• Archives of Reconstructive Microsurgery
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• v.16 no.1
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• pp.39-47
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• 2007

With the advent of microsurgery, perforator free flap is nowadays considered the first choice for reconstruction of the extensive defect of the extremities because of their moderate thickness. Among them, anterior (anterolateral and anteromedial) thigh perforator free flaps provide the first choice for reconstruction of various soft tissue defects of the extremities with many advantage such as its large, uniform thickness, long vascular pedicle with proper vessel size and minimal donor site morbidity. But, it has still some criticism of unreliable perforators which makes us very careful in elevating the flap. Between March of 2006 and February of 2007, we treated 7 patients of soft tissue defects in the hand and lower extremities with anterior thigh perforator free flap at Hallym and DongGuk University Hospital. We performed 6 anterolateral thigh perforator free flaps based on the descending branch of lateral circumflex femoral artery (LCFA) and 1 anteromedial thigh perforator free flap based on the innominate branch of the LCFA. While approaching for the anterolateral thigh free flap, we happen to meet the cases which we should change into the anteromedial thigh free flap uneventfully on the operating field. In contrast to the original design of anterolateral thigh free flap, we had to harvest the anteromedial thigh perforator free flap in 1 case. All the anterior thigh perforator free flaps survived completely except 1 case of partial necrosis due to venous congestion. Donor sites were closed primarily and healed uneventfully within 2 weeks. Patients were satisfied with the functionally and aesthetically acceptable results. Although doppler sonography is strongly recommended preoperatively in planning the anterior thigh perforator free flaps, we should always remember the variation in vascular anatomy and be ready to change the flap choice from the anterolateral to anteromedial intraoperatively. we provide a review of the literature and present our series of anterior thigh perforator free flaps for reconstruction of the extremities.

• Archives of Reconstructive Microsurgery
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• v.8 no.1
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• pp.28-34
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• 1999

The need for reconstruction of large bone, soft tissue defect of mandible has greater emphasis due to development of industry, traumatic accident and increase of tumor. The mandibular reconstruction had greatly progressed through the first and the second World Wars. The Fibular free flap by using microscope was reported in 1970 and many maxillofacial reconstructive surgeons had used. In 1988, Dr. Hidalgo first reported mandibular reconstruction by using fibular free flap. Mandibular reconstruction by using fibular free flap has several advantages. First, it provides up to 25 cm of bone, enough to reconstruct any length of mandible defect. Second, a skin island, based on a septocutaneous blood supply, is available in a size large enough to simultaneously reconstruct internal and external soft tissue defect. Third, The fibular donor site morbidity is low, fourth, it provides a esthetic effect of mandible line. And finally bone viability is good. The Fibular osteocutaneous free flap was performed after COMMANDO operation due to squamous cell cancer in oral cavity (15 cases). Therefore we report out successful operation of the mandible reconstruction by using fibular osteocutaneous free flap.

• Archives of Plastic Surgery
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• v.42 no.1
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• pp.73-77
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• 2015

The latissimus dorsi flap is popular due to the versatile nature of its applications. When used as a pedicled flap it provides a robust solution when soft tissue coverage is required following breast, thoracic and head and neck surgery. Its utilization as a free flap is extensive due to the muscle's size, constant anatomy, large caliber of the pedicle and the fact it can be used for functional muscle transfers. In facial palsy it provides the surgeon with a long neurovascular pedicle that is invaluable in situations where commonly used facial vessels are not available, in congenital cases or where previous free functional muscle transfers have been attempted, or patients where a one-stage procedure is indicated and a long nerve is required to reach the contra-lateral side. Although some facial palsy surgeons use the trans-axillary approach, an operative guide of raising the flap by this method has not been provided. A clear guide of raising the flap with the patient in the supine position is described in detail and offers the benefits of reducing the risk of potential brachial plexus injury and allows two surgical teams to work synchronously to reduce operative time.

• Structural Engineering and Mechanics
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• v.74 no.2
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• pp.175-187
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• 2020

The theories having been developed thus far account for higher-order variation of transverse shear strain through the depth of the beam and satisfy the stress-free boundary conditions on the top and bottom surfaces of the beam. A shear correction factor, therefore, is not required. In this paper, the effect of surface on the axial buckling and free vibration of nanobeams is studied using various refined higher-order shear deformation beam theories. Furthermore, these theories have strong similarities with Euler-Bernoulli beam theory in aspects such as equations of motion, boundary conditions, and expressions of the resultant stress. The equations of motion and boundary conditions were derived from Hamilton's principle. The resultant system of ordinary differential equations was solved analytically. The effects of the nanobeam length-to-thickness ratio, thickness, and modes on the buckling and free vibration of the nanobeams were also investigated. Finally, it was found that the buckling and free vibration behavior of a nanobeam is size-dependent and that surface effects and surface energy produce significant effects by increasing the ratio of surface area to bulk at nano-scale. The results indicated that surface effects influence the buckling and free vibration performance of nanobeams and that increasing the length-to-thickness increases the buckling and free vibration in various higher-order shear deformation beam theories. This study can assist in measuring the mechanical properties of nanobeams accurately and designing nanobeam-based devices and systems.

• Archives of Reconstructive Microsurgery
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• v.22 no.1
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• pp.18-23
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• 2013

Purpose: For reconstruction of lower extremity defects, various flaps can be used and the appropriate flap must be selected and applied according to the size of the defect. In particular, in cases where the defect size is small to moderate, thinner or smaller volume flaps are useful. The authors performed reconstruction of small to moderate defects on the lower extremities using superficial circumflex iliac artery perforator free flaps and are reporting the results. Materials and Methods: Fifteen patients underwent reconstruction of defects on lower extremity areas using superficial circumflex iliac artery perforator free flaps from July 2011 to July 2012 at this hospital. The flaps were elevated from above the deep fat layer, and, in all cases, the vessel diameter of the flaps was less than 1mm, with the exception of superficial vein that accompanied it. Results: The mean follow up period was 4.46 months, and, despite a partial loss in the flap in two cases, there were no total losses. All donor sites were closed with primary closure, and there was no occurrence of complications, such as hematomas, seromas, or lymphorrheas. The patients were highly satisfied with the donor site scar since it could be masked by underwear. Conclusion: Compared to other flaps, superficial circumflex iliac artery perforator free flaps are thinner in thickness and smaller in volume, which results in a more natural contour of the recipient site after the operation. In addition, since the flap can be elevated from supra-deep fat layer, the operation time can be shortened, and lymphorrhea can be prevented, which in turn lessens donor-site morbidity.

• Archives of Plastic Surgery
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• v.51 no.1
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• pp.87-93
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• 2024

This study aimed to analyze cases of anterolateral thigh (ALT) free flap used for hand reconstruction with terminal perforator-to-digital artery anastomosis. Patients who underwent ALT free flap placement with terminal perforator-to-digital artery anastomosis for hand reconstruction between January 2011 and August 2021 were included. The number, length, and diameter of the perforators and veins, flap size, and operative time were investigated through a retrospective review of charts and photographs. The occurrences of arterial thrombosis, venous thrombosis, arterial spasm, and flap necrosis were analyzed. In total, 50 patients were included in this study. The mean diameter and length of the perforators were 0.68 mm and 3.25 cm, respectively, and the mean number of veins anastomosed was 1.88, with a mean diameter of 0.54 mm. Complications included four cases of arterial thrombosis, one case of venous thrombosis, seven cases of partial necrosis, and one case of total flap failure. Regression analysis showed that a longer perforator was associated with arterial thrombosis whereas larger flap size and number of anastomosed veins were associated with partial necrosis (p < 0.05). The terminal perforator-to-digital artery anastomosis offers advantages in using compact free flaps with short pedicle lengths to cover small hand defects.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.454-458
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• 2010

Velopharyngeal insufficiency is defined as a status in which nasal cavity and oral cavity can not be sepa-rated when speaking, swallowing by any reason. It has been treated by palatorrhaphy, pharyn-geal flap, local flap, free flap etc. When the size of the defect is small, it can be restored by palatorrhaphy, pharyngeal flap etc. But they are not proper for treatment of the large size of defect. In that case, local flap and free flap are more beneficial. Although large defect can be restored by free flap technique, but it is very complex, time-consuming and may bring about esthetical, functional complications of donor site. Buccinator myomucosal flap is a kind of local flap and reported for the first time by Bozola et al in 1989 and it has become a useful way for reconstruction of large intraoral defect. Authors experienced the use of buccinators myomucosal flap for treating secondary velopharyngeal insufficiency with large soft palate defect and obtained good result. So we report the case with literature reviews.

• Smart Structures and Systems
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• v.19 no.6
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• pp.601-614
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• 2017

In this work, free vibration analysis of size-dependent functionally graded (FG) nanoplates resting on two-parameter elastic foundation is investigated based on a novel nonlocal refined trigonometric shear deformation theory for the first time. This theory includes undetermined integral variables and contains only four unknowns, with is even less than the conventional first shear deformation theory (FSDT). Mori-Tanaka model is employed to describe gradually distribution of material properties along the plate thickness. Size-dependency of nanosize FG plate is captured via the nonlocal elasticity theory of Eringen. By implementing Hamilton's principle the equations of motion are obtained for a refined four-variable shear deformation plate theory and then solved analytically. To show the accuracy of the present theory, our research results in specific cases are compared with available results in the literature and a good agreement will be demonstrated. Finally, the influence of various parameters such as nonlocal parameter, power law indexes, elastic foundation parameters, aspect ratio, and the thickness ratio on the non-dimensional frequency of rectangular FG nanoscale plates are presented and discussed in detail.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.632-638
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• 2002

Extensible 3D(X3D) is a software standard for defining interactive web and broadcast-based 3D content integrated with multimedia. The data size of Web3D representation based on polygon meshes is so large that transferring practical data fast is a hard problem. This paper proposes 3D object structure, a new framework for compact 3D representation with high quality surface shape. By utilizing a free form surface technique, qualified surface are transferred with limited amount of data size and rendered. 3D graphic structure can be regarded ad both polygon meshes and free form surfaces. Therefore, it can be easily integrated to existing Web3D data formats, for example VRML ＆ XML. 3D object structure also enables modeling free form surface shapes intuitively with polygon modeling like operations.

• Smart Structures and Systems
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• v.19 no.3
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• pp.243-257
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• 2017

In this paper, free vibration of functionally graded (FG) size-dependent nanobeams is studied within the framework of nonlocal Timoshenko beam model. It is assumed that material properties of the FG nanobeam, vary continuously through the thickness according to a power-law form. The small scale effect is taken into consideration based on nonlocal elasticity theory of Eringen. The non-classical governing differential equations of motion are derived through Hamilton's principle and they are solved utilizing both Navier-based analytical method and an efficient and semi-analytical technique called differential transformation method (DTM). Various types of boundary conditions such as simply-supported, clamped-clamped, clamped-simply and clamped-free are assumed for edge supports. The good agreement between the presented DTM and analytical results of this article and those available in the literature validated the presented approach. It is demonstrated that the DTM has high precision and computational efficiency in the vibration analysis of FG nanobeams. The obtained results show the significance of the material graduation, nonlocal effect, slenderness ratio and boundary conditions on the vibration characteristics of FG nanobeams.