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Studies on the Anther Culture of Some Woody Species (목본식물(木本植物)의 약배양(葯培養)에 관(關)한 연구(硏究))

  • Kim, Jai Saing
    • Journal of Korean Society of Forest Science
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    • v.13 no.1
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    • pp.25-39
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    • 1971
  • Recently successful induction of haploid plant by means of anther culture method has become a big topic among geneticists and plant breeders. The haploid plant can be used as a precious material for such basic researches as mutation or genetics. Once the haploid is obtained, production of homozygous plant is not a difficult problem. The method of producing homozygous plant can, also, be applied to the practical breeding works. When applied to the hybridization of self-fertilizing breeding period would be greatly shortened and in cross-fertilizing vegetables production of uniform hybrid seed would be very easily obtained. Last few years many scientists attempted anther cultures using various plant species, but it was successful only in several species. Unlike the other tissue cultures which use somatic organs or tissues as explants, anther culture seems to be very difficult because the plants or calli have to be induced from the haploid microspores or pollen grains. In the present experiment anther culture of fruit trees and ornamental shrubs of four genera and seven species was attemped. Anthers of Various stages ranging from tetrad and late microspore were cultured on the modified Murashige and Skoog's medium supplemented with various concentrations of auxins and kinetin as growth regulators. Handling of materials, sterilization, and other operations of culture were done by routine methods. The results were summarized as follows: 1. Calli were induced in the anthers of Forsythia Koreana Nak., Rhododendron mucronuratum Turcz., R. yedoense Max. var. Poukhanense Nak., and Prunus armeniaca L. var. ansu Max. No signs of callus were observed in Prunus persica Sieb. et Zucc. var. vurgaris Max., Pyrus ussuriensis var. macrostipes (Nak.), and Prunus salcina Lindley. 2. Calli were easily formed in any of the media with differing concentrations of auxins and kinetin. 3. In F. Koreana calli developed from anther surface and connective. Callus emerging out of anther locule was not observed. 4. Somatic calli arose from filament, connective, and inside of anther wall in R. mucronulatum. Many of the microspores accumulated starch grains. 5. The anther lobes located opposite the filament of R. yedoense turned easily to calli. This phenomenon was not observed in R. mucronulatum. Microspore embedded for a period in the medium became starch pollen. No callus was observed arising from microspore. 6. In P. armeniaca calli were not induced from somatic anther tissues. Instead, callus emerged out of anther locule rupturing the anther slit. Starch was not formed in the microspore. 7. In P. persica, Pyrus ussuriensis, and P. salcina, calli were not observed in the anthers examined more than 60 days after culture. Microspores of these species, however, were free of starch grains even after long period of subculture. 8. It was learned that somatic calli of the species examined arose usually from endothelium of anther wall, septum of two neighboring anther locules, parenchyma tissues of connectives, or anther lobes. 9. In the anther locule of P. armeniaca cultured long in medium, swollen microspores, polynucleate microspores, multicellular pollen grains, or callus mass were frequently observed, this indicating that the callus of this species was microspore-origin. 10. It was clarified that in P. armeniaca production of haploid plant by anther culture might be possible.

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A Study on the Properties of Plywoods Constructed by Sycamore and Lauan Veneer (푸라타누스와 나왕단판(羅王單板)을 구성(構成)한 합판(合板)의 성질(性質)에 관(關)한 연구(硏究))

  • Lee, Phil Woo
    • Journal of Korean Society of Forest Science
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    • v.30 no.1
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    • pp.8-18
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    • 1976
  • This study was carried out to exploit and utilize the exotic American Sycamore(Platanus occidentalis) grown in Korea as a veneer species for plywood manufacture. At present most parts of veneer Legs used in Korea were depended entirely upon the gonus Shorea woods(lauan logs) imported from Southeast Asia region. To decrease manufacturing cost and save imported lauan veneer logs, the effects on properties affecting to the six types of plywood made from proper veneer constructions composed by domestic American Sycamore and imported lauan veneers were compared and discussed. The study has important meanings for the promotion of plywood manufacture by domestic materials. Important items dealt with this study were dry and wet shear strength, moisture contents, specific gravties, and bending strength. By the results and discussions it may be summarized as follows: 1) In dry shear strength platanus(sycamore) core lauan plywood was shown most excellent strong results, and next orders were all lauan plywood, platanus faced lauan plywood, lauan core platanus plywood, lauan faced platanus plywood, and all platanus plywood. There was no difference between platanus core lauan plywood and all lauan plywood, but the differences between those plywoods and the other types of plywood were recognized. 2) In wet shear strength platanus core lauan plywood was shown excellent result the same as dry strength. The difference between platanus core lauan plywood and the other types of plywood was shown, but among the other types of plywood except platanus core lauan plywood were not recognized. 3) The differences among moisture contents according to the veneer construction were not recognized. 4) The plywood constructed by two or more sheets of lauan veneer was shown lower specific gravities than the plywood constructed by two or more sheets of platanus veneer. It is believed that this tendency due to the original specific gravities of veneer before construction. 5) The differences among specific gravities of lauan core platanus plywood, all platanus plywood and lauan faced platanus plywood were not recognized, and like this analyzed result among platanus core lauan plywood, all lauan plywood and platanus faced lauan plywood were not recognized. Accordingly it is believed that the differences are not shown among the plywood constructed by two or more veneers of same species. 6) In bending strength platanus core lauan plywood was shown most excellent values. Next orders were all lauan plywood, platanus faced lauan plywood and the other types of plywood. The differences among the plywood constructed by two or veneers of lauan were shown, but not shown among the plywood constructed by tow or more veneers of platanus.

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Investigation of Food Safety Knowledge, Attitudes, and Behavior for Analyzing Food Safety Risk Factors in the Elderly (노인들의 식품안전 위험요인 규명을 위한 식품위생 지식, 태도, 행동 조사)

  • Choi, Jung-Hwa;Lee, Yoon-Jin;Lee, Eun-Sil;Lee, Hye-Sang;Chang, Hye-Ja;Lee, Kyung-Eun;Yi, Na-Young;Kwak, Tong-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.5
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    • pp.746-756
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    • 2016
  • The purpose of this study was to investigate food safety knowledge, food safety attitudes, and handling behavior in the elderly. The survey was conducted on 358 individuals over 65 years old in urban and rural areas. Data were analyzed with descriptive analysis and ${\chi}^2$ test analysis of variance using SPSS. From the results on elderly's food safety knowledge, the item 'tangerines should be washed before eating' was correctly answered by urban subjects (75.4%) than rural subjects (49.7%). 'Is it okay to cook meat left on the sink since afternoon in the evening' showed the lowest correct answer rate in both urban (23.1%) and rural (31.9%) subjects. For the item related to food keeping, 'Bacterial cells do not multiply in Samgyetang when it is kept in a refrigerator right after boiling thoroughly', 58.5% of urban and 54.6% of rural elderly answered correctly. Most elderly people showed a tendency to think that boiled foods might be safe to eat. Secondly, for food safety attitudes, urban elderly had more proper attitude regarding the item, 'Namul is very tasty only when mixed with bare hands' (disagree rate 34.9%) than rural elderly (P<0.05)'. On the other hand, rural elderly had more positive attitudes regarding the store principle "first in, first out" compared to urban elderly (P<0.001). Thirdly, regarding food safety behaviors, only 67.9% of urban and 58.7% of rural elderly responded that they washed their hands right after answering the telephone while cooking. Exactly 33.8% of urban and 39.6% of rural older people replied 'defrost meat on top of sink or table' as the defrost method for frozen foods, showing that elderly did not recognize the risk of foodborne illness during improper defrosting at room temperature.

The difference of image quality using other radioactive isotope in uniformity correction map of myocardial perfusion SPECT (심근 관류 SPECT에서 핵종에 따른 Uniformity correction map 설정을 통한 영상의 질 비교)

  • Song, Jae hyuk;Kim, Kyeong Sik;Lee, Dong Hoon;Kim, Sung Hwan;Park, Jang Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.2
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    • pp.87-92
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    • 2015
  • Purpose When the patients takes myocardial perfusion SPECT using $^{201}Tl$, the operator gives the patients an injection of $^{201}Tl$. But the uniformity correction map in SPECT uses $^{99m}Tc$ uniformity correction map. Thus, we want to compare the image quality when it uses $^{99m}Tc$ uniformity correction map and when it uses $^{201}Tl$ uniformity correction map. Materials and Methods Phantom study is performed. We take the data by Asan medical center daily QC condition with flood phantom including $^{201}Tl$ 21.3 kBq/mL. After postprocessing with this data, we analyze CFOV integral uniformity(I.U) and differential uniformity(D.U). And we take the data with Jaszczak ECT Phantom by American college of radiology accreditation program instruction including $^{201}Tl$ 33.4 kBq/mL. After post processing with this data, we analyze spatial Resolution, Integral Uniformity(I.U), coefficient of variation(C.V) and Contrast with Interactive data language program. Results In the flood phantom test, when it uses $^{99m}Tc$ uniformity correction map, Flood I.U is 3.6% and D.U is 3.0%. When it uses $^{201}Tl$ uniformity correction map, Flood I.U is 3.8% and D.U is 2.1%. The flood I.U is worsen about 5%, but the D.U is improved about 30% inversely. In the Jaszczak ECT phantom test, when it uses $^{99m}Tc$ uniformity correction map, SPECT I.U, C.V and contrast is 13.99%, 4.89% and 0.69. When it uses $^{201}Tl$ uniformity correction map, SPECT I.U, C.V and contrast is 11.37%, 4.79% and 0.78. All of data are improved about 18%, 2%, 13% The spatial resolution was no significant changes. Conclusion In the flood phantom test, Flood I.U is worsen but Flood D.U is improved. Therefore, it's uncertain that an image quality is improved with flood phantom test. On the other hand, SPECT I.U, C.V, Contrast are improved about 18%, 2%, 13% in the Jaszczak ECT phantom test. This study has limitations that we can't take all variables into account and study with two phantoms. We need think about things that it has a good effect when doctors decipher the nuclear medicine image and it's possible to improve the image quality using the uniformity correction map of other radionuclides other than $^{99m}Tc$, $^{201}Tl$ when we make other nuclear medicine examinations.

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Quality of Life and Its Related Factors of Radiation Therapy Cancer Patients (방사선 치료를 받은 암환자의 삶의 질과 관련요인)

  • Shin, Ryung-Mi;Jung, Won-Seok;Oh, Byeong-Cheon;Jo, Jun-Young;Kim, Gi-Chul;Choi, Tae-Gyu;Lee, Sok-Goo
    • The Journal of Korean Society for Radiation Therapy
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    • v.23 no.1
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    • pp.21-29
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    • 2011
  • Purpose: The purpose of this master's thesis is to utilize basic data in order to improve the quality of life of cancer patients who received radiation therapy after analysing related factors that influence patient's quality of life and obtaining information about physical, mental problems of patients. Materials and Methods: By using a structured questionnaire about various characteristics and forms of support, I carried out a survey targeting 107 patients that experienced radiation therapy at a university hospital in the Daejeon metropolitan area from July 15 to August 15, 2010 and analysed the factors influencing quality of life. Results: In case of pain due to disease, 65.15 and painless 81.87 showed a high grade quality of life. As body weight decreases, the quality of life become lower. When the grade of quality of life according to economic characteristics was compared, all items except treatment period showed a difference (P=0.000). When the score of social support, family support, medical support and self-esteem was low, the mark of quality of life showed respectively 61.71, 68.77, 71.31, and 69.39 on the basis of 128 points. When the score of support form was high, the mark of quality of life showed 90.47, 83.29, 90.40, and 90.36 (P<0.05). When analyzing the correlation between social support, family support, medical support and self-esteem and the degree of quality of life, social support was 0.768, family support 0.596, medical support 0.434, self-esteem 0.516. They indicated the correlation of meaningful quantity statistically (P<0.01). The factors that improved the quality of life were married state, having a job and painless status. As monthly income increases, the quality of life was also much improved (P<0.05). Among the factors related to quality of life, social support and medical support and higher self-esteem scores of the quality of life score increased 0.979 point, 0.508 points and 1.667 point, respectively. Conclusion: In conclusion, the quality of life of cancer patients that received radiation treatment is related to social support, medical support and self esteem. Self-esteem is an important factor that influenced quality of life, so if government offers works that doesn't affect patient's health, they are a useful method that maximize self-esteem and lessen their financial burden at the same time. Along with these policies, the developments of the attention of medical and the program for cancer patient's family are needed for the purpose of improving quality of life of cancer patients. Lastly, medical team, patients and family have to cooperate in harmony to overcome difficulties of cancer patients.

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Smart Store in Smart City: The Development of Smart Trade Area Analysis System Based on Consumer Sentiments (Smart Store in Smart City: 소비자 감성기반 상권분석 시스템 개발)

  • Yoo, In-Jin;Seo, Bong-Goon;Park, Do-Hyung
    • Journal of Intelligence and Information Systems
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    • v.24 no.1
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    • pp.25-52
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    • 2018
  • This study performs social network analysis based on consumer sentiment related to a location in Seoul using data reflecting consumers' web search activities and emotional evaluations associated with commerce. The study focuses on large commercial districts in Seoul. In addition, to consider their various aspects, social network indexes were combined with the trading area's public data to verify factors affecting the area's sales. According to R square's change, We can see that the model has a little high R square value even though it includes only the district's public data represented by static data. However, the present study confirmed that the R square of the model combined with the network index derived from the social network analysis was even improved much more. A regression analysis of the trading area's public data showed that the five factors of 'number of market district,' 'residential area per person,' 'satisfaction of residential environment,' 'rate of change of trade,' and 'survival rate over 3 years' among twenty two variables. The study confirmed a significant influence on the sales of the trading area. According to the results, 'residential area per person' has the highest standardized beta value. Therefore, 'residential area per person' has the strongest influence on commercial sales. In addition, 'residential area per person,' 'number of market district,' and 'survival rate over 3 years' were found to have positive effects on the sales of all trading area. Thus, as the number of market districts in the trading area increases, residential area per person increases, and as the survival rate over 3 years of each store in the trading area increases, sales increase. On the other hand, 'satisfaction of residential environment' and 'rate of change of trade' were found to have a negative effect on sales. In the case of 'satisfaction of residential environment,' sales increase when the satisfaction level is low. Therefore, as consumer dissatisfaction with the residential environment increases, sales increase. The 'rate of change of trade' shows that sales increase with the decreasing acceleration of transaction frequency. According to the social network analysis, of the 25 regional trading areas in Seoul, Yangcheon-gu has the highest degree of connection. In other words, it has common sentiments with many other trading areas. On the other hand, Nowon-gu and Jungrang-gu have the lowest degree of connection. In other words, they have relatively distinct sentiments from other trading areas. The social network indexes used in the combination model are 'density of ego network,' 'degree centrality,' 'closeness centrality,' 'betweenness centrality,' and 'eigenvector centrality.' The combined model analysis confirmed that the degree centrality and eigenvector centrality of the social network index have a significant influence on sales and the highest influence in the model. 'Degree centrality' has a negative effect on the sales of the districts. This implies that sales decrease when holding various sentiments of other trading area, which conflicts with general social myths. However, this result can be interpreted to mean that if a trading area has low 'degree centrality,' it delivers unique and special sentiments to consumers. The findings of this study can also be interpreted to mean that sales can be increased if the trading area increases consumer recognition by forming a unique sentiment and city atmosphere that distinguish it from other trading areas. On the other hand, 'eigenvector centrality' has the greatest effect on sales in the combined model. In addition, the results confirmed a positive effect on sales. This finding shows that sales increase when a trading area is connected to others with stronger centrality than when it has common sentiments with others. This study can be used as an empirical basis for establishing and implementing a city and trading area strategy plan considering consumers' desired sentiments. In addition, we expect to provide entrepreneurs and potential entrepreneurs entering the trading area with sentiments possessed by those in the trading area and directions into the trading area considering the district-sentiment structure.

Development and application of prediction model of hyperlipidemia using SVM and meta-learning algorithm (SVM과 meta-learning algorithm을 이용한 고지혈증 유병 예측모형 개발과 활용)

  • Lee, Seulki;Shin, Taeksoo
    • Journal of Intelligence and Information Systems
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    • v.24 no.2
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    • pp.111-124
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    • 2018
  • This study aims to develop a classification model for predicting the occurrence of hyperlipidemia, one of the chronic diseases. Prior studies applying data mining techniques for predicting disease can be classified into a model design study for predicting cardiovascular disease and a study comparing disease prediction research results. In the case of foreign literatures, studies predicting cardiovascular disease were predominant in predicting disease using data mining techniques. Although domestic studies were not much different from those of foreign countries, studies focusing on hypertension and diabetes were mainly conducted. Since hypertension and diabetes as well as chronic diseases, hyperlipidemia, are also of high importance, this study selected hyperlipidemia as the disease to be analyzed. We also developed a model for predicting hyperlipidemia using SVM and meta learning algorithms, which are already known to have excellent predictive power. In order to achieve the purpose of this study, we used data set from Korea Health Panel 2012. The Korean Health Panel produces basic data on the level of health expenditure, health level and health behavior, and has conducted an annual survey since 2008. In this study, 1,088 patients with hyperlipidemia were randomly selected from the hospitalized, outpatient, emergency, and chronic disease data of the Korean Health Panel in 2012, and 1,088 nonpatients were also randomly extracted. A total of 2,176 people were selected for the study. Three methods were used to select input variables for predicting hyperlipidemia. First, stepwise method was performed using logistic regression. Among the 17 variables, the categorical variables(except for length of smoking) are expressed as dummy variables, which are assumed to be separate variables on the basis of the reference group, and these variables were analyzed. Six variables (age, BMI, education level, marital status, smoking status, gender) excluding income level and smoking period were selected based on significance level 0.1. Second, C4.5 as a decision tree algorithm is used. The significant input variables were age, smoking status, and education level. Finally, C4.5 as a decision tree algorithm is used. In SVM, the input variables selected by genetic algorithms consisted of 6 variables such as age, marital status, education level, economic activity, smoking period, and physical activity status, and the input variables selected by genetic algorithms in artificial neural network consist of 3 variables such as age, marital status, and education level. Based on the selected parameters, we compared SVM, meta learning algorithm and other prediction models for hyperlipidemia patients, and compared the classification performances using TP rate and precision. The main results of the analysis are as follows. First, the accuracy of the SVM was 88.4% and the accuracy of the artificial neural network was 86.7%. Second, the accuracy of classification models using the selected input variables through stepwise method was slightly higher than that of classification models using the whole variables. Third, the precision of artificial neural network was higher than that of SVM when only three variables as input variables were selected by decision trees. As a result of classification models based on the input variables selected through the genetic algorithm, classification accuracy of SVM was 88.5% and that of artificial neural network was 87.9%. Finally, this study indicated that stacking as the meta learning algorithm proposed in this study, has the best performance when it uses the predicted outputs of SVM and MLP as input variables of SVM, which is a meta classifier. The purpose of this study was to predict hyperlipidemia, one of the representative chronic diseases. To do this, we used SVM and meta-learning algorithms, which is known to have high accuracy. As a result, the accuracy of classification of hyperlipidemia in the stacking as a meta learner was higher than other meta-learning algorithms. However, the predictive performance of the meta-learning algorithm proposed in this study is the same as that of SVM with the best performance (88.6%) among the single models. The limitations of this study are as follows. First, various variable selection methods were tried, but most variables used in the study were categorical dummy variables. In the case with a large number of categorical variables, the results may be different if continuous variables are used because the model can be better suited to categorical variables such as decision trees than general models such as neural networks. Despite these limitations, this study has significance in predicting hyperlipidemia with hybrid models such as met learning algorithms which have not been studied previously. It can be said that the result of improving the model accuracy by applying various variable selection techniques is meaningful. In addition, it is expected that our proposed model will be effective for the prevention and management of hyperlipidemia.

Effects of NG-monomethyl-L-arginine and L-arginine on cerebral hemodynamics and energy metabolism during reoxygenation-reperfusion after cerebral hypoxia-ischemia in newborn piglets (급성 저산소성 허혈성 뇌손상이 유발된 신생자돈에서 재산소-재관류기 동안 NG-monomethyl-L-arginine과 L-arginine이 뇌의 혈역학 및 에너지 대사에 미치는 영향)

  • Ko, Sun Young;Kang, Saem;Chang, Yun Sil;Park, Eun Ae;Park, Won Soon
    • Clinical and Experimental Pediatrics
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    • v.49 no.3
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    • pp.317-325
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    • 2006
  • Purpose : This study was carried out to elucidate the effects of nitric oxide synthase(NOS) inhibitor, NG-monomethyl-L-arginine(L-NMMA) and nitric oxide precursor, L-arginine(L-Arg) on cerebral hemodynamics and energy metabolism during reoxygenation-reperfusion(RR) after hypoxia-ischemia(HI) in newborn piglets. Methods : Twenty-eight newborn piglets were divided into 4 groups; Sham normal control(NC), experimental control(EC), L-NMMA(HI & RR with L-NMMA), and L-Arg(HI & RR with L-Arg) groups. HI was induced by occlusion of bilateral common carotid arteries and simultaneously breathing with 8 percent oxygen for 30 mins, and followed RR by release of carotid occlusion and normoxic ventilation for one hour. All groups were monitored with cerebral hemodynamics and cytochrome $aa_3$ (Cyt $aa_3$) using near infrared spectroscopy(NIRS). $Na^+$, $K^+$-ATPase activity, lipid peroxidation products, and tissue high energy phosphate levels were determined biochemically in the cerebral cortex. Results : In experimental groups, mean arterial blood pressure, $PaO_2$, and pH decreased, and base excess and blood lactate level increased after HI compared to NC group(P<0.05). These variables subsequently returned to baseline after RR except pH. There were no differences among the experimental groups. In NIRS, oxidized hemoglobin($HbO_2$) decreased and hemoglobin(Hb) increased during HI(P<0.05) but returned to base line immediately after RR; 40 min after RR, the $HbO_2$ had decreased significantly compared to NC group(P<0.05). Changes of Cyt $aa_3$ decreased significantly compared to NC after HI and recovered at the end of the experiment. Significantly reduced cerebral cortical cell membrane $Na^+$, $K^+$-ATPase activity and increased lipid peroxidation products(P<0.05) were not improved with L-NMMA or L-Arg. Conclusion : These findings suggest that NO is not involved in the mechanism of HI and RR brain damage during the early acute phase of RR.

Health Status and Use of Health Care Services of the Elderly Utilizing Senior citizen Centers (경로당 노인의 건강상태와 건강관리서비스 이용 관련요인 분석)

  • Shin, Sun-Hye;Kim, Jin-Soon
    • Journal of agricultural medicine and community health
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    • v.27 no.1
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    • pp.99-113
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    • 2002
  • For this study a sample of 205 people, 66 males and 139 females, over 65 years of age, residing in C-gu of S-si and utilizing senior centers, were selected, The objective of the study was to provide basic data for health promotion program development provided by health centers. A questionnaire was used to collect date on general characteristics, health status, social health status and utilization rate for health services. The instruments used in this study were the Lawton scale, to measure daily routine function, the MMSE-K developed by Folstein and modified to fit the Korea situation, for mental health status, and the CES-Dtool developed by Radloff, for emotional health status. the SPSS Window program was used to calculate percentages. Tests of significance were done using t-test and ANOVA. Multiple regression analysis was used to identify variables influencing the use of health services. The results are as follows : Of those utilizing senior citizen centers, 40.9% of males and 17.3% of the female thought they were healthy. The average score for IADL was 7.4. The daily routine of female respondents consisted of buying household articles and drugs, and other IADLs such as riding the bus or subway alone. These resulted in a higher score compared to males. For emotional health, 7.6% of the males reported depression compared to 21.6% of the females. For mental health, 48.5% of the males and 28.8% of the females were found to be in the group suspicious for dementia. On social health, 57.6% of the males and 62.6% of the females reported no intimate human relations. Of those older people who had close human relations, 52.5% of the males indicated a friend as the closest person and 53.8% of the females, their children. On use of health services, there was a significantly higher need for mobile medical care services treatment for those with lower education levels and status of window/widower. There was a significantly higher need for health exmination services for those with lower levels of exercise, greater satisfaction with sleep, higher levels of oral health care, and higher social contacts. In conclusion, there is a need to provide varied programs for the promotion of health, along with parallel resolution of social, psychological and economic issues. It is recommended that health services for elderly people provided by the health centers be implemented with full recognition of these characteristics and differences.

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The Study on Usefulness of LEAP Collimator in Lung Ventilation SPECT (Lung Ventilation SPECT에서 LEAP Collimator의 유용성에 관한 연구)

  • Kim, Jung Soo;Kim, Soo Mee;Kim, Jin Eui;Lee, Jae Sung;Lee, Dong Soo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.2
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    • pp.18-24
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    • 2012
  • Purpose : Although lung ventilation SPECT (LV-SPECT) has a good sensitivity in detection of deep lung lesions, it is difficult to apply the LV-SPECT to patients having breathing problems due to limited examination time. In this study, we evaluated the usefulness of LEAP collimator, which provides high detection sensitivity and tolerable resolution, for the LV-SPECT in terms of diagnostic accuracy and examination time. Materials and Methods : Four volunteers inhaled Technegas (370 MBq) and the lung ventilation planar scan (LVPS, 300 counts/view (cpv)) with LEHR collimator was performed using Siemens E.cam scanner as a reference test. LV-SPECT scans were performed with three collimators, LEHR, LEUHR, and LEAP, in low (7 kcpv) and high (70 kcpv) counting modes. The count ratios of left (LT) and right (RT) lung segments were calculated on the geometric mean view of anterior and posterior images for LVPS and on the summed coronal images of LV-SPECT, respectively. Comparing to LVPS, the usefulness of three different collimators for LV-SPECT was evaluated through statistical analysis (paired t-test), on count ratios of lung segments. Results : The average LT:RT ratio in LVPS was 47:53. For LV-SPECT, there were negligible difference of the LT:RT ratios (48:52 on average) among three different collimators in low and high counting modes. Comparing to standard LVPS with LEHR, all LV-SPECTs with different collimators resulted in similar diagnostic accuracy through paired t-test (p>0.05). The scan time in LVPS (6 views) was 17.3 min. For LV-SPECT (128 views) in low counting mode, it took 18.7 (LEUHR), 15.0 (LEHR), and 12.3 min (LEAP), respectively. Conclusion : Comparing to standard LVPS, the LV-SPECT with LEAP in low counting mode provided the comparable diagnostic accuracy in addition to shortened scan time.

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