가 온도와 농도분포에 미치는 영향을 실험하였으며, 동결이 진행됨에 따라 이동하는 고액상 혼합영역의 계명위치를 측정하였다. 다공성물질은 평균직경이 2.85mm, 6mm인 구형의 유리구슬을 이용하였다. 수용성 혼합용액의 초기농도는 공융농도도 이하로 하였으며 상부 전열면은 공융온도 이하로, 하부전열면은 액상선온도 이상으로 유지하여 동결 실험한 결과 상부 전열면으로 부터 고체 영역, 고액상혼합영역, 액체영역으로 구분되었다. 액체의 초기농도가 5%인 경우 과냉현상이 관찰되었으나 10%, 15%인 경우 액체온도는 액상선 온도보다 더 높았다. 용액의 초기농도를 감소시킬수록 고체와 고액상혼합영역의 범위는 증대되었으며 고액상혼합영역과 고체영역의 계면은 더욱 강해진 자연대류에 의하여 2차원성이 증가된 형상을 보였다. 용액의 자연대류는 다공성물질의 직경이 클수록 증가되었으며 계면에서의 제융해현상은 관찰되지 않았다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.723-726
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• 2000

본 논문은 가상현실 기술을 이용하여 개구리에 관한 내용을 보다 실감 있게 학습할 수 있도록 제작된 개구리 학습 교육용 소프트웨어이다. 개구리 학습시스템은 생명의 존엄성과 자연보호측면 그리고 생물 혹은 과학기술과정과 연계해서 개구리 이야기, 개구리 겉모양, 개구리 생활, 개구리 특징, 개구리의 내부구조관찰, 한국의 개구리, 형성평가문제, 학습목표 8가지로 구성되어 있다. 특히 개구리 내부구조 관찰은 초 중 고 학생들의 필수 학습과정으로 되어 있으나 학생들은 해부에 대한 혐오감과 거부감 등이 그대로 한해 수만$\sim$십여만 마리의 개구리해부는 자연보호 환경차원에서 개구리의 몰락을 가져올 수가 있어서 가상적 해부가 필요하다 하겠다. 본 논문은 이러한 점을 착안하여 가상적으로 개구리를 해부하지 않고도 가르칠 수 있고 생명의 존엄성에 대해 부정적인 전통적 해부실험 대신 가상적으로 해부할 수 있는 시스템을 제안하고 구현하였다.

• The Journal of Natural Sciences
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• v.4
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• pp.29-58
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• 1991

Ethanol은 섭취량에 따라 간 대사에 여러가지 영향을 미치는 것으로 알려져 있다. 과량의 ethanol 섭취가 유해한 것은 ethanol 그 자체보다는 산화과정에서 생성된 acetaldehyde와 과량의 수소(NADH)에 기인한다. 과량의 NADH는 간 세포의 화학적 평형을 저해하고 대사이상을 초래한다. 본 연구에서는 in vitro 뿐만 아니라 in vivo에서 alcohol dehydrogenase(ADH), aldehyde dehydroge-nase(ALDH), microsomal ethanol oxidizing system(MEOS)에 미치는 인삼 사포닌의 영향을 조사하고, 간에서의 수소 평형, 간에서의 $[1^(-14)C]$-ethanol의 분포, ethanol의 acetaldehyde와 lipid로의 전환 등을 관찰하였다. 인삼 사포닌은 상기 효소외에도 ethanol 대상에 관련된 다른 효소들의 활성을 증가시키는 것으로 관찰되었으며 이는 동물 체내로부터 acetaldehyde와 과량의 수소를 신속히 제거하는 것으로 사료된다.

• Journal of Genetic Medicine
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• v.8 no.1
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• pp.44-52
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• 2011

Purpose: Cytogenetic analysis of spontaneous abortions (SABs) provides valuable information to establish the causes of fetal loss, information that is essential to provide accurate reproductive and genetic counseling couples. Such analysis also provides information on the frequencies and types of chromosomal abnormalities and associated risks of recurrence. However, there have only been a few reports of chromosomal abnormalities in small samples of SABs in the Korean population. Here, we report the incidence and spectrum of chromosomal abnormalities for cases of 470 SAB in Korea. Material and Methods: Between 2005 and 2010, a total of 470 products of conception (POC) resulting from SABs were submitted to our laboratory for cytogenetic analysis from various medical sites in Korea. The incidences and types of specific chromosomal abnormalities were determined. The abnormalities were distinguished by gestational age at the time of SAB and by maternal age. Results: The frequency of chromosomal abnormalities in POCs was 54.3% (255/470), including 228 (89.3%) numerical and 27 (10.7%: 3 balanced and 24 unbalanced) structural abnormalities. Among the numerical abnormalities, trisomy was predominant (67.0%), followed by monosomy X (12.5%), polyploidy (8.2%), triple X (0.8%), and autosomal monosomy (0.8%). The overall sex ratio (male: female) among the 470 POCs with normal and abnormal karyotypes were 0.58 and 0.65, respectively. Trisomies were identified for each autosome, with the exceptions of 1, 3, and 19. Among the 171 autosomal trisomies, trisomy 16 was the most common (19.9%), followed by trisomy 22 (13.5%), trisomy 21 (12.3 %), trisomy 15 (9.9%), and trisomies 18 and 13 (5.3%). The frequency of chromosomal abnormalities decreased with gestational age and increased with maternal age, but only because of increases in trisomies and complex abnormalities. Conclusions: We have presented a large collection of cytogenetic data for SABs collected during the past 6 years and provided a database for prenatal genetic counseling of parents who have experienced SABs in Korea.

• Membrane Journal
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• v.20 no.2
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• pp.120-126
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• 2010

In this study, the effect of surface deposition of $TiO_2$ nanoparticles at polyethersulfone (PES) microfiltraiton (MF) membrane on humic acid fouling was investigated. The effect was observed as a function of crystal structures of $TiO_2$ nanoparticles and solution chemistries including pH and divalent cation such as calcium. Our results showed clearly that $TiO_2$-deposited membrane could mitigate membrane fouling significantly. However, this effect was observed to be dependent upon crystal structures of $TiO_2$ nanoparticles and solution chemistries. In the absence of calcium, fouling mitigation was less pronounced for both anatase and hybrid $TiO_2$-deposited membrane than for rutile $TiO_2$-deposited membrane while opposite trend was observed after addition of calcium. In the presence of calcium, the adsorption of humic acid to $TiO_2$-deposited membrane can be reduced by electrostatic repulsions between humic acid and $TiO_2$ surface. Addition of calcium provided further beneficial effect on fouling mitigation particularly at higher pH for the anatase $TiO_2$ deposited membrane, implying that both increased hydrophilicity due to $TiO_2$ nanoparticles and negative surface charge of the membrane should affect fouling mitigation. However, rutile $TiO_2$ having more inertness generally than the anatase $TiO_2$ showed relatively robust effect on the fouling mitigation regardless of solution properties.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.158-170
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• 2022

The purpose of this study is to understand the characteristics of Aristotle's view of nature that is, the static view of the universe, and find implications for education. Plato sought to interpret the natural world using a rational approach rather than an incomplete observation, in terms of from the perspective of geometry and mathematical regularity, as the best way to understand the world. On the other hand, Aristotle believed that we could understand the world by observing what we see. This world is a static worldview full of the purpose of the individual with a sense of purposive legitimacy. In addition, the natural motion of earthly objects and celestial bodies, which are natural movements towards the world of order, are the original actions. Aristotle thought that, given the opportunity, all natural things would carry out some movement, that is, their natural movement. Above all, the world that Plato and Aristotle built is a static universe. It is possible to fully grasp the world by approaching the objective nature that exists independently of human being with human reason and observation. After all, for Aristotle, like Plato, their belief that the natural world was subject to regular and orderly laws of nature, despite the complexity of what seemed to be an embarrassingly continual change, became the basis of Western thought. Since the universe, the metaphysical perspective of ancient Greece and modern philosophy, relies on the development of a dichotomy of understanding (cutting branches) into what has already been completed or planned, ideal and inevitable, so it is the basis of traditional teaching-learning that does not value learner's opinions.