• Elastomers and Composites
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• v.52 no.2
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• pp.143-153
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• 2017

Herein we studied the characterization of the PBO films formed via solution casting and thermal cyclization of poly(o-hyroxyamide)s(PHAs) that were synthesized by direct polycondensation of 3,3'-dihydroxybenzidine with 4,4'-(2,3-quinoxalinedioxy) dibenzoic acid and/or 4,4'-(2,3-pyridinedioxy) dibenzoic acid. All the PHAs exhibited inherent viscosities in the range of 0.55~0.84 dL/g in DMAc solution. The copolymers, CPH-2-5, were partially soluble in less polar solvents like pyridine and THF. However, all the PBOs were not soluble in polar solvents, but only partially soluble in sulfuric acid. The temperatures corresponding to 10% weight loss of the PBOs with increasing content of quinoxalinedioxy unit were higher than those of the PHAs, and the char yields at $900^{\circ}C$ in $N_2$, tensile strength, and initial modulus of the PBOs were 1.1~1.3 times, 1.2~1.8, and 1.6~3.3 times higher, respectively, than those of the PHAs. The LOI value of CPB-2 was 38.5%, while that of CPB-1 was the highest at 40.0%. The LOI test confirmed that excellent flame retardants were synthesized.

• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.260-267
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• 1998

This study was undertaken to find a new formulation of soil amendment, and selection of antogonists and to effectively control brown and large patch of turfgrasses caused by Rhizoctoniz solani AG1-1 and AG 2-2. Fourteen inorgainc chemicals (1%, w/w) were added individually in vitro, and some chemicals showed suppressiveness to R. solani. Alum suppressed effectively mycelial growth of R. solani in the range of 17 to 77% as compared with control. The four chemicals such as Al2(SO4)3, alum, CaO, and NH4NO3 were finally selected. Out of three organic compounds, composted pine bark (CPB) showed prominent suppressive effect as compared with milled alfalfa and pine leaves. After inoculation of R. solani isolates AG-1 and AG2-2 on the turf seedlings, water soaked lesions and blight symptoms were developed on the whole seedlings. According to inhibition zone method, mycelial growth of the fungus were greatly suppressed by culture filterates of the antagonists, Gliocladium virens (Gl1-) and Pseudomonas sp. (P713). CPB soil amendment mixed with antagonists (1% w/w) controlled not only brown and large patch of turfgrasses, but also promote the good growth of the seedlings. In addition, the controlling effect was maintained more than 30 days. Especially, the controlling effect of two antagonists was similar to Cㅖㅠ soil amendment with the antagonists and also stimulated a favorable growth of the seedlings. Therefore, its is expected that continuous control of Rhizoctonia blight of turfgrasses can be obtained in field by subsequent applications of the antagonists.

• Journal of Chest Surgery
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• v.33 no.9
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• pp.729-733
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• 2000

Background: Recent trends suggest that minimally invasive cardiac surgery reduces postoperative morbidity and offers a cosmetic benefit. This study was performed to evaluate the CPB time, ACC time, OP time, ICU stay and postoperative hospital stay following a lower partial sternotomy and those of the median sternotomy. Material and Method: A group of 26 adult patients who underwent cardiac surgery through lower partial sternotomy from August 1997 to July 1999(A group) were compared to 45 adult patients who underwent cardiac surgery through median sternotomy from January 1996 to July 1997(B group). The mean ages(46.4$\pm$14.6 years, A group and 46.8$\pm$13.2 years, B group) were similar. Operations were performed with central cannula and antegrade/retrograde blood cardioplegia. Result: There was no death in each group. No differences were found in CPB time, ACC time, OP time, ICU stay and postoperative hospital stay. Postoperative complications were sternal splitting in a patient in group A and a patient with bleeding that required reoperation and a patient with delayed wound closure in group B. Conclusion: The lower partial sternotomy offered a cosmetic benefit, but does not significantly reduced the length of operative time and hospital stay. Minimally invasive cardiac surgery will be applied increasing because of the suggested advantage and choosing a proper operative technique will be helpful.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.771-779
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• 1985

It has been recognized that the proper matching of ventilation and perfusion within the lung is essential for the efficient exchange of gases following open heart surgery. Physiologic shunt reflects the amount of blood going to lung units with inadequate ventilation and these are also areas of the lung with adequate ventilation but inadequate blood flow. This can be quantified by measuring physiological dead space. From January to August 1985, The physiologic dead space and shunt during postoperative course had been taken in 30 patients of open heart surgery in Soonchunhyang University Hospital. Twenty cases had congenital heart disease and acquired valvular heart disease were noticed in 10 cases. The physiological dead space and shunt during postoperative periods were calculated and we made 5 items of conclusion: 1. There is high probability of ventilation-perfusion mismatch in the acquired heart disease group compared to the congenital group. 2. Duration of the CPB can exert significant influences in the physiological dead space but less in the shunt fraction. 3. There is positive relationship between Qs/Qt and Vd/Vt in the group B [CPB>90 min.] but less reliable in correlation. 4. Perfusion impairment is more significant in the diminished pulmonic blood flow group compared to the increased pulmonic blood flow [Qp/Qs>2.0] group. 5. There is no significant ventilation-perfusion mismatch within the lung during all postoperative courses.

• Journal of Veterinary Science
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• v.24 no.3
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• pp.47.1-47.7
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• 2023

Del-Nido cardioplegia (DNc) is a single-dose cardioplegia that is widely used in human medicine because of its long duration. In this report, we describe two cases of open-heart surgery with cardiopulmonary bypass (CPB) using DNc. One dog was diagnosed with partial atrioventricular septal defect, and the other dog was diagnosed with myxomatous mitral valve disease stage D. Both dogs were treated with open-heart surgery with DNc to induce temporary cardiac arrest. No complications from DNc were observed, and the patients were discharged. Veterinary heart surgeons should consider DNc as an option for temporary cardiac arrest during open-heart surgery with CPB.

• Journal of Chest Surgery
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• v.34 no.8
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• pp.591-596
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• 2001

Coronary artery bypass graft with cardiopulmonary bypass is a conventional method of operative revascularization of coronary artery disease. Because of many troubles of cardiopulmonary bypass such as systemic inflammatory reaction, mechanical trauma of blood components and coagulopathy, coronary artery bypass graft without cardiopulmonary bypass has been popularized. Material and Method: From March 1999 to September 2000, 35 patients under went CABG at our institution. Among them, 14 patients received CABG without the use of CPB and 21 patients under went CABG with the use of CPB. Mean operative time, mean postoperative tracheal intubation time, mean ICU stay, mean hospital stay, the amount of transfusion, postoperative use of inotropic agents, and postoperative changes of cardiac enzymes were compared in both groups. Result: There were differences between the CABG without CPB group and CABG with CPB group with regard to mean tracheal intubation time, the amount of transfusion and the elevation of postoperative cardiac enzymes(p<0.05). Conclusion: While CABG without CPB provided satisfactory results, more long term follow-up is required.

• Journal of Chest Surgery
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• v.33 no.12
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• pp.941-947
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• 2000

Background: Central nervous system complication after coronary artery bypass grafting(CABG) is one of the major prognostic determinants and the use of the cardiopulmonary bypass(CPB) may increase the incidence of this devastating complication. In this study, the outcomes after off-pump CABG were studied and compared with those following the conventional CABG using CPB. Material and Method: Among the consecutive isolated CABG's performed in SNUH during Feb. 1995 and Jun. 1999, 338 coronary artery bypass grafting were divided into two groups. 223 patients underwent CABG using the CPB(Group I), and 115 patients underwent CABG without CPB(OPCAB)(Group II). All patients enrolled in this study received extensive preoperative examinations including thorough neurologic examination before and after surgery, transcranial doppler study, carotid duplex ultrasonography, and magnetic resonance angiography if necessary. Central nervous system(CNS) complications were defined as stroke, seizure, metabolic or hypoxic encephalopathy and transient delirium after surgery. Result: There were 61 cases(27.3%) who developed postoperative CNS complication in Group I, whereas 8 cases(7.0%) of CNS complications developed postoperatively in group II(p<0.05). Statistically significant predictors of postoperative CNS complications in group I were age and the use of cardiac assist devices perioperatively. Conclusion: This study suggested that omitting the use of CPB in CABG resulted in significant decrease of the postoperative CNS complications. OPCAB should be more widely applied especially to the elderly who have preexisting cerebrovascular disease.

• Journal of Chest Surgery
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• v.47 no.2
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• pp.100-105
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• 2014

Background: We evaluated the safety and efficacy of percutaneous extracorporeal membrane oxygenation (ECMO) in patients with primary graft dysfunction after heart transplantation. Methods: Of 65 patients (44 males and 21 females) who underwent heart transplantation from January 2006 to December 2012, 13 patients (group I) needed peripheral ECMO support due to difficulty in weaning from cardiopulmonary bypass (CPB) and 52 patients (group II) were weaned from CPB without mechanical support. The mean age of the patients at the time of operation was $54.4{\pm}13.6$ years. There were no differences in the preoperative characteristics of the two groups. Multivariable analysis was performed to identify the risk factors for ECMO therapy. Results: All group I patients were successfully weaned from ECMO after $53{\pm}9$ hours of circulatory support. Early mortality occurred in four patients (1 [7.7%] in group I and 3 [5.8%] in group II, p>0.999). There were no differences in the postoperative complications between the two groups, with the exception of reoperation for bleeding. A greater number of group I patients underwent reoperation for bleeding (5 [38.5%] in group I vs. 6 [11.5%] in group II, p=0.035). In multivariable analysis, preoperative mechanical support (ECMO and intra-aortic balloon pump) and longer CPB time were the risk factors of ECMO therapy for graft dysfunction (odds ratio, 6.377; 95% confidence interval, 1.519 to 26.77; p=0.011 and odds ratio, 1.010; 95% confidence interval, 1.001 to 1.019; p=0.033). Conclusion: Percutaneous ECMO support could be a viable option for rescuing patients when graft dysfunction refractory to medical management develops after heart transplantation.

• The Korean Journal of Pain
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• v.28 no.2
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• pp.109-115
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• 2015

Background: This study sought to determine safe ranges of oblique angle, skin entry point and needle length by reviewing computed tomography (CT) scans and to evaluate the usefulness of a bent tip needle during celiac plexus block (CPB). Methods: CT scans of 60 CPB patients were reviewed. Image of the uppermost margin of L2 vertebral body was used to measure the minimal and maximal oblique angles and the distances from the midline to skin puncture point. The imaginary needle trajectory distance was calculated by three-dimensional measurement. When the procedure was performed by using a $10^{\circ}$ bent tip needle under a $20^{\circ}$ oblique X-ray fluoroscopic view, the distance (GF/G'F) from the midline to the actual puncture site was measured. Results: The imaginary safe oblique angle range was $26.4-34.2^{\circ}$ and $27.7-36.0^{\circ}$ on the right and left, respectively. The distance from the midline to skin puncture point was 6.1-7.6 cm on the right and 6.3-7.6 cm on the left. The needle trajectory distance at minimal angle was 9.6-11.6 cm on the right and 9.5-11.5 cm on the left. The distance of GF/G'F was 5.1-6.5 cm and 5.0-6.4 cm on the right and left, respectively. All imaginary parameters were correlated with BMI except for GF/G'F. All complications were mild and transient. Conclusions: We identified safe values of angles and distances using a straight needle. Furthermore, using a bent tip needle under a $20^{\circ}$ oblique fluoroscopic view, we could safely perform CPB with smaller parameter values.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.108-108
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• 2012

이전의 연구에서 기존의 ATY 장치에 ITY 노즐을 접목하여 개조한 사가공기로 제조한 탄성복합사를 자동차 시트용 트리코트 원단으로 편직하여 일광견뢰도가 우수한 염료를 선정하고 $125^{\circ}C$에서 염색하여야 견뢰도와 spandex의 물성을 저해하지 않음을 알 수 있었다. 폴리에스테르 탄성복합사의 염색성 평가에 이어 본 연구에서는 나일론 필라멘트 (70/24, Full-dull, 2ply사와 40D spandex 1ply사 복합)와 레이온사(75D, 1ply)를 투입하여 직물 원단(중량 216g/yd, 밀도 경사 78, 위사 52본/inch)을 제직한 후 2욕에서의 염색공정을 거칠 경우, 탄성복합사의 견뢰도와 물성에 미치는 영향을 조사하였다. 나일론, 레이온, 폴리우레탄의 3종 원단을 염색성 평가를 위하여 반응성염료로 먼저 레이온 부분을 염색한 후 산성염료로 나일론 부분을 염색하였으며, 이 때 spandex가 미치는 영향을 비교하기 위하여 spandex가 함유되지 않은 나일론, 레이온 복합 제직원단도 함께 염색한 후 견뢰도를 평가하였다. 또한, 레이온 부분은 CPB염색법과 제트염색기로 나누어 염색하여 염색기에 따른 인장강도와 인열강도를 평가하였다. 레이온 염색에는 셀룰로오스용 2관능기 반응성염료 3원색을 이용하여 khaki color로 combination염색하였으며, 나일론 부분에는 입자크기가 커서 견뢰도가 우수한 산성염료를 선정하여 combination염색한 후 냉수세하였다. 견뢰도를 비교한 결과, spandex가 포함된 탄성복합사 원단과 나일론과 레이온 만으로 제직된 원단 모두 세탁, 마찰, 물, 땀, 일광 견뢰도 모두가 4~5급으로 우수하여 spandex에 이염된 염료가 견뢰도에 미치는 영향은 없음을 확인하였다. 또한, 레이온 부분의 반응성염료 염색 시 CPB와 제트염색법의 두 가지 종류에 대한 인장강도와 인열강도 평가결과는 CPB 염색물이 제트염색물보다 약간 높게 나타났지만 3% 이내의 차이로 거의 차이가 없음을 나타내었다. 일반적으로 제트염색 시 원단은 로프상으로 이동하고, CPB염법은 확포상태 그대로 염색되기 때문에 제트염색 시 강도가 낮아지는 것으로 알려져 있으나, 본 연구에서는 탄성복합사를 경사, 위사 모두 사용함으로써 spandex가 신장하는 특성 때문에 강도의 저하가 없는 것으로 사료된다.