• Archives of Plastic Surgery
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• v.37 no.6
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• pp.827-830
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• 2010

Purpose: Congenital spinal dermal sinus tract is a rare lesion connecting skin to deeper structures including neural tissue. It results from the failure of the neuroectoderm to separate from the cutaneous ectoderm in the third to fifth week of gestation. The common locations are the lumbosacral and occipital regions. Sometimes it extends to spinal canal. In this paper we report a case of congenital spinal dermal sinus tract in the coccyx. Methods: A 21-month-old male child born after an uncomplicated full-term pregnancy was admitted to our institute with a midline dermal sinus and a cartilaginous protrusion in the coccygeal region. There were no signs of infection. Neurologic examination showed no functional deficit in both lower limbs. He was treated with complete excision of the tract and an underlying accessory cartilage. Results: The spinal dermal sinus tract was extended from the skin to the coccyx. The stalk was loosely attached to the accessory cartilage of coccyx. At that point, it was dissected from the accessory cartilage and resected. The accessory cartilage was also resected at the bone and cartilage junction. During the follow-up period of 6 months, the wound healed well without any complication nor recurrence. Conclusion: Congenital spinal dermal sinus tract is known as a form of spinal dysraphism. In order to prevent complications, timely surgical intervention including complete resection of sinus tract with correction of associated abnormalities is of utmost importance.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.585-596
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• 2012

PVDF(poly vinylidene fluoride) and P(VDF-TrFE)(poly vinylidene fluoride-tetrafluoroethylene) are the typical piezoelectric polymers with unique properties. Even they are inferior to conventional piezoelectric ceramics PZT in electromechanical conversion efficiency and interior loss, though they are superior in receiving sensitivity and frequency bandwidth. Their acoustic impedances are relatively close to water or biological tissue and it is easier to make thin film than other piezoelectric materials. Futhermore, the film is so flexible that it is easy to attach on a complex surface. Those properties are suitable for the ultrasound transducers which are useful for medical and biological application, so that various types of polymer transducers have been developed. In this paper, several important considerations for design and fabrication of piezoelectric polymer transducers were described and their effect on the transducer performance were demonstrated through the KLM model analysis. Then, it was briefly reviewed about the structures of the polymer transducers developed for obtaining images as well as the characteristics of the images in several important medical and biological application fields.

• Korean Journal of Head & Neck Oncology
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• v.13 no.1
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• pp.35-39
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• 1997

Background: Completion thyroidectomy is defined as the surgical removal of the remnant thyroid tissue following procedures less than total or near-total thyroidectomy. Although some authors advocate subtotal thyroidectomy with lower complication rates, total or completion thyroidectomy have been defended by others because of the improved survival and lower morbidity that is comparable with subtotal thyroidectomy. Objectives: The purpose of this paper is to review the necessity and safety of completion thyroidectomy for differentiated thyroid carcinoma(DTC). Materials & Methods: During the past 10 years(1986 to 1996) , authors have performed 211 total thyroidectomy. Ten of these patients were treated by completion thyroidectomy for DTC. Initial operation of 7 patients had been performed at St. Vincents Hospital and 3 patients at other hospital. The medical records of patients undergoing completion thyroidectomy were retrospectively reviewed. Results: The completion thyroidectomy specimen contained residual tumor cells in 8 of the 8 patients with papillary carcinoma and none of the two patients with follicular carcinoma. Complications of completion thyroidectomy were transient hypoparathyroidism in two patients and transient unilateral recurrent laryngeal nerve palsy in one patient. But permanent complications were not noticed. Conclusion: We recommend completion thyroidectomy as an efficient and safe method of surgical treatment with a low complication rate for DTC.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2077-2082
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• 2008

Recent the advanced technologies in medical imaging such as magnetic resonance imaging (MRI) and computed tomography (CT) make doctors improve the diagnostic skill with detailed anatomical information. In general, it is necessary to get a number of MRI images in order to obtain more detail information. However, the performance of MRI machines of privately run hospitals is not good and thus we may obtain only a few of MRI images. If 3D surface reconstruction is accomplished with a few slices, then it generates 3D surface of poor qualify. This paper propose a way to Set a 3D surface of high quality from a few of number of slices. First of all, our algorithm detects the boundary of tissues which we want to reconstruct as a 3D object and find out the set of vortices on the boundary. And then we generate a 3D implicit surface to interpolate the boundary points by using radial basis function. Lastly, we render the 3D implicit surface by using Marching cube algorithms.

• Korean Journal of Metals and Materials
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• v.50 no.5
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• pp.401-406
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• 2012

When viewed using a magnetic resonance imaging (MRI) system, invasive materials inside the human body, in many cases, severely distort the MR image of human tissues. The degree of the MR image distortion increases in proportion not only to the difference in the susceptibility between the invasive material and the human tissue, but also to the intensity of the magnetic field induced by the MRI system. In this study, by blending paramagnetic Ti particles with diamagnetic graphite, we synthesized $Ti_{100-x}C_x$ composites that can reduce the artifact in the MR image under the high-strength magnetic field. Of the developed composites, $Ti_{70}C_{30}$ showed the magnetic susceptibility of ${\chi}=67.6{\times}10^{-6}$, which corresponds to 30% of those of commercially available Ti alloys, the lowest reported in the literature. The level of the MR image distortion in the vicinity of the $Ti_{70}C_{30}$ composite insert was nearly negligible even under the high magnetic field of 4.7 T. In this paper, we reported on a methodology of designing new structural materials for bio-applications, their synthesis, experimental confirmation and measurement of MR images.

• Korean Journal of Optics and Photonics
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• v.25 no.2
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• pp.67-71
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• 2014

Intravascular optical coherence tomography (OCT) enables imaging of the three-dimensional (3D) microstructure of a blood vessel wall. While 3D vascular visualization provides detailed information of the vessel wall and intraluminal structures, a longitudinal imaging pitch that is several times bigger than the imaging resolution of the system has limited true high-resolution 3D imaging. In this paper we demonstrate high-speed intravascular OCT in vivo, acquiring images at a rate of 350 frames per second. A 47-mm-long rabbit aorta was imaged in 3.7 seconds, after a short flush with contrast agent. The longitudinal imaging pitch was 34 micrometers, comparable to the transverse imaging resolution of the system. Three-dimensional volume rendering showed greatly enhanced visualization of tissue microstructure and stent struts, relative to what is provided by conventional intravascular imaging speeds.

• Journal of Korean Foot and Ankle Society
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• v.25 no.3
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• pp.133-140
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• 2021

Purpose: This paper reports the surgical treatment results of open calcaneal fractures performed at the author's clinics focusing on open calcaneal fractures to help understand the appropriate treatment and realistic outcomes. Materials and Methods: This study was conducted on 22 cases out of 30 patients who visited the hospital from February 2009 to December 2019 and were followed up for more than one year. In open fractures, the fracture was classified using the Gustilo-Anderson classification and was evaluated using the soft tissue status at the time of visit. Intra-articular calcaneal fractures were classified using Sanders classification. The radiological parameters were measured for the Böhler angle, Gissane angle, calcaneal length, height, and width before and after surgery, and at the last follow-up. The clinical outcomes were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale and investigated complications. In addition, statistical analysis of the incidence and associated factors of posttraumatic arthritis was conducted. Results: In all cases, the surgical treatment was performed by minimally invasive surgery. The AOFAS ankle-hindfoot scale conducted for a clinical evaluation of the final follow-up was averaged 72.5 points. In the classification of open fractures, the Gustilo-Anderson classification type IIIA was the most common, and the Sanders type III was the most common. Of the 22 cases after surgery, 15 cases had complications, 11 cases had posttraumatic arthritis, eight cases had an infection, and 4 cases had both complications. Only the Sanders classification showed a statistically significant correlation with the incidence of posttraumatic osteoarthritis (p-value 0.032). Conclusion: In treating open calcaneal fractures, internal fixation by a minimally invasive approach showed relatively satisfactory results. However, follow-up research will be needed, including the results of a long-term follow-up through a large number of cases and comparative studies with other surgical methods.

• Genes and Genomics
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• v.40 no.12
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• pp.1363-1371
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• 2018

One of the main concerns in biology is extracting sophisticated features from DNA sequence for gene interaction determination, receiving a great deal of researchers' attention. The epigenetic modifications along with their patterns have been intensely recognized as dominant features affecting on gene expression. However, studying sequenced-based features highly correlated to this key element has remained limited. The main objective in this research was to propose a new feature highly correlated to epigenetic modifications capable of classification of genes. In this paper, classification of 34 genes in PPAR signaling pathway associated with muscle fat tissue in human was performed. Using different statistical outlier detection methods, we proposed that 5-mers highly correlated to epigenetic modifications can correctly categorize the genes involved in the same biological pathway or process. Thirty-four genes in PPAR signaling pathway were classified via applying a proposed feature, 5-mers strongly associated to 17 different epigenetic modifications. For this, diverse statistical outlier detection methods were applied to specify the group of thoroughly correlated genes. The results indicated that these 5-mers can appropriately identify correlated genes. In addition, our results corresponded to GeneMania interaction information, leading to support the suggested method. The appealing findings imply that not only epigenetic modifications but also their highly correlated 5-mers can be applied for reconstructing gene regulatory networks as supplementary data as well as other applications like physical interaction, genes prioritization, indicating some sort of data fusion in this analysis.

• Current Optics and Photonics
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• v.3 no.3
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• pp.256-262
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• 2019

Extensive tumor resection accompanied by radiotherapy and chemotherapy is the standard of care for malignant gliomas. However, there is a significant obstacle to the complete resection of the tumor due to the difficulty of distinguishing tumor and normal brain tissue with a conventional surgical microscope. Recently, multiple studies have shown the possibility of fluorescence-guided surgery in malignant gliomas. The most used fluorescence dyes for brain tumor surgery are 5-aminolevulinic acid (5-ALA) and indocyanine green (ICG). In this paper, a new fluorescence guided operation system, which can detect both 5-ALA and ICG fluorescent images simultaneously, is presented. This operation system consists of light emitting diodes (LEDs) which emits 410 nm and 740 nm wavelengths. We have performed experiments on rats in order to verify the operation of the newly developed operation system. Oral administration and imaging were performed to observe the fluorescence of 5-ALA and ICG fluorescence in rats. When LEDs at wavelengths of 410 nm and 740 nm were irradiated on rats, 628 nm wavelength with a violet fluorescence color and 825 nm wavelength with a red fluorescence color were expressed in 5-ALA and ICG fluorescent material, respectively, thus we were able to distinguish the tumor tissues easily. Previously, due to the poor resolution of the conventional surgical microscope and the fact that the color of the vein is similar to that of the tumor, the tumor resection margin was not easy to observe, thus increasing the likelihood for cancer recurrence. However, when the tumor is observed through the fluorescence guided operation system, it is possible to easily distinguish the color with the naked eye and it can be completely removed. Therefore, it is expected that surgical removal of cancerous tumors will be possible and surgical applications and surgical microscopes for cancer tumor removal surgery will be promising in the future.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.2
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• pp.51-67
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• 2019

As dental implant surgery and bone grafts were widely operated in Korean dentist, many bone substitutes are commercially available, currently. For commercially used in Korea, all bone substitutes are firstly evaluated by the Ministry of Health and Welfare (MOHW) for safety and efficacy of the product. After being priced, classified, and registration by the Health Insurance Review and Assessment Service (HIRA), the post-application management is obligatory for the manufacturer (or representative importer) to receive a certificate of Good Manufacturing Practice by Ministry of Food and Drug Safety. Currently, bone substitutes are broadly classified into C group (bone union and fracture fixation), T group (human tissue), L group (general and dental material) and non-insurance material group in MOHW notification No. 2018-248. Among them, bone substitutes classified as dental materials (L7) are divided as xenograft and alloplastic bone graft. The purpose of this paper is to analyze alloplastic bone substitutes of 37 products in MOHW notification No. 2018-248 and to evaluate the reference level based on the ISI Web of Knowledge, PubMed, EMBASE (1980-2019), Cochrane Database, and Google Scholar using the criteria of registered or trademarked product name.