• Steel and Composite Structures
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• 제24권5호
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• pp.549-559
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• 2017

As few multi-tower single-box multi-cell cable-stayed bridges with corrugated steel webs have been built, analysis is mostly achieved by combining single-girder model, beam grillage model and solid model in support of the design. However, such analysis methods usually suffer from major limitations in terms of the engineering applications: single-girder model fails to account for spatial effect such as shear lag effect of the box girder and the relevant effective girder width and eccentric load coefficient; owing to the approximation in the principle equivalence, the plane grillage model cannot accurately capture shear stress distribution and local stress state in both top and bottom flange of composite box girder; and solid model is difficult to be practically combined with the overall calculation. The usual effective width method fails to provide a uniform and accurate "effective length" (and the codes fail to provide a unified design approach at those circumstance) considering different shear lag effects resulting from dead load, prestress and cable tension in the construction. Therefore, a novel spatial grid model has been developed to account for shear lag effect. The theoretical principle of the proposed spatial grid model has been elaborated along with the relevant illustrations of modeling parameters of composite box girder with corrugated steel webs. Then typical transverse and longitudinal shear lag coefficient distribution pattern at the side-span and mid-span key cross sections have been analyzed and summarized to provide reference for similar bridges. The effectiveness and accuracy of spatial grid analysis methods has been finally validated through a practical cable-stayed bridge.

• 대한두개안면성형외과학회지
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• 제21권5호
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• pp.309-314
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• 2020

Reconstructions of extensive composite scalp and cranial defects are challenging due to high incidence of postoperative infection and reconstruction failure. In such cases, cranial reconstruction and vascularized soft tissue coverage are required. However, optimal reconstruction timing and material for cranioplasty are not yet determined. Herein, we present a large skull defect with a chronically infected wound that was not improved by repeated debridement and antibiotic treatment for 3 months. It was successfully treated with anterolateral thigh (ALT) free flap transfer for wound salvage and delayed cranioplasty with a patient-specific polyetheretherketone implant. To reduce infection risk, we performed the cranioplasty 1 year after the infection had resolved. In the meantime, depression of ALT flap at the skull defect site was observed, and the midline shift to the contralateral side was reported in a brain computed tomography (CT) scan, but no evidence of neurologic deterioration was found. After the surgery, sufficient cerebral expansion without noticeable dead-space was confirmed in a follow-up CT scan, and there was no complication over the 1-year follow-up period.

• Asian-Australasian Journal of Animal Sciences
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• 제10권3호
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• pp.318-323
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• 1997

In order to assess the effect of solar exposure on pulmonary functions and evaporative losses from skin and pulmonary surfaces, in six healthy Sahiwal (S) and six Sahiwal ${\times}$ Holstein ($S{\times}H$) cattle were exposed to direct sun during summer. Breed differences were observed during exposure. Increase in sweating rate was higher in crossbreds (222%) than in Sahiwal (125%). Pre-exposure (ambient temperature, $32.6{\pm}0.85^\circ}C$, solar radiation, $0.9cal\;cm^{-2}min^{-1}$) evaporative loss from skin accounted for about 90% of the losses and remaining losses were contributed by pulmonary surfaces in Sahiwal. The contribution of evaporation through skin increased to 92% (ambient temperature $39.4{\pm}0.68^\circ}C$, solar radiation, $1.35cal\;cm^{-2}min^{-1}$). In crossbreds 80% of the evaporative losses were through skin before exposure which increased to 87% after exposure to solar radiations. Rectal temperature increase was higher in crossbreds ($1.5^{\circ}C$) than in Sahiwal ($0.8^{\circ}C$). With the increase in pulmonary evaporative losses, respiratory frequency increased to 2 fold in Sahiwal and pulmonary ventilation increased 1.6 times the resting value in Sahiwal due to solar exposure. In $S{\times}H$ crossbreds the respiratory frequency increased 3.5 times and pulmonary ventilation increased only to 1.8 times due to decrease in tidal volume. There was about 2 fold increase in alveolar ventilation in both the breeds, the increase in dead space ventilation was more in crossbreds than in Sahiwal. Behavioral symptoms exhibited by animals after exposure were profuse salivation, open mouth panting, tongue protrusion and general restlessness.

• 터널과지하공간
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• 제14권3호
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• pp.188-202
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• 2004

고준위폐기물의 처분개념 실증을 위해 원자력연구소부지 내에 지하연구시설을 건설하는 경우, 지표면지형의 변화, 두터운 풍화대의 존재가 예상된다. 본 연구에서는 부지 특성과 터널의 경사 및 터별의 크기에 따른 영향 분석과 함께 수백 m의 터널을 단계적으로 굴착하는데 따른 영향을 FLAC3D를 이용한 3차원 구조해석을 통해 분석하였다. 해석결과 굴착을 단계적으로 실시하는데 따르는 응력이나 변위분포에는 차이가 없는 것으로 나타났으며 이는 지하연구시설의 부근에서는 응력재분포에 의한 소성영역의 발생은 없기 때문이다. 최대 응력으은 5 ㎫로 압축응력이 작용할 것으로 예상된다. 최대응력은 터별의 끝 부분에서 20 m 전방으로 터별의 벽면에서 발생할 것으로 예상되며 터널 경사각이나 풍화대의 크기, 터널의 크기변화에 따른 터널에서의 응력과 변위분포 변화는 거의 없는 것으로 나타났다. 진입터널과 연구모듈의 교차지점에 대한 모델링 결과 응력비 K가 3인 경우 구조적으로 가장 취약한 지점에서의 안전계수가 3이상으로 나타난다. 본 연구를 통해 원자력연구소 내 예상 부지에 소규모 지하연구시설을 구조적으로 안전하게 건설하는 것이 가능함을 보일 수 있었다.

• Archives of Plastic Surgery
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• 제35권1호
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• pp.86-91
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• 2008

Purpose: The performance of rhinoplasty on the patient who has already undergone unsatisfactory results or complications after augmentation rhinoplasty is a challenging surgical problem. Because the dead space is remained after removal of the foreign body and the thickness of the skin is not even, the deformity would be more conspicuous if the nose is reconstructed again with hard implant only or autogenous cartilage. In these cases, the autogenous fascia can be used to get a good result. We present our clinical experience of secondary rhinoplasty using Scarpa's fascia of lower abdomen. Methods: Thirty-two patients underwent the procedure from March of 2002 to February of 2007. Nine patients were reconstructed with Scarpa's fascia only, eighteen patients were reconstructed with silicone implant and fascia, and five patients were reconstructed with cartilage and fascia for secondary rhinoplasty. Results: There were no major complications. Most of the patients were satisfied with the results. The deviation of the silicone implant and postoperative hypertrophic scar of the donor site were seen in one case each. Postoperative absorption of fascia were seen in two cases using Scarpa's fascia only. Conclusion: Secondary rhinoplasty using Scarpa's fascia is very useful method which offers a minimized donor site scar, low complication rate, shorter operation time and patient satisfaction and prevents the alopecia caused by the harvest of temporalis fascia.

• Archives of Plastic Surgery
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• 제35권4호
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• pp.446-449
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• 2008

Purpose: Pilonidal sinus is a frequent disease that occurs mostly in hairy young men, defined as chronic inflammation and infection of the postsacral sinuses. Wide excision of the affected area is the treatment of choice. Many techniques have been described to cover the defect. However none appears to be the ideal procedure to prevent infection, recurrence, and delayed wound healing. We present the results of an alternative technique that we performed by using partial deepithelized gluteal transposition flap for reconstruction of the defect following wide excision. Methods: From October 2004 to September 2007, we performed the partial deepithelized gluteal transposition flap method on 6 patients. We modified the transposition flap techniques by deepithelialising the medial parts of the flap and burying them under the opposing edge of the flap. The results were compared with previous studies and evaluated regarding duration of surgery, size of defect, hospitalization periods, and complications. Results: All the flaps were healed well with no partial or complete loss of the flap. Hospitalization and immobilization periods were acceptably shortened. Recurrence was not seen. The aesthetic outcome was also satisfactory and all patients were satisfied with the results. Conclusion: The main advantage of our techniques is using healthy tissues to obliterate the dead space, to provide an extra-cushion, and to prevent deep dehiscence. We believe that the partial deepithelized gluteal transposition flap is a good alternative method for treatment of pilonidal sinus.

• Archives of Plastic Surgery
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• 제39권4호
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• pp.345-351
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• 2012

Background Cranial base defects are challenging to reconstruct without serious complications. Although free tissue transfer has been used widely and efficiently, it still has the limitation of requiring a long operation time along with the burden of microanastomosis and donor site morbidity. We propose using a reverse temporalis muscle flap and calvarial bone graft as an alternative option to a free flap for anterior cranial base reconstruction. Methods Between April 2009 and February 2012, cranial base reconstructions using an autologous calvarial split bone graft combined with a reverse temporalis muscle flap were performed in five patients. Medical records were retrospectively analyzed and postoperative computed tomography scans, magnetic resonance imaging, and angiography findings were examined to evaluate graft survival and flap viability. Results The mean follow-up period was 11.8 months and the mean operation time for reconstruction was $8.4{\pm}3.36$ hours. The defects involved the anterior cranial base, including the orbital roof and the frontal and ethmoidal sinus. All reconstructions were successful. Viable flap vascularity and bone survival were observed. There were no serious complications except for acceptable donor site depressions, which were easily corrected with minor procedures. Conclusions The reverse temporalis muscle flap could provide sufficient bulkiness to fill dead space and sufficient vascularity to endure infection. The calvarial bone graft provides a rigid framework, which is critical for maintaining the cranial base structure. Combined anterior cranial base reconstruction with a reverse temporalis muscle flap and calvarial bone graft could be a viable alternative to free tissue transfer.

• Archives of Plastic Surgery
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• 제39권4호
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• pp.367-375
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• 2012

Background The anterolateral thigh (ALT) perforator flap has become a popular option for treating soft tissue defects of lower extremity reconstruction and can be combined with a segment of the vastus lateralis muscle. We present a comparison of the use of the ALT fasciocutaneous (ALT-FC) and myocutaneous flaps. Methods We retrospectively reviewed patients in whom free-tissue transfer was performed between 2005 and 2011 for the reconstruction of lower extremity soft-tissue defects. Twenty-four patients were divided into two groups: reconstruction using an ALT-FC flap (12 cases) and reconstruction using a vastus lateralis myocutaneous (VL-MC) flap (12 cases). Postoperative complications, functional results, cosmetic results, and donor-site morbidities were studied. Results Complete flap survival was 100% in both groups. A flap complication was noted in one case (marginal dehiscence) of the ALT-FC group, and no complications were noted in the VL-MC group. In both groups, one case of partial skin graft loss occurred at the donor site, and debulking surgeries were needed for two cases. There were no significant differences in the mean scores for either functional or cosmetic outcomes in either group. Conclusions The VL-MC flap is able to fill occasional dead space and has comparable survival rates to ALT-FC with minimal donor-site morbidity. Additionally, the VL-MC flap is easily elevated without myocutaneous perforator injury.

• 대한핵의학회지
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• 제17권1호
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• pp.33-39
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• 1983

Sixty-nine patients with diffuse lung uptake of $^{99m}Tc-tin$ colloid were evaluated to determine the kinds of associated diseases, the incidence of associated liver scan abnormalities, and prognosis. The results were as follows: 1) Diseases associated with diffuse lung uptake included malignancies in 31 patients, infectious diseases in 19, chronic liver diseases in 14, and others in 5. It appeared that the marked degree of lung uptake was associated with severe diseases. 2) Thirty-one of the 69 patients(45%) had abnormal liver size, 43(62%) had space occupying lesions or nonhomogeneity in liver image, 37(54%) had splenomegaly and 45(65%) had increased splenic uptake. Increased bone marrow uptake was found in 48(70%) and renal uptake in 15(22%). As the degree of lung uptake increased, there was a statistically significant (p<0.05) tendency for the incidences of the abnormal liver image and renal uptake to increase. 3) Sixty-two of the 69 patients were followed up for one to 439 days(mean 44 days) after liver scanning. Eleven(18%) were dead, 10(16%) were aggravated, and 13(21%) were improved. Most of improved patients had infectious diseases. It appeared that diffuse lung uptake of $^{99m}Tc-Tn$ colloid was found in the various diseases including malignancies, infections, and chronic liver diseases, and that it was strongly associated with other liver scan abnormalities, but was not necessarily associated with a poor prognosis, particularly when underlying diseases were infections.

• 대한핵의학회지
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• 제6권2호
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• pp.21-39
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• 1972

The employment of gamma-ray scintillation camera with the use of short-lived radioisotopic pharmaceuticals, sucu as $^{99m}Tc$ sodium pertechnetate, have enabled us to perform RI (radioisotopic) angiocardiography. Although conventional cardiac catheterization or angiocardiography using contrast media have been an important diagnostic tool, they may carry some risks or serious complications. The author investigated on RI angiocardiography in twelve normal and twenty five patients with cardiovascular diseases in an effort to evaluate its diagnostic value. The results obtained with this study are as follows; 1. In normal subjects, the scintillation camera transit time of arm-to-right heart was found to be $2.1{\pm}0.67$ seconds, right heart-to-lung $1.5{\pm}0.40$ seconds and lung-to-left heart $3.5{\pm}0.86$ seconds. 2. Transformation or displacement of the heart and the great vessel are easily discriminated by RI angiocardiography. Both in the cases with tricuspid atresia and tetralogy of Fallot, ventricular septal defects are well recongnized by sequential RI angiocardiography. 3. It is also helpful in determinining the site and extent of obstruction, and estimatiing the postoperative course both in the cases with superior vena cava syndrome and pulmonary stenosis. 4. Pericarditis with effusion is readilly diagnosed by RI angiocardiogram showing characteristic "dead space" between intracardiac and intrapulmonary radioactivity. 5. It was found that the diagnostic accuracy of this study was 78.4%. It is concluded that above results obtained are useful and accurate enough for the diagnostic screening methode for clinical practice.