• Journal of Chest Surgery
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• v.35 no.5
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• pp.350-355
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• 2002

Background: Most of pulmonary regurgitation with or without stenosis appears to be well tolerated early after the repair of pulmonary outflow tract. However, it may result in symptomatic right ventricular dilatation, dysfunction and arrhythmias over a long period of time. We studied the early outcome of pulmonary valve replacement with tissue valves for patients with the above clinical features. Material and Method: Sixteen consecutive patients who underwent pulmonary valve replacement from September 1999 to February 2002 were reviewed(9 males and 7 females). The initial diagnoses included tetralogy of Fallot(n=11), and other congenital heart anomalies with pulmonary outflow obstruction(n=5). Carpentier-Edwards PERIMOUNT Pericardial Bioprostheses and Hancock porcine valves were used. The posterior two thirds of the bioprosthetic rim was placed on the native pulmonary valve annulus and the anterior one third was covered with a bovine pericardial patch. Preoperative pulmonary regurgitation was greater than moderate degree in 13 patients. Three patients had severe pulmonary stenosis. Tricuspid regurgitation was present in 12 patients. Result: Follow-up was complete with a mean duration of 15.8 $\pm$ 8.5months. There was no operative mortality. Cardiothoracic ratio was decreased from 66.0 $\pm$ 6.5% to 57.6 $\pm$ 4.5%(n=16, p=0.001). All patients remained in NYHA class I at the most recent follow-up (n=16, p=0.016). Pulmonary regurgitation was mild or absent in all patients. Tricuspid regurgitation was less than trivial in all patients. Conclusion: In this study we demonstrated that early pulmonary valve replacement for the residual pulmonary regurgitation with or without right ventricular dysfunction was a reasonal option. This technique led to reduce the heart size, decrease pulmonary regurgitation and tricuspid regurgitation as well as to improve the patients'functional status. However, a long term outcome should be cautiously investigated.

• Journal of Chest Surgery
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• v.37 no.10
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• pp.833-838
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• 2004

Background: Despite the excellent early results after the repair of congenital bicuspid aortic valve (BAV) disease, the mid-term durability of the repaired valve has still controversies. Material and Method: To evaluate the mid-term results of BAV repair, retrospective review of medical records and echocardiographic data were done. Between 1994 and 2003, twenty-two patients underwent reparative procedure for either regurgitant or stenotic congenital bicuspid aortic valve (BAV). Result: Mean age was $41\pm14$ years with male predominance (Male=17, Female=5). The pathophysiologies of the BAV were regurgitation-dominant in 20 (91%) and stenosis-dominant in 2 (9%) cases. Various repair techniques were used for raphe, prolapsed leaflet, thickened leaflet, and commissures; 1) release of raphe in 19 (86%), 2) wedge resection and primary repair in 11 (50%), pericardial patch reinforcement after plication of the leaflet in 6 (27%), and plication of the leaflet in 3 (14%), 3) slicing of thickened leaflet was used in 12 (55%) cases, 4) commissuroplasty in 8 (36%), and commissurotomy in 6 (27%) cases. There was no in-hospital mortality. During the mean follow-up of $38\pm17$ months, one patient underwent aortic valve replacement after developing acute severe regurgitation from dehiscence of the suture on postoperative 2 months. New York Heart Association functional class was improved from $1.9\pm0.6$ to $1.2\pm0.5$ (p<0.01). Left ventricular end-systolic and diastolic dimension (LVESD/LVEDD) were also improved from $45\pm9$ and $67\pm10$ to $37\pm10$ and $56\pm10,$ respectively (p<0.01). The grade of aortic regurgitation (AR) was improved from preoperative $(3.1\pm1.2)$ to post-bypass $(0.9\pm0.7).$ However, the grade at last follow-up $(1.7\pm1.1)$ was deteriorated during the follow-up period (p<0.01). Freedom from grade III and more AR at one, three, and four year were 89.7%, 89.7%, and 39.9% respectively. Conclusion: Midterm clinical result of the BAV repair was favorable. But, the durability of the repaired valve was not satisfactory.

• Journal of Chest Surgery
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• v.34 no.9
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• pp.672-679
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• 2001

Background: Surgical correction of partial anomalous pulmonary venous connection to the superior vena cava has been associated with postoperative venous obstruction and sinus node dysfunction. In this paper we describe our current approach and its short-term results. Material and Method: Between April 1999 and January 2000, 5 consecutive patients, ranging from 2 months to 66 years old, underwent corrective operation for partial anomalous pulmonary venous connection to the superior vena cava at Sejong General Hospital and Daegu Catholic University Medical Center. Surgical correction involved diversion of the pulmonary venous drainage to the left atrium using a right atrial flap(2 patients) or prosthetic patch(3 patients) with division of the superior vena cava superior to the restore site of the pulmonary veins and reimplantation on the right atrial appendage to restore systemic venous drainage. Result: All patients were discharged between postoperative day 9 and 15 without complications. One Russian boy returned to his country, therefore, he was lost to follow-up after discharge. Remaining 4 patients were asymptomatic and in normal regular sinus rhythm at a mean follow-up of 17.75$\pm$4.27 months. Follow-up echocardiographic study (range, 12 to 24 months) revealed no incidence of narrowing of the venous pathways or of residual shunt. Conclusion: Our current approach is relatively simple and reproducible in achieving unobstructive pulmonay venous and SVC pathways. By avoiding incision across the cavoatrial junction, surgical injury to the sinus node and its artery may be minimized. The presented surgical technique can be safely and effectively applied to the selected patients.

• Journal of the Korean Geographical Society
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• v.38 no.4
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• pp.630-639
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• 2003

This study aims to analysis the distribution and change of cropland and forest, the Onseong, Saebyeol, and Eundeok counties on the lower reach of Duman(Tumen) river, northeast Korea, using 1992 year Landsat TM data, 2000 year Landsat ETM data, and digital terrain elevation data(DTED). Land cover and land use of the study areas are classified into cropland, forest, village, and water body, using the supervised classification method including 1:50,000 DTED analysis, image band composition, and principal component analysis(PCA). Results of quantitative analysis present that each growth rate of cropland of Onseong and Eundeok are 22.8% and 14.7% corresponding to decreasing rates of forest, 8% and 13.6% during 8 years from 1992 to 2000. In Onseong, Saebyeol, and Eundeok, each values of mean elevations and slope gradients increased to 192m, 95m, and 91m from 157m, 85m, and 78m, and to 6.6$^{\circ}$, 3.0$^{\circ}$, and 4.4$^{\circ}$ from 5.2$^{\circ}$, 2.5$^{\circ}$, and 3.0$^{\circ}$. Especially, in case of newly developed cropland, the values of mean elevation and mean gradient have 225m, 122m, and 127m, and 9.4$^{\circ}$, 5.1$^{\circ}$, and 8.0$^{\circ}$, in above three regions. These new croplands were developing along to deeper valleys and toward lower hill and mountain slope up to knickpoint zone of gradient change. Deforested lands for cropland have formed irregular pattern of patch-type, and become sources for the sheet erosion, rilling and gulleying in mountain slope and sedimentation in local river channel. Though there were no field checking, analysis using landsat images and GIS mapping can help understand actual environmental problems relating to cropland development of mountain slope in North Korea.

• The Korean Journal of Quaternary Research
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• v.16 no.1
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• pp.1-16
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• 2002

A total of 4 muddy sediment samples collected from the Central Yellow Sea were analyzed for chemical composition. The results are compared with the previously published Huanghe, Changjiang and Keum River geochemical data in order to understand provenance and sedimentation of fine-grained mud, and the sediment accumulation rates estimated. The sandy sediment facies is distributed in the eastern area, a patch of fine-grained mud exists in the western central prat, and the sandy mud and clay sedimentary facies shot. north to south zonal distribution in the central region. The content of calcium carbonate ranges from 2.8 to 10.5%, and its distributional trends to be more concentrated on the western muddy sediments near toward the China side rather than on the eastern sandy sediments. The accumulation rates obtained using Pb-210 geochronologies for the muddy sediments in the Central Yellow Sea showed ranges from 0.21 to 0.68 cm/yr or 0.176 to 0.714 g/$\textrm{cm}^2$. yr. The sedimentation rate from core CY96010 located in the eastern near side of Shandong Peninsula which is affected by the Huanghe River shows 0.68 cm/yr or 0.714 g/$\textrm{cm}^2$ . yr. The sediment cores CY96008 and CY96002 in the Central Yellow Sea, the estimated of sediment accumulation rates shows 0.21~0.23cm1yr or 0.176~0.220 9/$\textrm{cm}^2$.Vr respectively, which are much lower than above samples. These indicate that the muddy sediments in central area of the Yellow Sea may have received influence of the sediment discharge from the Huanghe River. The concentrations of Ca, Na, Sr, Ho, La, Tb, Ta and Ca/Ti ratio of the muddy sediments in the Central Yellow Sea are higher than those of the Changjiang sediments and lower than those of the Huanghe sediments. However, these element values showed similar concentration patterns than those of the Huanghe sediment. The element contents such as Fe, Ti, Nl, Co, Cr, Cu, Pb, Sc, Ce, Nd, Sm, Eu, Cd and Dy in the study area are higher than those of the Huanghe sediments and lower than the Changjiang River sediments, but these values showed close to resemblance content trends those of the Changjiang sediment. The concentration of Mn, K and Sr in sediments of the study area are similar to those of the Keum River and eastern Yellow Sea sediment. They are rich in Zn, Rb, Cd, U, Cs and Li than those of the other comparison legions. Therefore, the terrigenous materials sources of the muddy sediment in the Central Yellow Sea comes mainly from Huanghe River in the past and present, and also have party derived from the Changjiang and Keum River, while the biological deposit in this area are carried by the Yellow Sea Warm Current.

• Journal of the Korean association of regional geographers
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• v.23 no.2
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• pp.403-419
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• 2017

This study analyzed the forces to drive the change of urban green spaces in Daegu from 1989 to 2009. First, the loss and fragmentation of green spaces in the past 20 years were spatially identified by performing the hot spots analysis for the cell-based spatial metrics quantifying the size and diversity of green spaces. Next, seven drivers such as slope, distance to roads, land price, population density, ratios of residential, commercial, and industrial areas were selected based on the previous studies and the direction of the association between the loss and fragmentation of green spaces and seven drivers was analyzed with the stepwise logistic regression. Finally, the relative importance of the seven drivers and their interactions in the past 20 years were analyzed with the geographical detector. The results show that the loss of green spaces was concentrated on a part of the Anshim housing development district from 1989 to 2009 and green spaces were highly fragmented around the housing development districts such as Seongseo, Anshim, Dalseong-gun and Chilgok. The forces to drive the loss and fragmentation of green spaces in these areas were different at the administrative levels, but the drivers such as slope and ratios of residential and industrial areas were commonly significant. These drivers were positively correlated with largest patch index(LPI) quantifying the loss of green spaces while they were negatively correlated with Shannon's diversity index(SHDI) measuring the fragmentation of green spaces. In other words, the loss and fragmentation of urban green spaces in Daegu appeared around such regions with lower slope and lower ratios of residential and industrial areas. The relative importance of drivers for LPI was listed as ratio of industrial area, land price, and ratio of commercial area in descending order whereas that of drivers for SHDI was listed as ratio of industrial area, land price, and distance to roads in descending order. Also, the interaction between slope and ratio of residential area had a great impact on LPI and SHDI. The ratio of industrial area was a single driver to most significantly explain the loss and fragmentation of urban green spaces in Daegu in the past 20 years. The interaction between slope and ratio of residential area was greater than the independent influence of a single driver. This study will provide the base data to build a sustainable urban green policy for the city of Daegu in the near future.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.4
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• pp.183-192
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• 1998

The long-term observation of temperature in the coastal waters adjacent to the Wolsung Nuclear Power Plant has been carried out from November 10, 1996 to August 22, 1997, for approximately 280 days using a real-time temperature measurement buoy system. The sea-surface temperature was measured at every 10 minute using 10 buoys. The vertical structure of temperature was investigated near the outlet of the plant with two thermistor chains equipped with 10 sensors at 1 m interval The monthly averaged temperature was the lowest with spatial average of $12.8^{\circ}C$ in February and was the highest in August with spatial average of $19.6^{\circ}C$. The extremely low temperature was frequently observed between June and August, which seems to be the consequence of the intrusion of cold water near the southeastern coast of Korea. Distributions of the daily and hourly averaged temperature show that the highest temperature always occurred near the outlet of the plant and the warm-water patch moved along the north-south direction with the semidiurnal period. The semidiurnal fluctuation of temperature was also observed near the surface of the vertical profiles. The spectral analysis of temperature between February and April 1997 shows that the semidiurnal components prevailed near the outlet. It is likely that the semidiurnal components were due to the prevailing semidiurnal tide in this region. In August 1997, the diurnal components were dominant at the surface water of all stations except Station 12, which suggests that the warm water from the outlet of the plant has less effects in summer on the surrounding waters than the strong solar radiation.

• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.193-200
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• 2000

Purpose : This study was designed and performed for evaluations of clinical manifestation and course of the children under 2 year of age with respiratory tract infection and positive respiratory syncytial virus(RSV) antigen. Methods : The selection criteria of the patients were children under 24 month-of-age, Clinical manifestation of respiratory tract infection, and positive RSV antigen that was detected by Vitek ImmunoDiagnostic Assay System(VIDAS) from nasal cavity. The additional laboratory and simple chest X-ray findings were reviewed from the chart of children who were admitted Wonkwang university hospital from October 1999 to March 2000. Results : Total number of patients enrolled on this study was 102. The 48(47%) children were RSV antigen positive by VIDAS method. Abnormal chest X-ray findings were noticed in 38 cases. The male to female sex ratio of 48 RSV antigen positive cases was 1.2 : 1. The mean and range of age was $10.2{\pm}5.9$ and 1.0~24 months. The peak outbreak of cases was noticed on November, 1999. All of the cases shows coughing but rale was audible in 30 cases(60%). Dyspnea, wheezing, and intercostal retraction were noticed 11(23%), 15(31%), and 10(21%) cases respectively. The most common chest X-ray finding was scattered patch infiltration that was noticed in 30 cases(63%). The mean total white blood cell counts in peripheral blood was $12,608{\pm}4,686/mm^3$. The mean blood level of IgA and IgE were $50.8{\pm}20.9$ and $72.1{\pm}98.3mg/dL$ respectively. The C-reactive protein was $16.0{\pm}18.5mg/L$. Total 5 cases need a mechanical respiraton. The duration of admission was under 7 days in 36 cases(75%). Conclusion : The RSV antigen was detected commonly in late fall and winter season. The severity of children under 2 years old with RSV respiratory tract infection take in some degree a gave courses.

• Radiation Oncology Journal
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• v.17 no.3
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• pp.238-248
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• 1999

Purpose : To assess the histomorphologic changes in the rat lung injury induced by radiation, to determine whether captopril reduces the rat lung injury and to evaluate change in TNF-${\alpha}$ and TGF-${\beta}$ in rat lung damage by radiation and captopril Methods and material : Right lungs in male Sprague-Dawley rats were divided irradiation alone (10, 20, 30 Gy) or radiation (same dose with radiation alone group) with captopril (500 mg/L). Radiation alone group were sacrificed at twelve hours and eleven weeks after radiation and radiation with captopril group (captopril group) were sacrificed at eleven weeks after radiation with captopril. We examined the light microscope and electron microscopic features in the groups. Results : In radiation alone group, there were patch parenchymal collapse and consolidation at twelve hours after radiation. The increase of radiation dose shows more prominent the severity and broader the affected areas. Eleven weeks after radiation, the severity and areas of fibrosis had increased in proportion to radiation dose given in the radiation alone group. There was notable decrease of lung fibrosis in captopril group than in radiation alone group. The number of mast cells rapidly increased with increase of radiation dose in radiation alone group and the degree of increase of mast cell number and severity of collagen accumulation more decreased in captopril group than in radiation alone group. In radiation alone group, expression of TNF-${\alpha}$ and TGF-${\beta}$ increased according to increase of radiation dose at twelve hours after radiation in both group. At eleven weeks after radiation, expression of TGF-${\beta}$ increased according to increase of radiation dose in radiation group but somewhat decreased in captopril group. In the captopril group the collagen deposition increased but less dense than those of radiation alone group. The severity of perivascular thickening, capillary change, the number and degranulation of mast cells more decreased in the captopril group than in the radiation alone group. Conclusion : It is concluded that the effect of captopril in the rat lungs after radiation was considered to be due to its effect on inhibition of mast cells and reduction of collagen deposition, and captopril may be protect in lung damage after radiation. We observed expression of TNF-${\alpha}$ and TGF-${\beta}$ increased at the early phase after radiation and expression of TGF-${\beta}$ increased in proportion to increase of radiation dose at the chronic phase after radiation. This results will contribute to future investigation in reduction mechanism of captopril in lung damage after radiation.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1062-1068
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• 1997

From August 1989 to January 1996, a total of 105 cases of bidirectional Glean operations have been done as the interim stage for the patien s with some risk of univentricular correction at Sejong General Hospital. From December 1992, we started the conversion to Fontal operations for them, and 42 cases underwent Fontal-stage operation till February 1996. Their diagnoses were univentricular heart in 19(right ventricular type : 14), tricuspid atresia 11, double outlet of right ventricle 9, and others in 3 cases. The median age of bidirectional Glerln-stage operation was 12.5 months(range 2 months to 8 years) and Fontan-stage operation was at 59.6 months of median age(range 1 year 5 months to ,9 year 7 months). The mean waiting interval between the two operations was 33.88 $\pm$ 17.85 months with a range of 10 months to 6 years 3 months. During the waiting periods, 18 patients developed significant systemic-pulmonary collaterals andfor systemic verso-veno collateral channels. There were 5 hospital deaths after operations due to low cardiac output in 4 and sepsis in one. Most of the Fontal-stage operations were done by the late al tunneling with Core-Tex tube graft patch and fenestrated with the size of 2.5 ~6 mm. All the patients were followed-up(7 months to 4 years 2 months, mean 21.97$\pm$10.82 months) and there were 5 late deaths(postoperatively 6 months to 2 years) due to thromboembolism in 1, after heart transplantation 1, plastic bronchitis 1, protein loosing enteropathy 1, and pneumonia in 1. Dividing the patients by the waiting interval of 2 years, the early correction to Fontal group (N=16) showed the better results(hospital mortality 1116, late mortality 1116, significant collateral development 2/16) compared to the other group(N=26) (4/26, 4/26, 16/26). In conclusion, after the bidirectional Glean-stage operation successfully got rid of the previous risk factors, we recommand to do the Fontan-stage operation no later than 2 years of interval.