• Steel and Composite Structures
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• 제21권4호
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• pp.863-882
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• 2016

This study aims to introduce a new bracing system by which even super-wide frames with large openings can be braced. The proposed system, hereafter called Cable-Pulley Brace (CPB), is a tension-only bracing system with a rectilinear configuration. In CPB, a wire rope passes through a rectilinear path around the opening(s) and connects the lower corner of the frame to its opposite upper one. CPB is a secondary load resisting system with a nonlinear-elastic hysteretic behavior due to its initial pre-tension load. As a result, the required energy dissipation would be provided by the MRF itself, and the main intention of using CPB is to contribute to the initial and post-yield stiffness of the whole system. Using a stiffness calibration technique, optimum placement of the CPBs is discussed to yield a uniform displacement demand along the height of the structure. A displacement-based design procedure is proposed by which the MRF with CPB can be designed to achieve a uniform distribution of inter-story drifts with predefined values. Obtained results indicated that CPB leads to significant reductions in maximum and residual deformations of the MRF at the expense of minor increase in the maximum base shear and developed axial force demands in the columns. In the case of a typical 5-story residential building, compared to SMRF system, CPB system reduces maximum amounts of inter-story and residual drifts by 35% and 70%, respectively. Moreover, openings of the frame are not interrupted by the CPB. This is the most appealing feature of the proposed bracing system from architectural point of view.

• Journal of Chest Surgery
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• 제25권7호
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• pp.693-701
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• 1992

Extracorporeal cardiopulmonary bypass[CPB] has been associated with a wide variety of hematologic derangements, including a transient deformation and hemolysis of red blood cells[RBCs], which is supposed to be due to mechanical trauma and/or metabolic alterations. Since membrane integrity is, in part, maintained by energy requiring process, inadequate function of erythrocyte glycolytic pathway, which is inevitalble during CPB, may cause depletion of high energy phosphate pool and result in hemolysis. The authors performed an investigation to assess whether administration of Fructose-l, 6-diphsphate [FDP], which has been known to enhance intracellular glycolytic activities, could counteract erythrocyte hemolytic events caused by CPB. Sixty pateints with cyanotic congenital heart diseases, who underwent open heart surgery under CPB longer than 60 minutes, were randomly divided into two groups depending on whether use of FDP[Group FDP] or not[Group Control]. The age, sex, CPB time, preoperative hemoglobin level, disease entities were all similar[Table 1], and membrane type oxygenators were used in all patients. In Group, FDP, a dose of 250mg/kg body weight of FDP was administered by intravenous dripping every 12 hours from the morning of the operation to postoperative 48 hours, To demonstrate the degree and pattern of hemolysis of erythrocyte, reticulocyte count, indirect /direct bilirubin, haptoglobin, plasma hemoglobin, lactate dehydrogenase were measured every 12 hours from the time of cessation of CPB to 48 hours and RBC morphologic study, osmotic fragility test were done every 24 hours. All parameters revealed less hemolytic in group FDP [Fig. 1~5], though the differences between two groups were not significant, except plasma hemoglobin, lactate dehydrogenase changes. A pattern of sequential changes of plasma hemoglobin, lactate deh-ydrogenase showed the highest level at the time of CPB stop and abrupt decrease in following 24 hours in both groups, and statistically significant differences were demonstrated in group FDP at least for the first 12 hours postoperatively[p<0.05]. The authors conclude that they can expect the benificial effect of FDP on the maintenance of membrane stability of RBC probably by energy enhancement during the shock status of CPB, but FDP could not completely prevent the damaging effect on RBC by cardiopulmonary bypass

• Journal of Chest Surgery
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• 제37권10호
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• pp.817-826
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• 2004

배경: 심혈관 수술 시 일반적으로 사용하는 저체온 체외순환이 세포의 저체온 손상, 말초혈관계의 비정상적 반응 및 수술 후 높은 출혈 경향을 일으키는데 비해 정상체온 체외순환은 이러한 저체온 체외순환의 유해한 효과들을 예방하고 심장의 빠른 회복을 가져다준다고 한다. 저자들의 연구는 염증 및 혈액학적 반응에 대한 저체온 체외순환과 정상체온 체외순환의 영향을 비교하기 위해 전향적으로 실시되었다. 대상 및 방법: 심장수술이 계획된 34명의 성인 환자들을 연구목적에 따라 무작위로 저체온 체외순환군(비인두 온도 26～28$^{\circ}C$, n=17, 저체온군)과 정상체온 체외순환군(비인두 온도&35.5$^{\circ}C$, n=17, 정상체온군)으로 나누었다. 심근보호는 양 군 모두 비혈액성 냉각심정지법을 적용하였다. 환자들로부터 체외순환 시작 전(Pre-CPB), 체외순환 실시 10분(CPB-10), 체외순환 종료 후(CPB-OFF)에 요골동맥으로부터 혈액을 채취하여 총 백혈구 수, 혈소판 수, interleukin-6 (IL-6)농도의 변화율(백분율로 표시), D-dimer 농도, protein C 활성도 및 Protein S 활성도를 측정하였고 수술 후 24시간 출혈량, 혈액제제 사용량도 조사하여 양 군 간에 비교 평가하였다. 결과: Pre-CPB에 비해 CPB-OFF의 경우 정상체온군의 총 백혈구 수(10,032$\pm$65/mm$^3$) 및 IL-6 증가율(353$\pm$7.0%)이 저체온군의 총 백혈구 수(7,254$\pm$$48/mm^3$) 및 IL-6 증가율(298$\pm$7.3%)보다 유의하게 높았다(p=0.02 및 p=0.03). 그러나 정상체온군의 protein C activity (32$\pm$3.8%) 및 protein S activity (35$\pm$4.1%)는 저체온군의 protein C activity (45$\pm$4.3%) 및 Protein S activity (51$\pm$3.8%)보다 유의하게 낮았다(p=0.04 및 p=0.009). 체외 순환 중 혈소판 수와 D-dimer농도의 변화는 양 군 간에 유의한 차이가 없었다. 정상체온군의 수술 후 24시간 출혈량(850$\pm$23.2 mL) 및 수혈을 위한 농축적혈구(1,402$\pm$20.5 mL), 신선냉동혈장(970$\pm$20.8 mL), 농축 혈소판(252$\pm$6.4 rnL) 사용량은 저체온군의 수술 후 24시간 출혈량(530$\pm$21.5 mL) 및 수혈을 위한 농축적혈구(696$\pm$15.7 mL), 신선냉동혈장(603$\pm$18.2 mL), 농축혈소판(50$\pm$0.0 mL) 사용량보다 유의하게 더 높았다(p=0.04 및 p=0.01, p=0.04, p=0.01). 결론: 정상체온 체외순환은 저체온 체외순환에 비해 더 높은 염증반응, 수술 후 더 많은 출혈 및 혈액제제 사용량의 증가를 유발하므로, 저자들은 심장수술시 정상체온 순환법을 일상적으로 사용하기 위해서는 더 많은 연구가 필요할 것으로 생각한다.

• Journal of Chest Surgery
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• 제33권5호
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• pp.407-418
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• 2000

Background: With open heart surgery(OHS), it has been recognized that many postoperative complications and postperfusion syndrome are associated with the activations of complements and leulocytes. Recently, some investigators also demonstrated that interlukin-6(IL-6) linked highly with postperfusion syndrome. The puropose of this study was to investigate the sequential changes of the IL-6 and to clarify each IL-6 relationship to the complements(C3, C4) and inflammatory response following cardiopulmonary bypass(CPB). Material and Method: To determine serum levels of IL-6, complements, leukocytes, and biochemistric markers of liver and renal function, blood samples were taken from th radial artery in 30 adult patients undergoing OHS with CPB. Result: Serum IL-6 levels incrased significantly at 10 minutes after CPB-on(CPB-10) in comparison with the control levels and reached the peak at CPB-off(p<0.05). Serum complement levels declined rapidly at CPB-10 and remained at the lower levels during CPB(p<0.01). Sequential changes of IL-6 levels had positive correlations with the changes of total leukocytes and neutrophil fractions(p<0.05), but had negative correlations with lymphocyte fractions(p<0.05). Changes of C3 related postively to monocyte fractions(p<0.05). Postoperative levels of total protein and albumin, decreased significantly in comparison with the control levels(p<0.01), while the postoperative levels of AST(aspartate transaminase) and bilirubin increased (p<0.01). At CPB-off, IL-6 levels had negative correlations with total protein and albumin levels(r=-0.60, -0.47 respectively, p<0.05), whereas C3 levels had positive correlations with albumin levels(r=0.40, p<0.05). IL-6 levels, as well as neutrophil fractions, had positive correlations with aortic clamp time(ACT) and total bypass time(TBT) (IL-6; r=0.82, 0.79 respectively, neutrophil fractions; r=0.50, 0.56 respectively, p<0.05), wheres lymphocyte frations and albumin levels had negative correlations whith ACT and TBT(lymphocyte fractions; r=-0.52, -0.58 respectively, albumin; r=-0.58, -0.55 respectively, p<0.05). Conclusion: These data showed that elevated production of serum IL-6 during CPB may play a pivotal role in systemic inflammatory responses and prologed CPB period may be assosiated with more sever postperfusion syndromes.

• 생명과학회지
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• 제18권11호
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• pp.1493-1498
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• 2008

본 연구는 심폐바이패스를 이용한 성인 심장수술 시 수술 후 환자의 회복 결과에 영향을 미치는 인자들을 규명하기 위해 시행하였다. 성인 심장수술 환자 32명을 대상으로 하여 연구하였다. 심장수술 시 밸혈구 수, GOT, troponin-I (cTNI), interleukin-6 (IL-6), endothelin-1 (ET-1), D-dimer, neuron-specific enolase (NSE) 등의 혈장농도는 유의하게 증가한데 비해 혈소판 수는 감소하였다. 수술 직후 GOT 및 D-dimer 농도와 24 시간 및 총출혈량, 기계호흡보조 시간, 중환자실 치료기간, 재원일수와 각각 양의 상관성이 있었다. 혈소판 수와 기계호흡보조 시간, 중환자실 치료기간, 재원일수와 각각 음의 상관관계가 있었다. Creatinine 농도와 기계호흡보조 시간, 중환자실 치료기간 사이에 양의 상관성이 있었다. NSE 농도와 24 시간 출혈량 사이에 양의 상관관계를 보였다. cTNI 농도와 재원일수 간에 양의 상관성이 있었다. 대동맥 교차차단 및 총심폐바이패스 실시 시간과 24 시간 및 총 출혈량, 재원일수 사이에 양의 상관관계를 나타내었다. 결론적으로 본 연구의 결과들은 심폐바이패스를 적용한 성인 심장수술 시 수술 후 환자의 결과와 회복에 영향을 미치는 가장 중요한 변수는 수술 종료 직후(CPB-off)의 GOT, BUN, creatinine, D-dimer 등의 농도와 혈소판 수임을 시사하고 있다.

• Journal of Chest Surgery
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• 제38권1호
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• pp.29-37
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• 2005

저자득은 최근 논의되고 있는 정상체온 체외순환의 임상적 유용성과 생리학적 영향을 규명하기 위해 저체온 체외순환과의 비교 연구를 시행하게 되었다. 대상 및 방법: 심장수술이 계획된 36명의 성인 환자들을 연구목적에 따라 무작위로 중등도 저 체온 체외순환군(이하 저체온군, 비인두 온도$26\~28^{\circ}C,\;n=18)$과 정상체온 체외순환군(이하 정상체온군, 비인두 온도>,$35.5^{\circ}C,\;n=18)$으로 나누었다. 전체 환자들로부터 체외순환 전, 체외순환 중, 체외순환 종료 직후에 각각 혈액을 채취하여 총 백혈구 수, neuron-specific enolase 증가율(NSE), interleukin-6 증가율(IL-6), endothelin-1 (ET-1), cortisol 증가율, troponin I (TNI), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, blood urea nitrogen (BUN)을 측정하였다. 그 외 수술 중 소변 배출량, 수술 후 페지수$(PaO_{2}/FiO_{2}),$ 기계호흡 보조시간, 중환자실 치료기간, 합병증, 재원일수 등을 조사하여 양 군 간에 비교 평가하였다 결과: 정상체온군이 저체온군에 비해 심장수술 동안 총 백혈구 수, NSE 증가율, IL-6 증가율, cortisol 증가율은 유의하게 더 높았으나 소변 배출량은 더 낮았다. 또한 기계 호흡 보조 시간, 중환자실 치료기간, 재원일수 역시 정상체온군이 저체온군보다 유의하게 더 길었다. 결론: 저자들의 연구 결과를 볼 때 정질 냉각 심정지액을 이용한 심장 수술 동안 정상체온 체외순환은 중등도저체온 체외순환보다 더 높은 염증 및 스트레스 반응을 유도하여 생리학적으로 유해할 것으로 생각된다. 그러나 좀더 많은 환자 수를 대상으로 한 추가적 연구가 필요할 것으로 판단된다.

• 한국염색가공학회지
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• 제29권3호
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• pp.155-161
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• 2017

In CPB(Cold-Pad-Batch) dyeing, the rubber of the padder roll is influenced by the heat, chemical and mechanical influences and thus aging of the padder roll rubber occurs. This study presents an accelerated thermal aging test of the CPB padder roll rubber with strong alkali conditions. Using Arrhenius formula of the various property values for the various aging temperatures($80^{\circ}C$, $90^{\circ}C$, $100^{\circ}C$) of the padder roll, the accelerated life predictions could be calculated. The threshold value of the property was set at different values. The hardness was set at the point where 5% degradation occurs based on the actual use conditions, and the tensile strength was set at the point where 50% degradation occurs based on the general life prediction standards. From the results of the different physical properties at differing temperatures, the Arrhenius plot could be obtained. Through the usage of the Arrhenius Equation, significant duration expectation could be predicted, and the chemical aging behavior of the CPB padder roll could be found at the arbitrary and actual temperatures.

• Journal of Chest Surgery
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• 제26권10호
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• pp.743-748
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• 1993

Alterations in thyroid function test results are frequently seen in patients with nonthyroidal illness & correlate with the severity of the illness & prognosis. We studied thyroid hormone changes in 14 patients received cardiopulmonary bypass[CPB]. All patients were biochemical euthyroidism preoperatively. TSH[Thyroid Stimulating Hormone] level reached its nadir[0.46 $\pm$ 0.11 ulU/ml, P<0.0005] at 12 hours after the start of CPB & showed elevating pattern to the preoperative level thereafter. FT4[Free Thyroxine] reached to its nadir[10.16$\pm$ 1.17 pmol/L, P<0.01] at POD[Post Operative Day] #4 & reached to the preoperative level at POD #7. Mean serum TSH & FT4 concentration were within normal limits[P>0.25] during CPB & thereafter. TT3[Total Triiodothyronine] reached to its nadir[38.6 $\pm$ 8.4 ng/dl, P<0.001] at 30 minutes after the start of CPB & remained low[P<0.05] throughout the study period. The patients whose recovery was uneventful[Group I] had higher serum TSH, TT3 levels[P<0.05] than who had complications or died[Group II]. Group I showed the elevating pattern of TSH, TT3 at POD #4, but Group II failed to show such elevating pattern. In Group I, FT4 was within normal limits[P>0.5] throughout the study period, and also within normal limits[P>0.1] in Group II.

• Clinical and Experimental Pediatrics
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• 제57권5호
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• pp.222-225
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• 2014

Purpose: A recent study analyzing several cytokines reported that long cardiopulmonary bypass (CPB) time and long aortic cross clamp (ACC) time were accompanied by enhanced postoperative inflammation, which contrasted with the modest influence of the degree of hypothermia. In this present study, we aimed to examine the effect of CPB temperature on the clinical outcome in infants undergoing repair of isolated ventricular septal defect (VSD). Methods: Of the 212 infants with isolated VSD who underwent open heart surgery (OHS) between January 2001 and December 2010, 43 infants were enrolled. They were classified into 2 groups: group 1, infants undergoing hypothermic CPB ($26^{\circ}C-28^{\circ}C$; n=19) and group 2, infants undergoing near-normothermic CPB ($34^{\circ}C-36^{\circ}C$; n=24). Results: The age at the time of the OHS, and number of infants aged<3 months showed no significant differences between the groups. The CPB time and ACC time in group 1 were longer than those in group 2 (88 minutes vs. 59 minutes, P =0.002, and 54 minutes vs. 37 minutes, P =0.006 respectively). The duration of postoperative mechanical ventilation was 1.6 days in group 1 and 1.8 days in group 2. None of the infants showed postoperative neurological and developmental abnormalities. Moreover, no postoperative differences in the white blood cell count and C-reactive protein levels were noted between two groups. Conclusion: This study revealed that hypothermic and near-normothermic CPB were associated with similar clinical outcomes and inflammatory reactions in neonates and infants treated for simple congenital heart disease.

• Journal of Chest Surgery
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• 제28권7호
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• pp.649-657
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• 1995

From December 1993 to April 1994, to investigate complement activation and pulmonary leukostasis, thirty adult patients were studied during cardiopulmonary bypass[CPB for cardiac surgery in Department of Cardiovascular & Thoracic Surgery, Pusan Paik Hospital, Inje University. Total patients were divided into group I and II according to the purpose of study ; Group I was 15 patients undergoing CPB with bubble oxygenator, Group II was 15 patients undergoing CPB with membrane oxygenator. The results of study were summarized as follows.1. The decrease of C3 and C4 levels were observed within few minutes of beginning of CPB in all patients[P<0.05 , and this decrease was proved to be due to complement activation, not by the influence of hemodilution.2. In the correlation between the change of C3 and C4, group I showed linear correlation each other suggesting complement activation occurred through the classical pathway, group II showed a correlation at only partial sampling times suggesting complement activation via both classical and alternative pathway, however there was no significant statistical difference at the change of C3 and C4 concentrations in two groups[P>0.05 .3. After switching to partial CPB, a few difference between right atrial and left atrial WBC count was observed, but statistically not significant and median cell count difference between group I and II was not significant, too [P>0.05 . With the above result, we concluded that CPB itself contributes to the activation of complement system, but bubble oxygenator does not activate always complement system more than membrane oxygenator.