• Archives of Pharmacal Research
• /
• v.29 no.10
• /
• pp.859-865
• /
• 2006

With an approach to study the anti-tumor effects and mechanism of selenium compound, we investigated the anti-tumor activity and mechanism of $Na_5SeV_5O_{18}{\cdot}3H_2O$ (NaSeVO) in K562 cells. The results showed that $0.625{\sim}20\;mg/L$ NaSeVO could significantly inhibit the proliferation of K562 cells in vitro in a time- and concentration-dependent manner as determined by microculture tetrazolium (MTT) assay, the IC50 values were 14.41 (4.45-46.60) and 3.45 (2.29-5.22) mg/L after 48 hand 72 h treatment with NaSeVO respectively. In vivo experiments demonstrated that i.p. administration of 5, 10 mg/kg NaSeVO exhibited an significant inhibitory effect on the growth of transplantation tumor sarcoma 180 (S180) and hepatoma 22 (H22) in mice, with inhibition rate 26.8% and 58.4% on S180 and 31.3% and 47.4% on H22, respectively. Cell cycle studies indicated that the proportion of G0/G1 phase was increased at 2.5 mg/L while decreased at 10 mg/L after treatment for 24, 48 h. Whereas S phase was decreased at 2.5-5 mg/L and markedly increased at 10 mg/L after treatment for 48 h. After treatment for 24 h, 10 mg/L NaSeVO also markedly increased S and G2/M phases. Take together, the result clearly showed that NaSeVO markedly increased S and G2/M phases at 10 mg/L. The study of immunocytochemistry showed that the expression bcl-2 is significantly inhibited by 10 mg/L NaSeVO, and bax increased. Morphology observation also revealed typical apoptotic features. NaSeVO also significantly caused the accumulation of $Ca^{2+}$ and $Mg^{2+}$, reactive oxygen species (ROS) and the reduction of pH value and mitochondrial membrane potential in K562 cells as compared with control by confocal laser scanning microscope. These results suggest that NaSeVO has anti-tumor effects and its mechanism is attributed partially to apoptosis induced by the elevation of intracellular $Ca^{2+}$, $Mg^{2+}$ and ROS concentration, and a reduction of pH value and mitochondria membrane potential (MMP).

• Journal of the Korean Chemical Society
• /
• v.35 no.4
• /
• pp.329-334
• /
• 1991

The x values and electrical conductivity of the nonstoichiometric compound NbO$_x$ have been measured in a temperature range 700$^{\circ}C$ to 1100$^{\circ}C$ under oxygen partial pressure of 2 ${\times}$ 10$^{-1}$ ∼ 1 ${\times}$ 10$^{-5}$ atm. The NbO$_x$ is a stoichiometrical compound of Nb$_2$O$_5$ under oxygen partial pressure higher than 1.0 ${\times}$ 10$^{-2}$ atm at the above temperature range. The x values were found to vary between 2.48491 and 2.49900 in a temperature range 700$^{\circ}C$ to 1100$^{\circ}C$ under oxygen partial pressure lower than 1 ${\times}$ 10$^{-3}$ atm. The enthalpy of the formation for x' in NbO$_{2.50000-x'}$(${\Delta}H_f$) increased of 15.98 to 17.26 kcal/mol under the conditions. The electrical conductivity (${\sigma}$) of the oxide varied from 10$_4$ to 10$_1$ ohm$_1$cm$_1$ in the above conditions. The activation energy for the conduction was about 1.7 eV. The oxygen pressure dependency of the conductivity (or 1/n value) was about -1/4. The nonstoichiometric conduction mechanism of the oxide has been discussed with the x' values, the ${\sigma}$ values, and the thermodynamic data.

• The Journal of Korean Academy of Prosthodontics
• /
• v.43 no.2
• /
• pp.191-203
• /
• 2005

Statement of problem. In Korea, the preliminary impression trays for dental and edentulous maxillae are manufactured on the base of the statistical value of Westerners. There had been less study on the dental and edentulous arches of Koreans. Purpose. The purpose of this study was to evaluate an average dental cast, preliminary impression trays, three-dimensional relation of dental and edentulous maxilla of Koreans Material and methods. The subjects for this study were 173 dental casts of maxilla (dental: 52, edentulous : 146) with ages $18\{\sim}60$ years old. Each of the master casts was measured 69 measuring points on the dental cast or maxilla, and 46 measuring points on the edentulous cast of maxilla with three-dimensional digital measuring machine. Each measuring points were analysed and were overlapped, that three dimensional dental graphic manufactured by CAD/CAM system. Results. 1. A standard of distribution to alveolar bone were width between left and right buccal border lines of the standard 3/4 line. The mean value of dental and edentulous casts were 67.27mm, 63.49mm respectively. 2. Morphological classification of dental casts were divided into three groups or V-shape, O-shape, U-shape, that proportion of distribution were 17%, 16%, 67%, respectively. Dimensional classification of the dental casts were divided into five groups of less than 63mm, 63 up to 65mm, 65 up to 67mm. 67 up to 69mm, more than 69mm, respectively. 3. Morphological classification of edentulous casts were divided into three groups or V-shape, O-shape, U-shape, that proportion of distribution were 18%, 17%, 65%, respectively Dimensional classification of the edentulous casts were divided into five groups of less than 57mm, 57 up to 61mm, 61 up to 65mm, 65 up to 69mm, more than 69mm, respectively. 4. Mean dental and edentulous cast of maxilla were overlapped, the proportion of bone resorption to alveolar bone is higher than that of palatal bone, its difference were higher anterior 2/4 area than posterior 3/4 area. Conclusion. It obtains information of preliminary impression trays for dental and edentulous maxilla of Koreans.

• The Bulletin of The Korean Astronomical Society
• /
• v.41 no.1
• /
• pp.54.1-54.1
• /
• 2016

Multi-wavelength variability is a staple of active galactic nuclei (AGN). Optical variability probes the nature of the central engine of AGN at smaller linear scales than conventional imaging and spectroscopic techniques. Previous studies have shown that optical variability is more prevalent at longer timescales and at shorter wavelengths. Intra-night variability can be explained through the damped random walk model but small samples and inhomogeneous data have made constraining this model hard. To understand the properties and physical mechanism of intra-night optical variability, we are performing the KMTNet Active Nuclei Variability Survey (KANVaS). Using KMTNet, we aim to study the intra-night variability of ~1000 AGN at a magnitude depth of ~19mag in R band over a total area of ${\sim}24deg^2$ on the sky. Test data in the COSMOS, XMM-LSS, and S82-2 fields was obtained over 4, 6, and 8 nights respectively during 2015, in B, V, R, and I bands. Each night was composed of 5-13 epoch with ~30 min cadence and 80-120 sec exposure times. As a pilot study, we analyzed data in the COSMOS field where we reach a magnitude depth of ~19.5 in R band (at S/N~100) with seeing varying between 1.5-2.0 arcsec. We used the Chandra-COSMOS catalog to identify 166 AGNs among 549 AGNs at B<23. We performed differential photometry between the selected AGN and nearby stars, achieving photometric uncertainty ~0.01mag. We employ various standard time-series analysis tools to identify variable AGN, including the chi-square test. Preliminarily results indicate that intra-night variability is found for ~17%, 17%, 8% and 7% of all X-ray selected AGN in the B, V, R, and I band, respectively. The majority of the identified variable AGN are classified as Type 1 AGN, with only a handful of Type 2 AGN showing evidence for variability. The work done so far confirms there are more variable AGN at shorter wavelengths and that intra-night variability most likely originates in the accretion disk of these objects. We will briefly discuss the quality of the data, challenges we encountered, solutions we employed for this work, and our updated future plans.

• Korean journal of applied entomology
• /
• v.47 no.2
• /
• pp.149-154
• /
• 2008

Pyrausta panopealis is the major pest in green perilla. The larva weaves a web on the shoot of green perilla and damages. In case of extreme, The larva cuts the main branch of green perilla and the leaf of green perilla isn't harvested anymore. A field study was conducted to estimate economic injury levels (EILs) and control thresholds (CTs) for P. panopealis injuring green perilla in green-houses. Different densities of P. panopealis ranged from 1 to 20 crops (2 units per crop) per 100 crops on 13. June, early inoculation. The number of injured leaf and the rate of injured crop were increased by 23. June, on the other hand were decreased after that day. Also, the amount of yield sow the same result above. The economic loss time calculated by the ratio of cost managing this moth to market price (C/V) (C: cost managing a moth, V: Market price) was 4.0%. The economic injury level was 5.1 larval per 100 crops. The control thresholds calculated by 80% level of economic injury level was 4.1 larval per 100 crops.

• Journal of IKEEE
• /
• v.21 no.4
• /
• pp.368-374
• /
• 2017

In this Paper, we developed a low power type LED security light using LED lighting that substitutes a 220[V] commercial power source for a solar cell module instead of a halogen or a sodium lamp. in addition, a PWM type drive control circuit is designed to minimize the heat generation problem and the drive current of the LED drive controller. in developed system, The light efficiency measurement value is 93.6[lm/W], and a high precision temperature sensor is used inside the controller to control the heat generation of the LED lamp. In order to eliminate the high heat generated from the LED lamp, it is designed to disperse quickly into the atmosphere through the metal insertion type heat sink. The heat control range of LED lighting was $50-55[^{\circ}C]$. The luminous flux and the lighting speed of the LED security lamp were 0.5[s], and the beam diffusion angle of the LED lamp was about $110[^{\circ}C]$ by the light distribution curve based on the height of 6[m].

• Korean Journal of Food Science and Technology
• /
• v.32 no.1
• /
• pp.161-167
• /
• 2000

The protease produced by a newly isolated Aspergillus wentti from Korean traditional Meju was purified and characterized. The optimal medium composition and culture conditions for maximum protease production were ; bran :1% glucose solution =1 : 1, pH 9.0, $30^{\circ}C$, and 4 days of fermentation. Protease was purified by QAE-Sephadex, SP-Sephadex ion exchange chromatography and Sephadex G-100 chromatography. The specific activity and the purification fold of the purified enzyme were 213 unit/mg protein and 27.3, respectively. The molecular weight of purified protease was found to be 32 kDa by SDS-PAGE. Km and Vmax value's for hammastein milk casein were $3.049{\times}10^{-4}\;M\;and\;151.1\;{\mu}g/min$, respectively. Kinetic parameters showed that the enzyme has higher affinity to casein than isolated soybean protein, hemoglobin and bovine serum albumin. Optimal pH and temperature for reaction of the purified enzyme were 9.0 and $50^{\circ}C$, respectively. The enzyme was stable at pH 4.0-11.0, below $40^{\circ}C$, and the activity was not stimulated by metal ions. 1mM phenylmethylsulfonyl fluoride inhibited the enzyme activity by 98.5%. It means that the enzyme is one of serine protease.

• Journal of Life Science
• /
• v.27 no.9
• /
• pp.1031-1039
• /
• 2017

The aim of this study was to investigate the potential effects of extracts from silkworm Bombyx mori L. fermented with Bacillus subtilis KACC 91157 at levels of 5%(v/w) and 10%(v/w) in Sprague-Dawley rats intoxicated with 1%(w/w) orotic acid (OA) for 10 days. The rats were divided into a normal group (N), a control group (C: OA), and treatment groups (SP10: OA + 10% extracts from B. mori L.; BSP5: OA + 5% extracts from B. mori L. fermented with B. subtilis KACC 91157; BSP10: OA + 10% extracts from B. mori L. fermented with B. subtilis KACC 91157). Serum activities of aspartate aminotransferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) increased following OA feeding, but the rise was slightly reduced by administration of BSP10. The total lipid, free fatty acid, phospholipid, total cholesterol, and triglyceride contents in serum were significantly lower in the OA treatment groups than in the N group. However, the contents slightly increased following the administration of BSP10. Glutathione concentrations in liver and serum were reduced in the OA-induced fatty liver, but they increased following the administration of BSP10. Hepatocytes in the OA-induced fatty liver contained numerous large droplets. However, SP10, BSP5, and BSP10 feeding prevented OA-induced lipid droplet accumulation in hepatocytes. Accordingly, extracts from silkworm powder fermented with B. subtilis could be an ideal material as a dietary supplement in healthy functional foods to improve the effects of fatty liver.

• KSBB Journal
• /
• v.19 no.6 s.89
• /
• pp.484-488
• /
• 2004

Fermentation studies were conducted in batch and continuous flow cell-recycle reactors with food by-products as substrates. The genus Propionibacterium acidipropionici ATCC 4965 was utilized in the production of organic acids. Good performance was achieved in the batch fermentation using hydrol as a carbon source and corn steep liquor (CSL) as nitrogen and vitamin sources. Product yields and productivity based on maximum values were 0.80 g total acids/g glucose and 0.26 g total acids/L/h, respectively, when $3\%$, (w/v) of hydrol and $2.5\%$, (w/v) of CSL were utilized. Continuous fermentation with cell-recycling system using the optimum amounts of substrates resulted in dramatic increase in cell concentration (X) and maximum productivity (P). Compared to the batch fermentation, X and P were increased by as much as 21 and 13 times, respectively, at the dilution ratio of $0.2\;hr^{-1}$, indicating that cell recycling fermentation of food by-products provides valuable means for the mass production of organic acids as well as utilizing cell mass as good nutrient resources.

• Resources Recycling
• /
• v.18 no.6
• /
• pp.30-37
• /
• 2009

Silica sol was prepared from the mixture of sodium silicate solution and oxidized silicate solution in which sodium had been removed by sol-gel process. The properties of sodium silicate solution and silicate solution thus prepared were characterized by yellow silicomolydate method. Moreover, the formation and growth of silica sol from sodium silicate solution was investigated. Sodium silicate solution with 2% of $SiO_2$ contains 95% of reactive silicate, and 50% of reactive silicate participates sol-gel reaction. From the results of FT-IR analysis, it was found that the intensity of silanol bond decreased and the intensity of siloxane bond increased with increasing reaction temperature. Zeta potential of silica sol prepared at each condition was -40~-60 mV and it could be known that silica sol in this study was well dispersed. The silica sol with 5~10 nm size could be prepared by heating the mixed solution of sodium silicate and silicate solution. And the silica sol grew into about 20 nm as silicate solution was added to silica sol solution.