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Expression of TIMP1, TIMP2 Genes by Ionizing Radiation (이온화 방사선에 의한 TIMP1, TIMP2 유전자 발현 측정)

  • Park Kun-Koo;Jin Jung Sun;Park Ki Yong;Lee Yun Hee;Kim Sang Yoon;Noh Young Ju;Ahn Seung Do;Kim Jong Hoon;Choi Eun Kyung;Chang Hyesook
    • Radiation Oncology Journal
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    • v.19 no.2
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    • pp.171-180
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    • 2001
  • Purpose : Expression of TIMP, intrinsic inhibitor of MMP, is regulated by signal transduction in response to genotoxins and is likely to be an important step in metastasis, angiogenesis and wound healing after ionizing radiation. Therefore, we studied radiation mediated TIMP expression and its mechanism in head and neck cancer cell lines. Materials and Methods : Human head and neck cancer cell lines established at Asan Medical Center were used and radiosensitivity $(D_0)$, radiation cytotoxicity and metastatic potential were measured by clonogenic assay, n assay and invasion assay, respectively. The conditioned medium was prepared at 24 hours and 48 hours after 2 Gy and 10 Gy irradiation and expression of TIMP protein was measured by Elisa assay with specific antibodies against human TIMP. hTIMP1 promoter region was cloned and TIMP1 luciferase reporter vector was constructed. The reporter vector was transfected to AMC-HN-1 and -HN-9 cells with or without expression vector Ras, then the cells were exposed to radiation or PMA, PKC activator. EMSA was peformed with oligonucleotide (-59/-53 element and SP1) of TIMP1 promoter. Results : $D_0$ of HN-1, -2, -3, -5 and -9 cell lines were 1.55 Gy, 1.8 Gy, 1.5 Gt, 1.55 Gy and 2.45 Gy respectively. n assay confirmed cell viability, over $94\%$ at 24hrs, 48hrs after 2 Gy irradiation and over 73% after 10 Gy irradiation. Elisa assay confirmed that cells secreted TIMP1, 2 proteins continuously. After 2 Gy irradiation, TIMP2 secretion was decreased at 24hrs in HN-1 and HN-9 cell lines but after 10 Gy irradiation, it was increased in all cell lines. At 48hrs after irradiation, it was increased in HN-1 but decreased in HN-9 cells. But the change in TIMP secretion by RT was mild. The transcription of TIMP1 gene in HN-1 was induced by PMA but in HN-9 cell lines, it was suppressed. Wild type Ras induced the TIMP-1 transcription by 20 fold and 4 fold in HN-1 and HN-9 respectively. The binding activity to -59/-53, AP1 motif was increased by RT, but not to SP1 motif in both cell lines. Conclusions : We observed the difference of expression and activity of TIMPs between radiosensitive and radioresistant cell line and the different signal transduction pathway between in these cell lines may contribute the different radiosensitivity. Further research to investigate the radiation response and its signal pathway of TIMPs is needed.

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No-tillage Agriculture of Korean-Type on Recycled Ridge I. Changes in Physical Properties : Soil Crack, Penetration Resistance, Drainage, and Capacity to Retain Water at Plastic Film Greenhouse Soil by Different Tillage System (두둑을 재활용한 한국형 무경운 농업 I. 경운방법에 따른 시설재배 토양의 물리적 특성: 균열, 관입저항, 배수, 보수력 변화)

  • Yang, Seung-Koo;Jung, Woo-Jin
    • Korean Journal of Organic Agriculture
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    • v.24 no.4
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    • pp.699-717
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    • 2016
  • This study was carried out to investigate the effect of no-tillage on sequential cropping supported from recycling of first crop ridge on the growth of pepper plant and physical properties of soil under green house condition. 1. Degree of crack on soil by tillage and no-tillage Soil cracks found in ridge and not found in row. At five months of tillage, crack number and crack length in length ridge were 3 and 37~51 cm in tillage. Maximum width and maximum depth in length ridge were 30 mm and 15.3cm in tillage. Crack number and crack length in width ridge were 7.5 and 7~28 cm in tillage. Maximum width and maximum depth in width ridge were 29 mm and 15.3 cm in tillage. At a year of no-tillage, crack number and crack length in length ridge were 1.0 and 140~200 cm in tillage. Maximum width and maximum depth in length ridge were 18 mm and 30 cm in a year of no-tillage. Crack number and crack length in width ridge were 11 and 6~22 cm in a year of no-tillage. Maximum width and maximum depth in width ridge were 22 mm and 18.5 cm in a year of no-tillage. Soil crack was not found at 2 years of no-tillage in sandy Jungdong series (jd) soil. Soil crack was found at 7 years of no-tillage in clayish Jisan series (ji) soil. 2. Penetration resistance on soil Penetration resistance was increased significantly at no-tillage in Jungdong series (jd). Depth of cultivation layer was extended at no-tillage soil compared with tillage soil. Penetration resistance of plow pan was decreased at 1 year of no-tillage compared with than tillage soil. Penetration resistance was linearly increased with increasing soil depth at tillage in Jisan series (ji). Penetration resistance on top soil was remarkably increased and then maintained continuously at no-tillage soil. 3. Drainage and moisture content of soil Moisture content of ridge in top soil was not significant difference at both tillage and no-tillage. Moisture content of ridge in 20 cm soil was 14% at no-tillage soil and 25% at tillage soil. 4. Change of capacity to retain water in soil Capacity to retain water in top soil was not significant difference at 1 bar both tillage and no-tillage. Capacity to retain water in soil was slightly higher tendency in 1 year and 2 years of no-tillage soil than tillage soil. Capacity to retain water in soil was increased at 15 bar both tillage and no-tillage. Capacity to retain water in subsoil was slightly higher tendency at 1 bar and 3 bar in 2 years of no-tillage than tillage soil and a year of no-tillage soil.

A Study on Growth Type of Comic strips Heroes through Journey of Life (삶의 여정을 통한 만화 히어로 성장유형 연구)

  • Kim, MiRim
    • Cartoon and Animation Studies
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    • s.29
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    • pp.173-207
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    • 2012
  • The four-phased plot which consists of introduction, development, turn and conclusion in the long-story structure tends to be patterned and schematized. The behavior of characters is in line with the beginning of human beings and the plot of comic strips basically has four phases. It is, however, not a simple arrangement but a complex one which was developed by organizing patterns of human power, behavior and emotions. With the results from a survey with college students studying comic strips, this study aims to categorize four characters from the archetypal system by Carol Pearson, four phases of the hero's journey by Joseph Campbell, and the four phases of the plot based on Aristotle's theory, which is the frame of the comic strip structure through supporting evidence extracted from comic strips in an integrated way. In this study, the categorization is performed by simplifying and systemizing a character's life cycle, which is a factor of a story structure in complex comic strips. This study is to identify what comic strip writers express by using the metaphor in the complicated long-story structure of comic strips This study reveals that the structure of introduction, development, turn and conclusion based on the plot theory by Aristotle is the metaphor of human life and fate and that the phases of development in the archetypal system by Carol Pearson, a Jung researcher influenced by Jung's theory are the metaphor of human life and fate. Also, the theories of Joseph Campbell, who also was influenced by Jung, are the metaphor of human life and fate as they projected complex emotions of joy, anger, sorrow, and pleasure onto the archetype of heroes and used the metaphor of the hero's journey. Lastly, the theories are introduced with the approach of 'guide to screenwriters' by Christopher Vogler. Meanwhile, this metaphor is the objective and goal of this study. The comic strips selected for this study seem to have long complex stories which have characters leaving their homes, going through adventures and difficulties, meeting the world in another way, experiencing tension, competition, wars, and hardship and returning home with compensation. They grow mentally and psychologically through their journeys and finally become heroes. They express the meaning of our introspection in a narrative through plots and images of comic strips. This appears complex but the basic structure of long comic strips has four phases of plot. The life style of an extraordinary character traveling for adventures and growing in long comic strips can be divided into four phases symbolizing childhood, adolescence, adulthood, and senescence and it is a psychological growth process. The archetypes of the character can be divided into four phases and the growth process can be explained. The hero's journey symbolized by the character can be also divided into four phases. Through theories, the complex arrangement of four-phased plots in comic strips corresponds with the growth process of introduction, development, turn and conclusion through the stages of life. At the same time, this study found that the characters becoming heroes are the metaphor of introspection and that the characters' growth and life correspond with the four phases in life through long comic strips. Long stories in long comic strips written by comic strip writers show that characters go on their journeys and change their lives through hardship and difficulty by logical construction of plot and their growth processes are presented in archetypal images and they reach introspection as heroes. The readers share time and space through images in comic strips and realize that they had the same experience as the characters emotionally by being moved by the stories.

Relationship between Stress and Eating Habits of Adults in Ulsan (울산지역 성인 남녀의 스트레스와 식습관)

  • Kim, Hye-Kyung;Kim, Jin-Hee
    • Journal of Nutrition and Health
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    • v.42 no.6
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    • pp.536-546
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    • 2009
  • This study was done to investigate the effect of stress on appetite and eating habits, and other health-related behaviors. The subjects of this study consisted of 188 males and 224 females in Ulsan area. The results were as follows: When stressed, 56% (n = 231) of the subjects experienced a change in appetite and of these, 32% (n = 132) experienced an increased appetite. Stress-induced eating may be one factor contributing to the development of obesity. There was a gender-specific response to stress in which women are more likely to use food to deal with stress, whereas men are more likely to use alcohol consumption or smoking. It was found that types of stressors were individual (52.9%), social (50.7%), family relations (34.5%), work demands (34.2%) and physical environment (32.3%). Stress-induced symptoms of the subjects were anxiety (38.3%), headache (36.7%) and neck or shoulder aches (36.2%), and females experienced those symptoms more than males. Those older than 50 years had a higher eating habit score and lower stress score compared with younger subjects. There were significant differences between sex, age, occupation, family type, BMI, exercise, sleeping hours and eating habits or stress level. This study may be helpful in advancing findings in this area to better provide health professionals with appropriate counseling tools to improve the health of all individuals.

The Structural Relationships between Control Types over Salespeople, Their Responses, and Job Satisfaction - Mediating Roles of Role Clarity and Self-Efficacy - (영업사원에 대한 통제유형, 반응, 그리고 직무만족 간의 구조적 관계 - 역할명확성과 자기효능감의 매개효과 -)

  • Yoo, Dong-Keun;Lim, Jong-Koo;Lim, Ji-Hoon
    • Journal of Global Scholars of Marketing Science
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    • v.17 no.4
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    • pp.23-49
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    • 2007
  • Salespeople act at the point of MOT with customers and deliver the enterprise's message to the customers. They build up relationships with customers as well as deliver the customer's message to the enterprise. The salespeople's activity at the point of MOT with the customers and the degree of satisfaction of the customers' needs will affect the customers' attitude toward the enterprise, brand loyalty, and retention intention. Ultimately, it will influence the enterprise's financial performance. The control of salespe1ople is one of the most interesting topics of marketing. This research investigates the relationships of the control types over salespeople(positive/negative outcome control, positive/negative behavior control) and job satisfaction and their mediating variables. The mediating variables in the relationships have been identified as outcome/behavior-related role clarity and self-efficacy. The purpose of this study is more specifically as follows: First, it investigate how the perception of salespeople control types affect role-clarity. Second, it examines how the perception of salespeople control types influence self-efficacy. Third, it investigate the mediating role of role-clarity between the perception of salespeople control types and self-efficacy. Fourth, it investigates how role-clarity affect self-efficacy and job satisfaction. Finally, it will investigates how self-efficacy influences job satisfaction. Data were collected from the pharmaceutical industry salespeople and analyzed by SPSS 12.0 and AMOS 6.0. The data were collected by 400 respondents and 377 valid questionnaires were analyzed. The results are summarized as follows: First, positive/negative outcome controls had a positive relationship with outcome-related role clarity. Also positive behavior control had a positive effect on behavior-related role clarity, but negative behavior control didn't influence behavior-related role clarity. Second, positive outcome control influenced self-efficacy positively, but positive behavior control didn't have a positive effect on self-efficacy. In addition negative outcome control and negative behavior control had a positive effect on self-efficacy due to the mediating role of outcome-related and behavior-related role clarity. Third, outcome-related role clarity and behavior-related role clarity influenced self-efficacy positively. Behavior-related role clarity had a positive effect on job satisfaction, but outcome-related role clarity didn't influence job satisfaction. Finally, self-efficacy didn't have any effect on job satisfaction. The contributions of this study are as follows: First, existing studies have investigated the direct causal relationship between salespeoples' control type and performance, but this study investigates the structural causality between salespeoples' control types, responses, and performances. Second, this study found the mediating role of outcome-related/behavior-related role-clarity between outcome/behavior control and self-efficacy. Finally, the findings of this study further insight to existing studies on the relationship between job satisfaction and self-efficacy. The confidence of salespeoples' task influenced job satisfaction positively in existing articles,field studies, but the relationship between these two variables was not significant in this study. This means that there can be a different relationship between confidence and job satisfaction according to salespeoples' business. That is, the business environment may not be satisfying, even if the salespeople say that they have ability and confidence about their business. This means that able salespeople who have ability and confidence about their business are not satisfied with their job advancement in the company. Therefore, enterprise need to provide training that can establish a business environment that can satisfy the salespeole's expectation level which will secure good salespeople. This study may have limitation when applied to future studies. First,in this study as with existing studies it investigates the control level that salespeople feel is being measured. Actuality, the control level that a manager enforces and the control level that salespeople perceive when one is late can be different. There is need to measure lateness from both the perspective of the manager and salespeople should be done to supplement this study in the future Second, this study used variables that were connected with action result but salespeople's job satisfaction is due to the result of control. But, focusing on result of control can provide a more important financial result than sales performance. This study is also limited in that it did not consider financial result by result of control. Further studies on this will need to be done in the future. Third, this study may have a further limitation,because the investigation was restricted to pharmaceutical salespeople selling to hospitals. It is necessary to execute investigations in various industries to increase the generalization of the study findings Fourth, in this study, role clarity and self-efficacy by response variable for control and considered job satisfaction by outcome variable of control was considered. But, can other variables be considered beside response variable and result variable for control? For example, can financial affairs and change of post by outcome variable along with business stress by response variable for control be considered? Therefore, future studies need to consider various control variables. Finally, there is limited supporting research in the field of marketing which restricts the generalization of the study finding along with collecting material through random sampling of a limited size. This research summarizes the research in this area, the difference from the previous research, and provides a discussion of its limitations and the need and direction for further future research.

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Effect of $H_2O_2$ on Alveolar Epithelial Barrier Properties (폐상피세포 장벽에 대한 $H_2O_2$의 영향)

  • Suh, Duk-Joon;Cho, Se-Heon;Kang, Chang-Woon
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.3
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    • pp.236-249
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    • 1993
  • Background: Among the injurious agents to which the lung airspaces are constantly exposed are reactive species of oxygen. It has been widely believed that reactive oxygen species may be implicated in the etiology of lung injuries. In order to elucidated how this oxidant causes lung cell injury, we investigated the effects of exogenous $H_2O_2$ on alveolar epithelial barrier characteristics. Methods: Rat type II alveolar epithelial cells were plated onto tissue culture-treated polycarbonate membrane filters. The resulting confluent monolayers on days 3 and 4 were mounted in a modified Ussing chamber and bathed on both sides with HEPES-buffered Ringer solution. The changes in short-circuit current (Isc) and monolayer resistance (R) in response to the exogenous hydroperoxide were measured. To determine the degree of cellular catalase participation in protection against $H_2O_2$ injury to the barrier, experiments were repeated in the presence of 20 mM aminotriazole (ATAZ, an inhibitor of catalase) in the same bathing fluid as the hydroperoxide. Results: These monolayers have a high transepithelial resistance (>2000 ohm-$cm^2$) and actively transport $Na^+$ from apical fluid. $H_2O_2$(0-100 mM) was then delivered to either apical or basolateral fluid. Resulting indicated that $H_2O_2$ decreased Isc and R gradually in dose-dependent manner. The effective concentration of apical $H_2O_2$ at which Isc (or R) was decreased by 50% at one hour ($ED_{50}$) was about 4 mM. However, basolateral $H_2O_2$ exposure led to $ED_{50}$ for Isc (and R) of about 0.04 mM. Inhibition of cellular catalase yielded $ED_{50}$ for Isc (and R) of about 0.4 mM when $H_2O_2$ was given apically, while $ED_{50}$ for basolateral exposure to $H_2O_2$ did not change in the presence of ATAZ. The rate of $H_2O_2$ consumption in apical and basolateral bathing fluids was the same, while cellualr catalase activity rose gradually with time in culture. Conclusion: Our data suggest that basolateral $H_2O_2$ may affect directly membrane component (e.g., $Na^+,\;K^+$-ATPase) located on the basolateral cell surface. Apical $H_2O_2$, on the other hand, may be largely degraded by catalase as it passes through the cells before reaching these membrane components. We conclude that alveolar epithelial barrier integrity as measured by Isc and R are compromised by $H_2O_2$ being relatively sensitive to basolateral (and insensitive to apical) $H_2O_2$.

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Tuberculin Skin Test and Change of Cytokines in Patients with Allergic Asthma (알레르기성 천식환자에 있어서 투베르쿨린 피부반응 검사와 Cytokine의 변화)

  • Yoon, Hyoung-Kyu;Shin, Yoon;Lee, Sang-Haak;Lee, Sook-Young;Kim, Seok-Chan;Ahn, Joong-Hyun;Kim, Kwan-Hyoung;Moon, Hwa-Sik;Park, Sung-Hak;Song, Jeong-Sup
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.2
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    • pp.175-184
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    • 1999
  • Background: Bronchial asthma is characterized by chronic eosinophilic inflammatory airway disease associated with bronchial hyperresponsiveness and reversible airway obstruction. Bronchial inflammation in asthma may depend in part on the activation of T helper lymphocytes that elaborate proinflammatory cytokines. T helper (Th) lymphocytes can be divided into two categories; Th1 lymphocytes, which secrete IL-2, IL-12 and IFN-$\gamma$, and Th2 lymphocytes, which secrete IL-4, IL-5, IL-6 and IL-10. Th2 lymphocytes appear to induce allergic responses, whereas Th1 lymphocytes induce delayed-type hypersensitivity response. Some infections, such as tuberculosis, cultivate a Th1 immunological environment and inhibit Th2 lymphocytes function. The presence of such infections might inhibit Th2 immune responses and thus protect development of atopic diseases. Method: 15 patients with allergic bronchial asthma, 10 patients with intrinsic bronchial asthma, and 10 healthy volunteers were studied. The serum concentrations of IFN-$\gamma$, IL-12, IL-4, IL-5, and IL-10 were measured by ELISA method and tuberculin skin test was estimated in different groups. Results: The positive response rates of tuberculin test were 46.7% in patients with allergic asthma, 100% in patients with intrinsic asthma and 60% in normal controls. The positive response rates were significantly lower in patients with allergic asthma than those of in patients with intrinsic asthma (p<0.05). Degree of responses to tuberculin test were $12.0{\pm}9.6mm$ in patients with allergic asthma, $18.4{\pm}4.5mm$ in patients with intrinsic asthma and $10.9{\pm}8.8mm$ in normal controls. The degree of responses were significantly reduced in patients with allergic asthma than those of patients with intrinsic asthma (p<0.05). The serum levels of IL-5 in patients with allergic asthma were significantly higher than in patients with intrinsic asthma and normal controls (p<0.05), although it was insignificant. the serum levels of IL-4 and IL-10 in patients with allergic asthma were higher than that of intrinsic asthma and normal controls. The serum levels of IL-12 and IFN-$\gamma$ in patients with allergic asthma and intrinsic asthma were significantly lower than those in normal controls(p<0.05). The serum levels of total immunoglobulin E (IgE) and peripheral blood eosinophile counts in patients with allergic asthma were significantly higher than those in normal controls. Peripheral blood esinophil counts had a significant correlation with the serum levels of total IgE, IL-5 and IL-10 in patients with allergic asthma (p<0.05). Conclusion: These results have showed that Th1 lymphocyte functions were lowered and Th2 lymphocyte functions were elevated in patients with allergic asthma than those in normal controls. Suppression of Th1 lymphocyte functions by activation of Th2 lymphocyte might be one of the important aspects of pathogenesis in allergic bronchial asthma.

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Nutritional Studies for Improvement of Feeding on Korean Native Goat - Absorption of Nutrients in Rumen - (한국재래산양(韓國在來山羊)의 사양개선(飼養改善)에 관(關)한 연구(硏究) - 제일위((第一胃)에서의 영양소(營養素) 흡수(吸收)에 대(對)하여 -)

  • Kwon, Soon Ki
    • Korean Journal of Agricultural Science
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    • v.9 no.1
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    • pp.284-302
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    • 1982
  • Development of protein resources as food has been a big issue especially in Southeast Asia region, and intake of protein is also insufficient in Korea. To cope with this shortage of protein resources and its improvement together with increased production of high nutritive animal protein, studies were carried out on feeding of Korean native goats. In the experiments were made absorption of carbohydrate and volatile fatty acid in miniature rumen, and absorption of amino acid in rumen as in vivo were conducted as part of studies on nutritional absorption in rumen. Those nutritional for improvement of feeding and management as described above are summarized as following. 1. According to the result of test on the nutritional absorption of native goat by means of miniature rumen method, absorption ratio of VFA measured at 0.5, 1 and 2 hours after injection of nutrition showed propionic acid 70-86%, acetic acid 74-87%, and lactic acid 76-89%. In the absorption of organic substances, ethyl alcohol of 0.5% showed 29-87% and lactic acid of 0.1M showed 12-27% of absorption ratio. 2. Result of absorption measurement in rumen from L-type free amino acid injection in the content of rumen vein showed lower rate at menthionine-free group compared to whole-egg amino acid injection in the content of rumen vein showed lower rate at methioine-free group compared to whole-egg amino acid group, and high absorption ratio was observed at methionine 3 times group and urea added group. Deficiency of methionine caused no change of the content in mucous membranes. 3. Absorption of amino acid in rumen muscular layer showed equal tendency as in the mucous membrane without exerting any influence of methionine deficiency. At the methionine3-times group, content of methionine and glutamine were increased by 14.7 and 4.4 times as compared to whole-egg amino acid group, an absorption ratio of glutamine, proline and valine were increased at urea added group. 4. In general, concentration of amino acid in rumen vein plasma was lower than in rumen mucous membrane and muscular layer. Absorption ratio of amino acid is decreased due to methionine deficiency, and tripling of methionine or urea adding caused increment of amino acid. Absorption pattern is thus varied depending on the composition of amino acid. 5. At the urea added group, content of ammonia-N, amino-N and urea were increased in rumen muscular layer. As the inside of goat's rumen was unable to clean thoroughly, investigation was made on remaining bacteria, however, variation of ammonia-N was affected by these bacterial content. 6. Variation in rumen structure by differential absorption of amino acid was observed by general microscope and fluorescent microscope. According to the result of observation in the methionine 3 times group, single cylinder epithelium of mucous membrane showed rather thin, and it was thick at urea added group though no significant differences existed among test groups in submucous membrane and muscular layer.

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Image Quality Evaluation of CsI:Tl and Gd2O2S Detectors in the Indirect-Conversion DR System (간접변환방식 DR장비에서 CsI:Tl과 Gd2O2S의 검출기 화질 평가)

  • Kong, Changgi;Choi, Namgil;Jung, Myoyoung;Song, Jongnam;Kim, Wook;Han, Jaebok
    • Journal of the Korean Society of Radiology
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    • v.11 no.1
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    • pp.27-35
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    • 2017
  • The purpose of this study was to investigate the features of CsI:Tl and $Gd_2O_2S$ detectors with an indirect conversion method using phantom in the DR (digital radiography) system by obtaining images of thick chest phantom, medium thickness thigh phantom, and thin hand phantom and by analyzing the SNR and CNR. As a result of measuring the SNR and CNR according to the thickness change of the subject, the SNR and CNR were higher in CsI:Tl detector than in $Gd_2O_2S$ detector when the medium thickness thigh phantom and thin hand phantom were scanned. However, when the thick chest phantom was used, for the SNR at 80~125 kVp and the CNR at 80~110 kVp in the $Gd_2O_2S$ detector, the values were higher than those of CsI:Tl detector. The SNR and CNR both increased as the tube voltage increased. The SNR and CNR of CsI:Tl detector in the medium thickness thigh phantom increased at 40~50 kVp and decreased as the tube voltage increased. The SNR and CNR of $Gd_2O_2S$ detector increased at 40~60 kVp and decreased as the tube voltage increased. The SNR and CNR of CsI:Tl detctor in the thin hand phantom decreased at the low tube voltage and increased as the tube voltage increased, but they decreased again at 100~110 kVp, while the SNR and CNR of $Gd_2O_2S$ detector were found to decrease as the tube voltage increased. The MTF of CsI:Tl detector was 6.02~90.90% higher than that of $Gd_2O_2S$ detector at 0.5~3 lp/mm. The DQE of CsI:Tl detector was 66.67~233.33% higher than that of $Gd_2O_2S$ detector. In conclusion, although the values of CsI:Tl detector were higher than those of $Gd_2O_2S$ detector in the comparison of MTF and DQE, the cheaper $Gd_2O_2S$ detector had higher SNR and CNR than the expensive CsI:Tl detector at a certain tube voltage range in the thick check phantom. At chest X-ray, if the $Gd_2O_2S$ detector is used rather than the CsI:Tl detector, chest images with excellent quality can be obtained, which will be useful for examination. Moreover, price/performance should be considered when determining the detector type from the viewpoint of the user.

The Evaluation of SUV Variations According to the Errors of Entering Parameters in the PET-CT Examinations (PET/CT 검사에서 매개변수 입력오류에 따른 표준섭취계수 평가)

  • Kim, Jia;Hong, Gun Chul;Lee, Hyeok;Choi, Seong Wook
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.43-48
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    • 2014
  • Purpose: In the PET/CT images, The SUV (standardized uptake value) enables the quantitative assessment according to the biological changes of organs as the index of distinction whether lesion is malignant or not. Therefore, It is too important to enter parameters correctly that affect to the SUV. The purpose of this study is to evaluate an allowable error range of SUV as measuring the difference of results according to input errors of Activity, Weight, uptake Time among the parameters. Materials and Methods: Three inserts, Hot, Teflon and Air, were situated in the 1994 NEMA Phantom. Phantom was filled with 27.3 MBq/mL of 18F-FDG. The ratio of hotspot area activity to background area activity was regulated as 4:1. After scanning, Image was re-reconstructed after incurring input errors in Activity, Weight, uptake Time parameters as ${\pm}5%$, 10%, 15%, 30%, 50% from original data. ROIs (region of interests) were set one in the each insert areas and four in the background areas. $SUV_{mean}$ and percentage differences were calculated and compared in each areas. Results: $SUV_{mean}$ of Hot. Teflon, Air and BKG (Background) areas of original images were 4.5, 0.02. 0.1 and 1.0. The min and max value of $SUV_{mean}$ according to change of Activity error were 3.0 and 9.0 in Hot, 0.01 and 0.04 in Teflon, 0.1 and 0.3 in Air, 0.6 and 2.0 in BKG areas. And percentage differences were equally from -33% to 100%. In case of Weight error showed $SUV_{mean}$ as 2.2 and 6.7 in Hot, 0.01 and 0.03 in Tefron, 0.09 and 0.28 in Air, 0.5 and 1.5 in BKG areas. And percentage differences were equally from -50% to 50% except Teflon area's percentage deference that was from -50% to 52%. In case of uptake Time error showed $SUV_{mean}$ as 3.8 and 5.3 in Hot, 0.01 and 0.02 in Teflon, 0.1 and 0.2 in Air, 0.8 and 1.2 in BKG areas. And percentage differences were equally from 17% to -14% in Hot and BKG areas. Teflon area's percentage difference was from -50% to 52% and Air area's one was from -12% to 20%. Conclusion: As shown in the results, It was applied within ${\pm}5%$ of Activity and Weight errors if the allowable error range was configured within 5%. So, The calibration of dose calibrator and weighing machine has to conduct within ${\pm}5%$ error range because they can affect to Activity and Weight rates. In case of Time error, it showed separate error ranges according to the type of inserts. It showed within 5% error when Hot and BKG areas error were within ${\pm}15%$. So we have to consider each time errors if we use more than two clocks included scanner's one during the examinations.

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