• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.349-362
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• 1999

To understand the role of protozoa in the early formation of microbial fouling community, the studies on the formation of microbial film, the succession of microbial fouling communities, and the grazing pressure on bacteria population in microbial film were carried out in the laboratory, Inchon outer port and Inchon inner harbour. Bacteria and heterotrophic flagellates formed primary microbial film on the aluminum surface within 6 hours and oligotrich ciliates were observed 2 cells $mm^{-2}$ on the same surface at 9 hours in Inchon inner harbour which had physically stagnant condition. The larvaes of Balanus albicostatus which were dominant meiobenthos in Inchon coastal area attached on the glass surface at the first day of experiment. Heterotrophic flagellates showed maximum abundance of 465 cells $mm^{-2}$ at the 13rd day and ciliates showed maximum abundance of 63 cells $mm^{-2}$ at the 11st day in the Inchon inner harbour. In the Inchon outer port which opens to the outer sea, the maximum abundance of protozoa occurred at early phase, but not so many. The dominant heterotrophic flagellates were Metrornonas simplex and Bodonids. Dominant ciliates were small tintinnids and oligotrich ciliate Strombidium sp., Large Strombidium (oligotrich ciliate) and sessile Acineta turberosa (suctorian ciliate) occurred after 10 days. The attached larvae of Balanus occurred as biofouling organism on the early surface and showed maximum abundance of 18 indiv. $cm^{-2}$ at 7th day. At that time, adult barnacles were observed on the surface and dead barnacles were observed after two days. Except barnacles, the larvaes of Anthozoa sp., Oysters (Crassostrea gigas) and Polychaeta were observed on the surface from 3rd day. 3 benthic copepods including Harpacticus sp., I isopod, 1 polychaeta and 1 gastropoda were observed as predators of the microbial film on the surface after 7 days when microbial film developed very well. Although the ingestion rates of protozoa on the bactctia of the rnicrobi31 film were relatively low, the average grazing rate of protozoa on bacteria was high of 0.058 $h^{-1}$. This implied that the grazing pressure of protozoa influences the mortality of bacteria populations on the microbial film. but protozoa cannot get enough energy from only bacteria on the microbial film.

• Korean Journal of Weed Science
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• v.2 no.1
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• pp.20-30
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• 1982

A field experiment was conducted in 1981 at the Crop Experiment Station, Suweon, Korea, in machine transplanted paddy rice field, to study the effectiveness of single herbicide, mixture, and systematic application of herbicides on diversity of weed control spectrum. The rice variety planted was Taebaegbyeo, Indica ${\times}$ Japonica cross bred. Experimental field was dominated by Echinochtoa crusgalli, Eleocharis kuroguwai, and Scirpus hotarui, and importance values based on dry weight of these weeds were 89%, 5%, and 3%, respectively. The mixture or systematic treatments of herbicide were generally more effective than single herbicide applications on weed control. Coefficients of similarity based on floristic composition after herbicide application between Perfluidone (5G) and Chloromethoxynil (7G), and between Pertluidone (5G) and Bifenox (7G), and between Perfluidone (5G) and three types of Butachlor (6G) were low, and these sets seemed to be a good mixture herbicide in paddy fields. While, Perfluidone (5G) had low coefficient of similarity with other single herbicides tested. The information on coefficient of similarity could be used as parameter for selecting herbicides to increase the efficiency of herbicidal performance. Simpson's indices from Butachlor (3.5G)/SL-49 (7G), Butachlor (3.5G)/Pyrazolate (6G), and Perfluidone (5G) treatments were high, and these herbicide treatments tended to the weed community type simplified, while the indices from Perfluidone (5G) + Chloromethoxynil (7G), Butachlor (6G) fb Perftuidone (5G), and Butachlor (4G)/Naproanilide (6G) treatments were low, and these herbicide treatments caused to the community type diversified in terms of floristic composition.

• Journal of Chest Surgery
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• v.31 no.6
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• pp.560-566
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• 1998

Background: Bovine pericardial bioprosthesis treated with glutaraldehyde (GA) is one of the most popular prosthetic materials, but late calcific degeneration after implantation is a problem that remains unsolved. For the purpose of mitigating the calcific degeneration, we added MgCl2 into the 0.625% GA solution to compete with calcium for binding to the free aldehyde from GA and pretreated with the surfactants like sodium dodecyl sulfate (SDS) and Triton X-100 before GA fixation for preventing the phospholipid infiltration into the pericardial tissue, the first step of the calcific degeneration. Material and Method: 40 square-shaped pieces of bovine pericardia were fixed in 0.625% GA solution with 4g/L MgCl2 6H2O as a control group (group 1). 40 pieces pretreated with 1% SDS were also fixed in the same GA solution (group 2) and other 40 pieces pretreated with 1% Triton X-100 were prepared with the same method (group 3). After 1 month of fixation these were implanted into the belly of 40 Sprague-Dawley subdermally and extracted 1 month, 2 months, 3 months and 6 months after implantation. With atomic absorption spectrophotometry we measured the deposited calcium amount. Result: 1 month after implantation we could not find any differences between the three groups, but by the 2nd month calcium deposition was 0.921$\pm$0.121 mg/g in group 1, 0.481$\pm$0.037 mg/g in group 2 and 1.369$\pm$0.200 mg/g in group 3. By the 3rd month it was 0.786$\pm$0.080 mg/g in group 1, 0.584$\pm$0.054 mg/g in group 2 and 1.139$\pm$0.188 mg/g in group 3, and on the 6th month 1.623$\pm$0.601 mg/g in group 1,0.501$\pm$0.043 mg/g in group 2 and 1.625$\pm$0.382 mg/g in group 3, with statistical significance in group 2(p<0.05). Conclusion: Pretreatment with SDS showed meaningful calcium mitigation effects on subcutaneously implanted bovine pericardium in the rat models but the neutral type surfactant, Triton X-100, had no positive mitigation effect in this experiment.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.659-665
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• 2003

The aim of this study was to evaluate the early and midterm results of off-pump total arterial revascularization using the skeletonized right gastroepiploic artery (RGEA) as a third arterial conduit. Material and Method: We prospectively analyzed 103 patients who underwent off-pump total arterial revascularization using bilateral internal thoracic arteries (ITAS) and RGEA. The RGEA was used as in situ graft in 88 patients, composite graft in 10 patients, and free graft in 5 patients. Postoperative coronary angiographies were performed before discharge in 100 patients, and at postoperative one year in 88 patients. Result: The RGEA showed a significantly higher free flow (130$\pm$95 ml/min) than that of right ITA(113$\pm$57 ml/min) or left ITA (107$\pm$55 ml/min), which was measured before anastomosis (p < 0.05). The total number of distal anastomoses was 3.8$\pm$0.7. The number of distal anastomoses per bilateral ITAs was 2.8$\pm$0.7 and the number of distal anastomosis per RGEA was 1.0. There were two morialities including one operative mortality. The late mortality was not related to cardiac events. Early postoperative morbidities were atrial fibrillation in 15 patients, bleeding reoperation in 4 patients, mediastinitis in 1 patients, perioperative myocardial infarction in 2 patient, and transient ARF in 3 patients. Postoperative coronary angiographies showed the early patency rate of 98.6％ (272/276) for ITAs and 97.0％ (97/100) for RGEA, respectively (p=ns), and the one-year patency rate of 95.9％ (234/244) for ITAs and 88.6％ (78/88) for RGEA, respectively (p=0.07). Flow competition between the RGEA and NCA (native coronary artery) was seen in 5 of the 100 patients (5.0％) immediate postoperatively and 7 of the 88 patients (8.0％) 1 year after surgery. Since July, 2000, we measured transit time flow intraoperatively and could reduce flow competition significantly Conclusion: The skeletonized RGEA demonstrated excellent early and midterm patency rates and could be used as a third arterial graft following the bilateral ITAs.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.768-773
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• 2004

Failure of mitral valve repair sometimes may be ascribed to severe or progressive alteration of the subvalvar apparatus. The aim of this study was to evaluate the effects of new chordae formation on mitral repair. Material and Method: From March 1997 to february 1999, 26 patients underwent mitral valve repairs with new chordae formation, we compared the symptoms and echocardiographic findings checked at preoperative state, and intraoperative period, discharge, and their last OPD visit. There were 45 male, and 11 female patients, and their mean age was 51.2$\pm$43.4 years. Etiology of the lesions was degenerative (18), rheumatic (6), infective (1) and ischemic (1). Chordal lesions were caused by rupture (18), elongation (6), and a combination of two causes (2). Associated lesions included atrial septal defect (2), tricuspid insufficiency (7), aortic insufficiency(4), and a combination of previous two factors (2). The number of mean artificial chordae was 3.6$\pm$1.6. Annuloplasty was per-formed in all cases. The CPB time was 182,1$\pm$63.7 minutes and the ACC time was 133.1$\pm$45.6 minutes. Aver-age follow up period was 49.2$\pm$7.1 months. Result: There was no early death. Early reoperation was performed in bud patients, one patient received mitral valve replacement because of an abnormality of annuloplasty and ano-ther received pericardiostomy due to postoperative pericardial effusion. During the follow up of 49.2$\pm$7.1 moths, there was no late mortality. Postoperative NYHA functional class checked at last OPD visit was class I in 22 patients (88%), class II in 2 (8%), and class III in 1 (4%). Regarding the late echocardiogram MR was absent in 20 patients (78%), 1 in 4 (15%), and II in 1 (4%). The postrepair mitral valve area was 2.2$\pm$0.35 $\textrm{cm}^2$ Conclusion: This study suggests that mitral valve repair using new chordae formation provides good early and mid term survivals and functional improvement. We think that the artificial chorda formation with polytetrafluoroethylene suture might be safe and effective technique for mitral valve repair.

• Journal of Chest Surgery
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• v.38 no.4 s.249
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• pp.271-276
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• 2005

We analysed differences in operative methods and postoperative outcome according to the severity of preoperative cyanosis in adult ToF (Tetralogy of Fallot) patients. Material and Method: From August 1989 to June 2001, thirty three adult patients, 18 females and 15 males, underwent total correction for ToF. Their age ranged from 15 years to 54 years (median: 34). Patients were divided into 2 groups by preoperative $SaO_2$ (arterial oxygen saturation): group I$(n=cyanotic,\;SaO_2\;\geq94\%)$ and group II $(acyanotic,\; SaO_2\geq95%)$. Preoperative median hemoglobin level was higher in group I compared to group II (17.5 g/dl vs 15 g/dl). Postoperative follow-up duration ranged from 1 to 94 months (670 patient-month, median: 14 months), and 63 two-dimensional echocardiographic examinations were done during this period. Result: There were no early or late mortality. With regard to RVOT (right ventricular outflow tract) reconstruction, trans-annular patch and RV-PA extracardiac conduit were used in 7 and 3 patients respectively, and all of them belonged to group I. In group I, cardiopulmonary bypass time, aortic cross-clamping time, ICU day, hospital day were significantly longer than in group II, and postoperative inotropic support was significantly greater than in group II. There was no ventricular arrhythmia in both groups, and one patient in group I suffered from atrial arrhythmia, which was resolved spontaneously after tricuspid and pulmonary valve replacement. During follow-up periods, functional class, residual RVOT stenosis and pulmonary regurgitation, tricuspid regurgitation, occurrence of ventricular and atrial arrhythmias were comparable between two groups. Conclusion: In adult ToF patients with severe preoperative cyanosis, more aggressive RVOT reconstruction and careful postoperative care are mandatory. However intermediate-term outcome of this group of patients is comparable to the patients with minimal or no preoperative cyanosis.

• Journal of Chest Surgery
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• v.38 no.4 s.249
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• pp.291-300
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• 2005

One-stage repair of aortic arch anomalies and intracardiac defects through median sternotomy has been recently adopted by many institutions since it is known to be safer than the staged repair. The early and midterm results of the one-stage repair of aortic arch anomalies and intracardiac defects were retrospectively evaluated. Material and Method: 45 patients who underwent one-stage repair of aortic arch anomalies and intracardiac defects performed by one surgeon from January 1996 to July 2003 were included in this retrospective study. The median age of repair was 16 days (range, 3 days$\~$23.7 months) and the mean weight was $3.62\;\pm\;1.30 kg$. Thirty one $(68.9\%)$ had coarctation and 14 $(31.1\%)$ had interrupted aortic arch. Associated intracardiac anomalies were VSD in 31 patients (VSD group), TGA or Taussig-Bing anomaly in 10 (TGA group), and others in 4 (ASD in 1, aortopulmonary window 1, truncus arteriosus 1, aortic and mitral stenoses 1, miscellaneous group). The arch obstruction was repaired with end-to-side anastomosis in 23 patients and end-to-end anastomosis in 22. Result: Overall postoperative hospital mortality was $22.2\%\;(10/45);\;16.1\%$ (5/31) in VSD group, $40\%$ (4/10) in TGA group, and$25\%$ (1/4) in miscellaneous group. There was no mortality in VSD group since 1998, and the mortality in TGA group has remarkably reduced since technical modification for coronary transfer was adopted $(75\%\;vs\;16.7\%)$. There was no postoperative seizure or other neurological complications. Postoperative aortic restenosis occurred in 5 patients $(5/35,\;14.3\%)$. Two patients underwent balloon aortoplasty with successful results. There was no reoperation. There was one late death caused by pneumonia 5 months after the operation. Two-year actuarial survival rate including operative death was $72.9\%$. Conclusion: The operative mortality of one-stage repair has been reduced with time and aortic restenosis rate was also acceptable. We concluded that this procedure is a reproducible procedure for aortic arch anomalies associated with intracardiac defects.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.299-304
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• 2009

Background: Although the results of the surgical management for complete atrioventricular septal defect (c-AVSD) have improved, the optimal surgical strategy is still controversial. The aims of this study are to evaluate the outcome of c-AVSD repair and to define the risk factors related to reoperation. Material and Method: We retrospectively reviewed the medical records of 35 patients (8 males and 27 females) who underwent the total correction of c-AVSD from August 1996 to March 2008. The median age at repair was 5.2 months (range: 3 days$\sim$82 months). Sixteen patients (45.7%) were associated with Down syndrome. Prior palliative operations were performed in 4 patients. The one-patch techniques were performed in 3 patients, and the two-patch techniques were done in 32 patients. Result: There was 1 early death (2.9%). The median follow-up period was 68 months (range: $2\sim134$ months) for 34 survivors. There was no late death. Reoperations were performed in 5 patients (14.3%) for severe left atrioventricular valvular regurgitation (AVVR). Nine patients (25.7%) showed left an AVVR of more than grade III. Associated major cardiac anomalies and the use of Gore-Tex patch for ventricular septal closure were the risk factors for postoperative left atrioventricular valve failure and reoperation. Conclusion: In this study, we found that surgical repair of c-AVSD was safe and effective. However, the high reoperation rate after repair remains a problem to be solved.

• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.49-56
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• 2011

To investigate the toxicological effects of ${\beta}$-glucan, we performed basic studying on ${\beta}$-glucan in Sprague-Dawley (SD) rats. Standard endpoints in this study included mortality, clinical observations, changes of body weights, analysis on food consumption, ophthalmoscopic examination, hematologic examination, serum biochemistry, analysis of organ weights, gross anatomic pathology and histopathology. No clinical signs and mortality were observed in animals treated with beta-glucan throughout the experimental period. The average body weight of each treatment groups showed similar levels at end of experiment. There were no treatment-related changes in mortality, body weights changes, food consumption, ophthalmoscopic examination. Although there were statistically significant differences between the control and treated groups in some relative and absolute organ weights, and hematological and biochemical analysis, the data were in biologically normal ranges and did not show a dose-dependent manner. In the morphological change, hepatic tissue were not showed ballooning degeneration and irregular arrangement of hepatic cell in ${\beta}$-glucan treatment groups with control group. Also, organs weights (liver, heart, kidney and stomach) and hematological indices (WBC, RBC, Hb, Hct and Platelet) did not show statistically significant differences among the experimental groups. In summary of these results, there were no changes in mortality, mean body weight, clinical signs, food consumption. There were no changes in ophthalmological examination, hematology, blood chemistry, necropsy and histopathology. In conclusion, although further investigation of glucan should be performed in the functions registered in many ancient literatures, ${\beta}$-glucan is physiologically safe and may have potential as candidate food for human health.

• Journal of Chest Surgery
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• v.38 no.3 s.248
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• pp.221-228
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• 2005

Reduction aortoplasty has been advocated for dilatation of the ascending aorta associated with aortic valve disease in older, high-risk patients. We report our results with modification of reduction aortoplasty and aortic valve replacement. Material and Method: Between July 2001 and December 2002, 14 consecutive patients who underwent modification of reduction aortoplasty, suture plication technique without excision of the dilated aortic wall, were reviewed. The mean age was 63.7$\pm$6.7 (50 to 75) years. Ten patients had congenital bicuspid aortic valve, Twelve patients had severe aortic valve stenosis and 6 had regurgitation of grade III$\~$IV. The diameter of the ascending aorta was measured before and immediately after surgery and 6 and 12 months postoperatively using echocardiography or computed tomography. Follow-up was complete in an average of 14.7$\~$5.4 (7 to 24) months. Result: There were no early postoperative deaths and no bleeding complications. Reduction aortoplasty with suture plication technique decreased the diameter of ascending aorta from 49.4$\pm$3.5 mm preoperatively to 33.2$\pm$3.4 mm postoperatively (p <0.001). During follow-up, there were no late deaths and no aneurysm recurrence on the ascending aorta. Conclusion: Suture plication technique of reduction aortoplasty without excision of the dilated aortic wall offers good early and short-term results in older, high-risk patients with dilatation of the ascending aorta associated with aortic valve disease. Surgical long-term results of our technique should be evaluated in further studies.