• Journal of Chest Surgery
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• v.39 no.5 s.262
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• pp.354-358
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• 2006

Background: Pulsatile pumps for extracorporeal circulation have been known to be better for tissue perfusion than non-pulsatile pumps but be detrimental to blood corpuscles. This study is intended to examine the risks and benefits of $T-PLS^{TM}$ through the comparison of clinical effects of $T-PLS^{TM}$ (pulsatile pump) and $Bio-pump^{TM}$ (non-pulsatile pump) used for coronary bypass surgery. Material and Method: The comparison was made on 40 patients who had coronary bypass using $T-PLS^{TM}\;and\;Bio-pump^{TM}$ (20 patients for each) from April 2003 to June 2005. All of the surgeries were operated on pump beating coronary artery bypass graft using cardiopulmonary extra-corporeal circulation. Risk factors before surgery and the condition during surgery and the results were compared. Result: There was no significant difference in age, gender ratio, and risk factors before surgery such as history of diabetes, hypertension, smoking, obstructive pulmonary disease, coronary infarction, and renal failure between the two groups. Surgery duration, hours of heart-lung machine operation, used shunt and grafted coronary branch were little different between the two groups. The two groups had a similar level of systolic arterial pressure, diastolic arterial pressure and mean arterial pressure, but pulse pressure was measured higher in the group with $T-PLS^{TM}\;(46{\pm}15\;mmHg\;in\;T-PLS^{TM}\;vs\;35{\pm}13\;mmHg\;in\;Bio-pump^{TM},\;p<0.05)$. The $T-PLS^{TM}$-operated patients tended to produce more urine volume during surgery, but the difference was not statistically significant $(9.7{\pm}3.9\;cc/min\;in\;T-PLS^{TM}\;vs\;8.9{\pm}3.6\;cc/min\;in\;Bio-pump^{TM},\;p=0.20)$. There was no significant difference in mean duration of respirator usage and 24-hour blood loss after surgery between the two groups. Plasma free Hb was measured lower in the group with $T-PLS^{TM}\;(24.5{\pm}21.7\;mg/dL\;in\;T-PLS^{TM}\;versus\;46.8{\pm}23.0mg/dL\;in\;Bio-pump^{TM},\;p<0.05)$. There was no significant difference in coronary infarction, arrhythmia, renal failure and morbidity rate of cerebrovascular disease. There was a case of death after surgery (death rate of 5%) in the group tested with $T-PLS^{TM}$, but the death rate was not statistically significant. Conclusion: Coronary bypass was operated with $T-PLS^{TM}$ (Pulsatile flow pump) using a heart-lung machine. There was no unexpected event caused by mechanical error during surgery, and the clinical process of the surgery was the same as the surgery for which $Bio-pump^{TM}$ was used. In addition, $T-PLS^{TM}$ used surgery was found to be less detrimental to blood corpuscles than the pulsatile flow has been known to be. Authors of this study could confirm the safety of $T-PLS^{TM}$.

• Journal of Chest Surgery
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• v.37 no.10
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• pp.845-855
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• 2004

Background: No general consensus has been available regarding the necessity of postoperative radiation therapy (PORT) and its optimal techniques in the patients with chest wall invasion (pT3cw) and node negative (N0) non-small cell lung cancer (NSCLC). We did retrospective analyses on the pT3cwN0 NSCLC patients who received PORT because of presumed inadequate resection margin on surgical findings. And we compared them with the pT3cwN0 NSCLC patients who did not received PORT during the same period. Material and Method: From Aug. of 1994 till June of 2002, 22 pT3cwN0 NSCLC patients received PORT-PORT (＋) group- and 16 pT3cwN0 NSCLC patients had no PORT-PORT (-) group. The radiation target volume for PORT (＋) group was confined to the tumor bed plus the immediate adjacent tissue only, and no regional lymphatics were included. The prognostic factors for all patients were analyzed and survival rates, failure patterns were compared with two groups. Result: Age, tumor size, depth of chest wall invasion, postoperative mobidities were greater in PORT (-) group than PORT (＋) group. In PORT (-) group, four patients who were consulted for PORT did not receive the PORT because of self refusal (3 patients) and delay in the wound repair (1 patient). For all patients, overall survival (OS), disease-free survival (DFS), loco-regional recurrence-free survival (LRFS), and distant metastases-free survival (DMFS) rates at 5 years were 35.3%, 30.3%, 80.9%, 36.3%. In univariate and multivariate analysis, only PORT significantly affect the survival. The 5 year as rates were 43.3% in the PORT (＋) group and 25.0% in PORT (-) group (p=0.03). DFS, LRFS, DMFS rates were 36.9%, 84.9%, 43.1 % in PORT (＋) group and 18.8%, 79.4%, 21.9% in PORT(-) group respectively. Three patients in PORT (-) group died of intercurrent disease without the evidence of recurrence. Few suffered from acute and late radiation side effects, all of which were RTOG grade 2 or lower. Conclusion: The strategy of adding PORT to surgery to improve the probability not only of local control but also of survival could be justified, considering that local control was the most important component in the successful treatment of pT3cw NSCLC patients, especially when the resection margin was not adequate. Authors were successful in the marked reduction of the incidence as well as the severity of the acute and late side effects of PORT, without taking too high risk of the regional failures by eliminating the regional lymphatics from the radiation target volume.

• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.7-24
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• 1977

This paper is the forth and fifth one of the study on balanced type oscillating mole drainer. In the light of the results from previous reports about the model tests, some design criteria were established and a prototype machine was set up for experimental purpose. Motion characteristics and functionof the each parts of the machine were checked and analyzed. After that, performance tests of the prototype machine were carried out in thefield. Obtained results are summarized as follows ; 1. Ten centimeter of the bullet diameter was determined so as to be able to attach it to the tractors with capacity of 30 PS to 40 PS. 2. To maintain the balance between the moments of the front shank and rear shank, the oscillating amplitude of the rear bullet was determined to be larger than that of the front bullet. At the same time , the oscillating direction of the rear bullet was designed with the inclines of ten to thirty degrees. 3. An octagonal dynamo transduced was developed for measuring the compressive force of the upper link is measuring the draft force of the machine. Acceptable linear relationship between forces and strain responses from O.D.T. was obtained. 4. Analysing the balancing mechanism of the acting part of the machine , it was found that the total draft force of the machine was equal to the difference between the sum of the draft force produced from the right and left side bending moments of the lower drawber and the compressive force on the upper link. 5. There are acceptable linear relationship between the strain and twisting moment by driving shaft, and between strain and shank moment. Above results enable us to carry out the field experiment with prototype machine. 6. When the test machine was used in the field, it was possible to reduce the oscillating acceleration by forty percent in average as compared it with the single bullet mole drainer. 7. When the test machine was used under the oscillating condition, the dratt torce was reduced by 27 percent to 59 percent as compared it with the test machine under non-oscillating condition, while the draft force was increased by 7 percent to 20 percent as compared it with the mole drainer having oscillating single bullet. The reasoning behind this fact was considered as the resistance force due to the rear shank and bullet. 8. As the amplitude and frequency of the bullet were increased, the torque was increased accordingly. This tendency could be varied with the various characteristics of the given soils. And the larger frequency and amplitute, the more increasing oscil\ulcornerlating power but decreasing draft brce were needed, and draft force was increased as the velocity was increased.9. When the amplitude of the rear bullet was designed to be larger than that of the front bullet, the minimum value of the moment was lowered and oscillating acceleration was reduced. And when the oscillating direction of the rear bullet was declined back\ulcornerwards, oscillating acceleration was increased along with the increasing angle of decli\ulcornernation. When the test machine was operated in high speed, the difference between maximum moments and minimum ones became narrow. This varying magnitude of moments appeared on the moment oscillogram seems to be correlated to the oscillating acceleration and draft force. 10. From the analysis of variance, it was found that those factors such as frequency, amplitude, and operating velocity significantly affected in the oscillating acceleration, the draft resistance, the torque, the moment, and the total power required. And interaction between frequency and amplitude affected in the oscillating acceleration. 11. Within the given situation of this study, the most preferable operating conditions of the test machine were 7 Hz in oscillating frequency, 0.54 m/sec in operating velocity, and 39.1 mm in oscillating amplitude of front and rear bullets. However, it is necessary to select the proper frequency and magnitude of oscillation depending on the soil properties of the field in which the mole drainer is practiced by use of a bal1nced type oscillating mole drainer. 12. It is recommended that a comparative study of the mole drainers would be performed in the near future using two separate balanced oscillating bullet with the one which is operated by oscillating the movable bullet in a single cylinder or other balanced type which may be single oscillating bullet with spring, damper or balancing weight, and that of thing. To expand the applicability of the balanced type oscillating mole drainer in practical use, it is suggested to develop a new mechanism which perform mole drain with vinyl pipe or filling material such as rice hull.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.591-596
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• 2004

Recently, thoracic sympathicotomy for craniofacial hyperhidrosis (FH) is increasingly avoided contrast to palmar hyperhidrosis. We recently demonstrated that selective T2 sympathicotomy for FH in woman might be recommended because of differences of the postoperative satisfaction between man and woman. Therefore, this study was designed to analyze the postoperative long term results, evaluate the effectiveness of T2 sympathicotomy and establish the new strategy in treatment of FH in woman. Material and Method: From May 1998 to July 2001, 27 cases of FH in woman that were performed T2 sympathicotomy and minimum 2 years have passed since then at the follow up period. Among them, 20 cases were evaluated by telephone review and medical record. Bilateral sympathetic trunks were severed on the 2nd rib with 2mm thoracoscopic instruments. 7 patients combined with gustatory sweating (GS). Ages ranged from 25 to 62 (mean age, 46.4 years). Result: All patients were relieved of symptom immediately after operation. At postoperative 1 week, all patients were satisfied: 15 patients, “very satisfaction” and 5 patients, “relatively satisfaction”. However, during long term follow up period (from 25 to 63 months postoperatively), 9 patients (45%) were relatively satisfied, 8 patients (40%) complained that there was no difference of postoperative satisfaction and 3 patients (15%) complained of non satisfactory results (regret for surgery). 16 patients (80%) had complaint of uncomfortable feeling because of postoperative GS. Some degree of compensatory sweating (CS) had occurred in all patients: severe 10 patients (50%), severe but acceptable 6 patients (30%), and just conventional 4 patients (20%). The sites of CS were trunk, back, axilla and extremities. Conclusion: Thoracoscopic T2 sympathicotomy is relatively considerable method for FH in woman and the postoperative satisfaction depends on GS and the degree of individual adaptation for CS. Therefore, it is required that the prediction of preoperative risk factors for GS and CS and then careful selection of patients to increase the postoperative satisfaction, and the development of acceptable new treatment modalities.

• Journal of Environmental Impact Assessment
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• v.27 no.4
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• pp.367-377
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• 2018

A cultural ecosystem service(CES), which is non-material benefit that human gains from ecosystem, has been recently further recognized as gross national income increases. Previous researches proposed to quantify the value of CES, which still remains as a challenging issue today due to its social and cultural subjectivity. This study proposes new way of assessing CES which is called Cultural Service Opportunity Spectrum(CSOS). CSOS is accessibility based CES assessment methodology for regional scale and it is designed to be applicable for any regions in Korea for supporting decision making process. CSOS employed public spatial data which are road network and population density map. In addition, the results of 'Rapid Assessment of Natural Assets' implemented by National Institute of Ecology, Korea were used as a complementary data. CSOS was applied to Namyangju-si and the methodology resulted in revealing specific areas with great accessibility to 'Natural Assets' in the region. Based on the results, the advantages and limitations of the methodology were discussed with regard to weighting three main factors and in contrast to Scenic Quality model and Recreation model of InVEST which have been commonly used for assessing CES today due to its convenience today.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.838-850
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• 2015

In this study, dilute acid pretreatment was operated using small-diameter Quercus mongolica for evaluating the yield change of furfural and levulinic acid depending on pretreatment factors. The dilute acid pretreatment was conducted depending on reaction temperature ($140-180^{\circ}C$), reaction time (10-30 min), and sulfuric acid concentration (0-2%, w/w). Then, glucose, XMG (xylose + mannose + galactose), furfural, and levulinic acid contents in the liquid hydrolyzate were measured and analyzed after pretreatment. Glucose content increased to 16.02% as reaction temperature, reaction time, and sulfuric acid concentration increased, but it decreased at the sulfuric acid concentration of 2% (reaction temperature: > $170^{\circ}C$, reaction time: > 20 min). On the other hand, reaction temperature had a strong influenced on XMG content, and XMG content decreased to 1.63% through increasing of reaction temperature and sulfuric acid concentration, but XMG content was less affected by changes of reaction time. Furfural content increased with the increase of reaction temperature, reaction time, and sulfuric acid concentration, and maximum furfural content was 7.61% (reaction temperature: $180^{\circ}C$, reaction time: 20 min, sulfuric acid concentration: 1%) based on a weight of raw material, while furfural content was dropped in more severe condition than in maximum furfural content condition. Levulinic acid content also increased with higher reaction temperature, reaction time, and sulfuric acid concentration. Especially, the sharp increase of levulinic acid content was observed above $170^{\circ}C$, and maximum levulinic acid content was 10.98% (reaction temperature: $180^{\circ}C$, reaction time: 30 min, sulfuric acid concentration: 2%). However, less than 1% of furfural and levulinic acid content was obtained in non-acidic catalyst condition that in whole conditions of reaction temperature and reaction time.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.308-315
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• 1998

This study was conducted to evaluate the availability of the forest topsoil as a source of the "Native-soil(seed-fertilizer-soil materials)" for the hydroseeding measures which are environmentally and ecologically stable revegetation measures on rock cut-slopes. Soil sampling and factorial experiments were used with a split plot design(main plot : forest soil type and soil spraying thickness, subplot : seeding rate) in 1996. Results obtained in this study were summarized as follows : Because of the competition between the seeded(introduced) species and the native species, the number of naturally emerged species in the non-seeded plot and that of in the seeded plot were $5{\sim}9species/0.07m^2$ and $2{\sim}6species/0.07m^2$, respectively. As increasing the seeding rate(introduced species), the appearance ratio of naturally emerged species was decreased. The total number of individuals was high in the plot which used coniferous forest soil as a seed source, however the ratio of the individuals of naturally emerged species was high(30%) in the plot which used deciduous forest soil. The usage of the forest topsoil as seed bank source onto the "Native-soil" materials for hydroseeding could be reduce the seeding rate to $1,000seedlings/m^2$. According to the several factors which are competition between seeded species and naturally emerged species, dryness of soil materials, and seed burial, spraying thickness with more than 5cm was suitable for the growth of plants in variety.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.893-910
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• 2013

The purpose of this study was to identify changes in mental models of students in the elementary school about causes of seasonal changes. During a total of eight sessions, eight sixth graders were asked to describe the causes of seasonal changes through pictures, writing and thinking aloud by using microgenetic research methods, and the changes in mental models were examined. When the research was conducted, linguistic and behavioral factors and contents of interviews of participants were recorded on video. Moreover, a variety of materials such as field observation chart were written by a researcher and mental models records were written by a student. The protocol was written by integration of collected results, and it was repeated to read and was inductively categorized. The results of this study were as follows: First, participants' mental models about causes of seasonal changes were changed in various paths within and across sessions. Participants' mental models that had been more changed in various ways were closer to the scientific model. In addition, like rotation and revolution, students who correctly established the preconceptions related to seasonal changes formed the mental models consistent with scientific concept based on new information. On the other hand, students who did not correctly establish the preconceptions did not deviate from non-scientific mental models. Second, prior knowledge, experience and information which participants held in advance, accuracy of prior knowledge, resolution of inconsistency between new knowledge and existing mental models, activation of mental models through operation of models and drawing an picture affected the changes of mental models. Teachers should provide to learners with sufficient experience which can be configured to various mental models in order to form the scientific concepts. And they need to let learners feel the doubt and resolve it through presentation of new teaching material which is inconsistent with the existing mental models.

• Journal of Chest Surgery
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• v.23 no.3
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• pp.452-464
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• 1990

It is well known that extracellular Calcium plays a very important role in several steps of smooth muscle excitability and contractility, and there have been many concerns about factors influencing the distribution of extracellular Ca++ and the Ca++ flux through the cell membrane of the smooth muscle. Based on the assumption that Mg++ may also play an important role in the excitation and contraction processes of the smooth muscle by taking part in affecting Ca++ distribution and flux, many researches are being performed about the exact role of Mg++, especially in the vascular smooth muscle. But yet the effect of Mg++ in the smooth muscle activity is not clarified, and moreover the mechanism of Mg++ action is almost completely unknown. Present study attempted to clarify the effect of Mg++ on the excitability and contractility in the multiunit and unitary smooth muscle, and the mechanism concerned in it. The preparations used were the guinea-pig aortic strip as the experimental material of the multiunit smooth muscle and the rat uterine strip as the one of the unitary smooth muscle. The tissues were isolated from the sacrificed animal and were prepared for recording the isometric contraction. The effects of Mg++ and Ca++ were examined on the electrically driven or spontaneous contraction of the preparations. And the effects of these ions were also studied on the K+ or norepinephrine contracture. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% 02 and kept at 35oC. The results obtained were as follows: 1] Mg++ suppressed the phasic contraction induced by electrical field stimulation dose-dependently in the guinea-pig aortic strip, while the high concentration of Ca++ never recovered the decreased tension. These phenomena were not changed by the a - or b - adrenergic blocker. 2]Mg++ played the suppressing effect on the low concentration [20 and 40 mM] of K+-contracture in the aortic muscle, but the effect was not shown in the case of 100mM K+-contracture. 3] Mg++ also suppressed the contracture induced by norepinephrine in the aortic preparation. And the effect of Mg++ was most prominent in the contracture by the lowest [10 mM] concentration of norepinephrine. 4] In both the spontaneous and electrically driven contractions of the uterine strip, Mg++ decreased the amplitude of peak tension, and by the high concentration of Ca++ the amplitude of tension was recovered unlike the aortic muscle. 5] The frequency of the uterine spontaneous contraction increased as the [Ca++] / [Mg++] ratio increased up to 2, but the frequency decreased above this level. 6] Mg++ decreased the tension of the low[20 and 40mM] K+-contracture in the uterine smooth muscle, but the effect did not appear in the 100mM K+-contracture. From the above results, the following conclusion could be made. 1] Mg++ seems to suppress the contractility directly by acting on the smooth muscle itself, besides through the indirect action on the nerve terminal, in both the aortic and uterine smooth muscles. 2] The fact that the depressant effect of Mg++ on the K+-contracture is in inverse proportion to an increase of K+ concentration appears resulted from the extent of the opening state of the Ca++ channel. 3] Mg++ may play a depressant role on both the potential dependent and the receptor-operated Ca++ channels. 4] The relationship between the actions of Mg++ and Ca++ seems to be competitive in uterine muscle and non-competitive in aortic strip.

• Journal of Chest Surgery
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• v.40 no.9
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• pp.607-612
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• 2007

Background: Surgical resection is a standard treatment for pulmonary metastases in patients with osteosarcoma, but the role of performing repeated resections is not clear. This study was designed to clarify the feasibility of performing a repeated pulmonary metastasectomy and the prognostic factors for pulmonary metastases in patients with osteosarcoma. Material and Method: Between January 1990 and July 2005, 62 patients with osteosarcoma were diagnosed with pulmonary metastases and 36 patients underwent pulmonary resection. We reviewed the patients retrospectively. Result: The total number of pulmonary metastasectomies was 62 in 30 patients. Among 36 patients, 18 had a second metastasectomy, 7 had a third metastasectomy, and one patient had a fourth metastasectomy. There was no distinctive difference between the first and second metastatectomy in terms of median survival time, and the 3-year and 5-year survival rate (first resection: 20.5 months, 32.0% and 29,4%; second resection: 11.3 months, 34.9% and 34.%). However, the median survival time (7.1 months) was shorter in patients with a third metastatectomy than in patients with one metastatectomy (p=0.01). In long-term survivors, the number of female patients, patients with a disease free time longer than 12 months, patients with a single metastasis and patients with anatomic resection was larger when compared to non-long term survivors, but showed no statistical significance. Conclusion: Repeated pulmonary metastasectomy is expected to prolong survival time in patients with osteosarcoma, and is expected to increase long-term survival in selected cases. Further studies with a large number of patients are necessary.