• Title/Summary/Keyword: Crossover study

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An Investigation on the Perception of the Effects of Particulate Matter on Oral Health (미세먼지가 구강건강에 미치는 영향에 관한 인식도 조사)

  • Kim, Jue-young;Son, Hwa-kyung
    • The Journal of the Korea Contents Association
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    • v.21 no.6
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    • pp.620-628
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    • 2021
  • This study was conducted to investigate public's perception of the effects of particulate matter (PM) in oral health and to provide specific motivation to prevent oral disease by PM. A total of 134 adults were selected as final analysis subjects from some people all over the country. The data collected is analyzed using SPSS 21.0 for windows. Frequency analysis was used to identify general characteristics and hygiene habit. For identifying perception of effects of PM on oral health, crossover analysis was used. The largest number of people recognized that the level of PM had deteriorated, compared to five years ago. That perception was highest among those in 30 years of age and service professions. Those who check the concentration of PM are more concerned with oral health care when the PM is occurred in high concentration. People who perceive PM as a threat to the oral health are more concerned about oral health care when the PM is occurred in high concentration. It is concerned those who are aware of the relationship between PM and oral health specifically manage the oral health to protect the oral cavity from PM.

Effects of Dangui-jakyak-san on Common Carotid Artery Elasticity in Healthy Subjects ; A Randomized controlled crossover study (당귀작약산이 정상인의 총경동맥 탄력도에 미치는 영향 : 무작위대조군 교차시험)

  • Kim, Soohyun;Seo, Yuna;Bae, In-hu;Cho, Ki-Ho;Moon, Sang-Kwan;Jung, Woo-Sang;Kwon, Seungwon;Jin, Chul
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.21 no.1
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    • pp.21-32
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    • 2020
  • ■ Objectives 당귀작약산 단회 복용으로 정상인의 총경동맥 탄력도에 미치는 영향을 평가하고자 하였다. ■ Methods 본 연구는 정상인 남성을 대상으로 한 전향적 무작위 대조군 교차시험연구다. 모든 대상자들은 임의로 당귀작약산 복용군과 비복용군인 대조군으로 나누어졌다. 1주일 간격으로 총 2회 방문하며, 첫 번째 방문 시에 당귀작약산 복용군은 당귀작약산 1포(2.5g)과 물을 제공받고, 대조군은 물만 제공받아 복용하였다. 두 번째 방문 시 첫 번째 방문과 반대로 당귀작약산을 복용했던 복용군은 물만 제공받고, 물만 복용했던 피험자들은 당귀작약산 1포와 물을 제공받았다. 물은 100 cc로 매번 동일하게 제공되었다. 모든 대상자들은 복용 직전과 복용 2시간, 4시간 후에 총경동맥 탄력도, 혈압, 총경동맥 내막-중막 두께와 맥박수를 측정하였다. ■ Results 총 20명의 정상인 남성이 모집되었으며, 시간에 따라 당귀작약산 복용 후의 총경동맥 탄력도가 대조군에 비하여 유의하게 상승한 것이 확인되었다. 내막-중막 두께, 혈압 및 맥압, 맥박은 유의한 변화가 나타나지 않았다. ■ Conclusion 당귀작약산의 단회 복용으로 총경동맥 탄력도가 즉시 개선되는 것을 확인하였고, 이로써 당귀작약산이 동맥 경직도 완화 및 탄성의 개선에 영향을 미친다는 것을 알 수 있었다.

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Effect of Bi-/Unilateral Masticatory Training on Memory and Concentration - Assessor-blind, Cross-over, Randomized Controlled Clinical Trial

  • Bae, Jun-hyeong;Kim, Hyungsuk;Kang, Do Young;Kim, Hyeji;Kim, Jongyeon;Kim, Koh-Woon;Cho, Jae-Heung;Song, Mi-yeon;Chung, Won-Seok
    • The Journal of Korean Medicine
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    • v.43 no.2
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    • pp.61-74
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    • 2022
  • Objectives: This study aimed to explore the short-term effects of bilateral masticatory training using an intraoral device on memory and concentration, which is an advanced form of Gochi, compared to the unilateral form with gum. Methods: Thirty young healthy participants (age, 16-30 years) were screened and randomly assigned to one of two sequences in a crossover design. The participants assigned to sequence A (n=15) performed bilateral mastication using an intraoral device with a total of 300 taps, followed by unilateral mastication using gum with the same number of repetitions and frequency, separated by a 7-day washout period. A reverse order was used for sequence B. The primary and secondary outcomes were the digit span test result and the symbol digit modality test and the word list recall results, respectively, which were conducted before and after each intervention. Results: Symbol digit modality test scores increased by 12.03±8.33 with bilateral mastication, which was significantly higher than that obtained with chewing gum (5.17 points;95% confidence interval: 0.99, 9.34; p<0.05). Changes in the digit span test and word list recall scores were not significantly different between the two groups. In the digit span test forward, symbol digit modality test, and word list recall test, bilateral mastication was not inferior to unilateral mastication in improving memory and concentration. Conclusions: Bilateral masticatory exercises using an intraoral device are not inferior to unilateral mastication with gum for improving memory in healthy young individuals. Further research is needed to determine the efficacy of bilateral masticatory training on cognitive function.

The Effect of Cross-Cumulation of Rule of Origin: Case Study of Korea-Canada FTA in terms of Auto Parts Import from U.S. (원산지 교차누적 효과 분석: 한-캐나다 FTA를 활용한 대(對)미 자동차 부품 수입을 중심으로)

  • Kim, Kyu-Rim;Ra, Hee-Ryang
    • Korea Trade Review
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    • v.43 no.1
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    • pp.109-130
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    • 2018
  • The cumulative standard is one of the criteria determining the origin of imported goods and is a provision that allows non-origin materials to be treated as origin goods when satisfying certain conditions. Regarding the Korea-Canada FTA, new cumulative standards were applied concerning cross accumulation of automobile products. It would benefit U.S. originating intermediate goods of HS code chapter 84, 85, 87, and 94 obtained into HS code heading from 8701 into 8706. We examine the effectiveness of crossover cumulative standards through the change in the import values of 84, 85, 87, 94, which are target items for cross cumulation. Only items designated for automobile parts were selected and analyzed. From the estimation results, significant changes appeared in 20 of the 35 items. It was found that the import amount increased significantly as of January 2015 or the rate of change in trend increases more than before. In addition, the estimation results show that Korean auto companies utilizing the cumulative standards through increased imports of auto parts form the U.S.

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Bioequivalence of pioglitazone tablet to Actos® tablet (Pioglitazone 30 mg) (액토스정®(피오글리타존 30 mg)에 대한 염산피오글리타존정의 생물학적동등성)

  • Yeom, Hyesun;Lee, Tae Ho;Youm, Jeong-Rok;Song, Jin-Ho;Han, Sang Beom
    • Analytical Science and Technology
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    • v.22 no.1
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    • pp.101-108
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    • 2009
  • The bioequivalence of two pioglitazone tablets, Actos$^{(R)}$ tablet (Takeda Chemical Industries, reference drug) and Pioglitazone tablet (Boryung Company, test drug) was evaluated according to the guidelines of Korea Food and Drug Administration. Twenty-eight healthy male Korean volunteers received each medicine (pioglitazone dose of 30 mg) in a $2{\times}2$ crossover study with one week washout interval. After drug administration, blood samples were collected at specific time intervals from 0-36 hours. The plasma concentrations of pioglitazone were determined by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The total chromatographic run time was 5 min and calibration curves were linear over the concentration range of 5-2000 ng/mL for pioglitazone. The method was validated for selectivity, sensitivity, linearity, accuracy and precision. The pharmacokinetic parameters were determined from the plasma concentration-time profiles of both formulations. The primary calculated pharmacokinetic parameters were compared statistically to evaluate bioequivalence between the two preparations. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Pioglitazone tablet and Actos$^{(R)}$ tablet were log0.9422~log1.1040 and log0.9200~log1.1556, respectively. Based on the statistical considerations, we can conclude that the test drug, Pioglitazone tablet was bioequivalent to the reference drug, Actos$^{(R)}$ tablet.

Effects of Velocity Structures on Tracer Mixing in a Meandering Channel (사행수로에서 유속구조가 추적물질의 혼합에 미치는 영향)

  • Seo, Il Won;Park, Sung Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1B
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    • pp.35-45
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    • 2009
  • In this study, a laboratory experiment has been performed on a S-curved channel with two curved sections. In the experiments, effects of 3-D velocity structures on mixing characteristics of tracer material were investigated. As a result, it was clearly noticed that the primary flow travels taking the shortest course of the meandering channel and has a very ununiform distribution at the bends. The secondary cell which was developing at the first bend disappears at the crossover, and then, at the next bend, secondary cell is re-developing in the opposite direction. The experimental results show that mixing of tracer is significantly affected by the combined action of ununiform primary flow and secondary cell. The ununiform primary flow separates the tracer cloud in the longitudinal direction, and the secondary cell further separates the retarding tracer cloud mainly in the transverse direction. As a result, these complex flow structures cause separation and spreading of tracer cloud both in the longitudinal and in the transverse directions. The measured dimensionless transverse dispersion coefficients calculated using 2-D routing procedure ranges 0.012-0.875, and is generally proportional to width to depth ratio (W/h). The predicted values calculated by the theoretical equation overestimate slightly the measured transverse dispersion coefficients.

Optimization of Support Vector Machines for Financial Forecasting (재무예측을 위한 Support Vector Machine의 최적화)

  • Kim, Kyoung-Jae;Ahn, Hyun-Chul
    • Journal of Intelligence and Information Systems
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    • v.17 no.4
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    • pp.241-254
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    • 2011
  • Financial time-series forecasting is one of the most important issues because it is essential for the risk management of financial institutions. Therefore, researchers have tried to forecast financial time-series using various data mining techniques such as regression, artificial neural networks, decision trees, k-nearest neighbor etc. Recently, support vector machines (SVMs) are popularly applied to this research area because they have advantages that they don't require huge training data and have low possibility of overfitting. However, a user must determine several design factors by heuristics in order to use SVM. For example, the selection of appropriate kernel function and its parameters and proper feature subset selection are major design factors of SVM. Other than these factors, the proper selection of instance subset may also improve the forecasting performance of SVM by eliminating irrelevant and distorting training instances. Nonetheless, there have been few studies that have applied instance selection to SVM, especially in the domain of stock market prediction. Instance selection tries to choose proper instance subsets from original training data. It may be considered as a method of knowledge refinement and it maintains the instance-base. This study proposes the novel instance selection algorithm for SVMs. The proposed technique in this study uses genetic algorithm (GA) to optimize instance selection process with parameter optimization simultaneously. We call the model as ISVM (SVM with Instance selection) in this study. Experiments on stock market data are implemented using ISVM. In this study, the GA searches for optimal or near-optimal values of kernel parameters and relevant instances for SVMs. This study needs two sets of parameters in chromosomes in GA setting : The codes for kernel parameters and for instance selection. For the controlling parameters of the GA search, the population size is set at 50 organisms and the value of the crossover rate is set at 0.7 while the mutation rate is 0.1. As the stopping condition, 50 generations are permitted. The application data used in this study consists of technical indicators and the direction of change in the daily Korea stock price index (KOSPI). The total number of samples is 2218 trading days. We separate the whole data into three subsets as training, test, hold-out data set. The number of data in each subset is 1056, 581, 581 respectively. This study compares ISVM to several comparative models including logistic regression (logit), backpropagation neural networks (ANN), nearest neighbor (1-NN), conventional SVM (SVM) and SVM with the optimized parameters (PSVM). In especial, PSVM uses optimized kernel parameters by the genetic algorithm. The experimental results show that ISVM outperforms 1-NN by 15.32%, ANN by 6.89%, Logit and SVM by 5.34%, and PSVM by 4.82% for the holdout data. For ISVM, only 556 data from 1056 original training data are used to produce the result. In addition, the two-sample test for proportions is used to examine whether ISVM significantly outperforms other comparative models. The results indicate that ISVM outperforms ANN and 1-NN at the 1% statistical significance level. In addition, ISVM performs better than Logit, SVM and PSVM at the 5% statistical significance level.

Variability in Drug Interaction According to Genetic Polymorphisms in Drug Metabolizing Enzymes

  • Jang, In-Jin;Yu, Kyung-Sang;Cho, Joo-Youn;Chung, Jae-Yong;Kim, Jung-Ryul;Lim, Hyeong-Seok;Shin, Sang-Goo
    • Environmental Mutagens and Carcinogens
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    • v.24 no.1
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    • pp.15-18
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    • 2004
  • There are significant differences in the extent of drug interactions between subjects. The influence of the genetic make up of drug metabolizing enzyme activities (CYP3A5, CYP2C19 and UDP-glucuronosyl transferase) on the pharmacokinetic drug interaction potential were studied in vivo. Nineteen healthy volunteers were grouped with regard to the $CYP3A5^{*}3$ allele, into homozygous wild-type (CYP3A5^{*}1/1^{*}1$, n=6), heterozygous $(CYP3A5^{*}1/^{*}3$, n=6), and homozygous variant-type $(CYP3A5^{*}3/^{*}3$, n=7) subject groups. The pharmacokinetic profile of intravenous midazolam was characterized before and after itraconazole administration (200 mg once daily for 4 days), and also following rifampin pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between. For omeprazole and moclobemide pharmacokinetic interaction study 16 healthy volunteers were recruited. The volunteer group comprised 8 extensive metabolizers and 8 poor metabolizers of CYP2C19, which was confirmed by genotyping. Subjects were randomly allocated into two sequence groups, and a single-blind, placebo-controlled, two-period crossover study was performed. In study I, a placebo was orally administered for 7 days. On the eighth morning, 300 mg of moclobemide and 40 mg of placebo were coadministered with 200 mL of water, and a pharmacokinetic study was performed. During study n, 40 mg of omeprazole was given each morning instead of placebo, and pharmacokinetic studies were performed on the first and eighth day with 300 mg of moclobemide coadministration. In the UGT study pharmacokinetics and dynamics of 2 mg intravenous lorazepam were evaluated before and after rifampin pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between. The subjective and objective pharmacodynamic tests were done before and 1, 2, 4, 6, 8, and 12 hrs after lorazepam administration. The pharmacokinetic profiles of midazolam and of its hydroxy metabolites did not show differences between the genotype groups under basal and induced metabolic conditions. However, during the inhibited metabolic state, the $CYP3A5^{*}3/^{*}3$ group showed a greater decrease in systemic clearance than the $CYP3A5^{*}1/^{*}1$ group $(8.5\pm3.8$ L/h/70 kg vs. $13.5\pm2.7$ L/h/70 kg, P=0.027). The 1'-hydroxymidazolam to midazolam AUC ratio was also significantly lower in the $CYP3A5^{*}3/^{*}3$,/TEX> group $(0.58\pm0.35,$ vs. $1.09\pm0.37$ for the homozygous wild-type group, P=0.026). The inhibition of moclo-bemide metabolism was significant in extensive metabolizers even after a single dose of omeprazole. After daily administration of omeprazole for 1 week, the pharmacokinetic parameters of moclobemide and its metabolites in extensive metabolizers changed to values similar to those in poor metabolizers. In poor meta-bolizers, no remarkable changes in the pharmacokinetic parameters were observed. The area under the time-effect curves of visual analog scale(VAS), choice reaction time, and continuous line tracking test results of lorazepam was reduced by 20%, 7%, 23% respectively in induced state, and in spite of large interindividual variablity, significant statistical difference was shown in VAS(repeated measures ANOVA, p=0.0027).

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A Study on the Color coordination System to fashion (섬유.패션디자인을 위한 컬러코디네이션 지원모델 개발)

  • Jung, Jae-Woo;Lee, Jae-Jung
    • Archives of design research
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    • v.18 no.1 s.59
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    • pp.167-174
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    • 2005
  • This study is to objectively support the emotional and intuitional decision making of the designer by means of developing the supporting models and tools of color coordination. Based on the color grouping system and representative vocabularies suggested in the precedent 'Study on the Grouping System of Fabric Color,' this study suggested the manufacture of the supporting model of color coordination that could be used practically through the design of coloring group. The results of this study can be summarized as below. Firstly, 687 colors in total have been collected from the four world famous collections, the street fashion of 2002 F/W 2003 S/S Season and the representative brands in each group for five years from 1999 to 2003 in order to single out the basic colors for the purpose of composing the color groups. Secondly, 687 collected colors have been grouped into 144 colors in total through the three-step process for the extraction of coloring groups. Thirdly, the final extracted colors have been divided into , , , group by the grouping system specified in the precedent study and the said four large groups have been again subdivided into 12 small groups. Fourthly, the suggested colors in each group have established a color coordination system by introducing the concept of the crossover coordination that could be matched with other groups as well as the coordination within the group. Fifthly, we have dyed 144 colors in total that have consisted of the coloring system of four representative groups (twelve subgroups) in each methodical tone as in the above in cotton yarn, one of the representative materials in fabric fashion design industry. Besides, we have specified the symbol of the Pantone Color Book and CMYK values in each color that has consisted of the system considering the industrial characteristics of fashion as a global business and the compatibility with the related design industry. Sixthly, we have packed the completed yam made of fabrics in the designed container for the easy use of cross-coordination and have completed a color coordination system that could be easily utilized for the fashion-related working-level staffs.

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Variability in Drug Interaction According to Genetic Polymorph isms in Drug Metabolizing Enzymes

  • Jang, In-Jin;Yu, Kyung-Sang;Cho, Joo-Youn;Chung, Jae-Yong;Kim, Jung-Ryul;Lim, Hyeong-Seok;Shin, Sang-Goo
    • Environmental Mutagens and Carcinogens
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    • v.23 no.4
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    • pp.131-134
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    • 2003
  • There are significant differences in the extent of drug interactions between subjects. The influence of the genetic make up of drug metabolizing enzyme activities (CYP3A5, CYP2C19 and UDP-glucuronosyl transferase) on the pharmacokinetic drug interaction potential were studied in vivo. Nineteen healthy volunteers were grouped with regard to the $CYP3A5^{*}3$ allele, into homozygous wild-type (CYP3A5^{*}1/1^{*}1$, n=6), heterozygous $(CYP3A5^{*}1/^{*}3$, n=6), and homozygous variant-type $(CYP3A5^{*}3/^{*}3$, n=7) subject groups. The pharmacokinetic profile of intravenous midazolam was characterized before and after itraconazole administration (200 mg once daily for 4 days), and also following rifampin pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between. For omeprazole and moclobemide pharmacokinetic interaction study 16 healthy volunteers were recruited. The volunteer group comprised 8 extensive metabolizers and 8 poor metabolizers of CYP2C19, which was confirmed by genotyping. Subjects were randomly allocated into two sequence groups, and a single-blind, placebo-controlled, two-period crossover study was performed. In study I, a placebo was orally administered for 7 days. On the eighth morning, 300 mg of moclobemide and 40 mg of placebo were coadministered with 200 mL of water, and a pharmacokinetic study was performed. During study n, 40 mg of omeprazole was given each morning instead of placebo, and pharmacokinetic studies were performed on the first and eighth day with 300 mg of moclobemide coadministration. In the UGT study pharmacokinetics and dynamics of 2 mg intravenous lorazepam were evaluated before and after rifampin pretreatment (600 mg once daily for 10 days), with a washout period of 2 weeks in between. The subjective and objective pharmacodynamic tests were done before and 1, 2, 4, 6, 8, and 12 hrs after lorazepam administration. The pharmacokinetic profiles of midazolam and of its hydroxy metabolites did not show differences between the genotype groups under basal and induced metabolic conditions. However, during the inhibited metabolic state, the $CYP3A5^{*}3/^{*}3$ group showed a greater decrease in systemic clearance than the $CYP3A5^{*}1/^{*}1$ group $(8.5\pm3.8$ L/h/70 kg vs. $13.5\pm2.7$ L/h/70 kg, P=0.027). The 1'-hydroxymidazolam to midazolam AUC ratio was also significantly lower in the $CYP3A5^{*}3/^{*}3$,/TEX> group $(0.58\pm0.35,$ vs. $1.09\pm0.37$ for the homozygous wild-type group, P=0.026). The inhibition of moclo-bemide metabolism was significant in extensive metabolizers even after a single dose of omeprazole. After daily administration of omeprazole for 1 week, the pharmacokinetic parameters of moclobemide and its metabolites in extensive metabolizers changed to values similar to those in poor metabolizers. In poor meta-bolizers, no remarkable changes in the pharmacokinetic parameters were observed. The area under the time-effect curves of visual analog scale(VAS), choice reaction time, and continuous line tracking test results of lorazepam was reduced by 20%, 7%, 23% respectively in induced state, and in spite of large interindividual variablity, significant statistical difference was shown in VAS(repeated measures ANOVA, p=0.0027).

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