• Biomedical Science Letters
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• v.11 no.2
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• pp.103-108
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• 2005

2-Deoxyribonolactone (dL) arises as a major DNA damage induced by a variety of agents, involving free radical attack and oxidation of C1'-deoxyribose in DNA. We investigated whether dL lesions can be repaired in mammalian cells and the mechanisms underlying the role of DNA polymerase $\beta$ in processing of dL lesions. Pol $\beta$ appeared to be trapped by dL residues, resulting in stable DNA-protein cross-links. However, repair DNA synthesis at site-specific dL sites occurred effectively in cell-free extracts, but predominantly accompanied by long-patch base excision repair (BER) pathway. Reconstitution of long-patch BER demonstrated that FEN1 was capable of removing the displaced flap DNA containing a 5'-dL residue. Cellular repair of dL lesions was largely dependent on the DNA polymerase activity of Pol $\beta$. Our observations reveal repair mechanisms of dL and define how mammalian cells prevent cytotoxic effects of oxidative DNA lesions that may threaten the genetic integrity of DNA.

• Steel and Composite Structures
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• v.20 no.6
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• pp.1173-1182
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• 2016

The objective of this work was to evaluate the ductile cracked structures with bonded composite patch used in probabilistic elastic plastic fracture mechanics subjected to tensile load. The finite element method is used to analyze the stress intensity factors for elastic case, the effect of cracks and the thickness of the patch ($e_r$) are presented for calculating the stress intensity factors. For elastic-plastic the Monte Carlo method is used to predict the distribution function of the mechanical response. According to the obtained results, we note that the stress variations are important factors influencing on the distribution function of (J/Je).

• Composites Research
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• v.12 no.4
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• pp.17-24
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• 1999

Finite element analysis and experiment are performed to investigate residual deformation induced by the repair of composite shell structures using a prepreg patch method. The finite element program is developed on the basis of a three-dimensional degenerated shell element and the first order shear deformation theory. The results analyzed for the laminated shell with free boundary conditions are compared with strains measured during the prepreg patch repair. Final residual stresses occur greatly near the patch when the laminated shell with all edges clamped is repaired using the prepreg patch. Stacking sequences of the laminated shell and patch affect significantly the residual stresses which occur even if they are the same.

• Journal of Chest Surgery
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• v.21 no.3
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• pp.574-582
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• 1988

Endocardial cushion defects is a rare congenital heart disease. We experienced two complete endocardial cushion defects[ECD] and three partial ones, which were successfully repaired between 1986 and 1987. In a patient of complete ECD, associated with secundum ASD, Pulmonary stenosis and Down`s syndrome, the atrial and ventricular septal defects were closed separately with bovine pericardium and Dacron patches respectively, and then pulmonary stenosis was relieved by transannular patch widening in addition to valvotomy and infundibulectomy. In another patient with complete ECD, small interventricular communication was closed with simple suture with pledget and primum ASD was closed with pericardial patch. In first patient of partial ECD, primum atrial septal defect was closed with pericardial patch. In second patient of partial ECD, associated with secundum ASD, direct closure of secundum ASD and patch closure of primum ASD were performed. In third patient of partial ECD, associated with patent foramen ovale[PFO], primum ASD was closed with bovine pericardial patch and PFO was closed directly. In all patient except third patient of partial ECD, mitral clefts were closed with three or four 5-0 prolene interrupted sutures. Transient A-V dissociation developed postoperatively in two patients and transient nodal rhythm developed postoperatively in other two patients. Heart failure in complete ECD with Down`s syndrome was overcome with medical treatment.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.148-152
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• 2000

The aluminum alloy 6061-T6 has been successfully used in structural applications especially the pressure vessel of the Advanced Neutron Source research reactor. And aluminum alloys, including 6061-T6, have a face-centered-cubic crystals structure. Under normal circumstances face-centered-cubic crystal structures do not exhibit cleavage fractures even at very lo9w temperatures. In aluminum-based structures, plates frequently find use as connecting links. Mechanical fasteners are often utilized in instances where ease of application, familiarity with fabrication processes, and severe dynamic loading are of concern. Plates frequently find use as connecting elements in structures built from aluminum alloys. Many structural elements employ mechanical fasteners. Twenty and twenty aluminum alloy 6061-T6 plates, representing four different bolt patterns, were mechanically deformed. And variable materials such as A1 6061-T6, Al 2024-T3, Carbon/Epoxy, Glass/Epoxy Composite and Woven fiber composite, are used as patch materials. From this experiment, it has been shown that the strength of patch-repaired specimens is different with the patch materials.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.2091-2099
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• 2001

Fatigue crack growth behavior of inclined cracked Al 6061-T6 thick aluminum plate(6mm) repaired with the bonded composite patch was studied. A 0°inclined crack bonded reinforced composite patch and 15°, 30°, 45°, 60°inclined crack plates were tested. The effect of patch and inclined angle were studied and compared to each other. Also we investigated to the crack propagation direction and debonding behavior during the fatigue crack growth test. In this paper. a study was con(ducted to get an fatigue life, fatigue crack growth ratio and crack growth direction. Finally, the effectiveness of composite patch on inclined cracked plate was investigated. The results demonstrated thats there was a definite variation in fatigue life and fatigue crack growth behavior depending on the inclined crack angle.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.2
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• pp.133-139
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• 2003

In order to extend the life time of building and civil infra-structure, nowadays, patch type fibrous composite materials are widely used. Repaired concrete columns and beams gain the stiffness and strength, but they lose toughness and show brittle failure. Usually, the cracks of concrete structures are visible with naked eyes and the status of the structure in the life cycle is estimated with visible inspection. After repairing of the structure, crack visibility is blocked by repaired carbon sheets. Therefore, structural monitoring after repairing is indispensible and self diagnosis method with optical fiber sensor is very useful. In this paper, peel-out effects is detected with optical fiber sensors and the strain difference between main structure and repaired carbon sheets when they separate each other.

• Journal of Chest Surgery
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• v.25 no.4
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• pp.383-390
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• 1992

From Oct. 1983 to Dec. 1991, 135 cases of atrial septal defect which were operated at the department of Thoracic and Cardiovascualr Surgery, Chonnam National University Hospital, were analysed retrospectively. They were 23.7% of all congenital heart diseases operated in the same period. Among the 135 cases, 62 cases were male and 73 cases were female. Their ages were ranged from 2 to 54 years and the mean was 18 years old. Main symptoms at admission were exertional dyspnea[70.37%], frequent URI[49.12%] and palpitation[32.59%], but 12 cases[8.88%] were asymptomatic. Electrocardiographic findings wer regular sinus rhythm in 96.99%, RVH in 64.66%, incomplete RBBB in 27.06%, complete RBBB in 42.10%, and first degree AV block in 9.02% All 135 cases were operated under the direct vision with cardiopulmonary bypass. Anatomically, most frequent type was fossa ovalis defect with complete septal rim[78.52%]. 117 of 135 ASD patients were repaired with pathch closure[86.66%] and 14 patients were repaired with direct closure[10.37%] and 4 patients in mutiple ASD were repaired with patch and direct closure[2.96%]. Postoperative complications were occured in 21 cases[15.56%], and they were wound infection, pleural effusion, postoperative bleeding, urinary tract infection, and heart failure mainly. One case died due to epidural hematoma and operative mortality was 0.74%.

• Journal of Chest Surgery
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• v.18 no.1
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• pp.7-12
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• 1985

The frequency of intraventricular conduction disturbance [IVCD] following right ventriculotomy and right atriotomy approach for ventricular septal defect [VSD] closure was compared in various conditions. Of the 170 isolated VSD patients, 114 patients were repaired via right ventriculotomy and 56 patients were repaired via right atriotomy. The results were as follows; 1. The frequency of IVCD was 45.6% in right ventriculotomy, and 21.2% in right atriotomy group [P<0.01]. The frequency of IVCD following transverse ventriculotomy and vertical ventriculotomy was not significantly different. 2. The frequency of IVCD in subarterial VSD following right ventriculotomy and right atriotomy was not significantly different. But the frequency of IVCD in perimembranous VSD was 50.8% in right ventriculotomy and 27.5% in right atriotomy group [P<0.01]. 3. The frequency of IVCD was higher in groups with larger VSD and it was more significant in right ventriculotomy group. 4. The frequency of IVCD was higher in patch graft closure and it was more significant in right ventriculotomy group. 5. Overall frequency of IVCD was lower in right atriotomy than right ventriculotomy group.

• Journal of Chest Surgery
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• v.22 no.6
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• pp.990-995
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• 1989

Since 1984, 24 patients underwent repair of atrioventricular septal defect. Nineteen had a partial defect and 5 had a complete atrioventricular septal defect. There were 9 men and 15 women, ranging in age from 1 to 50 years [mean age, 13.3 years]. Four patients had a Downs syndrome. Additional congenital heart defects were present in 11 patients. One patient had palliative operation prior to total correction. In partial defects, the primum atrial septal defect was closed with Xenomedica patch and the mitral valve was repaired with simple closure of the septal commissure. Central incompetence from annular dilatation was repaired by a local annuloplasty. In complete defect, the septal defects were closed with two patches except one. Operative mortality was 5% in partial defects and 60% in complete defects and low cardiac output was the commonest etiology. In a mean follow-up period of 27.9 months [range, 4 to 63 months] there were no late death and no instances of late-onset complete heart block. One patient required reoperation [MVR] for residual mitral regurgitation. The majority of patients were asymptomatic and mean postop. NYHA functional class was 1.2.