• Archives of Plastic Surgery
• /
• v.36 no.4
• /
• pp.462-468
• /
• 2009

Purpose: The liposuction has been generalized & undergone in the field of plastic surgery and it has had a great influence on fat graft. But despite of liposuction and fat injection being performed widely, we did not focus on complication associated with donor site. So we reported satisfactory result with the intraoperative sustained limited expansion & direct closure to donor site tissue necrosis after liposuction and analyzed the cause & measures of donor site necrosis with the literature investigation Methods: From November 2007 to June 2008, we treated four cases of tissue necrosis and infection surrounding the thigh and forearm. Necrosis after liposuction was 1 case, donor site necrosis after fat injection were 3 cases and MRSA was detected in 2 cases. first, we debrided the necrotic tissue and treated with potadine gauze soaking dressing & susceptible antibiotics. After confirmation of healthy granulation tissue, we used intraoperative sustained limited expansion and closed directly of defect & observed the results. Results: The patient was displeased and worried with the unexpected damage concerning the donor site and the procedure concerning time and financial exhaustion, but after confirming no contracture of the scar tissues and only a thin or slightly widened line of scar, showed satisfaction. Conclusion: Because it is fastidious to avoid donor site complication after liposuction & fat injection, enough explanation and understanding on possible complication to donor site are necessary and careful surgery procedure & materials are required. But if donor site necrosis were occurred although close consideration of possible causes of necrosis, we should think about not only wound healing process but also the sequela like scar contracture & cosmetic effect and treat the most adequate method to satisfying both concerns.

• Journal of Chest Surgery
• /
• v.38 no.7 s.252
• /
• pp.507-509
• /
• 2005

Open heart surgery via right thoracotomy can be accomplished in atrial septal defects, and mitral valve diseases. Recently, thoracoscopic atrial septal defect closure, mitral valve repair, Maze operation, and minimal invasive direct coronary artery bypass (MIDCAB) are accomplished with AESOP 3000. However, there is no report of thoracoscopic aortic valve replacement in Korea. We report a successful thoracospic aortic valve replacement assisted with AESOP 3000 in a 31-year-old female patient.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.20 no.4
• /
• pp.65-76
• /
• 2017

The purpose of this study was to present a prediction model that reflects crime risk area analysis, including factors and spatial characteristics, as a precursor to preparing an alternative plan for crime prevention and design. This analysis of criminal cases in high-risk areas revealed clusters in which approximately 25% of the cases within the study area occurred, distributed evenly throughout the region. This means that using a multiple linear regression model might overestimate the crime rate in some regions and underestimate in others. It also suggests that the number of deserted houses in an analyzed region has a negative relationship with the dependent variable, based on the multiple linear regression model results, and can also have different influences depending on the region. These results reveal that closure signs in a study area affect the dependent variable differently, depending on the region, rather than a simple or direct relationship with the dependent variable, as indicated by the results of the multiple linear regression model.

• Journal of Korea Water Resources Association
• /
• v.46 no.4
• /
• pp.389-400
• /
• 2013

In this study, a conventional pipeline unsteady friction model has been integrated into Levenberg Marquardt method to calibrate friction coefficient in a pipeline system. The method of characteristics has been employed as the modeling platform for the frequency dependant model of unsteady friction. In order to obtain Hessian and Jacobian matrix for optimization, the direct differentiation of pressure to friction factor was calculated and sensitivities to friction for heads and discharges were formulated for implementation to the integration constant in the characteristic method. Using a hypothetical simple pipeline system, time series of pressure, introduced by a sudden valve closure, were obtained for various Reynolds numbers. Convergency in fiction factors were evaluated both in steady and unsteady friction models. The comparison of calibration performance between the proposed method and genetic algorithm indicates that faster and stabler behaviour of Levenberg Marquardt method than those of evolutionary calibration.

• Molecules and Cells
• /
• v.37 no.4
• /
• pp.322-329
• /
• 2014

N-acetylglucosamine kinase (GlcNAc kinase or NAGK; EC 2.7.1.59) is highly expressed and plays a critical role in the development of dendrites in brain neurons. In this study, the authors conducted structure-function analysis to verify the previously proposed 3D model structure of GlcNAc/ATP-bound NAGK. Three point NAGK mutants with different substrate binding capacities and reaction velocities were produced. Wild-type (WT) NAGK showed strong substrate preference for GlcNAc. Conversion of Cys143, which does not make direct hydrogen bonds with GlcNAc, to Ser (i.e., C143S) had the least affect on the enzymatic activity of NAGK. Conversion of Asn36, which plays a role in domain closure by making a hydrogen bond with GlcNAc, to Ala (i.e., N36A) mildly reduced NAGK enzyme activity. Conversion of Asp107, which makes hydrogen bonds with GlcNAc and would act as a proton acceptor during nucleophilic attack on the ${\gamma}$-phosphate of ATP, to Ala (i.e., D107A), caused a total loss in enzyme activity. The overexpression of EGFP-tagged WT or any of the mutant NAGKs in rat hippocampal neurons (DIV 5-9) increased dendritic architectural complexity. Finally, the overexpression of the small, but not of the large, domain of NAGK resulted in dendrite degeneration. Our data show the effect of structure on the functional aspects of NAGK, and in particular, that the small domain of NAGK, and not its NAGK kinase activity, plays a critical role in the upregulation of dendritogenesis.

• Archives of Plastic Surgery
• /
• v.38 no.5
• /
• pp.585-589
• /
• 2011

Purpose: Microcirculation of diabetic patients is commonly comporomised, regardless of the condition of the macrocirculation. Therefore, direct tissue oxygenation measurement is recommended in determining tissue viability and predicting wound healing potential. This study was designed to determine cut-off value of the tissue oxygenation in predicting wound healing in diabetic foot patients. Methods: This study included 41 feet of 41 diabetic foot patients who were treated in the Diabetic Wound Center of author's institution between January and June, 2009. Main inclusion criteria were type 1 or 2 diabetes and a foot ulcer (duration > 3 weeks) and ulcer area (from 1 $cm^2$ to 4 $cm^2$). Measurements of the area of diabetic foot ulcer were carried out before treatment. Transcutaneous oxygen pressure ($TcpO_2$) was measured at adjacent site of ulcer. The healing wound was defined as complete wound closure within 12 weeks. Results: Average diabetic foot ulcer areas with healing and nonhealing wounds were $2.67{\pm}0.76$ and $2.59{\pm}0.75\;cm^2$, respectively. There was no significant difference in the wound area between the groups. Average foot $TcpO_2$ in healing and nonhealing wounds were $68.56{\pm}23.07$ and $30.98{\pm}16.66$ mmHg, respectively ($p$ <0.01). The rate of healing wound increased as $TcpO_2$ increased. In particular, $TcpO_2$ lower than 40 mmHg and higher than 40 mmHg showed the most significant difference (wound healing rates of 25% and 71%, respectively). Conclusion: Based on the results of the study, the minimal $TcpO_2$ value thought to be required for adequate wound healing in diabetic wounds (cut-off value) is 40 mmHg.

• Archives of Reconstructive Microsurgery
• /
• v.7 no.1
• /
• pp.28-34
• /
• 1998

The traditionally useful coverage methods of the wrist and hand soft tissue defect are the chinese forearm flap, the ulnar forearm flap. But, this flaps are inevitably sacrifice major vessel to the hand. Advantages of the posterior interosseous artery island flap(PIA Flap) is no need to sacrifice blood supply to the hand and supply relatively large thin, good quality flap and more cosmetic than other forearm flaps. But, it is difficult to dissect and raise because of deep seat, close relation with the posterior interosseous nerve and anatomic variation. Authors evaluated 8 cases of 7 patients in the department of orthopaedic surgery, college of medicine, Hallym University from January, 1993 to December, 1995. The results are as follows: 1. The satisfactory coverage was achieved 7 cases and 1 case failed because of anatomic variation. 2 The pedicle length is average 9cm and the flap size is variable from 3cm by 4cm to 5cm by 8cm. 3. The donor site defect was repaired by direct closure in 5 cases, remained 3 cases combined with skin graft. From our experience we conclude that the PIA flap is one of the useful coverage methods of the wrist and hand soft tissue defect.

• Journal of Korea Trade
• /
• v.24 no.6
• /
• pp.173-193
• /
• 2020

Purpose - This study aims to examine the effect of entrepreneurship of start-ups on export performance when the business closure rate is higher than business start-up rate in Korea. Thus, this study analyzes various factors for start-ups established within the past seven years and uses export performance as an indicator. Prior to analysis of factors, the study defines the concepts of start-up factors based on various studies. Design/methodology - In order to analyze the export performance of startups, this study conducted an empirical analysis using statistical analysis. Theories were established based on previous studies, and hypotheses and research models were designed based on the established theories. Subsequently, in order to verify the research hypothesis and research model, factor analysis such as validity and reliability, and structural equation modeling were analyzed. Findings - As a result of analysis based on previous studies, we found that there is a difference between theoretical and practical aspects. Whereas previous studies showed that market orientation, technology orientation, and social capital have a direct impact on export performance, the present study analyzed that there is no such impact, and that technology capabilities were important as a result of the unique traits of start-ups. Originality/value - Existing studies have limitations in understanding the overall characteristics of a company by using market orientation, technology orientation, and social capital as individual independent variables. In addition, the existing researches have been analyzed in relation to corporate performance, whereas this study has been limited to export performance, so it can be regarded as different from other studies.

• Archives of Plastic Surgery
• /
• v.49 no.3
• /
• pp.378-396
• /
• 2022

Several reconstructive methods have been reported to restore the continuity of the aerodigestive tract following resection of pharyngeal and hypopharyngeal cancers. However, high complication rates have been reported after voice prosthesis insertion. In this setting, the ileocolon free flap (ICFF) offers a tubularized flap for reconstruction of the hypopharynx while providing a natural phonation tube. Herein, we systematically reviewed the current evidence on the use of the ICFF for reconstruction of the aerodigestive tract. A systematic literature search was conducted across PubMed MEDLINE, Web of Science, ScienceDirect, Scopus, and Ovid MEDLINE(R). Data on the technical considerations and surgical and functional outcomes were extracted. Twenty-one studies were included. The mean age and follow-up were 54.65 years and 24.72 months, respectively. An isoperistaltic or antiperistaltic standard ICFF, patch flap, or chimeric seromuscular-ICFF can be used depending on the patients' needs. The seromuscular chimeric flap is useful to augment the closure of the distal anastomotic site. The maximum phonation time, frequency, and sound pressure level (dB) were higher with ileal segments of 7 to 15 cm. The incidence of postoperative leakage ranged from 0 to 13.3%, and the majority was occurring at the coloesophageal junction. The revision rate of the microanastomosis ranged from 0 to 16.6%. The ICFF provides a reliable and versatile alternative for reconstruction of middle-size defects of the aerodigestive tract. Its three-dimensional configuration and functional anatomy encourage early speech and deglutition without a prosthetic valve and minimal donor-site morbidity.

• Archives of Plastic Surgery
• /
• v.36 no.5
• /
• pp.611-616
• /
• 2009

Purpose: The rate of fistulas occuring followed by resection of oral cavity, oropharyngeal, hypopharyngeal, and laryngeal cancer are reported to be 9 ~ 23% according to various documents. Neglected treatment of the fistula can result in a setback in proper treatment with restrictions in oral intake leading to delayed return to daily life. Furthurmore, in severe cases, it may injure important vessels and adjacent structures of the neck area. The author reviewed previously reported cases of treatment methods for fistulas recurring after diverse head and neck operations and with sharing the treatment experiments of our patients, we tried to present a treatment algorism for different fistula types. Methods: Our study was based on retrograde analysis of 64 patients who were clinically diagnosed with fistula after operation for cancer of the head and neck from 1997 to 2008 at Severance Hospital. Their primary sites of cancer were 8 oral cavity, 22 oropharynx, 25 hypopharynx, and 9 larynx. The patients were aged 45 to 75 years and the male to female ratio was 11 to 1. The patient's operation records and progress notes were evaluated for determination of degree of fistula and treatment methods. Results: Most fistulas were clinically suspected after postoperative 5 days and symptoms noted for detection of the fistula were erythema, purulent discharge, edema, tenderness, and fluctuation. The fistula was definitely diagnosed at postoperative 2 weeks with barium test and treatment method ranging from conservative management to operative procedure were applied to each patients. Total 21 patients were managed with conservative protocol. In 15 cases, direct repair of the fistula was done and more stable repair of the fistula was possible with using of TachoComb$^{(R)}$. Pharyngostoma was performed in 14 patients. Among them, 4 patients healed spontaneously, 5 patients were taken direct closure, 4 patients were taken pectoralis major musculocutaneous flap, and one patient was taken esophageal transfer. The other 14 patients were taken 11 pectoralis major musculocutaneous flaps and 3 free flaps without pharyngostoma formation. Conclusion: Fistula is a troublesome complication resulting after resection of head and neck cancer. Early detection and adequate treatment according to the period and condition of the fistula may prevent further complications and reduce the pain of the patient.