• Title/Summary/Keyword: P/C Based Method

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In Vitro Dissolution of Felodipine from Extended-Release Pellets (펠로디핀 방출연장형 펠렛의 용출 특성 평가)

  • Park, Jeong-Sook;Nam, Kyung-Wan;Shin, Kwang-Hyun;Park, Jong-Bum;Kim, Min-Soo;Hwang, Sung-Joo
    • Journal of Pharmaceutical Investigation
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    • v.37 no.3
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    • pp.193-196
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    • 2007
  • This study aimed to evaluate and develop $Eudragit^{(R)}$-coated pellets based on the dissolution using the paddle method. As coating materials, two types of $Eudragit^{(R)}$ were applied to obtain either sustained release form or fast released form. The dissolution test was carried out in phosphate buffer solution (pH 6.5) at $37^{\circ}C$, 100 rpm. In order to develop a sustained release preparation containing felodipine, a comparative dissolution study was done using commercial product as a control. The dissolution at 30 min of felodipine from $Eudragit^{(R)}$ RS or RL-coated pellets were 0.96% and 99.65, respectively. The weight ratio of $Eudragit^{(R)}$ RL pellets to RS pellets altered the dissolution rate, but did not optimize the dissolution rate. However, the sustained dissolution of felodipine from pellets was optimized by varying the coating ratios of $Eudragit^{(R)}$ RS. It is suggested that the coating ratio of pellets is the main factor which controls dissolution rate. Taken together, $Eudragit^{(R)}$ RS 30D-coated pellets showed the most comparable dissolution rate pattern to commercial product, $Splendil^{(R)}$. This sustained release pellets for oral delivery system of felodipine was simply manufactured, and drug release behavior was highly reproducible.

Determination of Intracellular ATP of bacteria on the surface of Chicken (Bioluminescence방법에 의한 계육표면에 존재하는 세균수 측정)

  • Choi, Byung-Kyu;Kim, Jong-Bae;Shin, Heuyn-Kil;Lee, Seoung-Bae
    • Korean Journal of Food Science and Technology
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    • v.18 no.2
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    • pp.88-92
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    • 1986
  • Determination of bacterial adenosine triphosphate (ATP) based on luciferin-luciferase bioluminescene reaction was applied to the measurement of bacteria on the surface of chicken as an alternative rapid method. The light yield was proportional to the concentration of ATP giving a straight line within a range of $10^{-10}\;to\;10^{-6}M$. The bacteria isolated from the surface of chicken were identified as Escherichia coli, Hafnia alvei, Pseudomonas putida and Aeromonas hydrophila. When the ATP contents of each bacteria were determined by bioluminescence reaction and compared, there was no significant difference (r = 0.95). The Patterns of growth curves for E. coli look very similar, when the bacterial growth was monitored by ATP content and viable cell count. When bacterial ATP of each samples collected every 2 days during storage for 14 days at $4^{\circ}C$was determined and compared with viable cell count, it gave a good correlation (r = 0.95, n = 32).

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A novel MLL2 gene mutation in a Korean patient with Kabuki syndrome

  • Kim, Soo Jin;Cho, Sung Yoon;Maeng, Se Hyun;Sohn, Young Bae;Kim, Su-Jin;Ki, Chang-Seok;Jin, Dong-Kyu
    • Clinical and Experimental Pediatrics
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    • v.56 no.8
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    • pp.355-358
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    • 2013
  • Kabuki syndrome (KS) is a rare genetic disease with a distinctive dysmorphic face, intellectual disability, and multiple congenital abnormalities. KS is inherited in an autosomal dominant manner. As the primary cause of KS, MLL2 mutations have been identified in 56-76% of affected individuals who have been tested, suggesting that there may be additional genes associated with KS. Recently, a few KS individuals have been found to have de novo partial or complete deletions of an X chromosome gene, KDM6A, which encodes a histone demethylase that interacts with MLL2. Nevertheless, mutations in MLL2 are the major cause of KS. Although there are a few reports of KS patients in Korea, none of these had been confirmed by genetic analysis. Here, we report a case of a Korean patient with clinical features of KS. Using direct sequencing, we identified a frameshift heterozygous mutation for MLL2 : (c.5256_5257delGA;p.Lys1753Alafs$^*34$). Clinically, the patient presented with typical facial features, and diagnosis of KS was based on the diagnostic criteria. While KS is a rare disease, other malformations that overlap with those found in individuals with KS are common. Hence, the diagnosis of KS by mutational analysis can be a valuable method for patients with KS-like syndromes. Furthermore, in the near future, other genes could be identified in patients with KS without a detectable MLL2 mutation.

Implications of yield penetration on confinement requirements of r.c. wall elements

  • Tastani, Souzana P.;Pantazopoulou, Stavroula J.
    • Earthquakes and Structures
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    • v.9 no.4
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    • pp.831-849
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    • 2015
  • Seismic-design procedures for walls require that the confinement in the critical (plastic hinge) regions should extend over a length in the compression zone of the cross section at the wall base where concrete strains in the Ultimate Limit State (ULS) exceed the limit of 0.0035. In a performance-based framework, confinement is linked to required curvature ductility so that the drift demand at the performance point of the structure for the design earthquake may be met. However, performance of flexural walls in the recent earthquakes in Chile (2010) and Christchurch (2011) indicates that the actual compression strains in the critical regions of many structural walls were higher than estimated, being responsible for several of the reported failures by toe crushing. In this study, the method of estimating the confined region and magnitude of compression strain demands in slender walls are revisited. The objective is to account for a newly identified kinematic interaction between the normal strains that arise in the compression zone, and the lumped rotations that occur at the other end of the wall base due to penetration of bar tension yielding into the supporting anchorage. Design charts estimating the amount of yield penetration in terms of the resulting lumped rotation at the wall base are used to quantify the increased demands for compression strain in the critical section. The estimated strain increase may exceed by more than 30% the base value estimated from the existing design expressions, which explains the frequently reported occurrence of toe crushing even in well confined slender walls under high drift demands. Example cases are included in the presentation to illustrate the behavioral parametric trends and implications in seismic design of walls.

Relationships of Dietary Behavioral Factors and Stress Perception Levels in College Students in Gwang-ju City (광주지역 일부 대학생에서 식생활 요인과 스트레스 인지수준과의 상관관계)

  • Kim, Bok Hee;Shim, Bang Geul;Jeong, Eun
    • The Korean Journal of Food And Nutrition
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    • v.27 no.5
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    • pp.771-784
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    • 2014
  • The purpose of this study was to estimate the relationships between dietary factors and the stress perception levels of College students. A survey was conducted in June, 2010, targeting 332 college students in Gwangju. General environmental factors, stress perception levels, dietary behaviors, and dietary action guide performance of the subjects were evaluated by questionnaire, and food intakes was determined by the 24-hour recall method. The results are summarized as follows.: The score of frequency experiencing was $45.1{\pm}16.9$ for male students, and $47.0{\pm}16.7$ for female students. The importance scores were $50.8{\pm}18.5$ for males, and $53.3{\pm}18.7$ for females. The total score for dietary action guide performance was $39.6{\pm}7.2$ for males and $40.6{\pm}6.5$ for females. Nutrient intake levels were evaluated based on dietary reference intake (DRI), revealing energy intakes to be 68.5% EER in males and 73.9% in females. The mean intakes of nutrient were 54.2% RI for calcium, 73.6% RI for riboflavin, and 51.2% RI for vitamin C but 203.6% AI for sodium, which indicates an imbalance in nutrient intake. Analysis of the correlations between stress perception levels and dietary factors, scholarship achievements, financial problems, future problems, value senses, and family relationships revealed significant correlations with general environment factors, dietary behaviors, Dietary action guide performance, and nutrient intakes (p<0.05). The higher the stress perception levels of the students, the higher the energy, coffee and alcohol intake, which predicts that appropriate stress control in college students will lead to better dietary habits. It is expected that the results above will be used as basic data for the development of proper nutrition education programs and stress control strategies.

The Response Characteristics of as Addition Ratio of Arsenic in $CaWO_4/a-Se$ based X-ray Conversion Sensor ($CaWO_4/a-Se$ 구조의 X선 변환센서에서 a-Se의 Arsenic 첨가량에 따른 반응 특성)

  • Kang, Sang-Sik;Suk, Dae-Woo;Cho, Sung-Ho;Kim, Jae-Hyung;Nam, Namg-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.416-419
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    • 2002
  • There are being two prominent studying for Digital Radiography. Direct and Indirect method of Digital Radiography are announced for producing high quality digital image. The one is using amorphous selenium as photoconductor and the other is using phosphor layer as a light conversion. But each two systems have strength and weakness such as high voltage and blurring effect. In this study, we investigated the electrical characteristic of $multi-layer\left(CaWO_{4}+a-Se \right)$ as a photoconductor according to the changing arsenic composition ratio. This is a basic research for developing of Hybrid digital radiography which is a new type X-ray detector. The arsenic composition ratio of a-Se compound is classified into 7 different kinds which have 0.1%, 0.3%, 0.5%, 1%, 1.5%, 5%, 10% and were made test sample throught thermo-evaporation. The phosphor layer of $CaWO_4$ was overlapped on a-Se using EFIRON optical adhesives. We measured the dark and photo current about the test sample and compared the electrical characteristic of the net charge and signal-to-noise ratio. Among other things, test sample of compound material of 0.3% arsenic showed good characteristic of $2.45nA/cm^2$ dark current and $357.19pC/cm^2/mR$ net charge at $3V/{\mu}m$.

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Evaluation of Microbial Load in Oropharyngeal Mucosa from Tannery Workers

  • Castellanos-Arevalo, Diana C.;Castellanos-Arevalo, Andrea P.;Camarena-Pozos, David A.;Colli-Mull, Juan G.;Maldonado-Vega, Maria
    • Safety and Health at Work
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    • v.6 no.1
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    • pp.62-70
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    • 2015
  • Background: Animal skin provides an ideal medium for the propagation of microorganisms and it is used like raw material in the tannery and footware industry. The aim of this study was to evaluate and identify the microbial load in oropharyngeal mucosa of tannery employees. Methods: The health risk was estimated based on the identification of microorganisms found in the oropharyngeal mucosa samples. The study was conducted in a tanners group and a control group. Samples were taken from oropharyngeal mucosa and inoculated on plates with selective medium. In the samples, bacteria were identified by 16S ribosomal DNA analysis and the yeasts through a presumptive method. In addition, the sensitivity of these microorganisms to antibiotics/antifungals was evaluated. Results: The identified bacteria belonged to the families Enterobacteriaceae, Pseudomonadaceae, Neisseriaceae, Alcaligenaceae, Moraxellaceae, and Xanthomonadaceae, of which some species are considered as pathogenic or opportunistic microorganisms; these bacteria were not present in the control group. Forty-two percent of bacteria identified in the tanners group are correlated with respiratory diseases. Yeasts were also identified, including the following species: Candida glabrata, Candida tropicalis, Candida albicans, and Candida krusei. Regarding the sensitivity test of bacteria identified in the tanners group, 90% showed sensitivity to piperacillin/tazobactam, 87% showed sensitivity to ticarcillin/clavulanic acid, 74% showed sensitivity to ampicillin/sulbactam, and 58% showed sensitivity to amoxicillin/clavulanic acid. Conclusion: Several of the bacteria and yeast identified in the oropharyngeal mucosa of tanners have been correlated with infections in humans and have already been reported as airborne microorganisms in this working environment, representing a health risk for workers.

Synthesis and Characterization of Dense Ceramic Membranes for Methane Conversion - Part II

  • Santos, A.;Fontes, V.A.;Fontes, F.A.Oliveira;De Sousa, J.F.;De Souza, C.P.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1112-1113
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    • 2006
  • The perovskite- type oxide $(ABO_3)$ containing transition metals on the B-site show mixed (electronic/ionic) conductivity. These mixed-conductivity oxides are promising materials for oxygen permeating membranes. The main objective of this research work is to synthesize and characterization ceramic powders of the Sr-Co-Fe-O system for methane conversion using membrane reactor. SCFO powders were synthesized from the route was based on the complex method of combination of acid EDTA and citrate and shown be available by control efficient of synthesis to performed $SrCo_{0.8}Fe_{0.2}O_{3-\delta$, moreover, it presented easy implementation, reproducibility and operation. Powder ceramic was characterized by XRD, microscopic optic, SEM and TG-DTA.

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Homology Modeling and Molecular Docking Study of Translationally Controlled Tumor Protein and Artemisinin

  • Chae, Jin-Sun;Choi, In-Hee;Kim, Choon-Mi
    • Archives of Pharmacal Research
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    • v.29 no.1
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    • pp.50-58
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    • 2006
  • Translationally controlled tumor protein (TCTP), also known as histamine releasing factor (HRF), is found abundantly in different eukaryotic cell types. The sequence homology of TCTP between different species is very high, belonging to the MSS4/DSS4 superfamily of proteins. TCTP is involved in both cell growth and human late allergy reaction, as well as having a calcium binding property; however, its primary biological functions remain to be clearly elucidated. In regard to many possible functions, the TCTP of Plasmodium falciparum (Pf) is known to bind with an antimalarial agent, artemisinin, which is activated by heme. It is assumed that the endoperoxide-bridge of artemisinin is opened up by heme to form a free radical, which then eventually alkylates, probably to the Cys14 of PfTCTP. Study of the docking of artemisinin with heme, and subsequently with PfTCTP, was carried out to verify the above hypothesis on the basis of structural interactions. The three dimensional (3D) structure of PfTCTP was built by homology modeling, using the NMR structure of the TCTP of Schizosaccharomyces pombe as a template. The quality of the model was examined based on its secondary structure and biological function, as well as with the use of structure evaluating programs. The interactions between artemisinin, heme and PfTCTP were then studied using the docking program, FlexiDock. The center of the peroxide bond of artemisinin and the Fe of heme were docked within a short distance of $2.6{\AA}$, implying the strong possibility of an interaction between the two molecules, as proposed. When the activated form of artemisinin was docked on the PfTCTP, the C4-radical of the drug faced towards the sulfur of Cys14 within a distance of $2.48{\AA}$, again suggesting the possibility of alkylation having occurred. These results confirm the proposed mechanism of the antimalarial effect of artemisinin, which will provide a reliable method for establishing the mechanism of its biological activity using a molecular modeling study.

Marked Difference in Solvation Effects and Mechanism between Solvolyses of Substituted Acetylchloride with Alkyl Groups and with Aromatic Rigns in Aqueous Fluorinated Alcohol and in 2,2,2-Trifluoroethanol-Ethanol Solvent Systems

  • Oh, Yung-Hee;Jang, Gyeong-Gu;Lim, Gyi-Taek;Ryu, Zoon-Ha
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1089-1096
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    • 2002
  • Solvolyses rate constants of trimethylacetyl chloride (2), isobutyryl chloride (3), diphenylacetyl chloride (4) and p-methoxyphenylacetyl chloride (5) in 2,2,2-trifluoroethanol (TFE)-water, 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)-water and TFE-et hanol solvent systems at $10^{\circ}C$ are determined by a conductimetric method. Kinetic solvent isotope effects (KSIE) are reported from additional kinetic data for methanolyses of various substituted acetylchlorides in methanol According to the results of those reactions analyzed in terms of rate-rate profiles,extended Grunwald-Winstein type correlations, application of a third order reaction model based a general base catalyzed (GBC) and KSIE values. Regardless of the kind of neighboring groups (CH3- or Ph-groups) of reaction center, for aqueous fluorinated alcohol systems, solvolyses of 2, 3, 4, and 5 were exposed to the reaction with the same mechanism (a loose SN2 type mechanism by electrophilic solvation) controlled by a similarity of solvation of the transition sate (TS). Whereas, for TFE-ethanol solvent systems, the reactivity depended on whether substituted acetyl chloride have aromatic rings (Ph-) or alkyl groups (CH3-); the solvations by the predominant stoichiometric effect (third order reaction mechanism by GBC and/or by push-pull type) for Ph- groups (4 and 5) and the same solvation effects as those shown in TFE-water solvent systems for CH3- groups (2 and 3) were exhibited Such phenomena can be interpreted as having relevance to the inductive effect ( $\sigmaI)$ of substituted groups; the plot of log (KSIE) vs. ${\sigma}I$ parameter give an acceptable the linear correlation with r = 0.970 (slope = 0.44 $\pm$ 0.06, n = 5).