• Title/Summary/Keyword: Activity Coefficient

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Synthesis and Biopharmaceutical Studies of Cefazolin Butyrolactone Ester, a Novel Prodrug of Cefazolin (Cefazolin Butyrolactone Ester의 합성 및 생물약제학적 연구)

  • 이진환;조행남;최준식
    • YAKHAK HOEJI
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    • v.47 no.5
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    • pp.331-338
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    • 2003
  • A butyrolactone ester of cefazolin (CFZ-BTL) was synthesized by the esterification of cefazolin (CFZ) with $\alpha$-bromo-${\gamma}$-butyrolactone. The synthesis was confirmed by the spectroscopic analysis. The CFZ-BTL was more lipophilic than the CFZ when assessed by n-octanol/water partition coefficients at various pH. The CFZ-BTL itself did not show any antimicrobial activity in vitro, but after oral administration of CFZ-BTL to rabbits, exerted significant anti-microbial activity in serum samples when measured by the inhibion zone method in nutrient agar plates, due to conversion of CFZ-BTL to an active metabolite, probably CFZ, in the body. The CFZ-BTL was also converted into CFZ as confirmed by in vitro incubation study, with tissue homogenates (liver, blood and intestine) of rabbits. The liver showed the fastest conversion rate, probably via the hydrolysis mechanism. In vivo metabolism of CFZ-BTL to CFZ was also confirmed in vivo serum samples by HPLC. The oral bioavailability of CFZ-BTL in rabbits was 1.6-fold increased when compared to CFZ, resulting from followed by enhanced lipophilicity increased passive absorption in the intestine.

Study on the Biosynthesis on Neomycin: Characterization of Isocitrate Dehydrogenase of the Neomycin Producer, Streptomyces fradiae and its Possible Relation to the Regulation of Biosynthesis of Neomycin

  • Chang Hoon Lee;Yang Mo Goo;Kong Hwan Kim
    • Bulletin of the Korean Chemical Society
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    • v.12 no.5
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    • pp.504-509
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    • 1991
  • S. fradiae showed very high activity of isocitrate dehydrogenase compared to other microorganisms. The activity of this enzyme was increased with the growth of the organism. But the increase might not imply its involvement in the growth. Rather its increased activity seemed to have a connection with the biosynthesis of neomycin. The enzyme showed high specificity toward $NADP^+$ and D-isocitrate with Km values of 5.75 and 6.74 uM, respectively, It was activated by $Mn^{2+}$. Its molecular weight was estimated from its gel retardation coefficient to be in the range of 61,000-63,000 daltons and its optimum pH was 8.0. The enzyme was thermally unstable.

The Pressure Effect on the Activity Coefficient of Sodium Chloride and Bromide Ions

  • Jee, Jong-Gi;Lee, Sun-Haing;Cha, Seong-Keuck
    • Bulletin of the Korean Chemical Society
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    • v.7 no.3
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    • pp.163-166
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    • 1986
  • A new paraffin salt bridge was developed for the concentration cell in high pressure system. The emf values of the concentration cells were measured to calculate the activity coefficients of the electrolytic ions depending upon the pressure of the system. The activity coefficients of sodium, chloride and bromide ions increase with the temperature of the cell and decreased, nearly half at 2500 bars, $20^{\circ}C$, with the pressure. These results can be explained to be attributed to the volume change of the hydrated ion due to the electrostriction. The volume change decreased with pressure due to an increase in the degree of the hydration.

A Study on the Usefulness of Auto Dispenser and Optimized Dispensing Method (방사성 의약품 자동 분주장치의 유용성 및 최적화된 분주방법에 관한 고찰)

  • Lee, JeoungEun;Kim, Hosung;Ryu, Jaekwang;Jung, Wooyoung
    • The Korean Journal of Nuclear Medicine Technology
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    • v.17 no.2
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    • pp.59-66
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    • 2013
  • Purpose: Recently, there is an increase of the number of hospitals using auto dispenser to reduce occupational radiation exposure when drawing up of the $^{18}F-FDG$ dose (5.18 MBq/kg) in a syringe from the dramatic high activity of $^{18}F-FDG$ multidose vial. The aim of this study is to confirm that using auto dispenser actually reduces the radiation exposure for technologists. Also we analyzed the reproducibility of auto dispenser to find optimized dispensing method for the device. Materials and Methods: We conducted three experiments. Comparison of radiation exposure on chest and hands: The chest and hands exposure dose received by technologists during the injection were measured by electronic personal dosimeter (EPD) and ring TLD respectively. Reproducibility of dispensed volume: We draw up the normal saline into 5 and 2 mL syringe using auto dispenser by changing the volume from 1 to 15 mm for 5 times in the same setting of the volume. The weight of 5 normal saline dispensed from the device at same volume was measured using micro balance and calculated standard deviation and coefficient of variation. Reproducibility of dispensed radioactivity: We dispensed 362.6 $MBq{\pm}10%$ of $^{18}F-FDG$ in 5 and 2 mL syringes from the multidose vial of different specific activity. In the same setting of volume, we repeated dispensing for 4 times and compared standard deviation and coefficient of variation of radioactivity between 5 syringes. Results: There was significant difference in the average of chest exposure dose according to the dispensing methods (P<0.05). Also, when dispensing $^{18}F-FDG$ in manual method, exposure dose was 11.5 times higher in right hand and 4.8 times higher in left hand than in auto method. In the result of reproducibility of dispensed volume, standard deviation and coefficient of variation shows decline as the dispensing volume increases. As a result of reproducibility of dispensed radioactivity, standard deviation and coefficient of variation increases as the specific activity increases. Conclusion: We approved that the occupational radiation exposure dose of technologists were reduced when dispensing $^{18}F-FDG$ using auto dose dispenser. Secondly, using small syringes helps to increase reproducibility of auto dose dispense. And also, if you lower the specific activity of $^{18}F-FDG$ in multidose vial below 915-1,020 MBq/mL, you can use auto dispenser more effectively keeping the coefficient of variation lower than 10%.

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Implementation of Wearable Heart Activity Monitoring System having Modified Bipolar Electrode and Correlation Analysis with Clinical Electrocardiograph(ECG) (수정된 바이폴라 전극을 갖는 착용형 심장활동 모니터링 시스템 구현 및 임상 심전도와의 상관관계 분석)

  • Lee, Kang-Hwi;Lee, Jeong-Whan;Lee, Young-Jae;Kim, Kyeong-Seop;Yang, Heui-Koung;Shin, Kun-Su;Lee, Myoung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.6
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    • pp.1102-1108
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    • 2008
  • Wearable physiological signal monitoring systems are regarded as an important sensing unit platforms in ubiquitous/mobile healthcare application. In this paper, we suggested the modified bipolar electrodes implemented on the portable heart activity monitoring system, which minimized the distance of electrodes formed on a attachable pad. The proposed electrode configuration is useful in mobile measurement environments, but has a disadvantage of reduced amplitude of the heart action potential. In order to overcome the shortcoming of the suggested electrode configuration, we implemented the amplifying circuit to increase the signal-gain and decrease the artifacts. For evaluations, we analyzed the specificity of measured cardiography using the proposed electrodes through the comparing of heart activity monitoring system with standard clinical ECG(lead2) by pearson correlation coefficients. The result showed that the average correlation coefficient is $0.903{\pm}0.036,\;0.873{\pm}0.072$ at V3, V4 chest lead position, respectively. Thus, the modified bipolar electrode is quite suitable to monitor the electrical activity of the heart in the situation of the mobile environment, and could be considered having high similarity with standard clinical ECG.

The Relationship Between Activity Daily Living and Powerlessness of Spinal Cord Injury Patient's (척수손상환자의 일상생활동작과 무력감에 관한 연구)

  • Jeong, Hyeon-Suk;Park, Hyoung-Sook
    • The Korean Journal of Rehabilitation Nursing
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    • v.7 no.2
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    • pp.197-206
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    • 2004
  • Purpose: This study examined the relationship between the level of activity daily living and powerlessness of spinal cord injury patients'. Method: The subjects for the study consisted of 68 persons agreed above twenty below seventy had had spinal cord injury. The data were collected from November 1, 2003 to January 30, 2004. The instruments used for this study were ADL check List and Powerlessness Scale. The data were analysed by using SPSS computerlized program and included number, percentage, t-test and ANOVA, Pearson Correlation Coefficient. Results: The mean of activity daily living was paraplegia $49.53{\pm}10.91$ and tetraplegia $25.65{\pm}13.24$. The mean of powerlessness was paraplegia $35.22{\pm}9.50$ and tetraplegia $37.55{\pm}9.01$. In the relationship between activity daily living and powerlessness were significant difference. Conclusion: in order to increase the level of activity daily living of rehabilization nurse should be helpful to provide them. Also, it could be identified that informational support was important, that is, the lesser the informational support, spinal cord injury patient don't feel the powerlessness.

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Excess Enthalpies and Activity Coefficients for the Binary Nonionic Amphiphile 2-Butoxyethanol/Water System (양친매성 2-butoxyethanol과 물 혼합계에서의 과잉 엔탈피 및 활동도 계수)

  • Lim, Kyung-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.17 no.2
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    • pp.132-138
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    • 2000
  • Excess enthalpies ($H^{E}$) were measured by isothermal flow calorimetry for the nonionic amphiphile 2-butoxyethanol/water mixtures at 10 different temperatures (48.5 to $70^{\circ}C$) around and above the lower consolute solution temperature, $T_{lc}$. $H^{E}$ exhibits U-shape for the binary mixtures, and is large and negative which reflects substantial interaction between two chemical species. When the commonly used, semi-empirical Redlich-Kister (RK) polynomials were fitted to the measured $H^{E}$, plots of $H^{E}$ vs. weight fraction provided more accurate fitting with fewer parameters than conventionally drawn $H^{E}$ vs. mole fraction plots. This was due to the enhanced symmetry of $H^{E}$ vs. weight fraction plots. Using the fitted Redlich-Kister polynomials and the Gibbs-Helmholtz relation, temperature dependence of the activity coefficients were found and compared to the values determined from vapor-liquid equilibria. The activity coefficients were in the range of one to three, indicating that the binary system deviates from ideality but not substantially. They slightly depended on temperature and the temperature effect was equivalent to 10 % change in the activity coefficients.

The Structural Chracteristics That Influence on the fungicidal activity of N-Phenylbenzenesulfonamide Derivatives against Dapping-off (Pythium ultimum) (모잘록병균(Pythium ultimum)에 대한 N-Phenylbenzenesulfonamide 유도체의 살균활성에 미치는 구조적 특성)

  • Cho, Yun-Gi;Chang, Ki-Woon;Sung, Nack-Do
    • Korean Journal of Agricultural Science
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    • v.35 no.1
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    • pp.33-40
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    • 2008
  • The structural characteristics that influence on the fungicidal activities of N-phenylbenzenesulfonamide (1~24) and N-phenyltheinylsulfonamide (25~30) derivatives against Dampping-off (Pythium ultimum) were discussed quantitatively using the models of molecular holographic quantitative structure-activity relationships (HQSAR). From the based on these findings, the statistical results of the optimized HQSAR F-3 model showed better predictablity ($r^2_{cv.}$ or $q^2=0.581$) and correlation coefficient ($r^2_{ncv.}=0.963$). And, from the analytical results of the atomic contribution maps on the fungicidal activities, the most active compound is $R_1=2-fluoro-4-chloro$ substituent (4) and the most inactive one is $R_1=4-methoxy$ substituent (20). It was found that the 2-fluoro-4-chlorophenyl group as a $R_1$-group was an important structure and a characteristic factor not only for herbicidal activity but also for fungicidal activity.

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The Effect of the Structured Education on the Early Rehabilitation Knowledge and Activity Performance of the C.V.A. Patients (구조화된 환자교육이 뇌졸중 환자의 조기재활에 관한 지식과 활동수행에 미치는 영향)

  • 이혜진;이향련
    • Journal of Korean Academy of Nursing
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    • v.27 no.1
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    • pp.109-119
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    • 1997
  • This study has been attempted to set up the strategies of the nursing which can promote the activity performance for early rehabilitation for the patients by examining the effect of the structured patient education on the early rehabilitation knowledge and activity performance of the C.V.A patients. The study method has been done by investigating the experiment group and control group in advance through the question papers and interview and observation on 65 patients who had been hospitalized at oriental medicine hospital of K Medical Center from July 1st 1995 to the end of Sep, 1995. The analysis of the collected material had been done for the homogeneity test in which general characters of experiment group and control group had been tested by X²and the homogeneity test of ADL by t-test. To test the hypothesis the t-test had been given for the difference of the early rehabilitation knowledge and activity performance between the two groups and the correlation between early rehabilitation knowledge and activity performance had been tested by Pearson's Correlation Coefficient. The result of the test of the hypothesis is as the below. 1 The 1st hypothesis “The experiment group which had received the structured education should be higher in the early rehabilitation knowledge than the control group” was supported(t=4.45. p=.000). 2. The 2nd hypothesis “The experiment group which received the structured education should be higher in the early rehabilitation activity performance than the control group”was supported(t=2.11, p=.036). 3. The 3rd hypothesis “The higher the early rehabilitation knowledge of the patient the higher the activity performance degree” was rejected (r=.1546, p=.219). In conclusion, the patients who received the structured education showed the increase in the degree of early rehabilitation knowledge and activity performance, so it has been judged that education has been prerequisite in increasing the knowledge and activity performance of early rehabilitation.

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Mediation Effects of Health Self-efficacy and Activity Confidence on the Relationship between Body Image and Health Promoting Behavior in Middle School Girls (여중생의 신체이미지와 건강증진행위와의 관계: 건강자기효능감과 활동역량의 매개효과를 중심으로)

  • Ryu, Jeong Lim;Back, Su-Mi
    • The Journal of Korean Society for School & Community Health Education
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    • v.22 no.4
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    • pp.11-24
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    • 2021
  • Purpose: This study aims to explore the mediating effect of the health self-efficacy and activity confidence in the relationship between body image and health promoting behavior in middle school girls. Methods: A descriptive correlational design was used. Participants were 142 in middle school girls. The questionnaire consisted of measuring tools for body image, health promoting behavior, health self-efficacy and activity confidence. The collected data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, Pearson's correlation coefficient and the PROCESS Macro for SPSS 23.0 to verify the multiple mediated effect with a parallel structure. Results: Body image showed a significant positive correlation with health self-efficacy (r=.28, p=.001), activity confidence (r=.45, p<.001) and health promoting behavior (r=.37, p<.001). Health self-efficacy was also significantly correlated with activity confidence (r=.51, p<.001) and health promoting behavior (r=.63, p<.001). Activity confidence was significantly health promoting behavior (r=.67, p<.001). Furthermore, health self-efficacy (B=.35, p<.001) and activity confidence (B=.38, p<.001) showed a mediation effect on the relationship between body image and health promoting behavior. Conclusion: The impact of body image on health promoting behavior in middle school girls was mediated by health self-efficacy and activity confidence. Result suggest that strategies for improving health self-efficacy and activity confidence in middle school girls should be considered when developing an educational program for enhancing their health promoting behavior.