• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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• pp.143-145
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• 2003

External shunt resistor is used in Nb/AlOx/Nb Josephson junction which is basic component of RSFQ circuit. This is to increase damping and to make the so called 'self-reset' optimized for high speed operation. In this study, we fabricated and investigated sheet resistance of Pd and PdAu thin film, and simulated the inductance effect of the shunt resistor to the Josepshon junction dynamics.

• Journal of Korean Neurosurgical Society
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• 제41권6호
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• pp.429-431
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• 2007

Although the ventriculo-peritoneal shunt is the treatment of choice when hydrocephalus should be corrected, the ventriculo-atrial shunt still holds strong alternative when the peritonium is precluded due to the several reasons. During the ventriculo-atrial shunt operation, it is not always easy to dissect and find the corresponding venous structures. In this technical note, the author describes a simple method of percutaneous insertion for placement of the atrial end.

• Journal of Korean Neurosurgical Society
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• 제43권6호
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• pp.300-303
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• 2008

Shunt infections are a common complication of ventriculoperitoneal (VP) shunts, but the formation of a brain abscess related to a shunt system is very rare. A 44-year-old woman had a VP shunt inserted for hydrocephalus secondary to a subarachnoid hemorrhage. She suffered an episode of meningitis and sepsis 8 months after the shunt operation. After recovering from the meningitis, she complained of a loss of cognitive function. An enhancing mass was found in the frontal lobe, around the frontal horn of the lateral ventricle, and the ventricular catheter was embedded inside the mass. The ventricular catheter and cerebral abscess were removed using neuroendoscopy. We present an interesting case of a shunt-related brain abscess which illustrates the usefulness of neuroendoscopy.

• Journal of Chest Surgery
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• 제22권2호
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• pp.256-264
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• 1989

Modified Blalock-Taussig operation remains the standard technique of systemic-to-pulmonary artery shunt in patients of congenital heart disease with decreased pulmonary blood flow. We reviewed the 41 patients who had been performed modified Blalock-Taussig operation from March 1985 to Feb. 1988, and angiographically measured pulmonary artery size before and after shunt, and calculated pulmonary artery index [PAI] and ratio of left and right pulmonary artery to descending aorta[[LPA+RPA]/dAo]. The mean duration of palliation after shunt operation was 624 days and mean age of the patient at shunt operation was 3.59 years. Mean PAI increased significantly from 131.15*67.11 mm2/M2 preoperatively to 232.70*84.46 mm2/M2 postoperatively. Mean ratio of right and left pulmonary artery to descending aorta also increased significantly from 1.48*0.40 preoperatively to 1.92*0.50 postoperatively. All patients manifested clinical improvement; there was mean decrease in hematocrit of 8.95%, mean increase in arterial oxygen saturation of 11.08%. Pulmonary arterial growth was not influenced by age at operation, initial pulmonary artery size, or graft size, but significantly influenced by antegrade flow. The patients who have some antegrade flow were in more increase of PAI. There were no linear correlation between change of PAI, change of [[LPA+RPA]/dAo], SaO2, and duration. But, according to Scatterplot between change of PAI and duration, some complex correlation was suggested and mean PAI was decreased after 2-year palliation. We concluded that modified Blalock-Taussig operation is excellent palliative surgery for pulmonary artery growth especially on the patient who have some antegrade flow, and the proper duration of palliation was about 2 years.

• Journal of Chest Surgery
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• 제28권8호
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• pp.754-758
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• 1995

Between February 1987 and April 1994,30 modified Blalock- Taussing shunts[MBTS were carried out at the Department of Thoracic and Cardiovascular Surgery of the Keimyung University Dongsan Medical Center.The operation consists of interposing between the subclavian artery and the pulmonary artery a polytetrafluoroethylene graft.There were 19 boys and 11 girls.The average age at the time of shunt construction was 14 months [range 4 days to 5 years .Seventy-six percent [23/30 were less than 1 year of age.Cardiac defects treated with MBTS included tetralogy of Fallot[10 , pulmonary atresia with ventricular septal defect[8 , pulmonary atresia with intact ventricular septum[4 , uni-ventricular heart[3 , and other complex cardiac anomalies[5 .Prosthesis of 4mm were used in 13 cases, and 5mm in 17.Of the 30 operations, 21 were performed on the right side and 9 on the left side.The hemoglobin level decreased from 21.1 gm/dl preoperatively to 16.3 gm/dl postoperatively and systemic oxygen saturation level increased from 60.5 % preoperatively to 85.4 % postoperatively.In the 30 patients who recieved MBTS, there were one early [3% and three late deaths [10% .Seven patients have had an corrective operation and two patient required second palliative procedure.The remaining patients are awaiting further operation with ingestion of aspirin [5 mg/kg/day as an antiplatelet agent.These results indicate that the MBTS provide excellent palliation at a low operative mortality for most patients.

• Journal of Korean Neurosurgical Society
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• 제52권4호
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• pp.320-324
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• 2012

Objective : The purposes of this study are to investigate the factors that may be related to ventriculoperitoneal (VP) shunt in patients with cerebellar hematoma and the effect of severe fourth ventricular hemorrhage, causing obstructive hydrocephalus on subsequent VP shunt performance. Methods : This study included 31 patients with spontaneous cerebellar hematoma and concomitant fourth ventricular hemorrhage, who did not undergo a surgical evacuation of hematoma. We divided this population into two groups; the VP shunt group, and the non-VP shunt group. The demographic data, radiologic findings, and clinical factors were compared in each group. The location of the hematoma (whether occupying the cerebellar hemisphere or the vermis) and the degree of the fourth ventricular obstruction were graded respectively. The intraventricular hemorrhage (IVH) score was used to assess the IVH severity. Results : Ten out of 31 patients underwent VP shunt operations. The midline location of cerebellar hematoma, the grade of fourth ventricle obstruction, and IVH severity were significantly correlated with that of VP shunt operation (p=0.015, p=0.013, p=0.028). The significant variables into a logistic regression multivariate model resulted in statistical significance for the location of cerebellar hemorrhage [p=0.05; odds ratio (OR), 8.18; 95% confidence interval (CI), 1.00 to 67.0], the grade of fourth ventricle obstruction (p=0.044; OR, 19.26; 95% CI, 1.07 to 346.6). Conclusion : The location of the cerebellar hematoma on CT scans and the degree of fourth ventricle obstruction by IVH were useful signs for the selection of VP shunt operation in patients with spontaneous cerebellar hematoma and concomitant acute hydrocephalus.

• Journal of Chest Surgery
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• 제33권1호
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• pp.7-19
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• 2000

Background :To assess the accuracy of Electron-Beam Tomography(EBT) in following evaluation of the pulmonary vascular system after a shunt operation in the cyanotic con-genital heart disease with pulmonary stenosis or pulmonary atresia. Material and Method : Sixteen patients(M:F=11:5) who received Blalock-Taussig(n=8) bidirectional cavo-pulmonary shunt(n=10) and unifocalization (n=2) were ncluded in the study. We evaluated the patency of the shunt the morphology of intrapericardial and hilar pulmonary arteries(PA) peripheral pulmonary vascularity by background lung attenuation and the abundance of arterial & venous collateral. Angiography(n=12) and echocardiography(n=20) were used as the gold standard for the comparison of EBT results. Result: EBT was consistent with angiogram/ echo in 100% of the evaluation for the patency of the shunt and in 12(by angiogram 100%) and 19(by echo 95%) for the detection the hypoplasia stenosis or interruption of central PA In measuring of PA EBT and angiogram corrlated(r=0.91) better than EBT-echo(r=0.88) or echo-angiogram(r=0.72) Abundant systemic arterial collateral were noted in 4 and venous collateral in 3 cases. In evaluating the peripheral pulmonary vascularity the homogenous and normal-ranged lung attenuation(m=6) decreased but homo-genous attenuation(n=1) segment-by-sgment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) segment-by-segment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) and venous congestion(n=2) were observed nd 12 of them were compatible with the blood flow pattern revealed by cardiac catheterization. Conclusion: EBT was accurate in the integrated evaluation of the pulmonary vascular system after the shunt including the patency of the shunt operaion the morphology and dimension of the central and hilar PAs and the loco-regional pulmonary flow in the lung parenchyma. It suggests the useful information about the need of secondary shunt operation the proper timing time for total repair and the need of interventional procedure prior to total repair.

• Journal of Chest Surgery
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• 제5권2호
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• pp.107-112
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• 1972

Recently we experienced a case of the portal hypertension, extrahepatlc origin in the National Medical Center, Seoul. The case was a male aged 19 who was undergone the elective splenorenal shunt with splenectomy 9 years ago and emergency ligation of the coronary vein because of recurred variceal rupture 6 years later and had recurring esophageal varices with bleeding this time.At the age of 10 he had been occasionally suffering from nasal bleeding and visited to our Pediatric department, when there was encountered for the first time the splenomegaly, esophageal varices in the lower third esophagus on the esophagogram, and stenosis and kinking of the portal vein with rich collateral circulation on the splenoportography without hepatic functional impairment.The elective splenorenal shunt with splenectomy was undergone under the diagnosis of portal hypertension due to congenital anomaly of the portal vein and postoperatlvely no troubles had been obtained until postoperative 1st attack of massive hematemesis due to esophagenl variceal rupture recurred about 6 years later which was confirmed by control esophagogram and it was resulted by stenosis of previous anastomotic site of the splenorenal shunt.Then emergency ligation of the coronary vein was only made for bleeding control and no episodes of hematemesis had been encountered thereafter until April 1972 about 3 years after the 2nd operation, when hematemesis recurred again. In this time, recurring esophageal varices were noted in the lower third esophagus on the control esophagogram and he was employed side to end mesocaval shunt as the final step of portal decompression,and following results were obtained. 1] No postoperatlve troubles as leg edema or pain: Postoperatively leg elevation and elastic bandage on the both legs were employed until discharge. 2] During operation the portal pressure was 300 mm $H_2O$ and immediately lowered to 170 mm $H_2O$ after shunt.

• Journal of Chest Surgery
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• 제21권1호
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• pp.55-61
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• 1988

This report provides follow-up data on 116 patients with congenital cyanotic heart disease, aging 1 month to 13 years [median: 1.8 years], who underwent the modified Blalock-Taussig shunt using polytetrafluoroethylene graft at Seoul National University Hospital between September, 1984 and June, 1987. Among 116 patients complete follow-up studies were done on 95 patients. The mean preoperative arterial oxygen tension was 36 torr. Thirty-Six patients [38%] underwent operation in infancy. Conduit diameters included 4mm [15 cases], 5mm [47 cases], and 6mm [33 cases] sizes. The mean postoperative arterial oxygen tension was 52 torr [P<0.001]. The effectiveness of shunts was evaluated clinically and by shunt murmur, echocardiography and cardiac catheterization with angiography 1 to 31 months after operation. The incidence of shunt occlusion was 9.5% and the mortality was 14.8%. The actuarial patency rate was 83.1 * 6.4% and the actuarial survival rate was 82.5 * 4.5% at 30 months` follow-up for all patients. The effectiveness of the 4mm diameter conduit may be limited. Blalock-Taussig procedure is an effective alternative to the classic B-T shunt in congenital cyanotic heart disease.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.285-288
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• 2001

In this paper we proposed the on line volt/var control schemes of the load Tap Changer (LTC) transformer and shunt capacitor bank for distribution volt/var regulation. In the existing volt/var control of the distribution substation, the voltage of feeders and var of distribution systems is mainly controlled by the LTC transformer tap position and on/off status of the shunt capacitor. The LTC and shunt capacitor bank has discrete operation characteristics and therefore it is very difficult to control volt/var at the distribution networks within the satisfactory levels. Also there is limitation of the operation times of the LTC and shunt capacitor bank because it is affects on their functional lifetime. The proposed volt/var control algorithm determine an optimal tap position of LTC and on/off status of shunt capacitors at a distribution network with the multiple feeders. The mathematical equations of the proposed method are introduced. Simple case study was performed to verify the effectiveness of the proposed method.