• The korean journal of orthodontics
• /
• v.37 no.5
• /
• pp.376-385
• /
• 2007

Esthetic brackets which resemble the color of natural teeth have been widely used. But the frictional resistance of ceramic brackets, a typical esthetic bracket, is greater than that of metal brackets. The purpose of this study was to measure the frictional resistance of the new calcium phosphate brackets (CPB) which were recently developed and to evaluate its clinical usability by comparing the frictional differences of CPB with metal brackets and metal slot inserted ceramic brackets. Methods: Experimental groups were CPB (Hyaline II, Tomy, Tokyo, Japan), metal bracket (Kosaka, Tomy, Tokyo, Japan) and metal slot inserted ceramic bracket (Clarity, 3M Unitek, Monrovia, CA, USA). All of the brackets had 0.022-inch slot sizes. The brackets were tested with $0.019\;{\times}\;0.025$ inch stainless steel wire (3M Unitek, Monrovia, CA, USA). A biologic model was used to simulate the situation which would occur during orthodontic treatment with fixed appliances. Retraction force was applied at a speed of 5 mm/min for 30 seconds. The frictional resistance was measured on a universal testing machine (Instron 4467, Instron, Norwood, MA, USA). Results: CPB showed significantly higher friction than metal brackets (p < 0.05) and lower friction than metal slot inserted ceramic brackets (p < 0.01). Conclusions: CPB can be considered to be a useful orthodontic esthetic bracket with respect to frictional resistance, as its friction is remarkably lower than that of metal slot inserted ceramic brackets.

• Journal of Life Science
• /
• v.18 no.11
• /
• pp.1551-1560
• /
• 2008

Cytokines play a pivotal role in systemic inflammatory response following cardiac surgery with cardiopulmonary bypass (CPB). The purpose of this study was to investigate the perioperative changes in proinflammatory [tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and interleukin-6 (IL-6)] and antiinflammatory cytokines [interleukin-10 (IL-10)], and each correlation between the cytokines and other variables in valvular heart surgery with CPB. Serum IL-6 and IL-10 levels and leukocyte counts significantly increased following CPB. CPB caused hepatic, renal and myocardial dysfunctions. IL-6 levels had positive correlations with IL-10 levels at postoperative periods. TNF-$\alpha$ levels had correlations with leukocyte counts and myocardial marker levels at postoperative 24 hr (PO-24 h). Furthermore, IL-6 or IL-10 levels had positive correlations with other variable such as hepatic, renal or myocardial marker at postoperative periods. These results showed that balance between proinflammatory and antiinflammatory cytokines is maintained during cardiac surgery with CPB, and that these cytokines exert postoperatively inflammatory and antiinflammatory reactions.

• Journal of Chest Surgery
• /
• v.30 no.2
• /
• pp.131-136
• /
• 1997

The hemodynamic effects of thyroid hormones which is well established, affect myocardial contractility, heart rate, and myocardial oxygen consumption. The alterations in thyroid function test are frequently seen in patients with nonthyroidal illness and often correlate with the severity of the illness and the prosnosis. In this study, thyroid hormone changes were investigated in 20 patients who received cardiopulmonary bypass(CPB). All patients showed a state of biochemical euthyroidism preoperatively: The results were as follows : 1. Serum triiodothyronine(73) reached to its nadir(30.05 $\pm$ 17.5ng/dl, p(0.001) at 10 minutes after the start of CPB and remained low(p(0.05) throughout the study period. 2. Serum thyroxine(74) concentr tion slightly decreased after CPB, but maintained within normal range. 3. Serum free thyroxine(W4) concentration slightly increased after CPB, but maintained within normal range. 4. Serum thyroid stimulating hormone(TSH) concentration increased 10 minute after CPB, reached to its nadir(3.37 $\pm$ 0.81u1U/m1, p(0.001) at 2 hours after CPB. After then, serum TSH concentration decreased and reached its normal levels at 24 hours after CPB. 5. The patients whose postoperative recovery was uneventful(Group 1) had higher serum 73 levels than those who had postoperative complications(Group 2)(p<0.05). Group 1 showed elevating patterns of serum 73 in the fourth day after operation, whereas group 2 did not show such an elevating pattern. These findings are similar to the euthyroid sick syndrome seen in severely ill patients and indicate that patients undergoing open heart surgery have suppression of the pituitary-thyroid axis.

• Journal of Chest Surgery
• /
• v.31 no.10
• /
• pp.964-972
• /
• 1998

Background: The purpose of this study was to independently evaluate the beneficial effects of a high dose of transamine administrated prior to CPB on the postoperative hematologic aspect and bleeding. Materials and methods: This study included randomly selected groups of 40 adult patients undergoing OHS with CPB. All patients were divided into 2 groups: transamine group (T-group, n=20) and placebo group(P-group, n=20). The T-group received a high-dose of transamine(10 g) before and during CPB. The P-group received normal saline at the same times and served as a control group. Results: The results of comparative studies between the 2 groups in the same hematologic variables were summarized as follows. \circled1 During CPB, the fibrinogen concentrations and platelet counts were significantly lower in the P-group than in the T-group(p<0.01). \circled2 During CPB, production of D-dimer occurred in 18 patients(90%) in the P-group and did not occur in the T-group(0%) (p<0.0001). \circled3 At CPB-off, the % concentration of fibrinogen(70.2$\pm$3.9%) and the % platelet counts(72.4$\pm$4.5%) of the T-group were significantly higher than those(54.5$\pm$3.8%, 64.3$\pm$2.9%) of the P-group(p<0.01). \circled4 Postoperative values of PT(14.0$\pm$0.03 sec.) and aPTT (27.6$\pm$0.1 sec.) of the T-group were significantly lower than those(16.0$\pm$0.02sec., 30.1$\pm$0.1sec.) of the P-group(p<0.05). \circled5 Postoperative bleeding and requirement of whole blood and other blood products were significantly less in the T-group than in the P-group(p <0.05). \circled6 There were no significant hypercoagulability signs such as cerebral em bolism, myocardial infarction, pulmonary embolism, or any other neurological prob lems in either group. Conclusions: We concluded that a high dose of transamine administered prior to CPB prevents the activation of fibri nolytic system and has beneficial effects of reducing the postoperative bleeding t endency without apparent hypercoagulability signs.

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2001.05a
• /
• pp.32-32
• /
• 2001

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2004.04a
• /
• pp.207-210
• /
• 2004

• Journal of Chest Surgery
• /
• v.19 no.2
• /
• pp.238-242
• /
• 1986

The prognosis of patients with VSD and pulmonary hypertension is at least partially related to the reversibility of pulmonary hypertension after surgery. To predict postoperative pulmonary arterial pressure, immediate postbypass values were compared with preoperative hemodynamic data in 18 surgically closed VSD patients aged 6 to 80 months. The following results were obtained. 2] There was a good correlation between preoperative PP/PS and postoperative PP/PS in patients aged over 24 months [r=0.685, p<0.05], and in patients whose QP/QS were over 2.0 [r=0.686, p<0.01]. 3] There was also a good correlation between pump time and postoperative PP in total patients [r=0.697, p<0.005]. 4] Direct correlations were found between preoperative PP/PS and immediate postbypass PP/PS in patients aged over 24 months and in patients whose QP/QS>2.0, but the effect of CPB would participate in some degree. So it may be necessary to reevaluate their relationship after the effect of CPB have been disappeared.

• Journal of Chest Surgery
• /
• v.30 no.3
• /
• pp.326-329
• /
• 1997

Coronary artery bypass grafting(CABG) without cardiopulmonary bypass(CPB) is now an accepted technique of myocardial revascularization in selective cases of coronary arterial occlusive disease. The lesion was total(100%) occlusion of proximal right coronary artery(RCA) without any evidence of dis,Base in the rest of coronary arteries. Percutaneous transluminal angioplasty(PTCA) was tried but unsuccessful. We herein report a case of successful CABG to right coronary artery without CPB on a patient with complete occlusion of RCA and symptomatic wit minimal activity.

• Journal of Information Processing Systems
• /
• v.3 no.2
• /
• pp.73-81
• /
• 2007

In this paper, we introduce a domain-independent classification framework based on both k-nearest neighbor and Naive Bayesian classification algorithms. The architecture of our system is simple and modularized in that each sub-module of the system could be changed or improved efficiently. Moreover, it provides various feature selection mechanisms to be applied to optimize the general-purpose classifiers for a specific domain. As for the enhanced classification performance, our system provides conditional probability boosting (CPB) mechanism which could be used in various domains. In the mood classification domain, our optimized framework using the CPB algorithm showed 1% of improvement in precision and 2% in recall compared with the baseline.

• Journal of Chest Surgery
• /
• v.24 no.3
• /
• pp.287-291
• /
• 1991

Intra-aortic balloon pump [IABP] was applied to 12 patients between July, 1987, and September, 1990. The 12 patients included 8 who were assisted with IABP intraoperatively; 4 patients used IABP postoperatively. 8 patients could not be withdrawn from cardiopulmonary bypass [CPB], but 6 of them [75%] were able to separate from CPB with IABP. They all were withdrawn from the balloon. Four [50%] of them are hospital survivors, and alive at the time of this report. 4 additional patients were assisted with IABP, postoperatively. 2 of them [50Yo] were withdrawn from the balloon but died. The overall survival and balloon weaning rates are 33.3% [4/12] % 66.7% [8/12], respectively. IABP was most effective when applied early to patients who had transient and reversible injury to the myocardium.