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The Study On Quality Control of Magnetic Resonance Imaging System (자기공명영상장치의 정도관리에 관한 연구)

  • Jeong, Cheon-Soo;Lim, Cheong-Hwan
    • The Journal of the Korea Contents Association
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    • v.9 no.6
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    • pp.178-186
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    • 2009
  • The quality control is needed to ensure the accuracy of medical information and achieved by evaluating the performance of and maintaining the system and practicing various measurements and evaluations. The Korean Institute for Accreditation of Medical Image, therefore, have held educational program for quality control of special medical equipments. The major of programs participants, however, are radiology specialists with only small number of radiological technologists from some hospitals, furthermore, the follow-up education and the share of information between participants and non-participants are insufficient in general, thus, the knowledge level of radiological technologists, regardless of their participation, is relatively low. This study carried out the questionnaire research for the 500 radiological technologists registered in Korean Society of MRI Technology, on the basis of 2008, and performed analysis for five months from May to Oct., 2008. The questionnaires were delivered by post to each radiological technologists and the response rate was 36%(n=180). The results of this revealed that the 86.7% of respondents felt the necessity of inspection on quality management, while only the 27.8% completed the educational program for manager of special medical equipment. and only the half(53.9%) had the knowledge about inspection on quality management. The completion of educational program had no correlations with sex, age, size of occupying hospital, the number of radiological technologists in occupying site and MRI laboratory, career year of general radiologist and in MRI laboratory, and the presence of biomedical engineering department in occupying hospital. The 78.0% of participants at the educational program for quality management held by the Korean Institute for Accreditation of Medical Image had the knowledge about inspection on quality management(p<.05) whereas the 43.9% of the hospitals held such program and the 54.4% of radiological technologists from those hospitals had related knowledge, which indicated that such programs held by hospitals had not effects on the knowledge level of radiological technologists. This indicates also that the contents, methods, and other conditional factors of educational programs are important for the outcome of them.

Prediction of Air Temperature and Relative Humidity in Greenhouse via a Multilayer Perceptron Using Environmental Factors (환경요인을 이용한 다층 퍼셉트론 기반 온실 내 기온 및 상대습도 예측)

  • Choi, Hayoung;Moon, Taewon;Jung, Dae Ho;Son, Jung Eek
    • Journal of Bio-Environment Control
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    • v.28 no.2
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    • pp.95-103
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    • 2019
  • Temperature and relative humidity are important factors in crop cultivation and should be properly controlled for improving crop yield and quality. In order to control the environment accurately, we need to predict how the environment will change in the future. The objective of this study was to predict air temperature and relative humidity at a future time by using a multilayer perceptron (MLP). The data required to train MLP was collected every 10 min from Oct. 1, 2016 to Feb. 28, 2018 in an eight-span greenhouse ($1,032m^2$) cultivating mango (Mangifera indica cv. Irwin). The inputs for the MLP were greenhouse inside and outside environment data, and set-up and operating values of environment control devices. By using these data, the MLP was trained to predict the air temperature and relative humidity at a future time of 10 to 120 min. Considering typical four seasons in Korea, three-day data of the each season were compared as test data. The MLP was optimized with four hidden layers and 128 nodes for air temperature ($R^2=0.988$) and with four hidden layers and 64 nodes for relative humidity ($R^2=0.990$). Due to the characteristics of MLP, the accuracy decreased as the prediction time became longer. However, air temperature and relative humidity were properly predicted regardless of the environmental changes varied from season to season. For specific data such as spray irrigation, however, the numbers of trained data were too small, resulting in poor predictive accuracy. In this study, air temperature and relative humidity were appropriately predicted through optimization of MLP, but were limited to the experimental greenhouse. Therefore, it is necessary to collect more data from greenhouses at various places and modify the structure of neural network for generalization.

The Attitude of the Bereaved Family Attending a Bereavement Memorial Service (사별가족모임과 관련된 사별가족 태도 연구)

  • Jung, In-Soon;Shim, Byoung-Yong;Kim, Young-Seon;Lee, Ok-Kyung;Han, Sun-Ae;Shin, Ju-Hyun;Lee, Jong-Ku;Hwang, Su-Hyun;Ok, Jong-Sun;Kim, Hoon-Kyo
    • Journal of Hospice and Palliative Care
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    • v.8 no.2
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    • pp.143-151
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    • 2005
  • Purpose: Bereavement Memorial Service has been held every year by the hospice team at St. Vincent's Hospital for the purpose of supporting the bereaved family who feel grief and mourning. The purpose of this study is to find out the attitude of the bereaved attending at bereavement memorial service (BMS) and to find out the areas needing improvements to set up better memorial service. Methods: Hospice team sent invitation card to 180 families of patients who admitted and passed away at hospice ward Nov., 2003${\sim}$Oct., 2004. Among them 22 families attended the BMS meeting, which was held on 26th Nov., 2004. The researcher collected data from 22 families with 'Questionnaire' survey. Except identifying data and 2 dichotomy questions, we used open-ended questionnaire. 1 researcher conducted a telephone interview survey in 18 families who couldn't attend at BMS meeting. Results: The median age was 56 (range $16{\sim}19$) and there were 37 females and 3 males. They were patient's wife (22), mother (4), husband (5), daughter (4), mother-in-law (1), siblings (1), brothers wife (1). Duration after bereavement, $1{\sim}3$ months (17) was the highest frequency. 36 families agreed 'the dead experienced the death with dignity'. The reason of agreement to the death with dignity was 'the patient died in preparation' (16). 'the patient died in well-being condition spiritually' (9), 'the patient died in comfort physically (7). 4. persons thought the dead died with indignity. The bereaved defined 'the death with dignity' as follows: 'acceptance of death & death in spiritual well-being' (9), 'death in physical comfort condition' (7), 'the death in psycho-social well-being' (3), non-respondents (10). Most families (21) were still in difficulty to overcome bereavement grief. The answer regarding the method to overcome the difficulty was 'with spiritual sublimation' (13), 'with devotion of oneself in daily life' (10), 'with devotion to mourning as it is' (3). With regard to their attitude to invitation, 'having joy and thanks from hospice team' (21), 'grief' (4), 'suffering' (4). Toward the existence of hesitation about attendance at BMS meeting, the result as follows. Nonexistence of hesitation respondent (34), existence respondent (6), the reason for hesitation was various; 'the meeting reminds me of the suffering times', 'the meeting makes me to recall, and it will be likely to cry', and so on. The needs and feelings to memorial service meeting were various; 'it was meaningful time', 'it was good to recall about the dead', 'more meeting annually' and so on. In respect of the most difficulty after bereavement, in attendant family, 'depression' (10) was the highest frequency, whereas, in non-attendant family, the most difficult thing was 'financial problem/role difficulty (6). Conclusion: This study shows the rate of attendance was high in bereaved whose bereavement duration $1{\sim}3$ month. Most of bereaved were still suffering from bereavement grief within 1 year. Although most families didn't hesitate and felt positive mood to invitation, the rate of attendance was low. Comparing with two groups between attendant family and non-attendant, the latter felt more difficulty in 'financial problem/role difficulty, on the other hand, the former felt difficulty in 'depression'. Hereafter, the additional study about the factor relating to these attitude and needs of the bereaved relating to memorial service will be necessary.

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Radiotherapy in Supraglottic Carcinoma - With Respect to Locoregional Control and Survival - (성문상부암의 방사선치료 -국소종양 제어율과 생존율을 중심으로-)

  • Nam Taek-Keun;Chung Woong-Ki;Cho Jae-Shik;Ahn Sung-Ja;Nah Byung-Sik;Oh Yoon-Kyeong
    • Radiation Oncology Journal
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    • v.20 no.2
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    • pp.108-115
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    • 2002
  • Purpose : A retrospective study was undertaken to determine the role of conventional radiotherapy with or without surgery for treating a supraglottic carcinoma in terms of the local control and survival. Materials and Methods : From Jan. 1986 to Oct. 1996, a total of 134 patients were treated for a supraglottic carcinoma by radiotherapy with or without surgery. Of them, 117 patients who had completed the radiotherapy formed the base of this study. The patients were redistributed according to the revised AJCC staging system (1997). The number of patients of stage I, II, III, IVA, IVB were $6\;(5\%),\;16\;(14\%),\;53\;(45\%),\;32\;(27\%),\;10\;(9\%)$, respectively. Eighty patients were treated by radical radiotherapy in the range of $61.2\~79.2\;Gy$ (mean : 69.2 Gy) to the primary tumor and $45.0\~93.6\;Gy$ (mean : 54.0 Gy) to regional lymphatics. All patients with stage I and IVB were treated by radiotherapy alone. Thirty-seven patients underwent surgery plus postoperative radiotherapy in the range of $45.0\~68.4\;Gy$ (mean : 56.1 Gy) to the primary tumor bed and $45.0\~59.4\;Gy$ (mean : 47.2 Gy) to the regional lymphatics. Of them, 33 patients received a total laryngectomy (${\pm}lymph$ node dissection), three had a supraglottic horizontal laryngectomy (${\pm}lymph$ node dissection), and one had a primary excision alone. Results : The 5-year survival rate (5YSR) of all patients was $43\%$. The 5YSRs of the patients with stage I+II, III+IV were $49.9\%,\;41.2\%$, respectively (p=0.27). However, the disease-specific survival rate of the patients with stage I (n=6) was $100\%$. The 5YSRs of patients who underwent surgery plus radiotherapy (S+RT) vs radiotherapy alone (RT) in stage II, III, IVA were $100\%\;vs\;43\%$ (p=0.17), $62\%\;vs\;52\%$ (p=0.32), $58\%\;vs\;6\%$ (p<0.001), respectively. The 5-year actuarial locoregional control rate (5YLCR) of all the patients was $57\%$. The 5YLCR of the patients with stage I, II, III, IVA, IVB was $100\%,\;74\%,\;60\%,\;44\%,\;30\%$, respectively (p=0.008). The 5YLCR of the patients with S+RT vs RT in stage II, III, IVA was $100\%\;vs\;68\%$ (p=0.29), $67\%\;vs\;55\%$ (p=0.23), $81\%\;vs\;20\%$ (p<0.001), respectively. In the radiotherapy alone group, the 5YLCR of the patients with a complete, partial, and minimal response were $76\%,\;20\%,\;0\%$, respectively (p<0.001). In all patients, multivariate analysis showed that the N-stage, surgery or not, and age were significant factors affecting the survival rate and that the N-stage, surgery or not, and the ECOG performance index were significant factors affecting the locoregional control. In the radiotherapy alone group, multivariate analysis showed that the radiation response and N-stage were significant factors affecting the overall survival rate as well as locoregional control. Conclusion : In early stage supraglottic carcinoma, conventional radiotherapy alone is an equally effective modality compared to surgery plus radiotherapy and could preserve the laryngeal function. However, in the advanced stages, radiotherapy combined with concurrent chemotherapy for laryngeal preservation or surgery should be considered. In bulky neck disease, all the possible planned neck dissections after induction chemotherapy or before radiotherapy should be attempted.

Thymus Size and Its Relationship to Perinatal Diseases; Respiratory Distress Syndrome and Intrauterine Growth Retardation (흉선의 크기와 주산기 질환들과의 관계)

  • Chung, Sun Mi;Kim, Woo Taek
    • Clinical and Experimental Pediatrics
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    • v.45 no.7
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    • pp.855-861
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    • 2002
  • Purpose : Thymus size can be affected by several factors and perinatal diseases can be estimated by its size. The purpose of this study was to search for a relationship between cardiothymic/thoracic(CT/T) ratio and perinatal diseases such as neonatal respiratory distress syndrome(RDS) and intrauterine growth retardation(IUGR) by measuring the width of the cardiothymic shadow at the level of the carina and dividing it by the width of the thorax at the costophrenic angles. Methods : A clinical study was conducted on newborn infants with RDS(n=51), IUGR(n=27), and premature rupture of membranes(PROM, n=48), who were admitted at NICU of Catholic University of Daegu from June 2000 to Oct. 2001. CT/T ratio was measured within six hrs of age, at 2-3 days of age, and at 5-7 days of age. Results : CT/T ratios of RDS group, IUGR group, and PROM group were $0.46{\pm}0.07$, $0.32{\pm}0.04$. $0.36{\pm}0.06$, respectively. CT/T ratios of RDS group within 6hrs of age, at 2-3 days of age, and at 5-7 days of age were $0.43{\pm}0.07$, $0.34{\pm}0.06$, $0.25{\pm}0.04$, respectively. There were statistically significances among the RDS group, the IUGR group, and the PROM group and in the RDS group at different times. Regression for gestational age among three groups was not statistically significant but correlation for gestational age in the entire groups was statistically significant. CT/T ratio between normal spontaneous vaginal delivery and c-section among three groups was not statistically significant. CT/T ratios with dexamethasone-treated group and untreated group was not statistically significant. Conclusion : We concluded that thymus size differed significantly in the perinatal diseases such as RDS and IUGR, and so can be used as an early diagnostic tool for perinatal diseases.

Study on Ego states in the view of Transactional analysis, Coping style and Health states of Nursing Students (상호교류분석으로 본 간호학생의 자아상태와 스트레스 대처방법 및 건강상태에 관한 연구)

  • Won, Jeong-Sook;Kim, Jeong-Hwa
    • Journal of East-West Nursing Research
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    • v.7 no.1
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    • pp.68-81
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    • 2002
  • The purpose of this study is to analyze the type of ego states and stress coping style on female college students who are in the course of nursing study. This study is performed in the view of Transactional Analysis and designed to scrutinize descriptive correlations between the type of ego states and stress coping style. The subject is consists of 144 freshmen and sophomore, 138 junior and senior students group, who are students of K nursing college located in Seoul. The sampling investigation period is on Sept. 14, 2002 to Oct. 26, 2002. The measuring instrument used for Transactional Analysis ego state is 50 items Ego-gram research paper devised by Dusay(1997). For studying coping style, Folkman & Lazarus's measurement(1984) was adopted, which is translated and modified by Han, and Oh,(1990). Health states is adopted by standardized health inspecting instrumental table (Cornell Medical Index:CMI) which is designed for Korean people by Ko and Park(1980) Statistic average and standard deviation were generated by using SPSS PC+, t=test and Pearson correlation. The results were as follows: 1) In the type of ego states on both groups indicated the arithmetic apex NP(maximum value), then the point A was high and the data made a down slope to point AC. In the comparison to type of ego states between two groups, only at point CP, the data value of upper year students represented higher than that of lower year ones by c(t=2.28, p=.023). 2) Stress coping style of whole students were highly and affirmatively dedicated to research. Especially hopeful aspect(t=.67, p=.05), relaxation of tension(t=-2.16, p=.03) made significant difference each other in the view of arithmetic calculation. 3) In view of nursing students' physical health states, there is significant difference in past history(t=2.50, p=.013) and in case of mental health states, there are considerable discrepancies between lower group(73.52) and upper group(75.11)(p<.05). In view of all field, state of tension(t=2.13, p=.048) has difference. 4) While verifying coping style in terms of ego states level between lower and upper students group, In type CP, high level ego states group indicated significant difference on stress coping style area than low leveled group and made such sequences as the central point of problem, In type NP, sequences such as the central point of problem, In type A, the central point of problem, In type FC, hopeful aspect and In type AC, hopeful aspect and indifference were derived significantly different (p<.05). 5) While verifying health state differences in the level of lower and upper ego states, In type FC, low level group(150.29) marked higher point than upper group(145.19), there is remarkable discrepancy and so did whole health state(p=.014), In type AC both mental state(p=.000) and whole health state (p=.015) showed differences. 6) When analyzing correlations between whole students' ego states, copying style and health state, all type of ego state showed differences(p<.001). In correlations between ego state and health state, in type FC physical state had an apex and there are inverse correlations among the other types. Especially, type FC showed inverse correlations with great discrepancies(p<.05). In mental state, type NP(${\gamma}=.198$, p<.001) and type A(${\gamma}=.166$, p<.05) represented straight correlations with remarkable differences. Especially, In type AC showed inverse correlations(${\gamma}=.282$, p<.001). In case of correlations between copying style and health state, indifference(${\gamma}=-.157$) and relaxation of tension(${\gamma}=-.158$) presented great difference(p<.05). In mental state, central point of problem and search for social support showed straight correlations with great discrepancies(p<.05), hopeful aspect and indifference showed inverse correlations with considerable differences(p<.001).

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A Study on the Knowledge, Attitude and Practice of Handwashing of Middle School Students (일부 중학생의 손씻기 지식, 태도 및 실천에 관한 연구)

  • Jang, Yun-Jeong;Na, Bak-Ju;Kim, Keon-Yeop;Bae, Seok-Hwan;Kim, Chul-Woung;Kim, Eun-Young;Lee, Moo-Sik
    • Korean Journal of Health Education and Promotion
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    • v.24 no.4
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    • pp.1-22
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    • 2007
  • Objectives: This study attempted to understand the relationship between handwashing knowledge, attitude and practice of middle school students and to provide the basic information for handwashing training of the students and help them to form a healthy habit. Methods: Data was collected by a standardized self-administered questionnaire between Sep. 20 to Oct. 6 2006 with a total of 710 students in 1, 2, 3 grades at 6 middle schools in metropolitan cities(490 students from four schools situated in an urban center, 220 from 2 in a suburban district). The data was then analyzed using the SPSS WIN 12.0 program, employing many statistical techniques such as chi-square($x^2$) test, t-test, ANOVA analysis with post hoc test, correlations analysis, and regression analysis. Results: The results of the study were as follows. First, total number of handwashing times of middle school students is 6.69 per day. 66.1% of the students used soap and most of the students washed hands for $6{\sim}10$ seconds(44.7%). Second, in the knowledge of handwashing, "both of the parents"(p<0.01), "catholic", "city"(p<0.05) were the highest and the practice of handwashing was active with "city", "high economic level"(p<0.05) and "both of the parents"(p<0.01). In the experience of teaching handwashing, "Yes" was 24.3% which was statistically significant with handwashing knowledge(p<0.05), attitude and practice(p<0.01). Third, in the correlation of handwashing knowledge, attitude and practice, there was statistical significancy between handwashing attitude and knowledge(p<0.01) and showed positive correlation with the knowledge(.534). The practice of handwashing has meaningful difference from the knowledge and the attitude and the coefficient of correlation shows positive co-relation in knowledge(.335) and attitude(0525). Fourth, based on the result for regression analysis with handwashing knowledge, attitude and practice as dependent variables, handwashing knowledge showed statistical significancy with sex, type of school(p<0.05) and residential area(p<0.01). There were also statistical significancy between handwashing attitude and knowledge(p<0.01) and between handwashing practice and religion, knowledge(p<0.05) and economic level, attitude(p<0.01). Conclusion: There were consistent results with handwashing knowledge, attitude and practice. If they had better knowledge, their attitude was more positive and if they had better knowledge and more positive attitude, their practice was active. The knowledge, attitude and practice of the students who learned about handwashing were higher than those of the students who had no experience of learning handwashing. To enhance handwashing habit of middle school students, the handwashing environment should be maintained. The training plans should also be made according to sex, type of school, economic level, residential area, and the consistent study on handwashing training is required.

Ichthyotoxic Cochlodinium polykrikoides red tides offshore in the South Sea, Korea in 2014: I. Temporal variations in three-dimensional distributions of red-tide organisms and environmental factors

  • Jeong, Hae Jin;Lim, An Suk;Lee, Kitack;Lee, Moo Joon;Seong, Kyeong Ah;Kang, Nam Seon;Jang, Se Hyeon;Lee, Kyung Ha;Lee, Sung Yeon;Kim, Mi Ok;Kim, Ji Hye;Kwon, Ji Eun;Kang, Hee Chang;Kim, Jae Seong;Yih, Wonho;Shin, Kyoungsoon;Jang, Poong Kook;Ryu, Joo-Hyung;Kim, Sung Young;Park, Jae Yeon;Kim, Kwang Young
    • ALGAE
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    • v.32 no.2
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    • pp.101-130
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    • 2017
  • The ichthyotoxic Cochlodinium polykrikoides red tides have caused great economic losses in the aquaculture industry in the waters of Korea and other countries. Predicting outbreak of C. polykrikoides red tides 1-2 weeks in advance is a critical step in minimizing losses. In the South Sea of Korea, large C. polykrikoides red tide patches have often been recorded offshore and transported to nearshore waters. To explore the processes of offshore C. polykrikoides red tides, temporal variations in 3-dimensional (3-D) distributions of red tide organisms and environmental parameters were investigated by analyzing 4,432 water samples collected from 2-5 depths of 60 stations in the South Sea, Korea 16 times from May to Nov, 2014. In the study area, the vegetative cells of C. polykrikoides were found as early as May 7, but C. polykrikoides red tide patches were observed from Aug 21 until Oct 9. Cochlodinium red tides occurred in both inner and outer stations. Prior to the occurrence of large C. polykrikoides red tides, the phototrophic dinoflagellates Prorocentrum donghaiense (Jun 12 to Jul 11), Ceratium furca (Jul 11 to Aug 21), and Alexandrium fraterculus (Aug 21) formed red tides in sequence, and diatom red tides formed 2-3 times without a certain distinct pattern. The temperature for the optimal growth of these four red tide dinoflagellates is known to be similar. Thus, the sequence of the maximum growth rates of P. donghaiense > C. furca > A. fraterculus > C. polykrikoides may be partially responsible for this sequence of red tides in the inner stations following high nutrients input in the surface waters because of heavy rains. Furthermore, Cochlodinium red tides formed and persisted at the outer stations when $NO_3$ concentrations of the surface waters were < $2{\mu}M$ and thermocline depths were >20 m with the retreat of deep cold waters, and the abundance of the competing red-tide species was relatively low. The sequence of the maximum swimming speeds and thus potential reachable depths of C. polykrikoides > A. fraterculus > C. furca > P. donghaiense may be responsible for the large C. polykrikoides red tides after the small blooms of the other dinoflagellates. Thus, C. polykrikoides is likely to outgrow over the competitors at the outer stations by descending to depths >20 m and taking nutrients up from deep cold waters. Thus, to predict the process of Cochlodinium red tides in the study area, temporal variations in 3-D distributions of red tide organisms and environmental parameters showing major nutrient sources, formation and depth of thermoclines, intrusion and retreat of deep cold waters, and the abundance of competing red tide species should be well understood.

Clinical and Histopathological Study in Repaired Cartilage after Microfracture Surgery in Degenerative Arthritis of the Knee (퇴행성 슬관절염에서 미세 천공술후 재생된 연골의 임상 및 병리조직학적 연구)

  • Bae, Dae-Kyung;Yoon, Kyoung-Ho;So, Jae-Keun
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.4 no.1
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    • pp.18-28
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    • 2005
  • Purpose: The purpose of this study is to evaluate the clinical, radiological and histopathological results after microfracture surgery for degenerative arthritis of the knee. Materials and Methods: From Oct. 1997 to Dec. 1998, 48 knees in 46 patients were treated by microfracture technique. Their mean age at the time of operation was 56 years(range, 40-75 years) and mean period of follow-up study was one year(range, 7-20 months). For 24 knees in 22 patients, 'second-look' arthroscopies and biopsies were performed at 6 months following microfracture. At the last follow up clinical results were evaluated with Baumgaertner's scale. The specimens of 24 cases were stained with H-E, Safranin-O, and Masson's trichrome. Eighteen of 24 cases were stained immunohistochemically and the Western blotting test was performed on 12 cases for type II collagen. We analyzed the relationship of the Western blotting for type II collagen with clinical score, preoperative varus deformity, joint space widening in radiological result, extent of repaired articular cartilage in '2nd-look' arthroscopic findings, patient's age and weight. Results: Clinical results were excellent in 90% and good in 10%. Among the 24 knees, more than 80% of areas of chondral defect were covered with regenerated cartilage in 21 knees Histologically, the repaired tissue appears to be a hybrid of hyaline cartilage and fibrocartilage. Repaired cartilage contains variable amounts of type II collagen with immunohistochemical staining. The results of the Western blotting test were similar. The amounts of type II collagen formation had positive correlation with the extent of repaired cartilage and preoperative varus deformity. Conclusion: 'Second-look' showed that the chondral defect areas were covered with newly grown grayish white tissue. Articular cartilage repair was confirmed with histological and immunohisto-chemical study qualitatively, and the amount of type II collagen was calculated with the Western blotting test quantitatively. The exact nature and fate of repaired cartilagenous tissues need further long term follow-up study. The results of this study provide the rationale to select osteoarthritic patients indicated for microfracture surgery.

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Mesh Selectivity of Beam Trawl for Shrimps (새우조망의 망목선택성)

  • Oh, Taek-Yun;Cho, Young-Bok;Park, Gwang-Jei;Jeong, Sun-Beom;Kim, Min-Seok;Kim, Hyeong-Seok;Lee, Ju-Hee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.1
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    • pp.86-94
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    • 2004
  • This study was conducted to mesh selectivity of Beam trawl for shrimps fishing experiment in the coastal waters around Geomundo, South sea of Korea, during from Oct. to Nov. 2002. The selectivity parameters of big head shrimp (Solenocera melantho) have been studied on the covered con-end method. with mesh of 8, 38, 51 and 61 mm. Selection curves and selection parameters were calculated by using a logistic function S=1/(1+exp-(aCL+b)). The mesh selection master curves were estimated by S=1/(1+exp$^{({\alpha}(CL/M)+{\beta}}$), and the optimum mesh size were calculated with (L/M)50 of master curve. Optimum mesh size and selectivity master curves for the southern rough shrimp (Yrachysalambria curvirostris) and smoothshell shrimp (Parapenaeopsis tenella) optimum mesh size and selectivity master curves were estimated by big head shrimp master curves. The results obtained are summarized as follows : Selection parameters '${\alpha}$' and '${\beta}$' of the master curve for big head shrimp were 8.84 and -5.89, and The selection factor of the master curve (L/M)$_{50}$ was 0.67. The optimum mesh size of minimum length for sexual maturity for big head shrimp was 30.7 mm. Estimated (L/M)$_{50}$ for southern rough shrimp and smoothshell shrimp by using the master curve of big head shrimp was 0.73 and the optimum mesh sizes were 25.5 mm for southern rough shrimp and 16.9 mm for smoothshell shrimp, respectively.