• Journal of Pharmaceutical Investigation
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• v.35 no.6
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• pp.471-481
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• 2005

In Korea, generic drug and bioequivalence test are the hot issues since a new medical system of separation of dispensary from medical practice was started in 2000. The KFDA(Korea FDA) had revised several times ${\ulcorner}Guidance\;for\;bioequivalence\;test{\lrcorner}$. In vitro dissolution test has been extensively used as a quality control tool for solid oral dosage forms. In an effort to minimize unnecessary human testing, in vitro/in vivo correlations (IVIVC) between in vitro dissolution and in vivo bioavailability are increasingly becoming an integral part on extended release drug product development. The recently published US guidance, ${\ulcorner}Extended\;release\;oral\;dosage\;forms\;:\;development,\;evaluation,\;and\;application\;of\;in\;vitro/in\;vivo\;correlations{\lrcorner}$ will be helpful for us to make our own guideline.

• Journal of Nutrition and Health
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• v.28 no.2
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• pp.115-126
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• 1995

The effects of energy-yielding substrates on coronary circulation, myocardial oxygen metabolism, and intramyocytic adenylates of perfused Wistar control rat(WC) and spontaneously hypertensive rat(SHR) hearts were examined under basal and $\beta$-adrenergic stimulation conditions. The perfusion medium (1.0mM Ca2+) contained 5mM glucose (+5U/l insulin) in combination with 5mM pyruvate, 5mM lacate, 5mM acetate, or 5mM octanoate as energy substrates. Hearts were perfused with each substrate buffer for 20min under basal conditions. Coronary functinal hyperemia was induced by infusing for 20min isoproterenol (ISO, 1uM), a $\beta$-receptor agonist. Cardiac adenylates, glycolytic intermediates, and coronary venous lactate were measured by using an enzymatic analysis technique. Under basal conditions, acetate and octanoate significantly increased coronary flow(CF) of WC in parallel with myocardial oxygen consumption. However, CF of SHR was partly attenuated by coronary vasoconstriction despite metabolic acidosis. In addition, pyruvate and lactate depressd ISO-induced coronary functional hyperemia in SHR. It should be noted that octanoate exhibited coronary dysfunction under ISO conditions. On the other hand, fat substrates depleted myocardial high energy phosphate pool and accumulated breakdown intermediates. In SHR with coronary vasoconstriction under basal conditions, and with depressed coronary functional hyperemia, high energy phosphates were greatly depleted. These results suggest that energy substrates in the myocardium and coronary smooth muscle alter remarkably coronary circulation, and that coronary circulatory function is associated with a reserve of high energy phosphates and a balance between breakdown and nono synthesis of energy phosphates. These findings could be explained by alterations in the cytosolic redox state manipulated by LDH and hence in the cytosolic phosphorylation potential, which might be involved in hypertension of SHR.

• Polymer(Korea)
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• v.25 no.6
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• pp.893-901
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• 2001

We developed the nerve growth factor (NGF) loaded poly (L - lactide) (PLA) scaffolds by means of emulsion freeze drying method to the possibility for the application of the nerve regeneration of spinal cord disease and the degeneration in Alzheimer's disease. The release amount of NGF from NGF loaded PLA scaffold were analyzed over a 4 week period in vitro at phosphate buffered saline (PBS), pH 7.4, at $37^{\circ}C$. It can be observed the open cell pore structure of porous scaffolds and can be easily controlled the pore structure by the controlling of formulation factors resulting in the controlling of the release rate and the release period. The stability of NGF during the preparation of PLA scaffold was evaluated by comparing the released amounts of total NGF, assayed NGF enzyme - linked immunosorbent assay (ELISA). Released NGF has been found to enhance the neurite sprouting and outgrowth from pheochromocytoma (PC-12) cells. These results suggest that the released NGF from NGF loaded PLA scaffold such as conduit type can be very useful for the nerve regeneration in the neural tissue engineering area.

• Journal of Aquaculture
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• v.11 no.3
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• pp.401-419
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• 1998

The structure of benthic algal flora and feeding behavior of sea urchins (Anthocidaris crassispina and Hemicentrotus pulcherrimus), were investigated from the eight different locations along the coast of Cheju Island, Korea. Biomass distribution and dominance of the algal communities were studied in relation to the gut contents and population parameters of the sea urchins. As a result, although the largest algal biomass and biological characteristics of sea urchins, such as test diameter, test hight, body weight, gonad weight, etc. This inhdicated that sea urchins would not be dependednt sorely on the abundance of algal foods, and they might feed on other food items. In order to know such a trend with regard to food selectivity, the diets consumed by sea urchins were analyzed, and it was found that they were composed of benthic and drifted algae, various animal components (sponges, bryozoans, crustaceans, and various unidentified capsulated eggs, etc.) and biets turned out to be smaller than might be expected, and it is postulated that sea urchins were not likely to be the major grazing animals for the formation of algal bed and also canopy deterioration, so-called "white incrustation."

• Restorative Dentistry and Endodontics
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• v.14 no.1
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• pp.7-24
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• 1989

The purpose of the study was to evaluate the cytotoxic effects of polycarboxylate cements and zinc phosphate cements in vitro. Human fibroblasts were cultured in ${\alpha}$-MEM, and each cement was manually mixed and filled in glass ring cylinder (8${\times}$8mm in diameter, in height.) Cement filled cylinders were placed in the center of the dish (35mm in diameter) containing 3ml of ${\alpha}$-MEM. Millipore filters to simulate dentinal barrier were also placed between the cylinder and the dish, then stored in 5% $CO_2$ containing chamber for 1 and 2 weeks at the temperature of $36.6^{\circ}C$. The results of the experiments were analyzed by counting the cells in the period of one week and two weeks respectively, and were assessed by calculating the cell multiplication rate and the relative growth rate. The experimental groups and the control group were compared. The results of the study were summarized as follows. 1. Durelone brand of the polycarboxylate cements showed marked cytotoxicity after one week, but after two weeks the toxicity decreased remarkably. Poly-F brand exhibited moderate cytotoxicity after one week, but after two weeks the toxicity slightly decreased. HY-BOND brand was weakly cytotoxic after one week, but after two weeks the toxicity became significant. 2. The cytotoxicity of the zinc phosphate cements was negligible after one week, but after two weeks Lee Smith brand revealed considerable cytotoxicity. 3. In general, the zinc phosphate cements were less cytotoxic than the polycarboxylate cements.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.53-62
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• 1990

Fully grown amphibian oocytes undergo their maturation (germinal vesicle breakdown, GVBD) during in vitro follicle culture when they are stimulated with frog pituitary homogenate (FPH) or progesterone. Present experiments were designed to determine whether proteolytic enzymes are involved in the regulation of the matunation process. Treatment of a $\alpha$ -chymoiyypsin inhibitor, N a -tosyl-L-phenylalanine-chloromethyl-ketone(TP) to the oocytes exhibited a biphasic phenomenon, the induction of the maturation without added hormone at relatively low doses (0.001-1 $\mu$M) and inhibition of the hormone induced oocyte maturation at a high dose (100 $\mu$M). Treatment of a trypsin inhibitor, N a -tosyl-L-lysine-chloromethyl ketone(TLCK) to the oocytes did not induce the maturation, but rather suppressed the hormone induced oocyte maturation in a high dose(100 $\mu$ M). Treatment of exogenous iyypsin to the oocyte induced their maturation without added hormone in a dose dependent manner (0.001-1 $\mu$ M). The data presented here indicate that some proteolytic enzymes play a role in the regulation of the maturation(meiotic arrest or reinitiation) in amphibians.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.678-686
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• 1997

This experiment was carried out to develop the mass propagation system for producing plug plantlets using stem cuttings of virus-tree microtubers in potato. Cocopeat, vermiculite, perlite and peatmoss were combined and used as plug nursery media to find out the best combination suitable for the growth of seedlings derived from microtubers. Seedling growth was favored in high temperature (above 2$0^{\circ}C$) and a long-day photoperiod(above 16 hours) condition, while stolons and microtubers formed in outdoor condition. Shoot and root multiplication was not affected by NAA 10mg /1 or IAA 10mg /1 treatment. At the early growth stage of plug plantlets, the number of leaves and roots and the length of root increased significantly when nodes from the upper (near to apex) part of shoots rather than from basal part were taken. But after transplanting, these differences among these characters were not observed. At ninety days after transplanting the plug plantlets in spring time, plant was around 70 to 80cm in height, and the number of stolons and tubers were ten and seven, respectively.

• Journal of Life Science
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• v.17 no.12
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• pp.1760-1765
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• 2007

Proteins are involved in promoting or controlling virtually every event on which our lives depend. Proteins are synthesized in cytosol and in the endoplasmic reticulum where their synthesis machinery are tightly controlled. However, not all of newly synthesized proteins are survived and conduct their essential functions to maintain cell's lives. It was reported that one-third of synthesized proteins are rapidly destroyed by proteasome under the most physiological conditions. full-length translated proteins, which survived, must undergo proper folding and assemble process. Some proteins are spontaneously folded while others require molecular chaperones and folding enzymes to be properly folded. Molecular chaperones are ubiquitously present within the subcellular organelles and from bacteria to animals and plants. Among those members of Hsp70 family have been extensively studied and their regulators have been discovered in the last decade. Here, a brief overview is presented for functional mechanism of Hsp70 homologues and the roles of their regulators. Since biological function of Hsp70 family other than chaperonic function are expending the review would give basic understanding of partnership between Hsp70 family and their regulators.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.3
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• pp.181-186
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• 2021

The research was aimed to improve pre-harvest methods to maintain marketability in postharvest coniferous lettuce. Non-woven pots or plug plates were used to generate seedlings. No difference was found in growth characteristics of lettuce grown in non-woven pots vs plug plates. Since, seedling method with non-woven pots was convenient, lettuce harvested from non-woven pots used for water dipping treatment. The quality parameters, such as fresh weight loss, SPAD value, and appearance of lettuce were investigated after harvest. The lettuce with dipping treatment inside the plastic box container showed lower weight loss, higher SPAD value and better appearance compared to those exposed to the control (non-packaging) during the storage at 2℃. The treated plant showed higher SPAD and hue angle values 21.9 and 113.8°, respectively, compared to that of 18.8 and 108.3°, in non-treated plants. Therefore, it seems that the water dipping treatment is effective for storage method to maintain freshness of the lettuce. We showed the non-woven pot growing as a convenient seedling method for packaging treatment. Further studies will be continued to improve freshness postharvest of other horticultural crops.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.233-242
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• 2018

The purpose of this study is to evaluate the effect of resin cement color on the color of commercially available zirconia crown. The zirconia and resin cements used for the experiment were $NuSmile^{(R)}$ ZR Zirconia LT Shade (LT), $RelyX^{TM}$ U200 TR, A2, and A3O (TR, A2, A3O). The disks of zirconia and resin cements with diameters of 5 mm and thicknesses of 1 mm were prepared. Five disks were made for each specimen. The CIE $L^*a^*b^*$ values of zirconia, resin cements and the combinations thereof were measured on black and white backgrounds, respectively, using a spectrophotometer. The color effect of resin cement on the color of the zirconia crown was evaluated by calculating translucency parameter (TP), contrast ratio (CR), and color differences (${\Delta}E{^*}_{ab}$) based on the measured CIE $L^*a^*b^*$ values. The statistical significances were verified by one-way ANOVA and the Tukey-multiple comparisons tests. As a result, the TP and CR values were decreased (p<0.05) and increased, respectively, in the combination of zirconia and resin cement disks compared to zirconia disk per se. When using the black background, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of the zirconia and three resin cement disks were imperceptible level. The A3O showed the lowest ${\Delta}E{^*}_{ab}$ value among three resin cements. When using the white background, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and TR resin cement (LT/TR) disks showed acceptable level. However, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and A2 resin cement (LT/A2) disks showed unacceptable level. Meanwhile, the ${\Delta}E{^*}_{ab}$ values between zirconia and the combination of zirconia and A3O resin cement (LT/A3O) disks showed perceptible but acceptable level. Within the limits of this study, the colors of resin cements did not cause unacceptable color changes of zirconia except the combination of LT/A2 on the white background. The resin cement that gave the least color changes to zirconia was A3O. This means that the resin cement A3O is recommended to use for minimizing color changes when cementing commercially available zirconia crown to tooth.