• Journal of Chest Surgery
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• v.18 no.3
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• pp.456-460
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• 1985

A case of Annuloaortic Ectasia associated with Marfan syndrome was treated by replacement of aorta and aortic valve with a valved conduit. A 26 years old man had suffered from palpitation and precordial pain. He had stigmata of Marfan`s syndrome. Aortogram and 2-D echocardiogram confirmed aneurysm of the ascending aorta with aortic insufficiency. Surgery was performed under the moderate hypothermia to 28oC. There was marked dilatation of the aortic annulus as well as sinus of Valsalva, with displacement of the coronary ostia. Aortic valve and aneurysm was replacement with 25mm, woven Dacron tubular graft, to which a 25mm, S.T. Jude Medical valve had been previously sutured. Right & left coronary ostia were anastomosed to the graft with the use of 3O Nylon pledget suture. The patient had a satisfactory post operation period with out specific complication.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.506-511
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• 1987

Increased clinical interest, stimulated by newer diagnostic techniques, has made it apparent that Ebstein`s anomaly represents a spectrum of right heart abnormalities. In the usual case, the septal and posterior leaflets of the tricuspid valve are not attached to the true annulus, but are displaced distally into the ventricle. Also the degree of malattachment and the structural deformities of the cusps may vary greatly. Recently we experienced 6 cases of Ebstein`s anomaly who underwent corrective operation in our hospital. Five patients were operated by plication and annuloplasty techniques based on the construction of a monocusp valve by the use of the anterior leaflet. Remained one was operated on by tricuspid valve replacement using No 31 mm C-E tissue valve. There was no operative mortality and the postoperative courses were relatively good with marked symptom improvement.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.718-730
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• 2004

The solution for the natural convection in internally finned horizontal annuli is obtained by using a numerical simulation of time-dependent and two-dimensional governing equations. The fins existing in annuli influence the flow pattern, temperature distribution and heat transfer rate. The variations of the On configuration suppress or accelerate the free convective effects compared to those of the smooth tubes. The effects of fin configuration, number of fins and ratio of annulus gap width to the inner cylinder radius on the fluid flow and heat transfer in annuli are demonstrated by the distribution of the velocity vector, isotherms and streamlines. The governing equations are solved efficiently by using a parallel implementation. The technique is adopted for reduction of the computation cost. The parallelization is performed with the domain decomposition technique and message passing between sub-domains on the basis of the MPI library. The results from parallel computation reveal in consistency with those of the sequential program. Moreover, the speed-up ratio shows linearity with the number of processor.

• Journal of Chest Surgery
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• v.11 no.2
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• pp.185-193
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• 1978

Between April 1976 and March 1978, six cases of tricuspid valve replacement were done in the Department of Thoracic Surgery, Seoul National University Hospital. There were 4 men and 2 women and the age of the patients ranged from 17 years of the youngest to 48 years of the oldest. Most of them had characteristic symptoms of tricuspid valve disease, such as a systolic murmur audible over the lower sternum and varying with respiration, pulsatile and distended neck vein, and an enlarged and pulsatile liver. Preoperative functional levels according to NYHA Calcification were class III in 4 cases, and class IV in 2 eases. Most of the cases showed moderate to severe cardiomegaly in chest films and elevated right atrial pressure on preoperative right heart catheterization. Five of them underwent concomittent mitral valve replacement and one pulmonary valvotomy. All of them showed tricuspid insufficiency resulted from massive dilatation of annulus, destructive lesions of valve structure, or both anomalies. One postoperative hospital death was encountered and the cause of death was low out-put syndrome. All survivors showed clinical improvement and cardiomegaly regressed and left hospital in a good condition . *Attendum; Recently 2 more cases of tricuspid valve replacement with mitral valve replacement were done after this review.

• Journal of Chest Surgery
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• v.21 no.3
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• pp.583-587
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• 1988

Bilateral coronary artery-pulmonary artery fistula is very uncommon congenital heart disease which occupy small percentage of all coronary arterio-venous fistulas. We experienced a case who was 52 years old female with bilateral coronary artery-pulmonary artery fistula. She complained exertional dyspnea k angina[coronary steal syndrome]. On physical examination, any cardiac murmur was not audible. There was no 0y step-up in right heart catheterization. But selective coronary angiography revealed tortuous aberrant vessels which originated from the canal branch of the right coronary artery k the left anterior descending coronary artery. Both aberrant vessels traversed the right ventricular outflow tract, and conjoined just proximal the pulmonic annulus and drained into the main pulmonary artery. The operation was performed under the extracorporeal circulation with beating heart. The procedures were suture-ligation of the draining orifice in main pulmonary artery & the feeding vessels on the right ventricular outflow tract. Postoperatively her complaints were completely disappeared and the selective coronary angiography revealed no left-to-right shunt.

• Journal of Chest Surgery
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• v.21 no.3
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• pp.518-525
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• 1988

Between 1977 and 1987, 8 patients underwent excision of cardiac myxomas at the Hanyang University Hospital. All had a left atrial myxoma. There were 4 female and 4 male patients ranging from 15 to 62 years of age. Preoperative findings consist of symptoms and signs of congestive heart failure except one. Diagnosis was confirmed by echocardiography[8 cases] and angiography[2 cases], preoperatively. A biatrial operative approach was utilized in all but 2, who were small sized. Complete excision of the tumor with a cuff of normal tissue[1 was atrial wall and 7 were atrial septum] was performed. all heart chambers were carefully explored for presence of multicentric myxomas or tumor debris. There were no operative deaths or intraoperative embolization. Follow-up has been 1/3 to 10 years. There has been 1 late death, due to recurrence and 1 patient had reoperation for mitral regurgitation due to dilatation of the annulus by a huge tumor mass. Surgical excision of the myxoma can be performed with low morbidity, and it provides excellent and sustained symptomatic relief. The recurrence rate is low, but long-term follow-up and serial echocardiography are advisable.

• Bulletin of the Korean Mathematical Society
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• v.57 no.2
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• pp.331-343
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• 2020

This paper is concerned with the global behavior of components of radial nodal solutions of semilinear elliptic problems -Δv = λh(x, v) in Ω, v = 0 on ∂Ω, where Ω = {x ∈ R^N : r₁ < |x| < r₂} with 0 < r₁ < r₂, N ≥ 2. The nonlinear term is continuous and satisfies h(x, 0) = h(x, s₁(x)) = h(x, s₂(x)) = 0 for suitable positive, concave function s₁ and negative, convex function s₂, as well as sh(x, s) > 0 for s ∈ ℝ \ {0, s₁(x), s₂(x)}. Moreover, we give the intervals for the parameter λ which ensure the existence and multiplicity of radial nodal solutions for the above problem. For this, we use global bifurcation techniques to prove our main results.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1252-1255
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• 1987

In this paper an approach for the analysis of the transient field response of radially symmetric transducer due to a wideband ultrasonic pulse is presented, which is based on a development of Green's function and applies the linear system theory to obtain an analytic expression for the impulse response of an annulus with a planar or spherical geometry. For the focused annular array, the impulse responses of the indivisual annuli are convolved with the delayed excitation pulse, and then summed to obtain the resultant response of the array. This process is very effective in the study of the various focusing abilities of the annular array. For illustration, the field distribution of a five element annular array is treated in detail for several focusing system.

• Journal of Korean Neurosurgical Society
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• v.47 no.3
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• pp.224-227
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• 2010

Small bowel injury resulting from unforeseen penetration of the anterior annulus fibrosus and longitudinal ligament is a rare complication of lumbar microdiscectomy. The patient complained of abdominal tenderness and distention immediately after microdiscectomy for L4-5 and L5-S1 disc herniation. Using abdominal computed tomography, we found several foci of air overlying the anterior aspect of the vertebral body at the L5-S1 level. Segmental resection of the small bowel including small tears and primary anastomosis of the jejunum were performed. Here, we present a case of intestinal perforation after lumbar microdiscectomy and discuss technical methods to prevent this complication with a review of literature.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.91-102
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• 2015

Analytical solutions for the forced convection heat transfer of viscoelastic fluids obeying the Giesekus model are obtained in a concentric annulus under laminar flow for both thermal and hydrodynamic fully developed conditions. Boundary conditions are assumed to be (a) constant fluxes at the walls and (b) constant temperature at the walls. Temperature profiles and Nusselt numbers are derived from dimensionless energy equation. Subsequently, effects of elasticity, mobility parameter and viscous dissipation are discussed. Results show that by increasing elasticity, Nusselt number increases. However, this trend is reversed for constant wall temperature when viscous dissipation is weak. By increasing viscous dissipation, the Nusselt number decreases for the constant flux and increases for the constant wall temperature. For the wall cooling case, when the viscous dissipation exceeds a critical value, the generated heat overcomes the heat which is removed at the walls, and fluid heats up longitudinally.