• Advances in pediatric surgery
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• v.15 no.1
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• pp.1-10
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• 2009

Recently, amniotic fluid has gained attention as one of the potential sources for cell therapy and tissue engineering because it has characteristics of multipotent stem cells. However, current knowledge about what types of cells are naturally found in amniotic fluid is still limited. In this study, we aimed to investigate whether human amniotic fluid contains cells that have characteristics of respiratory cells. Samples of human amniotic fluid (5 mL per sample) obtained from amniocenteses were cultured with small airway growth medium (SAGM). Cells were grown until the third passage and the presence of type II alveolar cells were characterized by inverted microscopy, immunofluorescence, and reverse transcription polymerase chain reaction (RT-PCR). On inverted microscopy, cultured cells showed typical polygonal and cobblestone-like epithelial morphology. The morphology of cells was not changed after selection and passing. Immunofluorescence analysis demonstrated that the isolated cells stained positive for surfactant protein C (SPC), specific marker for type II alveolar cells. Cells also stained positive for TTF-1 protein but negative for CD 31 and vimentin. RT-PCR analysis of cells showed expression of SPC mRNA. This study has demonstrated that respiratory cells can be isolated and identified from human amniotic fluid cultured in SAGM medium. Our results may provide the basis for further investigations of amniotic fluid.

• Advances in pediatric surgery
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• v.15 no.1
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• pp.11-17
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• 2009

Choledochal cyst is a congenital dilatation of the bile duct. Intrahepatic bile duct dilatation of type IVa by Todani's classification at the time of diagnosis resolved spontaneously after cyst excision and hepaticojejunostomy in many cases. It should be distinguished from the true cystic dilatation of the intrahepatic ducts, which tends to persist, albeit after some regression. We therefore studied postoperative intrahepatic duct dilatation changes in choledochal cyst. A total of seventy-six choledochal cysts were managed at the Division of Pediatric Surgery, Department of Surgery, Samsung Medical Center from May 1995 to December 2005. The ratio of males to females was 1:2.8. Preoperative radiologic diagnosis by Todani's classification was Type I (n=52, 68.4 %), II (n=1, 1.3 %), IVa (n=23, 30.3 %). Among fifty-five patients with intrahepatic bile duct dilatation we were able to follow up forty-eight by ultrasonography. Twenty-two patients were type IVa, and twenty-six patients were type I and showed intrahepatic duct dilatation. Mean follow-up duration was 35.3 months (9~105 months). Complete regression of dilated intrahepatic duct was observed in fifteen patients of type IVa and twenty-four patients of type I. Incomplete regression of dilated intrahepatic duct was observed in six patients in type IVa and two patients in type I. Only one patient in type IVa showed no change in ductal dilatation during a follow-up period of 15 months. We conclude that true type IVa is much less frequent than what was diagnosed preoperatively by imaging study. Therefore in type IVa patients who are diagnosed preoperatively the decision to perform liver resection should be carefully considered. Postoperative long term follow up of choledochal cyst with intrahepatic bile duct dilation is needed.

• Journal of Environmental Health Sciences
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• v.13 no.1
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• pp.17-33
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• 1987

As a result of technical advances and industrialization, the characteristics of domestic and industrial wastes are becoming more complex. Accordingly, improved treatment and disposal systems are being continuously sought to take account of complex characteristics and to comply with economic restrictions. In this study, an application of pyrolysis to the treatment of industrial wastes, including waste scrap rubber, waste raw material used in making the slipper bottom and waste PVC pipe, and the effectiveness of pyrolysis in resource recovery from these wastes were investigated. Batches of wastes were pyrolysed by external heating to a temperature of 400-800$\circ$C in a 32 mm diameter x 0.9 m long silica tube to produce combustible gases, oils and chars. Before the start of pyrolysis runs, the entire system was purged with nitrogen gas to exclude the air. The temperature inside the retort was controlled by the thermocouple in the gas stream, and referred to as the pyrolysis temperature. Under these conditions three products were separately collected and further analyzed. The results were summarized as follows. 1. More gases and less chars were produced with higher pyrolyzing temperature and with higher rates of heating, but the yields of oils tended downwards at temperatures above 700$\circ$C. Accordingly, operating conditions of pyrolysis should be varied with desired material. 2. Calorific values and sulfur contents of produced oils were sufficient and suitable for fuel use. Chars from waste rubber had high heating values with low sulfur contents, but calorific values of chars from waste PVC and waste slipper were as low as 3, 065-4, 273 kcal/kg and 942-2, 545 kcal/kg, respectively. Therefore, char from these wastes are inappropriate for fuel. 3. Soluble contents of Pb, Cd, Cu and Zn in chars from waste rubber and waste slipper were below the Specific Hazardous Waste Treatment Standards. However soluble contents of Pb and Cd in chars from waste PVC were one or two times and five or seven times exceedingly the Specific Hazardous Waste Treatment Standards, respectively. 4. Post high heating is desirable for treatment method of waste PVC which generates toxic hydrogen chloride. 5. The proportions of hydrogen, methane and ethane in produced gases were in the range of 3.99-35.61% V/V, 18.22-32.50% V/V and 5.17-5.87% V/V, respectively. 6. Pyrolysis is a useful disposal method in case of waste slipper, which was hardly combustible, and thus investigations of this kind of materials are required for effective management of industrial waste. 7. Based upon the possible market development for products, overall pyroly economics to take account of treatment values of noncombustible or hazardous materials should be evaluated.

• Korean Journal of Social Welfare
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• v.68 no.4
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• pp.143-167
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• 2016

While there have been numerous studies on various issues of aging of the individuals and the population, little is known about the process and consequences of aging of the disabled. Aging is irreversible for the disabled as well as for the not-disabled. With the advances of age, the disabled confront double jeopardy from disability and old age. This study aims to explore the meaning of aging and death for 40s and 50s living with disability for more than 20 years. It utilizes the data set collected through focus groups discussions of the disabled The cases in our analysis are composed of the disabled capable of articulating their feelings and thoughts. Thus, they are selected from the less privileged ones. The analysis shows that aging of the disabled, often involving secondary disability, overwhelms their current disability. Nonetheless, it does not necessary mean that they become an ordinary elderly person. Rather they still feel exclusion from the elderly for their disability. As getting older they turn to face social barrier for both disability and old age. Also, they are trying to live their present lives in full while accepting the presence of death Our findings are hoped to help to understand how the disabled get old and view their death in their own way.

• Clinical and Experimental Pediatrics
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• v.46 no.11
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• pp.1112-1117
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• 2003

Purpose : Recent advances in the methods of treating cancer in young patients have led to both an increased frequency of CNS complications as well as prolonged life expectancy. We intend to analyze the clinical aspects and laboratory findings of patients with CNS complications during and after treatment. Methods : We reviewed the medical records of 174 childhood cancer patients treated with chemotherapy admitted to the Dept. of Pediatrics, Keimyung University Dongsan Hospital, from January 1995 to November 2002. Among them, 15 cases with CNS complications were investigated in this study. Results : CNS abnormalities were found in 13 patients by CT or MRI during treatment such as leukoencephalopathy(n=7), mineralizing microangiopathy(n=4), brain infarction(n=3), intracranial hemorrhage(n=1), and hypoxic ischemic encephalopathy(n=1). It was found that two patients had two or more CNS abnormalities. Two patients who had no imaging abnormalities had convulsions, possibly after the addition of intrathecal methotrexate. The patients with intracranial hemorrhage and brain infarction had rapid and fatal clinical courses. The hypoxic ischemic encephalopathy following electrolyte imbalance completely recovered after correction of electrolyte. Conclusion : The CNS complications that occur during and after chemotherapy influence prognoses significantly, and remain neurologic sequelae. Therefore early diagnosis and prophylaxis for CNS complications and regular physical examination of patients who have recieved cancer therapy are strongly recommended.

• Journal of Life Science
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• v.30 no.8
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• pp.722-730
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• 2020

As one of the most serious health risk factors, air pollution can no longer be ignored. Particulate matter (PM) is an important and harmful component of air pollution that originates from a variety of sources. Numerous recent studies have linked PM to a range of conditions including cancer, cardiovascular, respiratory, and skin disease. The eye, despite being directly exposed to air pollution, has been investigated in very few of these studies. In this review, we describe the evidence from in vitro and in vivo studies, as well as epidemiological investigations, that supports the association between exposure to PM and the development of ocular conditions such as surface and retinal disease and glaucoma. Based on the results of previous studies, we suggest that PM exposure can lead to oxidative stress, inflammation, autophagy, and, ultimately, ocular surface disease. Nevertheless, almost no studies focus on ocular surface damage from PM while some epidemiological and clinical studies report on the posterior of the eye. However, the underlying pathological mechanisms in the posterior following PM exposure have yet to be identified, and further studies are therefore warranted of the ocular surface as well as the posterior part of the eye.

• Journal of Genetic Medicine
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• v.6 no.2
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• pp.131-145
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• 2009

Preimplantation genetic diagnosis (PGD) has become an assisted reproductive technique for couples who are at risk that enables them to have unaffected baby without facing the risk of pregnancy termination after invasive prenatal diagnosis. The molecular biology and technology for single-cell genetics has reached an extremely high level of accuracy, and has enabled the possibility of performing multiple diagnoses on one cell using whole genome amplification. These technological advances have contributed to the avoidance of misdiagnosis in PGD for single gene disorders. Polymerase chain reaction (PCR)-based PGD will lead to a significant increase in the number of disorders diagnosed and will find more widespread use, benefiting many more couples who are at risk of transmitting an inherited disease to their baby. In this review, we will focus on the molecular biological techniques that are currently in use in the most advanced centers for PGD for single gene disorders, including biopsy procedure, multiplex PCR and post-PCR diagnostic methods, and multiple displacement amplification (MDA) and the problems in the single cell genetic analysis.

• Information Systems Review
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• v.11 no.2
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• pp.1-22
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• 2009

IT advances rapidly and is widely used both in for-profit and non-profit organizations. Academic institutions are no exception in the adoption of new IT such as e-libraries, e-blackboards, as well as Web 2.0 services. However, administrative information systems in colleges and universities often lag relatively behind. One of the reasons of this is that academic institutions tend to focus only on the implementation of IT, while neglecting the mindfulness needed for post-implementation. This study develops a new perspective for the sustainability of academic information systems through the lens of mindfulness. The results from administrating a nation-wide survey of universities and colleges provide the variations of a ranking of the critical success factors between implementation and post-implementation. The findings imply that both individual and collective mindfulness are needed to implement and, especially, sustain administrative IS successfully in academic institutions.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.2
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• pp.157-164
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• 2009

The metals such as Al, Ag, Au, Cu, Cd, Co, Fe, Ni, Pb, Zn, etc are present at very low concentration in seawater and are classified as so-called trace metals. Whiles some of them are used in metabolism of living organism as a micronutrient, they may show toxic effects on organisms in case of a limited threshold concentration of them Plenty of studies on trace metals have been performed bemuse trace metals have a persistent influence and an adverse effect on marine environment and ecosystem. For long years, when the concentration of trace metals in natural waters such as seawater and fresh water are measured with high precision and accuracy, some systematic errors have been recognized to be present in measurements. Since 1975 in US and European countries, the measured concentration of trace metals in seawater have been found to be lower by factors of 10-1,000 than the previous data of trace metals measurements and the vertical profiles of the measurements have been shown to reflect well-known biological, physical and geochemical processes. These results are attributed to great advances in analytical instrumentation and methodology for trace metals measurements. Precautions against the contamination of samples are required to be taken in the process of sampling, storage, and analysis of samples. However, in Korea, erroneous data of trace metals with regard to ocean and marine environment related survey and investigations are reported The lock of exact understanding and information regarding precautions in sampling, storage and analysis of samples lead to the deterioration of data quality, especially in the analysis of trace metals. The major procedures to obtain the accurate data of trace metals in natural waters are introduced for applying to the study and assessment of marine environments.

• Wind and Structures
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• v.31 no.2
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• pp.103-142
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• 2020

One of the next frontiers in structural wind engineering is the design of tall buildings using performance-based approaches. Currently, tall buildings are being designed using provisions in the building codes and standards to meet an acceptable level of public safety and serviceability. However, recent studies in wind and earthquake engineering have highlighted the conceptual and practical limitations of the code-oriented design methods. Performance-based wind design (PBWD) is the logical extension of the current wind design approaches to overcome these limitations. Towards the development of PBWD, in this paper, we systematically review the advances made in this field, highlight the research gaps, and provide a basis for future research. Initially, the anatomy of the Wind Loading Chain is presented, in which emphasis was given to the early works of Alan G. Davenport. Next, the current state of practice to design tall buildings for wind load is presented, and its limitations are highlighted. Following this, we critically review the state of development of PBWD. Our review on PBWD covers the existing design frameworks and studies conducted on the nonlinear response of structures under wind loads. Thereafter, to provide a basis for future research, the nonlinear response of simple yielding systems under long-duration turbulent wind loads is studied in two phases. The first phase investigates the issue of damage accumulation in conventional structural systems characterized by elastic-plastic, bilinear, pinching, degrading, and deteriorating hysteretic models. The second phase introduces methods to develop new performance objectives for PBWD based on joint peak and residual deformation demands. In this context, the utility of multi-variate demand modeling using copulas and kernel density estimation techniques is presented. This paper also presents joined fragility curves based on the results of incremental dynamic analysis. Subsequently, the efficiency of tuned mass dampers and self-centering systems in controlling the accumulation of damage in wind-excited structural systems are investigated. The role and the need for explicit modeling of uncertainties in PBWD are also discussed with a case study example. Lastly, two unified PBWD frameworks are proposed by adapting and revisiting the Wind Loading Chain. This paper concludes with a summary and a proposal for future research.