• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.251-259
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• 1995

Pharmacokinetics and pharmacodynamics of metoprolol, a selective beta-l blocker, were examined for 360 minutes after intravenous bolus administration of metoprolol to 6 dogs. Plasma concentration and excreted amount in the urine metoprolol were measured by liquid chromatography with fluorescence detection. PR interval and heart rate were measured by ECG monitoring. Blood pressure was monitored through intraarterial catheter in femoral artery and cardiac output by thermodilution method using Swan-Ganz catheter. To analyze the effect site concentration-response relationship, plasma concentration and pharmacological effects were simultaneously fitted to a two pharmacokinetic compartment linked to pharmacodynamic model with NONLIN program. Results are as follows. 1) The plasma concentration of metoprolol after intrvenous injection decreased biexponentially. The terminal half-life estimated was $1.33{\pm}0.40$ hours and the volume of distribution at steady state (Vdss) and the total body clearance were $1.04{\pm}0.4\;L/kg,\;6.55{\pm}2.21\;L/hr$, respectively. The central compartment volume of distribution and peripheral compartment volume of distribution were $0.35{\pm}0.14L/kg\;and\;0.69{\pm}0.34L/kg$. The renal clearance and intercompartment clearance were $0.53{\pm}0.25\;L/min\;and\;0.35{\pm}0.19\;L/min$. 2) Simulated biophase concentration-response curve shows hyperbolic relationship and the estimated concentration-effect relationship was best explained by Emax model when the prolongation of PR interval and the reduction of the heart rate were used as pharmacodynamic parameters. Emax and EC50 were estimated to be $26.3{\pm}4.7\;msec\;and\;88.8{\pm}82.3\;g/ml$ for PR interval, and $48.7{\pm}18.8\;beats/min\;and\;113.5{\pm}78.7\;ng/ml$ for heart rate, respectively. 3) The changes of cardiac output-effect site concentration relationship was best fitted by a linear model and the slope of the relationship was $0.005{\pm}0.003$. Diastolic blood pressure-effect site concentration relationship was also explained by the linear model and the slope of the relationship was $0.038{\pm}0.034$.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.710-718
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• 2017

Contents of water soluble vitamin $B_6$ in a total of 62 agricultural products cultivated in local areas in Korea were analyzed by high performance liquid chromatography with fluorescence detector (HPLC/FLD). To verify the method of vitamin $B_6$ analysis, a quality control chart was formulated with in-house control using a mixture of broccoli and shiitake mushrooms. Among cereals, high content of vitamin $B_6$ measured $234.3{\sim}260.3{\mu}g/100g$ in dried mung bean and soybean. Vitamin $B_6$ content of non-glutinous and glutinous black rice measured $105.0{\mu}g/100g$ and $129.7{\mu}g/100g$, respectively. In vegetables, high content of vitamin $B_6$ were measured in passion fruit ($104.3{\mu}g/100g$), gat ($55.7{\sim}84.3{\mu}g/100g$), gomchwi ($31.3{\sim}88.0{\mu}g/100g$) and garlic ($72.7{\sim}98.3{\mu}g/100g$). Among fruits, gold kiwi 'Zespri' and green kiwi 'Hayward' revealed high vitamin $B_6$ content of $116.3{\mu}g/100g$ and $78.7{\mu}g/100g$, respectively. In persimmons, daebongsi had high vitamin $B_6$ content ($36.0{\sim}72.7{\mu}g/100g$) than bansi and sweet persimmon. Vitamin $B_6$ content in dried jujube and persimmon increased more than $86.7{\mu}g/100g$ compared to fresh materials. Among specialty crops, green tea powder ($64.7{\sim}251.0{\mu}g/100g$) and sansuyu ($172.3{\mu}g/100g$) revealed high content. Of mushrooms, vitamin $B_6$ content of Sparassis crispa ($139.3{\mu}g/100g$) was the highest. Vitamin $B_6$ content information of agricultural products in local areas in Korea collected from this experiment will be used as valuable preliminary data for grasp national nutritional status.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.202-208
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• 2015

The aim of this retrospective study was to evaluate the relationship between periodontal health condition and the results of a new method such as Cariview which could evaluate the acidity of dental biofilms. Fifty four subjects more than 20 years old were selected for the candidates of this study. The periodontal health conditions of the candidates were divided into 4 groups according to the assessment of X-ray and Quantitative Light-induced Fluorescence-Digital (QLF-D; Inspektor Research Systems BV) images; gingivitis, slight periodontitis, moderate periodontitis, severe periodontitis. The biofilm acidogenicity of each subject was examined using Cariview (All in ONE BIO) according to manufacturer's instruction, and the Cariview score was calculated. The mean differences of Cariview score between 4 groups of periodontal health condition were examined by ANCOVA test with the covariance of decayed, missing, and filled teeth (DMFT) index. As a result, the mean Cariview score was different, however it was not significantly different from the 4 groups (p=0.12). The mean score was the lowest in the gingivitis group ($40.54{\pm}11.01$), and the highest in slight periodontitis group ($57.26{\pm}20.51$). In conclusion, the significant mean differences were not confirmed in Cariview score according to the periodontal health condition.

• YAKHAK HOEJI
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• v.52 no.3
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• pp.195-200
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• 2008

Gabapentin, [1-(aminomethyl) cyclohexaneacetic acid], a structural analog of $\gamma$-aminobutyric acid (GABA), is being developed for the treatment of epilepsy. Unlike GABA, gabapentin crosses the blood-brain barrier after systemic administration. Gabapentin is an effective antiepileptic drug in patients with partial and secondarily generalized seizures who are uncontrolled with use of existing anticonvulsant drug therapy. The purpose of the present study was to evaluate the bioequivalence of two gabapentin 400 mg capsules, $Neurontin^{(R)}$ capsule 400 mg (Pfizer Inc.) and Gabatin capsule 400 mg (Korean Drug Co. Ltd), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of gabapentin from the two gabapentin formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty six healthy male subjects, 23.58$\pm$1.50 years in age and 66.74$\pm$8.31 kg in body weight, were divided into two groups and a randomized 2$\times$2 cross-over study was employed. After one capsule containing 400 mg as gabapentin were orally administered, blood was taken at predetermined time intervals and the concentrations of gabapentin in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, the pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Neurontin^{(R)}$ capsule 400 mg, were 2.04, -3.68 and 16.79% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., log 0.91$\sim$log 1.16 and log 0.87$\sim$log 1.11 for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Gabatin capsule 400 mg was bioequivalent to $Neurontin^{(R)}$ capsule 400 mg.

• YAKHAK HOEJI
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• v.52 no.3
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• pp.188-194
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• 2008

Fexofenadine, ($\pm$)-4-1-hydroxy-4-{4-(hydroxydiphenylmethyl)-1-piperidinyl}-butyl-a,a-dimethyl benzeneacetic acid, is a selective histamine $H_1$ receptor antagonist, and is clinically effective in the treatment of seasonal allergic rhinitis and chronic idiopathic urticaria as a first-line therapeutic agent. The purpose of the present study was to evaluate the bioequivalence of two fexofenadine hydrochloride tablets, $Allegra^{(R)}$ (Handok Pharmaceuticals Co., Ltd.) and Alecort (Samchundang Pharmaceutical Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of fexofenadine from the two fexofenadine hydrochloride formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media. Twenty six healthy male subjects, 25.62$\pm$3.35 years in age and 70.05$\pm$11.71 kg in body weight, were divided into two groups and a randomized 2$\times$2 cross-over study was employed. After a single tablet containing 120 mg as fexofenadine hydrochloride was orally administered, blood samples were taken at predetermined time intervals and the concentrations of fexofenadine in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar in all tested dissolution media. The harmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated, and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Allegra^{(R)}$, were -1.37, 5.22 and 16.50% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., log 0.83$\sim$log 1.08 and log 0.81$\sim$log 1.03 for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Alecort tablet was bioequivalent to $Allegra^{(R)}$ tablet.

• Resources Recycling
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• v.30 no.5
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• pp.38-48
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• 2021

In this study, we determine the optimal process conditions for selectively recovering Si from a solar cell surface by removal of impurities (Al, Zn, Ag, etc.). To selectively recover Si from solar cells, leaching is performed using HCl solution and an ultrasonic cleaner. After leaching, the solar cells are washed using distilled water and dried in an oven. Decompression filtration is performed on the HCl solution, and ICP-OES (Inductively Coupled Plasma Optical Emission spectroscopy) full scan analysis is performed on the filtered solution. Furthermore, XRD (X-ray powder diffraction), XRF (X-ray fluorescence), and ICP-OES are performed on the dried solar cells after crushing, and the purity and recovery rate of Si are obtained. In this experiment, the concentration of acid solution, reaction temperature, reaction time, and ultrasonic intensity are considered as variables. The results show that the optimal process conditions for the selective recovery of Si from the solar cells are as follows: the concentration of acid solution = 3 M HCl, reaction temperature = 60℃, reaction time = 120 min, and ultrasonic intensity = 150 W. Further, the Si purity and recovery rate are 99.85 and 99.24%, respectively.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.3
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• pp.293-300
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• 2019

As a common side effect of fixed orthodontic treatment, demineralization of the enamel adjacent to the bracket and band occurs in patients with poor oral hygiene. The purpose of this study was to investigate what is the most effective method to prevent demineralization around the fixed orthodontic appliance among various methods using fluoride. 80 extracted bovine incisors with a healthy surface were classified into four groups as experimental materials: (Group I) Control group, (Group II) V $varnish^{TM}$, (Group III) Tooth Mousse $Plus^{(R)}$, (Group IV) $Vanish^{TM}$ XT. After treatment for each group, mineral loss and Vickers surface microhardness were measured at 0, 30, 60 and 90 days after demineralization in artificial carious solution. Mineral loss was the lowest in group IV, followed by group II and group III, which showed a significant difference. The surface microhardness was the lowest in group IV, followed by group II and group III, which showed a significant difference. Through this study, group IV showed the best effect to prevent enamel demineralization around the bracket. Group III showed significant prevention of enamel demineralization compared with the control group, but the effect was less than that of the other groups.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.23-29
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• 2011

The oxidation slag has been widely used in civil engineering project, whereas the reduced slag from electric furnace has yet to be applied. Consequently in order to find out the recycling method in civil engineering field, the mineral compositions of the reduced slag were analyzed and some tests on water quality were performed to estimate the potential release of toxic compounds. Slag-soil mixtures of 0, 10, 20 and 30%(dry weight) soil were prepared in lysimeter columns and the effluents were collected with the period of one, two and four week options in closed system, respectively. The result from qualitative and quantitative analysis using X-ray Diffraction(XRD) and X-ray Fluorescence(XRF) indicates that the main mineral of the reduced slag is $Ca_2(SiO_4)$, a kind of calcium silicate. Also, the leaching medium analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy(ICP-OES) showed that main heavy metals such as Al, Fe and Mn are included in the reduced slag due to the effect of steel production process. It can be seen that the leachate does not violate the regulation guide line of waste material of heavy metal. Also the pH levels were increased from pH 6.9 for 0% soil to pH 10 for 30% soil. However the influence on leachate circulation period of one through four weeks was negligible.

• Korean Journal of Materials Research
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• v.32 no.11
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• pp.481-488
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• 2022

The Cu₂ZnSn(S_xSe_1-x)₄ (CZTSSe) absorbers are promising thin film solar cells (TFSCs) materials, to replace existing Cu(In,Ga)Se₂ (CIGS) and CdTe photovoltaic technology. However, the best reported efficiency for a CZTSSe device, of 13.6 %, is still too low for commercial use. Recently, partially replacing the Zn²⁺ element with a Cd²⁺element has attracting attention as one of the promising strategies for improving the photovoltaic characteristics of the CZTSSe TFSCs. Cd²⁺ elements are known to improve the grain size of the CZTSSe absorber thin films and improve optoelectronic properties by suppressing potential defects, causing short-circuit current (J_sc) loss. In this study, the structural, compositional, and morphological characteristics of CZTSSe and CZCTSSe thin films were investigated using X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), and Field-emission scanning electron microscopy (FE-SEM), respectively. The FE-SEM images revealed that the grain size improved with increasing Cd²⁺ alloying in the CZTSSe thin films. Moreover, there was a slight decrease in small grain distribution as well as voids near the CZTSSe/Mo interface after Cd²⁺ alloying. The solar cells prepared using the most promising CZTSSe absorber thin films with Cd²⁺ alloying (8 min. 30 sec.) exhibited a power conversion efficiency (PCE) of 9.33 %, J_sc of 34.0 mA/cm², and fill factor (FF) of 62.7 %, respectively.

• Korean Journal of Poultry Science
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• v.49 no.1
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• pp.15-23
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• 2022

We compared the degrees of vitality of 12 Korean native chicken breeds, such as Jaeraejong, Korean Rhode Island Red (Rhode), Korean White Leghorn, Korean Cornish (Cornish), and Korean Ogye breeds. The survival rate and telomere length were measured as vital markers. Telomere length was analyzed via quantitative fluorescence in situ hybridization method using the lymphocytes of 466 chickens. We found that the telomere length decreased linearly with increasing chronological age in all chicken breeds. Telomere length and telomere shortening rates (TSR) were significantly different among the chicken breeds after 20 weeks of age (P<0.01). Rhode had the longest telomere length and the lowest TSR, whereas Cornish had the shortest telomere length and the highest TSR. In terms of TSR, the telomere length of 50-week-old chickens was half of that of 8-week-old chickens. There was also a significant difference in survival rates among the breeds. Both Rhode and Korean Ogye had the highest survival rates, while Cornish had the lowest. There was a significant positive correlation between survival rate and telomere length, and telomere length in old age showed a higher correlation with survival rate than that in young age. Therefore, it is considered that TSR is more closely related to survival rate than the telomere length. Based on the telomere dynamics and survival rates of 12 Korean native chicken breeds, it was concluded that the Rhode breed and Cornish breed had the highest and lowest vitality, respectively.