• Journal of Chest Surgery
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• v.31 no.8
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• pp.763-769
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• 1998

Background: Supravalvular aortic stenosis is a rare form of congenital cardiac anomaly involving ascending aorta distal to coronary orifice. Materials and methods: We operated 12 cases of supravalvular aortic stenosis between July 1986 and March 1997. Age ranged from 4 to 17(mean 10.2) years and 11 of them were male. Nine patients had clinical features of Williams syndrome. We experienced two types of supravalvular aortic stenosis, including 10 hour glass type and 2 diffuse type. Results: Preoperative transaortic pressure gradient ranged from 40 to 180(mean 92) mmHg by cardiac catheterization. Pulmonary stenosis was associated in 5 and 2 of them required angioplasty. Operative techniques included 6 standard aortoplasty with elliptical patch, 4 extended aortoplasty with inverted Y shaped patch, and 2 modified Brom's repair. There were no operative deaths. Postoperative echocardiographic evaluation was done at a mean interval of 12 months. Grade I or II aortic regurgitation was found in 3 cases. Postoperative cardiac catheterization revealed a mean transaortic pressure gradient of 26 (range 0 to 75) mmHg. A mean pressure drop was 78(range 30 to 114) mmHg. All patients were followed up for a mean of 40(range 1 to 67) months with uneventful clinical course. Conclusions: Our data proved the low mortality and excellent hemodynamic improvement after surgical relief of supravalvular aortic stenosis in children.

• Journal of Chest Surgery
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• v.35 no.10
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• pp.755-759
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• 2002

A 64-year-old man was admitted for gross hematuria. Preoperative study revealed right renal cell carcinoma with inferior vena cava(IVC) tumor thrombus. Right radical nephrectomy was performed, and deep hypothermic circulatory arrest(DHCA) with retrograde cerebral perfusion(RCP) was used for extraction of tumor thrombus in the IVC. The thrombus originated from the right kidney, which extended the orifice of the gonadal vein in the left renal vein laterally, the hepatic vein superiorly, and 3cm below the right renal vein inferiorly. The thrombus was removed completely without caval wall injury under DHCA with RCP, and the postoperative course was uneventful. He received immunotherapy with interferon, and followed up without any surgical problem.

• Journal of Chest Surgery
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• v.35 no.10
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• pp.750-754
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• 2002

Primary cardiac tumors are rare and about 20~25% of primary cardiac tumors are malignant. Moreover, primary malignant mesenchymoma of the heart is extremely rare. Recently, we have experienced two cases of cardiac malignant mesenchymoma. In the first case, malignant mesenchymoma which was originated from the posterior wall of the left atrium obstructing the mitral orifice was revealed pathologically in a 61-year-old woman with mitral regurgitation. The mass, which was 2.7$\times$3.7cm in size on the posterior wall of left atrium, was extended to the posteromedial commissure and annulus of the mitral valve. The mass was resected partially without excision of the left atrial free wall. She was discharged after 30 days without any problems and she received chemotherapy and followed up for 19months. The second case was a 4$\times$5cm in size, friable, yellow-whitish multilobulated mass in the left atrium which was originated from the left lower pulmonary vein. Multiple minor tumor nodules were found in the wall of the left atrium and the posterior leaflet of mitral valve. Partial mass excision and mitral valve replacement were performed.

• Journal of Korean Medical classics
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• v.13 no.2 s.17
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• pp.21-21
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• 2000

All living things including human being consist of soul(spirit) and body. Soul is the root of a life and body frames it. I wrote this paper to tell how internal injury due to endogenous etiological factors and affection due to exegenous pathogenic factors, affect the internal organs and the external bodily from. This paper begins with description of the patterns of disharmony of the internal organs. General disorders of each Five-Jang(五藏) an be classified into two types of soul and body. The Liver and the Heart which lead changing to Yang(陽) of vital energy, have close relationship with spiritual symptoms because spirit is related to Yang. The Lung, Kidneys, the Spleen which lead changing to m(陰) of vital energy, mainly connected with physical disorders because body is relatively close to m. The Five-Jang are ruled by the Five-Phases(五行) system and cause troubles with Oche(五體) and the nine body orifice. Otherwise the main function of the Six-Bu(六府) is to receive food, absorb the usuable portions, and transmit and excrete waste. Therefore they can cause such problems as abdominal pain, distention, difficulty in urination, and constipation. The spleen is responsible for sending Grain-Ki)穀氣) 내 that is closely connected with the six-Bu. The Gall bladder takes care of control of giving out spirit. That's why it presents many symptoms related to the spirit that is ruled by the Five-Jang. Patterns of disharmony of external bodily form is influenced by the state of Maridians. Bodily forms get divided into many parts by the function of six-meridians(六經) to which they belong. Six-meridians have their own function related to excretion, related to excretion, retention, and balance(開闔樞). If local bodily froms get affected by pernicious influences, the Meridians to which they are attached will lose harmony and connot fulfil their own functions. Because the meridian symtem unifies all parts of the body, the whole body will be under the influence of the affection although local parts of the bodily forms get affected. Therefore the symptoms of disharmony should be considered in a synthetic view. There are however, also cases which should be focused on the very meridian channels affected. Disorder within a Meridian generates derangement in the pathway make it not to benefit the muscles and skin belong to it. Because the meridians connect the interior organs with the exterior bodily form, they are influenced by each other.

• Journal of Korean Medical classics
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• v.13 no.2 s.17
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• pp.22-42
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• 2000

All living things including human being consist of soul(spirit) and body. Soul is the root of a life and body frames it. I wrote this paper to tell how internal injury due to endogenous etiological factors and affection due to exogenous pathogenic factors, affect the internal organs and the external bodily from. This paper begins with description of the patterns of disharmony of the internal organs. General disorders of each Five-Jang(五藏) an be classified into two types of soul and body. The Liver and the Heart which lead changing to Yang(陽) of vital energy, have close relationship with spiritual symptoms because spirit is related to Yang. The Lung, Kidneys, the Spleen which lead changing to m(陰) of vital energy, mainly connected with physical disorders because body is relatively close to m. The Five-Jang are ruled by the Five-Phases(五行) system and cause troubles with Oche(五體) and the nine body orifice. Otherwise the main function of the Six-Bu(六府) is to receive food, absorb the usable portions, and transmit and excrete waste. Therefore they can cause such problems as abdominal pain, distention, difficulty in urination, and constipation. The spleen is responsible for sending Grain-Ki(穀氣) so that is closely connected with the six-Bu. The Gall bladder takes care of control of giving out spirit. That's why it presents many symptoms related to the spirit that is ruled by the Five-Jang. Patterns of disharmony of external bodily form is influenced by the state of Meridians. Bodily forms get divided into many parts by the function of six-meridians(六經) to which they belong. Six-meridians have their own function related to excretion, related to excretion, retention, and balance(開闔樞). If local bodily forms get affected by pernicious influences, the Meridians to which they are attached will lose harmony and cannot fulfil their own functions. Because the meridian system unifies all parts of the body, the whole body will be under the influence of the affection although local parts of the bodily forms get affected. Therefore the symptoms of disharmony should be considered in a synthetic view. There are however, also cases which should be focused on the very meridian channels affected. Disorder within a Meridian generates derangement in the pathway make it not to benefit the muscles and skin belong to it. Because the meridians connect the interior organs with the exterior bodily form, they are influenced by each other.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.7.1-7.9
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• 2013

Objectives We investigated the particle mass size distribution and chemical properties of air pollution particulate matter (PM) in the urban area and its capacity to induce cytotoxicity in human bronchial epithelial (BEAS-2B) cells. Methods To characterize the mass size distributions and chemical concentrations associated with urban PM, PM samples were collected by a 10-stage Micro-Orifice Uniform Deposit Impactor close to nearby traffic in an urban area from December 2007 to December 2009. PM samples for in vitro cytotoxicity testing were collected by a mini-volume air sampler with $PM_{10}$ and $PM_{2.5}$ inlets. Results The PM size distributions were bi-modal, peaking at 0.18 to 0.32 and 1.8 to $3.2{\mu}m$. The mass concentrations of the metals in fine particles (0.1 to $1.8{\mu}m$) accounted for 45.6 to 80.4% of the mass concentrations of metals in $PM_{10}$. The mass proportions of fine particles of the pollutants related to traffic emission, lead (80.4%), cadmium (69.0%), and chromium (63.8%) were higher than those of other metals. Iron was the dominant transition metal in the particles, accounting for 64.3% of the $PM_{10}$ mass in all the samples. We observed PM concentration-dependent cytotoxic effects on BEAS-2B cells. Conclusions We found that exposure to $PM_{2.5}$ and $PM_{10}$ from a nearby traffic area induced significant increases in protein expression of inflammatory cytokines (IL-6 and IL-8). The cell death rate and release of cytokines in response to the $PM_{2.5}$ treatment were higher than those with $PM_{10}$. The combined results support the hypothesis that ultrafine particles from vehicular sources can induce inflammatory responses related to environmental respiratory injury.

• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.418-426
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• 2006

In the artificial heart application, productivity and hemodynamic properties of artificial heart valves are crucial in successiful application to long term in vivo trials. This paper is about manufacture and assessment of trileaflet polymer heart valves using vacuum forming process(VFP). The VFP has many advantages such as reduced fabrication time, reproducibility due to relatively easy and simple process for manufacturing. Prior to VFP of trileaflet polymer heart valves, polyurethane(Pellethane 2363 80AE, Dow Chemical) sheet was prepared by extrusion. The sheets were heated and formed to mold shape by vacuum pressure. The vacuum formed trileaflet polymer heart valves fabrication is composed of two step method, first, leaflet forming and second, conduit forming. This two-step forming process made the leaflet-conduit bonding stable with any organic solvents. Hydrodynamic properties and hemocompatibility of the vacuum formed trileaflet polymer heart valves was compared with sorin bicarbon bileaflet heart valve. The percent effective orifice area of vacuum formed trileaflet polymer heart valves was inferior to bileaflet heart valve, but the increase of plasma free hemoglobin level which reflect blood damage was superior in vacuum formed trileaflet polymer heart valves Vacuum formed trileaflet polymer heart valves has high productivity, and superior hemodynamic property than bileaflet heart valves. Low manufacturing cost and blood compatible trileaflet polymer heart valves shows the advantages of vacuum forming process, and these results give feasibility in in vivo animal trials in near future, and the clinical artificial heart development program.

• Journal of the Korean Magnetics Society
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• v.3 no.3
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• pp.201-207
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• 1993

Starting ingot of $Pr_{15}Fe_{77}B_{8}$ were prepared by vacuum induction melting under argon atmosphere. The ingot were induction melted in a quartz crucible and then ejected as a molten alloy throuth a 0.6 mrn orifice onto a rotating cop¬per wheel. An anisotropic magnet was prepared from ribbon by hot deformation techniques. A fully dense precursor magnet first made by pressing ribbons at $680^{\circ}C$ under a pressure of $21.8\;kg/mm^{2}$. A substantially oriented magnets were obtained by die-upset under various conditions. As the compression ratio increases, the $B_{r}$ value increases pronouncedly though $_{i}H_{c}$ decreases. Also, XRD analyses show increased diffraction peak from (006). From these results, it can be known that the magnetic easy axis was formed along the compression axis. As the die-upset speed increases, $_{i}H_{c}$ increases though $B_{r}$ decreases. The $B_{r}$ increases up to $750^{\circ}C$ of die-upset temperature and above this temperature decreases. The value of $4{\pi}M_{s}$ of the $Pr_{15}Fe_{77}B_{8}$ alloy prepared is found to be 11.8 KG. When the alloy was compressed by 0.8 under the die-upset speed of 0.05 m/sec at $750^{\circ}C$, $B_{r}$ was 11.0 KG indicating that the alloy has excellent magnetic anistropy. However, this alloy has some limitation because of low $_{i}H_{c}$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.6
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• pp.397-402
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• 2016

To produce adequate electricity in nuclear and thermal power plants, an optimal amount of steam should be supplied to a generator connected to high- and low-pressure steam turbines. A turbine output control device, which is a special steam valve employed to supply or interrupt the steam to the turbine, is operated using a hydraulic servo actuator. In power plants, the performance of servo actuators is degraded by the air generated from the hydraulic system, or causes frequent failures owing to an increase in the wear of the seal. This is due to the seal being burnt as generated heat using the produced compressed air. Some power plants have exhausted air using a fixed orifice, and thus they encounter power loss due to mass flow exhaust. Failures are generated in hydraulic pumps, electric motors, and valves, which are frequently operated. In this study, we perform modeling and analysis of the load-sensing air-exhaust valves, which can be passed through very fine flow under normal use conditions, and exhaust mass flow air at the beginning stage as with existing fixed orifices. Then, we propose a method to prevent failures due to the compressed air, and to ensure the control accuracy of hydraulic servo actuators.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.2
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• pp.173-180
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• 2006

Objectives The aim of this study is to compare the quality of root canal preparation completed using MFile-$System^{(R)}$ instrument ( Komet, Gebr.Brsaseler, Germany) and conventional stainless steel file in the canals of Maxillary molar teeth that had a canal curvature between $25^{\circ}$ or more Materials & Methods Buccal canals of 24 first and second maxillary molar teeth, extracted for periodontal and prosthetic reasons were used. Tissue fragments and calcified debris were removed from teeth by scaling and the teeth were stored in 10% formalin solution for 24 hour. Then, teeth were stored in saline until used. To be included the roots had to have completed formed apices and angle of curvature ranging between $25^{\circ}$ or more according to the criteria described by Schneider(1971). Palatal and Second mesiobuccal canals were not included. Teeth were embedded into transparent acrylic. The teeth were randomly divided into two experimental groups. All teeth were scanned by Dental CT (PSR9000N, Asahi, Japan) to determine the root canal shape before instrumentation. Image slices were prepared from the apical end point to the pulp chamber. The first two sections were 2 mm from the apical end of root and 2 mm below the orifice. Further section was recorded, dividing the distance between the sections of apical and coronal levels into two equal lengths. 12 teeth were instrumented using stainless steel fileand another 12 teeth were instrumented using MFile-$System^{(R)}$. Following the completion of the instrumentation, the teeth were again scanned and compared with the cross sectional images taken prior to canal preparation. Amount of transportation and centering ability was assessed. Student's t-test was used for statistical analysis. Result Less transportation occurred with MFile-$System^{(R)}$ rotary instrumentation than stainless steel instrument. MFile-$System^{(R)}$ had better centering ability than stainless steel instrument. Conclusion MFile-$System^{(R)}$ rotary instrumentation transported canals less and had good centering ability.