• Journal of Chest Surgery
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• v.20 no.3
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• pp.458-472
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• 1987

A heart supplies bloods of about 15, 000 liters to each human organ in a day. A normal function of heart valves is necessary to this act of heart. The disease of heart valve develops to a narrowness of a closure, resulting in an abnormal circulation of bloods. In an attempt to eliminate the affliction of heart valves, the operation method to repair with artificial heart valves has been developed and saved numerous patients over past 30 years. This replacement operation has been performed since early 1960`s in Korea, but all the artificial heart valves used are imported from abroad with very high costs until recent years. The artificial heart valve using pyrolytic carbon has been developed at KAIST, which was proved to be stable in the mechanical performance and durability. Therefore, the in viva performance of this valve was examined through animal tests. The artificial heart valves used in this study are tilting disc type valves, in which the disc were made of graphite coated with pyrolytic carbon and the cages were made of titanium. In viva testings of these valves were performed in 12 dogs, in which right ventriculo-pulmonary arterial [Croup I] or inter-aortic [Croup IV] valved conduit was implanted using polytetrafluoroethylene conduits containing KAIST valve and aortic valve [Group II] or pulmonary valve [Croup III] was replaced by a KAIST valve with a 21mm or 19mm tissue annulus diameter. In group I and II, pre-and post-operative transvalvular pressure gradient was measured and compared with other prosthetic valves. During post operative period laboratory examination was performed including hemoglobin, hematocrit, red cell count, white cell, lactic acid dehydrogenase and platelet. The eight surviving dogs were sacrificed and autopsy was performed at 2, 6, and 8 weeks. KAIST valve has low transvalvular gradient and relatively high orifice area. Average ventriculo-aortic peak systolic transvalvular gradient was 14 mmHg in 21 mm valve and 19 mmHg in 19 mm valve. The valve has slight intravascular hemolysis effect. Thrombogenic effect of low polishing quality and eddy currents around small orifice is high. The valve has vulnerability of disc movement. These animal tests suggest that the improvement of the heart valve design, surface polishing state and prescription methods.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10469-10473
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• 2015

Background: Solanum nigrum L. has been used in traditional Chinese medicine because of its diuretic and antipyretic effects. The present research concerned effects of crude polysaccharides isolated from Solanum nigrum L. on erythrocyte membranes of tumor-bearing $S_{180}$ and $H_{22}$ in mice. Materials and Methods: Fluorescence-labeled red blood cell membranes were used with DPH fluorescence spectrophotometry to examine erythrocyte membrane fluidity, and colorimetry to determine degree of erythrocyte surface membrane blocking. Extent of reaction by tumor-bearing mice with the enzyme erythrocyte membrane bubble shadow detection of red cell membrane variation in the degree of closure before and after administration. Results: Solanum nigrum polysaccharide could significantly improve the $S_{180}$ and $H_{22}$ tumor-bearing mice erythrocyte membrane fluidity, compared with the control group, the difference was significant (p<0.01), SNL can significantly improve the red blood cell membrane and then $S_{180}$ tumor-bearing mice sealing ability, compared with the negative control group, the difference was significant(p<0.05, p<0.01). $H_{22}$ tumor-bearing mice can increase red cell membrane and then sealing ability, the difference was significant (p<0.05). Solanum nigrum polysaccharide degree of fluidity and blocking two transplanted tumors in mice restored the ability to raise the red cell membrane has a significant effect. Conclusions: Solanum nigrum L.-type mice transplanted tumor can affect the red blood cell membrane fluidity and re-closed, through the red cell membrane of red blood cells to enhance the immune function of the possibility of erythrocyte immunity against tumor formation garland provide experimental basis.

• Strategy21
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• s.41
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• pp.5-29
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• 2017

The Mahan's seapower theory has been the basis of US Navy to date as it can enjoy the supremacy status in all of the seas of the world. His theory is very straightforward. A nation can be a great country in the world just through the use of maritime commerce that could be protected by a strong and powerful navy. Mahan's theory on seapower was substantiated in the Spanish-American War with respect to how important the naval power is. The best thing to make US a great nation was to make sure that flow of international trade is smooth, and the unhindered trade could be made possible only by the destruction of enemy's fleet that may obstruct the SLOCs. That's why Mahan insisted that a strong navy was needed and a decisive battle by the navy's fleet at sea should be encouraged as a way of ensuring the safety of the SLOCs. The newly-arrived Trump administration seems to be in line with the Mahan's theory seapower in its policy on naval forces structure. It is expected that US will continue to support the Pivot to Asia policy that has been adopted by the previous administration through an increase in its naval fleet forces. The number of US navy ships will be 355 in 2030, rendering it much more powerful navy than before. The catch phrase "3rd Fleet Forward" proposed by the president Trump indicates that two carrier strike groups will be present in the Asia Pacific region, being able to make the confrontation between US and China more tense than before. The presence of the US naval forces in the area may function as some sort of pressure against China that Trump insisted had been responsible for the closure of 60,000 factories and the loss of 3,000,000 jobs in the United States.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.2
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• pp.129-133
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• 2007

Background and Objectives: Nasometry is an easy, noninvasive method to obtain objective data regarding the function of velopharynx. However, because articulation errors may affect the results of nasometry, the examiner should interpret the nasalance score based on appropriate speech stimuli. The purpose of this study is to examine the difference of nasalance score between glottal and oral articulations in patients with velopharyngeal insufficiency (VPI). Materials and Method: Nineteen children between 3.4 and 12.1 years of age (mean age 5.7 years) with a confirmed VPl showing hypernasality and articulation errors (glottal stops) were included. Nasalance scores were obtained for two speech patterns of glottal and oral stops. In addition, the velopharyngeal functions were analyzed in four subjects using video nasopharyngoscopy. Results: The $mean{\pm}S.D$ nasalance scores of the glottal stops and oral stops were $42.54{\pm}16.26%$ and $25.47{\pm}16.51%$ respectively (p=.000). Six of 19 patients achieved normal nasalance scores when glottal stops changed to oral stops by the trial speech therapy. Video nasopharyngoscope confirmed that large velopharyngeal gaps can be decreased into tiny gaps or complete closure when compensatory articulations were corrected for some cases. Conclusion: Compensatory articulation errors must be corrected for the reliable interpretation of the nasalance scores that are obtained in children with velopharyngeal insufficiency, which would facilitate to make a better decision for further management of these patients.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.269-277
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• 2009

The current paper focuses on the analysis of transient cavitating flow in pressurised polyethylene pipes, which are characterized by viscoelastic rheological behaviour. A hydraulic transient solver that describes fluid transients in plastic pipes has been developed. This solver incorporates the description of dynamic effects related to the energy dissipation (unsteady friction), the rheological mechanical behaviour of the viscoelastic pipe and the cavitating pipe flow. The Discrete Vapour Cavity Model (DVCM) and the Discrete Gas Cavity Model (DGCM) have been used to describe transient cavitating flow. Such models assume that discrete air cavities are formed in fixed sections of the pipeline and consider a constant wave speed in pipe reaches between these cavities. The cavity dimension (and pressure) is allowed to grow and collapse according to the mass conservation principle. An extensive experimental programme has been carried out in an experimental set-up composed of high-density polyethylene (HDPE) pipes, assembled at Instituto Superior T$\acute{e}$cnico of Lisbon, Portugal. The experimental facility is composed of a single pipeline with a total length of 203 m and inner diameter of 44 mm. The creep function of HDPE pipes was determined by using an inverse model based on transient pressure data collected during experimental runs without cavitating flow. Transient tests were carried out by the fast closure of the ball valves located at downstream end of the pipeline for the non-cavitating flow and at upstream for the cavitating flow. Once the rheological behaviour of HDPE pipes were known, computational simulations have been run in order to describe the hydraulic behaviour of the system for the cavitating pipe flow. The calibrated transient solver is capable of accurately describing the attenuation, dispersion and shape of observed transient pressures. The effects related to the viscoelasticity of HDPE pipes and to the occurrence of vapour pressures during the transient event are discussed.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.379-386
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• 2014

Background Vulvar defects result chiefly from oncologic resection of vulvar tumors. Reconstruction of vulvar defects restores form and function for the purpose of coitus, micturition, and defecation. Many surgical options exist for vulvar reconstruction. The purpose of this article is to present our experience with vulvar reconstruction. Methods From 2007 to 2013, 43 women presented to us with vulvar defects for reconstruction. Their mean age at the time of reconstruction was 61.1 years. The most common cause of vulvar defect was from resection of vulvar carcinoma and extramammary Paget's disease of the vulva. Method s of reconstruction ranged from primary closure to skin grafting to the use of pedicled flaps. Results The main complications were that of long term hypertrophic and/or unaesthetic scarring of the donor site in 4 patients. Twenty-two patients (51%) were able to resume sexual intercourse. There were no complications of flap loss, wound dehiscence, and urethral stenosis. Conclusions We present a subunit algorithmic approach to vulvar reconstruction based on defect location within the vulva, dimension of the defect, and patient age and comorbidity. The gracilis and gluteal fold flaps are particularly versatile and aesthetically suited for reconstruction of a variety of vulvar defects. From an aesthetic viewpoint the gluteal fold flap was superior because of the well-concealed donor scar. We advocate the routine use of these 2 flaps for vulvar reconstruction.

• Archives of Plastic Surgery
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• v.40 no.1
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• pp.28-35
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• 2013

Background If a chronically infected abdominal wound develops, complications such as peritonitis and an abdominal wall defect could occur. This could prolong the patient's hospital stay and increase the possibility of re-operation or another infection as well. For this reason, a solution for infection control is necessary. In this study, surgery using a rectus abdominis muscle myofascial splitting flap was performed on an abdominal wall defect. Methods From 2009 to 2012, 5 patients who underwent surgery due to ovarian rupture, cesarean section, or uterine myoma were chosen. In each case, during the first week after operation, the wound showed signs of infection. Surgery was chosen because the wounds did not resolve with dressing. Debridement was performed along the previous operation wound and dissection of the skin was performed to separate the skin and subcutaneous tissue from the attenuated rectus muscle and Scarpa's fascial layers. Once the anterior rectus sheath and muscle were adequately mobilized, the fascia and muscle flap were advanced medially so that the skin defect could be covered for reconstruction. Results Upon 3-week follow-up after a rectus abdominis myofascial splitting flap operation, no major complication occurred. In addition, all of the patients showed satisfaction in terms of function and esthetics at 3 to 6 months post-surgery. Conclusions Using a rectus abdominis myofascial splitting flap has many esthetic and functional benefits over previous methods of abdominal defect treatment, and notably, it enabled infection control by reconstruction using muscle.

• Journal of Chest Surgery
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• v.27 no.12
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• pp.989-994
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• 1994

Between January 1986 and August 1993, 11 patients underwent surgical repair of ventricular septal defect [VSD] complicated with myocardial infarction. The ages of patients were ranged from 22 years to 83 years with a mean of 64 years. There were 8 male and 3 female patients. The preoperative cineangiograms of all patients were reviewed to measure both ventricular function and to evaluate coronary artery disease. The mean time interval between occurance of VSD and operation was 13 days. The operations were performed as soon as possible if there were hemodynamic derangement. Postmyocardial infarction VSD were repaired simultaneuously with coronary artery bypass graft in 3 patients, repaired with left ventricular aneurysmectomy in 6 patients, with left ventricular thrombectomy in 1 patient and with mitral valve chordae repair in 1 patient. There was no early death [within 30 days]. There were 6 postoperative complications; one with perioperative myocardial infarction, two with recurred VSD on postoperative 1 and 6 days respectively, two with lower leg embolism associated with intraaortic balloon pump insertion, one with wound infection. Of the complicated patients, 1 patient with lower leg embolism performed left above ankle amputation. Among two patients with recurred ventricular septal defect, one patient is doing well without problem. On follow up echocardiogram, the residual VSD was occluded completely. However another patient was with recurred VSD died 3 months after the operation because of congestive heart failure. Of the long term survivors, all patients are in NEW YORK Heart Association functional Class I or II. Although number of patients were small, our results of surgical closure of postmyocardial infarction VSD were favored to the others. Moreover, seven patients with preoperative cardiogenic shock among 11 were performed early operation after diagnosis of ventricular septal rupture. All of the patients were survived and doing well during the follow up period. Therefore early diagnosis with aggressive preoperative care with intraaortic balloon pumping and early operation seems to be very important for prevention of deterioration of vital organ.

• Journal of Chest Surgery
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• v.43 no.1
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• pp.63-66
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• 2010

Apical muscular ventricular septal defects (VSDs) are relatively rare conditions among all the different types of VSDs. Apical VSDs are difficult to treat because of they are difficult to visualize through a trans-atrioventricular approach, and especially in infants. Treatment by left ventriculotomy is associated with long-term ventricular dysfunction. Catheter-based intervention still shows less than satisfactory results and this type of intervention may not be possible in small infants. This report describes the benefits of right apical ventriculotomy in terms of successful closure of the lesion without harming the ventricular function.

• Archives of Plastic Surgery
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• v.40 no.5
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• pp.603-609
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• 2013

Background Although the conventional direct brow lift operation provides a simple means of managing lateral brow ptosis, the scars produced have been unacceptable. However, using the modifications proposed here, scarring showed remarkable improvement. This article reviews our experiences with the presented technique, mainly with respect to postoperative scarring. Methods Measured amounts of supra-eyebrow skin and subcutaneous fat were excised en bloc in the conventional manner under 'hyper-hydrated' local infiltration anesthesia. The lower flap and the edge of the upper flap were undermined above the muscular plane, and the orbicularis oculi muscle was directly suture-plicated and suspended upward to the distal frontalis muscle. Skin closure was performed in a basic plastic surgical manner. Results From April 2007 to April 2012, a consecutive series of 60 patients underwent surgery using the above method. The average width of the excised skin was 8 mm (range, 5-15 mm) at the apex of the eyebrow. Preoperative complaints were resolved without occurrence of significant complications. The surgical scars showed remarkable improvement and were negligible in the majority of the cases. Conclusions The direct brow lift operation combined with plication/suspension of the superior and lateral portion of the orbicularis oculi muscle provides a simple, safe, and predictable means of correcting lateral brow ptosis. The scars were acceptable to all of the patients. For proper management of the frontalis tone, upper blepharoplasty and/or repair of eyelid levator function must be considered in addition to brow lift procedures.