• The Korean Journal of Physiology and Pharmacology
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• v.24 no.5
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• pp.403-412
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• 2020

Diabetic nephropathy (DN) is a hyperglycemia-induced progressive development of renal insufficiency. Excessive glucose can increase mitochondrial reactive oxygen species (ROS) and induce cell damage, causing mitochondrial dysfunction. Our previous study indicated that cilostazol (CTZ) can reduce ROS levels and decelerate DN progression in streptozotocin (STZ)-induced type 1 diabetes. This study investigated the potential mechanisms of CTZ in rats with DN and in high glucose-treated mesangial cells. Male Sprague-Dawley rats were fed 5 mg/kg/day of CTZ after developing STZ-induced diabetes mellitus. Electron microscopy revealed that CTZ reduced the thickness of the glomerular basement membrane and improved mitochondrial morphology in mesangial cells of diabetic kidney. CTZ treatment reduced excessive kidney mitochondrial DNA copy numbers induced by hyperglycemia and interacted with the intrinsic pathway for regulating cell apoptosis as an antiapoptotic mechanism. In high-glucose-treated mesangial cells, CTZ reduced ROS production, altered the apoptotic status, and down-regulated transforming growth factor beta (TGF-β) and nuclear factor kappa light chain enhancer of activated B cells (NF-κB). Base on the results of our previous and current studies, CTZ deceleration of hyperglycemia-induced DN is attributable to ROS reduction and thereby maintenance of the mitochondrial function and reduction in TGF-β and NF-κB levels.

• Korean Journal of Veterinary Research
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• v.35 no.3
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• pp.563-573
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• 1995

To know the effect of Ivermectin(IVM) toxicity in testis, histopathologic changes as well as clinical signs were observed in experimental animals including dogs by the subcutaneous injection with 3-50mg/kg of IVM. Clinically, it was observed to have depression and ataxia in all groups whereas tremor and coma in mice, rats and guinea pigs, coma in hamsters and rabbits, and tremor and salivation in dogs were shown. The clinical signs were different by the dosage of IVM, species and individuals in all animals. Susceptibility to IVM was most sensitive in dogs, especially in a Tosa dog and this was susceptible in mice, hamsters and rabbits, guinea pigs and rats in order. Microscopical observation revealed that the seminiferous tubules of testis had decreased thickness of germinal epithelium due to the necrosis and desquamation of the spermatids and spermatocytes. The progressive pattern by the times of administration showed vacuolar formation between the layer of spermatids and spermatogonia due to the marked necrosis of spermatocytes and the presence of multinucleated giant cells derived from spermatid throughout the seminiferous tubules of testis. Only a layer of spermatogonia, a few spermatogonia, and Sertoli cells wore observed with atrophied wavelike basement membrane in the seminiferous tubules of testis. Necrotic germinal cells, sloughed immature spermatids and spermatocytes were present in the lumen of epididymis and ductus deferens. Microscopical observation showed different susceptibility to IVM with clinical observation in which it was also most sensitive in dogs, especially in a Tosa dog and this was susceptible in rabbits and guinea pigs, hamsters, rats and mice in order. It was considered that IVM affects mainly spermatocyte or spermatid stage in the spermatogenesis and disturbs their developing beyond these stage.

• Journal of the Korean Geotechnical Society
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• v.37 no.10
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• pp.65-76
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• 2021

There is a possibility of cavities occurring inside and behind the lining of an aged tunnel structure. In most cases, it is not easy to check the cavity because it exists in a place where visual inspection is impossible. Recently, attempts have been made to evaluate the condition of the tunnel lining and the backfill materials using non-destructive tests such as Ground Penetrating Radar, and various related model tests and numerical analysis studies have been conducted. In this study, the GPR signal characteristics for tunnel lining model testing were analyzed using gprMax software, which was compared with model test results. The numerical model applied to the model test reasonably simulated the electromagnetic wave signal according to the change of the material such as tunnel lining and internal cavity. Using the verified GPR model, B-scan data for the development of the GPR signal analysis technique were obtained, which can evaluate the thickness of the tunnel lining, the presence of the cavity, the effect of the waterproof membrane, and the frequency band.

• The Journal of Korean Medicine
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• v.39 no.4
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• pp.86-113
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• 2018

Objectives: We examined the effects of a mixed formula consisting of dried pomegranate concentrate powder (PCP) and the aqueous extracts of Eucommiae cortex (EC) and Achyranthis radix (AR) in rats with surgically induced osteoarthritis (OA). Methods: Two weeks after OA-inducing surgery, a PCP:EC:AR 5:4:1 (g/g) combination or single formula was orally administered. Changes in body weight, knee thickness, maximum knee extension angle, bone mineral density of the knee joints, femoral and tibial articular surfaces, and compressive strength of the femoral and tibial articular cartilage (AC) were assessed, along with the prostaglandin E2 level, 5-lipoxygenase, matrix metalloproteinase (MMP)-2 and MMP-9 activity, and chondrogenic gene mRNA expression in the femoral and tibial AC with the synovial membrane (SM). In addition, the number of cleaved poly(ADP-ribose) polymerase, cyclooxygenase and tumor necrosis factor-${\alpha}$-immunoreactive cells in the femoral and tibial AC with SM were monitored, and the rate of cell proliferation was determined with a 5-bromo-2'-deoxyuridine uptake assay. Results : The signs of surgically induced OA in rats were significantly inhibited by both PCP, EC and AR combined and single formulas. In particular, the combination formula-treated OA model rats showed dose-dependent, significantly increased inhibitory activity against all tested criteria compared with single formula-treated rats. Conclusions: Taken together, our results suggest that the combination formula synergistically increased the anti-OA effects of its components through anti-inflammatory and chondrogenic activity in rats with surgically induced OA. In addition, 200, 100 and 50 mg/kg combination formula treatments showed dose-dependent inhibitory activity against all of the tested criteria.

• Journal of Sensor Science and Technology
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• v.32 no.5
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• pp.328-333
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• 2023

This study experimentally verified the etch rate of the SiO₂ sacrificial layer etching process with a single etch hole using vapor-phase hydrogen fluoride (VHF) etching. To fabricate small-sized polysilicon etch holes, both circular and triangular pattern masks were employed. Etch holes were fabricated in the polysilicon thin film on the SiO₂ sacrificial layer, and VHF etching was performed to release the polysilicon thin film. The lateral etch rate was measured for varying etch hole sizes and sacrificial layer thicknesses. Based on the measured results, we obtained an approximate equation for the etch rate as a function of the etch hole size and sacrificial layer thickness. The etch rates obtained in this study can be utilized to minimize structural damage caused by incomplete or excessive etching in sacrificial layer processes. In addition, the results of this study provide insights for optimizing sacrificial layer etching and properly designing the size and spacing of the etch holes. In the future, further research will be conducted to explore the formation of structures using chemical vapor deposition (CVD) processes to simultaneously seal etch hole and prevent adhesion owing to polysilicon film vibration.

• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1049-1055
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• 2018

Purpose: To investigate the factors associated with glaucoma in patients with pseudoexfoliation syndrome by comparing features of the anterior segments and ocular biometry according to the presence or absence of open-angle glaucoma in pseudoexfoliation syndrome. Methods: We analyzed 96 patients (115 eyes) diagnosed as having pseudoexfoliation syndrome in this study. The patients were divided into two groups of simple pseudoexfoliation syndrome (64 patients, 76 eyes) and pseudoexfoliation glaucoma (32 patients, 39 eyes). We compared the age, sex, underlying disease, location of pseudoexfoliative material, iris change, degree of nuclear cataract, pupil dilatation, corneal endothelial cell counts, central corneal thickness, anterior chamber depth, axial length, corneal curvature, and intraocular pressure (IOP). Results: There were no significant differences between the two groups in terms of age (p = 0.694), sex (p = 0.161), diabetes (p = 0.440), hypertension (p = 0.238), pseudoexfoliative material observed in anterior capsule (p = 0.700), pupillary margin (p = 0.210), iris depigmentation (p = 0.526), pupillary ruff loss (p = 0.708), degree of nuclear cataract (p = 0.617), pupil dilatation (p = 0.526), central corneal thickness (p = 0.097), anterior chamber depth (p = 0.283), axial length (p = 0.095), or horizontal and vertical corneal curvature (p = 0.066 and 0.306, respectively). In pseudoexfoliation glaucoma, significantly higher IOP (p = 0.026), a high frequency of membrane formation (p = 0.047), and decreased corneal endothelial cell counts (p = 0.048) were observed. Conclusions: Pseudoexfoliation syndrome with open-angle glaucoma was shown to be associated with high IOP, decreased corneal endothelial cell counts, and a high frequency of membrane formation. Therefore, when such changes are observed in pseudoexfoliation syndrome patients, a higher risk of open-angle glaucoma should be recognized, and careful attentionis required accordingly.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.243-249
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• 2006

Porous polymer gel electrolytes (PGEs) based on poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) as a polymer matrix and polyvinylpyrolidone (PVP) as a pore-forming agent were prepared and electrochemical properties were investigated for an electric double layer capacitor (EDLC) in order to increase a permeability of an electrolyte into the PGE. Propylene carbonate (PC) and ethylene carbonate (EC) as plasticizers, and tetraethylammonium tetrafluoroborate ($TEABF_4$) as a supporting salt for the PGE were used. EDLC unit cells were assembled with the PGE and electrode comprising BP-20 and MSP-20 as activated carbon powders, Super P as a conducting agent, and P(VdF-co-HFP)/PVP as a mixed binder. Ion conductivity of PGEs increased with an increased PVP content and was the best at 7 wt% PVP, whereas electrochemical characteristics such as AC-ESR of unit cell were better in 3 wt%. And electrochemical characteristics of the unit cell with PGE were the best at a 33 : 33 weight ratio of PC to EC. Specific capacitance of a mixed plasticizer system of PE and EC was higher than that of pure PC. Ion conductivity of PGEs with a film thickness of $20{\mu}m$ was higher, but electrochemical characteristics of unit cells were higher for a $50{\mu}m$ membrane thickness. Also, the unit cell has shown the highest capacitance of 31.41 F/g and more stable electrochemical performance when PGE and electrode were hot pressed. Consequently, the optimum composition ratio of PGE for EDLCs was 23 : 66 : 11 wt% such as P(VdF-co-HFP) : PVP = 20 : 3 wt% and PC : EC = 44 : 22 wt%. In this case, $3.17{\times}10^{-3}S/cm$ of ion conductivity was achieved at the $50{\mu}m$ thickness of PGE for EDLCs. And the electrochemical characteristics of unit cells were $2.69{\Omega}$ of DC-ESR, 28 F/g of specific capacitance, and 100% of coulombic efficiency.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1469-1475
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• 2004

Skin is the most frequently exposed tissues to oxidative stress from exogenous and endogenous sources. Dietary antioxidants, which suppress oxidative stress including reactive oxygen metabolites, play an important role in protecting skin from deleterious reactive oxygen species. Kimchi containing lots of antioxidative compounds shows anti-aging effect on skin. Therefore the morphologic changes on the skin of hairless mice fed diets containing Korean cabbage, mustard leaf, and buchu kimchi for 16 weeks were determined. Although epidermal thickness was decreased with age, kimchi prevented this thinning of epidermis compared to control group. In kimchi groups, the staining area of cytokeratin was smaller and stratum corneum was thinner than control group. It suggests that various kinds of kimchi diets prevent the increase of keratinization in epidermis with aging. Type Ⅳ collagen, a major structural protein of basement membrane supporting matrices, existed greater amount in kimchi groups than control group, especially in mustard leaf kimchi group. Rough endoplasmic reticulum (RER) of fibroblast was well developed in dermis of Korean cabbage and mustard leaf kimchi groups, which means collagen synthesis at dermis increased in those kimchi groups. This morphological changes of skin suggest that kimchi consumption can retard skin aging due to the presence of antioxidant and anti-aging compounds, especially some components of mustard leaf kimchi may largely affect on the skin rejuvenescence.

• Applied Microscopy
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• v.40 no.1
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• pp.9-14
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• 2010

Coreoleuciscus splendidus is a teleost belonging to Gobioninae, Cyprinidae. The oogenesis was investigated by light microscope. The ovary was located between intestine and air bladder, a grayish and ellipsoidal shape with the major axis 20 mm and the minor axis 5 mm. Cytoplasm of oogonia was basophilic and many nucleoli were located at inside of nuclear membrane. In primary oocytes, yolk vesicles were distributed only in the marginal area and egg envelope was not formed on the outside of an egg. In secondary oocytes, the egg envelope was formed and yolk vesicles in the cytoplasm were increased than the earlier stage. The basophilic substance of cytoplasm was changed to acidic. In case of matured egg, thickness of egg envelope and size of egg were increased. The yolk vesicles were changed to yolk mass in accordance with development. In conclusion, the oogenesis of C. splendidus was characterized by the increase in cell size, the formation and accumulation of yolk, and the decrease of basophilic substance in the cytoplasm. The oogenesis of C. splendidus is similar with other Cyprinidae fishes. But further study on ultrastructural study of fertilized egg envelope will be necessary to get the species specificity.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.4
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• pp.347-353
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• 2002

A structure of a glass electrode-type pH sensor for measuring any concentration of $H^+$ in an aqueous solution was embodied with bulk micromachining technology. Two open well structures were formed, and a reference electrode was secured by the Ag/AgCl thin film in the sloped side of the etched structure. A sensitive membrane of an indicator electrode for generating a potential by an exchange reaction to $H^+$ was made with a glass containing Na 20% or more finely so that its thickness might be $100{\mu}m$ or so, and then it was bonded to one pyramidal structure. A liquid junction for a current path was formed by filling an agar in the anisotropically etched part of the Si wafer, which had a size of $50{\mu}m{\times}50{\mu}m$, and then bonded it to the other. After complete fabrication of each part, it was filled with a 2M KCl reference solution and encapsulated the sensor structure with a cold expoxy. The potential value of fabricated pH sensor was about 90mV/pH in the standard pH solutions.