• Archives of Reconstructive Microsurgery
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• v.6 no.1
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• pp.29-38
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• 1997

A peripheral nerve when approximation of the ends imparts tension at the anastomosis and with a relatively long segment defect after excision of neuroma and neurofibroma cannnot be repaired by early primary suture. The one of the optimistic reconstruction method of severed peripheral nerves is to restore tension-free continuity at the repair site putting an autogenous nerve graft into the neural gap despite of ancipating motor or sensory deficit of the donor nerve area. To overcome the deficit of the autogenous nerve graft, several other conduits supplying a metabolically active environment which is able to support axon regeneration and progression, providing protection against scar invasion, and guiding the regrowing axons to the distal stump of the nerve have been studied. An author have used ipsilateral femoral vein, ipsilateral femoral vein filled with fresh thigh muscle, and autogenous sciatic nerve for the sciatic nerve defect of around 10 mm in length to observe the regeneration pattern in rat by light and electron microscopy. The results were as follows. 1. Light microscopically regeneration pattern of nerve fibers in the autogenous graft group was more abundant than vein graft and vein filled with muscle group. 2. On ultrastructural findings, the proxial end of the graft in various groups showed similar regenerating features of the axons, myelin sheaths, and Schwann cells. The fascicular arrangement of the myelinated and unmyelinated fibers was same regardless of the type of conduits. There were more or less increasing tendency in the number and the diameter of myelinated fibers correlated with the regeneration time. 3. In the middle of the graft, myelinated nerve fibers of vein filled with muscle group were more in number and myelin sheath was thinner than in the venous graft, but the number of regenerating axons in autogenous nerve graft was superior to that in both groups of the graft. The amount of collagen fibrils and amorphous materials in the endoneurial space was increased to elapsed time. 4. There was no difference in regenerating patterns of the nerve fibers of distal end of the graft. The size and shape of the myelinated nerve fbers were more different than that of proximal and middle portion of the graft. From the above results, the degree of myelination and regenerating activity in autogenous nerve is more effective and active in other types of the graft and there were no morphological differences in either ends of the graft regardless of regeneration time.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1325-1331
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• 2012

Tumor formation and growth is dictated by a very small number of tumor cells, called cancer stem cells, which are capable of self-renewal. The genesis of cancer stem cells and their resistance to conventional chemotherapy and radiotherapy via mechanisms such as multidrug resistance, quiescence, enhanced DNA repair abilities and anti-apoptotic mechanisms, make it imperative to develop methods to identify and use these cells as diagnostic or therapeutic targets. Aldehyde dehydrogenase 1 (ALDH1) is used as a cancer stem cell marker. In this study, we evaluated ALDH1 expression in CaSki, HeLa and SiHa cervical cancer cells using the Aldefluor method to isolate ALDH1-positive cells. We showed that higher ALDH1 expression correlated with significantly higher rates of cell proliferation, microsphere formation and migration. We also could demonstrate that SiHa-ALDH1-positive cells were significantly more tumorigenic compared to SiHa-ALDH1-negative cells. Similarly, SiHa cells overexpressing ALDH1 were significantly more tumorigenic and showed higher rates of cell proliferation and migration compared to SiHa cells where ALDH1 expression was knocked down using a lentivirus vector. Our data suggested that ALDH1 is a marker of cervical cancer stem cells and expand our understanding of its functional role.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.3
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• pp.275-281
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• 2004

Socket weldment used to change the flow direction of fluid nay have flaws such as lack of fusion and cracks. Liquid penetrant testing or Radiography testing have been applied as NDT methods for flaw detection of the socket weldment. But it is difficult to detect the flaw inside of the socket weldment with these methods. In order to inspect the flaws inside the socket weldment, a ultrasonic testing method is established and a ultrasonic transducer and automated ultrasonic testing system are developed for the inspection. The automated ultrasonic testing system is based on the portable personal computer and operated by the program based Windows 98 or 2000. The system has a pulser/receiver, 100MHz high speed A/D board, and basic functions of ultrasonic flaw detector using the program. For the automated testing, motion controller board of ISA interface type is developed to control the 4-axis scanner and a real time iC-scan image of the automated testing is displayed on the monitor. A flaws with the size of less than 1mm in depth are evaluated smaller than its actual site in the testing, but the flaws larger than 1mm appear larger than its actual size on the contrary. This tendency is shown to be increasing as the flaw size increases. h reliable and objective testing results are obtained with the developed system, so that it is expected that it can contribute to safety management and detection of repair position of pipe lines of nuclear power plants and chemical plants.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.368-375
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• 2013

Failure of small bore piping welds is a recurring problem at nuclear power plants. And the socket weld cracking in small bore piping has caused unplanned plant shutdowns for repair and high economic impact on the plants. Consequently, early crack detection, including the detection of manufacturing defects, is of the utmost importance. Until now, the surface inspection methods has been applied according to ASME Section XI requirements. But the ultrasonic inspection as a volumetric method is also applying to enforce the inspection requirement. However, the conventional manual ultrasonic inspection techniques are used to detect service induced fatigue cracks. And there was uncertainty on manual ultrasonic inspection because of limited access to the welds and difficulties with contact between the ultrasonic probe and the OD(outer diameter) surface of small bore piping. In this study, phased array ultrasonic inspection technique is applied to increase inspection speed and reliability. To achieve this object, the 3.5 MHz phased array ultrasonic transducer are designed and fabricated. The manually encoded scanner was also developed to enhance contact conditions and maintain constant signal quality. Additionally inspection system is configured and inspection procedure is developed.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.95-110
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• 1992

Much progress has been made in understanding the subcellular events of the human lung injuries after acute exposure to environmental air pollutants. Host of those events represent oxidative damages mediated by reactive oxygen species such as superoxide, hydrogen peroxide, and the hydroxy, free radical. Recently, nitric oxide (NO) was found to be endogenously produced by endothelial cells and cells of the reticulo-endothelial system as endothelialderived relaxation factor (EDRF) which is a vasoactive and neurotransmitter substance. Together with superoxide, NO can form another strong oxidant, peroxonitrite. The relative importance of exogenous sources of $N0/N0_2$ and endogenous production of NO by the EDRF producing enzymes in the oxidative stresses to the heman lung has to be elucidated. The exact events leading to chronic irreversible damage are still yet to be known. From chronic exposure to oxidant gases, progressive epithelial and interstitial damages develop. Type I epithelial cells become thicker and cover a smaller average alveolar surface area while thee II cells proliferate instead. Under acute damages, the extent of loss of the alveolar epithelial cell lining, especially type II cells appears to be a good predictor of the ensuing irreversible damage to alveolar compartment. Interstitial matrix undergo remodeling during chronic exposure with increased collagen fibers and interstitial fibroblasts. However, Inany of these changes can be reversed after cessation of exposure. Among chronic lung injuries, genetic damages and repair responses received particular attention in view of the known increased lung cancer risks from exposure to several air pollutants. Heavy metals from foundry emission, automobile traffics, and total suspended particulate, especially polycystic aromatic hydrocarbons have been positively linked with the development of lung cancer. Asbestos in another air pollutant with known risk of lung cancer and mesothelioma, but asbestos fibers are nonauthentic in most bioassays. Studies using the electron spin resonance spin trapping method show that the presence of iron in asbestos accelerates the production of the hydroxy, radical in vitro. Interactions of these reactive oxygen species with particular cellular components and disruption of cell defense mechanisms still await further studies to elucidate the carcinogenic potential of asbestos fibers of different size and chemical composition. The distribution of inhaled pollutants and the magnitude of their eventual effects on the respiratory tract are determined by pollutant-independent physical factors such as anatomy of the respiratory tract and level and pattern of breathing, as well as by pollutant-specific phyco-chemical factors such as the reactivity, solubility, and diffusivity of the foreign gas in mucus, blood and tissue. Many of these individual factors determining dose can be quantified in vitro. However, mathematical models based on these factors should be validated for its integrity by using data from intact human lungs.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.379-382
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• 1999

Background: There are several advantages to the ministernotomy approach. The skin incision is much smaller than the traditional median sternotomy incision. This approach allows the patients to return to normal life more quickly and provide them with good self-image. Material and Method: From April to July 1998, we performed a ministernotomy via lower half sternum in 25 patients. There were 10 males(40%) and 15 females(60%) with a mean age of 30${\pm}$16 years(range 3 to 55 years). The body surface area ranged from 0.58 to 1.9 m2(mean 1.5 to 0.4 m2). A vertical skin incision of 11cm in mean length was made in the midline over the sternum extending inferiorly from the third intercostal space. The sternum was divided vertically in the midline from the xyphoid process to the level of second intercostal space using a standard saw and then transversely to the left(n=17) or to both sides(n=4) of the second intercostal space using an oscillating saw. The sternum was divided vertically only in children (n=4). Result: The ministernotomy was used in 25 consecutive patients undergoing mitral valve replacement(n=10), repair of ventricular septal defect(n=4) and atrial septal defect(n=11). There was no significant complication related to ministernotomy. The mean ICU stay time 20 hours. Patient and family acceptance was very high. Conclusion: We concluded that minimally invasive cardiac surgery via ministernotomy can be done safely. These methods may benefit the patients with lesser discomfort, smaller incision, and earlier ICU discharge than the traditional incision.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.509-516
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• 2020

Since the 1960s, many rivers have been polluted and destroyed due to river repair projects for economic development and the covering of small rivers due to urbanization. Many studies have analyzed rivers using measured river topographic factors, but surveying is not easy when the flow rate changes rapidly, such as during a flood. In addition, the previous research has been mainly about the cross section of a river, so information on the longitudinal profile is insufficient. This research used informational entropy theory to obtain an equation that can calculate the average river slope, river slope, and river longitudinal elevation for a river basin in real time. The applicability was analyzed through comparison with measured data of a river's characteristic factors obtained from a river plan. The parameters were calculated using informational entropy theory, nonlinear regression analysis, and actual data. The longitudinal elevation entropy equation for each stream was then calculated, and so was the average river slope. All of the values were over 0.96, so it seems that reliable results can be obtained when calculating river characteristic factors.

• Journal of Korean Foot and Ankle Society
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• v.20 no.1
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• pp.12-18
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• 2016

Purpose: The purpose of this study is to review the indications of ankle lateral complex reconstruction using tendon graft. Materials and Methods: We searched PubMed using the index, "ankle, instability, lateral ligament, reconstruction" from 1990 to present (September 30, 2015). We excluded 1) modified Brőstrom operation (MBO), 2) conventional tenodesis surgery, 3) review article, 4) technical note, and 5) articles written in another foreign language. We reviewed 24 papers through the publication events, operational method, the indications of surgery, and the specific features of the patient group. Results: There were the indications of 1) previous ligament surgery failure, 2) situation when ligament repair is impossible due to the ligament defect, 3) severe instability (preoperative talar tilt >$15^{\circ}$, anterior draw >10 mm or the difference of contralateral side talar tilt >$5^{\circ}$, anterior draw >3 mm), and 4) overweight (body mass index >$30kg/m^2$). Other considerations included 1) generalized joint laxity and 2) workers, highly-demanded or athlete highly-affected by instability. Conclusion: The ankle lateral complex reconstruction using tendon graft could be indicated in patients with the possibility of MBO failure with several considerations.

• Archives of Plastic Surgery
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• v.37 no.1
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• pp.59-66
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• 2010

Purpose: In the finger, there are three major palmar arches in the arterial system. The location of this arches are constant. The middle and distal transverse arches are consistently large (almost 1 mm) and may be used for arterial vessel repairs either proximally or distally, depending on the length and direction needed. This paper describes our experiences in reconstruction and replantation of the finger using rerouting the transverse digital palmar arch. Methods: 31 patients with injuries according to our classification were treated from March of 2005 to October of 2008. In this study the authors subdivided injuries into those with amputation distal to the insertion of the flexor digitorum profundus (Class I, 31 fingers); those with amputation distal to the insertion of the flexor digitorum superficialis (Class II, 4 fingers). Replantation was performed using the artery-only technique with neither vein nor nerve repair. Because the artery has been damaged, it is still possible to make a direct suture by transposing the arterial arch in an inverted Y to I arterial configuration or converting the arch. Venous drainage was provided by an external bleeding method with partial nail excision, medical leech, and repaired margin. Results: The success rate was 87% (n=27) in class I and 75% (n=4) in class II. The authors conclude that crushing and complete avulsion injuries & amputations are salvageable, with acceptable functional results in select patients, especially those with amputation distal to the insertion of the flexor digitorum superficialis. Conclusion: We performed replantation and reconstruction with only-arterial transposing anastomosis successfully, resulting in good recovery of aesthetic and functional outcome. Three major digital palmar arches, especially distal two branches, give us additional treatment options. In the finger replantation and reconstructive techniques using rerouting healthy the transverse digital palmar arch increase the survival rate of the finger.

• Journal of Chest Surgery
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• v.39 no.10 s.267
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• pp.765-769
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• 2006

Background: Nuss procedure is a minimally invasive technique for correcting the pectus excavatum. But there are some limitations of correcting the complex anomaly or grown-up patients. Material and Method: we retrospectively reviewed 135 consecutive patients who underwent repair of pectus excavatum by the Nuss procedure and its modifications between November 1999 and December 2004. We analyzed the computed tomography, age on operation, operative technique, and complications. Result: We operated 135 patients of pectus excavatum during 62 months. Total number of operations about Nuss procedure is 216, including bar removal procedure of 64 cases, redo Nuss procedures of 47 cases. We modified the point of bar insertion to the hinge point, made a shoulder in the bar to prevent a displacement. And then we changed the fixation material from Vicryl to steel wire. If the patients are old, we retract the sternum during bar rotation and fixation. Until 2002, the number of redo Nuss operations were 17, complications were 23. but, after modifications, the number of redo Nuss operation were 0, complications were 2. Conclusion: This result indicates that our modifications of Nuss operation is effective, and could decrease the number of redo Nuss operation and complications.