• 한국유가공학회:학술대회논문집
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• 2007.09a
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• pp.49-58
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• 2007

Inflammatory process leads to the well-known mucosal damage and therefore a further disturbance of the epithelial barrier function, resulting abnormal intestinal wall function, even further accelerating the inflammatory process[1]. Despite of the records, etiology and pathogenesis of IBD remain rather unclear. There are many studies over the past couple of years have led to great advanced in understanding the inflammatory bowel disease(IBD) and their underlying pathophysiologic mechanisms. From the current understanding, it is likely that chronic inflammation in IBD is due to aggressive cellular immune responses including increased serum concentrations of different cytokines. Therefore, targeted molecules can be specifically eliminated in their expression directly on the transcriptional level. Interesting therapeutic trials are expected against adhesion molecules and pro-inflammatory cytokines such as TNF-${\alpha}$. The future development of immune therapies in IBD therefore holds great promises for better treatment modalities of IBD but will also open important new insights into a further understanding of inflammation pathophysiology. Treatment of cytokine inhibitors such as Immunex(Enbrel) and J&J/Centocor(Remicade) which are mouse-derived monoclonal antibodies have been shown in several studies to modulate the symptoms of patients, however, theses TNF inhibitors also have an adverse effect immune-related problems and also are costly and must be administered by injection. Because of the eventual development of unwanted side effects, these two products are used in only a select patient population. The present study was performed to elucidate the ability of TNF-${\alpha}$ antibodies produced in sheep colostrums to neutralize TNF-${\alpha}$ action in a cell-based bioassay and in a small animal model of intestinal inflammation. In vitro study, inhibitory effect of anti-TNF-${\alpha}$ antibody from the sheep was determined by cell bioassay. The antibody from the sheep at 1 in 10,000 dilution was able to completely inhibit TNF-${\alpha}$ activity in the cell bioassay. The antibodies from the same sheep, but different milkings, exhibited some variability in inhibition of TNF-${\alpha}$ activity, but were all greater than the control sample. In vivo study, the degree of inflammation was severe to experiment, despite of the initial pilot trial, main trial 1 was unable to figure out of any effect of antibody to reduce the impact of PAF and LPS. Main rat trial 2 resulted no significant symptoms like characteristic acute diarrhea and weight loss of colitis. This study suggested that colostrums from sheep immunized against TNF-${\alpha}$ significantly inhibited TNF-${\alpha}$ bioactivity in the cell based assay. And the higher than anticipated variability in the two animal models precluded assessment of the ability of antibody to prevent TNF-${\alpha}$ induced intestinal damage in the intact animal. Further study will require to find out an alternative animal model, which is more acceptable to test anti-TNF-${\alpha}$ IgA therapy for reducing the impact of inflammation on gut dysfunction. And subsequent pre-clinical and clinical testing also need generation of more antibody as current supplies are low.

• Journal of Chest Surgery
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• v.38 no.10 s.255
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• pp.693-698
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• 2005

Background: Sinus valsalva aneurysm (SVA) is a rare disease, and it is frequently accompanied by ventricular septal defect and aortic valve regurgitaion. For treatment of SVA, several surgical mordalities were applied, but there was no report on the long-term result after surgical repair in Korea. We reviewed our 28 years of experiences and analyzed the long-term results after treatment of sinus valsalva aneurysm with or without rupture. Material and Method: Between March 1974 and February 2002, 81 patients were operated under the impression of sinus valvsalva aneurysm or sinus valsalva aneurym rupture. Retrospectively we reviewed the patients' record. Mean age of patients was $29.2\pm11.5$ and there were 49 males. Accompanyng diseases were as follows: VSD in 50, PDA in 2, Behcet's disease in 2, TOF in 1, RVOTO in 1, AAE in 1. Seventy-seven $(95\%)$ patients had sinus valsalva rupture and in 14 patients, subacute bacterial endocarditis was accompanied. Degree of aortic valve regurgitation was as follows: grade I: 8, II: 10, III: 9, IV: 4. Most common rupture site was right coronary sinus (66 patients, $81\%$) and most common communication site was right ventricle (53 patients). In repair of sinus valsalva rupture, patch was used in 37 patients, and direct suture was done in 38 patients. Result: There was one surgical death $(1.2\%)$. Follow up was done in 78 patients $(97.5\%)$, mean follow up period was $123.3\pm80.9(3\~330\;months)$. During the follow up period, 3 patients died $(3.8\%)$. One patient died of heart failure, another patient died of arrhythmia and the other one died of unknown cause. In two patients, complete atrio-ventricular block was developed during follow up period, and there was no operation related event or complication. Kaplan-Meier survival analysis revealed $92.5\pm3.5\%$ survival at 15 and 27 years and it seems to be satisfactory. Conclusion: Long-term surgical results and survival is satisfactory after repair of sinus valsalva aneurysm with or without rupture.

• Radiation Oncology Journal
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• v.19 no.4
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• pp.369-380
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• 2001

Purpose : By developing on-line statistics program to record the information of radiation oncology to share the information with internet. It is possible to supply basic reference data for administrative plans to improve radiation oncology. Materials and methods : The information of radiation oncology statistics had been collected by paper forms about 52 hospitals in the past. Now, we can input the data by internet web browsers. The statistics program used windows NT 4.0 operation system, Internal Information Server 4.0 (IIS4.0) as a web server and the Microsoft Access MDB. We used Structured Query Language (SQL), Visual Basic, VBScript and JAVAScript to display the statistics according to years and hospitals. Results : This program shows present conditions about man power, research, therapy machines, technics, brachytherapy, clinic statistics, radiation safety management, institution, quality assurance and radioisotopes in radiation oncology department. The database consists of 38 inputs and 6 outputs windows. Statistical output windows can be increased continuously according to user's need. Conclusion : We have developed statistics program to process all of the data in department of radiation oncology for reference information. Users easily could input the data by internet web browsers and share the information.

• Clinical and Experimental Pediatrics
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• v.48 no.3
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• pp.315-320
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• 2005

Objective : Toll like receptor(TLR) is known to be involved in innate immunity. Many microbial antigens stimulate TLR, and as a result of intracellular signal transduction, they activate nuclear factor-kB which produces diverse inflammtory cytokines. Until now, many research topics in Kawasaki disease focused on cytokine increasement. In this study, we aim to reveal TLR increasement which might be associated with initiation of inflammatory response. Methods : We obtained the peripheral blood of ten patients who were diagnosed with Kawasaki disease in Yonsei University College of Medicine from March 2003 to August 2003, as well as those of a febrile control group and the same number of a normal control group. Flow cytometry was done in all samples for quantification of TLR-2 expression in CD14 positive monocyte. And we also extracted total RNA of periphral monocyte and quantificated expression of TLR-2 mRNA by RT-PCR. Results : The expression of TLR-2 in Kawasaki disease increased significantly compared with the normal control group but not when compared with the febrile control group. And the expression decreased slightly in the subacute phase of Kawasaki disease compared with the acute phase, but this was statistically insignificant. mRNA expression of TLR-2 in peripheral blood monocyte also increased in the acute phase of Kawasaki disease. Conclusion : Expression of TLR-2 in Kawasaki disease increased when compared with the normal control group, which means that innate immunity is associated with the pathogenesis of Kawasaki disease.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.3
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• pp.99-109
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• 2015

The investment in healthcare industry has recently increased not only for global ventures but also for the domestic ventures. However, there has been hardship of founding and investment caused by healthcare startups characteristics that are costly and time consuming. In this study, the applicability of 'Lean Startup' theory to healthcare ventures was explored through the case of a domestic startup which accomplished funding from VC and KOSDAQ after establishing based on its technology in healthcare industry. There have been numerous case studies that applied 'Lean Startup' to IT industry. However, this case study that applied 'Lean Startup' to healthcare industry have some implications as follow: First, it is critical to conduct a hypothesis testing at initial research stage through R&D of 'MVP' (Minimum Viable Product) as the prototype testing is strictly prohibited in healthcare industry. Second, healthcare R&D teams ought to be well organized as startup teams and all researchers should be equipped with entrepreneurship as the licensing process in healthcare industry is time-consuming and costly due to issues like clinical studies. Lastly, management skills as smart and light as 'Lean Startup' are required in order to encourage young engineers' technology startups.

• Journal of Chest Surgery
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• v.39 no.10 s.267
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• pp.775-778
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• 2006

Hypertrophic cardiomyopathy is characterized by inappropriate hypertrophy of the myocardium and is associated with various clinical presentations ranging from complete absence of symptoms to sudden, unexpected death. These are caused by dynamic obstruction of the left ventricular outflow tract and surgical approaches were initiated. But, the complete resection of hypertrophied midventricular septum is impossible by standard, transaortic approach, because of narrow vision and limited approach. And it leads to inadequate excision, will leave residual left ventricular out-flow tract obstruction or systolic anterior motion of mitral leaflet, and limit symptomatic improvement and patient's survival. We report a case of extended septal myectomy for hypertrophic cardiomyopathy of mid-septum in a child. The extended septal myectomy was performed by aortotomy and left ventricular apical incision, and made possible the complete resection of mid-ventricular septum, abnormal papillary muscles and chordae. The patient's symptom was improved and the postoperative course was uneventful.

• Journal of Radiation Protection and Research
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• v.32 no.2
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• pp.45-50
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• 2007

In this study, uptake rates of internal organs and daily urinary excretion rates were measured to get more reliable estimation results for Korean. Radioactive iodine($^{131}I$) of $100{\mu}Ci$ was administered by ingestion to 28 adult males for the experiment and then the radioactivity in thyroid gland, liver, stomach, small intestine, kidneys, and urine was measured after time intervals of 2, 4, 6 and 24 hours. Uptake rates of each organ and daily urinary excretion rates were calculated on the basis of these experimental results. As a result, uptake rates of 19.70% for thyroid and daily urinary excretion rates of 71.12%, on the average, were indicated. The maximum of uptake rates and daily urinary excretion rates were recorded after 2 hours of administration of $^{131}I$, but those rates were decreased gradually later. It was also found that uptake rates were the highest in stomach, followed by the left kidney, liver, small intestine and right kidney except for thyroid gland. In this experiment, the calculated uptake change rate in thyroid gland after 24 hours of administration of $^{131}I$ was different from that of ICRP-54/67(30%) and ICRP-78(25%). Thus, it is necessary to apply more reliable approach, reflecting the characteristic of Korean physiology and to obtain the basic data of results using this approach for calculation of the internal adsorbed dose. In the future, this approach can be helpful for the internal dose assessment of radiation workers in a nuclear power plant or in a hospital.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.374-381
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• 2023

The travel time of flash floods along mountain streams is mainly governed by reach-average velocity, rather than by the point velocity of the locations of interest. Reach-average velocity is influenced by various factors such as stream geometry, streambed materials, and the hydraulic roughness of streams. In this study, the reach-average velocity in mountain streams was measured for storm periods using rhodamine dye tracing. The point cloud data obtained from a LiDAR survey was used to extract the average hydraulic roughness height, such as R_a, R_max, and R_z. The size distribution of the streambed materials (D₅₀, D₈₄) was also considered in the estimation of the roughness height. The field experiments revealed that the reach-average velocities had a significant relationship with flow discharges (v = 0.5499Q^0.6165 ), with an R² value of 0.77. The root mean square error in the roughness height of the R_a-based estimation (0.45) was lower than those of the other estimations (0.47-1.04). Among the parameters for roughness height estimation, the R_a -based roughness height was the most reliable and suitable for developing the reach-average velocity equation for estimating the travel time of flood waves in mountain streams.

• The Mathematical Education
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• v.61 no.1
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• pp.1-28
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• 2022

The purpose of this study is to explore how students' fractional knowledge is related to their solving of proportion problems. To this end, 28 clinical interviews with four middle-grade students, each lasting about 30~50 minutes, were carried out from May 2021 to August 2021. The present study focuses on two 7th grade students who exhibited their ability to coordinate three levels of units prior to solving whole number problems. Although the students showed interiorization of three levels of units in solving whole number problems, how they coordinated three levels of units were different in solving proportion problems depending on whether the problems required reasoning with whole numbers or fractions. The students could coordinate three levels of units prior to solving the problems involving whole numbers, they coordinated three levels of units in activity for the problems involving fractions. In particular, the ways the two students employed partitioning operations and how they coordinated quantitative unit structures were different in solving proportion problems involving improper fractions. The study contributes to the field by adding empirical data corroborating the hypotheses that students' ability to transform one three levels of units structure into another one may not only be related to their interiorization of recursive partitioning operations, but it is an important foundation for their construction of splitting operations for composite units.