• Title/Summary/Keyword: effect of factors

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Dynamical Study on the Blasting with One-Free-Face to Utilize AN-FO Explosives (초유폭약류(硝油爆藥類)를 활용(活用)한 단일자유면발파(單一自由面發破)의 역학적(力學的) 연구(硏究))

  • Huh, Ginn
    • Economic and Environmental Geology
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    • v.5 no.4
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    • pp.187-209
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    • 1972
  • Drilling position is one of the most important factors affecting on the blasting effects. There has been many reports on several blasting factors of burn-cut by Messrs. Brown and Cook, but in this study the author tried to compare drilling positions of burn-cut to pyramid-cut, and also to correlate burn-cut effects of drilling patterns, not being dealt by Prof. Ito in his theory, which emphasized on dynamical stress analysis between explosion and free face. According to former theories, there break out additional tensile stress reflected at the free face supplemented to primary compressive stress on the blasting with one-free-face. But with these experimented new drilling patterns of burn-cut, more free faces and nearer distance of each drilling holes make blasting effects greater than any other methods. To promote the above explosive effect rationary, it has to be considered two important categories under-mentioned. First, unloaded hole in the key holes should be drilled in wider diameter possibly so that it breaks out greater stress relief. Second, key holes possibly should have closer distances each other to result clean blasting. These two important factors derived from experiments with, theories of that the larger the dia of the unloaded hole, it can be allowed wider secondary free faces and closes distances of each holes make more developed stress relief, between loaded and unloaded holes. It was suggested that most ideal distance between holes is about 4 clearance in U. S. A., but the author, according to the experiments, it results that the less distance allow, the more effective blasting with increased broken rock volume and longer drifted length can be accomplished. Developed large hole burn-cut method aimed to increase drifting length technically under the above considerations, and progressive success resulted to achieve maximum 7 blasting cycles per day with 3.1m drifting length per cycle. This achievement originated high-speed-drifting works, and it was also proven that application of Metallic AN-FO on large hole burn-cut method overcomes resistance of one-free-face. AN-FO which was favored with low price and safety handling is the mixture of the fertilizer or industrial Ammonium-Nitrate and fuel oil, and it is also experienced that it shows insensible property before the initiation, but once it is initiated by the booster, it has equal explosive power of Ammonium Nitrate Explosives (ANE). There was many reports about AN-FO. On AN-FO mixing ratio, according to these experiments, prowdered AN-FO, 93.5 : 6.5 and prilled AN-FO 94 : 6, are the best ratios. Detonation, shock, and friction sensities are all more insensitive than any other explosives. Residual gas is not toxic, too. On initation and propagation of the detonation test, prilled AN-FO is more effective than powered AN-FO. AN-FO has the best explosion power at 7 days elapsed after it has mixed. While AN-FO was used at open pit in past years prior to other conditions, the author developed new improved explosives, Metallic AN-FO and Underwater explosive, based on the experiments of these fundmental characteristics by study on its usage utilizing AN-FO. Metallic AN-FO is the mixture of AN-FO and Al, Fe-Si powder, and Underwater explosive is made from usual explosive and AN-FO. The explanations about them are described in the other paper. In this study, it is confirmed that the blasting effects of utilizing AN-FO explosives are very good.

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Corporate Governance and Managerial Performance in Public Enterprises: Focusing on CEOs and Internal Auditors (공기업의 지배구조와 경영성과: CEO와 내부감사인을 중심으로)

  • Yu, Seung-Won
    • KDI Journal of Economic Policy
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    • v.31 no.1
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    • pp.71-103
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    • 2009
  • Considering the expenditure size of public institutions centering on public enterprises, about 28% of Korea's GDP in 2007, public institutions have significant influence on the Korean economy. However, still in the new government, there are voices of criticism about the need of constant reform on public enterprises due to their irresponsible management impeding national competitiveness. Especially, political controversy over appointment of executives such as CEOs of public enterprises has caused the distrust of the people. As one of various reform measures for public enterprises, this study analyzes the effect of internal governance structure of public enterprises on their managerial performance, since, regardless of privatization of public enterprises, improving the governance structure of public enterprises is a matter of great importance. There are only a few prior researches focusing on the governance structure and managerial performance of public enterprises compared to those of private enterprises. Most of prior researches studied the relationship between parachuting employment of CEO and managerial performance, and concluded that parachuting produces negative effect on managerial performance. However, different from the results of such researches, recent studies suggest that there is no relationship between employment type of CEOs and managerial performance in public enterprises. This study is distinguished from prior researches in view of following. First, prior researches focused on the relationship between employment type of public enterprises' CEOs and managerial performance. However, in addition to this, this study analyzes the relationship of internal auditors and managerial performance. Second, unlike prior researches studying the relationship between employment type of public corporations' CEOs and managerial performance with an emphasis on parachuting employment, this study researches impact of employment type as well as expertise of CEOs and internal auditors on managerial performance. Third, prior researchers mainly used non-financial indicators from various samples. However, this study eliminated subjectivity of researchers by analyzing public enterprises designated by the government and their financial statements, which were externally audited and inspected. In this study, regression analysis is applied in analyzing the relationship of independence and expertise of public enterprises' CEOs and internal auditors and managerial performance in the same year. Financial information from 2003 to 2007 of 24 public enterprises, which are designated by the government, and their personnel information from the board of directors are used as samples. Independence of CEOs is identified by dividing CEOs into persons from the same public enterprise and persons from other organization, and independence of internal auditors is determined by classifying them into two groups, people from academic field, economic world, and civic groups, and people from political community, government ministries, and military. Also, expertise of CEOs and internal auditors is divided into business expertise and financial expertise. As control variables, this study applied foundation year, asset size, government subsidies as a proportion to corporate earnings, and dummy variables by year. Analysis showed that there is significantly positive relationship between independence and financial expertise of internal auditors and managerial performance. In addition, although business expertise and financial expertise of CEOs were not statistically significant, they have positive relationship with managerial performance. However, unlike a general idea, independence of CEOs is not statistically significant, but it is negatively related to managerial performance. Contrary to general concerns, it seems that the impact of independence of public enterprises' CEOs on managerial performance has slightly decreased. Instead, it explains that expertise of public enterprises' CEOs and internal auditors plays more important role in managerial performance rather than their independence. Meanwhile, there are limitations in this study as follows. First, in contrast to private enterprises, public enterprises simultaneously pursue publicness and entrepreneurship. However, this study focuses on entrepreneurship, excluding considerations on publicness of public enterprises. Second, public enterprises in this study are limited to those in the central government. Accordingly, it should be carefully considered when the result of this study is applied to public enterprises in local governments. Finally, this study excludes factors related to transparency and democracy issues which are raised in appointment process of executives of public enterprises, as it may cause the issue of subjectivity of researchers.

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The Effect of Spiritual Well-being on the Mental Health of the Cho-Sun Tribal Women Residing in P.R. of China (중국거주 조선족 여성의 영적 안녕정도가 정신건강에 미치는 영향)

  • Cheung, Seung-Deuk;Lee, Jong-Bum;Kim, Jin-Sung;Seo, Wan-Seok;Bai, Dai-Seg;Park, Soon-Jae;Joo, Yeol;Youm, Hyoung-Uk;Jin, Cheung-Yuan;Jin, Jiu-Miao;Ahn, Yeung-Log;Huang, Da-Hong;Biao, Mei-Zi;Zheng, Tai-Ji;Zhao, Chang-Lie
    • Journal of Yeungnam Medical Science
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    • v.21 no.2
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    • pp.151-166
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    • 2004
  • Background: Spirituality has been an important part of Transpersonal Psychology and is believed to have a large effect on the mental health because it has been systematized. The aim of this study was to determine the level of spiritual disposition on human beings along with its effects on one's mental health. Materials and Methods: The study targeted 400 women residing in Youn-Gil city of JiLin Prov., which is a district of the Cho-Sun tribe in China. Their spiritual well-being was studied using the Spiritual Well-being Scale-Korean Version. The spiritual well-being scale consists of 2 sub-scales of religious well-being and existential well-being. The study was evaluated using a lie scale, psychotic trend, and a combined anxiety-depression scale. The results were considered to be factors of one's mental health. The correlation between the spiritual well-being and each tendency was analyzed by regression analysis. Results: The total score of the Cho-Sun tribal women according to the spiritual well-being scale was 68.29 which was much less than the 100.65 of Korean Christian women. There was no significant correlation between the spiritual well-being and the Lie trend. However, it was found that 86%(344) of Cho-Sun tribal women scored above 70 in the Lie trend with a mean score of 74.57 which is higher than normal populations. Regarding the correlation between the spiritual well-being and psychotic trend, the psychotic trend became significantly higher when the religious well-being was at a high level. On the other hand, the psychotic trend became significantly lower when the existential well-being was at a high level. Regarding the correlation between the spiritual well-being and anxiety, the anxiety was significantly higher when the religious well-being was at a high level. However, the anxiety level was significantly low when the existential well-being was at a high level. Regarding the correlation between the spiritual well-being and depression, the depression level was somewhat significantly high when the religious well-being was at a high level. However, the depression level was significantly low when the existential well-being was at a high level. Conclusion: This study evaluated the effects of spiritual well-being on a person's mental health among Cho-Sun tribal women in Youn-Gil city of JiLIn Prov., P.R. of China. The results found that the religious well-being, which is a sub-scale of spiritual well-being, had negative effects while the existential well-being had positive effects on the mental health. These results proved that a person's religious disposition had negative effects on their mental health in a communitarian society.

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A Preliminary Study of Ecological Aspects of Food on a Kind of Gom-Tang(Beef Soup made with Internal Organs and Bone) Intake (식생태학적(食生態學的) 관점(觀點)에서 본 곰탕류(類) 섭취(攝取)에 관한 예비적연구(豫備的硏究))

  • Kwon, Sun-Ja;Adachi, Miyuki;Mo, Su-Mi;Choi, Kyung-Suk;Kim, Ju-Hye;Koh, Hee-Jung
    • Journal of the Korean Society of Food Culture
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    • v.6 no.4
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    • pp.421-432
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    • 1991
  • This study was conducted to investigate the intake of a kind of Gom-Tang (Beef soup made with internal organs and bone), which is the Korean traditional food, and factors affecting the eating behavior of customers. Two hundred male customers of a H Korean Restaurant specialized in Gom-Tang, which is a well-known restaurant in Seoul, were surveyed from June 26 to 29, 1990. The results were shown as follows. (1) ${\ulcorner}$Frequency of intake${\lrcorner}$ and ${\ulcorner}$preference${\lrcorner}$ were very high. Those who took a kind of Gom-Tang ${\ulcorner}$more than once a week${\lrcorner}$ were 66.5% of the subjects. Those who evaluated ${\ulcorner}$good${\lrcorner}$ for the taste and flavor were 86.5% and 59.0% of the subjects, respectively. (2) The reasons why they chose a kind of Gom-Tang from among many Korean traditional foods were ${\ulcorner}$preference${\lrcorner}$ and ${\ulcorner}$phygiological condition${\lrcorner}$ in ${\ulcorner}$high frequency of intake${\lrcorner}$ group. ${\ulcorner}$Phygiological condition${\lrcorner}$ was more critical factor than ${\ulcorner}$preference${\lrcorner}$ in ${\ulcorner}$low frequency of intake${\lrcorner}$ group. (3) The effect of the intake of a kind of Gom-Tang on health was evaluated as ${\ulcorner}$healthy${\lrcorner}$ (80.5%). ${\ulcorner}$No effect${\lrcorner}$ and ${\ulcorner}$harmful${\lrcorner}$ were 30.5% and 6.5%, respectively. (4) ${\ulcorner}$High frequency of intake${\lrcorner}$ group, mainly more than 50 years of age, had a high ${\ulcorner}$preference${\lrcorner}$ and ${\ulcorner}$food knowledge${\lrcorner}$ as well as positive ${\ulcorner}$eating behavior${\lrcorner}$ and ${\ulcorner}$healthy state${\lrcorner}$, ${\ulcorner}$Middle frequency of intake${\lrcorner}$ group, mainly the forties, had a high ${\ulcorner}$preference${\lrcorner}$, but had less positive ${\ulcorner}$eating behavior${\lrcorner}$ than ${\ulcorner}$high frequency of intake${\lrcorner}$ group. ${\ulcorner}$Low frequency of intake${\lrcorner}$ group, mainly the twenties and thirties, had a medial ${\ulcorner}$preference${\lrcorner}$. They took a kind of Gom-Tang for reasons of ${\ulcorner}$on the recommendation of friends${\lrcorner}$ better than ${\ulcorner}$preference${\lrcorner}$. Foregoing results showed that ${\ulcorner}$a kind of Gom-Tang${\lrcorner}$ was a typical food recognized as ${\ulcorner}$healthy${\lrcorner}$ as well as ${\ulcorner}$delicious${\lrcorner}$. This may suggest that ${\ulcorner}$a kind of Gom-Tang${\lrcorner}$ is a candidate for the effective food on nutritional education.

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The Effect of Deep Layer Split Application of Nitrogen Fertilizer on the Growth of Rice Plant (질소비료(窒素肥料)의 심층추비시용(深層追肥施用)이 수도생육(水稻生育)에 미치는 영향(影響))

  • Maeng, D.W.;Kim, W.C.
    • Applied Biological Chemistry
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    • v.20 no.1
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    • pp.147-155
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    • 1977
  • In this experiment, we expected yield increase depending on the control of ineffective tiller, heightening of effective tillering ratio and continuous supply of nitrogen until later growth stage of rice plant by deep layer split application. Treats were applied at Tongil and Jinheung variety, clayey loam and sandy loam soil, and drained and non-drained condition. Nitrogenous fertilizer application wab adopted as liquefied(50%) and lumped (50% and 80%) fertilizer at 12cm depth of soil before 35 days of rice heading time against the standard soil surface application. The results are summarized as follaw. 1. a. Jinheung showed great variant width of tiller numbers per rice plant growth stage, and low effective tillering ratio at soil surface dressing. But in the case of deep layer split application, the number of tiller increased normally, and effective tillering ratio was high. b. At Tonsil, the width of increase and decrease range of effective tiller number between soil surface dressing and deep layer split application was not so high as Jinheung. Deep layer split application of 80% lumped fertilizer showed maximum effective tillering ratio ($83%{\sim}93%$). C. In the case of Jinheung, it was supposed that deep layer split application of 80% lumped fertilizer was excessive nitrogen quantity. d. Effective tillering ratio was higher than Tonsil at Jinheung. 2. The number of grains per hill was increased by the deep layer split application, but the ripening ratio was decreased inversely with the increase of total grain number. 3. Length of top leaves was elongated at Jinheung by deep layer split application. It showed significant correlation between top leaves length and grain yield. 4. Deep layer split application inclosed N content of harvested straw. Yield and N content of straw showed possitive correlation. 5. The ratio of unhulled grain yield per straw weight was increased by deep layer splication. This ratio was higher at Jinheung than Tonsil. 6. Grain yield was appeared in order of 80% lumped fertilizer>50% lumped fertilizer>50% liquefied fertilizer>surface dressing by the deep layer split application. The yield increasing factors were the increasing of effective tillering ratio, number of panicles per hill and number of ripening grains per hill. 7. Grain yield was increased at Tongil in sandy loam soil and at Jinheung in clayey loam soil by deep layer split application. 8. The grain yield was increased at drained conditions of clayey loam soil and non-drained conditions of sandy loam soil. But in the case of 80% lumped fertilizer of deep layer split application at the sandy loam soil, the yield was not increased at non-drained conditions. 9. The effect of yield increase by deep layer split application comparing with the surface dressing was higher at Tonsil than ginheung, in spite of low ripening ratio of Tonsil caused by low temperature at heading and harvesting time.

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Effect of Carbon Couch Side Rail and Vac-lok In case of Lung RPO irradiation (Lung RPO 선량전달시, Carbon Couch Side Rail과 Vac-lok이 미치는 영향)

  • Kim, Seok Min;Gwak, Geun Tak;Lee, Seung Hun;Kim, Jung Soo;Kwon, Hyoung Cheol;Kim, Yang Su;Lee, Sun Young
    • The Journal of Korean Society for Radiation Therapy
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    • v.30 no.1_2
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    • pp.27-34
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    • 2018
  • Purpose : To evaluate the effect of carbon couch side rail and vacuum immobilization device in case of lung RPO irradiation. Materials and Methods : The 10, 20, 30 mm thickness of vac-lok's right side were obtained. To measure of doses, glass dosimeters were used and measured reference point is left lung center at the phantom. A, B, C, and D points are left, right, down, and up directions based on the center point. In the state of Side-Rail-Out, place the without vac-lok, with the thickness of 10, 20, and 30 mm vac-lok. After the glass dosimeters was inserted in center, A, B, C, and D points, 100 MU of 6 MV X-ray were irradiated to the referenced center point in the condition of $10{\times}10cm^2$ field size, SAD 100 cm, gantry angle 225, 300 MU/min dose rate. Five measurements were made for each point. In the state of Side-Rail-In, five measurement were made for each point under the same conditions. The average is measured on each of the five Side-Rail-Out and Side-Rail-In measurements. Results : In the presence of side rail, the dose reduction ratio was -11.8 %, -12.3 %, -4.1 %, -12.3 %, -7.3 % for each A, B, C, and D points. In the state of Side-Rail-Out, the dose reduction ratio for the using 10 mm thickness of vac-lok was -0.9 % than without vac-lok. The dose reduction ratio for the using 20 mm thickness of vac-lok was -2.0 %, for the using 30 mm thickness of the vac-lok was -3.0 % than without vac-lok. In the state of Side-Rail-In, the dose reduction ratio for the using 10 mm thickness of vac-lok was -1.0 % than without vac-lok. The dose reduction ratio for the using 20 mm vac-lok was -2.1 %, for the using 30 mm vac-lok was -3.0 % than without vac-lok. Based on the value of no vac-lok dose in the Side-Rail-In state, The dose reduction ratios for the using 10 mm, 20 mm and 30 mm thickness of vac-loks In the Side-Rail-Out that the center point were -12.7 %, -13.7 %, -14.2 % and -12.8 %, -13.8 %, -14.5 % respectively at point A. The dose reduction ratios for the same conditions to the B point were -4.9 %, -6.1 %, -7.1 % and -13.4 %, -14.4 %, -15.5 % respectively at point C. The dose reduction ratios for the same conditions to the D point were -8.4 %, -9.0 %, -10.4 % respectively. Conclusion : The attenuation was caused by presence of side rails and thickness of vac-lok. Pay attention to these attenuation factors, making it a more effective radiation therapy.

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A Structural Relationship among Job Requirements, Job Resources and Job Burnout, and Organizational Effectiveness of Private Security Guards (민간경비원의 직무요구 직무자원과 소진, 조직유효성의 구조적 관계)

  • Kim, Sung-Cheol;Kim, Young-Hyun
    • Korean Security Journal
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    • no.48
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    • pp.9-33
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    • 2016
  • The purpose of the present study was to find out cause-and-effect relationship between job requirements and job resources, with job burnout as a mediator variable, and the effects of these variables on organizational effectiveness. The population in the present study was private security guards employed by 13 private security companies in Seoul and Gyeonggi-do areas, and a survey was conducted on 500 security guards selected using purposive sampling technique. Out of 460 questionnaires distributed, 429 responses, excluding 31 outliers or insincere responses, were used for data analysis. For analysis, data were coded and entered into SPSS 18.0 and AMOS 18.0, which were used to analyze the data. Descriptive analyses were performed to find out sociodemographic characteristics of the respondents. The exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to test the validity of the measurement tool, and the Cronbach's Alpha coefficients were calculated to test the reliability. To find out the significance of relationships among variables, Pearson's correlation analysis was performed. Covariance Structure Analysis (CSA) was performed to test the relationship among latent factors of a model for job requirements, job resources, job burnout, and organizational effectiveness of the private security guards, and the fitness of the model analyzed with CSA was determined by the goodness-of-fit index ($x^2$, df, p, RMR, GFI, CFI, TLI, RMSEA). The level of significance was set at .05, and the following results were obtained. First, even though the effect of job requirements on job burnout was not statistically significant, it had a positive influence overall, and this result can be considered such that the higher the perception of job requirements by the member of the organization, the higher the perception of job burnout. Second, the influence of job resources on job burnout was negative, which can be considered that the higher the perception of job resources, the lower the perception of job burnout. Third, even though the influence of job requirements on organizational effectiveness was statistically nonsignificant, it had a negative influence overall, and this result can be considered that the higher the perception of job requirements, the lower the perception of organizational effectiveness. Fourth, job resources had a positive influence on organizational effectiveness, and it can be considered that the higher the perception of job resources, the higher the perception of organizational effectiveness. Fifth, the results of the analysis between job burnout and organizational effectiveness revealed that, even though the influence of job burnout on organizational effectiveness was statistically nonsignificant, it had partial negative influences on sublevels of organizational effectiveness, and this may suggest that the higher the perception of job burnout by the organization members, the lower the organizational effectiveness. Sixth, the analysis of mediating role in the relationship between job requirements and organizational effectiveness, job burnout was taking partial mediating role between job requirements and organizational effectiveness. These results suggest that reducing job burnout by managing job requirements, organizational effectiveness that leads to job satisfaction, organizational commitment, and turnover intention can be maximized. Seventh, the analysis of mediating role in the relationship among job requirements, job resources, and organizational effectiveness, job burnout was assuming a partial mediating role in the relationships among job requirements, job resources, and organizational effectiveness. These results suggest that organizational effectiveness can be maximized by either lowering job requirements or burnout management through reorganizing job resources.

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Retrograde Autologous Priming: Is It Really Effective in Reducing Red Blood Cell Transfusions during Extracorporeal Circulation? (역행성 자가혈액 충전법: 체외순환 중 동종적혈구 수혈량을 줄일 수 있는가?)

  • Lim, Cheong;Son, Kuk-Hui;Park, Kay-Hyun;Jheon, Sang-Hoon;Sung, Sook-Whan
    • Journal of Chest Surgery
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    • v.42 no.4
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    • pp.473-479
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    • 2009
  • Background: Retrograde autologous priming (RAP) is known to be useful in decreasing the need of transfusions in cardiac surgery because it prevents excessive hemodilution due to the crystalloid priming of cardiopulmonary bypass circuit. However, there are also negative side effects in terms of blood conservation. We analyzed the intraoperative blood-conserving effect of RAP and also investigated the efficacy of autotransfusion and ultrafiltration as a supplemental method for RAP. Material and Method: From January 2005 to December 2007, 117 patients who underwent isolated coronary artery bypass operations using cardiopulmonary bypass (CPB) were enrolled. Mean age was 63.9$\pm$9.1 years (range 36$\sim$83 years) and 34 patients were female. There were 62 patients in the RAP group and 55 patients in he control group. Intraoperative autotransfusion was performed via the arterial line. RAP was done just before initiating CPB using retrograde drainage of the crystalloid priming solution. Both conventional (CUF) and modified (MUF) ultrafiltrations were done during and after CPB, respectively. The transfusion threshold was less than 20% in hematocrit. Result: Autotransfusions were done in 79 patients (67.5%) and the average amount was 142.5$\pm$65.4 mL (range 30$\sim$320 mL). Homologous red blood cell (RBC) transfusion was done in 47 patients (40.2%) and mean amount of transfused RBC was 404.3$\pm$222.6 mL. Risk factors for transfusions were body surface area (OR 0.01, 95% CI 0.00 $\sim$ 0.63, p=0.030) and cardiopulmonary bypass time (OR 1.04, 95% CI 1.01 $\sim$ 1.08, p=0.019). RAP was not effective in terms of the rate of transfusion (34.5% vs 45.2%, p=0.24). However, the amount of transfused RBC was significantly decreased (526.3$\pm$242.3ml vs 321.4$\pm$166.3 mL, p=0.001). Autotransfusion and ultrafiltration revealed additive and cumulative effects decreasing transfusion amount (one; 600.0$\pm$231.0 mL, two; 533.3$\pm$264.6 mL, three; 346.7$\pm$176.7 mL, four; 300.0$\pm$146.1 mL, p=0.002). Conclusion: Even though RAP did not appear to be effective in terms of the number of patients receiving intraoperative RBC transfusions, it could conserve blood in terms of the amount transfused and with the additive effects of autotransfusion and ultrafiltration. If we want to maximize the blood conserving effect of RAP, more aggressive control will be necessary - such as high threshold of transfusion trigger or strict regulation of crystalloid infusion, and so forth.

The Effect of a Bypass Operation for Atherosclerotic Arterial Obstructive Disease at the Lower Extremity (동맥경화성 하지 동맥 폐색증에 대한 우회로 수술의 효과)

  • Choi, Won-Suk;Park, Jae-Min;Lee, Yang-Haeng;Han, Il-Yong;Jun, Hee-Jae;Yoon, Young-Chul;Hwang, Youn-Ho;Cho, Kwang-Hyun
    • Journal of Chest Surgery
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    • v.41 no.5
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    • pp.610-618
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    • 2008
  • Background: There are various treatment modalities for atherosclerotic arterial obstructive disease at the lower limbs, for example, conservative physical therapy, medication, operation etc. Yet it has been established that an arterial bypass operation is the most effective treatment. The aim of this study is to evaluate the effect of arterial bypass operation within our experience and to determine the indicators of treatment. Material and Method: Ninety six patients received arterial bypass operation for atherosclerotic arterial obstructive disease from June 2002 to April 2006. We evaluated the feasibility of arterial bypass operation based on the improvement of symptoms and the ankle-brachial index (ABI) and the surgical outcomes, as based on the complications, the amputation rates and the patency rates. We also assessed the possible risk factors such as gender, age, a smoking history, co-morbidities, the anastomotic sites, the graft size and the graft type. We retrospectively reviewed the medical records of the patients. The total mean follow-up period was $29.4{\pm}13.1$ months. Result: The mean age was $65.95{\pm}9.61$ and there were 88 male patients. The most common clinical manifestation was ischemic resting pain in the lower extremities. The underlying combined diseases were hypertension (61%), diabetes (43%), cardiac problems (35%) and smoking (91.7%). The most frequent site of arterial obstruction was the superficial femoral artery (44 cases, 40%). A femoropopliteal artery bypass operation with a Polytetrafluoroethylene(PTFE) synthetic graft was done in 44 cases (40%) and the great saphenous vein graft was used in 11 cases. The postoperative ABI increased significantly from $0.30{\pm}0.11$ preoperatively to $0.63{\pm}0.11$ (p<0.001) postoperatively. In 8 cases, amputations above the ankle level were necessary. The graft patency rates were 86.4% and 68.0% after 1 and 3 years, respectively. There were 29 cases (30.21%) of patency failure; the male gender, smokers and hypertension were significantly more frequent in the failure group. Of these, hypertension was the most powerful risk factor (p=0.042). Conclusion: The arterial bypass operation is an effective treatment modality for controlling the symptoms such as pain and claudication, and for preventing major amputations for the patients with atherosclerotic arterial obstructive disease. This study suggests quitting smoking, strict blood pressure control, selection of an appropriate graft, regular outpatient follow up and proper medication would offer higher patency rates and more favorable outcomes.

Long Term Follow Up of Interferon-alpha Treatment in Children with Chronic Hepatitis B (만성 B형간염 환아에 대한 Interferon-alpha 치료결과의 장기 추적관찰)

  • Baek, Seoung-Yon;Eom, Ji-Hyun;Chung, Ki-Sup
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.6 no.2
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    • pp.140-151
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    • 2003
  • Purpose: We tried to evaluate the long term efficacy and positive predictive factors of interferon-alpha treatment in children with chronic hepatitis B. Methods: The study population included 113 children who received interferon therapy between May 1982 and July 2002 (20 years) for chronic hepatitis B in Department of Pediatrics, Yonsei University College of Medicine. Male to female ratio was 2.3 : 1 and the mean age at diagnosis was $11.1{\pm}4.1$ years old. Response to treatment was defined as normalization of alanine aminotransferase (ALT), disappearance of HBeAg and HBV-DNA Eighty two children responded while 32 did not. Interferon-alpha was given intramuscularly for 6 months at a dosage of $3{\times}10^6$ unit, 3 times weekly. In relapsed cases, lamivudine or interferon retreatment was done. Results: Seroconversion rate was 77.0% in terms of HBeAg, 74.3% in terms of HBV-DNA, and 80.5% in terms of ALT normalization after treatment. Seroconversion rate of both HBeAg and HBV-DNA was 72.6%. Analyzed by life table method, the effect of the treatment had been maintained over 10 years after cessation of therapy. Pre-treatment ALT level was the only significant positive predictive factor of response. Eleven cases (13.4%) relapsed, and 2 out of 3 showed response when treated with lamivudine and 1 out of 3 with interferon retreatment. Conclusion: Interferon-alpha showed significant efficacy in the treatment of chronic hepatitis B in our study. Further studies about the effect of interferon therapy on complications of hepatitis such as hepatocarcinoma, cirrhosis are warranted.

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