• Journal of Chest Surgery
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• v.22 no.4
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• pp.594-600
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• 1989

Primary intracardiac repair of tetralogy of Fallot with low mortality and early good results, has been accomplished in recent years. But palliative procedures have been reserved for those hypoplastic pulmonary arteries, a hypoplastic left ventricle or anomalies of the coronary artery would make total correction difficult. And the Blalock-Taussig shunt operation is recognized as a standard and popular palliative procedure. I undertook a retrospective determination of the effect of the Blalock-Taussig shunt operation on the development of the main pulmonary artery and the right and left pulmonary arteries. Between January, 1980, and April, 1987, at the Severance Hospital, 16 patients were studied by cardiac catheterization and angiocardiography, before undergoing Blalock-Taussig shunting procedures for the palliation of severe symptoms of tetralogy of Fallot, and some time later, usually prior to a second procedure. The mean interval between catheterizations was 22.25 months. Patients with tetralogy of Fallot and pulmonary atresia or with an occluded shunt were not included. The primary and secondary angiograms of each patient were reviewed, and measurements of the diameter of the main pulmonary artery, the right and left pulmonary arteries, and the descending thoracic aorta were taken. The results are as follows; 1. The hematocrit decreased from 56.39% to 50.34%[p< 0.05], and the arterial oxygen saturation increased from 62.00 % to 81.31 %[p< 0.001] following shunt procedures 2. The ratio of the diameter of the right pulmonary artery plus the left pulmonary artery to the diameter of the descending thoracic aorta increased 1.30 k 0.28 times [p< 0.01]; but the ratio of the diameter of the main pulmonary artery to the diameter of the descending thoracic aorta increased 1.10 * 0.33 times, which was not. significant[p< 0.05]. 3. The interval between shunting and second catheterization was not related to the magnitude of change in the pulmonary arteries[r=0.141, p >0.05]. 4. The changes in the ratio of the diameter of the right pulmonary artery plus the diameter of the left pulmonary artery to the diameter of the descending thoracic aorta was inversely related to the initial ratio[r=0.757, p >0.001], but the change in the ratio of the diameter of the main pulmonary artery to the descending thoracic aorta was not related[r=0.059, p >0.05]. 5. There were no differences in enlargement of the pulmonary artery on the side of the shunt [ipsilateral] versus enlargement on the opposite side [p >0.05], nor according to the size of the shunt[p >0.05]. In conclusion, this study suggests that the Blalock-Taussig shunt is effective for the development of the right and left pulmonary arteries but not effective for the main pulmonary artery.

• Journal of Chest Surgery
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• v.35 no.8
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• pp.580-583
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• 2002

Background: Obtaining precise hemodynamic and morphological information in the early postoperative period after surgical correction of congenital heart disease is important in determining the need for future medical or surgical intervention. We investigated the residual shunting after surgical repair of simple ventricular septal defect in order to know the incidence of residual shunting in the postoperative period and the natural history of small residual shunts located in the peripatch area. Material and Method: Forty three consecutive patients under one year of age who underwent patch repair of a simple ventricular septal defect were evaluated for incidence of residual shunts by echocardiography. Result: Eleven patients had echocardiographic residual shunt in the peripatch area at immediate postoperative period, however, there were no patients who needed reoperation due to deteriorated hemodynamic effect of residual shunt. The incidence of residual shunts was not significantly different with type of ventricular septal defect and material used for closure. During follow up period, two patients were lost and remaining nine patients no longer showed evidence of residual shunt. The mean time of last evidence of shunt was $4.2{\pm}3.6$ months after operation. Conclusion: Residual peripatch shunt flow was frequently noted in the immediate postoperative period following surgical repair of ventricular septal defect, however, most of them were disappeared within six months.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.32-38
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• 2020

This study examined the problems of existing vehicles to propose alternatives to improve the crashworthiness of railway freight cars through collision acceleration analysis using a one-dimensional collision analysis method. A collision scenario of railway shunting and crash accidents was selected from the collision accident cases and international standards. A one-dimensional collision simulation using LS-DYNA was performed according to those scenarios. As a result, the acceleration level of the freight wagon was calculated to be under 2g and was predicted to meet the EN 12663 standard in the shunting situation. On the other hand, the result of crash simulation with an impact velocity between 10 and 15 km/h revealed the shock absorber capacity of the railway coupler to be insufficient in a crash situation, resulting in increased acceleration, and carbody deformation could be predicted. As a method of improving the crashworthiness, a deformation tube-type energy absorber was applied to the coupler system, and collision analysis was performed again with new energy absorption strategy. Overall, the simulation showed that the acceleration level was decreased by 12% of the conventional freight-car energy absorption system.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.664-667
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• 2005

Hydrosyringomyelia is a dilation of the spinal cord central canal. In human it may be caused by congenital malformations such as Dandy-Walker syndrome and Chiari malformations or may be acquired as a result of infection, trauma or neoplasia. Hydrocephalus is an excessive accumulation of cerebrospinal fluid within the ventricles and occipital dysplasia is the dorsal extension of the foramen magnum. Hydrosyringomyelia and hydrocephalus can be confirmed by computed tomography or magnetic resonance imaging (MRI). A 3-year-old male maltese was presented with a history of long-term seizure. Blood examination was all unremarkable. On rostrodorsal-caudoventral oblique radiograph of the skull showed severe occipital dysplasia. On brain sonography through the persistent fontanelle, severe lateral ventriculomegaly was revealed. MRI examination revealed hydrocephalus and hydrosyringomyelia. Diuretic therapy didn't reduce clinical symptoms and surgical decompression was conducted. The dog responded well with ventriculo-peritoneal shunting. MRI is the most superior modality to diagnose hydrocephalus and hydrosyringomyelia, to plan therapy and to determine the prognosis.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1459-1467
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• 2011

This paper proposes the effective method to improve the protection from induced lightning Surge by making common grounding from individual grounding. Common grounding under equipotential principle is more effective than individual grounding for lightning Surge protection, and so common grounding is indicated as international technical standard under the AC power supply system with neutral line. So, this paper is to propose the effective way of induced lightning Surge protection method for currently installed power supply system which has no neutral grounded line and individual grounding which are weak for lightning Surge protection. This proposal can improve the power supply system as has neutral line, and improve the grounding system to common grounding system. And also this paper proposes to make effective equipotential system with voltage variable shunting devices for lightning Surge protection.

• Journal of Chest Surgery
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• v.50 no.6
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• pp.448-452
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• 2017

Background: Proper monitoring of cerebral perfusion during carotid artery surgery is crucial for determining if a shunt is needed. We compared the safety and reliability of near-infrared spectroscopy (NIRS) w ith transcranial Doppler (TCD) for cerebral monitoring. Methods: This single-center, retrospective review was conducted on patients who underwent carotid endarterectomy (CEA) using selective shunt-based TCD or NIRS at Daegu Catholic University Medical Center from November 2009 to June 2016. Postoperative complications were the primary outcome, and the distribution of risk factors between the 2 groups was compared. Results: The medical records of 74 patients (45 TCD, 29 NIRS) were reviewed. The demographic characteristics were similar between the 2 groups. One TCD patient died within the 30-day postoperative period. Postoperative stroke (n=4, p=0.15) and neurologic complications (n=10, p=0.005) were only reported in the TCD group. Shunt usage was 44.4% and 10.3% in the TCD and NIRS groups, respectively (p=0.002). Conclusion: NIRS-based selective shunting during CEA seems to be safe and reliable for monitoring cerebral perfusion in terms of postoperative stroke and neurologic symptoms. It also reduces unnecessary shunt usage.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.968-972
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• 2000

Post-shunting subdural hemorrhages are usually small and self-limited, and they can be recognized on the routine post-operative CT examinations. However, delayed subdural bleeding may occur without any clinical symptoms or signs. Thus the hematoma remains undetected, and it can be increased in size and sometimes become calcified with time. We experienced a case of 15-year-old male with a large calcified subdural hematoma who had undergone shunt operation 10 years previously. With pertinent review of the literatures, we discuss the possible mechanism of calcification and the proper way of treatment in calcified chronic subdural hematoma.

• Journal of Korean Neurosurgical Society
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• v.29 no.2
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• pp.255-260
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• 2000

The authors report a posttraumatic syringomyelia in a 30-year-old man who has complained pain, weakness of upper arm and dissociation sensory loss since 2 months before. He was underwent by decompressive laminectomy from T12 to L1, reduction of encroached bony fragments, transpedicular screw fixation from T12 to L2 and posterolateral bony fusion due to burst fracture of L1 at other hospital 3 years ago. Preoperative spinal MRI was highly suggestive of wide-spread, multiseptated syringomyelia from C3 to thoracolumbar junction. We performed wide decompressive laminectomy from T10 to L2 and subarachnoid space reconstrucion composed of microdissection of meningeal fibrosis widely, iatrogenic meningocele formation with lefting the dura mater opened for treatment of spinal-spinal pressure dissociation. Clinical manifestations and radiological findings of the patient were improved after the operation. This technique was thought to be superior to shunting procedures in cases of wide-spread, multiseptated post-traumatic syringomyelia.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.1
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• pp.1-19
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• 2014

Attaching a piezoelectric transducer to a vibrating structure, and shunting it with an electric circuit, gives rise to different passive, semi-passive, and semi-active control techniques. This paper attempts to review the research related to structural vibration control, via passive, semi-passive, and semi-active control methods. First, the existing electromechanical modeling is reviewed, along with the modeling methods. These range from lumped parameters, to distributed parameters modeling of piezostructural systems shunted by electrical networks. Vibration control laws are then discussed, covering passive, semi-passive, and semi-active control techniques, which are classified according to whether external power is supplied to the piezoelectric transducers, or not. Emphasis is placed on recent articles covering semi-passive and semi-active control techniques, based upon switched shunt circuits. This review provides the necessary background material for researchers interested in the growing field of vibration damping and control, via shunted piezostructural systems.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1200-1210
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• 2004

Metabolic flux analysis was established by adapting previous stoichiometric model developed during growth with cellulose to cell grown with cellobiose for further direct comparison of the bacterial metabolism. In carbon limitation with cellobiose, a shift from acetate-ethanol fermentation to ethanol-lactate fermentation is observed and the pyruvate overflow is much higher than with cellulose. In nitrogen limitation with cellobiose, the cellodextrin and exopolysaccharide overflows are much higher than on cellulose. In carbon and nitrogen saturation with cellobiose, the cellodextrin, exopolysaccharide, and free amino acids overflows reach the highest levels observed but all remain limited on cellulose. By completely shunting the cellulosome, the use of cellobiose allows to reach much higher carbon consumption rates which, in return, highlights the metabolic limitation of C. cellulolyticum. Therefore, the physical nature of the carbon source has a profound impact on the metabolism of C. cellulolyticum and most probably of other cellulolytic bacteria. For cellulolytic bacteria, the use of soluble carbon substrate must carefully be taken into consideration for the interpretation of results. Direct comparison of metabolic flux analysis from cellobiose and cellulose revealed the importance of cellulosome, phosphoglucomutase and pyruvate-ferredoxin oxidoreductase in the distribution of carbon flow in the central metabolism. In the light of these findings, future directions for improvement of cellulose catabolism by this bacterium are discussed.