• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.3
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• pp.281-289
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• 1994

This is a clinical study on 235 inpatients who sustained a total of 350 mandibular fractures and who were treated in our department during the period of Oug., 1989 through Dec., 1993. The results obtained are as follows : 1. The mumber of patients has not been increased year after year. In respect of incidence, there were the highest frequency as 67 patients(28.5%) in 1991 and the least frequency as 16 patients(6.8%) in 1989 and the highest frequency as 28 patients(11.9%) in October and the least frequncy as 12 patients(5.2%) in February. 2. The age frequency was the highest in the second decade(30.6%). The youngest patient was 8 months and the eldest patient was 80 years and mean age was 27.8 years. The ratio of men to Wemen was 4 : 1. 3. The most frequent cause was fall down as 86 patients(36.6%) and the next was fist blow 4 as 75 patients(31.9%), traffic accident as 56 patients(23.9%) in order. 4. The most common location was symphysis as 141 numbers(40.3%) and the next was condyle as 96 numbers(27.4%), angle as 94 numbers(26.8%), body as 14 numbers(4.0%) in order. The sum of fracture sites were 350 and there were 1.49 fracture sites per one patient and multiple fractures occured in 100 patients(40.5%) of the 235 patients. The ratio of Left to Right except for symphysis was 1.71 : 1. 5. Among the 333 associated injuries, facial laceration was 136(57.9%) and tooth injury was 58(24.7%) and extremity was 31(13.2%). 6. Among the 350 mandibular fractures, complications after treatment occured in 51(14.6%) and infection as 20(5.7%) was the most frequent complication. 7. In respect of treatment of mandibular fracture, close reduction was 64 patients(27.2%) and open reduction was 164 patients(69.8%) and other were 7 patients(3.0%) of all and so open reduction was the most common in type of treatment.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.59-66
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• 1984

Although it is well established that steroid is effective for treatment of neonatal respiratory distress syndrome (NRDS), the action mechanism of steroid on NRDS is not well known. Several authors have insisted that steroid increases secretion of pulmonary surfactant from type II pneumocyte, but others have insisted that steroid does not affect the secretory function of the type II pneumocyte. And some authors have suggested that steroid may ca use compositional change of pulmonary surfactant phospholipid. From these aspects, it is desirable to confirm the effect of steroid on (he secretory function of the type II pneumocyte. In order to know the effect of steroid on pulmonary surfactant activity, phospholipid phosphorus of lung lavage was measured and composition of pulmonary surfactant phospholipid of lung lavage was analyzed by thin layer chromatography (TLC) in control (C), pneumonectomized (PN), and pneumonectomized with betamethasone treated (PNS) rabbits. And lung weight and lung weight-body weight ratio were measured in each experimental group also. In PN group, right lung pneumonectomy was performed under general anesthesia with pentobarbital sodium (30mg/kg). On the fifth day after the surgery, the left lung was excised and measured above parameters. In PNS group, pneumonectomy was performed as PN group, and one day after the surgery, betamethasone was injected for four days intramusculary (4mg/day) and rabbits were sacrificed. The experiment yielded following results. PNS group's lung weight was significantly (p<0.01) heavier than C group's, but in comparison with PN group's it showed no significant change. PNS group's L/B ratio was significantly (p<0.05) higher than C group's, but compared with PN group's it showed no significant change. The value of phospholipid phosphorus content of PNS group was significantly (p<0.01) higher than that of C group. Even if the value of phospholipid phosphorus content in PNS group was not significantly higher than that of PN group, it showed increasing tendency compared with that of PN group. And in an analysis of the thin layer chromatogram, quantity (${\mu}mol/gm$ of wet weight lung) of phosphatidylcholine in PNS group decreased significantly (p<0.05) compared with C and PN group. From these results, it may be suggested that though steroid inhibits cellular hyperplasia in the compensatory growing lung, it auguments the secretory function of type II pneumocyte and causes compositional change of pulmonary surfactant phospholipid.

• Korean Journal of Optics and Photonics
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• v.22 no.1
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• pp.23-29
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• 2011

Bistable chiral splay nematic liquid crystal display (BCSN LCD) is a memory type liquid crystal display using splay and $-\pi$ twist states as two stable states. When the cell thickness to pitch (d/p) ratio is 0.25, splay and $-\pi$ twist states have permanent memory time. However, when the transition from $-\pi$ twist state to splay state is caused by a fringe field, pixel regions show that the splay state is not perfect, but rather includes a contribution from the $-\pi$ twist state. In this paper, we propose a reflective BCSN LCD using $-\pi$ twist state in which the two stable states do not coexist. The fabricated reflective BCSN LC cell shows a high contrast ratio of over 30:1 and response times of 950 ms and 450 ms in vertical and fringe field switching, respectively. The proposed cell also shows wide viewing angle characteristics of $180^{\circ}$ in left- and right directions.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.373-378
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• 1999

Background: Minimally invasive technique for various cardiac surgeries has become widely accepted since it has been proven to have distinct advantages for the patients. We describe here the results of our experiences of minimal incision in cardiac surgery. Material and Method: From February 1997 to November 1998, we successfully performed 31 cases of minimally invasive cardiac surgery. Male and female ratio was 17:14, and the patients age ranged from 1 to 75 years. A left parasternal incision was used in 9 patients with single vessel coronary heart disease. A direct coronary bypass grafting was done under the condition of the beating heart without cardiopulmonary bypass support(MIDCAB). Among these, one was a case of a reoperation 1 week after the first operation due to a kinked mammary artery graft. A right parasternal incision was used in one case of a redo mitral valve replacement. Mini-sternotomy was used in the remaining 21 patients. The procedures were mitral valve replacement and tricuspid annuloplasty in 6 patients, mitral valve replacement 5, double valve replacement 2, aortic valve replacement 1, removal of left atrial myxoma 1, closure of atrial septal defect 2, repair of ventricular septal defect 2, and primary closure of r ght ventricular stab wound 1. The initial 5 cases underwent a T-shaped mini-sternotomy, however, we adopted an arrow-shaped ministernotomy in the remaining cases because it provided better exposure of the aortic root and stability of the sternum after a sternal wiring. Result: The operation time, the cardiopulmonary bypass time, the aorta cross-clamping time, the mechanical ventilation time, the amount of chest tube drainage until POD#1, the chest tube indwelling time, and the duration of intensive care unit staying were in an acceptable range. There were two surgical mortalities. One was due to a rupture of the aorta cannulation site after double valve replacement on POD#1 in the mini-sternotomy case, and the other was due to a sudden ventricular arrhythmia after MIDCAB on POD#2 in the parasternal incision case. Postoperative complications were observed in 2 cases in which a cerebral embolism developed on POD#2 after a mini-sternotomy in mitral valve replacement and wound hematoma developed after a right parasternal incision in a single coronary bypass grafting. Neither mortality nor complication was directly related to the incision technique itself. Conclusion: Minimally invasive surgery using parasternal or mini-sternotomy incision can be used in cardiac surgeries since it is as safe as the standard full sternotomy incisions.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.179-186
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• 1997

The frequency of primary lung cancer is increasing compared to other cancer. Complete surgical resection is the most effective method of treatment, but it is limited to only 25 to 30 percent of patients after initial clinical presentation. The survival rate is different by the subtypes of carcinoma, stages, and general condition of patients. The author investigated the survival rate of 87 patients with squamous cell carcinoma of the lung after surgery. Age ranged from 31 to 73 years, with Lean 57.1) $\pm$ 7.15 and 80.5% (70 cases) was initially diagnosed at sixth and seventh decades. Male to female ratio was 8.9'1. Initial complaints were cough with sputum in 78.1%, weight loss in 31.0%, chest pain and discomfort in 29.9%, and hemoptysis in 24.1%. The location of the tumor was right side in 44.8% and left slde in 55.2% ; LUL in 39.1%, RLL in 20.7%, LLL in'16. 1%, RUL in 14.9% and RML in 9.2%. Stage I was 19.5%, stage II 25.3%, stage olla 54.1% and stage lIIb 1.1%. Operative procedures were as follow : pneumonectomy in 52.9%, lobectomy in 47.1%, sleeve upper lobectomy in 4 cases. Single mediastinal Iymph node involvement was observed in 17 cases, and multi-level mediastinal Iymph node involvement in 23 cases. Lower paratracheal Iymph node and subcarinal Lymph node were more frequently involved in right side lung cancer, with 8 and 10 cases, respectively and subaortic Iymph node was most frequently involved in left side lung cancer with 9 cases. Operative complications were hoarseness, wound infection and chylothorax in 7, 5 and 4 cases, respectively. The operative mortality was 2.2% and the cause of death was pulmonary edema. Postoperative follow-up period ranged from 1 month to 99 months with a mean of 29.95 $\pm$ 17.21 months. Overall one-year survival rate was 75.1 % and five-year survival rate was 29.8%. One-year and five-year survival rates were 93.7% and 52.4% for stage 1, 92.2% and 30.5% for st ge ll, and 61.2% and 17.4% for stage llla, respectively. These findings correlate survival rate with tumor size, mediastinal Iymph node metastasis and surgical resectability, and long-term survival can be expected with small sized tumor, absent mediastinal Iymph node metastasis and complete surgical resection.

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.19-47
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• 2015

In this era of knowledge economy, a variety of virtual communities are proliferating for the purpose of knowledge creation and utilization. Since the voluntary contributions of members are the essential source of knowledge, member turnover can have significant implications on the survival and success of virtual communities. However, there is a dearth of research on the effect of membership turnover and even the method of measurement for membership turnover is left unclear in virtual communities. In a traditional context, membership turnover is calculated as the ratio of the number of departing members to the average number of members for a given time period. In virtual communities, while the influx of newcomers can be clearly measured, the magnitude of departure is elusive since explicit withdrawals are seldom executed. In addition, there doesn't exist a common way to determine the average number of community members who return and contribute intermittently at will. This study initially examines the limitations in applying the concept of traditional turnover to virtual communities, and proposes five membership fluidity measures based on a preliminary analysis of editing behaviors of 2,978 featured articles in English Wikipedia. Subsequently, this work investigates the relationships between three selected membership fluidity measures and group collaboration performance, reflecting a moderating effect dependent on work characteristic. We obtained the following results: First, membership turnover relates to collaboration efficiency in a right-shortened U-shaped manner, with a moderating effect from work characteristic; given the same turnover rate, the promotion likelihood for a more professional task is lower than that for a less professional task, and the likelihood difference diminishes as the turnover rate increases. Second, contribution period relates to collaboration efficiency in a left-shortened U-shaped manner, with a moderating effect from work characteristic; the marginal performance change per unit change of contribution period is greater for a less professional task. Third, the number of new participants per month relates to collaboration efficiency in a left-shortened reversed U-shaped manner, for which the moderating effect from work characteristic appears to be insignificant.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.907-913
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• 1997

Background : Congenital bronchoesophageal fistula(BEF) presented in adult life is a rare disorder and has characteristic clinical findings such as paroxysmal cough after water ingestion and recurrent respiratory infections. It usually manifested recurrent pneumonia and chronic cough with purulent phlegmon which was mis-or under-diagnosed as chronic bronchitis, bronchiectasis or lung abscess so forth. Methods : We reviewed retrospectively 13 cases of congenital BEF in adult of Paik Hospital, College of Medicine, Inje University including 22 cases of congenital BEF previously reported in literature of Korea from 1979 through 1995. Results : The mean age at diagnosis was $40.2{\pm}14.3$. There was no difference in sex ratio(Male : Female 18 : 17). The most common symptom was cough(91.4%), followed by chronic sputum(74.3), hemoptysis(25.7), and paroxysmal nocturnal cough at specific position(20%). Twenty one of 31 patients who were able to review have the most specific sign, Ono's sign presented as paroxysmal cough after liquid ingestion. By classification of Braimbridge-Keith, Fourteen(45.1%) of 31 patients were group I (associated with esophageal diverticulum), 15(48.4%) were group II (simple fistula), and group Ill and IV was one case in each. The opening of fistula confined to right lower lobe in 26(76.5%), left lower lobe in 6(17.6%), and left main bronchus in 2(5.9%) cases. Conclusion : Congenital bronchoesophageal fistula is uncommon disorder which has characteristic histories and specific symptoms such as chronic and recurrent lower respiratory infections, and paroxysmal cough after liquid ingestion. Medical attention and careful history should be done in patients who have localized recurrent lower respiratory infections in right lower lobe.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.199-208
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• 2016

$^{99}mTc-MAG_3$ Renal scan is a method that acquires dynamic renal scan image by using $^{99}mTc-MAG_3$ and dynamically visualizes process of radioactive agent being absorbed to kidney and excreted continuously. Once the test starts, ratio in both kidneys in 1~2.5 minutes was measured to obtain split renal function and split renal function can be expressed in ratio based on overall renal function. This study is based on compares split renal function obtained from data acquired from posterior detector, which is a conventional renal function test method, with split renal function acquired from the geometric mean of values obtained from anterior and posterior detectors, and studies utility of attenuation compensation depending on difference in geometric mean kidney depth. From July, 2015 to February 2016, 33 patients who undertook $^{99}mTc-MAG_3$ Renal scan(13 male, 20 female, average age of 44.66 with range of 5~70, average height of 160.40cm, average weight of 55.40kg) were selected as subjects. Depth of kidney was shown to be 65.82 mm at average for left and 71.62 mm at average for right. In supine position, 30 out of 33 patients showed higher ratio of deep-situated kidney and lower ratio of shallow-situated kidney. Such result is deemed to be due to correction by attenuation between deep-situated kidney and detector and in case where there is difference between the depth of both kidneys such as, lesions in or around kidney, spine malformation, and ectopic kidney, ratio of deep-situated kidney must be compensated for more accurate calculation of split renal function, when compared to the conventional test method (posterior detector counting).

• Journal of Chest Surgery
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• v.31 no.7
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• pp.660-667
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• 1998

Background: This study is to evaluate the effectiveness and application of Lecompte procedure as a treatment for various complex cardiac anomalies with pulmonary outflow tract obstruction. Methods: Between July 1988 and December 1997, 44 patients underwent Lecompte procedure in Seoul National University Children's Hospital. The male to female ratio was 24 to 20 and the mean age was 29.2 months(range, 3 to 83). Of these patients, 28(63.6%) had transposition of great arteries with ventricular septal defect and pulmonary stenosis(or pulmonary atresia), 14(31.8%) had double outlet right ventricle with pulmonary stenosis(or pulmonary atresia), and so on. The principles of the technique are 1) extension of the ventricular septal defect or conal resection, 2) construction of a intracardiac tunnel connecting the left ventricle to the aorta, and 3) direct connection, without a prosthetic conduit, of the pulmonary trunk to the right ventricle. Results: There were 3 in-hospital deaths and their causes were sustained hypoxia, myocardial failure, and sepsis, respectively. There was 1 late death due to sepsis. Reoperations were performed in 6 patients who had pulmonary outflow tract obstructions(4 cases), residual muscular ventricular septal defect(1 case), and recurrent septic vegetation(1 case). The cumulative survival rates by the Kaplan-Meier method were 92.7%, 92.7%, and 92.7% at 1, 2, and over 4 years. The reoperation free survival rates were 92.7%, 92.7%, and 70.2% at 1, 3, and over 5 years. Among the risk factors for the operative death, aortic cross clamping time had statistical significance(p<0.05) and all the risk factors for the recurrent pulmonary stenosis such as age, pulmonary artery index, and materials used for the pulmonary outflow tract reconstruction had no statistical significance(p>0.05). Conclusions: Our review suggests that Lecompte procedure is an effective treatment modality for various complex cardiac anomalies with pulmonary outflow tract obstruction. Repair in early age is possible and the rates of mortality and morbidity are also acceptable.

• The korean journal of orthodontics
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• v.32 no.4 s.93
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• pp.275-291
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• 2002

Of various factors indicated for effective use of straight wire appliances, there was a great lack of studies both domestic and international about the curvatures of tooth crowns. This study was performed to investigate the labio/buccal clinical crown curvatures of Korean permanent teeth. For this study, three-dimensional laser scanning was performed on 36 dental casts with normal anatomic structures. Andrews plane and Facial axis of clinical crown (FACC) were designated as horizontal and vertical reference planes respectively. 2 or 3 lines, 1mm apart, were drawn superior, inferior, left and right of these reference planes. A three-dimensional coordinate table was made for points formed by crossing these lines, and averages of each coordinate point on the 36 dental casts were obtained. The curvature equation was made using three-dimensional coordinate points (x,y,z) and by this curvature equation, the curve ratio of each tooth was obtained. Curve ratio changes of each section of teeth were calculated by curve ratios of simplified curves. These two dimensional curves were simplified horizontally and vertically Conclusions for this study are as follows. 1. The basic data of labial and buccal clinical crown curvatures were obtained about Korean permanent teeth. 2. No significant difference was found between male and females. 3. Individual tooth characteristics 1) In maxillary central incisors, the difference in the curve ratio between the gingival and incisal sides was greater than for the other teeth. And the gingival side showed a greater curve ratio. 2) Maxillary canines showed more curvatures in the mesio-occlusal surface than the other surfaces. 3) In maxillary $1^{st}$ premolars, more curvatures were found in mesio-occlusal and disto-gingival surface, thus showing a twisted crown surface, but in maxillary $2^{nd}$ premolars, the crown curvatures of mesial and distal ends became parallel to each other. 4) No significant difference in crown curvatures was found between mandibular central and lateral incisors. 5) Occluso-gingival curvatures of mandibular$2^{nd}$ premolar turned out to be more rounded than mandibular $1^{st}$ premolars or maxillary $2^{nd}$ premolars. From the above conclusions, it can be deduced that the same bracket bases can be used for mandibular central and lateral incisors. But for maxillary $1^{st}\;and\;2^{nd}$ premolars and for mandibular $1^{st}\;and\;2^{nd}$ premolars, because crown curvatures showed significant differences, when making bracket bases there is ample reason to make bracket base curves differently for each type of tooth.