• Korean Journal of Materials Research
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• v.3 no.6
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• pp.632-637
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• 1993

The optical properties and electrochromism of amorphous $WO_3$ thin films were studied. $WO_3$ thin films with thickness of 3000$\AA$~6000$\AA$ were deposited by vacuum evaporat.ion. All these films were transparent and found to be amorphous in structure by X-ray diffraction analysis and the visible wave length refractive indices were found to be between 1.9 and 2.1 and the optical energey gap to be 3.25 eV. Electrochromic devices were made consisting of IT0 transparent electrode, $WO_3$ thin films, $LiCIO_4$- propylene carbonate and Pt counter electrode. In terms of their operation, the amorphous $WO_3$ films were colored blue by a double injection of electrons from the transparent electrode and lithium ions from the $LiCIO_4$-propylene carbonate organic electrolyte and made colorless by electrochemical oxidation reaction. The electrochromic properties of $WO_3$ thin films including coloration and bleaching, optical density and response time were all found to be strongly dependent on the film deposition condition, electrolyte concentration, sheet resistance of the transparent electrode and applied voltage.

• Journal of Pharmaceutical Investigation
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• v.38 no.4
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• pp.261-267
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• 2008

The aim of the present study was to evaluate the bioequivalence of two gabapentin preparations. We used Neurontin tablet 800 mg (Pfizer Korea Inc.) as a reference drug for bioequivalence of Gabalep tablet 800 mg (Chong Kun Dang Pharmaceutical Co., Korea), and performed this whole study according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty five healthy male volunteers were administered with each drug in a randomized $2{\times}2$ cross-over study with one week washout interval. After drug administration, blood was taken at predetermined time intervals ($0{\sim}24$ hours) and the concentrations of gabapentin in serum were determined using an high performance liquid chromatography-tandem mass spectrometer (LC-MS/MS) employing electrospray ionization technique and operating in multiple reaction mornitoring (MRM). The analytical method was validated in specificity, accuracy, precision and linearity. The phar-macokinetic parameters such as AUCt and Cmax were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed AUCt and Cmax. $Mean{\pm}SD$. of AUCt and Cmax value for reference drug and test drug were $29.94{\pm}9.23\;({\mu}g/mL{\cdot}hr)$ and $3.12{\pm}1.11\;({\mu}g/mL{\cdot}hr)$, and $31.48{\pm}9.77\;({\mu}g/mL{\cdot}hr)$ and $3.15{\pm}1.03\;({\mu}g/mL)$, respectively. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) for AUCt and Cmax, respectively. These results indicate that Gabalep tablet 800 mg is bioequivalent to Neurontin tablet 800 mg.

• Journal of Gastric Cancer
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• v.20 no.2
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• pp.139-151
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• 2020

Purpose: Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods: The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results: The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions: LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.

• Journal of Ginseng Research
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• v.39 no.3
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• pp.230-237
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• 2015

Background: Colorectal cancer (CRC) is a leading cause of death worldwide. Chronic gut inflammation is recognized as a risk factor for tumor development, including CRC. American ginseng is a very commonly used ginseng species in the West. Methods: A genetically engineered $Apc^{Min/+}$ mouse model was used in this study. We analyzed the saponin composition of American ginseng used in this project, and evaluated its effects on the progression of high-fat-diet-enhanced CRC carcinogenesis. Results: After oral ginseng administration (10-20 mg/kg/d for up to 32 wk), experimental data showed that, compared with the untreated mice, ginseng very significantly reduced tumor initiation and progression in both the small intestine (including the proximal end, middle end, and distal end) and the colon (all p < 0.01). This tumor number reduction was more obvious in those mice treated with a low dose of ginseng. The tumor multiplicity data were supported by body weight changes and gut tissue histology examinations. In addition, quantitative real-time polymerase chain reaction analysis showed that compared with the untreated group, ginseng very significantly reduced the gene expression of inflammatory cytokines, including interleukin-$1{\alpha}$ (IL-$1{\alpha}$), IL-$1{\beta}$, IL-6, tumor necrosis factor-${\alpha}$, granulocyte-colony stimulating factor, and granulocyte-macrophage colony-stimulating factor in both the small intestine and the colon (all p < 0.01). Conclusion: Further studies are needed to link our observed effects to the actions of the gut microbiome in converting the parent ginsenosides to bioactive ginseng metabolites. Our data suggest that American ginseng may have potential value in CRC chemoprevention.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.75-84
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• 2018

In this study, the analysis of torrefaction products was carried out for fueling of sewage sludge. The mixed samples were composed as follows : 50% of sewage sludge and 50% of rice husk and CR(Coffee Residue). In this experiment, the reaction time(30min, 60min) and temperature($200^{\circ}C$, $250^{\circ}C$, $300^{\circ}C$) were expressed as a single variable using SF(Severity Factor). As a result, it was confirmed that as the SF increased, the heating value and fuel ratio increased, but the CI(Combustibility Index) decreased. The heating value was similarly increased as CR(Coffee Residue) and SF increased. The fuel ratio range of mixed samples was equal to that of lignite(0.5~1.0) in case of SF lower than 6.19 and that of bituminous coal(1.0~1.8) in case of SF higher than 7.36 or above. The CI showed a stable range(3,000~5,500kcal/kg) in low SF as the content of mixed samples contained more rice husk than CR.

• Food Science of Animal Resources
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• v.38 no.4
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• pp.780-793
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• 2018

This study was conducted to compare the anti-allergic effects of a whey protein concentrate (WPC) and WPC hydrolysate. WPC hydrolysate was prepared using enzymatic digestion for 8 h with trypsin and ${\alpha}$-chymotrypsin, after which it was freeze-dried. The allergic parameters assessed in rat basophilic leukemia (RBL)-2H3 cells were degranulation and release of ${\beta}$-hexosaminidase, release of tumor necrosis factor $(TNF)-{\alpha}$, and changes in the expression of $IL-1{\beta}$, IL-4, and IL-10 by real time polymerase chain reaction (PCR). During preparation of the WPC hydrolysate, hydrolysis increased rapidly from 0 to 10 min and then gradually increased slowly from 1 h onwards, achieving a final degree of hydrolysis of 78.50%. The SDS-PAGE analysis revealed a reduction in the intensity of several protein bands in the WPC hydrolysate compared to the WPC. IgE-induced ${\beta}$-hexosaminidase release from RBL-2H3 cells was decreased to a higher degree following treatment with the hydrolysate compared to WPC treatment. W500 ($500{\mu}g/mL$ WPC) showed the least inhibition of ${\beta}$-hexosaminidase release, but there was no significant difference between W500 and W1000 ($1,000{\mu}g/mL$) (p<0.05). H1000 ($1,000{\mu}g/mL$ WPC hydrolysate) inhibited ${\beta}$-hexosaminidase release by 39%. Compared to the control, treatment with H1000 decreased $TNF-{\alpha}$ secretion to 11.87 pg/mL. The gene expression levels of IL-1${\beta}$, IL-4, and IL-13 were all significantly decreased in hydrolysate (p<0.05). In the case of $IL-1{\beta}$ and IL-4, the expression levels in W1000 treated cells were decreased by 73.67% and 65%, respectively, and that of IL-13 was decreased by 66.43% compared to the control.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.419-427
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• 2016

There is a high association of heat shock on the alteration of energy and lipid metabolism. The alterations associated with thermal stress are composed of gene expression changes and adaptation through biochemical responses. Previous study showed that Angelica gigas Nakai (AGN) root extract promoted adipogenic differentiation in murine 3T3-L1 preadipocytes under the normal temperature condition. However, its effect in heat shocked 3T3-L1 cells has not been established. In this study, we investigated the effect of AGN root hot water extract in the adipogenic differentiation of murine 3T3-L1 preadipocytes following heat shock and its possible mechanism of action. Thermal stress procedure was executed within the same stage of preadipocyte confluence (G0) through incubation at $42^{\circ}C$ for one hour and then allowed to recover at normal incubation temperature of $37^{\circ}C$ for another hour before AGN treatment for both cell viability assay and Oil Red O. Cell viability assay showed that AGN was able to dose dependently (0 to $400{\mu}g/mL$) increase cell proliferation under normal incubation temperature and also was able to prevent cytotoxicity due to heat shock accompanied by cell proliferation. Confluent preadipocytes were subjected into heat shock procedure, recovery and then AGN treatment prior to stimulation with the differentiation solution. Heat shocked preadipocytes exhibited reduced differentiation as supported by decreased amount of lipid accumulation in Oil Red O staining and triglyceride measurement. However, those heat shocked preadipocytes that then were given AGN extract showed a dose dependent increase in lipid accumulation as shown by both evaluation procedures. In line with these results, real-time polymerase chain reaction (RT-PCR) and Western blot analysis showed that AGN increased adipogenic differentiation by upregulating heat shock protection related genes and proteins together with the adipogenic markers. These findings imply the potential of AGN in heat shock amelioration among 3T3-L1 preadipocytes through heat shock factor and proteins augmentation and enhanced adipogenic marker expression.

• Korean Journal of Applied Biomechanics
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• v.25 no.2
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• pp.175-182
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• 2015

Objective : The purpose of this study was to investigate difference in fascicle behavior of the medial gastrocnemius during the locomotion with varying intensities, such as gait and one-legged and two-legged vertical jumping. Methods : Six subjects (3 males and 3 females; age: $27.2{\pm}1.6yrs.$, body mass: $62.8{\pm}9.8kg$, height: $169.6{\pm}8.5cm$) performed normal gait (G) at preferred speed and maximum vertical jumping with one (OJ) and two (TJ) legs. While subjects were performing the given tasks, the hip, knee and ankle joint motion and ground reaction force was monitored using a 8-infrared camera motion analysis system with two forceplates. Simultaneously, electromyography of the triceps surae muscles, and the fascicle length of the medial gastrocnemius were recorded using a real-time ultrasound imaging machine. Results : Comparing to gait, the kinematic and kinetic parameters of TJ and OJ were found to be significantly different. Along with those parameters, change in the medial gastrocnemius (MG) muscle-tendon complex (MTC) length ($50.57{\pm}6.20mm$ for TJ and $44.14{\pm}5.39mm$ for OJ) and changes in the fascicle length of the MG ($18.97{\pm}3.58mm$ for TJ and $20.31{\pm}4.59mm$ for OJ) were observed. Although the total excursion of the MTC and the MG fascicle length during the two types of jump were not significantly different, however the pattern of length changes were found to be different. For TJ, the fascicle length maintained isometric longer during the propulsive phase than OJ. Conclusion : One-legged and two-legged vertical jumping use different muscle-tendon interaction strategies.

• Journal of the Korean Ceramic Society
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• v.41 no.12 s.271
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• pp.921-928
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• 2004

Calcium phosphate powders have been prepared by using $Ca(OH)_2\;and\;H_{3}PO_4$ solution under various conditions such as pH, calcination temperature, and reaction time. ${\beta}-TCP({\beta}-tricalcium phosphate)$and HAp(hydroxyapatite) were synthesized at pH=5.21 and pH > 7.62, respectively. From XRD results, $Ca(OH)_2\;and\;H_{3}PO_4$ solution reacted quickly to form HAp, which was structurally stable up to 16h. Calcination temperature having good crystallinity is revealed to be at $1200^{\circ}C$. SEM analysis showed that ${\beta}-TCP$ and HAp with needle type were synthesized at pH 5.21 and pH 7.62, respectively. However, at pH 9.16, tiny and homogeneous HAp having sphere was prepared and rearranged to show needle morphology. HAp synthesized at pH 9.16 was utilized as bonechina body and calcined. The sample was analyzed its crystallinity, water absorbtion, color, and shape to check physical properties.

• The korean journal of orthodontics
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• v.39 no.4
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• pp.248-256
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• 2009

Objective: The aim of this study was to determine if human PDL cells can produce osteoclastogenic mRNA and examine how compressive stress affects the expression of osteoclastogenic mRNA in human PDL cells. Methods: Human PDL cells were obtained from biscupids extracted for orthodontic treatment. The compressive force was adjusted by increasing the number of cover glasses. PDL cells were subjected to a compressive force of 0.5, 1.0, 2.0, 3.0 or $4.0\;g/cm^2$ for 0.5, 1.5, 6, 24 or 48 hours. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed to examine levels of M-CSF, IL-$1{\beta}$, RANKL, OPG mRNA expression. Results: Human PDL cells could produce M-CSF mRNA. Human PDL cells under compressive stress showed increased M-CSF, IL-$1{\beta}$ and RANKL mRNAs expression in a force (up to $2\;g/cm^2$) and time-dependent manner. However, OPG mRNA expression was constant regardless of the level and duration of stress. Conclusions: Continuous compressive stress induced the mRNA expression of osteoclastogenic cytokines including M-CSF, RANKL, IL-$1{\beta}$ in PDL cells. Together with an unchanged OPG mRNA level, these results suggest that compressive stress-induced osteoclastogenesis in vivo is partly controlled by M-CSF, RANKL and IL-$1{\beta}$ expression in PDL cells.