• Title/Summary/Keyword: 시간측정

Search Result 14,953, Processing Time 0.053 seconds

Studies on the Breeding of the Response to short photoperiod, Fiber weight, and Qualitative characters and of the Associations Among these characters in Kenaf (섬유용양마의 육종에 관한 연구 -단일반응성과 섬유종의 유전 및 연소)

  • Johng-Moon Park
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.4 no.1
    • /
    • pp.115-124
    • /
    • 1968
  • It was shown that the most desirable characters for kenaf are high-fiber weight and moderately early maturity. Therefore, the objectives of this research on this crop is to find varieties possessing these characteristics. The experiments covered in this report provided new information relative to segregation, mode of inheritance, estimate of the number of genes involved in fiber weight and their response to short day length of 10 hours and the qualitative characters, such as, color of stem, capsule, petiole and shape of leaves. The associations which exist among these characters are also indicated. Fiber weight per plant, days to flowering, Stem color, Petiole color, Capsule color, and shape of leaves were studied in parental, $F_1$.$F_2$and backcross populations of a cross between Dashkent, a low-fiber weight but early maturing kenaf variety, and G 38 F-1, a high-fiber weight but late maturing kenaf variety. Crosses were made using the varieties, Dashkent and G 38 F-1 as parents. The Dashkent parent had the following characteristics: green stems, capsules and petioles and lobed shaped leaves; 105.8234 mean-days to flowering in the field, and 106.9222 mean-days under 10 hours short day treatment. The other parent, G 38 F-1 had red stems yellow capsules and red petioles and unlobed shaped leaves; 149.8921 mean-days to flowering in the field, and 62.3684 mean-days under 10 hours short day treatment. Both of the parents, $F_1$, $F_2$, $BC_1$ ($F_1$ X Dashkent, ) and $BC_2$($F_1$ ${\times}$ G38F-1) of the kenaf cross were grown at the Crops Experiment Station, Suwon, Korea in 1965. Color of stems, petioles and capsules, and shape of leaves were noted to be simply inherited as a single factor. Red stem color was dominant over green stem color, red petiole color was dominant over green petiole, lobed shaped leaves were dominant over unlobed shaped leaves and yellow capsules were dominant over green capsule. It was, also, noted that the factor for color of petiole was linked with the factor for shape of leaf with a 11.9587 percent recombination value, however no interaction or linkage were found among the color of stem and capsule color. Using Powers partitioning method, theoretical means and frequency distributions for each population, the days to flowering were calculated with the assumption that two gene pairs were involved. The values obtained fitted the theoretical values. In general this would indicate that Dashkent and G 38 F -1 were differentiated by two gene pairs. Heritability values were calculated as the percent of additive genetic variance. Heritability value of days to flowering, 89.5% in the broad sense and 79.91% in the narrow sense, indicated that the selection for this character would be effective in relatively early generations. Particularly, high positive correlations were found between days to flowering and the color of petioles and shape of leaves. However, there was no relation between days to flowering and capsule color nor between these and stem color. On the basis of the results of this experiment there is evidence that the hereditary factor for shape of leaves and the color of petioles is linked with an effective factor or factors for the characters of days to flowering. The association was sufficiently close to offer a possible simple and efficient means of selection for moderately early mat. uring plants by leaf shape and petiole color selection. Again using Powers partitioning method the frequency distribution for each population to the fiber weight were calculated with the assumption that two gene pairs, AaBb, were involved. Both phenotypic and genotypic dominance were complete. The obtained value did not agree with the theoretical value for $F_2$ and $BC_1$ ($F_1$ ${\times}$ Dashkent.) It seems that Dashkent and G 38 F-1 were differentiated by two major gene pairs but some the other minor genes are necessary. It is certain that the hereditary factor for shape of leaves and color of petioles is linked with an effective factor or factors for fiber weight. Also, high. yielding plants with moderately early maturity were found in the $F_2$ population. Thus, simultaneous selection for high-fiber yield and moderately early maturing plants should be possible in these populations. Phenotypic and genotypic correlation coefficients between fiber weight per plant and days to flowering, stem height and stem diameter were calculated. In general, genotypic correlations are higher than the phenotypic correlation. The highest correlation is found between stem height and fiber weight per plant (0.7852 in genotypic and 0.4103 in phenotypic) and between days to flowering and fiber weight per plant (0.7398 in genotypic and 0.3983 in phenotypic.) It was also expected that the selection of high stem height and moderately early maturing plants were given the efficient means of selection for high fiber weight.

  • PDF

A Proposal of a Keyword Extraction System for Detecting Social Issues (사회문제 해결형 기술수요 발굴을 위한 키워드 추출 시스템 제안)

  • Jeong, Dami;Kim, Jaeseok;Kim, Gi-Nam;Heo, Jong-Uk;On, Byung-Won;Kang, Mijung
    • Journal of Intelligence and Information Systems
    • /
    • v.19 no.3
    • /
    • pp.1-23
    • /
    • 2013
  • To discover significant social issues such as unemployment, economy crisis, social welfare etc. that are urgent issues to be solved in a modern society, in the existing approach, researchers usually collect opinions from professional experts and scholars through either online or offline surveys. However, such a method does not seem to be effective from time to time. As usual, due to the problem of expense, a large number of survey replies are seldom gathered. In some cases, it is also hard to find out professional persons dealing with specific social issues. Thus, the sample set is often small and may have some bias. Furthermore, regarding a social issue, several experts may make totally different conclusions because each expert has his subjective point of view and different background. In this case, it is considerably hard to figure out what current social issues are and which social issues are really important. To surmount the shortcomings of the current approach, in this paper, we develop a prototype system that semi-automatically detects social issue keywords representing social issues and problems from about 1.3 million news articles issued by about 10 major domestic presses in Korea from June 2009 until July 2012. Our proposed system consists of (1) collecting and extracting texts from the collected news articles, (2) identifying only news articles related to social issues, (3) analyzing the lexical items of Korean sentences, (4) finding a set of topics regarding social keywords over time based on probabilistic topic modeling, (5) matching relevant paragraphs to a given topic, and (6) visualizing social keywords for easy understanding. In particular, we propose a novel matching algorithm relying on generative models. The goal of our proposed matching algorithm is to best match paragraphs to each topic. Technically, using a topic model such as Latent Dirichlet Allocation (LDA), we can obtain a set of topics, each of which has relevant terms and their probability values. In our problem, given a set of text documents (e.g., news articles), LDA shows a set of topic clusters, and then each topic cluster is labeled by human annotators, where each topic label stands for a social keyword. For example, suppose there is a topic (e.g., Topic1 = {(unemployment, 0.4), (layoff, 0.3), (business, 0.3)}) and then a human annotator labels "Unemployment Problem" on Topic1. In this example, it is non-trivial to understand what happened to the unemployment problem in our society. In other words, taking a look at only social keywords, we have no idea of the detailed events occurring in our society. To tackle this matter, we develop the matching algorithm that computes the probability value of a paragraph given a topic, relying on (i) topic terms and (ii) their probability values. For instance, given a set of text documents, we segment each text document to paragraphs. In the meantime, using LDA, we can extract a set of topics from the text documents. Based on our matching process, each paragraph is assigned to a topic, indicating that the paragraph best matches the topic. Finally, each topic has several best matched paragraphs. Furthermore, assuming there are a topic (e.g., Unemployment Problem) and the best matched paragraph (e.g., Up to 300 workers lost their jobs in XXX company at Seoul). In this case, we can grasp the detailed information of the social keyword such as "300 workers", "unemployment", "XXX company", and "Seoul". In addition, our system visualizes social keywords over time. Therefore, through our matching process and keyword visualization, most researchers will be able to detect social issues easily and quickly. Through this prototype system, we have detected various social issues appearing in our society and also showed effectiveness of our proposed methods according to our experimental results. Note that you can also use our proof-of-concept system in http://dslab.snu.ac.kr/demo.html.

Four-year change and tracking of serum lipids in Korean adolescents (강화지역 청소년의 4년간 혈청 지질의 변화와 지속성)

  • Lee, Kang-Hee;Suh, Il;Jee, Sun-Ha;Nam, Chung-Mo;Kim, Sung-Soon;Shim, Won-Heum;Ha, Jong-Won;Kim, Suk-Il;Kang, Hyung-Gon
    • Journal of Preventive Medicine and Public Health
    • /
    • v.30 no.1 s.56
    • /
    • pp.45-59
    • /
    • 1997
  • It has been known that there is a tracking phenomenon in the level of serum lipids. However, no study has been performed to examine the change and tracking of serum lipids in Korean adolescents. The purpose of this study is to examine the changes of serum lipids in Korean adolescents from 12 to 16 years of age, and to examine whether or not there is a tracking phenomenon in serum lipids level during the period. In 1992 serum lipids(total cholesterol(TC), triglyceride(TG), LDL cholesterol(LDL-C), HDL cholesterol(HDL-C)) were measured in 318 males, 365 females who were 12 years of age in Kangwha county, Korea. These participants have been followed up to 1996 and serum lipids level were examined in 1994 and 1996. Among the participants 162 males and 147 females completed all three examinations in fasting state. To examine the effect of eliminating adolescents with incomplete data, we compared serum lipids, blood pressure and anthropometric measures at baseline between adolescents with complete follow-up and adolescents who were withdrawn. To examine the change of serum lipids we compared mean values of serum lipids according to age in males and females. Repeated analysis of variance was used to test the change according to age. We used three methods to examine the existence of tracking. First, we analyzed the trends in serum lipids over 4-year period within quartile groups formed on the basis of the first-year serum lipids level to see whether or not the relative ranking of the mean serum lipids among the quartile groups remained in the same group for 4-year period. Second, we quantified the degree of tracking by calculating Spearman's rank correlation coefficient between every tests. Third, the persistence extreme quartile method was used. This method divides the population into quartile groups according to the initial level of blood lipids and then calculates the percent of the subjects who stayed in the same group at follow-up measurement. The decreases in levels were noted during 4 years for TC, LDL-C, primarily for boys. The level of HDL-C decreased between baseline and first follow-up for both sexes. Tracking, as measured by both correlation coefficients and persistence extreme quartiles, was evident for all of the lipids. The correlation coefficients of TC between baseline and 4 years later in boys and girls were 0.55 and 0.68, respectively. And the corresponding values for HDL-C were 0.58 and 0.69. More than 50% of adolescents who belonged to the highest quartile group in TC, HDL-C and LDL-C at the baseline were remained at the same group at the examination performed 2 years later for both sexes. The probabilities of remaining at the same group were more than 35% when examined 4 years later. The tracking phenomenon of TG was less evident compared with the other lipids. Percents of girls who stayed at the same group 2 years later and 4 years later were 42.9% and 25.7%, respectively. It was evident that serum lipid levels tracked in Korean adolescents. Researches with longer follow-up would be needed in the future to investigate the long-term change of lipids from adolescents to adults.

  • PDF

Contribution of Emotional Labor to Burnout and Work Engagement of School Foodservice Employees in Daegu and Gyeongbuk Province (대구·경북 일부지역 학교급식 조리종사자의 감정노동이 직무 소진 및 직무 열의에 미치는 영향)

  • Heo, Chang-Goo;Lee, Kyung-A
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.44 no.4
    • /
    • pp.610-618
    • /
    • 2015
  • The purpose of this study was to analyze differences in emotional labor strategies, burnout, and work engagement according to general characteristics of school foodservice employees as well as verify differential effects of two emotional labor strategies on burnout and work engagement. Our survey was administered to 400 school foodservice employees in Gyeongbuk from March 3 to April 25, 2014. A total of 358 completed questionnaires were returned, and 350 questionnaires were used for final analysis. For verification of mean differences, the mean scores for surface acting, deep acting, burnout, and work engagement were shown to be 2.38/5.00, 3.46, 2.67, and 3.41, respectively. The mean surface acting was significantly different according to cooking certification (P<0.001), turnover number (P<0.001), salary (P<0.001), and school level (P<0.01). The mean deep acting was significantly different according to educational background (P<0.001), cooking certification (P<0.001), employment status (P<0.001), salary (P<0.001), school level (P<0.01), and meal service time (P<0.05). The mean burnout was significantly different according to educational background (P<0.01), cooking certification (P<0.05), employment status (P<0.001), school level (P<0.001), and meal service time (P<0.001). The mean work engagement was significantly different according to cooking certification (P<0.001), employment satus (P<0.001), salary (P<0.001), school level (P<0.01), and meal service time (P<0.05). Verification of causal models found that surface acting and deep acting increased burnout and deep acting, respectively (research model). Additionally, surface acting did not influence work engagement, and deep acting did not influence burnout (alternative models). In other words, we identified that emotional labor strategies have differential influences on burnout and work engagement. Finally, implications and limitations of this study are discussed.

Tracheal gas insufflation (TGI) in patients with increased deadspace fraction: the effect and its determining factors (사강호흡율이 증가된 환자에서 기관내 가스주입법(Tracheal Gas Imsufflation)이 가스교환에 미치는 효과와 그 결정인자)

  • Lim, Chae Man;Jung, Bok Hyun;Koh, Youn Suck;Lee, Sang Do;Kim, Woo Sung;Park, Pyung Hwan;Kim, Dong Soon;Kim, Won Dong
    • Tuberculosis and Respiratory Diseases
    • /
    • v.44 no.1
    • /
    • pp.136-145
    • /
    • 1997
  • Background : Tracheal Gas Insufflation (TGI) is one of the newer ancillary measures in mechanical ventilation employed to enhance carbon dioxide elimination. TGI exerts its effect through reduction of deadspace ventilation, but the factors determining its effect are not well studied yet. Method : The subjects were seven mechanically-ventilated patients ($58.8{\pm}10.6$ yrs) who showed increased physiologic deadspace greater than 60%. After 30 nun of stabilization with 100% oxygen on pressure control ventilation, continuous flow TGI was administered via the insufflation lumen of Hi-Lo Jet Tracheal Tube (Mallincrodt, USA) for 15 min at 3 L/min and 5 L/min each. Results : $PaCO_2$ was decreased ($51.4{\pm}17.6$ at baseline, $49.1{\pm}18.9$ at TGJ 3 L/min $45.0{\pm}14.9$ mm Hg at TGI 5 L/min, p=0.050), and pH was increased ($7.37{\pm}0.12$, $7.38{\pm}0.13$, $7.39{\pm}0.12$, respectively, p=0.037) while mixed expired $CO_2$ ($P_ECO_2$) was not changed significantly from baseline (p=0.336) by TGI. Physiologic deadspace(Vdphy) was decreased ($73.0{\pm}7.9$% at baseline, $69.8{\pm}10.0$% at TGI 3 L/min, and $67.1{\pm}10.1$% at TGI 5 L/min, p=0.015). $AaDO_2$(p=0.147), Vt(p=0.2140), Pmean(p=0.7788) and mean arterial pressure(p=0.4169) were not changed. The correlation between % maximal decrease of Vdphy were r=0.790 with the ratio of baseline Vdana/Vdphy(p=0.035) and r=-0.754 with baseline Vdalv(p=0.050). Conclusion: TGI was effective in reducing $PaCO_2$ and deadspace, and the deadspace-reducing effect was best correlated with baseline anatomic/physiologic deadspace ratio.

  • PDF

A Study of the Health Promoting Life Style in Rural Area (일부 농촌주민의 건강증진 생활양식 수행정도)

  • Jung, Young-Ok;Kim, Sang-Soon
    • Journal of agricultural medicine and community health
    • /
    • v.20 no.2
    • /
    • pp.133-148
    • /
    • 1995
  • This study was to identify the factors affecting the performance in health promoting lifestyle and measuring health promoting lifestyle. The subjects for this study were all adult in rural area, Kakbuk Nyun, Chung-do Gun, Kyungpook, Korea. The data were collected during the period from April 1 to April 30, 1995. The instruments used for this study were the health promoting lifestyle by Park(1995). The results of this study are as follows. Health condition felt by the subjects was worse in female group and was getting worse according as the age increase. According to health promoting life style implementation questionnaire, more than half of the subjects responded "never" in deep breathing 3 times a day item and non-smoking item; more than half of the subjects responded "yes" in 3 meal a day item, home-cooked meals item, never to omit breakfast item and frequent wearing of cotton underwear item. Health promoting life style implementation by health condition is higher in healthy group and frequency of consulting a specialist is higher in unhealthy group. Health promoting life style implementation by sex is higher in male group. Frequency, of consulting a specialist and non-excessive drinking are higher in female group. Health promoting life style implementation by age showed that the implementation of never omitting breakfast, keeping early hours and proper sleeping is higher in old age group ; that of enjoying hobby, pastime, cleaning as well as reading health books is higher in young age group. Health promoting life style implementation by religion showed that the implementation of deep breathing 3 times more a day, regular checking of blood pressure, never having non-healthful food and keeping right posture in sitting and standing is higher in religion group. Health promoting life style implementation by education is higher in highly-educated group ; the implementation of keeping early hours is higher in low-educated group. Health promoting life style implementation by marriage state showed that the implementation of deep breathing 3 times more a day, twenty minutes of brisk physical movement three or four times a week, enjoying his or her own time, relaxation to relieve from tension and pressure and equalized movement of each part of body is higher in unmarred group ; that of having elaborately cooked food, never omitting three meals a day and keeping early hours is higher in married group. Health promoting life style implementation by the number of family members showed that more-member-group has more plans and objectives for their future. Health promoting life style implementation by family type showed that the implementation of reading health books and articles, living with positive way of thinking and enjoying favorite hobby in pastime is higher in nuclear families ; that of having three meals a day never omitting breakfast is higher in large families.

  • PDF

A Comparative Study of Diabetes Mellitus Patients with Cerebral Infarction or without Cerebral Infarction - Focused on Nutrient Intakes and Dietary Quality - (뇌경색 당뇨병 환자와 비뇌경색 당뇨병 환자의 비교연구 - 영양소 섭취, 식사의 질 평가를 중심으로 -)

  • Lim, Hyun-Jung;Woo, Mi-Hye;Moon, Sang-Kwan;Choue, Ryo-Won
    • Journal of Nutrition and Health
    • /
    • v.41 no.7
    • /
    • pp.621-633
    • /
    • 2008
  • Diabetes mellitus (DM) is a well-established independent risk factor for cerebral infarction (CI). Additionally, the DM as well as CI are influenced significantly by health-related behaviors and diets. The aim of this study was to compare the food habits, nutrient intakes, and dietary patterns and quality in DM patients with CI (DM-CI) and without CI. This study was accomplished with 68 subjects (DM-CI group = 28, DM group = 40). Health-related behaviors, food habits, nutrient intakes and dietary quality were investigated. As a result, the mean ages and durations of diabetes in DM-CI and DM groups were $65.6{\pm}9.2$, $10.9{\pm}8.5$ and $69.2{\pm}3.0$, $9.7{\pm}8.4$ years, respectively. The health-related behaviors such as, smoking, alcohol drinking, and regular exercising in both groups were significantly different (p < 0.05) showing the number of subjects who were smoking and drinking alcohol was significantly higher in DM-CI group and the opposit result was seen for exercise. In male subjects, the intake of carbohydrate and sodium of DM-CI group were significantly higher than those of DM group (p < 0.05). In female subjects, the intake of calorie, carbohydrate, fat, sodium, and cholesterol were significantly higher in the DM-CI group (p < 0.05). Daily intake of vitamin $B_1$, vitamin $B_2$, folate, vitamin C, and calcium were significantly higher in DM group (p < 0.05). In the comparison with the dietary reference intake for Koreans (KDRI), vitamin $B_1$, vitamin $B_2$, folate, and calcium intakes were lower in DM-CI group whereas calcium and zinc intakes were in DM group. Moreover, index of nutritional quality (INQ) of vitamin $B_1$, vitamin $B_2$, vitamin C, folate, and calcium were lower significantly in DM-CI group (p < 0.05). Dietary quality including dietary diversity score (DDS), GMVDF (grain, meat, vegetable, dairy, fruit), and dietary quality index (DQI) was significantly lower in DM-CI group (p < 0.05). According to the results, diabetic mellitus patients accompanied by cerebral infarction had poorer eating patterns and dietary quality in accordance with poorer health-related behaviors compared with the DM patients without CI.

Smoking-Induced Dopamine Release Studied with $[^{11}C]Raclopride$ PET ($[^{11}C]Raclopride$ PET을 이용한 흡연에 의한 도파민 유리 영상 연구)

  • Kim, Yu-Kyeong;Cho, Sang-Soo;Lee, Do-Hoon;Ryu, Hye-Jung;Lee, Eun-Ju;Ryu, Chang-Hung;Jeong, In-Soon;Hong, Soo-Kyung;Lee, Jae-Sung;Seo, Hong-Gwan;Jeong, Jae-Min;Lee, Won-Woo;Kim, Sang-Eun
    • The Korean Journal of Nuclear Medicine
    • /
    • v.39 no.6
    • /
    • pp.421-429
    • /
    • 2005
  • Purpose: It has been postulated that dopamine release in the striatum underlies the reinforcing properties of nicotine. Substantial evidence in the animal studies demonstrates that nicotine interacts with dopaminergic neuron and regulates the activation of the dopaminergic system. The aim of this study was to visualize the dopamine release by smoking in human brain using PET scan with $[^{11}C]raclopride$. Materials and Methods: Five male non-smokers or ex-smokers with an abstinence period longer than 1 year (mean age of $24.4{\pm}1.7$ years) were enrolled in this study $[^{11}C]raclopride$, a dopamine D2 receptor radioligand, was administrated with bolus-plus-constant infusion. Dynamic PET was performed during 120 minutes ($3{\times}20s,\;2{\times}60s,\;2{\times}120s,\;1{\times}180s\;and\;22{\times}300s$). following the 50 minute-scanning, subjects smoked a cigarette containing 1 mg of nicotine while in the scanner. Blood samples for the measurement of plasma nicotine level were collected at 0, 5, 10, 15, 20, 25, 30, 45, 60, and 90 minute after smoking. Regions for striatal structures were drawn on the coronal summed PET images guided with co-registered MRI. Binding potential, calculated as (striatal-cerebellar)/cerebellar activity, was measured under equilibrium condition at baseline and smoking session. Results: The mean decrease in binding potential of $[^{11}C]raclopride$ between the baseline and smoking in caudate head, anterior putamen and ventral striatum was 4.7%, 4.0% and 7.8%, respectively. This indicated the striatal dopamine release by smoking. Of these, the reduction in binding potential in the ventral striatum was significantly correlated with the cumulated plasma level of the nicotine (Spearman's rho=0.9, p=0.04). Conclusion: These data demonstrate that in vivo imaging with $[^{11}C]raclopride$ PET could measure nicotine-induced dopamine release in the human brain, which has a significant positive correlation with the amount or nicotine administered bt smoking.

Evaluation of Artifacts by Dental Metal Prostheses and Implants on PET/CT Images: Phantom and Clinical Studies (PET/CT 영상에서의 치과재료에 의한 인공물에 관한 연구)

  • Bahn, Young-Kag;Park, Hoon-Hee;NamKoong, Hyuk;Cho, Suk-Won;Lim, Han-Sang;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.14 no.2
    • /
    • pp.110-116
    • /
    • 2010
  • Purpose: The X-ray attenuation coefficient based on CT images is used for attenuation correction in PET/CT. The polychromatic X-ray beam can introduce beam-hardening artifact on CT images. The aims of the study were to evaluate the effect of dental metal prostheses in phantom and patients on apparent tracer activity measured with PET/CT when using CT attenuation correction. Materials and Methods: 40 normal patients (mean age $54{\pm}12$) was scanned between Jan and Feb 2010. NEMA(National Electrical Manufactures Association) PET $Phantom^{TM}$ (NU2-1994) was filled with $^{18}F$-FDG injected into the water that insert implant and metal prostheses dental cast. Region of interest were drawn in non-artifact region, bright steak artifact region and dark streak artifact region on the same transaxial CT and PET slices. Patients and phantom with dental metal prostheses and dental implant were evaluated the change rate of CT Number and $SUV_{mean}$ in PET/CT. A paired t-test was performed to compare the ratio and the difference of the calculated values. Results: In patients with dental metal prostheses, $SUV_{mean}$ was reduced 19.64% (p<0.05) in the non-steak artifact region than the brightstreak artifact region whereas was increased 90.1% (p>0.05) in the non-steak artifact region than the dark streak artifact region. In phantom with dental metal prostheses, $SUV_{mean}$ was reduced 18.1% (p<0.05) in the non-steak artifact region than the bright streak artifact region whereas was increased 18.0% (p>0.05) in the non-steak artifact region than the dark streak artifact region. In patients with dental implant, $SUV_{mean}$ was increased 19.1% (p<0.05) in the non-steak artifact region than the bright streak artifact region whereas was increased 96.62% (p>0.05) in the non-steak artifact region than the dark streak artifact region. In phantom with dental implant, $SUV_{mean}$ was increased 14.4% (p<0.05) in the non-steak artifact region than the bright streak artifact region whereas was increased 7.0% (p>0.05) in the non-steak artifact region than the dark streak artifact region. Conclusion: When CT is used for attenuation correction in patients with dental metal prostheses, 19.1% reduced $SUV_{mean}$ is anticipated in the dark streak artifact region on CT images. The dark streak artifacts of CT by dental metal prostheses may cause false negative finding in PET/CT. We recommend that the non-attenuation corrected PET images also be evaluated for clinical use.

  • PDF

Steroid Effect on the Brain Protection During OPen Heart Surgery Using Hypothermic Circulatory Arrest in the Rabbit Cardiopulmonary bypass Model (저체온순환정지법을 이용한 개심술시 스테로이드의 뇌보호 효과 - 토끼를 이용한 심폐바이패스 실험모델에서 -)

  • Kim, Won-Gon;Lim, Cheong;Moon, Hyun-Jong;Chun, Eui-Kyung;Chi, Je-Geun;Won, Tae-Hee;Lee, Young-Tak;Chee, Hyun-Keun;Kim, Jun-Woo
    • Journal of Chest Surgery
    • /
    • v.30 no.5
    • /
    • pp.471-478
    • /
    • 1997
  • Introduction: The use of rabbits as a cardiopulmonary bypass(CPB) animal model is extremely dif%cult mainly due to technical problems. On the other hand, deep hypothermic circulatory arrest(CA) is used to facilitate surgical repair in a variety of cardiac diseases. Although steroids are generally known to be effective in the treatment of cerebral edema, the protective effects of steroids on the brain during CA are not conclusively established. Objectives of this study are twofold: the establishment of CPB technique in rabbits and the evaluation of preventive effect of steroid on the development of brain edema during CA. Material '||'&'||' Methods: Fifteen New Zealan white rabbits(average body weight 3.5kg) were divided into three experimental groups; control CA group(n=5), CA with Trendelenberg position group(n=5), and CA with Trendelenberg position + steroid(methylprednisolone 30 mglkg) administration group(n=5). After anesthetic induction and tracheostomy, a median sternotomy was performed. An aortic cannula(3.3mm) and a venous ncannula(14 Fr) were inserted, respectively in the ascending aorta and the right atrium. The CPB circuit consisted of a roller pump and a bubble oxygenator. Priming volume of the circuit was approximately 450m1 with 120" 150ml of blood. CPB was initiated at a flow rate of 80~85ml/kg/min, Ten min after the start of CPB, CA was established with duration of 40min at $20^{\circ}C$ of rectal temperature. After CA, CPB was restarted with 20min period of rewarming. Ten min after weaning, the animal was sacrif;cod. One-to-2g portions of the following tissues were rapidly d:ssected and water contents were examined and compared among gr ups: brain, cervical spinal cord, kidney, duodenum, lung, heart, liver, spleen, pancreas. stomach. Statistical significances were analyzed by Kruskal-Wallis nonparametric test. Results: CPB with CA was successfully performed in all cases. Flow rate of 60-100 mlfkgfmin was able to be maintained throughout CPB. During CPB, no significant metabolic acidosis was detected and aortic pressure ranged between 35-55 mmHg. After weaning from CPB, all hearts resumed normal beating spontaneously. There were no statistically significant differences in the water contents of tissues including brain among the three experimental groups. Conclusion: These results indicate (1) CPB can be reliably administered in rabbits if proper technique is used, (2) the effect of steroid on the protection of brain edema related to Trendelenburg position during CA is not established within the scope of this experiment.

  • PDF