• The Journal of Internal Korean Medicine
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• v.31 no.1
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• pp.11-24
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• 2010

Objectives : This study was carried out to investigate the hepatoprotective effects of mixture with Hovenia dulcis Thunb (HDT) and Acer tegmentosum Maxim(ATM) on D-galactosamine-induced liver failure in rats. Methods : The animals were divided into 4 groups: control, with liver failure and no treatment; H1A1, with liver failure and oral treatment with HDT 1 and ATM 1; H1A2, with liver failure and oral treatment with HDT 1 and ATM 2; H1A4, with liver failure and oral treatment with HDT 1 and ATM 4. The animals were treated for 3 weeks and then examinations of change of body weight, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transpeptidase ($\gamma$-GTP), total cholesterol, triglyceride, total bilirubin, superoxide dismutase (SOD), catalase, histopathologic change, and complete blood count (CBC) were performed. Results : All experimental groups had significantly decreased AST in serum and markedly increased activity of SOD as compared with the control group. H1A1, and H1A4 significantly decreased ALT in serum and H1A4 at 2 weeks was significantly higher on the change of body weight as compared with the control group. In histopathologic change of liver tissue by light microscopy, all experimental groups showed recovery effects of liver cells which were damaged by D-galactosamine. Conclusions : Based upon these results, it could be assumed that a mixture of HDT and ATM has hepatoprotective and antioxidative effects on D-galactosamine-induced liver failure. Therefore, a mixture of HDT and ATM might be utilized as a protective agent in therapy for liver diseases.

• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.261-270
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• 1988

This study was performed to investigate the effect of gestation on the histological and histochemical changes of the uterine cervix of the native Korean cattle. A total of 110 cows obtained from the Chonhuk abattoir were divided into six groups. The 1st group was of 9 non-pregnant cows and 101 singleton pregnant cows were grouped into 5 groups from pregnant I to pregnant V according to gestation periods by means of crown rump length measures. For light microscopy the tissues were fixed in 10% neutral formalin and processed routinely for paraffin sections The $6{\mu}m$ sections were taken and stained with H-E, Alcian blue pH 1.0, Alcian blue pH 2.5, Alcian blue pH 2.5/PAS, PAS reaction, toluidin blue, and trichrome. The results obtained were as follows: 1. The cervical lengths and widths were increased in relation to advancing gestation. 2. The cervical folds of the pregnant groups were increased and complicated with many branches, and the cervical muscosal epithelia were increased in according to advancing gestation. 3. As advancing gestation, the tunics muscularis of cervix was increased following moderate distribution of fibroblast and vascularity, meanwhile decreased mast cells were found. 4. The cervical mucosubstance was composed of mixed mucopolysaccharides; the acid mucus was increased from the early pregnant state but the neutral mucus was found after pregnant IV, and the mucus was stained deeply in each staining in the fold cavity in according to gestation state.

• Korean Journal of Veterinary Research
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• v.39 no.5
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• pp.865-877
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• 1999

Hemal nodes and hemolymph nodes are lymphoid organs which share morphologic and functional characteristics of lymph nodes and spleens. Hemal nodes and hemolymph nodes are normally present in Korean native goats. Hemal nodes bad extensive subcapsular and deep sinuses distended by a great number of erythrocytes, and no typical cortex and medulla were observed. Blood vessels commonly occurred, but lymph vessel was not observed in the hemal node. Hemolymph nodes had distinct cortex and medulla, and also had afferent and efferent lymph vessels. The aim of the present study was to obtain new information on the distinct morphological structures of hemal nodes and hemolymph nodes according to ages, and have the basic data for their functions. Goats are divided into 5 groups, consisting of 3 animals aged 1, 3, 6, 10, and 12 months. The morphological studies of the organs were carried out by gross anatomy, light microscopy and immunohistochemistry. During aging, there was an increase in the size of the organs, while there were no significant changes of their numbers, locations and colors. As the goat got older, the lymphatic nodules of hemal nodes were more developed, and the number of macrophage containing phagocytosed erythrocytes was more increased. As the goat was younger, the lymphatic tissues of hemolymph nodes were less developed. There was no difference in distribution of T- and B- lymphocytes according to ages.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.31-36
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• 2006

Tritium has been used to directly measure the exchangeable hydrogen in bleached softwood kraft pulp. The hydrogen atoms associated with hydroxyl groups in pulp or with water contained in the pulp can dissociate and exchange with the hydrogen atoms in bulk water. Tritium is a radioactive isotope of hydrogen and behaves almost identically to it. The distribution of tritium between pulp and water ($k_{pw}$) can be easily measured and becomes an index of the protons available fur hydrogen bonding. Bleached kraft pulp was refined in a PFI mill to a range of freenesses. Tritiated water was added and the amount exchanged measured. There was a slight steady increase in $k_{pw}$ until approximately 300 CSF; $k_{pw}$ then rose sharply between 300 CSF and 100 CSF. This rise appears to correlate with FSP. It is likely that the action of refining on the fiber reaches a threshold at about 300 CSF causing the fiber surface to break open creating exponentially more surface area. This theory is visually confirmed through light microscopy. The slow increase in fibrillation of the fibers above 300 CSF correlates with the increase in $k_{pw}$. Beyond the threshold of 300 CSF a dramatic difference in fibrillation is shown, also corresponding with the large increase in $k_{pw}$. The freeness difference around 300 CSF is small, but the change in fiber properties is extreme within this region. This change in properties could lead to sheet breaks and other disruptions when producing products around the threshold. This study leads to a better understanding of how fiber changes during refining, resulting in a practical benefit of target freeness determination. Presently, freeness is selected based on product quality and on some measure of runnability. Yet, there are other considerations, demonstrated by the extreme change in fiber properties around 300 CSF.

• Korean Journal of Ichthyology
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• v.20 no.2
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• pp.97-104
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• 2008

Comparative study of retinal structure in two Korean endemic freshwater fishes, Zacco koreanus and Pseudobagrus koreanus, was carried out by light and scanning electron microscopy. In the visual cell layer comprised of cone cells and rod cells, the cone cells showed a distinct difference between both species. Z. koreanus had two types of cone cells, single cone cells including a long single and short single cone cells, and double cone cells, whereas P. koreanus had only one type of single cone cells having no its short single and long single cones. Meanwhile, the cone cells of Z. koreanus were arranged in more compact-rowed pattern, but it was more loose and irregular in P. koreanus. Based on field observation, Z. koreanus is mainly a epipelagic or sometimes benthopelagic and a diurnal fish with a round and large eye, while P. koreanus is a demersal and nocturnal fish with an oval and small eye. Therefore, the difference in the retinal structure of two species seems to be closely related to their ecological habitats.

• Journal of the Korean Ceramic Society
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• v.56 no.4
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• pp.360-364
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• 2019

PZT suspensions for photo-curable 3D printing were fabricated and their characteristics were evaluated. After mixing the PZT, photopolymer, photo-initiator, and dispersant for 10 min by using a high-shear mixer, the viscosity characteristics were investigated based on the powder content. To determine an appropriate dispersant content, the dispersant was mixed at 1, 3, and 5 wt% of the powder and a precipitation test was conducted for two hours. Consequently, it was confirmed that the dispersibility was excellent at 3 wt%. Through thermogravimetric analysis, it was confirmed that weight reduction occurred in the photopolymer between 120? and 500?, thereby providing a debinding heat treatment profile. The fabricated suspensions were cured using UV light, and the polymer was removed through debinding. Subsequently, the density and surface characteristics were analyzed by using the Archimedes method and field-emission scanning electron microscopy. Consequently, compared with the theoretical density, an excellent characteristic of 97% was shown at a powder content of 87 wt%. Through X-ray diffraction analysis, it was confirmed that the crystallizability improved as the solid content increased. At the mixing ratio of 87 wt% powder and 13 wt% photo-curable resin, the viscosity was 3,100 cps, confirming an appropriate viscosity characteristic as a stereolithography suspension for 3D printing.

• Journal of Periodontal and Implant Science
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• v.23 no.2
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• pp.203-218
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• 1993

This study was designed to examine the effect of tetracycline application to the planed periodontal surgery of the experimentally induced periodontal disease in dogs. Modified Widman flap surgery was done and aqueous tetracycline (1%) was applied to the root surface for 5min, after which the wound was rinsed with saline, and flaps were coronally repositioned. Root surface ntoches were used as reference points. The animals were sacrificed 1 week, 2 weeks, 4 weeks, and 8 weeks after surgery, and block sections of tooth and surround tissue were processed for conventional light and electron microscopy. The results were as follows : 1. A more coronal position of junctional epithelium was observed in the area treated with tetracycline. 2. In the most of the tetracycline - treated teeth, the new collagen fibrils of connective tissue were oriented vertical/or oblique and parallel to the root surface. The vertical or oblique fibers were inserted into the denuded dentin matrix and contacted with exposed dentin collagen fibrils. 3. In the tetracycline - treated root, new cementum apposition, most of acellular extrinsic fiber cementum, was seen with bundles of oriented collagen fibrils incoporating into the cementum. 4. In the control and tetracyclin - treated teeth, bone resorption was observed at the alveolar crest in the 1 week groups.

• Journal of Periodontal and Implant Science
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• v.47 no.6
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• pp.381-387
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• 2017

Purpose: The aim of this study was to evaluate volumetric and histologic changes in edentulous alveolar ridge areas after ridge preservation using basic fibroblast growth factor-2 (bFGF-2) in combination with collagenated biphasic calcium phosphate (BCP). Methods: The experiments were performed in 6 adult male beagle dogs. The following 3 groups were created: 1) ridge preservation with bFGF-2 and collagenated BCP (experimental group), 2) ridge preservation with collagenated BCP (positive control group), and 3) a negative control group in which no ridge preservation procedure was performed. Volumetric change analysis was performed using an optical scanner and casts. Histological observations were made using light microscopy. Results: After the initial swelling subsided, the magnitude of the volumetric change in the experimental group and positive control group was smaller than in the negative control group. In the experimental group, a distinct trend was observed for the resorption of residual bone and collagen fibers at 4 weeks and for more mature bone and faster healing at 12 weeks. Conclusions: Based on the findings of the present study, bFGF-2 may be considered for use as a therapeutic molecule in ridge preservation procedures.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.217-221
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• 2000

Radiotheraphy may be considered as one of the most effective treatments for digestive tumors. This procedure has major side effects, especially in fast growing tissues like intestinal mucosa. For this reason, the morphological changes in mouse jejunal villi after whole body ${\gamma}-irradiation$ were analysed. Four week old ICR male mice were irradiatied with 6.5Gy or 12Gy of whole body ${\gamma}-irradiation$ and were sacrificed 3 days later. Jejunum among intestine were taken for morphology. Samples were carried out dehydration process and sliced sample covered with paraffin was hold on the slide and then light microscopy was observed by Hematoxylin & Eosin staining. villi at both irradiated doses were showed that the length of villi were shortened and thickened and that lumen were expanded in comparison with non-irradiated group. Since willi have an important role in digestion and very sensitive to radiation from this test, it has a role of test parameter for finding radioprotectors as well as evaluating the biological effect by radiaton.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1501-1508
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• 2004

In this study the effect of extenders and temperatures on sperm viability and fertilizing capacity of boar sperm during long-term storage was investigated. Acrosomal integrity, membrane integrity, motility and hypo-osmotic resistance were evaluated by fluorescence and light microscopy. An in vitro fertilization test was performed to assess the fertilizing capacity of stored spermatozoa. The five diluents tested were ranked according to their ability to maintain sperm functional parameters and Zorlesco (ZO) extender with BSA or with PVA instead of BSA produced the best results. Zorlesco extender substituted with PVA (ZO+PVA) was found to maintain motility both at 15 and 20$^{\circ}C$. within 5 days of storage, but the quality of semen stored at 15$^{\circ}C$ decreased thereafter as compared to semen stored at 20$^{\circ}C$ Semen stored at 5$^{\circ}C$ demonstrated rapid loss of motility already within 24 h. Both fertilization and cleavage of semen stored at 20$^{\circ}C$ in ZO substituted with PVA instead of BSA did not change significantly until day 8 of storage. It is therefore concluded that PVA can be used to substitute for BSA and 20$^{\circ}C$ was more suitable than 15$^{\circ}C$ for boar semen storage, and in vitro fertilizing capacity of spermatozoa was maintained for at least 8 days in ZO+PVA at 20$^{\circ}C$.